btrfs: Factor out the main deletion process from btrfs_ioctl_snap_destroy()
Factor out the second half of btrfs_ioctl_snap_destroy() as
btrfs_delete_subvolume(), which performs some subvolume specific checks
before deletion:
1. send is not in progress
2. the subvolume is not the default subvolume
3. the subvolume does not contain other subvolumes
and actual deletion process. btrfs_delete_subvolume() requires
inode_lock for both @dir and inode of @dentry. The remaining part of
btrfs_ioctl_snap_destroy() is mainly permission checks.
Note that call of d_delete() is not included in btrfs_delete_subvolume()
as this function will also be used by btrfs_rmdir() to delete an empty
subvolume and in that case d_delete() is called in VFS layer.
As a result, btrfs_unlink_subvol() and may_destroy_subvol()
become static functions. No functional changes.
Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor comment updates ]
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 592ef10..7beec1b 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2255,12 +2255,7 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *dest = NULL;
struct btrfs_ioctl_vol_args *vol_args;
- struct btrfs_trans_handle *trans;
- struct btrfs_block_rsv block_rsv;
- u64 root_flags;
- u64 qgroup_reserved;
int namelen;
- int ret;
int err = 0;
if (!S_ISDIR(dir->i_mode))
@@ -2344,133 +2339,11 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file,
}
inode_lock(inode);
-
- /*
- * Don't allow to delete a subvolume with send in progress. This is
- * inside the i_mutex so the error handling that has to drop the bit
- * again is not run concurrently.
- */
- spin_lock(&dest->root_item_lock);
- root_flags = btrfs_root_flags(&dest->root_item);
- if (dest->send_in_progress == 0) {
- btrfs_set_root_flags(&dest->root_item,
- root_flags | BTRFS_ROOT_SUBVOL_DEAD);
- spin_unlock(&dest->root_item_lock);
- } else {
- spin_unlock(&dest->root_item_lock);
- btrfs_warn(fs_info,
- "Attempt to delete subvolume %llu during send",
- dest->root_key.objectid);
- err = -EPERM;
- goto out_unlock_inode;
- }
-
- down_write(&fs_info->subvol_sem);
-
- err = may_destroy_subvol(dest);
- if (err)
- goto out_up_write;
-
- btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
- /*
- * One for dir inode, two for dir entries, two for root
- * ref/backref.
- */
- err = btrfs_subvolume_reserve_metadata(root, &block_rsv,
- 5, &qgroup_reserved, true);
- if (err)
- goto out_up_write;
-
- trans = btrfs_start_transaction(root, 0);
- if (IS_ERR(trans)) {
- err = PTR_ERR(trans);
- goto out_release;
- }
- trans->block_rsv = &block_rsv;
- trans->bytes_reserved = block_rsv.size;
-
- btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
-
- ret = btrfs_unlink_subvol(trans, root, dir,
- dest->root_key.objectid,
- dentry->d_name.name,
- dentry->d_name.len);
- if (ret) {
- err = ret;
- btrfs_abort_transaction(trans, ret);
- goto out_end_trans;
- }
-
- btrfs_record_root_in_trans(trans, dest);
-
- memset(&dest->root_item.drop_progress, 0,
- sizeof(dest->root_item.drop_progress));
- dest->root_item.drop_level = 0;
- btrfs_set_root_refs(&dest->root_item, 0);
-
- if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
- ret = btrfs_insert_orphan_item(trans,
- fs_info->tree_root,
- dest->root_key.objectid);
- if (ret) {
- btrfs_abort_transaction(trans, ret);
- err = ret;
- goto out_end_trans;
- }
- }
-
- ret = btrfs_uuid_tree_rem(trans, fs_info, dest->root_item.uuid,
- BTRFS_UUID_KEY_SUBVOL,
- dest->root_key.objectid);
- if (ret && ret != -ENOENT) {
- btrfs_abort_transaction(trans, ret);
- err = ret;
- goto out_end_trans;
- }
- if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
- ret = btrfs_uuid_tree_rem(trans, fs_info,
- dest->root_item.received_uuid,
- BTRFS_UUID_KEY_RECEIVED_SUBVOL,
- dest->root_key.objectid);
- if (ret && ret != -ENOENT) {
- btrfs_abort_transaction(trans, ret);
- err = ret;
- goto out_end_trans;
- }
- }
-
-out_end_trans:
- trans->block_rsv = NULL;
- trans->bytes_reserved = 0;
- ret = btrfs_end_transaction(trans);
- if (ret && !err)
- err = ret;
- inode->i_flags |= S_DEAD;
-out_release:
- btrfs_subvolume_release_metadata(fs_info, &block_rsv);
-out_up_write:
- up_write(&fs_info->subvol_sem);
- if (err) {
- spin_lock(&dest->root_item_lock);
- root_flags = btrfs_root_flags(&dest->root_item);
- btrfs_set_root_flags(&dest->root_item,
- root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
- spin_unlock(&dest->root_item_lock);
- }
-out_unlock_inode:
+ err = btrfs_delete_subvolume(dir, dentry);
inode_unlock(inode);
- if (!err) {
- d_invalidate(dentry);
- btrfs_invalidate_inodes(dest);
+ if (!err)
d_delete(dentry);
- ASSERT(dest->send_in_progress == 0);
- /* the last ref */
- if (dest->ino_cache_inode) {
- iput(dest->ino_cache_inode);
- dest->ino_cache_inode = NULL;
- }
- }
out_dput:
dput(dentry);
out_unlock_dir: