====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u4:8/1088 is trying to acquire lock: ffff88805cef0100 (&rl->lock){++++}-{3:3}, at: ntfs_read_block fs/ntfs/aops.c:248 [inline] ffff88805cef0100 (&rl->lock){++++}-{3:3}, at: ntfs_read_folio+0x144d/0x2980 fs/ntfs/aops.c:436 but task is already holding lock: ffff88805cef2ad0 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x50/0x650 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+0x129/0xcc0 kernel/locking/mutex.c:747 map_mft_record+0x50/0x650 fs/ntfs/mft.c:154 ntfs_attr_extend_allocation+0x549/0x44a0 fs/ntfs/attrib.c:2002 ntfs_prepare_file_for_write fs/ntfs/file.c:391 [inline] ntfs_file_write_iter+0x33f/0x19c0 fs/ntfs/file.c:1914 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x79a/0xc70 fs/read_write.c:860 vfs_writev fs/read_write.c:933 [inline] do_pwritev+0x205/0x340 fs/read_write.c:1030 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520 ntfs_read_block fs/ntfs/aops.c:248 [inline] ntfs_read_folio+0x144d/0x2980 fs/ntfs/aops.c:436 filemap_read_folio+0x167/0x760 mm/filemap.c:2420 do_read_cache_folio+0x470/0x7e0 mm/filemap.c:3789 do_read_cache_page+0x32/0x250 mm/filemap.c:3855 read_mapping_page include/linux/pagemap.h:892 [inline] ntfs_map_page fs/ntfs/aops.h:75 [inline] ntfs_sync_mft_mirror+0x236/0x1aa0 fs/ntfs/mft.c:480 write_mft_record_nolock+0x116f/0x18c0 fs/ntfs/mft.c:787 write_mft_record+0x136/0x300 fs/ntfs/mft.h:95 __ntfs_write_inode+0x731/0xc00 fs/ntfs/inode.c:3051 write_inode fs/fs-writeback.c:1473 [inline] __writeback_single_inode+0x705/0xee0 fs/fs-writeback.c:1690 writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1916 wb_writeback+0x450/0xba0 fs/fs-writeback.c:2095 wb_do_writeback fs/fs-writeback.c:2242 [inline] wb_workfn+0x3ff/0xe20 fs/fs-writeback.c:2282 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 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/u4:8/1088: #0: ffff88801a27a138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88801a27a138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900045dfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900045dfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff88805cef2ad0 (&ni->mrec_lock){+.+.}-{3:3}, at: map_mft_record+0x50/0x650 fs/ntfs/mft.c:154 stack backtrace: CPU: 0 PID: 1088 Comm: kworker/u4:8 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 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+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1520 ntfs_read_block fs/ntfs/aops.c:248 [inline] ntfs_read_folio+0x144d/0x2980 fs/ntfs/aops.c:436 filemap_read_folio+0x167/0x760 mm/filemap.c:2420 do_read_cache_folio+0x470/0x7e0 mm/filemap.c:3789 do_read_cache_page+0x32/0x250 mm/filemap.c:3855 read_mapping_page include/linux/pagemap.h:892 [inline] ntfs_map_page fs/ntfs/aops.h:75 [inline] ntfs_sync_mft_mirror+0x236/0x1aa0 fs/ntfs/mft.c:480 write_mft_record_nolock+0x116f/0x18c0 fs/ntfs/mft.c:787 write_mft_record+0x136/0x300 fs/ntfs/mft.h:95 __ntfs_write_inode+0x731/0xc00 fs/ntfs/inode.c:3051 write_inode fs/fs-writeback.c:1473 [inline] __writeback_single_inode+0x705/0xee0 fs/fs-writeback.c:1690 writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1916 wb_writeback+0x450/0xba0 fs/fs-writeback.c:2095 wb_do_writeback fs/fs-writeback.c:2242 [inline] wb_workfn+0x3ff/0xe20 fs/fs-writeback.c:2282 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293