possible deadlock in xfs_ilock (3)

Status: auto-obsoleted due to no activity on 2025/04/07 15:47
Subsystems: xfs
[Documentation on labels]
Reported-by: syzbot+b143b25b374fbc5c3a04@syzkaller.appspotmail.com
First crash: 630d, last: 586d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [xfs?] possible deadlock in xfs_ilock (3) 0 (1) 2024/11/18 06:10
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in xfs_ilock (2) xfs 4 1422 771d 843d 0/29 auto-obsoleted due to no activity on 2024/09/04 06:27
upstream possible deadlock in xfs_ilock xfs 4 30 848d 875d 25/29 fixed on 2024/04/10 03:59
upstream possible deadlock in xfs_ilock (4) xfs 4 1 217d 213d 0/29 auto-obsoleted due to no activity on 2026/04/11 02:34

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.13.0-rc4-syzkaller-00071-gfd0584d220fe #0 Not tainted
------------------------------------------------------
kworker/u8:4/61 is trying to acquire lock:
ffff8880589a65d8 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_ilock+0x198/0x210 fs/xfs/xfs_inode.c:165

but task is already holding lock:
ffff88807ad92610 (sb_internal#4){.+.+}-{0:0}, at: xfs_dquot_disk_alloc+0x22b/0xbe0 fs/xfs/xfs_dquot.c:357

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #6 (sb_internal#4){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1725 [inline]
       sb_start_intwrite include/linux/fs.h:1908 [inline]
       xfs_trans_alloc+0x4fa/0x940 fs/xfs/xfs_trans.c:266
       xfs_vn_update_time+0x1e9/0x5e0 fs/xfs/xfs_iops.c:1103
       inode_update_time fs/inode.c:2124 [inline]
       touch_atime+0x352/0x5d0 fs/inode.c:2197
       file_accessed include/linux/fs.h:2539 [inline]
       xfs_file_mmap+0x4ad/0x630 fs/xfs/xfs_file.c:1589
       call_mmap include/linux/fs.h:2183 [inline]
       mmap_file mm/internal.h:124 [inline]
       __mmap_new_file_vma mm/vma.c:2291 [inline]
       __mmap_new_vma mm/vma.c:2355 [inline]
       __mmap_region+0x1826/0x2760 mm/vma.c:2456
       mmap_region+0x270/0x320 mm/mmap.c:1348
       do_mmap+0xc00/0xfc0 mm/mmap.c:496
       vm_mmap_pgoff+0x1ba/0x360 mm/util.c:580
       ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:542
       __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
       __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
       __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #5 (&mm->mmap_lock){++++}-{4:4}:
       __might_fault mm/memory.c:6751 [inline]
       __might_fault+0x11b/0x190 mm/memory.c:6744
       _inline_copy_from_user include/linux/uaccess.h:162 [inline]
       _copy_from_user+0x29/0xd0 lib/usercopy.c:18
       copy_from_user include/linux/uaccess.h:212 [inline]
       __blk_trace_setup+0xa8/0x180 kernel/trace/blktrace.c:626
       blk_trace_setup+0x47/0x70 kernel/trace/blktrace.c:648
       sg_ioctl_common drivers/scsi/sg.c:1114 [inline]
       sg_ioctl+0x65e/0x2750 drivers/scsi/sg.c:1156
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:906 [inline]
       __se_sys_ioctl fs/ioctl.c:892 [inline]
       __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:892
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #4 (&q->debugfs_mutex){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735
       blk_mq_init_sched+0x42b/0x640 block/blk-mq-sched.c:473
       elevator_init_mq+0x2cd/0x420 block/elevator.c:610
       add_disk_fwnode+0x113/0x1300 block/genhd.c:413
       sd_probe+0xa86/0x1000 drivers/scsi/sd.c:4024
       call_driver_probe drivers/base/dd.c:579 [inline]
       really_probe+0x241/0xa90 drivers/base/dd.c:658
       __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
       driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
       __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
       bus_for_each_drv+0x15a/0x1e0 drivers/base/bus.c:459
       __device_attach_async_helper+0x1d3/0x290 drivers/base/dd.c:987
       async_run_entry_fn+0x9f/0x530 kernel/async.c:129
       process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229
       process_scheduled_works kernel/workqueue.c:3310 [inline]
       worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
       kthread+0x2c4/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #3 (&q->q_usage_counter(queue)#50){++++}-{0:0}:
       blk_queue_enter+0x50f/0x640 block/blk-core.c:328
       blk_mq_alloc_request+0x59b/0x950 block/blk-mq.c:652
       scsi_alloc_request drivers/scsi/scsi_lib.c:1222 [inline]
       scsi_execute_cmd+0x1eb/0xf40 drivers/scsi/scsi_lib.c:304
       read_capacity_16+0x213/0xe10 drivers/scsi/sd.c:2655
       sd_read_capacity drivers/scsi/sd.c:2824 [inline]
       sd_revalidate_disk.isra.0+0x1a06/0xa8d0 drivers/scsi/sd.c:3734
       sd_probe+0x904/0x1000 drivers/scsi/sd.c:4010
       call_driver_probe drivers/base/dd.c:579 [inline]
       really_probe+0x241/0xa90 drivers/base/dd.c:658
       __driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
       driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
       __device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
       bus_for_each_drv+0x15a/0x1e0 drivers/base/bus.c:459
       __device_attach_async_helper+0x1d3/0x290 drivers/base/dd.c:987
       async_run_entry_fn+0x9f/0x530 kernel/async.c:129
       process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229
       process_scheduled_works kernel/workqueue.c:3310 [inline]
       worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
       kthread+0x2c4/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #2 (&q->limits_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735
       queue_limits_start_update include/linux/blkdev.h:947 [inline]
       loop_reconfigure_limits+0x407/0x8c0 drivers/block/loop.c:998
       loop_set_block_size drivers/block/loop.c:1473 [inline]
       lo_simple_ioctl drivers/block/loop.c:1496 [inline]
       lo_ioctl+0x901/0x18b0 drivers/block/loop.c:1559
       blkdev_ioctl+0x279/0x6d0 block/ioctl.c:693
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:906 [inline]
       __se_sys_ioctl fs/ioctl.c:892 [inline]
       __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:892
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&q->q_usage_counter(io)#17){++++}-{0:0}:
       bio_queue_enter block/blk.h:75 [inline]
       blk_mq_submit_bio+0x1fb6/0x24c0 block/blk-mq.c:3090
       __submit_bio+0x384/0x540 block/blk-core.c:629
       __submit_bio_noacct_mq block/blk-core.c:710 [inline]
       submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:739
       submit_bio_noacct+0x93a/0x1e20 block/blk-core.c:868
       xfs_buf_ioapply_map fs/xfs/xfs_buf.c:1586 [inline]
       _xfs_buf_ioapply+0x9f6/0xd70 fs/xfs/xfs_buf.c:1674
       __xfs_buf_submit+0x28b/0x820 fs/xfs/xfs_buf.c:1758
       xfs_buf_submit fs/xfs/xfs_buf.c:61 [inline]
       _xfs_buf_read fs/xfs/xfs_buf.c:809 [inline]
       xfs_buf_read_map+0x3fa/0xb70 fs/xfs/xfs_buf.c:873
       xfs_trans_read_buf_map+0x352/0x9a0 fs/xfs/xfs_trans_buf.c:304
       xfs_trans_read_buf fs/xfs/xfs_trans.h:213 [inline]
       xfs_read_agf+0x292/0x560 fs/xfs/libxfs/xfs_alloc.c:3378
       xfs_alloc_read_agf+0x12a/0xb10 fs/xfs/libxfs/xfs_alloc.c:3413
       xfs_alloc_fix_freelist+0x947/0x1050 fs/xfs/libxfs/xfs_alloc.c:2877
       xfs_alloc_vextent_prepare_ag+0x7a/0x6e0 fs/xfs/libxfs/xfs_alloc.c:3543
       xfs_alloc_vextent_iterate_ags.constprop.0+0x1b8/0xa00 fs/xfs/libxfs/xfs_alloc.c:3727
       xfs_alloc_vextent_start_ag+0x335/0x820 fs/xfs/libxfs/xfs_alloc.c:3816
       xfs_bmap_btalloc_best_length fs/xfs/libxfs/xfs_bmap.c:3766 [inline]
       xfs_bmap_btalloc+0x1076/0x17d0 fs/xfs/libxfs/xfs_bmap.c:3811
       xfs_bmapi_allocate+0x232/0xe70 fs/xfs/libxfs/xfs_bmap.c:4224
       xfs_bmapi_write+0x5bc/0xcf0 fs/xfs/libxfs/xfs_bmap.c:4553
       xfs_dquot_disk_alloc+0x67c/0xbe0 fs/xfs/xfs_dquot.c:380
       xfs_qm_dqread+0x532/0x5c0 fs/xfs/xfs_dquot.c:719
       xfs_qm_dqget+0x151/0x4a0 fs/xfs/xfs_dquot.c:931
       xfs_qm_quotacheck_dqadjust+0xb3/0x570 fs/xfs/xfs_qm.c:1331
       xfs_qm_dqusage_adjust+0x5cb/0x6f0 fs/xfs/xfs_qm.c:1464
       xfs_iwalk_ag_recs+0x53f/0x870 fs/xfs/xfs_iwalk.c:209
       xfs_iwalk_run_callbacks+0x1f3/0x540 fs/xfs/xfs_iwalk.c:370
       xfs_iwalk_ag+0x81d/0xa30 fs/xfs/xfs_iwalk.c:476
       xfs_iwalk_ag_work+0x144/0x1c0 fs/xfs/xfs_iwalk.c:625
       xfs_pwork_work+0x82/0x160 fs/xfs/xfs_pwork.c:47
       process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229
       process_scheduled_works kernel/workqueue.c:3310 [inline]
       worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
       kthread+0x2c4/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 (&xfs_nondir_ilock_class){++++}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain kernel/locking/lockdep.c:3904 [inline]
       __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
       lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
       down_write_nested+0x97/0x210 kernel/locking/rwsem.c:1693
       xfs_ilock+0x198/0x210 fs/xfs/xfs_inode.c:165
       xfs_dquot_disk_alloc+0x3ad/0xbe0 fs/xfs/xfs_dquot.c:362
       xfs_qm_dqread+0x532/0x5c0 fs/xfs/xfs_dquot.c:719
       xfs_qm_dqget+0x151/0x4a0 fs/xfs/xfs_dquot.c:931
       xfs_qm_quotacheck_dqadjust+0xb3/0x570 fs/xfs/xfs_qm.c:1331
       xfs_qm_dqusage_adjust+0x5cb/0x6f0 fs/xfs/xfs_qm.c:1464
       xfs_iwalk_ag_recs+0x53f/0x870 fs/xfs/xfs_iwalk.c:209
       xfs_iwalk_run_callbacks+0x1f3/0x540 fs/xfs/xfs_iwalk.c:370
       xfs_iwalk_ag+0x81d/0xa30 fs/xfs/xfs_iwalk.c:476
       xfs_iwalk_ag_work+0x144/0x1c0 fs/xfs/xfs_iwalk.c:625
       xfs_pwork_work+0x82/0x160 fs/xfs/xfs_pwork.c:47
       process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229
       process_scheduled_works kernel/workqueue.c:3310 [inline]
       worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
       kthread+0x2c4/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

Chain exists of:
  &xfs_nondir_ilock_class --> &mm->mmap_lock --> sb_internal#4

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(sb_internal#4);
                               lock(&mm->mmap_lock);
                               lock(sb_internal#4);
  lock(&xfs_nondir_ilock_class);

 *** DEADLOCK ***

3 locks held by kworker/u8:4/61:
 #0: ffff88807c126148 ((wq_completion)xfs_iwalk-14201){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204
 #1: ffffc9000212fd80 ((work_completion)(&pwork->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205
 #2: ffff88807ad92610 (sb_internal#4){.+.+}-{0:0}, at: xfs_dquot_disk_alloc+0x22b/0xbe0 fs/xfs/xfs_dquot.c:357

stack backtrace:
CPU: 0 UID: 0 PID: 61 Comm: kworker/u8:4 Not tainted 6.13.0-rc4-syzkaller-00071-gfd0584d220fe #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: xfs_iwalk-14201 xfs_pwork_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x419/0x5d0 kernel/locking/lockdep.c:2074
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain kernel/locking/lockdep.c:3904 [inline]
 __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
 down_write_nested+0x97/0x210 kernel/locking/rwsem.c:1693
 xfs_ilock+0x198/0x210 fs/xfs/xfs_inode.c:165
 xfs_dquot_disk_alloc+0x3ad/0xbe0 fs/xfs/xfs_dquot.c:362
 xfs_qm_dqread+0x532/0x5c0 fs/xfs/xfs_dquot.c:719
 xfs_qm_dqget+0x151/0x4a0 fs/xfs/xfs_dquot.c:931
 xfs_qm_quotacheck_dqadjust+0xb3/0x570 fs/xfs/xfs_qm.c:1331
 xfs_qm_dqusage_adjust+0x5cb/0x6f0 fs/xfs/xfs_qm.c:1464
 xfs_iwalk_ag_recs+0x53f/0x870 fs/xfs/xfs_iwalk.c:209
 xfs_iwalk_run_callbacks+0x1f3/0x540 fs/xfs/xfs_iwalk.c:370
 xfs_iwalk_ag+0x81d/0xa30 fs/xfs/xfs_iwalk.c:476
 xfs_iwalk_ag_work+0x144/0x1c0 fs/xfs/xfs_iwalk.c:625
 xfs_pwork_work+0x82/0x160 fs/xfs/xfs_pwork.c:47
 process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c4/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/28 15:46 upstream fd0584d220fe d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root possible deadlock in xfs_ilock
2024/11/25 16:31 upstream 9f16d5e6f220 a84878fc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root possible deadlock in xfs_ilock
2024/11/14 06:00 upstream f1b785f4c787 a8c99394 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root possible deadlock in xfs_ilock
* Struck through repros no longer work on HEAD.