[lustre-devel] [PATCH] Remove sparse warnings in mdc_request.c

[lustre-devel] [PATCH] Remove sparse warnings in mdc_request.c

[Dilger, Andreas]

On Mar 27, 2017, at 23:40, Skanda Guruanand <skanda.kashyap@gmail.com> wrote:
> 
> I have tried to fix the endian issues in the mdc_request.c in the
> lustre file system drivers in the staging area. Your feedback is
> welcome.

Sorry, but this patch is totally wrong.  This would break the handling of this structure
on big-endian systems.

The right fix would be to change the declaration of ldp_hash_start and ldp_hash_end from
__u64 to __le64, along with ldp_flags and ldp_pad0 (though it should be unused).

Cheers, Andreas

> CHECK   drivers/staging/lustre/lustre/mdc/mdc_request.c
> drivers/staging/lustre/lustre/mdc/mdc_request.c:958:42: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:959:42: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:962:42: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:963:42: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:985:50: warning: cast
> to restricted __le32
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1193:24: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1328:25: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1329:23: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1332:25: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1333:23: warning: cast
> to restricted __le64
> 
> ---
> drivers/staging/lustre/lustre/mdc/mdc_request.c | 20 ++++++++++----------
> 1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/staging/lustre/lustre/mdc/mdc_request.c b/drivers/staging/lustre/lustre/mdc/mdc_request.c
> index 6bc2fb8..aa8837c 100644
> --- a/drivers/staging/lustre/lustre/mdc/mdc_request.c
> +++ b/drivers/staging/lustre/lustre/mdc/mdc_request.c
> @@ -955,12 +955,12 @@ static struct page *mdc_page_locate(struct address_space *mapping, __u64 *hash,
> 		if (PageUptodate(page)) {
> 			dp = kmap(page);
> 			if (BITS_PER_LONG == 32 && hash64) {
> -				*start = le64_to_cpu(dp->ldp_hash_start) >> 32;
> -				*end   = le64_to_cpu(dp->ldp_hash_end) >> 32;
> +				*start = dp->ldp_hash_start >> 32;
> +				*end   = dp->ldp_hash_end >> 32;
> 				*hash  = *hash >> 32;
> 			} else {
> -				*start = le64_to_cpu(dp->ldp_hash_start);
> -				*end   = le64_to_cpu(dp->ldp_hash_end);
> +				*start = dp->ldp_hash_start;
> +				*end   = dp->ldp_hash_end;
> 			}
> 			if (unlikely(*start == 1 && *hash == 0))
> 				*hash = *start;
> @@ -982,7 +982,7 @@ static struct page *mdc_page_locate(struct address_space *mapping, __u64 *hash,
> 				 */
> 				kunmap(page);
> 				mdc_release_page(page,
> -						 le32_to_cpu(dp->ldp_flags) & LDF_COLLIDE);
> +						 dp->ldp_flags & LDF_COLLIDE);

Note that it would also be acceptable to use "cpu_to_le32(LDF_COLLIDE)" here, since swabbing
a constant is a compile-time operation, while swabbing a variable adds runtime overhead on
big-endian systems.

> 				page = NULL;
> 			}
> 		} else {
> @@ -1190,7 +1190,7 @@ static int mdc_read_page_remote(void *data, struct page *page0)
> 		SetPageUptodate(page);
> 
> 		dp = kmap(page);
> -		hash = le64_to_cpu(dp->ldp_hash_start);
> +		hash = dp->ldp_hash_start;
> 		kunmap(page);
> 
> 		offset = hash_x_index(hash, rp->rp_hash64);
> @@ -1325,12 +1325,12 @@ static int mdc_read_page(struct obd_export *exp, struct md_op_data *op_data,
> hash_collision:
> 	dp = page_address(page);
> 	if (BITS_PER_LONG == 32 && rp_param.rp_hash64) {
> -		start = le64_to_cpu(dp->ldp_hash_start) >> 32;
> -		end = le64_to_cpu(dp->ldp_hash_end) >> 32;
> +		start = dp->ldp_hash_start >> 32;
> +		end = dp->ldp_hash_end >> 32;
> 		rp_param.rp_off = hash_offset >> 32;
> 	} else {
> -		start = le64_to_cpu(dp->ldp_hash_start);
> -		end = le64_to_cpu(dp->ldp_hash_end);
> +		start = dp->ldp_hash_start;
> +		end = dp->ldp_hash_end;
> 		rp_param.rp_off = hash_offset;
> 	}
> 	if (end == start) {
> -- 
> 1.9.1
> 

Cheers, Andreas
--
Andreas Dilger
Lustre Principal Architect
Intel Corporation

[lustre-devel] [PATCH] Remove sparse warnings in mdc_request.c

[Greg KH]

On Thu, Mar 30, 2017 at 10:09:19PM -0700, skanda.kashyap at gmail.com wrote:
> From: Skanda Guruanand <skanda.kashyap@gmail.com>
> 
> ---
>  drivers/staging/lustre/lustre/include/lustre/lustre_idl.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)


Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- Your patch does not have a Signed-off-by: line.  Please read the
  kernel file, Documentation/SubmittingPatches and resend it after
  adding that line.  Note, the line needs to be in the body of the
  email, before the patch, not at the bottom of the patch or in the
  email signature.

- Your patch did many different things all at once, making it difficult
  to review.  All Linux kernel patches need to only do one thing at a
  time.  If you need to do multiple things (such as clean up all coding
  style issues in a file/driver), do it in a sequence of patches, each
  one doing only one thing.  This will make it easier to review the
  patches to ensure that they are correct, and to help alleviate any
  merge issues that larger patches can cause.

- You did not specify a description of why the patch is needed, or
  possibly, any description at all, in the email body.  Please read the
  section entitled "The canonical patch format" in the kernel file,
  Documentation/SubmittingPatches for what is needed in order to
  properly describe the change.

- You did not write a descriptive Subject: for the patch, allowing Greg,
  and everyone else, to know what this patch is all about.  Please read
  the section entitled "The canonical patch format" in the kernel file,
  Documentation/SubmittingPatches for what a proper Subject: line should
  look like.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot

[lustre-devel] [PATCH v2] Remove sparse warnings in mdc_request.c

[Greg KH]

On Mon, Apr 03, 2017 at 10:25:37PM -0700, skanda.kashyap at gmail.com wrote:
> From: Skanda Guruanand <skanda.kashyap@gmail.com>
> 
> Signed-off-by: Skanda Guruanand <skanda.kashyap@gmail.com>
> 
> I have modified  struct lu_dirpage as suggested in lustre_idl.h file
> 
> CHECK   drivers/staging/lustre/lustre/mdc/mdc_request.c
> drivers/staging/lustre/lustre/mdc/mdc_request.c:958:42: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:959:42: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:962:42: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:963:42: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:985:50: warning: cast
> to restricted __le32
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1193:24: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1328:25: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1329:23: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1332:25: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1333:23: warning: cast
> to restricted __le64
> 
> ---
>  drivers/staging/lustre/lustre/include/lustre/lustre_idl.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

What changed from v1?

Always put that here below the --- line.

v3?

thanks,

greg k-h

[lustre-devel] [PATCH v2] Remove sparse warnings in mdc_request.c

[Greg KH]

On Mon, Apr 03, 2017 at 10:25:37PM -0700, skanda.kashyap at gmail.com wrote:
> From: Skanda Guruanand <skanda.kashyap@gmail.com>
> 
> Signed-off-by: Skanda Guruanand <skanda.kashyap@gmail.com>

Changelog text goes between those two lines, right?

> 
> I have modified  struct lu_dirpage as suggested in lustre_idl.h file

Why the extra ' '?

> 
> CHECK   drivers/staging/lustre/lustre/mdc/mdc_request.c
> drivers/staging/lustre/lustre/mdc/mdc_request.c:958:42: warning: cast
> to restricted __le64

Why is this all wrapped?




> drivers/staging/lustre/lustre/mdc/mdc_request.c:959:42: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:962:42: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:963:42: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:985:50: warning: cast
> to restricted __le32
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1193:24: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1328:25: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1329:23: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1332:25: warning: cast
> to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1333:23: warning: cast
> to restricted __le64
> 
> ---
>  drivers/staging/lustre/lustre/include/lustre/lustre_idl.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
> index 60b827e..df48b8d 100644
> --- a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
> +++ b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
> @@ -846,10 +846,10 @@ struct luda_type {
>  #endif
>  
>  struct lu_dirpage {
> -	__u64	    ldp_hash_start;
> -	__u64	    ldp_hash_end;
> -	__u32	    ldp_flags;
> -	__u32	    ldp_pad0;
> +	__le64	    ldp_hash_start;
> +	__le64	    ldp_hash_end;
> +	__le32	    ldp_flags;
> +	__le32	    ldp_pad0;


Are you sure this is correct?  How was it tested?

Also, please fix your subject to properly match those already made for
this driver...

thanks,

greg k-h

[lustre-devel] [PATCH v2] Fix endianness issues in mdc_request.c

[Greg KH]

On Mon, Apr 10, 2017 at 10:05:25PM -0700, skanda.kashyap at gmail.com wrote:
> From: Skanda Guruanand <skanda.kashyap@gmail.com>
> 
> Signed-off-by: Skanda Guruanand <skanda.kashyap@gmail.com>

I can't take patches with no changelog text at all, sorry.

Please fix up and resend.

greg k-h

[lustre-devel] [PATCH v2] Fix endianness issues in mdc_request.c

[Greg KH]

On Tue, Apr 11, 2017 at 09:22:37PM -0700, skanda.kashyap at gmail.com wrote:
> From: Skanda Guruanand <skanda.kashyap@gmail.com>

Your subject is odd, please match other commits made for this driver
when you resend it.

> Sparse generates warnings where cast to restricted types are made.
> This commit changes types of struct fields to match endianness.

Why do you have info below --- that should be up here?

> 
> Signed-off-by: Skanda Guruanand <skanda.kashyap@gmail.com>
> ---
> I have modified struct lu_dirpage in lustre_idl.h file to remove the sparse warnings
> where cast to restricted types are made.
> 
> Following warnings were removed by this fix.
> 
> drivers/staging/lustre/lustre/mdc/mdc_request.c:958:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:959:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:962:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:963:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:985:50: warning: cast to restricted __le32
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1193:24: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1328:25: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1329:23: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1332:25: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1333:23: warning: cast to restricted __le64
> 
> I have not got a chance to test it as I don't have a big endian system. I feel the change
> is reasonably correct as the elements of the structure lu_dirpage are always converted from
> little-endian format to processor's native format.
> 
>  drivers/staging/lustre/lustre/include/lustre/lustre_idl.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
> index 60b827e..df48b8d 100644
> --- a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
> +++ b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
> @@ -846,10 +846,10 @@ struct luda_type {
>  #endif
>  
>  struct lu_dirpage {
> -	__u64	    ldp_hash_start;
> -	__u64	    ldp_hash_end;
> -	__u32	    ldp_flags;
> -	__u32	    ldp_pad0;
> +	__le64	    ldp_hash_start;
> +	__le64	    ldp_hash_end;
> +	__le32	    ldp_flags;
> +	__le32	    ldp_pad0;

I need a bit more confidence that this is the correct change before I
can take it.  What can you do to provide that?

thanks,

greg k-h

[lustre-devel] [PATCH v2] staging: lustre: Fix sparse endianness warnings cast to restricted __le64 and __le32

[Greg KH]

On Thu, Apr 13, 2017 at 12:09:23AM -0700, skanda.kashyap at gmail.com wrote:
> From: Skanda Guruanand <skanda.kashyap@gmail.com>
> 
> Modified struct lu_dirpage in lustre_idl.h file to remove the sparse
> warnings where cast to restricted types are made.
> 
> Following warnings are removed by this fix.
> 
> drivers/staging/lustre/lustre/mdc/mdc_request.c:958:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:959:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:962:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:963:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:985:50: warning: cast to restricted __le32
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1193:24: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1328:25: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1329:23: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1332:25: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1333:23: warning: cast to restricted __le64
> 
> Signed-off-by: Skanda Guruanand <skanda.kashyap@gmail.com>
> ---
> Isn't the below reason good enough?
> Since the structure elements are always converted from little endian to processor native format
> in mdc_request.c, struct lu_dirpage element types is modified.

Why isn't this above in the changelog text?

And I need an ack from a lustre maintainer before I can take this...

thanks,

greg k-h

[lustre-devel] [PATCH v2] staging: lustre: Fix sparse endianness warnings cast to restricted __le64 and __le32

[Dilger, Andreas]

On Apr 15, 2017, at 18:48, skanda.kashyap at gmail.com wrote:
> 
> From: Skanda Guruanand <skanda.kashyap@gmail.com>
> 
> The struct lu_dirpage elements in lustre_idl.h file are modified to
> __le64 and __le32 types since the  elements are always converted from
> litte endian to processor native format in mdc_request.c file.
> 
> Following warnings are removed by this fix.
> 
> drivers/staging/lustre/lustre/mdc/mdc_request.c:958:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:959:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:962:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:963:42: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:985:50: warning: cast to restricted __le32
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1193:24: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1328:25: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1329:23: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1332:25: warning: cast to restricted __le64
> drivers/staging/lustre/lustre/mdc/mdc_request.c:1333:23: warning: cast to restricted __le64
> 
> Signed-off-by: Skanda Guruanand <skanda.kashyap@gmail.com>

Thanks for the patch.

The resend of this patch should really have been marked "[PATCH v3]", but hopefully Greg
will still notice this one.

Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>

> ---
> drivers/staging/lustre/lustre/include/lustre/lustre_idl.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
> index 60b827e..df48b8d 100644
> --- a/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
> +++ b/drivers/staging/lustre/lustre/include/lustre/lustre_idl.h
> @@ -846,10 +846,10 @@ struct luda_type {
> #endif
> 
> struct lu_dirpage {
> -	__u64	    ldp_hash_start;
> -	__u64	    ldp_hash_end;
> -	__u32	    ldp_flags;
> -	__u32	    ldp_pad0;
> +	__le64	    ldp_hash_start;
> +	__le64	    ldp_hash_end;
> +	__le32	    ldp_flags;
> +	__le32	    ldp_pad0;
> 	struct lu_dirent ldp_entries[0];
> };
> 
> -- 
> 1.9.1
> 

Cheers, Andreas
--
Andreas Dilger
Lustre Principal Architect
Intel Corporation