btrfs-progs: kernel-lib: add rbtree_types.h from linux

In order to use rb_root_cached we need to sync with kernel sources. Copy the file from linux.git/include/linux/rbtree_types.h and update so it's C++ protected for inclusion to libbtrfs and remove duplicate definitions. Signed-off-by: David Sterba <[email protected]>
kdave · May 12, 2022 · c1b24d7 · c1b24d7
1 parent df77a23
commit c1b24d7
Show file tree

Hide file tree

Showing 3 changed files with 46 additions and 14 deletions.
diff --git a/Makefile b/Makefile
@@ -213,7 +213,7 @@ libbtrfs_objects = \
 		crypto/crc32c.o
 
 libbtrfs_headers = libbtrfs/send-stream.h libbtrfs/send-utils.h kernel-shared/send.h kernel-lib/rbtree.h \
-	       kernel-lib/list.h kerncompat.h \
+	       kernel-lib/list.h kernel-lib/rbtree_types.h kerncompat.h \
 	       common/extent-cache.h kernel-shared/extent_io.h ioctl.h \
 	       kernel-shared/ctree.h version.h
 libbtrfsutil_major := $(shell sed -rn 's/^\#define BTRFS_UTIL_VERSION_MAJOR ([0-9])+$$/\1/p' libbtrfsutil/btrfsutil.h)

diff --git a/kernel-lib/rbtree.h b/kernel-lib/rbtree.h
@@ -28,31 +28,21 @@
 
 #ifndef	_LINUX_RBTREE_H
 #define	_LINUX_RBTREE_H
+
 #if BTRFS_FLAT_INCLUDES
 #include "kerncompat.h"
+#include "kernel-lib/rbtree_types.h"
 #else
 #include <btrfs/kerncompat.h>
+#include <btrfs/rbtree_types.h>
 #endif /* BTRFS_FLAT_INCLUDES */
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-struct rb_node {
-	unsigned long  __rb_parent_color;
-	struct rb_node *rb_right;
-	struct rb_node *rb_left;
-} __attribute__((aligned(sizeof(long))));
-    /* The alignment might seem pointless, but allegedly CRIS needs it */
-
-struct rb_root {
-	struct rb_node *rb_node;
-};
-
-
 #define rb_parent(r)   ((struct rb_node *)((r)->__rb_parent_color & ~3))
 
-#define RB_ROOT	(struct rb_root) { NULL, }
 #define	rb_entry(ptr, type, member) container_of(ptr, type, member)
 
 #define RB_EMPTY_ROOT(root)  ((root)->rb_node == NULL)

diff --git a/kernel-lib/rbtree_types.h b/kernel-lib/rbtree_types.h
@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _LINUX_RBTREE_TYPES_H
+#define _LINUX_RBTREE_TYPES_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct rb_node {
+	unsigned long  __rb_parent_color;
+	struct rb_node *rb_right;
+	struct rb_node *rb_left;
+} __attribute__((aligned(sizeof(long))));
+/* The alignment might seem pointless, but allegedly CRIS needs it */
+
+struct rb_root {
+	struct rb_node *rb_node;
+};
+
+/*
+ * Leftmost-cached rbtrees.
+ *
+ * We do not cache the rightmost node based on footprint
+ * size vs number of potential users that could benefit
+ * from O(1) rb_last(). Just not worth it, users that want
+ * this feature can always implement the logic explicitly.
+ * Furthermore, users that want to cache both pointers may
+ * find it a bit asymmetric, but that's ok.
+ */
+struct rb_root_cached {
+	struct rb_root rb_root;
+	struct rb_node *rb_leftmost;
+};
+
+#define RB_ROOT (struct rb_root) { NULL, }
+#define RB_ROOT_CACHED (struct rb_root_cached) { {NULL, }, NULL }
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif