X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=mm%2Freadahead.c;h=8d6eeaaa6296f9fb2372cff059138cbdd4b89723;hb=432e7c0dfe884b6ab1c32fd3f17c64c31d8fa7e2;hp=d0b50034e245a0095c7d359388b59676af0bdb59;hpb=f5c7f03113fc9c547012cf403aec4b534d575ef0;p=linux-2.6-omap-h63xx.git

diff --git a/mm/readahead.c b/mm/readahead.c
index d0b50034e24..8d6eeaaa629 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -158,7 +158,7 @@ static int read_pages(struct address_space *mapping, struct file *filp,
 {
 	unsigned page_idx;
 	struct pagevec lru_pvec;
-	int ret = 0;
+	int ret;
 
 	if (mapping->a_ops->readpages) {
 		ret = mapping->a_ops->readpages(filp, mapping, pages, nr_pages);
@@ -171,14 +171,17 @@ static int read_pages(struct address_space *mapping, struct file *filp,
 		list_del(&page->lru);
 		if (!add_to_page_cache(page, mapping,
 					page->index, GFP_KERNEL)) {
-			mapping->a_ops->readpage(filp, page);
-			if (!pagevec_add(&lru_pvec, page))
-				__pagevec_lru_add(&lru_pvec);
-		} else {
-			page_cache_release(page);
+			ret = mapping->a_ops->readpage(filp, page);
+			if (ret != AOP_TRUNCATED_PAGE) {
+				if (!pagevec_add(&lru_pvec, page))
+					__pagevec_lru_add(&lru_pvec);
+				continue;
+			} /* else fall through to release */
 		}
+		page_cache_release(page);
 	}
 	pagevec_lru_add(&lru_pvec);
+	ret = 0;
 out:
 	return ret;
 }
@@ -254,7 +257,7 @@ out:
  */
 static int
 __do_page_cache_readahead(struct address_space *mapping, struct file *filp,
-			unsigned long offset, unsigned long nr_to_read)
+			pgoff_t offset, unsigned long nr_to_read)
 {
 	struct inode *inode = mapping->host;
 	struct page *page;
@@ -274,7 +277,7 @@ __do_page_cache_readahead(struct address_space *mapping, struct file *filp,
 	 */
 	read_lock_irq(&mapping->tree_lock);
 	for (page_idx = 0; page_idx < nr_to_read; page_idx++) {
-		unsigned long page_offset = offset + page_idx;
+		pgoff_t page_offset = offset + page_idx;
 		
 		if (page_offset > end_index)
 			break;
@@ -311,7 +314,7 @@ out:
  * memory at once.
  */
 int force_page_cache_readahead(struct address_space *mapping, struct file *filp,
-		unsigned long offset, unsigned long nr_to_read)
+		pgoff_t offset, unsigned long nr_to_read)
 {
 	int ret = 0;
 
@@ -368,7 +371,7 @@ static inline int check_ra_success(struct file_ra_state *ra,
  * request queues.
  */
 int do_page_cache_readahead(struct address_space *mapping, struct file *filp,
-			unsigned long offset, unsigned long nr_to_read)
+			pgoff_t offset, unsigned long nr_to_read)
 {
 	if (bdi_read_congested(mapping->backing_dev_info))
 		return -1;
@@ -385,7 +388,7 @@ int do_page_cache_readahead(struct address_space *mapping, struct file *filp,
  */
 static int
 blockable_page_cache_readahead(struct address_space *mapping, struct file *filp,
-			unsigned long offset, unsigned long nr_to_read,
+			pgoff_t offset, unsigned long nr_to_read,
 			struct file_ra_state *ra, int block)
 {
 	int actual;
@@ -430,14 +433,27 @@ static int make_ahead_window(struct address_space *mapping, struct file *filp,
 	return ret;
 }
 
-/*
- * page_cache_readahead is the main function.  If performs the adaptive
+/**
+ * page_cache_readahead - generic adaptive readahead
+ * @mapping: address_space which holds the pagecache and I/O vectors
+ * @ra: file_ra_state which holds the readahead state
+ * @filp: passed on to ->readpage() and ->readpages()
+ * @offset: start offset into @mapping, in PAGE_CACHE_SIZE units
+ * @req_size: hint: total size of the read which the caller is performing in
+ *            PAGE_CACHE_SIZE units
+ *
+ * page_cache_readahead() is the main function.  If performs the adaptive
  * readahead window size management and submits the readahead I/O.
+ *
+ * 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).
+ * Also, @ra may not be equal to &@filp->f_ra.
+ *
  */
 unsigned long
 page_cache_readahead(struct address_space *mapping, struct file_ra_state *ra,
-		     struct file *filp, unsigned long offset,
-		     unsigned long req_size)
+		     struct file *filp, pgoff_t offset, unsigned long req_size)
 {
 	unsigned long max, newsize;
 	int sequential;