From mboxrd@z Thu Jan 1 00:00:00 1970 From: hare@suse.de (Hannes Reinecke) Date: Fri, 17 Aug 2018 09:29:06 +0200 Subject: [PATCH 4/6] nvme-discover: Retry discovery log if the generation counter changes In-Reply-To: <20180817072908.56784-1-hare@suse.de> References: <20180817072908.56784-1-hare@suse.de> Message-ID: <20180817072908.56784-5-hare@suse.de> 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 --- fabrics.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/fabrics.c b/fabrics.c index 9bf2594..b277d36 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