X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=mm%2Freadahead.c;h=a30e0dc60e9474413b75531b3ca727219625bdea;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=54d3393219345f0f6c593f535917caba20fcc1d2;hpb=16c70f8c1b54b61c3b951b6fb220df250fe09b32;p=linux-2.6.git

diff --git a/mm/readahead.c b/mm/readahead.c
index 54d339321..a30e0dc60 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -13,8 +13,8 @@
 #include <linux/module.h>
 #include <linux/blkdev.h>
 #include <linux/backing-dev.h>
+#include <linux/task_io_accounting_ops.h>
 #include <linux/pagevec.h>
-#include <linux/buffer_head.h>
 
 void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 {
@@ -39,6 +39,7 @@ file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping)
 	ra->ra_pages = mapping->backing_dev_info->ra_pages;
 	ra->prev_page = -1;
 }
+EXPORT_SYMBOL_GPL(file_ra_state_init);
 
 /*
  * Return max readahead size for this inode in number-of-pages.
@@ -118,26 +119,6 @@ static inline unsigned long get_next_ra_size(struct file_ra_state *ra)
 
 #define list_to_page(head) (list_entry((head)->prev, struct page, lru))
 
-/*
- * see if a page needs releasing upon read_cache_pages() failure
- * - the caller of read_cache_pages() may have set PG_private before calling,
- *   such as the NFS fs marking pages that are cached locally on disk, thus we
- *   need to give the fs a chance to clean up in the event of an error
- */
-static void read_cache_pages_release_page(struct address_space *mapping,
-					  struct page *page)
-{
-	if (PagePrivate(page)) {
-		if (TestSetPageLocked(page))
-			BUG();
-		page->mapping = mapping;
-		try_to_release_page(page, GFP_KERNEL);
-		page->mapping = NULL;
-		unlock_page(page);
-	}
-	page_cache_release(page);
-}
-
 /**
  * read_cache_pages - populate an address space with some pages & start reads against them
  * @mapping: the address_space
@@ -161,22 +142,17 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages,
 		page = list_to_page(pages);
 		list_del(&page->lru);
 		if (add_to_page_cache(page, mapping, page->index, GFP_KERNEL)) {
-			read_cache_pages_release_page(mapping, page);
+			page_cache_release(page);
 			continue;
 		}
 		ret = filler(data, page);
 		if (!pagevec_add(&lru_pvec, page))
 			__pagevec_lru_add(&lru_pvec);
 		if (ret) {
-			while (!list_empty(pages)) {
-				struct page *victim;
-
-				victim = list_to_page(pages);
-				list_del(&victim->lru);
-				read_cache_pages_release_page(mapping, victim);
-			}
+			put_pages_list(pages);
 			break;
 		}
+		task_io_account_read(PAGE_CACHE_SIZE);
 	}
 	pagevec_lru_add(&lru_pvec);
 	return ret;
@@ -193,6 +169,8 @@ static int read_pages(struct address_space *mapping, struct file *filp,
 
 	if (mapping->a_ops->readpages) {
 		ret = mapping->a_ops->readpages(filp, mapping, pages, nr_pages);
+		/* Clean up the remaining pages */
+		put_pages_list(pages);
 		goto out;
 	}
 
@@ -229,6 +207,8 @@ out:
  *              If page_cache_readahead sees that it is again being called for
  *              a page which it just looked at, it can return immediately without
  *              making any state changes.
+ * offset:      Offset in the prev_page where the last read ended - used for
+ *              detection of sequential file reading.
  * ahead_start,
  * ahead_size:  Together, these form the "ahead window".
  * ra_pages:	The externally controlled max readahead for this fd.
@@ -474,7 +454,7 @@ static int make_ahead_window(struct address_space *mapping, struct file *filp,
  *
  * Note that @filp is purely used for passing on to the ->readpage[s]()
  * handler: it may refer to a different file from @mapping (so we may not use
- * @filp->f_mapping or @filp->f_dentry->d_inode here).
+ * @filp->f_mapping or @filp->f_path.dentry->d_inode here).
  * Also, @ra may not be equal to &@filp->f_ra.
  *
  */
@@ -495,6 +475,7 @@ page_cache_readahead(struct address_space *mapping, struct file_ra_state *ra,
 	/* Note that prev_page == -1 if it is a first read */
 	sequential = (offset == ra->prev_page + 1);
 	ra->prev_page = offset;
+	ra->offset = 0;
 
 	max = get_max_readahead(ra);
 	newsize = min(req_size, max);