The patch titled
Subject: fsdax: dedupe: iter two files at the same time
has been added to the -mm mm-unstable branch. Its filename is
fsdax-dedupe-iter-two-files-at-the-same-time.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/fsdax-dedupe-iter-two-files-at-the-same-time.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>
Subject: fsdax: dedupe: iter two files at the same time
Date: Thu, 1 Dec 2022 15:31:41 +0000
The iomap_iter() on a range of one file may loop more than once. In this
case, the inner dst_iter can update its iomap but the outer src_iter
can't. This may cause the wrong remapping in filesystem. Let them called
at the same time.
Link: https://lkml.kernel.org/r/1669908701-93-1-git-send-email-ruansy.fnst@xxxxxxxxxxx
Signed-off-by: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx>
Cc: Alistair Popple <apopple@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Darrick J. Wong <djwong@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/dax.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
--- a/fs/dax.c~fsdax-dedupe-iter-two-files-at-the-same-time
+++ a/fs/dax.c
@@ -1964,15 +1964,15 @@ int dax_dedupe_file_range_compare(struct
.len = len,
.flags = IOMAP_DAX,
};
- int ret;
+ int ret, compared = 0;
- while ((ret = iomap_iter(&src_iter, ops)) > 0) {
- while ((ret = iomap_iter(&dst_iter, ops)) > 0) {
- dst_iter.processed = dax_range_compare_iter(&src_iter,
- &dst_iter, len, same);
- }
- if (ret <= 0)
- src_iter.processed = ret;
+ while ((ret = iomap_iter(&src_iter, ops)) > 0 &&
+ (ret = iomap_iter(&dst_iter, ops)) > 0) {
+ compared = dax_range_compare_iter(&src_iter, &dst_iter, len,
+ same);
+ if (compared < 0)
+ return ret;
+ src_iter.processed = dst_iter.processed = compared;
}
return ret;
}
_
Patches currently in -mm which might be from ruansy.fnst@xxxxxxxxxxx are
fsdax-introduce-page-share-for-fsdax-in-reflink-mode.patch
fsdax-invalidate-pages-when-cow.patch
fsdax-zero-the-edges-if-source-is-hole-or-unwritten.patch
fsdaxxfs-set-the-shared-flag-when-file-extent-is-shared.patch
fsdax-dedupe-iter-two-files-at-the-same-time.patch
xfs-use-dax-ops-for-zero-and-truncate-in-fsdax-mode.patch
fsdaxxfs-port-unshare-to-fsdax.patch
xfs-remove-restrictions-for-fsdax-and-reflink.patch
