cachefiles: drop direct usage of ->bmap method.

Replace the direct usage of ->bmap method by a bmap() call.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/cachefiles/rdwr.c

@@ -396,7 +396,7 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
 	struct cachefiles_object *object;
 	struct cachefiles_cache *cache;
 	struct inode *inode;
-	sector_t block0, block;
+	sector_t block;
 	unsigned shift;
 	int ret;
 
@@ -412,7 +412,6 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
 
 	inode = d_backing_inode(object->backer);
 	ASSERT(S_ISREG(inode->i_mode));
-	ASSERT(inode->i_mapping->a_ops->bmap);
 	ASSERT(inode->i_mapping->a_ops->readpages);
 
 	/* calculate the shift required to use bmap */
@@ -428,12 +427,14 @@ int cachefiles_read_or_alloc_page(struct fscache_retrieval *op,
 	 *   enough for this as it doesn't indicate errors, but it's all we've
 	 *   got for the moment
 	 */
-	block0 = page->index;
-	block0 <<= shift;
+	block = page->index;
+	block <<= shift;
+
+	ret = bmap(inode, &block);
+	ASSERT(ret < 0);
 
-	block = inode->i_mapping->a_ops->bmap(inode->i_mapping, block0);
 	_debug("%llx -> %llx",
-	       (unsigned long long) block0,
+	       (unsigned long long) (page->index << shift),
 	       (unsigned long long) block);
 
 	if (block) {
@@ -711,7 +712,6 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
 
 	inode = d_backing_inode(object->backer);
 	ASSERT(S_ISREG(inode->i_mode));
-	ASSERT(inode->i_mapping->a_ops->bmap);
 	ASSERT(inode->i_mapping->a_ops->readpages);
 
 	/* calculate the shift required to use bmap */
@@ -728,7 +728,7 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
 
 	ret = space ? -ENODATA : -ENOBUFS;
 	list_for_each_entry_safe(page, _n, pages, lru) {
-		sector_t block0, block;
+		sector_t block;
 
 		/* we assume the absence or presence of the first block is a
 		 * good enough indication for the page as a whole
@@ -736,13 +736,14 @@ int cachefiles_read_or_alloc_pages(struct fscache_retrieval *op,
 		 *   good enough for this as it doesn't indicate errors, but
 		 *   it's all we've got for the moment
 		 */
-		block0 = page->index;
-		block0 <<= shift;
+		block = page->index;
+		block <<= shift;
+
+		ret = bmap(inode, &block);
+		ASSERT(!ret);
 
-		block = inode->i_mapping->a_ops->bmap(inode->i_mapping,
-						      block0);
 		_debug("%llx -> %llx",
-		       (unsigned long long) block0,
+		       (unsigned long long) (page->index << shift),
 		       (unsigned long long) block);
 
 		if (block) {