btrfs: move the subvolume reservation stuff out of extent-tree.c
This is just two functions, put it in root-tree.c since it involves root
items.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 2212412..47733fb 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -9,6 +9,8 @@
#include "transaction.h"
#include "disk-io.h"
#include "print-tree.h"
+#include "qgroup.h"
+#include "space-info.h"
/*
* Read a root item from the tree. In case we detect a root item smaller then
@@ -497,3 +499,57 @@ void btrfs_update_root_times(struct btrfs_trans_handle *trans,
btrfs_set_stack_timespec_nsec(&item->ctime, ct.tv_nsec);
spin_unlock(&root->root_item_lock);
}
+
+/*
+ * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
+ * root: the root of the parent directory
+ * rsv: block reservation
+ * items: the number of items that we need do reservation
+ * use_global_rsv: allow fallback to the global block reservation
+ *
+ * This function is used to reserve the space for snapshot/subvolume
+ * creation and deletion. Those operations are different with the
+ * common file/directory operations, they change two fs/file trees
+ * and root tree, the number of items that the qgroup reserves is
+ * different with the free space reservation. So we can not use
+ * the space reservation mechanism in start_transaction().
+ */
+int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
+ struct btrfs_block_rsv *rsv, int items,
+ bool use_global_rsv)
+{
+ u64 qgroup_num_bytes = 0;
+ u64 num_bytes;
+ int ret;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
+
+ if (test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags)) {
+ /* One for parent inode, two for dir entries */
+ qgroup_num_bytes = 3 * fs_info->nodesize;
+ ret = btrfs_qgroup_reserve_meta_prealloc(root,
+ qgroup_num_bytes, true);
+ if (ret)
+ return ret;
+ }
+
+ num_bytes = btrfs_calc_trans_metadata_size(fs_info, items);
+ rsv->space_info = btrfs_find_space_info(fs_info,
+ BTRFS_BLOCK_GROUP_METADATA);
+ ret = btrfs_block_rsv_add(root, rsv, num_bytes,
+ BTRFS_RESERVE_FLUSH_ALL);
+
+ if (ret == -ENOSPC && use_global_rsv)
+ ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes, true);
+
+ if (ret && qgroup_num_bytes)
+ btrfs_qgroup_free_meta_prealloc(root, qgroup_num_bytes);
+
+ return ret;
+}
+
+void btrfs_subvolume_release_metadata(struct btrfs_fs_info *fs_info,
+ struct btrfs_block_rsv *rsv)
+{
+ btrfs_block_rsv_release(fs_info, rsv, (u64)-1);
+}
