NeilBrown bcc7f5b4be block_dev: don't test bdev->bd_contains when it is not stable ... bdev->bd_contains is not stable before calling __blkdev_get(). When __blkdev_get() is called on a parition with ->bd_openers == 0 it sets bdev->bd_contains = bdev; which is not correct for a partition. After a call to __blkdev_get() succeeds, ->bd_openers will be > 0 and then ->bd_contains is stable. When FMODE_EXCL is used, blkdev_get() calls bd_start_claiming() -> bd_prepare_to_claim() -> bd_may_claim() This call happens before __blkdev_get() is called, so ->bd_contains is not stable. So bd_may_claim() cannot safely use ->bd_contains. It currently tries to use it, and this can lead to a BUG_ON(). This happens when a whole device is already open with a bd_holder (in use by dm in my particular example) and two threads race to open a partition of that device for the first time, one opening with O_EXCL and one without. The thread that doesn't use O_EXCL gets through blkdev_get() to __blkdev_get(), gains the ->bd_mutex, and sets bdev->bd_contains = bdev; Immediately thereafter the other thread, using FMODE_EXCL, calls bd_start_claiming() from blkdev_get(). This should fail because the whole device has a holder, but because bdev->bd_contains == bdev bd_may_claim() incorrectly reports success. This thread continues and blocks on bd_mutex. The first thread then sets bdev->bd_contains correctly and drops the mutex. The thread using FMODE_EXCL then continues and when it calls bd_may_claim() again in: BUG_ON(!bd_may_claim(bdev, whole, holder)); The BUG_ON fires. Fix this by removing the dependency on ->bd_contains in bd_may_claim(). As bd_may_claim() has direct access to the whole device, it can simply test if the target bdev is the whole device. Fixes: 6b4517a791 ("block: implement bd_claiming and claiming block") Cc: stable@vger.kernel.org (v2.6.35+) Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>		2016-12-13 21:07:08 -07:00
..
9p	block,fs: untangle fs.h and blk_types.h	2016-11-01 09:43:26 -06:00
adfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
affs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
afs	afs: call->operation_ID sometimes used as __be32 sometimes as u32	2016-10-13 17:03:52 +01:00
autofs4	autofs: refactor ioctl fn vector in iookup_dev_ioctl()	2016-10-11 15:06:31 -07:00
befs	befs fixes for 4.9-rc1	2016-10-15 12:09:13 -07:00
bfs	Merge remote-tracking branch 'ovl/rename2' into for-linus	2016-10-10 23:02:51 -04:00
btrfs	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
cachefiles	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
ceph	ceph: don't set req->r_locked_dir in ceph_d_revalidate	2016-12-08 14:32:16 +01:00
cifs	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
coda	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
configfs	Merge remote-tracking branch 'ovl/rename2' into for-linus	2016-10-10 23:02:51 -04:00
cramfs	…
crypto	fscrypto: don't use on-stack buffer for key derivation	2016-11-19 20:56:13 -05:00
debugfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
devpts	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
dlm	genetlink: mark families as __ro_after_init	2016-10-27 16:16:09 -04:00
ecryptfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
efivarfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
efs	…
exofs	fs: exofs: print a hex number after a 0x prefix	2016-10-27 18:43:43 -07:00
exportfs	exportfs: be careful to only return expected errors.	2016-10-06 09:07:44 -04:00
ext2	ext2: avoid bogus -Wmaybe-uninitialized warning	2016-10-18 11:29:35 +02:00
ext4	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
f2fs	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
fat	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
freevxfs	…
fscache	…
fuse	fuse: fix clearing suid, sgid for chown()	2016-12-06 16:18:45 +01:00
gfs2	writeback: add wbc_to_write_flags()	2016-11-02 10:24:03 -06:00
hfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
hfsplus	block,fs: use REQ_* flags directly	2016-11-01 09:43:26 -06:00
hostfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
hpfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
hugetlbfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
isofs	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
jbd2	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
jffs2	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
jfs	block,fs: use REQ_* flags directly	2016-11-01 09:43:26 -06:00
kernfs	kernfs: Declare two local data structures static	2016-11-29 20:58:31 +01:00
lockd	netns: make struct pernet_operations::id unsigned int	2016-11-18 10:59:15 -05:00
logfs	fs: logfs: remove unnecesary check	2016-11-22 08:57:55 -07:00
minix	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
ncpfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
nfs	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2016-11-26 23:42:21 -05:00
nfs_common	netns: make struct pernet_operations::id unsigned int	2016-11-18 10:59:15 -05:00
nfsd	netns: make struct pernet_operations::id unsigned int	2016-11-18 10:59:15 -05:00
nilfs2	block,fs: use REQ_* flags directly	2016-11-01 09:43:26 -06:00
nls	…
notify	fsnotify: clean up spinlock assertions	2016-10-07 18:46:26 -07:00
ntfs	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
ocfs2	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
omfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
openpromfs	fs: Replace CURRENT_TIME with current_time() for inode timestamps	2016-09-27 21:06:21 -04:00
orangefs	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
overlayfs	ovl: fix d_real() for stacked fs	2016-11-29 10:20:24 +01:00
proc	xen: features and fixes for 4.10 rc0	2016-12-13 16:07:55 -08:00
pstore	Improvements and fixes to pstore subsystem:	2016-12-13 09:16:11 -08:00
qnx4	…
qnx6	…
quota	genetlink: mark families as __ro_after_init	2016-10-27 16:16:09 -04:00
ramfs	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
reiserfs	mm: only include blk_types in swap.h if CONFIG_SWAP is enabled	2016-11-01 09:43:26 -06:00
romfs	…
squashfs	block,fs: untangle fs.h and blk_types.h	2016-11-01 09:43:26 -06:00
sysfs	Merge branch 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2016-10-14 12:18:50 -07:00
sysv	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
tracefs	fs: Replace CURRENT_TIME with current_time() for inode timestamps	2016-09-27 21:06:21 -04:00
ubifs	ubifs: Fix regression in ubifs_readdir()	2016-10-28 14:48:31 +02:00
udf	block,fs: untangle fs.h and blk_types.h	2016-11-01 09:43:26 -06:00
ufs	block,fs: untangle fs.h and blk_types.h	2016-11-01 09:43:26 -06:00
xfs	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
Kconfig	mm/hugetlb: introduce ARCH_HAS_GIGANTIC_PAGE	2016-10-07 18:46:29 -07:00
Kconfig.binfmt	docs: fix locations of several documents that got moved	2016-10-24 08:12:35 -02:00
Makefile	…
aio.c	aio: fix freeze protection of aio writes	2016-10-30 13:09:42 -04:00
anon_inodes.c	…
attr.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
bad_inode.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
binfmt_aout.c	…
binfmt_elf.c	binfmt_elf: use vmalloc() for allocation of vma_filesz	2016-12-12 18:55:10 -08:00
binfmt_elf_fdpic.c	…
binfmt_em86.c	…
binfmt_flat.c	…
binfmt_misc.c	fs: Replace current_fs_time() with current_time()	2016-09-27 21:06:22 -04:00
binfmt_script.c	…
block_dev.c	block_dev: don't test bdev->bd_contains when it is not stable	2016-12-13 21:07:08 -07:00
buffer.c	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
char_dev.c	…
compat.c	compat: remove compat_printk()	2016-09-27 21:20:53 -04:00
compat_binfmt_elf.c	…
compat_ioctl.c	fs: compat_ioctl: add pretimeout functions for watchdogs	2016-09-24 09:27:18 +02:00
coredump.c	coredump: fix unfreezable coredumping task	2016-11-11 08:12:37 -08:00
dax.c	lib: radix-tree: update callback for changing leaf nodes	2016-12-12 18:55:08 -08:00
dcache.c	…
dcookies.c	…
direct-io.c	block: move poll code to blk-mq	2016-11-11 13:40:25 -07:00
drop_caches.c	…
eventfd.c	…
eventpoll.c	…
exec.c	posix-timers: Make them configurable	2016-11-16 09:26:35 +01:00
fcntl.c	…
fhandle.c	…
file.c	fs/file: more unsigned file descriptors	2016-09-27 18:47:38 -04:00
file_table.c	…
filesystems.c	…
fs-writeback.c	fs/fs-writeback.c: remove redundant if check	2016-12-12 18:55:08 -08:00
fs_pin.c	…
fs_struct.c	…
inode.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
internal.h	Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 13:04:49 -07:00
ioctl.c	…
iomap.c	fs: Do to trim high file position bits in iomap_page_mkwrite_actor	2016-10-24 14:20:25 +11:00
libfs.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
locks.c	locking, fs/locks: Add missing file_sem locks	2016-10-18 12:21:28 +02:00
mbcache.c	…
mount.h	mnt: Add a per mount namespace limit on the number of mounts	2016-09-30 12:46:48 -05:00
mpage.c	writeback: add wbc_to_write_flags()	2016-11-02 10:24:03 -06:00
namei.c	Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs	2016-10-14 17:23:33 -07:00
namespace.c	This adds a new gcc plugin named "latent_entropy". It is designed to	2016-10-15 10:03:15 -07:00
no-block.c	…
nsfs.c	net: add an ioctl to get a socket network namespace	2016-10-31 10:56:36 -04:00
open.c	xfs: reflink update for 4.9-rc1	2016-10-13 20:28:22 -07:00
pipe.c	pipe: cap initial pipe capacity according to pipe-max-size limit	2016-10-11 15:06:32 -07:00
pnode.c	mnt: Add a per mount namespace limit on the number of mounts	2016-09-30 12:46:48 -05:00
pnode.h	mnt: Add a per mount namespace limit on the number of mounts	2016-09-30 12:46:48 -05:00
posix_acl.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2016-10-10 20:16:43 -07:00
proc_namespace.c	…
read_write.c	iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector()	2016-10-14 20:00:34 -04:00
readdir.c	…
select.c	fs/select: add vmalloc fallback for select(2)	2016-10-11 15:06:30 -07:00
seq_file.c	seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char	2016-10-07 18:46:30 -07:00
signalfd.c	…
splice.c	Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block	2016-12-13 10:19:16 -08:00
stack.c	…
stat.c	…
statfs.c	…
super.c	fs/super.c: don't fool lockdep in freeze_super() and thaw_super() paths	2016-10-14 20:41:59 -04:00
sync.c	…
timerfd.c	…
userfaultfd.c	…
utimes.c	Merge remote-tracking branch 'jk/vfs' into work.misc	2016-10-08 11:06:08 -04:00
xattr.c	xattr: Fix setting security xattrs on sockfs	2016-11-17 00:00:23 -05:00