[linux-cifs-client] slab error: cache `cifs_small_rq': Can't free all objects

[Igor Mammedov]

While testing DFS root code, I've stumbled upon following error:

[  145.145962]  /tmp/linux-2.6.22.9/kernel/fs/cifs/cifsfs.c: exit_cifs
[  145.147948] slab error in kmem_cache_destroy(): cache `cifs_small_rq': Can't free all objects
[  145.148371] Pid: 1895, comm: rmmod Not tainted 2.6.28-rc5 #28
[  145.148722] Call Trace:
[  145.149003]  [<c0457e52>] kmem_cache_destroy+0x5a/0x9e
[  145.149303]  [<c7e80071>] cifs_destroy_request_bufs+0x2b/0x2d [cifs]
[  145.149617]  [<c7e9ea12>] exit_cifs+0x4e/0xca [cifs]
[  145.149940]  [<c042dc40>] sys_delete_module+0x158/0x1a4
[  145.150232]  [<c040f469>] ? do_page_fault+0x27f/0x532
[  145.150519]  [<c040381d>] sysenter_do_call+0x12/0x21

Then I returned to original Steve git tree and get the same error.

To reproduce it run something like this: 

# while /bin/true; do insmod cifs.ko ; mount bla /bla; umount /bla; rmmod cifs done

That's probably caused by alive cifs_demultiplex_thread because we only tell it to die
in umount, but we do not wait till it will happen.

PS:
Seldom I can get more nasty oops messages.

-- 

Best regards,

-------------------------
Igor Mammedov,
niallain "at" gmail.com