[PATCH 3/3] btrfs: Use btrfs_find_name_in_backref in backref_in_log

[Nikolay Borisov]

By not opencoding btrfs_find_name_in_backref most of the local variables
can be removed, this in turn alleviates stack pressure. Additionally,
backref_in_log is only used as predicate so make it return bool.

Signed-off-by: Nikolay Borisov <nbori...@suse.com>
---
 fs/btrfs/tree-log.c | 57 +++++++++++++--------------------------------
 1 file changed, 16 insertions(+), 41 deletions(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 7d45a4869bc9..070016e023b8 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -938,60 +938,35 @@ static noinline int inode_in_dir(struct btrfs_root *root,
  * want to delete valid links to a file from the subvolume if that
  * link is also in the log.
  */
-static noinline int backref_in_log(struct btrfs_root *log,
-                                  struct btrfs_key *key,
-                                  u64 ref_objectid,
-                                  const char *name, int namelen)
+static noinline bool backref_in_log(struct btrfs_root *log,
+                                   struct btrfs_key *key,
+                                   u64 ref_objectid,
+                                   const char *name, int namelen)
 {
        struct btrfs_path *path;
-       struct btrfs_inode_ref *ref;
-       unsigned long ptr;
-       unsigned long ptr_end;
-       unsigned long name_ptr;
-       int found_name_len;
-       int item_size;
+       bool found = false;
        int ret;
-       int match = 0;
 
        path = btrfs_alloc_path();
        if (!path)
-               return -ENOMEM;
+               return false;
 
        ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
        if (ret != 0)
                goto out;
 
-       ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
-
-       if (key->type == BTRFS_INODE_EXTREF_KEY) {
-               if (btrfs_find_name_in_ext_backref(path->nodes[0],
-                                                  path->slots[0],
-                                                  ref_objectid,
-                                                  name, namelen))
-                       match = 1;
-
-               goto out;
-       }
-
-       item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
-       ptr_end = ptr + item_size;
-       while (ptr < ptr_end) {
-               ref = (struct btrfs_inode_ref *)ptr;
-               found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
-               if (found_name_len == namelen) {
-                       name_ptr = (unsigned long)(ref + 1);
-                       ret = memcmp_extent_buffer(path->nodes[0], name,
-                                                  name_ptr, namelen);
-                       if (ret == 0) {
-                               match = 1;
-                               goto out;
-                       }
-               }
-               ptr = (unsigned long)(ref + 1) + found_name_len;
-       }
+       if (key->type == BTRFS_INODE_EXTREF_KEY)
+               found = !!btrfs_find_name_in_ext_backref(path->nodes[0],
+                                                        path->slots[0],
+                                                        ref_objectid,
+                                                        name, namelen);
+       else
+               found = !!btrfs_find_name_in_backref(path->nodes[0],
+                                                    path->slots[0],
+                                                    name, namelen);
 out:
        btrfs_free_path(path);
-       return match;
+       return found;
 }
 
 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
-- 
2.17.1