From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andreas Gruenbacher <agruenba@redhat.com>,
"Darrick J. Wong" <djwong@kernel.org>,
Anand Jain <anand.jain@oracle.com>
Subject: [PATCH 5.15 25/33] iomap: Support partial direct I/O on user copy failures
Date: Fri, 29 Apr 2022 12:42:12 +0200 [thread overview]
Message-ID: <20220429104053.068440240@linuxfoundation.org> (raw)
In-Reply-To: <20220429104052.345760505@linuxfoundation.org>
From: Andreas Gruenbacher <agruenba@redhat.com>
commit 97308f8b0d867e9ef59528cd97f0db55ffdf5651 upstream
In iomap_dio_rw, when iomap_apply returns an -EFAULT error and the
IOMAP_DIO_PARTIAL flag is set, complete the request synchronously and
return a partial result. This allows the caller to deal with the page
fault and retry the remainder of the request.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/iomap/direct-io.c | 6 ++++++
include/linux/iomap.h | 7 +++++++
2 files changed, 13 insertions(+)
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -581,6 +581,12 @@ __iomap_dio_rw(struct kiocb *iocb, struc
if (iov_iter_rw(iter) == READ && iomi.pos >= dio->i_size)
iov_iter_revert(iter, iomi.pos - dio->i_size);
+ if (ret == -EFAULT && dio->size && (dio_flags & IOMAP_DIO_PARTIAL)) {
+ if (!(iocb->ki_flags & IOCB_NOWAIT))
+ wait_for_completion = true;
+ ret = 0;
+ }
+
/* magic error code to fall back to buffered I/O */
if (ret == -ENOTBLK) {
wait_for_completion = true;
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -330,6 +330,13 @@ struct iomap_dio_ops {
*/
#define IOMAP_DIO_OVERWRITE_ONLY (1 << 1)
+/*
+ * When a page fault occurs, return a partial synchronous result and allow
+ * the caller to retry the rest of the operation after dealing with the page
+ * fault.
+ */
+#define IOMAP_DIO_PARTIAL (1 << 2)
+
ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
unsigned int dio_flags);
next prev parent reply other threads:[~2022-04-29 10:45 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-29 10:41 [PATCH 5.15 00/33] 5.15.37-rc1 review Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 01/33] floppy: disable FDRAWCMD by default Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 02/33] bpf: Introduce composable reg, ret and arg types Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 03/33] bpf: Replace ARG_XXX_OR_NULL with ARG_XXX | PTR_MAYBE_NULL Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 04/33] bpf: Replace RET_XXX_OR_NULL with RET_XXX " Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 05/33] bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX " Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 06/33] bpf: Introduce MEM_RDONLY flag Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 07/33] bpf: Convert PTR_TO_MEM_OR_NULL to composable types Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 08/33] bpf: Make per_cpu_ptr return rdonly PTR_TO_MEM Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 09/33] bpf: Add MEM_RDONLY for helper args that are pointers to rdonly mem Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 10/33] bpf/selftests: Test PTR_TO_RDONLY_MEM Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 11/33] bpf: Fix crash due to out of bounds access into reg2btf_ids Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 12/33] spi: cadence-quadspi: fix write completion support Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 13/33] ARM: dts: socfpga: change qspi to "intel,socfpga-qspi" Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 14/33] mm: kfence: fix objcgs vector allocation Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 15/33] gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable} Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 16/33] iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 17/33] iov_iter: Introduce fault_in_iov_iter_writeable Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 18/33] gfs2: Add wrapper for iomap_file_buffered_write Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 19/33] gfs2: Clean up function may_grant Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 20/33] gfs2: Introduce flag for glock holder auto-demotion Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 21/33] gfs2: Move the inode glock locking to gfs2_file_buffered_write Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 22/33] gfs2: Eliminate ip->i_gh Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 23/33] gfs2: Fix mmap + page fault deadlocks for buffered I/O Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 24/33] iomap: Fix iomap_dio_rw return value for user copies Greg Kroah-Hartman
2022-04-29 10:42 ` Greg Kroah-Hartman [this message]
2022-04-29 10:42 ` [PATCH 5.15 26/33] iomap: Add done_before argument to iomap_dio_rw Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 27/33] gup: Introduce FOLL_NOFAULT flag to disable page faults Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 28/33] iov_iter: Introduce nofault " Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 29/33] gfs2: Fix mmap + page fault deadlocks for direct I/O Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 30/33] btrfs: fix deadlock due to page faults during direct IO reads and writes Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 31/33] btrfs: fallback to blocking mode when doing async dio over multiple extents Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 32/33] mm: gup: make fault_in_safe_writeable() use fixup_user_fault() Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 33/33] selftests/bpf: Add test for reg2btf_ids out of bounds access Greg Kroah-Hartman
2022-06-24 10:33 ` Po-Hsu Lin
2022-06-24 11:09 ` Greg Kroah-Hartman
2022-07-01 12:51 ` Po-Hsu Lin
2022-04-29 16:39 ` [PATCH 5.15 00/33] 5.15.37-rc1 review Florian Fainelli
2022-04-29 18:36 ` Shuah Khan
2022-04-29 21:14 ` Naresh Kamboju
2022-04-29 23:47 ` Guenter Roeck
2022-04-29 23:54 ` Ron Economos
2022-04-30 10:17 ` Sudip Mukherjee
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