BTRFS info (device loop6): first mount of filesystem c9fe44da-de57-406a-8241-57ec7d4412cf BTRFS info (device loop6): using crc32c (crc32c-intel) checksum algorithm BTRFS info (device loop6): using free-space-tree ====================================================== WARNING: possible circular locking dependency detected 6.12.0-syzkaller-10296-gaaf20f870da0 #0 Not tainted ------------------------------------------------------ syz.6.761/8746 is trying to acquire lock: ffff8880262b3598 (btrfs-tree-00){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146 but task is already holding lock: ffff8880262b2878 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #8 (btrfs-tree-01){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649 btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146 btrfs_tree_read_lock fs/btrfs/locking.h:178 [inline] btrfs_read_lock_root_node+0x3f/0xd0 fs/btrfs/locking.c:267 btrfs_search_slot_get_root fs/btrfs/ctree.c:1790 [inline] btrfs_search_slot+0x4f7/0x3150 fs/btrfs/ctree.c:2112 btrfs_lookup_file_extent+0x14c/0x210 fs/btrfs/file-item.c:267 btrfs_drop_extents+0x453/0x33e0 fs/btrfs/file.c:233 __cow_file_range_inline+0x2e9/0x1140 fs/btrfs/inode.c:679 cow_file_range_inline+0x317/0x3d0 fs/btrfs/inode.c:738 cow_file_range+0x39e/0x11f0 fs/btrfs/inode.c:1357 run_delalloc_cow+0x107/0x1f0 fs/btrfs/inode.c:1743 submit_uncompressed_range+0x191/0x3a0 fs/btrfs/inode.c:1128 submit_one_async_extent fs/btrfs/inode.c:1183 [inline] submit_compressed_extents+0x7b4/0x16e0 fs/btrfs/inode.c:1632 run_ordered_work fs/btrfs/async-thread.c:245 [inline] btrfs_work_helper+0x56d/0xc50 fs/btrfs/async-thread.c:324 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #7 (btrfs_trans_num_extwriters){++++}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 join_transaction+0x19c/0xda0 fs/btrfs/transaction.c:313 start_transaction+0xaf8/0x1670 fs/btrfs/transaction.c:697 btrfs_rebuild_free_space_tree+0xaf/0x490 fs/btrfs/free-space-tree.c:1327 btrfs_start_pre_rw_mount+0xeed/0x1300 fs/btrfs/disk-io.c:2998 open_ctree+0x24f5/0x2a30 fs/btrfs/disk-io.c:3543 btrfs_fill_super fs/btrfs/super.c:972 [inline] btrfs_get_tree_super fs/btrfs/super.c:1894 [inline] btrfs_get_tree+0x1274/0x1a10 fs/btrfs/super.c:2105 vfs_get_tree+0x92/0x2b0 fs/super.c:1814 fc_mount+0x1b/0xb0 fs/namespace.c:1231 btrfs_get_tree_subvol fs/btrfs/super.c:2068 [inline] btrfs_get_tree+0x65b/0x1a10 fs/btrfs/super.c:2106 vfs_get_tree+0x92/0x2b0 fs/super.c:1814 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4057 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #6 (btrfs_trans_num_writers){++++}-{0:0}: reacquire_held_locks+0x3eb/0x690 kernel/locking/lockdep.c:5374 __lock_release kernel/locking/lockdep.c:5563 [inline] lock_release+0x396/0xa30 kernel/locking/lockdep.c:5870 percpu_up_read include/linux/percpu-rwsem.h:99 [inline] __sb_end_write include/linux/fs.h:1720 [inline] sb_end_intwrite+0x26/0x1c0 include/linux/fs.h:1837 __btrfs_end_transaction+0x251/0x630 fs/btrfs/transaction.c:1068 btrfs_dirty_inode+0x151/0x1a0 fs/btrfs/inode.c:6059 inode_update_time fs/inode.c:2124 [inline] touch_atime+0x27f/0x690 fs/inode.c:2197 file_accessed include/linux/fs.h:2539 [inline] btrfs_file_mmap+0xbd/0x120 fs/btrfs/file.c:1953 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+0x2206/0x2cd0 mm/vma.c:2456 mmap_region+0x226/0x2c0 mm/mmap.c:1347 do_mmap+0x8f0/0x1000 mm/mmap.c:496 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:580 ksys_mmap_pgoff+0x4eb/0x720 mm/mmap.c:542 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #5 (&mm->mmap_lock){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __might_fault+0xc6/0x120 mm/memory.c:6751 _inline_copy_from_user include/linux/uaccess.h:162 [inline] _copy_from_user+0x2a/0xc0 lib/usercopy.c:18 copy_from_user include/linux/uaccess.h:212 [inline] __blk_trace_setup kernel/trace/blktrace.c:626 [inline] blk_trace_ioctl+0x1ad/0x9a0 kernel/trace/blktrace.c:740 blkdev_ioctl+0x40c/0x6a0 block/ioctl.c:682 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&q->debugfs_mutex){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 blk_mq_init_sched+0x3fa/0x830 block/blk-mq-sched.c:473 elevator_init_mq+0x20e/0x320 block/elevator.c:610 add_disk_fwnode+0x10d/0xf80 block/genhd.c:413 sd_probe+0xba6/0x1100 drivers/scsi/sd.c:4024 really_probe+0x2ba/0xad0 drivers/base/dd.c:658 __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800 driver_probe_device+0x50/0x430 drivers/base/dd.c:830 __device_attach_driver+0x2d6/0x530 drivers/base/dd.c:958 bus_for_each_drv+0x250/0x2e0 drivers/base/bus.c:459 __device_attach_async_helper+0x22d/0x300 drivers/base/dd.c:987 async_run_entry_fn+0xaa/0x420 kernel/async.c:129 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 blk_queue_enter+0xe1/0x600 block/blk-core.c:328 blk_mq_alloc_request+0x4fa/0xaa0 block/blk-mq.c:652 scsi_alloc_request drivers/scsi/scsi_lib.c:1222 [inline] scsi_execute_cmd+0x177/0x1090 drivers/scsi/scsi_lib.c:304 read_capacity_16+0x2b4/0x1450 drivers/scsi/sd.c:2655 sd_read_capacity drivers/scsi/sd.c:2824 [inline] sd_revalidate_disk+0x1013/0xbce0 drivers/scsi/sd.c:3734 sd_probe+0x9fa/0x1100 drivers/scsi/sd.c:4010 really_probe+0x2ba/0xad0 drivers/base/dd.c:658 __driver_probe_device+0x1a2/0x390 drivers/base/dd.c:800 driver_probe_device+0x50/0x430 drivers/base/dd.c:830 __device_attach_driver+0x2d6/0x530 drivers/base/dd.c:958 bus_for_each_drv+0x250/0x2e0 drivers/base/bus.c:459 __device_attach_async_helper+0x22d/0x300 drivers/base/dd.c:987 async_run_entry_fn+0xaa/0x420 kernel/async.c:129 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa65/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735 queue_limits_start_update include/linux/blkdev.h:945 [inline] loop_reconfigure_limits+0x283/0x9e0 drivers/block/loop.c:1003 loop_set_block_size drivers/block/loop.c:1473 [inline] lo_simple_ioctl drivers/block/loop.c:1496 [inline] lo_ioctl+0x1351/0x1f50 drivers/block/loop.c:1559 blkdev_ioctl+0x57f/0x6a0 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf7/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&q->q_usage_counter(io)#23){++++}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 bio_queue_enter block/blk.h:75 [inline] blk_mq_submit_bio+0x1536/0x23a0 block/blk-mq.c:3092 __submit_bio+0x2c6/0x560 block/blk-core.c:629 __submit_bio_noacct_mq block/blk-core.c:710 [inline] submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:739 btrfs_submit_chunk fs/btrfs/bio.c:745 [inline] btrfs_submit_bbio+0xf93/0x18e0 fs/btrfs/bio.c:773 read_extent_buffer_pages+0x65a/0x910 fs/btrfs/extent_io.c:3558 btrfs_read_extent_buffer+0xd9/0x770 fs/btrfs/disk-io.c:229 read_block_for_search+0x79e/0xbb0 fs/btrfs/ctree.c:1619 btrfs_search_slot+0x121b/0x3150 fs/btrfs/ctree.c:2236 btrfs_init_root_free_objectid+0x148/0x330 fs/btrfs/disk-io.c:4837 btrfs_init_fs_root fs/btrfs/disk-io.c:1137 [inline] btrfs_get_root_ref+0x5d7/0xc30 fs/btrfs/disk-io.c:1364 btrfs_get_fs_root fs/btrfs/disk-io.c:1416 [inline] open_ctree+0x2470/0x2a30 fs/btrfs/disk-io.c:3532 btrfs_fill_super fs/btrfs/super.c:972 [inline] btrfs_get_tree_super fs/btrfs/super.c:1894 [inline] btrfs_get_tree+0x1274/0x1a10 fs/btrfs/super.c:2105 vfs_get_tree+0x92/0x2b0 fs/super.c:1814 fc_mount+0x1b/0xb0 fs/namespace.c:1231 btrfs_get_tree_subvol fs/btrfs/super.c:2068 [inline] btrfs_get_tree+0x65b/0x1a10 fs/btrfs/super.c:2106 vfs_get_tree+0x92/0x2b0 fs/super.c:1814 do_new_mount+0x2be/0xb40 fs/namespace.c:3507 do_mount fs/namespace.c:3847 [inline] __do_sys_mount fs/namespace.c:4057 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (btrfs-tree-00){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649 btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146 btrfs_tree_read_lock fs/btrfs/locking.h:178 [inline] btrfs_search_slot+0x136b/0x3150 fs/btrfs/ctree.c:2260 btrfs_lookup_file_extent+0x14c/0x210 fs/btrfs/file-item.c:267 run_delalloc_nocow+0x350/0x11e0 fs/btrfs/inode.c:2022 btrfs_run_delalloc_range+0x31d/0xf70 fs/btrfs/inode.c:2290 writepage_delalloc+0x8aa/0xc70 fs/btrfs/extent_io.c:1239 extent_writepage fs/btrfs/extent_io.c:1499 [inline] extent_write_cache_pages fs/btrfs/extent_io.c:2194 [inline] btrfs_writepages+0x1157/0x2370 fs/btrfs/extent_io.c:2325 do_writepages+0x361/0x880 mm/page-writeback.c:2702 filemap_fdatawrite_wbc mm/filemap.c:397 [inline] __filemap_fdatawrite_range mm/filemap.c:430 [inline] filemap_fdatawrite_range+0x215/0x2c0 mm/filemap.c:448 btrfs_fdatawrite_range fs/btrfs/file.c:3719 [inline] start_ordered_ops fs/btrfs/file.c:1454 [inline] btrfs_sync_file+0x3ac/0x1230 fs/btrfs/file.c:1536 generic_write_sync include/linux/fs.h:2904 [inline] btrfs_do_write_iter+0x5e0/0x760 fs/btrfs/file.c:1406 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaed/0xd30 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: btrfs-tree-00 --> btrfs_trans_num_extwriters --> btrfs-tree-01 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(btrfs-tree-01); lock(btrfs_trans_num_extwriters); lock(btrfs-tree-01); rlock(btrfs-tree-00); *** DEADLOCK *** 3 locks held by syz.6.761/8746: #0: ffff88807e73ed38 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x254/0x320 fs/file.c:1191 #1: ffff8880245de420 (sb_writers#17){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2964 [inline] #1: ffff8880245de420 (sb_writers#17){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:675 #2: ffff8880262b2878 (btrfs-tree-01){++++}-{4:4}, at: btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146 stack backtrace: CPU: 1 UID: 0 PID: 8746 Comm: syz.6.761 Not tainted 6.12.0-syzkaller-10296-gaaf20f870da0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074 check_noncircular+0x36a/0x4a0 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+0x18ef/0x5920 kernel/locking/lockdep.c:3904 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_read_nested+0xb5/0xa50 kernel/locking/rwsem.c:1649 btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146 btrfs_tree_read_lock fs/btrfs/locking.h:178 [inline] btrfs_search_slot+0x136b/0x3150 fs/btrfs/ctree.c:2260 btrfs_lookup_file_extent+0x14c/0x210 fs/btrfs/file-item.c:267 run_delalloc_nocow+0x350/0x11e0 fs/btrfs/inode.c:2022 btrfs_run_delalloc_range+0x31d/0xf70 fs/btrfs/inode.c:2290 writepage_delalloc+0x8aa/0xc70 fs/btrfs/extent_io.c:1239 extent_writepage fs/btrfs/extent_io.c:1499 [inline] extent_write_cache_pages fs/btrfs/extent_io.c:2194 [inline] btrfs_writepages+0x1157/0x2370 fs/btrfs/extent_io.c:2325 do_writepages+0x361/0x880 mm/page-writeback.c:2702 filemap_fdatawrite_wbc mm/filemap.c:397 [inline] __filemap_fdatawrite_range mm/filemap.c:430 [inline] filemap_fdatawrite_range+0x215/0x2c0 mm/filemap.c:448 btrfs_fdatawrite_range fs/btrfs/file.c:3719 [inline] start_ordered_ops fs/btrfs/file.c:1454 [inline] btrfs_sync_file+0x3ac/0x1230 fs/btrfs/file.c:1536 generic_write_sync include/linux/fs.h:2904 [inline] btrfs_do_write_iter+0x5e0/0x760 fs/btrfs/file.c:1406 new_sync_write fs/read_write.c:586 [inline] vfs_write+0xaed/0xd30 fs/read_write.c:679 ksys_write+0x18f/0x2b0 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1a48580809 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1a49300058 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f1a48745fa0 RCX: 00007f1a48580809 RDX: 0000000000000006 RSI: 0000000020000000 RDI: 0000000000000004 RBP: 00007f1a485f393e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1a48745fa0 R15: 00007ffec059ee68