diff mbox series

+ ocfs2-fix-data-corruption-after-failed-write.patch added to mm-hotfixes-unstable branch

Message ID 20230303230527.7951CC433EF@smtp.kernel.org (mailing list archive)
State New, archived
Headers show
Series + ocfs2-fix-data-corruption-after-failed-write.patch added to mm-hotfixes-unstable branch | expand

Commit Message

Andrew Morton March 3, 2023, 11:05 p.m. UTC
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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Jan Kara via Ocfs2-devel <ocfs2-devel@oss.oracle.com>
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@suse.cz
Fixes: 6dbf7bb55598 ("fs: Don't invalidate page buffers in block_write_full_page()")
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
diff mbox series

Patch

--- 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);