general protection fault (btrfs_real_readdir)

[Markus Trippelsdorf]

I'm running the latest Linus git tree and the parallel filesystem directory
handling update seems to cause the following issue:

 general protection fault: 0000 [#1] SMP
 CPU: 0 PID: 24801 Comm: ld Not tainted 4.6.0-03623-g0b7962a6c4a3-dirty #118
 Hardware name: System manufacturer System Product Name/M4A78T-E, BIOS 3503    04/13/2011
 task: ffff88016cafa800 ti: ffff8801076e0000 task.ti: ffff8801076e0000
 RIP: 0010:[<ffffffff8134e9f3>]  [<ffffffff8134e9f3>] btrfs_readdir_delayed_dir_index+0x73/0x120
 RSP: 0018:ffff8801076e3dc0  EFLAGS: 00010202
 RAX: dead000000000100 RBX: ffff8800dbbd3840 RCX: ffff8800dbbd3880
 RDX: dead000000000200 RSI: ffff8801076e3e30 RDI: ffff8801076e3ef0
 RBP: ffff8801076e3e30 R08: ffff88006ac4b798 R09: ffff880000000000
 R10: 0000160000000000 R11: 0000000000001000 R12: dead000000000200
 R13: dead000000000100 R14: ffff8801076e3ef0 R15: dead0000000000c0
 FS:  00007f4782e04740(0000) GS:ffff88021fc00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f47821ef000 CR3: 00000001b9e38000 CR4: 00000000000006f0
 Stack:
  ffff8801076e3e2f 0000000000003000 0000000000000001 ffff88006ac4b6f8
  ffff8801076e3e30 ffff8801076e3ef0 0000000000000000 0000000000000008
  ffffffff812f038b 0000001281e62a80 ffff880214ea8800 ffff8801986fdbd0
 Call Trace:
  [<ffffffff812f038b>] ? btrfs_real_readdir+0x44b/0x540
  [<ffffffff811b064d>] ? SyS_getdents+0x12d/0x2a0
  [<ffffffff811affa0>] ? SyS_ioctl+0x6a0/0x6a0
  [<ffffffff810923db>] ? entry_SYSCALL_64_fastpath+0x13/0x8f
 Code: 02 00 00 00 00 ad de eb 1e f0 ff 4b 60 74 73 49 8b 47 40 49 8d 57 40 4c 89 fb 48 39 d5 4c 8d 78 c0 0f 84 8d 00 00 00 48 8b 53 48 <48> 89 50 08 48 89 02 4c 89 6b 40 4c 89 63 48 48 8b 4b 21 49 3b 
 RIP  [<ffffffff8134e9f3>] btrfs_readdir_delayed_dir_index+0x73/0x120
  RSP <ffff8801076e3dc0>
 ---[ end trace 91067801e8a68a7e ]---

This happened while I was building gcc, so the system was very busy.

-- 
Markus