autofs-5.0.3 - eliminate redundant DNS name lookups

From: Ian Kent <raven@themaw.net>

When autofs tries to lookup a DNS host name where one or more DNS

servers aren't available the mount can take a long time. This is

caused by autofs doing the name lookups more often than it needs

to. This patch removes a number of these redundant name lookups.

---

 CHANGELOG            |    1 +

 include/replicated.h |    1 +

 include/rpc_subs.h   |    4 +++-

 lib/rpc_subs.c       |   22 ++++++++++++++++++++--

 modules/replicated.c |   25 +++++++++++++++++++------

 5 files changed, 44 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG

index 3ed84d3..995daea 100644

--- a/CHANGELOG

+++ b/CHANGELOG

@@ -17,6 +17,7 @@

 - add check for exports automatically mounted by NFS kernel client.

 - update nsswitch parser to ignore nsswitch sources that aren't supported.

 - check for map key in (possible) alternate map sources when doing lookup.

+- eliminate redundant DNS name lookups.

 14/01/2008 autofs-5.0.3

 -----------------------

diff --git a/include/replicated.h b/include/replicated.h

index 672f853..88cd08a 100644

--- a/include/replicated.h

+++ b/include/replicated.h

@@ -52,6 +52,7 @@

 struct host {

 	char *name;

 	char *addr;

+	size_t addr_len;

 	char *path;

 	unsigned int version;

 	unsigned int proximity;

diff --git a/include/rpc_subs.h b/include/rpc_subs.h

index 3292e01..e20a89d 100644

--- a/include/rpc_subs.h

+++ b/include/rpc_subs.h

@@ -46,6 +46,8 @@

 struct conn_info {

 	const char *host;

+	const char *addr;

+	size_t addr_len;

 	unsigned short port;

 	unsigned long program;

 	unsigned long version;

@@ -61,7 +63,7 @@ int rpc_udp_getclient(struct conn_info *, unsigned int, unsigned int);

 void rpc_destroy_udp_client(struct conn_info *);

 int rpc_tcp_getclient(struct conn_info *, unsigned int, unsigned int);

 void rpc_destroy_tcp_client(struct conn_info *);

-int rpc_portmap_getclient(struct conn_info *, const char *, const char *, unsigned int);

+int rpc_portmap_getclient(struct conn_info *, const char *, const char *, size_t, const char *, unsigned int);

 unsigned short rpc_portmap_getport(struct conn_info *, struct pmap *);

 int rpc_ping_proto(struct conn_info *);

 int rpc_ping(const char *, long, long, unsigned int);

diff --git a/lib/rpc_subs.c b/lib/rpc_subs.c

index 5797639..6be86c6 100644

--- a/lib/rpc_subs.c

+++ b/lib/rpc_subs.c

@@ -86,6 +86,11 @@ static CLIENT *create_udp_client(struct conn_info *info)

 	memset(&raddr, 0, sizeof(raddr));

 	raddr.sin_family = AF_INET;

+	if (info->addr) {

+		memcpy(&raddr.sin_addr.s_addr, info->addr, info->addr_len);

+		goto got_addr;

+	}

+

 	if (inet_aton(info->host, &raddr.sin_addr))

 		goto got_addr;

@@ -295,6 +300,11 @@ static CLIENT *create_tcp_client(struct conn_info *info)

 	memset(&addr, 0, sizeof(addr));

 	addr.sin_family = AF_INET;

+	if (info->addr) {

+		memcpy(&addr.sin_addr.s_addr, info->addr, info->addr_len);

+		goto got_addr;

+	}

+

 	if (inet_aton(info->host, &addr.sin_addr))

 		goto got_addr;

@@ -407,8 +417,8 @@ void rpc_destroy_tcp_client(struct conn_info *info)

 }

 int rpc_portmap_getclient(struct conn_info *info,

-			  const char *host, const char *proto,

-			  unsigned int option)

+			  const char *host, const char *addr, size_t addr_len,

+			  const char *proto, unsigned int option)

 {

 	struct protoent *pe_proto;

 	CLIENT *client;

@@ -418,6 +428,8 @@ int rpc_portmap_getclient(struct conn_info *info,

 		return 0;

 	info->host = host;

+	info->addr = addr;

+	info->addr_len = addr_len;

 	info->program = PMAPPROG;

 	info->port = PMAPPORT;

 	info->version = PMAPVERS;

@@ -462,6 +474,8 @@ unsigned short rpc_portmap_getport(struct conn_info *info, struct pmap *parms)

 		client = info->client;

 	else {

 		pmap_info.host = info->host;

+		pmap_info.addr = info->addr;

+		pmap_info.addr_len = info->addr_len;

 		pmap_info.port = PMAPPORT;

 		pmap_info.program = PMAPPROG;

 		pmap_info.version = PMAPVERS;

@@ -589,6 +603,8 @@ static unsigned int __rpc_ping(const char *host,

 	struct pmap parms;

 	info.host = host;

+	info.addr = NULL;

+	info.addr_len = 0;

 	info.program = NFS_PROGRAM;

 	info.version = version;

 	info.send_sz = 0;

@@ -769,6 +785,8 @@ exports rpc_get_exports(const char *host, long seconds, long micros, unsigned in

 	int status;

 	info.host = host;

+	info.addr = NULL;

+	info.addr_len = 0;

 	info.program = MOUNTPROG;

 	info.version = MOUNTVERS;

 	info.send_sz = 0;

diff --git a/modules/replicated.c b/modules/replicated.c

index 90b2925..efbe6b4 100644

--- a/modules/replicated.c

+++ b/modules/replicated.c

@@ -225,7 +225,9 @@ static unsigned int get_proximity(const char *host_addr, int addr_len)

 	return PROXIMITY_OTHER;

 }

-static struct host *new_host(const char *name, const char *addr, unsigned int proximity, unsigned int weight)

+static struct host *new_host(const char *name,

+			     const char *addr, size_t addr_len,

+			     unsigned int proximity, unsigned int weight)

 {

 	struct host *new;

 	char *tmp1, *tmp2;

@@ -237,11 +239,12 @@ static struct host *new_host(const char *name, const char *addr, unsigned int pr

 	if (!tmp1)

 		return NULL;

-	tmp2 = strdup(addr);

+	tmp2 = malloc(addr_len);

 	if (!tmp2) {

 		free(tmp1);

 		return NULL;

 	}

+	memcpy(tmp2, addr, addr_len);

 	new = malloc(sizeof(struct host));

 	if (!new) {

@@ -253,6 +256,7 @@ static struct host *new_host(const char *name, const char *addr, unsigned int pr

 	memset(new, 0, sizeof(struct host));

 	new->name = tmp1;

+	new->addr_len = addr_len;

 	new->addr = tmp2;

 	new->proximity = proximity;

 	new->weight = weight;

@@ -437,7 +441,8 @@ static unsigned int get_nfs_info(unsigned logopt, struct host *host,

 v3_ver:

 	if (!have_port_opt) {

 		status = rpc_portmap_getclient(pm_info,

-				 host->name, proto, RPC_CLOSE_DEFAULT);

+				host->name, host->addr, host->addr_len,

+				proto, RPC_CLOSE_DEFAULT);

 		if (!status)

 			goto done_ver;

 	}

@@ -551,6 +556,8 @@ static int get_vers_and_cost(unsigned logopt, struct host *host,

 		timeout = RPC_TIMEOUT * 8;

 	rpc_info.host = host->name;

+	rpc_info.addr = host->addr;

+	rpc_info.addr_len = host->addr_len;

 	rpc_info.program = NFS_PROGRAM;

 	rpc_info.timeout.tv_sec = timeout;

 	rpc_info.close_option = RPC_CLOSE_DEFAULT;

@@ -606,6 +613,8 @@ static int get_supported_ver_and_cost(unsigned logopt, struct host *host,

 		timeout = RPC_TIMEOUT * 8;

 	rpc_info.host = host->name;

+	rpc_info.addr = host->addr;

+	rpc_info.addr_len = host->addr_len;

 	rpc_info.program = NFS_PROGRAM;

 	rpc_info.timeout.tv_sec = timeout;

 	rpc_info.close_option = RPC_CLOSE_DEFAULT;

@@ -652,7 +661,8 @@ static int get_supported_ver_and_cost(unsigned logopt, struct host *host,

 			return 0;

 	} else {

 		int ret = rpc_portmap_getclient(&pm_info,

-				 host->name, proto, RPC_CLOSE_DEFAULT);

+				host->name, host->addr, host->addr_len,

+				proto, RPC_CLOSE_DEFAULT);

 		if (!ret)

 			return 0;

@@ -868,7 +878,7 @@ static int add_host_addrs(struct host **list, const char *host, unsigned int wei

 		if (prx == PROXIMITY_ERROR)

 			return 0;

-		if (!(new = new_host(host, thost, prx, weight)))

+		if (!(new = new_host(host, thost, sizeof(saddr.sin_addr), prx, weight)))

 			return 0;

 		if (!add_host(list, new))

@@ -891,11 +901,14 @@ static int add_host_addrs(struct host **list, const char *host, unsigned int wei

 	}

 	for (haddr = phe->h_addr_list; *haddr; haddr++) {

+		struct in_addr tt;

+

 		prx = get_proximity(*haddr, phe->h_length);

 		if (prx == PROXIMITY_ERROR)

 			return 0;

-		if (!(new = new_host(host, *haddr, prx, weight)))

+		memcpy(&tt, *haddr, sizeof(struct in_addr));

+		if (!(new = new_host(host, *haddr, phe->h_length, prx, weight)))

 			return 0;

 		if (!add_host(list, new)) {