[Cluster-devel] [GFS2] Missing bit of readpages() fix

[Russell Cattelan]

On Thu, 2006-12-14 at 18:09 +0000, Steven Whitehouse wrote:
> Hi,
> 
> The patch below is the missing bit of the readpages fix which hasn't yet
> made it upstream. Its derived from Russell's original patch with a
> slight change in that I've fixed up the original comment at the top of
> the function rather than adding one in the body of the function. I'll
> commit this tomorrow if there are no objections & also add it to the
> pending RHEL5 patches,
ya don't move the comment, it doesn't make much sense when it is moved
out of context.

I'm still having trouble understanding why this patch is getting chopped
up and rewritten? Doing so is significantly confusing things.

> 
> Steve.
> 
> diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
> index d8d69a7..6903153 100644
> --- a/fs/gfs2/ops_address.c
> +++ b/fs/gfs2/ops_address.c
> @@ -256,7 +256,7 @@ out_unlock:
>   *    the page lock and the glock) and return having done no I/O. Its
>   *    obviously not something we'd want to do on too regular a basis.
>   *    Any I/O we ignore at this time will be done via readpage later.
> - * 2. We have to handle stuffed files here too.
> + * 2. We don't handle stuffed files here we let readpage do the honours.
>   * 3. mpage_readpages() does most of the heavy lifting in the common case.
>   * 4. gfs2_get_block() is relied upon to set BH_Boundary in the right places.
>   * 5. We use LM_FLAG_TRY_1CB here, effectively we then have lock-ahead as
> @@ -269,8 +269,7 @@ static int gfs2_readpages(struct file *f
>  	struct gfs2_inode *ip = GFS2_I(inode);
>  	struct gfs2_sbd *sdp = GFS2_SB(inode);
>  	struct gfs2_holder gh;
> -	unsigned page_idx;
> -	int ret;
> +	int ret = 0;
>  	int do_unlock = 0;
>  
>  	if (likely(file != &gfs2_internal_file_sentinel)) {
> @@ -289,29 +288,8 @@ static int gfs2_readpages(struct file *f
>  			goto out_unlock;
>  	}
>  skip_lock:
> -	if (gfs2_is_stuffed(ip)) {
> -		struct pagevec lru_pvec;
> -		pagevec_init(&lru_pvec, 0);
> -		for (page_idx = 0; page_idx < nr_pages; page_idx++) {
> -			struct page *page = list_entry(pages->prev, struct page, lru);
> -			prefetchw(&page->flags);
> -			list_del(&page->lru);
> -			if (!add_to_page_cache(page, mapping,
> -					       page->index, GFP_KERNEL)) {
> -				ret = stuffed_readpage(ip, page);
> -				unlock_page(page);
> -				if (!pagevec_add(&lru_pvec, page))
> -					 __pagevec_lru_add(&lru_pvec);
> -			} else {
> -				page_cache_release(page);
> -			}
> -		}
> -		pagevec_lru_add(&lru_pvec);
> -		ret = 0;
> -	} else {
> -		/* What we really want to do .... */
> +	if (!gfs2_is_stuffed(ip))
>  		ret = mpage_readpages(mapping, pages, nr_pages, gfs2_get_block);
> -	}
>  
>  	if (do_unlock) {
>  		gfs2_glock_dq_m(1, &gh);
> 
-- 
Russell Cattelan <cattelan at redhat.com>