linux/fs
Kiran Kumar Modukuri 5ce83d4bb7 cachefiles: Fix missing clear of the CACHEFILES_OBJECT_ACTIVE flag
In cachefiles_mark_object_active(), the new object is marked active and
then we try to add it to the active object tree.  If a conflicting object
is already present, we want to wait for that to go away.  After the wait,
we go round again and try to re-mark the object as being active - but it's
already marked active from the first time we went through and a BUG is
issued.

Fix this by clearing the CACHEFILES_OBJECT_ACTIVE flag before we try again.

Analysis from Kiran Kumar Modukuri:

[Impact]
Oops during heavy NFS + FSCache + Cachefiles

CacheFiles: Error: Overlong wait for old active object to go away.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000002

CacheFiles: Error: Object already active kernel BUG at
fs/cachefiles/namei.c:163!

[Cause]
In a heavily loaded system with big files being read and truncated, an
fscache object for a cookie is being dropped and a new object being
looked. The new object being looked for has to wait for the old object
to go away before the new object is moved to active state.

[Fix]
Clear the flag 'CACHEFILES_OBJECT_ACTIVE' for the new object when
retrying the object lookup.

[Testcase]
Have run ~100 hours of NFS stress tests and have not seen this bug recur.

[Regression Potential]
 - Limited to fscache/cachefiles.

Fixes: 9ae326a690 ("CacheFiles: A cache that backs onto a mounted filesystem")
Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-07-25 14:49:00 +01:00
..
9p treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
adfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
affs affs: fix potential memory leak when parsing option 'prefix' 2018-05-28 12:36:41 +02:00
afs Merge branch 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-16 16:32:04 +09:00
autofs autofs: Fix typo s/thenew new/the new/ in AUTOFS4_FS description 2018-06-12 12:31:19 -07:00
befs fix a series of Documentation/ broken file name references 2018-06-15 18:10:01 -03:00
bfs bfs_add_entry: pass name/len as qstr pointer 2018-05-22 14:27:50 -04:00
btrfs for-4.18-rc2-tag 2018-07-01 12:38:16 -07:00
cachefiles cachefiles: Fix missing clear of the CACHEFILES_OBJECT_ACTIVE flag 2018-07-25 14:49:00 +01:00
ceph ceph: fix dentry leak in splice_dentry() 2018-06-26 18:42:44 +02:00
cifs cifs: Fix invalid check in __cifs_calc_signature() 2018-06-15 19:17:40 -05:00
coda vfs: change inode times to use struct timespec64 2018-06-05 16:57:31 -07:00
configfs vfs: change inode times to use struct timespec64 2018-06-05 16:57:31 -07:00
cramfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
crypto f2fs-for-4.18-rc1 2018-06-11 10:16:13 -07:00
debugfs Revert "debugfs: inode: debugfs_create_dir uses mode permission from parent" 2018-06-12 20:52:16 -07:00
devpts
dlm treewide: Use array_size() in vmalloc() 2018-06-12 16:19:22 -07:00
ecryptfs Merge branch 'fixes' of https://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs into aio-base 2018-05-26 09:16:25 +02:00
efivarfs
efs
exofs exofs: avoid VLA in structures 2018-06-15 07:55:24 +09:00
exportfs ovl: do not try to reconnect a disconnected origin dentry 2018-04-12 12:04:49 +02:00
ext2 ext2: add warning when specifying nocheck option 2018-06-20 11:04:26 +02:00
ext4 vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
f2fs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
fat Merge branch 'akpm' (patches from Andrew) 2018-06-15 08:51:42 +09:00
freevxfs freevxfs_lookup(): use d_splice_alias() 2018-05-22 14:27:51 -04:00
fscache fscache: Fix reference overput in fscache_attach_object() error handling 2018-07-25 14:49:00 +01:00
fuse vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
gfs2 vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
hfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
hfsplus vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
hostfs vfs: change inode times to use struct timespec64 2018-06-05 16:57:31 -07:00
hpfs treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
hugetlbfs hugetlbfs: fix bug in pgoff overflow checking 2018-04-05 21:36:21 -07:00
isofs isofs: fix potential memory leak in mount option parsing 2018-04-16 09:47:41 +02:00
jbd2 treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
jffs2 vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
jfs This fixes a too-small allocation in the xattr code. 2018-06-19 07:47:32 +09:00
kernfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
lockd
minix minix_lookup: use d_splice_alias() 2018-05-22 14:27:52 -04:00
nfs NFS client bugfixes for Linux 4.18 2018-06-22 06:21:34 +09:00
nfs_common
nfsd vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
nilfs2 do d_instantiate/unlock_new_inode combinations safely 2018-05-11 15:36:37 -04:00
nls
notify fsnotify: add fsnotify_add_inode_mark() wrappers 2018-05-18 14:58:22 +02:00
ntfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
ocfs2 vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
omfs omfs_lookup(): report IO errors, use d_splice_alias() 2018-05-22 14:27:58 -04:00
openpromfs openpromfs: switch to d_splice_alias() 2018-05-22 14:27:57 -04:00
orangefs Solve a series of broken links for files under Documentation: 2018-06-17 05:25:18 +09:00
overlayfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
proc Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-07-01 12:32:19 -07:00
pstore pstore: Remove bogus format string definition 2018-06-14 14:57:24 +02:00
qnx4 qnx4_lookup: use d_splice_alias() 2018-05-22 14:27:52 -04:00
qnx6 qnx6_lookup: switch to d_splice_alias() 2018-05-22 14:27:54 -04:00
quota quota: Cleanup list iteration in dqcache_shrink_scan() 2018-06-20 11:04:26 +02:00
ramfs
reiserfs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
romfs romfs_lookup: switch to d_splice_alias() 2018-05-22 14:27:55 -04:00
squashfs
sysfs unfuck sysfs_mount() 2018-05-21 14:30:09 -04:00
sysv sysv_lookup: use d_splice_alias() 2018-05-22 14:27:53 -04:00
tracefs
ubifs vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
udf udf: Drop unused arguments of udf_delete_aext() 2018-06-20 11:05:49 +02:00
ufs treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
xfs xfs: fix fdblocks accounting w/ RMAPBT per-AG reservation 2018-06-24 12:00:12 -07:00
aio.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
anon_inodes.c
attr.c vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
bad_inode.c vfs: change inode times to use struct timespec64 2018-06-05 16:57:31 -07:00
binfmt_aout.c exec: introduce finalize_exec() before start_thread() 2018-04-11 10:28:37 -07:00
binfmt_elf_fdpic.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
binfmt_elf.c coredump: fix spam with zero VMA process 2018-06-15 07:55:24 +09:00
binfmt_em86.c
binfmt_flat.c exec: introduce finalize_exec() before start_thread() 2018-04-11 10:28:37 -07:00
binfmt_misc.c docs: Fix more broken references 2018-06-15 18:11:26 -03:00
binfmt_script.c
block_dev.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
buffer.c fs: move page_cache_seek_hole_data to iomap.c 2018-06-01 18:37:33 -07:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c autofs: clean up includes 2018-06-07 17:34:40 -07:00
compat.c ncpfs: remove compat functionality 2018-06-05 19:23:26 +02:00
coredump.c
d_path.c
dax.c libnvdimm for 4.18 2018-06-08 17:21:52 -07:00
dcache.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 10:14:28 -07:00
dcookies.c fs: add do_lookup_dcookie() helper; remove in-kernel call to syscall 2018-04-02 20:15:39 +02:00
direct-io.c block: consistently use GFP_NOIO instead of __GFP_NORECLAIM 2018-05-14 08:55:18 -06:00
drop_caches.c
eventfd.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
eventpoll.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
exec.c Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-10 10:17:09 -07:00
fcntl.c mm: restructure memfd code 2018-06-07 17:34:35 -07:00
fhandle.c
file_table.c
file.c fs: add ksys_close() wrapper; remove in-kernel calls to sys_close() 2018-04-02 20:16:00 +02:00
filesystems.c proc: introduce proc_create_single{,_data} 2018-05-16 07:23:35 +02:00
fs_pin.c
fs_struct.c
fs-writeback.c bdi: Fix oops in wb_workfn() 2018-05-03 16:11:37 -06:00
inode.c vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
internal.h Revert "fs: fold open_check_o_direct into do_dentry_open" 2018-06-03 10:58:23 -07:00
ioctl.c fs: Allow CAP_SYS_ADMIN in s_user_ns to freeze and thaw filesystems 2018-05-24 12:04:28 -05:00
iomap.c Changes since last update: 2018-06-12 15:49:00 -07:00
Kconfig autofs: remove left-over autofs4 stubs 2018-06-11 08:22:34 -07:00
Kconfig.binfmt docs: Fix more broken references 2018-06-15 18:11:26 -03:00
libfs.c
locks.c vfs/y2038: inode timestamps conversion to timespec64 2018-06-15 07:31:07 +09:00
Makefile autofs: remove left-over autofs4 stubs 2018-06-11 08:22:34 -07:00
mbcache.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
mount.h
mpage.c
namei.c Merge branch 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-16 16:32:04 +09:00
namespace.c fs: Allow superblock owner to access do_remount_sb() 2018-05-24 12:02:25 -05:00
no-block.c
nsfs.c
open.c Revert "fs: fold open_check_o_direct into do_dentry_open" 2018-06-03 10:58:23 -07:00
pipe.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
pnode.c
pnode.h
posix_acl.c
proc_namespace.c
read_write.c treewide: kmalloc() -> kmalloc_array() 2018-06-12 16:19:22 -07:00
readdir.c fs: add ksys_getdents64() helper; remove in-kernel calls to sys_getdents64() 2018-04-02 20:16:02 +02:00
select.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
seq_file.c proc: fix smaps and meminfo alignment 2018-05-25 18:12:11 -07:00
signalfd.c Merge branch 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-16 16:21:50 +09:00
splice.c Merge branch 'work.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-16 16:21:50 +09:00
stack.c
stat.c fs: add do_readlinkat() helper; remove internal call to sys_readlinkat() 2018-04-02 20:15:34 +02:00
statfs.c
super.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2018-06-04 10:14:28 -07:00
sync.c Changes for this release: 2018-04-04 12:44:02 -07:00
timerfd.c Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
userfaultfd.c userfaultfd: hugetlbfs: fix userfaultfd_huge_must_wait() pte access 2018-07-03 17:32:18 -07:00
utimes.c fs: add do_compat_futimesat() helper; remove in-kernel call to compat syscall 2018-04-02 20:15:44 +02:00
xattr.c vfs: delete unnecessary assignment in vfs_listxattr 2018-05-29 13:22:41 -04:00