BTRFS info (device loop5): clearing compat-ro feature flag for FREE_SPACE_TREE (0x1) BTRFS info (device loop5): clearing compat-ro feature flag for FREE_SPACE_TREE_VALID (0x2) BTRFS info (device loop5): checking UUID tree ====================================================== WARNING: possible circular locking dependency detected 6.3.0-syzkaller-10197-g91ec4b0d11fe #0 Not tainted ------------------------------------------------------ syz-executor.5/14082 is trying to acquire lock: ffff88805175f078 (btrfs-tree-01){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:135 but task is already holding lock: ffff888022065078 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:135 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (btrfs-tree-00){++++}-{3:3}: lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691 down_read_nested+0x40/0x60 kernel/locking/rwsem.c:1645 __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:135 btrfs_search_slot+0x13a7/0x2f50 fs/btrfs/ctree.c:2252 btrfs_init_root_free_objectid+0x148/0x320 fs/btrfs/disk-io.c:5193 btrfs_init_fs_root fs/btrfs/disk-io.c:1369 [inline] btrfs_get_root_ref+0x537/0xa90 fs/btrfs/disk-io.c:1573 btrfs_get_fs_root fs/btrfs/disk-io.c:1625 [inline] open_ctree+0x2944/0x2fa0 fs/btrfs/disk-io.c:3711 btrfs_fill_super+0x1c7/0x2f0 fs/btrfs/super.c:1152 btrfs_mount_root+0x80f/0x950 fs/btrfs/super.c:1520 legacy_get_tree+0xef/0x190 fs/fs_context.c:610 vfs_get_tree+0x8c/0x270 fs/super.c:1510 fc_mount fs/namespace.c:1035 [inline] vfs_kern_mount+0xbc/0x150 fs/namespace.c:1065 btrfs_mount+0x39f/0xb50 fs/btrfs/super.c:1580 legacy_get_tree+0xef/0x190 fs/fs_context.c:610 vfs_get_tree+0x8c/0x270 fs/super.c:1510 do_new_mount+0x28f/0xae0 fs/namespace.c:3039 do_mount fs/namespace.c:3382 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (btrfs-tree-01){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3108 [inline] check_prevs_add kernel/locking/lockdep.c:3227 [inline] validate_chain+0x166b/0x58e0 kernel/locking/lockdep.c:3842 __lock_acquire+0x1295/0x2000 kernel/locking/lockdep.c:5074 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691 down_read_nested+0x40/0x60 kernel/locking/rwsem.c:1645 __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:135 btrfs_tree_read_lock fs/btrfs/locking.c:141 [inline] btrfs_read_lock_root_node+0x292/0x3c0 fs/btrfs/locking.c:280 btrfs_search_slot_get_root fs/btrfs/ctree.c:1782 [inline] btrfs_search_slot+0x502/0x2f50 fs/btrfs/ctree.c:2104 btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:412 btrfs_read_locked_inode fs/btrfs/inode.c:3768 [inline] btrfs_iget_path+0x2d9/0x1520 fs/btrfs/inode.c:5584 btrfs_search_path_in_tree_user fs/btrfs/ioctl.c:1960 [inline] btrfs_ioctl_ino_lookup_user+0x774/0xf50 fs/btrfs/ioctl.c:2104 btrfs_ioctl+0xb08/0xd40 fs/btrfs/ioctl.c:4676 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(btrfs-tree-00); lock(btrfs-tree-01); lock(btrfs-tree-00); rlock(btrfs-tree-01); *** DEADLOCK *** 1 lock held by syz-executor.5/14082: #0: ffff888022065078 (btrfs-tree-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:135 stack backtrace: CPU: 1 PID: 14082 Comm: syz-executor.5 Not tainted 6.3.0-syzkaller-10197-g91ec4b0d11fe #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2fe/0x3b0 kernel/locking/lockdep.c:2188 check_prev_add kernel/locking/lockdep.c:3108 [inline] check_prevs_add kernel/locking/lockdep.c:3227 [inline] validate_chain+0x166b/0x58e0 kernel/locking/lockdep.c:3842 __lock_acquire+0x1295/0x2000 kernel/locking/lockdep.c:5074 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691 down_read_nested+0x40/0x60 kernel/locking/rwsem.c:1645 __btrfs_tree_read_lock+0x2f/0x220 fs/btrfs/locking.c:135 btrfs_tree_read_lock fs/btrfs/locking.c:141 [inline] btrfs_read_lock_root_node+0x292/0x3c0 fs/btrfs/locking.c:280 btrfs_search_slot_get_root fs/btrfs/ctree.c:1782 [inline] btrfs_search_slot+0x502/0x2f50 fs/btrfs/ctree.c:2104 btrfs_lookup_inode+0xdc/0x480 fs/btrfs/inode-item.c:412 btrfs_read_locked_inode fs/btrfs/inode.c:3768 [inline] btrfs_iget_path+0x2d9/0x1520 fs/btrfs/inode.c:5584 btrfs_search_path_in_tree_user fs/btrfs/ioctl.c:1960 [inline] btrfs_ioctl_ino_lookup_user+0x774/0xf50 fs/btrfs/ioctl.c:2104 btrfs_ioctl+0xb08/0xd40 fs/btrfs/ioctl.c:4676 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f3661a8c169 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3662818168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f3661babf80 RCX: 00007f3661a8c169 RDX: 00000000200000c0 RSI: 00000000d000943e RDI: 0000000000000004 RBP: 00007f3661ae7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd95e18d0f R14: 00007f3662818300 R15: 0000000000022000