[Linux-cachefs] Cache Consistency

[Derek Siu]

>
> Can you be more specific about the nature of the crash?
>

After I run the cachefilesd daemon with the -s option, only the "About
to bind cache" message appears. After that , it causes segmantation
fault. The following error messages are from dmesg:

BUG: unable to handle kernel NULL pointer dereference at virtual
address 000001a9
 printing eip:
f88cb9cc
*pde = 00000000
Oops: 0000 [#1]
Modules linked in: cachefiles fscache i915 drm ppdev autofs4 hidp
rfcomm l2cap sunrpc arc4 ieee80211_crypt_wep video button battery ac
ipv6 lp parport_pc parport nvram snd_intel8x0m snd_intel8x0
snd_ac97_codec snd_ac97_bus snd_seq_dummy snd_seq_oss
snd_seq_midi_event snd_seq hci_usb bluetooth snd_seq_device ipw2200
snd_pcm_oss ieee80211 ieee80211_crypt i2c_i801 i2c_core 8139cp
snd_mixer_oss ohci1394 snd_pcm ieee1394 joydev 8139too uhci_hcd
ehci_hcd snd_timer snd mii soundcore snd_page_alloc dm_snapshot
dm_zero dm_mirror dm_mod ext3 jbd
CPU:    0
EIP:    0060:[<f88cb9cc>]    Not tainted VLI
EFLAGS: 00010286   (2.6.17-rc6 #7)
EIP is at ext3_statfs+0xc/0x103 [ext3]
eax: e9b81400   ebx: e66e0f08   ecx: f88cb9c0   edx: e66e0eb4
esi: e66e0eb4   edi: 00000001   ebp: f08bf180   esp: e66e0e84
ds: 007b   es: 007b   ss: 0068
Process cachefilesd (pid: 2715, threadinfo=e66e0000 task=e669da90)
Stack: e70b9680 00000246 e66e0f08 fffffff4 e66e0f08 ffffffe2 e73dcce8 f08bf180
       f8c9b1b9 00000000 c1539e00 e7308e80 c013d0d9 00000001 e7999800 0000000a
       00000feb c0203f42 00000001 00000286 e8c8a000 e8c8a158 00000000 c02d609c
Call Trace:
 <f8c9b1b9> cachefiles_proc_bind+0x1b9/0x3fd [cachefiles]  <c013d0d9>
get_page_from_freelist+0x29d/0x30a
 <c0203f42> pty_write+0x2a/0x34  <c02d609c> _spin_lock_irqsave+0x9/0xd
 <c01294ce> remove_wait_queue+0xc/0x34  <c0202355> write_chan+0x293/0x2a8
 <f8c9e5a6> cachefiles_proc_write+0x18b/0x1cb [cachefiles]  <f8c9e41b>
cachefiles_proc_write+0x0/0x1cb [cachefiles]
 <c0152820> vfs_write+0xa1/0x140  <c0152d28> sys_write+0x3c/0x63
 <c01029ef> sysenter_past_esp+0x54/0x75
Code: a1 38 88 c7 8b 44 9c 30 89 84 9f e4 00 00 00 43 83 fb 02 75 d9
83 c4 3c 89 e8 5b 5e 5f 5d c3 55 57 56 89 d6 53 83 ec 10 8b 78 5c <8b>
87 a8 01 00 00 89 44 24 04 8b 50 2c 89 54 24 08 31 d2 80 78
EIP: [<f88cb9cc>] ext3_statfs+0xc/0x103 [ext3] SS:ESP 0068:e66e0e84

Derek