Hi, I hit this bug an hour ago while executing some cp --reflink:
Jul 5 13:54:02 oglaroon kernel: [ 2654.545244] ------------[ cut here ]------------ Jul 5 13:54:02 oglaroon kernel: [ 2654.600508] kernel BUG at fs/btrfs/delayed-inode.c:1637! Jul 5 13:54:02 oglaroon kernel: [ 2654.664052] invalid opcode: 0000 [#1] SMP Jul 5 13:54:02 oglaroon kernel: [ 2654.713244] last sysfs file: /sys/devices/pci0000:00/0000:00:1c.4/0000:04:00.0/net/eth3/broadcast Jul 5 13:54:02 oglaroon kernel: [ 2654.819429] CPU 1 Jul 5 13:54:02 oglaroon kernel: [ 2654.841372] Modules linked in: btrfs mpt2sas scsi_transport_sas raid_class [last unloaded: btrfs] Jul 5 13:54:02 oglaroon kernel: [ 2654.950364] Jul 5 13:54:02 oglaroon kernel: [ 2654.968147] Pid: 22343, comm: cp Tainted: G W 2.6.39+ #2 Supermicro X8SIL/X8SIL Jul 5 13:54:02 oglaroon kernel: [ 2655.065386] RIP: 0010:[<ffffffffa0222490>] [<ffffffffa0222490>] btrfs_delayed_update_inode+0x120/0x130 [btrfs] Jul 5 13:54:02 oglaroon kernel: [ 2655.186237] RSP: 0018:ffff88023010dbd8 EFLAGS: 00010286 Jul 5 13:54:02 oglaroon kernel: [ 2655.249780] RAX: 00000000ffffffe4 RBX: ffff8802356bec40 RCX: 0000000000018000 Jul 5 13:54:02 oglaroon kernel: [ 2655.335164] RDX: 0000000000000047 RSI: 0000000000000000 RDI: ffff880230a84390 Jul 5 13:54:02 oglaroon kernel: [ 2655.420652] RBP: ffff88023010dc18 R08: ffffffff825eb2a0 R09: 0000000000000001 Jul 5 13:54:02 oglaroon kernel: [ 2655.506036] R10: 00000000000003e0 R11: ffff8802317c4560 R12: ffff8802356bec88 Jul 5 13:54:02 oglaroon kernel: [ 2655.591419] R13: ffff88023569c6f8 R14: ffff88023334f000 R15: ffff880234318000 Jul 5 13:54:02 oglaroon kernel: [ 2655.676803] FS: 00007f07d396c700(0000) GS:ffff88023fc40000(0000) knlGS:0000000000000000 Jul 5 13:54:02 oglaroon kernel: [ 2655.773733] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jul 5 13:54:02 oglaroon kernel: [ 2655.842476] CR2: 0000000000407407 CR3: 0000000230974000 CR4: 00000000000006e0 Jul 5 13:54:02 oglaroon kernel: [ 2655.927859] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Jul 5 13:54:02 oglaroon kernel: [ 2656.013245] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Jul 5 13:54:02 oglaroon kernel: [ 2656.098733] Process cp (pid: 22343, threadinfo ffff88023010c000, task ffff8802317c3e80) Jul 5 13:54:02 oglaroon kernel: [ 2656.194516] Stack: Jul 5 13:54:02 oglaroon kernel: [ 2656.218540] ffff88023010dc38 0000000000018000 000000000000013b ffff88023569c6f8 Jul 5 13:54:02 oglaroon kernel: [ 2656.307564] ffff88023334f000 ffff88023569c6f8 ffff88023568d000 0000000000000000 Jul 5 13:54:02 oglaroon kernel: [ 2656.396483] ffff88023010dc68 ffffffffa01db4de 0000000000000068 0000000000000000 Jul 5 13:54:02 oglaroon kernel: [ 2656.485403] Call Trace: Jul 5 13:54:02 oglaroon kernel: [ 2656.514742] [<ffffffffa01db4de>] btrfs_update_inode+0x3e/0x150 [btrfs] Jul 5 13:54:02 oglaroon kernel: [ 2656.593884] [<ffffffffa0209160>] btrfs_ioctl_clone+0x9e0/0xca0 [btrfs] Jul 5 13:54:02 oglaroon kernel: [ 2656.673022] [<ffffffff81151f00>] ? might_fault+0x40/0xa0 Jul 5 13:54:02 oglaroon kernel: [ 2656.737613] [<ffffffffa0209b05>] btrfs_ioctl+0x335/0xf70 [btrfs] Jul 5 13:54:02 oglaroon kernel: [ 2656.810612] [<ffffffff81151f57>] ? might_fault+0x97/0xa0 Jul 5 13:54:02 oglaroon kernel: [ 2656.875198] [<ffffffff81151f0e>] ? might_fault+0x4e/0xa0 Jul 5 13:54:02 oglaroon kernel: [ 2656.939782] [<ffffffff81859006>] ? _raw_spin_unlock+0x26/0x30 Jul 5 13:54:02 oglaroon kernel: [ 2657.009567] [<ffffffff8117fcd3>] ? cp_new_stat+0xf3/0x110 Jul 5 13:54:02 oglaroon kernel: [ 2657.075325] [<ffffffff8118cb5c>] do_vfs_ioctl+0x9c/0x560 Jul 5 13:54:02 oglaroon kernel: [ 2657.139982] [<ffffffff818607ac>] ? sysret_check+0x27/0x62 Jul 5 13:54:02 oglaroon kernel: [ 2657.205604] [<ffffffff8118d0b9>] sys_ioctl+0x99/0xa0 Jul 5 13:54:02 oglaroon kernel: [ 2657.266133] [<ffffffff8186077b>] system_call_fastpath+0x16/0x1b Jul 5 13:54:02 oglaroon kernel: [ 2657.337995] Code: f8 05 00 00 8d 0c 49 48 89 ca 48 89 4d c8 e8 c8 c7 f9 ff 85 c0 48 8b 4d c8 75 10 48 89 4b 08 e9 3d ff ff ff 0f 1f 80 00 00 00 00 <0f> 0b eb fe 66 66 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 Jul 5 13:54:02 oglaroon kernel: [ 2657.570642] RIP [<ffffffffa0222490>] btrfs_delayed_update_inode+0x120/0x130 [btrfs] Jul 5 13:54:02 oglaroon kernel: [ 2657.663516] RSP <ffff88023010dbd8> Jul 5 13:54:02 oglaroon kernel: [ 2657.705561] ---[ end trace 0ae6cc23c8022b5b ]--- I was testing some completely different modifications I made myself, but I'm quite certain that my changes did not trigger this error. With the fs I could reproducably get to this bug by creating 10 reflinks of a certain file in a shell loop. I lost the file system while trying to setup a clean, tight test case. The fs I used had something like 50 files, some reflinks and a snapshot with some files deleted. The tree had explicit backrefs and shared backrefs. Anyway, I could not setup a new file system triggering this bug. The line that triggered is the BUG_ON in btrfs_delayed_update_inode (line 1693 in for-linus branch). We seem to have missed some reservation in some special case. The patch Miao sent some days ago does not interrelate at first sight. If I get back to a situation where I can reproduce the bug, I'll send a follow up. -Jan -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html