Jeff Layton 267f112858 locks: remove conditional lock release in middle of flock_lock_file ... As Linus pointed out: Say we have an existing flock, and now do a new one that conflicts. I see what looks like three separate bugs. - We go through the first loop, find a lock of another type, and delete it in preparation for replacing it - we *drop* the lock context spinlock. - BUG #1? So now there is no lock at all, and somebody can come in and see that unlocked state. Is that really valid? - another thread comes in while the first thread dropped the lock context lock, and wants to add its own lock. It doesn't see the deleted or pending locks, so it just adds it - the first thread gets the context spinlock again, and adds the lock that replaced the original - BUG #2? So now there are *two* locks on the thing, and the next time you do an unlock (or when you close the file), it will only remove/replace the first one. ...remove the "drop the spinlock" code in the middle of this function as it has always been suspicious. This should eliminate the potential race that can leave two locks for the same struct file on the list. He also pointed out another thing as a bug -- namely that you flock_lock_file removes the lock from the list unconditionally when doing a lock upgrade, without knowing whether it'll be able to set the new lock. Bruce pointed out that this is expected behavior and may help prevent certain deadlock situations. We may want to revisit that at some point, but it's probably best that we do so in the context of a different patchset. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>		2015-02-17 15:23:09 -05:00
..
9p	Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block	2015-02-12 13:50:21 -08:00
adfs	adfs: add __printf verification, fix format/argument mismatches	2014-08-08 15:57:24 -07:00
affs	fs/affs/file.c: remove obsolete pagesize check	2014-12-13 12:42:52 -08:00
afs	Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block	2015-02-12 13:50:21 -08:00
autofs4	assorted conversions to %p[dD]	2014-11-19 13:01:20 -05:00
befs	befs: remove dead code	2014-12-13 12:42:51 -08:00
bfs	fs/bfs: use bfs prefix for dump_imap	2014-08-08 15:57:24 -07:00
btrfs	Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block	2015-02-12 13:50:21 -08:00
cachefiles	assorted conversions to %p[dD]	2014-11-19 13:01:20 -05:00
ceph	Revert "locks: keep a count of locks on the flctx lists"	2015-02-16 14:32:03 -05:00
cifs	Revert "locks: keep a count of locks on the flctx lists"	2015-02-16 14:32:03 -05:00
coda	fs: introduce f_op->mmap_capabilities for nommu mmap support	2015-01-20 14:02:58 -07:00
configfs	fs: remove mapping->backing_dev_info	2015-01-20 14:03:05 -07:00
cramfs	fs/cramfs/inode.c: use linux/uaccess.h	2014-08-08 15:57:25 -07:00
debugfs	Driver core patches for 3.19-rc1	2014-12-14 16:10:09 -08:00
devpts	…
dlm	netlink: make nlmsg_end() and genlmsg_end() void	2015-01-18 01:03:45 -05:00
ecryptfs	fs: remove mapping->backing_dev_info	2015-01-20 14:03:05 -07:00
efivarfs	* Move efivarfs from the misc filesystem section to pseudo filesystem,	2015-01-29 19:16:40 +01:00
efs	fs/efs/namei.c: return is not a function	2014-08-08 15:57:18 -07:00
exofs	fs: remove mapping->backing_dev_info	2015-01-20 14:03:05 -07:00
exportfs	move d_rcu from overlapping d_child to overlapping d_alias	2014-11-03 15:20:29 -05:00
ext2	Merge branch 'for-3.20/core' of git://git.kernel.dk/linux-block	2015-02-12 14:13:23 -08:00
ext3	ext3: destroy sbi mutexes in put_super	2015-01-05 11:13:55 +01:00
ext4	Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block	2015-02-12 13:50:21 -08:00
f2fs	Merge tag 'for-f2fs-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs	2015-02-12 19:28:50 -08:00
fat	fat: fix data past EOF resulting from fsx testsuite	2014-12-13 12:42:51 -08:00
freevxfs	…
fscache	fs/fscache/object-list.c: use __seq_open_private()	2014-10-13 17:52:21 +01:00
fuse	Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block	2015-02-12 13:50:21 -08:00
gfs2	Merge branch 'akpm' (patches from Andrew)	2015-02-12 18:54:28 -08:00
hfs	fs/hfs/catalog.c: fix comparison bug in hfs_cat_keycmp	2014-12-10 17:41:16 -08:00
hfsplus	hfsplus: fix longname handling	2014-12-18 19:08:10 -08:00
hostfs	hostfs: support rename flags	2014-08-07 14:40:09 -04:00
hpfs	fs/hpfs/dnode.c: fix suspect code indent	2014-08-08 15:57:22 -07:00
hppfs	vfs: make first argument of dir_context.actor typed	2014-10-31 17:48:54 -04:00
hugetlbfs	fs: remove mapping->backing_dev_info	2015-01-20 14:03:05 -07:00
isofs	isofs: Fix bug in the way to check if the year is a leap year	2015-01-07 09:51:49 +01:00
jbd	jbd: Deletion of an unnecessary check before the function call "iput"	2014-11-18 10:15:29 +01:00
jbd2	Lots of bugs fixes, including Zheng and Jan's extent status shrinker	2014-12-12 09:28:03 -08:00
jffs2	jffs2: Drop bogus if in comment	2014-11-28 18:23:44 -08:00
jfs	jfs: Deletion of an unnecessary check before the function call "unload_nls"	2015-02-02 15:02:34 -06:00
kernfs	kernfs: remove KERNFS_STATIC_NAME	2015-02-13 21:21:36 -08:00
lockd	Merge branch 'for-3.20' of git://linux-nfs.org/~bfields/linux	2015-02-12 10:39:41 -08:00
logfs	…
minix	minix zmap block counts calculation fix	2014-08-08 15:57:20 -07:00
ncpfs	fs: remove mapping->backing_dev_info	2015-01-20 14:03:05 -07:00
nfs	Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block	2015-02-12 13:50:21 -08:00
nfs_common	lockd: move lockd's grace period handling into its own module	2014-09-17 16:33:11 -04:00
nfsd	nfsd: default NFSv4.2 to on	2015-02-09 14:58:50 -05:00
nilfs2	Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block	2015-02-12 13:50:21 -08:00
nls	…
notify	fanotify: don't set FAN_ONDIR implicitly on a marks ignored mask	2015-02-10 14:30:28 -08:00
ntfs	fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info	2015-01-20 14:03:04 -07:00
ocfs2	Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block	2015-02-12 13:50:21 -08:00
omfs	FS/OMFS: block number sanity check during fill_super operation	2014-10-14 02:18:22 +02:00
openpromfs	…
overlayfs	Merge branch 'iov_iter' into for-next	2014-12-08 20:39:29 -05:00
proc	proc: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
pstore	pstore: Fix sprintf format specifier in pstore_dump()	2015-01-16 16:01:29 -08:00
qnx4	…
qnx6	fs/qnx6: update debugging to current functions	2014-08-08 15:57:26 -07:00
quota	Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2015-02-10 15:52:38 -08:00
ramfs	fs: remove mapping->backing_dev_info	2015-01-20 14:03:05 -07:00
reiserfs	Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs	2014-12-16 15:46:01 -08:00
romfs	fs: remove mapping->backing_dev_info	2015-01-20 14:03:05 -07:00
squashfs	Squashfs: Add LZ4 compression configuration option	2014-11-27 18:48:44 +00:00
sysfs	driver core patches for 3.20-rc1	2015-02-15 11:11:47 -08:00
sysv	…
ubifs	Merge branch 'for-linus-v3.20' of git://git.infradead.org/linux-ubifs	2015-02-15 10:11:39 -08:00
udf	udf: remove bool assignment to 0/1	2015-02-05 16:34:25 +01:00
ufs	fs/ufs/balloc.c: remove unused variable	2014-10-14 02:18:20 +02:00
xfs	Merge branch 'akpm' (patches from Andrew)	2015-02-12 18:54:28 -08:00
Kconfig	fs: Make efivarfs a pseudo filesystem, built by default with EFI	2015-01-05 14:15:58 +00:00
Kconfig.binfmt	binfmt_elf: allow arch code to examine PT_LOPROC ... PT_HIPROC headers	2014-11-24 07:45:02 +01:00
Makefile	Merge branch 'nsfs' into for-next	2014-12-10 21:31:59 -05:00
aio.c	Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block	2015-02-12 13:50:21 -08:00
anon_inodes.c	…
attr.c	…
bad_inode.c	bad_inode: add ->rename2()	2014-08-07 14:40:09 -04:00
binfmt_aout.c	assorted conversions to %p[dD]	2014-11-19 13:01:20 -05:00
binfmt_elf.c	Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus	2014-12-11 17:56:37 -08:00
binfmt_elf_fdpic.c	handle suicide on late failure exits in execve() in search_binary_handler()	2014-10-09 02:39:00 -04:00
binfmt_em86.c	syscalls: implement execveat() system call	2014-12-13 12:42:51 -08:00
binfmt_flat.c	…
binfmt_misc.c	unfuck binfmt_misc.c (broken by commit e6084d4)	2014-12-17 08:27:14 -05:00
binfmt_script.c	syscalls: implement execveat() system call	2014-12-13 12:42:51 -08:00
binfmt_som.c	…
block_dev.c	Merge branch 'for-3.20/core' of git://git.kernel.dk/linux-block	2015-02-12 14:13:23 -08:00
buffer.c	fs: clarify rate limit suppressed buffer I/O errors	2014-10-21 13:55:11 -06:00
char_dev.c	fs: introduce f_op->mmap_capabilities for nommu mmap support	2015-01-20 14:02:58 -07:00
compat.c	vfs: make first argument of dir_context.actor typed	2014-10-31 17:48:54 -04:00
compat_binfmt_elf.c	…
compat_ioctl.c	…
coredump.c	coredump: add %i/%I in core_pattern to report the tid of the crashed thread	2014-10-14 02:18:21 +02:00
dcache.c	fs: dcache: manually unpoison dname after allocation to shut up kasan's reports	2015-02-13 21:21:41 -08:00
dcookies.c	…
direct-io.c	fuse: honour max_read and max_write in direct_io mode	2014-09-26 21:16:51 -04:00
drop_caches.c	vmscan: per memory cgroup slab shrinkers	2015-02-12 18:54:09 -08:00
eventfd.c	fs: Convert show_fdinfo functions to void	2014-11-05 14:13:23 -05:00
eventpoll.c	epoll: optimize setting task running after blocking	2015-02-13 21:21:40 -08:00
exec.c	syscalls: implement execveat() system call	2014-12-13 12:42:51 -08:00
fcntl.c	vfs: renumber FMODE_NONOTIFY and add to uniqueness check	2015-01-08 15:10:52 -08:00
fhandle.c	…
file.c	fs/file.c: replace get_unused_fd() with get_unused_fd_flags(0)	2014-12-10 17:41:10 -08:00
file_table.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-10-13 11:28:42 +02:00
filesystems.c	…
fs-writeback.c	fs: make inode_to_bdi() handle NULL inode	2015-01-22 08:13:17 -07:00
fs_pin.c	make fs/{namespace,super}.c forget about acct.h	2014-08-07 14:40:09 -04:00
fs_struct.c	…
inode.c	Merge branch 'akpm' (patches from Andrew)	2015-02-12 18:54:28 -08:00
internal.h	list_lru: introduce list_lru_shrink_{count,walk}	2015-02-12 18:54:08 -08:00
ioctl.c	fsioctl.c: make generic_block_fiemap() signal-tolerant	2015-02-10 14:30:30 -08:00
libfs.c	move d_rcu from overlapping d_child to overlapping d_alias	2014-11-03 15:20:29 -05:00
locks.c	locks: remove conditional lock release in middle of flock_lock_file	2015-02-17 15:23:09 -05:00
mbcache.c	…
mount.h	common object embedded into various struct ....ns	2014-12-04 14:31:00 -05:00
mpage.c	vfs: guard end of device for mpage interface	2014-10-09 22:25:53 -04:00
namei.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2014-12-16 15:53:03 -08:00
namespace.c	fs/namespace: convert devname allocation to kstrdup_const	2015-02-13 21:21:36 -08:00
no-block.c	…
nsfs.c	take the targets of /proc/*/ns/* symlinks to separate fs	2014-12-10 21:30:20 -05:00
open.c	Merge branch 'for-3.19' of git://linux-nfs.org/~bfields/linux	2014-12-16 15:25:31 -08:00
pipe.c	…
pnode.c	mnt: Move the clear of MNT_LOCKED from copy_tree to it's callers.	2014-12-02 10:46:50 -06:00
pnode.h	…
posix_acl.c	…
proc_namespace.c	vfs: make mounts and mountstats honor root dir like mountinfo does	2014-12-17 08:27:15 -05:00
read_write.c	locks: convert posix locks to file_lock_context	2015-01-16 16:08:16 -05:00
readdir.c	vfs: make first argument of dir_context.actor typed	2014-10-31 17:48:54 -04:00
select.c	all arches, signal: move restart_block to struct task_struct	2015-02-12 18:54:12 -08:00
seq_file.c	bitmap, cpumask, nodemask: remove dedicated formatting functions	2015-02-13 21:21:39 -08:00
signalfd.c	fs: Convert show_fdinfo functions to void	2014-11-05 14:13:23 -05:00
splice.c	vfs: export do_splice_direct() to modules	2014-10-24 00:14:35 +02:00
stack.c	fs: fix comment for 'CONFIG_LBADF'	2014-08-26 09:35:56 +02:00
stat.c	…
statfs.c	…
super.c	Merge branch 'akpm' (patches from Andrew)	2015-02-12 18:54:28 -08:00
sync.c	kill f_dentry uses	2014-11-19 13:01:25 -05:00
timerfd.c	fs: Convert show_fdinfo functions to void	2014-11-05 14:13:23 -05:00
utimes.c	…
xattr.c	new helper: audit_file()	2014-11-19 13:01:26 -05:00