snapshot points to missing/incorrect tree: u64s 8 type snapshot 0:4294967295:0 len 0 ver 0: is_subvol 1 deleted 0 parent 0 children 0 0 subvol 1 tree 0, fixing done bcachefs (loop0): check_subvols... done bcachefs (loop0): check_subvol_children... done bcachefs (loop0): delete_dead_snapshots... done bcachefs (loop0): check_inodes... done bcachefs (loop0): check_extents... done bcachefs (loop0): check_indirect_extents... done bcachefs (loop0): check_dirents... done bcachefs (loop0): check_xattrs... done bcachefs (loop0): check_root... done bcachefs (loop0): check_unreachable_inodes... done bcachefs (loop0): check_subvolume_structure... done bcachefs (loop0): check_directory_structure... done bcachefs (loop0): check_nlinks... done bcachefs (loop0): resume_logged_ops... done bcachefs (loop0): delete_dead_inodes... done bcachefs (loop0): set_fs_needs_rebalance... done bcachefs (loop0): Fixed errors, running fsck a second time to verify fs is clean bcachefs (loop0): check_alloc_info... done bcachefs (loop0): check_lrus... done bcachefs (loop0): check_btree_backpointers... done bcachefs (loop0): check_backpointers_to_extents... done bcachefs (loop0): check_extents_to_backpointers... bcachefs (loop0): scanning for missing backpointers in 1/128 buckets done bcachefs (loop0): check_alloc_to_lru_refs... done bcachefs (loop0): bucket_gens_init... done bcachefs (loop0): check_snapshot_trees... done bcachefs (loop0): check_snapshots... done bcachefs (loop0): check_subvols... done bcachefs (loop0): check_subvol_children... done bcachefs (loop0): delete_dead_snapshots... done bcachefs (loop0): check_inodes... done bcachefs (loop0): check_extents... done bcachefs (loop0): check_indirect_extents... done bcachefs (loop0): check_dirents... done bcachefs (loop0): check_xattrs... done bcachefs (loop0): check_root... done bcachefs (loop0): check_unreachable_inodes... done bcachefs (loop0): check_subvolume_structure... done bcachefs (loop0): check_directory_structure... done bcachefs (loop0): check_nlinks... done bcachefs (loop0): resume_logged_ops... done bcachefs (loop0): delete_dead_inodes... done bcachefs (loop0): set_fs_needs_rebalance... done bcachefs (loop0): done starting filesystem overlay: filesystem on ./bus not supported as upperdir ============================================ WARNING: possible recursive locking detected 6.13.0-syzkaller-00918-g95ec54a420b8 #0 Not tainted -------------------------------------------- syz.0.0/5317 is trying to acquire lock: ffff888052faaed8 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:832 [inline] ffff888052faaed8 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: bch2_symlink+0x176/0x310 fs/bcachefs/fs.c:839 but task is already holding lock: ffff888052fa9078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:832 [inline] ffff888052fa9078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline] ffff888052fa9078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] ffff888052fa9078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] ffff888052fa9078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: ovl_copy_up_flags+0x19c0/0x47b0 fs/overlayfs/copy_up.c:1257 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&sb->s_type->i_mutex_key#21); lock(&sb->s_type->i_mutex_key#21); *** DEADLOCK *** May be due to missing lock nesting notation 6 locks held by syz.0.0/5317: #0: ffff888000b3a420 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547 #1: ffff888052fa5e50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:867 [inline] #1: ffff888052fa5e50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: filename_create+0x260/0x540 fs/namei.c:4080 #2: ffff888052fa6418 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:832 [inline] #2: ffff888052fa6418 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: vfs_link+0x3b2/0x6e0 fs/namei.c:4784 #3: ffff888052fa67d0 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:650 [inline] #3: ffff888052fa67d0 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_copy_up_start+0x53/0x310 fs/overlayfs/util.c:727 #4: ffff88804052a420 (sb_writers#13){.+.+}-{0:0}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:781 [inline] #4: ffff88804052a420 (sb_writers#13){.+.+}-{0:0}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] #4: ffff88804052a420 (sb_writers#13){.+.+}-{0:0}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] #4: ffff88804052a420 (sb_writers#13){.+.+}-{0:0}, at: ovl_copy_up_flags+0x19a9/0x47b0 fs/overlayfs/copy_up.c:1257 #5: ffff888052fa9078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: inode_lock include/linux/fs.h:832 [inline] #5: ffff888052fa9078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline] #5: ffff888052fa9078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] #5: ffff888052fa9078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] #5: ffff888052fa9078 (&sb->s_type->i_mutex_key#21){++++}-{4:4}, at: ovl_copy_up_flags+0x19c0/0x47b0 fs/overlayfs/copy_up.c:1257 stack backtrace: CPU: 0 UID: 0 PID: 5317 Comm: syz.0.0 Not tainted 6.13.0-syzkaller-00918-g95ec54a420b8 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037 check_deadlock kernel/locking/lockdep.c:3089 [inline] validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 down_write+0x99/0x220 kernel/locking/rwsem.c:1577 inode_lock include/linux/fs.h:832 [inline] bch2_symlink+0x176/0x310 fs/bcachefs/fs.c:839 vfs_symlink+0x137/0x2e0 fs/namei.c:4669 ovl_do_symlink+0x85/0xd0 fs/overlayfs/overlayfs.h:267 ovl_create_real+0x346/0x550 fs/overlayfs/dir.c:206 ovl_copy_up_workdir fs/overlayfs/copy_up.c:783 [inline] ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] ovl_copy_up_flags+0x19f3/0x47b0 fs/overlayfs/copy_up.c:1257 ovl_link+0x85/0x320 fs/overlayfs/dir.c:730 vfs_link+0x4f0/0x6e0 fs/namei.c:4793 do_linkat+0x555/0x6f0 fs/namei.c:4863 __do_sys_link fs/namei.c:4897 [inline] __se_sys_link fs/namei.c:4895 [inline] __x64_sys_link+0x82/0x90 fs/namei.c:4895 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: 0033:0x7f2681785d29 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:00007f26825d8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000056 RAX: ffffffffffffffda RBX: 00007f2681975fa0 RCX: 00007f2681785d29 RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000020000200 RBP: 00007f2681801b08 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2681975fa0 R15: 00007ffe377f8298 syz.0.0 (5317) used greatest stack depth: 9520 bytes left