Re: [PATCH 1/3] cifs: add new module parameter 'enable_oplocks'

[Suresh Jayaraman <sjayaraman-l3A5Bk7waGM@public.gmane.org>]

On 10/11/2011 10:14 PM, Jeff Layton wrote:
> On Tue, 11 Oct 2011 21:28:00 +0530
> Suresh Jayaraman <sjayaraman-l3A5Bk7waGM@public.gmane.org> wrote:
> 
>> Thus spake Jeff Layton:
>>
>> "Making that a module parm would allow you to set that parameter at boot
>> time without needing to add special startup scripts. IMO, all of the
>> procfile "switches" under /proc/fs/cifs should be module parms
>> instead."
>>
>> This patch doesn't alter the default behavior (Oplocks are enabled by
>> default).
>>
>> To disable oplocks when loading the module, use
>>  
>>    modprobe cifs enable_oplocks=0
>>
>> (any of '0' or 'n' or 'N' conventions can be used).
>>
>> To disable oplocks at runtime using the new interface, use
>>
>>    echo 0 > /sys/module/cifs/parameters/enable_oplocks
>>
>> The older /proc/fs/cifs/OplockEnabled interface will be deprecated
>> after two releases. A subsequent patch will add an warning message
>> about the deprecation.
>>
>> Reported-by: Alexander Swen <alex-UE4+9DRHXtc@public.gmane.org>
>> Cc: Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
>> Signed-off-by: Suresh Jayaraman <sjayaraman-l3A5Bk7waGM@public.gmane.org>
>> ---
>>  fs/cifs/cifsfs.c   |    5 +++++
>>  fs/cifs/cifsglob.h |    3 +++
>>  fs/cifs/dir.c      |    2 +-
>>  fs/cifs/file.c     |    4 ++--
>>  4 files changed, 11 insertions(+), 3 deletions(-)
>>
>> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
>> index 3e29899..675ab40 100644
>> --- a/fs/cifs/cifsfs.c
>> +++ b/fs/cifs/cifsfs.c
>> @@ -81,6 +81,11 @@ module_param(echo_retries, ushort, 0644);
>>  MODULE_PARM_DESC(echo_retries, "Number of echo attempts before giving up and "
>>  			       "reconnecting server. Default: 5. 0 means "
>>  			       "never reconnect.");
>> +unsigned int enable_oplocks = 1;
>> +module_param(enable_oplocks, bool, 0644);
>> +MODULE_PARM_DESC(enable_oplocks, "Enable or disable oplocks (bool). Default:"
>> +				 "y/Y/1");
>> +
>>  extern mempool_t *cifs_sm_req_poolp;
>>  extern mempool_t *cifs_req_poolp;
>>  extern mempool_t *cifs_mid_poolp;
>> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
>> index 6255fa8..b3e229c 100644
>> --- a/fs/cifs/cifsglob.h
>> +++ b/fs/cifs/cifsglob.h
>> @@ -936,6 +936,9 @@ GLOBAL_EXTERN unsigned int cifs_max_pending; /* MAX requests at once to server*/
>>  /* reconnect after this many failed echo attempts */
>>  GLOBAL_EXTERN unsigned short echo_retries;
>>  
>> +/* enable or disable oplocks */
>> +GLOBAL_EXTERN unsigned int enable_oplocks;
>> +
> 
> Let's not add an extra variable for this. I'd just rename oplockEnabled
> to enable_oplocks and fix up all the references to it. It should
> probably also be a bool too...
> 

Need not be I think. Looking in to it further it looks like 'bool' type
of module parameter are stored in variable of type 'int'. Looking into a
few examples comfirms this too (e.g. enable_ino64 and printk_time etc.).
So, I'll make it an int.