[PATCH 11/43] btrfs: hold a ref on the root in resolve_indirect_ref

Josef Bacik
2020-01-17T21:26:29Z

We're looking up a random root, we need to hold a ref on it while we're
using it.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/btrfs/backref.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index e5d85311d5d5..193747b6e1f9 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -524,7 +524,13 @@ static int resolve_indirect_ref(struct btrfs_fs_info *fs_info,
if (IS_ERR(root)) {
srcu_read_unlock(&fs_info->subvol_srcu, index);
ret = PTR_ERR(root);
- goto out;
+ goto out_free;
+ }
+
+ if (!btrfs_grab_fs_root(root)) {
+ srcu_read_unlock(&fs_info->subvol_srcu, index);
+ ret = -ENOENT;
+ goto out_free;
}

if (btrfs_is_testing(fs_info)) {
@@ -577,6 +583,8 @@ static int resolve_indirect_ref(struct btrfs_fs_info *fs_info,
ret = add_all_parents(root, path, parents, ref, level, time_seq,
extent_item_pos, total_refs, ignore_offset);
out:
+ btrfs_put_fs_root(root);
+out_free:
path->lowest_level = 0;
btrfs_release_path(path);
return ret;
--
2.24.1