syzbot

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kswapd0/254 is trying to acquire lock:
ffff88805495c300 (&rl->lock){++++}-{3:3}, at: __ntfs_clear_inode+0x32/0x1e0 fs/ntfs/inode.c:2189

but task is already holding lock:
ffffffff8c3de9c0 (fs_reclaim){+.+.}-{0:0}, at: 0x1

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (fs_reclaim){+.+.}-{0:0}:
       __fs_reclaim_acquire mm/page_alloc.c:4580 [inline]
       fs_reclaim_acquire+0x6d/0x100 mm/page_alloc.c:4594
       prepare_alloc_pages+0x15a/0x5f0 mm/page_alloc.c:5272
       __alloc_pages+0x11b/0x480 mm/page_alloc.c:5490
       __page_cache_alloc+0xce/0x440 mm/filemap.c:1022
       do_read_cache_page+0x1da/0x1030 mm/filemap.c:3457
       read_mapping_page include/linux/pagemap.h:515 [inline]
       ntfs_map_page+0x24/0x390 fs/ntfs/aops.h:75
       map_mft_record_page fs/ntfs/mft.c:73 [inline]
       map_mft_record+0x1c9/0x620 fs/ntfs/mft.c:156
       ntfs_read_locked_inode+0x1ae/0x4de0 fs/ntfs/inode.c:550
       ntfs_iget+0x108/0x1a0 fs/ntfs/inode.c:177
       ntfs_lookup+0x24f/0xc40 fs/ntfs/namei.c:117
       __lookup_slow+0x29d/0x410 fs/namei.c:1671
       lookup_slow+0x53/0x70 fs/namei.c:1688
       walk_component+0x319/0x460 fs/namei.c:1984
       link_path_walk+0x665/0xd70 fs/namei.c:-1
       path_openat+0x28d/0x2fa0 fs/namei.c:3746
       do_filp_open+0x1e2/0x410 fs/namei.c:3777
       do_sys_openat2+0x150/0x4b0 fs/open.c:1255
       do_sys_open fs/open.c:1271 [inline]
       __do_sys_openat fs/open.c:1287 [inline]
       __se_sys_openat fs/open.c:1282 [inline]
       __x64_sys_openat+0x135/0x160 fs/open.c:1282
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (&ni->mrec_lock){+.+.}-{3:3}:
       __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       map_mft_record+0x4e/0x620 fs/ntfs/mft.c:154
       ntfs_truncate+0x280/0x27c0 fs/ntfs/inode.c:2383
       ntfs_truncate_vfs fs/ntfs/inode.c:2862 [inline]
       ntfs_setattr+0x2bc/0x3a0 fs/ntfs/inode.c:2914
       notify_change+0xbcd/0xee0 fs/attr.c:505
       do_truncate+0x1ac/0x240 fs/open.c:65
       vfs_truncate+0x262/0x2f0 fs/open.c:111
       do_sys_truncate+0xf2/0x1c0 fs/open.c:134
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&rl->lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
       lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       __ntfs_clear_inode+0x32/0x1e0 fs/ntfs/inode.c:2189
       ntfs_evict_big_inode+0x2c4/0x4a0 fs/ntfs/inode.c:2278
       evict+0x4c9/0x8d0 fs/inode.c:647
       dispose_list fs/inode.c:680 [inline]
       prune_icache_sb+0x220/0x2d0 fs/inode.c:879
       super_cache_scan+0x343/0x440 fs/super.c:107
       do_shrink_slab+0x510/0xd00 mm/vmscan.c:765
       shrink_slab_memcg mm/vmscan.c:834 [inline]
       shrink_slab+0x450/0x7a0 mm/vmscan.c:913
       shrink_node_memcgs mm/vmscan.c:2958 [inline]
       shrink_node+0x110c/0x2610 mm/vmscan.c:3079
       kswapd_shrink_node mm/vmscan.c:3821 [inline]
       balance_pgdat+0xe92/0x1a10 mm/vmscan.c:4012
       kswapd+0x7dd/0xdd0 mm/vmscan.c:4271
       kthread+0x436/0x520 kernel/kthread.c:334
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

other info that might help us debug this:

Chain exists of:
  &rl->lock --> &ni->mrec_lock --> fs_reclaim

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

3 locks held by kswapd0/254:
 #0: ffffffff8c3de9c0 (fs_reclaim){+.+.}-{0:0}, at: 0x1
 #1: ffffffff8c3bbfd0 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab_memcg mm/vmscan.c:807 [inline]
 #1: ffffffff8c3bbfd0 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x22f/0x7a0 mm/vmscan.c:913
 #2: ffff8880240820e0 (&type->s_umount_key#53){++++}-{3:3}, at: trylock_super fs/super.c:418 [inline]
 #2: ffff8880240820e0 (&type->s_umount_key#53){++++}-{3:3}, at: super_cache_scan+0x70/0x440 fs/super.c:80

stack backtrace:
CPU: 1 PID: 254 Comm: kswapd0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 down_write+0x38/0x60 kernel/locking/rwsem.c:1551
 __ntfs_clear_inode+0x32/0x1e0 fs/ntfs/inode.c:2189
 ntfs_evict_big_inode+0x2c4/0x4a0 fs/ntfs/inode.c:2278
 evict+0x4c9/0x8d0 fs/inode.c:647
 dispose_list fs/inode.c:680 [inline]
 prune_icache_sb+0x220/0x2d0 fs/inode.c:879
 super_cache_scan+0x343/0x440 fs/super.c:107
 do_shrink_slab+0x510/0xd00 mm/vmscan.c:765
 shrink_slab_memcg mm/vmscan.c:834 [inline]
 shrink_slab+0x450/0x7a0 mm/vmscan.c:913
 shrink_node_memcgs mm/vmscan.c:2958 [inline]
 shrink_node+0x110c/0x2610 mm/vmscan.c:3079
 kswapd_shrink_node mm/vmscan.c:3821 [inline]
 balance_pgdat+0xe92/0x1a10 mm/vmscan.c:4012
 kswapd+0x7dd/0xdd0 mm/vmscan.c:4271
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>