Andrew Morton
2023-Mar-08 01:05 UTC
[Ocfs2-devel] [merged mm-hotfixes-stable] ocfs2-fix-data-corruption-after-failed-write.patch removed from -mm tree
The quilt patch titled Subject: ocfs2: fix data corruption after failed write has been removed from the -mm tree. Its filename was ocfs2-fix-data-corruption-after-failed-write.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: Jan Kara via Ocfs2-devel <ocfs2-devel at 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 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> --- --- 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 at oss.oracle.com are