Btrfs: Integrate metadata reservation with start_transaction

Besides simplify the code, this change makes sure all metadata
reservation for normal metadata operations are released after
committing transaction.

Changes since V1:

Add code that check if unlink and rmdir will free space.

Add ENOSPC handling for clone ioctl.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 0 insertions, 101 deletions

diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 902ce507c4e3..e807b143b857 100644
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -319,107 +319,6 @@ out:
 }
 
 /*
- * helper function to lookup reference count and flags of extent.
- *
- * the head node for delayed ref is used to store the sum of all the
- * reference count modifications queued up in the rbtree. the head
- * node may also store the extent flags to set. This way you can check
- * to see what the reference count and extent flags would be if all of
- * the delayed refs are not processed.
- */
-int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
-                             struct btrfs_root *root, u64 bytenr,
-                             u64 num_bytes, u64 *refs, u64 *flags)
-{
-        struct btrfs_delayed_ref_node *ref;
-        struct btrfs_delayed_ref_head *head;
-        struct btrfs_delayed_ref_root *delayed_refs;
-        struct btrfs_path *path;
-        struct btrfs_extent_item *ei;
-        struct extent_buffer *leaf;
-        struct btrfs_key key;
-        u32 item_size;
-        u64 num_refs;
-        u64 extent_flags;
-        int ret;
-
-        path = btrfs_alloc_path();
-        if (!path)
-                return -ENOMEM;
-
-        key.objectid = bytenr;
-        key.type = BTRFS_EXTENT_ITEM_KEY;
-        key.offset = num_bytes;
-        delayed_refs = &trans->transaction->delayed_refs;
-again:
-        ret = btrfs_search_slot(trans, root->fs_info->extent_root,
-                                &key, path, 0, 0);
-        if (ret < 0)
-                goto out;
-
-        if (ret == 0) {
-                leaf = path->nodes[0];
-                item_size = btrfs_item_size_nr(leaf, path->slots[0]);
-                if (item_size >= sizeof(*ei)) {
-                        ei = btrfs_item_ptr(leaf, path->slots[0],
-                                            struct btrfs_extent_item);
-                        num_refs = btrfs_extent_refs(leaf, ei);
-                        extent_flags = btrfs_extent_flags(leaf, ei);
-                } else {
-#ifdef BTRFS_COMPAT_EXTENT_TREE_V0
-                        struct btrfs_extent_item_v0 *ei0;
-                        BUG_ON(item_size != sizeof(*ei0));
-                        ei0 = btrfs_item_ptr(leaf, path->slots[0],
-                                             struct btrfs_extent_item_v0);
-                        num_refs = btrfs_extent_refs_v0(leaf, ei0);
-                        /* FIXME: this isn't correct for data */
-                        extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;
-#else
-                        BUG();
-#endif
-                }
-                BUG_ON(num_refs == 0);
-        } else {
-                num_refs = 0;
-                extent_flags = 0;
-                ret = 0;
-        }
-
-        spin_lock(&delayed_refs->lock);
-        ref = find_ref_head(&delayed_refs->root, bytenr, NULL);
-        if (ref) {
-                head = btrfs_delayed_node_to_head(ref);
-                if (!mutex_trylock(&head->mutex)) {
-                        atomic_inc(&ref->refs);
-                        spin_unlock(&delayed_refs->lock);
-
-                        btrfs_release_path(root->fs_info->extent_root, path);
-
-                        mutex_lock(&head->mutex);
-                        mutex_unlock(&head->mutex);
-                        btrfs_put_delayed_ref(ref);
-                        goto again;
-                }
-                if (head->extent_op && head->extent_op->update_flags)
-                        extent_flags |= head->extent_op->flags_to_set;
-                else
-                        BUG_ON(num_refs == 0);
-
-                num_refs += ref->ref_mod;
-                mutex_unlock(&head->mutex);
-        }
-        WARN_ON(num_refs == 0);
-        if (refs)
-                *refs = num_refs;
-        if (flags)
-                *flags = extent_flags;
-out:
-        spin_unlock(&delayed_refs->lock);
-        btrfs_free_path(path);
-        return ret;
-}
-
-/*
  * helper function to update an extent delayed ref in the
  * rbtree.  existing and update must both have the same
  * bytenr and parent