linux/fs/ocfs2
Junxiao Bi 9449ad33be ocfs2: issue zeroout to EOF blocks
For punch holes in EOF blocks, fallocate used buffer write to zero the
EOF blocks in last cluster.  But since ->writepage will ignore EOF
pages, those zeros will not be flushed.

This "looks" ok as commit 6bba4471f0 ("ocfs2: fix data corruption by
fallocate") will zero the EOF blocks when extend the file size, but it
isn't.  The problem happened on those EOF pages, before writeback, those
pages had DIRTY flag set and all buffer_head in them also had DIRTY flag
set, when writeback run by write_cache_pages(), DIRTY flag on the page
was cleared, but DIRTY flag on the buffer_head not.

When next write happened to those EOF pages, since buffer_head already
had DIRTY flag set, it would not mark page DIRTY again.  That made
writeback ignore them forever.  That will cause data corruption.  Even
directio write can't work because it will fail when trying to drop pages
caches before direct io, as it found the buffer_head for those pages
still had DIRTY flag set, then it will fall back to buffer io mode.

To make a summary of the issue, as writeback ingores EOF pages, once any
EOF page is generated, any write to it will only go to the page cache,
it will never be flushed to disk even file size extends and that page is
not EOF page any more.  The fix is to avoid zero EOF blocks with buffer
write.

The following code snippet from qemu-img could trigger the corruption.

  656   open("6b3711ae-3306-4bdd-823c-cf1c0060a095.conv.2", O_RDWR|O_DIRECT|O_CLOEXEC) = 11
  ...
  660   fallocate(11, FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE, 2275868672, 327680 <unfinished ...>
  660   fallocate(11, 0, 2275868672, 327680) = 0
  658   pwrite64(11, "

Link: https://lkml.kernel.org/r/20210722054923.24389-2-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-07-30 10:14:39 -07:00
..
cluster ocfs2: remove redundant initialization of variable ret 2021-06-29 10:53:46 -07:00
dlm ocfs2: remove redundant assignment to pointer queue 2021-06-29 10:53:46 -07:00
dlmfs treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
acl.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
acl.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
alloc.c ext4: add discard/zeroout flags to journal flush 2021-06-22 19:27:10 -04:00
alloc.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
aops.c mm: require ->set_page_dirty to be explicitly wired up 2021-06-29 10:53:48 -07:00
aops.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
blockcheck.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
blockcheck.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
buffer_head_io.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
buffer_head_io.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
dcache.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
dcache.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
dir.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
dir.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
dlmglue.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
dlmglue.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
export.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
export.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
extent_map.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
extent_map.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
file.c ocfs2: issue zeroout to EOF blocks 2021-07-30 10:14:39 -07:00
file.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
filecheck.c ocfs2: fix snprintf() checking 2021-06-29 10:53:46 -07:00
filecheck.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
heartbeat.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
heartbeat.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
inode.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
inode.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
ioctl.c ocfs2: convert to fileattr 2021-04-12 15:04:30 +02:00
ioctl.h ocfs2: convert to fileattr 2021-04-12 15:04:30 +02:00
journal.c ext4: add discard/zeroout flags to journal flush 2021-06-22 19:27:10 -04:00
journal.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
Kconfig ocfs2: replace HTTP links with HTTPS ones 2020-08-07 11:33:22 -07:00
localalloc.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
localalloc.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
locks.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
locks.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
Makefile ocfs2: improve ocfs2 Makefile 2018-12-28 12:11:45 -08:00
mmap.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
mmap.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
move_extents.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
move_extents.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
namei.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
namei.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
ocfs1_fs_compat.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
ocfs2_fs.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
ocfs2_ioctl.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
ocfs2_lockid.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
ocfs2_lockingver.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
ocfs2_trace.h ocfs2: fix the application IO timeout when fstrim is running 2019-03-05 21:07:13 -08:00
ocfs2.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
quota_global.c quota: Check that quota is not dirty before release 2019-10-31 19:07:42 +01:00
quota_local.c ocfs2: return -EROFS when filesystem becomes read-only 2018-08-17 16:20:27 -07:00
quota.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
refcounttree.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
refcounttree.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
reservations.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
reservations.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
resize.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
resize.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
slot_map.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
slot_map.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
stack_o2cb.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
stack_user.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
stackglue.c ocfs2: fix snprintf() checking 2021-06-29 10:53:46 -07:00
stackglue.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
suballoc.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
suballoc.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
super.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
super.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
symlink.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
symlink.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
sysfile.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
sysfile.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
uptodate.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
uptodate.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
xattr.c treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
xattr.h treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00