1 files changed, 27 insertions, 1 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 3a7928f825e4..91ae46098ea4 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3023,6 +3023,14 @@ out:
         return err;
 }
 
+static void unmap_underlying_metadata_blocks(struct block_device *bdev,
+                        sector_t block, int count)
+{
+        int i;
+        for (i = 0; i < count; i++)
+                unmap_underlying_metadata(bdev, block + i);
+}
+
 static int
 ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
                         ext4_lblk_t iblock, unsigned int max_blocks,
@@ -3098,6 +3106,18 @@ out:
         } else
                 allocated = ret;
         set_buffer_new(bh_result);
+        /*
+         * if we allocated more blocks than requested
+         * we need to make sure we unmap the extra block
+         * allocated. The actual needed block will get
+         * unmapped later when we find the buffer_head marked
+         * new.
+         */
+        if (allocated > max_blocks) {
+                unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
+                                        newblock + max_blocks,
+                                        allocated - max_blocks);
+        }
 map_out:
         set_buffer_mapped(bh_result);
 out1:
@@ -3190,7 +3210,13 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
          * this situation is possible, though, _during_ tree modification;
          * this is why assert can't be put in ext4_ext_find_extent()
          */
-        BUG_ON(path[depth].p_ext == NULL && depth != 0);
+        if (path[depth].p_ext == NULL && depth != 0) {
+                ext4_error(inode->i_sb, __func__, "bad extent address "
+                           "inode: %lu, iblock: %d, depth: %d",
+                           inode->i_ino, iblock, depth);
+                err = -EIO;
+                goto out2;
+        }
         eh = path[depth].p_hdr;
 
         ex = path[depth].p_ext;