1 files changed, 107 insertions, 28 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 0a77b48..0d40d08 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2726,11 +2726,11 @@ void set_page_extent_mapped(struct page *page)
  * handlers)
  * XXX JDM: This needs looking at to ensure proper page locking
  */
-static int __extent_read_full_page(struct extent_io_tree *tree,
-				   struct page *page,
-				   get_extent_t *get_extent,
-				   struct bio **bio, int mirror_num,
-				   unsigned long *bio_flags, int rw)
+static int __do_readpage(struct extent_io_tree *tree,
+			 struct page *page,
+			 get_extent_t *get_extent,
+			 struct bio **bio, int mirror_num,
+			 unsigned long *bio_flags, int rw)
 {
 	struct inode *inode = page->mapping->host;
 	u64 start = page_offset(page);
@@ -2744,7 +2744,6 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
 	sector_t sector;
 	struct extent_map *em;
 	struct block_device *bdev;
-	struct btrfs_ordered_extent *ordered;
 	int ret;
 	int nr = 0;
 	size_t pg_offset = 0;
@@ -2755,24 +2754,15 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
 
 	set_page_extent_mapped(page);
 
+	end = page_end;
 	if (!PageUptodate(page)) {
 		if (cleancache_get_page(page) == 0) {
 			BUG_ON(blocksize != PAGE_SIZE);
+			unlock_extent(tree, start, end);
 			goto out;
 		}
 	}
 
-	end = page_end;
-	while (1) {
-		lock_extent(tree, start, end);
-		ordered = btrfs_lookup_ordered_extent(inode, start);
-		if (!ordered)
-			break;
-		unlock_extent(tree, start, end);
-		btrfs_start_ordered_extent(inode, ordered, 1);
-		btrfs_put_ordered_extent(ordered);
-	}
-
 	if (page->index == last_byte >> PAGE_CACHE_SHIFT) {
 		char *userpage;
 		size_t zero_offset = last_byte & (PAGE_CACHE_SIZE - 1);
@@ -2901,6 +2891,101 @@ out:
 	return 0;
 }
 
+static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
+					     struct page *pages[], int nr_pages,
+					     u64 start, u64 end,
+					     get_extent_t *get_extent,
+					     struct bio **bio, int mirror_num,
+					     unsigned long *bio_flags, int rw)
+{
+	struct inode *inode;
+	struct btrfs_ordered_extent *ordered;
+	int index;
+
+	inode = pages[0]->mapping->host;
+	while (1) {
+		lock_extent(tree, start, end);
+		ordered = btrfs_lookup_ordered_range(inode, start,
+						     end - start + 1);
+		if (!ordered)
+			break;
+		unlock_extent(tree, start, end);
+		btrfs_start_ordered_extent(inode, ordered, 1);
+		btrfs_put_ordered_extent(ordered);
+	}
+
+	for (index = 0; index < nr_pages; index++) {
+		__do_readpage(tree, pages[index], get_extent, bio, mirror_num,
+			      bio_flags, rw);
+		page_cache_release(pages[index]);
+	}
+}
+
+static void __extent_readpages(struct extent_io_tree *tree,
+			       struct page *pages[],
+			       int nr_pages, get_extent_t *get_extent,
+			       struct bio **bio, int mirror_num,
+			       unsigned long *bio_flags, int rw)
+{
+	u64 start;
+	u64 end = 0;
+	u64 page_start;
+	int index;
+	int first_index;
+
+	for (index = 0; index < nr_pages; index++) {
+		page_start = page_offset(pages[index]);
+		if (!end) {
+			start = page_start;
+			end = start + PAGE_CACHE_SIZE - 1;
+			first_index = index;
+		} else if (end + 1 == page_start) {
+			end += PAGE_CACHE_SIZE;
+		} else {
+			__do_contiguous_readpages(tree, &pages[first_index],
+						  index - first_index, start,
+						  end, get_extent, bio,
+						  mirror_num, bio_flags, rw);
+			start = page_start;
+			end = start + PAGE_CACHE_SIZE - 1;
+			first_index = index;
+		}
+	}
+
+	if (end)
+		__do_contiguous_readpages(tree, &pages[first_index],
+					  index - first_index, start,
+					  end, get_extent, bio,
+					  mirror_num, bio_flags, rw);
+}
+
+static int __extent_read_full_page(struct extent_io_tree *tree,
+				   struct page *page,
+				   get_extent_t *get_extent,
+				   struct bio **bio, int mirror_num,
+				   unsigned long *bio_flags, int rw)
+{
+	struct inode *inode = page->mapping->host;
+	struct btrfs_ordered_extent *ordered;
+	u64 start = page_offset(page);
+	u64 end = start + PAGE_CACHE_SIZE - 1;
+	int ret;
+
+	while (1) {
+		lock_extent(tree, start, end);
+		ordered = btrfs_lookup_ordered_extent(inode, start);
+		if (!ordered)
+			break;
+		unlock_extent(tree, start, end);
+		btrfs_start_ordered_extent(inode, ordered, 1);
+		btrfs_put_ordered_extent(ordered);
+	}
+
+	ret = __do_readpage(tree, page, get_extent, bio, mirror_num, bio_flags,
+			    rw);
+	return ret;
+}
+
 int extent_read_full_page(struct extent_io_tree *tree, struct page *page,
 			    get_extent_t *get_extent, int mirror_num)
 {
@@ -3751,7 +3836,6 @@ int extent_readpages(struct extent_io_tree *tree,
 	unsigned long bio_flags = 0;
 	struct page *pagepool[16];
 	struct page *page;
-	int i = 0;
 	int nr = 0;
 
 	for (page_idx = 0; page_idx < nr_pages; page_idx++) {
@@ -3768,18 +3852,13 @@ int extent_readpages(struct extent_io_tree *tree,
 		pagepool[nr++] = page;
 		if (nr < ARRAY_SIZE(pagepool))
 			continue;
-		for (i = 0; i < nr; i++) {
-			__extent_read_full_page(tree, pagepool[i], get_extent,
-					&bio, 0, &bio_flags, READ);
-			page_cache_release(pagepool[i]);
-		}
+		__extent_readpages(tree, pagepool, nr, get_extent,
+				   &bio, 0, &bio_flags, READ);
 		nr = 0;
 	}
-	for (i = 0; i < nr; i++) {
-		__extent_read_full_page(tree, pagepool[i], get_extent,
-					&bio, 0, &bio_flags, READ);
-		page_cache_release(pagepool[i]);
-	}
+	if (nr)
+		__extent_readpages(tree, pagepool, nr, get_extent,
+				   &bio, 0, &bio_flags, READ);
 
 	BUG_ON(!list_empty(pages));
 	if (bio)