[RFC] stop using ->read and ->write for kernel access

[RFC] stop using ->read and ->write for kernel access

[Christoph Hellwig]

Hi Al and Linus,

as part of removing set_fs entirely (for which I have a working
prototype), we need to stop calling ->read and ->write with kernel
pointers under set_fs.

My previous "clean up kernel_{read,write} & friends v5" series, on which
this one builds, consolidate those calls into the __ḵernel_{read,write}
helpers.  This series goes further and removes the option to call
->read and ->write with kernel pointers entirely.  The replacement
options are either the existing ->read_iter and ->write_iter methods
which cope with kvecs and kernel pointers just fine and are used by
many instances including all the "real" file systems.  For for other
files like devices they are not suitable.  Fortunately we don't really
do pure kernel reads and writes to any of those.  Traditionally the only
real exception has been splice, which could be used every file for the
last few years, although initially it was optional.

So in addition to some more cleanup like moving the seq_file code to
the iter interface this series introduces a new uptr_t type for a
"universal" pointer that can point to either user or kernel memory
in a properly tagged way, and then adds new read_uptr an write_uptr
ops based on that.  It then converts over the sysctl code as 5.8 added
new code that actually does a kernel_write to it.  Any driver that really
wants splice to work can also be converted over to it, although I haven't
run into one yet.

A git branch is available here:

    git://git.infradead.org/users/hch/misc.git uptr

Gitweb:

    http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/uptr

Diffstat:
 Documentation/filesystems/seq_file.rst                            |    2 
 Documentation/process/clang-format.rst                            |    4 
 Documentation/translations/it_IT/process/clang-format.rst         |    4 
 arch/alpha/kernel/srm_env.c                                       |    2 
 arch/arm/mm/alignment.c                                           |    2 
 arch/arm/mm/ptdump_debugfs.c                                      |    2 
 arch/arm64/kvm/vgic/vgic-debug.c                                  |    2 
 arch/c6x/platforms/pll.c                                          |    2 
 arch/mips/cavium-octeon/oct_ilm.c                                 |    2 
 arch/mips/kernel/segment.c                                        |    2 
 arch/mips/ralink/bootrom.c                                        |    2 
 arch/powerpc/kernel/rtas-proc.c                                   |   10 -
 arch/powerpc/kvm/book3s_xive_native.c                             |    2 
 arch/powerpc/kvm/timing.c                                         |    2 
 arch/powerpc/mm/numa.c                                            |    2 
 arch/powerpc/mm/ptdump/bats.c                                     |    2 
 arch/powerpc/mm/ptdump/hashpagetable.c                            |    2 
 arch/powerpc/mm/ptdump/ptdump.c                                   |    2 
 arch/powerpc/mm/ptdump/segment_regs.c                             |    2 
 arch/powerpc/platforms/cell/spufs/file.c                          |    8 -
 arch/powerpc/platforms/pseries/hvCall_inst.c                      |    2 
 arch/powerpc/platforms/pseries/lpar.c                             |    4 
 arch/powerpc/platforms/pseries/lparcfg.c                          |    2 
 arch/s390/kernel/diag.c                                           |    2 
 arch/s390/mm/dump_pagetables.c                                    |    2 
 arch/s390/pci/pci_debug.c                                         |    2 
 arch/sh/mm/alignment.c                                            |    2 
 arch/sh/mm/asids-debugfs.c                                        |    2 
 arch/sh/mm/cache-debugfs.c                                        |    2 
 arch/sh/mm/pmb.c                                                  |    2 
 arch/sh/mm/tlb-debugfs.c                                          |    2 
 arch/sparc/kernel/led.c                                           |    2 
 arch/um/kernel/exitcode.c                                         |    2 
 arch/um/kernel/process.c                                          |    2 
 arch/x86/kernel/cpu/mce/severity.c                                |    2 
 arch/x86/kernel/cpu/mtrr/if.c                                     |    2 
 arch/x86/mm/pat/memtype.c                                         |    2 
 arch/x86/mm/pat/set_memory.c                                      |    2 
 arch/x86/platform/uv/tlb_uv.c                                     |    2 
 arch/x86/xen/p2m.c                                                |    2 
 block/blk-mq-debugfs.c                                            |    2 
 drivers/acpi/battery.c                                            |    2 
 drivers/acpi/proc.c                                               |    2 
 drivers/base/power/wakeup.c                                       |    2 
 drivers/block/aoe/aoeblk.c                                        |    2 
 drivers/block/drbd/drbd_debugfs.c                                 |   10 -
 drivers/block/nbd.c                                               |    4 
 drivers/block/pktcdvd.c                                           |    2 
 drivers/block/rsxx/core.c                                         |    4 
 drivers/bus/mvebu-mbus.c                                          |    4 
 drivers/char/tpm/eventlog/common.c                                |    2 
 drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c                 |    2 
 drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c                 |    2 
 drivers/crypto/amlogic/amlogic-gxl-core.c                         |    2 
 drivers/crypto/caam/dpseci-debugfs.c                              |    2 
 drivers/crypto/cavium/zip/zip_main.c                              |    6 
 drivers/crypto/hisilicon/qm.c                                     |    2 
 drivers/crypto/qat/qat_common/adf_cfg.c                           |    2 
 drivers/crypto/qat/qat_common/adf_transport_debug.c               |    4 
 drivers/firmware/tegra/bpmp-debugfs.c                             |    2 
 drivers/gpio/gpiolib.c                                            |    2 
 drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c                          |    4 
 drivers/gpu/drm/arm/display/komeda/komeda_dev.c                   |    2 
 drivers/gpu/drm/arm/malidp_drv.c                                  |    2 
 drivers/gpu/drm/armada/armada_debugfs.c                           |    2 
 drivers/gpu/drm/drm_debugfs.c                                     |    6 
 drivers/gpu/drm/drm_debugfs_crc.c                                 |    2 
 drivers/gpu/drm/drm_mipi_dbi.c                                    |    2 
 drivers/gpu/drm/i915/display/intel_display_debugfs.c              |   16 +-
 drivers/gpu/drm/i915/gt/debugfs_gt.h                              |    2 
 drivers/gpu/drm/i915/i915_debugfs_params.c                        |   12 -
 drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c                      |    2 
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c                          |    4 
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c                       |    2 
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c                           |    4 
 drivers/gpu/drm/msm/msm_debugfs.c                                 |    2 
 drivers/gpu/drm/nouveau/nouveau_debugfs.c                         |    2 
 drivers/gpu/drm/omapdrm/dss/dss.c                                 |    2 
 drivers/gpu/host1x/debug.c                                        |    4 
 drivers/gpu/vga/vga_switcheroo.c                                  |    2 
 drivers/hid/hid-picolcd_debugfs.c                                 |    2 
 drivers/hid/hid-wiimote-debug.c                                   |    2 
 drivers/hwmon/dell-smm-hwmon.c                                    |    2 
 drivers/ide/ide-proc.c                                            |    4 
 drivers/infiniband/hw/cxgb4/device.c                              |    4 
 drivers/infiniband/hw/qib/qib_debugfs.c                           |    2 
 drivers/infiniband/ulp/ipoib/ipoib_fs.c                           |    4 
 drivers/input/input.c                                             |    4 
 drivers/macintosh/via-pmu.c                                       |    2 
 drivers/md/bcache/closure.c                                       |    2 
 drivers/md/md.c                                                   |    2 
 drivers/media/cec/core/cec-core.c                                 |    2 
 drivers/media/pci/saa7164/saa7164-core.c                          |    2 
 drivers/memory/emif.c                                             |    4 
 drivers/memory/tegra/tegra124-emc.c                               |    2 
 drivers/memory/tegra/tegra186-emc.c                               |    2 
 drivers/memory/tegra/tegra20-emc.c                                |    2 
 drivers/memory/tegra/tegra30-emc.c                                |    2 
 drivers/mfd/ab3100-core.c                                         |    2 
 drivers/mfd/ab3100-otp.c                                          |    2 
 drivers/mfd/ab8500-debugfs.c                                      |   14 -
 drivers/mfd/tps65010.c                                            |    2 
 drivers/misc/habanalabs/debugfs.c                                 |    2 
 drivers/misc/sgi-gru/gruprocfs.c                                  |    6 
 drivers/mmc/core/mmc_test.c                                       |    2 
 drivers/mtd/mtdcore.c                                             |    4 
 drivers/mtd/ubi/debug.c                                           |    2 
 drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c                |   38 ++---
 drivers/net/ethernet/chelsio/cxgb4/l2t.c                          |    2 
 drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c               |    8 -
 drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-debugfs.c          |    6 
 drivers/net/ethernet/intel/fm10k/fm10k_debugfs.c                  |    2 
 drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c           |    2 
 drivers/net/wireless/ath/ath5k/debug.c                            |    2 
 drivers/net/wireless/ath/wil6210/debugfs.c                        |   14 -
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/debug.c          |    2 
 drivers/net/wireless/intel/ipw2x00/libipw_module.c                |    2 
 drivers/net/wireless/intel/iwlwifi/fw/debugfs.c                   |    2 
 drivers/net/wireless/intel/iwlwifi/pcie/trans.c                   |    2 
 drivers/net/wireless/intersil/hostap/hostap_download.c            |    2 
 drivers/net/wireless/mediatek/mt76/mt7603/debugfs.c               |    2 
 drivers/net/wireless/mediatek/mt76/mt7615/debugfs.c               |    2 
 drivers/net/wireless/mediatek/mt76/mt76x02_debugfs.c              |    4 
 drivers/net/wireless/mediatek/mt76/mt7915/debugfs.c               |    4 
 drivers/net/wireless/mediatek/mt7601u/debugfs.c                   |    4 
 drivers/net/wireless/realtek/rtlwifi/debug.c                      |    2 
 drivers/net/wireless/realtek/rtw88/debug.c                        |    4 
 drivers/net/wireless/rsi/rsi_91x_debugfs.c                        |    4 
 drivers/net/xen-netback/xenbus.c                                  |    2 
 drivers/nvme/host/fabrics.c                                       |    2 
 drivers/parisc/led.c                                              |    2 
 drivers/pci/controller/pci-tegra.c                                |    2 
 drivers/platform/x86/asus-wmi.c                                   |    2 
 drivers/platform/x86/intel_pmc_core.c                             |    2 
 drivers/platform/x86/intel_telemetry_debugfs.c                    |    4 
 drivers/platform/x86/thinkpad_acpi.c                              |    2 
 drivers/platform/x86/toshiba_acpi.c                               |    8 -
 drivers/pnp/pnpbios/proc.c                                        |    2 
 drivers/power/supply/da9030_battery.c                             |    2 
 drivers/pwm/core.c                                                |    2 
 drivers/ras/cec.c                                                 |    2 
 drivers/ras/debugfs.c                                             |    2 
 drivers/s390/block/dasd.c                                         |    2 
 drivers/s390/block/dasd_proc.c                                    |    2 
 drivers/s390/cio/blacklist.c                                      |    2 
 drivers/s390/cio/qdio_debug.c                                     |    2 
 drivers/scsi/hisi_sas/hisi_sas_main.c                             |   32 ++--
 drivers/scsi/qedf/qedf_dbg.h                                      |    2 
 drivers/scsi/qedi/qedi_dbg.h                                      |    2 
 drivers/scsi/qla2xxx/qla_dfs.c                                    |   12 -
 drivers/scsi/scsi_devinfo.c                                       |    2 
 drivers/scsi/scsi_proc.c                                          |    4 
 drivers/scsi/sg.c                                                 |    4 
 drivers/scsi/snic/snic_debugfs.c                                  |    4 
 drivers/sh/intc/virq-debugfs.c                                    |    2 
 drivers/soc/qcom/cmd-db.c                                         |    2 
 drivers/soc/qcom/socinfo.c                                        |    4 
 drivers/soc/ti/knav_dma.c                                         |    2 
 drivers/soc/ti/knav_qmss_queue.c                                  |    2 
 drivers/staging/rtl8192u/ieee80211/ieee80211_module.c             |    2 
 drivers/staging/vc04_services/interface/vchiq_arm/vchiq_debugfs.c |    4 
 drivers/usb/chipidea/debug.c                                      |    4 
 drivers/usb/dwc2/debugfs.c                                        |    2 
 drivers/usb/dwc3/debugfs.c                                        |    8 -
 drivers/usb/gadget/function/rndis.c                               |    2 
 drivers/usb/gadget/udc/lpc32xx_udc.c                              |    2 
 drivers/usb/gadget/udc/renesas_usb3.c                             |    2 
 drivers/usb/host/xhci-debugfs.c                                   |    6 
 drivers/usb/mtu3/mtu3_debugfs.c                                   |    8 -
 drivers/usb/musb/musb_debugfs.c                                   |    4 
 drivers/video/fbdev/via/viafbdev.c                                |   14 -
 drivers/visorbus/visorbus_main.c                                  |    2 
 drivers/xen/xenfs/xensyms.c                                       |    2 
 fs/cifs/cifs_debug.c                                              |   14 -
 fs/cifs/dfs_cache.c                                               |    2 
 fs/debugfs/file.c                                                 |    4 
 fs/dlm/debug_fs.c                                                 |    8 -
 fs/file_table.c                                                   |    7 
 fs/fscache/object-list.c                                          |    2 
 fs/gfs2/glock.c                                                   |    6 
 fs/internal.h                                                     |   10 +
 fs/jbd2/journal.c                                                 |    2 
 fs/jfs/jfs_debug.c                                                |    2 
 fs/nfsd/nfs4state.c                                               |    4 
 fs/nfsd/nfsctl.c                                                  |   12 -
 fs/nfsd/stats.c                                                   |    2 
 fs/ocfs2/cluster/netdebug.c                                       |    6 
 fs/ocfs2/dlm/dlmdebug.c                                           |    2 
 fs/ocfs2/dlmglue.c                                                |    2 
 fs/open.c                                                         |    8 -
 fs/openpromfs/inode.c                                             |    2 
 fs/orangefs/orangefs-debugfs.c                                    |    2 
 fs/proc/array.c                                                   |    2 
 fs/proc/base.c                                                    |   24 +--
 fs/proc/cpuinfo.c                                                 |    2 
 fs/proc/fd.c                                                      |    2 
 fs/proc/generic.c                                                 |    4 
 fs/proc/inode.c                                                   |   28 +++
 fs/proc/proc_net.c                                                |    4 
 fs/proc/proc_sysctl.c                                             |   41 +++--
 fs/proc/stat.c                                                    |    2 
 fs/proc/task_mmu.c                                                |    8 -
 fs/proc/task_nommu.c                                              |    2 
 fs/proc_namespace.c                                               |    6 
 fs/read_write.c                                                   |   49 ++++--
 fs/seq_file.c                                                     |   34 ++--
 fs/splice.c                                                       |   40 +++--
 include/linux/fs.h                                                |   10 +
 include/linux/proc_fs.h                                           |    1 
 include/linux/seq_file.h                                          |    7 
 include/linux/uptr.h                                              |   72 ++++++++++
 ipc/util.c                                                        |    2 
 kernel/bpf/inode.c                                                |    2 
 kernel/fail_function.c                                            |    2 
 kernel/gcov/fs.c                                                  |    2 
 kernel/irq/debugfs.c                                              |    2 
 kernel/irq/proc.c                                                 |    6 
 kernel/kallsyms.c                                                 |    2 
 kernel/kcsan/debugfs.c                                            |    2 
 kernel/latencytop.c                                               |    2 
 kernel/locking/lockdep_proc.c                                     |    2 
 kernel/module.c                                                   |    2 
 kernel/profile.c                                                  |    2 
 kernel/sched/debug.c                                              |    2 
 kernel/sched/psi.c                                                |    6 
 kernel/time/test_udelay.c                                         |    2 
 kernel/trace/ftrace.c                                             |   16 +-
 kernel/trace/trace.c                                              |   20 +-
 kernel/trace/trace_dynevent.c                                     |    2 
 kernel/trace/trace_events.c                                       |   10 -
 kernel/trace/trace_events_hist.c                                  |    4 
 kernel/trace/trace_events_synth.c                                 |    2 
 kernel/trace/trace_events_trigger.c                               |    2 
 kernel/trace/trace_kprobe.c                                       |    4 
 kernel/trace/trace_printk.c                                       |    2 
 kernel/trace/trace_stack.c                                        |    4 
 kernel/trace/trace_stat.c                                         |    2 
 kernel/trace/trace_uprobe.c                                       |    4 
 lib/debugobjects.c                                                |    2 
 lib/dynamic_debug.c                                               |    4 
 lib/error-inject.c                                                |    2 
 lib/kunit/debugfs.c                                               |    2 
 mm/kmemleak.c                                                     |    2 
 mm/slab_common.c                                                  |    2 
 mm/swapfile.c                                                     |    2 
 net/6lowpan/debugfs.c                                             |    2 
 net/atm/mpoa_proc.c                                               |    2 
 net/batman-adv/debugfs.c                                          |    4 
 net/bluetooth/6lowpan.c                                           |    2 
 net/core/pktgen.c                                                 |    6 
 net/hsr/hsr_debugfs.c                                             |    2 
 net/ipv4/netfilter/ipt_CLUSTERIP.c                                |    2 
 net/ipv4/route.c                                                  |    4 
 net/l2tp/l2tp_debugfs.c                                           |    2 
 net/netfilter/xt_recent.c                                         |    2 
 net/sunrpc/cache.c                                                |    4 
 net/sunrpc/debugfs.c                                              |    4 
 net/sunrpc/rpc_pipe.c                                             |    2 
 net/sunrpc/stats.c                                                |    2 
 security/apparmor/apparmorfs.c                                    |   10 -
 security/integrity/ima/ima_fs.c                                   |    6 
 security/selinux/selinuxfs.c                                      |    2 
 security/smack/smackfs.c                                          |   20 +-
 sound/core/info.c                                                 |    2 
 264 files changed, 700 insertions(+), 549 deletions(-)

[PATCH 01/11] uptr: add a new "universal pointer" type

[Christoph Hellwig]

Add a uptr_t type that can hold a pointer to either a user or kernel
memory region, and simply helpers to copy to and from it.  For
architectures like x86 that have non-overlapping user and kernel
address space it just is a union and uses a TASK_SIZE check to
select the proper copy routine.  For architectures with overlapping
address spaces a flag to indicate the address space is used instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/uptr.h | 72 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 include/linux/uptr.h

diff --git a/include/linux/uptr.h b/include/linux/uptr.h
new file mode 100644
index 00000000000000..1373511f9897b4
--- /dev/null
+++ b/include/linux/uptr.h
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2020 Christoph Hellwig.
+ *
+ * Support for "universal" pointers that can point to either kernel or userspace
+ * memory.
+ */
+#ifndef _LINUX_UPTR_H
+#define _LINUX_UPTR_H
+
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+typedef union {
+	void		*kernel;
+	void __user	*user;
+} uptr_t;
+
+static inline uptr_t USER_UPTR(void __user *p)
+{
+	return (uptr_t) { .user = p };
+}
+
+static inline uptr_t KERNEL_UPTR(void *p)
+{
+	return (uptr_t) { .kernel = p };
+}
+
+static inline bool uptr_is_kernel(uptr_t uptr)
+{
+	return (unsigned long)uptr.kernel >= TASK_SIZE;
+}
+#else /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
+typedef struct {
+	union {
+		void		*kernel;
+		void __user	*user;
+	};
+	bool		is_kernel : 1;
+} uptr_t;
+
+static inline uptr_t USER_UPTR(void __user *p)
+{
+	return (uptr_t) { .user = p };
+}
+
+static inline uptr_t KERNEL_UPTR(void *p)
+{
+	return (uptr_t) { .kernel = p, .is_kernel = true };
+}
+
+static inline bool uptr_is_kernel(uptr_t uptr)
+{
+	return uptr.is_kernel;
+}
+#endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */
+
+static inline int copy_from_uptr(void *dst, uptr_t src, size_t size)
+{
+	if (!uptr_is_kernel(src))
+		return copy_from_user(dst, src.user, size);
+	memcpy(dst, src.kernel, size);
+	return 0;
+}
+
+static inline int copy_to_uptr(uptr_t dst, const void *src, size_t size)
+{
+	if (!uptr_is_kernel(dst))
+		return copy_to_user(dst.user, src, size);
+	memcpy(dst.kernel, src, size);
+	return 0;
+}
+
+#endif /* _LINUX_UPTR_H */
-- 
2.26.2

[PATCH 02/11] fs: factor out a set_fmode_can_read_write helper

[Christoph Hellwig]

Add a helper to set the FMODE_CAN_READ and FMODE_CAN_WRITE logic
instead of duplicating it in two places.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/file_table.c |  7 +------
 fs/internal.h   | 10 ++++++++++
 fs/open.c       |  8 +-------
 3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/fs/file_table.c b/fs/file_table.c
index 656647f9575a7c..646b83f07a9589 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -199,16 +199,11 @@ static struct file *alloc_file(const struct path *path, int flags,
 	file->f_mapping = path->dentry->d_inode->i_mapping;
 	file->f_wb_err = filemap_sample_wb_err(file->f_mapping);
 	file->f_sb_err = file_sample_sb_err(file);
-	if ((file->f_mode & FMODE_READ) &&
-	     likely(fop->read || fop->read_iter))
-		file->f_mode |= FMODE_CAN_READ;
-	if ((file->f_mode & FMODE_WRITE) &&
-	     likely(fop->write || fop->write_iter))
-		file->f_mode |= FMODE_CAN_WRITE;
 	file->f_mode |= FMODE_OPENED;
 	file->f_op = fop;
 	if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
 		i_readcount_inc(path->dentry->d_inode);
+	set_fmode_can_read_write(file);
 	return file;
 }
 
diff --git a/fs/internal.h b/fs/internal.h
index 9b863a7bd70892..242f2845b3428b 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -185,3 +185,13 @@ int sb_init_dio_done_wq(struct super_block *sb);
  */
 int do_statx(int dfd, const char __user *filename, unsigned flags,
 	     unsigned int mask, struct statx __user *buffer);
+
+static inline void set_fmode_can_read_write(struct file *f)
+{
+	if ((f->f_mode & FMODE_READ) &&
+	    (f->f_op->read || f->f_op->read_iter))
+		f->f_mode |= FMODE_CAN_READ;
+	if ((f->f_mode & FMODE_WRITE) &&
+	    (f->f_op->write || f->f_op->write_iter))
+		f->f_mode |= FMODE_CAN_WRITE;
+}
diff --git a/fs/open.c b/fs/open.c
index 6cd48a61cda3b9..01f2de93c91710 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -832,13 +832,7 @@ static int do_dentry_open(struct file *f,
 	f->f_mode |= FMODE_OPENED;
 	if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
 		i_readcount_inc(inode);
-	if ((f->f_mode & FMODE_READ) &&
-	     likely(f->f_op->read || f->f_op->read_iter))
-		f->f_mode |= FMODE_CAN_READ;
-	if ((f->f_mode & FMODE_WRITE) &&
-	     likely(f->f_op->write || f->f_op->write_iter))
-		f->f_mode |= FMODE_CAN_WRITE;
-
+	set_fmode_can_read_write(f);
 	f->f_write_hint = WRITE_LIFE_NOT_SET;
 	f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
 
-- 
2.26.2

[PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Christoph Hellwig]

Add two new file operations that are identical to ->read and ->write
except that they can also safely take kernel pointers using the uptr_t
type.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/internal.h      |  4 ++--
 fs/read_write.c    | 18 ++++++++++++++----
 include/linux/fs.h |  3 +++
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/fs/internal.h b/fs/internal.h
index 242f2845b3428b..b6777a47b05163 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -189,9 +189,9 @@ int do_statx(int dfd, const char __user *filename, unsigned flags,
 static inline void set_fmode_can_read_write(struct file *f)
 {
 	if ((f->f_mode & FMODE_READ) &&
-	    (f->f_op->read || f->f_op->read_iter))
+	    (f->f_op->read || f->f_op->read_uptr || f->f_op->read_iter))
 		f->f_mode |= FMODE_CAN_READ;
 	if ((f->f_mode & FMODE_WRITE) &&
-	    (f->f_op->write || f->f_op->write_iter))
+	    (f->f_op->write || f->f_op->write_uptr || f->f_op->write_iter))
 		f->f_mode |= FMODE_CAN_WRITE;
 }
diff --git a/fs/read_write.c b/fs/read_write.c
index e7f36b15683049..24ffbf3cbda243 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -430,7 +430,9 @@ ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
 
 	if (count > MAX_RW_COUNT)
 		count =  MAX_RW_COUNT;
-	if (file->f_op->read) {
+	if (file->f_op->read_uptr) {
+		ret = file->f_op->read_uptr(file, KERNEL_UPTR(buf), count, pos);
+	} else if (file->f_op->read) {
 		mm_segment_t old_fs = get_fs();
 
 		set_fs(KERNEL_DS);
@@ -485,7 +487,9 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 	if (count > MAX_RW_COUNT)
 		count =  MAX_RW_COUNT;
 
-	if (file->f_op->read)
+	if (file->f_op->read_uptr)
+		ret = file->f_op->read_uptr(file, USER_UPTR(buf), count, pos);
+	else if (file->f_op->read)
 		ret = file->f_op->read(file, buf, count, pos);
 	else if (file->f_op->read_iter)
 		ret = new_sync_read(file, buf, count, pos);
@@ -530,7 +534,10 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count,
 
 	if (count > MAX_RW_COUNT)
 		count =  MAX_RW_COUNT;
-	if (file->f_op->write) {
+	if (file->f_op->write_uptr) {
+		ret = file->f_op->write_uptr(file, KERNEL_UPTR((void *)buf),
+				count, pos);
+	} else if (file->f_op->write) {
 		mm_segment_t old_fs = get_fs();
 
 		set_fs(KERNEL_DS);
@@ -592,7 +599,10 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
 	if (count > MAX_RW_COUNT)
 		count =  MAX_RW_COUNT;
 	file_start_write(file);
-	if (file->f_op->write)
+	if (file->f_op->write_uptr)
+		ret = file->f_op->write_uptr(file,
+				USER_UPTR((char __user *)buf), count, pos);
+	else if (file->f_op->write)
 		ret = file->f_op->write(file, buf, count, pos);
 	else if (file->f_op->write_iter)
 		ret = new_sync_write(file, buf, count, pos);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index fac6aead402a98..d8fc3015f5a197 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -39,6 +39,7 @@
 #include <linux/fs_types.h>
 #include <linux/build_bug.h>
 #include <linux/stddef.h>
+#include <linux/uptr.h>
 
 #include <asm/byteorder.h>
 #include <uapi/linux/fs.h>
@@ -1830,6 +1831,8 @@ struct file_operations {
 	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
 	ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
 	ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
+	ssize_t (*read_uptr) (struct file *, uptr_t, size_t, loff_t *);
+	ssize_t (*write_uptr) (struct file *, uptr_t, size_t, loff_t *);
 	int (*iopoll)(struct kiocb *kiocb, bool spin);
 	int (*iterate) (struct file *, struct dir_context *);
 	int (*iterate_shared) (struct file *, struct dir_context *);
-- 
2.26.2

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Linus Torvalds]

On Wed, Jun 24, 2020 at 9:29 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Add two new file operations that are identical to ->read and ->write
> except that they can also safely take kernel pointers using the uptr_t
> type.

Honestly, I think this is the wrong way to go.

All of this new complexity and messiness, just to remove a few
unimportant final cases?

If somebody can't be bothered to convert a driver to
iter_read/iter_write, why would they be bothered to convert it to
read_uptr/write_uptr?

And this messiness will stay around for decades.

So let's not go down that path.

If you want to do "splice() and kernel_read() requires read_iter"
(with a warning so that we find any cases), then that's fine. But
let's not add yet _another_ read type.

Why did you care so much about sysctl, and why couldn't they use the iter ops?

                    Linus

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Christoph Hellwig]

On Wed, Jun 24, 2020 at 10:19:16AM -0700, Linus Torvalds wrote:
> Honestly, I think this is the wrong way to go.
> 
> All of this new complexity and messiness, just to remove a few
> unimportant final cases?
> 
> If somebody can't be bothered to convert a driver to
> iter_read/iter_write, why would they be bothered to convert it to
> read_uptr/write_uptr?
> 
> And this messiness will stay around for decades.
> 
> So let's not go down that path.
> 
> If you want to do "splice() and kernel_read() requires read_iter"
> (with a warning so that we find any cases), then that's fine. But
> let's not add yet _another_ read type.
> 
> Why did you care so much about sysctl, and why couldn't they use the iter ops?

I don't care at all.  Based on our previous chat I assumed you
wanted something like this.  We might still need the uptr_t for
setsockopt, though.

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Linus Torvalds]

On Wed, Jun 24, 2020 at 10:55 AM Christoph Hellwig <hch@lst.de> wrote:
>
> I don't care at all.  Based on our previous chat I assumed you
> wanted something like this.  We might still need the uptr_t for
> setsockopt, though.

No.

What I mean was *not* something like uptr_t.

Just keep the existing "set_fs()". It's not harmful if it's only used
occasionally. We should rename it once it's rare enough, though.

Then, make the following changes:

 - all the normal user access functions stop caring. They use
TASK_SIZE_MAX and are done with it. They basically stop reacting to
set_fs().

 - then, we can have a few *very* specific cases (like setsockopt,
maybe some random read/write) that we teach to use the new set_fs()
thing.

So in *those* cases, we'd basically just do "oh, ok, we are supposed
to use a kernel pointer" based on the setfs value.

IOW, I mean tto do something much more gradual. No new interfaces, no
new types, just a couple of (very clearly marked!) cases of the legacy
set_fs() behavior.

                Linus

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Christoph Hellwig]

On Wed, Jun 24, 2020 at 11:11:50AM -0700, Linus Torvalds wrote:
> What I mean was *not* something like uptr_t.
> 
> Just keep the existing "set_fs()". It's not harmful if it's only used
> occasionally. We should rename it once it's rare enough, though.
> 
> Then, make the following changes:
> 
>  - all the normal user access functions stop caring. They use
> TASK_SIZE_MAX and are done with it. They basically stop reacting to
> set_fs().
> 
>  - then, we can have a few *very* specific cases (like setsockopt,
> maybe some random read/write) that we teach to use the new set_fs()
> thing.
> 
> So in *those* cases, we'd basically just do "oh, ok, we are supposed
> to use a kernel pointer" based on the setfs value.
> 
> IOW, I mean tto do something much more gradual. No new interfaces, no
> new types, just a couple of (very clearly marked!) cases of the legacy
> set_fs() behavior.

So we'd need new user copy functions for just those cases, and make
sure everything below the potential get_fs-NG uses them.  But without
any kind of tape safety to easily validate all users below actually
use them?  I just don't see how that makes sense.

FYI, I think the only users where we really need it are setsockopt
and a s390-specific driver from my audits so far.  Everything else
shouldn't need anything like that.

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Linus Torvalds]

On Wed, Jun 24, 2020 at 11:14 AM Christoph Hellwig <hch@lst.de> wrote:
>
> So we'd need new user copy functions for just those cases

No. We'd open-code them. They'd look at "oh, I'm supposed to use a
kernel pointer" and just use those.

IOW, basically IN THE CODE that cares (and the whole argument is that
this code is one or two special cases) you do

    /* This has not been converted to the new world order */
    if (get_fs() == KERNEL_DS) memcpy(..) else copy_from_user();

You're overdesigning things. You're making them more complex than they
need to be.

Basically, I do *NOT* want to pollute the VFS layer with new
interfaces that shouldn't exist in the long run. I'd much rather make
the eventual goal be to get rid of 'read/write' entirely in favour of
the 'iter' things, but what I absolutely do *NOT* want to see is to
make a _third_ interface for reading and writing. Quite the reverse.
We should strive to make it a _single_ interface, not add a new one.

And I'd rather have a couple of ugly code details in odd places (that
we can hopefully fix up later) than have new VFS infrastructure that
will then hang around forever more.

                Linus

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Christoph Hellwig]

On Wed, Jun 24, 2020 at 11:20:26AM -0700, Linus Torvalds wrote:
> On Wed, Jun 24, 2020 at 11:14 AM Christoph Hellwig <hch@lst.de> wrote:
> >
> > So we'd need new user copy functions for just those cases
> 
> No. We'd open-code them. They'd look at "oh, I'm supposed to use a
> kernel pointer" and just use those.
> 
> IOW, basically IN THE CODE that cares (and the whole argument is that
> this code is one or two special cases) you do
> 
>     /* This has not been converted to the new world order */
>     if (get_fs() == KERNEL_DS) memcpy(..) else copy_from_user();
> 
> You're overdesigning things. You're making them more complex than they
> need to be.

I wish it was so simple.  I really don't like overdesigns, trust me.

But please take a look at setsockopt and all the different instances
(count 90 .setsockopt wireups, and they then branch out into
various subroutines as well).  I really don't want to open code that
there, but we could do helper specific to setsockopt.

Honestly my preference would be to say that no eBPF isn't actually
a user API and just rip out the crap added to it, but I fear that
is not an option.  Because in that case we'd basically be done.

> Basically, I do *NOT* want to pollute the VFS layer with new
> interfaces that shouldn't exist in the long run. I'd much rather make
> the eventual goal be to get rid of 'read/write' entirely in favour of
> the 'iter' things, but what I absolutely do *NOT* want to see is to
> make a _third_ interface for reading and writing. Quite the reverse.
> We should strive to make it a _single_ interface, not add a new one.

Completele agreement on this.  I actually hate the new fops, and only
added them reluctantly as I mis-interpreted what you said.

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Matthew Wilcox]

On Wed, Jun 24, 2020 at 08:24:37PM +0200, Christoph Hellwig wrote:
> On Wed, Jun 24, 2020 at 11:20:26AM -0700, Linus Torvalds wrote:
> > On Wed, Jun 24, 2020 at 11:14 AM Christoph Hellwig <hch@lst.de> wrote:
> > >
> > > So we'd need new user copy functions for just those cases
> > 
> > No. We'd open-code them. They'd look at "oh, I'm supposed to use a
> > kernel pointer" and just use those.
> > 
> > IOW, basically IN THE CODE that cares (and the whole argument is that
> > this code is one or two special cases) you do
> > 
> >     /* This has not been converted to the new world order */
> >     if (get_fs() == KERNEL_DS) memcpy(..) else copy_from_user();
> > 
> > You're overdesigning things. You're making them more complex than they
> > need to be.
> 
> I wish it was so simple.  I really don't like overdesigns, trust me.
> 
> But please take a look at setsockopt and all the different instances
> (count 90 .setsockopt wireups, and they then branch out into
> various subroutines as well).  I really don't want to open code that
> there, but we could do helper specific to setsockopt.

Can we do a setsockopt_iter() which replaces optval/optlen with an iov_iter?

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Christoph Hellwig]

On Wed, Jun 24, 2020 at 07:29:44PM +0100, Matthew Wilcox wrote:
> On Wed, Jun 24, 2020 at 08:24:37PM +0200, Christoph Hellwig wrote:
> > On Wed, Jun 24, 2020 at 11:20:26AM -0700, Linus Torvalds wrote:
> > > On Wed, Jun 24, 2020 at 11:14 AM Christoph Hellwig <hch@lst.de> wrote:
> > > >
> > > > So we'd need new user copy functions for just those cases
> > > 
> > > No. We'd open-code them. They'd look at "oh, I'm supposed to use a
> > > kernel pointer" and just use those.
> > > 
> > > IOW, basically IN THE CODE that cares (and the whole argument is that
> > > this code is one or two special cases) you do
> > > 
> > >     /* This has not been converted to the new world order */
> > >     if (get_fs() == KERNEL_DS) memcpy(..) else copy_from_user();
> > > 
> > > You're overdesigning things. You're making them more complex than they
> > > need to be.
> > 
> > I wish it was so simple.  I really don't like overdesigns, trust me.
> > 
> > But please take a look at setsockopt and all the different instances
> > (count 90 .setsockopt wireups, and they then branch out into
> > various subroutines as well).  I really don't want to open code that
> > there, but we could do helper specific to setsockopt.
> 
> Can we do a setsockopt_iter() which replaces optval/optlen with an iov_iter?

We could.  The only downside is int-sized sockopts are common, and used
in the fast path of networking applications (e.g. cork,uncork) and this
might introduce enough overhead to be noticable.

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Linus Torvalds]

On Wed, Jun 24, 2020 at 11:11 AM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> So in *those* cases, we'd basically just do "oh, ok, we are supposed
> to use a kernel pointer" based on the setfs value.

The important part here si that we don't need to change any
interfaces, because we don't add that whole "carry the bit around with
the pointer".

I agree that that would be the nice clean interface _if_ we intended
for this to be something we care about. But we already _have_ that
interface in the "iter" code, I absolutely do not think we should
create a new one.

So that's why the (admittedly hacky) "just support the old model for
special cases" kind of approach. Make it really easy to convert some
very specific individual places that might care, and make it very
obvious what those places are.

Maybe in a year or two, there's only a couple such places, and we can
see if we can clean those up separately. But make it easy do the
transition to the new model by _not_ changing the basic logic for now.

See what I'm aiming for?

In particular, for architectures that haven't been modified, this
results in zero changes what-so-ever.

            Linus

RE: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[David Laight]

From: Linus Torvalds
> Sent: 24 June 2020 19:12
> On Wed, Jun 24, 2020 at 10:55 AM Christoph Hellwig <hch@lst.de> wrote:
> >
> > I don't care at all.  Based on our previous chat I assumed you
> > wanted something like this.  We might still need the uptr_t for
> > setsockopt, though.
> 
> No.
> 
> What I mean was *not* something like uptr_t.
> 
> Just keep the existing "set_fs()". It's not harmful if it's only used
> occasionally. We should rename it once it's rare enough, though.

Am I right in thinking that it just sets a flag in 'current' ?
Although I don't remember access_ok() doing a suitable check
(would need to be (address - base) < limit).

> Then, make the following changes:
> 
>  - all the normal user access functions stop caring. They use
> TASK_SIZE_MAX and are done with it. They basically stop reacting to
> set_fs().
> 
>  - then, we can have a few *very* specific cases (like setsockopt,
> maybe some random read/write) that we teach to use the new set_fs()
> thing.

Certainly there is a 'BPF' hook in the setsockopt() syscall handler
that can substitute a kernel buffer for any setsockopt() request.

If that is needed (I presume it was added for a purpose) then all
the socket option code needs to be able to handle kernel buffers.
(Actually given what some getsockopt() do, if there was a
requirement to 'adjust' setsockopt() then there should be a hook
in the getsockopt() code as well.)

If you are going to go through all the socket option code to change
the name of all the buffer access functions then it is probably
almost as easy to move the usercopies out into the wrappers.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Linus Torvalds]

On Sat, Jun 27, 2020 at 3:49 AM David Laight <David.Laight@aculab.com> wrote:
>
> > Just keep the existing "set_fs()". It's not harmful if it's only used
> > occasionally. We should rename it once it's rare enough, though.
>
> Am I right in thinking that it just sets a flag in 'current' ?

Basically, yes. That's what it has always done.

Well "always" is not true - it used to set the %fs segment register
originally (thus the name), but _conceptually_ it sets a flag for
"should user accesses be kernel accesses instead".

On x86 - and most other architectures where user space and kernel
space are in the same address space and accessed with the same
instructions, that has then been implemented as just a "what is the
limit for an access".

On other architectures - architectures that need different access
methods (or different flags to the load/store instruction) - it's an
actual flag that changes which access method you use.

> Although I don't remember access_ok() doing a suitable check
> (would need to be (address - base) < limit).

So again, on the architectures with a unified address space,
access_ok() is exactly that "address + access_size <= limit", although
often done with some inline asm just to get the overflow case done
efficiently.

On other architectures, there's no limit check, because _all_
addresses are either user space or kernel space addresses, and what
changes isn't the address limit, but the access itself.

So what I was suggesting is literally

 - keep this flag around as a flag

 - but make all _normal_ user accesses ignore it, and always do user
accesses (so on a unified address space architecture like x86 it
always checks the _fixed_ limit, and on something like sparc32 which
has separate kernel and user address spaces, it just always does a
user access with no conditionals at all)

 - then make the really odd and hopefully very rare cases check that
flag explicitly and manually, and do

        if (current->legacy_uptr_is_kernel)
                memcpy(...);
        else
                copy_to/from_user(...);

and my hope is that we'd have only a handful of cases (like the
setsockopt thing: one for each protocol or whatever) that actually
want this.

Note that the legacy behavior would still remain in architectures that
haven't been modified to remove the use of set_fs(), so I would
further suggest that the two approaches live side-by-side for at least
a while. But _generic_ code (and with Christoph's patches at least
x86) would make set_fs() cause a build error.

So we'd have a new

     set_force_kernel_pointers();
     ....
     clear_force_kernel_pointers();

that would set/clear that 'current->legacy_uptr_is_kernel' variable,
and we'd have a handful of places that would check it.

The naming above is all random, and I'm not claiming that any of this
is particularly _clean_. I'm also not claiming that it's really any
better than our current "set_fs()" mess conceptually.

The only thing that makes it better than our current "set_fs()" is

 - there would hopefully be very few cases of this

 - it would *not* affect random incidental user accesses that just
happen to be in the shadow of this thing.

That second point is the important one, I feel. The real problem with
"set_fs()" has been that we've occasionally had bugs where we ended up
running odd paths that we really didn't _intend_ to run with kernel
pointers. The classic example is the SCSI "write as ioctl" example,
where a write to a SCSI generic device would do various odd things and
follow pointers and what-not. Then you get into real trouble when
"splice()" ends up truiong to write a kernel buffer, and because of
"set_fs()" suddenly the sg code started accessing kernel memory
willy-nilly.

So my suggestion was basically a new version of set_fs(), but one that
is just much more targeted, and doesn't affect all random user
accesses, only those very special ones that are then very *explicitly*
aware of the fact that "hey, I might be called in this situation where
I'm going to get a kernel address instead".

> If that is needed (I presume it was added for a purpose) then all
> the socket option code needs to be able to handle kernel buffers.

So that's very much what I'd like to avoid.

The plan would be that all the *normal* stuff would be handled by
either (a) always having the data come from user space, or (b) the
data has a known size (either fixed, or "optlen" or whatever) and then
being copied to a kernel buffer and then always handled as a kernel
field that bpf can then call with kernel data.

I thought there was just one very specific case of "oh, in certain
cases of setsockopt we don't know what size this address is and optlen
is ignored", so we have to just pass the pointer down to the protocol,
which is the point that knows how much of an address it wants..

Was that a misunderstanding on my part?

Because if there are tons and tons of places that want this "either
kernel or user" then we could still have a helper function for it, but
it means that the whole "limit the cases" advantage to some degree
goes away.

It would still fix the 99% of normal "copy/from/to_user()" cases,
though. They'd be fixed and "safe" and coule never ever touch kernel
memory even if there was some confusion about things. So it would be
an improvement, but I was really hoping that the cases where there can
be confusion would be pretty rare.

             Linus

RE: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[David Laight]

From: Linus Torvalds
> Sent: 27 June 2020 17:33
> On Sat, Jun 27, 2020 at 3:49 AM David Laight <David.Laight@aculab.com> wrote:
> >
> > > Just keep the existing "set_fs()". It's not harmful if it's only used
> > > occasionally. We should rename it once it's rare enough, though.
> >
> > Am I right in thinking that it just sets a flag in 'current' ?
> 
> Basically, yes. That's what it has always done.

I could check, but I suspect it sets what TASK_SIZE uses to ~0u
so that access_ok() can't fail.

> Well "always" is not true - it used to set the %fs segment register
> originally (thus the name), but _conceptually_ it sets a flag for
> "should user accesses be kernel accesses instead".
> 
> On x86 - and most other architectures where user space and kernel
> space are in the same address space and accessed with the same
> instructions, that has then been implemented as just a "what is the
> limit for an access".
> 
> On other architectures - architectures that need different access
> methods (or different flags to the load/store instruction) - it's an
> actual flag that changes which access method you use.
> 
> > Although I don't remember access_ok() doing a suitable check
> > (would need to be (address - base) < limit).
> 
> So again, on the architectures with a unified address space,
> access_ok() is exactly that "address + access_size <= limit", although
> often done with some inline asm just to get the overflow case done
> efficiently.

I realised afterwards that the 'kernel address is actually user'
check isn't really done on architectures like x86 until stac/clac.

I had another thought.
While setting up a full-blown scatter-gather 'iter' structure for
functions like [gs]etsockopt, ioctl and fcntl is OTT and probably
measurably expensive a lightweight 'buffer' structure that just
contained address, length and user/kernel flag could be used.

Although the uses would need an extra level of indirection this
would be offset by reducing the number of parameters passed
through all the layers.

...
> I thought there was just one very specific case of "oh, in certain
> cases of setsockopt we don't know what size this address is and optlen
> is ignored", so we have to just pass the pointer down to the protocol,
> which is the point that knows how much of an address it wants..

I can't help feeling that userspace passes a suitable length but
the kernel doesn't verify it.

It is worse than that, one of the SCTP getsockopt() calls has to return
a length that is shorter than the buffer it wrote.

So any buffer descriptor length would have to be advisory.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Christoph Hellwig]

On Sat, Jun 27, 2020 at 09:33:03AM -0700, Linus Torvalds wrote:
> I thought there was just one very specific case of "oh, in certain
> cases of setsockopt we don't know what size this address is and optlen
> is ignored", so we have to just pass the pointer down to the protocol,
> which is the point that knows how much of an address it wants..

The setsock issue is a little more complicated.  Let me try to summarize
it:

 - setsock takes a (user) pointer and len
 - unfortunately while the designed of the BSD socket API designed the
   len to be correct some protocol implementations have been sloppy
   and just use a hardcoded len for the value plus some other funnies
 - unfortunately there is some BPF magic that can attach to a socket
   and be run, and that (and only that in the latest kernel) can cause
   a setsockopt to take a kernel buffer.  One that was copied from
   userspace earlier and had the BPF program run on it.
 - unfortunately we have about 90 ->setsockopt instances, and the BPF
   hook is not specific to one particular of them.  In fact the
   BPF program can run for options that don't even exist, and based on
   my previous dicussion Facebook has setups that rely on that.

> Was that a misunderstanding on my part?
> 
> Because if there are tons and tons of places that want this "either
> kernel or user" then we could still have a helper function for it, but
> it means that the whole "limit the cases" advantage to some degree
> goes away.

But except for setsockopt we don't really have anything like that left.
There is some alpha arch code that would need to be duplicated for
user vs kernel pointers, but I suspect it will get cleaner by that,
and the messy s390 crypto driver whіch will be a bit of work, but all
internal to that driver.

So based on that I'd rather get away without our flag and tag the
kernel pointer case in setsockopt explicitly.

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Linus Torvalds]

[-- Attachment #1: Type: text/plain, Size: 1781 bytes --]

On Mon, Jun 29, 2020 at 8:29 AM Christoph Hellwig <hch@lst.de> wrote:
>
> So based on that I'd rather get away without our flag and tag the
> kernel pointer case in setsockopt explicitly.

Yeah, I'd be ok to pass that kind of flag around for setsockopt, in
ways I _don't_ want to do for some very core vfs thing like 'read()'.

That said, is there no practical limit on how big "optlen" can be?
Sure, I realize that a lot of setsockopt users may not use all of the
data, but let's say that "optlen" is 128, but the actual low-level
setsockopt operation only uses the first 16 bytes, maybe we could
always just copy the 128 bytes from user space into kernel space, and
just say "setsockopt() always gets a kernel pointer".

Then the bpf use is even simpler. It would just pass the kernel
pointer natively.

Because that seems to be what the BPF code really wants to do: it
takes the user optval, and munges it into a kernel optval, and then
(if that has been done) runs the low-level sock_setsockopt() under
KERNEL_DS.

Couldn't we switch things around instead, and just *always* copy
things from user space, and sock_setsockopt (and
sock->ops->setsockopt) _always_ get a kernel buffer?

And avoid the set_fs(KERNEL_DS) games entirely that way?

Attached it a RFC patch just for __sys_setsockopt() - note that it
does *not* change all the low-level setsockopt callers to just do the
kernel access instead, so this is completely broken, but you can kind
of see what I mean.

Wouldn't this work? In fact, wouldn't this simplify all the setsockopt
places that now don't need to do "get_user()" etc any more?

It would be better if we could limit "optlen" to something sane, but
right now it just does a kmalloc() of whatever the user claims the opt
len is..

                    Linus

[-- Attachment #2: patch --]
[-- Type: application/octet-stream, Size: 2079 bytes --]

 net/socket.c | 36 ++++++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/net/socket.c b/net/socket.c
index 976426d03f09..39060a5f0caa 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2086,25 +2086,37 @@ SYSCALL_DEFINE4(recv, int, fd, void __user *, ubuf, size_t, size,
  */
 
 static int __sys_setsockopt(int fd, int level, int optname,
-			    char __user *optval, int optlen)
+			    char __user *u_optval, int optlen)
 {
-	mm_segment_t oldfs = get_fs();
-	char *kernel_optval = NULL;
 	int err, fput_needed;
 	struct socket *sock;
+	char *optval;
 
 	if (optlen < 0)
 		return -EINVAL;
 
+	/* Can we have some upper limit on optlen */
+	optval = kmalloc(optlen, GFP_KERNEL | __GFP_NOWARN);
+	if (!optval)
+		return -ENOMEM;
+
+	if (copy_from_user(optval, u_optval, optlen)) {
+		kfree(optval);
+		return -EFAULT;
+	}
+
 	sock = sockfd_lookup_light(fd, &err, &fput_needed);
 	if (sock != NULL) {
+		char *bpf_optval = NULL;
+		char *use_optval;
+
 		err = security_socket_setsockopt(sock, level, optname);
 		if (err)
 			goto out_put;
 
 		err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, &level,
 						     &optname, optval, &optlen,
-						     &kernel_optval);
+						     &bpf_optval);
 
 		if (err < 0) {
 			goto out_put;
@@ -2113,27 +2125,23 @@ static int __sys_setsockopt(int fd, int level, int optname,
 			goto out_put;
 		}
 
-		if (kernel_optval) {
-			set_fs(KERNEL_DS);
-			optval = (char __user __force *)kernel_optval;
-		}
+		use_optval = bpf_optval ? bpf_optval : optval;
 
 		if (level == SOL_SOCKET)
 			err =
-			    sock_setsockopt(sock, level, optname, optval,
+			    sock_setsockopt(sock, level, optname, use_optval,
 					    optlen);
 		else
 			err =
-			    sock->ops->setsockopt(sock, level, optname, optval,
+			    sock->ops->setsockopt(sock, level, optname, use_optval,
 						  optlen);
 
-		if (kernel_optval) {
-			set_fs(oldfs);
-			kfree(kernel_optval);
-		}
+		if (bpf_optval)
+			kfree(bpf_optval);
 out_put:
 		fput_light(sock->file, fput_needed);
 	}
+	kfree(optval);
 	return err;
 }
 

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Christoph Hellwig]

On Mon, Jun 29, 2020 at 10:02:48AM -0700, Linus Torvalds wrote:
> That said, is there no practical limit on how big "optlen" can be?

There are some pretty huge ones, like the sctp one that can take
a basically unlimited list of sockaddr structures.

> Sure, I realize that a lot of setsockopt users may not use all of the
> data, but let's say that "optlen" is 128, but the actual low-level
> setsockopt operation only uses the first 16 bytes, maybe we could
> always just copy the 128 bytes from user space into kernel space, and
> just say "setsockopt() always gets a kernel pointer".

One issue is that a lot setsockopt calls are in the fast path, and
even have micro-optimizations like putting an int on stack for the
fast path to avoid the memory allocation.  While I don't know for
sure I fear that always doing a large allocation could end up having
a performance impact.  But otherwise I like that idea, and did in
fact start some prep work until I realized what I did was futile.

> Then the bpf use is even simpler. It would just pass the kernel
> pointer natively.
> 
> Because that seems to be what the BPF code really wants to do: it
> takes the user optval, and munges it into a kernel optval, and then
> (if that has been done) runs the low-level sock_setsockopt() under
> KERNEL_DS.
> 
> Couldn't we switch things around instead, and just *always* copy
> things from user space, and sock_setsockopt (and
> sock->ops->setsockopt) _always_ get a kernel buffer?
> 
> And avoid the set_fs(KERNEL_DS) games entirely that way?

I'd love to be able to do that.  And now that we want through this
whole mess than Nth time I have another idea:

 - we assume optlen is correct, which should cover about 90% of
   the protocols
 - but to override that a new setsockopt_len method is added that
   returns the correct length for all the messy ones.

Let me try if that works out.

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Linus Torvalds]

On Mon, Jun 29, 2020 at 11:07 AM Christoph Hellwig <hch@lst.de> wrote:
>
> One issue is that a lot setsockopt calls are in the fast path, and
> even have micro-optimizations like putting an int on stack for the
> fast path to avoid the memory allocation.

Yeah., An the RFC patch I posted could easily be updated to do exactly
that for small optlen values (say, avoid the kmalloc and use a stack
buffer for oplen smaller than 16 bytes or whatever).

Most of the setsockopt's I'm aware of are just a single integer, so if
that's the bulk of them, then we'd never actually need to do the
kmalloc() in those cases, and only fall back to the kmalloc for the
(hopefully quite unusual) bigger options..

> I'd love to be able to do that.  And now that we want through this
> whole mess than Nth time I have another idea:
>
>  - we assume optlen is correct, which should cover about 90% of
>    the protocols
>  - but to override that a new setsockopt_len method is added that
>    returns the correct length for all the messy ones.
>
> Let me try if that works out.

Doing a quick grep, there's about 100 different ".setsockopt" function
initializers, but a quarter of them are just setting it to
'sock_no_setsockopt'.

A number of others are using 'sock_common_setsockopt'.

Which leaves something like 50 different implementations of the
.setsockopt functions.  But I didn't go any deeper than that - maybe
they then have hundreds of different option cases each and this is all
a nightmare.

Looking at a couple of them, the "int val" situation does seem to be
the most common one by _far_, and is often handled by a common
"get_user()" thing, so converting them to just getting the thing as a
kernel pointer doesn't look _too_ nasty, because even when they have a
lot of subcases, the actual optval accesses are much fewer.

Which is not to say that it looks all that much fun, but it doesn't
look entirely undoable either.

The good news (I guess) is that any missed transformation will be
fairly obvious (ie somebody uses a "get_user()" on what is now a
kernel pointer, and returns -EFAULT. So it shouldn't cause any subtle
failures, and it shouldn't cause any security issues.

I didn't look at the compat cases, but if anything I'd expect those to
become simpler by having kernel pointers. And there doesn't actually
seem to be that many of them (possibly because the "int" case si so
common that it all ends up being the same?)

              Linus

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Christoph Hellwig]

On Mon, Jun 29, 2020 at 11:29:22AM -0700, Linus Torvalds wrote:
> I didn't look at the compat cases, but if anything I'd expect those to
> become simpler by having kernel pointers. And there doesn't actually
> seem to be that many of them (possibly because the "int" case si so
> common that it all ends up being the same?)

Having resurrect my work there really are tons of int cases.  Which
makes me thing that splitting out a setsockopt_int method which gets
passed value instead of a pointer, then converting all the simple cases
to that first and then doing the real shit later sounds like a promіsing
idea.  Let me think a bit more about that.

And yes, a lot of the common methods have tons of cases and
sub-dispatchers and everything else you'd expect from an ioctl-like
interface..

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Linus Torvalds]

On Mon, Jun 29, 2020 at 11:36 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Having resurrect my work there really are tons of int cases.  Which
> makes me thing that splitting out a setsockopt_int method which gets
> passed value instead of a pointer, then converting all the simple cases
> to that first and then doing the real shit later sounds like a promіsing
> idea.

Try my hacky patch first, and just change the code that does

                if (get_user(val, (int __user *)optval)) {
                        err = -EFAULT;

to do

                val = *(int *)optval;

In fact, that pattern seems to be so common that you can probably
almost do it with a sed-script or something.

                   Linus

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Christoph Hellwig]

Next fund one, in net/ipv6/ip6_flowlabel.c:ipv6_flowlabel_opt() we
have this gem toward the end:

		if (!freq->flr_label) {
			if (copy_to_user(&((struct in6_flowlabel_req __user *)optval)->flr_label,
					 &fl->label, sizeof(fl->label))) {
				/* Intentionally ignore fault. */

so it writes back to what was supposed to be the input parameter,
and only does it for a partial region.  Not sure how we could handle
that with any kind of copy to kernel in the caller scheme?

RE: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[David Laight]

From: Linus Torvalds
> Sent: 29 June 2020 18:03
> On Mon, Jun 29, 2020 at 8:29 AM Christoph Hellwig <hch@lst.de> wrote:
> >
> > So based on that I'd rather get away without our flag and tag the
> > kernel pointer case in setsockopt explicitly.
> 
> Yeah, I'd be ok to pass that kind of flag around for setsockopt, in
> ways I _don't_ want to do for some very core vfs thing like 'read()'.
> 
> That said, is there no practical limit on how big "optlen" can be?
> Sure, I realize that a lot of setsockopt users may not use all of the
> data, but let's say that "optlen" is 128, but the actual low-level
> setsockopt operation only uses the first 16 bytes, maybe we could
> always just copy the 128 bytes from user space into kernel space, and
> just say "setsockopt() always gets a kernel pointer".
> 
> Then the bpf use is even simpler. It would just pass the kernel
> pointer natively.
> 
> Because that seems to be what the BPF code really wants to do: it
> takes the user optval, and munges it into a kernel optval, and then
> (if that has been done) runs the low-level sock_setsockopt() under
> KERNEL_DS.
> 
> Couldn't we switch things around instead, and just *always* copy
> things from user space, and sock_setsockopt (and
> sock->ops->setsockopt) _always_ get a kernel buffer?
> 
> And avoid the set_fs(KERNEL_DS) games entirely that way?

I did a patch for SCTP to do the copies in the protocol wrapper.
Apart from the issue of bad applications providing overlarge
buffers and effecting a local DoS attack there were some odd issues:

1) SCTP completely abuses both setsockopt and getsockopt
   to perform additional socket operations.
   I suspect the original implementation didn't want to
   add new system calls.
2) SCTP treats getsockopt as RMW on the user buffer.
   Mostly it only needs 4 bytes, but it can in include
   a sockaddr_storage.
3) SCTP has one getsockopt that is really a setsockopt
   (ie changes things) but is implemented using getsockopt
   so that it can return a value.
4) One of the SCTP getsockopt calls has to return the
   'wrong' value to userspace (ie not the length of the
   transferred data) for compatibility with the orginal
   broken code.

I'm wondering if the [sg]etsockopt wrapper should actually
pass through a structure containing:
	Kernel buffer address (on stack if short)
	User buffer address (may be NULL)
	Length of buffer
	copy_to_user length (normally zero)
	flag: embedded pointers are user/kernel

Most code will just use the kernel buffer and return length/error.

Code that knows the supplied length is invalid can use the
user pointer - but only support direct user requests.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Luis Chamberlain]

On Sat, Jun 27, 2020 at 09:33:03AM -0700, Linus Torvalds wrote:
> The real problem with
> "set_fs()" has been that we've occasionally had bugs where we ended up
> running odd paths that we really didn't _intend_ to run with kernel
> pointers. The classic example is the SCSI "write as ioctl" example,
> where a write to a SCSI generic device would do various odd things and
> follow pointers and what-not. Then you get into real trouble when
> "splice()" ends up truiong to write a kernel buffer, and because of
> "set_fs()" suddenly the sg code started accessing kernel memory
> willy-nilly.

So the semantics of this interface can create chaos fast if not used
carefully and conservatively.

Christoph, it would be great if you're future series can include some
version of a verbiage for the motivation for the culling of set_fs().
Maybe it was just me, but the original motivation wasn't clear at first
and took some thread digging to get it.

  Luis

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Matthew Wilcox]

On Wed, Jun 24, 2020 at 10:19:16AM -0700, Linus Torvalds wrote:
> On Wed, Jun 24, 2020 at 9:29 AM Christoph Hellwig <hch@lst.de> wrote:
> >
> > Add two new file operations that are identical to ->read and ->write
> > except that they can also safely take kernel pointers using the uptr_t
> > type.
> 
> Honestly, I think this is the wrong way to go.
> 
> All of this new complexity and messiness, just to remove a few
> unimportant final cases?
> 
> If somebody can't be bothered to convert a driver to
> iter_read/iter_write, why would they be bothered to convert it to
> read_uptr/write_uptr?
> 
> And this messiness will stay around for decades.
> 
> So let's not go down that path.
> 
> If you want to do "splice() and kernel_read() requires read_iter"
> (with a warning so that we find any cases), then that's fine. But
> let's not add yet _another_ read type.
> 
> Why did you care so much about sysctl, and why couldn't they use the iter ops?

Heh, when I saw patch 4, I started working on that.  It doesn't seem all
that bad, except I've never used the iov_iter before, so I have no idea
if I did this right.  Also, this fixes a bug if 'count' is too large,
which I should split out and send separately.

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 42c5128c7d1c..7a8c474bc196 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -12,6 +12,7 @@
 #include <linux/cred.h>
 #include <linux/namei.h>
 #include <linux/mm.h>
+#include <linux/uio.h>
 #include <linux/module.h>
 #include <linux/bpf-cgroup.h>
 #include <linux/mount.h>
@@ -540,12 +541,13 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
 	return err;
 }
 
-static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
-		size_t count, loff_t *ppos, int write)
+static ssize_t proc_sys_call_handler(struct kiocb *iocb, struct iov_iter *iter,
+		int write)
 {
-	struct inode *inode = file_inode(filp);
+	struct inode *inode = file_inode(iocb->ki_filp);
 	struct ctl_table_header *head = grab_header(inode);
 	struct ctl_table *table = PROC_I(inode)->sysctl_entry;
+	size_t count = iov_iter_count(iter);
 	void *kbuf;
 	ssize_t error;
 
@@ -566,35 +568,32 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 		goto out;
 
 	/* don't even try if the size is too large */
+	error = -ENOMEM;
 	if (count > KMALLOC_MAX_SIZE)
-		return -ENOMEM;
+		goto out;
+	kbuf = kzalloc(count, GFP_KERNEL);
+	if (!kbuf)
+		goto out;
 
 	if (write) {
-		kbuf = memdup_user_nul(ubuf, count);
-		if (IS_ERR(kbuf)) {
-			error = PTR_ERR(kbuf);
-			goto out;
-		}
-	} else {
-		error = -ENOMEM;
-		kbuf = kzalloc(count, GFP_KERNEL);
-		if (!kbuf)
+		error = -EFAULT;
+		if (!copy_from_iter_full(kbuf, count, iter))
 			goto out;
 	}
 
 	error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, &kbuf, &count,
-					   ppos);
+					   &iocb->ki_pos);
 	if (error)
 		goto out_free_buf;
 
 	/* careful: calling conventions are nasty here */
-	error = table->proc_handler(table, write, kbuf, &count, ppos);
+	error = table->proc_handler(table, write, kbuf, &count, &iocb->ki_pos);
 	if (error)
 		goto out_free_buf;
 
 	if (!write) {
 		error = -EFAULT;
-		if (copy_to_user(ubuf, kbuf, count))
+		if (copy_to_iter(kbuf, count, iter) < count)
 			goto out_free_buf;
 	}
 
@@ -607,16 +606,14 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 	return error;
 }
 
-static ssize_t proc_sys_read(struct file *filp, char __user *buf,
-				size_t count, loff_t *ppos)
+static ssize_t proc_sys_read(struct kiocb *iocb, struct iov_iter *iter)
 {
-	return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0);
+	return proc_sys_call_handler(iocb, iter, 0);
 }
 
-static ssize_t proc_sys_write(struct file *filp, const char __user *buf,
-				size_t count, loff_t *ppos)
+static ssize_t proc_sys_write(struct kiocb *iocb, struct iov_iter *iter)
 {
-	return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1);
+	return proc_sys_call_handler(iocb, iter, 1);
 }
 
 static int proc_sys_open(struct inode *inode, struct file *filp)
@@ -853,8 +850,8 @@ static int proc_sys_getattr(const struct path *path, struct kstat *stat,
 static const struct file_operations proc_sys_file_operations = {
 	.open		= proc_sys_open,
 	.poll		= proc_sys_poll,
-	.read		= proc_sys_read,
-	.write		= proc_sys_write,
+	.read_iter	= proc_sys_read,
+	.write_iter	= proc_sys_write,
 	.llseek		= default_llseek,
 };
 

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Christoph Hellwig]

On Wed, Jun 24, 2020 at 06:56:44PM +0100, Matthew Wilcox wrote:
>  	/* don't even try if the size is too large */
> +	error = -ENOMEM;
>  	if (count > KMALLOC_MAX_SIZE)
> -		return -ENOMEM;
> +		goto out;
> +	kbuf = kzalloc(count, GFP_KERNEL);
> +	if (!kbuf)
> +		goto out;
>  
>  	if (write) {
> +		error = -EFAULT;
> +		if (!copy_from_iter_full(kbuf, count, iter))
>  			goto out;
>  	}

The nul-termination for the write cases seems to be lost here.

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Christoph Hellwig]

On Wed, Jun 24, 2020 at 07:59:05PM +0200, Christoph Hellwig wrote:
> On Wed, Jun 24, 2020 at 06:56:44PM +0100, Matthew Wilcox wrote:
> >  	/* don't even try if the size is too large */
> > +	error = -ENOMEM;
> >  	if (count > KMALLOC_MAX_SIZE)
> > -		return -ENOMEM;
> > +		goto out;
> > +	kbuf = kzalloc(count, GFP_KERNEL);
> > +	if (!kbuf)
> > +		goto out;
> >  
> >  	if (write) {
> > +		error = -EFAULT;
> > +		if (!copy_from_iter_full(kbuf, count, iter))
> >  			goto out;
> >  	}
> 
> The nul-termination for the write cases seems to be lost here.

Version with the count and termination fixed below.  Can I get your
signoff?  If testing passes that means I can go back to my
kernel_read/write version from the set_fs removal tree with it.

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 42c5128c7d1c76..36ac7b0e4ba80d 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -12,6 +12,7 @@
 #include <linux/cred.h>
 #include <linux/namei.h>
 #include <linux/mm.h>
+#include <linux/uio.h>
 #include <linux/module.h>
 #include <linux/bpf-cgroup.h>
 #include <linux/mount.h>
@@ -540,12 +541,13 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
 	return err;
 }
 
-static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
-		size_t count, loff_t *ppos, int write)
+static ssize_t proc_sys_call_handler(struct kiocb *iocb, struct iov_iter *iter,
+		int write)
 {
-	struct inode *inode = file_inode(filp);
+	struct inode *inode = file_inode(iocb->ki_filp);
 	struct ctl_table_header *head = grab_header(inode);
 	struct ctl_table *table = PROC_I(inode)->sysctl_entry;
+	size_t count = iov_iter_count(iter);
 	void *kbuf;
 	ssize_t error;
 
@@ -566,35 +568,33 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 		goto out;
 
 	/* don't even try if the size is too large */
-	if (count > KMALLOC_MAX_SIZE)
-		return -ENOMEM;
+	error = -ENOMEM;
+	if (count + !!write > KMALLOC_MAX_SIZE)
+		goto out;
+	kbuf = kzalloc(count, GFP_KERNEL);
+	if (!kbuf)
+		goto out;
 
 	if (write) {
-		kbuf = memdup_user_nul(ubuf, count);
-		if (IS_ERR(kbuf)) {
-			error = PTR_ERR(kbuf);
-			goto out;
-		}
-	} else {
-		error = -ENOMEM;
-		kbuf = kzalloc(count, GFP_KERNEL);
-		if (!kbuf)
+		error = -EFAULT;
+		if (!copy_from_iter_full(kbuf, count, iter))
 			goto out;
+		((char *)kbuf)[count] = '\0';
 	}
 
 	error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, &kbuf, &count,
-					   ppos);
+					   &iocb->ki_pos);
 	if (error)
 		goto out_free_buf;
 
 	/* careful: calling conventions are nasty here */
-	error = table->proc_handler(table, write, kbuf, &count, ppos);
+	error = table->proc_handler(table, write, kbuf, &count, &iocb->ki_pos);
 	if (error)
 		goto out_free_buf;
 
 	if (!write) {
 		error = -EFAULT;
-		if (copy_to_user(ubuf, kbuf, count))
+		if (copy_to_iter(kbuf, count, iter) < count)
 			goto out_free_buf;
 	}
 
@@ -607,16 +607,14 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 	return error;
 }
 
-static ssize_t proc_sys_read(struct file *filp, char __user *buf,
-				size_t count, loff_t *ppos)
+static ssize_t proc_sys_read(struct kiocb *iocb, struct iov_iter *iter)
 {
-	return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0);
+	return proc_sys_call_handler(iocb, iter, 0);
 }
 
-static ssize_t proc_sys_write(struct file *filp, const char __user *buf,
-				size_t count, loff_t *ppos)
+static ssize_t proc_sys_write(struct kiocb *iocb, struct iov_iter *iter)
 {
-	return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1);
+	return proc_sys_call_handler(iocb, iter, 1);
 }
 
 static int proc_sys_open(struct inode *inode, struct file *filp)
@@ -853,8 +851,8 @@ static int proc_sys_getattr(const struct path *path, struct kstat *stat,
 static const struct file_operations proc_sys_file_operations = {
 	.open		= proc_sys_open,
 	.poll		= proc_sys_poll,
-	.read		= proc_sys_read,
-	.write		= proc_sys_write,
+	.read_iter	= proc_sys_read,
+	.write_iter	= proc_sys_write,
 	.llseek		= default_llseek,
 };
 
-- 
2.26.2

Re: [PATCH 03/11] fs: add new read_uptr and write_uptr file operations

[Matthew Wilcox]

[-- Attachment #1: Type: text/plain, Size: 1154 bytes --]

On Wed, Jun 24, 2020 at 08:37:43PM +0200, Christoph Hellwig wrote:
> On Wed, Jun 24, 2020 at 07:59:05PM +0200, Christoph Hellwig wrote:
> > On Wed, Jun 24, 2020 at 06:56:44PM +0100, Matthew Wilcox wrote:
> > >  	/* don't even try if the size is too large */
> > > +	error = -ENOMEM;
> > >  	if (count > KMALLOC_MAX_SIZE)
> > > -		return -ENOMEM;
> > > +		goto out;
> > > +	kbuf = kzalloc(count, GFP_KERNEL);
> > > +	if (!kbuf)
> > > +		goto out;
> > >  
> > >  	if (write) {
> > > +		error = -EFAULT;
> > > +		if (!copy_from_iter_full(kbuf, count, iter))
> > >  			goto out;
> > >  	}
> > 
> > The nul-termination for the write cases seems to be lost here.
> 
> Version with the count and termination fixed below.  Can I get your
> signoff?  If testing passes that means I can go back to my
> kernel_read/write version from the set_fs removal tree with it.

Sure!

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

I went with some slightly different fixes, but I'm having trouble
sending email (the new infradead.org is not quite set up right yet).
I've attached the two fixes to this email in case you want to
incorporate them in some way.

[-- Attachment #2: 0001-sysctl-Call-sysctl_head_finish-on-error.patch --]
[-- Type: text/plain, Size: 1251 bytes --]

From 3c68e4efcc50192962a8cd18c67fb6fad2493713 Mon Sep 17 00:00:00 2001
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: Wed, 24 Jun 2020 14:12:02 -0400
Subject: [PATCH 1/2] sysctl: Call sysctl_head_finish on error
To: hch@lst.de

This error path returned directly instead of calling sysctl_head_finish().

Fixes: ef9d965bc8b6 ("sysctl: reject gigantic reads/write to sysctl files")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/proc/proc_sysctl.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 42c5128c7d1c..6c1166ccdaea 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -566,8 +566,9 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 		goto out;
 
 	/* don't even try if the size is too large */
-	if (count > KMALLOC_MAX_SIZE)
-		return -ENOMEM;
+	error = -ENOMEM;
+	if (count >= KMALLOC_MAX_SIZE)
+		goto out;
 
 	if (write) {
 		kbuf = memdup_user_nul(ubuf, count);
@@ -576,7 +577,6 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 			goto out;
 		}
 	} else {
-		error = -ENOMEM;
 		kbuf = kzalloc(count, GFP_KERNEL);
 		if (!kbuf)
 			goto out;
-- 
2.27.0


[-- Attachment #3: 0002-sysctl-Convert-to-iter-interfaces.patch --]
[-- Type: text/plain, Size: 5022 bytes --]

From 93775b67bbc3e4f761808b216bc76127f89f9ad7 Mon Sep 17 00:00:00 2001
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: Wed, 24 Jun 2020 14:31:08 -0400
Subject: [PATCH 2/2] sysctl: Convert to iter interfaces
To: hch@lst.de

Using the read_iter/write_iter interfaces allows for in-kernel users
to set sysctls without using set_fs().  Also, the buffer is a string,
so give it the real type of 'char *', not void *.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 fs/proc/proc_sysctl.c      | 44 ++++++++++++++++++--------------------
 include/linux/bpf-cgroup.h |  2 +-
 kernel/bpf/cgroup.c        |  2 +-
 3 files changed, 23 insertions(+), 25 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 6c1166ccdaea..9f6b9c3e3fda 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -12,6 +12,7 @@
 #include <linux/cred.h>
 #include <linux/namei.h>
 #include <linux/mm.h>
+#include <linux/uio.h>
 #include <linux/module.h>
 #include <linux/bpf-cgroup.h>
 #include <linux/mount.h>
@@ -540,13 +541,14 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
 	return err;
 }
 
-static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
-		size_t count, loff_t *ppos, int write)
+static ssize_t proc_sys_call_handler(struct kiocb *iocb, struct iov_iter *iter,
+		int write)
 {
-	struct inode *inode = file_inode(filp);
+	struct inode *inode = file_inode(iocb->ki_filp);
 	struct ctl_table_header *head = grab_header(inode);
 	struct ctl_table *table = PROC_I(inode)->sysctl_entry;
-	void *kbuf;
+	size_t count = iov_iter_count(iter);
+	char *kbuf;
 	ssize_t error;
 
 	if (IS_ERR(head))
@@ -569,32 +571,30 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 	error = -ENOMEM;
 	if (count >= KMALLOC_MAX_SIZE)
 		goto out;
+	kbuf = kzalloc(count + 1, GFP_KERNEL);
+	if (!kbuf)
+		goto out;
 
 	if (write) {
-		kbuf = memdup_user_nul(ubuf, count);
-		if (IS_ERR(kbuf)) {
-			error = PTR_ERR(kbuf);
-			goto out;
-		}
-	} else {
-		kbuf = kzalloc(count, GFP_KERNEL);
-		if (!kbuf)
+		error = -EFAULT;
+		if (!copy_from_iter_full(kbuf, count, iter))
 			goto out;
+		kbuf[count] = '\0';
 	}
 
 	error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, &kbuf, &count,
-					   ppos);
+					   &iocb->ki_pos);
 	if (error)
 		goto out_free_buf;
 
 	/* careful: calling conventions are nasty here */
-	error = table->proc_handler(table, write, kbuf, &count, ppos);
+	error = table->proc_handler(table, write, kbuf, &count, &iocb->ki_pos);
 	if (error)
 		goto out_free_buf;
 
 	if (!write) {
 		error = -EFAULT;
-		if (copy_to_user(ubuf, kbuf, count))
+		if (copy_to_iter(kbuf, count, iter) < count)
 			goto out_free_buf;
 	}
 
@@ -607,16 +607,14 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 	return error;
 }
 
-static ssize_t proc_sys_read(struct file *filp, char __user *buf,
-				size_t count, loff_t *ppos)
+static ssize_t proc_sys_read(struct kiocb *iocb, struct iov_iter *iter)
 {
-	return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0);
+	return proc_sys_call_handler(iocb, iter, 0);
 }
 
-static ssize_t proc_sys_write(struct file *filp, const char __user *buf,
-				size_t count, loff_t *ppos)
+static ssize_t proc_sys_write(struct kiocb *iocb, struct iov_iter *iter)
 {
-	return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1);
+	return proc_sys_call_handler(iocb, iter, 1);
 }
 
 static int proc_sys_open(struct inode *inode, struct file *filp)
@@ -853,8 +851,8 @@ static int proc_sys_getattr(const struct path *path, struct kstat *stat,
 static const struct file_operations proc_sys_file_operations = {
 	.open		= proc_sys_open,
 	.poll		= proc_sys_poll,
-	.read		= proc_sys_read,
-	.write		= proc_sys_write,
+	.read_iter	= proc_sys_read,
+	.write_iter	= proc_sys_write,
 	.llseek		= default_llseek,
 };
 
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index c66c545e161a..f81d3b3752f9 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -132,7 +132,7 @@ int __cgroup_bpf_check_dev_permission(short dev_type, u32 major, u32 minor,
 
 int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 				   struct ctl_table *table, int write,
-				   void **buf, size_t *pcount, loff_t *ppos,
+				   char **buf, size_t *pcount, loff_t *ppos,
 				   enum bpf_attach_type type);
 
 int __cgroup_bpf_run_filter_setsockopt(struct sock *sock, int *level,
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 4d76f16524cc..45a918fc573d 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -1202,7 +1202,7 @@ const struct bpf_verifier_ops cg_dev_verifier_ops = {
  */
 int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 				   struct ctl_table *table, int write,
-				   void **buf, size_t *pcount, loff_t *ppos,
+				   char **buf, size_t *pcount, loff_t *ppos,
 				   enum bpf_attach_type type)
 {
 	struct bpf_sysctl_kern ctx = {
-- 
2.27.0

[PATCH 04/11] sysctl: switch to ->{read,write}_uptr

[Christoph Hellwig]

This allows the sysctl handler to safely take kernel space pointers,
as required for the new code to set sysctl parameters at boot time.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/proc/proc_sysctl.c | 39 ++++++++++++++++++++-------------------
 1 file changed, 20 insertions(+), 19 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 42c5128c7d1c76..dd5eb693bd00df 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -540,7 +540,7 @@ static struct dentry *proc_sys_lookup(struct inode *dir, struct dentry *dentry,
 	return err;
 }
 
-static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
+static ssize_t proc_sys_call_handler(struct file *filp, uptr_t buf,
 		size_t count, loff_t *ppos, int write)
 {
 	struct inode *inode = file_inode(filp);
@@ -566,20 +566,21 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 		goto out;
 
 	/* don't even try if the size is too large */
-	if (count > KMALLOC_MAX_SIZE)
+	if (count >= KMALLOC_MAX_SIZE)
 		return -ENOMEM;
 
+	error = -ENOMEM;
+
+	/* allow for NULL termination on writes */
+	kbuf = kzalloc(count + (write ? 1 : 0), GFP_KERNEL);
+	if (!kbuf)
+		goto out;
+
 	if (write) {
-		kbuf = memdup_user_nul(ubuf, count);
-		if (IS_ERR(kbuf)) {
-			error = PTR_ERR(kbuf);
-			goto out;
-		}
-	} else {
-		error = -ENOMEM;
-		kbuf = kzalloc(count, GFP_KERNEL);
-		if (!kbuf)
-			goto out;
+		error = -EFAULT;
+		if (copy_from_uptr(kbuf, buf, count))
+			goto out_free_buf;
+		((char *)kbuf)[count] = '\0';
 	}
 
 	error = BPF_CGROUP_RUN_PROG_SYSCTL(head, table, write, &kbuf, &count,
@@ -594,7 +595,7 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 
 	if (!write) {
 		error = -EFAULT;
-		if (copy_to_user(ubuf, kbuf, count))
+		if (copy_to_uptr(buf, kbuf, count))
 			goto out_free_buf;
 	}
 
@@ -607,16 +608,16 @@ static ssize_t proc_sys_call_handler(struct file *filp, void __user *ubuf,
 	return error;
 }
 
-static ssize_t proc_sys_read(struct file *filp, char __user *buf,
+static ssize_t proc_sys_read(struct file *filp, uptr_t buf,
 				size_t count, loff_t *ppos)
 {
-	return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 0);
+	return proc_sys_call_handler(filp, buf, count, ppos, 0);
 }
 
-static ssize_t proc_sys_write(struct file *filp, const char __user *buf,
+static ssize_t proc_sys_write(struct file *filp, uptr_t buf,
 				size_t count, loff_t *ppos)
 {
-	return proc_sys_call_handler(filp, (void __user *)buf, count, ppos, 1);
+	return proc_sys_call_handler(filp, buf, count, ppos, 1);
 }
 
 static int proc_sys_open(struct inode *inode, struct file *filp)
@@ -853,8 +854,8 @@ static int proc_sys_getattr(const struct path *path, struct kstat *stat,
 static const struct file_operations proc_sys_file_operations = {
 	.open		= proc_sys_open,
 	.poll		= proc_sys_poll,
-	.read		= proc_sys_read,
-	.write		= proc_sys_write,
+	.read_uptr	= proc_sys_read,
+	.write_uptr	= proc_sys_write,
 	.llseek		= default_llseek,
 };
 
-- 
2.26.2

[PATCH 05/11] fs: refactor new_sync_read

[Christoph Hellwig]

Pass the read_iter method as a parameter and mark the function
non-static.  This allows reusing it for additional callsites e.g.
in procfs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/read_write.c    | 8 +++++---
 include/linux/fs.h | 2 ++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index 24ffbf3cbda243..b92c222ca886ca 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -401,7 +401,8 @@ int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t
 				read_write == READ ? MAY_READ : MAY_WRITE);
 }
 
-static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
+ssize_t iter_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos,
+		ssize_t (*cb)(struct kiocb *iocb, struct iov_iter *iter))
 {
 	struct iovec iov = { .iov_base = buf, .iov_len = len };
 	struct kiocb kiocb;
@@ -412,7 +413,7 @@ static ssize_t new_sync_read(struct file *filp, char __user *buf, size_t len, lo
 	kiocb.ki_pos = (ppos ? *ppos : 0);
 	iov_iter_init(&iter, READ, &iov, 1, len);
 
-	ret = call_read_iter(filp, &kiocb, &iter);
+	ret = cb(&kiocb, &iter);
 	BUG_ON(ret == -EIOCBQUEUED);
 	if (ppos)
 		*ppos = kiocb.ki_pos;
@@ -492,7 +493,8 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 	else if (file->f_op->read)
 		ret = file->f_op->read(file, buf, count, pos);
 	else if (file->f_op->read_iter)
-		ret = new_sync_read(file, buf, count, pos);
+		ret = iter_read(file, buf, count, pos,
+				file->f_op->read_iter);
 	else
 		ret = -EINVAL;
 	if (ret > 0) {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d8fc3015f5a197..d0fea0281ef29b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1919,6 +1919,8 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
 			      unsigned long nr_segs, unsigned long fast_segs,
 			      struct iovec *fast_pointer,
 			      struct iovec **ret_pointer);
+ssize_t iter_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos,
+		ssize_t (*cb)(struct kiocb *iocb, struct iov_iter *iter));
 
 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
-- 
2.26.2

[PATCH 06/11] proc: add a read_iter method to proc proc_ops

[Christoph Hellwig]

This will allow proc files to implement iter read semantics.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/proc/inode.c         | 28 ++++++++++++++++++++++++++++
 include/linux/proc_fs.h |  1 +
 2 files changed, 29 insertions(+)

diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index 28d6105e908e4c..fa86619cebc2be 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -297,6 +297,29 @@ static loff_t proc_reg_llseek(struct file *file, loff_t offset, int whence)
 	return rv;
 }
 
+static ssize_t pde_read_iter(struct proc_dir_entry *pde, struct kiocb *iocb,
+		struct iov_iter *iter)
+{
+	if (!pde->proc_ops->proc_read_iter)
+		return -EINVAL;
+	return pde->proc_ops->proc_read_iter(iocb, iter);
+}
+
+static ssize_t proc_reg_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct proc_dir_entry *pde = PDE(file_inode(iocb->ki_filp));
+	ssize_t ret;
+
+	if (pde_is_permanent(pde))
+		return pde_read_iter(pde, iocb, iter);
+
+	if (!use_pde(pde))
+		return -EIO;
+	ret = pde_read_iter(pde, iocb, iter);
+	unuse_pde(pde);
+	return ret;
+}
+
 static ssize_t pde_read(struct proc_dir_entry *pde, struct file *file, char __user *buf, size_t count, loff_t *ppos)
 {
 	typeof_member(struct proc_ops, proc_read) read;
@@ -312,6 +335,9 @@ static ssize_t proc_reg_read(struct file *file, char __user *buf, size_t count,
 	struct proc_dir_entry *pde = PDE(file_inode(file));
 	ssize_t rv = -EIO;
 
+	if (pde->proc_ops->proc_read_iter)
+		return iter_read(file, buf, count, ppos, proc_reg_read_iter);
+
 	if (pde_is_permanent(pde)) {
 		return pde_read(pde, file, buf, count, ppos);
 	} else if (use_pde(pde)) {
@@ -569,6 +595,7 @@ static int proc_reg_release(struct inode *inode, struct file *file)
 static const struct file_operations proc_reg_file_ops = {
 	.llseek		= proc_reg_llseek,
 	.read		= proc_reg_read,
+	.read_iter	= proc_reg_read_iter,
 	.write		= proc_reg_write,
 	.poll		= proc_reg_poll,
 	.unlocked_ioctl	= proc_reg_unlocked_ioctl,
@@ -585,6 +612,7 @@ static const struct file_operations proc_reg_file_ops = {
 static const struct file_operations proc_reg_file_ops_no_compat = {
 	.llseek		= proc_reg_llseek,
 	.read		= proc_reg_read,
+	.read_iter	= proc_reg_read_iter,
 	.write		= proc_reg_write,
 	.poll		= proc_reg_poll,
 	.unlocked_ioctl	= proc_reg_unlocked_ioctl,
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index d1eed1b4365172..97b3f5f06db9d8 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -30,6 +30,7 @@ struct proc_ops {
 	unsigned int proc_flags;
 	int	(*proc_open)(struct inode *, struct file *);
 	ssize_t	(*proc_read)(struct file *, char __user *, size_t, loff_t *);
+	ssize_t (*proc_read_iter)(struct kiocb *, struct iov_iter *);
 	ssize_t	(*proc_write)(struct file *, const char __user *, size_t, loff_t *);
 	loff_t	(*proc_lseek)(struct file *, loff_t, int);
 	int	(*proc_release)(struct inode *, struct file *);
-- 
2.26.2

[PATCH 07/11] seq_file: add seq_read_iter

[Christoph Hellwig]

iov_iter based variant for reading a seq_file.  seq_read is
reimplemented on top of the iter variant.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/seq_file.c            | 34 +++++++++++++++++++++-------------
 include/linux/seq_file.h |  1 +
 2 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/fs/seq_file.c b/fs/seq_file.c
index 4e6239f33c066a..159a3e12cadd30 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -18,6 +18,7 @@
 #include <linux/mm.h>
 #include <linux/printk.h>
 #include <linux/string_helpers.h>
+#include <linux/uio.h>
 
 #include <linux/uaccess.h>
 #include <asm/page.h>
@@ -146,7 +147,17 @@ static int traverse(struct seq_file *m, loff_t offset)
  */
 ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
 {
-	struct seq_file *m = file->private_data;
+	return iter_read(file, buf, size, ppos, seq_read_iter);
+}
+EXPORT_SYMBOL(seq_read);
+
+/*
+ * Ready-made ->f_op->read_iter()
+ */
+ssize_t seq_read_iter(struct kiocb *iocb, struct iov_iter *iter)
+{
+	struct seq_file *m = iocb->ki_filp->private_data;
+	size_t size = iov_iter_count(iter);
 	size_t copied = 0;
 	size_t n;
 	void *p;
@@ -158,14 +169,14 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
 	 * if request is to read from zero offset, reset iterator to first
 	 * record as it might have been already advanced by previous requests
 	 */
-	if (*ppos == 0) {
+	if (iocb->ki_pos == 0) {
 		m->index = 0;
 		m->count = 0;
 	}
 
-	/* Don't assume *ppos is where we left it */
-	if (unlikely(*ppos != m->read_pos)) {
-		while ((err = traverse(m, *ppos)) == -EAGAIN)
+	/* Don't assume ki_pos is where we left it */
+	if (unlikely(iocb->ki_pos != m->read_pos)) {
+		while ((err = traverse(m, iocb->ki_pos)) == -EAGAIN)
 			;
 		if (err) {
 			/* With prejudice... */
@@ -174,7 +185,7 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
 			m->count = 0;
 			goto Done;
 		} else {
-			m->read_pos = *ppos;
+			m->read_pos = iocb->ki_pos;
 		}
 	}
 
@@ -187,13 +198,11 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
 	/* if not empty - flush it first */
 	if (m->count) {
 		n = min(m->count, size);
-		err = copy_to_user(buf, m->buf + m->from, n);
-		if (err)
+		if (copy_to_iter(m->buf + m->from, n, iter) != n)
 			goto Efault;
 		m->count -= n;
 		m->from += n;
 		size -= n;
-		buf += n;
 		copied += n;
 		if (!size)
 			goto Done;
@@ -254,8 +263,7 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
 	}
 	m->op->stop(m, p);
 	n = min(m->count, size);
-	err = copy_to_user(buf, m->buf, n);
-	if (err)
+	if (copy_to_iter(m->buf, n, iter) != n)
 		goto Efault;
 	copied += n;
 	m->count -= n;
@@ -264,7 +272,7 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
 	if (!copied)
 		copied = err;
 	else {
-		*ppos += copied;
+		iocb->ki_pos += copied;
 		m->read_pos += copied;
 	}
 	mutex_unlock(&m->lock);
@@ -276,7 +284,7 @@ ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
 	err = -EFAULT;
 	goto Done;
 }
-EXPORT_SYMBOL(seq_read);
+EXPORT_SYMBOL(seq_read_iter);
 
 /**
  *	seq_lseek -	->llseek() method for sequential files.
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 813614d4b71fbc..b83b3ae3c877f3 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -107,6 +107,7 @@ void seq_pad(struct seq_file *m, char c);
 char *mangle_path(char *s, const char *p, const char *esc);
 int seq_open(struct file *, const struct seq_operations *);
 ssize_t seq_read(struct file *, char __user *, size_t, loff_t *);
+ssize_t seq_read_iter(struct kiocb *iocb, struct iov_iter *iter);
 loff_t seq_lseek(struct file *, loff_t, int);
 int seq_release(struct inode *, struct file *);
 int seq_write(struct seq_file *seq, const void *data, size_t len);
-- 
2.26.2

[PATCH 08/11] seq_file: switch over direct seq_read method calls to seq_read_iter

[Christoph Hellwig]

Switch over all instances used directly as methods using these sed
expressions:

sed -i -e 's/\.read\(\s*=\s*\)seq_read/\.read_iter\1seq_read_iter/g'

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 Documentation/filesystems/seq_file.rst        |  2 +-
 Documentation/process/clang-format.rst        |  4 +-
 .../it_IT/process/clang-format.rst            |  4 +-
 arch/arm/mm/ptdump_debugfs.c                  |  2 +-
 arch/arm64/kvm/vgic/vgic-debug.c              |  2 +-
 arch/c6x/platforms/pll.c                      |  2 +-
 arch/mips/cavium-octeon/oct_ilm.c             |  2 +-
 arch/mips/kernel/segment.c                    |  2 +-
 arch/mips/ralink/bootrom.c                    |  2 +-
 arch/powerpc/kvm/book3s_xive_native.c         |  2 +-
 arch/powerpc/kvm/timing.c                     |  2 +-
 arch/powerpc/mm/ptdump/bats.c                 |  2 +-
 arch/powerpc/mm/ptdump/hashpagetable.c        |  2 +-
 arch/powerpc/mm/ptdump/ptdump.c               |  2 +-
 arch/powerpc/mm/ptdump/segment_regs.c         |  2 +-
 arch/powerpc/platforms/cell/spufs/file.c      |  8 ++--
 arch/powerpc/platforms/pseries/hvCall_inst.c  |  2 +-
 arch/s390/kernel/diag.c                       |  2 +-
 arch/s390/mm/dump_pagetables.c                |  2 +-
 arch/s390/pci/pci_debug.c                     |  2 +-
 arch/sh/mm/asids-debugfs.c                    |  2 +-
 arch/sh/mm/cache-debugfs.c                    |  2 +-
 arch/sh/mm/pmb.c                              |  2 +-
 arch/sh/mm/tlb-debugfs.c                      |  2 +-
 arch/x86/kernel/cpu/mce/severity.c            |  2 +-
 arch/x86/mm/pat/memtype.c                     |  2 +-
 arch/x86/mm/pat/set_memory.c                  |  2 +-
 arch/x86/xen/p2m.c                            |  2 +-
 block/blk-mq-debugfs.c                        |  2 +-
 drivers/base/power/wakeup.c                   |  2 +-
 drivers/block/aoe/aoeblk.c                    |  2 +-
 drivers/block/drbd/drbd_debugfs.c             | 10 ++---
 drivers/block/nbd.c                           |  4 +-
 drivers/block/pktcdvd.c                       |  2 +-
 drivers/block/rsxx/core.c                     |  4 +-
 drivers/bus/mvebu-mbus.c                      |  4 +-
 drivers/char/tpm/eventlog/common.c            |  2 +-
 .../crypto/allwinner/sun8i-ce/sun8i-ce-core.c |  2 +-
 .../crypto/allwinner/sun8i-ss/sun8i-ss-core.c |  2 +-
 drivers/crypto/amlogic/amlogic-gxl-core.c     |  2 +-
 drivers/crypto/caam/dpseci-debugfs.c          |  2 +-
 drivers/crypto/cavium/zip/zip_main.c          |  6 +--
 drivers/crypto/hisilicon/qm.c                 |  2 +-
 drivers/crypto/qat/qat_common/adf_cfg.c       |  2 +-
 .../qat/qat_common/adf_transport_debug.c      |  4 +-
 drivers/firmware/tegra/bpmp-debugfs.c         |  2 +-
 drivers/gpio/gpiolib.c                        |  2 +-
 drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c      |  4 +-
 .../gpu/drm/arm/display/komeda/komeda_dev.c   |  2 +-
 drivers/gpu/drm/arm/malidp_drv.c              |  2 +-
 drivers/gpu/drm/armada/armada_debugfs.c       |  2 +-
 drivers/gpu/drm/drm_debugfs.c                 |  6 +--
 drivers/gpu/drm/drm_debugfs_crc.c             |  2 +-
 drivers/gpu/drm/drm_mipi_dbi.c                |  2 +-
 .../drm/i915/display/intel_display_debugfs.c  | 16 ++++----
 drivers/gpu/drm/i915/gt/debugfs_gt.h          |  2 +-
 drivers/gpu/drm/i915/i915_debugfs_params.c    | 12 +++---
 drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c  |  2 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c      |  4 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c   |  2 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c       |  4 +-
 drivers/gpu/drm/msm/msm_debugfs.c             |  2 +-
 drivers/gpu/drm/nouveau/nouveau_debugfs.c     |  2 +-
 drivers/gpu/drm/omapdrm/dss/dss.c             |  2 +-
 drivers/gpu/host1x/debug.c                    |  4 +-
 drivers/gpu/vga/vga_switcheroo.c              |  2 +-
 drivers/hid/hid-picolcd_debugfs.c             |  2 +-
 drivers/hid/hid-wiimote-debug.c               |  2 +-
 drivers/ide/ide-proc.c                        |  2 +-
 drivers/infiniband/hw/cxgb4/device.c          |  4 +-
 drivers/infiniband/hw/qib/qib_debugfs.c       |  2 +-
 drivers/infiniband/ulp/ipoib/ipoib_fs.c       |  4 +-
 drivers/md/bcache/closure.c                   |  2 +-
 drivers/media/cec/core/cec-core.c             |  2 +-
 drivers/media/pci/saa7164/saa7164-core.c      |  2 +-
 drivers/memory/emif.c                         |  4 +-
 drivers/memory/tegra/tegra124-emc.c           |  2 +-
 drivers/memory/tegra/tegra186-emc.c           |  2 +-
 drivers/memory/tegra/tegra20-emc.c            |  2 +-
 drivers/memory/tegra/tegra30-emc.c            |  2 +-
 drivers/mfd/ab3100-core.c                     |  2 +-
 drivers/mfd/ab3100-otp.c                      |  2 +-
 drivers/mfd/ab8500-debugfs.c                  | 14 +++----
 drivers/mfd/tps65010.c                        |  2 +-
 drivers/misc/habanalabs/debugfs.c             |  2 +-
 drivers/mmc/core/mmc_test.c                   |  2 +-
 drivers/mtd/mtdcore.c                         |  4 +-
 drivers/mtd/ubi/debug.c                       |  2 +-
 .../ethernet/chelsio/cxgb4/cxgb4_debugfs.c    | 38 +++++++++----------
 drivers/net/ethernet/chelsio/cxgb4/l2t.c      |  2 +-
 .../ethernet/chelsio/cxgb4vf/cxgb4vf_main.c   |  8 ++--
 .../freescale/dpaa2/dpaa2-eth-debugfs.c       |  6 +--
 .../net/ethernet/intel/fm10k/fm10k_debugfs.c  |  2 +-
 .../marvell/octeontx2/af/rvu_debugfs.c        |  2 +-
 drivers/net/wireless/ath/ath5k/debug.c        |  2 +-
 drivers/net/wireless/ath/wil6210/debugfs.c    | 14 +++----
 .../broadcom/brcm80211/brcmsmac/debug.c       |  2 +-
 .../net/wireless/intel/iwlwifi/fw/debugfs.c   |  2 +-
 .../net/wireless/intel/iwlwifi/pcie/trans.c   |  2 +-
 .../wireless/mediatek/mt76/mt7603/debugfs.c   |  2 +-
 .../wireless/mediatek/mt76/mt7615/debugfs.c   |  2 +-
 .../wireless/mediatek/mt76/mt76x02_debugfs.c  |  4 +-
 .../wireless/mediatek/mt76/mt7915/debugfs.c   |  4 +-
 .../net/wireless/mediatek/mt7601u/debugfs.c   |  4 +-
 drivers/net/wireless/realtek/rtlwifi/debug.c  |  2 +-
 drivers/net/wireless/realtek/rtw88/debug.c    |  4 +-
 drivers/net/wireless/rsi/rsi_91x_debugfs.c    |  4 +-
 drivers/net/xen-netback/xenbus.c              |  2 +-
 drivers/nvme/host/fabrics.c                   |  2 +-
 drivers/pci/controller/pci-tegra.c            |  2 +-
 drivers/platform/x86/asus-wmi.c               |  2 +-
 drivers/platform/x86/intel_pmc_core.c         |  2 +-
 .../platform/x86/intel_telemetry_debugfs.c    |  4 +-
 drivers/power/supply/da9030_battery.c         |  2 +-
 drivers/pwm/core.c                            |  2 +-
 drivers/ras/cec.c                             |  2 +-
 drivers/ras/debugfs.c                         |  2 +-
 drivers/s390/block/dasd.c                     |  2 +-
 drivers/s390/cio/qdio_debug.c                 |  2 +-
 drivers/scsi/hisi_sas/hisi_sas_main.c         | 32 ++++++++--------
 drivers/scsi/qedf/qedf_dbg.h                  |  2 +-
 drivers/scsi/qedi/qedi_dbg.h                  |  2 +-
 drivers/scsi/qla2xxx/qla_dfs.c                | 12 +++---
 drivers/scsi/snic/snic_debugfs.c              |  4 +-
 drivers/sh/intc/virq-debugfs.c                |  2 +-
 drivers/soc/qcom/cmd-db.c                     |  2 +-
 drivers/soc/qcom/socinfo.c                    |  4 +-
 drivers/soc/ti/knav_dma.c                     |  2 +-
 drivers/soc/ti/knav_qmss_queue.c              |  2 +-
 .../interface/vchiq_arm/vchiq_debugfs.c       |  4 +-
 drivers/usb/chipidea/debug.c                  |  4 +-
 drivers/usb/dwc2/debugfs.c                    |  2 +-
 drivers/usb/dwc3/debugfs.c                    |  8 ++--
 drivers/usb/gadget/udc/lpc32xx_udc.c          |  2 +-
 drivers/usb/gadget/udc/renesas_usb3.c         |  2 +-
 drivers/usb/host/xhci-debugfs.c               |  6 +--
 drivers/usb/mtu3/mtu3_debugfs.c               |  8 ++--
 drivers/usb/musb/musb_debugfs.c               |  4 +-
 drivers/visorbus/visorbus_main.c              |  2 +-
 drivers/xen/xenfs/xensyms.c                   |  2 +-
 fs/debugfs/file.c                             |  4 +-
 fs/dlm/debug_fs.c                             |  8 ++--
 fs/gfs2/glock.c                               |  6 +--
 fs/nfsd/nfs4state.c                           |  4 +-
 fs/nfsd/nfsctl.c                              | 10 ++---
 fs/ocfs2/cluster/netdebug.c                   |  6 +--
 fs/ocfs2/dlm/dlmdebug.c                       |  2 +-
 fs/ocfs2/dlmglue.c                            |  2 +-
 fs/openpromfs/inode.c                         |  2 +-
 fs/orangefs/orangefs-debugfs.c                |  2 +-
 fs/proc/array.c                               |  2 +-
 fs/proc/base.c                                | 24 ++++++------
 fs/proc/fd.c                                  |  2 +-
 fs/proc/task_mmu.c                            |  8 ++--
 fs/proc/task_nommu.c                          |  2 +-
 fs/proc_namespace.c                           |  6 +--
 include/linux/seq_file.h                      |  4 +-
 kernel/bpf/inode.c                            |  2 +-
 kernel/fail_function.c                        |  2 +-
 kernel/gcov/fs.c                              |  2 +-
 kernel/irq/debugfs.c                          |  2 +-
 kernel/kcsan/debugfs.c                        |  2 +-
 kernel/sched/debug.c                          |  2 +-
 kernel/time/test_udelay.c                     |  2 +-
 kernel/trace/ftrace.c                         | 16 ++++----
 kernel/trace/trace.c                          | 20 +++++-----
 kernel/trace/trace_dynevent.c                 |  2 +-
 kernel/trace/trace_events.c                   | 10 ++---
 kernel/trace/trace_events_hist.c              |  4 +-
 kernel/trace/trace_events_synth.c             |  2 +-
 kernel/trace/trace_events_trigger.c           |  2 +-
 kernel/trace/trace_kprobe.c                   |  4 +-
 kernel/trace/trace_printk.c                   |  2 +-
 kernel/trace/trace_stack.c                    |  4 +-
 kernel/trace/trace_stat.c                     |  2 +-
 kernel/trace/trace_uprobe.c                   |  4 +-
 lib/debugobjects.c                            |  2 +-
 lib/dynamic_debug.c                           |  2 +-
 lib/error-inject.c                            |  2 +-
 lib/kunit/debugfs.c                           |  2 +-
 mm/kmemleak.c                                 |  2 +-
 net/6lowpan/debugfs.c                         |  2 +-
 net/batman-adv/debugfs.c                      |  4 +-
 net/bluetooth/6lowpan.c                       |  2 +-
 net/hsr/hsr_debugfs.c                         |  2 +-
 net/l2tp/l2tp_debugfs.c                       |  2 +-
 net/sunrpc/cache.c                            |  2 +-
 net/sunrpc/debugfs.c                          |  4 +-
 net/sunrpc/rpc_pipe.c                         |  2 +-
 security/apparmor/apparmorfs.c                | 10 ++---
 security/integrity/ima/ima_fs.c               |  6 +--
 security/selinux/selinuxfs.c                  |  2 +-
 security/smack/smackfs.c                      | 20 +++++-----
 193 files changed, 375 insertions(+), 375 deletions(-)

diff --git a/Documentation/filesystems/seq_file.rst b/Documentation/filesystems/seq_file.rst
index 7f7ee06b26939f..74e07b550401d6 100644
--- a/Documentation/filesystems/seq_file.rst
+++ b/Documentation/filesystems/seq_file.rst
@@ -311,7 +311,7 @@ file_operations structure will look like::
 	static const struct file_operations ct_file_ops = {
 	        .owner   = THIS_MODULE,
 	        .open    = ct_open,
-	        .read    = seq_read,
+	        .read_iter    = seq_read_iter,
 	        .llseek  = seq_lseek,
 	        .release = seq_release
 	};
diff --git a/Documentation/process/clang-format.rst b/Documentation/process/clang-format.rst
index 6710c0707721da..7f04493cba4f20 100644
--- a/Documentation/process/clang-format.rst
+++ b/Documentation/process/clang-format.rst
@@ -136,7 +136,7 @@ In particular, some very common ones you will notice are:
         static const struct file_operations uprobe_events_ops = {
                 .owner          = THIS_MODULE,
                 .open           = probes_open,
-                .read           = seq_read,
+                .read_iter           = seq_read_iter,
                 .llseek         = seq_lseek,
                 .release        = seq_release,
                 .write          = probes_write,
@@ -147,7 +147,7 @@ In particular, some very common ones you will notice are:
         static const struct file_operations uprobe_events_ops = {
                 .owner = THIS_MODULE,
                 .open = probes_open,
-                .read = seq_read,
+                .read_iter = seq_read_iter,
                 .llseek = seq_lseek,
                 .release = seq_release,
                 .write = probes_write,
diff --git a/Documentation/translations/it_IT/process/clang-format.rst b/Documentation/translations/it_IT/process/clang-format.rst
index 77eac809a63929..b491789877a726 100644
--- a/Documentation/translations/it_IT/process/clang-format.rst
+++ b/Documentation/translations/it_IT/process/clang-format.rst
@@ -149,7 +149,7 @@ In particolare, quelli più comuni che noterete sono:
         static const struct file_operations uprobe_events_ops = {
                 .owner          = THIS_MODULE,
                 .open           = probes_open,
-                .read           = seq_read,
+                .read_iter           = seq_read_iter,
                 .llseek         = seq_lseek,
                 .release        = seq_release,
                 .write          = probes_write,
@@ -160,7 +160,7 @@ In particolare, quelli più comuni che noterete sono:
         static const struct file_operations uprobe_events_ops = {
                 .owner = THIS_MODULE,
                 .open = probes_open,
-                .read = seq_read,
+                .read_iter = seq_read_iter,
                 .llseek = seq_lseek,
                 .release = seq_release,
                 .write = probes_write,
diff --git a/arch/arm/mm/ptdump_debugfs.c b/arch/arm/mm/ptdump_debugfs.c
index 598b636615a29a..ec30bf13c41635 100644
--- a/arch/arm/mm/ptdump_debugfs.c
+++ b/arch/arm/mm/ptdump_debugfs.c
@@ -19,7 +19,7 @@ static int ptdump_open(struct inode *inode, struct file *file)
 
 static const struct file_operations ptdump_fops = {
 	.open		= ptdump_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/arm64/kvm/vgic/vgic-debug.c b/arch/arm64/kvm/vgic/vgic-debug.c
index b13a9e3f99ddc1..76998af2449bb0 100644
--- a/arch/arm64/kvm/vgic/vgic-debug.c
+++ b/arch/arm64/kvm/vgic/vgic-debug.c
@@ -284,7 +284,7 @@ static int debug_open(struct inode *inode, struct file *file)
 static const struct file_operations vgic_debug_fops = {
 	.owner   = THIS_MODULE,
 	.open    = debug_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release
 };
diff --git a/arch/c6x/platforms/pll.c b/arch/c6x/platforms/pll.c
index 6fdf20d64dc753..a952faff19ce9a 100644
--- a/arch/c6x/platforms/pll.c
+++ b/arch/c6x/platforms/pll.c
@@ -424,7 +424,7 @@ static int c6x_ck_open(struct inode *inode, struct file *file)
 
 static const struct file_operations c6x_ck_operations = {
 	.open		= c6x_ck_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/mips/cavium-octeon/oct_ilm.c b/arch/mips/cavium-octeon/oct_ilm.c
index 99e27155b3991f..4d91cb8da0a75a 100644
--- a/arch/mips/cavium-octeon/oct_ilm.c
+++ b/arch/mips/cavium-octeon/oct_ilm.c
@@ -51,7 +51,7 @@ static int oct_ilm_open(struct inode *inode, struct file *file)
 
 static const struct file_operations oct_ilm_ops = {
 	.open = oct_ilm_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/arch/mips/kernel/segment.c b/arch/mips/kernel/segment.c
index 0a9bd7b0983b93..9ea0c2e7915814 100644
--- a/arch/mips/kernel/segment.c
+++ b/arch/mips/kernel/segment.c
@@ -88,7 +88,7 @@ static int segments_open(struct inode *inode, struct file *file)
 
 static const struct file_operations segments_fops = {
 	.open		= segments_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/mips/ralink/bootrom.c b/arch/mips/ralink/bootrom.c
index 94ca8379b83c90..bc83a355fdb18d 100644
--- a/arch/mips/ralink/bootrom.c
+++ b/arch/mips/ralink/bootrom.c
@@ -26,7 +26,7 @@ static int bootrom_open(struct inode *inode, struct file *file)
 
 static const struct file_operations bootrom_file_ops = {
 	.open		= bootrom_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/powerpc/kvm/book3s_xive_native.c b/arch/powerpc/kvm/book3s_xive_native.c
index bdea91df149742..02e3cbbeac5b37 100644
--- a/arch/powerpc/kvm/book3s_xive_native.c
+++ b/arch/powerpc/kvm/book3s_xive_native.c
@@ -1234,7 +1234,7 @@ static int xive_native_debug_open(struct inode *inode, struct file *file)
 
 static const struct file_operations xive_native_debug_fops = {
 	.open = xive_native_debug_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/arch/powerpc/kvm/timing.c b/arch/powerpc/kvm/timing.c
index ba56a5cbba97f3..e045b6d5c7180f 100644
--- a/arch/powerpc/kvm/timing.c
+++ b/arch/powerpc/kvm/timing.c
@@ -198,7 +198,7 @@ static int kvmppc_exit_timing_open(struct inode *inode, struct file *file)
 static const struct file_operations kvmppc_exit_timing_fops = {
 	.owner   = THIS_MODULE,
 	.open    = kvmppc_exit_timing_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.write   = kvmppc_exit_timing_write,
 	.llseek  = seq_lseek,
 	.release = single_release,
diff --git a/arch/powerpc/mm/ptdump/bats.c b/arch/powerpc/mm/ptdump/bats.c
index e29b338d499f4d..7afcdac48a1617 100644
--- a/arch/powerpc/mm/ptdump/bats.c
+++ b/arch/powerpc/mm/ptdump/bats.c
@@ -154,7 +154,7 @@ static int bats_open(struct inode *inode, struct file *file)
 
 static const struct file_operations bats_fops = {
 	.open		= bats_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/powerpc/mm/ptdump/hashpagetable.c b/arch/powerpc/mm/ptdump/hashpagetable.c
index a2c33efc7ce8d9..94a6124f974060 100644
--- a/arch/powerpc/mm/ptdump/hashpagetable.c
+++ b/arch/powerpc/mm/ptdump/hashpagetable.c
@@ -533,7 +533,7 @@ static int ptdump_open(struct inode *inode, struct file *file)
 
 static const struct file_operations ptdump_fops = {
 	.open		= ptdump_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c
index de6e05ef871c1b..2306235b72a33a 100644
--- a/arch/powerpc/mm/ptdump/ptdump.c
+++ b/arch/powerpc/mm/ptdump/ptdump.c
@@ -407,7 +407,7 @@ static int ptdump_open(struct inode *inode, struct file *file)
 
 static const struct file_operations ptdump_fops = {
 	.open		= ptdump_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/powerpc/mm/ptdump/segment_regs.c b/arch/powerpc/mm/ptdump/segment_regs.c
index dde2fe8de4b2a8..8b15bad5ab2737 100644
--- a/arch/powerpc/mm/ptdump/segment_regs.c
+++ b/arch/powerpc/mm/ptdump/segment_regs.c
@@ -48,7 +48,7 @@ static int sr_open(struct inode *inode, struct file *file)
 
 static const struct file_operations sr_fops = {
 	.open		= sr_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index 62d90a5e23d1ef..dd2a5af8285e59 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -1943,7 +1943,7 @@ static int spufs_caps_open(struct inode *inode, struct file *file)
 
 static const struct file_operations spufs_caps_fops = {
 	.open		= spufs_caps_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -2189,7 +2189,7 @@ static int spufs_tid_open(struct inode *inode, struct file *file)
 
 static const struct file_operations spufs_tid_fops = {
 	.open		= spufs_tid_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -2279,7 +2279,7 @@ static int spufs_stat_open(struct inode *inode, struct file *file)
 
 static const struct file_operations spufs_stat_fops = {
 	.open		= spufs_stat_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -2532,7 +2532,7 @@ static int spufs_ctx_open(struct inode *inode, struct file *file)
 
 static const struct file_operations spufs_ctx_fops = {
 	.open           = spufs_ctx_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = single_release,
 };
diff --git a/arch/powerpc/platforms/pseries/hvCall_inst.c b/arch/powerpc/platforms/pseries/hvCall_inst.c
index c40c62ec432e27..5bee57a0a975b5 100644
--- a/arch/powerpc/platforms/pseries/hvCall_inst.c
+++ b/arch/powerpc/platforms/pseries/hvCall_inst.c
@@ -91,7 +91,7 @@ static int hcall_inst_seq_open(struct inode *inode, struct file *file)
 
 static const struct file_operations hcall_inst_seq_fops = {
 	.open = hcall_inst_seq_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release,
 };
diff --git a/arch/s390/kernel/diag.c b/arch/s390/kernel/diag.c
index ccba63aaeb470b..83ed3df5f7ebdb 100644
--- a/arch/s390/kernel/diag.c
+++ b/arch/s390/kernel/diag.c
@@ -111,7 +111,7 @@ static int show_diag_stat_open(struct inode *inode, struct file *file)
 
 static const struct file_operations show_diag_stat_fops = {
 	.open		= show_diag_stat_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index c2ac9b8ae61206..9adb10a0508e30 100644
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c
@@ -268,7 +268,7 @@ static int ptdump_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations ptdump_fops = {
 	.open		= ptdump_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/s390/pci/pci_debug.c b/arch/s390/pci/pci_debug.c
index 3408c0df3ebf11..e86fbaa4e331cd 100644
--- a/arch/s390/pci/pci_debug.c
+++ b/arch/s390/pci/pci_debug.c
@@ -163,7 +163,7 @@ static int pci_perf_seq_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations debugfs_pci_perf_fops = {
 	.open	 = pci_perf_seq_open,
-	.read	 = seq_read,
+	.read_iter	 = seq_read_iter,
 	.write	 = pci_perf_seq_write,
 	.llseek  = seq_lseek,
 	.release = single_release,
diff --git a/arch/sh/mm/asids-debugfs.c b/arch/sh/mm/asids-debugfs.c
index 4c1ca197e9c5f2..065519ba6c902f 100644
--- a/arch/sh/mm/asids-debugfs.c
+++ b/arch/sh/mm/asids-debugfs.c
@@ -56,7 +56,7 @@ static int asids_debugfs_open(struct inode *inode, struct file *file)
 static const struct file_operations asids_debugfs_fops = {
 	.owner		= THIS_MODULE,
 	.open		= asids_debugfs_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/sh/mm/cache-debugfs.c b/arch/sh/mm/cache-debugfs.c
index 17d78079449715..114085cd560961 100644
--- a/arch/sh/mm/cache-debugfs.c
+++ b/arch/sh/mm/cache-debugfs.c
@@ -102,7 +102,7 @@ static int cache_debugfs_open(struct inode *inode, struct file *file)
 static const struct file_operations cache_debugfs_fops = {
 	.owner		= THIS_MODULE,
 	.open		= cache_debugfs_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/sh/mm/pmb.c b/arch/sh/mm/pmb.c
index b20aba6e1b37c3..1944c412f37cfb 100644
--- a/arch/sh/mm/pmb.c
+++ b/arch/sh/mm/pmb.c
@@ -854,7 +854,7 @@ static int pmb_debugfs_open(struct inode *inode, struct file *file)
 static const struct file_operations pmb_debugfs_fops = {
 	.owner		= THIS_MODULE,
 	.open		= pmb_debugfs_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/sh/mm/tlb-debugfs.c b/arch/sh/mm/tlb-debugfs.c
index 11c6148283f3c7..ecd1c639f42d0b 100644
--- a/arch/sh/mm/tlb-debugfs.c
+++ b/arch/sh/mm/tlb-debugfs.c
@@ -142,7 +142,7 @@ static int tlb_debugfs_open(struct inode *inode, struct file *file)
 static const struct file_operations tlb_debugfs_fops = {
 	.owner		= THIS_MODULE,
 	.open		= tlb_debugfs_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c
index e1da619add1921..19825b0042c664 100644
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -397,7 +397,7 @@ static ssize_t severities_coverage_write(struct file *file,
 static const struct file_operations severities_coverage_fops = {
 	.open		= severities_coverage_open,
 	.release	= seq_release,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= severities_coverage_write,
 	.llseek		= seq_lseek,
 };
diff --git a/arch/x86/mm/pat/memtype.c b/arch/x86/mm/pat/memtype.c
index 8f665c352bf0d3..0f915e25052ddf 100644
--- a/arch/x86/mm/pat/memtype.c
+++ b/arch/x86/mm/pat/memtype.c
@@ -1200,7 +1200,7 @@ static int memtype_seq_open(struct inode *inode, struct file *file)
 
 static const struct file_operations memtype_fops = {
 	.open    = memtype_seq_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 77e04304a2a71d..95b12dd5bf0e08 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -173,7 +173,7 @@ static int cpastats_open(struct inode *inode, struct file *file)
 
 static const struct file_operations cpastats_fops = {
 	.open		= cpastats_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 0acba2c712ab84..4cf680e2e30b77 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -806,7 +806,7 @@ static int p2m_dump_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations p2m_dump_fops = {
 	.open		= p2m_dump_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 15df3a36e9fa43..824a11828c7d35 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -770,7 +770,7 @@ static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
 
 static const struct file_operations blk_mq_debugfs_fops = {
 	.open		= blk_mq_debugfs_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= blk_mq_debugfs_write,
 	.llseek		= seq_lseek,
 	.release	= blk_mq_debugfs_release,
diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c
index 92073ac68473c5..6742b20ff3fc98 100644
--- a/drivers/base/power/wakeup.c
+++ b/drivers/base/power/wakeup.c
@@ -1172,7 +1172,7 @@ static int wakeup_sources_stats_open(struct inode *inode, struct file *file)
 static const struct file_operations wakeup_sources_stats_fops = {
 	.owner = THIS_MODULE,
 	.open = wakeup_sources_stats_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release_private,
 };
diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index 5ca7216e9e01f3..57905a4959a829 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -188,7 +188,7 @@ static const struct attribute_group *aoe_attr_groups[] = {
 
 static const struct file_operations aoe_debugfs_fops = {
 	.open = aoe_debugfs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/block/drbd/drbd_debugfs.c b/drivers/block/drbd/drbd_debugfs.c
index b3b9cd5628fdf7..be08bb0d8ed5f8 100644
--- a/drivers/block/drbd/drbd_debugfs.c
+++ b/drivers/block/drbd/drbd_debugfs.c
@@ -457,7 +457,7 @@ static int in_flight_summary_release(struct inode *inode, struct file *file)
 static const struct file_operations in_flight_summary_fops = {
 	.owner		= THIS_MODULE,
 	.open		= in_flight_summary_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= in_flight_summary_release,
 };
@@ -565,7 +565,7 @@ static int callback_history_release(struct inode *inode, struct file *file)
 static const struct file_operations connection_callback_history_fops = {
 	.owner		= THIS_MODULE,
 	.open		= callback_history_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= callback_history_release,
 };
@@ -612,7 +612,7 @@ static int connection_oldest_requests_release(struct inode *inode, struct file *
 static const struct file_operations connection_oldest_requests_fops = {
 	.owner		= THIS_MODULE,
 	.open		= connection_oldest_requests_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= connection_oldest_requests_release,
 };
@@ -757,7 +757,7 @@ static int device_ ## name ## _release(struct inode *inode, struct file *file)	\
 static const struct file_operations device_ ## name ## _fops = {		\
 	.owner		= THIS_MODULE,						\
 	.open		= device_ ## name ## _open,				\
-	.read		= seq_read,						\
+	.read_iter		= seq_read_iter,						\
 	.llseek		= seq_lseek,						\
 	.release	= device_ ## name ## _release,				\
 };
@@ -859,7 +859,7 @@ static const struct file_operations drbd_version_fops = {
 	.owner = THIS_MODULE,
 	.open = drbd_version_open,
 	.llseek = seq_lseek,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.release = single_release,
 };
 
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 43cff01a5a675d..291adae3eddac9 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1539,7 +1539,7 @@ static int nbd_dbg_tasks_open(struct inode *inode, struct file *file)
 
 static const struct file_operations nbd_dbg_tasks_ops = {
 	.open = nbd_dbg_tasks_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -1574,7 +1574,7 @@ static int nbd_dbg_flags_open(struct inode *inode, struct file *file)
 
 static const struct file_operations nbd_dbg_flags_ops = {
 	.open = nbd_dbg_flags_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 27a33adc41e487..50c6d6eacb5907 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -464,7 +464,7 @@ static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
 
 static const struct file_operations debug_fops = {
 	.open		= pkt_debugfs_fops_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 	.owner		= THIS_MODULE,
diff --git a/drivers/block/rsxx/core.c b/drivers/block/rsxx/core.c
index 10f6368117d814..1adfd0f273b4e0 100644
--- a/drivers/block/rsxx/core.c
+++ b/drivers/block/rsxx/core.c
@@ -209,7 +209,7 @@ static const struct file_operations debugfs_cram_fops = {
 static const struct file_operations debugfs_stats_fops = {
 	.owner		= THIS_MODULE,
 	.open		= rsxx_attr_stats_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -217,7 +217,7 @@ static const struct file_operations debugfs_stats_fops = {
 static const struct file_operations debugfs_pci_regs_fops = {
 	.owner		= THIS_MODULE,
 	.open		= rsxx_attr_pci_regs_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/bus/mvebu-mbus.c b/drivers/bus/mvebu-mbus.c
index 5b2a11a88951b5..e76c866cda6a4d 100644
--- a/drivers/bus/mvebu-mbus.c
+++ b/drivers/bus/mvebu-mbus.c
@@ -477,7 +477,7 @@ static int mvebu_sdram_debug_open(struct inode *inode, struct file *file)
 
 static const struct file_operations mvebu_sdram_debug_fops = {
 	.open = mvebu_sdram_debug_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -527,7 +527,7 @@ static int mvebu_devs_debug_open(struct inode *inode, struct file *file)
 
 static const struct file_operations mvebu_devs_debug_fops = {
 	.open = mvebu_devs_debug_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/char/tpm/eventlog/common.c b/drivers/char/tpm/eventlog/common.c
index 7460f230bae4c6..5a738a7efe9aa8 100644
--- a/drivers/char/tpm/eventlog/common.c
+++ b/drivers/char/tpm/eventlog/common.c
@@ -66,7 +66,7 @@ static int tpm_bios_measurements_release(struct inode *inode,
 static const struct file_operations tpm_bios_measurements_ops = {
 	.owner = THIS_MODULE,
 	.open = tpm_bios_measurements_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = tpm_bios_measurements_release,
 };
diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
index b957061424a1f7..52c7785c0db11c 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
@@ -310,7 +310,7 @@ static int sun8i_ce_dbgfs_open(struct inode *inode, struct file *file)
 static const struct file_operations sun8i_ce_debugfs_fops = {
 	.owner = THIS_MODULE,
 	.open = sun8i_ce_dbgfs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c
index 5d9d0fedcb0689..fde5364695272e 100644
--- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c
+++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c
@@ -294,7 +294,7 @@ static int sun8i_ss_dbgfs_open(struct inode *inode, struct file *file)
 static const struct file_operations sun8i_ss_debugfs_fops = {
 	.owner = THIS_MODULE,
 	.open = sun8i_ss_dbgfs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/crypto/amlogic/amlogic-gxl-core.c b/drivers/crypto/amlogic/amlogic-gxl-core.c
index 411857fad8ba60..112be244136908 100644
--- a/drivers/crypto/amlogic/amlogic-gxl-core.c
+++ b/drivers/crypto/amlogic/amlogic-gxl-core.c
@@ -125,7 +125,7 @@ static int meson_dbgfs_open(struct inode *inode, struct file *file)
 static const struct file_operations meson_debugfs_fops = {
 	.owner = THIS_MODULE,
 	.open = meson_dbgfs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/crypto/caam/dpseci-debugfs.c b/drivers/crypto/caam/dpseci-debugfs.c
index c5bfc923abd811..aa10841b6bc5e9 100644
--- a/drivers/crypto/caam/dpseci-debugfs.c
+++ b/drivers/crypto/caam/dpseci-debugfs.c
@@ -60,7 +60,7 @@ static int dpseci_dbg_fqs_open(struct inode *inode, struct file *file)
 
 static const struct file_operations dpseci_dbg_fq_ops = {
 	.open = dpseci_dbg_fqs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/crypto/cavium/zip/zip_main.c b/drivers/crypto/cavium/zip/zip_main.c
index 194624b4855bd2..451e97fd893111 100644
--- a/drivers/crypto/cavium/zip/zip_main.c
+++ b/drivers/crypto/cavium/zip/zip_main.c
@@ -592,7 +592,7 @@ static int zip_stats_open(struct inode *inode, struct file *file)
 static const struct file_operations zip_stats_fops = {
 	.owner = THIS_MODULE,
 	.open  = zip_stats_open,
-	.read  = seq_read,
+	.read_iter  = seq_read_iter,
 	.release = single_release,
 };
 
@@ -604,7 +604,7 @@ static int zip_clear_open(struct inode *inode, struct file *file)
 static const struct file_operations zip_clear_fops = {
 	.owner = THIS_MODULE,
 	.open  = zip_clear_open,
-	.read  = seq_read,
+	.read_iter  = seq_read_iter,
 	.release = single_release,
 };
 
@@ -616,7 +616,7 @@ static int zip_regs_open(struct inode *inode, struct file *file)
 static const struct file_operations zip_regs_fops = {
 	.owner = THIS_MODULE,
 	.open  = zip_regs_open,
-	.read  = seq_read,
+	.read_iter  = seq_read_iter,
 	.release = single_release,
 };
 
diff --git a/drivers/crypto/hisilicon/qm.c b/drivers/crypto/hisilicon/qm.c
index 9bb263cec6c306..a5c3e21e0fe6a1 100644
--- a/drivers/crypto/hisilicon/qm.c
+++ b/drivers/crypto/hisilicon/qm.c
@@ -1054,7 +1054,7 @@ static int qm_regs_open(struct inode *inode, struct file *file)
 static const struct file_operations qm_regs_fops = {
 	.owner = THIS_MODULE,
 	.open = qm_regs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.release = single_release,
 };
 
diff --git a/drivers/crypto/qat/qat_common/adf_cfg.c b/drivers/crypto/qat/qat_common/adf_cfg.c
index 5c7fdb0fc53d94..4b77c6f05b3ee0 100644
--- a/drivers/crypto/qat/qat_common/adf_cfg.c
+++ b/drivers/crypto/qat/qat_common/adf_cfg.c
@@ -110,7 +110,7 @@ static int qat_dev_cfg_open(struct inode *inode, struct file *file)
 
 static const struct file_operations qat_dev_cfg_fops = {
 	.open = qat_dev_cfg_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release
 };
diff --git a/drivers/crypto/qat/qat_common/adf_transport_debug.c b/drivers/crypto/qat/qat_common/adf_transport_debug.c
index e794e9d97b2cbb..6133a869aeb1db 100644
--- a/drivers/crypto/qat/qat_common/adf_transport_debug.c
+++ b/drivers/crypto/qat/qat_common/adf_transport_debug.c
@@ -142,7 +142,7 @@ static int adf_ring_open(struct inode *inode, struct file *file)
 
 static const struct file_operations adf_ring_debug_fops = {
 	.open = adf_ring_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release
 };
@@ -253,7 +253,7 @@ static int adf_bank_open(struct inode *inode, struct file *file)
 
 static const struct file_operations adf_bank_debug_fops = {
 	.open = adf_bank_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release
 };
diff --git a/drivers/firmware/tegra/bpmp-debugfs.c b/drivers/firmware/tegra/bpmp-debugfs.c
index 636b40d4364dff..3f0a89ce131acb 100644
--- a/drivers/firmware/tegra/bpmp-debugfs.c
+++ b/drivers/firmware/tegra/bpmp-debugfs.c
@@ -292,7 +292,7 @@ static ssize_t debugfs_store(struct file *file, const char __user *buf,
 
 static const struct file_operations debugfs_fops = {
 	.open		= debugfs_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.write		= debugfs_store,
 	.release	= single_release,
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 4fa075d49fbc9d..0ca1acff0e37d6 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -5529,7 +5529,7 @@ static int gpiolib_open(struct inode *inode, struct file *file)
 static const struct file_operations gpiolib_operations = {
 	.owner		= THIS_MODULE,
 	.open		= gpiolib_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c b/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c
index 511712c2e382dd..d2b33ea38b7602 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c
@@ -69,7 +69,7 @@ static ssize_t kfd_debugfs_hang_hws_write(struct file *file,
 static const struct file_operations kfd_debugfs_fops = {
 	.owner = THIS_MODULE,
 	.open = kfd_debugfs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -77,7 +77,7 @@ static const struct file_operations kfd_debugfs_fops = {
 static const struct file_operations kfd_debugfs_hang_hws_fops = {
 	.owner = THIS_MODULE,
 	.open = kfd_debugfs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = kfd_debugfs_hang_hws_write,
 	.llseek = seq_lseek,
 	.release = single_release,
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
index 1d767473ba8a06..0246b2e94d8cbd 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
@@ -49,7 +49,7 @@ static int komeda_register_open(struct inode *inode, struct file *filp)
 static const struct file_operations komeda_register_fops = {
 	.owner		= THIS_MODULE,
 	.open		= komeda_register_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
index def8c9ffafcaf5..029a26def9f770 100644
--- a/drivers/gpu/drm/arm/malidp_drv.c
+++ b/drivers/gpu/drm/arm/malidp_drv.c
@@ -542,7 +542,7 @@ static ssize_t malidp_debugfs_write(struct file *file, const char __user *ubuf,
 static const struct file_operations malidp_debugfs_fops = {
 	.owner = THIS_MODULE,
 	.open = malidp_debugfs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = malidp_debugfs_write,
 	.llseek = seq_lseek,
 	.release = single_release,
diff --git a/drivers/gpu/drm/armada/armada_debugfs.c b/drivers/gpu/drm/armada/armada_debugfs.c
index c6fc2f1d58e99f..dd2b2892a2901c 100644
--- a/drivers/gpu/drm/armada/armada_debugfs.c
+++ b/drivers/gpu/drm/armada/armada_debugfs.c
@@ -85,7 +85,7 @@ static int armada_debugfs_crtc_reg_write(struct file *file,
 static const struct file_operations armada_debugfs_crtc_reg_fops = {
 	.owner = THIS_MODULE,
 	.open = armada_debugfs_crtc_reg_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = armada_debugfs_crtc_reg_write,
 	.llseek = seq_lseek,
 	.release = single_release,
diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
index 2bea221307037a..a0a1a598826fcd 100644
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -154,7 +154,7 @@ static int drm_debugfs_open(struct inode *inode, struct file *file)
 static const struct file_operations drm_debugfs_fops = {
 	.owner = THIS_MODULE,
 	.open = drm_debugfs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -379,7 +379,7 @@ static ssize_t edid_write(struct file *file, const char __user *ubuf,
 static const struct file_operations drm_edid_fops = {
 	.owner = THIS_MODULE,
 	.open = edid_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = edid_write
@@ -389,7 +389,7 @@ static const struct file_operations drm_edid_fops = {
 static const struct file_operations drm_connector_fops = {
 	.owner = THIS_MODULE,
 	.open = connector_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = connector_write
diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c
index 5d67a41f7c3a8f..e78fa4411dd186 100644
--- a/drivers/gpu/drm/drm_debugfs_crc.c
+++ b/drivers/gpu/drm/drm_debugfs_crc.c
@@ -167,7 +167,7 @@ static ssize_t crc_control_write(struct file *file, const char __user *ubuf,
 static const struct file_operations drm_crtc_crc_control_fops = {
 	.owner = THIS_MODULE,
 	.open = crc_control_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = crc_control_write
diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c
index bb27c82757f17c..d0298376d28a19 100644
--- a/drivers/gpu/drm/drm_mipi_dbi.c
+++ b/drivers/gpu/drm/drm_mipi_dbi.c
@@ -1279,7 +1279,7 @@ static int mipi_dbi_debugfs_command_open(struct inode *inode,
 static const struct file_operations mipi_dbi_debugfs_command_fops = {
 	.owner = THIS_MODULE,
 	.open = mipi_dbi_debugfs_command_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = mipi_dbi_debugfs_command_write,
diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
index 70525623bcdf09..147448e6f75032 100644
--- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
+++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
@@ -1009,7 +1009,7 @@ static ssize_t i915_ipc_status_write(struct file *file, const char __user *ubuf,
 static const struct file_operations i915_ipc_status_fops = {
 	.owner = THIS_MODULE,
 	.open = i915_ipc_status_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = i915_ipc_status_write
@@ -1326,7 +1326,7 @@ static int i915_displayport_test_active_open(struct inode *inode,
 static const struct file_operations i915_displayport_test_active_fops = {
 	.owner = THIS_MODULE,
 	.open = i915_displayport_test_active_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = i915_displayport_test_active_write
@@ -1627,7 +1627,7 @@ static ssize_t cur_wm_latency_write(struct file *file, const char __user *ubuf,
 static const struct file_operations i915_pri_wm_latency_fops = {
 	.owner = THIS_MODULE,
 	.open = pri_wm_latency_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = pri_wm_latency_write
@@ -1636,7 +1636,7 @@ static const struct file_operations i915_pri_wm_latency_fops = {
 static const struct file_operations i915_spr_wm_latency_fops = {
 	.owner = THIS_MODULE,
 	.open = spr_wm_latency_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = spr_wm_latency_write
@@ -1645,7 +1645,7 @@ static const struct file_operations i915_spr_wm_latency_fops = {
 static const struct file_operations i915_cur_wm_latency_fops = {
 	.owner = THIS_MODULE,
 	.open = cur_wm_latency_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = cur_wm_latency_write
@@ -1728,7 +1728,7 @@ static int i915_hpd_storm_ctl_open(struct inode *inode, struct file *file)
 static const struct file_operations i915_hpd_storm_ctl_fops = {
 	.owner = THIS_MODULE,
 	.open = i915_hpd_storm_ctl_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = i915_hpd_storm_ctl_write
@@ -1801,7 +1801,7 @@ static ssize_t i915_hpd_short_storm_ctl_write(struct file *file,
 static const struct file_operations i915_hpd_short_storm_ctl_fops = {
 	.owner = THIS_MODULE,
 	.open = i915_hpd_short_storm_ctl_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = i915_hpd_short_storm_ctl_write,
@@ -2179,7 +2179,7 @@ static int i915_dsc_fec_support_open(struct inode *inode,
 static const struct file_operations i915_dsc_fec_support_fops = {
 	.owner = THIS_MODULE,
 	.open = i915_dsc_fec_support_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = i915_dsc_fec_support_write
diff --git a/drivers/gpu/drm/i915/gt/debugfs_gt.h b/drivers/gpu/drm/i915/gt/debugfs_gt.h
index f77540f727e94d..d4cebf4c9f5b4e 100644
--- a/drivers/gpu/drm/i915/gt/debugfs_gt.h
+++ b/drivers/gpu/drm/i915/gt/debugfs_gt.h
@@ -18,7 +18,7 @@ struct intel_gt;
 static const struct file_operations __name ## _fops = {			\
 	.owner = THIS_MODULE,						\
 	.open = __name ## _open,					\
-	.read = seq_read,						\
+	.read_iter = seq_read_iter,						\
 	.llseek = seq_lseek,						\
 	.release = single_release,					\
 }
diff --git a/drivers/gpu/drm/i915/i915_debugfs_params.c b/drivers/gpu/drm/i915/i915_debugfs_params.c
index 62b2c5f0495d79..58ef14b028ead5 100644
--- a/drivers/gpu/drm/i915/i915_debugfs_params.c
+++ b/drivers/gpu/drm/i915/i915_debugfs_params.c
@@ -48,7 +48,7 @@ static ssize_t i915_param_int_write(struct file *file,
 static const struct file_operations i915_param_int_fops = {
 	.owner = THIS_MODULE,
 	.open = i915_param_int_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = i915_param_int_write,
 	.llseek = default_llseek,
 	.release = single_release,
@@ -57,7 +57,7 @@ static const struct file_operations i915_param_int_fops = {
 static const struct file_operations i915_param_int_fops_ro = {
 	.owner = THIS_MODULE,
 	.open = i915_param_int_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = default_llseek,
 	.release = single_release,
 };
@@ -101,7 +101,7 @@ static ssize_t i915_param_uint_write(struct file *file,
 static const struct file_operations i915_param_uint_fops = {
 	.owner = THIS_MODULE,
 	.open = i915_param_uint_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = i915_param_uint_write,
 	.llseek = default_llseek,
 	.release = single_release,
@@ -110,7 +110,7 @@ static const struct file_operations i915_param_uint_fops = {
 static const struct file_operations i915_param_uint_fops_ro = {
 	.owner = THIS_MODULE,
 	.open = i915_param_uint_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = default_llseek,
 	.release = single_release,
 };
@@ -160,7 +160,7 @@ static ssize_t i915_param_charp_write(struct file *file,
 static const struct file_operations i915_param_charp_fops = {
 	.owner = THIS_MODULE,
 	.open = i915_param_charp_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = i915_param_charp_write,
 	.llseek = default_llseek,
 	.release = single_release,
@@ -169,7 +169,7 @@ static const struct file_operations i915_param_charp_fops = {
 static const struct file_operations i915_param_charp_fops_ro = {
 	.owner = THIS_MODULE,
 	.open = i915_param_charp_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = default_llseek,
 	.release = single_release,
 };
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c
index f1bc6a1af7a714..99be6d8d4d1abb 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c
@@ -297,7 +297,7 @@ static const struct file_operations __prefix ## _fops = {		\
 	.owner = THIS_MODULE,						\
 	.open = __prefix ## _open,					\
 	.release = single_release,					\
-	.read = seq_read,						\
+	.read_iter = seq_read_iter,						\
 	.llseek = seq_lseek,						\
 }
 
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
index e15b42a780e041..2fa8d07979eb72 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -1256,7 +1256,7 @@ static const struct file_operations __prefix ## _fops = {		\
 	.owner = THIS_MODULE,						\
 	.open = __prefix ## _open,					\
 	.release = single_release,					\
-	.read = seq_read,						\
+	.read_iter = seq_read_iter,						\
 	.llseek = seq_lseek,						\
 }
 
@@ -1283,7 +1283,7 @@ static int _dpu_crtc_init_debugfs(struct drm_crtc *crtc)
 
 	static const struct file_operations debugfs_status_fops = {
 		.open =		_dpu_debugfs_status_open,
-		.read =		seq_read,
+		.read_iter =		seq_read_iter,
 		.llseek =	seq_lseek,
 		.release =	single_release,
 	};
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 63976dcd2ac87f..64c37ac4b550a5 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -1881,7 +1881,7 @@ static int _dpu_encoder_init_debugfs(struct drm_encoder *drm_enc)
 
 	static const struct file_operations debugfs_status_fops = {
 		.open =		_dpu_encoder_debugfs_status_open,
-		.read =		seq_read,
+		.read_iter =		seq_read_iter,
 		.llseek =	seq_lseek,
 		.release =	single_release,
 	};
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
index b8615d4fe8a3f7..a5ab16df27c347 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
@@ -107,7 +107,7 @@ static const struct file_operations __prefix ## _fops = {		\
 	.owner = THIS_MODULE,						\
 	.open = __prefix ## _open,					\
 	.release = single_release,					\
-	.read = seq_read,						\
+	.read_iter = seq_read_iter,						\
 	.llseek = seq_lseek,						\
 }
 
@@ -176,7 +176,7 @@ static int dpu_debugfs_open_regset32(struct inode *inode,
 
 static const struct file_operations dpu_fops_regset32 = {
 	.open =		dpu_debugfs_open_regset32,
-	.read =		seq_read,
+	.read_iter =		seq_read_iter,
 	.llseek =	seq_lseek,
 	.release =	single_release,
 };
diff --git a/drivers/gpu/drm/msm/msm_debugfs.c b/drivers/gpu/drm/msm/msm_debugfs.c
index ee2e270f464c1d..7952d56f2c0fe8 100644
--- a/drivers/gpu/drm/msm/msm_debugfs.c
+++ b/drivers/gpu/drm/msm/msm_debugfs.c
@@ -103,7 +103,7 @@ static int msm_gpu_open(struct inode *inode, struct file *file)
 static const struct file_operations msm_gpu_fops = {
 	.owner = THIS_MODULE,
 	.open = msm_gpu_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = msm_gpu_release,
 };
diff --git a/drivers/gpu/drm/nouveau/nouveau_debugfs.c b/drivers/gpu/drm/nouveau/nouveau_debugfs.c
index 63b5c8cf9ae430..838394c6fd3701 100644
--- a/drivers/gpu/drm/nouveau/nouveau_debugfs.c
+++ b/drivers/gpu/drm/nouveau/nouveau_debugfs.c
@@ -203,7 +203,7 @@ nouveau_debugfs_pstate_open(struct inode *inode, struct file *file)
 static const struct file_operations nouveau_pstate_fops = {
 	.owner = THIS_MODULE,
 	.open = nouveau_debugfs_pstate_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = nouveau_debugfs_pstate_set,
 };
 
diff --git a/drivers/gpu/drm/omapdrm/dss/dss.c b/drivers/gpu/drm/omapdrm/dss/dss.c
index 4d5739fa4a5d81..4f19dde961a475 100644
--- a/drivers/gpu/drm/omapdrm/dss/dss.c
+++ b/drivers/gpu/drm/omapdrm/dss/dss.c
@@ -912,7 +912,7 @@ static int dss_debug_open(struct inode *inode, struct file *file)
 
 static const struct file_operations dss_debug_fops = {
 	.open		= dss_debug_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/gpu/host1x/debug.c b/drivers/gpu/host1x/debug.c
index c0392672a84214..545fc0afb45a6b 100644
--- a/drivers/gpu/host1x/debug.c
+++ b/drivers/gpu/host1x/debug.c
@@ -141,7 +141,7 @@ static int host1x_debug_open_all(struct inode *inode, struct file *file)
 
 static const struct file_operations host1x_debug_all_fops = {
 	.open = host1x_debug_open_all,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -153,7 +153,7 @@ static int host1x_debug_open(struct inode *inode, struct file *file)
 
 static const struct file_operations host1x_debug_fops = {
 	.open = host1x_debug_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c
index 087304b1a5d71b..1be2ebabbfdbdc 100644
--- a/drivers/gpu/vga/vga_switcheroo.c
+++ b/drivers/gpu/vga/vga_switcheroo.c
@@ -900,7 +900,7 @@ static const struct file_operations vga_switcheroo_debugfs_fops = {
 	.owner = THIS_MODULE,
 	.open = vga_switcheroo_debugfs_open,
 	.write = vga_switcheroo_debugfs_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/hid/hid-picolcd_debugfs.c b/drivers/hid/hid-picolcd_debugfs.c
index d01176da889627..36a58f60094d62 100644
--- a/drivers/hid/hid-picolcd_debugfs.c
+++ b/drivers/hid/hid-picolcd_debugfs.c
@@ -60,7 +60,7 @@ static ssize_t picolcd_debug_reset_write(struct file *f, const char __user *user
 static const struct file_operations picolcd_debug_reset_fops = {
 	.owner    = THIS_MODULE,
 	.open     = picolcd_debug_reset_open,
-	.read     = seq_read,
+	.read_iter     = seq_read_iter,
 	.llseek   = seq_lseek,
 	.write    = picolcd_debug_reset_write,
 	.release  = single_release,
diff --git a/drivers/hid/hid-wiimote-debug.c b/drivers/hid/hid-wiimote-debug.c
index a99dcca2e09938..51bf8fca0c1dcd 100644
--- a/drivers/hid/hid-wiimote-debug.c
+++ b/drivers/hid/hid-wiimote-debug.c
@@ -163,7 +163,7 @@ static ssize_t wiidebug_drm_write(struct file *f, const char __user *u,
 static const struct file_operations wiidebug_drm_fops = {
 	.owner = THIS_MODULE,
 	.open = wiidebug_drm_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.write = wiidebug_drm_write,
 	.release = single_release,
diff --git a/drivers/ide/ide-proc.c b/drivers/ide/ide-proc.c
index 15c17f3781ee91..8ea282a3a19f0d 100644
--- a/drivers/ide/ide-proc.c
+++ b/drivers/ide/ide-proc.c
@@ -457,7 +457,7 @@ static int ide_media_proc_open(struct inode *inode, struct file *file)
 static const struct file_operations ide_media_proc_fops = {
 	.owner		= THIS_MODULE,
 	.open		= ide_media_proc_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/infiniband/hw/cxgb4/device.c b/drivers/infiniband/hw/cxgb4/device.c
index 541dbcf22d0ebf..b1d3bdced23bcc 100644
--- a/drivers/infiniband/hw/cxgb4/device.c
+++ b/drivers/infiniband/hw/cxgb4/device.c
@@ -191,7 +191,7 @@ static const struct file_operations wr_log_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = wr_log_open,
 	.release = single_release,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.write   = wr_log_clear,
 };
@@ -550,7 +550,7 @@ static const struct file_operations stats_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = stats_open,
 	.release = single_release,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.write   = stats_clear,
 };
diff --git a/drivers/infiniband/hw/qib/qib_debugfs.c b/drivers/infiniband/hw/qib/qib_debugfs.c
index caeb77d07a5859..bc166896b93641 100644
--- a/drivers/infiniband/hw/qib/qib_debugfs.c
+++ b/drivers/infiniband/hw/qib/qib_debugfs.c
@@ -61,7 +61,7 @@ static int _##name##_open(struct inode *inode, struct file *s) \
 static const struct file_operations _##name##_file_ops = { \
 	.owner   = THIS_MODULE, \
 	.open    = _##name##_open, \
-	.read    = seq_read, \
+	.read_iter    = seq_read_iter, \
 	.llseek  = seq_lseek, \
 	.release = seq_release \
 };
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_fs.c b/drivers/infiniband/ulp/ipoib/ipoib_fs.c
index 64c19f6fa93167..06c00dff1f51d0 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_fs.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_fs.c
@@ -149,7 +149,7 @@ static int ipoib_mcg_open(struct inode *inode, struct file *file)
 static const struct file_operations ipoib_mcg_fops = {
 	.owner   = THIS_MODULE,
 	.open    = ipoib_mcg_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release
 };
@@ -254,7 +254,7 @@ static int ipoib_path_open(struct inode *inode, struct file *file)
 static const struct file_operations ipoib_path_fops = {
 	.owner   = THIS_MODULE,
 	.open    = ipoib_path_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release
 };
diff --git a/drivers/md/bcache/closure.c b/drivers/md/bcache/closure.c
index 0164a1fe94a9b5..99222aa5d6e672 100644
--- a/drivers/md/bcache/closure.c
+++ b/drivers/md/bcache/closure.c
@@ -196,7 +196,7 @@ static int debug_seq_open(struct inode *inode, struct file *file)
 static const struct file_operations debug_ops = {
 	.owner		= THIS_MODULE,
 	.open		= debug_seq_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.release	= single_release
 };
 
diff --git a/drivers/media/cec/core/cec-core.c b/drivers/media/cec/core/cec-core.c
index 0c52e1bb391050..87e856788e0bf2 100644
--- a/drivers/media/cec/core/cec-core.c
+++ b/drivers/media/cec/core/cec-core.c
@@ -226,7 +226,7 @@ static int cec_error_inj_open(struct inode *inode, struct file *file)
 static const struct file_operations cec_error_inj_fops = {
 	.open = cec_error_inj_open,
 	.write = cec_error_inj_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/media/pci/saa7164/saa7164-core.c b/drivers/media/pci/saa7164/saa7164-core.c
index 126d085be9a7fd..50293396658cb5 100644
--- a/drivers/media/pci/saa7164/saa7164-core.c
+++ b/drivers/media/pci/saa7164/saa7164-core.c
@@ -1155,7 +1155,7 @@ static int saa7164_open(struct inode *inode, struct file *file)
 static const struct file_operations saa7164_operations = {
 	.owner          = THIS_MODULE,
 	.open           = saa7164_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = seq_release,
 };
diff --git a/drivers/memory/emif.c b/drivers/memory/emif.c
index 9d9127bf2a5906..58a82eea585047 100644
--- a/drivers/memory/emif.c
+++ b/drivers/memory/emif.c
@@ -138,7 +138,7 @@ static int emif_regdump_open(struct inode *inode, struct file *file)
 
 static const struct file_operations emif_regdump_fops = {
 	.open			= emif_regdump_open,
-	.read			= seq_read,
+	.read_iter			= seq_read_iter,
 	.release		= single_release,
 };
 
@@ -157,7 +157,7 @@ static int emif_mr4_open(struct inode *inode, struct file *file)
 
 static const struct file_operations emif_mr4_fops = {
 	.open			= emif_mr4_open,
-	.read			= seq_read,
+	.read_iter			= seq_read_iter,
 	.release		= single_release,
 };
 
diff --git a/drivers/memory/tegra/tegra124-emc.c b/drivers/memory/tegra/tegra124-emc.c
index 33b8216bac30c7..794431b2102c9c 100644
--- a/drivers/memory/tegra/tegra124-emc.c
+++ b/drivers/memory/tegra/tegra124-emc.c
@@ -1068,7 +1068,7 @@ static int tegra_emc_debug_available_rates_open(struct inode *inode,
 
 static const struct file_operations tegra_emc_debug_available_rates_fops = {
 	.open = tegra_emc_debug_available_rates_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/memory/tegra/tegra186-emc.c b/drivers/memory/tegra/tegra186-emc.c
index 97f26bc77ad41f..1445ab51af6a91 100644
--- a/drivers/memory/tegra/tegra186-emc.c
+++ b/drivers/memory/tegra/tegra186-emc.c
@@ -94,7 +94,7 @@ static int tegra186_emc_debug_available_rates_open(struct inode *inode,
 
 static const struct file_operations tegra186_emc_debug_available_rates_fops = {
 	.open = tegra186_emc_debug_available_rates_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index b16715e9515d03..c63b14f7b356cd 100644
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -546,7 +546,7 @@ static int tegra_emc_debug_available_rates_open(struct inode *inode,
 
 static const struct file_operations tegra_emc_debug_available_rates_fops = {
 	.open = tegra_emc_debug_available_rates_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
index b42bdb667e8530..2ed027408af204 100644
--- a/drivers/memory/tegra/tegra30-emc.c
+++ b/drivers/memory/tegra/tegra30-emc.c
@@ -1174,7 +1174,7 @@ static int tegra_emc_debug_available_rates_open(struct inode *inode,
 
 static const struct file_operations tegra_emc_debug_available_rates_fops = {
 	.open = tegra_emc_debug_available_rates_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/mfd/ab3100-core.c b/drivers/mfd/ab3100-core.c
index 57723f116bb585..0f461180d29f74 100644
--- a/drivers/mfd/ab3100-core.c
+++ b/drivers/mfd/ab3100-core.c
@@ -473,7 +473,7 @@ static int ab3100_registers_open(struct inode *inode, struct file *file)
 
 static const struct file_operations ab3100_registers_fops = {
 	.open = ab3100_registers_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
diff --git a/drivers/mfd/ab3100-otp.c b/drivers/mfd/ab3100-otp.c
index c4751fb9bc224b..3667fa4c9fedcc 100644
--- a/drivers/mfd/ab3100-otp.c
+++ b/drivers/mfd/ab3100-otp.c
@@ -117,7 +117,7 @@ static int ab3100_otp_open(struct inode *inode, struct file *file)
 
 static const struct file_operations ab3100_otp_operations = {
 	.open		= ab3100_otp_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/mfd/ab8500-debugfs.c b/drivers/mfd/ab8500-debugfs.c
index 1a9a3414d4fa85..fcdb618fe2db03 100644
--- a/drivers/mfd/ab8500-debugfs.c
+++ b/drivers/mfd/ab8500-debugfs.c
@@ -1376,7 +1376,7 @@ static int ab8500_all_banks_open(struct inode *inode, struct file *file)
 
 static const struct file_operations ab8500_all_banks_fops = {
 	.open = ab8500_all_banks_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -1959,7 +1959,7 @@ static ssize_t ab8500_unsubscribe_write(struct file *file,
 static const struct file_operations ab8500_bank_fops = {
 	.open = ab8500_bank_open,
 	.write = ab8500_bank_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -1968,7 +1968,7 @@ static const struct file_operations ab8500_bank_fops = {
 static const struct file_operations ab8500_address_fops = {
 	.open = ab8500_address_open,
 	.write = ab8500_address_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -1977,7 +1977,7 @@ static const struct file_operations ab8500_address_fops = {
 static const struct file_operations ab8500_val_fops = {
 	.open = ab8500_val_open,
 	.write = ab8500_val_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -1986,7 +1986,7 @@ static const struct file_operations ab8500_val_fops = {
 static const struct file_operations ab8500_subscribe_fops = {
 	.open = ab8500_subscribe_unsubscribe_open,
 	.write = ab8500_subscribe_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -1995,7 +1995,7 @@ static const struct file_operations ab8500_subscribe_fops = {
 static const struct file_operations ab8500_unsubscribe_fops = {
 	.open = ab8500_subscribe_unsubscribe_open,
 	.write = ab8500_unsubscribe_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -2004,7 +2004,7 @@ static const struct file_operations ab8500_unsubscribe_fops = {
 static const struct file_operations ab8500_hwreg_fops = {
 	.open = ab8500_hwreg_open,
 	.write = ab8500_hwreg_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
diff --git a/drivers/mfd/tps65010.c b/drivers/mfd/tps65010.c
index 65fcc58c02da8b..19ed0a37238978 100644
--- a/drivers/mfd/tps65010.c
+++ b/drivers/mfd/tps65010.c
@@ -290,7 +290,7 @@ static int dbg_tps_open(struct inode *inode, struct file *file)
 
 static const struct file_operations debug_fops = {
 	.open		= dbg_tps_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/misc/habanalabs/debugfs.c b/drivers/misc/habanalabs/debugfs.c
index 3c8dcdfba20cf1..01028a850c841b 100644
--- a/drivers/misc/habanalabs/debugfs.c
+++ b/drivers/misc/habanalabs/debugfs.c
@@ -1151,7 +1151,7 @@ static ssize_t hl_debugfs_write(struct file *file, const char __user *buf,
 static const struct file_operations hl_debugfs_fops = {
 	.owner = THIS_MODULE,
 	.open = hl_debugfs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = hl_debugfs_write,
 	.llseek = seq_lseek,
 	.release = single_release,
diff --git a/drivers/mmc/core/mmc_test.c b/drivers/mmc/core/mmc_test.c
index c21b3cb71775eb..41bddd115ee97e 100644
--- a/drivers/mmc/core/mmc_test.c
+++ b/drivers/mmc/core/mmc_test.c
@@ -3148,7 +3148,7 @@ static ssize_t mtf_test_write(struct file *file, const char __user *buf,
 
 static const struct file_operations mmc_test_fops_test = {
 	.open		= mtf_test_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= mtf_test_write,
 	.llseek		= seq_lseek,
 	.release	= single_release,
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 76d832a88e0c4f..bb7bb1fcbe55ce 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -351,7 +351,7 @@ static int mtd_partid_debugfs_open(struct inode *inode, struct file *file)
 
 static const struct file_operations mtd_partid_debug_fops = {
 	.open           = mtd_partid_debugfs_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = single_release,
 };
@@ -372,7 +372,7 @@ static int mtd_partname_debugfs_open(struct inode *inode, struct file *file)
 
 static const struct file_operations mtd_partname_debug_fops = {
 	.open           = mtd_partname_debugfs_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = single_release,
 };
diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index ac2bdba8bb1a3b..4f13e7b6942469 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -488,7 +488,7 @@ static int eraseblk_count_release(struct inode *inode, struct file *f)
 static const struct file_operations eraseblk_count_fops = {
 	.owner = THIS_MODULE,
 	.open = eraseblk_count_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = eraseblk_count_release,
 };
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
index 828499256004b3..f8115e3d638b2d 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c
@@ -229,7 +229,7 @@ static int cim_la_open(struct inode *inode, struct file *file)
 static const struct file_operations cim_la_fops = {
 	.owner   = THIS_MODULE,
 	.open    = cim_la_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release_private
 };
@@ -272,7 +272,7 @@ static int cim_pif_la_open(struct inode *inode, struct file *file)
 static const struct file_operations cim_pif_la_fops = {
 	.owner   = THIS_MODULE,
 	.open    = cim_pif_la_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release_private
 };
@@ -318,7 +318,7 @@ static int cim_ma_la_open(struct inode *inode, struct file *file)
 static const struct file_operations cim_ma_la_fops = {
 	.owner   = THIS_MODULE,
 	.open    = cim_ma_la_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release_private
 };
@@ -411,7 +411,7 @@ static int cim_ibq_open(struct inode *inode, struct file *file)
 static const struct file_operations cim_ibq_fops = {
 	.owner   = THIS_MODULE,
 	.open    = cim_ibq_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release_private
 };
@@ -440,7 +440,7 @@ static int cim_obq_open(struct inode *inode, struct file *file)
 static const struct file_operations cim_obq_fops = {
 	.owner   = THIS_MODULE,
 	.open    = cim_obq_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release_private
 };
@@ -686,7 +686,7 @@ static ssize_t tp_la_write(struct file *file, const char __user *buf,
 static const struct file_operations tp_la_fops = {
 	.owner   = THIS_MODULE,
 	.open    = tp_la_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release_private,
 	.write   = tp_la_write
@@ -722,7 +722,7 @@ static int ulprx_la_open(struct inode *inode, struct file *file)
 static const struct file_operations ulprx_la_fops = {
 	.owner   = THIS_MODULE,
 	.open    = ulprx_la_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release_private
 };
@@ -812,7 +812,7 @@ static ssize_t pm_stats_clear(struct file *file, const char __user *buf,
 static const struct file_operations pm_stats_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = pm_stats_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = single_release,
 	.write   = pm_stats_clear
@@ -1136,7 +1136,7 @@ static int devlog_open(struct inode *inode, struct file *file)
 static const struct file_operations devlog_fops = {
 	.owner   = THIS_MODULE,
 	.open    = devlog_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release_private
 };
@@ -1234,7 +1234,7 @@ static int mboxlog_open(struct inode *inode, struct file *file)
 static const struct file_operations mboxlog_fops = {
 	.owner   = THIS_MODULE,
 	.open    = mboxlog_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
@@ -1317,7 +1317,7 @@ static ssize_t mbox_write(struct file *file, const char __user *buf,
 static const struct file_operations mbox_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = mbox_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = single_release,
 	.write   = mbox_write
@@ -1610,7 +1610,7 @@ inval:				count = -EINVAL;
 static const struct file_operations mps_trc_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = mps_trc_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = single_release,
 	.write   = mps_trc_write
@@ -1930,7 +1930,7 @@ static int mps_tcam_open(struct inode *inode, struct file *file)
 static const struct file_operations mps_tcam_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = mps_tcam_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
@@ -2007,7 +2007,7 @@ static int rss_open(struct inode *inode, struct file *file)
 static const struct file_operations rss_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = rss_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release_private
 };
@@ -2226,7 +2226,7 @@ static ssize_t rss_key_write(struct file *file, const char __user *buf,
 static const struct file_operations rss_key_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = rss_key_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = single_release,
 	.write   = rss_key_write
@@ -2310,7 +2310,7 @@ static int rss_pf_config_open(struct inode *inode, struct file *file)
 static const struct file_operations rss_pf_config_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = rss_pf_config_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release_private
 };
@@ -2373,7 +2373,7 @@ static int rss_vf_config_open(struct inode *inode, struct file *file)
 static const struct file_operations rss_vf_config_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = rss_vf_config_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release_private
 };
@@ -2562,7 +2562,7 @@ static int dcb_info_open(struct inode *inode, struct file *file)
 static const struct file_operations dcb_info_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = dcb_info_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
@@ -3184,7 +3184,7 @@ static int sge_qinfo_open(struct inode *inode, struct file *file)
 static const struct file_operations sge_qinfo_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = sge_qinfo_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
diff --git a/drivers/net/ethernet/chelsio/cxgb4/l2t.c b/drivers/net/ethernet/chelsio/cxgb4/l2t.c
index 72b37a66c7d889..a213270edfa7b6 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/l2t.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/l2t.c
@@ -759,7 +759,7 @@ static int l2t_seq_open(struct inode *inode, struct file *file)
 const struct file_operations t4_l2t_fops = {
 	.owner = THIS_MODULE,
 	.open = l2t_seq_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release,
 };
diff --git a/drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c b/drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c
index cec865a97464d2..1352a03a4563d3 100644
--- a/drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4vf/cxgb4vf_main.c
@@ -2040,7 +2040,7 @@ static int mboxlog_open(struct inode *inode, struct file *file)
 static const struct file_operations mboxlog_fops = {
 	.owner   = THIS_MODULE,
 	.open    = mboxlog_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
@@ -2193,7 +2193,7 @@ static int sge_qinfo_open(struct inode *inode, struct file *file)
 static const struct file_operations sge_qinfo_debugfs_fops = {
 	.owner   = THIS_MODULE,
 	.open    = sge_qinfo_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
@@ -2339,7 +2339,7 @@ static int sge_qstats_open(struct inode *inode, struct file *file)
 static const struct file_operations sge_qstats_proc_fops = {
 	.owner   = THIS_MODULE,
 	.open    = sge_qstats_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
@@ -2437,7 +2437,7 @@ static int interfaces_open(struct inode *inode, struct file *file)
 static const struct file_operations interfaces_proc_fops = {
 	.owner   = THIS_MODULE,
 	.open    = interfaces_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-debugfs.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-debugfs.c
index c453a23045c11c..bc99fe0aabf0cd 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-debugfs.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-debugfs.c
@@ -56,7 +56,7 @@ static int dpaa2_dbg_cpu_open(struct inode *inode, struct file *file)
 
 static const struct file_operations dpaa2_dbg_cpu_ops = {
 	.open = dpaa2_dbg_cpu_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -116,7 +116,7 @@ static int dpaa2_dbg_fqs_open(struct inode *inode, struct file *file)
 
 static const struct file_operations dpaa2_dbg_fq_ops = {
 	.open = dpaa2_dbg_fqs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -161,7 +161,7 @@ static int dpaa2_dbg_ch_open(struct inode *inode, struct file *file)
 
 static const struct file_operations dpaa2_dbg_ch_ops = {
 	.open = dpaa2_dbg_ch_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_debugfs.c b/drivers/net/ethernet/intel/fm10k/fm10k_debugfs.c
index 1d27b2fb23af8f..6caf722a991b03 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k_debugfs.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_debugfs.c
@@ -134,7 +134,7 @@ static int fm10k_dbg_desc_open(struct inode *inode, struct file *filep)
 static const struct file_operations fm10k_dbg_desc_fops = {
 	.owner   = THIS_MODULE,
 	.open    = fm10k_dbg_desc_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c
index 77adad4adb1bc2..f2b41fa0af602a 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c
+++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_debugfs.c
@@ -123,7 +123,7 @@ static int rvu_dbg_open_##name(struct inode *inode, struct file *file) \
 static const struct file_operations rvu_dbg_##name##_fops = { \
 	.owner		= THIS_MODULE, \
 	.open		= rvu_dbg_open_##name, \
-	.read		= seq_read, \
+	.read_iter		= seq_read_iter, \
 	.write		= rvu_dbg_##write_op, \
 	.llseek		= seq_lseek, \
 	.release	= single_release, \
diff --git a/drivers/net/wireless/ath/ath5k/debug.c b/drivers/net/wireless/ath/ath5k/debug.c
index 2eaba1ccab2082..c62d0b78437f28 100644
--- a/drivers/net/wireless/ath/ath5k/debug.c
+++ b/drivers/net/wireless/ath/ath5k/debug.c
@@ -182,7 +182,7 @@ static int open_file_registers(struct inode *inode, struct file *file)
 
 static const struct file_operations fops_registers = {
 	.open = open_file_registers,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 	.owner = THIS_MODULE,
diff --git a/drivers/net/wireless/ath/wil6210/debugfs.c b/drivers/net/wireless/ath/wil6210/debugfs.c
index 11d0c79e905626..4e0408f0cd4680 100644
--- a/drivers/net/wireless/ath/wil6210/debugfs.c
+++ b/drivers/net/wireless/ath/wil6210/debugfs.c
@@ -957,7 +957,7 @@ static int wil_pmcring_seq_open(struct inode *inode, struct file *file)
 static const struct file_operations fops_pmcring = {
 	.open		= wil_pmcring_seq_open,
 	.release	= single_release,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 };
 
@@ -1833,7 +1833,7 @@ static ssize_t wil_tx_latency_write(struct file *file, const char __user *buf,
 static const struct file_operations fops_tx_latency = {
 	.open		= wil_tx_latency_seq_open,
 	.release	= single_release,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= wil_tx_latency_write,
 	.llseek		= seq_lseek,
 };
@@ -1996,7 +1996,7 @@ static ssize_t wil_link_stats_write(struct file *file, const char __user *buf,
 static const struct file_operations fops_link_stats = {
 	.open		= wil_link_stats_seq_open,
 	.release	= single_release,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= wil_link_stats_write,
 	.llseek		= seq_lseek,
 };
@@ -2050,7 +2050,7 @@ wil_link_stats_global_write(struct file *file, const char __user *buf,
 static const struct file_operations fops_link_stats_global = {
 	.open		= wil_link_stats_global_seq_open,
 	.release	= single_release,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= wil_link_stats_global_write,
 	.llseek		= seq_lseek,
 };
@@ -2187,7 +2187,7 @@ static int wil_fw_capabilities_seq_open(struct inode *inode, struct file *file)
 static const struct file_operations fops_fw_capabilities = {
 	.open		= wil_fw_capabilities_seq_open,
 	.release	= single_release,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 };
 
@@ -2213,7 +2213,7 @@ static int wil_fw_version_seq_open(struct inode *inode, struct file *file)
 static const struct file_operations fops_fw_version = {
 	.open		= wil_fw_version_seq_open,
 	.release	= single_release,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 };
 
@@ -2326,7 +2326,7 @@ wil_compressed_rx_status_seq_open(struct inode *inode, struct file *file)
 static const struct file_operations fops_compressed_rx_status = {
 	.open  = wil_compressed_rx_status_seq_open,
 	.release = single_release,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = wil_compressed_rx_status_write,
 	.llseek	= seq_lseek,
 };
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/debug.c b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/debug.c
index 6d776ef6ff54eb..cfc7ff6d35038c 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/debug.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/debug.c
@@ -182,7 +182,7 @@ static const struct file_operations brcms_debugfs_def_ops = {
 	.owner = THIS_MODULE,
 	.open = brcms_debugfs_entry_open,
 	.release = single_release,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek
 };
 
diff --git a/drivers/net/wireless/intel/iwlwifi/fw/debugfs.c b/drivers/net/wireless/intel/iwlwifi/fw/debugfs.c
index 6e72c27f527bfd..cf3b7ec4db73b8 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/debugfs.c
+++ b/drivers/net/wireless/intel/iwlwifi/fw/debugfs.c
@@ -419,7 +419,7 @@ static int iwl_dbgfs_fw_info_open(struct inode *inode, struct file *filp)
 static const struct file_operations iwl_dbgfs_fw_info_ops = {
 	.owner = THIS_MODULE,
 	.open = iwl_dbgfs_fw_info_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release_private,
 };
diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index e5160d62086880..b3e740f1b601f4 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
@@ -2947,7 +2947,7 @@ DEBUGFS_READ_WRITE_FILE_OPS(rfkill);
 static const struct file_operations iwl_dbgfs_tx_queue_ops = {
 	.owner = THIS_MODULE,
 	.open = iwl_dbgfs_tx_queue_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release_private,
 };
diff --git a/drivers/net/wireless/mediatek/mt76/mt7603/debugfs.c b/drivers/net/wireless/mediatek/mt76/mt7603/debugfs.c
index 8ce6880b2bb83e..fc913aad29b262 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7603/debugfs.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7603/debugfs.c
@@ -99,7 +99,7 @@ mt7603_ampdu_stat_open(struct inode *inode, struct file *f)
 
 static const struct file_operations fops_ampdu_stat = {
 	.open = mt7603_ampdu_stat_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/debugfs.c b/drivers/net/wireless/mediatek/mt76/mt7615/debugfs.c
index fd3ef483a87ce7..c61bd9803078a0 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/debugfs.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/debugfs.c
@@ -181,7 +181,7 @@ mt7615_ampdu_stat_open(struct inode *inode, struct file *f)
 
 static const struct file_operations fops_ampdu_stat = {
 	.open = mt7615_ampdu_stat_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_debugfs.c b/drivers/net/wireless/mediatek/mt76/mt76x02_debugfs.c
index ff448a1ad4e398..eda1e49c61dfcd 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x02_debugfs.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x02_debugfs.c
@@ -50,7 +50,7 @@ static int read_txpower(struct seq_file *file, void *data)
 
 static const struct file_operations fops_ampdu_stat = {
 	.open = mt76x02_ampdu_stat_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -89,7 +89,7 @@ mt76x02_dfs_stat_open(struct inode *inode, struct file *f)
 
 static const struct file_operations fops_dfs_stat = {
 	.open = mt76x02_dfs_stat_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/debugfs.c b/drivers/net/wireless/mediatek/mt76/mt7915/debugfs.c
index 5278bee812f1cc..9ef9743ac9e80c 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/debugfs.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/debugfs.c
@@ -224,7 +224,7 @@ mt7915_tx_stats_open(struct inode *inode, struct file *f)
 
 static const struct file_operations fops_tx_stats = {
 	.open = mt7915_tx_stats_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -450,7 +450,7 @@ mt7915_sta_stats_open(struct inode *inode, struct file *f)
 
 static const struct file_operations fops_sta_stats = {
 	.open = mt7915_sta_stats_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/net/wireless/mediatek/mt7601u/debugfs.c b/drivers/net/wireless/mediatek/mt7601u/debugfs.c
index 300242bce799a4..eaabba20d2ac70 100644
--- a/drivers/net/wireless/mediatek/mt7601u/debugfs.c
+++ b/drivers/net/wireless/mediatek/mt7601u/debugfs.c
@@ -81,7 +81,7 @@ mt7601u_ampdu_stat_open(struct inode *inode, struct file *f)
 
 static const struct file_operations fops_ampdu_stat = {
 	.open = mt7601u_ampdu_stat_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -139,7 +139,7 @@ mt7601u_eeprom_param_open(struct inode *inode, struct file *f)
 
 static const struct file_operations fops_eeprom_param = {
 	.open = mt7601u_eeprom_param_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/net/wireless/realtek/rtlwifi/debug.c b/drivers/net/wireless/realtek/rtlwifi/debug.c
index 55db71c766fe3b..004c5296bd3dd5 100644
--- a/drivers/net/wireless/realtek/rtlwifi/debug.c
+++ b/drivers/net/wireless/realtek/rtlwifi/debug.c
@@ -86,7 +86,7 @@ static int dl_debug_open_common(struct inode *inode, struct file *file)
 
 static const struct file_operations file_ops_common = {
 	.open = dl_debug_open_common,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/net/wireless/realtek/rtw88/debug.c b/drivers/net/wireless/realtek/rtw88/debug.c
index 09f04feb8fe180..189b4eff55e204 100644
--- a/drivers/net/wireless/realtek/rtw88/debug.c
+++ b/drivers/net/wireless/realtek/rtw88/debug.c
@@ -76,7 +76,7 @@ static int rtw_debugfs_close(struct inode *inode, struct file *filp)
 static const struct file_operations file_ops_single_r = {
 	.owner = THIS_MODULE,
 	.open = rtw_debugfs_single_open_rw,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -85,7 +85,7 @@ static const struct file_operations file_ops_single_rw = {
 	.owner = THIS_MODULE,
 	.open = rtw_debugfs_single_open_rw,
 	.release = single_release,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.write = rtw_debugfs_single_write,
 };
diff --git a/drivers/net/wireless/rsi/rsi_91x_debugfs.c b/drivers/net/wireless/rsi/rsi_91x_debugfs.c
index c71b41e45423b1..9896792ab683d4 100644
--- a/drivers/net/wireless/rsi/rsi_91x_debugfs.c
+++ b/drivers/net/wireless/rsi/rsi_91x_debugfs.c
@@ -253,14 +253,14 @@ static ssize_t rsi_debug_zone_write(struct file *filp,
 #define FOPS(fopen) { \
 	.owner = THIS_MODULE, \
 	.open = (fopen), \
-	.read = seq_read, \
+	.read_iter = seq_read_iter, \
 	.llseek = seq_lseek, \
 }
 
 #define FOPS_RW(fopen, fwrite) { \
 	.owner = THIS_MODULE, \
 	.open = (fopen), \
-	.read = seq_read, \
+	.read_iter = seq_read_iter, \
 	.llseek = seq_lseek, \
 	.write = (fwrite), \
 }
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c
index 286054b60d4743..06b253eba25d8d 100644
--- a/drivers/net/xen-netback/xenbus.c
+++ b/drivers/net/xen-netback/xenbus.c
@@ -152,7 +152,7 @@ static int xenvif_io_ring_open(struct inode *inode, struct file *filp)
 static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
 	.owner = THIS_MODULE,
 	.open = xenvif_io_ring_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.write = xenvif_write_io_ring,
diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
index 2a6c8190eeb766..13496542b6d719 100644
--- a/drivers/nvme/host/fabrics.c
+++ b/drivers/nvme/host/fabrics.c
@@ -1140,7 +1140,7 @@ static int nvmf_dev_release(struct inode *inode, struct file *file)
 static const struct file_operations nvmf_dev_fops = {
 	.owner		= THIS_MODULE,
 	.write		= nvmf_dev_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.open		= nvmf_dev_open,
 	.release	= nvmf_dev_release,
 };
diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
index 235b456698fc79..bfb8dbc2d0ea10 100644
--- a/drivers/pci/controller/pci-tegra.c
+++ b/drivers/pci/controller/pci-tegra.c
@@ -2634,7 +2634,7 @@ static int tegra_pcie_ports_open(struct inode *inode, struct file *file)
 static const struct file_operations tegra_pcie_ports_ops = {
 	.owner = THIS_MODULE,
 	.open = tegra_pcie_ports_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release,
 };
diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 877aade194979d..9efa854fff133f 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -2502,7 +2502,7 @@ static int asus_wmi_debugfs_open(struct inode *inode, struct file *file)
 static const struct file_operations asus_wmi_debugfs_io_ops = {
 	.owner = THIS_MODULE,
 	.open = asus_wmi_debugfs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index 7c8bdab078cf5e..4941349004f604 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -894,7 +894,7 @@ static int pmc_core_ltr_ignore_open(struct inode *inode, struct file *file)
 
 static const struct file_operations pmc_core_ltr_ignore_ops = {
 	.open           = pmc_core_ltr_ignore_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.write          = pmc_core_ltr_ignore_write,
 	.llseek         = seq_lseek,
 	.release        = single_release,
diff --git a/drivers/platform/x86/intel_telemetry_debugfs.c b/drivers/platform/x86/intel_telemetry_debugfs.c
index 1d4d0fbfd63cc6..2a1083f251d801 100644
--- a/drivers/platform/x86/intel_telemetry_debugfs.c
+++ b/drivers/platform/x86/intel_telemetry_debugfs.c
@@ -706,7 +706,7 @@ static int telem_pss_trc_verb_open(struct inode *inode, struct file *file)
 
 static const struct file_operations telem_pss_trc_verb_ops = {
 	.open		= telem_pss_trc_verb_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= telem_pss_trc_verb_write,
 	.llseek		= seq_lseek,
 	.release	= single_release,
@@ -754,7 +754,7 @@ static int telem_ioss_trc_verb_open(struct inode *inode, struct file *file)
 
 static const struct file_operations telem_ioss_trc_verb_ops = {
 	.open		= telem_ioss_trc_verb_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= telem_ioss_trc_verb_write,
 	.llseek		= seq_lseek,
 	.release	= single_release,
diff --git a/drivers/power/supply/da9030_battery.c b/drivers/power/supply/da9030_battery.c
index 88582423b87d40..292ecf875163a5 100644
--- a/drivers/power/supply/da9030_battery.c
+++ b/drivers/power/supply/da9030_battery.c
@@ -179,7 +179,7 @@ static int debug_open(struct inode *inode, struct file *file)
 
 static const struct file_operations bat_debug_fops = {
 	.open		= debug_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 004b2ea9b5fde3..ad39b0bb0b03d2 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -1342,7 +1342,7 @@ static int pwm_seq_open(struct inode *inode, struct file *file)
 static const struct file_operations pwm_debugfs_ops = {
 	.owner = THIS_MODULE,
 	.open = pwm_seq_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release,
 };
diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c
index 569d9ad2c59428..a992bb426fdb37 100644
--- a/drivers/ras/cec.c
+++ b/drivers/ras/cec.c
@@ -475,7 +475,7 @@ static int array_open(struct inode *inode, struct file *filp)
 static const struct file_operations array_ops = {
 	.owner	 = THIS_MODULE,
 	.open	 = array_open,
-	.read	 = seq_read,
+	.read_iter	 = seq_read_iter,
 	.llseek	 = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/ras/debugfs.c b/drivers/ras/debugfs.c
index 0d4f985afbf37f..3da982426904a8 100644
--- a/drivers/ras/debugfs.c
+++ b/drivers/ras/debugfs.c
@@ -32,7 +32,7 @@ static int trace_release(struct inode *inode, struct file *file)
 
 static const struct file_operations trace_fops = {
 	.open    = trace_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = trace_release,
 };
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index cf87eb27879f08..17a9a35e9aedbf 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -1089,7 +1089,7 @@ static int dasd_stats_open(struct inode *inode, struct file *file)
 static const struct file_operations dasd_stats_raw_fops = {
 	.owner		= THIS_MODULE,
 	.open		= dasd_stats_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 	.write		= dasd_stats_write,
diff --git a/drivers/s390/cio/qdio_debug.c b/drivers/s390/cio/qdio_debug.c
index da95c923d81a2e..31e3f86ac81dc6 100644
--- a/drivers/s390/cio/qdio_debug.c
+++ b/drivers/s390/cio/qdio_debug.c
@@ -281,7 +281,7 @@ static int qperf_seq_open(struct inode *inode, struct file *filp)
 static const struct file_operations debugfs_perf_fops = {
 	.owner	 = THIS_MODULE,
 	.open	 = qperf_seq_open,
-	.read	 = seq_read,
+	.read_iter	 = seq_read_iter,
 	.write	 = qperf_seq_write,
 	.llseek  = seq_lseek,
 	.release = single_release,
diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 11caa4b0d79773..852d2620e40833 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -2878,7 +2878,7 @@ static int hisi_sas_debugfs_global_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations hisi_sas_debugfs_global_fops = {
 	.open = hisi_sas_debugfs_global_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -2905,7 +2905,7 @@ static int hisi_sas_debugfs_axi_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations hisi_sas_debugfs_axi_fops = {
 	.open = hisi_sas_debugfs_axi_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -2932,7 +2932,7 @@ static int hisi_sas_debugfs_ras_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations hisi_sas_debugfs_ras_fops = {
 	.open = hisi_sas_debugfs_ras_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -2958,7 +2958,7 @@ static int hisi_sas_debugfs_port_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations hisi_sas_debugfs_port_fops = {
 	.open = hisi_sas_debugfs_port_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -3026,7 +3026,7 @@ static int hisi_sas_debugfs_cq_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations hisi_sas_debugfs_cq_fops = {
 	.open = hisi_sas_debugfs_cq_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -3059,7 +3059,7 @@ static int hisi_sas_debugfs_dq_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations hisi_sas_debugfs_dq_fops = {
 	.open = hisi_sas_debugfs_dq_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -3087,7 +3087,7 @@ static int hisi_sas_debugfs_iost_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations hisi_sas_debugfs_iost_fops = {
 	.open = hisi_sas_debugfs_iost_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -3126,7 +3126,7 @@ static int hisi_sas_debugfs_iost_cache_open(struct inode *inode,
 
 static const struct file_operations hisi_sas_debugfs_iost_cache_fops = {
 	.open = hisi_sas_debugfs_iost_cache_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -3154,7 +3154,7 @@ static int hisi_sas_debugfs_itct_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations hisi_sas_debugfs_itct_fops = {
 	.open = hisi_sas_debugfs_itct_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -3193,7 +3193,7 @@ static int hisi_sas_debugfs_itct_cache_open(struct inode *inode,
 
 static const struct file_operations hisi_sas_debugfs_itct_cache_fops = {
 	.open = hisi_sas_debugfs_itct_cache_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 	.owner = THIS_MODULE,
@@ -3422,7 +3422,7 @@ static int hisi_sas_debugfs_bist_linkrate_open(struct inode *inode,
 
 static const struct file_operations hisi_sas_debugfs_bist_linkrate_ops = {
 	.open = hisi_sas_debugfs_bist_linkrate_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = hisi_sas_debugfs_bist_linkrate_write,
 	.llseek = seq_lseek,
 	.release = single_release,
@@ -3512,7 +3512,7 @@ static int hisi_sas_debugfs_bist_code_mode_open(struct inode *inode,
 
 static const struct file_operations hisi_sas_debugfs_bist_code_mode_ops = {
 	.open = hisi_sas_debugfs_bist_code_mode_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = hisi_sas_debugfs_bist_code_mode_write,
 	.llseek = seq_lseek,
 	.release = single_release,
@@ -3561,7 +3561,7 @@ static int hisi_sas_debugfs_bist_phy_open(struct inode *inode,
 
 static const struct file_operations hisi_sas_debugfs_bist_phy_ops = {
 	.open = hisi_sas_debugfs_bist_phy_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = hisi_sas_debugfs_bist_phy_write,
 	.llseek = seq_lseek,
 	.release = single_release,
@@ -3640,7 +3640,7 @@ static int hisi_sas_debugfs_bist_mode_open(struct inode *inode,
 
 static const struct file_operations hisi_sas_debugfs_bist_mode_ops = {
 	.open = hisi_sas_debugfs_bist_mode_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = hisi_sas_debugfs_bist_mode_write,
 	.llseek = seq_lseek,
 	.release = single_release,
@@ -3696,7 +3696,7 @@ static int hisi_sas_debugfs_bist_enable_open(struct inode *inode,
 
 static const struct file_operations hisi_sas_debugfs_bist_enable_ops = {
 	.open = hisi_sas_debugfs_bist_enable_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = hisi_sas_debugfs_bist_enable_write,
 	.llseek = seq_lseek,
 	.release = single_release,
@@ -3742,7 +3742,7 @@ static int hisi_sas_debugfs_phy_down_cnt_open(struct inode *inode,
 
 static const struct file_operations hisi_sas_debugfs_phy_down_cnt_ops = {
 	.open = hisi_sas_debugfs_phy_down_cnt_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = hisi_sas_debugfs_phy_down_cnt_write,
 	.llseek = seq_lseek,
 	.release = single_release,
diff --git a/drivers/scsi/qedf/qedf_dbg.h b/drivers/scsi/qedf/qedf_dbg.h
index 2386bfb73c4616..df4d4aa4b1dd4f 100644
--- a/drivers/scsi/qedf/qedf_dbg.h
+++ b/drivers/scsi/qedf/qedf_dbg.h
@@ -141,7 +141,7 @@ struct qedf_list_of_funcs {
 { \
 	.owner = THIS_MODULE, \
 	.open = drv##_dbg_##ops##_open, \
-	.read = seq_read, \
+	.read_iter = seq_read_iter, \
 	.llseek = seq_lseek, \
 	.release = single_release, \
 }
diff --git a/drivers/scsi/qedi/qedi_dbg.h b/drivers/scsi/qedi/qedi_dbg.h
index 37d084086fd434..5399116d862b5b 100644
--- a/drivers/scsi/qedi/qedi_dbg.h
+++ b/drivers/scsi/qedi/qedi_dbg.h
@@ -124,7 +124,7 @@ struct qedi_debugfs_ops {
 { \
 	.owner = THIS_MODULE, \
 	.open = drv##_dbg_##ops##_open, \
-	.read = seq_read, \
+	.read_iter = seq_read_iter, \
 	.llseek = seq_lseek, \
 	.release = single_release, \
 }
diff --git a/drivers/scsi/qla2xxx/qla_dfs.c b/drivers/scsi/qla2xxx/qla_dfs.c
index e62b2115235e15..581ed75973e611 100644
--- a/drivers/scsi/qla2xxx/qla_dfs.c
+++ b/drivers/scsi/qla2xxx/qla_dfs.c
@@ -47,7 +47,7 @@ qla2x00_dfs_tgt_sess_open(struct inode *inode, struct file *file)
 
 static const struct file_operations dfs_tgt_sess_ops = {
 	.open		= qla2x00_dfs_tgt_sess_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -116,7 +116,7 @@ qla2x00_dfs_tgt_port_database_open(struct inode *inode, struct file *file)
 
 static const struct file_operations dfs_tgt_port_database_ops = {
 	.open		= qla2x00_dfs_tgt_port_database_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -164,7 +164,7 @@ qla_dfs_fw_resource_cnt_open(struct inode *inode, struct file *file)
 
 static const struct file_operations dfs_fw_resource_cnt_ops = {
 	.open           = qla_dfs_fw_resource_cnt_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = single_release,
 };
@@ -254,7 +254,7 @@ qla_dfs_tgt_counters_open(struct inode *inode, struct file *file)
 
 static const struct file_operations dfs_tgt_counters_ops = {
 	.open           = qla_dfs_tgt_counters_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = single_release,
 };
@@ -351,7 +351,7 @@ qla2x00_dfs_fce_release(struct inode *inode, struct file *file)
 
 static const struct file_operations dfs_fce_ops = {
 	.open		= qla2x00_dfs_fce_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= qla2x00_dfs_fce_release,
 };
@@ -424,7 +424,7 @@ qla_dfs_naqp_write(struct file *file, const char __user *buffer,
 
 static const struct file_operations dfs_naqp_ops = {
 	.open		= qla_dfs_naqp_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 	.write		= qla_dfs_naqp_write,
diff --git a/drivers/scsi/snic/snic_debugfs.c b/drivers/scsi/snic/snic_debugfs.c
index 2b349365592f8c..dbaee7b69e0840 100644
--- a/drivers/scsi/snic/snic_debugfs.c
+++ b/drivers/scsi/snic/snic_debugfs.c
@@ -349,7 +349,7 @@ snic_stats_open(struct inode *inode, struct file *filp)
 static const struct file_operations snic_stats_fops = {
 	.owner	= THIS_MODULE,
 	.open	= snic_stats_open,
-	.read	= seq_read,
+	.read_iter	= seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -455,7 +455,7 @@ snic_trc_open(struct inode *inode, struct file *filp)
 static const struct file_operations snic_trc_fops = {
 	.owner	= THIS_MODULE,
 	.open	= snic_trc_open,
-	.read	= seq_read,
+	.read_iter	= seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release,
 };
diff --git a/drivers/sh/intc/virq-debugfs.c b/drivers/sh/intc/virq-debugfs.c
index 9e62ba9311f077..a2759073ee6d1d 100644
--- a/drivers/sh/intc/virq-debugfs.c
+++ b/drivers/sh/intc/virq-debugfs.c
@@ -44,7 +44,7 @@ static int intc_irq_xlate_open(struct inode *inode, struct file *file)
 
 static const struct file_operations intc_irq_xlate_fops = {
 	.open = intc_irq_xlate_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/soc/qcom/cmd-db.c b/drivers/soc/qcom/cmd-db.c
index fc5610603b1732..d60ef44b1b62c7 100644
--- a/drivers/soc/qcom/cmd-db.c
+++ b/drivers/soc/qcom/cmd-db.c
@@ -303,7 +303,7 @@ static const struct file_operations cmd_db_debugfs_ops = {
 #ifdef CONFIG_DEBUG_FS
 	.open = open_cmd_db_debugfs,
 #endif
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/soc/qcom/socinfo.c b/drivers/soc/qcom/socinfo.c
index 5983c6ffb07801..ab2a56c75f13e6 100644
--- a/drivers/soc/qcom/socinfo.c
+++ b/drivers/soc/qcom/socinfo.c
@@ -228,7 +228,7 @@ static int qcom_open_##name(struct inode *inode, struct file *file)	\
 									\
 static const struct file_operations qcom_ ##name## _ops = {		\
 	.open = qcom_open_##name,					\
-	.read = seq_read,						\
+	.read_iter = seq_read_iter,						\
 	.llseek = seq_lseek,						\
 	.release = single_release,					\
 }
@@ -291,7 +291,7 @@ static int open_image_##type(struct inode *inode, struct file *file)	  \
 									  \
 static const struct file_operations qcom_image_##type##_ops = {	  \
 	.open = open_image_##type,					  \
-	.read = seq_read,						  \
+	.read_iter = seq_read_iter,						  \
 	.llseek = seq_lseek,						  \
 	.release = single_release,					  \
 }
diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c
index 6285cd8efb21bb..fa6bb14f88527f 100644
--- a/drivers/soc/ti/knav_dma.c
+++ b/drivers/soc/ti/knav_dma.c
@@ -377,7 +377,7 @@ static int knav_dma_debug_open(struct inode *inode, struct file *file)
 
 static const struct file_operations knav_dma_debug_ops = {
 	.open		= knav_dma_debug_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/soc/ti/knav_qmss_queue.c b/drivers/soc/ti/knav_qmss_queue.c
index aa071d96ef362d..85702d66b05abc 100644
--- a/drivers/soc/ti/knav_qmss_queue.c
+++ b/drivers/soc/ti/knav_qmss_queue.c
@@ -485,7 +485,7 @@ static int knav_queue_debug_open(struct inode *inode, struct file *file)
 
 static const struct file_operations knav_queue_debug_ops = {
 	.open		= knav_queue_debug_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_debugfs.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_debugfs.c
index 89cc52211de44f..f5a4c4c33c0f9e 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_debugfs.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_debugfs.c
@@ -110,7 +110,7 @@ static const struct file_operations debugfs_log_fops = {
 	.owner		= THIS_MODULE,
 	.open		= debugfs_log_open,
 	.write		= debugfs_log_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -178,7 +178,7 @@ static const struct file_operations debugfs_trace_fops = {
 	.owner		= THIS_MODULE,
 	.open		= debugfs_trace_open,
 	.write		= debugfs_trace_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c
index e0376ee646adff..d734b97a7327bd 100644
--- a/drivers/usb/chipidea/debug.c
+++ b/drivers/usb/chipidea/debug.c
@@ -110,7 +110,7 @@ static int ci_port_test_open(struct inode *inode, struct file *file)
 static const struct file_operations ci_port_test_fops = {
 	.open		= ci_port_test_open,
 	.write		= ci_port_test_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -296,7 +296,7 @@ static int ci_role_open(struct inode *inode, struct file *file)
 static const struct file_operations ci_role_fops = {
 	.open		= ci_role_open,
 	.write		= ci_role_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/usb/dwc2/debugfs.c b/drivers/usb/dwc2/debugfs.c
index 3a0dcbfbc82721..19a083e4f3968d 100644
--- a/drivers/usb/dwc2/debugfs.c
+++ b/drivers/usb/dwc2/debugfs.c
@@ -109,7 +109,7 @@ static const struct file_operations testmode_fops = {
 	.owner		= THIS_MODULE,
 	.open		= testmode_open,
 	.write		= testmode_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index 6d9de334e46ad0..14c075ad29f93d 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -380,7 +380,7 @@ static ssize_t dwc3_lsp_write(struct file *file, const char __user *ubuf,
 static const struct file_operations dwc3_lsp_fops = {
 	.open			= dwc3_lsp_open,
 	.write			= dwc3_lsp_write,
-	.read			= seq_read,
+	.read_iter			= seq_read_iter,
 	.llseek			= seq_lseek,
 	.release		= single_release,
 };
@@ -445,7 +445,7 @@ static ssize_t dwc3_mode_write(struct file *file,
 static const struct file_operations dwc3_mode_fops = {
 	.open			= dwc3_mode_open,
 	.write			= dwc3_mode_write,
-	.read			= seq_read,
+	.read_iter			= seq_read_iter,
 	.llseek			= seq_lseek,
 	.release		= single_release,
 };
@@ -528,7 +528,7 @@ static ssize_t dwc3_testmode_write(struct file *file,
 static const struct file_operations dwc3_testmode_fops = {
 	.open			= dwc3_testmode_open,
 	.write			= dwc3_testmode_write,
-	.read			= seq_read,
+	.read_iter			= seq_read_iter,
 	.llseek			= seq_lseek,
 	.release		= single_release,
 };
@@ -620,7 +620,7 @@ static ssize_t dwc3_link_state_write(struct file *file,
 static const struct file_operations dwc3_link_state_fops = {
 	.open			= dwc3_link_state_open,
 	.write			= dwc3_link_state_write,
-	.read			= seq_read,
+	.read_iter			= seq_read_iter,
 	.llseek			= seq_lseek,
 	.release		= single_release,
 };
diff --git a/drivers/usb/gadget/udc/lpc32xx_udc.c b/drivers/usb/gadget/udc/lpc32xx_udc.c
index 465d0b7c6522a7..bac74bb6729062 100644
--- a/drivers/usb/gadget/udc/lpc32xx_udc.c
+++ b/drivers/usb/gadget/udc/lpc32xx_udc.c
@@ -532,7 +532,7 @@ static int proc_udc_open(struct inode *inode, struct file *file)
 static const struct file_operations proc_ops = {
 	.owner		= THIS_MODULE,
 	.open		= proc_udc_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/drivers/usb/gadget/udc/renesas_usb3.c b/drivers/usb/gadget/udc/renesas_usb3.c
index 0c418ce50ba0f4..619d70d7086b16 100644
--- a/drivers/usb/gadget/udc/renesas_usb3.c
+++ b/drivers/usb/gadget/udc/renesas_usb3.c
@@ -2543,7 +2543,7 @@ static ssize_t renesas_usb3_b_device_write(struct file *file,
 static const struct file_operations renesas_usb3_b_device_fops = {
 	.open = renesas_usb3_b_device_open,
 	.write = renesas_usb3_b_device_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/usb/host/xhci-debugfs.c b/drivers/usb/host/xhci-debugfs.c
index 76c3f29562d2b9..4a640031d944ee 100644
--- a/drivers/usb/host/xhci-debugfs.c
+++ b/drivers/usb/host/xhci-debugfs.c
@@ -248,7 +248,7 @@ static int xhci_ring_open(struct inode *inode, struct file *file)
 
 static const struct file_operations xhci_ring_fops = {
 	.open			= xhci_ring_open,
-	.read			= seq_read,
+	.read_iter			= seq_read_iter,
 	.llseek			= seq_lseek,
 	.release		= single_release,
 };
@@ -329,7 +329,7 @@ static int xhci_context_open(struct inode *inode, struct file *file)
 
 static const struct file_operations xhci_context_fops = {
 	.open			= xhci_context_open,
-	.read			= seq_read,
+	.read_iter			= seq_read_iter,
 	.llseek			= seq_lseek,
 	.release		= single_release,
 };
@@ -390,7 +390,7 @@ static ssize_t xhci_port_write(struct file *file,  const char __user *ubuf,
 static const struct file_operations port_fops = {
 	.open			= xhci_port_open,
 	.write                  = xhci_port_write,
-	.read			= seq_read,
+	.read_iter			= seq_read_iter,
 	.llseek			= seq_lseek,
 	.release		= single_release,
 };
diff --git a/drivers/usb/mtu3/mtu3_debugfs.c b/drivers/usb/mtu3/mtu3_debugfs.c
index fdeade6254aecc..3530f1aa4af6d5 100644
--- a/drivers/usb/mtu3/mtu3_debugfs.c
+++ b/drivers/usb/mtu3/mtu3_debugfs.c
@@ -271,7 +271,7 @@ static int mtu3_ep_open(struct inode *inode, struct file *file)
 
 static const struct file_operations mtu3_ep_fops = {
 	.open = mtu3_ep_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -341,7 +341,7 @@ static ssize_t mtu3_probe_write(struct file *file, const char __user *ubuf,
 static const struct file_operations mtu3_probe_fops = {
 	.open = mtu3_probe_open,
 	.write = mtu3_probe_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -467,7 +467,7 @@ static ssize_t ssusb_mode_write(struct file *file, const char __user *ubuf,
 static const struct file_operations ssusb_mode_fops = {
 	.open = ssusb_mode_open,
 	.write = ssusb_mode_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -513,7 +513,7 @@ static ssize_t ssusb_vbus_write(struct file *file, const char __user *ubuf,
 static const struct file_operations ssusb_vbus_fops = {
 	.open = ssusb_vbus_open,
 	.write = ssusb_vbus_write,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/usb/musb/musb_debugfs.c b/drivers/usb/musb/musb_debugfs.c
index 30a89aa8a3e7ad..14b0f094e8f56b 100644
--- a/drivers/usb/musb/musb_debugfs.c
+++ b/drivers/usb/musb/musb_debugfs.c
@@ -224,7 +224,7 @@ static ssize_t musb_test_mode_write(struct file *file,
 static const struct file_operations musb_test_mode_fops = {
 	.open			= musb_test_mode_open,
 	.write			= musb_test_mode_write,
-	.read			= seq_read,
+	.read_iter			= seq_read_iter,
 	.llseek			= seq_lseek,
 	.release		= single_release,
 };
@@ -316,7 +316,7 @@ static ssize_t musb_softconnect_write(struct file *file,
 static const struct file_operations musb_softconnect_fops = {
 	.open			= musb_softconnect_open,
 	.write			= musb_softconnect_write,
-	.read			= seq_read,
+	.read_iter			= seq_read_iter,
 	.llseek			= seq_lseek,
 	.release		= single_release,
 };
diff --git a/drivers/visorbus/visorbus_main.c b/drivers/visorbus/visorbus_main.c
index 152fd29f04f295..a0b8142bdd114e 100644
--- a/drivers/visorbus/visorbus_main.c
+++ b/drivers/visorbus/visorbus_main.c
@@ -479,7 +479,7 @@ static int bus_info_debugfs_open(struct inode *inode, struct file *file)
 static const struct file_operations bus_info_debugfs_fops = {
 	.owner = THIS_MODULE,
 	.open = bus_info_debugfs_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/drivers/xen/xenfs/xensyms.c b/drivers/xen/xenfs/xensyms.c
index c6c73a33c44d55..bfc92190d1b695 100644
--- a/drivers/xen/xenfs/xensyms.c
+++ b/drivers/xen/xenfs/xensyms.c
@@ -146,7 +146,7 @@ static int xensyms_release(struct inode *inode, struct file *file)
 
 const struct file_operations xensyms_ops = {
 	.open = xensyms_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = xensyms_release
 };
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index ae49a55bda001b..8ba32c2feb1b73 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -1080,7 +1080,7 @@ static int debugfs_open_regset32(struct inode *inode, struct file *file)
 
 static const struct file_operations fops_regset32 = {
 	.open =		debugfs_open_regset32,
-	.read =		seq_read,
+	.read_iter =		seq_read_iter,
 	.llseek =	seq_lseek,
 	.release =	single_release,
 };
@@ -1126,7 +1126,7 @@ static const struct file_operations debugfs_devm_entry_ops = {
 	.owner = THIS_MODULE,
 	.open = debugfs_devm_entry_open,
 	.release = single_release,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek
 };
 
diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c
index d6bbccb0ed152f..95aebaca9033b1 100644
--- a/fs/dlm/debug_fs.c
+++ b/fs/dlm/debug_fs.c
@@ -663,7 +663,7 @@ static int table_open4(struct inode *inode, struct file *file)
 static const struct file_operations format1_fops = {
 	.owner   = THIS_MODULE,
 	.open    = table_open1,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release
 };
@@ -671,7 +671,7 @@ static const struct file_operations format1_fops = {
 static const struct file_operations format2_fops = {
 	.owner   = THIS_MODULE,
 	.open    = table_open2,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release
 };
@@ -679,7 +679,7 @@ static const struct file_operations format2_fops = {
 static const struct file_operations format3_fops = {
 	.owner   = THIS_MODULE,
 	.open    = table_open3,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release
 };
@@ -687,7 +687,7 @@ static const struct file_operations format3_fops = {
 static const struct file_operations format4_fops = {
 	.owner   = THIS_MODULE,
 	.open    = table_open4,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release
 };
diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 2299dcc417eae9..91e9f4da7a5f22 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -2470,7 +2470,7 @@ static int gfs2_sbstats_open(struct inode *inode, struct file *file)
 static const struct file_operations gfs2_glocks_fops = {
 	.owner   = THIS_MODULE,
 	.open    = gfs2_glocks_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = gfs2_glocks_release,
 };
@@ -2478,7 +2478,7 @@ static const struct file_operations gfs2_glocks_fops = {
 static const struct file_operations gfs2_glstats_fops = {
 	.owner   = THIS_MODULE,
 	.open    = gfs2_glstats_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = gfs2_glocks_release,
 };
@@ -2486,7 +2486,7 @@ static const struct file_operations gfs2_glstats_fops = {
 static const struct file_operations gfs2_sbstats_fops = {
 	.owner   = THIS_MODULE,
 	.open	 = gfs2_sbstats_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index bb3d2c32664ad9..a4dadd2c5aa122 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2364,7 +2364,7 @@ static int client_info_open(struct inode *inode, struct file *file)
 
 static const struct file_operations client_info_fops = {
 	.open		= client_info_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -2611,7 +2611,7 @@ static int client_opens_release(struct inode *inode, struct file *file)
 
 static const struct file_operations client_states_fops = {
 	.open		= client_states_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= client_opens_release,
 };
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index b68e96681522ec..1b36a8ba82d204 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -171,7 +171,7 @@ static int exports_nfsd_open(struct inode *inode, struct file *file)
 
 static const struct file_operations exports_nfsd_operations = {
 	.open		= exports_nfsd_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
@@ -189,7 +189,7 @@ static int export_features_open(struct inode *inode, struct file *file)
 
 static const struct file_operations export_features_operations = {
 	.open		= export_features_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -208,7 +208,7 @@ static int supported_enctypes_open(struct inode *inode, struct file *file)
 
 static const struct file_operations supported_enctypes_ops = {
 	.open		= supported_enctypes_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -216,14 +216,14 @@ static const struct file_operations supported_enctypes_ops = {
 
 static const struct file_operations pool_stats_operations = {
 	.open		= nfsd_pool_stats_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= nfsd_pool_stats_release,
 };
 
 static const struct file_operations reply_cache_stats_operations = {
 	.open		= nfsd_reply_cache_stats_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/fs/ocfs2/cluster/netdebug.c b/fs/ocfs2/cluster/netdebug.c
index 667a5c5e1f663c..eb9b7f60bbfb76 100644
--- a/fs/ocfs2/cluster/netdebug.c
+++ b/fs/ocfs2/cluster/netdebug.c
@@ -186,7 +186,7 @@ static int nst_fop_release(struct inode *inode, struct file *file)
 
 static const struct file_operations nst_seq_fops = {
 	.open = nst_fop_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = nst_fop_release,
 };
@@ -418,7 +418,7 @@ static int stats_fop_open(struct inode *inode, struct file *file)
 
 static const struct file_operations stats_seq_fops = {
 	.open = stats_fop_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = sc_fop_release,
 };
@@ -430,7 +430,7 @@ static int sc_fop_open(struct inode *inode, struct file *file)
 
 static const struct file_operations sc_seq_fops = {
 	.open = sc_fop_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = sc_fop_release,
 };
diff --git a/fs/ocfs2/dlm/dlmdebug.c b/fs/ocfs2/dlm/dlmdebug.c
index 4b8b41d23e91d5..3166d544245df6 100644
--- a/fs/ocfs2/dlm/dlmdebug.c
+++ b/fs/ocfs2/dlm/dlmdebug.c
@@ -653,7 +653,7 @@ static int debug_lockres_release(struct inode *inode, struct file *file)
 static const struct file_operations debug_lockres_fops = {
 	.open =		debug_lockres_open,
 	.release =	debug_lockres_release,
-	.read =		seq_read,
+	.read_iter =		seq_read_iter,
 	.llseek =	seq_lseek,
 };
 /* end - debug lockres funcs */
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 152a0fc4e90514..92e8adf843499e 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -3269,7 +3269,7 @@ static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
 static const struct file_operations ocfs2_dlm_debug_fops = {
 	.open =		ocfs2_dlm_debug_open,
 	.release =	ocfs2_dlm_debug_release,
-	.read =		seq_read,
+	.read_iter =		seq_read_iter,
 	.llseek =	seq_lseek,
 };
 
diff --git a/fs/openpromfs/inode.c b/fs/openpromfs/inode.c
index 40c8c2e32fa3e5..bc327cb2673e08 100644
--- a/fs/openpromfs/inode.c
+++ b/fs/openpromfs/inode.c
@@ -159,7 +159,7 @@ static int property_open(struct inode *inode, struct file *file)
 
 static const struct file_operations openpromfs_prop_ops = {
 	.open		= property_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
diff --git a/fs/orangefs/orangefs-debugfs.c b/fs/orangefs/orangefs-debugfs.c
index 29eaa454437279..dc314c6d83722d 100644
--- a/fs/orangefs/orangefs-debugfs.c
+++ b/fs/orangefs/orangefs-debugfs.c
@@ -116,7 +116,7 @@ static const struct seq_operations help_debug_ops = {
 static const struct file_operations debug_help_fops = {
 	.owner		= THIS_MODULE,
 	.open           = orangefs_debug_help_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.release        = seq_release,
 	.llseek         = seq_lseek,
 };
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 55ecbeb3a7213c..49456efa31e381 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -766,7 +766,7 @@ static int children_seq_open(struct inode *inode, struct file *file)
 
 const struct file_operations proc_tid_children_operations = {
 	.open    = children_seq_open,
-	.read    = seq_read,
+	.read_iter    = seq_read_iter,
 	.llseek  = seq_lseek,
 	.release = seq_release,
 };
diff --git a/fs/proc/base.c b/fs/proc/base.c
index d86c0afc8a8590..6f2e921c471e2d 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -538,7 +538,7 @@ static ssize_t lstats_write(struct file *file, const char __user *buf,
 
 static const struct file_operations proc_lstats_operations = {
 	.open		= lstats_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= lstats_write,
 	.llseek		= seq_lseek,
 	.release	= single_release,
@@ -776,7 +776,7 @@ static int proc_single_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations proc_single_file_operations = {
 	.open		= proc_single_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -1460,7 +1460,7 @@ static int sched_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations proc_pid_sched_operations = {
 	.open		= sched_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= sched_write,
 	.llseek		= seq_lseek,
 	.release	= single_release,
@@ -1535,7 +1535,7 @@ static int sched_autogroup_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations proc_pid_sched_autogroup_operations = {
 	.open		= sched_autogroup_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= sched_autogroup_write,
 	.llseek		= seq_lseek,
 	.release	= single_release,
@@ -1638,7 +1638,7 @@ static int timens_offsets_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations proc_timens_offsets_operations = {
 	.open		= timens_offsets_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= timens_offsets_write,
 	.llseek		= seq_lseek,
 	.release	= single_release,
@@ -1695,7 +1695,7 @@ static int comm_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations proc_pid_set_comm_operations = {
 	.open		= comm_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= comm_write,
 	.llseek		= seq_lseek,
 	.release	= single_release,
@@ -2484,7 +2484,7 @@ static int proc_timers_open(struct inode *inode, struct file *file)
 
 static const struct file_operations proc_timers_operations = {
 	.open		= proc_timers_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release_private,
 };
@@ -2576,7 +2576,7 @@ static int timerslack_ns_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations proc_pid_set_timerslack_ns_operations = {
 	.open		= timerslack_ns_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= timerslack_ns_write,
 	.llseek		= seq_lseek,
 	.release	= single_release,
@@ -3028,7 +3028,7 @@ static int proc_projid_map_open(struct inode *inode, struct file *file)
 static const struct file_operations proc_uid_map_operations = {
 	.open		= proc_uid_map_open,
 	.write		= proc_uid_map_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= proc_id_map_release,
 };
@@ -3036,7 +3036,7 @@ static const struct file_operations proc_uid_map_operations = {
 static const struct file_operations proc_gid_map_operations = {
 	.open		= proc_gid_map_open,
 	.write		= proc_gid_map_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= proc_id_map_release,
 };
@@ -3044,7 +3044,7 @@ static const struct file_operations proc_gid_map_operations = {
 static const struct file_operations proc_projid_map_operations = {
 	.open		= proc_projid_map_open,
 	.write		= proc_projid_map_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= proc_id_map_release,
 };
@@ -3095,7 +3095,7 @@ static int proc_setgroups_release(struct inode *inode, struct file *file)
 static const struct file_operations proc_setgroups_operations = {
 	.open		= proc_setgroups_open,
 	.write		= proc_setgroups_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= proc_setgroups_release,
 };
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index 81882a13212d3d..4259f3dd46985a 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -76,7 +76,7 @@ static int seq_fdinfo_open(struct inode *inode, struct file *file)
 
 static const struct file_operations proc_fdinfo_file_operations = {
 	.open		= seq_fdinfo_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index dbda4499a859a5..df2f0f05f5ba72 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -351,7 +351,7 @@ static int pid_maps_open(struct inode *inode, struct file *file)
 
 const struct file_operations proc_pid_maps_operations = {
 	.open		= pid_maps_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= proc_map_release,
 };
@@ -933,14 +933,14 @@ static int smaps_rollup_release(struct inode *inode, struct file *file)
 
 const struct file_operations proc_pid_smaps_operations = {
 	.open		= pid_smaps_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= proc_map_release,
 };
 
 const struct file_operations proc_pid_smaps_rollup_operations = {
 	.open		= smaps_rollup_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= smaps_rollup_release,
 };
@@ -1879,7 +1879,7 @@ static int pid_numa_maps_open(struct inode *inode, struct file *file)
 
 const struct file_operations proc_pid_numa_maps_operations = {
 	.open		= pid_numa_maps_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= proc_map_release,
 };
diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c
index a6d21fc0033c64..b9ea64ddcf7d7b 100644
--- a/fs/proc/task_nommu.c
+++ b/fs/proc/task_nommu.c
@@ -295,7 +295,7 @@ static int pid_maps_open(struct inode *inode, struct file *file)
 
 const struct file_operations proc_pid_maps_operations = {
 	.open		= pid_maps_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= map_release,
 };
diff --git a/fs/proc_namespace.c b/fs/proc_namespace.c
index 3059a9394c2d6d..5b06fc7f5a5f35 100644
--- a/fs/proc_namespace.c
+++ b/fs/proc_namespace.c
@@ -319,7 +319,7 @@ static int mountstats_open(struct inode *inode, struct file *file)
 
 const struct file_operations proc_mounts_operations = {
 	.open		= mounts_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= mounts_release,
 	.poll		= mounts_poll,
@@ -327,7 +327,7 @@ const struct file_operations proc_mounts_operations = {
 
 const struct file_operations proc_mountinfo_operations = {
 	.open		= mountinfo_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= mounts_release,
 	.poll		= mounts_poll,
@@ -335,7 +335,7 @@ const struct file_operations proc_mountinfo_operations = {
 
 const struct file_operations proc_mountstats_operations = {
 	.open		= mountstats_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= mounts_release,
 };
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index b83b3ae3c877f3..0c9e9c8607e788 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -160,7 +160,7 @@ static int __name ## _open(struct inode *inode, struct file *file)	\
 static const struct file_operations __name ## _fops = {			\
 	.owner		= THIS_MODULE,					\
 	.open		= __name ## _open,				\
-	.read		= seq_read,					\
+	.read_iter		= seq_read_iter,					\
 	.llseek		= seq_lseek,					\
 	.release	= seq_release,					\
 }
@@ -174,7 +174,7 @@ static int __name ## _open(struct inode *inode, struct file *file)	\
 static const struct file_operations __name ## _fops = {			\
 	.owner		= THIS_MODULE,					\
 	.open		= __name ## _open,				\
-	.read		= seq_read,					\
+	.read_iter		= seq_read_iter,					\
 	.llseek		= seq_lseek,					\
 	.release	= single_release,				\
 }
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index fb878ba3f22f03..9f73d2ab6e7d28 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -311,7 +311,7 @@ static int bpffs_map_release(struct inode *inode, struct file *file)
  */
 static const struct file_operations bpffs_map_fops = {
 	.open		= bpffs_map_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.release	= bpffs_map_release,
 };
 
diff --git a/kernel/fail_function.c b/kernel/fail_function.c
index 63b349168da725..d4b5501e944fe0 100644
--- a/kernel/fail_function.c
+++ b/kernel/fail_function.c
@@ -314,7 +314,7 @@ static ssize_t fei_write(struct file *file, const char __user *buffer,
 
 static const struct file_operations fei_ops = {
 	.open =		fei_open,
-	.read =		seq_read,
+	.read_iter =		seq_read_iter,
 	.write =	fei_write,
 	.llseek =	seq_lseek,
 	.release =	seq_release,
diff --git a/kernel/gcov/fs.c b/kernel/gcov/fs.c
index 82babf5aa077b7..e17f2fc6f2509f 100644
--- a/kernel/gcov/fs.c
+++ b/kernel/gcov/fs.c
@@ -401,7 +401,7 @@ static void add_links(struct gcov_node *node, struct dentry *parent)
 static const struct file_operations gcov_data_fops = {
 	.open		= gcov_seq_open,
 	.release	= gcov_seq_release,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.write		= gcov_seq_write,
 };
diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c
index 4f9f844074db15..bac13f73cb52e7 100644
--- a/kernel/irq/debugfs.c
+++ b/kernel/irq/debugfs.c
@@ -201,7 +201,7 @@ static ssize_t irq_debug_write(struct file *file, const char __user *user_buf,
 static const struct file_operations dfs_irq_ops = {
 	.open		= irq_debug_open,
 	.write		= irq_debug_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c
index 023e49c58d55ec..a069114d147148 100644
--- a/kernel/kcsan/debugfs.c
+++ b/kernel/kcsan/debugfs.c
@@ -337,7 +337,7 @@ debugfs_write(struct file *file, const char __user *buf, size_t count, loff_t *o
 
 static const struct file_operations debugfs_ops =
 {
-	.read	 = seq_read,
+	.read_iter	 = seq_read_iter,
 	.open	 = debugfs_open,
 	.write	 = debugfs_write,
 	.release = single_release
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 36c54265bb2b0f..f0f79d7f1e8c97 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -164,7 +164,7 @@ static int sched_feat_open(struct inode *inode, struct file *filp)
 static const struct file_operations sched_feat_fops = {
 	.open		= sched_feat_open,
 	.write		= sched_feat_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/kernel/time/test_udelay.c b/kernel/time/test_udelay.c
index 77c63005dc4e03..f6b964a17c1972 100644
--- a/kernel/time/test_udelay.c
+++ b/kernel/time/test_udelay.c
@@ -129,7 +129,7 @@ static ssize_t udelay_test_write(struct file *file, const char __user *buf,
 static const struct file_operations udelay_test_debugfs_ops = {
 	.owner = THIS_MODULE,
 	.open = udelay_test_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = udelay_test_write,
 	.llseek = seq_lseek,
 	.release = single_release,
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1903b80db6ebc5..6a645f2ebf4752 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5561,21 +5561,21 @@ int ftrace_regex_release(struct inode *inode, struct file *file)
 
 static const struct file_operations ftrace_avail_fops = {
 	.open = ftrace_avail_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release_private,
 };
 
 static const struct file_operations ftrace_enabled_fops = {
 	.open = ftrace_enabled_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release_private,
 };
 
 static const struct file_operations ftrace_filter_fops = {
 	.open = ftrace_filter_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = ftrace_filter_write,
 	.llseek = tracing_lseek,
 	.release = ftrace_regex_release,
@@ -5583,7 +5583,7 @@ static const struct file_operations ftrace_filter_fops = {
 
 static const struct file_operations ftrace_notrace_fops = {
 	.open = ftrace_notrace_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = ftrace_notrace_write,
 	.llseek = tracing_lseek,
 	.release = ftrace_regex_release,
@@ -5981,7 +5981,7 @@ ftrace_graph_write(struct file *file, const char __user *ubuf,
 
 static const struct file_operations ftrace_graph_fops = {
 	.open		= ftrace_graph_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= ftrace_graph_write,
 	.llseek		= tracing_lseek,
 	.release	= ftrace_graph_release,
@@ -5989,7 +5989,7 @@ static const struct file_operations ftrace_graph_fops = {
 
 static const struct file_operations ftrace_graph_notrace_fops = {
 	.open		= ftrace_graph_notrace_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= ftrace_graph_write,
 	.llseek		= tracing_lseek,
 	.release	= ftrace_graph_release,
@@ -7306,7 +7306,7 @@ ftrace_pid_release(struct inode *inode, struct file *file)
 static const struct file_operations ftrace_pid_fops = {
 	.open		= ftrace_pid_open,
 	.write		= ftrace_pid_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= tracing_lseek,
 	.release	= ftrace_pid_release,
 };
@@ -7314,7 +7314,7 @@ static const struct file_operations ftrace_pid_fops = {
 static const struct file_operations ftrace_no_pid_fops = {
 	.open		= ftrace_no_pid_open,
 	.write		= ftrace_no_pid_write,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= tracing_lseek,
 	.release	= ftrace_pid_release,
 };
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index bb62269724d5f4..36dbb58680fc33 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4611,7 +4611,7 @@ loff_t tracing_lseek(struct file *file, loff_t offset, int whence)
 
 static const struct file_operations tracing_fops = {
 	.open		= tracing_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= tracing_write_stub,
 	.llseek		= tracing_lseek,
 	.release	= tracing_release,
@@ -4619,7 +4619,7 @@ static const struct file_operations tracing_fops = {
 
 static const struct file_operations show_traces_fops = {
 	.open		= show_traces_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= show_traces_release,
 };
@@ -4957,7 +4957,7 @@ static int tracing_trace_options_open(struct inode *inode, struct file *file)
 
 static const struct file_operations tracing_iter_fops = {
 	.open		= tracing_trace_options_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= tracing_single_release_tr,
 	.write		= tracing_trace_options_write,
@@ -5297,7 +5297,7 @@ static int tracing_saved_tgids_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations tracing_saved_tgids_fops = {
 	.open		= tracing_saved_tgids_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
@@ -5376,7 +5376,7 @@ static int tracing_saved_cmdlines_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations tracing_saved_cmdlines_fops = {
 	.open		= tracing_saved_cmdlines_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
@@ -5542,7 +5542,7 @@ static int tracing_eval_map_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations tracing_eval_map_fops = {
 	.open		= tracing_eval_map_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
@@ -7119,7 +7119,7 @@ static const struct file_operations tracing_mark_raw_fops = {
 
 static const struct file_operations trace_clock_fops = {
 	.open		= tracing_clock_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= tracing_single_release_tr,
 	.write		= tracing_clock_write,
@@ -7127,7 +7127,7 @@ static const struct file_operations trace_clock_fops = {
 
 static const struct file_operations trace_time_stamp_mode_fops = {
 	.open		= tracing_time_stamp_mode_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= tracing_single_release_tr,
 };
@@ -7135,7 +7135,7 @@ static const struct file_operations trace_time_stamp_mode_fops = {
 #ifdef CONFIG_TRACER_SNAPSHOT
 static const struct file_operations snapshot_fops = {
 	.open		= tracing_snapshot_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= tracing_snapshot_write,
 	.llseek		= tracing_lseek,
 	.release	= tracing_snapshot_release,
@@ -7391,7 +7391,7 @@ static int tracing_err_log_release(struct inode *inode, struct file *file)
 static const struct file_operations tracing_err_log_fops = {
 	.open           = tracing_err_log_open,
 	.write		= tracing_err_log_write,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = tracing_err_log_release,
 };
diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index 9f2e8520b7486e..2c435fdef5659d 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -197,7 +197,7 @@ static ssize_t dyn_event_write(struct file *file, const char __user *buffer,
 static const struct file_operations dynamic_events_ops = {
 	.owner          = THIS_MODULE,
 	.open           = dyn_event_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = seq_release,
 	.write		= dyn_event_write,
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f6f55682d3e2d0..780cf3be35d15a 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1828,14 +1828,14 @@ static const struct seq_operations show_set_no_pid_seq_ops = {
 
 static const struct file_operations ftrace_avail_fops = {
 	.open = ftrace_event_avail_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release,
 };
 
 static const struct file_operations ftrace_set_event_fops = {
 	.open = ftrace_event_set_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = ftrace_event_write,
 	.llseek = seq_lseek,
 	.release = ftrace_event_release,
@@ -1843,7 +1843,7 @@ static const struct file_operations ftrace_set_event_fops = {
 
 static const struct file_operations ftrace_set_event_pid_fops = {
 	.open = ftrace_event_set_pid_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = ftrace_event_pid_write,
 	.llseek = seq_lseek,
 	.release = ftrace_event_release,
@@ -1851,7 +1851,7 @@ static const struct file_operations ftrace_set_event_pid_fops = {
 
 static const struct file_operations ftrace_set_event_notrace_pid_fops = {
 	.open = ftrace_event_set_npid_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = ftrace_event_npid_write,
 	.llseek = seq_lseek,
 	.release = ftrace_event_release,
@@ -1866,7 +1866,7 @@ static const struct file_operations ftrace_enable_fops = {
 
 static const struct file_operations ftrace_event_format_fops = {
 	.open = trace_format_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release,
 };
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 0b933546142e8b..f7bcfeb7edd0c9 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -4724,7 +4724,7 @@ static int event_hist_open(struct inode *inode, struct file *file)
 
 const struct file_operations event_hist_fops = {
 	.open = event_hist_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
@@ -4996,7 +4996,7 @@ static int event_hist_debug_open(struct inode *inode, struct file *file)
 
 const struct file_operations event_hist_debug_fops = {
 	.open = event_hist_debug_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index c6cca0d1d5840a..e2a623f2136c60 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -1749,7 +1749,7 @@ static ssize_t synth_events_write(struct file *file,
 static const struct file_operations synth_events_fops = {
 	.open           = synth_events_open,
 	.write		= synth_events_write,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = seq_release,
 };
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 3a74736da363ae..bea3026c02ff41 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -310,7 +310,7 @@ event_trigger_release(struct inode *inode, struct file *file)
 
 const struct file_operations event_trigger_fops = {
 	.open = event_trigger_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = event_trigger_write,
 	.llseek = tracing_lseek,
 	.release = event_trigger_release,
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index aefb6065b508de..467a3c8512abbd 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1148,7 +1148,7 @@ static ssize_t probes_write(struct file *file, const char __user *buffer,
 static const struct file_operations kprobe_events_ops = {
 	.owner          = THIS_MODULE,
 	.open           = probes_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = seq_release,
 	.write		= probes_write,
@@ -1193,7 +1193,7 @@ static int profile_open(struct inode *inode, struct file *file)
 static const struct file_operations kprobe_profile_ops = {
 	.owner          = THIS_MODULE,
 	.open           = profile_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = seq_release,
 };
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c
index d4e31e96920650..941bbfcd326640 100644
--- a/kernel/trace/trace_printk.c
+++ b/kernel/trace/trace_printk.c
@@ -360,7 +360,7 @@ ftrace_formats_open(struct inode *inode, struct file *file)
 
 static const struct file_operations ftrace_formats_fops = {
 	.open = ftrace_formats_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release,
 };
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 98bba4764c5273..5810fb81bfa288 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -487,7 +487,7 @@ static int stack_trace_open(struct inode *inode, struct file *file)
 
 static const struct file_operations stack_trace_fops = {
 	.open		= stack_trace_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
@@ -506,7 +506,7 @@ stack_trace_filter_open(struct inode *inode, struct file *file)
 
 static const struct file_operations stack_trace_filter_fops = {
 	.open = stack_trace_filter_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.write = ftrace_filter_write,
 	.llseek = tracing_lseek,
 	.release = ftrace_regex_release,
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index d1fa19773cc8e6..759a51f95f4e30 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -269,7 +269,7 @@ static int tracing_stat_release(struct inode *i, struct file *f)
 
 static const struct file_operations tracing_stat_fops = {
 	.open		= tracing_stat_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= tracing_stat_release
 };
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index fdd47f99b18fdb..5ce4e80ccf4c67 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -786,7 +786,7 @@ static ssize_t probes_write(struct file *file, const char __user *buffer,
 static const struct file_operations uprobe_events_ops = {
 	.owner		= THIS_MODULE,
 	.open		= probes_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 	.write		= probes_write,
@@ -828,7 +828,7 @@ static int profile_open(struct inode *inode, struct file *file)
 static const struct file_operations uprobe_profile_ops = {
 	.owner		= THIS_MODULE,
 	.open		= profile_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index 48054dbf1b51fb..5d2bbfc55345bc 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -1030,7 +1030,7 @@ static int debug_stats_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations debug_stats_fops = {
 	.open		= debug_stats_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 321437bbf87dd3..76750e73dcaf9d 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -870,7 +870,7 @@ static int ddebug_proc_open(struct inode *inode, struct file *file)
 static const struct file_operations ddebug_proc_fops = {
 	.owner = THIS_MODULE,
 	.open = ddebug_proc_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release_private,
 	.write = ddebug_proc_write
diff --git a/lib/error-inject.c b/lib/error-inject.c
index aa63751c916fa1..fd9345f40d6eaa 100644
--- a/lib/error-inject.c
+++ b/lib/error-inject.c
@@ -208,7 +208,7 @@ static int ei_open(struct inode *inode, struct file *filp)
 
 static const struct file_operations debugfs_ei_ops = {
 	.open           = ei_open,
-	.read           = seq_read,
+	.read_iter           = seq_read_iter,
 	.llseek         = seq_lseek,
 	.release        = seq_release,
 };
diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
index 9214c493d8b761..5d767103444c1e 100644
--- a/lib/kunit/debugfs.c
+++ b/lib/kunit/debugfs.c
@@ -84,7 +84,7 @@ static int debugfs_results_open(struct inode *inode, struct file *file)
 
 static const struct file_operations debugfs_results_fops = {
 	.open = debugfs_results_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = debugfs_release,
 };
diff --git a/mm/kmemleak.c b/mm/kmemleak.c
index e362dc3d2028c3..29a684a4656a99 100644
--- a/mm/kmemleak.c
+++ b/mm/kmemleak.c
@@ -1834,7 +1834,7 @@ static ssize_t kmemleak_write(struct file *file, const char __user *user_buf,
 static const struct file_operations kmemleak_fops = {
 	.owner		= THIS_MODULE,
 	.open		= kmemleak_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= kmemleak_write,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
diff --git a/net/6lowpan/debugfs.c b/net/6lowpan/debugfs.c
index 1c140af06d5273..f37d439eda04f1 100644
--- a/net/6lowpan/debugfs.c
+++ b/net/6lowpan/debugfs.c
@@ -157,7 +157,7 @@ static ssize_t lowpan_ctx_pfx_write(struct file *fp,
 
 static const struct file_operations lowpan_ctx_pfx_fops = {
 	.open		= lowpan_ctx_pfx_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= lowpan_ctx_pfx_write,
 	.llseek		= seq_lseek,
 	.release	= single_release,
diff --git a/net/batman-adv/debugfs.c b/net/batman-adv/debugfs.c
index 452856c27d20b7..111c2103e9fa42 100644
--- a/net/batman-adv/debugfs.c
+++ b/net/batman-adv/debugfs.c
@@ -204,7 +204,7 @@ struct batadv_debuginfo batadv_debuginfo_##_name = {	\
 	.fops = {					\
 		.owner = THIS_MODULE,			\
 		.open = _open,				\
-		.read	= seq_read,			\
+		.read_iter	= seq_read_iter,			\
 		.llseek = seq_lseek,			\
 		.release = single_release,		\
 	},						\
@@ -272,7 +272,7 @@ struct batadv_debuginfo batadv_hardif_debuginfo_##_name = {	\
 	.fops = {						\
 		.owner = THIS_MODULE,				\
 		.open = _open,					\
-		.read	= seq_read,				\
+		.read_iter	= seq_read_iter,				\
 		.llseek = seq_lseek,				\
 		.release = single_release,			\
 	},							\
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index bb55d92691b068..573ef0c8052101 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -1205,7 +1205,7 @@ static int lowpan_control_open(struct inode *inode, struct file *file)
 
 static const struct file_operations lowpan_control_fops = {
 	.open		= lowpan_control_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= lowpan_control_write,
 	.llseek		= seq_lseek,
 	.release	= single_release,
diff --git a/net/hsr/hsr_debugfs.c b/net/hsr/hsr_debugfs.c
index 9787ef11ca71cd..d994c83b01787a 100644
--- a/net/hsr/hsr_debugfs.c
+++ b/net/hsr/hsr_debugfs.c
@@ -80,7 +80,7 @@ void hsr_debugfs_rename(struct net_device *dev)
 
 static const struct file_operations hsr_fops = {
 	.open	= hsr_node_table_open,
-	.read	= seq_read,
+	.read_iter	= seq_read_iter,
 	.llseek = seq_lseek,
 	.release = single_release,
 };
diff --git a/net/l2tp/l2tp_debugfs.c b/net/l2tp/l2tp_debugfs.c
index 35bb4f3bdbe017..6268c42e6beee3 100644
--- a/net/l2tp/l2tp_debugfs.c
+++ b/net/l2tp/l2tp_debugfs.c
@@ -318,7 +318,7 @@ static int l2tp_dfs_seq_release(struct inode *inode, struct file *file)
 static const struct file_operations l2tp_dfs_fops = {
 	.owner		= THIS_MODULE,
 	.open		= l2tp_dfs_seq_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= l2tp_dfs_seq_release,
 };
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index baef5ee43dbbdb..e5c01697c3f1d6 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -1842,7 +1842,7 @@ static int content_release_pipefs(struct inode *inode, struct file *filp)
 
 const struct file_operations content_file_operations_pipefs = {
 	.open		= content_open_pipefs,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= content_release_pipefs,
 };
diff --git a/net/sunrpc/debugfs.c b/net/sunrpc/debugfs.c
index fd9bca24272427..2453042f6daf42 100644
--- a/net/sunrpc/debugfs.c
+++ b/net/sunrpc/debugfs.c
@@ -112,7 +112,7 @@ tasks_release(struct inode *inode, struct file *filp)
 static const struct file_operations tasks_fops = {
 	.owner		= THIS_MODULE,
 	.open		= tasks_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= tasks_release,
 };
@@ -211,7 +211,7 @@ xprt_info_release(struct inode *inode, struct file *filp)
 static const struct file_operations xprt_info_fops = {
 	.owner		= THIS_MODULE,
 	.open		= xprt_info_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= xprt_info_release,
 };
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 39e14d5edaf132..3a7427d661747a 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -449,7 +449,7 @@ rpc_info_release(struct inode *inode, struct file *file)
 static const struct file_operations rpc_info_operations = {
 	.owner		= THIS_MODULE,
 	.open		= rpc_info_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= rpc_info_release,
 };
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 5fd4a64e431f67..ae77761011e9c6 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -1015,7 +1015,7 @@ static int aa_sfs_seq_open(struct inode *inode, struct file *file)
 const struct file_operations aa_sfs_seq_file_ops = {
 	.owner		= THIS_MODULE,
 	.open		= aa_sfs_seq_open,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= single_release,
 };
@@ -1034,7 +1034,7 @@ static int seq_profile_ ##NAME ##_open(struct inode *inode, struct file *file)\
 static const struct file_operations seq_profile_ ##NAME ##_fops = {	      \
 	.owner		= THIS_MODULE,					      \
 	.open		= seq_profile_ ##NAME ##_open,			      \
-	.read		= seq_read,					      \
+	.read_iter		= seq_read_iter,					      \
 	.llseek		= seq_lseek,					      \
 	.release	= seq_profile_release,				      \
 }									      \
@@ -1136,7 +1136,7 @@ static int seq_ns_ ##NAME ##_open(struct inode *inode, struct file *file)     \
 static const struct file_operations seq_ns_ ##NAME ##_fops = {	      \
 	.owner		= THIS_MODULE,					      \
 	.open		= seq_ns_ ##NAME ##_open,			      \
-	.read		= seq_read,					      \
+	.read_iter		= seq_read_iter,					      \
 	.llseek		= seq_lseek,					      \
 	.release	= single_release,				      \
 }									      \
@@ -1212,7 +1212,7 @@ static int seq_rawdata_ ##NAME ##_open(struct inode *inode, struct file *file)\
 static const struct file_operations seq_rawdata_ ##NAME ##_fops = {	      \
 	.owner		= THIS_MODULE,					      \
 	.open		= seq_rawdata_ ##NAME ##_open,			      \
-	.read		= seq_read,					      \
+	.read_iter		= seq_read_iter,					      \
 	.llseek		= seq_lseek,					      \
 	.release	= seq_rawdata_release,				      \
 }									      \
@@ -2280,7 +2280,7 @@ static int profiles_release(struct inode *inode, struct file *file)
 
 static const struct file_operations aa_sfs_profiles_fops = {
 	.open = profiles_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = profiles_release,
 };
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index e3fcad871861a3..7cc4c5862c3f6e 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -199,7 +199,7 @@ static int ima_measurements_open(struct inode *inode, struct file *file)
 
 static const struct file_operations ima_measurements_ops = {
 	.open = ima_measurements_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release,
 };
@@ -265,7 +265,7 @@ static int ima_ascii_measurements_open(struct inode *inode, struct file *file)
 
 static const struct file_operations ima_ascii_measurements_ops = {
 	.open = ima_ascii_measurements_open,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.llseek = seq_lseek,
 	.release = seq_release,
 };
@@ -441,7 +441,7 @@ static int ima_release_policy(struct inode *inode, struct file *file)
 static const struct file_operations ima_measure_policy_ops = {
 	.open = ima_open_policy,
 	.write = ima_write_policy,
-	.read = seq_read,
+	.read_iter = seq_read_iter,
 	.release = ima_release_policy,
 	.llseek = generic_file_llseek,
 };
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 4781314c251094..4809fb4203aadf 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -1598,7 +1598,7 @@ static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
 
 static const struct file_operations sel_avc_cache_stats_ops = {
 	.open		= sel_open_avc_cache_stats,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
 };
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index c21b656b32631e..02d48f363f0570 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -671,7 +671,7 @@ static ssize_t smk_write_load(struct file *file, const char __user *buf,
 
 static const struct file_operations smk_load_ops = {
 	.open           = smk_open_load,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek         = seq_lseek,
 	.write		= smk_write_load,
 	.release        = seq_release,
@@ -944,7 +944,7 @@ static ssize_t smk_write_cipso(struct file *file, const char __user *buf,
 
 static const struct file_operations smk_cipso_ops = {
 	.open           = smk_open_cipso,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek         = seq_lseek,
 	.write		= smk_write_cipso,
 	.release        = seq_release,
@@ -1018,7 +1018,7 @@ static ssize_t smk_write_cipso2(struct file *file, const char __user *buf,
 
 static const struct file_operations smk_cipso2_ops = {
 	.open           = smk_open_cipso2,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek         = seq_lseek,
 	.write		= smk_write_cipso2,
 	.release        = seq_release,
@@ -1283,7 +1283,7 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
 
 static const struct file_operations smk_net4addr_ops = {
 	.open           = smk_open_net4addr,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek         = seq_lseek,
 	.write		= smk_write_net4addr,
 	.release        = seq_release,
@@ -1540,7 +1540,7 @@ static ssize_t smk_write_net6addr(struct file *file, const char __user *buf,
 
 static const struct file_operations smk_net6addr_ops = {
 	.open           = smk_open_net6addr,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek         = seq_lseek,
 	.write		= smk_write_net6addr,
 	.release        = seq_release,
@@ -2028,7 +2028,7 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
 
 static const struct file_operations smk_onlycap_ops = {
 	.open		= smk_open_onlycap,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.write		= smk_write_onlycap,
 	.llseek		= seq_lseek,
 	.release	= seq_release,
@@ -2252,7 +2252,7 @@ static ssize_t smk_write_load_self(struct file *file, const char __user *buf,
 
 static const struct file_operations smk_load_self_ops = {
 	.open           = smk_open_load_self,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek         = seq_lseek,
 	.write		= smk_write_load_self,
 	.release        = seq_release,
@@ -2386,7 +2386,7 @@ static ssize_t smk_write_load2(struct file *file, const char __user *buf,
 
 static const struct file_operations smk_load2_ops = {
 	.open           = smk_open_load2,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek         = seq_lseek,
 	.write		= smk_write_load2,
 	.release        = seq_release,
@@ -2459,7 +2459,7 @@ static ssize_t smk_write_load_self2(struct file *file, const char __user *buf,
 
 static const struct file_operations smk_load_self2_ops = {
 	.open           = smk_open_load_self2,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek         = seq_lseek,
 	.write		= smk_write_load_self2,
 	.release        = seq_release,
@@ -2756,7 +2756,7 @@ static ssize_t smk_write_relabel_self(struct file *file, const char __user *buf,
 
 static const struct file_operations smk_relabel_self_ops = {
 	.open		= smk_open_relabel_self,
-	.read		= seq_read,
+	.read_iter		= seq_read_iter,
 	.llseek		= seq_lseek,
 	.write		= smk_write_relabel_self,
 	.release	= seq_release,
-- 
2.26.2

[PATCH 09/11] proc: switch over direct seq_read method calls to seq_read_iter

[Christoph Hellwig]

Switch over all instances used directly as methods using these sed
expressions:

sed -i -e 's/\.proc_read\(\s*=\s*\)seq_read/\.proc_read_iter\1seq_read_iter/g'

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/alpha/kernel/srm_env.c                        |  2 +-
 arch/arm/mm/alignment.c                            |  2 +-
 arch/powerpc/kernel/rtas-proc.c                    | 10 +++++-----
 arch/powerpc/mm/numa.c                             |  2 +-
 arch/powerpc/platforms/pseries/lpar.c              |  4 ++--
 arch/powerpc/platforms/pseries/lparcfg.c           |  2 +-
 arch/sh/mm/alignment.c                             |  2 +-
 arch/sparc/kernel/led.c                            |  2 +-
 arch/um/kernel/exitcode.c                          |  2 +-
 arch/um/kernel/process.c                           |  2 +-
 arch/x86/kernel/cpu/mtrr/if.c                      |  2 +-
 arch/x86/platform/uv/tlb_uv.c                      |  2 +-
 drivers/acpi/battery.c                             |  2 +-
 drivers/acpi/proc.c                                |  2 +-
 drivers/hwmon/dell-smm-hwmon.c                     |  2 +-
 drivers/ide/ide-proc.c                             |  2 +-
 drivers/input/input.c                              |  4 ++--
 drivers/macintosh/via-pmu.c                        |  2 +-
 drivers/md/md.c                                    |  2 +-
 drivers/misc/sgi-gru/gruprocfs.c                   |  6 +++---
 drivers/net/wireless/intel/ipw2x00/libipw_module.c |  2 +-
 .../net/wireless/intersil/hostap/hostap_download.c |  2 +-
 drivers/parisc/led.c                               |  2 +-
 drivers/platform/x86/thinkpad_acpi.c               |  2 +-
 drivers/platform/x86/toshiba_acpi.c                |  8 ++++----
 drivers/pnp/pnpbios/proc.c                         |  2 +-
 drivers/s390/block/dasd_proc.c                     |  2 +-
 drivers/s390/cio/blacklist.c                       |  2 +-
 drivers/scsi/scsi_devinfo.c                        |  2 +-
 drivers/scsi/scsi_proc.c                           |  4 ++--
 drivers/scsi/sg.c                                  |  4 ++--
 .../staging/rtl8192u/ieee80211/ieee80211_module.c  |  2 +-
 drivers/usb/gadget/function/rndis.c                |  2 +-
 drivers/video/fbdev/via/viafbdev.c                 | 14 +++++++-------
 fs/cifs/cifs_debug.c                               | 14 +++++++-------
 fs/cifs/dfs_cache.c                                |  2 +-
 fs/fscache/object-list.c                           |  2 +-
 fs/jbd2/journal.c                                  |  2 +-
 fs/jfs/jfs_debug.c                                 |  2 +-
 fs/nfsd/nfsctl.c                                   |  2 +-
 fs/nfsd/stats.c                                    |  2 +-
 fs/proc/cpuinfo.c                                  |  2 +-
 fs/proc/generic.c                                  |  4 ++--
 fs/proc/proc_net.c                                 |  4 ++--
 fs/proc/stat.c                                     |  2 +-
 include/linux/seq_file.h                           |  2 +-
 ipc/util.c                                         |  2 +-
 kernel/irq/proc.c                                  |  6 +++---
 kernel/kallsyms.c                                  |  2 +-
 kernel/latencytop.c                                |  2 +-
 kernel/locking/lockdep_proc.c                      |  2 +-
 kernel/module.c                                    |  2 +-
 kernel/profile.c                                   |  2 +-
 kernel/sched/psi.c                                 |  6 +++---
 lib/dynamic_debug.c                                |  2 +-
 mm/slab_common.c                                   |  2 +-
 mm/swapfile.c                                      |  2 +-
 net/atm/mpoa_proc.c                                |  2 +-
 net/core/pktgen.c                                  |  6 +++---
 net/ipv4/netfilter/ipt_CLUSTERIP.c                 |  2 +-
 net/ipv4/route.c                                   |  4 ++--
 net/netfilter/xt_recent.c                          |  2 +-
 net/sunrpc/cache.c                                 |  2 +-
 net/sunrpc/stats.c                                 |  2 +-
 sound/core/info.c                                  |  2 +-
 65 files changed, 99 insertions(+), 99 deletions(-)

diff --git a/arch/alpha/kernel/srm_env.c b/arch/alpha/kernel/srm_env.c
index 528d2be5818298..8ad9c100ef7612 100644
--- a/arch/alpha/kernel/srm_env.c
+++ b/arch/alpha/kernel/srm_env.c
@@ -121,7 +121,7 @@ static ssize_t srm_env_proc_write(struct file *file, const char __user *buffer,
 
 static const struct proc_ops srm_env_proc_ops = {
 	.proc_open	= srm_env_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= srm_env_proc_write,
diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c
index 81a627e6e1c599..412cab88402acd 100644
--- a/arch/arm/mm/alignment.c
+++ b/arch/arm/mm/alignment.c
@@ -164,7 +164,7 @@ static ssize_t alignment_proc_write(struct file *file, const char __user *buffer
 
 static const struct proc_ops alignment_proc_ops = {
 	.proc_open	= alignment_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= alignment_proc_write,
diff --git a/arch/powerpc/kernel/rtas-proc.c b/arch/powerpc/kernel/rtas-proc.c
index 2d33f342a29307..3aace56aacc1df 100644
--- a/arch/powerpc/kernel/rtas-proc.c
+++ b/arch/powerpc/kernel/rtas-proc.c
@@ -161,7 +161,7 @@ static int poweron_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops ppc_rtas_poweron_proc_ops = {
 	.proc_open	= poweron_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= ppc_rtas_poweron_write,
 	.proc_release	= single_release,
@@ -174,7 +174,7 @@ static int progress_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops ppc_rtas_progress_proc_ops = {
 	.proc_open	= progress_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= ppc_rtas_progress_write,
 	.proc_release	= single_release,
@@ -187,7 +187,7 @@ static int clock_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops ppc_rtas_clock_proc_ops = {
 	.proc_open	= clock_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= ppc_rtas_clock_write,
 	.proc_release	= single_release,
@@ -200,7 +200,7 @@ static int tone_freq_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops ppc_rtas_tone_freq_proc_ops = {
 	.proc_open	= tone_freq_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= ppc_rtas_tone_freq_write,
 	.proc_release	= single_release,
@@ -213,7 +213,7 @@ static int tone_volume_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops ppc_rtas_tone_volume_proc_ops = {
 	.proc_open	= tone_volume_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= ppc_rtas_tone_volume_write,
 	.proc_release	= single_release,
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 9fcf2d19583004..2f3aef6c0b513b 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -1672,7 +1672,7 @@ static ssize_t topology_write(struct file *file, const char __user *buf,
 }
 
 static const struct proc_ops topology_proc_ops = {
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= topology_write,
 	.proc_open	= topology_open,
 	.proc_release	= single_release,
diff --git a/arch/powerpc/platforms/pseries/lpar.c b/arch/powerpc/platforms/pseries/lpar.c
index fd26f3d21d7b4b..2b13a67d60e206 100644
--- a/arch/powerpc/platforms/pseries/lpar.c
+++ b/arch/powerpc/platforms/pseries/lpar.c
@@ -584,7 +584,7 @@ static int vcpudispatch_stats_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops vcpudispatch_stats_proc_ops = {
 	.proc_open	= vcpudispatch_stats_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= vcpudispatch_stats_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
@@ -628,7 +628,7 @@ static int vcpudispatch_stats_freq_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops vcpudispatch_stats_freq_proc_ops = {
 	.proc_open	= vcpudispatch_stats_freq_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= vcpudispatch_stats_freq_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
diff --git a/arch/powerpc/platforms/pseries/lparcfg.c b/arch/powerpc/platforms/pseries/lparcfg.c
index b8d28ab881789d..35eb0e4b8fd31a 100644
--- a/arch/powerpc/platforms/pseries/lparcfg.c
+++ b/arch/powerpc/platforms/pseries/lparcfg.c
@@ -699,7 +699,7 @@ static int lparcfg_open(struct inode *inode, struct file *file)
 }
 
 static const struct proc_ops lparcfg_proc_ops = {
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= lparcfg_write,
 	.proc_open	= lparcfg_open,
 	.proc_release	= single_release,
diff --git a/arch/sh/mm/alignment.c b/arch/sh/mm/alignment.c
index fb517b82a87b10..66115241ad93a4 100644
--- a/arch/sh/mm/alignment.c
+++ b/arch/sh/mm/alignment.c
@@ -154,7 +154,7 @@ static ssize_t alignment_proc_write(struct file *file,
 
 static const struct proc_ops alignment_proc_ops = {
 	.proc_open	= alignment_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= alignment_proc_write,
diff --git a/arch/sparc/kernel/led.c b/arch/sparc/kernel/led.c
index bd48575172c323..a0b893d216c443 100644
--- a/arch/sparc/kernel/led.c
+++ b/arch/sparc/kernel/led.c
@@ -106,7 +106,7 @@ static ssize_t led_proc_write(struct file *file, const char __user *buffer,
 
 static const struct proc_ops led_proc_ops = {
 	.proc_open	= led_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= led_proc_write,
diff --git a/arch/um/kernel/exitcode.c b/arch/um/kernel/exitcode.c
index 43edc2aa57e4fb..95184d271a47cf 100644
--- a/arch/um/kernel/exitcode.c
+++ b/arch/um/kernel/exitcode.c
@@ -57,7 +57,7 @@ static ssize_t exitcode_proc_write(struct file *file,
 
 static const struct proc_ops exitcode_proc_ops = {
 	.proc_open	= exitcode_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= exitcode_proc_write,
diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c
index e3a2cf92a3738b..f3e4bd48f6d5b6 100644
--- a/arch/um/kernel/process.c
+++ b/arch/um/kernel/process.c
@@ -312,7 +312,7 @@ static ssize_t sysemu_proc_write(struct file *file, const char __user *buf,
 
 static const struct proc_ops sysemu_proc_ops = {
 	.proc_open	= sysemu_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= sysemu_proc_write,
diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c
index a5c506f6da7fa1..f5743b5ecaf232 100644
--- a/arch/x86/kernel/cpu/mtrr/if.c
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -398,7 +398,7 @@ static int mtrr_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops mtrr_proc_ops = {
 	.proc_open		= mtrr_open,
-	.proc_read		= seq_read,
+	.proc_read_iter		= seq_read_iter,
 	.proc_lseek		= seq_lseek,
 	.proc_write		= mtrr_write,
 	.proc_ioctl		= mtrr_ioctl,
diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c
index 0ac96ca304c7b5..cd6ee86283e6e1 100644
--- a/arch/x86/platform/uv/tlb_uv.c
+++ b/arch/x86/platform/uv/tlb_uv.c
@@ -1670,7 +1670,7 @@ static int tunables_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops uv_ptc_proc_ops = {
 	.proc_open	= ptc_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= ptc_proc_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 366c389175d844..c8e5972ad6c952 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -1204,7 +1204,7 @@ static int acpi_battery_alarm_proc_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops acpi_battery_alarm_proc_ops = {
 	.proc_open	= acpi_battery_alarm_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= acpi_battery_write_alarm,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
diff --git a/drivers/acpi/proc.c b/drivers/acpi/proc.c
index 7892980b3ce4d3..774da498c77265 100644
--- a/drivers/acpi/proc.c
+++ b/drivers/acpi/proc.c
@@ -136,7 +136,7 @@ acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file)
 
 static const struct proc_ops acpi_system_wakeup_device_proc_ops = {
 	.proc_open	= acpi_system_wakeup_device_open_fs,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= acpi_system_write_wakeup_device,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
index 16be012a95ed84..29ac388429620f 100644
--- a/drivers/hwmon/dell-smm-hwmon.c
+++ b/drivers/hwmon/dell-smm-hwmon.c
@@ -597,7 +597,7 @@ static int i8k_open_fs(struct inode *inode, struct file *file)
 
 static const struct proc_ops i8k_proc_ops = {
 	.proc_open	= i8k_open_fs,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_ioctl	= i8k_ioctl,
diff --git a/drivers/ide/ide-proc.c b/drivers/ide/ide-proc.c
index 8ea282a3a19f0d..a0b56737152fb5 100644
--- a/drivers/ide/ide-proc.c
+++ b/drivers/ide/ide-proc.c
@@ -383,7 +383,7 @@ static ssize_t ide_settings_proc_write(struct file *file, const char __user *buf
 
 static const struct proc_ops ide_settings_proc_ops = {
 	.proc_open	= ide_settings_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= ide_settings_proc_write,
diff --git a/drivers/input/input.c b/drivers/input/input.c
index 3cfd2c18eebd9d..c8180d7f92d576 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -1220,7 +1220,7 @@ static int input_proc_devices_open(struct inode *inode, struct file *file)
 static const struct proc_ops input_devices_proc_ops = {
 	.proc_open	= input_proc_devices_open,
 	.proc_poll	= input_proc_devices_poll,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
 };
@@ -1282,7 +1282,7 @@ static int input_proc_handlers_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops input_handlers_proc_ops = {
 	.proc_open	= input_proc_handlers_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
 };
diff --git a/drivers/macintosh/via-pmu.c b/drivers/macintosh/via-pmu.c
index 73e6ae88fafd4e..9415eddb419402 100644
--- a/drivers/macintosh/via-pmu.c
+++ b/drivers/macintosh/via-pmu.c
@@ -973,7 +973,7 @@ static ssize_t pmu_options_proc_write(struct file *file,
 
 static const struct proc_ops pmu_options_proc_ops = {
 	.proc_open	= pmu_options_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= pmu_options_proc_write,
diff --git a/drivers/md/md.c b/drivers/md/md.c
index f567f536b529bd..0bae6c1523cec6 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8301,7 +8301,7 @@ static __poll_t mdstat_poll(struct file *filp, poll_table *wait)
 
 static const struct proc_ops mdstat_proc_ops = {
 	.proc_open	= md_seq_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
 	.proc_poll	= mdstat_poll,
diff --git a/drivers/misc/sgi-gru/gruprocfs.c b/drivers/misc/sgi-gru/gruprocfs.c
index 97b8b38ab47dfd..fc9498ec797762 100644
--- a/drivers/misc/sgi-gru/gruprocfs.c
+++ b/drivers/misc/sgi-gru/gruprocfs.c
@@ -257,7 +257,7 @@ static int options_open(struct inode *inode, struct file *file)
 /* *INDENT-OFF* */
 static const struct proc_ops statistics_proc_ops = {
 	.proc_open	= statistics_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= statistics_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
@@ -265,7 +265,7 @@ static const struct proc_ops statistics_proc_ops = {
 
 static const struct proc_ops mcs_statistics_proc_ops = {
 	.proc_open	= mcs_statistics_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= mcs_statistics_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
@@ -273,7 +273,7 @@ static const struct proc_ops mcs_statistics_proc_ops = {
 
 static const struct proc_ops options_proc_ops = {
 	.proc_open	= options_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= options_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
diff --git a/drivers/net/wireless/intel/ipw2x00/libipw_module.c b/drivers/net/wireless/intel/ipw2x00/libipw_module.c
index 43bab92a4148f2..1929db6921d7e0 100644
--- a/drivers/net/wireless/intel/ipw2x00/libipw_module.c
+++ b/drivers/net/wireless/intel/ipw2x00/libipw_module.c
@@ -242,7 +242,7 @@ static ssize_t debug_level_proc_write(struct file *file,
 
 static const struct proc_ops debug_level_proc_ops = {
 	.proc_open	= debug_level_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= debug_level_proc_write,
diff --git a/drivers/net/wireless/intersil/hostap/hostap_download.c b/drivers/net/wireless/intersil/hostap/hostap_download.c
index 7c6a5a6d1d45d8..8980fd57b2eda4 100644
--- a/drivers/net/wireless/intersil/hostap/hostap_download.c
+++ b/drivers/net/wireless/intersil/hostap/hostap_download.c
@@ -234,7 +234,7 @@ static int prism2_download_aux_dump_proc_open(struct inode *inode, struct file *
 
 static const struct proc_ops prism2_download_aux_dump_proc_ops = {
 	.proc_open		= prism2_download_aux_dump_proc_open,
-	.proc_read		= seq_read,
+	.proc_read_iter		= seq_read_iter,
 	.proc_lseek		= seq_lseek,
 	.proc_release		= seq_release_private,
 };
diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c
index 36c6613f7a36b7..d75df3977926b3 100644
--- a/drivers/parisc/led.c
+++ b/drivers/parisc/led.c
@@ -232,7 +232,7 @@ static ssize_t led_proc_write(struct file *file, const char __user *buf,
 
 static const struct proc_ops led_proc_ops = {
 	.proc_open	= led_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= led_proc_write,
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index ff7f0a4f247563..f571d6254e7c34 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -901,7 +901,7 @@ static ssize_t dispatch_proc_write(struct file *file,
 
 static const struct proc_ops dispatch_proc_ops = {
 	.proc_open	= dispatch_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= dispatch_proc_write,
diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c
index 1ddab5a6dead6d..770477bb407d49 100644
--- a/drivers/platform/x86/toshiba_acpi.c
+++ b/drivers/platform/x86/toshiba_acpi.c
@@ -1428,7 +1428,7 @@ static ssize_t lcd_proc_write(struct file *file, const char __user *buf,
 
 static const struct proc_ops lcd_proc_ops = {
 	.proc_open	= lcd_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= lcd_proc_write,
@@ -1534,7 +1534,7 @@ static ssize_t video_proc_write(struct file *file, const char __user *buf,
 
 static const struct proc_ops video_proc_ops = {
 	.proc_open	= video_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= video_proc_write,
@@ -1611,7 +1611,7 @@ static ssize_t fan_proc_write(struct file *file, const char __user *buf,
 
 static const struct proc_ops fan_proc_ops = {
 	.proc_open	= fan_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= fan_proc_write,
@@ -1655,7 +1655,7 @@ static ssize_t keys_proc_write(struct file *file, const char __user *buf,
 
 static const struct proc_ops keys_proc_ops = {
 	.proc_open	= keys_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= keys_proc_write,
diff --git a/drivers/pnp/pnpbios/proc.c b/drivers/pnp/pnpbios/proc.c
index a806830e3a407f..10d0181c4430ab 100644
--- a/drivers/pnp/pnpbios/proc.c
+++ b/drivers/pnp/pnpbios/proc.c
@@ -212,7 +212,7 @@ static ssize_t pnpbios_proc_write(struct file *file, const char __user *buf,
 
 static const struct proc_ops pnpbios_proc_ops = {
 	.proc_open	= pnpbios_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= pnpbios_proc_write,
diff --git a/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c
index 62a859ea67f893..278f0dccc85ff1 100644
--- a/drivers/s390/block/dasd_proc.c
+++ b/drivers/s390/block/dasd_proc.c
@@ -322,7 +322,7 @@ static ssize_t dasd_stats_proc_write(struct file *file,
 
 static const struct proc_ops dasd_stats_proc_ops = {
 	.proc_open	= dasd_stats_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= dasd_stats_proc_write,
diff --git a/drivers/s390/cio/blacklist.c b/drivers/s390/cio/blacklist.c
index 4dd2eb63485699..05f58c453b060c 100644
--- a/drivers/s390/cio/blacklist.c
+++ b/drivers/s390/cio/blacklist.c
@@ -401,7 +401,7 @@ cio_ignore_proc_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops cio_ignore_proc_ops = {
 	.proc_open	= cio_ignore_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release_private,
 	.proc_write	= cio_ignore_write,
diff --git a/drivers/scsi/scsi_devinfo.c b/drivers/scsi/scsi_devinfo.c
index eed31021e7885c..87fb440ddfc5d8 100644
--- a/drivers/scsi/scsi_devinfo.c
+++ b/drivers/scsi/scsi_devinfo.c
@@ -738,7 +738,7 @@ static ssize_t proc_scsi_devinfo_write(struct file *file,
 
 static const struct proc_ops scsi_devinfo_proc_ops = {
 	.proc_open	= proc_scsi_devinfo_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= proc_scsi_devinfo_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
diff --git a/drivers/scsi/scsi_proc.c b/drivers/scsi/scsi_proc.c
index d6982d3557396b..81601a9e79c4db 100644
--- a/drivers/scsi/scsi_proc.c
+++ b/drivers/scsi/scsi_proc.c
@@ -86,7 +86,7 @@ static int proc_scsi_host_open(struct inode *inode, struct file *file)
 static const struct proc_ops proc_scsi_ops = {
 	.proc_open	= proc_scsi_host_open,
 	.proc_release	= single_release,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= proc_scsi_host_write
 };
@@ -438,7 +438,7 @@ static int proc_scsi_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops scsi_scsi_proc_ops = {
 	.proc_open	= proc_scsi_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= proc_scsi_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 20472aaaf630a4..c5d482190066bc 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -2328,7 +2328,7 @@ static ssize_t sg_proc_write_adio(struct file *filp, const char __user *buffer,
 			          size_t count, loff_t *off);
 static const struct proc_ops adio_proc_ops = {
 	.proc_open	= sg_proc_single_open_adio,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= sg_proc_write_adio,
 	.proc_release	= single_release,
@@ -2339,7 +2339,7 @@ static ssize_t sg_proc_write_dressz(struct file *filp,
 		const char __user *buffer, size_t count, loff_t *off);
 static const struct proc_ops dressz_proc_ops = {
 	.proc_open	= sg_proc_single_open_dressz,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= sg_proc_write_dressz,
 	.proc_release	= single_release,
diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_module.c b/drivers/staging/rtl8192u/ieee80211/ieee80211_module.c
index a5a1b14f5a40c5..e198779db6fc2e 100644
--- a/drivers/staging/rtl8192u/ieee80211/ieee80211_module.c
+++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_module.c
@@ -265,7 +265,7 @@ static int open_debug_level(struct inode *inode, struct file *file)
 
 static const struct proc_ops debug_level_proc_ops = {
 	.proc_open	= open_debug_level,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= write_debug_level,
 	.proc_release	= single_release,
diff --git a/drivers/usb/gadget/function/rndis.c b/drivers/usb/gadget/function/rndis.c
index 64de9f1b874c55..562781b95101d3 100644
--- a/drivers/usb/gadget/function/rndis.c
+++ b/drivers/usb/gadget/function/rndis.c
@@ -1166,7 +1166,7 @@ static int rndis_proc_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops rndis_proc_ops = {
 	.proc_open	= rndis_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= rndis_proc_write,
diff --git a/drivers/video/fbdev/via/viafbdev.c b/drivers/video/fbdev/via/viafbdev.c
index 22deb340a0484f..6cf91191de7f15 100644
--- a/drivers/video/fbdev/via/viafbdev.c
+++ b/drivers/video/fbdev/via/viafbdev.c
@@ -1175,7 +1175,7 @@ static ssize_t viafb_dvp0_proc_write(struct file *file,
 
 static const struct proc_ops viafb_dvp0_proc_ops = {
 	.proc_open	= viafb_dvp0_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= viafb_dvp0_proc_write,
@@ -1239,7 +1239,7 @@ static ssize_t viafb_dvp1_proc_write(struct file *file,
 
 static const struct proc_ops viafb_dvp1_proc_ops = {
 	.proc_open	= viafb_dvp1_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= viafb_dvp1_proc_write,
@@ -1273,7 +1273,7 @@ static ssize_t viafb_dfph_proc_write(struct file *file,
 
 static const struct proc_ops viafb_dfph_proc_ops = {
 	.proc_open	= viafb_dfph_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= viafb_dfph_proc_write,
@@ -1307,7 +1307,7 @@ static ssize_t viafb_dfpl_proc_write(struct file *file,
 
 static const struct proc_ops viafb_dfpl_proc_ops = {
 	.proc_open	= viafb_dfpl_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= viafb_dfpl_proc_write,
@@ -1442,7 +1442,7 @@ static ssize_t viafb_vt1636_proc_write(struct file *file,
 
 static const struct proc_ops viafb_vt1636_proc_ops = {
 	.proc_open	= viafb_vt1636_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= viafb_vt1636_proc_write,
@@ -1519,7 +1519,7 @@ static ssize_t viafb_iga1_odev_proc_write(struct file *file,
 
 static const struct proc_ops viafb_iga1_odev_proc_ops = {
 	.proc_open	= viafb_iga1_odev_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= viafb_iga1_odev_proc_write,
@@ -1558,7 +1558,7 @@ static ssize_t viafb_iga2_odev_proc_write(struct file *file,
 
 static const struct proc_ops viafb_iga2_odev_proc_ops = {
 	.proc_open	= viafb_iga2_odev_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= viafb_iga2_odev_proc_write,
diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index fc98b97b396a44..65eb425cc3adf0 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -615,7 +615,7 @@ static int cifs_stats_proc_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops cifs_stats_proc_ops = {
 	.proc_open	= cifs_stats_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= cifs_stats_proc_write,
@@ -644,7 +644,7 @@ static int name##_open(struct inode *inode, struct file *file) \
 \
 static const struct proc_ops cifs_##name##_proc_fops = { \
 	.proc_open	= name##_open, \
-	.proc_read	= seq_read, \
+	.proc_read_iter	= seq_read_iter, \
 	.proc_lseek	= seq_lseek, \
 	.proc_release	= single_release, \
 	.proc_write	= name##_write, \
@@ -778,7 +778,7 @@ static ssize_t cifsFYI_proc_write(struct file *file, const char __user *buffer,
 
 static const struct proc_ops cifsFYI_proc_ops = {
 	.proc_open	= cifsFYI_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= cifsFYI_proc_write,
@@ -809,7 +809,7 @@ static ssize_t cifs_linux_ext_proc_write(struct file *file,
 
 static const struct proc_ops cifs_linux_ext_proc_ops = {
 	.proc_open	= cifs_linux_ext_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= cifs_linux_ext_proc_write,
@@ -840,7 +840,7 @@ static ssize_t cifs_lookup_cache_proc_write(struct file *file,
 
 static const struct proc_ops cifs_lookup_cache_proc_ops = {
 	.proc_open	= cifs_lookup_cache_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= cifs_lookup_cache_proc_write,
@@ -871,7 +871,7 @@ static ssize_t traceSMB_proc_write(struct file *file, const char __user *buffer,
 
 static const struct proc_ops traceSMB_proc_ops = {
 	.proc_open	= traceSMB_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= traceSMB_proc_write,
@@ -982,7 +982,7 @@ static ssize_t cifs_security_flags_proc_write(struct file *file,
 
 static const struct proc_ops cifs_security_flags_proc_ops = {
 	.proc_open	= cifs_security_flags_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= cifs_security_flags_proc_write,
diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c
index df81c718d2faec..a4fe155fc92a7a 100644
--- a/fs/cifs/dfs_cache.c
+++ b/fs/cifs/dfs_cache.c
@@ -214,7 +214,7 @@ static int dfscache_proc_open(struct inode *inode, struct file *file)
 
 const struct proc_ops dfscache_proc_ops = {
 	.proc_open	= dfscache_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= dfscache_proc_write,
diff --git a/fs/fscache/object-list.c b/fs/fscache/object-list.c
index e106a1a1600d82..fab5a4197f50c3 100644
--- a/fs/fscache/object-list.c
+++ b/fs/fscache/object-list.c
@@ -408,7 +408,7 @@ static int fscache_objlist_release(struct inode *inode, struct file *file)
 
 const struct proc_ops fscache_objlist_proc_ops = {
 	.proc_open	= fscache_objlist_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= fscache_objlist_release,
 };
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index e4944436e733d0..db661b953c4378 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1080,7 +1080,7 @@ static int jbd2_seq_info_release(struct inode *inode, struct file *file)
 
 static const struct proc_ops jbd2_info_proc_ops = {
 	.proc_open	= jbd2_seq_info_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= jbd2_seq_info_release,
 };
diff --git a/fs/jfs/jfs_debug.c b/fs/jfs/jfs_debug.c
index 44b62b3c322e9a..235df6bac1d71a 100644
--- a/fs/jfs/jfs_debug.c
+++ b/fs/jfs/jfs_debug.c
@@ -45,7 +45,7 @@ static ssize_t jfs_loglevel_proc_write(struct file *file,
 
 static const struct proc_ops jfs_loglevel_proc_ops = {
 	.proc_open	= jfs_loglevel_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= jfs_loglevel_proc_write,
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 1b36a8ba82d204..a73899dfc09b9d 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -159,7 +159,7 @@ static int exports_proc_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops exports_proc_ops = {
 	.proc_open	= exports_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
 };
diff --git a/fs/nfsd/stats.c b/fs/nfsd/stats.c
index b1bc582b0493e4..1076f87715ad88 100644
--- a/fs/nfsd/stats.c
+++ b/fs/nfsd/stats.c
@@ -86,7 +86,7 @@ static int nfsd_proc_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops nfsd_proc_ops = {
 	.proc_open	= nfsd_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 };
diff --git a/fs/proc/cpuinfo.c b/fs/proc/cpuinfo.c
index d0989a443c77df..419760fd77bdd8 100644
--- a/fs/proc/cpuinfo.c
+++ b/fs/proc/cpuinfo.c
@@ -19,7 +19,7 @@ static int cpuinfo_open(struct inode *inode, struct file *file)
 static const struct proc_ops cpuinfo_proc_ops = {
 	.proc_flags	= PROC_ENTRY_PERMANENT,
 	.proc_open	= cpuinfo_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
 };
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 2f9fa179194d72..4323b28db5643a 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -590,7 +590,7 @@ static int proc_seq_release(struct inode *inode, struct file *file)
 static const struct proc_ops proc_seq_ops = {
 	/* not permanent -- can call into arbitrary seq_operations */
 	.proc_open	= proc_seq_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= proc_seq_release,
 };
@@ -621,7 +621,7 @@ static int proc_single_open(struct inode *inode, struct file *file)
 static const struct proc_ops proc_single_ops = {
 	/* not permanent -- can call into arbitrary ->single_show */
 	.proc_open	= proc_single_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 };
diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c
index dba63b2429f05f..8274f4fc4d4338 100644
--- a/fs/proc/proc_net.c
+++ b/fs/proc/proc_net.c
@@ -92,7 +92,7 @@ static int seq_release_net(struct inode *ino, struct file *f)
 
 static const struct proc_ops proc_net_seq_ops = {
 	.proc_open	= seq_open_net,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= proc_simple_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release_net,
@@ -204,7 +204,7 @@ static int single_release_net(struct inode *ino, struct file *f)
 
 static const struct proc_ops proc_net_single_ops = {
 	.proc_open	= single_open_net,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= proc_simple_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release_net,
diff --git a/fs/proc/stat.c b/fs/proc/stat.c
index 46b3293015fe61..4695b6de315129 100644
--- a/fs/proc/stat.c
+++ b/fs/proc/stat.c
@@ -226,7 +226,7 @@ static int stat_open(struct inode *inode, struct file *file)
 static const struct proc_ops stat_proc_ops = {
 	.proc_flags	= PROC_ENTRY_PERMANENT,
 	.proc_open	= stat_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 };
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index 0c9e9c8607e788..04f342179f5572 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -187,7 +187,7 @@ static int __name ## _open(struct inode *inode, struct file *file)	\
 									\
 static const struct proc_ops __name ## _proc_ops = {			\
 	.proc_open	= __name ## _open,				\
-	.proc_read	= seq_read,					\
+	.proc_read_iter	= seq_read_iter,					\
 	.proc_lseek	= seq_lseek,					\
 	.proc_release	= single_release,				\
 }
diff --git a/ipc/util.c b/ipc/util.c
index cfa0045e748d55..189c835108afc8 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -887,7 +887,7 @@ static int sysvipc_proc_release(struct inode *inode, struct file *file)
 static const struct proc_ops sysvipc_proc_ops = {
 	.proc_flags	= PROC_ENTRY_PERMANENT,
 	.proc_open	= sysvipc_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= sysvipc_proc_release,
 };
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 32c071d7bc0338..6c541898f614c4 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -200,7 +200,7 @@ static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops irq_affinity_proc_ops = {
 	.proc_open	= irq_affinity_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= irq_affinity_proc_write,
@@ -208,7 +208,7 @@ static const struct proc_ops irq_affinity_proc_ops = {
 
 static const struct proc_ops irq_affinity_list_proc_ops = {
 	.proc_open	= irq_affinity_list_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= irq_affinity_list_proc_write,
@@ -270,7 +270,7 @@ static int default_affinity_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops default_affinity_proc_ops = {
 	.proc_open	= default_affinity_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= default_affinity_write,
diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 16c8c605f4b0fa..90facda3b723ab 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -699,7 +699,7 @@ const char *kdb_walk_kallsyms(loff_t *pos)
 
 static const struct proc_ops kallsyms_proc_ops = {
 	.proc_open	= kallsyms_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release_private,
 };
diff --git a/kernel/latencytop.c b/kernel/latencytop.c
index 166d7bf49666b0..543c7f552c45ce 100644
--- a/kernel/latencytop.c
+++ b/kernel/latencytop.c
@@ -257,7 +257,7 @@ static int lstats_open(struct inode *inode, struct file *filp)
 
 static const struct proc_ops lstats_proc_ops = {
 	.proc_open	= lstats_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= lstats_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index 5525cd3ba0c83c..60c725f53c26d7 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -669,7 +669,7 @@ static int lock_stat_release(struct inode *inode, struct file *file)
 static const struct proc_ops lock_stat_proc_ops = {
 	.proc_open	= lock_stat_open,
 	.proc_write	= lock_stat_write,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= lock_stat_release,
 };
diff --git a/kernel/module.c b/kernel/module.c
index e8a198588f26ee..019e7b21dbbf3c 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4386,7 +4386,7 @@ static int modules_open(struct inode *inode, struct file *file)
 static const struct proc_ops modules_proc_ops = {
 	.proc_flags	= PROC_ENTRY_PERMANENT,
 	.proc_open	= modules_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
 };
diff --git a/kernel/profile.c b/kernel/profile.c
index 6f69a4195d5630..101090397235ae 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -444,7 +444,7 @@ static ssize_t prof_cpu_mask_proc_write(struct file *file,
 
 static const struct proc_ops prof_cpu_mask_proc_ops = {
 	.proc_open	= prof_cpu_mask_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 	.proc_write	= prof_cpu_mask_proc_write,
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 8f45cdb6463b88..6795170140a031 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -1305,7 +1305,7 @@ static int psi_fop_release(struct inode *inode, struct file *file)
 
 static const struct proc_ops psi_io_proc_ops = {
 	.proc_open	= psi_io_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= psi_io_write,
 	.proc_poll	= psi_fop_poll,
@@ -1314,7 +1314,7 @@ static const struct proc_ops psi_io_proc_ops = {
 
 static const struct proc_ops psi_memory_proc_ops = {
 	.proc_open	= psi_memory_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= psi_memory_write,
 	.proc_poll	= psi_fop_poll,
@@ -1323,7 +1323,7 @@ static const struct proc_ops psi_memory_proc_ops = {
 
 static const struct proc_ops psi_cpu_proc_ops = {
 	.proc_open	= psi_cpu_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= psi_cpu_write,
 	.proc_poll	= psi_fop_poll,
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 76750e73dcaf9d..2317d29e16def9 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -878,7 +878,7 @@ static const struct file_operations ddebug_proc_fops = {
 
 static const struct proc_ops proc_fops = {
 	.proc_open = ddebug_proc_open,
-	.proc_read = seq_read,
+	.proc_read_iter = seq_read_iter,
 	.proc_lseek = seq_lseek,
 	.proc_release = seq_release_private,
 	.proc_write = ddebug_proc_write
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 9e72ba2241750c..8497bdf79a770f 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1584,7 +1584,7 @@ static int slabinfo_open(struct inode *inode, struct file *file)
 static const struct proc_ops slabinfo_proc_ops = {
 	.proc_flags	= PROC_ENTRY_PERMANENT,
 	.proc_open	= slabinfo_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= slabinfo_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 987276c557d1f1..2e50f52a14c7c2 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -2835,7 +2835,7 @@ static int swaps_open(struct inode *inode, struct file *file)
 static const struct proc_ops swaps_proc_ops = {
 	.proc_flags	= PROC_ENTRY_PERMANENT,
 	.proc_open	= swaps_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
 	.proc_poll	= swaps_poll,
diff --git a/net/atm/mpoa_proc.c b/net/atm/mpoa_proc.c
index 829db9eba0cb95..fe8f822c7750a6 100644
--- a/net/atm/mpoa_proc.c
+++ b/net/atm/mpoa_proc.c
@@ -55,7 +55,7 @@ static int parse_qos(const char *buff);
 
 static const struct proc_ops mpc_proc_ops = {
 	.proc_open	= proc_mpc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= proc_mpc_write,
 	.proc_release	= seq_release,
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index b53b6d38c4dff8..200b976202d0d1 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -537,7 +537,7 @@ static int pgctrl_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops pktgen_proc_ops = {
 	.proc_open	= pgctrl_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= pgctrl_write,
 	.proc_release	= single_release,
@@ -1709,7 +1709,7 @@ static int pktgen_if_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops pktgen_if_proc_ops = {
 	.proc_open	= pktgen_if_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= pktgen_if_write,
 	.proc_release	= single_release,
@@ -1846,7 +1846,7 @@ static int pktgen_thread_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops pktgen_thread_proc_ops = {
 	.proc_open	= pktgen_thread_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_write	= pktgen_thread_write,
 	.proc_release	= single_release,
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c
index f8755a4ae9d4bd..67472389c9c395 100644
--- a/net/ipv4/netfilter/ipt_CLUSTERIP.c
+++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c
@@ -806,7 +806,7 @@ static ssize_t clusterip_proc_write(struct file *file, const char __user *input,
 
 static const struct proc_ops clusterip_proc_ops = {
 	.proc_open	= clusterip_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= clusterip_proc_write,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= clusterip_proc_release,
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 1d7076b78e630b..4d5f26478f1001 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -239,7 +239,7 @@ static int rt_cache_seq_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops rt_cache_proc_ops = {
 	.proc_open	= rt_cache_seq_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
 };
@@ -330,7 +330,7 @@ static int rt_cpu_seq_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops rt_cpu_proc_ops = {
 	.proc_open	= rt_cpu_seq_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= seq_release,
 };
diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c
index 19bef176145eb9..f9cc00f7486058 100644
--- a/net/netfilter/xt_recent.c
+++ b/net/netfilter/xt_recent.c
@@ -618,7 +618,7 @@ recent_mt_proc_write(struct file *file, const char __user *input,
 
 static const struct proc_ops recent_mt_proc_ops = {
 	.proc_open	= recent_seq_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_write	= recent_mt_proc_write,
 	.proc_release	= seq_release_private,
 	.proc_lseek	= seq_lseek,
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index e5c01697c3f1d6..3671c464e0d30f 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -1623,7 +1623,7 @@ static int content_release_procfs(struct inode *inode, struct file *filp)
 
 static const struct proc_ops content_proc_ops = {
 	.proc_open	= content_open_procfs,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= content_release_procfs,
 };
diff --git a/net/sunrpc/stats.c b/net/sunrpc/stats.c
index c964b48eaabae4..95b56f0e5a01e8 100644
--- a/net/sunrpc/stats.c
+++ b/net/sunrpc/stats.c
@@ -71,7 +71,7 @@ static int rpc_proc_open(struct inode *inode, struct file *file)
 
 static const struct proc_ops rpc_proc_ops = {
 	.proc_open	= rpc_proc_open,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 	.proc_lseek	= seq_lseek,
 	.proc_release	= single_release,
 };
diff --git a/sound/core/info.c b/sound/core/info.c
index 8c6bc5241df50c..6e2a35a37b5e6b 100644
--- a/sound/core/info.c
+++ b/sound/core/info.c
@@ -426,7 +426,7 @@ static const struct proc_ops snd_info_text_entry_ops =
 	.proc_release	= snd_info_text_entry_release,
 	.proc_write	= snd_info_text_entry_write,
 	.proc_lseek	= seq_lseek,
-	.proc_read	= seq_read,
+	.proc_read_iter	= seq_read_iter,
 };
 
 static struct snd_info_entry *create_subdir(struct module *mod,
-- 
2.26.2

[PATCH 10/11] fs: don't allow kernel reads and writes using ->read and ->write

[Christoph Hellwig]

Don't allow calling ->read or ->write with set_fs as a preparation for
killing off set_fs.  While I've not triggered any of these cases in my
setups as all the usual suspect (file systems, pipes, sockets, block
devices, system character devices) use the iter ops this is almost
going to be guaranteed to eventuall break something, so print a detailed
error message helping to debug such cases.  The fix will be to switch the
affected driver to use ->read_uptr / ->write_uptr or ->read_iter /
->write_iter.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/read_write.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/fs/read_write.c b/fs/read_write.c
index b92c222ca886ca..1b813d9bcf08b7 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -420,6 +420,18 @@ ssize_t iter_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos,
 	return ret;
 }
 
+static void warn_unsupported(struct file *file, const char *op)
+{
+	char pathname[128], *path;
+
+	path = file_path(file, pathname, sizeof(pathname));
+	if (IS_ERR(path))
+		path = "(unknown)";
+	pr_warn_ratelimited(
+		"kernel space %s not supported for file %s (pid: %d comm: %.20s)\n",
+		op, path, current->pid, current->comm);
+}
+
 ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
 {
 	ssize_t ret;
@@ -433,12 +445,6 @@ ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
 		count =  MAX_RW_COUNT;
 	if (file->f_op->read_uptr) {
 		ret = file->f_op->read_uptr(file, KERNEL_UPTR(buf), count, pos);
-	} else if (file->f_op->read) {
-		mm_segment_t old_fs = get_fs();
-
-		set_fs(KERNEL_DS);
-		ret = file->f_op->read(file, (void __user *)buf, count, pos);
-		set_fs(old_fs);
 	} else if (file->f_op->read_iter) {
 		struct kvec iov = { .iov_base = buf, .iov_len = count };
 		struct kiocb kiocb;
@@ -450,6 +456,8 @@ ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
 		ret = file->f_op->read_iter(&kiocb, &iter);
 		*pos = kiocb.ki_pos;
 	} else {
+		if (file->f_op->read)
+			warn_unsupported(file, "read");
 		ret = -EINVAL;
 	}
 	if (ret > 0) {
@@ -539,13 +547,6 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count,
 	if (file->f_op->write_uptr) {
 		ret = file->f_op->write_uptr(file, KERNEL_UPTR((void *)buf),
 				count, pos);
-	} else if (file->f_op->write) {
-		mm_segment_t old_fs = get_fs();
-
-		set_fs(KERNEL_DS);
-		ret = file->f_op->write(file, (__force const char __user *)buf,
-				count, pos);
-		set_fs(old_fs);
 	} else if (file->f_op->write_iter) {
 		struct kvec iov = { .iov_base = (void *)buf, .iov_len = count };
 		struct kiocb kiocb;
@@ -558,6 +559,8 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count,
 		if (ret > 0)
 			*pos = kiocb.ki_pos;
 	} else {
+		if (file->f_op->write)
+			warn_unsupported(file, "write");
 		ret = -EINVAL;
 	}
 	if (ret > 0) {
-- 
2.26.2

[PATCH 11/11] fs: don't allow splice read/write without explicit ops

[Christoph Hellwig]

Now that __kernel_write or __kernel_write don't just work on all
file operations instances there is not much of a point of providing
default splice methods.  Renamed the existing default ones to
simple_ and wire them up for the few instancas actually implementing
->read_uptr and ->write_uptr.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/proc/proc_sysctl.c |  2 ++
 fs/splice.c           | 40 ++++++++++++++++++++++++++++------------
 include/linux/fs.h    |  5 ++++-
 3 files changed, 34 insertions(+), 13 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index dd5eb693bd00df..5adbc1c8f899cd 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -856,6 +856,8 @@ static const struct file_operations proc_sys_file_operations = {
 	.poll		= proc_sys_poll,
 	.read_uptr	= proc_sys_read,
 	.write_uptr	= proc_sys_write,
+	.splice_read	= simple_splice_read,
+	.splice_write	= simple_splice_write,
 	.llseek		= default_llseek,
 };
 
diff --git a/fs/splice.c b/fs/splice.c
index d1efc53875bd93..d5bba2cd695b5d 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -342,9 +342,8 @@ const struct pipe_buf_operations nosteal_pipe_buf_ops = {
 };
 EXPORT_SYMBOL(nosteal_pipe_buf_ops);
 
-static ssize_t default_file_splice_read(struct file *in, loff_t *ppos,
-				 struct pipe_inode_info *pipe, size_t len,
-				 unsigned int flags)
+ssize_t simple_splice_read(struct file *in, loff_t *ppos,
+		struct pipe_inode_info *pipe, size_t len, unsigned int flags)
 {
 	struct iov_iter to;
 	struct page **pages;
@@ -779,9 +778,8 @@ static int write_pipe_buf(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
 	return ret;
 }
 
-static ssize_t default_file_splice_write(struct pipe_inode_info *pipe,
-					 struct file *out, loff_t *ppos,
-					 size_t len, unsigned int flags)
+ssize_t simple_splice_write(struct pipe_inode_info *pipe, struct file *out,
+		loff_t *ppos, size_t len, unsigned int flags)
 {
 	ssize_t ret;
 
@@ -813,15 +811,30 @@ ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out,
 
 EXPORT_SYMBOL(generic_splice_sendpage);
 
+static void warn_unsupported(struct file *file, const char *op)
+{
+	char pathname[128], *path;
+
+	path = file_path(file, pathname, sizeof(pathname));
+	if (IS_ERR(path))
+		path = "(unknown)";
+	pr_debug_ratelimited(
+		"splice %s not supported for file %s (pid: %d comm: %.20s)\n",
+		op, path, current->pid, current->comm);
+}
+
 /*
  * Attempt to initiate a splice from pipe to file.
  */
 static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
 			   loff_t *ppos, size_t len, unsigned int flags)
 {
-	if (out->f_op->splice_write)
-		return out->f_op->splice_write(pipe, out, ppos, len, flags);
-	return default_file_splice_write(pipe, out, ppos, len, flags);
+	if (!out->f_op->splice_write) {
+		warn_unsupported(out, "write");
+		return -EINVAL;
+	}
+
+	return out->f_op->splice_write(pipe, out, ppos, len, flags);
 }
 
 /*
@@ -843,9 +856,12 @@ static long do_splice_to(struct file *in, loff_t *ppos,
 	if (unlikely(len > MAX_RW_COUNT))
 		len = MAX_RW_COUNT;
 
-	if (in->f_op->splice_read)
-		return in->f_op->splice_read(in, ppos, pipe, len, flags);
-	return default_file_splice_read(in, ppos, pipe, len, flags);
+	if (!in->f_op->splice_read) {
+		warn_unsupported(in, "read");
+		return -EINVAL;
+	}
+
+	return in->f_op->splice_read(in, ppos, pipe, len, flags);
 }
 
 /**
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d0fea0281ef29b..64a6506cba0446 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3175,7 +3175,10 @@ extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
 		struct file *out, loff_t *, size_t len, unsigned int flags);
 extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
 		loff_t *opos, size_t len, unsigned int flags);
-
+ssize_t simple_splice_read(struct file *in, loff_t *ppos,
+		struct pipe_inode_info *pipe, size_t len, unsigned int flags);
+ssize_t simple_splice_write(struct pipe_inode_info *pipe, struct file *out,
+		loff_t *ppos, size_t len, unsigned int flags);
 
 extern void
 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
-- 
2.26.2