mtd/fs/jffs2 nodelist.c, 1.94, 1.95 nodelist.h, 1.130, 1.131 readinode.c, 1.119, 1.120

David Woodhouse dwmw2 at infradead.org
Tue Jul 5 17:03:10 EDT 2005


Update of /home/cvs/mtd/fs/jffs2
In directory phoenix.infradead.org:/tmp/cvs-serv27187

Modified Files:
	nodelist.c nodelist.h readinode.c 
Log Message:
JFFS2: Optimise jffs2_add_tn_to_list to use an rbtree
instead of a simple linked list. We were wasting an amazing amount of
time in jffs2_add_tn_to_list(). Thanks to Artem Bityuckiy for noticing.

Signed-off-by: David Woodhouse <dwmw2 at infradead.org> 


Index: nodelist.c
===================================================================
RCS file: /home/cvs/mtd/fs/jffs2/nodelist.c,v
retrieving revision 1.94
retrieving revision 1.95
diff -u -r1.94 -r1.95
--- nodelist.c	13 Apr 2005 13:22:35 -0000	1.94
+++ nodelist.c	5 Jul 2005 21:03:07 -0000	1.95
@@ -58,27 +58,61 @@
 /* Put a new tmp_dnode_info into the list, keeping the list in 
    order of increasing version
 */
-static void jffs2_add_tn_to_list(struct jffs2_tmp_dnode_info *tn, struct jffs2_tmp_dnode_info **list)
-{
-	struct jffs2_tmp_dnode_info **prev = list;
-	
-	while ((*prev) && (*prev)->version < tn->version) {
-		prev = &((*prev)->next);
-	}
-	tn->next = (*prev);
-        *prev = tn;
-}
 
-static void jffs2_free_tmp_dnode_info_list(struct jffs2_tmp_dnode_info *tn)
+static void jffs2_add_tn_to_list(struct jffs2_tmp_dnode_info *tn, struct rb_root *list)
 {
-	struct jffs2_tmp_dnode_info *next;
+	struct rb_node **p = &list->rb_node;
+	struct rb_node * parent = NULL;
+	struct jffs2_tmp_dnode_info *this;
+
+	while (*p) {
+		parent = *p;
+		this = rb_entry(parent, struct jffs2_tmp_dnode_info, rb);
+
+		if (tn->version < this->version)
+			p = &(*p)->rb_left;
+		else if (tn->version > this->version)
+			p = &(*p)->rb_right;
+		else if (tn < this)
+			p = &(*p)->rb_left;
+		else
+			p = &(*p)->rb_right;
+        }
+
+	rb_link_node(&tn->rb, parent, p);
+	rb_insert_color(&tn->rb, list);
+}
+
+static void jffs2_free_tmp_dnode_info_list(struct rb_root *list)
+{
+	struct rb_node *this;
+	struct jffs2_tmp_dnode_info *tn;
+
+	this = list->rb_node;
+
+	/* Now at bottom of tree */
+	while (this) {
+		if (this->rb_left)
+			this = this->rb_left;
+		else if (this->rb_right)
+			this = this->rb_right;
+		else {
+			tn = rb_entry(this, struct jffs2_tmp_dnode_info, rb);
+			jffs2_free_full_dnode(tn->fn);
+			jffs2_free_tmp_dnode_info(tn);
+
+			this = this->rb_parent;
+			if (!this)
+				break;
 
-	while (tn) {
-		next = tn;
-		tn = tn->next;
-		jffs2_free_full_dnode(next->fn);
-		jffs2_free_tmp_dnode_info(next);
+			if (this->rb_left == &tn->rb)
+				this->rb_left = NULL;
+			else if (this->rb_right == &tn->rb)
+				this->rb_right = NULL;
+			else BUG();
+		}
 	}
+	list->rb_node = NULL;
 }
 
 static void jffs2_free_full_dirent_list(struct jffs2_full_dirent *fd)
@@ -108,12 +142,13 @@
    with this ino, returning the former in order of version */
 
 int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
-			  struct jffs2_tmp_dnode_info **tnp, struct jffs2_full_dirent **fdp,
+			  struct rb_root *tnp, struct jffs2_full_dirent **fdp,
 			  uint32_t *highest_version, uint32_t *latest_mctime,
 			  uint32_t *mctime_ver)
 {
 	struct jffs2_raw_node_ref *ref, *valid_ref;
-	struct jffs2_tmp_dnode_info *tn, *ret_tn = NULL;
+	struct jffs2_tmp_dnode_info *tn;
+	struct rb_root ret_tn = RB_ROOT;
 	struct jffs2_full_dirent *fd, *ret_fd = NULL;
 	union jffs2_node_union node;
 	size_t retlen;
@@ -450,7 +485,7 @@
 	return 0;
 
  free_out:
-	jffs2_free_tmp_dnode_info_list(ret_tn);
+	jffs2_free_tmp_dnode_info_list(&ret_tn);
 	jffs2_free_full_dirent_list(ret_fd);
 	return err;
 }

Index: nodelist.h
===================================================================
RCS file: /home/cvs/mtd/fs/jffs2/nodelist.h,v
retrieving revision 1.130
retrieving revision 1.131
diff -u -r1.130 -r1.131
--- nodelist.h	9 Apr 2005 10:46:59 -0000	1.130
+++ nodelist.h	5 Jul 2005 21:03:07 -0000	1.131
@@ -161,7 +161,7 @@
 */
 struct jffs2_tmp_dnode_info
 {
-	struct jffs2_tmp_dnode_info *next;
+	struct rb_node rb;
 	struct jffs2_full_dnode *fn;
 	uint32_t version;
 };       
@@ -387,7 +387,7 @@
 D2(void jffs2_print_frag_list(struct jffs2_inode_info *f));
 void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list);
 int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
-			  struct jffs2_tmp_dnode_info **tnp, struct jffs2_full_dirent **fdp,
+			  struct rb_root *tnp, struct jffs2_full_dirent **fdp,
 			  uint32_t *highest_version, uint32_t *latest_mctime,
 			  uint32_t *mctime_ver);
 void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state);

Index: readinode.c
===================================================================
RCS file: /home/cvs/mtd/fs/jffs2/readinode.c,v
retrieving revision 1.119
retrieving revision 1.120
diff -u -r1.119 -r1.120
--- readinode.c	1 Mar 2005 10:34:03 -0000	1.119
+++ readinode.c	5 Jul 2005 21:03:07 -0000	1.120
@@ -500,7 +500,9 @@
 					struct jffs2_inode_info *f,
 					struct jffs2_raw_inode *latest_node)
 {
-	struct jffs2_tmp_dnode_info *tn_list, *tn;
+	struct jffs2_tmp_dnode_info *tn = NULL;
+	struct rb_root tn_list;
+	struct rb_node *rb, *repl_rb;
 	struct jffs2_full_dirent *fd_list;
 	struct jffs2_full_dnode *fn = NULL;
 	uint32_t crc;
@@ -522,9 +524,10 @@
 	}
 	f->dents = fd_list;
 
-	while (tn_list) {
-		tn = tn_list;
+	rb = rb_first(&tn_list);
 
+	while (rb) {
+		tn = rb_entry(rb, struct jffs2_tmp_dnode_info, rb);
 		fn = tn->fn;
 
 		if (f->metadata) {
@@ -556,7 +559,30 @@
 			mdata_ver = tn->version;
 		}
 	next_tn:
-		tn_list = tn->next;
+		BUG_ON(rb->rb_left);
+		repl_rb = NULL;
+		if (rb->rb_parent && rb->rb_parent->rb_left == rb) {
+			/* We were then left-hand child of our parent. We need
+			   to move our own right-hand child into our place. */
+			repl_rb = rb->rb_right;
+			if (repl_rb)
+				repl_rb->rb_parent = rb->rb_parent;
+		} else
+			repl_rb = NULL;
+
+		rb = rb_next(rb);
+
+		/* Remove the spent tn from the tree; don't bother rebalancing
+		   but put our right-hand child in our own place. */
+		if (tn->rb.rb_parent) {
+			if (tn->rb.rb_parent->rb_left == &tn->rb)
+				tn->rb.rb_parent->rb_left = repl_rb;
+			else if (tn->rb.rb_parent->rb_right == &tn->rb)
+				tn->rb.rb_parent->rb_right = repl_rb;
+			else BUG();
+		} else if (tn->rb.rb_right)
+			tn->rb.rb_right->rb_parent = NULL;
+
 		jffs2_free_tmp_dnode_info(tn);
 	}
 	D1(jffs2_sanitycheck_fragtree(f));





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