Issue

• CIFS ファイルシステムでファイルをフラッシュしようとすると、以下のエラーが発生してシステムがパニックになります。

  Unable to handle kernel paging request at 0000000000005c07 RIP: 
   [<ffffffff887ba461>] :cifs:find_writable_file+0xad/0xd2
  PGD 196c34067 PUD 18da58067 PMD 1c3aa0067 PTE 0
  Oops:0000 [1] SMP 
  last sysfs file:/devices/pci0000:40/0000:40:0f.0/0000:43:00.1/irq
  CPU 2 
  Modules linked in: cpqci(U) mptctl ipmi_devintf ipmi_si ipmi_msghandler nfsd
  exportfs nfs lockd fscache nfs_acl nls_utf8 cifs sunrpc bonding dmpaa(U)
  vxspec(U) vxio(U) vxdmp(U) fdd(U) vxportal(U) vxfs(U) dm_mirror dm_multipath
  dm_mod video sbs backlight i2c_ec i2c_core button battery asus_acpi
  acpi_memhotplug ac parport_pc lp parport sg ide_cd k8_edac lpfc edac_mc cdrom
  serio_raw scsi_transport_fc k8temp shpchp e1000 hwmon bnx2 pcspkr usb_storage
  ata_piix sata_nv libata mptsas scsi_transport_sas mptspi mptscsih
  scsi_transport_spi mptbase cciss sd_mod scsi_mod ext3 jbd ehci_hcd ohci_hcd
  uhci_hcd
  Pid:413, comm: pdflush Tainted:PF     2.6.18-53.1.14.el5 #1
  RIP:0010:[<ffffffff887ba461>]  [<ffffffff887ba461>]
  :cifs:find_writable_file+0xad/0xd2
  RSP:0018:ffff81042fa05bc0  EFLAGS:00010202
  RAX:00000000ffffff90 RBX:0000000000005bf7 RCX: ffff8103dc881540
  RDX: ffff8103dc881540 RSI:000000000d83dc38 RDI: ffffffff887e82c0
  RBP: ffff8103d4f642f8 R08: ffff81042fa04000 R09:000000000000003f
  R10: ffff810107bcc008 R11:0000000000000000 R12: ffff81042fa05e10
  R13: ffff8103d4f64448 R14:00000000fffffff5 R15:0000000000000009
  FS:0000000040110940(0000) GS:ffff810107b193c0(0000) knlGS:00000000ac7fbb90
  CS:0010 DS:0018 ES:0018 CR0:000000008005003b
  CR2:0000000000005c07 CR3:00000001caf3e000 CR4:00000000000006e0
  Process pdflush (pid:413, threadinfo ffff81042fa04000, task ffff81022fa71100)
  Stack:0000000000001000 0000000000000524 0000000000000600 ffffffff887bc9d2
   ffff81020fc19800 0000860000000009 ffff810220e65140 000000008001c85a
   ffffffffffffffff 000000002f888c00 0000000000000524 000000000051b000
  Call Trace:
   [<ffffffff887bc9d2>] :cifs:cifs_writepages+0x3d2/0x5ff
   [<ffffffff80059052>] do_writepages+0x20/0x2f
   [<ffffffff8002f8c0>] __writeback_single_inode+0x1a8/0x322
   [<ffffffff88572733>] :vxdmp:vxdmp_congested+0x148/0x158
   [<ffffffff88602756>] :vxio:vol_rwsleep_unrdlock+0x15/0x4e
   [<ffffffff80020b0a>] sync_sb_inodes+0x1a9/0x267
   [<ffffffff8009c2c4>] keventd_create_kthread+0x0/0x61
   [<ffffffff8004ed14>] writeback_inodes+0x82/0xd8
   [<ffffffff800c23e4>] wb_kupdate+0x9e/0x10d
   [<ffffffff800544f7>] pdflush+0x0/0x1fb
   [<ffffffff80054648>] pdflush+0x151/0x1fb
   [<ffffffff800c2346>] wb_kupdate+0x0/0x10d
   [<ffffffff800321fc>] kthread+0xfe/0x132
   [<ffffffff8005cfb1>] child_rip+0xa/0x11
   [<ffffffff8009c2c4>] keventd_create_kthread+0x0/0x61
   [<ffffffff800320fe>] kthread+0x0/0x132
   [<ffffffff8005cfa7>] child_rip+0x0/0x11
  
  
  Code:48 8b 43 10 0f 18 08 48 8d 53 10 48 8d 45 10 48 39 c2 75 80 
  RIP  [<ffffffff887ba461>] :cifs:find_writable_file+0xad/0xd2
   RSP <ffff81042fa05bc0>        
  

• ログに以下のメッセージが記録されます。

   CIFS VFS: server not responding
   CIFS VFS:No response for cmd 50 mid 15528
   CIFS VFS:No response to cmd 47 mid 15526
   CIFS VFS:No response to cmd 47 mid 15527
   CIFS VFS:Write2 ret -11, written = 0
   CIFS VFS:No response for cmd 50 mid 15529
   CIFS VFS:Write2 ret -11, written = 0
   CIFS VFS: server not responding
   CIFS VFS: server not responding
   CIFS VFS:No response for cmd 50 mid 15537
   CIFS VFS:No response for cmd 50 mid 15536
   CIFS VFS:No response for cmd 50 mid 15538
   CIFS VFS:No response to cmd 47 mid 15535
   CIFS VFS:Write2 ret -11, written = 0
   CIFS VFS:No writable handles for inode
   CIFS VFS:No response to cmd 47 mid 15534
   CIFS VFS:Write2 ret -11, written = 0
   CIFS VFS: server not responding
   CIFS VFS:No response for cmd 114 mid 15539
   CIFS VFS:No writable handles for inode
  Unable to handle kernel paging request at 0000000000005c07 RIP: 
   [<ffffffff887ba461>] :cifs:find_writable_file+0xad/0xd2