autofs-5.1.2 - work around sss startup delay

From: Ian Kent <raven@themaw.net>

When sssd is starting up there can be a delay before the map

information is read. During that time an ENOENT can be returned

when there actually is a map and autofs must respect the ENOENT

return and continue because no map present is a valid response.

To work around that make the master map read wait and retry for

for a time to give sssd a chance to read the map before returning

either an ENOENT or, if the retry limit is exceeded, ETIMEDOUT.

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

---

 CHANGELOG            |    1 

 modules/lookup_sss.c |   61 +++++++++++++++++++++++++++++++++++++++++++++++++++

 2 files changed, 62 insertions(+)

--- autofs-5.0.7.orig/CHANGELOG

+++ autofs-5.0.7/CHANGELOG

@@ -240,6 +240,7 @@

 - log functions to prefix messages with attempt_id if available.

 - factor out set_thread_mount_request_log_id().

 - add config option to use mount request log id.

+- work around sss startup delay.

 25/07/2012 autofs-5.0.7

 =======================

--- autofs-5.0.7.orig/modules/lookup_sss.c

+++ autofs-5.0.7/modules/lookup_sss.c

@@ -30,6 +30,11 @@

 #define MAPFMT_DEFAULT "sun"

+/* Half a second between retries */

+#define SETAUTOMOUNTENT_MASTER_INTERVAL	500000000

+/* Try for 10 seconds */

+#define SETAUTOMOUNTENT_MASTER_RETRIES	10 * 2

+

 #define MODPREFIX "lookup(sss): "

 #define SSS_SO_NAME "libsss_autofs"

@@ -219,6 +224,53 @@ static int setautomntent(unsigned int lo

 	return ret;

 }

+static int setautomntent_wait(unsigned int logopt,

+			      struct lookup_context *ctxt,

+			      const char *mapname,

+			      void **sss_ctxt, unsigned int retries)

+{

+	unsigned int retry = 0;

+	int ret = 0;

+

+	*sss_ctxt = NULL;

+

+	while (++retry < retries) {

+		struct timespec t = { 0, SETAUTOMOUNTENT_MASTER_INTERVAL };

+		struct timespec r;

+

+		ret = ctxt->setautomntent(mapname, sss_ctxt);

+		if (ret != ENOENT)

+			break;

+

+		if (*sss_ctxt) {

+			free(*sss_ctxt);

+			*sss_ctxt = NULL;

+		}

+

+		while (nanosleep(&t, &r) == -1 && errno == EINTR)

+			memcpy(&t, &r, sizeof(struct timespec));

+	}

+

+

+	if (ret) {

+		char buf[MAX_ERR_BUF];

+		char *estr;

+

+		if (*sss_ctxt) {

+			free(*sss_ctxt);

+			*sss_ctxt = NULL;

+		}

+

+		if (retry == retries)

+			ret = ETIMEDOUT;

+

+		estr = strerror_r(ret, buf, MAX_ERR_BUF);

+		error(logopt, MODPREFIX "setautomntent: %s", estr);

+	}

+

+	return ret;

+}

+

 static int endautomntent(unsigned int logopt,

 			 struct lookup_context *ctxt, void **sss_ctxt)

 {

@@ -247,6 +299,15 @@ int lookup_read_master(struct master *ma

 	ret = setautomntent(logopt, ctxt, ctxt->mapname, &sss_ctxt);

 	if (ret) {

+		unsigned int retries;

+

+		if (ret != ENOENT)

+			return NSS_STATUS_UNAVAIL;

+

+		retries = SETAUTOMOUNTENT_MASTER_RETRIES;

+		ret = setautomntent_wait(logopt,

+					 ctxt, ctxt->mapname, &sss_ctxt,

+					 retries);

 		if (ret == ENOENT)

 			return NSS_STATUS_NOTFOUND;

 		return NSS_STATUS_UNAVAIL;