device-mapper-multipath/0020-RH-add-wwids-from-kernel-cmdline-mpath.wwids-with-A.patch

From 0000000000000000000000000000000000000000 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         |  5 ++++-
 multipathd/multipathd.service |  1 +
 5 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/libmultipath/wwids.c b/libmultipath/wwids.c
index bc70a27..88bb72b 100644
--- a/libmultipath/wwids.c
+++ b/libmultipath/wwids.c
@@ -321,3 +321,47 @@ remember_wwid(char *wwid)
 		condlog(4, "wwid %s already in wwids file", wwid);
 	return 0;
 }
+
+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 9527012..b665232 100644
--- a/libmultipath/wwids.h
+++ b/libmultipath/wwids.h
@@ -17,5 +17,6 @@ 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);
 
 #endif /* _WWIDS_H */
diff --git a/multipath/main.c b/multipath/main.c
index d2415a9..ff570ac 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -102,7 +102,7 @@ usage (char * progname)
 {
 	fprintf (stderr, VERSION_STRING);
 	fprintf (stderr, "Usage:\n");
-	fprintf (stderr, "  %s [-a|-c|-w|-W] [-d] [-r] [-i] [-v lvl] [-p pol] [-b fil] [-q] [dev]\n", progname);
+	fprintf (stderr, "  %s [-a|-A|-c|-w|-W] [-d] [-r] [-i] [-v lvl] [-p pol] [-b fil] [-q] [dev]\n", progname);
 	fprintf (stderr, "  %s -l|-ll|-f [-v lvl] [-b fil] [-R num] [dev]\n", progname);
 	fprintf (stderr, "  %s -F [-v lvl] [-R num]\n", progname);
 	fprintf (stderr, "  %s -t\n", progname);
@@ -116,6 +116,8 @@ 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"
@@ -602,7 +604,7 @@ main (int argc, char *argv[])
 		exit(1);
 	multipath_conf = conf;
 	conf->retrigger_tries = 0;
-	while ((arg = getopt(argc, argv, ":adcChl::FfM:v:p:b:BrR:itquUwW")) != EOF ) {
+	while ((arg = getopt(argc, argv, ":aAdcChl::FfM:v:p:b:BrR:itquUwW")) != EOF ) {
 		switch(arg) {
 		case 1: printf("optarg : %s\n",optarg);
 			break;
@@ -669,6 +671,10 @@ main (int argc, char *argv[])
 		case 't':
 			r = dump_config(conf);
 			goto out_free_config;
+		case 'A':
+			if (remember_cmdline_wwid() != 0)
+				exit(1);
+			exit(0);
 		case 'h':
 			usage(argv[0]);
 			exit(0);
diff --git a/multipath/multipath.8 b/multipath/multipath.8
index 56f8703..9fc2317 100644
--- a/multipath/multipath.8
+++ b/multipath/multipath.8
@@ -25,7 +25,7 @@ multipath \- Device mapper target autoconfig.
 .RB [\| \-b\ \c
 .IR bindings_file \|]
 .RB [\| \-d \|]
-.RB [\| \-h | \-l | \-ll | \-f | \-t | \-F | \-B | \-c | \-C | \-q | \-r | \-i | \-a | \-u | \-U | \-w | \-W \|]
+.RB [\| \-h | \-l | \-ll | \-f | \-t | \-F | \-B | \-c | \-C | \-q | \-r | \-i | \-a | \-A | \-u | \-U | \-w | \-W \|]
 .RB [\| \-p\ \c
 .IR failover | multibus | group_by_serial | group_by_prio | group_by_node_name \|]
 .RB [\| \-R\ \c
@@ -128,6 +128,9 @@ Add the WWID for the specified device to the WWIDs file.
 Check if the device specified in the program environment should be
 a path in a multipath device.
 .
+.B \-A
+add wwids from any kernel command line mpath.wwid parameters to the wwids file
+.
 .TP
 .B \-U
 Check if the device specified in the program environment is a multipath device
diff --git a/multipathd/multipathd.service b/multipathd/multipathd.service
index fafd088..a623a3f 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
 
-- 
2.7.4