Btrfs: cleanup backref search commit root flag stuff

Looking into this backref problem I noticed we're using a macro to what turns
out to essentially be a NULL check to see if we need to search the commit root.
I'm killing this, let's just do what everybody else does and checks if trans ==
NULL.  I've also made it so we pass in the path to __resolve_indirect_refs which
will have the search_commit_root flag set properly already and that way we can
avoid allocating another path when we have a perfectly good one to use.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fusionio.com>

2 files changed, 16 insertions, 27 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 290e347b6db3..431ea9211bc1 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -255,13 +255,11 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
  * to a logical address
  */
 static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
-                                        int search_commit_root,
-                                        u64 time_seq,
-                                        struct __prelim_ref *ref,
-                                        struct ulist *parents,
-                                        const u64 *extent_item_pos)
+                                  struct btrfs_path *path, u64 time_seq,
+                                  struct __prelim_ref *ref,
+                                  struct ulist *parents,
+                                  const u64 *extent_item_pos)
 {
-        struct btrfs_path *path;
         struct btrfs_root *root;
         struct btrfs_key root_key;
         struct extent_buffer *eb;
@@ -269,11 +267,6 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
         int root_level;
         int level = ref->level;
 
-        path = btrfs_alloc_path();
-        if (!path)
-                return -ENOMEM;
-        path->search_commit_root = !!search_commit_root;
-
         root_key.objectid = ref->root_id;
         root_key.type = BTRFS_ROOT_ITEM_KEY;
         root_key.offset = (u64)-1;
@@ -314,7 +307,8 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
                                 time_seq, ref->wanted_disk_byte,
                                 extent_item_pos);
 out:
-        btrfs_free_path(path);
+        path->lowest_level = 0;
+        btrfs_release_path(path);
         return ret;
 }
 
@@ -322,7 +316,7 @@ out:
  * resolve all indirect backrefs from the list
  */
 static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
-                                   int search_commit_root, u64 time_seq,
+                                   struct btrfs_path *path, u64 time_seq,
                                    struct list_head *head,
                                    const u64 *extent_item_pos)
 {
@@ -349,9 +343,8 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
                         continue;
                 if (ref->count == 0)
                         continue;
-                err = __resolve_indirect_ref(fs_info, search_commit_root,
-                                             time_seq, ref, parents,
-                                             extent_item_pos);
+                err = __resolve_indirect_ref(fs_info, path, time_seq, ref,
+                                             parents, extent_item_pos);
                 if (err == -ENOMEM)
                         goto out;
                 if (err)
@@ -795,7 +788,6 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
         struct btrfs_delayed_ref_head *head;
         int info_level = 0;
         int ret;
-        int search_commit_root = (trans == BTRFS_BACKREF_SEARCH_COMMIT_ROOT);
         struct list_head prefs_delayed;
         struct list_head prefs;
         struct __prelim_ref *ref;
@@ -810,7 +802,8 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
         path = btrfs_alloc_path();
         if (!path)
                 return -ENOMEM;
-        path->search_commit_root = !!search_commit_root;
+        if (!trans)
+                path->search_commit_root = 1;
 
         /*
          * grab both a lock on the path and a lock on the delayed ref head.
@@ -825,7 +818,7 @@ again:
                 goto out;
         BUG_ON(ret == 0);
 
-        if (trans != BTRFS_BACKREF_SEARCH_COMMIT_ROOT) {
+        if (trans) {
                 /*
                  * look if there are updates for this ref queued and lock the
                  * head
@@ -890,8 +883,8 @@ again:
 
         __merge_refs(&prefs, 1);
 
-        ret = __resolve_indirect_refs(fs_info, search_commit_root, time_seq,
-                                      &prefs, extent_item_pos);
+        ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs,
+                                      extent_item_pos);
         if (ret)
                 goto out;
 
@@ -1459,7 +1452,7 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
                                 iterate_extent_inodes_t *iterate, void *ctx)
 {
         int ret;
-        struct btrfs_trans_handle *trans;
+        struct btrfs_trans_handle *trans = NULL;
         struct ulist *refs = NULL;
         struct ulist *roots = NULL;
         struct ulist_node *ref_node = NULL;
@@ -1471,9 +1464,7 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
         pr_debug("resolving all inodes for extent %llu\n",
                         extent_item_objectid);
 
-        if (search_commit_root) {
-                trans = BTRFS_BACKREF_SEARCH_COMMIT_ROOT;
-        } else {
+        if (!search_commit_root) {
                 trans = btrfs_join_transaction(fs_info->extent_root);
                 if (IS_ERR(trans))
                         return PTR_ERR(trans);
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index 0f446d7ca2c0..8f2e76702932 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -23,8 +23,6 @@
 #include "ulist.h"
 #include "extent_io.h"
 
-#define BTRFS_BACKREF_SEARCH_COMMIT_ROOT ((struct btrfs_trans_handle *)0)
-
 struct inode_fs_paths {
         struct btrfs_path               *btrfs_path;
         struct btrfs_root               *fs_root;