Btrfs: remove extent mapping if we fail to add chunk
I got a double free error when unmounting a file system that failed to add a
chunk during its operation. This is because we will kfree the mapping that
we created but leave the extent_map in the em_tree for chunks. So to fix
this just remove the extent_map when we error out so we don't run into this
problem. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 13efbcf..c784334 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3821,9 +3821,10 @@
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
- free_extent_map(em);
- if (ret)
+ if (ret) {
+ free_extent_map(em);
goto error;
+ }
for (i = 0; i < map->num_stripes; ++i) {
struct btrfs_device *device;
@@ -3848,6 +3849,7 @@
goto error_dev_extent;
}
+ free_extent_map(em);
kfree(devices_info);
return 0;
@@ -3863,6 +3865,14 @@
break;
}
}
+ write_lock(&em_tree->lock);
+ remove_extent_mapping(em_tree, em);
+ write_unlock(&em_tree->lock);
+
+ /* One for our allocation */
+ free_extent_map(em);
+ /* One for the tree reference */
+ free_extent_map(em);
error:
kfree(map);
kfree(devices_info);