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Commit 9dee7503 authored by David Woodhouse's avatar David Woodhouse Committed by Thomas Gleixner
Browse files

[JFFS2] Optimise jffs2_add_tn_to_list 



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 and Jarkko Jlavinen  for noticing.

Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 10c96f2e

fs/jffs2/nodelist.c

+54 −19
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ 
 *

 * For licensing information, see the file 'LICENCE' in this directory.

 *

 * $Id: nodelist.c,v 1.94 2005/04/13 13:22:35 dwmw2 Exp $

 * $Id: nodelist.c,v 1.95 2005/07/05 21:03:07 dwmw2 Exp $

 *

 */
@@ -58,27 +58,61 @@ void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new 
/* 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);

static void jffs2_add_tn_to_list(struct jffs2_tmp_dnode_info *tn, struct rb_root *list)

{

	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;

        }

	tn->next = (*prev);

        *prev = tn;



	rb_link_node(&tn->rb, parent, p);

	rb_insert_color(&tn->rb, list);

}



static void jffs2_free_tmp_dnode_info_list(struct jffs2_tmp_dnode_info *tn)

static void jffs2_free_tmp_dnode_info_list(struct rb_root *list)

{

	struct jffs2_tmp_dnode_info *next;

	struct rb_node *this;

	struct jffs2_tmp_dnode_info *tn;



	this = list->rb_node;



	while (tn) {

		next = tn;

		tn = tn->next;

		jffs2_free_full_dnode(next->fn);

		jffs2_free_tmp_dnode_info(next);

	/* 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;



			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 @@ static struct jffs2_raw_node_ref *jffs2_first_valid_node(struct jffs2_raw_node_r 
   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 @@ int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_info *f, 
	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;

}

fs/jffs2/nodelist.h

+3 −3
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ 
 *

 * For licensing information, see the file 'LICENCE' in this directory.

 *

 * $Id: nodelist.h,v 1.130 2005/04/09 10:46:59 dedekind Exp $

 * $Id: nodelist.h,v 1.131 2005/07/05 21:03:07 dwmw2 Exp $

 *

 */
@@ -161,7 +161,7 @@ struct jffs2_full_dnode 
*/

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 @@ static inline struct jffs2_node_frag *frag_last(struct rb_root *root) 
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);

fs/jffs2/readinode.c

+31 −5
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ 
 *

 * For licensing information, see the file 'LICENCE' in this directory.

 *

 * $Id: readinode.c,v 1.119 2005/03/01 10:34:03 dedekind Exp $

 * $Id: readinode.c,v 1.120 2005/07/05 21:03:07 dwmw2 Exp $

 *

 */
@@ -500,7 +500,9 @@ static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c, 
					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 @@ static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c, 
	}

	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 @@ static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c, 
			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));