btrfs: extent-tree: Refactor add_pinned_bytes() to add|sub_pinned_bytes()

Instead of using @sign to determine whether we're adding or subtracting.
Even it only has 3 callers, it's still (and in fact already caused
problem in the past) confusing to use.

Refactor add_pinned_bytes() to add_pinned_bytes() and sub_pinned_bytes()
to explicitly show what we're doing.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 5faf057..caaa79a 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -756,27 +756,38 @@ static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info,
        return NULL;
 }
 
-static void add_pinned_bytes(struct btrfs_fs_info *fs_info,
-                            struct btrfs_ref *ref, int sign)
+static u64 generic_ref_to_space_flags(struct btrfs_ref *ref)
 {
-       struct btrfs_space_info *space_info;
-       s64 num_bytes;
-       u64 flags;
-
-       ASSERT(sign == 1 || sign == -1);
-       num_bytes = sign * ref->len;
        if (ref->type == BTRFS_REF_METADATA) {
                if (ref->tree_ref.root == BTRFS_CHUNK_TREE_OBJECTID)
-                       flags = BTRFS_BLOCK_GROUP_SYSTEM;
+                       return BTRFS_BLOCK_GROUP_SYSTEM;
                else
-                       flags = BTRFS_BLOCK_GROUP_METADATA;
-       } else {
-               flags = BTRFS_BLOCK_GROUP_DATA;
+                       return BTRFS_BLOCK_GROUP_METADATA;
        }
+       return BTRFS_BLOCK_GROUP_DATA;
+}
+
+static void add_pinned_bytes(struct btrfs_fs_info *fs_info,
+                            struct btrfs_ref *ref)
+{
+       struct btrfs_space_info *space_info;
+       u64 flags = generic_ref_to_space_flags(ref);
+
+       space_info = __find_space_info(fs_info, flags);
+       ASSERT(space_info);
+       percpu_counter_add_batch(&space_info->total_bytes_pinned, ref->len,
+                   BTRFS_TOTAL_BYTES_PINNED_BATCH);
+}
+
+static void sub_pinned_bytes(struct btrfs_fs_info *fs_info,
+                            struct btrfs_ref *ref)
+{
+       struct btrfs_space_info *space_info;
+       u64 flags = generic_ref_to_space_flags(ref);
 
        space_info = __find_space_info(fs_info, flags);
        ASSERT(space_info);
-       percpu_counter_add_batch(&space_info->total_bytes_pinned, num_bytes,
+       percpu_counter_add_batch(&space_info->total_bytes_pinned, -ref->len,
                    BTRFS_TOTAL_BYTES_PINNED_BATCH);
 }
 
@@ -2065,7 +2076,7 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans,
        btrfs_ref_tree_mod(fs_info, generic_ref);
 
        if (ret == 0 && old_ref_mod < 0 && new_ref_mod >= 0)
-               add_pinned_bytes(fs_info, generic_ref, -1);
+               sub_pinned_bytes(fs_info, generic_ref);
 
        return ret;
 }
@@ -7191,7 +7202,7 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
        }
 out:
        if (pin)
-               add_pinned_bytes(fs_info, &generic_ref, 1);
+               add_pinned_bytes(fs_info, &generic_ref);
 
        if (last_ref) {
                /*
@@ -7239,7 +7250,7 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref)
                btrfs_ref_tree_mod(fs_info, ref);
 
        if (ret == 0 && old_ref_mod >= 0 && new_ref_mod < 0)
-               add_pinned_bytes(fs_info, ref, 1);
+               add_pinned_bytes(fs_info, ref);
 
        return ret;
 }