[PATCH] fuse: fix error case in fuse_readpages

Don't let fuse_readpages leave the @pages list not empty when exiting
on error.

[akpm@osdl.org: kernel-doc fixes]
Signed-off-by: Alexander Zarochentsev <zam@namesys.com>
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 29 insertions, 2 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 63614ed163..5c4fcd1dbf 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -395,14 +395,16 @@ static int fuse_readpages(struct file *file, struct address_space *mapping,
         struct fuse_readpages_data data;
         int err;
 
+        err = -EIO;
         if (is_bad_inode(inode))
-                return -EIO;
+                goto clean_pages_up;
 
         data.file = file;
         data.inode = inode;
         data.req = fuse_get_req(fc);
+        err = PTR_ERR(data.req);
         if (IS_ERR(data.req))
-                return PTR_ERR(data.req);
+                goto clean_pages_up;
 
         err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
         if (!err) {
@@ -412,6 +414,10 @@ static int fuse_readpages(struct file *file, struct address_space *mapping,
                         fuse_put_request(fc, data.req);
         }
         return err;
+
+clean_pages_up:
+        put_pages_list(pages);
+        return err;
 }
 
 static size_t fuse_send_write(struct fuse_req *req, struct file *file,
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 990957e092..f0b135cd86 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -336,6 +336,7 @@ static inline void init_page_count(struct page *page)
 }
 
 void put_page(struct page *page);
+void put_pages_list(struct list_head *pages);
 
 void split_page(struct page *page, unsigned int order);
 
diff --git a/mm/swap.c b/mm/swap.c
index 8fd095c4ae..687686a61f 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -54,6 +54,26 @@ void put_page(struct page *page)
 }
 EXPORT_SYMBOL(put_page);
 
+/**
+ * put_pages_list(): release a list of pages
+ *
+ * Release a list of pages which are strung together on page.lru.  Currently
+ * used by read_cache_pages() and related error recovery code.
+ *
+ * @pages: list of pages threaded on page->lru
+ */
+void put_pages_list(struct list_head *pages)
+{
+        while (!list_empty(pages)) {
+                struct page *victim;
+
+                victim = list_entry(pages->prev, struct page, lru);
+                list_del(&victim->lru);
+                page_cache_release(victim);
+        }
+}
+EXPORT_SYMBOL(put_pages_list);
+
 /*
  * Writeback is about to end against a page which has been marked for immediate
  * reclaim.  If it still appears to be reclaimable, move it to the tail of the