1
linux/fs
Trond Myklebust b274b48f3e NFSv4: Fix circular locking dependency in nfs4_kill_renewd
Erez Zadok reports:

=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.24-rc6-unionfs2 #80
-------------------------------------------------------
umount.nfs4/4017 is trying to acquire lock:
 (&(&clp->cl_renewd)->work){--..}, at: [<c0223e53>]
__cancel_work_timer+0x83/0x17f

but task is already holding lock:
 (&clp->cl_sem){----}, at: [<f8879897>] nfs4_kill_renewd+0x17/0x29 [nfs]

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&clp->cl_sem){----}:
       [<c0230699>] __lock_acquire+0x9cc/0xb95
       [<c0230c39>] lock_acquire+0x5f/0x78
       [<c0397cb8>] down_read+0x3a/0x4c
       [<f88798e6>] nfs4_renew_state+0x1c/0x1b8 [nfs]
       [<c0223821>] run_workqueue+0xd9/0x1ac
       [<c0224220>] worker_thread+0x7a/0x86
       [<c0226b49>] kthread+0x3b/0x62
       [<c02033a3>] kernel_thread_helper+0x7/0x10
       [<ffffffff>] 0xffffffff

-> #0 (&(&clp->cl_renewd)->work){--..}:
       [<c0230589>] __lock_acquire+0x8bc/0xb95
       [<c0230c39>] lock_acquire+0x5f/0x78
       [<c0223e87>] __cancel_work_timer+0xb7/0x17f
       [<c0223f5a>] cancel_delayed_work_sync+0xb/0xd
       [<f887989e>] nfs4_kill_renewd+0x1e/0x29 [nfs]
       [<f885a8f6>] nfs_free_client+0x37/0x9e [nfs]
       [<f885ab20>] nfs_put_client+0x5d/0x62 [nfs]
       [<f885ab9a>] nfs_free_server+0x75/0xae [nfs]
       [<f8862672>] nfs4_kill_super+0x27/0x2b [nfs]
       [<c0258aab>] deactivate_super+0x3f/0x51
       [<c0269668>] mntput_no_expire+0x42/0x67
       [<c025d0e4>] path_release_on_umount+0x15/0x18
       [<c0269d30>] sys_umount+0x1a3/0x1cb
       [<c0269d71>] sys_oldumount+0x19/0x1b
       [<c02026ca>] sysenter_past_esp+0x5f/0xa5
       [<ffffffff>] 0xffffffff

Looking at the code, it would seem that taking the clp->cl_sem in
nfs4_kill_renewd is completely redundant, since we're already guaranteed to
have exclusive access to the nfs_client (we're shutting down).

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-03 09:37:16 -05:00
..
9p 9p: use copy of the options value instead of original 2007-11-06 08:02:53 -06:00
adfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
affs fs: mark nibblemap const 2007-10-17 08:42:47 -07:00
afs fs/afs/vlocation.c: fix off-by-one 2007-11-05 15:12:32 -08:00
autofs Use task_pid_nr() instead of pid_nr(task_pid()) 2007-10-19 11:53:43 -07:00
autofs4 pid namespaces: round up the API 2007-10-19 11:53:37 -07:00
befs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
bfs regression: bfs endianness bug 2007-12-05 09:25:20 -08:00
cifs regression: cifs endianness bug 2007-12-05 09:25:19 -08:00
coda pid namespaces: round up the API 2007-10-19 11:53:37 -07:00
configfs r/o bind mounts: filesystem helpers for custom 'struct file's 2007-10-17 08:43:04 -07:00
cramfs fs/cramfs/inode.c: replace hardcoded value with preprocessor constant 2007-10-18 14:37:29 -07:00
debugfs [PATCH] pass dentry to audit_inode()/audit_inode_child() 2007-10-21 02:37:18 -04:00
devpts
dlm [DLM] lowcomms: Do not muck with sysctl_rmem_max. 2007-11-07 04:11:42 -08:00
ecryptfs ecryptfs: redo dget,mntget on dentry_open failure 2007-12-23 12:54:37 -08:00
efs exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
exportfs exportfs: update documentation 2007-10-22 08:13:21 -07:00
ext2 fix up ext2_fs.h for userspace after reservations backport 2007-11-29 09:24:53 -08:00
ext3 ext3, ext4: avoid divide by zero 2007-12-17 19:28:16 -08:00
ext4 ext3, ext4: avoid divide by zero 2007-12-17 19:28:16 -08:00
fat exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
freevxfs
fuse fuse: fix attribute caching after rename 2007-11-29 09:24:54 -08:00
gfs2 exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
hfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
hfsplus Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
hostfs uml: fix hostfs style 2007-10-16 09:43:07 -07:00
hpfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
hppfs
hugetlbfs hugetlb: allow bulk updating in hugetlb_*_quota() 2007-11-14 18:45:40 -08:00
isofs exportfs: make struct export_operations const 2007-10-22 08:13:21 -07:00
jbd jbd: Fix assertion failure in fs/jbd/checkpoint.c 2007-12-05 09:21:20 -08:00
jbd2 JBD2: debug code cleanup. 2007-10-17 18:49:59 -04:00
jffs2 Freezer: Fix JFFS2 garbage collector freezing issue (rev. 2) 2007-12-04 01:35:41 -05:00
jfs Forbid user to change file flags on quota files 2007-11-14 18:45:38 -08:00
lockd NFS/SUNRPC: use transport protocol naming 2007-10-09 17:17:53 -04:00
minix limit minixfs printks on corrupted dir i_size 2007-10-17 08:42:53 -07:00
msdos
ncpfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
nfs NFSv4: Fix circular locking dependency in nfs4_kill_renewd 2008-01-03 09:37:16 -05:00
nfs_common
nfsd nfsd4: recheck for secure ports in fh_verify 2007-11-12 14:28:08 -08:00
nls sparse pointer use of zero as null 2007-10-18 14:37:31 -07:00
ntfs NTFS: Fix read regression. 2007-11-03 12:27:21 -07:00
ocfs2 ocfs2: Re-journal buffers after transaction extend 2007-12-17 10:51:23 -08:00
openpromfs Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
partitions fs/partitions/sun.c endianness annotations 2007-10-14 12:41:51 -07:00
proc restrict reading from /proc/<pid>/maps to those who share ->mm or can ptrace pid 2008-01-02 13:13:27 -08:00
qnx4 Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
ramfs Remove valueless definition of hard-selected RAMFS option 2007-10-17 08:42:56 -07:00
reiserfs proc: fix proc_dir_entry refcounting 2007-12-05 09:21:20 -08:00
romfs fs/romfs/inode.c: trivial improvements 2007-10-17 08:42:47 -07:00
smbfs smbfs: fix debug builds 2007-11-14 18:45:43 -08:00
sysfs sysfs: fix off-by-one error in fill_read_buffer() 2007-11-28 13:53:53 -08:00
sysv Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
udf fs/udf/balloc.c: mark a variable as uninitialized_var() 2007-10-17 08:43:00 -07:00
ufs ufs: fix nexstep dir block size 2007-12-05 09:21:18 -08:00
vfat
xfs [XFS] Initialise current offset in xfs_file_readdir correctly 2007-12-21 11:40:05 +11:00
aio.c aio: only account I/O wait time in read_events if there are active requests 2007-12-05 09:21:18 -08:00
anon_inodes.c anon-inodes use open coded atomic_inc for the shared inode 2007-10-17 08:43:00 -07:00
attr.c VFS: make notify_change pass ATTR_KILL_S*ID to setattr operations 2007-10-18 14:37:22 -07:00
bad_inode.c
binfmt_aout.c mm: fix exit_mmap BUG() on a.out binary exit 2007-12-20 07:49:53 -08:00
binfmt_elf_fdpic.c pid namespaces: changes to show virtual ids to user 2007-10-19 11:53:40 -07:00
binfmt_elf.c pid namespaces: changes to show virtual ids to user 2007-10-19 11:53:40 -07:00
binfmt_em86.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
binfmt_flat.c binfmt_flat: warning fixes 2007-10-17 08:42:54 -07:00
binfmt_misc.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
binfmt_script.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
binfmt_som.c core_pattern: ignore RLIMIT_CORE if core_pattern is a pipe 2007-10-17 08:42:50 -07:00
bio.c bio: make freeing of ->bi_io_vec conditional in bio_free() 2007-10-16 11:03:52 +02:00
block_dev.c Slab API: remove useless ctor parameter and reorder parameters 2007-10-17 08:42:45 -07:00
buffer.c nobh: nobh_write_end fix 2007-10-21 08:54:05 -07:00
char_dev.c mm: bdi init hooks 2007-10-17 08:42:45 -07:00
compat_ioctl.c tty: add the new termios2 ioctls to the compatible list. 2007-11-29 09:24:55 -08:00
compat.c
dcache.c dcache: don't expose uninitialized memory in /proc/<pid>/fd/<fd> 2007-10-22 08:13:18 -07:00
dcookies.c
direct-io.c remove ZERO_PAGE 2007-10-16 09:42:53 -07:00
dnotify.c
dquot.c Don't send quota messages repeatedly when hardlimit reached 2007-12-23 12:54:36 -08:00
drop_caches.c
eventfd.c
eventpoll.c fs/eventpoll.c: use list_for_each_entry() instead of list_for_each() 2007-10-19 11:53:38 -07:00
exec.c vfs: coredumping fix 2007-11-28 10:58:01 -08:00
fcntl.c pid namespaces: changes to show virtual ids to user 2007-10-19 11:53:40 -07:00
fifo.c
file_table.c fs/file_table.c: use list_for_each_entry() instead of list_for_each() 2007-10-19 11:53:38 -07:00
file.c
filesystems.c
fs-writeback.c Use helpers to obtain task pid in printks 2007-10-19 11:53:43 -07:00
generic_acl.c
inode.c introduce I_SYNC 2007-10-17 08:43:02 -07:00
inotify_user.c change inotifyfs magic as the same magic is used for futexfs 2007-10-17 08:43:00 -07:00
inotify.c [PATCH] new helper - inotify_evict_watch() 2007-10-21 02:37:38 -04:00
internal.h
ioctl.c
ioprio.c ioprio: allow sys_ioprio_set() value of 0 to reset ioprio setting 2007-11-07 13:54:07 +01:00
Kconfig fs/Kconfig: grammar fix 2007-12-17 19:28:16 -08:00
Kconfig.binfmt
libfs.c exportfs: add new methods 2007-10-22 08:13:19 -07:00
locks.c locks: fix possible infinite loop in posix deadlock detection 2007-10-30 09:04:18 -07:00
Makefile Remove valueless definition of hard-selected RAMFS option 2007-10-17 08:42:56 -07:00
mbcache.c fs: Fix to correct the mbcache entries counter 2007-10-25 15:18:29 -07:00
mpage.c mm: buffered write cleanup 2007-10-16 09:42:54 -07:00
namei.c [PATCH] pass dentry to audit_inode()/audit_inode_child() 2007-10-21 02:37:18 -04:00
namespace.c [PATCH] new helpers - collect_mounts() and release_collected_mounts() 2007-10-21 02:37:25 -04:00
nfsctl.c
no-block.c
open.c mark sys_open/sys_read exports unused 2007-11-14 18:45:42 -08:00
pipe.c sched: affine sync wakeups 2007-10-15 17:00:19 +02:00
pnode.c
pnode.h [PATCH] new helpers - collect_mounts() and release_collected_mounts() 2007-10-21 02:37:25 -04:00
posix_acl.c
quota_v1.c
quota_v2.c
quota.c
read_write.c mark sys_open/sys_read exports unused 2007-11-14 18:45:42 -08:00
read_write.h
readdir.c
select.c fs/select, remove unused macros 2007-10-19 11:53:41 -07:00
seq_file.c [FS] seq_file: Introduce the seq_open_private() 2007-10-10 16:55:33 -07:00
signalfd.c rename signalfd_siginfo fields 2007-10-17 08:43:01 -07:00
splice.c Implement file posix capabilities 2007-10-17 08:43:07 -07:00
stack.c
stat.c
super.c Convert files to UTF-8 and some cleanups 2007-10-19 23:21:04 +02:00
sync.c
timerfd.c
utimes.c VFS: check nanoseconds in utimensat 2007-10-17 08:42:52 -07:00
xattr_acl.c
xattr.c [PATCH] pass dentry to audit_inode()/audit_inode_child() 2007-10-21 02:37:18 -04:00