[PATCH 18/44] btrfs: hold a ref on the root in search_ioctl

Josef Bacik
2019-12-06T14:46:16Z

We lookup a arbitrary fs root, we need to hold a ref on that root. If
we're using our own inodes root then grab a ref on that as well to make
the cleanup easier.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/btrfs/ioctl.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 29c363a70fe7..e01363cd2bbe 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2180,7 +2180,7 @@ static noinline int search_ioctl(struct inode *inode,

if (sk->tree_id == 0) {
/* search the root of the inode that was passed */
- root = BTRFS_I(inode)->root;
+ root = btrfs_grab_fs_root(BTRFS_I(inode)->root);
} else {
key.objectid = sk->tree_id;
key.type = BTRFS_ROOT_ITEM_KEY;
@@ -2190,6 +2190,10 @@ static noinline int search_ioctl(struct inode *inode,
btrfs_free_path(path);
return PTR_ERR(root);
}
+ if (!btrfs_grab_fs_root(root)) {
+ btrfs_free_path(path);
+ return -ENOENT;
+ }
}

key.objectid = sk->min_objectid;
@@ -2214,6 +2218,7 @@ static noinline int search_ioctl(struct inode *inode,
ret = 0;
err:
sk->nr_items = num_found;
+ btrfs_put_fs_root(root);
btrfs_free_path(path);
return ret;
}
--
2.23.0