btrfs: Open-code add_delayed_data_ref

Now that the initialization part and the critical section code have been
split it's a lot easier to open code add_delayed_data_ref. Do so in the
following manner:

1. The common init function is put immediately after memory-to-be-initialized
   is allocated, followed by the specific data ref initialization.

2. The only piece of code that remains in the critical section is
   insert_delayed_ref call.

3. Tracing and memory freeing code is moved outside of the critical
   section.

No functional changes, just an overall shorter critical section.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 184722274bbe60f76a467629ab3cc23bea568cce..3fa8ea5cbbc6b32d1d46545cd455aa25138cefe0 100644 (file)
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -695,44 +695,6 @@ static void init_delayed_ref_common(struct btrfs_fs_info *fs_info,
        INIT_LIST_HEAD(&ref->add_list);
 }
 
-/*
- * helper to insert a delayed data ref into the rbtree.
- */
-static noinline void
-add_delayed_data_ref(struct btrfs_trans_handle *trans,
-                    struct btrfs_delayed_ref_head *head_ref,
-                    struct btrfs_delayed_ref_node *ref, u64 bytenr,
-                    u64 num_bytes, u64 parent, u64 ref_root, u64 owner,
-                    u64 offset, int action)
-{
-       struct btrfs_delayed_data_ref *full_ref;
-       struct btrfs_delayed_ref_root *delayed_refs;
-       u8 ref_type;
-       int ret;
-
-       delayed_refs = &trans->transaction->delayed_refs;
-       full_ref = btrfs_delayed_node_to_data_ref(ref);
-       if (parent)
-               ref_type = BTRFS_SHARED_DATA_REF_KEY;
-       else
-               ref_type = BTRFS_EXTENT_DATA_REF_KEY;
-
-       init_delayed_ref_common(trans->fs_info, ref, bytenr, num_bytes,
-                               ref_root, action, ref_type);
-       full_ref->root = ref_root;
-       full_ref->parent = parent;
-       full_ref->objectid = owner;
-       full_ref->offset = offset;
-
-       trace_add_delayed_data_ref(trans->fs_info, ref, full_ref,
-                                  action == BTRFS_ADD_DELAYED_EXTENT ?
-                                  BTRFS_ADD_DELAYED_REF : action);
-
-       ret = insert_delayed_ref(trans, delayed_refs, head_ref, ref);
-       if (ret > 0)
-               kmem_cache_free(btrfs_delayed_data_ref_cachep, full_ref);
-}
-
 /*
  * add a delayed tree ref.  This does all of the accounting required
  * to make sure the delayed ref is eventually processed before this
@@ -832,11 +794,25 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
        struct btrfs_delayed_ref_root *delayed_refs;
        struct btrfs_qgroup_extent_record *record = NULL;
        int qrecord_inserted;
+       int ret;
+       u8 ref_type;
 
        ref = kmem_cache_alloc(btrfs_delayed_data_ref_cachep, GFP_NOFS);
        if (!ref)
                return -ENOMEM;
 
+       if (parent)
+               ref_type = BTRFS_SHARED_DATA_REF_KEY;
+       else
+               ref_type = BTRFS_EXTENT_DATA_REF_KEY;
+       init_delayed_ref_common(fs_info, &ref->node, bytenr, num_bytes,
+                               ref_root, action, ref_type);
+       ref->root = ref_root;
+       ref->parent = parent;
+       ref->objectid = owner;
+       ref->offset = offset;
+
+
        head_ref = kmem_cache_alloc(btrfs_delayed_ref_head_cachep, GFP_NOFS);
        if (!head_ref) {
                kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
@@ -868,10 +844,16 @@ int btrfs_add_delayed_data_ref(struct btrfs_fs_info *fs_info,
                                        action, 1, 0, &qrecord_inserted,
                                        old_ref_mod, new_ref_mod);
 
-       add_delayed_data_ref(trans, head_ref, &ref->node, bytenr, num_bytes,
-                            parent, ref_root, owner, offset, action);
+       ret = insert_delayed_ref(trans, delayed_refs, head_ref, &ref->node);
        spin_unlock(&delayed_refs->lock);
 
+       trace_add_delayed_data_ref(trans->fs_info, &ref->node, ref,
+                                  action == BTRFS_ADD_DELAYED_EXTENT ?
+                                  BTRFS_ADD_DELAYED_REF : action);
+       if (ret > 0)
+               kmem_cache_free(btrfs_delayed_data_ref_cachep, ref);
+
+
        if (qrecord_inserted)
                return btrfs_qgroup_trace_extent_post(fs_info, record);
        return 0;