udf: Handle error when adding extent to symlink

When adding extent describing symlink data fails, make sure to handle
the error properly, propagate it up and free the already allocated
block.
Signed-off-by: Jan Kara <jack@suse.cz>

fs/udf/namei.c

@@ -613,8 +613,12 @@ static int udf_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 				iinfo->i_location.partitionReferenceNum;
 		bsize = sb->s_blocksize;
 		iinfo->i_lenExtents = bsize;
-		udf_add_aext(inode, &epos, &eloc, bsize, 0);
+		err = udf_add_aext(inode, &epos, &eloc, bsize, 0);
 		brelse(epos.bh);
+		if (err < 0) {
+			udf_free_blocks(sb, inode, &eloc, 0, 1);
+			goto out_no_entry;
+		}
 
 		block = udf_get_pblock(sb, block,
 				iinfo->i_location.partitionReferenceNum,
@@ -622,6 +626,7 @@ static int udf_symlink(struct user_namespace *mnt_userns, struct inode *dir,
 		epos.bh = udf_tgetblk(sb, block);
 		if (unlikely(!epos.bh)) {
 			err = -ENOMEM;
+			udf_free_blocks(sb, inode, &eloc, 0, 1);
 			goto out_no_entry;
 		}
 		lock_buffer(epos.bh);