syzbot

======================================================
WARNING: possible circular locking dependency detected
6.7.0-rc3-syzkaller-00048-ge8f60209d6cf #0 Not tainted
------------------------------------------------------
kworker/u4:5/1136 is trying to acquire lock:
ffff888079dc8940 (&rl->lock){++++}-{3:3}, at: ntfs_read_block fs/ntfs/aops.c:242 [inline]
ffff888079dc8940 (&rl->lock){++++}-{3:3}, at: ntfs_read_folio+0x1308/0x23e0 fs/ntfs/aops.c:430

but task is already holding lock:
ffff888079dd4bd0 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x4c/0x630 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}:
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x136/0xd60 kernel/locking/mutex.c:747
       map_mft_record+0x4c/0x630 fs/ntfs/mft.c:154
       ntfs_attr_extend_allocation+0x2d0/0x3ec0 fs/ntfs/attrib.c:2002
       ntfs_prepare_file_for_write fs/ntfs/file.c:391 [inline]
       ntfs_file_write_iter+0x37e/0x1970 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+0x792/0xb20 fs/read_write.c:584
       ksys_write+0x1a0/0x2c0 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x45/0x110 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+0x1909/0x5ab0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526
       ntfs_read_block fs/ntfs/aops.c:242 [inline]
       ntfs_read_folio+0x1308/0x23e0 fs/ntfs/aops.c:430
       filemap_read_folio+0x19c/0x780 mm/filemap.c:2323
       do_read_cache_folio+0x134/0x810 mm/filemap.c:3691
       do_read_cache_page+0x30/0x200 mm/filemap.c:3757
       read_mapping_page include/linux/pagemap.h:871 [inline]
       ntfs_map_page fs/ntfs/aops.h:75 [inline]
       ntfs_sync_mft_mirror+0x25f/0x1ae0 fs/ntfs/mft.c:480
       write_mft_record_nolock+0x1155/0x18f0 fs/ntfs/mft.c:787
       write_mft_record+0x149/0x310 fs/ntfs/mft.h:95
       __ntfs_write_inode+0x703/0xbb0 fs/ntfs/inode.c:3052
       write_inode fs/fs-writeback.c:1473 [inline]
       __writeback_single_inode+0x69b/0xfc0 fs/fs-writeback.c:1690
       writeback_sb_inodes+0x8e3/0x1220 fs/fs-writeback.c:1916
       __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1987
       wb_writeback+0x461/0xc70 fs/fs-writeback.c:2094
       wb_check_background_flush fs/fs-writeback.c:2164 [inline]
       wb_do_writeback fs/fs-writeback.c:2252 [inline]
       wb_workfn+0xc33/0xfb0 fs/fs-writeback.c:2279
       process_one_work kernel/workqueue.c:2630 [inline]
       process_scheduled_works+0x90f/0x1420 kernel/workqueue.c:2703
       worker_thread+0xa5f/0x1000 kernel/workqueue.c:2784
       kthread+0x2d3/0x370 kernel/kthread.c:388
       ret_from_fork+0x48/0x80 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 ***

4 locks held by kworker/u4:5/1136:
 #0: ffff888141a5d538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
 #0: ffff888141a5d538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2703
 #1: ffffc9000529fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2605 [inline]
 #1: ffffc9000529fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x825/0x1420 kernel/workqueue.c:2703
 #2: ffff8880742700e0 (&type->s_umount_key#66){++++}-{3:3}, at: super_trylock_shared+0x22/0xf0 fs/super.c:610
 #3: ffff888079dd4bd0 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x4c/0x630 fs/ntfs/mft.c:154

stack backtrace:
CPU: 0 PID: 1136 Comm: kworker/u4:5 Not tainted 6.7.0-rc3-syzkaller-00048-ge8f60209d6cf #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Workqueue: writeback wb_workfn (flush-7:5)
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x366/0x490 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+0x1909/0x5ab0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1345/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1e3/0x530 kernel/locking/lockdep.c:5754
 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1526
 ntfs_read_block fs/ntfs/aops.c:242 [inline]
 ntfs_read_folio+0x1308/0x23e0 fs/ntfs/aops.c:430
 filemap_read_folio+0x19c/0x780 mm/filemap.c:2323
 do_read_cache_folio+0x134/0x810 mm/filemap.c:3691
 do_read_cache_page+0x30/0x200 mm/filemap.c:3757
 read_mapping_page include/linux/pagemap.h:871 [inline]
 ntfs_map_page fs/ntfs/aops.h:75 [inline]
 ntfs_sync_mft_mirror+0x25f/0x1ae0 fs/ntfs/mft.c:480
 write_mft_record_nolock+0x1155/0x18f0 fs/ntfs/mft.c:787
 write_mft_record+0x149/0x310 fs/ntfs/mft.h:95
 __ntfs_write_inode+0x703/0xbb0 fs/ntfs/inode.c:3052
 write_inode fs/fs-writeback.c:1473 [inline]
 __writeback_single_inode+0x69b/0xfc0 fs/fs-writeback.c:1690
 writeback_sb_inodes+0x8e3/0x1220 fs/fs-writeback.c:1916
 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:1987
 wb_writeback+0x461/0xc70 fs/fs-writeback.c:2094
 wb_check_background_flush fs/fs-writeback.c:2164 [inline]
 wb_do_writeback fs/fs-writeback.c:2252 [inline]
 wb_workfn+0xc33/0xfb0 fs/fs-writeback.c:2279
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x90f/0x1420 kernel/workqueue.c:2703
 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2784
 kthread+0x2d3/0x370 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>