loop0: detected capacity change from 0 to 32768 bcachefs (loop0): starting version 1.7: mi_btree_bitmap opts=errors=continue,metadata_checksum=none,data_checksum=none,compression=lz4,nocow allowing incompatible features above 0.0: (unknown version) bcachefs (loop0): initializing new filesystem bcachefs (loop0): going read-write bcachefs (loop0): marking superblocks bcachefs (loop0): initializing freespace bcachefs (loop0): done initializing freespace bcachefs (loop0): reading snapshots table bcachefs (loop0): reading snapshots done bcachefs (loop0): done starting filesystem ============================================ WARNING: possible recursive locking detected 6.15.0-rc4-syzkaller #0 Not tainted -------------------------------------------- syz.0.0/5324 is trying to acquire lock: ffff888052131078 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] ffff888052131078 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: bch2_symlink+0xf2/0x240 fs/bcachefs/fs.c:885 but task is already holding lock: ffff888052130148 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] ffff888052130148 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline] ffff888052130148 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] ffff888052130148 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] ffff888052130148 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_flags+0x10ee/0x2fb0 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#20); lock(&sb->s_type->i_mutex_key#20); *** DEADLOCK *** May be due to missing lock nesting notation 7 locks held by syz.0.0/5324: #0: ffff888055264420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff888052141e50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff888052141e50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3265 [inline] #1: ffff888052141e50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: do_renameat2+0x3dd/0xc50 fs/namei.c:5216 #2: ffff888052142418 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #2: ffff888052142418 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: lock_two_nondirectories+0xe7/0x180 fs/inode.c:1233 #3: ffff8880521429e0 (&ovl_i_mutex_key[depth]/4){+.+.}-{4:4}, at: vfs_rename+0x69a/0xec0 fs/namei.c:5092 #4: ffff888052142d98 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:649 [inline] #4: ffff888052142d98 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_copy_up_start+0x56/0x310 fs/overlayfs/util.c:727 #5: ffff88805502e420 (sb_writers#12){.+.+}-{0:0}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:781 [inline] #5: ffff88805502e420 (sb_writers#12){.+.+}-{0:0}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] #5: ffff88805502e420 (sb_writers#12){.+.+}-{0:0}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] #5: ffff88805502e420 (sb_writers#12){.+.+}-{0:0}, at: ovl_copy_up_flags+0x10df/0x2fb0 fs/overlayfs/copy_up.c:1257 #6: ffff888052130148 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #6: ffff888052130148 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline] #6: ffff888052130148 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] #6: ffff888052130148 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] #6: ffff888052130148 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_flags+0x10ee/0x2fb0 fs/overlayfs/copy_up.c:1257 stack backtrace: CPU: 0 UID: 0 PID: 5324 Comm: syz.0.0 Not tainted 6.15.0-rc4-syzkaller #0 PREEMPT(full) 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_lvl+0x189/0x250 lib/dump_stack.c:120 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3042 check_deadlock kernel/locking/lockdep.c:3094 [inline] validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3896 __lock_acquire+0xaac/0xd20 kernel/locking/lockdep.c:5235 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1577 inode_lock include/linux/fs.h:867 [inline] bch2_symlink+0xf2/0x240 fs/bcachefs/fs.c:885 vfs_symlink+0x140/0x2f0 fs/namei.c:4723 ovl_do_symlink+0x89/0xd0 fs/overlayfs/overlayfs.h:268 ovl_create_real+0x228/0x3f0 fs/overlayfs/dir.c:176 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+0x1108/0x2fb0 fs/overlayfs/copy_up.c:1257 ovl_rename+0x5ca/0x1650 fs/overlayfs/dir.c:1122 vfs_rename+0xb99/0xec0 fs/namei.c:5121 do_renameat2+0x878/0xc50 fs/namei.c:5270 __do_sys_rename fs/namei.c:5317 [inline] __se_sys_rename fs/namei.c:5315 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5315 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb1d1b8e969 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:00007fb1d29e1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007fb1d1db5fa0 RCX: 00007fb1d1b8e969 RDX: 0000000000000000 RSI: 0000200000000840 RDI: 0000200000000800 RBP: 00007fb1d1c10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb1d1db5fa0 R15: 00007ffe87782bb8 bcachefs (loop0): requested incompat feature 1.16: reflink_p_may_update_opts currently not enabled set version_upgrade=incompat to enable