Btrfs: return value of btrfs_read_buffer is checked correctly

btrfs_read_buffer() has the possibility of returning the error.
Therefore, I add the code in which the return value of btrfs_read_buffer()
is checked.

Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>

2 files changed, 18 insertions, 4 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 26847999c64..99fcad631a2 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -739,7 +739,11 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                                 if (!cur)
                                         return -EIO;
                         } else if (!uptodate) {
-                                btrfs_read_buffer(cur, gen);
+                                err = btrfs_read_buffer(cur, gen);
+                                if (err) {
+                                        free_extent_buffer(cur);
+                                        return err;
+                                }
                         }
                 }
                 if (search_start == 0)
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index eb1ae908582..6f22a4fca8d 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -1628,7 +1628,9 @@ static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
         int i;
         int ret;
 
-        btrfs_read_buffer(eb, gen);
+        ret = btrfs_read_buffer(eb, gen);
+        if (ret)
+                return ret;
 
         level = btrfs_header_level(eb);
 
@@ -1749,7 +1751,11 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 
                         path->slots[*level]++;
                         if (wc->free) {
-                                btrfs_read_buffer(next, ptr_gen);
+                                ret = btrfs_read_buffer(next, ptr_gen);
+                                if (ret) {
+                                        free_extent_buffer(next);
+                                        return ret;
+                                }
 
                                 btrfs_tree_lock(next);
                                 btrfs_set_lock_blocking(next);
@@ -1766,7 +1772,11 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
                         free_extent_buffer(next);
                         continue;
                 }
-                btrfs_read_buffer(next, ptr_gen);
+                ret = btrfs_read_buffer(next, ptr_gen);
+                if (ret) {
+                        free_extent_buffer(next);
+                        return ret;
+                }
 
                 WARN_ON(*level <= 0);
                 if (path->nodes[*level-1])