[Unionfs] Can't mount NFS-exported union anymore in unionfs-1.4

[Wilhelm Meier]

Am Montag, 27. November 2006 15:01 schrieb hooanon05 at yahoo.co.jp:
> Wilhelm Meier:
> > But the result remains unchanged
>
> Will you try inserting printk("hello\n") at the top of share_imap() in
> persistent_inode.c, in order to check the function is called as
> expected?

Yes, it gets called!

Registering unionfs 1.4
unionfs: debugging is not enabled
hello: share_imap()
BUG: unable to handle kernel NULL pointer dereference at virtual address 
00000009
 printing eip:
d0a0bf60
*pde = 00000000
Oops: 0000 [#1]
SMP
Modules linked in: unionfs nfsd exportfs floppy parport_pc parport pcspkr 
pcnet32 mii mptspi mptscsih mptbase scsi_transport_spi rtc nfs lockd sunrpc 
raid10 raid1 raid0 dm_mirror dm_mod pdc_adma sata_mv ata_piix ahci sata_qstor 
sata_vsc sata_uli sata_sis sata_sx4 sata_nv sata_via sata_svw sata_sil24 
sata_sil sata_promise libata sbp2 ohci1394 ieee1394 sl811_hcd ohci_hcd 
uhci_hcd usb_storage usbhid ehci_hcd usbcore
CPU:    0
EIP:    0060:[<d0a0bf60>]    Not tainted VLI
EFLAGS: 00010246   (2.6.18-gentoo-r3 #1)
EIP is at read_uin+0x60/0x150 [unionfs]
eax: 00000000   ebx: 00000001   ecx: 00000000   edx: 0006800d
esi: ce975140   edi: ced40ca8   ebp: cffd4c4c   esp: ced40c50
ds: 007b   es: 007b   ss: 0068
Process mount (pid: 10650, ti=ced40000 task=cfeb9550 task.ti=ced40000)
Stack: c014fab0 00000000 00000000 00000010 00340098 00000000 ce5d8400 00000000
       cece4b40 00000001 d0a047f7 cffd4c00 00000000 0006800d 00000040 ced40ca8
       00000000 00000286 00000008 ce5e6e14 d0a0b135 00000008 00000000 00000002
Call Trace:
 [<c014fab0>] cache_alloc_refill+0x2ac/0x431
 [<d0a047f7>] unionfs_interpose+0x97/0x480 [unionfs]
 [<d0a0b135>] new_dentry_private_data+0x125/0x1c0 [unionfs]
 [<d0a05809>] unionfs_read_super+0xb89/0xe13 [unionfs]
 [<c0111c09>] default_wake_function+0x0/0x15
 [<c01d7d12>] idr_get_new_above_int+0x123/0x1fb
 [<c01d7df9>] idr_get_new+0xf/0x30
 [<c0168994>] get_filesystem+0x12/0x31
 [<c0157bd3>] sget+0x2ac/0x2b6
 [<c01583c5>] get_sb_nodev+0x4e/0x91
 [<d0a04c80>] unionfs_read_super+0x0/0xe13 [unionfs]
 [<c0157df1>] vfs_kern_mount+0x35/0x66
 [<d0a04c80>] unionfs_read_super+0x0/0xe13 [unionfs]
 [<c0157e5f>] do_kern_mount+0x29/0x39
 [<c016a0f8>] do_mount+0x5cf/0x647
 [<c0169380>] mntput_no_expire+0x14/0x67
 [<c015f74a>] link_path_walk+0xa8/0xb3
 [<c013c010>] filemap_nopage+0xbf/0x31b
 [<c013c0f0>] filemap_nopage+0x19f/0x31b
 [<c01447ee>] __handle_mm_fault+0x3ff/0x756
 [<c014932e>] page_add_file_rmap+0x17/0x1a
 [<c01445d0>] __handle_mm_fault+0x1e1/0x756
 [<c015e828>] putname+0x2d/0x30
 [<c013d98a>] get_page_from_freelist+0x9f/0x356
 [<c013ded6>] __get_free_pages+0x29/0x2e
 [<c0169015>] copy_mount_options+0x28/0x10b
 [<c016a1e8>] sys_mount+0x78/0xb1
 [<c010284d>] sysenter_past_esp+0x56/0x79
Code: e8 e8 79 28 8c ef 8b 54 24 34 89 5c 24 04 8b 46 48 8b 1c 98 8d 04 d5 30 
00 00 00 89 44 24 10 31 c0 89 44 24 14 c7 07 00 00 00 00 <8b> 43 08 8b 54 24 
10 8b 4c 24 14 8b 40 0c 83 c2 08 83 d1 00 3b
EIP: [<d0a0bf60>] read_uin+0x60/0x150 [unionfs] SS:ESP 0068:ced40c50

gs ~ #                            

>
> Junjiro Okajima

-- 
Wilhelm Meier
email: wilhelm.meier at fh-kl.de