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 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-rc2-syzkaller-00037-g834a4a689699 #0 Not tainted -------------------------------------------- syz.0.0/5327 is trying to acquire lock: ffff8880446f9810 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] ffff8880446f9810 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: bch2_symlink+0x178/0x320 fs/bcachefs/fs.c:858 but task is already holding lock: ffff8880446f88e0 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] ffff8880446f88e0 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline] ffff8880446f88e0 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] ffff8880446f88e0 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] ffff8880446f88e0 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_flags+0x19d7/0x47f0 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.0.0/5327: #0: ffff888012a10420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:556 #1: ffff8880446b5e50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff8880446b5e50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: lock_rename fs/namei.c:3230 [inline] #1: ffff8880446b5e50 (&ovl_i_mutex_dir_key[depth]/1){+.+.}-{4:4}, at: do_renameat2+0x633/0x1290 fs/namei.c:5181 #2: ffff8880446b6418 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #2: ffff8880446b6418 (&ovl_i_mutex_key[depth]){+.+.}-{4:4}, at: lock_two_nondirectories+0xe1/0x170 fs/inode.c:1233 #3: ffff8880446b69e0 (&ovl_i_mutex_key[depth]/4){+.+.}-{4:4}, at: vfs_rename+0x686/0xf10 fs/namei.c:5057 #4: ffff8880446b6d98 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_inode_lock_interruptible fs/overlayfs/overlayfs.h:649 [inline] #4: ffff8880446b6d98 (&ovl_i_lock_key[depth]){+.+.}-{4:4}, at: ovl_copy_up_start+0x53/0x310 fs/overlayfs/util.c:727 #5: ffff8880562f6420 (sb_writers#12){.+.+}-{0:0}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:781 [inline] #5: ffff8880562f6420 (sb_writers#12){.+.+}-{0:0}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] #5: ffff8880562f6420 (sb_writers#12){.+.+}-{0:0}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] #5: ffff8880562f6420 (sb_writers#12){.+.+}-{0:0}, at: ovl_copy_up_flags+0x19c0/0x47f0 fs/overlayfs/copy_up.c:1257 #6: ffff8880446f88e0 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #6: ffff8880446f88e0 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_workdir fs/overlayfs/copy_up.c:782 [inline] #6: ffff8880446f88e0 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_do_copy_up fs/overlayfs/copy_up.c:1001 [inline] #6: ffff8880446f88e0 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_one fs/overlayfs/copy_up.c:1202 [inline] #6: ffff8880446f88e0 (&sb->s_type->i_mutex_key#20){++++}-{4:4}, at: ovl_copy_up_flags+0x19d7/0x47f0 fs/overlayfs/copy_up.c:1257 stack backtrace: CPU: 0 UID: 0 PID: 5327 Comm: syz.0.0 Not tainted 6.15.0-rc2-syzkaller-00037-g834a4a689699 #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 lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x2be/0x2d0 kernel/locking/lockdep.c:3042 check_deadlock kernel/locking/lockdep.c:3094 [inline] validate_chain+0x928/0x24e0 kernel/locking/lockdep.c:3896 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 down_write+0x9c/0x220 kernel/locking/rwsem.c:1577 inode_lock include/linux/fs.h:867 [inline] bch2_symlink+0x178/0x320 fs/bcachefs/fs.c:858 vfs_symlink+0x137/0x2e0 fs/namei.c:4688 ovl_do_symlink+0x85/0xd0 fs/overlayfs/overlayfs.h:268 ovl_create_real+0x271/0x460 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+0x1a0a/0x47f0 fs/overlayfs/copy_up.c:1257 ovl_rename+0x62c/0x1760 fs/overlayfs/dir.c:1122 vfs_rename+0xbce/0xf10 fs/namei.c:5086 do_renameat2+0xc8d/0x1290 fs/namei.c:5235 __do_sys_rename fs/namei.c:5282 [inline] __se_sys_rename fs/namei.c:5280 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5280 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f755e58d169 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:00007f755a9f5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007f755e7a5fa0 RCX: 00007f755e58d169 RDX: 0000000000000000 RSI: 0000200000000840 RDI: 0000200000000800 RBP: 00007f755e60e990 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f755e7a5fa0 R15: 00007ffd5ba0ea78