commit 342ab070d42625e6e4b65caf66f7b7117f7d4509

Author: Andrew Price <anprice@redhat.com>

Date:   Wed Sep 2 14:12:31 2015 -0500

    gfs2_edit savemeta: speed up is_block_in_per_node()

    Previously is_block_in_per_node() called lgfs2_inode_read() and

    do_dinode_extended() for each block and savemeta was spending the vast

    majority of its time in this function according to perf. This patch

    speeds up the lookups by keeping a tree of per_node block addresses

    which can be quickly consulted. In my tests with a full 700G filesystem

    this patch cuts the run time in half.

    Resolves: rhbz#1162216

    Signed-off-by: Andrew Price <anprice@redhat.com>

diff --git a/gfs2/edit/savemeta.c b/gfs2/edit/savemeta.c

index b68b0ff..b08eb5e 100644

--- a/gfs2/edit/savemeta.c

+++ b/gfs2/edit/savemeta.c

@@ -74,8 +74,70 @@ static int block_is_a_journal(void)

 	return FALSE;

 }

+struct osi_root per_node_tree;

+struct per_node_node {

+	struct osi_node node;

+	uint64_t block;

+};

+

+static void destroy_per_node_lookup(void)

+{

+	struct osi_node *n;

+	struct per_node_node *pnp;

+

+	while ((n = osi_first(&per_node_tree))) {

+		pnp = (struct per_node_node *)n;

+		osi_erase(n, &per_node_tree);

+		free(pnp);

+	}

+}

+

 static int block_is_in_per_node(void)

 {

+	struct per_node_node *pnp = (struct per_node_node *)per_node_tree.osi_node;

+

+	while (pnp) {

+		if (block < pnp->block)

+			pnp = (struct per_node_node *)pnp->node.osi_left;

+		else if (block > pnp->block)

+			pnp = (struct per_node_node *)pnp->node.osi_right;

+		else

+			return 1;

+	}

+

+	return 0;

+}

+

+static int insert_per_node_lookup(uint64_t blk)

+{

+	struct osi_node **newn = &per_node_tree.osi_node, *parent = NULL;

+	struct per_node_node *pnp;

+

+	while (*newn) {

+		struct per_node_node *cur = (struct per_node_node *)*newn;

+

+		parent = *newn;

+		if (blk < cur->block)

+			newn = &((*newn)->osi_left);

+		else if (blk > cur->block)

+			newn = &((*newn)->osi_right);

+		else

+			return 0;

+	}

+

+	pnp = calloc(1, sizeof(struct per_node_node));

+	if (pnp == NULL) {

+		perror("Failed to insert per_node lookup entry");

+		return 1;

+	}

+	pnp->block = blk;

+	osi_link_node(&pnp->node, parent, newn);

+	osi_insert_color(&pnp->node, &per_node_tree);

+	return 0;

+}

+

+static int init_per_node_lookup(void)

+{

 	int i;

 	struct gfs2_inode *per_node_di;

@@ -85,7 +147,7 @@ static int block_is_in_per_node(void)

 	per_node_di = lgfs2_inode_read(&sbd, masterblock("per_node"));

 	if (per_node_di == NULL) {

 		fprintf(stderr, "Failed to read per_node: %s\n", strerror(errno));

-		exit(1);

+		return 1;

 	}

 	do_dinode_extended(&per_node_di->i_di, per_node_di->i_bh);

@@ -94,11 +156,12 @@ static int block_is_in_per_node(void)

 	for (i = 0; i < indirect_blocks; i++) {

 		int d;

 		for (d = 0; d < indirect->ii[i].dirents; d++) {

-			if (block == indirect->ii[i].dirent[d].block)

-				return TRUE;

+			int ret = insert_per_node_lookup(indirect->ii[i].dirent[d].block);

+			if (ret != 0)

+				return ret;

 		}

 	}

-	return FALSE;

+	return 0;

 }

 static int block_is_systemfile(void)

@@ -749,6 +812,10 @@ void savemeta(char *out_fn, int saveoption, int gziplevel)

 	printf("Filesystem size: %s\n", anthropomorphize(sbd.fssize * sbd.bsize));

 	get_journal_inode_blocks();

+	err = init_per_node_lookup();

+	if (err)

+		exit(1);

+

 	/* Write the savemeta file header */

 	err = save_header(&mfd, sbd.fssize * sbd.bsize);

 	if (err) {

@@ -810,6 +877,7 @@ void savemeta(char *out_fn, int saveoption, int gziplevel)

 	}

 	savemetaclose(&mfd;;

 	close(sbd.device_fd);

+	destroy_per_node_lookup();

 	free(indirect);

 	gfs2_rgrp_free(&sbd.rgtree);

 	exit(0);