Re: cifs: ls of mount point gives input/output error (probably related to CIFS: getdents() broken for large dirs)

Konstantinos Skarlatos
2011-12-31T12:49:44Z

On Σάββατο, 31 Δεκέμβριος 2011 1:59:22 μμ, Jeff Layton wrote:
> On Fri, 30 Dec 2011 20:00:46 +0200
> Konstantinos Skarlatos<k.skarlatos@gmail.com> wrote:
>
>> On 30/12/2011 3:11 μμ, Jeff Layton wrote:
>>> On Fri, 30 Dec 2011 11:04:59 +0200
>>> Konstantinos Skarlatos<k.skarlatos@gmail.com> wrote:
>>>
>>>> On 29/12/2011 3:54 μμ, Konstantinos Skarlatos wrote:
>>>>> On Πέμπτη, 29 Δεκέμβριος 2011 3:39:30 μμ, Jeff Layton wrote:
>>>>>> On Thu, 29 Dec 2011 12:30:18 +0200
>>>>>> Konstantinos Skarlatos<k.skarlatos@gmail.com> wrote:
>>>>>>
>>>>>>> On 29/12/2011 4:04 πμ, Jeff Layton wrote:
>>>>>>>> On Thu, 29 Dec 2011 02:08:57 +0200
>>>>>>>> Konstantinos Skarlatos<k.skarlatos@gmail.com> wrote:
>>>>>>>>
>>>>>>>>> I mount via cifs a windows XP share, df gives me correct sizes,
>>>>>>>>> but when
>>>>>>>>> I ls the mount point i get input/output error.
>>>>>>>>> strace: http://pastebin.com/WXf8M1nu
>>>>>>>>>
>>>>>>>>> mount --verbose -t cifs -o username=administrator,password=blahblah
>>>>>>>>> //192.168.0.11/jobs /mnt/backups/montaz/jobs
>>>>>>>>> mount.cifs kernel mount options:
>>>>>>>>> ip=192.168.0.11,unc=\\192.168.0.11\jobs,,ver=1,user=administrator,pass=********
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> df
>>>>>>>>> //192.168.0.11/jobs 114464
>>>>>>>>> 105196 9268 92% /mnt/backups/montaz/jobs
>>>>>>>>>
>>>>>>>>> ls /mnt/backups/montaz/jobs/
>>>>>>>>> ls: reading directory /mnt/backups/montaz/jobs/: Input/output error
>>>>>>>>> total 0
>>>>>>>>>
>>>>>>>>> the fun thing is that i can cd to a lower level directory, and ls
>>>>>>>>> works
>>>>>>>>> fine there! only the mount point has the problem
>>>>>>>>>
>>>>>>>>> ls /mnt/backups/montaz/jobs/test
>>>>>>>>> total 44K
>>>>>>>>> drwxr-xr-x 1 root root 0 Apr 30 2010 blah blah/
>>>>>>>>> ......
>>>>>>>>>
>>>>>>>>> kernel version 3.2rc7
>>>>>>>>>
>>>>>>>>> this seems to be related to :
>>>>>>>>> https://lkml.org/lkml/2011/8/1/427
>>>>>>>>> Re: [3.0.0+][Regression][Bisected] CIFS: getdents() broken for
>>>>>>>>> large dirs
>>>>>>>>>
>>>>>>>> Hmmm, maybe. What makes you think that it's related? What sort of
>>>>>>>> server are you seeing this against?
>>>>>>> Windows XP service pack 2 (greek)
>>>>>>
>>>>>> How many files are in the directory?
>>>>>>
>>>>> 140 folders and 20 files
>>>>>
>>>> Attached is a tcp dump of my session.
>>> I tried reproducing this here, but wasn't able to. Testing against my
>>> xp box worked fine.
>>>
>>> Most likely, the FIND_FILE responses are falling afoul of the code in
>>> coalesce_t2 or check2ndT2. Unfortunately that code is pretty
>>> complicated and I'm not certain what the problem actually is...
>>>
>>> One thing that's interesting is that the total data being sent in the
>>> request is rather large (16336 bytes). I think that's legit, but maybe
>>> it's exceeding the end of the buffer once we try to coalesce it.
>>>
>>> Would it be possible to get the cFYI output from this test?
>> I did not get a cFYI output from that test, but i redid a
>> mount-ls-umount and am attaching the tcpdump
>> Also here http://pastebin.com/J20uC6kU you can find the cifsFYI and the
>> contents of /proc/fs/cifs/DebugData form the same test
>>>
>>> Is this a regression? Did it work with earlier kernels and only
>>> recently start failing?
>>>
>> I do not know, and i am a bit afraid to downgrade this machine below 3.0
>> due to some changes arch linux has introduced recently. I can always set
>> up a few virtual machines though, and i can even request permission from
>> my company to give you shell access if you like. Which kernel versions
>> would you like me to test?
>
>
> Ok, that tells us a little:
>
> -------------------[snip]---------------------
> [96268.787078] fs/cifs/cifssmb.c: In FindFirst for
> [96268.787083] fs/cifs/transport.c: For smb_command 50
> [96268.787086] fs/cifs/transport.c: Sending smb: total_len 88
>
> ...FIND_FIRST command is sent
>
> [96268.787690] fs/cifs/connect.c: RFC1002 header 0x1104
> [96268.787697] fs/cifs/connect.c: missing 12048 bytes from transact2, check next response
> [96268.787865] fs/cifs/connect.c: RFC1002 header 0x1104
> [96268.787870] fs/cifs/connect.c: missing 12036 bytes from transact2, check next response
> [96268.788037] fs/cifs/connect.c: RFC1002 header 0x1104
> [96268.788042] fs/cifs/connect.c: missing 12036 bytes from transact2, check next response
> [96268.788371] fs/cifs/connect.c: RFC1002 header 0xdb0
> [96268.788375] fs/cifs/connect.c: missing 12888 bytes from transact2, check next response
>
> ...all four parts of the response are collected here
>
> [96268.788391] fs/cifs/transport.c: cifs_sync_mid_result: cmd=50 mid=12 state=16
>
> ...but the state at this point is MID_RESPONSE_MALFORMED
>
> [96268.788395] fs/cifs/cifssmb.c: Error in FindFirst = -5
> [96268.788397] fs/cifs/readdir.c: initiate cifs search rc -5
> [96268.788398] fs/cifs/readdir.c: CIFS VFS: leaving cifs_readdir (xid = 737644) rc = -5
>
> ...which makes readdir return -EIO
>
> -------------------[snip]---------------------
>
> Based on that, it looks like something in one of these frames caused
> coalesce_t2() to return an error. I don't see the problem right offhand
> in the capture, but T2 response handling is pretty complex so it can be
> hard to see.
>
> Would it be possible for you to rebuild your kernel (or just cifs.ko)
> with this patch? Once you do that, rerun the test with cFYI turned up,
> and it should help point out what the problem is.
>
> Thanks,

Ok i am now rebuilding the kernel and will report when i have results.