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

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

[Suresh Jayaraman]

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;
+
 GLOBAL_EXTERN struct rb_root uidtree;
 GLOBAL_EXTERN struct rb_root gidtree;
 GLOBAL_EXTERN spinlock_t siduidlock;
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 81914df..6529b69 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -165,7 +165,7 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 	}
 	tcon = tlink_tcon(tlink);
 
-	if (oplockEnabled)
+	if (oplockEnabled || enable_oplocks)
 		oplock = REQ_OPLOCK;
 
 	if (nd && (nd->flags & LOOKUP_OPEN))
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index bb71471..b76c31d 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -369,7 +369,7 @@ int cifs_open(struct inode *inode, struct file *file)
 	cFYI(1, "inode = 0x%p file flags are 0x%x for %s",
 		 inode, file->f_flags, full_path);
 
-	if (oplockEnabled)
+	if (oplockEnabled || enable_oplocks)
 		oplock = REQ_OPLOCK;
 	else
 		oplock = 0;
@@ -493,7 +493,7 @@ static int cifs_reopen_file(struct cifsFileInfo *pCifsFile, bool can_flush)
 	cFYI(1, "inode = 0x%p file flags 0x%x for %s",
 		 inode, pCifsFile->f_flags, full_path);
 
-	if (oplockEnabled)
+	if (oplockEnabled || enable_oplocks)
 		oplock = REQ_OPLOCK;
 	else
 		oplock = 0;

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

[Jeff Layton]

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...

>  GLOBAL_EXTERN struct rb_root uidtree;
>  GLOBAL_EXTERN struct rb_root gidtree;
>  GLOBAL_EXTERN spinlock_t siduidlock;
> diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
> index 81914df..6529b69 100644
> --- a/fs/cifs/dir.c
> +++ b/fs/cifs/dir.c
> @@ -165,7 +165,7 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
>  	}
>  	tcon = tlink_tcon(tlink);
>  
> -	if (oplockEnabled)
> +	if (oplockEnabled || enable_oplocks)
>  		oplock = REQ_OPLOCK;
>  
>  	if (nd && (nd->flags & LOOKUP_OPEN))
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index bb71471..b76c31d 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -369,7 +369,7 @@ int cifs_open(struct inode *inode, struct file *file)
>  	cFYI(1, "inode = 0x%p file flags are 0x%x for %s",
>  		 inode, file->f_flags, full_path);
>  
> -	if (oplockEnabled)
> +	if (oplockEnabled || enable_oplocks)
>  		oplock = REQ_OPLOCK;
>  	else
>  		oplock = 0;
> @@ -493,7 +493,7 @@ static int cifs_reopen_file(struct cifsFileInfo *pCifsFile, bool can_flush)
>  	cFYI(1, "inode = 0x%p file flags 0x%x for %s",
>  		 inode, pCifsFile->f_flags, full_path);
>  
> -	if (oplockEnabled)
> +	if (oplockEnabled || enable_oplocks)
>  		oplock = REQ_OPLOCK;
>  	else
>  		oplock = 0;


-- 
Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

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

[Steve French]

Does that really work - to disable oplocks you would need to reset both
the old (/proc/fs/cifs/OplockEnabled) and new module parm (oplock_enabled)
to zero.

We should be using one global for this, not two (the /proc/fs/cifs one
could be changed to affect "enable_oplocks")

On Tue, Oct 11, 2011 at 10:58 AM, 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;
> +
>  GLOBAL_EXTERN struct rb_root uidtree;
>  GLOBAL_EXTERN struct rb_root gidtree;
>  GLOBAL_EXTERN spinlock_t siduidlock;
> diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
> index 81914df..6529b69 100644
> --- a/fs/cifs/dir.c
> +++ b/fs/cifs/dir.c
> @@ -165,7 +165,7 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
>        }
>        tcon = tlink_tcon(tlink);
>
> -       if (oplockEnabled)
> +       if (oplockEnabled || enable_oplocks)
>                oplock = REQ_OPLOCK;
>
>        if (nd && (nd->flags & LOOKUP_OPEN))
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index bb71471..b76c31d 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -369,7 +369,7 @@ int cifs_open(struct inode *inode, struct file *file)
>        cFYI(1, "inode = 0x%p file flags are 0x%x for %s",
>                 inode, file->f_flags, full_path);
>
> -       if (oplockEnabled)
> +       if (oplockEnabled || enable_oplocks)
>                oplock = REQ_OPLOCK;
>        else
>                oplock = 0;
> @@ -493,7 +493,7 @@ static int cifs_reopen_file(struct cifsFileInfo *pCifsFile, bool can_flush)
>        cFYI(1, "inode = 0x%p file flags 0x%x for %s",
>                 inode, pCifsFile->f_flags, full_path);
>
> -       if (oplockEnabled)
> +       if (oplockEnabled || enable_oplocks)
>                oplock = REQ_OPLOCK;
>        else
>                oplock = 0;
>



-- 
Thanks,

Steve

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

[Steve French]

On Tue, Oct 11, 2011 at 11:44 AM, Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 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...

Right, leave as one variable - as I mentioned in the earlier note, it
also looks like adding
another variable broke the logic in Suresh's patch.


-- 
Thanks,

Steve

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

[Suresh Jayaraman]

On 10/12/2011 12:20 AM, Steve French wrote:
> On Tue, Oct 11, 2011 at 11:44 AM, Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> 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...

Will make this change.

> Right, leave as one variable - as I mentioned in the earlier note, it
> also looks like adding
> another variable broke the logic in Suresh's patch.
> 

Bah, indeed it did. Will repost the patches.


-Suresh

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

[Suresh Jayaraman]

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.

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

[Jeff Layton]

On Wed, 12 Oct 2011 11:29:25 +0530
Suresh Jayaraman <sjayaraman-l3A5Bk7waGM@public.gmane.org> wrote:

> 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.

I don't think so...

types.h has this:

typedef _Bool                   bool;

...and _Bool is an internal type in gcc (and other C9X compilers). I
think gcc actually uses a char for this internally, but that's not
always guaranteed to be the case. In any event, why ask for more memory
than you need here? This is just a single-bit flag.

-- 
Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>