linux/fs
Miklos Szeredi 8110e16d42 vfs: dcache: fix deadlock in tree traversal
IBM reported a deadlock in select_parent().  This was found to be caused
by taking rename_lock when already locked when restarting the tree
traversal.

There are two cases when the traversal needs to be restarted:

 1) concurrent d_move(); this can only happen when not already locked,
    since taking rename_lock protects against concurrent d_move().

 2) racing with final d_put() on child just at the moment of ascending
    to parent; rename_lock doesn't protect against this rare race, so it
    can happen when already locked.

Because of case 2, we need to be able to handle restarting the traversal
when rename_lock is already held.  This patch fixes all three callers of
try_to_ascend().

IBM reported that the deadlock is gone with this patch.

[ I rewrote the patch to be smaller and just do the "goto again" if the
  lock was already held, but credit goes to Miklos for the real work.
   - Linus ]

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-29 17:41:40 -07:00
..
9p 9p: Push file_update_time() into v9fs_vm_page_mkwrite() 2012-07-31 01:02:46 +04:00
adfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
affs affs: use memweight() 2012-07-30 17:25:16 -07:00
afs VFS: Pass mount flags to sget() 2012-07-14 16:38:34 +04:00
autofs4 autofs4 - fix expire check 2012-08-17 06:56:39 -07:00
befs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
bfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2012-09-16 12:58:44 -07:00
cachefiles fs: cachefiles: add support for large files in filesystem caching 2012-07-30 17:25:21 -07:00
ceph ceph: avoid divide by zero in __validate_layout() 2012-08-21 15:55:28 -07:00
cifs cifs: fix return value in cifsConvertToUTF16 2012-09-18 15:35:25 -05:00
coda don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
configfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
cramfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
debugfs debugfs: fix u32_array race in format_array_alloc 2012-09-21 11:48:05 -07:00
devpts VFS: Pass mount flags to sget() 2012-07-14 16:38:34 +04:00
dlm dlm: fix missing dir remove 2012-07-16 14:24:43 -05:00
ecryptfs eCryptfs: Copy up attributes of the lower target inode after rename 2012-09-14 09:36:03 -07:00
efs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
exofs Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd 2012-08-03 13:24:07 -07:00
exportfs switch dentry_open() to struct path, make it grab references itself 2012-07-23 00:01:29 +04:00
ext2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
ext3 ext3: Fix fdatasync() for files with only i_size changes 2012-09-04 00:04:43 +02:00
ext4 The following are all bug fixes and regressions. The most notable are 2012-08-17 08:04:47 -07:00
fat Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
freevxfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
fscache
fuse fuse: fix retrieve length 2012-09-04 18:45:54 +02:00
gfs2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-fixes 2012-09-14 18:05:14 -07:00
hfs hfs: nuke write_super from comments 2012-08-04 12:15:38 +04:00
hfsplus hfsplus: use -ENOMEM when kzalloc() fails 2012-07-30 17:25:19 -07:00
hostfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
hpfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
hppfs switch dentry_open() to struct path, make it grab references itself 2012-07-23 00:01:29 +04:00
hugetlbfs hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages 2012-07-31 18:42:40 -07:00
isofs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2012-07-24 17:40:44 -07:00
jbd jbd: don't write superblock when unmounting an ro filesystem 2012-08-15 13:53:30 +02:00
jbd2 The following are all bug fixes and regressions. The most notable are 2012-08-17 08:04:47 -07:00
jffs2 don't expose I_NEW inodes via dentry->d_inode 2012-07-23 00:00:58 +04:00
jfs don't expose I_NEW inodes via dentry->d_inode 2012-07-23 00:00:58 +04:00
lockd close the race in nlmsvc_free_block() 2012-09-22 20:48:20 -04:00
logfs Pull request from git://github.com/prasad-joshi/logfs_upstream.git 2012-08-26 10:14:11 -07:00
minix minixfs: fix block limit check 2012-07-30 17:25:19 -07:00
ncpfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
nfs NFS: fsync() must exit with an error if page writeback failed 2012-09-11 15:38:32 -04:00
nfs_common
nfsd nfsd4: fix security flavor of NFSv4.0 callback 2012-08-20 18:38:36 -04:00
nilfs2 nilfs2: nuke write_super from comments 2012-08-04 12:15:38 +04:00
nls nls: fix (and rename) mac NLS table files and config options 2012-06-01 19:51:22 -07:00
notify switch dentry_open() to struct path, make it grab references itself 2012-07-23 00:01:29 +04:00
ntfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
ocfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
omfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
openpromfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
proc fs/proc: fix potential unregister_sysctl_table hang 2012-09-17 10:32:03 -07:00
pstore pstore/ram: Make tracing log versioned 2012-07-17 16:48:09 -07:00
qnx4 qnx4fs: use memweight() 2012-07-30 17:25:16 -07:00
qnx6 stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
quota quota: Move down dqptr_sem read after initializing default warn[] type at __dquot_alloc_space(). 2012-08-15 00:22:57 +02:00
ramfs don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
reiserfs reiserfs: fix deadlocks with quotas 2012-08-15 00:22:57 +02:00
romfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
squashfs stop passing nameidata to ->lookup() 2012-07-14 16:34:32 +04:00
sysfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
sysv fs/sysv: stop using write_super and s_dirt 2012-07-22 23:58:12 +04:00
ubifs UBIFS: fix error messages spelling 2012-08-22 17:41:09 +03:00
udf udf: Fix data corruption for files in ICB 2012-09-05 16:06:03 +02:00
ufs fs/ufs: get rid of write_super 2012-07-22 23:58:16 +04:00
xfs xfs: stop the sync worker before xfs_unmountfs 2012-09-18 16:51:26 -05:00
Kconfig Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-03-21 13:36:41 -07:00
Kconfig.binfmt C6X: add support to build with BINFMT_ELF_FDPIC 2012-05-15 09:17:34 -04:00
Makefile fs: initial qnx6fs addition 2012-03-20 21:29:38 -04:00
aio.c aio: now fput() is OK from interrupt context; get rid of manual delayed __fput() 2012-07-22 23:57:59 +04:00
anon_inodes.c anon_inodes: move allocation of anon_inode into ->mount() 2012-03-20 21:29:45 -04:00
attr.c notify_change(): check that i_mutex is held 2012-07-14 16:35:42 +04:00
bad_inode.c don't pass nameidata to ->create() 2012-07-14 16:34:47 +04:00
binfmt_aout.c VM: add "vm_mmap()" helper function 2012-04-20 17:29:13 -07:00
binfmt_elf.c binfmt_elf: switch elf_map() to vm_mmap/vm_munmap 2012-05-30 21:04:55 -04:00
binfmt_elf_fdpic.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-05-23 17:42:39 -07:00
binfmt_em86.c __register_binfmt() made void 2012-03-20 21:29:46 -04:00
binfmt_flat.c binfmt_flat: use vm_munmap, we are missing ->mmap_sem there 2012-05-30 21:04:56 -04:00
binfmt_misc.c vfs: Rename end_writeback() to clear_inode() 2012-05-06 13:43:41 +08:00
binfmt_script.c __register_binfmt() made void 2012-03-20 21:29:46 -04:00
binfmt_som.c VM: add "vm_mmap()" helper function 2012-04-20 17:29:13 -07:00
bio-integrity.c fs: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:21 +08:00
bio.c Merge branch 'for-linus' of git://git.kernel.dk/linux-block 2012-08-25 11:36:43 -07:00
block_dev.c fs/block-dev.c:fix performance regression in O_DIRECT writes to md block devices 2012-08-02 09:50:39 +02:00
buffer.c block: replace __getblk_slow misfix by grow_dev_page fix 2012-08-23 12:17:36 +02:00
char_dev.c
compat.c vfs: missed source of ->f_pos races 2012-08-20 10:11:47 -07:00
compat_binfmt_elf.c
compat_ioctl.c The following text was taken from the original review request: 2012-03-24 10:24:31 -07:00
dcache.c vfs: dcache: fix deadlock in tree traversal 2012-09-29 17:41:40 -07:00
dcookies.c
direct-io.c block: move down direct IO plugging 2012-08-09 15:23:09 +02:00
drop_caches.c
eventfd.c eventfd: change int to __u64 in eventfd_signal() 2012-05-31 17:49:32 -07:00
eventpoll.c eventpoll: use-after-possible-free in epoll_create1() 2012-08-22 10:26:55 -04:00
exec.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
fcntl.c c/r: fcntl: add F_GETOWNER_UIDS option 2012-07-30 17:25:21 -07:00
fhandle.c
fifo.c fifo: Do not restart open() if it already found a partner 2012-07-16 08:33:14 -07:00
file.c Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
file_table.c fs: Add freezing handling to mnt_want_write() / mnt_drop_write() 2012-07-31 09:40:38 +04:00
filesystems.c
fs-writeback.c mm: prepare for removal of obsolete /proc/sys/vm/nr_pdflush_threads 2012-07-31 18:42:40 -07:00
fs_struct.c get rid of ->mnt_longterm 2012-07-14 16:32:47 +04:00
generic_acl.c
inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
internal.h fs: Add freezing handling to mnt_want_write() / mnt_drop_write() 2012-07-31 09:40:38 +04:00
ioctl.c
ioprio.c Merge branch 'for-3.5/core' of git://git.kernel.dk/linux-block 2012-05-30 08:52:42 -07:00
libfs.c VFS: Pass mount flags to sget() 2012-07-14 16:38:34 +04:00
locks.c locks: remove unused lm_release_private 2012-08-01 09:01:46 -07:00
mbcache.c
mount.h get rid of magic in proc_namespace.c 2012-07-14 16:32:48 +04:00
mpage.c
namei.c fs: fix fs/namei.c kernel-doc warnings 2012-08-22 10:30:10 -04:00
namespace.c do_add_mount()/umount -l races 2012-09-22 20:48:18 -04:00
no-block.c
open.c vfs: canonicalize create mode in build_open_flags() 2012-08-15 13:01:24 +02:00
pipe.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
pnode.c VFS: Make clone_mnt()/copy_tree()/collect_mounts() return errors 2012-07-14 16:37:27 +04:00
pnode.h
posix_acl.c
proc_namespace.c get rid of magic in proc_namespace.c 2012-07-14 16:32:48 +04:00
read_write.c vfs: allow custom EOF in generic_file_llseek code 2012-07-23 00:00:15 +04:00
read_write.h
readdir.c switch readdir/getdents to fget_light/fput_light 2012-05-29 23:28:29 -04:00
select.c posix_types.h: Cleanup stale __NFDBITS and related definitions 2012-07-26 13:36:43 -07:00
seq_file.c seq_file: Add seq_vprintf function and export it 2012-06-11 13:16:35 +01:00
signalfd.c switch signalfd4() to fget_light/fput_light 2012-05-29 23:28:30 -04:00
splice.c fs: Protect write paths by sb_start_write - sb_end_write 2012-07-31 09:45:47 +04:00
stack.c
stat.c vfs: make O_PATH file descriptors usable for 'fstat()' 2012-09-14 14:48:21 -07:00
statfs.c switch statfs to fget_light/fput_light 2012-05-29 23:28:31 -04:00
super.c vfs: kill write_super and sync_supers 2012-08-04 01:24:44 +04:00
sync.c vfs: Avoid unnecessary WB_SYNC_NONE writeback during sys_sync and reorder sync passes 2012-07-22 23:59:01 +04:00
timerfd.c
utimes.c switch utimes() to fget_light/fput_light 2012-05-29 23:28:32 -04:00
xattr.c fs/xattr.c:getxattr(): improve handling of allocation failures 2012-07-30 17:25:11 -07:00
xattr_acl.c