[Cluster-devel] [GFS2 PATCH] GFS2: Lock i_mutex and use a local gfs2_holder for fallocate

[Steven Whitehouse]

Hi,

Now in the -nmw git tree. Thanks,

Steve.

On Thu, 2014-02-06 at 10:43 -0500, Bob Peterson wrote:
> Hi,
> 
> This patch causes GFS2 to lock the i_mutex during fallocate. It
> also switches from using a dinode's inode glock to using a local
> holder like the other GFS2 i_operations.
> 
> Regards,
> 
> Bob Peterson
> Red Hat File Systems
> 
> Signed-off-by: Bob Peterson <rpeterso at redhat.com> 
> ---
> diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
> index efc078f..6c79408 100644
> --- a/fs/gfs2/file.c
> +++ b/fs/gfs2/file.c
> @@ -811,6 +811,8 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset,
>  	loff_t bsize_mask = ~((loff_t)sdp->sd_sb.sb_bsize - 1);
>  	loff_t next = (offset + len - 1) >> sdp->sd_sb.sb_bsize_shift;
>  	loff_t max_chunk_size = UINT_MAX & bsize_mask;
> +	struct gfs2_holder gh;
> +
>  	next = (next + 1) << sdp->sd_sb.sb_bsize_shift;
>  
>  	/* We only support the FALLOC_FL_KEEP_SIZE mode */
> @@ -831,8 +833,10 @@ static long gfs2_fallocate(struct file *file, int mode, loff_t offset,
>  	if (error)
>  		return error;
>  
> -	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
> -	error = gfs2_glock_nq(&ip->i_gh);
> +	mutex_lock(&inode->i_mutex);
> +
> +	gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
> +	error = gfs2_glock_nq(&gh);
>  	if (unlikely(error))
>  		goto out_uninit;
>  
> @@ -900,9 +904,10 @@ out_trans_fail:
>  out_qunlock:
>  	gfs2_quota_unlock(ip);
>  out_unlock:
> -	gfs2_glock_dq(&ip->i_gh);
> +	gfs2_glock_dq(&gh);
>  out_uninit:
> -	gfs2_holder_uninit(&ip->i_gh);
> +	gfs2_holder_uninit(&gh);
> +	mutex_unlock(&inode->i_mutex);
>  	return error;
>  }
>  
>