[PATCH V6 00/30] loop: Issue O_DIRECT aio using bio_vec

[PATCH V6 00/30] loop: Issue O_DIRECT aio using bio_vec

[Dave Kleikamp]

Al,
I'd like to push this patchset to linux-next. Would you like to pull it
into your vfs tree, would you rather I submitted it separately, or do
you have any issues with it before including it?

This patchset was begun by Zach Brown and was originally submitted for
review in October, 2009. Feedback was positive, and I have picked up
where he left off, porting his patches to the latest mainline kernel
and adding support more file systems.

This patch series adds a kernel interface to fs/aio.c so that kernel code can
issue concurrent asynchronous IO to file systems.  It adds an aio command and
file system methods which specify io memory with pages instead of userspace
addresses.

This series was written to reduce the current overhead loop imposes by
performing synchronus buffered file system IO from a kernel thread.  These
patches turn loop into a light weight layer that translates bios into iocbs.

It introduces new file ops, read_iter() and write_iter(), that replace the
aio_read() and aio_write() operations. The iov_iter structure can now contain
either a user-space iovec or a kernel-space bio_vec. Since it would be
overly complicated to replace every instance of aio_read() and aio_write(),
the old operations are not removed, but file systems implementing the new
ones need not keep the old ones.

The only change from V5 is a fixing a serious cut-and-paste error in patch
17 that made aio writes fail.

These patches apply to 3.8-rc5 and are also available at:
git://github.com/kleikamp/linux-shaggy.git loop_v6

Asias He (1):
  block_dev: add support for read_iter, write_iter

Dave Kleikamp (17):
  iov_iter: iov_iter_copy_from_user() should use non-atomic copy
  fuse: convert fuse to use iov_iter_copy_[to|from]_user
  dio: Convert direct_IO to use iov_iter
  dio: add bio_vec support to __blockdev_direct_IO()
  fs: create file_readable() and file_writable() functions
  fs: use read_iter and write_iter rather than aio_read and aio_write
  fs: add read_iter and write_iter to several file systems
  ext4: add support for read_iter and write_iter
  nfs: add support for read_iter, write_iter
  nfs: simplify swap
  btrfs: add support for read_iter and write_iter
  xfs: add support for read_iter and write_iter
  gfs2: Convert aio_read/write ops to read/write_iter
  udf: convert file ops from aio_read/write to read/write_iter
  afs: add support for read_iter and write_iter
  ecrpytfs: Convert aio_read/write ops to read/write_iter
  ubifs: convert file ops from aio_read/write to read/write_iter

Zach Brown (12):
  iov_iter: move into its own file
  iov_iter: add copy_to_user support
  iov_iter: hide iovec details behind ops function pointers
  iov_iter: add bvec support
  iov_iter: add a shorten call
  iov_iter: let callers extract iovecs and bio_vecs
  fs: pull iov_iter use higher up the stack
  aio: add aio_kernel_() interface
  aio: add aio support for iov_iter arguments
  bio: add bvec_length(), like iov_length()
  loop: use aio to perform io on the underlying file
  ocfs2: add support for read_iter, write_iter, and direct_IO_bvec

 Documentation/filesystems/Locking    |   6 +-
 Documentation/filesystems/vfs.txt    |  12 +-
 drivers/block/loop.c                 | 148 +++++++++----
 drivers/char/raw.c                   |   4 +-
 drivers/mtd/nand/nandsim.c           |   4 +-
 drivers/staging/ccg/storage_common.c |   4 +-
 drivers/usb/gadget/storage_common.c  |   4 +-
 fs/9p/vfs_addr.c                     |  12 +-
 fs/9p/vfs_file.c                     |   8 +-
 fs/Makefile                          |   2 +-
 fs/adfs/file.c                       |   4 +-
 fs/affs/file.c                       |   4 +-
 fs/afs/file.c                        |   4 +-
 fs/afs/internal.h                    |   3 +-
 fs/afs/write.c                       |   9 +-
 fs/aio.c                             | 170 ++++++++++++++-
 fs/bad_inode.c                       |  14 ++
 fs/bfs/file.c                        |   4 +-
 fs/block_dev.c                       |  27 ++-
 fs/btrfs/file.c                      |  42 ++--
 fs/btrfs/inode.c                     |  61 +++---
 fs/ceph/addr.c                       |   3 +-
 fs/cifs/file.c                       |   4 +-
 fs/compat.c                          |  10 +-
 fs/direct-io.c                       | 223 ++++++++++++++------
 fs/ecryptfs/file.c                   |  15 +-
 fs/exofs/file.c                      |   4 +-
 fs/ext2/file.c                       |   4 +-
 fs/ext2/inode.c                      |   8 +-
 fs/ext3/file.c                       |   4 +-
 fs/ext3/inode.c                      |  15 +-
 fs/ext4/ext4.h                       |   3 +-
 fs/ext4/file.c                       |  34 +--
 fs/ext4/indirect.c                   |  16 +-
 fs/ext4/inode.c                      |  23 +-
 fs/f2fs/data.c                       |   4 +-
 fs/f2fs/file.c                       |   4 +-
 fs/fat/file.c                        |   4 +-
 fs/fat/inode.c                       |  10 +-
 fs/fuse/file.c                       |  40 ++--
 fs/gfs2/aops.c                       |   7 +-
 fs/gfs2/file.c                       |  21 +-
 fs/hfs/inode.c                       |  11 +-
 fs/hfsplus/inode.c                   |  10 +-
 fs/hostfs/hostfs_kern.c              |   4 +-
 fs/hpfs/file.c                       |   4 +-
 fs/iov-iter.c                        | 386 ++++++++++++++++++++++++++++++++++
 fs/jffs2/file.c                      |   8 +-
 fs/jfs/file.c                        |   4 +-
 fs/jfs/inode.c                       |   7 +-
 fs/logfs/file.c                      |   4 +-
 fs/minix/file.c                      |   4 +-
 fs/nfs/direct.c                      | 302 +++++++++++++++++---------
 fs/nfs/file.c                        |  33 ++-
 fs/nfs/internal.h                    |   4 +-
 fs/nfs/nfs4file.c                    |   4 +-
 fs/nilfs2/file.c                     |   4 +-
 fs/nilfs2/inode.c                    |   8 +-
 fs/ocfs2/aops.c                      |   8 +-
 fs/ocfs2/aops.h                      |   2 +-
 fs/ocfs2/file.c                      |  53 ++---
 fs/ocfs2/inode.h                     |   2 -
 fs/ocfs2/ocfs2_trace.h               |   6 +-
 fs/omfs/file.c                       |   4 +-
 fs/ramfs/file-mmu.c                  |   4 +-
 fs/ramfs/file-nommu.c                |   4 +-
 fs/read_write.c                      |  66 +++++-
 fs/read_write.h                      |   4 +
 fs/reiserfs/file.c                   |   4 +-
 fs/reiserfs/inode.c                  |   7 +-
 fs/romfs/mmap-nommu.c                |   2 +-
 fs/sysv/file.c                       |   4 +-
 fs/ubifs/file.c                      |  12 +-
 fs/udf/file.c                        |  13 +-
 fs/udf/inode.c                       |  10 +-
 fs/ufs/file.c                        |   4 +-
 fs/xfs/xfs_aops.c                    |  13 +-
 fs/xfs/xfs_file.c                    |  51 ++---
 include/linux/aio.h                  |  18 ++
 include/linux/bio.h                  |   8 +
 include/linux/blk_types.h            |   2 -
 include/linux/fs.h                   | 155 ++++++++++++--
 include/linux/nfs_fs.h               |  13 +-
 include/uapi/linux/aio_abi.h         |   2 +
 include/uapi/linux/loop.h            |   1 +
 mm/filemap.c                         | 395 +++++++++++++++--------------------
 mm/page_io.c                         |  15 +-
 87 files changed, 1789 insertions(+), 892 deletions(-)
 create mode 100644 fs/iov-iter.c

-- 
1.8.1.1

[PATCH V6 01/30] iov_iter: move into its own file

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

This moves the iov_iter functions in to their own file.  We're going to
be working on them in upcoming patches.  They become sufficiently large,
and remain self-contained, to justify seperating them from the rest of
the huge mm/filemap.c.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Cc: Zach Brown <zab@zabbo.net>
---
 fs/Makefile   |   2 +-
 fs/iov-iter.c | 151 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 mm/filemap.c  | 144 -------------------------------------------------------
 3 files changed, 152 insertions(+), 145 deletions(-)
 create mode 100644 fs/iov-iter.c

diff --git a/fs/Makefile b/fs/Makefile
index 9d53192..cecc8b9 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -11,7 +11,7 @@ obj-y :=	open.o read_write.o file_table.o super.o \
 		attr.o bad_inode.o file.o filesystems.o namespace.o \
 		seq_file.o xattr.o libfs.o fs-writeback.o \
 		pnode.o drop_caches.o splice.o sync.o utimes.o \
-		stack.o fs_struct.o statfs.o
+		stack.o fs_struct.o statfs.o iov-iter.o
 
 ifeq ($(CONFIG_BLOCK),y)
 obj-y +=	buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
diff --git a/fs/iov-iter.c b/fs/iov-iter.c
new file mode 100644
index 0000000..83f7594
--- /dev/null
+++ b/fs/iov-iter.c
@@ -0,0 +1,151 @@
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+#include <linux/hardirq.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+
+static size_t __iovec_copy_from_user_inatomic(char *vaddr,
+			const struct iovec *iov, size_t base, size_t bytes)
+{
+	size_t copied = 0, left = 0;
+
+	while (bytes) {
+		char __user *buf = iov->iov_base + base;
+		int copy = min(bytes, iov->iov_len - base);
+
+		base = 0;
+		left = __copy_from_user_inatomic(vaddr, buf, copy);
+		copied += copy;
+		bytes -= copy;
+		vaddr += copy;
+		iov++;
+
+		if (unlikely(left))
+			break;
+	}
+	return copied - left;
+}
+
+/*
+ * Copy as much as we can into the page and return the number of bytes which
+ * were successfully copied.  If a fault is encountered then return the number
+ * of bytes which were copied.
+ */
+size_t iov_iter_copy_from_user_atomic(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	char *kaddr;
+	size_t copied;
+
+	BUG_ON(!in_atomic());
+	kaddr = kmap_atomic(page);
+	if (likely(i->nr_segs == 1)) {
+		int left;
+		char __user *buf = i->iov->iov_base + i->iov_offset;
+		left = __copy_from_user_inatomic(kaddr + offset, buf, bytes);
+		copied = bytes - left;
+	} else {
+		copied = __iovec_copy_from_user_inatomic(kaddr + offset,
+						i->iov, i->iov_offset, bytes);
+	}
+	kunmap_atomic(kaddr);
+
+	return copied;
+}
+EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
+
+/*
+ * This has the same sideeffects and return value as
+ * iov_iter_copy_from_user_atomic().
+ * The difference is that it attempts to resolve faults.
+ * Page must not be locked.
+ */
+size_t iov_iter_copy_from_user(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	char *kaddr;
+	size_t copied;
+
+	kaddr = kmap(page);
+	if (likely(i->nr_segs == 1)) {
+		int left;
+		char __user *buf = i->iov->iov_base + i->iov_offset;
+		left = __copy_from_user(kaddr + offset, buf, bytes);
+		copied = bytes - left;
+	} else {
+		copied = __iovec_copy_from_user_inatomic(kaddr + offset,
+						i->iov, i->iov_offset, bytes);
+	}
+	kunmap(page);
+	return copied;
+}
+EXPORT_SYMBOL(iov_iter_copy_from_user);
+
+void iov_iter_advance(struct iov_iter *i, size_t bytes)
+{
+	BUG_ON(i->count < bytes);
+
+	if (likely(i->nr_segs == 1)) {
+		i->iov_offset += bytes;
+		i->count -= bytes;
+	} else {
+		const struct iovec *iov = i->iov;
+		size_t base = i->iov_offset;
+		unsigned long nr_segs = i->nr_segs;
+
+		/*
+		 * The !iov->iov_len check ensures we skip over unlikely
+		 * zero-length segments (without overruning the iovec).
+		 */
+		while (bytes || unlikely(i->count && !iov->iov_len)) {
+			int copy;
+
+			copy = min(bytes, iov->iov_len - base);
+			BUG_ON(!i->count || i->count < copy);
+			i->count -= copy;
+			bytes -= copy;
+			base += copy;
+			if (iov->iov_len == base) {
+				iov++;
+				nr_segs--;
+				base = 0;
+			}
+		}
+		i->iov = iov;
+		i->iov_offset = base;
+		i->nr_segs = nr_segs;
+	}
+}
+EXPORT_SYMBOL(iov_iter_advance);
+
+/*
+ * Fault in the first iovec of the given iov_iter, to a maximum length
+ * of bytes. Returns 0 on success, or non-zero if the memory could not be
+ * accessed (ie. because it is an invalid address).
+ *
+ * writev-intensive code may want this to prefault several iovecs -- that
+ * would be possible (callers must not rely on the fact that _only_ the
+ * first iovec will be faulted with the current implementation).
+ */
+int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
+{
+	char __user *buf = i->iov->iov_base + i->iov_offset;
+	bytes = min(bytes, i->iov->iov_len - i->iov_offset);
+	return fault_in_pages_readable(buf, bytes);
+}
+EXPORT_SYMBOL(iov_iter_fault_in_readable);
+
+/*
+ * Return the count of just the current iov_iter segment.
+ */
+size_t iov_iter_single_seg_count(struct iov_iter *i)
+{
+	const struct iovec *iov = i->iov;
+	if (i->nr_segs == 1)
+		return i->count;
+	else
+		return min(i->count, iov->iov_len - i->iov_offset);
+}
+EXPORT_SYMBOL(iov_iter_single_seg_count);
diff --git a/mm/filemap.c b/mm/filemap.c
index 83efee7..753ec48 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1922,150 +1922,6 @@ struct page *read_cache_page(struct address_space *mapping,
 }
 EXPORT_SYMBOL(read_cache_page);
 
-static size_t __iovec_copy_from_user_inatomic(char *vaddr,
-			const struct iovec *iov, size_t base, size_t bytes)
-{
-	size_t copied = 0, left = 0;
-
-	while (bytes) {
-		char __user *buf = iov->iov_base + base;
-		int copy = min(bytes, iov->iov_len - base);
-
-		base = 0;
-		left = __copy_from_user_inatomic(vaddr, buf, copy);
-		copied += copy;
-		bytes -= copy;
-		vaddr += copy;
-		iov++;
-
-		if (unlikely(left))
-			break;
-	}
-	return copied - left;
-}
-
-/*
- * Copy as much as we can into the page and return the number of bytes which
- * were successfully copied.  If a fault is encountered then return the number of
- * bytes which were copied.
- */
-size_t iov_iter_copy_from_user_atomic(struct page *page,
-		struct iov_iter *i, unsigned long offset, size_t bytes)
-{
-	char *kaddr;
-	size_t copied;
-
-	BUG_ON(!in_atomic());
-	kaddr = kmap_atomic(page);
-	if (likely(i->nr_segs == 1)) {
-		int left;
-		char __user *buf = i->iov->iov_base + i->iov_offset;
-		left = __copy_from_user_inatomic(kaddr + offset, buf, bytes);
-		copied = bytes - left;
-	} else {
-		copied = __iovec_copy_from_user_inatomic(kaddr + offset,
-						i->iov, i->iov_offset, bytes);
-	}
-	kunmap_atomic(kaddr);
-
-	return copied;
-}
-EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
-
-/*
- * This has the same sideeffects and return value as
- * iov_iter_copy_from_user_atomic().
- * The difference is that it attempts to resolve faults.
- * Page must not be locked.
- */
-size_t iov_iter_copy_from_user(struct page *page,
-		struct iov_iter *i, unsigned long offset, size_t bytes)
-{
-	char *kaddr;
-	size_t copied;
-
-	kaddr = kmap(page);
-	if (likely(i->nr_segs == 1)) {
-		int left;
-		char __user *buf = i->iov->iov_base + i->iov_offset;
-		left = __copy_from_user(kaddr + offset, buf, bytes);
-		copied = bytes - left;
-	} else {
-		copied = __iovec_copy_from_user_inatomic(kaddr + offset,
-						i->iov, i->iov_offset, bytes);
-	}
-	kunmap(page);
-	return copied;
-}
-EXPORT_SYMBOL(iov_iter_copy_from_user);
-
-void iov_iter_advance(struct iov_iter *i, size_t bytes)
-{
-	BUG_ON(i->count < bytes);
-
-	if (likely(i->nr_segs == 1)) {
-		i->iov_offset += bytes;
-		i->count -= bytes;
-	} else {
-		const struct iovec *iov = i->iov;
-		size_t base = i->iov_offset;
-		unsigned long nr_segs = i->nr_segs;
-
-		/*
-		 * The !iov->iov_len check ensures we skip over unlikely
-		 * zero-length segments (without overruning the iovec).
-		 */
-		while (bytes || unlikely(i->count && !iov->iov_len)) {
-			int copy;
-
-			copy = min(bytes, iov->iov_len - base);
-			BUG_ON(!i->count || i->count < copy);
-			i->count -= copy;
-			bytes -= copy;
-			base += copy;
-			if (iov->iov_len == base) {
-				iov++;
-				nr_segs--;
-				base = 0;
-			}
-		}
-		i->iov = iov;
-		i->iov_offset = base;
-		i->nr_segs = nr_segs;
-	}
-}
-EXPORT_SYMBOL(iov_iter_advance);
-
-/*
- * Fault in the first iovec of the given iov_iter, to a maximum length
- * of bytes. Returns 0 on success, or non-zero if the memory could not be
- * accessed (ie. because it is an invalid address).
- *
- * writev-intensive code may want this to prefault several iovecs -- that
- * would be possible (callers must not rely on the fact that _only_ the
- * first iovec will be faulted with the current implementation).
- */
-int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
-{
-	char __user *buf = i->iov->iov_base + i->iov_offset;
-	bytes = min(bytes, i->iov->iov_len - i->iov_offset);
-	return fault_in_pages_readable(buf, bytes);
-}
-EXPORT_SYMBOL(iov_iter_fault_in_readable);
-
-/*
- * Return the count of just the current iov_iter segment.
- */
-size_t iov_iter_single_seg_count(struct iov_iter *i)
-{
-	const struct iovec *iov = i->iov;
-	if (i->nr_segs == 1)
-		return i->count;
-	else
-		return min(i->count, iov->iov_len - i->iov_offset);
-}
-EXPORT_SYMBOL(iov_iter_single_seg_count);
-
 /*
  * Performs necessary checks before doing a write
  *
-- 
1.8.1.1

[PATCH V6 02/30] iov_iter: iov_iter_copy_from_user() should use non-atomic copy

[Dave Kleikamp]

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
---
 fs/iov-iter.c | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/fs/iov-iter.c b/fs/iov-iter.c
index 83f7594..5c4f3a5 100644
--- a/fs/iov-iter.c
+++ b/fs/iov-iter.c
@@ -6,8 +6,8 @@
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
 
-static size_t __iovec_copy_from_user_inatomic(char *vaddr,
-			const struct iovec *iov, size_t base, size_t bytes)
+static size_t __iovec_copy_from_user(char *vaddr, const struct iovec *iov,
+				     size_t base, size_t bytes, int atomic)
 {
 	size_t copied = 0, left = 0;
 
@@ -16,7 +16,10 @@ static size_t __iovec_copy_from_user_inatomic(char *vaddr,
 		int copy = min(bytes, iov->iov_len - base);
 
 		base = 0;
-		left = __copy_from_user_inatomic(vaddr, buf, copy);
+		if (atomic)
+			left = __copy_from_user_inatomic(vaddr, buf, copy);
+		else
+			left = __copy_from_user(vaddr, buf, copy);
 		copied += copy;
 		bytes -= copy;
 		vaddr += copy;
@@ -47,8 +50,8 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
 		left = __copy_from_user_inatomic(kaddr + offset, buf, bytes);
 		copied = bytes - left;
 	} else {
-		copied = __iovec_copy_from_user_inatomic(kaddr + offset,
-						i->iov, i->iov_offset, bytes);
+		copied = __iovec_copy_from_user(kaddr + offset, i->iov,
+						i->iov_offset, bytes, 1);
 	}
 	kunmap_atomic(kaddr);
 
@@ -75,8 +78,8 @@ size_t iov_iter_copy_from_user(struct page *page,
 		left = __copy_from_user(kaddr + offset, buf, bytes);
 		copied = bytes - left;
 	} else {
-		copied = __iovec_copy_from_user_inatomic(kaddr + offset,
-						i->iov, i->iov_offset, bytes);
+		copied = __iovec_copy_from_user(kaddr + offset, i->iov,
+						i->iov_offset, bytes, 0);
 	}
 	kunmap(page);
 	return copied;
-- 
1.8.1.1

[PATCH V6 03/30] iov_iter: add copy_to_user support

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

This adds iov_iter wrappers around copy_to_user() to match the existing
wrappers around copy_from_user().

This will be used by the generic file system buffered read path.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
 fs/iov-iter.c      | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/fs.h |  4 +++
 2 files changed, 84 insertions(+)

diff --git a/fs/iov-iter.c b/fs/iov-iter.c
index 5c4f3a5..d68b67f 100644
--- a/fs/iov-iter.c
+++ b/fs/iov-iter.c
@@ -6,6 +6,86 @@
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
 
+static size_t __iovec_copy_to_user(char *vaddr, const struct iovec *iov,
+				   size_t base, size_t bytes, int atomic)
+{
+	size_t copied = 0, left = 0;
+
+	while (bytes) {
+		char __user *buf = iov->iov_base + base;
+		int copy = min(bytes, iov->iov_len - base);
+
+		base = 0;
+		if (atomic)
+			left = __copy_to_user_inatomic(buf, vaddr, copy);
+		else
+			left = copy_to_user(buf, vaddr, copy);
+		copied += copy;
+		bytes -= copy;
+		vaddr += copy;
+		iov++;
+
+		if (unlikely(left))
+			break;
+	}
+	return copied - left;
+}
+
+/*
+ * Copy as much as we can into the page and return the number of bytes which
+ * were sucessfully copied.  If a fault is encountered then return the number of
+ * bytes which were copied.
+ */
+size_t iov_iter_copy_to_user_atomic(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	char *kaddr;
+	size_t copied;
+
+	BUG_ON(!in_atomic());
+	kaddr = kmap_atomic(page);
+	if (likely(i->nr_segs == 1)) {
+		int left;
+		char __user *buf = i->iov->iov_base + i->iov_offset;
+		left = __copy_to_user_inatomic(buf, kaddr + offset, bytes);
+		copied = bytes - left;
+	} else {
+		copied = __iovec_copy_to_user(kaddr + offset, i->iov,
+					      i->iov_offset, bytes, 1);
+	}
+	kunmap_atomic(kaddr);
+
+	return copied;
+}
+EXPORT_SYMBOL(iov_iter_copy_to_user_atomic);
+
+/*
+ * This has the same sideeffects and return value as
+ * iov_iter_copy_to_user_atomic().
+ * The difference is that it attempts to resolve faults.
+ * Page must not be locked.
+ */
+size_t iov_iter_copy_to_user(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	char *kaddr;
+	size_t copied;
+
+	kaddr = kmap(page);
+	if (likely(i->nr_segs == 1)) {
+		int left;
+		char __user *buf = i->iov->iov_base + i->iov_offset;
+		left = copy_to_user(buf, kaddr + offset, bytes);
+		copied = bytes - left;
+	} else {
+		copied = __iovec_copy_to_user(kaddr + offset, i->iov,
+					      i->iov_offset, bytes, 0);
+	}
+	kunmap(page);
+	return copied;
+}
+EXPORT_SYMBOL(iov_iter_copy_to_user);
+
 static size_t __iovec_copy_from_user(char *vaddr, const struct iovec *iov,
 				     size_t base, size_t bytes, int atomic)
 {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7617ee0..640f2cd 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -295,6 +295,10 @@ struct iov_iter {
 	size_t count;
 };
 
+size_t iov_iter_copy_to_user_atomic(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes);
+size_t iov_iter_copy_to_user(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes);
 size_t iov_iter_copy_from_user_atomic(struct page *page,
 		struct iov_iter *i, unsigned long offset, size_t bytes);
 size_t iov_iter_copy_from_user(struct page *page,
-- 
1.8.1.1

[PATCH V6 04/30] fuse: convert fuse to use iov_iter_copy_[to|from]_user

[Dave Kleikamp]

A future patch hides the internals of struct iov_iter, so fuse should
be using the supported interface.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Acked-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: fuse-devel@lists.sourceforge.net
---
 fs/fuse/file.c | 29 ++++++++---------------------
 1 file changed, 8 insertions(+), 21 deletions(-)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index f3ab824..27d10ca 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1631,30 +1631,17 @@ static int fuse_ioctl_copy_user(struct page **pages, struct iovec *iov,
 	while (iov_iter_count(&ii)) {
 		struct page *page = pages[page_idx++];
 		size_t todo = min_t(size_t, PAGE_SIZE, iov_iter_count(&ii));
-		void *kaddr;
+		size_t left;
 
-		kaddr = kmap(page);
-
-		while (todo) {
-			char __user *uaddr = ii.iov->iov_base + ii.iov_offset;
-			size_t iov_len = ii.iov->iov_len - ii.iov_offset;
-			size_t copy = min(todo, iov_len);
-			size_t left;
-
-			if (!to_user)
-				left = copy_from_user(kaddr, uaddr, copy);
-			else
-				left = copy_to_user(uaddr, kaddr, copy);
-
-			if (unlikely(left))
-				return -EFAULT;
+		if (!to_user)
+			left = iov_iter_copy_from_user(page, &ii, 0, todo);
+		else
+			left = iov_iter_copy_to_user(page, &ii, 0, todo);
 
-			iov_iter_advance(&ii, copy);
-			todo -= copy;
-			kaddr += copy;
-		}
+		if (unlikely(left))
+			return -EFAULT;
 
-		kunmap(page);
+		iov_iter_advance(&ii, todo);
 	}
 
 	return 0;
-- 
1.8.1.1

[PATCH V6 05/30] iov_iter: hide iovec details behind ops function pointers

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

This moves the current iov_iter functions behind an ops struct of
function pointers.  The current iov_iter functions all work with memory
which is specified by iovec arrays of user space pointers.

This patch is part of a series that lets us specify memory with bio_vec
arrays of page pointers.  By moving to an iov_iter operation struct we
can add that support in later patches in this series by adding another
set of function pointers.

I only came to this after having initialy tried to teach the current
iov_iter functions about bio_vecs by introducing conditional branches
that dealt with bio_vecs in all the functions.  It wasn't pretty.  This
approach seems to be the lesser evil.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
 fs/cifs/file.c     |  4 ++--
 fs/iov-iter.c      | 66 ++++++++++++++++++++++++++++----------------------
 include/linux/fs.h | 70 ++++++++++++++++++++++++++++++++++++++++++++----------
 3 files changed, 97 insertions(+), 43 deletions(-)

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 8ea6ca5..30d3009 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2708,8 +2708,8 @@ cifs_readdata_to_iov(struct cifs_readdata *rdata, const struct iovec *iov,
 		/* go while there's data to be copied and no errors */
 		if (copy && !rc) {
 			pdata = kmap(page);
-			rc = memcpy_toiovecend(ii.iov, pdata, ii.iov_offset,
-						(int)copy);
+			rc = memcpy_toiovecend(iov_iter_iovec(&ii), pdata,
+					       ii.iov_offset, (int)copy);
 			kunmap(page);
 			if (!rc) {
 				*copied += copy;
diff --git a/fs/iov-iter.c b/fs/iov-iter.c
index d68b67f..bae1553 100644
--- a/fs/iov-iter.c
+++ b/fs/iov-iter.c
@@ -36,9 +36,10 @@ static size_t __iovec_copy_to_user(char *vaddr, const struct iovec *iov,
  * were sucessfully copied.  If a fault is encountered then return the number of
  * bytes which were copied.
  */
-size_t iov_iter_copy_to_user_atomic(struct page *page,
+static size_t ii_iovec_copy_to_user_atomic(struct page *page,
 		struct iov_iter *i, unsigned long offset, size_t bytes)
 {
+	struct iovec *iov = (struct iovec *)i->data;
 	char *kaddr;
 	size_t copied;
 
@@ -46,45 +47,44 @@ size_t iov_iter_copy_to_user_atomic(struct page *page,
 	kaddr = kmap_atomic(page);
 	if (likely(i->nr_segs == 1)) {
 		int left;
-		char __user *buf = i->iov->iov_base + i->iov_offset;
+		char __user *buf = iov->iov_base + i->iov_offset;
 		left = __copy_to_user_inatomic(buf, kaddr + offset, bytes);
 		copied = bytes - left;
 	} else {
-		copied = __iovec_copy_to_user(kaddr + offset, i->iov,
+		copied = __iovec_copy_to_user(kaddr + offset, iov,
 					      i->iov_offset, bytes, 1);
 	}
 	kunmap_atomic(kaddr);
 
 	return copied;
 }
-EXPORT_SYMBOL(iov_iter_copy_to_user_atomic);
 
 /*
  * This has the same sideeffects and return value as
- * iov_iter_copy_to_user_atomic().
+ * ii_iovec_copy_to_user_atomic().
  * The difference is that it attempts to resolve faults.
  * Page must not be locked.
  */
-size_t iov_iter_copy_to_user(struct page *page,
+static size_t ii_iovec_copy_to_user(struct page *page,
 		struct iov_iter *i, unsigned long offset, size_t bytes)
 {
+	struct iovec *iov = (struct iovec *)i->data;
 	char *kaddr;
 	size_t copied;
 
 	kaddr = kmap(page);
 	if (likely(i->nr_segs == 1)) {
 		int left;
-		char __user *buf = i->iov->iov_base + i->iov_offset;
+		char __user *buf = iov->iov_base + i->iov_offset;
 		left = copy_to_user(buf, kaddr + offset, bytes);
 		copied = bytes - left;
 	} else {
-		copied = __iovec_copy_to_user(kaddr + offset, i->iov,
+		copied = __iovec_copy_to_user(kaddr + offset, iov,
 					      i->iov_offset, bytes, 0);
 	}
 	kunmap(page);
 	return copied;
 }
-EXPORT_SYMBOL(iov_iter_copy_to_user);
 
 static size_t __iovec_copy_from_user(char *vaddr, const struct iovec *iov,
 				     size_t base, size_t bytes, int atomic)
@@ -116,9 +116,10 @@ static size_t __iovec_copy_from_user(char *vaddr, const struct iovec *iov,
  * were successfully copied.  If a fault is encountered then return the number
  * of bytes which were copied.
  */
-size_t iov_iter_copy_from_user_atomic(struct page *page,
+static size_t ii_iovec_copy_from_user_atomic(struct page *page,
 		struct iov_iter *i, unsigned long offset, size_t bytes)
 {
+	struct iovec *iov = (struct iovec *)i->data;
 	char *kaddr;
 	size_t copied;
 
@@ -126,11 +127,11 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
 	kaddr = kmap_atomic(page);
 	if (likely(i->nr_segs == 1)) {
 		int left;
-		char __user *buf = i->iov->iov_base + i->iov_offset;
+		char __user *buf = iov->iov_base + i->iov_offset;
 		left = __copy_from_user_inatomic(kaddr + offset, buf, bytes);
 		copied = bytes - left;
 	} else {
-		copied = __iovec_copy_from_user(kaddr + offset, i->iov,
+		copied = __iovec_copy_from_user(kaddr + offset, iov,
 						i->iov_offset, bytes, 1);
 	}
 	kunmap_atomic(kaddr);
@@ -141,32 +142,32 @@ EXPORT_SYMBOL(iov_iter_copy_from_user_atomic);
 
 /*
  * This has the same sideeffects and return value as
- * iov_iter_copy_from_user_atomic().
+ * ii_iovec_copy_from_user_atomic().
  * The difference is that it attempts to resolve faults.
  * Page must not be locked.
  */
-size_t iov_iter_copy_from_user(struct page *page,
+static size_t ii_iovec_copy_from_user(struct page *page,
 		struct iov_iter *i, unsigned long offset, size_t bytes)
 {
+	struct iovec *iov = (struct iovec *)i->data;
 	char *kaddr;
 	size_t copied;
 
 	kaddr = kmap(page);
 	if (likely(i->nr_segs == 1)) {
 		int left;
-		char __user *buf = i->iov->iov_base + i->iov_offset;
+		char __user *buf = iov->iov_base + i->iov_offset;
 		left = __copy_from_user(kaddr + offset, buf, bytes);
 		copied = bytes - left;
 	} else {
-		copied = __iovec_copy_from_user(kaddr + offset, i->iov,
+		copied = __iovec_copy_from_user(kaddr + offset, iov,
 						i->iov_offset, bytes, 0);
 	}
 	kunmap(page);
 	return copied;
 }
-EXPORT_SYMBOL(iov_iter_copy_from_user);
 
-void iov_iter_advance(struct iov_iter *i, size_t bytes)
+static void ii_iovec_advance(struct iov_iter *i, size_t bytes)
 {
 	BUG_ON(i->count < bytes);
 
@@ -174,7 +175,7 @@ void iov_iter_advance(struct iov_iter *i, size_t bytes)
 		i->iov_offset += bytes;
 		i->count -= bytes;
 	} else {
-		const struct iovec *iov = i->iov;
+		struct iovec *iov = (struct iovec *)i->data;
 		size_t base = i->iov_offset;
 		unsigned long nr_segs = i->nr_segs;
 
@@ -196,12 +197,11 @@ void iov_iter_advance(struct iov_iter *i, size_t bytes)
 				base = 0;
 			}
 		}
-		i->iov = iov;
+		i->data = (unsigned long)iov;
 		i->iov_offset = base;
 		i->nr_segs = nr_segs;
 	}
 }
-EXPORT_SYMBOL(iov_iter_advance);
 
 /*
  * Fault in the first iovec of the given iov_iter, to a maximum length
@@ -212,23 +212,33 @@ EXPORT_SYMBOL(iov_iter_advance);
  * would be possible (callers must not rely on the fact that _only_ the
  * first iovec will be faulted with the current implementation).
  */
-int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
+static int ii_iovec_fault_in_readable(struct iov_iter *i, size_t bytes)
 {
-	char __user *buf = i->iov->iov_base + i->iov_offset;
-	bytes = min(bytes, i->iov->iov_len - i->iov_offset);
+	struct iovec *iov = (struct iovec *)i->data;
+	char __user *buf = iov->iov_base + i->iov_offset;
+	bytes = min(bytes, iov->iov_len - i->iov_offset);
 	return fault_in_pages_readable(buf, bytes);
 }
-EXPORT_SYMBOL(iov_iter_fault_in_readable);
 
 /*
  * Return the count of just the current iov_iter segment.
  */
-size_t iov_iter_single_seg_count(struct iov_iter *i)
+static size_t ii_iovec_single_seg_count(struct iov_iter *i)
 {
-	const struct iovec *iov = i->iov;
+	struct iovec *iov = (struct iovec *)i->data;
 	if (i->nr_segs == 1)
 		return i->count;
 	else
 		return min(i->count, iov->iov_len - i->iov_offset);
 }
-EXPORT_SYMBOL(iov_iter_single_seg_count);
+
+struct iov_iter_ops ii_iovec_ops = {
+	.ii_copy_to_user_atomic = ii_iovec_copy_to_user_atomic,
+	.ii_copy_to_user = ii_iovec_copy_to_user,
+	.ii_copy_from_user_atomic = ii_iovec_copy_from_user_atomic,
+	.ii_copy_from_user = ii_iovec_copy_from_user,
+	.ii_advance = ii_iovec_advance,
+	.ii_fault_in_readable = ii_iovec_fault_in_readable,
+	.ii_single_seg_count = ii_iovec_single_seg_count,
+};
+EXPORT_SYMBOL(ii_iovec_ops);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 640f2cd..5618301 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -289,29 +289,68 @@ struct address_space;
 struct writeback_control;
 
 struct iov_iter {
-	const struct iovec *iov;
+	struct iov_iter_ops *ops;
+	unsigned long data;
 	unsigned long nr_segs;
 	size_t iov_offset;
 	size_t count;
 };
 
-size_t iov_iter_copy_to_user_atomic(struct page *page,
-		struct iov_iter *i, unsigned long offset, size_t bytes);
-size_t iov_iter_copy_to_user(struct page *page,
-		struct iov_iter *i, unsigned long offset, size_t bytes);
-size_t iov_iter_copy_from_user_atomic(struct page *page,
-		struct iov_iter *i, unsigned long offset, size_t bytes);
-size_t iov_iter_copy_from_user(struct page *page,
-		struct iov_iter *i, unsigned long offset, size_t bytes);
-void iov_iter_advance(struct iov_iter *i, size_t bytes);
-int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
-size_t iov_iter_single_seg_count(struct iov_iter *i);
+struct iov_iter_ops {
+	size_t (*ii_copy_to_user_atomic)(struct page *, struct iov_iter *,
+					 unsigned long, size_t);
+	size_t (*ii_copy_to_user)(struct page *, struct iov_iter *,
+				  unsigned long, size_t);
+	size_t (*ii_copy_from_user_atomic)(struct page *, struct iov_iter *,
+					   unsigned long, size_t);
+	size_t (*ii_copy_from_user)(struct page *, struct iov_iter *,
+					  unsigned long, size_t);
+	void (*ii_advance)(struct iov_iter *, size_t);
+	int (*ii_fault_in_readable)(struct iov_iter *, size_t);
+	size_t (*ii_single_seg_count)(struct iov_iter *);
+};
+
+static inline size_t iov_iter_copy_to_user_atomic(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	return i->ops->ii_copy_to_user_atomic(page, i, offset, bytes);
+}
+static inline size_t iov_iter_copy_to_user(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	return i->ops->ii_copy_to_user(page, i, offset, bytes);
+}
+static inline size_t iov_iter_copy_from_user_atomic(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	return i->ops->ii_copy_from_user_atomic(page, i, offset, bytes);
+}
+static inline size_t iov_iter_copy_from_user(struct page *page,
+		struct iov_iter *i, unsigned long offset, size_t bytes)
+{
+	return i->ops->ii_copy_from_user(page, i, offset, bytes);
+}
+static inline void iov_iter_advance(struct iov_iter *i, size_t bytes)
+{
+	return i->ops->ii_advance(i, bytes);
+}
+static inline int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
+{
+	return i->ops->ii_fault_in_readable(i, bytes);
+}
+static inline size_t iov_iter_single_seg_count(struct iov_iter *i)
+{
+	return i->ops->ii_single_seg_count(i);
+}
+
+extern struct iov_iter_ops ii_iovec_ops;
 
 static inline void iov_iter_init(struct iov_iter *i,
 			const struct iovec *iov, unsigned long nr_segs,
 			size_t count, size_t written)
 {
-	i->iov = iov;
+	i->ops = &ii_iovec_ops;
+	i->data = (unsigned long)iov;
 	i->nr_segs = nr_segs;
 	i->iov_offset = 0;
 	i->count = count + written;
@@ -319,6 +358,11 @@ static inline void iov_iter_init(struct iov_iter *i,
 	iov_iter_advance(i, written);
 }
 
+static inline struct iovec *iov_iter_iovec(struct iov_iter *i)
+{
+	return (struct iovec *)i->data;
+}
+
 static inline size_t iov_iter_count(struct iov_iter *i)
 {
 	return i->count;
-- 
1.8.1.1

[PATCH V6 06/30] iov_iter: add bvec support

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

This adds a set of iov_iter_ops calls which work with memory which is
specified by an array of bio_vec structs instead of an array of iovec
structs.

The big difference is that the pages referenced by the bio_vec elements
are pinned.  They don't need to be faulted in and we can always use
kmap_atomic() to map them one at a time.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
 fs/iov-iter.c      | 128 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/fs.h |  19 ++++++++
 2 files changed, 147 insertions(+)

diff --git a/fs/iov-iter.c b/fs/iov-iter.c
index bae1553..22ef9ca 100644
--- a/fs/iov-iter.c
+++ b/fs/iov-iter.c
@@ -5,6 +5,7 @@
 #include <linux/hardirq.h>
 #include <linux/highmem.h>
 #include <linux/pagemap.h>
+#include <linux/bio.h>
 
 static size_t __iovec_copy_to_user(char *vaddr, const struct iovec *iov,
 				   size_t base, size_t bytes, int atomic)
@@ -86,6 +87,133 @@ static size_t ii_iovec_copy_to_user(struct page *page,
 	return copied;
 }
 
+#ifdef CONFIG_BLOCK
+/*
+ * As an easily verifiable first pass, we implement all the methods that
+ * copy data to and from bvec pages with one function.  We implement it
+ * all with kmap_atomic().
+ */
+static size_t bvec_copy_tofrom_page(struct iov_iter *iter, struct page *page,
+				    unsigned long page_offset, size_t bytes,
+				    int topage)
+{
+	struct bio_vec *bvec = (struct bio_vec *)iter->data;
+	size_t bvec_offset = iter->iov_offset;
+	size_t remaining = bytes;
+	void *bvec_map;
+	void *page_map;
+	size_t copy;
+
+	page_map = kmap_atomic(page);
+
+	BUG_ON(bytes > iter->count);
+	while (remaining) {
+		BUG_ON(bvec->bv_len == 0);
+		BUG_ON(bvec_offset >= bvec->bv_len);
+		copy = min(remaining, bvec->bv_len - bvec_offset);
+		bvec_map = kmap_atomic(bvec->bv_page);
+		if (topage)
+			memcpy(page_map + page_offset,
+			       bvec_map + bvec->bv_offset + bvec_offset,
+			       copy);
+		else
+			memcpy(bvec_map + bvec->bv_offset + bvec_offset,
+			       page_map + page_offset,
+			       copy);
+		kunmap_atomic(bvec_map);
+		remaining -= copy;
+		bvec_offset += copy;
+		page_offset += copy;
+		if (bvec_offset == bvec->bv_len) {
+			bvec_offset = 0;
+			bvec++;
+		}
+	}
+
+	kunmap_atomic(page_map);
+
+	return bytes;
+}
+
+static size_t ii_bvec_copy_to_user_atomic(struct page *page, struct iov_iter *i,
+					  unsigned long offset, size_t bytes)
+{
+	return bvec_copy_tofrom_page(i, page, offset, bytes, 0);
+}
+static size_t ii_bvec_copy_to_user(struct page *page, struct iov_iter *i,
+				   unsigned long offset, size_t bytes)
+{
+	return bvec_copy_tofrom_page(i, page, offset, bytes, 0);
+}
+static size_t ii_bvec_copy_from_user_atomic(struct page *page,
+					    struct iov_iter *i,
+					    unsigned long offset, size_t bytes)
+{
+	return bvec_copy_tofrom_page(i, page, offset, bytes, 1);
+}
+static size_t ii_bvec_copy_from_user(struct page *page, struct iov_iter *i,
+				     unsigned long offset, size_t bytes)
+{
+	return bvec_copy_tofrom_page(i, page, offset, bytes, 1);
+}
+
+/*
+ * bio_vecs have a stricter structure than iovecs that might have
+ * come from userspace.  There are no zero length bio_vec elements.
+ */
+static void ii_bvec_advance(struct iov_iter *i, size_t bytes)
+{
+	struct bio_vec *bvec = (struct bio_vec *)i->data;
+	size_t offset = i->iov_offset;
+	size_t delta;
+
+	BUG_ON(i->count < bytes);
+	while (bytes) {
+		BUG_ON(bvec->bv_len == 0);
+		BUG_ON(bvec->bv_len <= offset);
+		delta = min(bytes, bvec->bv_len - offset);
+		offset += delta;
+		i->count -= delta;
+		bytes -= delta;
+		if (offset == bvec->bv_len) {
+			bvec++;
+			offset = 0;
+		}
+	}
+
+	i->data = (unsigned long)bvec;
+	i->iov_offset = offset;
+}
+
+/*
+ * pages pointed to by bio_vecs are always pinned.
+ */
+static int ii_bvec_fault_in_readable(struct iov_iter *i, size_t bytes)
+{
+	return 0;
+}
+
+static size_t ii_bvec_single_seg_count(struct iov_iter *i)
+{
+	const struct bio_vec *bvec = (struct bio_vec *)i->data;
+	if (i->nr_segs == 1)
+		return i->count;
+	else
+		return min(i->count, bvec->bv_len - i->iov_offset);
+}
+
+struct iov_iter_ops ii_bvec_ops = {
+	.ii_copy_to_user_atomic = ii_bvec_copy_to_user_atomic,
+	.ii_copy_to_user = ii_bvec_copy_to_user,
+	.ii_copy_from_user_atomic = ii_bvec_copy_from_user_atomic,
+	.ii_copy_from_user = ii_bvec_copy_from_user,
+	.ii_advance = ii_bvec_advance,
+	.ii_fault_in_readable = ii_bvec_fault_in_readable,
+	.ii_single_seg_count = ii_bvec_single_seg_count,
+};
+EXPORT_SYMBOL(ii_bvec_ops);
+#endif	/* CONFIG_BLOCK */
+
 static size_t __iovec_copy_from_user(char *vaddr, const struct iovec *iov,
 				     size_t base, size_t bytes, int atomic)
 {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5618301..955d79e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -343,6 +343,25 @@ static inline size_t iov_iter_single_seg_count(struct iov_iter *i)
 	return i->ops->ii_single_seg_count(i);
 }
 
+#ifdef CONFIG_BLOCK
+extern struct iov_iter_ops ii_bvec_ops;
+
+struct bio_vec;
+static inline void iov_iter_init_bvec(struct iov_iter *i,
+				      struct bio_vec *bvec,
+				      unsigned long nr_segs,
+				      size_t count, size_t written)
+{
+	i->ops = &ii_bvec_ops;
+	i->data = (unsigned long)bvec;
+	i->nr_segs = nr_segs;
+	i->iov_offset = 0;
+	i->count = count + written;
+
+	iov_iter_advance(i, written);
+}
+#endif
+
 extern struct iov_iter_ops ii_iovec_ops;
 
 static inline void iov_iter_init(struct iov_iter *i,
-- 
1.8.1.1

[PATCH V6 07/30] iov_iter: add a shorten call

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

The generic direct write path wants to shorten its memory vector.  It
does this when it finds that it has to perform a partial write due to
LIMIT_FSIZE.  .direct_IO() always performs IO on all of the referenced
memory because it doesn't have an argument to specify the length of the
IO.

We add an iov_iter operation for this so that the generic path can ask
to shorten the memory vector without having to know what kind it is.
We're happy to shorten the kernel copy of the iovec array, but we refuse
to shorten the bio_vec array and return an error in this case.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
 fs/iov-iter.c      | 14 ++++++++++++++
 include/linux/fs.h |  5 +++++
 2 files changed, 19 insertions(+)

diff --git a/fs/iov-iter.c b/fs/iov-iter.c
index 22ef9ca..ac2d96e 100644
--- a/fs/iov-iter.c
+++ b/fs/iov-iter.c
@@ -202,6 +202,11 @@ static size_t ii_bvec_single_seg_count(struct iov_iter *i)
 		return min(i->count, bvec->bv_len - i->iov_offset);
 }
 
+static int ii_bvec_shorten(struct iov_iter *i, size_t count)
+{
+	return -EINVAL;
+}
+
 struct iov_iter_ops ii_bvec_ops = {
 	.ii_copy_to_user_atomic = ii_bvec_copy_to_user_atomic,
 	.ii_copy_to_user = ii_bvec_copy_to_user,
@@ -210,6 +215,7 @@ struct iov_iter_ops ii_bvec_ops = {
 	.ii_advance = ii_bvec_advance,
 	.ii_fault_in_readable = ii_bvec_fault_in_readable,
 	.ii_single_seg_count = ii_bvec_single_seg_count,
+	.ii_shorten = ii_bvec_shorten,
 };
 EXPORT_SYMBOL(ii_bvec_ops);
 #endif	/* CONFIG_BLOCK */
@@ -360,6 +366,13 @@ static size_t ii_iovec_single_seg_count(struct iov_iter *i)
 		return min(i->count, iov->iov_len - i->iov_offset);
 }
 
+static int ii_iovec_shorten(struct iov_iter *i, size_t count)
+{
+	struct iovec *iov = (struct iovec *)i->data;
+	i->nr_segs = iov_shorten(iov, i->nr_segs, count);
+	return 0;
+}
+
 struct iov_iter_ops ii_iovec_ops = {
 	.ii_copy_to_user_atomic = ii_iovec_copy_to_user_atomic,
 	.ii_copy_to_user = ii_iovec_copy_to_user,
@@ -368,5 +381,6 @@ struct iov_iter_ops ii_iovec_ops = {
 	.ii_advance = ii_iovec_advance,
 	.ii_fault_in_readable = ii_iovec_fault_in_readable,
 	.ii_single_seg_count = ii_iovec_single_seg_count,
+	.ii_shorten = ii_iovec_shorten,
 };
 EXPORT_SYMBOL(ii_iovec_ops);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 955d79e..cc4ed53 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -308,6 +308,7 @@ struct iov_iter_ops {
 	void (*ii_advance)(struct iov_iter *, size_t);
 	int (*ii_fault_in_readable)(struct iov_iter *, size_t);
 	size_t (*ii_single_seg_count)(struct iov_iter *);
+	int (*ii_shorten)(struct iov_iter *, size_t);
 };
 
 static inline size_t iov_iter_copy_to_user_atomic(struct page *page,
@@ -342,6 +343,10 @@ static inline size_t iov_iter_single_seg_count(struct iov_iter *i)
 {
 	return i->ops->ii_single_seg_count(i);
 }
+static inline int iov_iter_shorten(struct iov_iter *i, size_t count)
+{
+	return i->ops->ii_shorten(i, count);
+}
 
 #ifdef CONFIG_BLOCK
 extern struct iov_iter_ops ii_bvec_ops;
-- 
1.8.1.1

[PATCH V6 08/30] iov_iter: let callers extract iovecs and bio_vecs

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

direct IO treats memory from user iovecs and memory from arrays of
kernel pages very differently.  User memory is pinned and worked with in
batches while kernel pages are always pinned and don't require
additional processing.

Rather than try and provide an abstraction that includes these
different behaviours we let direct IO extract the memory structs and
hand them to the existing code.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
 include/linux/fs.h | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/include/linux/fs.h b/include/linux/fs.h
index cc4ed53..eb564d1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -365,6 +365,17 @@ static inline void iov_iter_init_bvec(struct iov_iter *i,
 
 	iov_iter_advance(i, written);
 }
+
+static inline int iov_iter_has_bvec(struct iov_iter *i)
+{
+	return i->ops == &ii_bvec_ops;
+}
+
+static inline struct bio_vec *iov_iter_bvec(struct iov_iter *i)
+{
+	BUG_ON(!iov_iter_has_bvec(i));
+	return (struct bio_vec *)i->data;
+}
 #endif
 
 extern struct iov_iter_ops ii_iovec_ops;
@@ -382,8 +393,14 @@ static inline void iov_iter_init(struct iov_iter *i,
 	iov_iter_advance(i, written);
 }
 
+static inline int iov_iter_has_iovec(struct iov_iter *i)
+{
+	return i->ops == &ii_iovec_ops;
+}
+
 static inline struct iovec *iov_iter_iovec(struct iov_iter *i)
 {
+	BUG_ON(!iov_iter_has_iovec(i));
 	return (struct iovec *)i->data;
 }
 
-- 
1.8.1.1

[PATCH V6 10/30] dio: add bio_vec support to __blockdev_direct_IO()

[Dave Kleikamp]

The trick here is to initialize the dio state so that do_direct_IO()
consumes the pages we provide and never tries to map user pages.  This
is done by making sure that final_block_in_request covers the page that
we set in the dio.  do_direct_IO() will return before running out of
pages.

The caller is responsible for dirtying these pages, if needed.  We add
an option to the dio struct that makes sure we only dirty pages when
we're operating on iovecs of user addresses.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
 fs/direct-io.c | 206 +++++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 148 insertions(+), 58 deletions(-)

diff --git a/fs/direct-io.c b/fs/direct-io.c
index b97a202..63e5a17 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -126,6 +126,7 @@ struct dio {
 	spinlock_t bio_lock;		/* protects BIO fields below */
 	int page_errors;		/* errno from get_user_pages() */
 	int is_async;			/* is IO async ? */
+	int should_dirty;		/* should we mark read pages dirty? */
 	int io_error;			/* IO error in completion path */
 	unsigned long refcount;		/* direct_io_worker() and bios */
 	struct bio *bio_list;		/* singly linked via bi_private */
@@ -376,7 +377,7 @@ static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
 	dio->refcount++;
 	spin_unlock_irqrestore(&dio->bio_lock, flags);
 
-	if (dio->is_async && dio->rw == READ)
+	if (dio->is_async && dio->rw == READ && dio->should_dirty)
 		bio_set_pages_dirty(bio);
 
 	if (sdio->submit_io)
@@ -447,13 +448,14 @@ static int dio_bio_complete(struct dio *dio, struct bio *bio)
 	if (!uptodate)
 		dio->io_error = -EIO;
 
-	if (dio->is_async && dio->rw == READ) {
+	if (dio->is_async && dio->rw == READ && dio->should_dirty) {
 		bio_check_pages_dirty(bio);	/* transfers ownership */
 	} else {
 		for (page_no = 0; page_no < bio->bi_vcnt; page_no++) {
 			struct page *page = bvec[page_no].bv_page;
 
-			if (dio->rw == READ && !PageCompound(page))
+			if (dio->rw == READ && !PageCompound(page) &&
+			    dio->should_dirty)
 				set_page_dirty_lock(page);
 			page_cache_release(page);
 		}
@@ -1020,6 +1022,101 @@ static inline int drop_refcount(struct dio *dio)
 	return ret2;
 }
 
+static ssize_t direct_IO_iovec(const struct iovec *iov, unsigned long nr_segs,
+			       struct dio *dio, struct dio_submit *sdio,
+			       unsigned blkbits, struct buffer_head *map_bh)
+{
+	size_t bytes;
+	ssize_t retval = 0;
+	int seg;
+	unsigned long user_addr;
+
+	for (seg = 0; seg < nr_segs; seg++) {
+		user_addr = (unsigned long)iov[seg].iov_base;
+		sdio->pages_in_io +=
+			((user_addr + iov[seg].iov_len + PAGE_SIZE-1) /
+				PAGE_SIZE - user_addr / PAGE_SIZE);
+	}
+
+	dio->should_dirty = 1;
+
+	for (seg = 0; seg < nr_segs; seg++) {
+		user_addr = (unsigned long)iov[seg].iov_base;
+		sdio->size += bytes = iov[seg].iov_len;
+
+		/* Index into the first page of the first block */
+		sdio->first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits;
+		sdio->final_block_in_request = sdio->block_in_file +
+						(bytes >> blkbits);
+		/* Page fetching state */
+		sdio->head = 0;
+		sdio->tail = 0;
+		sdio->curr_page = 0;
+
+		sdio->total_pages = 0;
+		if (user_addr & (PAGE_SIZE-1)) {
+			sdio->total_pages++;
+			bytes -= PAGE_SIZE - (user_addr & (PAGE_SIZE - 1));
+		}
+		sdio->total_pages += (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
+		sdio->curr_user_address = user_addr;
+
+		retval = do_direct_IO(dio, sdio, map_bh);
+
+		dio->result += iov[seg].iov_len -
+			((sdio->final_block_in_request - sdio->block_in_file) <<
+					blkbits);
+
+		if (retval) {
+			dio_cleanup(dio, sdio);
+			break;
+		}
+	} /* end iovec loop */
+
+	return retval;
+}
+
+static ssize_t direct_IO_bvec(struct bio_vec *bvec, unsigned long nr_segs,
+			      struct dio *dio, struct dio_submit *sdio,
+			      unsigned blkbits, struct buffer_head *map_bh)
+{
+	ssize_t retval = 0;
+	int seg;
+
+	sdio->pages_in_io += nr_segs;
+
+	for (seg = 0; seg < nr_segs; seg++) {
+		sdio->size += bvec[seg].bv_len;
+
+		/* Index into the first page of the first block */
+		sdio->first_block_in_page = bvec[seg].bv_offset >> blkbits;
+		sdio->final_block_in_request = sdio->block_in_file +
+						(bvec[seg].bv_len  >> blkbits);
+		/* Page fetching state */
+		sdio->curr_page = 0;
+		page_cache_get(bvec[seg].bv_page);
+		dio->pages[0] = bvec[seg].bv_page;
+		sdio->head = 0;
+		sdio->tail = 1;
+
+		sdio->total_pages = 1;
+		sdio->curr_user_address = 0;
+
+		retval = do_direct_IO(dio, sdio, map_bh);
+
+		dio->result += bvec[seg].bv_len -
+			((sdio->final_block_in_request - sdio->block_in_file) <<
+					blkbits);
+
+		if (retval) {
+			dio_cleanup(dio, sdio);
+			break;
+		}
+	}
+
+	return retval;
+}
+
 /*
  * This is a library function for use by filesystem drivers.
  *
@@ -1061,11 +1158,8 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
 	loff_t end = offset;
 	struct dio *dio;
 	struct dio_submit sdio = { 0, };
-	unsigned long user_addr;
-	size_t bytes;
 	struct buffer_head map_bh = { 0, };
 	struct blk_plug plug;
-	const struct iovec *iov = iov_iter_iovec(iter);
 	unsigned long nr_segs = iter->nr_segs;
 
 	if (rw & WRITE)
@@ -1085,20 +1179,49 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
 	}
 
 	/* Check the memory alignment.  Blocks cannot straddle pages */
-	for (seg = 0; seg < nr_segs; seg++) {
-		addr = (unsigned long)iov[seg].iov_base;
-		size = iov[seg].iov_len;
-		end += size;
-		if (unlikely((addr & blocksize_mask) ||
-			     (size & blocksize_mask))) {
-			if (bdev)
-				blkbits = blksize_bits(
-					 bdev_logical_block_size(bdev));
-			blocksize_mask = (1 << blkbits) - 1;
-			if ((addr & blocksize_mask) || (size & blocksize_mask))
-				goto out;
+	if (iov_iter_has_iovec(iter)) {
+		const struct iovec *iov = iov_iter_iovec(iter);
+
+		for (seg = 0; seg < nr_segs; seg++) {
+			addr = (unsigned long)iov[seg].iov_base;
+			size = iov[seg].iov_len;
+			end += size;
+			if (unlikely((addr & blocksize_mask) ||
+				     (size & blocksize_mask))) {
+				if (bdev)
+					blkbits = blksize_bits(
+						 bdev_logical_block_size(bdev));
+				blocksize_mask = (1 << blkbits) - 1;
+				if ((addr & blocksize_mask) ||
+				    (size & blocksize_mask))
+					goto out;
+			}
 		}
-	}
+	} else if (iov_iter_has_bvec(iter)) {
+		/*
+		 * Is this necessary, or can we trust the in-kernel
+		 * caller? Can we replace this with
+		 *	end += iov_iter_count(iter); ?
+		 */
+		struct bio_vec *bvec = iov_iter_bvec(iter);
+
+		for (seg = 0; seg < nr_segs; seg++) {
+			addr = bvec[seg].bv_offset;
+			size = bvec[seg].bv_len;
+			end += size;
+			if (unlikely((addr & blocksize_mask) ||
+				     (size & blocksize_mask))) {
+				if (bdev)
+					blkbits = blksize_bits(
+						 bdev_logical_block_size(bdev));
+				blocksize_mask = (1 << blkbits) - 1;
+				if ((addr & blocksize_mask) ||
+				    (size & blocksize_mask))
+					goto out;
+			}
+		}
+	} else
+		BUG();
 
 	/* watch out for a 0 len io from a tricksy fs */
 	if (rw == READ && end == offset)
@@ -1175,47 +1298,14 @@ do_blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
 	if (unlikely(sdio.blkfactor))
 		sdio.pages_in_io = 2;
 
-	for (seg = 0; seg < nr_segs; seg++) {
-		user_addr = (unsigned long)iov[seg].iov_base;
-		sdio.pages_in_io +=
-			((user_addr + iov[seg].iov_len + PAGE_SIZE-1) /
-				PAGE_SIZE - user_addr / PAGE_SIZE);
-	}
-
 	blk_start_plug(&plug);
 
-	for (seg = 0; seg < nr_segs; seg++) {
-		user_addr = (unsigned long)iov[seg].iov_base;
-		sdio.size += bytes = iov[seg].iov_len;
-
-		/* Index into the first page of the first block */
-		sdio.first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits;
-		sdio.final_block_in_request = sdio.block_in_file +
-						(bytes >> blkbits);
-		/* Page fetching state */
-		sdio.head = 0;
-		sdio.tail = 0;
-		sdio.curr_page = 0;
-
-		sdio.total_pages = 0;
-		if (user_addr & (PAGE_SIZE-1)) {
-			sdio.total_pages++;
-			bytes -= PAGE_SIZE - (user_addr & (PAGE_SIZE - 1));
-		}
-		sdio.total_pages += (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
-		sdio.curr_user_address = user_addr;
-
-		retval = do_direct_IO(dio, &sdio, &map_bh);
-
-		dio->result += iov[seg].iov_len -
-			((sdio.final_block_in_request - sdio.block_in_file) <<
-					blkbits);
-
-		if (retval) {
-			dio_cleanup(dio, &sdio);
-			break;
-		}
-	} /* end iovec loop */
+	if (iov_iter_has_iovec(iter))
+		retval = direct_IO_iovec(iov_iter_iovec(iter), nr_segs, dio,
+					 &sdio, blkbits, &map_bh);
+	else
+		retval = direct_IO_bvec(iov_iter_bvec(iter), nr_segs, dio,
+					&sdio, blkbits, &map_bh);
 
 	if (retval == -ENOTBLK) {
 		/*
-- 
1.8.1.1

[PATCH V6 11/30] fs: pull iov_iter use higher up the stack

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

Right now only callers of generic_perform_write() pack their iovec
arguments into an iov_iter structure.  All the callers higher up in the
stack work on raw iovec arguments.

This patch introduces the use of the iov_iter abstraction higher up the
stack.  Private generic path functions are changed to operation on
iov_iter instead of on raw iovecs.  Exported interfaces that take iovecs
immediately pack their arguments into an iov_iter and call into the
shared functions.

File operation struct functions are added with iov_iter as an argument
so that callers to the generic file system functions can specify
abstract memory rather than iovec arrays only.

Almost all of this patch only transforms arguments and shouldn't change
functionality.  The buffered read path is the exception.  We add a
read_actor function which uses the iov_iter helper functions instead of
operating on each individual iovec element.  This may improve
performance as the iov_iter helper can copy multiple iovec elements from
one mapped page cache page.

As always, the direct IO path is special.  Sadly, it may still be
cleanest to have it work on the underlying memory structures directly
instead of working through the iov_iter abstraction.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
 Documentation/filesystems/Locking |   2 +
 Documentation/filesystems/vfs.txt |   8 ++
 include/linux/fs.h                |  12 ++
 mm/filemap.c                      | 258 +++++++++++++++++++++++++-------------
 4 files changed, 190 insertions(+), 90 deletions(-)

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 509bf38..eb6491b 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -411,7 +411,9 @@ prototypes:
 	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
 	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
 	ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
+	ssize_t (*read_iter) (struct kiocb *, struct iov_iter *, loff_t);
 	ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
+	ssize_t (*write_iter) (struct kiocb *, struct iov_iter *, loff_t);
 	int (*readdir) (struct file *, void *, filldir_t);
 	unsigned int (*poll) (struct file *, struct poll_table_struct *);
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index abe11d8..452cff5 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -776,7 +776,9 @@ struct file_operations {
 	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
 	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
 	ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
+	ssize_t (*read_iter) (struct kiocb *, struct iov_iter *, loff_t);
 	ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
+	ssize_t (*write_iter) (struct kiocb *, struct iov_iter *, loff_t);
 	int (*readdir) (struct file *, void *, filldir_t);
 	unsigned int (*poll) (struct file *, struct poll_table_struct *);
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
@@ -811,10 +813,16 @@ otherwise noted.
 
   aio_read: called by io_submit(2) and other asynchronous I/O operations
 
+  read_iter: aio_read replacement, called by io_submit(2) and other
+	asynchronous I/O operations
+
   write: called by write(2) and related system calls
 
   aio_write: called by io_submit(2) and other asynchronous I/O operations
 
+  write_iter: aio_write replacement, called by io_submit(2) and other
+	asynchronous I/O operations
+
   readdir: called when the VFS needs to read the directory contents
 
   poll: called by the VFS when a process wants to check if there is
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 44cd365..ee9184e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1607,7 +1607,9 @@ struct file_operations {
 	ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
 	ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
 	ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
+	ssize_t (*read_iter) (struct kiocb *, struct iov_iter *, loff_t);
 	ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
+	ssize_t (*write_iter) (struct kiocb *, struct iov_iter *, loff_t);
 	int (*readdir) (struct file *, void *, filldir_t);
 	unsigned int (*poll) (struct file *, struct poll_table_struct *);
 	long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
@@ -2450,13 +2452,23 @@ extern int generic_file_remap_pages(struct vm_area_struct *, unsigned long addr,
 extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size);
 int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk);
 extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
+extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *,
+		loff_t);
 extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long,
 		loff_t *);
+extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *,
+		loff_t *);
 extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
+extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *,
+		loff_t);
 extern ssize_t generic_file_direct_write(struct kiocb *, const struct iovec *,
 		unsigned long *, loff_t, loff_t *, size_t, size_t);
+extern ssize_t generic_file_direct_write_iter(struct kiocb *, struct iov_iter *,
+		loff_t, loff_t *, size_t);
 extern ssize_t generic_file_buffered_write(struct kiocb *, const struct iovec *,
 		unsigned long, loff_t, loff_t *, size_t, ssize_t);
+extern ssize_t generic_file_buffered_write_iter(struct kiocb *,
+		struct iov_iter *, loff_t, loff_t *, size_t, ssize_t);
 extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos);
 extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos);
 extern int generic_segment_checks(const struct iovec *iov,
diff --git a/mm/filemap.c b/mm/filemap.c
index d428020..0d426d9 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1372,31 +1372,41 @@ int generic_segment_checks(const struct iovec *iov,
 }
 EXPORT_SYMBOL(generic_segment_checks);
 
+static int file_read_iter_actor(read_descriptor_t *desc, struct page *page,
+				unsigned long offset, unsigned long size)
+{
+	struct iov_iter *iter = desc->arg.data;
+	unsigned long copied = 0;
+
+	if (size > desc->count)
+		size = desc->count;
+
+	copied = iov_iter_copy_to_user(page, iter, offset, size);
+	if (copied < size)
+		desc->error = -EFAULT;
+
+	iov_iter_advance(iter, copied);
+	desc->count -= copied;
+	desc->written += copied;
+
+	return copied;
+}
+
 /**
- * generic_file_aio_read - generic filesystem read routine
+ * generic_file_read_iter - generic filesystem read routine
  * @iocb:	kernel I/O control block
- * @iov:	io vector request
- * @nr_segs:	number of segments in the iovec
+ * @iov_iter:	memory vector
  * @pos:	current file position
- *
- * This is the "read()" routine for all filesystems
- * that can use the page cache directly.
  */
 ssize_t
-generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
-		unsigned long nr_segs, loff_t pos)
+generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
 {
 	struct file *filp = iocb->ki_filp;
-	ssize_t retval;
-	unsigned long seg = 0;
-	size_t count;
+	read_descriptor_t desc;
+	ssize_t retval = 0;
+	size_t count = iov_iter_count(iter);
 	loff_t *ppos = &iocb->ki_pos;
 
-	count = 0;
-	retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
-	if (retval)
-		return retval;
-
 	/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
 	if (filp->f_flags & O_DIRECT) {
 		loff_t size;
@@ -1409,16 +1419,11 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 			goto out; /* skip atime */
 		size = i_size_read(inode);
 		if (pos < size) {
-			size_t bytes = iov_length(iov, nr_segs);
 			retval = filemap_write_and_wait_range(mapping, pos,
-					pos + bytes - 1);
-			if (!retval) {
-				struct iov_iter iter;
-
-				iov_iter_init(&iter, iov, nr_segs, bytes, 0);
+					pos + count - 1);
+			if (!retval)
 				retval = mapping->a_ops->direct_IO(READ, iocb,
-							&iter, pos);
-			}
+								   iter, pos);
 			if (retval > 0) {
 				*ppos = pos + retval;
 				count -= retval;
@@ -1439,42 +1444,47 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 		}
 	}
 
-	count = retval;
-	for (seg = 0; seg < nr_segs; seg++) {
-		read_descriptor_t desc;
-		loff_t offset = 0;
-
-		/*
-		 * If we did a short DIO read we need to skip the section of the
-		 * iov that we've already read data into.
-		 */
-		if (count) {
-			if (count > iov[seg].iov_len) {
-				count -= iov[seg].iov_len;
-				continue;
-			}
-			offset = count;
-			count = 0;
-		}
-
-		desc.written = 0;
-		desc.arg.buf = iov[seg].iov_base + offset;
-		desc.count = iov[seg].iov_len - offset;
-		if (desc.count == 0)
-			continue;
-		desc.error = 0;
-		do_generic_file_read(filp, ppos, &desc, file_read_actor);
-		retval += desc.written;
-		if (desc.error) {
-			retval = retval ?: desc.error;
-			break;
-		}
-		if (desc.count > 0)
-			break;
-	}
+	desc.written = 0;
+	desc.arg.data = iter;
+	desc.count = count;
+	desc.error = 0;
+	do_generic_file_read(filp, ppos, &desc, file_read_iter_actor);
+	if (desc.written)
+		retval = desc.written;
+	else
+		retval = desc.error;
 out:
 	return retval;
 }
+EXPORT_SYMBOL(generic_file_read_iter);
+
+/**
+ * generic_file_aio_read - generic filesystem read routine
+ * @iocb:      kernel I/O control block
+ * @iov:       io vector request
+ * @nr_segs:   number of segments in the iovec
+ * @pos:       current file position
+ *
+ * This is the "read()" routine for all filesystems
+ * that can use the page cache directly.
+ */
+ssize_t
+generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
+		unsigned long nr_segs, loff_t pos)
+{
+	struct iov_iter iter;
+	int ret;
+	size_t count;
+
+	count = 0;
+	ret = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
+	if (ret)
+		return ret;
+
+	iov_iter_init(&iter, iov, nr_segs, count, 0);
+
+	return generic_file_read_iter(iocb, &iter, pos);
+}
 EXPORT_SYMBOL(generic_file_aio_read);
 
 #ifdef CONFIG_MMU
@@ -2031,9 +2041,8 @@ int pagecache_write_end(struct file *file, struct address_space *mapping,
 EXPORT_SYMBOL(pagecache_write_end);
 
 ssize_t
-generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
-		unsigned long *nr_segs, loff_t pos, loff_t *ppos,
-		size_t count, size_t ocount)
+generic_file_direct_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+		loff_t pos, loff_t *ppos, size_t count)
 {
 	struct file	*file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
@@ -2041,12 +2050,14 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
 	ssize_t		written;
 	size_t		write_len;
 	pgoff_t		end;
-	struct iov_iter iter;
 
-	if (count != ocount)
-		*nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count);
+	if (count != iov_iter_count(iter)) {
+		written = iov_iter_shorten(iter, count);
+		if (written)
+			goto out;
+	}
 
-	write_len = iov_length(iov, *nr_segs);
+	write_len = count;
 	end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT;
 
 	written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1);
@@ -2073,9 +2084,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
 		}
 	}
 
-	iov_iter_init(&iter, iov, *nr_segs, write_len, 0);
-
-	written = mapping->a_ops->direct_IO(WRITE, iocb, &iter, pos);
+	written = mapping->a_ops->direct_IO(WRITE, iocb, iter, pos);
 
 	/*
 	 * Finally, try again to invalidate clean pages which might have been
@@ -2101,6 +2110,23 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
 out:
 	return written;
 }
+EXPORT_SYMBOL(generic_file_direct_write_iter);
+
+ssize_t
+generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
+		unsigned long *nr_segs, loff_t pos, loff_t *ppos,
+		size_t count, size_t ocount)
+{
+	struct iov_iter iter;
+	ssize_t ret;
+
+	iov_iter_init(&iter, iov, *nr_segs, ocount, 0);
+	ret = generic_file_direct_write_iter(iocb, &iter, pos, ppos, count);
+	/* generic_file_direct_write_iter() might have shortened the vec */
+	if (*nr_segs != iter.nr_segs)
+		*nr_segs = iter.nr_segs;
+	return ret;
+}
 EXPORT_SYMBOL(generic_file_direct_write);
 
 /*
@@ -2234,16 +2260,19 @@ again:
 }
 
 ssize_t
-generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
-		unsigned long nr_segs, loff_t pos, loff_t *ppos,
-		size_t count, ssize_t written)
+generic_file_buffered_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+		loff_t pos, loff_t *ppos, size_t count, ssize_t written)
 {
 	struct file *file = iocb->ki_filp;
 	ssize_t status;
-	struct iov_iter i;
 
-	iov_iter_init(&i, iov, nr_segs, count, written);
-	status = generic_perform_write(file, &i, pos);
+	if ((count + written) != iov_iter_count(iter)) {
+		int rc = iov_iter_shorten(iter, count + written);
+		if (rc)
+			return rc;
+	}
+
+	status = generic_perform_write(file, iter, pos);
 
 	if (likely(status >= 0)) {
 		written += status;
@@ -2252,13 +2281,24 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 	
 	return written ? written : status;
 }
+EXPORT_SYMBOL(generic_file_buffered_write_iter);
+
+ssize_t
+generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
+		unsigned long nr_segs, loff_t pos, loff_t *ppos,
+		size_t count, ssize_t written)
+{
+	struct iov_iter iter;
+	iov_iter_init(&iter, iov, nr_segs, count, written);
+	return generic_file_buffered_write_iter(iocb, &iter, pos, ppos,
+						count, written);
+}
 EXPORT_SYMBOL(generic_file_buffered_write);
 
 /**
  * __generic_file_aio_write - write data to a file
  * @iocb:	IO state structure (file, offset, etc.)
- * @iov:	vector with data to write
- * @nr_segs:	number of segments in the vector
+ * @iter:	iov_iter specifying memory to write
  * @ppos:	position where to write
  *
  * This function does all the work needed for actually writing data to a
@@ -2273,24 +2313,18 @@ EXPORT_SYMBOL(generic_file_buffered_write);
  * A caller has to handle it. This is mainly due to the fact that we want to
  * avoid syncing under i_mutex.
  */
-ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
-				 unsigned long nr_segs, loff_t *ppos)
+ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+				  loff_t *ppos)
 {
 	struct file *file = iocb->ki_filp;
 	struct address_space * mapping = file->f_mapping;
-	size_t ocount;		/* original count */
 	size_t count;		/* after file limit checks */
 	struct inode 	*inode = mapping->host;
 	loff_t		pos;
 	ssize_t		written;
 	ssize_t		err;
 
-	ocount = 0;
-	err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
-	if (err)
-		return err;
-
-	count = ocount;
+	count = iov_iter_count(iter);
 	pos = *ppos;
 
 	/* We can write back this queue in page reclaim */
@@ -2317,8 +2351,8 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		loff_t endbyte;
 		ssize_t written_buffered;
 
-		written = generic_file_direct_write(iocb, iov, &nr_segs, pos,
-							ppos, count, ocount);
+		written = generic_file_direct_write_iter(iocb, iter, pos,
+							 ppos, count);
 		if (written < 0 || written == count)
 			goto out;
 		/*
@@ -2327,9 +2361,9 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		 */
 		pos += written;
 		count -= written;
-		written_buffered = generic_file_buffered_write(iocb, iov,
-						nr_segs, pos, ppos, count,
-						written);
+		iov_iter_advance(iter, written);
+		written_buffered = generic_file_buffered_write_iter(iocb, iter,
+						pos, ppos, count, written);
 		/*
 		 * If generic_file_buffered_write() retuned a synchronous error
 		 * then we want to return the number of bytes which were
@@ -2361,13 +2395,57 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 			 */
 		}
 	} else {
-		written = generic_file_buffered_write(iocb, iov, nr_segs,
+		iter->count = count;
+		written = generic_file_buffered_write_iter(iocb, iter,
 				pos, ppos, count, written);
 	}
 out:
 	current->backing_dev_info = NULL;
 	return written ? written : err;
 }
+EXPORT_SYMBOL(__generic_file_write_iter);
+
+ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+				loff_t pos)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file->f_mapping->host;
+	ssize_t ret;
+
+	mutex_lock(&inode->i_mutex);
+	ret = __generic_file_write_iter(iocb, iter, &iocb->ki_pos);
+	mutex_unlock(&inode->i_mutex);
+
+	if (ret > 0 || ret == -EIOCBQUEUED) {
+		ssize_t err;
+
+		err = generic_write_sync(file, pos, ret);
+		if (err < 0 && ret > 0)
+			ret = err;
+	}
+	return ret;
+}
+EXPORT_SYMBOL(generic_file_write_iter);
+
+ssize_t
+__generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
+			 unsigned long nr_segs, loff_t *ppos)
+{
+	struct iov_iter iter;
+	size_t count;
+	int ret;
+
+	count = 0;
+	ret = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
+	if (ret)
+		goto out;
+
+	iov_iter_init(&iter, iov, nr_segs, count, 0);
+
+	ret = __generic_file_write_iter(iocb, &iter, ppos);
+out:
+	return ret;
+}
 EXPORT_SYMBOL(__generic_file_aio_write);
 
 /**
-- 
1.8.1.1

[PATCH V6 12/30] aio: add aio_kernel_() interface

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

This adds an interface that lets kernel callers submit aio iocbs without
going through the user space syscalls.  This lets kernel callers avoid
the management limits and overhead of the context.  It will also let us
integrate aio operations with other kernel apis that the user space
interface doesn't have access to.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
 fs/aio.c            | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/aio.h | 15 +++++++++
 2 files changed, 107 insertions(+)

diff --git a/fs/aio.c b/fs/aio.c
index 71f613c..9a1a6fc 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -912,6 +912,10 @@ int aio_complete(struct kiocb *iocb, long res, long res2)
 		iocb->ki_users = 0;
 		wake_up_process(iocb->ki_obj.tsk);
 		return 1;
+	} else if (is_kernel_kiocb(iocb)) {
+		iocb->ki_obj.complete(iocb->ki_user_data, res);
+		aio_kernel_free(iocb);
+		return 0;
 	}
 
 	info = &ctx->ring_info;
@@ -1504,6 +1508,94 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
 	return 0;
 }
 
+ /*
+ * This allocates an iocb that will be used to submit and track completion of
+ * an IO that is issued from kernel space.
+ *
+ * The caller is expected to call the appropriate aio_kernel_init_() functions
+ * and then call aio_kernel_submit().  From that point forward progress is
+ * guaranteed by the file system aio method.  Eventually the caller's
+ * completion callback will be called.
+ *
+ * These iocbs are special.  They don't have a context, we don't limit the
+ * number pending, they can't be canceled, and can't be retried.  In the short
+ * term callers need to be careful not to call operations which might retry by
+ * only calling new ops which never add retry support.  In the long term
+ * retry-based AIO should be removed.
+ */
+struct kiocb *aio_kernel_alloc(gfp_t gfp)
+{
+	struct kiocb *iocb = kzalloc(sizeof(struct kiocb), gfp);
+	if (iocb)
+		iocb->ki_key = KIOCB_KERNEL_KEY;
+	return iocb;
+}
+EXPORT_SYMBOL_GPL(aio_kernel_alloc);
+
+void aio_kernel_free(struct kiocb *iocb)
+{
+	kfree(iocb);
+}
+EXPORT_SYMBOL_GPL(aio_kernel_free);
+
+/*
+ * ptr and count can be a buff and bytes or an iov and segs.
+ */
+void aio_kernel_init_rw(struct kiocb *iocb, struct file *filp,
+			unsigned short op, void *ptr, size_t nr, loff_t off)
+{
+	iocb->ki_filp = filp;
+	iocb->ki_opcode = op;
+	iocb->ki_buf = (char __user *)(unsigned long)ptr;
+	iocb->ki_left = nr;
+	iocb->ki_nbytes = nr;
+	iocb->ki_pos = off;
+}
+EXPORT_SYMBOL_GPL(aio_kernel_init_rw);
+
+void aio_kernel_init_callback(struct kiocb *iocb,
+			      void (*complete)(u64 user_data, long res),
+			      u64 user_data)
+{
+	iocb->ki_obj.complete = complete;
+	iocb->ki_user_data = user_data;
+}
+EXPORT_SYMBOL_GPL(aio_kernel_init_callback);
+
+/*
+ * The iocb is our responsibility once this is called.  The caller must not
+ * reference it.  This comes from aio_setup_iocb() modifying the iocb.
+ *
+ * Callers must be prepared for their iocb completion callback to be called the
+ * moment they enter this function.  The completion callback may be called from
+ * any context.
+ *
+ * Returns: 0: the iocb completion callback will be called with the op result
+ * negative errno: the operation was not submitted and the iocb was freed
+ */
+int aio_kernel_submit(struct kiocb *iocb)
+{
+	int ret;
+
+	BUG_ON(!is_kernel_kiocb(iocb));
+	BUG_ON(!iocb->ki_obj.complete);
+	BUG_ON(!iocb->ki_filp);
+
+	ret = aio_setup_iocb(iocb, 0);
+	if (ret) {
+		aio_kernel_free(iocb);
+		return ret;
+	}
+
+	ret = iocb->ki_retry(iocb);
+	BUG_ON(ret == -EIOCBRETRY);
+	if (ret != -EIOCBQUEUED)
+		aio_complete(iocb, ret, 0);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(aio_kernel_submit);
+
 static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
 			 struct iocb *iocb, struct kiocb_batch *batch,
 			 bool compat)
diff --git a/include/linux/aio.h b/include/linux/aio.h
index 31ff6db..f9e0292 100644
--- a/include/linux/aio.h
+++ b/include/linux/aio.h
@@ -24,6 +24,7 @@ struct kioctx;
 #define KIOCB_C_COMPLETE	0x02
 
 #define KIOCB_SYNC_KEY		(~0U)
+#define KIOCB_KERNEL_KEY		(~1U)
 
 /* ki_flags bits */
 /*
@@ -99,6 +100,7 @@ struct kiocb {
 	union {
 		void __user		*user;
 		struct task_struct	*tsk;
+		void			(*complete)(u64 user_data, long res);
 	} ki_obj;
 
 	__u64			ki_user_data;	/* user's data for completion */
@@ -131,6 +133,11 @@ static inline bool is_sync_kiocb(struct kiocb *kiocb)
 	return kiocb->ki_key == KIOCB_SYNC_KEY;
 }
 
+static inline bool is_kernel_kiocb(struct kiocb *kiocb)
+{
+	return kiocb->ki_key == KIOCB_KERNEL_KEY;
+}
+
 static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
 {
 	*kiocb = (struct kiocb) {
@@ -218,6 +225,14 @@ struct mm_struct;
 extern void exit_aio(struct mm_struct *mm);
 extern long do_io_submit(aio_context_t ctx_id, long nr,
 			 struct iocb __user *__user *iocbpp, bool compat);
+struct kiocb *aio_kernel_alloc(gfp_t gfp);
+void aio_kernel_free(struct kiocb *iocb);
+void aio_kernel_init_rw(struct kiocb *iocb, struct file *filp,
+			unsigned short op, void *ptr, size_t nr, loff_t off);
+void aio_kernel_init_callback(struct kiocb *iocb,
+			      void (*complete)(u64 user_data, long res),
+			      u64 user_data);
+int aio_kernel_submit(struct kiocb *iocb);
 #else
 static inline ssize_t wait_on_sync_kiocb(struct kiocb *iocb) { return 0; }
 static inline int aio_put_req(struct kiocb *iocb) { return 0; }
-- 
1.8.1.1

[PATCH V6 13/30] aio: add aio support for iov_iter arguments

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

This adds iocb cmds which specify that memory is held in iov_iter
structures.  This lets kernel callers specify memory that can be
expressed in an iov_iter, which includes pages in bio_vec arrays.

Only kernel callers can provide an iov_iter so it doesn't make a lot of
sense to expose the IOCB_CMD values for this as part of the user space
ABI.

But kernel callers should also be able to perform the usual aio
operations which suggests using the the existing operation namespace and
support code.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
 fs/aio.c                     | 64 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/aio.h          |  3 +++
 include/uapi/linux/aio_abi.h |  2 ++
 3 files changed, 69 insertions(+)

diff --git a/fs/aio.c b/fs/aio.c
index 9a1a6fc..2c03681 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1424,6 +1424,26 @@ static ssize_t aio_setup_single_vector(int type, struct file * file, struct kioc
 	return 0;
 }
 
+static ssize_t aio_read_iter(struct kiocb *iocb)
+{
+	struct file *file = iocb->ki_filp;
+	ssize_t ret = -EINVAL;
+
+	if (file->f_op->read_iter)
+		ret = file->f_op->read_iter(iocb, iocb->ki_iter, iocb->ki_pos);
+	return ret;
+}
+
+static ssize_t aio_write_iter(struct kiocb *iocb)
+{
+	struct file *file = iocb->ki_filp;
+	ssize_t ret = -EINVAL;
+
+	if (file->f_op->write_iter)
+		ret = file->f_op->write_iter(iocb, iocb->ki_iter, iocb->ki_pos);
+	return ret;
+}
+
 /*
  * aio_setup_iocb:
  *	Performs the initial checks and aio retry method
@@ -1487,6 +1507,34 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
 		if (file->f_op->aio_write)
 			kiocb->ki_retry = aio_rw_vect_retry;
 		break;
+	case IOCB_CMD_READ_ITER:
+		ret = -EINVAL;
+		if (unlikely(!is_kernel_kiocb(kiocb)))
+			break;
+		ret = -EBADF;
+		if (unlikely(!(file->f_mode & FMODE_READ)))
+			break;
+		ret = security_file_permission(file, MAY_READ);
+		if (unlikely(ret))
+			break;
+		ret = -EINVAL;
+		if (file->f_op->read_iter)
+			kiocb->ki_retry = aio_read_iter;
+		break;
+	case IOCB_CMD_WRITE_ITER:
+		ret = -EINVAL;
+		if (unlikely(!is_kernel_kiocb(kiocb)))
+			break;
+		ret = -EBADF;
+		if (unlikely(!(file->f_mode & FMODE_WRITE)))
+			break;
+		ret = security_file_permission(file, MAY_WRITE);
+		if (unlikely(ret))
+			break;
+		ret = -EINVAL;
+		if (file->f_op->write_iter)
+			kiocb->ki_retry = aio_write_iter;
+		break;
 	case IOCB_CMD_FDSYNC:
 		ret = -EINVAL;
 		if (file->f_op->aio_fsync)
@@ -1553,6 +1601,22 @@ void aio_kernel_init_rw(struct kiocb *iocb, struct file *filp,
 }
 EXPORT_SYMBOL_GPL(aio_kernel_init_rw);
 
+/*
+ * The iter count must be set before calling here.  Some filesystems uses
+ * iocb->ki_left as an indicator of the size of an IO.
+ */
+void aio_kernel_init_iter(struct kiocb *iocb, struct file *filp,
+			  unsigned short op, struct iov_iter *iter, loff_t off)
+{
+	iocb->ki_filp = filp;
+	iocb->ki_iter = iter;
+	iocb->ki_opcode = op;
+	iocb->ki_pos = off;
+	iocb->ki_nbytes = iov_iter_count(iter);
+	iocb->ki_left = iocb->ki_nbytes;
+}
+EXPORT_SYMBOL_GPL(aio_kernel_init_iter);
+
 void aio_kernel_init_callback(struct kiocb *iocb,
 			      void (*complete)(u64 user_data, long res),
 			      u64 user_data)
diff --git a/include/linux/aio.h b/include/linux/aio.h
index f9e0292..2598e6c 100644
--- a/include/linux/aio.h
+++ b/include/linux/aio.h
@@ -126,6 +126,7 @@ struct kiocb {
 	 * this is the underlying eventfd context to deliver events to.
 	 */
 	struct eventfd_ctx	*ki_eventfd;
+	struct iov_iter		*ki_iter;
 };
 
 static inline bool is_sync_kiocb(struct kiocb *kiocb)
@@ -229,6 +230,8 @@ struct kiocb *aio_kernel_alloc(gfp_t gfp);
 void aio_kernel_free(struct kiocb *iocb);
 void aio_kernel_init_rw(struct kiocb *iocb, struct file *filp,
 			unsigned short op, void *ptr, size_t nr, loff_t off);
+void aio_kernel_init_iter(struct kiocb *iocb, struct file *filp,
+			  unsigned short op, struct iov_iter *iter, loff_t off);
 void aio_kernel_init_callback(struct kiocb *iocb,
 			      void (*complete)(u64 user_data, long res),
 			      u64 user_data);
diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h
index 86fa7a7..bd39bb2 100644
--- a/include/uapi/linux/aio_abi.h
+++ b/include/uapi/linux/aio_abi.h
@@ -44,6 +44,8 @@ enum {
 	IOCB_CMD_NOOP = 6,
 	IOCB_CMD_PREADV = 7,
 	IOCB_CMD_PWRITEV = 8,
+	IOCB_CMD_READ_ITER = 9,
+	IOCB_CMD_WRITE_ITER = 10,
 };
 
 /*
-- 
1.8.1.1

[PATCH V6 14/30] bio: add bvec_length(), like iov_length()

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
 include/linux/bio.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 820e7aa..f5f9829 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -290,6 +290,14 @@ extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set
 extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
 extern unsigned int bvec_nr_vecs(unsigned short idx);
 
+static inline ssize_t bvec_length(const struct bio_vec *bvec, unsigned long nr)
+{
+	ssize_t bytes = 0;
+	while (nr--)
+		bytes += (bvec++)->bv_len;
+	return bytes;
+}
+
 #ifdef CONFIG_BLK_CGROUP
 int bio_associate_current(struct bio *bio);
 void bio_disassociate_task(struct bio *bio);
-- 
1.8.1.1

[PATCH V6 15/30] loop: use aio to perform io on the underlying file

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

This uses the new kernel aio interface to process loopback IO by
submitting concurrent direct aio.  Previously loop's IO was serialized
by synchronous processing in a thread.

The aio operations specify the memory for the IO with the bio_vec arrays
directly instead of mappings of the pages.

The use of aio operations is enabled when the backing file supports the
read_iter, write_iter and direct_IO methods.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
---
 drivers/block/loop.c      | 148 +++++++++++++++++++++++++++++++++-------------
 include/uapi/linux/loop.h |   1 +
 2 files changed, 109 insertions(+), 40 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index ae12512..fc6f201 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -76,6 +76,7 @@
 #include <linux/sysfs.h>
 #include <linux/miscdevice.h>
 #include <linux/falloc.h>
+#include <linux/aio.h>
 
 #include <asm/uaccess.h>
 
@@ -213,6 +214,48 @@ lo_do_transfer(struct loop_device *lo, int cmd,
 	return lo->transfer(lo, cmd, rpage, roffs, lpage, loffs, size, rblock);
 }
 
+#ifdef CONFIG_AIO
+static void lo_rw_aio_complete(u64 data, long res)
+{
+	struct bio *bio = (struct bio *)(uintptr_t)data;
+
+	if (res > 0)
+		res = 0;
+	else if (res < 0)
+		res = -EIO;
+
+	bio_endio(bio, res);
+}
+
+static int lo_rw_aio(struct loop_device *lo, struct bio *bio)
+{
+	struct file *file = lo->lo_backing_file;
+	struct kiocb *iocb;
+	unsigned short op;
+	struct iov_iter iter;
+	struct bio_vec *bvec;
+	size_t nr_segs;
+	loff_t pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset;
+
+	iocb = aio_kernel_alloc(GFP_NOIO);
+	if (!iocb)
+		return -ENOMEM;
+
+	if (bio_rw(bio) & WRITE)
+		op = IOCB_CMD_WRITE_ITER;
+	else
+		op = IOCB_CMD_READ_ITER;
+
+	bvec = bio_iovec_idx(bio, bio->bi_idx);
+	nr_segs = bio_segments(bio);
+	iov_iter_init_bvec(&iter, bvec, nr_segs, bvec_length(bvec, nr_segs), 0);
+	aio_kernel_init_iter(iocb, file, op, &iter, pos);
+	aio_kernel_init_callback(iocb, lo_rw_aio_complete, (u64)(uintptr_t)bio);
+
+	return aio_kernel_submit(iocb);
+}
+#endif /* CONFIG_AIO */
+
 /**
  * __do_lo_send_write - helper for writing data to a loop device
  *
@@ -411,50 +454,33 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
 	pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset;
 
 	if (bio_rw(bio) == WRITE) {
-		struct file *file = lo->lo_backing_file;
-
-		if (bio->bi_rw & REQ_FLUSH) {
-			ret = vfs_fsync(file, 0);
-			if (unlikely(ret && ret != -EINVAL)) {
-				ret = -EIO;
-				goto out;
-			}
-		}
+		ret = lo_send(lo, bio, pos);
+	} else
+		ret = lo_receive(lo, bio, lo->lo_blocksize, pos);
 
-		/*
-		 * We use punch hole to reclaim the free space used by the
-		 * image a.k.a. discard. However we do not support discard if
-		 * encryption is enabled, because it may give an attacker
-		 * useful information.
-		 */
-		if (bio->bi_rw & REQ_DISCARD) {
-			struct file *file = lo->lo_backing_file;
-			int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
+	return ret;
+}
 
-			if ((!file->f_op->fallocate) ||
-			    lo->lo_encrypt_key_size) {
-				ret = -EOPNOTSUPP;
-				goto out;
-			}
-			ret = file->f_op->fallocate(file, mode, pos,
-						    bio->bi_size);
-			if (unlikely(ret && ret != -EINVAL &&
-				     ret != -EOPNOTSUPP))
-				ret = -EIO;
-			goto out;
-		}
+static int lo_discard(struct loop_device *lo, struct bio *bio)
+{
+	struct file *file = lo->lo_backing_file;
+	int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
+	loff_t pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset;
+	int ret;
 
-		ret = lo_send(lo, bio, pos);
+	/*
+	 * We use punch hole to reclaim the free space used by the
+	 * image a.k.a. discard. However we do not support discard if
+	 * encryption is enabled, because it may give an attacker
+	 * useful information.
+	 */
 
-		if ((bio->bi_rw & REQ_FUA) && !ret) {
-			ret = vfs_fsync(file, 0);
-			if (unlikely(ret && ret != -EINVAL))
-				ret = -EIO;
-		}
-	} else
-		ret = lo_receive(lo, bio, lo->lo_blocksize, pos);
+	if ((!file->f_op->fallocate) || lo->lo_encrypt_key_size)
+		return -EOPNOTSUPP;
 
-out:
+	ret = file->f_op->fallocate(file, mode, pos, bio->bi_size);
+	if (unlikely(ret && ret != -EINVAL && ret != -EOPNOTSUPP))
+		ret = -EIO;
 	return ret;
 }
 
@@ -518,7 +544,35 @@ static inline void loop_handle_bio(struct loop_device *lo, struct bio *bio)
 		do_loop_switch(lo, bio->bi_private);
 		bio_put(bio);
 	} else {
-		int ret = do_bio_filebacked(lo, bio);
+		int ret;
+
+		if (bio_rw(bio) == WRITE) {
+			if (bio->bi_rw & REQ_FLUSH) {
+				ret = vfs_fsync(lo->lo_backing_file, 1);
+				if (unlikely(ret && ret != -EINVAL))
+					goto out;
+			}
+			if (bio->bi_rw & REQ_DISCARD) {
+				ret = lo_discard(lo, bio);
+				goto out;
+			}
+		}
+#ifdef CONFIG_AIO
+		if (lo->lo_flags & LO_FLAGS_USE_AIO &&
+		    lo->transfer == transfer_none) {
+			ret = lo_rw_aio(lo, bio);
+			if (ret == 0)
+				return;
+		} else
+#endif
+			ret = do_bio_filebacked(lo, bio);
+
+		if ((bio_rw(bio) == WRITE) && bio->bi_rw & REQ_FUA && !ret) {
+			ret = vfs_fsync(lo->lo_backing_file, 0);
+			if (unlikely(ret && ret != -EINVAL))
+				ret = -EIO;
+		}
+out:
 		bio_endio(bio, ret);
 	}
 }
@@ -540,6 +594,12 @@ static int loop_thread(void *data)
 	struct loop_device *lo = data;
 	struct bio *bio;
 
+	/*
+	 * In cases where the underlying filesystem calls balance_dirty_pages()
+	 * we want less throttling to avoid lock ups trying to write dirty
+	 * pages through the loop device
+	 */
+	current->flags |= PF_LESS_THROTTLE;
 	set_user_nice(current, -20);
 
 	while (!kthread_should_stop() || !bio_list_empty(&lo->lo_bio_list)) {
@@ -862,6 +922,14 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
 	    !file->f_op->write)
 		lo_flags |= LO_FLAGS_READ_ONLY;
 
+#ifdef CONFIG_AIO
+	if (file->f_op->write_iter && file->f_op->read_iter &&
+	    mapping->a_ops->direct_IO) {
+		file->f_flags |= O_DIRECT;
+		lo_flags |= LO_FLAGS_USE_AIO;
+	}
+#endif
+
 	lo_blocksize = S_ISBLK(inode->i_mode) ?
 		inode->i_bdev->bd_block_size : PAGE_SIZE;
 
diff --git a/include/uapi/linux/loop.h b/include/uapi/linux/loop.h
index e0cecd2..6edc6b6 100644
--- a/include/uapi/linux/loop.h
+++ b/include/uapi/linux/loop.h
@@ -21,6 +21,7 @@ enum {
 	LO_FLAGS_READ_ONLY	= 1,
 	LO_FLAGS_AUTOCLEAR	= 4,
 	LO_FLAGS_PARTSCAN	= 8,
+	LO_FLAGS_USE_AIO	= 16,
 };
 
 #include <asm/posix_types.h>	/* for __kernel_old_dev_t */
-- 
1.8.1.1

[PATCH V6 16/30] fs: create file_readable() and file_writable() functions

[Dave Kleikamp]

Create functions to simplify if file_ops contain either a read
or aio_read op, or likewise write or aio_write. We will be adding
read_iter and write_iter and don't need to be complicating the code
in multiple places.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
---
 drivers/mtd/nand/nandsim.c           |  4 ++--
 drivers/staging/ccg/storage_common.c |  4 ++--
 drivers/usb/gadget/storage_common.c  |  4 ++--
 fs/compat.c                          |  4 ++--
 fs/read_write.c                      |  8 ++++----
 include/linux/fs.h                   | 10 ++++++++++
 6 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/drivers/mtd/nand/nandsim.c b/drivers/mtd/nand/nandsim.c
index 818b65c..cb47bdd 100644
--- a/drivers/mtd/nand/nandsim.c
+++ b/drivers/mtd/nand/nandsim.c
@@ -580,12 +580,12 @@ static int alloc_device(struct nandsim *ns)
 		cfile = filp_open(cache_file, O_CREAT | O_RDWR | O_LARGEFILE, 0600);
 		if (IS_ERR(cfile))
 			return PTR_ERR(cfile);
-		if (!cfile->f_op || (!cfile->f_op->read && !cfile->f_op->aio_read)) {
+		if (!file_readable(cfile)) {
 			NS_ERR("alloc_device: cache file not readable\n");
 			err = -EINVAL;
 			goto err_close;
 		}
-		if (!cfile->f_op->write && !cfile->f_op->aio_write) {
+		if (!file_writable(cfile)) {
 			NS_ERR("alloc_device: cache file not writeable\n");
 			err = -EINVAL;
 			goto err_close;
diff --git a/drivers/staging/ccg/storage_common.c b/drivers/staging/ccg/storage_common.c
index 8d9bcd8..d431eff 100644
--- a/drivers/staging/ccg/storage_common.c
+++ b/drivers/staging/ccg/storage_common.c
@@ -666,11 +666,11 @@ static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
 	 * If we can't read the file, it's no good.
 	 * If we can't write the file, use it read-only.
 	 */
-	if (!(filp->f_op->read || filp->f_op->aio_read)) {
+	if (!file_readable(filp)) {
 		LINFO(curlun, "file not readable: %s\n", filename);
 		goto out;
 	}
-	if (!(filp->f_op->write || filp->f_op->aio_write))
+	if (!file_writable(filp))
 		ro = 1;
 
 	size = i_size_read(inode->i_mapping->host);
diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c
index 0e3ae43..c9eaa50 100644
--- a/drivers/usb/gadget/storage_common.c
+++ b/drivers/usb/gadget/storage_common.c
@@ -511,11 +511,11 @@ static int fsg_lun_open(struct fsg_lun *curlun, const char *filename)
 	 * If we can't read the file, it's no good.
 	 * If we can't write the file, use it read-only.
 	 */
-	if (!(filp->f_op->read || filp->f_op->aio_read)) {
+	if (!file_readable(filp)) {
 		LINFO(curlun, "file not readable: %s\n", filename);
 		goto out;
 	}
-	if (!(filp->f_op->write || filp->f_op->aio_write))
+	if (!file_writable(filp))
 		ro = 1;
 
 	size = i_size_read(inode->i_mapping->host);
diff --git a/fs/compat.c b/fs/compat.c
index 015e1e1..7411d66 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1132,7 +1132,7 @@ static size_t compat_readv(struct file *file,
 		goto out;
 
 	ret = -EINVAL;
-	if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read))
+	if (!file_readable(file))
 		goto out;
 
 	ret = compat_do_readv_writev(READ, file, vec, vlen, pos);
@@ -1198,7 +1198,7 @@ static size_t compat_writev(struct file *file,
 		goto out;
 
 	ret = -EINVAL;
-	if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write))
+	if (!file_writable(file))
 		goto out;
 
 	ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos);
diff --git a/fs/read_write.c b/fs/read_write.c
index bb34af3..b5d0bff 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -360,7 +360,7 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 
 	if (!(file->f_mode & FMODE_READ))
 		return -EBADF;
-	if (!file->f_op || (!file->f_op->read && !file->f_op->aio_read))
+	if (!file_readable(file))
 		return -EINVAL;
 	if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
 		return -EFAULT;
@@ -416,7 +416,7 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
 
 	if (!(file->f_mode & FMODE_WRITE))
 		return -EBADF;
-	if (!file->f_op || (!file->f_op->write && !file->f_op->aio_write))
+	if (!file_writable(file))
 		return -EINVAL;
 	if (unlikely(!access_ok(VERIFY_READ, buf, count)))
 		return -EFAULT;
@@ -749,7 +749,7 @@ ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
 {
 	if (!(file->f_mode & FMODE_READ))
 		return -EBADF;
-	if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read))
+	if (!file_readable(file))
 		return -EINVAL;
 
 	return do_readv_writev(READ, file, vec, vlen, pos);
@@ -762,7 +762,7 @@ ssize_t vfs_writev(struct file *file, const struct iovec __user *vec,
 {
 	if (!(file->f_mode & FMODE_WRITE))
 		return -EBADF;
-	if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write))
+	if (!file_writable(file))
 		return -EINVAL;
 
 	return do_readv_writev(WRITE, file, vec, vlen, pos);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index ee9184e..b893a4f 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1634,6 +1634,16 @@ struct file_operations {
 	int (*show_fdinfo)(struct seq_file *m, struct file *f);
 };
 
+static inline int file_readable(struct file *filp)
+{
+	return filp && (filp->f_op->read || filp->f_op->aio_read);
+}
+
+static inline int file_writable(struct file *filp)
+{
+	return filp && (filp->f_op->write || filp->f_op->aio_write);
+}
+
 struct inode_operations {
 	struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
 	void * (*follow_link) (struct dentry *, struct nameidata *);
-- 
1.8.1.1

[PATCH V6 17/30] fs: use read_iter and write_iter rather than aio_read and aio_write

[Dave Kleikamp]

File systems implementing read_iter & write_iter should not be required
to keep aio_read and aio_write as well. The vfs should always call
read/write_iter if they exist. This will make it easier to remove the
aio_read/write operation in the future.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
---
 fs/aio.c           | 14 +++++++------
 fs/bad_inode.c     | 14 +++++++++++++
 fs/compat.c        |  6 ++++--
 fs/read_write.c    | 58 +++++++++++++++++++++++++++++++++++++++++++++++++-----
 fs/read_write.h    |  4 ++++
 include/linux/fs.h |  6 ++++--
 6 files changed, 87 insertions(+), 15 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 2c03681..9635e7a 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -39,6 +39,8 @@
 #include <asm/kmap_types.h>
 #include <asm/uaccess.h>
 
+#include "read_write.h"
+
 #if DEBUG > 1
 #define dprintk		printk
 #else
@@ -1315,10 +1317,10 @@ static ssize_t aio_rw_vect_retry(struct kiocb *iocb)
 
 	if ((iocb->ki_opcode == IOCB_CMD_PREADV) ||
 		(iocb->ki_opcode == IOCB_CMD_PREAD)) {
-		rw_op = file->f_op->aio_read;
+		rw_op = do_aio_read;
 		opcode = IOCB_CMD_PREADV;
 	} else {
-		rw_op = file->f_op->aio_write;
+		rw_op = do_aio_write;
 		opcode = IOCB_CMD_PWRITEV;
 	}
 
@@ -1467,7 +1469,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
 		if (ret)
 			break;
 		ret = -EINVAL;
-		if (file->f_op->aio_read)
+		if (file->f_op->read_iter || file->f_op->aio_read)
 			kiocb->ki_retry = aio_rw_vect_retry;
 		break;
 	case IOCB_CMD_PWRITE:
@@ -1482,7 +1484,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
 		if (ret)
 			break;
 		ret = -EINVAL;
-		if (file->f_op->aio_write)
+		if (file->f_op->write_iter || file->f_op->aio_write)
 			kiocb->ki_retry = aio_rw_vect_retry;
 		break;
 	case IOCB_CMD_PREADV:
@@ -1493,7 +1495,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
 		if (ret)
 			break;
 		ret = -EINVAL;
-		if (file->f_op->aio_read)
+		if (file->f_op->read_iter || file->f_op->aio_read)
 			kiocb->ki_retry = aio_rw_vect_retry;
 		break;
 	case IOCB_CMD_PWRITEV:
@@ -1504,7 +1506,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
 		if (ret)
 			break;
 		ret = -EINVAL;
-		if (file->f_op->aio_write)
+		if (file->f_op->write_iter || file->f_op->aio_write)
 			kiocb->ki_retry = aio_rw_vect_retry;
 		break;
 	case IOCB_CMD_READ_ITER:
diff --git a/fs/bad_inode.c b/fs/bad_inode.c
index 922ad46..988c04a 100644
--- a/fs/bad_inode.c
+++ b/fs/bad_inode.c
@@ -39,12 +39,24 @@ static ssize_t bad_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
 	return -EIO;
 }
 
+static ssize_t bad_file_read_iter(struct kiocb *iocb, struct iov_iter *iter,
+			loff_t pos)
+{
+	return -EIO;
+}
+
 static ssize_t bad_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 			unsigned long nr_segs, loff_t pos)
 {
 	return -EIO;
 }
 
+static ssize_t bad_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+			loff_t pos)
+{
+	return -EIO;
+}
+
 static int bad_file_readdir(struct file *filp, void *dirent, filldir_t filldir)
 {
 	return -EIO;
@@ -151,7 +163,9 @@ static const struct file_operations bad_file_ops =
 	.read		= bad_file_read,
 	.write		= bad_file_write,
 	.aio_read	= bad_file_aio_read,
+	.read_iter	= bad_file_read_iter,
 	.aio_write	= bad_file_aio_write,
+	.write_iter	= bad_file_write_iter,
 	.readdir	= bad_file_readdir,
 	.poll		= bad_file_poll,
 	.unlocked_ioctl	= bad_file_unlocked_ioctl,
diff --git a/fs/compat.c b/fs/compat.c
index 7411d66..545888b 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1098,10 +1098,12 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,
 	fnv = NULL;
 	if (type == READ) {
 		fn = file->f_op->read;
-		fnv = file->f_op->aio_read;
+		if (file->f_op->aio_read || file->f_op->read_iter)
+			fnv = do_aio_read;
 	} else {
 		fn = (io_fn_t)file->f_op->write;
-		fnv = file->f_op->aio_write;
+		if (file->f_op->aio_write || file->f_op->write_iter)
+			fnv = do_aio_write;
 	}
 
 	if (fnv)
diff --git a/fs/read_write.c b/fs/read_write.c
index b5d0bff..65c4846 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -23,7 +23,7 @@
 const struct file_operations generic_ro_fops = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.mmap		= generic_file_readonly_mmap,
 	.splice_read	= generic_file_splice_read,
 };
@@ -328,6 +328,29 @@ static void wait_on_retry_sync_kiocb(struct kiocb *iocb)
 	__set_current_state(TASK_RUNNING);
 }
 
+ssize_t do_aio_read(struct kiocb *kiocb, const struct iovec *iov,
+		    unsigned long nr_segs, loff_t pos)
+{
+	struct file *file = kiocb->ki_filp;
+
+	if (file->f_op->read_iter) {
+		size_t count;
+		struct iov_iter iter;
+		int ret;
+
+		count = 0;
+		ret = generic_segment_checks(iov, &nr_segs, &count,
+					     VERIFY_WRITE);
+		if (ret)
+			return ret;
+
+		iov_iter_init(&iter, iov, nr_segs, count, 0);
+		return file->f_op->read_iter(kiocb, &iter, pos);
+	}
+
+	return file->f_op->aio_read(kiocb, iov, nr_segs, pos);
+}
+
 ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos)
 {
 	struct iovec iov = { .iov_base = buf, .iov_len = len };
@@ -340,7 +363,7 @@ ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *pp
 	kiocb.ki_nbytes = len;
 
 	for (;;) {
-		ret = filp->f_op->aio_read(&kiocb, &iov, 1, kiocb.ki_pos);
+		ret = do_aio_read(&kiocb, &iov, 1, kiocb.ki_pos);
 		if (ret != -EIOCBRETRY)
 			break;
 		wait_on_retry_sync_kiocb(&kiocb);
@@ -384,6 +407,29 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
 
 EXPORT_SYMBOL(vfs_read);
 
+ssize_t do_aio_write(struct kiocb *kiocb, const struct iovec *iov,
+		     unsigned long nr_segs, loff_t pos)
+{
+	struct file *file = kiocb->ki_filp;
+
+	if (file->f_op->write_iter) {
+		size_t count;
+		struct iov_iter iter;
+		int ret;
+
+		count = 0;
+		ret = generic_segment_checks(iov, &nr_segs, &count,
+					     VERIFY_READ);
+		if (ret)
+			return ret;
+
+		iov_iter_init(&iter, iov, nr_segs, count, 0);
+		return file->f_op->write_iter(kiocb, &iter, pos);
+	}
+
+	return file->f_op->aio_write(kiocb, iov, nr_segs, pos);
+}
+
 ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
 {
 	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = len };
@@ -396,7 +442,7 @@ ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, lof
 	kiocb.ki_nbytes = len;
 
 	for (;;) {
-		ret = filp->f_op->aio_write(&kiocb, &iov, 1, kiocb.ki_pos);
+		ret = do_aio_write(&kiocb, &iov, 1, kiocb.ki_pos);
 		if (ret != -EIOCBRETRY)
 			break;
 		wait_on_retry_sync_kiocb(&kiocb);
@@ -720,10 +766,12 @@ static ssize_t do_readv_writev(int type, struct file *file,
 	fnv = NULL;
 	if (type == READ) {
 		fn = file->f_op->read;
-		fnv = file->f_op->aio_read;
+		if (file->f_op->aio_read || file->f_op->read_iter)
+			fnv = do_aio_read;
 	} else {
 		fn = (io_fn_t)file->f_op->write;
-		fnv = file->f_op->aio_write;
+		if (file->f_op->aio_write || file->f_op->write_iter)
+			fnv = do_aio_write;
 	}
 
 	if (fnv)
diff --git a/fs/read_write.h b/fs/read_write.h
index d3e00ef..4f00eb7 100644
--- a/fs/read_write.h
+++ b/fs/read_write.h
@@ -8,6 +8,10 @@ typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);
 typedef ssize_t (*iov_fn_t)(struct kiocb *, const struct iovec *,
 		unsigned long, loff_t);
 
+ssize_t do_aio_read(struct kiocb *kiocb, const struct iovec *iov,
+		unsigned long nr_segs, loff_t pos);
+ssize_t do_aio_write(struct kiocb *kiocb, const struct iovec *iov,
+		unsigned long nr_segs, loff_t pos);
 ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov,
 		unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn);
 ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index b893a4f..31d2e17 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1636,12 +1636,14 @@ struct file_operations {
 
 static inline int file_readable(struct file *filp)
 {
-	return filp && (filp->f_op->read || filp->f_op->aio_read);
+	return filp && (filp->f_op->read || filp->f_op->aio_read ||
+			filp->f_op->read_iter);
 }
 
 static inline int file_writable(struct file *filp)
 {
-	return filp && (filp->f_op->write || filp->f_op->aio_write);
+	return filp && (filp->f_op->write || filp->f_op->aio_write ||
+			filp->f_op->write_iter);
 }
 
 struct inode_operations {
-- 
1.8.1.1

[PATCH V6 19/30] ocfs2: add support for read_iter, write_iter, and direct_IO_bvec

[Dave Kleikamp]

From: Zach Brown <zab@zabbo.net>

ocfs2's .aio_read and .aio_write methods are changed to take
iov_iter and pass it to generic functions.  Wrappers are made to pack
the iovecs into iters and call these new functions.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: ocfs2-devel@oss.oracle.com
---
 fs/ocfs2/aops.h        |  2 +-
 fs/ocfs2/file.c        | 53 ++++++++++++++++++++++----------------------------
 fs/ocfs2/inode.h       |  2 --
 fs/ocfs2/ocfs2_trace.h |  6 +++---
 4 files changed, 27 insertions(+), 36 deletions(-)

diff --git a/fs/ocfs2/aops.h b/fs/ocfs2/aops.h
index ffb2da3..bd0425a 100644
--- a/fs/ocfs2/aops.h
+++ b/fs/ocfs2/aops.h
@@ -72,7 +72,7 @@ static inline void ocfs2_iocb_set_rw_locked(struct kiocb *iocb, int level)
 /*
  * Using a named enum representing lock types in terms of #N bit stored in
  * iocb->private, which is going to be used for communication between
- * ocfs2_dio_end_io() and ocfs2_file_aio_write/read().
+ * ocfs2_dio_end_io() and ocfs2_file_write/read_iter().
  */
 enum ocfs2_iocb_lock_bits {
 	OCFS2_IOCB_RW_LOCK = 0,
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 37d313e..94fc309 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2219,15 +2219,13 @@ out:
 	return ret;
 }
 
-static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
-				    const struct iovec *iov,
-				    unsigned long nr_segs,
-				    loff_t pos)
+static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
+				     struct iov_iter *iter,
+				     loff_t pos)
 {
 	int ret, direct_io, appending, rw_level, have_alloc_sem  = 0;
 	int can_do_direct, has_refcount = 0;
 	ssize_t written = 0;
-	size_t ocount;		/* original count */
 	size_t count;		/* after file limit checks */
 	loff_t old_size, *ppos = &iocb->ki_pos;
 	u32 old_clusters;
@@ -2238,11 +2236,11 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
 			       OCFS2_MOUNT_COHERENCY_BUFFERED);
 	int unaligned_dio = 0;
 
-	trace_ocfs2_file_aio_write(inode, file, file->f_path.dentry,
+	trace_ocfs2_file_write_iter(inode, file, file->f_path.dentry,
 		(unsigned long long)OCFS2_I(inode)->ip_blkno,
 		file->f_path.dentry->d_name.len,
 		file->f_path.dentry->d_name.name,
-		(unsigned int)nr_segs);
+		(unsigned long long)pos);
 
 	if (iocb->ki_left == 0)
 		return 0;
@@ -2344,28 +2342,24 @@ relock:
 	/* communicate with ocfs2_dio_end_io */
 	ocfs2_iocb_set_rw_locked(iocb, rw_level);
 
-	ret = generic_segment_checks(iov, &nr_segs, &ocount,
-				     VERIFY_READ);
-	if (ret)
-		goto out_dio;
 
-	count = ocount;
+	count = iov_iter_count(iter);
 	ret = generic_write_checks(file, ppos, &count,
 				   S_ISBLK(inode->i_mode));
 	if (ret)
 		goto out_dio;
 
 	if (direct_io) {
-		written = generic_file_direct_write(iocb, iov, &nr_segs, *ppos,
-						    ppos, count, ocount);
+		written = generic_file_direct_write_iter(iocb, iter, *ppos,
+						    ppos, count);
 		if (written < 0) {
 			ret = written;
 			goto out_dio;
 		}
 	} else {
 		current->backing_dev_info = file->f_mapping->backing_dev_info;
-		written = generic_file_buffered_write(iocb, iov, nr_segs, *ppos,
-						      ppos, count, 0);
+		written = generic_file_buffered_write_iter(iocb, iter, *ppos,
+							   ppos, count, 0);
 		current->backing_dev_info = NULL;
 	}
 
@@ -2524,7 +2518,7 @@ static ssize_t ocfs2_file_splice_read(struct file *in,
 			in->f_path.dentry->d_name.name, len);
 
 	/*
-	 * See the comment in ocfs2_file_aio_read()
+	 * See the comment in ocfs2_file_read_iter()
 	 */
 	ret = ocfs2_inode_lock_atime(inode, in->f_vfsmnt, &lock_level);
 	if (ret < 0) {
@@ -2539,19 +2533,18 @@ bail:
 	return ret;
 }
 
-static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
-				   const struct iovec *iov,
-				   unsigned long nr_segs,
+static ssize_t ocfs2_file_read_iter(struct kiocb *iocb,
+				   struct iov_iter *iter,
 				   loff_t pos)
 {
 	int ret = 0, rw_level = -1, have_alloc_sem = 0, lock_level = 0;
 	struct file *filp = iocb->ki_filp;
 	struct inode *inode = filp->f_path.dentry->d_inode;
 
-	trace_ocfs2_file_aio_read(inode, filp, filp->f_path.dentry,
+	trace_ocfs2_file_read_iter(inode, filp, filp->f_path.dentry,
 			(unsigned long long)OCFS2_I(inode)->ip_blkno,
 			filp->f_path.dentry->d_name.len,
-			filp->f_path.dentry->d_name.name, nr_segs);
+			filp->f_path.dentry->d_name.name, pos);
 
 
 	if (!inode) {
@@ -2587,7 +2580,7 @@ static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
 	 *
 	 * Take and drop the meta data lock to update inode fields
 	 * like i_size. This allows the checks down below
-	 * generic_file_aio_read() a chance of actually working.
+	 * generic_file_read_iter() a chance of actually working.
 	 */
 	ret = ocfs2_inode_lock_atime(inode, filp->f_vfsmnt, &lock_level);
 	if (ret < 0) {
@@ -2596,13 +2589,13 @@ static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
 	}
 	ocfs2_inode_unlock(inode, lock_level);
 
-	ret = generic_file_aio_read(iocb, iov, nr_segs, iocb->ki_pos);
-	trace_generic_file_aio_read_ret(ret);
+	ret = generic_file_read_iter(iocb, iter, iocb->ki_pos);
+	trace_generic_file_read_iter_ret(ret);
 
 	/* buffered aio wouldn't have proper lock coverage today */
 	BUG_ON(ret == -EIOCBQUEUED && !(filp->f_flags & O_DIRECT));
 
-	/* see ocfs2_file_aio_write */
+	/* see ocfs2_file_write_iter */
 	if (ret == -EIOCBQUEUED || !ocfs2_iocb_is_rw_locked(iocb)) {
 		rw_level = -1;
 		have_alloc_sem = 0;
@@ -2700,8 +2693,8 @@ const struct file_operations ocfs2_fops = {
 	.fsync		= ocfs2_sync_file,
 	.release	= ocfs2_file_release,
 	.open		= ocfs2_file_open,
-	.aio_read	= ocfs2_file_aio_read,
-	.aio_write	= ocfs2_file_aio_write,
+	.read_iter	= ocfs2_file_read_iter,
+	.write_iter	= ocfs2_file_write_iter,
 	.unlocked_ioctl	= ocfs2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl   = ocfs2_compat_ioctl,
@@ -2748,8 +2741,8 @@ const struct file_operations ocfs2_fops_no_plocks = {
 	.fsync		= ocfs2_sync_file,
 	.release	= ocfs2_file_release,
 	.open		= ocfs2_file_open,
-	.aio_read	= ocfs2_file_aio_read,
-	.aio_write	= ocfs2_file_aio_write,
+	.read_iter	= ocfs2_file_read_iter,
+	.write_iter	= ocfs2_file_write_iter,
 	.unlocked_ioctl	= ocfs2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl   = ocfs2_compat_ioctl,
diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h
index 88924a3..621fc73 100644
--- a/fs/ocfs2/inode.h
+++ b/fs/ocfs2/inode.h
@@ -147,8 +147,6 @@ void ocfs2_refresh_inode(struct inode *inode,
 int ocfs2_mark_inode_dirty(handle_t *handle,
 			   struct inode *inode,
 			   struct buffer_head *bh);
-int ocfs2_aio_read(struct file *file, struct kiocb *req, struct iocb *iocb);
-int ocfs2_aio_write(struct file *file, struct kiocb *req, struct iocb *iocb);
 struct buffer_head *ocfs2_bread(struct inode *inode,
 				int block, int *err, int reada);
 
diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h
index 3b481f4..1c5018c 100644
--- a/fs/ocfs2/ocfs2_trace.h
+++ b/fs/ocfs2/ocfs2_trace.h
@@ -1310,13 +1310,13 @@ DEFINE_OCFS2_FILE_OPS(ocfs2_file_release);
 
 DEFINE_OCFS2_FILE_OPS(ocfs2_sync_file);
 
-DEFINE_OCFS2_FILE_OPS(ocfs2_file_aio_write);
+DEFINE_OCFS2_FILE_OPS(ocfs2_file_write_iter);
 
 DEFINE_OCFS2_FILE_OPS(ocfs2_file_splice_write);
 
 DEFINE_OCFS2_FILE_OPS(ocfs2_file_splice_read);
 
-DEFINE_OCFS2_FILE_OPS(ocfs2_file_aio_read);
+DEFINE_OCFS2_FILE_OPS(ocfs2_file_read_iter);
 
 DEFINE_OCFS2_ULL_ULL_ULL_EVENT(ocfs2_truncate_file);
 
@@ -1474,7 +1474,7 @@ TRACE_EVENT(ocfs2_prepare_inode_for_write,
 		  __entry->direct_io, __entry->has_refcount)
 );
 
-DEFINE_OCFS2_INT_EVENT(generic_file_aio_read_ret);
+DEFINE_OCFS2_INT_EVENT(generic_file_read_iter_ret);
 
 /* End of trace events for fs/ocfs2/file.c. */
 
-- 
1.8.1.1

[PATCH V6 20/30] ext4: add support for read_iter and write_iter

[Dave Kleikamp]

use the generic_file_read_iter(), create ext4_file_write_iter() based on
ext4_file_write(), and make ext4_file_write() a wrapper around
ext4_file_write_iter().

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
---
 fs/ext4/file.c | 34 +++++++++++++++++-----------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 405565a..54aa681 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -73,12 +73,11 @@ void ext4_unwritten_wait(struct inode *inode)
  * or one thread will zero the other's data, causing corruption.
  */
 static int
-ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,
-		   unsigned long nr_segs, loff_t pos)
+ext4_unaligned_aio(struct inode *inode, struct iov_iter *iter, loff_t pos)
 {
 	struct super_block *sb = inode->i_sb;
 	int blockmask = sb->s_blocksize - 1;
-	size_t count = iov_length(iov, nr_segs);
+	size_t count = iov_iter_count(iter);
 	loff_t final_size = pos + count;
 
 	if (pos >= inode->i_size)
@@ -91,8 +90,8 @@ ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,
 }
 
 static ssize_t
-ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
-		    unsigned long nr_segs, loff_t pos)
+ext4_file_dio_write(struct kiocb *iocb, struct iov_iter *iter,
+		    loff_t pos)
 {
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file->f_mapping->host;
@@ -100,11 +99,11 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
 	int unaligned_aio = 0;
 	ssize_t ret;
 	int overwrite = 0;
-	size_t length = iov_length(iov, nr_segs);
+	size_t length = iov_iter_count(iter);
 
 	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
 	    !is_sync_kiocb(iocb))
-		unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos);
+		unaligned_aio = ext4_unaligned_aio(inode, iter, pos);
 
 	/* Unaligned direct AIO must be serialized; see comment above */
 	if (unaligned_aio) {
@@ -145,7 +144,7 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
 			overwrite = 1;
 	}
 
-	ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
+	ret = __generic_file_write_iter(iocb, iter, &iocb->ki_pos);
 	mutex_unlock(&inode->i_mutex);
 
 	if (ret > 0 || ret == -EIOCBQUEUED) {
@@ -164,8 +163,7 @@ ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
 }
 
 static ssize_t
-ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
-		unsigned long nr_segs, loff_t pos)
+ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
 {
 	struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
 	ssize_t ret;
@@ -177,22 +175,24 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
 
 	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
 		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-		size_t length = iov_length(iov, nr_segs);
+		size_t length = iov_iter_count(iter);
 
 		if ((pos > sbi->s_bitmap_maxbytes ||
 		    (pos == sbi->s_bitmap_maxbytes && length > 0)))
 			return -EFBIG;
 
 		if (pos + length > sbi->s_bitmap_maxbytes) {
-			nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
-					      sbi->s_bitmap_maxbytes - pos);
+			ret = iov_iter_shorten(iter,
+					       sbi->s_bitmap_maxbytes - pos);
+			if (ret)
+				return ret;
 		}
 	}
 
 	if (unlikely(iocb->ki_filp->f_flags & O_DIRECT))
-		ret = ext4_file_dio_write(iocb, iov, nr_segs, pos);
+		ret = ext4_file_dio_write(iocb, iter, pos);
 	else
-		ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+		ret = generic_file_write_iter(iocb, iter, pos);
 
 	return ret;
 }
@@ -630,8 +630,8 @@ const struct file_operations ext4_file_operations = {
 	.llseek		= ext4_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= ext4_file_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= ext4_file_write_iter,
 	.unlocked_ioctl = ext4_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext4_compat_ioctl,
-- 
1.8.1.1

[PATCH V6 21/30] nfs: add support for read_iter, write_iter

[Dave Kleikamp]

This patch implements the read_iter and write_iter file operations which
allow kernel code to initiate directIO. This allows the loop device to
read and write directly to the server, bypassing the page cache.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: linux-nfs@vger.kernel.org
---
 fs/nfs/direct.c        | 247 +++++++++++++++++++++++++++++++++++++------------
 fs/nfs/file.c          |  33 ++++---
 fs/nfs/internal.h      |   4 +-
 fs/nfs/nfs4file.c      |   4 +-
 include/linux/nfs_fs.h |   6 +-
 5 files changed, 210 insertions(+), 84 deletions(-)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index bceb47e..2b0ebcb 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -90,6 +90,7 @@ struct nfs_direct_req {
 	int			flags;
 #define NFS_ODIRECT_DO_COMMIT		(1)	/* an unstable reply was received */
 #define NFS_ODIRECT_RESCHED_WRITES	(2)	/* write verification failed */
+#define NFS_ODIRECT_MARK_DIRTY		(4)	/* mark read pages dirty */
 	struct nfs_writeverf	verf;		/* unstable write verifier */
 };
 
@@ -131,15 +132,13 @@ ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter,
 
 	return -EINVAL;
 #else
-	const struct iovec *iov = iov_iter_iovec(iter);
-
 	VM_BUG_ON(iocb->ki_left != PAGE_SIZE);
 	VM_BUG_ON(iocb->ki_nbytes != PAGE_SIZE);
 
 	if (rw == READ || rw == KERNEL_READ)
-		return nfs_file_direct_read(iocb, iov, iter->nr_segs, pos,
+		return nfs_file_direct_read(iocb, iter, pos,
 				rw == READ ? true : false);
-	return nfs_file_direct_write(iocb, iov, iter->nr_segs, pos,
+	return nfs_file_direct_write(iocb, iter, pos,
 				rw == WRITE ? true : false);
 #endif /* CONFIG_NFS_SWAP */
 }
@@ -269,7 +268,8 @@ static void nfs_direct_read_completion(struct nfs_pgio_header *hdr)
 		struct nfs_page *req = nfs_list_entry(hdr->pages.next);
 		struct page *page = req->wb_page;
 
-		if (!PageCompound(page) && bytes < hdr->good_bytes)
+		if ((dreq->flags & NFS_ODIRECT_MARK_DIRTY) &&
+		    !PageCompound(page) && bytes < hdr->good_bytes)
 			set_page_dirty(page);
 		bytes += req->wb_bytes;
 		nfs_list_remove_request(req);
@@ -401,24 +401,17 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
 	return result < 0 ? (ssize_t) result : -EFAULT;
 }
 
-static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
-					      const struct iovec *iov,
-					      unsigned long nr_segs,
-					      loff_t pos, bool uio)
+static ssize_t nfs_direct_do_schedule_read_iovec(
+		struct nfs_pageio_descriptor *desc, const struct iovec *iov,
+		unsigned long nr_segs, loff_t pos, bool uio)
 {
-	struct nfs_pageio_descriptor desc;
 	ssize_t result = -EINVAL;
 	size_t requested_bytes = 0;
 	unsigned long seg;
 
-	NFS_PROTO(dreq->inode)->read_pageio_init(&desc, dreq->inode,
-			     &nfs_direct_read_completion_ops);
-	get_dreq(dreq);
-	desc.pg_dreq = dreq;
-
 	for (seg = 0; seg < nr_segs; seg++) {
 		const struct iovec *vec = &iov[seg];
-		result = nfs_direct_read_schedule_segment(&desc, vec, pos, uio);
+		result = nfs_direct_read_schedule_segment(desc, vec, pos, uio);
 		if (result < 0)
 			break;
 		requested_bytes += result;
@@ -426,6 +419,78 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
 			break;
 		pos += vec->iov_len;
 	}
+	if (requested_bytes)
+		return requested_bytes;
+
+	return result < 0 ? result : -EIO;
+}
+
+#ifdef CONFIG_BLOCK
+static ssize_t nfs_direct_do_schedule_read_bvec(
+		struct nfs_pageio_descriptor *desc,
+		struct bio_vec *bvec, unsigned long nr_segs, loff_t pos)
+{
+	struct nfs_direct_req *dreq = desc->pg_dreq;
+	struct nfs_open_context *ctx = dreq->ctx;
+	struct inode *inode = ctx->dentry->d_inode;
+	ssize_t result = -EINVAL;
+	size_t requested_bytes = 0;
+	unsigned long seg;
+	struct nfs_page *req;
+	unsigned int req_len;
+
+	for (seg = 0; seg < nr_segs; seg++) {
+		result = -EIO;
+		req_len = bvec[seg].bv_len;
+		req = nfs_create_request(ctx, inode,
+					 bvec[seg].bv_page,
+					 bvec[seg].bv_offset, req_len);
+		if (IS_ERR(req)) {
+			result = PTR_ERR(req);
+			break;
+		}
+		req->wb_index = pos >> PAGE_SHIFT;
+		req->wb_offset = pos & ~PAGE_MASK;
+		if (!nfs_pageio_add_request(desc, req)) {
+			result = desc->pg_error;
+			nfs_release_request(req);
+			break;
+		}
+		requested_bytes += req_len;
+		pos += req_len;
+	}
+
+	if (requested_bytes)
+		return requested_bytes;
+
+	return result < 0 ? result : -EIO;
+}
+#endif /* CONFIG_BLOCK */
+
+static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq,
+					struct iov_iter *iter, loff_t pos,
+					bool uio)
+{
+	struct nfs_pageio_descriptor desc;
+	ssize_t result;
+
+	NFS_PROTO(dreq->inode)->read_pageio_init(&desc, dreq->inode,
+			     &nfs_direct_read_completion_ops);
+	get_dreq(dreq);
+	desc.pg_dreq = dreq;
+
+	if (iov_iter_has_iovec(iter)) {
+		if (uio)
+			dreq->flags = NFS_ODIRECT_MARK_DIRTY;
+		result = nfs_direct_do_schedule_read_iovec(&desc,
+				iov_iter_iovec(iter), iter->nr_segs, pos, uio);
+#ifdef CONFIG_BLOCK
+	} else if (iov_iter_has_bvec(iter)) {
+		result = nfs_direct_do_schedule_read_bvec(&desc,
+				iov_iter_bvec(iter), iter->nr_segs, pos);
+#endif
+	} else
+		BUG();
 
 	nfs_pageio_complete(&desc);
 
@@ -433,9 +498,9 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
 	 * If no bytes were started, return the error, and let the
 	 * generic layer handle the completion.
 	 */
-	if (requested_bytes == 0) {
+	if (result < 0) {
 		nfs_direct_req_release(dreq);
-		return result < 0 ? result : -EIO;
+		return result;
 	}
 
 	if (put_dreq(dreq))
@@ -443,8 +508,8 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
 	return 0;
 }
 
-static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
-			       unsigned long nr_segs, loff_t pos, bool uio)
+static ssize_t nfs_direct_read(struct kiocb *iocb, struct iov_iter *iter,
+			       loff_t pos, bool uio)
 {
 	ssize_t result = -ENOMEM;
 	struct inode *inode = iocb->ki_filp->f_mapping->host;
@@ -456,7 +521,7 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
 		goto out;
 
 	dreq->inode = inode;
-	dreq->bytes_left = iov_length(iov, nr_segs);
+	dreq->bytes_left = iov_iter_count(iter);
 	dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
 	l_ctx = nfs_get_lock_context(dreq->ctx);
 	if (IS_ERR(l_ctx)) {
@@ -467,8 +532,8 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
 	if (!is_sync_kiocb(iocb))
 		dreq->iocb = iocb;
 
-	NFS_I(inode)->read_io += iov_length(iov, nr_segs);
-	result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos, uio);
+	NFS_I(inode)->read_io += iov_iter_count(iter);
+	result = nfs_direct_read_schedule(dreq, iter, pos, uio);
 	if (!result)
 		result = nfs_direct_wait(dreq);
 out_release:
@@ -802,27 +867,18 @@ static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = {
 	.completion = nfs_direct_write_completion,
 };
 
-static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
-					       const struct iovec *iov,
-					       unsigned long nr_segs,
-					       loff_t pos, bool uio)
+static ssize_t nfs_direct_do_schedule_write_iovec(
+		struct nfs_pageio_descriptor *desc, const struct iovec *iov,
+		unsigned long nr_segs, loff_t pos, bool uio)
 {
-	struct nfs_pageio_descriptor desc;
-	struct inode *inode = dreq->inode;
-	ssize_t result = 0;
+	ssize_t result = -EINVAL;
 	size_t requested_bytes = 0;
 	unsigned long seg;
 
-	NFS_PROTO(inode)->write_pageio_init(&desc, inode, FLUSH_COND_STABLE,
-			      &nfs_direct_write_completion_ops);
-	desc.pg_dreq = dreq;
-	get_dreq(dreq);
-	atomic_inc(&inode->i_dio_count);
-
-	NFS_I(dreq->inode)->write_io += iov_length(iov, nr_segs);
 	for (seg = 0; seg < nr_segs; seg++) {
 		const struct iovec *vec = &iov[seg];
-		result = nfs_direct_write_schedule_segment(&desc, vec, pos, uio);
+		result = nfs_direct_write_schedule_segment(desc, vec,
+							   pos, uio);
 		if (result < 0)
 			break;
 		requested_bytes += result;
@@ -830,16 +886,92 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 			break;
 		pos += vec->iov_len;
 	}
+
+	if (requested_bytes)
+		return requested_bytes;
+
+	return result < 0 ? result : -EIO;
+}
+
+#ifdef CONFIG_BLOCK
+static ssize_t nfs_direct_do_schedule_write_bvec(
+		struct nfs_pageio_descriptor *desc,
+		struct bio_vec *bvec, unsigned long nr_segs, loff_t pos)
+{
+	struct nfs_direct_req *dreq = desc->pg_dreq;
+	struct nfs_open_context *ctx = dreq->ctx;
+	struct inode *inode = dreq->inode;
+	ssize_t result = 0;
+	size_t requested_bytes = 0;
+	unsigned long seg;
+	struct nfs_page *req;
+	unsigned int req_len;
+
+	for (seg = 0; seg < nr_segs; seg++) {
+		req_len = bvec[seg].bv_len;
+
+		req = nfs_create_request(ctx, inode, bvec[seg].bv_page,
+					 bvec[seg].bv_offset, req_len);
+		if (IS_ERR(req)) {
+			result = PTR_ERR(req);
+			break;
+		}
+		nfs_lock_request(req);
+		req->wb_index = pos >> PAGE_SHIFT;
+		req->wb_offset = pos & ~PAGE_MASK;
+		if (!nfs_pageio_add_request(desc, req)) {
+			result = desc->pg_error;
+			nfs_unlock_and_release_request(req);
+			break;
+		}
+		requested_bytes += req_len;
+		pos += req_len;
+	}
+
+	if (requested_bytes)
+		return requested_bytes;
+
+	return result < 0 ? result : -EIO;
+}
+#endif /* CONFIG_BLOCK */
+
+static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq,
+					 struct iov_iter *iter, loff_t pos,
+					 bool uio)
+{
+	struct nfs_pageio_descriptor desc;
+	struct inode *inode = dreq->inode;
+	ssize_t result = 0;
+
+	NFS_PROTO(inode)->write_pageio_init(&desc, inode, FLUSH_COND_STABLE,
+			      &nfs_direct_write_completion_ops);
+	desc.pg_dreq = dreq;
+	get_dreq(dreq);
+	atomic_inc(&inode->i_dio_count);
+
+	NFS_I(dreq->inode)->write_io += iov_iter_count(iter);
+
+	if (iov_iter_has_iovec(iter)) {
+		result = nfs_direct_do_schedule_write_iovec(&desc,
+				iov_iter_iovec(iter), iter->nr_segs, pos, uio);
+#ifdef CONFIG_BLOCK
+	} else if (iov_iter_has_bvec(iter)) {
+		result = nfs_direct_do_schedule_write_bvec(&desc,
+				iov_iter_bvec(iter), iter->nr_segs, pos);
+#endif
+	} else
+		BUG();
+
 	nfs_pageio_complete(&desc);
 
 	/*
 	 * If no bytes were started, return the error, and let the
 	 * generic layer handle the completion.
 	 */
-	if (requested_bytes == 0) {
+	if (result < 0) {
 		inode_dio_done(inode);
 		nfs_direct_req_release(dreq);
-		return result < 0 ? result : -EIO;
+		return result;
 	}
 
 	if (put_dreq(dreq))
@@ -847,9 +979,8 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
 	return 0;
 }
 
-static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov,
-				unsigned long nr_segs, loff_t pos,
-				size_t count, bool uio)
+static ssize_t nfs_direct_write(struct kiocb *iocb, struct iov_iter *iter,
+				loff_t pos, bool uio)
 {
 	ssize_t result = -ENOMEM;
 	struct inode *inode = iocb->ki_filp->f_mapping->host;
@@ -861,7 +992,7 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov,
 		goto out;
 
 	dreq->inode = inode;
-	dreq->bytes_left = count;
+	dreq->bytes_left = iov_iter_count(iter);
 	dreq->ctx = get_nfs_open_context(nfs_file_open_context(iocb->ki_filp));
 	l_ctx = nfs_get_lock_context(dreq->ctx);
 	if (IS_ERR(l_ctx)) {
@@ -872,7 +1003,7 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov,
 	if (!is_sync_kiocb(iocb))
 		dreq->iocb = iocb;
 
-	result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, uio);
+	result = nfs_direct_write_schedule(dreq, iter, pos, uio);
 	if (!result)
 		result = nfs_direct_wait(dreq);
 out_release:
@@ -884,12 +1015,11 @@ out:
 /**
  * nfs_file_direct_read - file direct read operation for NFS files
  * @iocb: target I/O control block
- * @iov: vector of user buffers into which to read data
- * @nr_segs: size of iov vector
+ * @iter: vector of buffers into which to read data
  * @pos: byte offset in file where reading starts
  *
  * We use this function for direct reads instead of calling
- * generic_file_aio_read() in order to avoid gfar's check to see if
+ * generic_file_read_iter() in order to avoid gfar's check to see if
  * the request starts before the end of the file.  For that check
  * to work, we must generate a GETATTR before each direct read, and
  * even then there is a window between the GETATTR and the subsequent
@@ -902,15 +1032,15 @@ out:
  * client must read the updated atime from the server back into its
  * cache.
  */
-ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov,
-				unsigned long nr_segs, loff_t pos, bool uio)
+ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
+			     loff_t pos, bool uio)
 {
 	ssize_t retval = -EINVAL;
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
 	size_t count;
 
-	count = iov_length(iov, nr_segs);
+	count = iov_iter_count(iter);
 	nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count);
 
 	dfprintk(FILE, "NFS: direct read(%s/%s, %zd@%Ld)\n",
@@ -928,7 +1058,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov,
 
 	task_io_account_read(count);
 
-	retval = nfs_direct_read(iocb, iov, nr_segs, pos, uio);
+	retval = nfs_direct_read(iocb, iter, pos, uio);
 	if (retval > 0)
 		iocb->ki_pos = pos + retval;
 
@@ -939,12 +1069,11 @@ out:
 /**
  * nfs_file_direct_write - file direct write operation for NFS files
  * @iocb: target I/O control block
- * @iov: vector of user buffers from which to write data
- * @nr_segs: size of iov vector
+ * @iter: vector of buffers from which to write data
  * @pos: byte offset in file where writing starts
  *
  * We use this function for direct writes instead of calling
- * generic_file_aio_write() in order to avoid taking the inode
+ * generic_file_write_iter() in order to avoid taking the inode
  * semaphore and updating the i_size.  The NFS server will set
  * the new i_size and this client must read the updated size
  * back into its cache.  We let the server do generic write
@@ -958,15 +1087,15 @@ out:
  * Note that O_APPEND is not supported for NFS direct writes, as there
  * is no atomic O_APPEND write facility in the NFS protocol.
  */
-ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
-				unsigned long nr_segs, loff_t pos, bool uio)
+ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
+			      loff_t pos, bool uio)
 {
 	ssize_t retval = -EINVAL;
 	struct file *file = iocb->ki_filp;
 	struct address_space *mapping = file->f_mapping;
 	size_t count;
 
-	count = iov_length(iov, nr_segs);
+	count = iov_iter_count(iter);
 	nfs_add_stats(mapping->host, NFSIOS_DIRECTWRITTENBYTES, count);
 
 	dfprintk(FILE, "NFS: direct write(%s/%s, %zd@%Ld)\n",
@@ -991,7 +1120,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
 
 	task_io_account_write(count);
 
-	retval = nfs_direct_write(iocb, iov, nr_segs, pos, count, uio);
+	retval = nfs_direct_write(iocb, iter, pos, uio);
 	if (retval > 0) {
 		struct inode *inode = mapping->host;
 
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 3c2b893..28119c5 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -172,29 +172,28 @@ nfs_file_flush(struct file *file, fl_owner_t id)
 EXPORT_SYMBOL_GPL(nfs_file_flush);
 
 ssize_t
-nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
-		unsigned long nr_segs, loff_t pos)
+nfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
 {
 	struct dentry * dentry = iocb->ki_filp->f_path.dentry;
 	struct inode * inode = dentry->d_inode;
 	ssize_t result;
 
 	if (iocb->ki_filp->f_flags & O_DIRECT)
-		return nfs_file_direct_read(iocb, iov, nr_segs, pos, true);
+		return nfs_file_direct_read(iocb, iter, pos, true);
 
-	dprintk("NFS: read(%s/%s, %lu@%lu)\n",
+	dprintk("NFS: read_iter(%s/%s, %lu@%lu)\n",
 		dentry->d_parent->d_name.name, dentry->d_name.name,
-		(unsigned long) iov_length(iov, nr_segs), (unsigned long) pos);
+		(unsigned long) iov_iter_count(iter), (unsigned long) pos);
 
 	result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
 	if (!result) {
-		result = generic_file_aio_read(iocb, iov, nr_segs, pos);
+		result = generic_file_read_iter(iocb, iter, pos);
 		if (result > 0)
 			nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, result);
 	}
 	return result;
 }
-EXPORT_SYMBOL_GPL(nfs_file_read);
+EXPORT_SYMBOL_GPL(nfs_file_read_iter);
 
 ssize_t
 nfs_file_splice_read(struct file *filp, loff_t *ppos,
@@ -250,7 +249,7 @@ EXPORT_SYMBOL_GPL(nfs_file_mmap);
  * disk, but it retrieves and clears ctx->error after synching, despite
  * the two being set at the same time in nfs_context_set_write_error().
  * This is because the former is used to notify the _next_ call to
- * nfs_file_write() that a write error occurred, and hence cause it to
+ * nfs_file_write_iter() that a write error occurred, and hence cause it to
  * fall back to doing a synchronous write.
  */
 int
@@ -610,19 +609,19 @@ static int nfs_need_sync_write(struct file *filp, struct inode *inode)
 	return 0;
 }
 
-ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
-		       unsigned long nr_segs, loff_t pos)
+ssize_t nfs_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+				   loff_t pos)
 {
 	struct dentry * dentry = iocb->ki_filp->f_path.dentry;
 	struct inode * inode = dentry->d_inode;
 	unsigned long written = 0;
 	ssize_t result;
-	size_t count = iov_length(iov, nr_segs);
+	size_t count = iov_iter_count(iter);
 
 	if (iocb->ki_filp->f_flags & O_DIRECT)
-		return nfs_file_direct_write(iocb, iov, nr_segs, pos, true);
+		return nfs_file_direct_write(iocb, iter, pos, true);
 
-	dprintk("NFS: write(%s/%s, %lu@%Ld)\n",
+	dprintk("NFS: write_iter(%s/%s, %lu@%lld)\n",
 		dentry->d_parent->d_name.name, dentry->d_name.name,
 		(unsigned long) count, (long long) pos);
 
@@ -642,7 +641,7 @@ ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
 	if (!count)
 		goto out;
 
-	result = generic_file_aio_write(iocb, iov, nr_segs, pos);
+	result = generic_file_write_iter(iocb, iter, pos);
 	if (result > 0)
 		written = result;
 
@@ -661,7 +660,7 @@ out_swapfile:
 	printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
 	goto out;
 }
-EXPORT_SYMBOL_GPL(nfs_file_write);
+EXPORT_SYMBOL_GPL(nfs_file_write_iter);
 
 ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe,
 			      struct file *filp, loff_t *ppos,
@@ -912,8 +911,8 @@ const struct file_operations nfs_file_operations = {
 	.llseek		= nfs_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= nfs_file_read,
-	.aio_write	= nfs_file_write,
+	.read_iter	= nfs_file_read_iter,
+	.write_iter	= nfs_file_write_iter,
 	.mmap		= nfs_file_mmap,
 	.open		= nfs_file_open,
 	.flush		= nfs_file_flush,
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index f0e6c7d..b56eee7 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -278,11 +278,11 @@ int nfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *)
 int nfs_file_fsync_commit(struct file *, loff_t, loff_t, int);
 loff_t nfs_file_llseek(struct file *, loff_t, int);
 int nfs_file_flush(struct file *, fl_owner_t);
-ssize_t nfs_file_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
+ssize_t nfs_file_read_iter(struct kiocb *, struct iov_iter *, loff_t);
 ssize_t nfs_file_splice_read(struct file *, loff_t *, struct pipe_inode_info *,
 			     size_t, unsigned int);
 int nfs_file_mmap(struct file *, struct vm_area_struct *);
-ssize_t nfs_file_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
+ssize_t nfs_file_write_iter(struct kiocb *, struct iov_iter *, loff_t);
 int nfs_file_release(struct inode *, struct file *);
 int nfs_lock(struct file *, int, struct file_lock *);
 int nfs_flock(struct file *, int, struct file_lock *);
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 08ddccc..0da1f48 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -122,8 +122,8 @@ const struct file_operations nfs4_file_operations = {
 	.llseek		= nfs_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= nfs_file_read,
-	.aio_write	= nfs_file_write,
+	.read_iter	= nfs_file_read_iter,
+	.write_iter	= nfs_file_write_iter,
 	.mmap		= nfs_file_mmap,
 	.open		= nfs4_file_open,
 	.flush		= nfs_file_flush,
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 4913e3c..9f8e8a9 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -445,11 +445,9 @@ extern int nfs3_removexattr (struct dentry *, const char *name);
  * linux/fs/nfs/direct.c
  */
 extern ssize_t nfs_direct_IO(int, struct kiocb *, struct iov_iter *, loff_t);
-extern ssize_t nfs_file_direct_read(struct kiocb *iocb,
-			const struct iovec *iov, unsigned long nr_segs,
+extern ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
 			loff_t pos, bool uio);
-extern ssize_t nfs_file_direct_write(struct kiocb *iocb,
-			const struct iovec *iov, unsigned long nr_segs,
+extern ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
 			loff_t pos, bool uio);
 
 /*
-- 
1.8.1.1

[PATCH V6 22/30] nfs: simplify swap

[Dave Kleikamp]

swap_writepage can now call nfs's write_iter f_op, eliminating the need to
implement for the special-case direct_IO a_op. There is no longer a need to
pass the uio flag through the direct write path.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: linux-nfs@vger.kernel.org
---
 fs/nfs/direct.c           | 94 ++++++++++++++++-------------------------------
 fs/nfs/file.c             |  4 +-
 include/linux/blk_types.h |  2 -
 include/linux/fs.h        |  2 -
 include/linux/nfs_fs.h    |  4 +-
 mm/page_io.c              | 13 +++----
 6 files changed, 42 insertions(+), 77 deletions(-)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 2b0ebcb..239c2fe 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -118,29 +118,18 @@ static inline int put_dreq(struct nfs_direct_req *dreq)
  * @nr_segs: size of iovec array
  *
  * The presence of this routine in the address space ops vector means
- * the NFS client supports direct I/O. However, for most direct IO, we
- * shunt off direct read and write requests before the VFS gets them,
- * so this method is only ever called for swap.
+ * the NFS client supports direct I/O. However, we shunt off direct
+ * read and write requests before the VFS gets them, so this method
+ * should never be called.
  */
 ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter,
 		      loff_t pos)
 {
-#ifndef CONFIG_NFS_SWAP
 	dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n",
 			iocb->ki_filp->f_path.dentry->d_name.name,
 			(long long) pos, iter->nr_segs);
 
 	return -EINVAL;
-#else
-	VM_BUG_ON(iocb->ki_left != PAGE_SIZE);
-	VM_BUG_ON(iocb->ki_nbytes != PAGE_SIZE);
-
-	if (rw == READ || rw == KERNEL_READ)
-		return nfs_file_direct_read(iocb, iter, pos,
-				rw == READ ? true : false);
-	return nfs_file_direct_write(iocb, iter, pos,
-				rw == WRITE ? true : false);
-#endif /* CONFIG_NFS_SWAP */
 }
 
 static void nfs_direct_release_pages(struct page **pages, unsigned int npages)
@@ -312,7 +301,7 @@ static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = {
  */
 static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *desc,
 						const struct iovec *iov,
-						loff_t pos, bool uio)
+						loff_t pos)
 {
 	struct nfs_direct_req *dreq = desc->pg_dreq;
 	struct nfs_open_context *ctx = dreq->ctx;
@@ -340,20 +329,12 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
 					  GFP_KERNEL);
 		if (!pagevec)
 			break;
-		if (uio) {
-			down_read(&current->mm->mmap_sem);
-			result = get_user_pages(current, current->mm, user_addr,
+		down_read(&current->mm->mmap_sem);
+		result = get_user_pages(current, current->mm, user_addr,
 					npages, 1, 0, pagevec, NULL);
-			up_read(&current->mm->mmap_sem);
-			if (result < 0)
-				break;
-		} else {
-			WARN_ON(npages != 1);
-			result = get_kernel_page(user_addr, 1, pagevec);
-			if (WARN_ON(result != 1))
-				break;
-		}
-
+		up_read(&current->mm->mmap_sem);
+		if (result < 0)
+			break;
 		if ((unsigned)result < npages) {
 			bytes = result * PAGE_SIZE;
 			if (bytes <= pgbase) {
@@ -403,7 +384,7 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
 
 static ssize_t nfs_direct_do_schedule_read_iovec(
 		struct nfs_pageio_descriptor *desc, const struct iovec *iov,
-		unsigned long nr_segs, loff_t pos, bool uio)
+		unsigned long nr_segs, loff_t pos)
 {
 	ssize_t result = -EINVAL;
 	size_t requested_bytes = 0;
@@ -411,7 +392,7 @@ static ssize_t nfs_direct_do_schedule_read_iovec(
 
 	for (seg = 0; seg < nr_segs; seg++) {
 		const struct iovec *vec = &iov[seg];
-		result = nfs_direct_read_schedule_segment(desc, vec, pos, uio);
+		result = nfs_direct_read_schedule_segment(desc, vec, pos);
 		if (result < 0)
 			break;
 		requested_bytes += result;
@@ -468,8 +449,7 @@ static ssize_t nfs_direct_do_schedule_read_bvec(
 #endif /* CONFIG_BLOCK */
 
 static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq,
-					struct iov_iter *iter, loff_t pos,
-					bool uio)
+					struct iov_iter *iter, loff_t pos)
 {
 	struct nfs_pageio_descriptor desc;
 	ssize_t result;
@@ -480,10 +460,8 @@ static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq,
 	desc.pg_dreq = dreq;
 
 	if (iov_iter_has_iovec(iter)) {
-		if (uio)
-			dreq->flags = NFS_ODIRECT_MARK_DIRTY;
 		result = nfs_direct_do_schedule_read_iovec(&desc,
-				iov_iter_iovec(iter), iter->nr_segs, pos, uio);
+				iov_iter_iovec(iter), iter->nr_segs, pos);
 #ifdef CONFIG_BLOCK
 	} else if (iov_iter_has_bvec(iter)) {
 		result = nfs_direct_do_schedule_read_bvec(&desc,
@@ -509,7 +487,7 @@ static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq,
 }
 
 static ssize_t nfs_direct_read(struct kiocb *iocb, struct iov_iter *iter,
-			       loff_t pos, bool uio)
+			       loff_t pos)
 {
 	ssize_t result = -ENOMEM;
 	struct inode *inode = iocb->ki_filp->f_mapping->host;
@@ -533,7 +511,7 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, struct iov_iter *iter,
 		dreq->iocb = iocb;
 
 	NFS_I(inode)->read_io += iov_iter_count(iter);
-	result = nfs_direct_read_schedule(dreq, iter, pos, uio);
+	result = nfs_direct_read_schedule(dreq, iter, pos);
 	if (!result)
 		result = nfs_direct_wait(dreq);
 out_release:
@@ -698,7 +676,7 @@ static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode
  */
 static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *desc,
 						 const struct iovec *iov,
-						 loff_t pos, bool uio)
+						 loff_t pos)
 {
 	struct nfs_direct_req *dreq = desc->pg_dreq;
 	struct nfs_open_context *ctx = dreq->ctx;
@@ -726,19 +704,12 @@ static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *d
 		if (!pagevec)
 			break;
 
-		if (uio) {
-			down_read(&current->mm->mmap_sem);
-			result = get_user_pages(current, current->mm, user_addr,
-						npages, 0, 0, pagevec, NULL);
-			up_read(&current->mm->mmap_sem);
-			if (result < 0)
-				break;
-		} else {
-			WARN_ON(npages != 1);
-			result = get_kernel_page(user_addr, 0, pagevec);
-			if (WARN_ON(result != 1))
-				break;
-		}
+		down_read(&current->mm->mmap_sem);
+		result = get_user_pages(current, current->mm, user_addr,
+					npages, 0, 0, pagevec, NULL);
+		up_read(&current->mm->mmap_sem);
+		if (result < 0)
+			break;
 
 		if ((unsigned)result < npages) {
 			bytes = result * PAGE_SIZE;
@@ -869,7 +840,7 @@ static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = {
 
 static ssize_t nfs_direct_do_schedule_write_iovec(
 		struct nfs_pageio_descriptor *desc, const struct iovec *iov,
-		unsigned long nr_segs, loff_t pos, bool uio)
+		unsigned long nr_segs, loff_t pos)
 {
 	ssize_t result = -EINVAL;
 	size_t requested_bytes = 0;
@@ -878,7 +849,7 @@ static ssize_t nfs_direct_do_schedule_write_iovec(
 	for (seg = 0; seg < nr_segs; seg++) {
 		const struct iovec *vec = &iov[seg];
 		result = nfs_direct_write_schedule_segment(desc, vec,
-							   pos, uio);
+							   pos);
 		if (result < 0)
 			break;
 		requested_bytes += result;
@@ -936,8 +907,7 @@ static ssize_t nfs_direct_do_schedule_write_bvec(
 #endif /* CONFIG_BLOCK */
 
 static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq,
-					 struct iov_iter *iter, loff_t pos,
-					 bool uio)
+					 struct iov_iter *iter, loff_t pos)
 {
 	struct nfs_pageio_descriptor desc;
 	struct inode *inode = dreq->inode;
@@ -953,7 +923,7 @@ static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq,
 
 	if (iov_iter_has_iovec(iter)) {
 		result = nfs_direct_do_schedule_write_iovec(&desc,
-				iov_iter_iovec(iter), iter->nr_segs, pos, uio);
+				iov_iter_iovec(iter), iter->nr_segs, pos);
 #ifdef CONFIG_BLOCK
 	} else if (iov_iter_has_bvec(iter)) {
 		result = nfs_direct_do_schedule_write_bvec(&desc,
@@ -980,7 +950,7 @@ static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq,
 }
 
 static ssize_t nfs_direct_write(struct kiocb *iocb, struct iov_iter *iter,
-				loff_t pos, bool uio)
+				loff_t pos)
 {
 	ssize_t result = -ENOMEM;
 	struct inode *inode = iocb->ki_filp->f_mapping->host;
@@ -1003,7 +973,7 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, struct iov_iter *iter,
 	if (!is_sync_kiocb(iocb))
 		dreq->iocb = iocb;
 
-	result = nfs_direct_write_schedule(dreq, iter, pos, uio);
+	result = nfs_direct_write_schedule(dreq, iter, pos);
 	if (!result)
 		result = nfs_direct_wait(dreq);
 out_release:
@@ -1033,7 +1003,7 @@ out:
  * cache.
  */
 ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
-			     loff_t pos, bool uio)
+			     loff_t pos)
 {
 	ssize_t retval = -EINVAL;
 	struct file *file = iocb->ki_filp;
@@ -1058,7 +1028,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
 
 	task_io_account_read(count);
 
-	retval = nfs_direct_read(iocb, iter, pos, uio);
+	retval = nfs_direct_read(iocb, iter, pos);
 	if (retval > 0)
 		iocb->ki_pos = pos + retval;
 
@@ -1088,7 +1058,7 @@ out:
  * is no atomic O_APPEND write facility in the NFS protocol.
  */
 ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
-			      loff_t pos, bool uio)
+			      loff_t pos)
 {
 	ssize_t retval = -EINVAL;
 	struct file *file = iocb->ki_filp;
@@ -1120,7 +1090,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
 
 	task_io_account_write(count);
 
-	retval = nfs_direct_write(iocb, iter, pos, uio);
+	retval = nfs_direct_write(iocb, iter, pos);
 	if (retval > 0) {
 		struct inode *inode = mapping->host;
 
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 28119c5..83cbc6c 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -179,7 +179,7 @@ nfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
 	ssize_t result;
 
 	if (iocb->ki_filp->f_flags & O_DIRECT)
-		return nfs_file_direct_read(iocb, iter, pos, true);
+		return nfs_file_direct_read(iocb, iter, pos);
 
 	dprintk("NFS: read_iter(%s/%s, %lu@%lu)\n",
 		dentry->d_parent->d_name.name, dentry->d_name.name,
@@ -619,7 +619,7 @@ ssize_t nfs_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
 	size_t count = iov_iter_count(iter);
 
 	if (iocb->ki_filp->f_flags & O_DIRECT)
-		return nfs_file_direct_write(iocb, iter, pos, true);
+		return nfs_file_direct_write(iocb, iter, pos);
 
 	dprintk("NFS: write_iter(%s/%s, %lu@%lld)\n",
 		dentry->d_parent->d_name.name, dentry->d_name.name,
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index cdf1119..3134079 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -174,7 +174,6 @@ enum rq_flag_bits {
 	__REQ_FLUSH_SEQ,	/* request for flush sequence */
 	__REQ_IO_STAT,		/* account I/O stat */
 	__REQ_MIXED_MERGE,	/* merge of different types, fail separately */
-	__REQ_KERNEL, 		/* direct IO to kernel pages */
 	__REQ_NR_BITS,		/* stops here */
 };
 
@@ -222,6 +221,5 @@ enum rq_flag_bits {
 #define REQ_IO_STAT		(1 << __REQ_IO_STAT)
 #define REQ_MIXED_MERGE		(1 << __REQ_MIXED_MERGE)
 #define REQ_SECURE		(1 << __REQ_SECURE)
-#define REQ_KERNEL		(1 << __REQ_KERNEL)
 
 #endif /* __LINUX_BLK_TYPES_H */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 31d2e17..679c7cc 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -180,8 +180,6 @@ typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 #define READ			0
 #define WRITE			RW_MASK
 #define READA			RWA_MASK
-#define KERNEL_READ		(READ|REQ_KERNEL)
-#define KERNEL_WRITE		(WRITE|REQ_KERNEL)
 
 #define READ_SYNC		(READ | REQ_SYNC)
 #define WRITE_SYNC		(WRITE | REQ_SYNC | REQ_NOIDLE)
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 9f8e8a9..6033367 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -446,9 +446,9 @@ extern int nfs3_removexattr (struct dentry *, const char *name);
  */
 extern ssize_t nfs_direct_IO(int, struct kiocb *, struct iov_iter *, loff_t);
 extern ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
-			loff_t pos, bool uio);
+			loff_t pos);
 extern ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
-			loff_t pos, bool uio);
+			loff_t pos);
 
 /*
  * linux/fs/nfs/dir.c
diff --git a/mm/page_io.c b/mm/page_io.c
index 33da274..60a5503 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -203,14 +203,14 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
 	if (sis->flags & SWP_FILE) {
 		struct kiocb kiocb;
 		struct file *swap_file = sis->swap_file;
-		struct address_space *mapping = swap_file->f_mapping;
-		struct iovec iov = {
-			.iov_base = kmap(page),
-			.iov_len  = PAGE_SIZE,
+		struct bio_vec bvec = {
+			.bv_page = kmap(page),
+			.bv_len = PAGE_SIZE,
+			.bv_offset = 0,
 		};
 		struct iov_iter iter;
 
-		iov_iter_init(&iter, &iov, 1, PAGE_SIZE, 0);
+		iov_iter_init_bvec(&iter, &bvec, 1, PAGE_SIZE, 0);
 
 		init_sync_kiocb(&kiocb, swap_file);
 		kiocb.ki_pos = page_file_offset(page);
@@ -218,8 +218,7 @@ int swap_writepage(struct page *page, struct writeback_control *wbc)
 		kiocb.ki_nbytes = PAGE_SIZE;
 
 		unlock_page(page);
-		ret = mapping->a_ops->direct_IO(KERNEL_WRITE, &kiocb, &iter,
-						kiocb.ki_pos);
+		ret = swap_file->f_op->write_iter(&kiocb, &iter, kiocb.ki_pos);
 		kunmap(page);
 		if (ret == PAGE_SIZE) {
 			count_vm_event(PSWPOUT);
-- 
1.8.1.1

[PATCH V6 23/30] btrfs: add support for read_iter and write_iter

[Dave Kleikamp]

btrfs can use generic_file_read_iter(). Base btrfs_file_write_iter()
on btrfs_file_aio_write(), then have the latter call the former.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: linux-btrfs@vger.kernel.org
---
 fs/btrfs/file.c | 42 ++++++++++++++----------------------------
 1 file changed, 14 insertions(+), 28 deletions(-)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index f76b1fd..f23e24b 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -437,7 +437,7 @@ static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
 		write_bytes -= copied;
 		total_copied += copied;
 
-		/* Return to btrfs_file_aio_write to fault page */
+		/* Return to btrfs_file_write_iter to fault page */
 		if (unlikely(copied == 0))
 			break;
 
@@ -1426,27 +1426,23 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
 }
 
 static ssize_t __btrfs_direct_write(struct kiocb *iocb,
-				    const struct iovec *iov,
-				    unsigned long nr_segs, loff_t pos,
-				    loff_t *ppos, size_t count, size_t ocount)
+				     struct iov_iter *iter, loff_t pos,
+				    loff_t *ppos, size_t count)
 {
 	struct file *file = iocb->ki_filp;
-	struct iov_iter i;
 	ssize_t written;
 	ssize_t written_buffered;
 	loff_t endbyte;
 	int err;
 
-	written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos,
-					    count, ocount);
+	written = generic_file_direct_write_iter(iocb, iter, pos, ppos, count);
 
 	if (written < 0 || written == count)
 		return written;
 
 	pos += written;
 	count -= written;
-	iov_iter_init(&i, iov, nr_segs, count, written);
-	written_buffered = __btrfs_buffered_write(file, &i, pos);
+	written_buffered = __btrfs_buffered_write(file, iter, pos);
 	if (written_buffered < 0) {
 		err = written_buffered;
 		goto out;
@@ -1481,9 +1477,8 @@ static void update_time_for_write(struct inode *inode)
 		inode_inc_iversion(inode);
 }
 
-static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
-				    const struct iovec *iov,
-				    unsigned long nr_segs, loff_t pos)
+static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
+				     struct iov_iter *iter, loff_t pos)
 {
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = fdentry(file)->d_inode;
@@ -1492,19 +1487,14 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
 	u64 start_pos;
 	ssize_t num_written = 0;
 	ssize_t err = 0;
-	size_t count, ocount;
+	size_t count;
 	bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
 
 	sb_start_write(inode->i_sb);
 
 	mutex_lock(&inode->i_mutex);
 
-	err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
-	if (err) {
-		mutex_unlock(&inode->i_mutex);
-		goto out;
-	}
-	count = ocount;
+	count = iov_iter_count(iter);
 
 	current->backing_dev_info = inode->i_mapping->backing_dev_info;
 	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
@@ -1557,14 +1547,10 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
 		atomic_inc(&BTRFS_I(inode)->sync_writers);
 
 	if (unlikely(file->f_flags & O_DIRECT)) {
-		num_written = __btrfs_direct_write(iocb, iov, nr_segs,
-						   pos, ppos, count, ocount);
+		num_written = __btrfs_direct_write(iocb, iter, pos, ppos,
+						   count);
 	} else {
-		struct iov_iter i;
-
-		iov_iter_init(&i, iov, nr_segs, count, num_written);
-
-		num_written = __btrfs_buffered_write(file, &i, pos);
+		num_written = __btrfs_buffered_write(file, iter, pos);
 		if (num_written > 0)
 			*ppos = pos + num_written;
 	}
@@ -2387,9 +2373,9 @@ const struct file_operations btrfs_file_operations = {
 	.llseek		= btrfs_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read       = generic_file_aio_read,
 	.splice_read	= generic_file_splice_read,
-	.aio_write	= btrfs_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= btrfs_file_write_iter,
 	.mmap		= btrfs_file_mmap,
 	.open		= generic_file_open,
 	.release	= btrfs_release_file,
-- 
1.8.1.1

[PATCH V6 24/30] block_dev: add support for read_iter, write_iter

[Dave Kleikamp]

From: Asias He <asias@redhat.com>

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
---
 drivers/char/raw.c |  4 ++--
 fs/block_dev.c     | 19 +++++++++----------
 include/linux/fs.h |  4 ++--
 3 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/char/raw.c b/drivers/char/raw.c
index 54a3a6d..443c2d8 100644
--- a/drivers/char/raw.c
+++ b/drivers/char/raw.c
@@ -285,9 +285,9 @@ static long raw_ctl_compat_ioctl(struct file *file, unsigned int cmd,
 
 static const struct file_operations raw_fops = {
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= blkdev_aio_write,
+	.write_iter	= blkdev_write_iter,
 	.fsync		= blkdev_fsync,
 	.open		= raw_open,
 	.release	= raw_release,
diff --git a/fs/block_dev.c b/fs/block_dev.c
index df8aa76..039ae6a 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1521,8 +1521,7 @@ static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
  * Does not take i_mutex for the write and thus is not for general purpose
  * use.
  */
-ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
-			 unsigned long nr_segs, loff_t pos)
+ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
 {
 	struct file *file = iocb->ki_filp;
 	struct blk_plug plug;
@@ -1531,7 +1530,7 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 	BUG_ON(iocb->ki_pos != pos);
 
 	blk_start_plug(&plug);
-	ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
+	ret = __generic_file_write_iter(iocb, iter, &iocb->ki_pos);
 	if (ret > 0 || ret == -EIOCBQUEUED) {
 		ssize_t err;
 
@@ -1542,10 +1541,10 @@ ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
 	blk_finish_plug(&plug);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(blkdev_aio_write);
+EXPORT_SYMBOL_GPL(blkdev_write_iter);
 
-static ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov,
-			 unsigned long nr_segs, loff_t pos)
+static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *iter,
+			 loff_t pos)
 {
 	struct file *file = iocb->ki_filp;
 	struct inode *bd_inode = file->f_mapping->host;
@@ -1556,8 +1555,8 @@ static ssize_t blkdev_aio_read(struct kiocb *iocb, const struct iovec *iov,
 
 	size -= pos;
 	if (size < INT_MAX)
-		nr_segs = iov_shorten((struct iovec *)iov, nr_segs, size);
-	return generic_file_aio_read(iocb, iov, nr_segs, pos);
+		iov_iter_shorten(iter, size);
+	return generic_file_read_iter(iocb, iter, pos);
 }
 
 /*
@@ -1590,8 +1589,8 @@ const struct file_operations def_blk_fops = {
 	.llseek		= block_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= blkdev_aio_read,
-	.aio_write	= blkdev_aio_write,
+	.read_iter	= blkdev_read_iter,
+	.write_iter	= blkdev_write_iter,
 	.mmap		= generic_file_mmap,
 	.fsync		= blkdev_fsync,
 	.unlocked_ioctl	= block_ioctl,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 679c7cc..8cc8b0d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2485,8 +2485,8 @@ extern int generic_segment_checks(const struct iovec *iov,
 		unsigned long *nr_segs, size_t *count, int access_flags);
 
 /* fs/block_dev.c */
-extern ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
-				unsigned long nr_segs, loff_t pos);
+extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+				 loff_t pos);
 extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
 			int datasync);
 extern void block_sync_page(struct page *page);
-- 
1.8.1.1

[PATCH V6 25/30] xfs: add support for read_iter and write_iter

[Dave Kleikamp]

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Ben Myers <bpm@sgi.com>
Cc: Alex Elder <elder@kernel.org>
Cc: xfs@oss.sgi.com
---
 fs/xfs/xfs_file.c | 51 ++++++++++++++++++++-------------------------------
 1 file changed, 20 insertions(+), 31 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 67284ed..c5d74e8 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -225,10 +225,9 @@ xfs_file_fsync(
 }
 
 STATIC ssize_t
-xfs_file_aio_read(
+xfs_file_read_iter(
 	struct kiocb		*iocb,
-	const struct iovec	*iovp,
-	unsigned long		nr_segs,
+	struct iov_iter		*iter,
 	loff_t			pos)
 {
 	struct file		*file = iocb->ki_filp;
@@ -249,9 +248,7 @@ xfs_file_aio_read(
 	if (file->f_mode & FMODE_NOCMTIME)
 		ioflags |= IO_INVIS;
 
-	ret = generic_segment_checks(iovp, &nr_segs, &size, VERIFY_WRITE);
-	if (ret < 0)
-		return ret;
+	size = iov_iter_count(iter);
 
 	if (unlikely(ioflags & IO_ISDIRECT)) {
 		xfs_buftarg_t	*target =
@@ -304,7 +301,7 @@ xfs_file_aio_read(
 
 	trace_xfs_file_read(ip, size, pos, ioflags);
 
-	ret = generic_file_aio_read(iocb, iovp, nr_segs, pos);
+	ret = generic_file_read_iter(iocb, iter, pos);
 	if (ret > 0)
 		XFS_STATS_ADD(xs_read_bytes, ret);
 
@@ -620,10 +617,9 @@ restart:
 STATIC ssize_t
 xfs_file_dio_aio_write(
 	struct kiocb		*iocb,
-	const struct iovec	*iovp,
-	unsigned long		nr_segs,
+	struct iov_iter		*iter,
 	loff_t			pos,
-	size_t			ocount)
+	size_t			count)
 {
 	struct file		*file = iocb->ki_filp;
 	struct address_space	*mapping = file->f_mapping;
@@ -631,7 +627,6 @@ xfs_file_dio_aio_write(
 	struct xfs_inode	*ip = XFS_I(inode);
 	struct xfs_mount	*mp = ip->i_mount;
 	ssize_t			ret = 0;
-	size_t			count = ocount;
 	int			unaligned_io = 0;
 	int			iolock;
 	struct xfs_buftarg	*target = XFS_IS_REALTIME_INODE(ip) ?
@@ -691,8 +686,8 @@ xfs_file_dio_aio_write(
 	}
 
 	trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
-	ret = generic_file_direct_write(iocb, iovp,
-			&nr_segs, pos, &iocb->ki_pos, count, ocount);
+	ret = generic_file_direct_write_iter(iocb, iter,
+			pos, &iocb->ki_pos, count);
 
 out:
 	xfs_rw_iunlock(ip, iolock);
@@ -705,10 +700,9 @@ out:
 STATIC ssize_t
 xfs_file_buffered_aio_write(
 	struct kiocb		*iocb,
-	const struct iovec	*iovp,
-	unsigned long		nr_segs,
+	struct iov_iter		*iter,
 	loff_t			pos,
-	size_t			ocount)
+	size_t			count)
 {
 	struct file		*file = iocb->ki_filp;
 	struct address_space	*mapping = file->f_mapping;
@@ -717,7 +711,6 @@ xfs_file_buffered_aio_write(
 	ssize_t			ret;
 	int			enospc = 0;
 	int			iolock = XFS_IOLOCK_EXCL;
-	size_t			count = ocount;
 
 	xfs_rw_ilock(ip, iolock);
 
@@ -730,7 +723,7 @@ xfs_file_buffered_aio_write(
 
 write_retry:
 	trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0);
-	ret = generic_file_buffered_write(iocb, iovp, nr_segs,
+	ret = generic_file_buffered_write_iter(iocb, iter,
 			pos, &iocb->ki_pos, count, 0);
 
 	/*
@@ -751,10 +744,9 @@ out:
 }
 
 STATIC ssize_t
-xfs_file_aio_write(
+xfs_file_write_iter(
 	struct kiocb		*iocb,
-	const struct iovec	*iovp,
-	unsigned long		nr_segs,
+	struct iov_iter		*iter,
 	loff_t			pos)
 {
 	struct file		*file = iocb->ki_filp;
@@ -762,17 +754,15 @@ xfs_file_aio_write(
 	struct inode		*inode = mapping->host;
 	struct xfs_inode	*ip = XFS_I(inode);
 	ssize_t			ret;
-	size_t			ocount = 0;
+	size_t			count = 0;
 
 	XFS_STATS_INC(xs_write_calls);
 
 	BUG_ON(iocb->ki_pos != pos);
 
-	ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ);
-	if (ret)
-		return ret;
+	count = iov_iter_count(iter);
 
-	if (ocount == 0)
+	if (count == 0)
 		return 0;
 
 	sb_start_write(inode->i_sb);
@@ -783,10 +773,9 @@ xfs_file_aio_write(
 	}
 
 	if (unlikely(file->f_flags & O_DIRECT))
-		ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos, ocount);
+		ret = xfs_file_dio_aio_write(iocb, iter, pos, count);
 	else
-		ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos,
-						  ocount);
+		ret = xfs_file_buffered_aio_write(iocb, iter, pos, count);
 
 	if (ret > 0) {
 		ssize_t err;
@@ -1416,8 +1405,8 @@ const struct file_operations xfs_file_operations = {
 	.llseek		= xfs_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= xfs_file_aio_read,
-	.aio_write	= xfs_file_aio_write,
+	.read_iter	= xfs_file_read_iter,
+	.write_iter	= xfs_file_write_iter,
 	.splice_read	= xfs_file_splice_read,
 	.splice_write	= xfs_file_splice_write,
 	.unlocked_ioctl	= xfs_file_ioctl,
-- 
1.8.1.1

[PATCH V6 26/30] gfs2: Convert aio_read/write ops to read/write_iter

[Dave Kleikamp]

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: cluster-devel@redhat.com
---
 fs/gfs2/file.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 991ab2d..63af1a6 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -655,10 +655,9 @@ static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
 }
 
 /**
- * gfs2_file_aio_write - Perform a write to a file
+ * gfs2_file_write_iter - Perform a write to a file
  * @iocb: The io context
- * @iov: The data to write
- * @nr_segs: Number of @iov segments
+ * @iter: The data to write
  * @pos: The file position
  *
  * We have to do a lock/unlock here to refresh the inode size for
@@ -668,11 +667,11 @@ static int gfs2_fsync(struct file *file, loff_t start, loff_t end,
  *
  */
 
-static ssize_t gfs2_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
-				   unsigned long nr_segs, loff_t pos)
+static ssize_t gfs2_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+				    loff_t pos)
 {
 	struct file *file = iocb->ki_filp;
-	size_t writesize = iov_length(iov, nr_segs);
+	size_t writesize = iov_iter_count(iter);
 	struct dentry *dentry = file->f_dentry;
 	struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
 	int ret;
@@ -692,7 +691,7 @@ static ssize_t gfs2_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		gfs2_glock_dq_uninit(&gh);
 	}
 
-	return generic_file_aio_write(iocb, iov, nr_segs, pos);
+	return generic_file_write_iter(iocb, iter, pos);
 }
 
 static int fallocate_chunk(struct inode *inode, loff_t offset, loff_t len,
@@ -1021,9 +1020,9 @@ static int gfs2_flock(struct file *file, int cmd, struct file_lock *fl)
 const struct file_operations gfs2_file_fops = {
 	.llseek		= gfs2_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= gfs2_file_aio_write,
+	.write_iter	= gfs2_file_write_iter,
 	.unlocked_ioctl	= gfs2_ioctl,
 	.mmap		= gfs2_mmap,
 	.open		= gfs2_open,
@@ -1053,9 +1052,9 @@ const struct file_operations gfs2_dir_fops = {
 const struct file_operations gfs2_file_fops_nolock = {
 	.llseek		= gfs2_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= gfs2_file_aio_write,
+	.write_iter	= gfs2_file_write_iter,
 	.unlocked_ioctl	= gfs2_ioctl,
 	.mmap		= gfs2_mmap,
 	.open		= gfs2_open,
-- 
1.8.1.1

[PATCH V6 27/30] udf: convert file ops from aio_read/write to read/write_iter

[Dave Kleikamp]

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Jan Kara <jack@suse.cz>
---
 fs/udf/file.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/udf/file.c b/fs/udf/file.c
index c4164dc..a5d69c0 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -133,8 +133,8 @@ const struct address_space_operations udf_adinicb_aops = {
 	.direct_IO	= udf_adinicb_direct_IO,
 };
 
-static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
-				  unsigned long nr_segs, loff_t ppos)
+static ssize_t udf_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+				   loff_t ppos)
 {
 	ssize_t retval;
 	struct file *file = iocb->ki_filp;
@@ -168,7 +168,7 @@ static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
 	} else
 		up_write(&iinfo->i_data_sem);
 
-	retval = generic_file_aio_write(iocb, iov, nr_segs, ppos);
+	retval = generic_file_write_iter(iocb, iter, ppos);
 	if (retval > 0)
 		mark_inode_dirty(inode);
 
@@ -242,12 +242,12 @@ static int udf_release_file(struct inode *inode, struct file *filp)
 
 const struct file_operations udf_file_operations = {
 	.read			= do_sync_read,
-	.aio_read		= generic_file_aio_read,
+	.read_iter		= generic_file_read_iter,
 	.unlocked_ioctl		= udf_ioctl,
 	.open			= generic_file_open,
 	.mmap			= generic_file_mmap,
 	.write			= do_sync_write,
-	.aio_write		= udf_file_aio_write,
+	.write_iter		= udf_file_write_iter,
 	.release		= udf_release_file,
 	.fsync			= generic_file_fsync,
 	.splice_read		= generic_file_splice_read,
-- 
1.8.1.1

[PATCH V6 28/30] afs: add support for read_iter and write_iter

[Dave Kleikamp]

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-afs@lists.infradead.org
---
 fs/afs/file.c     | 4 ++--
 fs/afs/internal.h | 3 +--
 fs/afs/write.c    | 9 ++++-----
 3 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/fs/afs/file.c b/fs/afs/file.c
index 8f6e923..27b9b66 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -32,8 +32,8 @@ const struct file_operations afs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= afs_file_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= afs_file_write,
 	.mmap		= generic_file_readonly_mmap,
 	.splice_read	= generic_file_splice_read,
 	.fsync		= afs_fsync,
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index a306bb6..9c048ff 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -747,8 +747,7 @@ extern int afs_write_end(struct file *file, struct address_space *mapping,
 extern int afs_writepage(struct page *, struct writeback_control *);
 extern int afs_writepages(struct address_space *, struct writeback_control *);
 extern void afs_pages_written_back(struct afs_vnode *, struct afs_call *);
-extern ssize_t afs_file_write(struct kiocb *, const struct iovec *,
-			      unsigned long, loff_t);
+extern ssize_t afs_file_write(struct kiocb *, struct iov_iter *, loff_t);
 extern int afs_writeback_all(struct afs_vnode *);
 extern int afs_fsync(struct file *, loff_t, loff_t, int);
 
diff --git a/fs/afs/write.c b/fs/afs/write.c
index 9aa52d9..2c2a6d2 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -624,16 +624,15 @@ void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call)
 /*
  * write to an AFS file
  */
-ssize_t afs_file_write(struct kiocb *iocb, const struct iovec *iov,
-		       unsigned long nr_segs, loff_t pos)
+ssize_t afs_file_write(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
 {
 	struct dentry *dentry = iocb->ki_filp->f_path.dentry;
 	struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode);
 	ssize_t result;
-	size_t count = iov_length(iov, nr_segs);
+	size_t count = iov_iter_count(iter);
 
 	_enter("{%x.%u},{%zu},%lu,",
-	       vnode->fid.vid, vnode->fid.vnode, count, nr_segs);
+	       vnode->fid.vid, vnode->fid.vnode, count, iter->nr_segs);
 
 	if (IS_SWAPFILE(&vnode->vfs_inode)) {
 		printk(KERN_INFO
@@ -644,7 +643,7 @@ ssize_t afs_file_write(struct kiocb *iocb, const struct iovec *iov,
 	if (!count)
 		return 0;
 
-	result = generic_file_aio_write(iocb, iov, nr_segs, pos);
+	result = generic_file_write_iter(iocb, iter, pos);
 	if (IS_ERR_VALUE(result)) {
 		_leave(" = %zd", result);
 		return result;
-- 
1.8.1.1

[PATCH V6 29/30] ecrpytfs: Convert aio_read/write ops to read/write_iter

[Dave Kleikamp]

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Cc: ecryptfs@vger.kernel.org
---
 fs/ecryptfs/file.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index d45ba45..5aaa180 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -36,22 +36,21 @@
 /**
  * ecryptfs_read_update_atime
  *
- * generic_file_read updates the atime of upper layer inode.  But, it
+ * generic_file_read_iter updates the atime of upper layer inode.  But, it
  * doesn't give us a chance to update the atime of the lower layer
- * inode.  This function is a wrapper to generic_file_read.  It
- * updates the atime of the lower level inode if generic_file_read
+ * inode.  This function is a wrapper to generic_file_read_iter.  It
+ * updates the atime of the lower level inode if generic_file_read_iter
  * returns without any errors. This is to be used only for file reads.
  * The function to be used for directory reads is ecryptfs_read.
  */
 static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,
-				const struct iovec *iov,
-				unsigned long nr_segs, loff_t pos)
+				struct iov_iter *iter, loff_t pos)
 {
 	ssize_t rc;
 	struct path lower;
 	struct file *file = iocb->ki_filp;
 
-	rc = generic_file_aio_read(iocb, iov, nr_segs, pos);
+	rc = generic_file_read_iter(iocb, iter, pos);
 	/*
 	 * Even though this is a async interface, we need to wait
 	 * for IO to finish to update atime
@@ -357,9 +356,9 @@ const struct file_operations ecryptfs_dir_fops = {
 const struct file_operations ecryptfs_main_fops = {
 	.llseek = generic_file_llseek,
 	.read = do_sync_read,
-	.aio_read = ecryptfs_read_update_atime,
+	.read_iter = ecryptfs_read_update_atime,
 	.write = do_sync_write,
-	.aio_write = generic_file_aio_write,
+	.write_iter = generic_file_write_iter,
 	.readdir = ecryptfs_readdir,
 	.unlocked_ioctl = ecryptfs_unlocked_ioctl,
 #ifdef CONFIG_COMPAT
-- 
1.8.1.1

[PATCH V6 30/30] ubifs: convert file ops from aio_read/write to read/write_iter

[Dave Kleikamp]

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: linux-mtd@lists.infradead.org
---
 fs/ubifs/file.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 5bc7781..cfe6210 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -44,7 +44,7 @@
  * 'ubifs_writepage()' we are only guaranteed that the page is locked.
  *
  * Similarly, @i_mutex is not always locked in 'ubifs_readpage()', e.g., the
- * read-ahead path does not lock it ("sys_read -> generic_file_aio_read ->
+ * read-ahead path does not lock it ("sys_read -> generic_file_read_iter ->
  * ondemand_readahead -> readpage"). In case of readahead, @I_SYNC flag is not
  * set as well. However, UBIFS disables readahead.
  */
@@ -1394,8 +1394,8 @@ static int update_mctime(struct ubifs_info *c, struct inode *inode)
 	return 0;
 }
 
-static ssize_t ubifs_aio_write(struct kiocb *iocb, const struct iovec *iov,
-			       unsigned long nr_segs, loff_t pos)
+static ssize_t ubifs_write_iter(struct kiocb *iocb, struct iov_iter *iter,
+				loff_t pos)
 {
 	int err;
 	struct inode *inode = iocb->ki_filp->f_mapping->host;
@@ -1405,7 +1405,7 @@ static ssize_t ubifs_aio_write(struct kiocb *iocb, const struct iovec *iov,
 	if (err)
 		return err;
 
-	return generic_file_aio_write(iocb, iov, nr_segs, pos);
+	return generic_file_write_iter(iocb, iter, pos);
 }
 
 static int ubifs_set_page_dirty(struct page *page)
@@ -1580,8 +1580,8 @@ const struct file_operations ubifs_file_operations = {
 	.llseek         = generic_file_llseek,
 	.read           = do_sync_read,
 	.write          = do_sync_write,
-	.aio_read       = generic_file_aio_read,
-	.aio_write      = ubifs_aio_write,
+	.read_iter       = generic_file_read_iter,
+	.write_iter      = ubifs_write_iter,
 	.mmap           = ubifs_file_mmap,
 	.fsync          = ubifs_fsync,
 	.unlocked_ioctl = ubifs_ioctl,
-- 
1.8.1.1

Re: [PATCH V6 00/30] loop: Issue O_DIRECT aio using bio_vec

[Jeff Moyer]

Dave Kleikamp <dave.kleikamp@oracle.com> writes:

> Al,
> I'd like to push this patchset to linux-next. Would you like to pull it
> into your vfs tree, would you rather I submitted it separately, or do
> you have any issues with it before including it?

I'm still chasing one regression in this patchset.  If you use the ext4
driver for ext2 file systems, and you run the libaio test harness, then
you will be able to successfully write beyond the maximum file size in a
file (see test case 8).

Cheers,
Jeff

Re: [PATCH V6 00/30] loop: Issue O_DIRECT aio using bio_vec

[Dave Kleikamp]

On 01/29/2013 12:42 PM, Jeff Moyer wrote:
> Dave Kleikamp <dave.kleikamp@oracle.com> writes:
> 
>> Al,
>> I'd like to push this patchset to linux-next. Would you like to pull it
>> into your vfs tree, would you rather I submitted it separately, or do
>> you have any issues with it before including it?
> 
> I'm still chasing one regression in this patchset.  If you use the ext4
> driver for ext2 file systems, and you run the libaio test harness, then
> you will be able to successfully write beyond the maximum file size in a
> file (see test case 8).

I'll take a look at that one too.

Thanks,
Shaggy

> 
> Cheers,
> Jeff
> 

[PATCH V6 18/30] fs: add read_iter and write_iter to several file systems

[Dave Kleikamp]

[-- Attachment #1: Type: text/plain, Size: 17324 bytes --]

[ Reposting with a much shorter cc list as this patch didn't make it to
lkml.]

These are the simple ones.

File systems that use generic_file_aio_read() and generic_file_aio_write()
can trivially support generic_file_read_iter() and
generic_file_write_iter().

This patch adds those file_operations for 9p, adfs, affs, bfs, exofs, ext2,
ext3, fat, f2fs, hfs, hfsplus, hostfs, hpfs, jfs, jffs2, logfs, minix,
nilfs2,
omfs, ramfs, reiserfs, romfs, sysv, and ufs.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: v9fs-developer@lists.sourceforge.net
Cc: Tigran A. Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Benny Halevy <bhalevy@tonian.com>
Cc: osd-dev@open-osd.org
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: jfs-discussion@lists.sourceforge.net
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: logfs@logfs.org
Cc: linux-nilfs@vger.kernel.org
Cc: Bob Copeland <me@bobcopeland.com>
Cc: linux-karma-devel@lists.sourceforge.net
Cc: reiserfs-devel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
---
 fs/9p/vfs_addr.c        | 4 ++--
 fs/9p/vfs_file.c        | 8 ++++----
 fs/adfs/file.c          | 4 ++--
 fs/affs/file.c          | 4 ++--
 fs/bfs/file.c           | 4 ++--
 fs/exofs/file.c         | 4 ++--
 fs/ext2/file.c          | 4 ++--
 fs/ext3/file.c          | 4 ++--
 fs/f2fs/file.c          | 4 ++--
 fs/fat/file.c           | 4 ++--
 fs/hfs/inode.c          | 4 ++--
 fs/hfsplus/inode.c      | 4 ++--
 fs/hostfs/hostfs_kern.c | 4 ++--
 fs/hpfs/file.c          | 4 ++--
 fs/jffs2/file.c         | 8 ++++----
 fs/jfs/file.c           | 4 ++--
 fs/logfs/file.c         | 4 ++--
 fs/minix/file.c         | 4 ++--
 fs/nilfs2/file.c        | 4 ++--
 fs/omfs/file.c          | 4 ++--
 fs/ramfs/file-mmu.c     | 4 ++--
 fs/ramfs/file-nommu.c   | 4 ++--
 fs/reiserfs/file.c      | 4 ++--
 fs/romfs/mmap-nommu.c   | 2 +-
 fs/sysv/file.c          | 4 ++--
 fs/ufs/file.c           | 4 ++--
 26 files changed, 55 insertions(+), 55 deletions(-)

diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index e70f239..01c0673 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -249,8 +249,8 @@ static int v9fs_launder_page(struct page *page)
  * the VFS gets them, so this method should never be called.
  *
  * Direct IO is not 'yet' supported in the cached mode. Hence when
- * this routine is called through generic_file_aio_read(), the
read/write fails
- * with an error.
+ * this routine is called through generic_file_read_iter(), the read/write
+ * fails with an error.
  *
  */
 static ssize_t
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index c2483e9..2e9441d 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -746,8 +746,8 @@ const struct file_operations
v9fs_cached_file_operations = {
 	.llseek = generic_file_llseek,
 	.read = v9fs_cached_file_read,
 	.write = v9fs_cached_file_write,
-	.aio_read = generic_file_aio_read,
-	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock,
@@ -759,8 +759,8 @@ const struct file_operations
v9fs_cached_file_operations_dotl = {
 	.llseek = generic_file_llseek,
 	.read = v9fs_cached_file_read,
 	.write = v9fs_cached_file_write,
-	.aio_read = generic_file_aio_read,
-	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock_dotl,
diff --git a/fs/adfs/file.c b/fs/adfs/file.c
index a36da53..da1e021 100644
--- a/fs/adfs/file.c
+++ b/fs/adfs/file.c
@@ -24,11 +24,11 @@
 const struct file_operations adfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.mmap		= generic_file_mmap,
 	.fsync		= generic_file_fsync,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.splice_read	= generic_file_splice_read,
 };
 diff --git a/fs/affs/file.c b/fs/affs/file.c
index af3261b..d09a2db 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -28,9 +28,9 @@ static int affs_file_release(struct inode *inode,
struct file *filp);
 const struct file_operations affs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.open		= affs_file_open,
 	.release	= affs_file_release,
diff --git a/fs/bfs/file.c b/fs/bfs/file.c
index ad3ea14..3d14806 100644
--- a/fs/bfs/file.c
+++ b/fs/bfs/file.c
@@ -24,9 +24,9 @@
 const struct file_operations bfs_file_operations = {
 	.llseek 	= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
 };
diff --git a/fs/exofs/file.c b/fs/exofs/file.c
index 491c6c0..20564f8a 100644
--- a/fs/exofs/file.c
+++ b/fs/exofs/file.c
@@ -69,8 +69,8 @@ const struct file_operations exofs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.open		= generic_file_open,
 	.release	= exofs_release_file,
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index a5b3a5d..6af043b 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -64,8 +64,8 @@ const struct file_operations ext2_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.unlocked_ioctl = ext2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext2_compat_ioctl,
diff --git a/fs/ext3/file.c b/fs/ext3/file.c
index 25cb413..a796771 100644
--- a/fs/ext3/file.c
+++ b/fs/ext3/file.c
@@ -52,8 +52,8 @@ const struct file_operations ext3_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.unlocked_ioctl	= ext3_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext3_compat_ioctl,
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 3191b52..d636c4e 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -634,8 +634,8 @@ const struct file_operations f2fs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.open		= generic_file_open,
 	.mmap		= f2fs_file_mmap,
 	.fsync		= f2fs_sync_file,
diff --git a/fs/fat/file.c b/fs/fat/file.c
index a62e0ec..92d587b 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -164,8 +164,8 @@ const struct file_operations fat_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.release	= fat_file_release,
 	.unlocked_ioctl	= fat_generic_ioctl,
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 2a87ba4..0db0679 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -666,9 +666,9 @@ static int hfs_file_fsync(struct file *filp, loff_t
start, loff_t end,
 static const struct file_operations hfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
 	.fsync		= hfs_file_fsync,
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index c87b26c..9b8cdb6 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -373,9 +373,9 @@ static const struct inode_operations
hfsplus_file_inode_operations = {
 static const struct file_operations hfsplus_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
 	.fsync		= hfsplus_file_fsync,
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 457addc..4593a9a 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -382,8 +382,8 @@ static const struct file_operations hostfs_file_fops = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.splice_read	= generic_file_splice_read,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.write		= do_sync_write,
 	.mmap		= generic_file_mmap,
 	.open		= hostfs_file_open,
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index fbfe2df..efc8cd9 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -162,9 +162,9 @@ const struct file_operations hpfs_file_ops =
 {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= hpfs_file_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.release	= hpfs_file_release,
 	.fsync		= hpfs_file_fsync,
diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
index 1506673..1d7ab8b 100644
--- a/fs/jffs2/file.c
+++ b/fs/jffs2/file.c
@@ -51,10 +51,10 @@ const struct file_operations jffs2_file_operations =
 {
 	.llseek =	generic_file_llseek,
 	.open =		generic_file_open,
- 	.read =		do_sync_read,
- 	.aio_read =	generic_file_aio_read,
- 	.write =	do_sync_write,
- 	.aio_write =	generic_file_aio_write,
+	.read =		do_sync_read,
+	.read_iter =	generic_file_read_iter,
+	.write =	do_sync_write,
+	.write_iter =	generic_file_write_iter,
 	.unlocked_ioctl=jffs2_ioctl,
 	.mmap =		generic_file_readonly_mmap,
 	.fsync =	jffs2_fsync,
diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index dd7442c..040b6c7 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -151,8 +151,8 @@ const struct file_operations jfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.write		= do_sync_write,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
 	.splice_write	= generic_file_splice_write,
diff --git a/fs/logfs/file.c b/fs/logfs/file.c
index 3886cde..ca35c88 100644
--- a/fs/logfs/file.c
+++ b/fs/logfs/file.c
@@ -263,8 +263,8 @@ const struct inode_operations logfs_reg_iops = {
 };
  const struct file_operations logfs_reg_fops = {
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.fsync		= logfs_fsync,
 	.unlocked_ioctl	= logfs_ioctl,
 	.llseek		= generic_file_llseek,
diff --git a/fs/minix/file.c b/fs/minix/file.c
index adc6f54..346d8f37 100644
--- a/fs/minix/file.c
+++ b/fs/minix/file.c
@@ -15,9 +15,9 @@
 const struct file_operations minix_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.fsync		= generic_file_fsync,
 	.splice_read	= generic_file_splice_read,
diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index 6194688..3e4337e 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -153,8 +153,8 @@ const struct file_operations nilfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.unlocked_ioctl	= nilfs_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= nilfs_compat_ioctl,
diff --git a/fs/omfs/file.c b/fs/omfs/file.c
index e0d9b3e..badafd8 100644
--- a/fs/omfs/file.c
+++ b/fs/omfs/file.c
@@ -339,8 +339,8 @@ const struct file_operations omfs_file_operations = {
 	.llseek = generic_file_llseek,
 	.read = do_sync_read,
 	.write = do_sync_write,
-	.aio_read = generic_file_aio_read,
-	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.mmap = generic_file_mmap,
 	.fsync = generic_file_fsync,
 	.splice_read = generic_file_splice_read,
diff --git a/fs/ramfs/file-mmu.c b/fs/ramfs/file-mmu.c
index 4884ac5..c4d8572 100644
--- a/fs/ramfs/file-mmu.c
+++ b/fs/ramfs/file-mmu.c
@@ -39,9 +39,9 @@ const struct address_space_operations ramfs_aops = {
  const struct file_operations ramfs_file_operations = {
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.fsync		= noop_fsync,
 	.splice_read	= generic_file_splice_read,
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index d5378d0..1d6be6c 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -39,9 +39,9 @@ const struct file_operations ramfs_file_operations = {
 	.mmap			= ramfs_nommu_mmap,
 	.get_unmapped_area	= ramfs_nommu_get_unmapped_area,
 	.read			= do_sync_read,
-	.aio_read		= generic_file_aio_read,
+	.read_iter		= generic_file_read_iter,
 	.write			= do_sync_write,
-	.aio_write		= generic_file_aio_write,
+	.write_iter		= generic_file_write_iter,
 	.fsync			= noop_fsync,
 	.splice_read		= generic_file_splice_read,
 	.splice_write		= generic_file_splice_write,
diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c
index 50302d6..831703d 100644
--- a/fs/reiserfs/file.c
+++ b/fs/reiserfs/file.c
@@ -304,8 +304,8 @@ const struct file_operations
reiserfs_file_operations = {
 	.open = reiserfs_file_open,
 	.release = reiserfs_file_release,
 	.fsync = reiserfs_sync_file,
-	.aio_read = generic_file_aio_read,
-	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.splice_read = generic_file_splice_read,
 	.splice_write = generic_file_splice_write,
 	.llseek = generic_file_llseek,
diff --git a/fs/romfs/mmap-nommu.c b/fs/romfs/mmap-nommu.c
index e1a7779..e34d51a 100644
--- a/fs/romfs/mmap-nommu.c
+++ b/fs/romfs/mmap-nommu.c
@@ -70,7 +70,7 @@ static int romfs_mmap(struct file *file, struct
vm_area_struct *vma)
 const struct file_operations romfs_ro_fops = {
 	.llseek			= generic_file_llseek,
 	.read			= do_sync_read,
-	.aio_read		= generic_file_aio_read,
+	.read_iter		= generic_file_read_iter,
 	.splice_read		= generic_file_splice_read,
 	.mmap			= romfs_mmap,
 	.get_unmapped_area	= romfs_get_unmapped_area,
diff --git a/fs/sysv/file.c b/fs/sysv/file.c
index 9d4dc68..ff4b363 100644
--- a/fs/sysv/file.c
+++ b/fs/sysv/file.c
@@ -22,9 +22,9 @@
 const struct file_operations sysv_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.fsync		= generic_file_fsync,
 	.splice_read	= generic_file_splice_read,
diff --git a/fs/ufs/file.c b/fs/ufs/file.c
index 33afa20..e155e4c 100644
--- a/fs/ufs/file.c
+++ b/fs/ufs/file.c
@@ -36,9 +36,9 @@
 const struct file_operations ufs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.open           = generic_file_open,
 	.fsync		= generic_file_fsync,
-- 
1.8.1.1


[-- Attachment #2: Attached Message Part --]
[-- Type: text/plain, Size: 0 bytes --]

[PATCH V6 18/30] fs: add read_iter and write_iter to several file systems

[Dave Kleikamp]

[Reposting again without word-wrap. Sorry for the noise.]

These are the simple ones.

File systems that use generic_file_aio_read() and generic_file_aio_write()
can trivially support generic_file_read_iter() and generic_file_write_iter().

This patch adds those file_operations for 9p, adfs, affs, bfs, exofs, ext2,
ext3, fat, f2fs, hfs, hfsplus, hostfs, hpfs, jfs, jffs2, logfs, minix, nilfs2,
omfs, ramfs, reiserfs, romfs, sysv, and ufs.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: v9fs-developer@lists.sourceforge.net
Cc: Tigran A. Aivazian <tigran@aivazian.fsnet.co.uk>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Benny Halevy <bhalevy@tonian.com>
Cc: osd-dev@open-osd.org
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: jfs-discussion@lists.sourceforge.net
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: logfs@logfs.org
Cc: linux-nilfs@vger.kernel.org
Cc: Bob Copeland <me@bobcopeland.com>
Cc: linux-karma-devel@lists.sourceforge.net
Cc: reiserfs-devel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
---
 fs/9p/vfs_addr.c        | 4 ++--
 fs/9p/vfs_file.c        | 8 ++++----
 fs/adfs/file.c          | 4 ++--
 fs/affs/file.c          | 4 ++--
 fs/bfs/file.c           | 4 ++--
 fs/exofs/file.c         | 4 ++--
 fs/ext2/file.c          | 4 ++--
 fs/ext3/file.c          | 4 ++--
 fs/f2fs/file.c          | 4 ++--
 fs/fat/file.c           | 4 ++--
 fs/hfs/inode.c          | 4 ++--
 fs/hfsplus/inode.c      | 4 ++--
 fs/hostfs/hostfs_kern.c | 4 ++--
 fs/hpfs/file.c          | 4 ++--
 fs/jffs2/file.c         | 8 ++++----
 fs/jfs/file.c           | 4 ++--
 fs/logfs/file.c         | 4 ++--
 fs/minix/file.c         | 4 ++--
 fs/nilfs2/file.c        | 4 ++--
 fs/omfs/file.c          | 4 ++--
 fs/ramfs/file-mmu.c     | 4 ++--
 fs/ramfs/file-nommu.c   | 4 ++--
 fs/reiserfs/file.c      | 4 ++--
 fs/romfs/mmap-nommu.c   | 2 +-
 fs/sysv/file.c          | 4 ++--
 fs/ufs/file.c           | 4 ++--
 26 files changed, 55 insertions(+), 55 deletions(-)

diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index e70f239..01c0673 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -249,8 +249,8 @@ static int v9fs_launder_page(struct page *page)
  * the VFS gets them, so this method should never be called.
  *
  * Direct IO is not 'yet' supported in the cached mode. Hence when
- * this routine is called through generic_file_aio_read(), the read/write fails
- * with an error.
+ * this routine is called through generic_file_read_iter(), the read/write
+ * fails with an error.
  *
  */
 static ssize_t
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index c2483e9..2e9441d 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -746,8 +746,8 @@ const struct file_operations v9fs_cached_file_operations = {
 	.llseek = generic_file_llseek,
 	.read = v9fs_cached_file_read,
 	.write = v9fs_cached_file_write,
-	.aio_read = generic_file_aio_read,
-	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock,
@@ -759,8 +759,8 @@ const struct file_operations v9fs_cached_file_operations_dotl = {
 	.llseek = generic_file_llseek,
 	.read = v9fs_cached_file_read,
 	.write = v9fs_cached_file_write,
-	.aio_read = generic_file_aio_read,
-	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.open = v9fs_file_open,
 	.release = v9fs_dir_release,
 	.lock = v9fs_file_lock_dotl,
diff --git a/fs/adfs/file.c b/fs/adfs/file.c
index a36da53..da1e021 100644
--- a/fs/adfs/file.c
+++ b/fs/adfs/file.c
@@ -24,11 +24,11 @@
 const struct file_operations adfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.mmap		= generic_file_mmap,
 	.fsync		= generic_file_fsync,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.splice_read	= generic_file_splice_read,
 };
 
diff --git a/fs/affs/file.c b/fs/affs/file.c
index af3261b..d09a2db 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -28,9 +28,9 @@ static int affs_file_release(struct inode *inode, struct file *filp);
 const struct file_operations affs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.open		= affs_file_open,
 	.release	= affs_file_release,
diff --git a/fs/bfs/file.c b/fs/bfs/file.c
index ad3ea14..3d14806 100644
--- a/fs/bfs/file.c
+++ b/fs/bfs/file.c
@@ -24,9 +24,9 @@
 const struct file_operations bfs_file_operations = {
 	.llseek 	= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
 };
diff --git a/fs/exofs/file.c b/fs/exofs/file.c
index 491c6c0..20564f8a 100644
--- a/fs/exofs/file.c
+++ b/fs/exofs/file.c
@@ -69,8 +69,8 @@ const struct file_operations exofs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.open		= generic_file_open,
 	.release	= exofs_release_file,
diff --git a/fs/ext2/file.c b/fs/ext2/file.c
index a5b3a5d..6af043b 100644
--- a/fs/ext2/file.c
+++ b/fs/ext2/file.c
@@ -64,8 +64,8 @@ const struct file_operations ext2_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.unlocked_ioctl = ext2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext2_compat_ioctl,
diff --git a/fs/ext3/file.c b/fs/ext3/file.c
index 25cb413..a796771 100644
--- a/fs/ext3/file.c
+++ b/fs/ext3/file.c
@@ -52,8 +52,8 @@ const struct file_operations ext3_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.unlocked_ioctl	= ext3_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext3_compat_ioctl,
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 3191b52..d636c4e 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -634,8 +634,8 @@ const struct file_operations f2fs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.open		= generic_file_open,
 	.mmap		= f2fs_file_mmap,
 	.fsync		= f2fs_sync_file,
diff --git a/fs/fat/file.c b/fs/fat/file.c
index a62e0ec..92d587b 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -164,8 +164,8 @@ const struct file_operations fat_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.release	= fat_file_release,
 	.unlocked_ioctl	= fat_generic_ioctl,
diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 2a87ba4..0db0679 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -666,9 +666,9 @@ static int hfs_file_fsync(struct file *filp, loff_t start, loff_t end,
 static const struct file_operations hfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
 	.fsync		= hfs_file_fsync,
diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index c87b26c..9b8cdb6 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -373,9 +373,9 @@ static const struct inode_operations hfsplus_file_inode_operations = {
 static const struct file_operations hfsplus_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
 	.fsync		= hfsplus_file_fsync,
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 457addc..4593a9a 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -382,8 +382,8 @@ static const struct file_operations hostfs_file_fops = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.splice_read	= generic_file_splice_read,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.write		= do_sync_write,
 	.mmap		= generic_file_mmap,
 	.open		= hostfs_file_open,
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index fbfe2df..efc8cd9 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -162,9 +162,9 @@ const struct file_operations hpfs_file_ops =
 {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= hpfs_file_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.release	= hpfs_file_release,
 	.fsync		= hpfs_file_fsync,
diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
index 1506673..1d7ab8b 100644
--- a/fs/jffs2/file.c
+++ b/fs/jffs2/file.c
@@ -51,10 +51,10 @@ const struct file_operations jffs2_file_operations =
 {
 	.llseek =	generic_file_llseek,
 	.open =		generic_file_open,
- 	.read =		do_sync_read,
- 	.aio_read =	generic_file_aio_read,
- 	.write =	do_sync_write,
- 	.aio_write =	generic_file_aio_write,
+	.read =		do_sync_read,
+	.read_iter =	generic_file_read_iter,
+	.write =	do_sync_write,
+	.write_iter =	generic_file_write_iter,
 	.unlocked_ioctl=jffs2_ioctl,
 	.mmap =		generic_file_readonly_mmap,
 	.fsync =	jffs2_fsync,
diff --git a/fs/jfs/file.c b/fs/jfs/file.c
index dd7442c..040b6c7 100644
--- a/fs/jfs/file.c
+++ b/fs/jfs/file.c
@@ -151,8 +151,8 @@ const struct file_operations jfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.write		= do_sync_write,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.splice_read	= generic_file_splice_read,
 	.splice_write	= generic_file_splice_write,
diff --git a/fs/logfs/file.c b/fs/logfs/file.c
index 3886cde..ca35c88 100644
--- a/fs/logfs/file.c
+++ b/fs/logfs/file.c
@@ -263,8 +263,8 @@ const struct inode_operations logfs_reg_iops = {
 };
 
 const struct file_operations logfs_reg_fops = {
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.fsync		= logfs_fsync,
 	.unlocked_ioctl	= logfs_ioctl,
 	.llseek		= generic_file_llseek,
diff --git a/fs/minix/file.c b/fs/minix/file.c
index adc6f54..346d8f37 100644
--- a/fs/minix/file.c
+++ b/fs/minix/file.c
@@ -15,9 +15,9 @@
 const struct file_operations minix_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.fsync		= generic_file_fsync,
 	.splice_read	= generic_file_splice_read,
diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index 6194688..3e4337e 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -153,8 +153,8 @@ const struct file_operations nilfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read_iter	= generic_file_read_iter,
+	.write_iter	= generic_file_write_iter,
 	.unlocked_ioctl	= nilfs_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= nilfs_compat_ioctl,
diff --git a/fs/omfs/file.c b/fs/omfs/file.c
index e0d9b3e..badafd8 100644
--- a/fs/omfs/file.c
+++ b/fs/omfs/file.c
@@ -339,8 +339,8 @@ const struct file_operations omfs_file_operations = {
 	.llseek = generic_file_llseek,
 	.read = do_sync_read,
 	.write = do_sync_write,
-	.aio_read = generic_file_aio_read,
-	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.mmap = generic_file_mmap,
 	.fsync = generic_file_fsync,
 	.splice_read = generic_file_splice_read,
diff --git a/fs/ramfs/file-mmu.c b/fs/ramfs/file-mmu.c
index 4884ac5..c4d8572 100644
--- a/fs/ramfs/file-mmu.c
+++ b/fs/ramfs/file-mmu.c
@@ -39,9 +39,9 @@ const struct address_space_operations ramfs_aops = {
 
 const struct file_operations ramfs_file_operations = {
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.fsync		= noop_fsync,
 	.splice_read	= generic_file_splice_read,
diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index d5378d0..1d6be6c 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -39,9 +39,9 @@ const struct file_operations ramfs_file_operations = {
 	.mmap			= ramfs_nommu_mmap,
 	.get_unmapped_area	= ramfs_nommu_get_unmapped_area,
 	.read			= do_sync_read,
-	.aio_read		= generic_file_aio_read,
+	.read_iter		= generic_file_read_iter,
 	.write			= do_sync_write,
-	.aio_write		= generic_file_aio_write,
+	.write_iter		= generic_file_write_iter,
 	.fsync			= noop_fsync,
 	.splice_read		= generic_file_splice_read,
 	.splice_write		= generic_file_splice_write,
diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c
index 50302d6..831703d 100644
--- a/fs/reiserfs/file.c
+++ b/fs/reiserfs/file.c
@@ -304,8 +304,8 @@ const struct file_operations reiserfs_file_operations = {
 	.open = reiserfs_file_open,
 	.release = reiserfs_file_release,
 	.fsync = reiserfs_sync_file,
-	.aio_read = generic_file_aio_read,
-	.aio_write = generic_file_aio_write,
+	.read_iter = generic_file_read_iter,
+	.write_iter = generic_file_write_iter,
 	.splice_read = generic_file_splice_read,
 	.splice_write = generic_file_splice_write,
 	.llseek = generic_file_llseek,
diff --git a/fs/romfs/mmap-nommu.c b/fs/romfs/mmap-nommu.c
index e1a7779..e34d51a 100644
--- a/fs/romfs/mmap-nommu.c
+++ b/fs/romfs/mmap-nommu.c
@@ -70,7 +70,7 @@ static int romfs_mmap(struct file *file, struct vm_area_struct *vma)
 const struct file_operations romfs_ro_fops = {
 	.llseek			= generic_file_llseek,
 	.read			= do_sync_read,
-	.aio_read		= generic_file_aio_read,
+	.read_iter		= generic_file_read_iter,
 	.splice_read		= generic_file_splice_read,
 	.mmap			= romfs_mmap,
 	.get_unmapped_area	= romfs_get_unmapped_area,
diff --git a/fs/sysv/file.c b/fs/sysv/file.c
index 9d4dc68..ff4b363 100644
--- a/fs/sysv/file.c
+++ b/fs/sysv/file.c
@@ -22,9 +22,9 @@
 const struct file_operations sysv_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.fsync		= generic_file_fsync,
 	.splice_read	= generic_file_splice_read,
diff --git a/fs/ufs/file.c b/fs/ufs/file.c
index 33afa20..e155e4c 100644
--- a/fs/ufs/file.c
+++ b/fs/ufs/file.c
@@ -36,9 +36,9 @@
 const struct file_operations ufs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
-	.aio_read	= generic_file_aio_read,
+	.read_iter	= generic_file_read_iter,
 	.write		= do_sync_write,
-	.aio_write	= generic_file_aio_write,
+	.write_iter	= generic_file_write_iter,
 	.mmap		= generic_file_mmap,
 	.open           = generic_file_open,
 	.fsync		= generic_file_fsync,
-- 
1.8.1.1

Re: [PATCH V6 19/30] ocfs2: add support for read_iter, write_iter, and direct_IO_bvec

[Joel Becker]

Acked-by: Joel Becker <jlbec@evilplan.org>

On Tue, Jan 29, 2013 at 10:23:32AM -0600, Dave Kleikamp wrote:
> From: Zach Brown <zab@zabbo.net>
> 
> ocfs2's .aio_read and .aio_write methods are changed to take
> iov_iter and pass it to generic functions.  Wrappers are made to pack
> the iovecs into iters and call these new functions.
> 
> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
> Cc: Zach Brown <zab@zabbo.net>
> Cc: Mark Fasheh <mfasheh@suse.com>
> Cc: Joel Becker <jlbec@evilplan.org>
> Cc: ocfs2-devel@oss.oracle.com
> ---
>  fs/ocfs2/aops.h        |  2 +-
>  fs/ocfs2/file.c        | 53 ++++++++++++++++++++++----------------------------
>  fs/ocfs2/inode.h       |  2 --
>  fs/ocfs2/ocfs2_trace.h |  6 +++---
>  4 files changed, 27 insertions(+), 36 deletions(-)
> 
> diff --git a/fs/ocfs2/aops.h b/fs/ocfs2/aops.h
> index ffb2da3..bd0425a 100644
> --- a/fs/ocfs2/aops.h
> +++ b/fs/ocfs2/aops.h
> @@ -72,7 +72,7 @@ static inline void ocfs2_iocb_set_rw_locked(struct kiocb *iocb, int level)
>  /*
>   * Using a named enum representing lock types in terms of #N bit stored in
>   * iocb->private, which is going to be used for communication between
> - * ocfs2_dio_end_io() and ocfs2_file_aio_write/read().
> + * ocfs2_dio_end_io() and ocfs2_file_write/read_iter().
>   */
>  enum ocfs2_iocb_lock_bits {
>  	OCFS2_IOCB_RW_LOCK = 0,
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index 37d313e..94fc309 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -2219,15 +2219,13 @@ out:
>  	return ret;
>  }
>  
> -static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
> -				    const struct iovec *iov,
> -				    unsigned long nr_segs,
> -				    loff_t pos)
> +static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
> +				     struct iov_iter *iter,
> +				     loff_t pos)
>  {
>  	int ret, direct_io, appending, rw_level, have_alloc_sem  = 0;
>  	int can_do_direct, has_refcount = 0;
>  	ssize_t written = 0;
> -	size_t ocount;		/* original count */
>  	size_t count;		/* after file limit checks */
>  	loff_t old_size, *ppos = &iocb->ki_pos;
>  	u32 old_clusters;
> @@ -2238,11 +2236,11 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
>  			       OCFS2_MOUNT_COHERENCY_BUFFERED);
>  	int unaligned_dio = 0;
>  
> -	trace_ocfs2_file_aio_write(inode, file, file->f_path.dentry,
> +	trace_ocfs2_file_write_iter(inode, file, file->f_path.dentry,
>  		(unsigned long long)OCFS2_I(inode)->ip_blkno,
>  		file->f_path.dentry->d_name.len,
>  		file->f_path.dentry->d_name.name,
> -		(unsigned int)nr_segs);
> +		(unsigned long long)pos);
>  
>  	if (iocb->ki_left == 0)
>  		return 0;
> @@ -2344,28 +2342,24 @@ relock:
>  	/* communicate with ocfs2_dio_end_io */
>  	ocfs2_iocb_set_rw_locked(iocb, rw_level);
>  
> -	ret = generic_segment_checks(iov, &nr_segs, &ocount,
> -				     VERIFY_READ);
> -	if (ret)
> -		goto out_dio;
>  
> -	count = ocount;
> +	count = iov_iter_count(iter);
>  	ret = generic_write_checks(file, ppos, &count,
>  				   S_ISBLK(inode->i_mode));
>  	if (ret)
>  		goto out_dio;
>  
>  	if (direct_io) {
> -		written = generic_file_direct_write(iocb, iov, &nr_segs, *ppos,
> -						    ppos, count, ocount);
> +		written = generic_file_direct_write_iter(iocb, iter, *ppos,
> +						    ppos, count);
>  		if (written < 0) {
>  			ret = written;
>  			goto out_dio;
>  		}
>  	} else {
>  		current->backing_dev_info = file->f_mapping->backing_dev_info;
> -		written = generic_file_buffered_write(iocb, iov, nr_segs, *ppos,
> -						      ppos, count, 0);
> +		written = generic_file_buffered_write_iter(iocb, iter, *ppos,
> +							   ppos, count, 0);
>  		current->backing_dev_info = NULL;
>  	}
>  
> @@ -2524,7 +2518,7 @@ static ssize_t ocfs2_file_splice_read(struct file *in,
>  			in->f_path.dentry->d_name.name, len);
>  
>  	/*
> -	 * See the comment in ocfs2_file_aio_read()
> +	 * See the comment in ocfs2_file_read_iter()
>  	 */
>  	ret = ocfs2_inode_lock_atime(inode, in->f_vfsmnt, &lock_level);
>  	if (ret < 0) {
> @@ -2539,19 +2533,18 @@ bail:
>  	return ret;
>  }
>  
> -static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
> -				   const struct iovec *iov,
> -				   unsigned long nr_segs,
> +static ssize_t ocfs2_file_read_iter(struct kiocb *iocb,
> +				   struct iov_iter *iter,
>  				   loff_t pos)
>  {
>  	int ret = 0, rw_level = -1, have_alloc_sem = 0, lock_level = 0;
>  	struct file *filp = iocb->ki_filp;
>  	struct inode *inode = filp->f_path.dentry->d_inode;
>  
> -	trace_ocfs2_file_aio_read(inode, filp, filp->f_path.dentry,
> +	trace_ocfs2_file_read_iter(inode, filp, filp->f_path.dentry,
>  			(unsigned long long)OCFS2_I(inode)->ip_blkno,
>  			filp->f_path.dentry->d_name.len,
> -			filp->f_path.dentry->d_name.name, nr_segs);
> +			filp->f_path.dentry->d_name.name, pos);
>  
>  
>  	if (!inode) {
> @@ -2587,7 +2580,7 @@ static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
>  	 *
>  	 * Take and drop the meta data lock to update inode fields
>  	 * like i_size. This allows the checks down below
> -	 * generic_file_aio_read() a chance of actually working.
> +	 * generic_file_read_iter() a chance of actually working.
>  	 */
>  	ret = ocfs2_inode_lock_atime(inode, filp->f_vfsmnt, &lock_level);
>  	if (ret < 0) {
> @@ -2596,13 +2589,13 @@ static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
>  	}
>  	ocfs2_inode_unlock(inode, lock_level);
>  
> -	ret = generic_file_aio_read(iocb, iov, nr_segs, iocb->ki_pos);
> -	trace_generic_file_aio_read_ret(ret);
> +	ret = generic_file_read_iter(iocb, iter, iocb->ki_pos);
> +	trace_generic_file_read_iter_ret(ret);
>  
>  	/* buffered aio wouldn't have proper lock coverage today */
>  	BUG_ON(ret == -EIOCBQUEUED && !(filp->f_flags & O_DIRECT));
>  
> -	/* see ocfs2_file_aio_write */
> +	/* see ocfs2_file_write_iter */
>  	if (ret == -EIOCBQUEUED || !ocfs2_iocb_is_rw_locked(iocb)) {
>  		rw_level = -1;
>  		have_alloc_sem = 0;
> @@ -2700,8 +2693,8 @@ const struct file_operations ocfs2_fops = {
>  	.fsync		= ocfs2_sync_file,
>  	.release	= ocfs2_file_release,
>  	.open		= ocfs2_file_open,
> -	.aio_read	= ocfs2_file_aio_read,
> -	.aio_write	= ocfs2_file_aio_write,
> +	.read_iter	= ocfs2_file_read_iter,
> +	.write_iter	= ocfs2_file_write_iter,
>  	.unlocked_ioctl	= ocfs2_ioctl,
>  #ifdef CONFIG_COMPAT
>  	.compat_ioctl   = ocfs2_compat_ioctl,
> @@ -2748,8 +2741,8 @@ const struct file_operations ocfs2_fops_no_plocks = {
>  	.fsync		= ocfs2_sync_file,
>  	.release	= ocfs2_file_release,
>  	.open		= ocfs2_file_open,
> -	.aio_read	= ocfs2_file_aio_read,
> -	.aio_write	= ocfs2_file_aio_write,
> +	.read_iter	= ocfs2_file_read_iter,
> +	.write_iter	= ocfs2_file_write_iter,
>  	.unlocked_ioctl	= ocfs2_ioctl,
>  #ifdef CONFIG_COMPAT
>  	.compat_ioctl   = ocfs2_compat_ioctl,
> diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h
> index 88924a3..621fc73 100644
> --- a/fs/ocfs2/inode.h
> +++ b/fs/ocfs2/inode.h
> @@ -147,8 +147,6 @@ void ocfs2_refresh_inode(struct inode *inode,
>  int ocfs2_mark_inode_dirty(handle_t *handle,
>  			   struct inode *inode,
>  			   struct buffer_head *bh);
> -int ocfs2_aio_read(struct file *file, struct kiocb *req, struct iocb *iocb);
> -int ocfs2_aio_write(struct file *file, struct kiocb *req, struct iocb *iocb);
>  struct buffer_head *ocfs2_bread(struct inode *inode,
>  				int block, int *err, int reada);
>  
> diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h
> index 3b481f4..1c5018c 100644
> --- a/fs/ocfs2/ocfs2_trace.h
> +++ b/fs/ocfs2/ocfs2_trace.h
> @@ -1310,13 +1310,13 @@ DEFINE_OCFS2_FILE_OPS(ocfs2_file_release);
>  
>  DEFINE_OCFS2_FILE_OPS(ocfs2_sync_file);
>  
> -DEFINE_OCFS2_FILE_OPS(ocfs2_file_aio_write);
> +DEFINE_OCFS2_FILE_OPS(ocfs2_file_write_iter);
>  
>  DEFINE_OCFS2_FILE_OPS(ocfs2_file_splice_write);
>  
>  DEFINE_OCFS2_FILE_OPS(ocfs2_file_splice_read);
>  
> -DEFINE_OCFS2_FILE_OPS(ocfs2_file_aio_read);
> +DEFINE_OCFS2_FILE_OPS(ocfs2_file_read_iter);
>  
>  DEFINE_OCFS2_ULL_ULL_ULL_EVENT(ocfs2_truncate_file);
>  
> @@ -1474,7 +1474,7 @@ TRACE_EVENT(ocfs2_prepare_inode_for_write,
>  		  __entry->direct_io, __entry->has_refcount)
>  );
>  
> -DEFINE_OCFS2_INT_EVENT(generic_file_aio_read_ret);
> +DEFINE_OCFS2_INT_EVENT(generic_file_read_iter_ret);
>  
>  /* End of trace events for fs/ocfs2/file.c. */
>  
> -- 
> 1.8.1.1
> 

-- 

"Win95 file and print sharing are for relatively friendly nets."
	- Paul Leach, Microsoft

			http://www.jlbec.org/
			jlbec@evilplan.org

Re: [PATCH V6 00/30] loop: Issue O_DIRECT aio using bio_vec

[Dave Kleikamp]

On 01/29/2013 12:42 PM, Jeff Moyer wrote:
> Dave Kleikamp <dave.kleikamp@oracle.com> writes:
> 
>> Al,
>> I'd like to push this patchset to linux-next. Would you like to pull it
>> into your vfs tree, would you rather I submitted it separately, or do
>> you have any issues with it before including it?
> 
> I'm still chasing one regression in this patchset.  If you use the ext4
> driver for ext2 file systems, and you run the libaio test harness, then
> you will be able to successfully write beyond the maximum file size in a
> file (see test case 8).

I found the problem. iov_iter_shorten() wasn't setting i->count to the new
value.

This fixes it. I'll fix the patchset tomorrow.

Thanks,
Shaggy

diff --git a/fs/iov-iter.c b/fs/iov-iter.c
index ac2d96e..ade8c11 100644
--- a/fs/iov-iter.c
+++ b/fs/iov-iter.c
@@ -370,6 +370,7 @@ static int ii_iovec_shorten(struct iov_iter *i, size_t count)
 {
 	struct iovec *iov = (struct iovec *)i->data;
 	i->nr_segs = iov_shorten(iov, i->nr_segs, count);
+	i->count = min(i->count, count);
 	return 0;
 }
 

Re: [PATCH V6 00/30] loop: Issue O_DIRECT aio using bio_vec

[Jeff Moyer]

Dave Kleikamp <dave.kleikamp@oracle.com> writes:

> On 01/29/2013 12:42 PM, Jeff Moyer wrote:
>> Dave Kleikamp <dave.kleikamp@oracle.com> writes:
>> 
>>> Al,
>>> I'd like to push this patchset to linux-next. Would you like to pull it
>>> into your vfs tree, would you rather I submitted it separately, or do
>>> you have any issues with it before including it?
>> 
>> I'm still chasing one regression in this patchset.  If you use the ext4
>> driver for ext2 file systems, and you run the libaio test harness, then
>> you will be able to successfully write beyond the maximum file size in a
>> file (see test case 8).
>
> I found the problem. iov_iter_shorten() wasn't setting i->count to the new
> value.
>
> This fixes it. I'll fix the patchset tomorrow.

I just re-ran the test, and I can confirm it fixed it as well.

Thanks!
Jeff

Re: [PATCH V6 00/30] loop: Issue O_DIRECT aio using bio_vec

[Dave Kleikamp]

By the way, I have updated the patchset in git. I removed the version
from the name of the branch and will keep this one updated:

git://github.com/kleikamp/linux-shaggy.git aio_loop

Re: [PATCH V6 00/30] loop: Issue O_DIRECT aio using bio_vec

[Sedat Dilek]

On Wed, Jan 30, 2013 at 8:26 PM, Dave Kleikamp <dave.kleikamp@oracle.com> wrote:
> By the way, I have updated the patchset in git. I removed the version
> from the name of the branch and will keep this one updated:
>
> git://github.com/kleikamp/linux-shaggy.git aio_loop

What's the status of this patchset?
Will it go into Linux-Next? Through Al's VFS tree? Any chance to have
it for-3.9?

- Sedat -

> --
> To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH V6 00/30] loop: Issue O_DIRECT aio using bio_vec

[Dave Kleikamp]

On 02/18/2013 03:42 PM, Sedat Dilek wrote:
> On Wed, Jan 30, 2013 at 8:26 PM, Dave Kleikamp <dave.kleikamp@oracle.com> wrote:
>> By the way, I have updated the patchset in git. I removed the version
>> from the name of the branch and will keep this one updated:
>>
>> git://github.com/kleikamp/linux-shaggy.git aio_loop
> 
> What's the status of this patchset?

Based on some feedback from Hugh, I've been testing some changes to
iov_iter_copy_to_user().

> Will it go into Linux-Next? Through Al's VFS tree? Any chance to have
> it for-3.9?

I think it's about ready to push to linux-next.

Al, do you want this to go through the vfs tree, or straight from me to
linux-next?

Thanks,
Shaggy

> 
> - Sedat -