[PATCH 24/44] btrfs: hold a ref on the root in prepare_to_merge

Josef Bacik
2019-12-06T14:46:26Z

We look up the reloc roots corresponding root, we need to hold a ref on
that root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/btrfs/relocation.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 473bbbd58d31..19d69ce41f06 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2433,6 +2433,8 @@ int prepare_to_merge(struct reloc_control *rc, int err)
list_del_init(&reloc_root->root_list);

root = read_fs_root(fs_info, reloc_root->root_key.offset);
+ if (!btrfs_grab_fs_root(root))
+ BUG();
BUG_ON(IS_ERR(root));
BUG_ON(root->reloc_root != reloc_root);

@@ -2445,6 +2447,7 @@ int prepare_to_merge(struct reloc_control *rc, int err)
btrfs_update_reloc_root(trans, root);

list_add(&reloc_root->root_list, &reloc_roots);
+ btrfs_put_fs_root(root);
}

list_splice(&reloc_roots, &rc->reloc_roots);
--
2.23.0