Ian Kent 8f63aaa8b9 autofs4: fix lookup deadlock ... A deadlock can occur when user space uses a signal (autofs version 4 uses SIGCHLD for this) to effect expire completion. The order of events is: Expire process completes, but before being able to send SIGCHLD to it's parent ... Another process walks onto a different mount point and drops the directory inode semaphore prior to sending the request to the daemon as it must ... A third process does an lstat on on the expired mount point causing it to wait on expire completion (unfortunately) holding the directory semaphore. The mount request then arrives at the daemon which does an lstat and, deadlock. For some time I was concerned about releasing the directory semaphore around the expire wait in autofs4_lookup as well as for the mount call back. I finally realized that the last round of changes in this function made the expiring dentry and the lookup dentry separate and distinct so the check and possible wait can be done anywhere prior to the mount call back. This patch moves the check to just before the mount call back and inside the directory inode mutex release. Signed-off-by: Ian Kent <raven@themaw.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2009-04-01 08:59:23 -07:00
..
9p	vfs: simple_set_mnt() should return void	2009-03-27 14:44:03 -04:00
adfs	constify dentry_operations: misc filesystems	2009-03-27 14:44:00 -04:00
affs	constify dentry_operations: misc filesystems	2009-03-27 14:44:00 -04:00
afs	proc 2/2: remove struct proc_dir_entry::owner	2009-03-31 01:14:44 +04:00
autofs	constify dentry_operations: autofs, autofs4	2009-03-27 14:44:00 -04:00
autofs4	autofs4: fix lookup deadlock	2009-04-01 08:59:23 -07:00
befs	fs/Kconfig: move befs out	2009-01-22 13:15:57 +03:00
bfs	fs/Kconfig: move bfs out	2009-01-22 13:15:57 +03:00
btrfs	fs: fix page_mkwrite error cases in core code and btrfs	2009-04-01 08:59:14 -07:00
cifs	proc 2/2: remove struct proc_dir_entry::owner	2009-03-31 01:14:44 +04:00
coda	constify dentry_operations: misc filesystems	2009-03-27 14:44:00 -04:00
configfs	constify dentry_operations: configfs	2009-03-27 14:44:03 -04:00
cramfs	fs/Kconfig: move cramfs out	2009-01-22 13:15:58 +03:00
debugfs	debugfs: add helpers for exporting a size_t simple value	2009-01-07 10:00:16 -08:00
devpts	Merge code for single and multiple-instance mounts	2009-03-27 14:44:04 -04:00
dlm	dlm: fix length calculation in compat code	2009-03-11 12:23:59 -05:00
ecryptfs	ecryptfs: use kzfree()	2009-04-01 08:59:23 -07:00
efs	fs/Kconfig: move efs out	2009-01-22 13:15:57 +03:00
exportfs
ext2	ext2: Zero our b_size in ext2_quota_read()	2009-03-26 02:18:38 +01:00
ext3	Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6	2009-03-27 14:48:34 -07:00
ext4	mm: page_mkwrite change prototype to match fault	2009-04-01 08:59:14 -07:00
fat	constify dentry_operations: FAT	2009-03-27 14:44:01 -04:00
freevxfs	fs/Kconfig: move vxfs out	2009-01-22 13:15:58 +03:00
fuse	mm: page_mkwrite change prototype to match fault	2009-04-01 08:59:14 -07:00
gfs2	mm: page_mkwrite change prototype to match fault	2009-04-01 08:59:14 -07:00
hfs	constify dentry_operations: misc filesystems	2009-03-27 14:44:00 -04:00
hfsplus	constify dentry_operations: misc filesystems	2009-03-27 14:44:00 -04:00
hostfs	constify dentry_operations: misc filesystems	2009-03-27 14:44:00 -04:00
hpfs	constify dentry_operations: misc filesystems	2009-03-27 14:44:00 -04:00
hppfs
hugetlbfs	mm: reintroduce and deprecate rlimit based access for SHM_HUGETLB	2009-04-01 08:59:12 -07:00
isofs	constify dentry_operations: misc filesystems	2009-03-27 14:44:00 -04:00
jbd	jbd: fix return value of journal_start_commit()	2009-02-11 14:25:35 -08:00
jbd2	jbd2: Avoid possible NULL dereference in jbd2_journal_begin_ordered_truncate()	2009-02-10 11:15:34 -05:00
jffs2	[JFFS2] fix mount crash caused by removed nodes	2009-02-21 11:09:29 +01:00
jfs	proc 2/2: remove struct proc_dir_entry::owner	2009-03-31 01:14:44 +04:00
lockd	NLM: Fix GRANT callback address comparison when IPv6 is enabled	2009-03-10 20:33:20 -04:00
minix	Update my email address	2009-03-22 11:28:37 -07:00
ncpfs	constify dentry_operations: misc filesystems	2009-03-27 14:44:00 -04:00
nfs	mm: page_mkwrite change prototype to match fault	2009-04-01 08:59:14 -07:00
nfs_common
nfsd	Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6	2009-03-27 14:48:34 -07:00
nls
notify	fs: avoid I_NEW inodes	2009-03-27 14:44:05 -04:00
ntfs	ntfs: remove private wrapper of endian helpers	2009-04-01 08:59:18 -07:00
ocfs2	mm: page_mkwrite change prototype to match fault	2009-04-01 08:59:14 -07:00
omfs	fs/Kconfig: move omfs out	2009-01-22 13:15:58 +03:00
openpromfs	zero i_uid/i_gid on inode allocation	2009-01-05 11:54:28 -05:00
partitions	Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6	2009-03-26 16:04:22 -07:00
proc	proc tty: remove struct tty_operations::read_proc	2009-04-01 08:59:10 -07:00
qnx4	fs/Kconfig: move qnx4 out	2009-01-22 13:15:59 +03:00
quota	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6	2009-03-27 16:23:12 -07:00
ramfs	ramfs: add support for "mode=" mount option	2009-04-01 08:59:22 -07:00
reiserfs	Merge branch 'proc-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc	2009-03-30 16:06:04 -07:00
romfs	fs/Kconfig: move romfs out	2009-01-22 13:15:59 +03:00
smbfs	constify dentry_operations: misc filesystems	2009-03-27 14:44:00 -04:00
squashfs	Squashfs: Valid filesystems are flagged as bad by the corrupted fs patch	2009-03-12 03:23:48 +00:00
sysfs	mm: page_mkwrite change prototype to match fault: fix sysfs	2009-04-01 08:59:14 -07:00
sysv	constify dentry_operations: misc filesystems	2009-03-27 14:44:00 -04:00
ubifs	mm: page_mkwrite change prototype to match fault	2009-04-01 08:59:14 -07:00
udf	udf: Use lowercase names of quota functions	2009-03-26 02:18:36 +01:00
ufs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6	2009-03-27 16:23:12 -07:00
xfs	mm: page_mkwrite change prototype to match fault	2009-04-01 08:59:14 -07:00
aio.c	aio: lookup_ioctx can return the wrong value when looking up a bogus context	2009-03-19 15:57:18 -07:00
anon_inodes.c	constify dentry_operations: rest	2009-03-27 14:44:03 -04:00
attr.c	vfs: Use lowercase names of quota functions	2009-03-26 02:18:35 +01:00
bad_inode.c
binfmt_aout.c
binfmt_elf.c	elf core dump: fix get_user use	2009-02-06 17:34:07 -08:00
binfmt_elf_fdpic.c	FDPIC: Don't attempt to expand the userspace stack to fill the space allocated	2009-01-08 12:04:47 +00:00
binfmt_em86.c
binfmt_flat.c	FLAT: Don't attempt to expand the userspace stack to fill the space allocated	2009-01-08 12:04:47 +00:00
binfmt_misc.c	fs/binfmt_misc.c: add terminating newline to /proc/sys/fs/binfmt_misc/status	2009-01-06 15:59:19 -08:00
binfmt_script.c
binfmt_som.c
bio-integrity.c	block: add private bio_set for bio integrity allocations	2009-03-24 12:35:17 +01:00
bio.c	block: add private bio_set for bio integrity allocations	2009-03-24 12:35:17 +01:00
block_dev.c	fs: move bdev code out of buffer.c	2009-03-27 14:44:03 -04:00
buffer.c	filesystem freeze: allow SysRq emergency thaw to thaw frozen filesystems	2009-04-01 08:59:17 -07:00
char_dev.c	fs: fix name overwrite in __register_chrdev_region()	2009-01-06 15:59:13 -08:00
compat.c	fix setuid sometimes doesn't	2009-03-28 17:30:00 -07:00
compat_binfmt_elf.c
compat_ioctl.c	Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6	2009-03-01 21:35:16 -08:00
dcache.c	cleanup d_add_ci	2009-03-27 14:43:57 -04:00
dcookies.c	[CVE-2009-0029] System call wrapper special cases	2009-01-14 14:15:18 +01:00
direct-io.c	fs: truncate blocks outside i_size after O_DIRECT write error	2009-01-06 15:59:06 -08:00
drop_caches.c	fs: avoid I_NEW inodes	2009-03-27 14:44:05 -04:00
eventfd.c	epoll keyed wakeups: make eventfd use keyed wakeups	2009-04-01 08:59:20 -07:00
eventpoll.c	epoll keyed wakeups: teach epoll about hints coming with the wakeup key	2009-04-01 08:59:20 -07:00
exec.c	fix setuid sometimes doesn't	2009-03-28 17:30:00 -07:00
fcntl.c	Fix a lockdep warning in fasync_helper()	2009-03-30 08:00:24 -06:00
fifo.c
file.c
file_table.c	Merge branch 'bkl-removal' of git://git.lwn.net/linux-2.6	2009-03-26 16:14:02 -07:00
filesystems.c	[CVE-2009-0029] System call wrappers part 27	2009-01-14 14:15:29 +01:00
fs-writeback.c	fs: new inode i_state corruption fix	2009-03-12 16:20:24 -07:00
generic_acl.c
inode.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6	2009-03-27 16:23:12 -07:00
internal.h	fix setuid sometimes doesn't	2009-03-28 17:30:00 -07:00
ioctl.c	Rationalize fasync return values	2009-03-16 08:34:35 -06:00
ioprio.c	[CVE-2009-0029] System call wrappers part 28	2009-01-14 14:15:30 +01:00
Kconfig	quota: Move quota files into separate directory	2009-03-26 02:18:35 +01:00
Kconfig.binfmt	CORE_DUMP_DEFAULT_ELF_HEADERS depends on ELF_CORE	2009-01-09 16:54:41 -08:00
libfs.c	vfs: simple_set_mnt() should return void	2009-03-27 14:44:03 -04:00
locks.c	[CVE-2009-0029] System call wrappers part 16	2009-01-14 14:15:25 +01:00
Makefile	quota: Move quota files into separate directory	2009-03-26 02:18:35 +01:00
mbcache.c
mpage.c	do_mpage_readpage(): remove useless clear_buffer_mapped() call	2009-01-06 15:59:01 -08:00
namei.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6	2009-03-27 16:23:12 -07:00
namespace.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6	2009-03-27 16:23:12 -07:00
nfsctl.c	[CVE-2009-0029] System call wrappers part 27	2009-01-14 14:15:29 +01:00
no-block.c
open.c	vfs: Use lowercase names of quota functions	2009-03-26 02:18:35 +01:00
pipe.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6	2009-03-27 16:23:12 -07:00
pnode.c
pnode.h
posix_acl.c
read_write.c	[CVE-2009-0029] System call wrappers part 20	2009-01-14 14:15:26 +01:00
read_write.h
readdir.c	[CVE-2009-0029] System call wrappers part 32	2009-01-14 14:15:31 +01:00
select.c	[CVE-2009-0029] System call wrappers part 32	2009-01-14 14:15:31 +01:00
seq_file.c	cpumask: fix seq_bitmap_*() functions.	2009-03-30 22:05:11 +10:30
signalfd.c	[CVE-2009-0029] System call wrappers part 31	2009-01-14 14:15:31 +01:00
splice.c	[CVE-2009-0029] System call wrappers part 31	2009-01-14 14:15:31 +01:00
stack.c
stat.c	[CVE-2009-0029] System call wrappers part 30	2009-01-14 14:15:30 +01:00
super.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6	2009-03-27 16:23:12 -07:00
sync.c	Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6	2009-03-27 14:48:34 -07:00
timerfd.c	timerfd: add flags check	2009-02-18 15:37:53 -08:00
utimes.c	[CVE-2009-0029] System call wrappers part 30	2009-01-14 14:15:30 +01:00
xattr.c	[CVE-2009-0029] System call wrappers part 13	2009-01-14 14:15:23 +01:00
xattr_acl.c