The quilt patch titled Subject: fsdax: dedupe should compare the min of two iters' length has been removed from the -mm tree. Its filename was fsdax-dedupe-should-compare-the-min-of-two-iters-length.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------ From: Shiyang Ruan ruansy.fnst@fujitsu.com Subject: fsdax: dedupe should compare the min of two iters' length Date: Wed, 22 Mar 2023 07:25:58 +0000

In an dedupe comparison iter loop, the length of iomap_iter decreases because it implies the remaining length after each iteration.

The dedupe command will fail with -EIO if the range is larger than one page size and not aligned to the page size. Also report warning in dmesg:

[ 4338.498374] ------------[ cut here ]------------ [ 4338.498689] WARNING: CPU: 3 PID: 1415645 at fs/iomap/iter.c:16 ...

The compare function should use the min length of the current iters, not the total length.

Link: https://lkml.kernel.org/r/1679469958-2-1-git-send-email-ruansy.fnst@fujitsu.... Fixes: 0e79e3736d54 ("fsdax: dedupe: iter two files at the same time") Signed-off-by: Shiyang Ruan ruansy.fnst@fujitsu.com Reviewed-by: Darrick J. Wong djwong@kernel.org Cc: Dan Williams dan.j.williams@intel.com Cc: Jan Kara jack@suse.cz Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

fs/dax.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/dax.c~fsdax-dedupe-should-compare-the-min-of-two-iters-length +++ a/fs/dax.c @@ -2027,8 +2027,8 @@ int dax_dedupe_file_range_compare(struct

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); + compared = dax_range_compare_iter(&src_iter, &dst_iter, + min(src_iter.len, dst_iter.len), same); if (compared < 0) return ret; src_iter.processed = dst_iter.processed = compared; _

Patches currently in -mm which might be from ruansy.fnst@fujitsu.com are

fsdax-force-clear-dirty-mark-if-cow.patch