[syzbot] [ntfs?] possible deadlock in ntfs_sync_mft_mirror

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 17214b70a159 Merge tag 'fsverity-for-linus' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13d86d31c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=cde06fe2cf5765b7
dashboard link: https://syzkaller.appspot.com/bug?extid=c9340661f4a0bb3e7e65
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c93406...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.3.0-rc3-syzkaller-00012-g17214b70a159 #0 Not tainted
------------------------------------------------------
kworker/u8:1/10 is trying to acquire lock:
ffff8880722f1840 (&rl->lock){++++}-{3:3}, at: ntfs_sync_mft_mirror+0x18bf/0x1ea0 fs/ntfs/mft.c:536

but task is already holding lock:
ffff8880723aa290 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x40/0x6c0 fs/ntfs/mft.c:154

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ni->mrec_lock){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747
map_mft_record+0x40/0x6c0 fs/ntfs/mft.c:154
ntfs_truncate+0x243/0x2a50 fs/ntfs/inode.c:2383
ntfs_truncate_vfs fs/ntfs/inode.c:2862 [inline]
ntfs_setattr+0x397/0x560 fs/ntfs/inode.c:2914
notify_change+0xb2c/0x1180 fs/attr.c:482
do_truncate+0x143/0x200 fs/open.c:66
handle_truncate fs/namei.c:3219 [inline]
do_open fs/namei.c:3564 [inline]
path_openat+0x2083/0x2750 fs/namei.c:3715
do_filp_open+0x1ba/0x410 fs/namei.c:3742
do_sys_openat2+0x16d/0x4c0 fs/open.c:1348
do_sys_open fs/open.c:1364 [inline]
__do_sys_creat fs/open.c:1440 [inline]
__se_sys_creat fs/open.c:1434 [inline]
__x64_sys_creat+0xcd/0x120 fs/open.c:1434
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&rl->lock){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain kernel/locking/lockdep.c:3832 [inline]
__lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056
lock_acquire kernel/locking/lockdep.c:5669 [inline]
lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634
down_read+0x3d/0x50 kernel/locking/rwsem.c:1520
ntfs_sync_mft_mirror+0x18bf/0x1ea0 fs/ntfs/mft.c:536
write_mft_record_nolock+0x198e/0x1cc0 fs/ntfs/mft.c:787
write_mft_record+0x14e/0x3b0 fs/ntfs/mft.h:95
__ntfs_write_inode+0x915/0xc40 fs/ntfs/inode.c:3050
write_inode fs/fs-writeback.c:1453 [inline]
__writeback_single_inode+0x9f8/0xdc0 fs/fs-writeback.c:1665
writeback_sb_inodes+0x54d/0xe70 fs/fs-writeback.c:1891
wb_writeback+0x294/0xa50 fs/fs-writeback.c:2065
wb_do_writeback fs/fs-writeback.c:2208 [inline]
wb_workfn+0x2a5/0xfc0 fs/fs-writeback.c:2248
process_one_work+0x991/0x15c0 kernel/workqueue.c:2390
worker_thread+0x669/0x1090 kernel/workqueue.c:2537
kthread+0x2e8/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&ni->mrec_lock);
lock(&rl->lock);
lock(&ni->mrec_lock);
lock(&rl->lock);

*** DEADLOCK ***

3 locks held by kworker/u8:1/10:
#0: ffff888015421938 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: ffff888015421938 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
#0: ffff888015421938 ((wq_completion)writeback){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
#0: ffff888015421938 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:639 [inline]
#0: ffff888015421938 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:666 [inline]
#0: ffff888015421938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x87a/0x15c0 kernel/workqueue.c:2361
#1: ffffc900004cfda8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x15c0 kernel/workqueue.c:2365
#2: ffff8880723aa290 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x40/0x6c0 fs/ntfs/mft.c:154

stack backtrace:
CPU: 0 PID: 10 Comm: kworker/u8:1 Not tainted 6.3.0-rc3-syzkaller-00012-g17214b70a159 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Workqueue: writeback wb_workfn (flush-7:2)
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106
check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2178
check_prev_add kernel/locking/lockdep.c:3098 [inline]
check_prevs_add kernel/locking/lockdep.c:3217 [inline]
validate_chain kernel/locking/lockdep.c:3832 [inline]
__lock_acquire+0x2ec7/0x5d40 kernel/locking/lockdep.c:5056
lock_acquire kernel/locking/lockdep.c:5669 [inline]
lock_acquire+0x1af/0x520 kernel/locking/lockdep.c:5634
down_read+0x3d/0x50 kernel/locking/rwsem.c:1520
ntfs_sync_mft_mirror+0x18bf/0x1ea0 fs/ntfs/mft.c:536
write_mft_record_nolock+0x198e/0x1cc0 fs/ntfs/mft.c:787
write_mft_record+0x14e/0x3b0 fs/ntfs/mft.h:95
__ntfs_write_inode+0x915/0xc40 fs/ntfs/inode.c:3050
write_inode fs/fs-writeback.c:1453 [inline]
__writeback_single_inode+0x9f8/0xdc0 fs/fs-writeback.c:1665
writeback_sb_inodes+0x54d/0xe70 fs/fs-writeback.c:1891
wb_writeback+0x294/0xa50 fs/fs-writeback.c:2065
wb_do_writeback fs/fs-writeback.c:2208 [inline]
wb_workfn+0x2a5/0xfc0 fs/fs-writeback.c:2248
process_one_work+0x991/0x15c0 kernel/workqueue.c:2390
worker_thread+0x669/0x1090 kernel/workqueue.c:2537
kthread+0x2e8/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>


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