Commit 91b467e0 authored by David Howells's avatar David Howells
Browse files

afs: Make afs_readpages() fetch data in bulk 



Make afs_readpages() use afs_vnode_fetch_data()'s new ability to take a
list of pages and do a bulk fetch.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
parent 196ee9cd

fs/afs/file.c

+129 −2
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include <linux/pagemap.h>

#include <linux/writeback.h>

#include <linux/gfp.h>

#include <linux/task_io_accounting_ops.h>

#include "internal.h"



static int afs_readpage(struct file *file, struct page *page);
@@ -261,6 +262,129 @@ static int afs_readpage(struct file *file, struct page *page) 
	return ret;

}



/*

 * Make pages available as they're filled.

 */

static void afs_readpages_page_done(struct afs_call *call, struct afs_read *req)

{

	struct afs_vnode *vnode = call->reply;

	struct page *page = req->pages[req->index];



	req->pages[req->index] = NULL;

	SetPageUptodate(page);



	/* send the page to the cache */

#ifdef CONFIG_AFS_FSCACHE

	if (PageFsCache(page) &&

	    fscache_write_page(vnode->cache, page, GFP_KERNEL) != 0) {

		fscache_uncache_page(vnode->cache, page);

		BUG_ON(PageFsCache(page));

	}

#endif

	unlock_page(page);

	put_page(page);

}



/*

 * Read a contiguous set of pages.

 */

static int afs_readpages_one(struct file *file, struct address_space *mapping,

			     struct list_head *pages)

{

	struct afs_vnode *vnode = AFS_FS_I(mapping->host);

	struct afs_read *req;

	struct list_head *p;

	struct page *first, *page;

	struct key *key = file->private_data;

	pgoff_t index;

	int ret, n, i;



	/* Count the number of contiguous pages at the front of the list.  Note

	 * that the list goes prev-wards rather than next-wards.

	 */

	first = list_entry(pages->prev, struct page, lru);

	index = first->index + 1;

	n = 1;

	for (p = first->lru.prev; p != pages; p = p->prev) {

		page = list_entry(p, struct page, lru);

		if (page->index != index)

			break;

		index++;

		n++;

	}



	req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *) * n,

		      GFP_NOFS);

	if (!req)

		return -ENOMEM;



	atomic_set(&req->usage, 1);

	req->page_done = afs_readpages_page_done;

	req->pos = first->index;

	req->pos <<= PAGE_SHIFT;



	/* Transfer the pages to the request.  We add them in until one fails

	 * to add to the LRU and then we stop (as that'll make a hole in the

	 * contiguous run.

	 *

	 * Note that it's possible for the file size to change whilst we're

	 * doing this, but we rely on the server returning less than we asked

	 * for if the file shrank.  We also rely on this to deal with a partial

	 * page at the end of the file.

	 */

	do {

		page = list_entry(pages->prev, struct page, lru);

		list_del(&page->lru);

		index = page->index;

		if (add_to_page_cache_lru(page, mapping, index,

					  readahead_gfp_mask(mapping))) {

#ifdef CONFIG_AFS_FSCACHE

			fscache_uncache_page(vnode->cache, page);

#endif

			put_page(page);

			break;

		}



		req->pages[req->nr_pages++] = page;

		req->len += PAGE_SIZE;

	} while (req->nr_pages < n);



	if (req->nr_pages == 0) {

		kfree(req);

		return 0;

	}



	ret = afs_vnode_fetch_data(vnode, key, req);

	if (ret < 0)

		goto error;



	task_io_account_read(PAGE_SIZE * req->nr_pages);

	afs_put_read(req);

	return 0;



error:

	if (ret == -ENOENT) {

		_debug("got NOENT from server"

		       " - marking file deleted and stale");

		set_bit(AFS_VNODE_DELETED, &vnode->flags);

		ret = -ESTALE;

	}



	for (i = 0; i < req->nr_pages; i++) {

		page = req->pages[i];

		if (page) {

#ifdef CONFIG_AFS_FSCACHE

			fscache_uncache_page(vnode->cache, page);

#endif

			SetPageError(page);

			unlock_page(page);

		}

	}



	afs_put_read(req);

	return ret;

}



/*

 * read a set of pages

 */
@@ -314,8 +438,11 @@ static int afs_readpages(struct file *file, struct address_space *mapping, 
		return ret;

	}



	/* load the missing pages from the network */

	ret = read_cache_pages(mapping, pages, afs_page_filler, key);

	while (!list_empty(pages)) {

		ret = afs_readpages_one(file, mapping, pages);

		if (ret < 0)

			break;

	}



	_leave(" = %d [netting]", ret);

	return ret;

fs/afs/volume.c

+1 −0
Original line number Diff line number Diff line
@@ -106,6 +106,7 @@ struct afs_volume *afs_volume_lookup(struct afs_mount_params *params) 
	volume->cell		= params->cell;

	volume->vid		= vlocation->vldb.vid[params->type];



	volume->bdi.ra_pages	= VM_MAX_READAHEAD*1024/PAGE_SIZE; 

	ret = bdi_setup_and_register(&volume->bdi, "afs");

	if (ret)

		goto error_bdi;