Ocfs2 devel - Mar 2023 - Patch "ocfs2: fix data corruption after failed write" has been added to the 5.4-stable tree

This is a note to let you know that I've just added the patch titled

    ocfs2: fix data corruption after failed write

to the 5.4-stable tree which can be found at:
   
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ocfs2-fix-data-corruption-after-failed-write.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.

>From 90410bcf873cf05f54a32183afff0161f44f9715 Mon Sep 17 00:00:00 2001
From: Jan Kara via Ocfs2-devel <ocfs2-devel at oss.oracle.com>
Date: Thu, 2 Mar 2023 16:38:43 +0100
Subject: ocfs2: fix data corruption after failed write

From: Jan Kara via Ocfs2-devel <ocfs2-devel at oss.oracle.com>

commit 90410bcf873cf05f54a32183afff0161f44f9715 upstream.

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 at suse.cz
Fixes: 6dbf7bb55598 ("fs: Don't invalidate page buffers in
block_write_full_page()")
Signed-off-by: Jan Kara <jack at suse.cz>
Reviewed-by: Joseph Qi <joseph.qi at linux.alibaba.com>
Cc: Mark Fasheh <mark at fasheh.com>
Cc: Joel Becker <jlbec at evilplan.org>
Cc: Junxiao Bi <junxiao.bi at oracle.com>
Cc: Changwei Ge <gechangwei at live.cn>
Cc: Gang He <ghe at suse.com>
Cc: Jun Piao <piaojun at huawei.com>
Cc: <stable at vger.kernel.org>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
[ replace block_invalidate_folio to block_invalidatepage ]
Signed-off-by: Joseph Qi <joseph.qi at linux.alibaba.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 fs/ocfs2/aops.c |   18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -1990,11 +1990,25 @@ 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_invalidatepage(wc->w_target_page, 0, PAGE_SIZE);
+		}
 	}
 	if (wc->w_target_page)
 		flush_dcache_page(wc->w_target_page);


Patches currently in stable-queue which might be from ocfs2-devel at
oss.oracle.com are

queue-5.4/ocfs2-fix-data-corruption-after-failed-write.patch