autofs-5.1.7 - fix hosts map offset order

From: Ian Kent <raven@themaw.net>

Map entry offset paths to be in shortest to longest order but exports

from a server could come in any order. If there are a large number of

exports this can result in a lot of overhead when adding the offset

to the ordered list use to mount the offset during parsing since the

path length of exports can cary a lot.

So leverage the tree implemention to sort the export offsets into

shortest to longest order as we go when constructing the mapent from

the exports list.

Signed-off-by: Ian Kent <raven@themaw.net>

---

 CHANGELOG              |    1 

 include/automount.h    |    2 -

 include/mounts.h       |    8 +++++

 include/rpc_subs.h     |    3 ++

 lib/mounts.c           |   57 +++++++++++++++++++++++++++++++++++++--

 modules/lookup_hosts.c |   71 ++++++++++++++++++++++++++++++++++++++-----------

 6 files changed, 124 insertions(+), 18 deletions(-)

--- autofs-5.1.7.orig/CHANGELOG

+++ autofs-5.1.7/CHANGELOG

@@ -74,6 +74,7 @@

 - fix offset entries order.

 - use mapent tree root for tree_mapent_add_node().

 - eliminate redundant cache lookup in tree_mapent_add_node().

+- fix hosts map offset order.

 25/01/2021 autofs-5.1.7

 - make bind mounts propagation slave by default.

--- autofs-5.1.7.orig/include/automount.h

+++ autofs-5.1.7/include/automount.h

@@ -31,9 +31,9 @@

 #include "master.h"

 #include "macros.h"

 #include "log.h"

+#include "mounts.h"

 #include "rpc_subs.h"

 #include "parse_subs.h"

-#include "mounts.h"

 #include "dev-ioctl-lib.h"

 #include "parse_amd.h"

--- autofs-5.1.7.orig/include/mounts.h

+++ autofs-5.1.7/include/mounts.h

@@ -52,6 +52,7 @@ extern const unsigned int t_direct;

 extern const unsigned int t_offset;

 struct mnt_list;

+struct exportinfo;

 struct mapent;

 struct tree_ops;

@@ -66,6 +67,9 @@ struct tree_node {

 #define MNT_LIST(n)		(container_of(n, struct mnt_list, node))

 #define MNT_LIST_NODE(ptr)	((struct tree_node *) &((struct mnt_list *) ptr)->node)

+#define EXPORTINFO(n)		(container_of(n, struct exportinfo, node))

+#define EXPORT_NODE(ptr)	((struct tree_node *) &((struct exportinfo *) ptr)->node)

+

 #define MAPENT(n)		(container_of(n, struct mapent, node))

 #define MAPENT_NODE(p)		((struct tree_node *) &((struct mapent *) p)->node)

 #define MAPENT_ROOT(p)		((struct tree_node *) ((struct mapent *) p)->mm_root)

@@ -166,9 +170,13 @@ struct mnt_list *mnts_add_mount(struct a

 void mnts_remove_mount(const char *mp, unsigned int flags);

 struct mnt_list *get_mnt_list(const char *path, int include);

 unsigned int mnts_has_mounted_mounts(struct autofs_point *ap);

+int tree_traverse_inorder(struct tree_node *n, tree_work_fn_t work, void *ptr);

+void tree_free(struct tree_node *root);

 void mnts_get_expire_list(struct list_head *mnts, struct autofs_point *ap);

 void mnts_put_expire_list(struct list_head *mnts);

 void mnts_set_mounted_mount(struct autofs_point *ap, const char *name, unsigned int flags);

+struct tree_node *tree_host_root(struct exportinfo *exp);

+struct tree_node *tree_host_add_node(struct tree_node *root, struct exportinfo *exp);

 struct tree_node *tree_mapent_root(struct mapent *me);

 int tree_mapent_add_node(struct mapent_cache *mc, struct tree_node *root, struct mapent *me);

 int tree_mapent_delete_offsets(struct mapent_cache *mc, const char *key);

--- autofs-5.1.7.orig/include/rpc_subs.h

+++ autofs-5.1.7/include/rpc_subs.h

@@ -23,6 +23,8 @@

 #include <linux/nfs2.h>

 #include <linux/nfs3.h>

+#include "automount.h"

+

 #define NFS4_VERSION		4

 /* rpc helper subs */

@@ -57,6 +59,7 @@ struct exportinfo {

 	char *dir;

 	struct hostinfo *hosts;

 	struct exportinfo *next;

+	struct tree_node node;

 };

 struct conn_info {

--- autofs-5.1.7.orig/lib/mounts.c

+++ autofs-5.1.7/lib/mounts.c

@@ -79,6 +79,17 @@ static struct tree_ops mnt_ops = {

 };

 static struct tree_ops *tree_mnt_ops = &mnt_ops;

+static struct tree_node *tree_host_new(void *ptr);

+static int tree_host_cmp(struct tree_node *n, void *ptr);

+static void tree_host_free(struct tree_node *n);

+

+static struct tree_ops host_ops = {

+	.new = tree_host_new,

+	.cmp = tree_host_cmp,

+	.free = tree_host_free,

+};

+static struct tree_ops *tree_host_ops = &host_ops;

+

 static struct tree_node *tree_mapent_new(void *ptr);

 static int tree_mapent_cmp(struct tree_node *n, void *ptr);

 static void tree_mapent_free(struct tree_node *n);

@@ -1341,7 +1352,7 @@ static struct tree_node *tree_add_node(s

 	return NULL;

 }

-static void tree_free(struct tree_node *root)

+void tree_free(struct tree_node *root)

 {

 	struct tree_ops *ops = root->ops;

@@ -1352,7 +1363,7 @@ static void tree_free(struct tree_node *

 	ops->free(root);

 }

-static int tree_traverse_inorder(struct tree_node *n, tree_work_fn_t work, void *ptr)

+int tree_traverse_inorder(struct tree_node *n, tree_work_fn_t work, void *ptr)

 {

 	int ret;

@@ -1479,6 +1490,48 @@ void mnts_put_expire_list(struct list_he

 	mnts_hash_mutex_unlock();

 }

+struct tree_node *tree_host_root(struct exportinfo *exp)

+{

+	return tree_root(tree_host_ops, exp);

+}

+

+static struct tree_node *tree_host_new(void *ptr)

+{

+	struct tree_node *n = EXPORT_NODE(ptr);

+

+	n->ops = tree_host_ops;

+	n->left = NULL;

+	n->right = NULL;

+

+	return n;

+}

+

+static int tree_host_cmp(struct tree_node *n, void *ptr)

+{

+	struct exportinfo *n_exp = EXPORTINFO(n);

+	size_t n_exp_len = strlen(n_exp->dir);

+	struct exportinfo *exp = ptr;

+	size_t exp_len = strlen(exp->dir);

+	int eq;

+

+	eq = strcmp(exp->dir, n_exp->dir);

+	if (!eq)

+		return 0;

+	return (exp_len < n_exp_len) ? -1 : 1;

+}

+

+static void tree_host_free(struct tree_node *n)

+{

+	n->ops = NULL;

+	n->left = NULL;

+	n->right = NULL;

+}

+

+struct tree_node *tree_host_add_node(struct tree_node *root, struct exportinfo *exp)

+{

+	return tree_add_node(root, exp);

+}

+

 struct tree_node *tree_mapent_root(struct mapent *me)

 {

 	return tree_root(tree_mapent_ops, me);

--- autofs-5.1.7.orig/modules/lookup_hosts.c

+++ autofs-5.1.7/modules/lookup_hosts.c

@@ -84,14 +84,38 @@ int lookup_read_master(struct master *ma

 	return NSS_STATUS_UNKNOWN;

 }

+struct work_info {

+	char *mapent;

+	const char *host;

+	int pos;

+};

+

+static int tree_host_work(struct tree_node *n, void *ptr)

+{

+	struct exportinfo *exp = EXPORTINFO(n);

+	struct work_info *wi = ptr;

+	int len;

+

+	if (!wi->pos)

+		len = sprintf(wi->mapent, "\"%s\" \"%s:%s\"",

+				exp->dir, wi->host, exp->dir);

+	else

+		len = sprintf(wi->mapent + wi->pos, " \"%s\" \"%s:%s\"",

+				exp->dir, wi->host, exp->dir);

+	wi->pos += len;

+

+	return 1;

+}

+

 static char *get_exports(struct autofs_point *ap, const char *host)

 {

 	char buf[MAX_ERR_BUF];

 	char *mapent;

 	struct exportinfo *exp, *this;

+	struct tree_node *tree = NULL;

+	struct work_info wi;

 	size_t hostlen = strlen(host);

 	size_t mapent_len;

-	int len, pos;

 	debug(ap->logopt, MODPREFIX "fetchng export list for %s", host);

@@ -100,7 +124,28 @@ static char *get_exports(struct autofs_p

 	this = exp;

 	mapent_len = 0;

 	while (this) {

+		struct tree_node *n;

+

 		mapent_len += hostlen + 2*(strlen(this->dir) + 2) + 3;

+

+		if (!tree) {

+			tree = tree_host_root(this);

+			if (!tree) {

+				error(ap->logopt, "failed to create exports tree root");

+				rpc_exports_free(exp);

+				return NULL;

+			}

+			goto next;

+		}

+

+		n = tree_host_add_node(tree, this);

+		if (!n) {

+			error(ap->logopt, "failed to add exports tree node");

+			tree_free(tree);

+			rpc_exports_free(exp);

+			return NULL;

+		}

+next:

 		this = this->next;

 	}

@@ -115,20 +160,16 @@ static char *get_exports(struct autofs_p

 	}

 	*mapent = 0;

-	pos = 0;

-	this = exp;

-	if (this) {

-		len = sprintf(mapent, "\"%s\" \"%s:%s\"",

-				this->dir, host, this->dir);

-		pos += len;

-		this = this->next;

-	}

-

-	while (this) {

-		len = sprintf(mapent + pos, " \"%s\" \"%s:%s\"",

-				this->dir, host, this->dir);

-		pos += len;

-		this = this->next;

+	wi.mapent = mapent;

+	wi.host = host;

+	wi.pos = 0;

+

+	if (!tree) {

+		free(mapent);

+		mapent = NULL;

+	} else {

+		tree_traverse_inorder(tree, tree_host_work, &wi;;

+		tree_free(tree);

 	}

 	rpc_exports_free(exp);