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authorJosef Bacik <josef@toxicpanda.com>2020-01-24 09:32:37 -0500
committerDavid Sterba <dsterba@suse.com>2020-03-23 17:01:29 +0100
commit2a2b5d62026633d6fc515b1c0fe3a5e58cae7891 (patch)
tree2cb741f40a0f39b1fda7da4b659a9bd422ae4353 /fs/btrfs/ioctl.c
parent04734e844894ccdfcb907d10eec1433e19d4918a (diff)
downloadlinux-2a2b5d62026633d6fc515b1c0fe3a5e58cae7891.tar.bz2
btrfs: hold ref on root in btrfs_ioctl_default_subvol
We look up an arbitrary fs root here, we need to hold a ref on the root for the duration. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/ioctl.c')
-rw-r--r--fs/btrfs/ioctl.c22
1 files changed, 14 insertions, 8 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 0aa47bc3e172..5fde22db1727 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3986,7 +3986,7 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
struct btrfs_root *new_root;
struct btrfs_dir_item *di;
struct btrfs_trans_handle *trans;
- struct btrfs_path *path;
+ struct btrfs_path *path = NULL;
struct btrfs_key location;
struct btrfs_disk_key disk_key;
u64 objectid = 0;
@@ -4017,44 +4017,50 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
ret = PTR_ERR(new_root);
goto out;
}
- if (!is_fstree(new_root->root_key.objectid)) {
+ if (!btrfs_grab_fs_root(new_root)) {
ret = -ENOENT;
goto out;
}
+ if (!is_fstree(new_root->root_key.objectid)) {
+ ret = -ENOENT;
+ goto out_free;
+ }
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
- goto out;
+ goto out_free;
}
path->leave_spinning = 1;
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
- btrfs_free_path(path);
ret = PTR_ERR(trans);
- goto out;
+ goto out_free;
}
dir_id = btrfs_super_root_dir(fs_info->super_copy);
di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
dir_id, "default", 7, 1);
if (IS_ERR_OR_NULL(di)) {
- btrfs_free_path(path);
+ btrfs_release_path(path);
btrfs_end_transaction(trans);
btrfs_err(fs_info,
"Umm, you don't have the default diritem, this isn't going to work");
ret = -ENOENT;
- goto out;
+ goto out_free;
}
btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
btrfs_mark_buffer_dirty(path->nodes[0]);
- btrfs_free_path(path);
+ btrfs_release_path(path);
btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
btrfs_end_transaction(trans);
+out_free:
+ btrfs_put_fs_root(new_root);
+ btrfs_free_path(path);
out:
mnt_drop_write_file(file);
return ret;