[-v3] ext4: add ext4_es_store_pblock_status()

Avoid false positives by static code analysis tools such as sparse and
coverity caused by the fact that we set the physical block, and then
the status in the extent_status structure.  It is also more efficient
to set both of these values at once.

Addresses-Coverity-Id: #989077
Addresses-Coverity-Id: #989078
Addresses-Coverity-Id: #1080722

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
 fs/ext4/extents_status.c | 14 ++++++--------
 fs/ext4/extents_status.h |  9 +++++++++
 2 files changed, 15 insertions(+), 8 deletions(-)

On Thu, Feb 20, 2014 at 08:59:56PM -0500, Theodore Ts'o wrote:
> Avoid false positives by static code analysis tools such as sparse and
> coverity caused by the fact that we set the physical block, and then
> the status in the extent_status structure.  It is also more efficient
> to set both of these values at once.
> 
> Addresses-Coverity-Id: #989077
> Addresses-Coverity-Id: #989078
> Addresses-Coverity-Id: #1080722
> 
> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Thanks for fixing this.  It looks good to me.
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>

                                                - Zheng

> ---
>  fs/ext4/extents_status.c | 14 ++++++--------
>  fs/ext4/extents_status.h |  9 +++++++++
>  2 files changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
> index 3981ff7..a900004 100644
> --- a/fs/ext4/extents_status.c
> +++ b/fs/ext4/extents_status.c
> @@ -658,8 +658,7 @@ int ext4_es_insert_extent(struct inode *inode, ext4_lblk_t lblk,
>  
>  	newes.es_lblk = lblk;
>  	newes.es_len = len;
> -	ext4_es_store_pblock(&newes, pblk);
> -	ext4_es_store_status(&newes, status);
> +	ext4_es_store_pblock_status(&newes, pblk, status);
>  	trace_ext4_es_insert_extent(inode, &newes);
>  
>  	ext4_es_insert_extent_check(inode, &newes);
> @@ -699,8 +698,7 @@ void ext4_es_cache_extent(struct inode *inode, ext4_lblk_t lblk,
>  
>  	newes.es_lblk = lblk;
>  	newes.es_len = len;
> -	ext4_es_store_pblock(&newes, pblk);
> -	ext4_es_store_status(&newes, status);
> +	ext4_es_store_pblock_status(&newes, pblk, status);
>  	trace_ext4_es_cache_extent(inode, &newes);
>  
>  	if (!len)
> @@ -812,13 +810,13 @@ retry:
>  
>  			newes.es_lblk = end + 1;
>  			newes.es_len = len2;
> +			block = 0x7FDEADBEEF;
>  			if (ext4_es_is_written(&orig_es) ||
> -			    ext4_es_is_unwritten(&orig_es)) {
> +			    ext4_es_is_unwritten(&orig_es))
>  				block = ext4_es_pblock(&orig_es) +
>  					orig_es.es_len - len2;
> -				ext4_es_store_pblock(&newes, block);
> -			}
> -			ext4_es_store_status(&newes, ext4_es_status(&orig_es));
> +			ext4_es_store_pblock_status(&newes, block,
> +						    ext4_es_status(&orig_es));
>  			err = __es_insert_extent(inode, &newes);
>  			if (err) {
>  				es->es_lblk = orig_es.es_lblk;
> diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
> index 167f4ab8..f1b62a4 100644
> --- a/fs/ext4/extents_status.h
> +++ b/fs/ext4/extents_status.h
> @@ -129,6 +129,15 @@ static inline void ext4_es_store_status(struct extent_status *es,
>  		       (es->es_pblk & ~ES_MASK));
>  }
>  
> +static inline void ext4_es_store_pblock_status(struct extent_status *es,
> +					       ext4_fsblk_t pb,
> +					       unsigned int status)
> +{
> +	es->es_pblk = (((ext4_fsblk_t)
> +			(status & EXTENT_STATUS_FLAGS) << ES_SHIFT) |
> +		       (pb & ~ES_MASK));
> +}
> +
>  extern void ext4_es_register_shrinker(struct ext4_sb_info *sbi);
>  extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi);
>  extern void ext4_es_lru_add(struct inode *inode);
> -- 
> 1.9.0
> 
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