File 0019-nvme-discover-Retry-discovery-log-if-the-generation-.patch of Package nvme-cli.7759

From 69ad17fc9375190c64b4c7f325685829d7232d20 Mon Sep 17 00:00:00 2001
From: Hannes Reinecke <hare@suse.de>
Date: Tue, 12 Jun 2018 16:22:31 +0200
Subject: [PATCH] nvme-discover: Retry discovery log if the generation counter
 changes

If the generation counter changes we need to validate if the number
of records has changed, too.
If so we need to retry retrieving the discovery log to the most recent
values. The retry will be terminated after MAX_DISC_RETRIES (currently
set to 30) to avoid infinite recursion.

Signed-off-by: Hannes Reinecke <hare@suse.com>
---
 fabrics.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/fabrics.c b/fabrics.c
index b64930d..d759e92 100644
--- a/fabrics.c
+++ b/fabrics.c
@@ -71,6 +71,7 @@ static struct config {
 #define PATH_NVMF_HOSTID	"/etc/nvme/hostid"
 #define SYS_NVME		"/sys/class/nvme"
 #define MAX_DISC_ARGS		10
+#define MAX_DISC_RETRIES	30
 
 enum {
 	OPT_INSTANCE,
@@ -281,7 +282,7 @@ static int nvmf_get_log_page_discovery(const char *dev_path,
 	struct nvmf_disc_rsp_page_hdr *log;
 	unsigned int log_size = 0;
 	unsigned long genctr;
-	int error, fd;
+	int error, fd, max_retries = MAX_DISC_RETRIES, retries = 0;
 
 	fd = open(dev_path, O_RDWR);
 	if (fd < 0) {
@@ -311,6 +312,7 @@ static int nvmf_get_log_page_discovery(const char *dev_path,
 		goto out_free_log;
 	}
 
+retry_log:
 	/* check numrec limits */
 	*numrec = le64_to_cpu(log->numrec);
 	genctr = le64_to_cpu(log->genctr);
@@ -346,7 +348,12 @@ static int nvmf_get_log_page_discovery(const char *dev_path,
 		goto out_free_log;
 	}
 
-	if (*numrec != le32_to_cpu(log->numrec) || genctr != le64_to_cpu(log->genctr)) {
+	if (genctr != le64_to_cpu(log->genctr) &&
+	    *numrec != le32_to_cpu(log->numrec) &&
+	    ++retries < max_retries)
+		goto retry_log;
+
+	if (*numrec != le32_to_cpu(log->numrec)) {
 		error = DISC_NOT_EQUAL;
 		goto out_free_log;
 	}
-- 
2.13.7