Re: [PATCH v5 0/4] [SCSI] sg: fix race condition in sg_open

[Douglas Gilbert <dgilbert@interlog.com>]

On 13-07-25 11:32 AM, vaughan wrote:
> On 07/23/2013 01:03 AM, Jörn Engel wrote:
>> On Mon, 22 July 2013 12:40:29 +0800, Vaughan Cao wrote:
>>> There is a race when open sg with O_EXCL flag. Also a race may happen between
>>> sg_open and sg_remove.
>>>
>>> Changes from v4:
>>>   * [3/4] use ERR_PTR series instead of adding another parameter in sg_add_sfp
>>>   * [4/4] fix conflict for cherry-pick from v3.
>>>
>>> Changes from v3:
>>>   * release o_sem in sg_release(), not in sg_remove_sfp().
>>>   * not set exclude with sfd_lock held.
>>>
>>> Vaughan Cao (4):
>>>    [SCSI] sg: use rwsem to solve race during exclusive open
>>>    [SCSI] sg: no need sg_open_exclusive_lock
>>>    [SCSI] sg: checking sdp->detached isn't protected when open
>>>    [SCSI] sg: push file descriptor list locking down to per-device
>>>      locking
>>>
>>>   drivers/scsi/sg.c | 178 +++++++++++++++++++++++++-----------------------------
>>>   1 file changed, 83 insertions(+), 95 deletions(-)
>> Patchset looks good to me, although I didn't test it on hardware yet.
>> Signed-off-by: Joern Engel <joern@logfs.org>
>>
>> James, care to pick this up?
>>
>> Jörn
> Hi James,
>
> sg driver has two races happen in
>   a) exclusive open and non-exclusive open
>   b) sg removal and sg open
> I explained the scenario detail in the separate patches. I did test
> those patches and
> Jörn has reviewed them.  I got no response from Doug Gilbert for a long
> time.
> Would you care to pick these up?

Hi,
Your patches applied with a little noise to lk 3.10.2 and
gave this warning from the build.

   CC [M]  drivers/scsi/sg.o
drivers/scsi/sg.c: In function ‘sg_open’:
drivers/scsi/sg.c:242:6: warning: unused variable ‘res’ [-Wunused-variable]

I'll keep testing ...

Doug Gilbert


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