6.6-stable review patch. If anyone has any objections, please let me know.
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From: Zhang Yi yi.zhang@huawei.com
commit 12e803c8827d049ae8f2c743ef66ab87ae898375 upstream.
During the movement of a written extent, mext_page_mkuptodate() is called to read data in the range [from, to) into the page cache and to update the corresponding buffers. Therefore, we should not wait on any buffer whose start offset is >= 'to'. Otherwise, it will return -EIO and fail the extents movement.
$ for i in `seq 3 -1 0`; \ do xfs_io -fs -c "pwrite -b 1024 $((i * 1024)) 1024" /mnt/foo; \ done $ umount /mnt && mount /dev/pmem1s /mnt # drop cache $ e4defrag /mnt/foo e4defrag 1.47.0 (5-Feb-2023) ext4 defragmentation for /mnt/foo [1/1]/mnt/foo: 0% [ NG ] Success: [0/1]
Cc: stable@kernel.org Fixes: a40759fb16ae ("ext4: remove array of buffer_heads from mext_page_mkuptodate()") Signed-off-by: Zhang Yi yi.zhang@huawei.com Reviewed-by: Jan Kara jack@suse.cz Message-ID: 20250912105841.1886799-1-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/move_extent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c index adae3caf175a..4b091c21908f 100644 --- a/fs/ext4/move_extent.c +++ b/fs/ext4/move_extent.c @@ -225,7 +225,7 @@ static int mext_page_mkuptodate(struct folio *folio, size_t from, size_t to) do { if (bh_offset(bh) + blocksize <= from) continue; - if (bh_offset(bh) > to) + if (bh_offset(bh) >= to) break; wait_on_buffer(bh); if (buffer_uptodate(bh))