device-mapper-multipath/0026-RH-add-wwids-from-kernel-cmdline-mpath.wwids-with-A.patch

From bba3bc3cfd910921ab5887acdc9503610e7efa18 Mon Sep 17 00:00:00 2001
From: Benjamin Marzinski <bmarzins@redhat.com>
Date: Fri, 17 Oct 2014 11:20:34 -0500
Subject: [PATCH] RH: add wwids from kernel cmdline mpath.wwids with -A

This patch adds another option to multipath, "-A", which reads
/proc/cmdline for mpath.wwid=<WWID> options, and adds any wwids it finds
to /etc/multipath/wwids.  While this isn't usually important during
normal operation, since these wwids should already be added, it can be
helpful during installation, to make sure that multipath can claim
devices as its own, before LVM or something else makes use of them.  The
patch also execs "/sbin/multipath -A" before running multipathd in
multipathd.service

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
 libmultipath/wwids.c          | 44 +++++++++++++++++++++++++++++++++++
 libmultipath/wwids.h          |  1 +
 multipath/main.c              | 10 ++++++--
 multipath/multipath.8         |  7 +++++-
 multipathd/multipathd.service |  1 +
 5 files changed, 60 insertions(+), 3 deletions(-)

diff --git a/libmultipath/wwids.c b/libmultipath/wwids.c
index ef748125..349da8b7 100644
--- a/libmultipath/wwids.c
+++ b/libmultipath/wwids.c
@@ -444,3 +444,47 @@ int op ## _wwid(const char *wwid) \
 declare_failed_wwid_op(is_failed, false)
 declare_failed_wwid_op(mark_failed, true)
 declare_failed_wwid_op(unmark_failed, true)
+
+int remember_cmdline_wwid(void)
+{
+	FILE *f = NULL;
+	char buf[LINE_MAX], *next, *ptr;
+	int ret = 0;
+
+	f = fopen("/proc/cmdline", "re");
+	if (!f) {
+		condlog(0, "can't open /proc/cmdline : %s", strerror(errno));
+		return -1;
+	}
+
+	if (!fgets(buf, sizeof(buf), f)) {
+		if (ferror(f))
+			condlog(0, "read of /proc/cmdline failed : %s",
+				strerror(errno));
+		else
+			condlog(0, "couldn't read /proc/cmdline");
+		fclose(f);
+		return -1;
+	}
+	fclose(f);
+	next = buf;
+	while((ptr = strstr(next, "mpath.wwid="))) {
+		ptr += 11;
+		next = strpbrk(ptr, " \t\n");
+		if (next) {
+			*next = '\0';
+			next++;
+		}
+		if (strlen(ptr)) {
+			if (remember_wwid(ptr) != 0)
+				ret = -1;
+		}
+		else {
+			condlog(0, "empty mpath.wwid kernel command line option");
+			ret = -1;
+		}
+		if (!next)
+			break;
+	}
+	return ret;
+}
diff --git a/libmultipath/wwids.h b/libmultipath/wwids.h
index 0c6ee54d..e32a0b0e 100644
--- a/libmultipath/wwids.h
+++ b/libmultipath/wwids.h
@@ -17,6 +17,7 @@ int remember_wwid(char *wwid);
 int check_wwids_file(char *wwid, int write_wwid);
 int remove_wwid(char *wwid);
 int replace_wwids(vector mp);
+int remember_cmdline_wwid(void);
 
 enum {
 	WWID_IS_NOT_FAILED = 0,
diff --git a/multipath/main.c b/multipath/main.c
index 4f4d8e89..22aff7be 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -138,7 +138,7 @@ usage (char * progname)
 	fprintf (stderr, "  %s [-v level] [-R retries] -F\n", progname);
 	fprintf (stderr, "  %s [-v level] [-l|-ll] [device]\n", progname);
 	fprintf (stderr, "  %s [-v level] [-a|-w] device\n", progname);
-	fprintf (stderr, "  %s [-v level] -W\n", progname);
+	fprintf (stderr, "  %s [-v level] [-A|-W]\n", progname);
 	fprintf (stderr, "  %s [-v level] [-i] [-c|-C] device\n", progname);
 	fprintf (stderr, "  %s [-v level] [-i] [-u|-U]\n", progname);
 	fprintf (stderr, "  %s [-h|-t|-T]\n", progname);
@@ -151,6 +151,8 @@ usage (char * progname)
 		"  -f      flush a multipath device map\n"
 		"  -F      flush all multipath device maps\n"
 		"  -a      add a device wwid to the wwids file\n"
+		"  -A      add devices from kernel command line mpath.wwids\n"
+		"          parameters to wwids file\n"
 		"  -c      check if a device should be a path in a multipath device\n"
 		"  -C      check if a multipath device has usable paths\n"
 		"  -q      allow queue_if_no_path when multipathd is not running\n"
@@ -905,7 +907,7 @@ main (int argc, char *argv[])
 		exit(RTVL_FAIL);
 	multipath_conf = conf;
 	conf->retrigger_tries = 0;
-	while ((arg = getopt(argc, argv, ":adcChl::FfM:v:p:b:BrR:itTquUwW")) != EOF ) {
+	while ((arg = getopt(argc, argv, ":aAdcChl::FfM:v:p:b:BrR:itTquUwW")) != EOF ) {
 		switch(arg) {
 		case 1: printf("optarg : %s\n",optarg);
 			break;
@@ -975,6 +977,10 @@ main (int argc, char *argv[])
 		case 'T':
 			cmd = CMD_DUMP_CONFIG;
 			break;
+		case 'A':
+			if (remember_cmdline_wwid() != 0)
+				exit(RTVL_FAIL);
+			exit(RTVL_OK);
 		case 'h':
 			usage(argv[0]);
 			exit(RTVL_OK);
diff --git a/multipath/multipath.8 b/multipath/multipath.8
index 9cdd05a3..8befc45a 100644
--- a/multipath/multipath.8
+++ b/multipath/multipath.8
@@ -63,7 +63,7 @@ multipath \- Device mapper target autoconfig.
 .B multipath
 .RB [\| \-v\ \c
 .IR level \|]
-.B -W
+.RB [\| \-A | \-W \|]
 .
 .LP
 .B multipath
@@ -145,6 +145,11 @@ device mapper, path checkers ...).
 Add the WWID for the specified device to the WWIDs file.
 .
 .TP
+.B \-A
+Add the WWIDs from any kernel command line \fImpath.wwid\fR parameters to the
+WWIDs file.
+.
+.TP
 .B \-w
 Remove the WWID for the specified device from the WWIDs file.
 .
diff --git a/multipathd/multipathd.service b/multipathd/multipathd.service
index 17434cef..0fbcc46b 100644
--- a/multipathd/multipathd.service
+++ b/multipathd/multipathd.service
@@ -15,6 +15,7 @@ Type=notify
 NotifyAccess=main
 LimitCORE=infinity
 ExecStartPre=-/sbin/modprobe -a scsi_dh_alua scsi_dh_emc scsi_dh_rdac dm-multipath
+ExecStartPre=-/sbin/multipath -A
 ExecStart=/sbin/multipathd -d -s
 ExecReload=/sbin/multipathd reconfigure
 TasksMax=infinity
-- 
2.17.2