[ 125.415910] BTRFS info (device loop0): disk space caching is enabled [ 125.550479] ------------[ cut here ]------------ [ 125.551145] WARNING: CPU: 6 PID: 1496 at fs/btrfs/locking.c:251 btrfs_tree_lock+0x22e/0x250 [ 125.552292] Modules linked in: [ 125.552602] CPU: 6 PID: 1496 Comm: btrfs.exe Tainted: G W 4.6.0-rc5 #130 [ 125.553138] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.2-20150714_191134- 04/01/2014 [ 125.553775] 0000000000000286 000000009b4bdd50 ffff88006a7478e0 ffffffff8157e563 [ 125.554299] 0000000000000000 0000000000000000 ffff88006a747920 ffffffff810a74ab [ 125.554825] 000000fb8146c531 ffff88006bfec460 ffff88006bc63000 0000000000000000 [ 125.555373] Call Trace: [ 125.555545] [] dump_stack+0x85/0xc2 [ 125.555892] [] __warn+0xcb/0xf0 [ 125.556226] [] warn_slowpath_null+0x1d/0x20 [ 125.556654] [] btrfs_tree_lock+0x22e/0x250 [ 125.557041] [] btrfs_init_new_buffer+0x81/0x160 [ 125.557458] [] btrfs_alloc_tree_block+0x22a/0x430 [ 125.557883] [] __btrfs_cow_block+0x141/0x590 [ 125.558279] [] btrfs_cow_block+0x11f/0x1f0 [ 125.558666] [] btrfs_search_slot+0x1fe/0xa30 [ 125.559063] [] ? kmem_cache_alloc+0xfd/0x240 [ 125.559482] [] btrfs_del_inode_ref+0x80/0x380 [ 125.559884] [] ? btrfs_del_inode_ref_in_log+0x8a/0x160 [ 125.560340] [] btrfs_del_inode_ref_in_log+0xbd/0x160 [ 125.560776] [] __btrfs_unlink_inode+0x1d7/0x470 [ 125.561188] [] btrfs_rename2+0x327/0x790 [ 125.561568] [] vfs_rename+0x4d8/0x840 [ 125.561928] [] SyS_rename+0x371/0x390 [ 125.562289] [] entry_SYSCALL_64_fastpath+0x1f/0xbd [ 125.562743] ---[ end trace 3b751f511705fb90 ]--- --------------------------------------------------------------------------- Fixed by patch: