linux/fs
Tejun Heo 5ff8eaac16 writeback: keep superblock pinned during cgroup writeback association switches
If cgroup writeback is in use, an inode is associated with a cgroup
for writeback.  If the inode's main dirtier changes to another cgroup,
the association gets updated asynchronously.  Nothing was pinning the
superblock while such switches are in progress and superblock could go
away while async switching is pending or in progress leading to
crashes like the following.

 kernel BUG at fs/jbd2/transaction.c:319!
 invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
 CPU: 1 PID: 29158 Comm: kworker/1:10 Not tainted 4.5.0-rc3 #51
 Hardware name: Google Google, BIOS Google 01/01/2011
 Workqueue: events inode_switch_wbs_work_fn
 task: ffff880213dbbd40 ti: ffff880209264000 task.ti: ffff880209264000
 RIP: 0010:[<ffffffff803e6922>]  [<ffffffff803e6922>] start_this_handle+0x382/0x3e0
 RSP: 0018:ffff880209267c30  EFLAGS: 00010202
 ...
 Call Trace:
  [<ffffffff803e6be4>] jbd2__journal_start+0xf4/0x190
  [<ffffffff803cfc7e>] __ext4_journal_start_sb+0x4e/0x70
  [<ffffffff803b31ec>] ext4_evict_inode+0x12c/0x3d0
  [<ffffffff8035338b>] evict+0xbb/0x190
  [<ffffffff80354190>] iput+0x130/0x190
  [<ffffffff80360223>] inode_switch_wbs_work_fn+0x343/0x4c0
  [<ffffffff80279819>] process_one_work+0x129/0x300
  [<ffffffff80279b16>] worker_thread+0x126/0x480
  [<ffffffff8027ed14>] kthread+0xc4/0xe0
  [<ffffffff809771df>] ret_from_fork+0x3f/0x70

Fix it by bumping s_active while cgroup association switching is in
flight.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Tahsin Erdogan <tahsin@google.com>
Link: http://lkml.kernel.org/g/CAAeU0aNCq7LGODvVGRU-oU_o-6enii5ey0p1c26D1ZzYwkDc5A@mail.gmail.com
Fixes: d10c809552 ("writeback: implement foreign cgroup inode bdi_writeback switching")
Cc: stable@vger.kernel.org #v4.5+
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-16 11:34:07 -07:00
..
9p wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
adfs fs/adfs/adfs.h: tidy up comments 2016-01-20 17:09:18 -08:00
affs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
afs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
autofs4 switch ->get_link() to delayed_call, kill ->put_link() 2015-12-30 13:01:03 -05:00
befs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
bfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
btrfs Merge branch 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2016-01-29 15:46:49 -08:00
cachefiles wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2016-01-24 12:34:13 -08:00
cifs Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6 2016-01-24 12:31:12 -08:00
coda Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
configfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
cramfs don't put symlink bodies in pagecache into highmem 2015-12-08 22:41:36 -05:00
debugfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
devpts wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
dlm [regression] fix braino in fs/dlm/user.c 2016-01-21 17:45:15 -05:00
ecryptfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
efivarfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
efs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
exofs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
exportfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
ext2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
f2fs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
fat wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
freevxfs don't put symlink bodies in pagecache into highmem 2015-12-08 22:41:36 -05:00
fscache FS-Cache: Handle a write to the page immediately beyond the EOF marker 2015-11-11 02:11:02 -05:00
fuse wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
gfs2 wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
hfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
hfsplus wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
hostfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
hpfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
hugetlbfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
isofs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
jbd2 fs: use block_device name vsprintf helper 2016-01-06 13:03:18 -05:00
jffs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
jfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
kernfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
lockd lockd: constify nlmsvc_binding structure 2016-01-07 10:10:50 -05:00
logfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
minix kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
ncpfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
nfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
nfs_common lockd: NLM grace period shouldn't block NFSv4 opens 2015-08-13 10:22:06 -04:00
nfsd wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
nilfs2 wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
nls
notify fsnotify: destroy marks with call_srcu instead of dedicated thread 2016-01-14 16:00:49 -08:00
ntfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
ocfs2 wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
omfs
openpromfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
overlayfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
proc wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
pstore wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
qnx4 kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
qnx6 kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
quota wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
ramfs don't put symlink bodies in pagecache into highmem 2015-12-08 22:41:36 -05:00
reiserfs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
romfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
squashfs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
sysfs platform/chrome: Branch for v4.4 2015-11-13 21:53:18 -08:00
sysv kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
tracefs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
ubifs wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
udf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
ufs kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
xfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
aio.c mm: move ->mremap() from file_operations to vm_operations_struct 2015-09-04 16:54:41 -07:00
anon_inodes.c
attr.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
bad_inode.c fs/bad_inode.c: is_bad_inode can be boolean 2015-12-06 21:17:14 -05:00
binfmt_aout.c
binfmt_elf_fdpic.c libnvdimm for 4.4: 2015-11-10 12:07:22 -08:00
binfmt_elf.c ELF: Also pass any interpreter's file header to `arch_check_elf' 2016-01-20 00:39:20 +01:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
binfmt_script.c
block_dev.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
buffer.c fs: use block_device name vsprintf helper 2016-01-06 13:03:18 -05:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-12 17:11:47 -08:00
compat.c saner calling conventions for copy_mount_options() 2016-01-04 10:28:32 -05:00
coredump.c fs/coredump: prevent "" / "." / ".." core path components 2016-01-20 17:09:18 -08:00
dax.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
dcache.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
dcookies.c
direct-io.c block: fix use-after-free in dio_bio_complete 2016-01-30 22:02:10 -07:00
drop_caches.c inode: convert inode_sb_list_lock to per-sb 2015-08-17 18:39:46 -04:00
eventfd.c Documentation: filesystem: Fix typo in fs/eventfd.c 2015-12-08 14:52:03 +01:00
eventpoll.c epoll: add EPOLLEXCLUSIVE flag 2016-01-20 17:09:18 -08:00
exec.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
fcntl.c fcntl: allow to set O_DIRECT flag on pipe 2016-01-09 02:55:37 -05:00
fhandle.c
file_table.c
file.c kmemcg: account certain kmem allocations to memcg 2016-01-14 16:00:49 -08:00
filesystems.c find_filesystem(): simplify comparison 2016-01-19 12:02:23 -05:00
fs_pin.c
fs_struct.c
fs-writeback.c writeback: keep superblock pinned during cgroup writeback association switches 2016-02-16 11:34:07 -07:00
inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-01-23 12:24:56 -08:00
internal.h Merge branch 'for-linus' into work.misc 2016-01-08 21:20:11 -05:00
ioctl.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
Kconfig dax: re-enable dax pmd mappings 2016-01-15 17:56:32 -08:00
Kconfig.binfmt
libfs.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
locks.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
Makefile ext4: promote ext4 over ext2 in the default probe order 2015-10-15 10:33:21 -04:00
mbcache.c
mount.h
mpage.c mm, fs: introduce mapping_gfp_constraint() 2015-11-06 17:50:42 -08:00
namei.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
namespace.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
no-block.c
nsfs.c fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void 2015-09-11 15:21:34 -07:00
open.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
pipe.c pipe: limit the per-user amount of pages allocated in pipes 2016-01-19 19:25:21 -05:00
pnode.c
pnode.h
posix_acl.c xattr handlers: Simplify list operation 2015-12-13 19:46:12 -05:00
proc_namespace.c vfs: show_vfsstat: remove redundant initialization and check of error code 2015-12-06 21:17:16 -05:00
read_write.c vfs: abort dedupe loop if fatal signals are pending 2016-01-22 20:29:55 -05:00
readdir.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
select.c poll: plug an unused argument to do_poll 2016-01-06 08:26:52 -05:00
seq_file.c fs, seqfile: always allow oom killer 2015-11-06 17:50:42 -08:00
signalfd.c
splice.c fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE 2016-01-09 02:55:35 -05:00
stack.c
stat.c fs/stat.c: drop the last new_valid_dev check 2016-01-16 11:17:23 -08:00
statfs.c
super.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2016-01-14 17:04:19 -08:00
sync.c fs/sync.c: make sync_file_range(2) use WB_SYNC_NONE writeback 2015-11-06 17:50:42 -08:00
timerfd.c
userfaultfd.c userfaultfd: revert "userfaultfd: waitqueue: add nr wake parameter to __wake_up_locked_key" 2015-09-22 15:09:53 -07:00
utimes.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
xattr.c wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00