The patch titled
Subject: ocfs2: fix data corruption after failed write
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
ocfs2-fix-data-corruption-after-failed-write.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ocfs2-fix-data-corruption-after-failed-write.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Jan Kara via Ocfs2-devel <ocfs2-devel@xxxxxxxxxxxxxx>
Subject: ocfs2: fix data corruption after failed write
Date: Thu, 2 Mar 2023 16:38:43 +0100
When buffered write fails to copy data into underlying page cache page,
ocfs2_write_end_nolock() just zeroes out and dirties the page. This can
leave dirty page beyond EOF and if page writeback tries to write this page
before write succeeds and expands i_size, page gets into inconsistent
state where page dirty bit is clear but buffer dirty bits stay set
resulting in page data never getting written and so data copied to the
page is lost. Fix the problem by invalidating page beyond EOF after
failed write.
Link: https://lkml.kernel.org/r/20230302153843.18499-1-jack@xxxxxxx
Fixes: 6dbf7bb55598 ("fs: Don't invalidate page buffers in block_write_full_page()")
Signed-off-by: Jan Kara <jack@xxxxxxx>
Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
Cc: Mark Fasheh <mark@xxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Cc: Changwei Ge <gechangwei@xxxxxxx>
Cc: Gang He <ghe@xxxxxxxx>
Cc: Jun Piao <piaojun@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/fs/ocfs2/aops.c~ocfs2-fix-data-corruption-after-failed-write
+++ a/fs/ocfs2/aops.c
@@ -1977,11 +1977,26 @@ int ocfs2_write_end_nolock(struct addres
}
if (unlikely(copied < len) && wc->w_target_page) {
+ loff_t new_isize;
+
if (!PageUptodate(wc->w_target_page))
copied = 0;
- ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
- start+len);
+ new_isize = max_t(loff_t, i_size_read(inode), pos + copied);
+ if (new_isize > page_offset(wc->w_target_page))
+ ocfs2_zero_new_buffers(wc->w_target_page, start+copied,
+ start+len);
+ else {
+ /*
+ * When page is fully beyond new isize (data copy
+ * failed), do not bother zeroing the page. Invalidate
+ * it instead so that writeback does not get confused
+ * put page & buffer dirty bits into inconsistent
+ * state.
+ */
+ block_invalidate_folio(page_folio(wc->w_target_page),
+ 0, PAGE_SIZE);
+ }
}
if (wc->w_target_page)
flush_dcache_page(wc->w_target_page);
_
Patches currently in -mm which might be from ocfs2-devel@xxxxxxxxxxxxxx are
ocfs2-fix-data-corruption-after-failed-write.patch
