[Cluster-devel] [GFS2 Patch] Simplify gfs2_write_alloc_required

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

Now in the -nmw tree. Thanks,

Steve.

On Thu, 2010-06-24 at 19:21 -0400, Bob Peterson wrote:
> Hi,
> 
> Here is a patch for a clean up I spotted:
> 
> Function gfs2_write_alloc_required always returned zero as its
> return code.  Therefore, it doesn't need to return a return code
> at all.  Given that, we can use the return value to return whether
> or not the dinode needs block allocations rather than passing
> that value in, which in turn simplifies a bunch of error checking.
> 
> Regards,
> 
> Bob Peterson
> Red Hat GFS
> 
> Signed-off-by: Bob Peterson <rpeterso@redhat.com> 
> --
>  fs/gfs2/aops.c  |    4 +---
>  fs/gfs2/bmap.c  |   15 +++++----------
>  fs/gfs2/bmap.h  |    2 +-
>  fs/gfs2/file.c  |    4 +---
>  fs/gfs2/quota.c |   15 +++------------
>  fs/gfs2/super.c |    9 +++------
>  6 files changed, 14 insertions(+), 35 deletions(-)
> 
> diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
> index 9485a88..5e96cbd 100644
> --- a/fs/gfs2/aops.c
> +++ b/fs/gfs2/aops.c
> @@ -634,9 +634,7 @@ static int gfs2_write_begin(struct file *file, struct address_space *mapping,
>  		}
>  	}
>  
> -	error = gfs2_write_alloc_required(ip, pos, len, &alloc_required);
> -	if (error)
> -		goto out_unlock;
> +	alloc_required = gfs2_write_alloc_required(ip, pos, len);
>  
>  	if (alloc_required || gfs2_is_jdata(ip))
>  		gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
> diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
> index 4a48c0f..11837fc 100644
> --- a/fs/gfs2/bmap.c
> +++ b/fs/gfs2/bmap.c
> @@ -1243,13 +1243,12 @@ int gfs2_file_dealloc(struct gfs2_inode *ip)
>   * @ip: the file being written to
>   * @offset: the offset to write to
>   * @len: the number of bytes being written
> - * @alloc_required: set to 1 if an alloc is required, 0 otherwise
>   *
> - * Returns: errno
> + * Returns: 1 if an alloc is required, 0 otherwise
>   */
>  
>  int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
> -			      unsigned int len, int *alloc_required)
> +			      unsigned int len)
>  {
>  	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
>  	struct buffer_head bh;
> @@ -1257,26 +1256,23 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
>  	u64 lblock, lblock_stop, size;
>  	u64 end_of_file;
>  
> -	*alloc_required = 0;
> -
>  	if (!len)
>  		return 0;
>  
>  	if (gfs2_is_stuffed(ip)) {
>  		if (offset + len >
>  		    sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode))
> -			*alloc_required = 1;
> +			return 1;
>  		return 0;
>  	}
>  
> -	*alloc_required = 1;
>  	shift = sdp->sd_sb.sb_bsize_shift;
>  	BUG_ON(gfs2_is_dir(ip));
>  	end_of_file = (ip->i_disksize + sdp->sd_sb.sb_bsize - 1) >> shift;
>  	lblock = offset >> shift;
>  	lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift;
>  	if (lblock_stop > end_of_file)
> -		return 0;
> +		return 1;
>  
>  	size = (lblock_stop - lblock) << shift;
>  	do {
> @@ -1284,12 +1280,11 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
>  		bh.b_size = size;
>  		gfs2_block_map(&ip->i_inode, lblock, &bh, 0);
>  		if (!buffer_mapped(&bh))
> -			return 0;
> +			return 1;
>  		size -= bh.b_size;
>  		lblock += (bh.b_size >> ip->i_inode.i_blkbits);
>  	} while(size > 0);
>  
> -	*alloc_required = 0;
>  	return 0;
>  }
>  
> diff --git a/fs/gfs2/bmap.h b/fs/gfs2/bmap.h
> index c983177..a20a521 100644
> --- a/fs/gfs2/bmap.h
> +++ b/fs/gfs2/bmap.h
> @@ -52,6 +52,6 @@ int gfs2_truncatei(struct gfs2_inode *ip, u64 size);
>  int gfs2_truncatei_resume(struct gfs2_inode *ip);
>  int gfs2_file_dealloc(struct gfs2_inode *ip);
>  int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset,
> -			      unsigned int len, int *alloc_required);
> +			      unsigned int len);
>  
>  #endif /* __BMAP_DOT_H__ */
> diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
> index ed9a94f..4edd662 100644
> --- a/fs/gfs2/file.c
> +++ b/fs/gfs2/file.c
> @@ -351,7 +351,6 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
>  	unsigned long last_index;
>  	u64 pos = page->index << PAGE_CACHE_SHIFT;
>  	unsigned int data_blocks, ind_blocks, rblocks;
> -	int alloc_required = 0;
>  	struct gfs2_holder gh;
>  	struct gfs2_alloc *al;
>  	int ret;
> @@ -364,8 +363,7 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
>  	set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
>  	set_bit(GIF_SW_PAGED, &ip->i_flags);
>  
> -	ret = gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE, &alloc_required);
> -	if (ret || !alloc_required)
> +	if (!gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE))
>  		goto out_unlock;
>  	ret = -ENOMEM;
>  	al = gfs2_alloc_get(ip);
> diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
> index 49667d6..b0954ea 100644
> --- a/fs/gfs2/quota.c
> +++ b/fs/gfs2/quota.c
> @@ -789,15 +789,9 @@ static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
>  		goto out;
>  
>  	for (x = 0; x < num_qd; x++) {
> -		int alloc_required;
> -
>  		offset = qd2offset(qda[x]);
> -		error = gfs2_write_alloc_required(ip, offset,
> -						  sizeof(struct gfs2_quota),
> -						  &alloc_required);
> -		if (error)
> -			goto out_gunlock;
> -		if (alloc_required)
> +		if (gfs2_write_alloc_required(ip, offset,
> +					      sizeof(struct gfs2_quota)))
>  			nalloc++;
>  	}
>  
> @@ -1586,10 +1580,7 @@ static int gfs2_set_dqblk(struct super_block *sb, int type, qid_t id,
>  		goto out_i;
>  
>  	offset = qd2offset(qd);
> -	error = gfs2_write_alloc_required(ip, offset, sizeof(struct gfs2_quota),
> -					  &alloc_required);
> -	if (error)
> -		goto out_i;
> +	alloc_required = gfs2_write_alloc_required(ip, offset, sizeof(struct gfs2_quota));
>  	if (alloc_required) {
>  		al = gfs2_alloc_get(ip);
>  		if (al == NULL)
> diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
> index 4d1aad3..4140811 100644
> --- a/fs/gfs2/super.c
> +++ b/fs/gfs2/super.c
> @@ -342,8 +342,6 @@ int gfs2_jdesc_check(struct gfs2_jdesc *jd)
>  {
>  	struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
>  	struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
> -	int ar;
> -	int error;
>  
>  	if (ip->i_disksize < (8 << 20) || ip->i_disksize > (1 << 30) ||
>  	    (ip->i_disksize & (sdp->sd_sb.sb_bsize - 1))) {
> @@ -352,13 +350,12 @@ int gfs2_jdesc_check(struct gfs2_jdesc *jd)
>  	}
>  	jd->jd_blocks = ip->i_disksize >> sdp->sd_sb.sb_bsize_shift;
>  
> -	error = gfs2_write_alloc_required(ip, 0, ip->i_disksize, &ar);
> -	if (!error && ar) {
> +	if (gfs2_write_alloc_required(ip, 0, ip->i_disksize)) {
>  		gfs2_consist_inode(ip);
> -		error = -EIO;
> +		return -EIO;
>  	}
>  
> -	return error;
> +	return 0;
>  }
>  
>  /**