syzbot

======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc2-syzkaller-00265-gd2da77f431ac #0 Not tainted
------------------------------------------------------
kworker/u4:1/5109 is trying to acquire lock:
ffff8880761c6400 (&rl->lock){++++}-{3:3}, at: ntfs_read_block fs/ntfs/aops.c:242 [inline]
ffff8880761c6400 (&rl->lock){++++}-{3:3}, at: ntfs_read_folio+0x1a98/0x2430 fs/ntfs/aops.c:430

but task is already holding lock:
ffff8880646d89d0 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x4a/0x730 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+0x175/0x9d0 kernel/locking/mutex.c:747
       map_mft_record+0x4a/0x730 fs/ntfs/mft.c:154
       ntfs_attr_extend_allocation+0x268/0x3840 fs/ntfs/attrib.c:2002
       ntfs_prepare_file_for_write fs/ntfs/file.c:391 [inline]
       ntfs_file_write_iter+0xaa0/0x2070 fs/ntfs/file.c:1907
       call_write_iter include/linux/fs.h:2020 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x64f/0xdf0 fs/read_write.c:584
       ksys_write+0x12f/0x250 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82
       entry_SYSCALL_64_after_hwframe+0x63/0x6b

-> #0 (&rl->lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2433/0x3b20 kernel/locking/lockdep.c:5137
       lock_acquire kernel/locking/lockdep.c:5754 [inline]
       lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719
       down_read+0x9a/0x330 kernel/locking/rwsem.c:1526
       ntfs_read_block fs/ntfs/aops.c:242 [inline]
       ntfs_read_folio+0x1a98/0x2430 fs/ntfs/aops.c:430
       filemap_read_folio+0xe9/0x2c0 mm/filemap.c:2323
       do_read_cache_folio+0x205/0x540 mm/filemap.c:3691
       do_read_cache_page mm/filemap.c:3757 [inline]
       read_cache_page+0x5b/0x160 mm/filemap.c:3766
       read_mapping_page include/linux/pagemap.h:871 [inline]
       ntfs_map_page fs/ntfs/aops.h:75 [inline]
       ntfs_sync_mft_mirror+0x242/0x1ed0 fs/ntfs/mft.c:480
       write_mft_record_nolock+0x1977/0x1da0 fs/ntfs/mft.c:787
       write_mft_record+0x14b/0x380 fs/ntfs/mft.h:95
       __ntfs_write_inode+0x91b/0xc30 fs/ntfs/inode.c:3052
       write_inode fs/fs-writeback.c:1473 [inline]
       __writeback_single_inode+0xa91/0xe90 fs/fs-writeback.c:1690
       writeback_sb_inodes+0x599/0x1080 fs/fs-writeback.c:1916
       wb_writeback+0x2a5/0xaa0 fs/fs-writeback.c:2092
       wb_do_writeback fs/fs-writeback.c:2239 [inline]
       wb_workfn+0x29c/0xfe0 fs/fs-writeback.c:2279
       process_one_work+0x886/0x15d0 kernel/workqueue.c:2630
       process_scheduled_works kernel/workqueue.c:2703 [inline]
       worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784
       kthread+0x2c6/0x3a0 kernel/kthread.c:388
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242

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);
  rlock(&rl->lock);

 *** DEADLOCK ***

3 locks held by kworker/u4:1/5109:
 #0: ffff888140054138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x789/0x15d0 kernel/workqueue.c:2605
 #1: ffffc90004477d80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7eb/0x15d0 kernel/workqueue.c:2606
 #2: ffff8880646d89d0 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x4a/0x730 fs/ntfs/mft.c:154

stack backtrace:
CPU: 1 PID: 5109 Comm: kworker/u4:1 Not tainted 6.7.0-rc2-syzkaller-00265-gd2da77f431ac #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 check_noncircular+0x317/0x400 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2433/0x3b20 kernel/locking/lockdep.c:5137
 lock_acquire kernel/locking/lockdep.c:5754 [inline]
 lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719
 down_read+0x9a/0x330 kernel/locking/rwsem.c:1526
 ntfs_read_block fs/ntfs/aops.c:242 [inline]
 ntfs_read_folio+0x1a98/0x2430 fs/ntfs/aops.c:430
 filemap_read_folio+0xe9/0x2c0 mm/filemap.c:2323
 do_read_cache_folio+0x205/0x540 mm/filemap.c:3691
 do_read_cache_page mm/filemap.c:3757 [inline]
 read_cache_page+0x5b/0x160 mm/filemap.c:3766
 read_mapping_page include/linux/pagemap.h:871 [inline]
 ntfs_map_page fs/ntfs/aops.h:75 [inline]
 ntfs_sync_mft_mirror+0x242/0x1ed0 fs/ntfs/mft.c:480
 write_mft_record_nolock+0x1977/0x1da0 fs/ntfs/mft.c:787
 write_mft_record+0x14b/0x380 fs/ntfs/mft.h:95
 __ntfs_write_inode+0x91b/0xc30 fs/ntfs/inode.c:3052
 write_inode fs/fs-writeback.c:1473 [inline]
 __writeback_single_inode+0xa91/0xe90 fs/fs-writeback.c:1690
 writeback_sb_inodes+0x599/0x1080 fs/fs-writeback.c:1916
 wb_writeback+0x2a5/0xaa0 fs/fs-writeback.c:2092
 wb_do_writeback fs/fs-writeback.c:2239 [inline]
 wb_workfn+0x29c/0xfe0 fs/fs-writeback.c:2279
 process_one_work+0x886/0x15d0 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784
 kthread+0x2c6/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>