======================================================
WARNING: possible circular locking dependency detected
4.14.307-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.5/10329 is trying to acquire lock:
 ("%s-%s""btrfs", name){+.+.}, at: [<ffffffff8135cb4b>] flush_workqueue+0xcb/0x1310 kernel/workqueue.c:2622

but task is already holding lock:
 (&fs_info->scrub_lock){+.+.}, at: [<ffffffff82b1bdb6>] btrfs_scrub_dev+0x506/0xcd0 fs/btrfs/scrub.c:4217

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (&fs_info->scrub_lock){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
       btrfs_scrub_dev+0x1f3/0xcd0 fs/btrfs/scrub.c:4150
       btrfs_ioctl_scrub fs/btrfs/ioctl.c:4451 [inline]
       btrfs_ioctl+0xba8/0x5b20 fs/btrfs/ioctl.c:5681
       vfs_ioctl fs/ioctl.c:46 [inline]
       file_ioctl fs/ioctl.c:500 [inline]
       do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
       SYSC_ioctl fs/ioctl.c:701 [inline]
       SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
       do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x5e/0xd3

-> #2 (&fs_devs->device_list_mutex){+.+.}:
       __mutex_lock_common kernel/locking/mutex.c:756 [inline]
       __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
       __reada_start_machine fs/btrfs/reada.c:765 [inline]
       reada_start_machine_worker+0x1d2/0xa90 fs/btrfs/reada.c:746
       normal_work_helper+0x304/0x1330 fs/btrfs/async-thread.c:376
       process_one_work+0x793/0x14a0 kernel/workqueue.c:2117
       worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251
       kthread+0x30d/0x420 kernel/kthread.c:232
       ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:406

-> #1 ((&work->normal_work)){+.+.}:
       process_one_work+0x736/0x14a0 kernel/workqueue.c:2093
       worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251
       kthread+0x30d/0x420 kernel/kthread.c:232
EXT4-fs error (device loop4): ext4_mb_generate_buddy:754: group 0, 
       ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:406

-> #0
block bitmap and bg descriptor inconsistent: 25 vs 150994969 free clusters
 ("%s-%s""btrfs", name){+.+.}:
       lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
EXT4-fs (loop4): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 2048 with error 28
       flush_workqueue+0xfa/0x1310 kernel/workqueue.c:2625
       drain_workqueue+0x177/0x3e0 kernel/workqueue.c:2790
       destroy_workqueue+0x71/0x710 kernel/workqueue.c:4116
EXT4-fs (loop4): This should not happen!! Data will be lost

       __btrfs_destroy_workqueue fs/btrfs/async-thread.c:436 [inline]
       btrfs_destroy_workqueue+0xf8/0x630 fs/btrfs/async-thread.c:447
       scrub_workers_put+0x90/0x1a0 fs/btrfs/scrub.c:4075
       btrfs_scrub_dev+0x536/0xcd0 fs/btrfs/scrub.c:4219
       btrfs_ioctl_scrub fs/btrfs/ioctl.c:4451 [inline]
       btrfs_ioctl+0xba8/0x5b20 fs/btrfs/ioctl.c:5681
EXT4-fs (loop4): Total free blocks count 0
       vfs_ioctl fs/ioctl.c:46 [inline]
       file_ioctl fs/ioctl.c:500 [inline]
       do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
       SYSC_ioctl fs/ioctl.c:701 [inline]
       SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
EXT4-fs (loop4): Free/Dirty block details
       do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
       entry_SYSCALL_64_after_hwframe+0x5e/0xd3

other info that might help us debug this:

EXT4-fs (loop4): free_blocks=2415919104
Chain exists of:
  "%s-%s""btrfs", name --> &fs_devs->device_list_mutex --> &fs_info->scrub_lock
EXT4-fs (loop4): dirty_blocks=8192


 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&fs_info->scrub_lock
EXT4-fs (loop4): Block reservation details
);
                               lock(&fs_devs->device_list_mutex);
                               lock(&fs_info->scrub_lock
EXT4-fs (loop4): i_reserved_data_blocks=512
);
  lock("%s-%s""btrfs", name);

 *** DEADLOCK ***

1 lock held by syz-executor.5/10329:
 #0:  (&fs_info->scrub_lock){+.+.}, at: [<ffffffff82b1bdb6>] btrfs_scrub_dev+0x506/0xcd0 fs/btrfs/scrub.c:4217

stack backtrace:
CPU: 0 PID: 10329 Comm: syz-executor.5 Not tainted 4.14.307-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258
 check_prev_add kernel/locking/lockdep.c:1905 [inline]
 check_prevs_add kernel/locking/lockdep.c:2022 [inline]
 validate_chain kernel/locking/lockdep.c:2464 [inline]
 __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491
 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
 flush_workqueue+0xfa/0x1310 kernel/workqueue.c:2625
 drain_workqueue+0x177/0x3e0 kernel/workqueue.c:2790
 destroy_workqueue+0x71/0x710 kernel/workqueue.c:4116
 __btrfs_destroy_workqueue fs/btrfs/async-thread.c:436 [inline]
 btrfs_destroy_workqueue+0xf8/0x630 fs/btrfs/async-thread.c:447
 scrub_workers_put+0x90/0x1a0 fs/btrfs/scrub.c:4075
 btrfs_scrub_dev+0x536/0xcd0 fs/btrfs/scrub.c:4219
 btrfs_ioctl_scrub fs/btrfs/ioctl.c:4451 [inline]
 btrfs_ioctl+0xba8/0x5b20 fs/btrfs/ioctl.c:5681
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3
RIP: 0033:0x7f24b41ae0f9
RSP: 002b:00007f24b2720168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f24b42cdf80 RCX: 00007f24b41ae0f9
RDX: 0000000020000100 RSI: 00000000c400941b RDI: 0000000000000004
RBP: 00007f24b4209ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd4de06f0f R14: 00007f24b2720300 R15: 0000000000022000
EXT4-fs (loop4): Delayed block allocation failed for inode 15 at logical offset 2050 with max blocks 2048 with error 28
EXT4-fs (loop4): This should not happen!! Data will be lost

BTRFS info (device loop0): enabling inode map caching
BTRFS info (device loop0): trying to use backup root at mount time
BTRFS info (device loop0): use zlib compression
BTRFS info (device loop0): enabling ssd optimizations
BTRFS info (device loop0): using spread ssd allocation scheme
BTRFS info (device loop0): using free space tree
BTRFS info (device loop0): has skinny extents
L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.
BTRFS info (device loop0): enabling inode map caching
BTRFS info (device loop0): trying to use backup root at mount time
BTRFS info (device loop0): use zlib compression
BTRFS info (device loop0): enabling ssd optimizations
BTRFS info (device loop0): using spread ssd allocation scheme
BTRFS info (device loop0): using free space tree
BTRFS info (device loop0): has skinny extents
BTRFS info (device loop0): enabling inode map caching
BTRFS info (device loop0): trying to use backup root at mount time
BTRFS info (device loop0): use zlib compression
BTRFS info (device loop0): enabling ssd optimizations
BTRFS info (device loop0): using spread ssd allocation scheme
BTRFS info (device loop0): using free space tree
BTRFS info (device loop0): has skinny extents
audit: type=1804 audit(1677543008.104:10): pid=10788 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir420903566/syzkaller.UJ05MF/55/bus/bus" dev="loop0" ino=8 res=1
audit: type=1804 audit(1677543008.264:11): pid=10805 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir420903566/syzkaller.UJ05MF/56/bus/bus" dev="loop0" ino=8 res=1
audit: type=1804 audit(1677543008.564:12): pid=10829 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir420903566/syzkaller.UJ05MF/57/bus/bus" dev="loop0" ino=8 res=1
audit: type=1804 audit(1677543008.844:13): pid=10846 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir420903566/syzkaller.UJ05MF/58/bus/bus" dev="loop0" ino=8 res=1
audit: type=1804 audit(1677543009.084:14): pid=10865 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir420903566/syzkaller.UJ05MF/59/bus/bus" dev="loop0" ino=8 res=1
audit: type=1804 audit(1677543009.284:15): pid=10878 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir420903566/syzkaller.UJ05MF/60/bus/bus" dev="loop0" ino=8 res=1
audit: type=1804 audit(1677543009.534:16): pid=10894 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir420903566/syzkaller.UJ05MF/61/bus/bus" dev="loop0" ino=8 res=1
audit: type=1804 audit(1677543009.744:17): pid=10911 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir420903566/syzkaller.UJ05MF/62/bus/bus" dev="loop0" ino=8 res=1
audit: type=1804 audit(1677543010.004:18): pid=10933 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir420903566/syzkaller.UJ05MF/63/bus/bus" dev="loop0" ino=8 res=1
audit: type=1804 audit(1677543010.494:19): pid=10972 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.0" name="/root/syzkaller-testdir420903566/syzkaller.UJ05MF/64/bus/bus" dev="loop0" ino=8 res=1
NILFS (loop1): invalid segment: Checksum error in segment payload
NILFS (loop1): trying rollback from an earlier position
NILFS (loop1): recovery complete
NILFS (loop1): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
NILFS (loop1): invalid segment: Checksum error in segment payload
NILFS (loop3): invalid segment: Checksum error in segment payload
NILFS (loop4): invalid segment: Checksum error in segment payload
NILFS (loop1): trying rollback from an earlier position
NILFS (loop3): trying rollback from an earlier position
NILFS (loop4): trying rollback from an earlier position
NILFS (loop1): recovery complete
NILFS (loop3): recovery complete
NILFS (loop3): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
NILFS (loop1): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
NILFS (loop4): recovery complete
NILFS (loop4): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
ntfs: volume version 3.1.
NILFS (loop3): invalid segment: Checksum error in segment payload
NILFS (loop1): invalid segment: Checksum error in segment payload
NILFS (loop3): trying rollback from an earlier position
NILFS (loop1): trying rollback from an earlier position
NILFS (loop3): recovery complete
NILFS (loop1): recovery complete
NILFS (loop4): invalid segment: Checksum error in segment payload
NILFS (loop3): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
NILFS (loop4): trying rollback from an earlier position
NILFS (loop1): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
NILFS (loop4): recovery complete
NILFS (loop4): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
ntfs: volume version 3.1.
ntfs: volume version 3.1.
NILFS (loop3): invalid segment: Checksum error in segment payload
NILFS (loop1): invalid segment: Checksum error in segment payload
NILFS (loop3): trying rollback from an earlier position