Btrfs: make sure we retry if we couldn't get the page

In inode.c:btrfs_page_exists_in_range(), if we can't get the page
we need to retry. However we weren't retrying because we weren't
setting page to NULL, which makes the while loop exit immediately
and will make us call page_cache_release after exiting the loop
which is incorrect because our page get didn't succeed. This could
also make us return true when we shouldn't.

Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 38d1e7b976d800caf17c38eee629d3ecb6119689..cdbd20e62bb65fccbbc99ab26ccf2f74b80577e3 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6777,8 +6777,10 @@ bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
                        break; /* TODO: Is this relevant for this use case? */
                }
 
-               if (!page_cache_get_speculative(page))
+               if (!page_cache_get_speculative(page)) {
+                       page = NULL;
                        continue;
+               }
 
                /*
                 * Has the page moved?