[Bug 571235] [NEW] Slow CIFS navigation

[Se6]

Public bug reported:

On Karmic, with 2.6.31-20, I have noticed an important decrease of
performances while navigating CIFS shares (with mount.cifs) on a Windows
2003 server. (Compared to a older installation with 2.6.27-8).
Navigating means here either using midnight commander, ls -l (with ls
unaliased first...), rsync, etc..

The kind of performance degradation I am talking about is in the order
of times ten or so. An rsync which takes less that 2 minutes on old
hardware, now takes over 15 minutes on newer hardware!

Doing a bit of investigation with tcpdump, we can see a lot
QUERY_PATH_INFO requests happening which are not necessary as all the
information is already returned by FIND_FIRST2 requests. A trivial
example will illustrate it. Lets have a directory with 3 files inside.

ls -l with my old machine, it gives:
Protocol Info
SMB      Trans2 Request, QUERY_PATH_INFO, Query File All Info, Path: \Temp
SMB      Trans2 Response, QUERY_PATH_INFO
SMB      Trans2 Request, FIND_FIRST2, Pattern: \Temp\*
SMB      Trans2 Response, FIND_FIRST2, Files: . .. file1 file2 file3

With the new one, it gives:
Protocol Info
SMB      Trans2 Request, QUERY_PATH_INFO, Query File All Info, Path: \Temp
SMB      Trans2 Response, QUERY_PATH_INFO
SMB      Trans2 Request, FIND_FIRST2, Pattern: \Temp\*
SMB      Trans2 Response, FIND_FIRST2, Files: . .. file1 file2 file3
SMB      Trans2 Request, QUERY_PATH_INFO, Query File All Info, Path:\Temp\file1
SMB      Trans2 Response, QUERY_PATH_INFO
SMB      Trans2 Request, QUERY_PATH_INFO, Query File All Info, Path:\Temp\file2
SMB      Trans2 Response, QUERY_PATH_INFO
SMB      Trans2 Request, QUERY_PATH_INFO, Query File All Info, Path:\Temp\file3
SMB      Trans2 Response, QUERY_PATH_INFO

So for every file in the directory, as returned by the FIRST_FIND2
response, it does a QUERY_PATH_INFO, which does not bring any new
information, all the attributes were already returned by FIRST_FIND2.

Looking around in linux-cifs-client mailing list and contacting a few developers, it is believed this problem is now fixed in 2.6.31.13, commit f12f98dba6ea1517cd7fbb912208893b9c014c15. (cifs: fix length calculation for converted unicode readdir names)
Will 2.6.31.13 make it to Karmic?

Thanks,

Seb.

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New

-- 
Slow CIFS navigation
https://bugs.launchpad.net/bugs/571235
You received this bug notification because you are a member of Kernel
Bugs, which is subscribed to linux in ubuntu.