splice: handle try_to_release_page() failure
Jens Axboe [Tue, 20 May 2008 19:27:41 +0000 (21:27 +0200)]
splice currently assumes that try_to_release_page() always suceeds,
but it can return failure. If it does, we cannot steal the page.

Acked-by: Mingming Cao <cmm@us.ibm.com
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

fs/splice.c

index a048ad2..aa5f6f6 100644 (file)
@@ -58,8 +58,8 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
                 */
                wait_on_page_writeback(page);
 
-               if (PagePrivate(page))
-                       try_to_release_page(page, GFP_KERNEL);
+               if (PagePrivate(page) && !try_to_release_page(page, GFP_KERNEL))
+                       goto out_unlock;
 
                /*
                 * If we succeeded in removing the mapping, set LRU flag
@@ -75,6 +75,7 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *pipe,
         * Raced with truncate or failed to remove page from current
         * address space, unlock and return failure.
         */
+out_unlock:
        unlock_page(page);
        return 1;
 }