#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);
return 0;
}
+/*
+ * Dispose of a ref to a read record.
+ */
+void afs_put_read(struct afs_read *req)
+{
+ int i;
+
+ if (atomic_dec_and_test(&req->usage)) {
+ for (i = 0; i < req->nr_pages; i++)
+ if (req->pages[i])
+ put_page(req->pages[i]);
+ kfree(req);
+ }
+}
+
#ifdef CONFIG_AFS_FSCACHE
/*
* deal with notification that a page was read from the cache
{
struct inode *inode = page->mapping->host;
struct afs_vnode *vnode = AFS_FS_I(inode);
+ struct afs_read *req;
struct key *key = data;
- size_t len;
- off_t offset;
int ret;
_enter("{%x},{%lu},{%lu}", key_serial(key), inode->i_ino, page->index);
_debug("cache said ENOBUFS");
default:
go_on:
- offset = page->index << PAGE_SHIFT;
- len = min_t(size_t, i_size_read(inode) - offset, PAGE_SIZE);
+ req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
+ GFP_KERNEL);
+ if (!req)
+ goto enomem;
+
+ atomic_set(&req->usage, 1);
+ req->pos = (loff_t)page->index << PAGE_SHIFT;
+ req->len = min_t(size_t, i_size_read(inode) - req->pos,
+ PAGE_SIZE);
+ req->nr_pages = 1;
+ req->pages[0] = page;
+ get_page(page);
/* read the contents of the file from the server into the
* page */
- ret = afs_vnode_fetch_data(vnode, key, offset, len, page);
+ ret = afs_vnode_fetch_data(vnode, key, req);
+ afs_put_read(req);
if (ret < 0) {
if (ret == -ENOENT) {
_debug("got NOENT from server"
_leave(" = 0");
return 0;
+enomem:
+ ret = -ENOMEM;
error:
SetPageError(page);
unlock_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)
+{
+#ifdef CONFIG_AFS_FSCACHE
+ struct afs_vnode *vnode = call->reply;
+#endif
+ 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
*/
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;
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