linux/fs
Josef Bacik 339f26ffdf btrfs: fix lockdep splat in btrfs_recover_relocation
commit fb28610097 upstream.

While testing the error paths of relocation I hit the following lockdep
splat:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.10.0-rc6+ #217 Not tainted
  ------------------------------------------------------
  mount/779 is trying to acquire lock:
  ffffa0e676945418 (&fs_info->balance_mutex){+.+.}-{3:3}, at: btrfs_recover_balance+0x2f0/0x340

  but task is already holding lock:
  ffffa0e60ee31da8 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x27/0x100

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (btrfs-root-00){++++}-{3:3}:
	 down_read_nested+0x43/0x130
	 __btrfs_tree_read_lock+0x27/0x100
	 btrfs_read_lock_root_node+0x31/0x40
	 btrfs_search_slot+0x462/0x8f0
	 btrfs_update_root+0x55/0x2b0
	 btrfs_drop_snapshot+0x398/0x750
	 clean_dirty_subvols+0xdf/0x120
	 btrfs_recover_relocation+0x534/0x5a0
	 btrfs_start_pre_rw_mount+0xcb/0x170
	 open_ctree+0x151f/0x1726
	 btrfs_mount_root.cold+0x12/0xea
	 legacy_get_tree+0x30/0x50
	 vfs_get_tree+0x28/0xc0
	 vfs_kern_mount.part.0+0x71/0xb0
	 btrfs_mount+0x10d/0x380
	 legacy_get_tree+0x30/0x50
	 vfs_get_tree+0x28/0xc0
	 path_mount+0x433/0xc10
	 __x64_sys_mount+0xe3/0x120
	 do_syscall_64+0x33/0x40
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #1 (sb_internal#2){.+.+}-{0:0}:
	 start_transaction+0x444/0x700
	 insert_balance_item.isra.0+0x37/0x320
	 btrfs_balance+0x354/0xf40
	 btrfs_ioctl_balance+0x2cf/0x380
	 __x64_sys_ioctl+0x83/0xb0
	 do_syscall_64+0x33/0x40
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #0 (&fs_info->balance_mutex){+.+.}-{3:3}:
	 __lock_acquire+0x1120/0x1e10
	 lock_acquire+0x116/0x370
	 __mutex_lock+0x7e/0x7b0
	 btrfs_recover_balance+0x2f0/0x340
	 open_ctree+0x1095/0x1726
	 btrfs_mount_root.cold+0x12/0xea
	 legacy_get_tree+0x30/0x50
	 vfs_get_tree+0x28/0xc0
	 vfs_kern_mount.part.0+0x71/0xb0
	 btrfs_mount+0x10d/0x380
	 legacy_get_tree+0x30/0x50
	 vfs_get_tree+0x28/0xc0
	 path_mount+0x433/0xc10
	 __x64_sys_mount+0xe3/0x120
	 do_syscall_64+0x33/0x40
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  other info that might help us debug this:

  Chain exists of:
    &fs_info->balance_mutex --> sb_internal#2 --> btrfs-root-00

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(btrfs-root-00);
				 lock(sb_internal#2);
				 lock(btrfs-root-00);
    lock(&fs_info->balance_mutex);

   *** DEADLOCK ***

  2 locks held by mount/779:
   #0: ffffa0e60dc040e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at: alloc_super+0xb5/0x380
   #1: ffffa0e60ee31da8 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x27/0x100

  stack backtrace:
  CPU: 0 PID: 779 Comm: mount Not tainted 5.10.0-rc6+ #217
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  Call Trace:
   dump_stack+0x8b/0xb0
   check_noncircular+0xcf/0xf0
   ? trace_call_bpf+0x139/0x260
   __lock_acquire+0x1120/0x1e10
   lock_acquire+0x116/0x370
   ? btrfs_recover_balance+0x2f0/0x340
   __mutex_lock+0x7e/0x7b0
   ? btrfs_recover_balance+0x2f0/0x340
   ? btrfs_recover_balance+0x2f0/0x340
   ? rcu_read_lock_sched_held+0x3f/0x80
   ? kmem_cache_alloc_trace+0x2c4/0x2f0
   ? btrfs_get_64+0x5e/0x100
   btrfs_recover_balance+0x2f0/0x340
   open_ctree+0x1095/0x1726
   btrfs_mount_root.cold+0x12/0xea
   ? rcu_read_lock_sched_held+0x3f/0x80
   legacy_get_tree+0x30/0x50
   vfs_get_tree+0x28/0xc0
   vfs_kern_mount.part.0+0x71/0xb0
   btrfs_mount+0x10d/0x380
   ? __kmalloc_track_caller+0x2f2/0x320
   legacy_get_tree+0x30/0x50
   vfs_get_tree+0x28/0xc0
   ? capable+0x3a/0x60
   path_mount+0x433/0xc10
   __x64_sys_mount+0xe3/0x120
   do_syscall_64+0x33/0x40
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

This is straightforward to fix, simply release the path before we setup
the balance_ctl.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-27 11:05:35 +01:00
..
9p 9P: Cast to loff_t before multiplying 2020-11-05 11:08:53 +01:00
adfs fs/adfs: super: fix use-after-free bug 2019-08-06 19:06:49 +02:00
affs affs: fix basic permission bits to actually work 2020-09-09 19:04:30 +02:00
afs afs: Fix NULL deref in afs_dynroot_depopulate() 2020-08-26 10:31:05 +02:00
autofs autofs: fix a leak in autofs_expire_indirect() 2019-12-13 08:51:01 +01:00
befs
bfs bfs: add sanity check at bfs_fill_super() 2018-12-01 09:37:27 +01:00
btrfs btrfs: fix lockdep splat in btrfs_recover_relocation 2021-01-27 11:05:35 +01:00
cachefiles cachefiles: Handle readpage error correctly 2020-11-05 11:08:54 +01:00
ceph ceph: fix race in concurrent __ceph_remove_cap invocations 2020-12-30 11:26:13 +01:00
cifs SMB3.1.1: do not log warning message if server doesn't populate salt 2020-12-30 11:26:13 +01:00
coda coda: add error handling for fget 2019-08-06 19:06:51 +02:00
configfs configfs: fix config_item refcnt leak in configfs_rmdir() 2020-05-27 17:37:32 +02:00
cramfs Cramfs: fix abad comparison when wrap-arounds occur 2018-11-13 11:08:55 -08:00
crypto fscrypt: add fscrypt_is_nokey_name() 2021-01-06 14:44:58 +01:00
debugfs debugfs: fix use-after-free on symlink traversal 2019-05-08 07:21:48 +02:00
devpts fs/devpts: always delete dcache dentry-s in dput() 2019-03-23 20:09:59 +01:00
dlm fs: dlm: fix configfs memory leak 2020-10-30 10:38:28 +01:00
ecryptfs ecryptfs: replace BUG_ON with error handling code 2020-02-28 16:38:59 +01:00
efivarfs efivarfs: revert "fix memory leak in efivarfs_create()" 2020-12-02 08:48:12 +01:00
efs
exofs exofs_mount(): fix leaks on failure exits 2019-12-05 09:20:32 +01:00
exportfs exportfs: fix 'passing zero to ERR_PTR()' warning 2020-01-27 14:50:02 +01:00
ext2 ext2: don't update mtime on COW faults 2020-09-09 19:04:28 +02:00
ext4 ext4: fix superblock checksum failure when setting password salt 2021-01-19 18:22:38 +01:00
f2fs f2fs: prevent creating duplicate encrypted filenames 2021-01-06 14:44:58 +01:00
fat fat: don't allow to mount if the FAT length == 0 2020-06-22 09:05:08 +02:00
freevxfs
fscache fscache: fix race between enablement and dropping of object 2018-12-17 09:24:40 +01:00
fuse fuse: fix page dereference after free 2020-11-05 11:08:34 +01:00
gfs2 gfs2: check for empty rgrp tree in gfs2_ri_update 2020-12-11 13:25:04 +01:00
hfs fs/hfs/extent.c: fix array out of bounds read of array extent 2019-12-01 09:17:10 +01:00
hfsplus hfsplus: fix crash and filesystem corruption when deleting files 2020-04-17 10:48:52 +02:00
hostfs
hpfs
hugetlbfs hugetlb: use same fault hash key for shared and private mappings 2019-05-22 07:37:40 +02:00
isofs
jbd2 jbd2: abort journal if free a async write error metadata buffer 2020-09-03 11:24:24 +02:00
jffs2 jffs2: Fix GC exit abnormally 2020-12-30 11:26:13 +01:00
jfs jfs: Fix array index bounds check in dbAdjTree 2020-12-30 11:26:13 +01:00
kernfs kernfs: fix ino wrap-around detection 2019-12-13 08:52:43 +01:00
lockd lockd: don't use interval-based rebinding over TCP 2020-12-30 11:25:59 +01:00
minix fs/minix: remove expected error message in block_to_path() 2020-08-21 11:05:38 +02:00
nfs NFS: nfs_igrab_and_active must first reference the superblock 2021-01-19 18:22:37 +01:00
nfs_common nfs_common: need lock during iterate through the list 2020-12-30 11:26:02 +01:00
nfsd nfsd4: readdirplus shouldn't return parent of export 2021-01-23 15:49:55 +01:00
nilfs2 nilfs2: fix null pointer dereference at nilfs_segctor_do_construct() 2020-06-22 09:05:03 +02:00
nls
notify fanotify: fix ignore mask logic for events on child and on dir 2020-06-30 23:17:00 -04:00
ntfs ntfs: add check for mft record size in superblock 2020-10-30 10:38:28 +01:00
ocfs2 ocfs2: initialize ip_next_orphan 2020-11-18 19:18:49 +01:00
omfs
openpromfs
orangefs help_next should increase position index 2020-02-24 08:34:53 +01:00
overlayfs ovl: fix unneeded call to ovl_change_flags() 2020-07-22 09:32:10 +02:00
proc proc: fix lookup in /proc/net subdirectories after setns(2) 2021-01-12 20:10:17 +01:00
pstore pstore: Fix linking when crypto API disabled 2020-08-19 08:15:04 +02:00
qnx4
qnx6
quota quota: Don't overflow quota file offsets 2021-01-06 14:45:01 +01:00
ramfs ramfs: fix nommu mmap with gaps in the page cache 2020-10-30 10:38:21 +01:00
reiserfs reiserfs: add check for an invalid ih_entry_count 2021-01-06 14:45:00 +01:00
romfs romfs: fix uninitialized memory leak in romfs_dev_read() 2020-08-26 10:30:59 +02:00
squashfs
sysfs
sysv sysv: return 'err' instead of 0 in __sysv_write_inode 2018-12-17 09:24:30 +01:00
tracefs
ubifs ubifs: prevent creating duplicate encrypted filenames 2021-01-06 14:44:59 +01:00
udf udf: Fix memory leak when mounting 2020-11-05 11:08:50 +01:00
ufs fs/ufs: avoid potential u32 multiplication overflow 2020-08-21 11:05:38 +02:00
xfs xfs: revert "xfs: fix rmap key and record comparison functions" 2020-11-24 13:27:23 +01:00
aio.c aio: fix async fsync creds 2020-06-22 09:05:01 +02:00
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info() 2020-06-03 08:19:41 +02:00
binfmt_em86.c
binfmt_flat.c fs/binfmt_flat.c: make load_flat_shared_library() work 2019-07-03 13:14:44 +02:00
binfmt_misc.c
binfmt_script.c exec: load_script: Do not exec truncated interpreter path 2019-11-06 13:05:37 +01:00
block_dev.c bdev: Reduce time holding bd_mutex in sync in blkdev_close() 2020-10-01 13:14:42 +02:00
buffer.c fs: Don't invalidate page buffers in block_write_full_page() 2020-11-05 11:08:46 +01:00
char_dev.c chardev: Avoid potential use-after-free in 'chrdev_open()' 2020-01-14 20:06:57 +01:00
compat_binfmt_elf.c
compat_ioctl.c fix compat handling of FICLONERANGE, FIDEDUPERANGE and FS_IOC_FIEMAP 2020-01-09 10:19:07 +01:00
compat.c
coredump.c coredump: fix crash when umh is disabled 2020-05-14 07:57:21 +02:00
d_path.c
dax.c dax: pass NOWAIT flag to iomap_apply 2020-03-05 16:42:12 +01:00
dcache.c fs, fscrypt: clear DCACHE_ENCRYPTED_NAME when unaliasing directory 2020-11-05 11:08:35 +01:00
dcookies.c
direct-io.c direct-io: allow direct writes to empty inodes 2019-03-05 17:58:50 +01:00
drop_caches.c fs: avoid softlockups in s_inodes iterators 2020-01-12 12:17:20 +01:00
eventfd.c eventfd: track eventfd_signal() recursion depth 2020-02-11 04:34:08 -08:00
eventpoll.c ep_create_wakeup_source(): dentry name can change under you... 2020-10-07 08:00:09 +02:00
exec.c mm: fix exec activate_mm vs TLB shootdown and lazy tlb switching race 2020-11-05 11:08:38 +01:00
fcntl.c fcntl: Fix potential deadlock in send_sig{io, urg}() 2021-01-06 14:45:00 +01:00
fhandle.c
file_table.c
file.c fix multiplication overflow in copy_fdtable() 2020-05-27 17:37:29 +02:00
filesystems.c fs/filesystems.c: downgrade user-reachable WARN_ONCE() to pr_warn_once() 2020-04-17 10:48:51 +02:00
fs_pin.c
fs_struct.c
fs-writeback.c writeback: Fix sync livelock due to b_dirty_time processing 2020-09-03 11:24:28 +02:00
inode.c futex: Fix inode life-time issue 2020-03-25 08:06:14 +01:00
internal.h acct_on(): don't mess with freeze protection 2019-05-31 06:46:05 -07:00
ioctl.c vfs: fix FIGETBSZ ioctl on an overlayfs file 2018-11-21 09:19:14 +01:00
iomap.c iomap: partially revert 4721a60109 (simulated directio short read on EFAULT) 2019-12-13 08:52:56 +01:00
Kconfig
Kconfig.binfmt
libfs.c libfs: fix error cast of negative value in simple_attr_write() 2020-11-24 13:27:23 +01:00
locks.c locks: print unsigned ino in /proc/locks 2020-01-09 10:19:00 +01:00
Makefile
mbcache.c
mount.h
mpage.c
namei.c namei: only return -ECHILD from follow_dotdot_rcu() 2020-03-05 16:42:20 +01:00
namespace.c fs/namespace.c: fix mountpoint reference counter race 2020-04-29 16:31:26 +02:00
no-block.c
nsfs.c dcache: sort the freeing-without-RCU-delay mess for good. 2019-05-25 18:23:26 +02:00
open.c cifs_atomic_open(): fix double-put on late allocation failure 2020-03-18 07:14:21 +01:00
pipe.c fs: prevent page refcount overflow in pipe_buf_get 2019-05-04 09:20:11 +02:00
pnode.c propagate_one(): mnt_set_mountpoint() needs mount_lock 2020-05-02 17:26:01 +02:00
pnode.h
posix_acl.c
proc_namespace.c
read_write.c vfs: avoid problematic remapping requests into partial EOF block 2019-12-01 09:17:04 +01:00
readdir.c filldir[64]: remove WARN_ON_ONCE() for bad directory entries 2020-01-04 19:13:26 +01:00
select.c
seq_file.c seq_file: fix problem when seeking mid-record 2019-08-25 10:47:43 +02:00
signalfd.c fs/signalfd.c: fix inconsistent return codes for signalfd4 2020-08-26 10:31:02 +02:00
splice.c splice: only read in as much information as there is pipe buffer space 2019-12-17 20:35:43 +01:00
stack.c
stat.c
statfs.c vfs: Fix EOVERFLOW testing in put_compat_statfs64 2019-10-11 18:21:39 +02:00
super.c vfs: remove lockdep bogosity in __sb_start_write 2020-11-24 13:27:20 +01:00
sync.c
timerfd.c
userfaultfd.c userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK 2020-01-04 19:13:18 +01:00
utimes.c
xattr.c xattr: break delegations in {set,remove}xattr 2020-08-11 15:32:34 +02:00