I have a system running 3.2.6 that creates and deletes a number of snapshots on a daily basis. It seems to have run into a problem while attempting to create a snapshot: [431642.714979] ------------[ cut here ]------------ [431642.714997] kernel BUG at /home/apw/COD/linux/fs/btrfs/locking.c:214! [431642.715005] invalid opcode: 0000 [#1] SMP [431642.715014] CPU 2 [431642.715018] Modules linked in: nfsd lockd nfs_acl auth_rpcgss sunrpc ufs qnx4 hfsplus hfs minix ntfs vfat msdos fat jfs xfs reiserfs ext2 snd_hda_codec_realtek nouveau ttm drm_kms_helper drm snd_hda_intel snd_hda_codec joydev mac_hid i2c_algo_bit video i7core_edac snd_hwdep snd_pcm psmouse edac_core snd_timer mxm_wmi snd soundcore snd_page_alloc asus_atk0110 wmi serio_raw softdog lp parport usbhid hid firewire_ohci firewire_core crc_itu_t sky2 btrfs zlib_deflate libcrc32c [431642.715147] [431642.715151] Pid: 813, comm: btrfs-cleaner Not tainted 3.2.6-030206-generic #201202131435 System manufacturer System Product Name/P6X58D-E [431642.715168] RIP: 0010:[<ffffffffa006a601>] [<ffffffffa006a601>] btrfs_tree_unlock+0x71/0xa0 [btrfs] [431642.715196] RSP: 0018:ffff88022fb99ca0 EFLAGS: 00010246 [431642.715203] RAX: 0000000000000000 RBX: ffff8801cb29dbe0 RCX: ffff8801041d2180 [431642.715211] RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffff8801cb29dbe0 [431642.715220] RBP: ffff88022fb99cb0 R08: 0000000000000001 R09: ffff88022fb99bd8 [431642.715228] R10: 0000000000000002 R11: ffff88019d5106c0 R12: ffff8801041d2180 [431642.715235] R13: ffff8801cb29dbe0 R14: ffff88020984d7e0 R15: ffff88022de5fc00 [431642.715244] FS: 0000000000000000(0000) GS:ffff88023fc40000(0000) knlGS:0000000000000000 [431642.715252] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [431642.715259] CR2: 000000000061ce20 CR3: 0000000001c05000 CR4: 00000000000006e0 [431642.715267] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [431642.715275] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [431642.715283] Process btrfs-cleaner (pid: 813, threadinfo ffff88022fb98000, task ffff880230c7c4a0) [431642.715291] Stack: [431642.715295] ffff88022fb99cb0 000000000000001a ffff88022fb99cc0 ffffffffa002391b [431642.715311] ffff88022fb99d10 ffffffffa0028f4c 0000000200000002 ffff88019d5106c0 [431642.715325] ffff88010a608388 ffff88020984d7e0 ffff88020984d7e0 0000000000000002 [431642.715340] Call Trace: [431642.715357] [<ffffffffa002391b>] btrfs_tree_unlock_rw+0x2b/0x50 [btrfs] [431642.715376] [<ffffffffa0028f4c>] walk_down_proc+0x1ac/0x240 [btrfs] [431642.715395] [<ffffffffa002904c>] walk_down_tree+0x6c/0x100 [btrfs] [431642.715414] [<ffffffffa002d771>] btrfs_drop_snapshot+0x2c1/0x590 [btrfs] [431642.715435] [<ffffffffa0039668>] btrfs_clean_old_snapshots+0x118/0x160 [btrfs] [431642.715456] [<ffffffffa0034dd0>] cleaner_kthread+0x160/0x1a0 [btrfs] [431642.715476] [<ffffffffa0034c70>] ? transaction_kthread+0x2a0/0x2a0 [btrfs] [431642.715489] [<ffffffff8108bba6>] kthread+0x96/0xa0 [431642.715498] [<ffffffff81659bb4>] kernel_thread_helper+0x4/0x10 [431642.715957] [<ffffffff8108bb10>] ? kthread_worker_fn+0x190/0x190 [431642.716417] [<ffffffff81659bb0>] ? gs_change+0x13/0x13 [431642.716979] Code: 1f 00 8b 47 68 85 c0 75 3d f0 ff 4b 5c 48 8d 7b 70 31 c9 ba 01 00 00 00 be 03 00 00 00 e8 18 9b fe e0 48 83 c4 08 31 c0 5b c9 c3 <0f> 0b eb fe 0f 0b eb fe be cd 00 00 00 48 c7 c7 a0 15 09 a0 e8 [431642.718210] RIP [<ffffffffa006a601>] btrfs_tree_unlock+0x71/0xa0 [btrfs] [431642.718785] RSP <ffff88022fb99ca0> [431642.722212] ---[ end trace 08dfc5a54c97fa7a ]--- The filesystem is mounted with noatime,nodiratime,compress=lzo,autodefrag. Has this been seen before? I''m wondering if the autodefrag option could have anything to do with this, as the failure happened not too long after I enabled that flag for this filesystem. Thanks, Nuno -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html