btrfs: move btrfs_path_cachep out of ctree.h

This is local to the ctree code, remove it from ctree.h and inode.c,
create new init/exit functions for the cachep, and move it locally to
ctree.c.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ctree.c

@@ -18,6 +18,8 @@
 #include "tree-mod-log.h"
 #include "tree-checker.h"
 
+static struct kmem_cache *btrfs_path_cachep;
+
 static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root
 		      *root, struct btrfs_path *path, int level);
 static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root *root,
@@ -4933,3 +4935,18 @@ int btrfs_previous_extent_item(struct btrfs_root *root,
 	}
 	return 1;
 }
+
+int __init btrfs_ctree_init(void)
+{
+	btrfs_path_cachep = kmem_cache_create("btrfs_path",
+			sizeof(struct btrfs_path), 0,
+			SLAB_MEM_SPREAD, NULL);
+	if (!btrfs_path_cachep)
+		return -ENOMEM;
+	return 0;
+}
+
+void __cold btrfs_ctree_exit(void)
+{
+	kmem_cache_destroy(btrfs_path_cachep);
+}

fs/btrfs/ctree.h

@@ -41,7 +41,6 @@ struct btrfs_pending_snapshot;
 struct btrfs_delayed_ref_root;
 struct btrfs_space_info;
 struct btrfs_block_group;
-extern struct kmem_cache *btrfs_path_cachep;
 extern struct kmem_cache *btrfs_free_space_cachep;
 extern struct kmem_cache *btrfs_free_space_bitmap_cachep;
 struct btrfs_ordered_sum;
@@ -2662,6 +2661,8 @@ void btrfs_end_write_no_snapshotting(struct btrfs_root *root);
 void btrfs_wait_for_snapshot_creation(struct btrfs_root *root);
 
 /* ctree.c */
+int __init btrfs_ctree_init(void);
+void __cold btrfs_ctree_exit(void);
 int btrfs_bin_search(struct extent_buffer *eb, const struct btrfs_key *key,
 		     int *slot);
 int __pure btrfs_comp_cpu_keys(const struct btrfs_key *k1, const struct btrfs_key *k2);

fs/btrfs/inode.c

@@ -107,7 +107,6 @@ static const struct address_space_operations btrfs_aops;
 static const struct file_operations btrfs_dir_file_operations;
 
 static struct kmem_cache *btrfs_inode_cachep;
-struct kmem_cache *btrfs_path_cachep;
 struct kmem_cache *btrfs_free_space_cachep;
 struct kmem_cache *btrfs_free_space_bitmap_cachep;
 
@@ -8925,7 +8924,6 @@ void __cold btrfs_destroy_cachep(void)
 	rcu_barrier();
 	bioset_exit(&btrfs_dio_bioset);
 	kmem_cache_destroy(btrfs_inode_cachep);
-	kmem_cache_destroy(btrfs_path_cachep);
 	kmem_cache_destroy(btrfs_free_space_cachep);
 	kmem_cache_destroy(btrfs_free_space_bitmap_cachep);
 }
@@ -8939,12 +8937,6 @@ int __init btrfs_init_cachep(void)
 	if (!btrfs_inode_cachep)
 		goto fail;
 
-	btrfs_path_cachep = kmem_cache_create("btrfs_path",
-			sizeof(struct btrfs_path), 0,
-			SLAB_MEM_SPREAD, NULL);
-	if (!btrfs_path_cachep)
-		goto fail;
-
 	btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
 			sizeof(struct btrfs_free_space), 0,
 			SLAB_MEM_SPREAD, NULL);

fs/btrfs/super.c

@@ -2743,10 +2743,14 @@ static int __init init_btrfs_fs(void)
 	if (err)
 		goto free_cachep;
 
-	err = extent_state_init_cachep();
+	err = btrfs_ctree_init();
 	if (err)
 		goto free_transaction;
 
+	err = extent_state_init_cachep();
+	if (err)
+		goto free_ctree;
+
 	err = extent_buffer_init_cachep();
 	if (err)
 		goto free_extent_cachep;
@@ -2815,6 +2819,8 @@ static int __init init_btrfs_fs(void)
 	extent_buffer_free_cachep();
 free_extent_cachep:
 	extent_state_free_cachep();
+free_ctree:
+	btrfs_ctree_exit();
 free_transaction:
 	btrfs_transaction_exit();
 free_cachep:
@@ -2828,6 +2834,7 @@ static int __init init_btrfs_fs(void)
 
 static void __exit exit_btrfs_fs(void)
 {
+	btrfs_ctree_exit();
 	btrfs_transaction_exit();
 	btrfs_destroy_cachep();
 	btrfs_delayed_ref_exit();