BTRFS info (device loop0): using sha256 (sha256-ce) checksum algorithm BTRFS info (device loop0): using free space tree BTRFS info (device loop0): enabling ssd optimizations ====================================================== WARNING: possible circular locking dependency detected 6.1.0-rc6-syzkaller-32662-g6d464646530f #0 Not tainted ------------------------------------------------------ syz-executor220/3357 is trying to acquire lock: ffff0000c9b90650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_join_transaction+0x30/0x40 fs/btrfs/transaction.c:764 but task is already holding lock: ffff0000ca11fb08 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] ffff0000ca11fb08 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0xa0/0x1d0 mm/util.c:518 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&mm->mmap_lock){++++}-{3:3}: __might_fault+0x7c/0xb4 mm/memory.c:5646 _copy_to_user include/linux/uaccess.h:143 [inline] copy_to_user include/linux/uaccess.h:169 [inline] btrfs_ioctl_get_subvol_rootref+0x3a8/0x4bc fs/btrfs/ioctl.c:3203 btrfs_ioctl+0xa08/0xa64 fs/btrfs/ioctl.c:5556 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xd0/0x140 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 -> #4 (btrfs-root-00){++++}-{3:3}: down_read_nested+0x64/0x84 kernel/locking/rwsem.c:1634 __btrfs_tree_read_lock fs/btrfs/locking.c:134 [inline] btrfs_tree_read_lock fs/btrfs/locking.c:140 [inline] btrfs_read_lock_root_node+0x13c/0x1c0 fs/btrfs/locking.c:279 btrfs_search_slot_get_root+0x8c/0x374 fs/btrfs/ctree.c:1665 btrfs_search_slot+0x1dc/0x107c fs/btrfs/ctree.c:1985 btrfs_update_root+0x6c/0x5a4 fs/btrfs/root-tree.c:132 commit_fs_roots+0x1f0/0x33c fs/btrfs/transaction.c:1441 btrfs_commit_transaction+0xa94/0x1574 fs/btrfs/transaction.c:2353 btrfs_sync_fs+0x2b8/0x48c fs/btrfs/super.c:1527 sync_filesystem+0xe0/0x134 fs/sync.c:66 generic_shutdown_super+0x38/0x198 fs/super.c:474 kill_anon_super+0x24/0x44 fs/super.c:1086 btrfs_kill_super+0x24/0x3c fs/btrfs/super.c:2441 deactivate_locked_super+0x70/0xe8 fs/super.c:332 deactivate_super+0xd0/0xd4 fs/super.c:363 cleanup_mnt+0x184/0x1c0 fs/namespace.c:1186 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 task_work_run+0x100/0x148 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1127 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 -> #3 (&fs_info->reloc_mutex){+.+.}-{3:3}: __mutex_lock_common+0xd4/0xca8 kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 btrfs_record_root_in_trans fs/btrfs/transaction.c:484 [inline] start_transaction+0x248/0x944 fs/btrfs/transaction.c:721 btrfs_start_transaction+0x34/0x44 fs/btrfs/transaction.c:750 btrfs_create_common+0xf0/0x1b4 fs/btrfs/inode.c:6633 btrfs_create+0x8c/0xb0 fs/btrfs/inode.c:6679 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x804/0x11c4 fs/namei.c:3710 do_filp_open+0xdc/0x1b8 fs/namei.c:3740 do_sys_openat2+0xb8/0x22c fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __arm64_sys_openat+0xb0/0xe0 fs/open.c:1337 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 -> #2 (btrfs_trans_num_extwriters){++++}-{0:0}: join_transaction+0x10c/0x65c fs/btrfs/transaction.c:299 start_transaction+0x460/0x944 fs/btrfs/transaction.c:658 btrfs_start_transaction+0x34/0x44 fs/btrfs/transaction.c:750 btrfs_create_common+0xf0/0x1b4 fs/btrfs/inode.c:6633 btrfs_create+0x8c/0xb0 fs/btrfs/inode.c:6679 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x804/0x11c4 fs/namei.c:3710 do_filp_open+0xdc/0x1b8 fs/namei.c:3740 do_sys_openat2+0xb8/0x22c fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __arm64_sys_openat+0xb0/0xe0 fs/open.c:1337 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 -> #1 (btrfs_trans_num_writers){++++}-{0:0}: join_transaction+0xe8/0x65c fs/btrfs/transaction.c:298 start_transaction+0x460/0x944 fs/btrfs/transaction.c:658 btrfs_start_transaction+0x34/0x44 fs/btrfs/transaction.c:750 btrfs_create_common+0xf0/0x1b4 fs/btrfs/inode.c:6633 btrfs_create+0x8c/0xb0 fs/btrfs/inode.c:6679 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x804/0x11c4 fs/namei.c:3710 do_filp_open+0xdc/0x1b8 fs/namei.c:3740 do_sys_openat2+0xb8/0x22c fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __arm64_sys_openat+0xb0/0xe0 fs/open.c:1337 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 -> #0 (sb_internal#2){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x1530/0x3084 kernel/locking/lockdep.c:5055 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_intwrite include/linux/fs.h:1948 [inline] start_transaction+0x360/0x944 fs/btrfs/transaction.c:652 btrfs_join_transaction+0x30/0x40 fs/btrfs/transaction.c:764 btrfs_dirty_inode+0x4c/0x13c fs/btrfs/inode.c:6085 btrfs_update_time+0x120/0x138 fs/btrfs/inode.c:6127 inode_update_time fs/inode.c:1871 [inline] touch_atime+0x1f0/0x4a8 fs/inode.c:1944 file_accessed include/linux/fs.h:2521 [inline] btrfs_file_mmap+0x50/0x88 fs/btrfs/file.c:2333 call_mmap include/linux/fs.h:2196 [inline] mmap_region+0x8a0/0x1064 mm/mmap.c:2625 do_mmap+0x6e8/0xa30 mm/mmap.c:1412 vm_mmap_pgoff+0xe8/0x1d0 mm/util.c:520 ksys_mmap_pgoff+0x1cc/0x278 mm/mmap.c:1458 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0x58/0x6c arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584 other info that might help us debug this: Chain exists of: sb_internal#2 --> btrfs-root-00 --> &mm->mmap_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_lock); lock(btrfs-root-00); lock(&mm->mmap_lock); lock(sb_internal#2); *** DEADLOCK *** 2 locks held by syz-executor220/3357: #0: ffff0000ca11fb08 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff0000ca11fb08 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0xa0/0x1d0 mm/util.c:518 #1: ffff0000c9b90460 (sb_writers#8){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2521 [inline] #1: ffff0000c9b90460 (sb_writers#8){.+.+}-{0:0}, at: btrfs_file_mmap+0x50/0x88 fs/btrfs/file.c:2333 stack backtrace: CPU: 1 PID: 3357 Comm: syz-executor220 Not tainted 6.1.0-rc6-syzkaller-32662-g6d464646530f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2055 check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x1530/0x3084 kernel/locking/lockdep.c:5055 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5668 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_intwrite include/linux/fs.h:1948 [inline] start_transaction+0x360/0x944 fs/btrfs/transaction.c:652 btrfs_join_transaction+0x30/0x40 fs/btrfs/transaction.c:764 btrfs_dirty_inode+0x4c/0x13c fs/btrfs/inode.c:6085 btrfs_update_time+0x120/0x138 fs/btrfs/inode.c:6127 inode_update_time fs/inode.c:1871 [inline] touch_atime+0x1f0/0x4a8 fs/inode.c:1944 file_accessed include/linux/fs.h:2521 [inline] btrfs_file_mmap+0x50/0x88 fs/btrfs/file.c:2333 call_mmap include/linux/fs.h:2196 [inline] mmap_region+0x8a0/0x1064 mm/mmap.c:2625 do_mmap+0x6e8/0xa30 mm/mmap.c:1412 vm_mmap_pgoff+0xe8/0x1d0 mm/util.c:520 ksys_mmap_pgoff+0x1cc/0x278 mm/mmap.c:1458 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline] __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline] __arm64_sys_mmap+0x58/0x6c arch/arm64/kernel/sys.c:21 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:584