Anand Jain fb4c7d2923 btrfs: fix lockdep warning while mounting sprout fs ... [ Upstream commit c124706900c20dee70f921bb3a90492431561a0a ] Following test case reproduces lockdep warning. Test case: $ mkfs.btrfs -f <dev1> $ btrfstune -S 1 <dev1> $ mount <dev1> <mnt> $ btrfs device add <dev2> <mnt> -f $ umount <mnt> $ mount <dev2> <mnt> $ umount <mnt> The warning claims a possible ABBA deadlock between the threads initiated by [#1] btrfs device add and [#0] the mount. [ 540.743122] WARNING: possible circular locking dependency detected [ 540.743129] 5.11.0-rc7+ #5 Not tainted [ 540.743135] ------------------------------------------------------ [ 540.743142] mount/2515 is trying to acquire lock: [ 540.743149] ffffa0c5544c2ce0 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: clone_fs_devices+0x6d/0x210 [btrfs] [ 540.743458] but task is already holding lock: [ 540.743461] ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.743541] which lock already depends on the new lock. [ 540.743543] the existing dependency chain (in reverse order) is: [ 540.743546] -> #1 (btrfs-chunk-00){++++}-{4:4}: [ 540.743566] down_read_nested+0x48/0x2b0 [ 540.743585] __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.743650] btrfs_read_lock_root_node+0x70/0x200 [btrfs] [ 540.743733] btrfs_search_slot+0x6c6/0xe00 [btrfs] [ 540.743785] btrfs_update_device+0x83/0x260 [btrfs] [ 540.743849] btrfs_finish_chunk_alloc+0x13f/0x660 [btrfs] <--- device_list_mutex [ 540.743911] btrfs_create_pending_block_groups+0x18d/0x3f0 [btrfs] [ 540.743982] btrfs_commit_transaction+0x86/0x1260 [btrfs] [ 540.744037] btrfs_init_new_device+0x1600/0x1dd0 [btrfs] [ 540.744101] btrfs_ioctl+0x1c77/0x24c0 [btrfs] [ 540.744166] __x64_sys_ioctl+0xe4/0x140 [ 540.744170] do_syscall_64+0x4b/0x80 [ 540.744174] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 540.744180] -> #0 (&fs_devs->device_list_mutex){+.+.}-{4:4}: [ 540.744184] __lock_acquire+0x155f/0x2360 [ 540.744188] lock_acquire+0x10b/0x5c0 [ 540.744190] __mutex_lock+0xb1/0xf80 [ 540.744193] mutex_lock_nested+0x27/0x30 [ 540.744196] clone_fs_devices+0x6d/0x210 [btrfs] [ 540.744270] btrfs_read_chunk_tree+0x3c7/0xbb0 [btrfs] [ 540.744336] open_ctree+0xf6e/0x2074 [btrfs] [ 540.744406] btrfs_mount_root.cold.72+0x16/0x127 [btrfs] [ 540.744472] legacy_get_tree+0x38/0x90 [ 540.744475] vfs_get_tree+0x30/0x140 [ 540.744478] fc_mount+0x16/0x60 [ 540.744482] vfs_kern_mount+0x91/0x100 [ 540.744484] btrfs_mount+0x1e6/0x670 [btrfs] [ 540.744536] legacy_get_tree+0x38/0x90 [ 540.744537] vfs_get_tree+0x30/0x140 [ 540.744539] path_mount+0x8d8/0x1070 [ 540.744541] do_mount+0x8d/0xc0 [ 540.744543] __x64_sys_mount+0x125/0x160 [ 540.744545] do_syscall_64+0x4b/0x80 [ 540.744547] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 540.744551] other info that might help us debug this: [ 540.744552] Possible unsafe locking scenario: [ 540.744553] CPU0 CPU1 [ 540.744554] ---- ---- [ 540.744555] lock(btrfs-chunk-00); [ 540.744557] lock(&fs_devs->device_list_mutex); [ 540.744560] lock(btrfs-chunk-00); [ 540.744562] lock(&fs_devs->device_list_mutex); [ 540.744564] *** DEADLOCK *** [ 540.744565] 3 locks held by mount/2515: [ 540.744567] #0: ffffa0c56bf7a0e0 (&type->s_umount_key#42/1){+.+.}-{4:4}, at: alloc_super.isra.16+0xdf/0x450 [ 540.744574] #1: ffffffffc05a9628 (uuid_mutex){+.+.}-{4:4}, at: btrfs_read_chunk_tree+0x63/0xbb0 [btrfs] [ 540.744640] #2: ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.744708] stack backtrace: [ 540.744712] CPU: 2 PID: 2515 Comm: mount Not tainted 5.11.0-rc7+ #5 But the device_list_mutex in clone_fs_devices() is redundant, as explained below. Two threads [1] and [2] (below) could lead to clone_fs_device(). [1] open_ctree <== mount sprout fs btrfs_read_chunk_tree() mutex_lock(&uuid_mutex) <== global lock read_one_dev() open_seed_devices() clone_fs_devices() <== seed fs_devices mutex_lock(&orig->device_list_mutex) <== seed fs_devices [2] btrfs_init_new_device() <== sprouting mutex_lock(&uuid_mutex); <== global lock btrfs_prepare_sprout() lockdep_assert_held(&uuid_mutex) clone_fs_devices(seed_fs_device) <== seed fs_devices Both of these threads hold uuid_mutex which is sufficient to protect getting the seed device(s) freed while we are trying to clone it for sprouting [2] or mounting a sprout [1] (as above). A mounted seed device can not free/write/replace because it is read-only. An unmounted seed device can be freed by btrfs_free_stale_devices(), but it needs uuid_mutex. So this patch removes the unnecessary device_list_mutex in clone_fs_devices(). And adds a lockdep_assert_held(&uuid_mutex) in clone_fs_devices(). Reported-by: Su Yue <l@damenly.su> Tested-by: Su Yue <l@damenly.su> Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2021-09-26 14:07:12 +02:00
..
9p	9P: Cast to loff_t before multiplying	2020-11-05 11:43:34 +01:00
adfs	Merge branch 'work.adfs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 11:33:22 -07:00
affs	fs/affs: release old buffer head on error path	2021-03-04 10:26:48 +01:00
afs	afs: Fix tracepoint string placement with built-in AFS	2021-07-28 13:30:58 +02:00
autofs	autofs: fix a leak in autofs_expire_indirect()	2019-10-25 00:03:11 -04:00
befs	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
bfs	bfs: don't use WARNING: string when it's just info.	2021-01-06 14:48:39 +01:00
btrfs	btrfs: fix lockdep warning while mounting sprout fs	2021-09-26 14:07:12 +02:00
cachefiles	cachefiles: Handle readpage error correctly	2020-11-05 11:43:36 +01:00
ceph	ceph: lockdep annotations for try_nonblocking_invalidate	2021-09-26 14:07:11 +02:00
cifs	cifs: fix wrong release in sess_alloc_buffer() failed path	2021-09-22 12:26:35 +02:00
coda	y2038: add inode timestamp clamping	2019-09-19 09:42:37 -07:00
configfs	configfs: fix memleak in configfs_release_bin_file	2021-07-14 16:53:46 +02:00
cramfs	cramfs: fix usage on non-MTD device	2019-11-23 21:44:49 -05:00
crypto	fscrypt: add fscrypt_symlink_getattr() for computing st_size	2021-09-12 08:56:38 +02:00
debugfs	debugfs: Return error during {full/open}_proxy_open() on rmmod	2021-09-15 09:47:33 +02:00
devpts	devpts_pty_kill(): don't bother with d_delete()	2019-09-03 09:30:56 -04:00
dlm	fs: dlm: fix memory leak when fenced	2021-07-14 16:53:17 +02:00
ecryptfs	Revert "ecryptfs: replace BUG_ON with error handling code"	2021-05-26 12:05:19 +02:00
efivarfs	efivarfs: revert "fix memory leak in efivarfs_create()"	2020-12-02 08:49:53 +01:00
efs	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
erofs	erofs: add unsupported inode i_format check	2021-05-11 14:04:02 +02:00
exportfs	exportfs_decode_fh(): negative pinned may become positive without the parent locked	2019-11-10 11:56:05 -05:00
ext2	ext2: don't update mtime on COW faults	2020-09-09 19:12:30 +02:00
ext4	ext4: report correct st_size for encrypted symlinks	2021-09-12 08:56:38 +02:00
f2fs	f2fs: fix to unmap pages from userspace process in punch_hole()	2021-09-22 12:26:26 +02:00
fat	fat: don't allow to mount if the FAT length == 0	2020-06-17 16:40:36 +02:00
freevxfs	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
fscache	fscache: Fix cookie key hashing	2021-09-22 12:26:25 +02:00
fuse	fuse: fix use after free in fuse_read_interrupt()	2021-09-22 12:26:43 +02:00
gfs2	gfs2: Don't call dlm after protocol is unmounted	2021-09-22 12:26:33 +02:00
hfs	hfs: add lock nesting notation to hfs_find_init	2021-07-31 08:19:38 +02:00
hfsplus	hfsplus: prevent corruption in shrinking truncate	2021-05-19 10:08:29 +02:00
hostfs	hostfs: fix memory handling in follow_link()	2021-04-14 08:24:14 +02:00
hpfs	fs: hpfs: Initialize filesystem timestamp ranges	2019-08-30 08:11:25 -07:00
hugetlbfs	hugetlbfs: fix mount mode command line processing	2021-07-28 13:31:01 +02:00
iomap	mm/swap: consider max pages in iomap_swapfile_add_extent	2021-09-15 09:47:35 +02:00
isofs	isofs: joliet: Fix iocharset=utf8 mount option	2021-09-15 09:47:27 +02:00
jbd2	jbd2: fix up sparse warnings in checkpoint code	2020-11-18 19:20:30 +01:00
jffs2	jffs2: check the validity of dstlen in jffs2_zlib_compress()	2021-05-11 14:04:16 +02:00
jfs	fs/jfs: Fix missing error code in lmLogInit()	2021-07-20 16:10:42 +02:00
kernfs	kernfs: do not call fsnotify() with name without a parent	2020-08-19 08:16:12 +02:00
lockd	lockd: lockd server-side shouldn't set fl_ops	2021-09-22 12:26:34 +02:00
minix	fs/minix: remove expected error message in block_to_path()	2020-08-21 13:05:37 +02:00
nfs	NFSv4/pNFS: Don't call _nfs4_pnfs_v3_ds_connect multiple times	2021-07-20 16:10:50 +02:00
nfs_common	nfs_common: need lock during iterate through the list	2020-12-30 11:51:22 +01:00
nfsd	nfsd4: Fix forced-expiry locking	2021-09-15 09:47:35 +02:00
nilfs2	nilfs2: use refcount_dec_and_lock() to fix potential UAF	2021-09-26 14:07:09 +02:00
nls	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
notify	fanotify: fix ignore mask logic for events on child and on dir	2020-06-17 16:40:24 +02:00
ntfs	ntfs: fix validity check for file name attribute	2021-07-14 16:53:01 +02:00
ocfs2	ocfs2: issue zeroout to EOF blocks	2021-08-04 12:27:37 +02:00
omfs	fs: omfs: Initialize filesystem timestamp ranges	2019-08-30 08:11:25 -07:00
openpromfs	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
orangefs	orangefs: fix orangefs df output.	2021-07-20 16:10:48 +02:00
overlayfs	ovl: fix BUG_ON() in may_delete() when called from ovl_cleanup()	2021-09-22 12:26:37 +02:00
proc	mm, oom: make the calculation of oom badness more accurate	2021-09-03 10:08:12 +02:00
pstore	pstore: Fix typo in compression option name	2021-03-04 10:26:45 +01:00
qnx4	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
qnx6	fs: Fill in max and min timestamps in superblock	2019-08-30 07:27:17 -07:00
quota	quota: Fix memory leak when handling corrupted quota file	2021-03-04 10:26:26 +01:00
ramfs	ramfs: fix nommu mmap with gaps in the page cache	2020-10-29 09:57:53 +01:00
reiserfs	reiserfs: check directory items on read from disk	2021-08-12 13:21:05 +02:00
romfs	romfs: fix uninitialized memory leak in romfs_dev_read()	2020-08-26 10:40:51 +02:00
squashfs	squashfs: fix divide error in calculate_skip()	2021-05-19 10:08:29 +02:00
sysfs	sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output	2021-03-07 12:20:48 +01:00
sysv	fs: sysv: Initialize filesystem timestamp ranges	2019-08-30 07:27:18 -07:00
tracefs	tracing: Do not create tracefs files if tracefs lockdown is in effect	2019-10-12 20:49:07 -04:00
ubifs	ubifs: report correct st_size for encrypted symlinks	2021-09-12 08:56:39 +02:00
udf	udf_get_extendedattr() had no boundary checks.	2021-09-15 09:47:28 +02:00
ufs	fs/ufs: avoid potential u32 multiplication overflow	2020-08-21 13:05:37 +02:00
unicode	unicode: make array 'token' static const, makes object smaller	2019-09-17 11:48:24 -04:00
verity	fs-verity: support builtin file signatures	2019-08-12 19:33:50 -07:00
xfs	xfs: Fix assert failure in xfs_setattr_size()	2021-03-07 12:20:42 +01:00
aio.c	aio: fix async fsync creds	2020-06-17 16:40:24 +02:00
anon_inodes.c	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
attr.c	utimes: Clamp the timestamps in notify_change()	2020-02-11 04:35:12 -08:00
bad_inode.c
binfmt_aout.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
binfmt_elf_fdpic.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
binfmt_elf.c	fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()	2020-06-03 08:21:27 +02:00
binfmt_em86.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
binfmt_flat.c	binfmt_flat: revert "binfmt_flat: don't offset the data start"	2020-09-03 11:26:39 +02:00
binfmt_misc.c	binfmt_misc: fix possible deadlock in bm_register_write	2021-03-17 17:03:57 +01:00
binfmt_script.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
block_dev.c	block: reexpand iov_iter after read/write	2021-05-22 11:38:29 +02:00
buffer.c	fs: Don't invalidate page buffers in block_write_full_page()	2020-11-05 11:43:24 +01:00
char_dev.c	chardev: Avoid potential use-after-free in 'chrdev_open()'	2020-01-14 20:08:18 +01:00
compat_binfmt_elf.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 193	2019-05-30 11:29:21 -07:00
compat_ioctl.c	fix compat handling of FICLONERANGE, FIDEDUPERANGE and FS_IOC_FIEMAP	2020-01-09 10:20:05 +01:00
compat.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
coredump.c	coredump: fix core_pattern parse error	2020-12-11 13:23:30 +01:00
d_path.c	fs: fix NULL dereference due to data race in prepend_path()	2020-10-29 09:57:45 +01:00
dax.c	dax: fix ENOMEM handling in grab_mapping_entry()	2021-07-14 16:53:25 +02:00
dcache.c	fix dget_parent() fastpath race	2020-10-01 13:17:19 +02:00
dcookies.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
direct-io.c	fs: direct-io: fix missing sdio->boundary	2021-04-14 08:24:11 +02:00
drop_caches.c	fs: avoid softlockups in s_inodes iterators	2020-01-12 12:21:37 +01:00
eventfd.c	eventfd: track eventfd_signal() recursion depth	2020-02-11 04:35:37 -08:00
eventpoll.c	ep_create_wakeup_source(): dentry name can change under you...	2020-10-07 08:01:31 +02:00
exec.c	exec: Transform exec_update_mutex into a rw_semaphore	2021-01-09 13:44:55 +01:00
fcntl.c	fcntl: fix potential deadlock for &fasync_struct.fa_lock	2021-09-15 09:47:28 +02:00
fhandle.c	fs/handle.c - fix up kerneldoc	2019-08-07 21:51:47 -04:00
file_table.c	vfs: Export flush_delayed_fput for use by knfsd.	2019-08-19 11:00:39 -04:00
file.c	fix multiplication overflow in copy_fdtable()	2020-05-27 17:46:12 +02:00
filesystems.c	fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once()	2020-04-17 10:50:21 +02:00
fs_context.c	vfs: subtype handling moved to fuse	2019-09-06 21:28:49 +02:00
fs_parser.c	vfs: Make fs_parse() handle fs_param_is_fd-type params better	2019-09-12 21:06:14 -04:00
fs_pin.c	switch the remnants of releasing the mountpoint away from fs_pin	2019-07-16 22:52:37 -04:00
fs_struct.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
fs_types.c
fs-writeback.c	writeback: fix obtain a reference to a freeing memcg css	2021-07-14 16:53:35 +02:00
fsopen.c	Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2019-07-19 10:42:02 -07:00
inode.c	futex: Fix inode life-time issue	2020-03-25 08:25:58 +01:00
internal.h	cgroup1: fix leaked context root causing sporadic NULL deref in LTP	2021-07-31 08:19:37 +02:00
io_uring.c	io_uring: Fix current->fs handling in io_sq_wq_submit_work()	2021-01-30 13:54:10 +01:00
ioctl.c	compat_ioctl: add compat_ptr_ioctl()	2019-12-17 19:55:30 +01:00
Kconfig	fs-verity for 5.4	2019-09-18 16:59:14 -07:00
Kconfig.binfmt	binfmt_flat: make support for old format binaries optional	2019-06-24 09:16:47 +10:00
libfs.c	libfs: fix error cast of negative value in simple_attr_write()	2020-11-24 13:29:19 +01:00
locks.c	locks: reinstate locks_delete_block optimization	2020-03-25 08:25:41 +01:00
Makefile	fs-verity for 5.4	2019-09-18 16:59:14 -07:00
mbcache.c	treewide: Add SPDX license identifier for more missed files	2019-05-21 10:50:45 +02:00
mount.h	switch the remnants of releasing the mountpoint away from fs_pin	2019-07-16 22:52:37 -04:00
mpage.c	fs: move guard_bio_eod() after bio_set_op_attrs	2020-01-17 19:48:21 +01:00
namei.c	namei: only return -ECHILD from follow_dotdot_rcu()	2020-03-05 16:43:48 +01:00
namespace.c	fs: warn about impending deprecation of mandatory locks	2021-08-26 08:36:22 -04:00
no-block.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152	2019-05-30 11:26:32 -07:00
nsfs.c	vfs: Convert nsfs to use the new mount API	2019-05-25 18:00:06 -04:00
open.c	cifs_atomic_open(): fix double-put on late allocation failure	2020-03-18 07:17:51 +01:00
pipe.c	pipe: increase minimum default pipe size to 2 pages	2021-08-12 13:21:02 +02:00
pnode.c	propagate_one(): mnt_set_mountpoint() needs mount_lock	2020-05-02 08:48:44 +02:00
pnode.h	mount: fix mounting of detached mounts onto targets that reside on shared mounts	2021-03-17 17:03:33 +01:00
posix_acl.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
proc_namespace.c	vfs: subtype handling moved to fuse	2019-09-06 21:28:49 +02:00
read_write.c	fs: allow deduplication of eof block into the end of the destination file	2020-02-11 04:35:23 -08:00
readdir.c	readdir: make sure to verify directory entry for legacy interfaces too	2021-04-21 12:56:16 +02:00
select.c	kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data()	2021-03-24 11:26:44 +01:00
seq_file.c	seq_file: disallow extremely large seq buffer allocations	2021-07-20 16:10:54 +02:00
signalfd.c	fs/signalfd.c: fix inconsistent return codes for signalfd4	2020-08-26 10:40:58 +02:00
splice.c	splice: only read in as much information as there is pipe buffer space	2019-12-17 19:56:52 +01:00
stack.c	treewide: Add SPDX license identifier for missed files	2019-05-21 10:50:45 +02:00
stat.c
statfs.c	vfs: Fix EOVERFLOW testing in put_compat_statfs64	2019-10-03 14:21:35 -07:00
super.c	vfs: remove lockdep bogosity in __sb_start_write	2020-11-24 13:29:01 +01:00
sync.c	fs/sync.c: sync_file_range(2) may use WB_SYNC_ALL writeback	2019-05-14 09:47:50 -07:00
timerfd.c	timerfd: Prepare for PREEMPT_RT	2019-08-01 20:51:23 +02:00
userfaultfd.c	userfaultfd: prevent concurrent API initialization	2021-09-22 12:26:26 +02:00
utimes.c	utimes: Clamp the timestamps in notify_change()	2020-02-11 04:35:12 -08:00
xattr.c	xattr: break delegations in {set,remove}xattr	2020-08-11 15:33:39 +02:00