system/linux
system/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux synced 2024-09-19 18:46:35 +00:00
Code Issues Packages Projects Releases Wiki Activity

btrfs: hold ref on root in btrfs_ioctl_default_subvol

Browse source 
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>
This commit is contained in:
Josef Bacik 2020-01-24 09:32:37 -05:00 committed by David Sterba
parent 04734e8448
commit 2a2b5d6202
1 changed files with 14 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

22
fs/btrfs/ioctl.c
View file

@ -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;