btrfs: Fix error handling in zlib

Return failure if alloc_page() fails to allocate memory,
and the upper code will just give up compression.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/btrfs/zlib.c b/fs/btrfs/zlib.c
index e5b8b22e07d6..b01558661e3b 100644
--- a/fs/btrfs/zlib.c
+++ b/fs/btrfs/zlib.c
@@ -225,6 +225,10 @@ int btrfs_zlib_compress_pages(struct address_space *mapping,
         data_in = kmap(in_page);
 
         out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+        if (out_page == NULL) {
+                ret = -1;
+                goto out;
+        }
         cpage_out = kmap(out_page);
         pages[0] = out_page;
         nr_pages = 1;
@@ -263,6 +267,10 @@ int btrfs_zlib_compress_pages(struct address_space *mapping,
                                 goto out;
                         }
                         out_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
+                        if (out_page == NULL) {
+                                ret = -1;
+                                goto out;
+                        }
                         cpage_out = kmap(out_page);
                         pages[nr_pages] = out_page;
                         nr_pages++;