[dm-devel] [RESEND][PATCH] multipath: don't set queue_if_no_path without multipathd

Benjamin Marzinski bmarzins at redhat.com
Fri Sep 23 04:41:58 UTC 2011


If multipathd is not running, when all paths to a device have failed, there's
no way for them to automatically get restored.  If the device is set to queue,
whatever is accessing it will hang forever. This can lead to problems if it
happens at boot-up.  This patch unsets queue_if_no_path for all devices created
when multipathd is not running. When multipathd starts, it will automatically
get reset queue_if_no_path to the proper value.  This new behaviour can be
overridden using the new "-q" option to multipath.

This patch applies against the current head, instead of building on my
find_multipaths patch.  It moves pidfile.[ch] into libmultipath, but is
functionally identical to the last version.

Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
---
 libmultipath/Makefile    |    2 
 libmultipath/config.h    |    1 
 libmultipath/configure.c |   13 +++++-
 libmultipath/pidfile.c   |   95 +++++++++++++++++++++++++++++++++++++++++++++++
 libmultipath/pidfile.h   |    2 
 multipath/main.c         |    8 ++-
 multipathd/Makefile      |    2 
 multipathd/main.c        |    2 
 multipathd/pidfile.c     |   67 ---------------------------------
 multipathd/pidfile.h     |    1 
 10 files changed, 119 insertions(+), 74 deletions(-)

Index: multipath-tools-110916/libmultipath/config.h
===================================================================
--- multipath-tools-110916.orig/libmultipath/config.h
+++ multipath-tools-110916/libmultipath/config.h
@@ -92,6 +92,7 @@ struct config {
 	int attribute_flags;
 	int fast_io_fail;
 	unsigned int dev_loss;
+	int allow_queueing;
 	uid_t uid;
 	gid_t gid;
 	mode_t mode;
Index: multipath-tools-110916/libmultipath/configure.c
===================================================================
--- multipath-tools-110916.orig/libmultipath/configure.c
+++ multipath-tools-110916/libmultipath/configure.c
@@ -35,6 +35,7 @@
 #include "alias.h"
 #include "prio.h"
 #include "util.h"
+#include "pidfile.h"
 
 extern int
 setup_map (struct multipath * mpp, char * params, int params_size)
@@ -555,7 +556,17 @@ coalesce_paths (struct vectors * vecs, v
 		if (r == DOMAP_DRY)
 			continue;
 
-		if (mpp->no_path_retry != NO_PATH_RETRY_UNDEF) {
+		if (!conf->daemon && !conf->allow_queueing &&
+		    !pidfile_check(DEFAULT_PIDFILE)) {
+			if (mpp->no_path_retry != NO_PATH_RETRY_UNDEF &&
+			    mpp->no_path_retry != NO_PATH_RETRY_FAIL)
+				condlog(3, "%s: multipathd not running, unset "
+					"queue_if_no_path feature", mpp->alias);
+			if (!dm_queue_if_no_path(mpp->alias, 0))
+				remove_feature(&mpp->features,
+					       "queue_if_no_path");
+		}
+		else if (mpp->no_path_retry != NO_PATH_RETRY_UNDEF) {
 			if (mpp->no_path_retry == NO_PATH_RETRY_FAIL) {
 				condlog(3, "%s: unset queue_if_no_path feature",
 					mpp->alias);
Index: multipath-tools-110916/multipath/main.c
===================================================================
--- multipath-tools-110916.orig/multipath/main.c
+++ multipath-tools-110916/multipath/main.c
@@ -79,7 +79,7 @@ usage (char * progname)
 {
 	fprintf (stderr, VERSION_STRING);
 	fprintf (stderr, "Usage:\n");
-	fprintf (stderr, "  %s [-d] [-r] [-v lvl] [-p pol] [-b fil] [dev]\n", progname);
+	fprintf (stderr, "  %s [-d] [-r] [-v lvl] [-p pol] [-b fil] [-q] [dev]\n", progname);
 	fprintf (stderr, "  %s -l|-ll|-f [-v lvl] [-b fil] [dev]\n", progname);
 	fprintf (stderr, "  %s -F [-v lvl]\n", progname);
 	fprintf (stderr, "  %s -t\n", progname);
@@ -92,6 +92,7 @@ usage (char * progname)
 		"  -ll     show multipath topology (maximum info)\n" \
 		"  -f      flush a multipath device map\n" \
 		"  -F      flush all multipath device maps\n" \
+		"  -q      allow queue_if_no_path when multipathd is not running\n"\
 		"  -d      dry run, do not create or update devmaps\n" \
 		"  -t      dump internal hardware table\n" \
 		"  -r      force devmap reload\n" \
@@ -397,7 +398,7 @@ main (int argc, char *argv[])
 		condlog(0, "multipath tools need sysfs mounted");
 		exit(1);
 	}
-	while ((arg = getopt(argc, argv, ":dhl::FfM:v:p:b:Brt")) != EOF ) {
+	while ((arg = getopt(argc, argv, ":dhl::FfM:v:p:b:Brtq")) != EOF ) {
 		switch(arg) {
 		case 1: printf("optarg : %s\n",optarg);
 			break;
@@ -414,6 +415,9 @@ main (int argc, char *argv[])
 		case 'B':
 			conf->bindings_read_only = 1;
 			break;
+		case 'q':
+			conf->allow_queueing = 1;
+			break;
 		case 'd':
 			conf->dry_run = 1;
 			break;
Index: multipath-tools-110916/multipathd/pidfile.c
===================================================================
--- multipath-tools-110916.orig/multipathd/pidfile.c
+++ /dev/null
@@ -1,67 +0,0 @@
-#include <sys/types.h> /* for pid_t */
-#include <sys/stat.h>  /* for open */
-#include <signal.h>    /* for kill() */
-#include <errno.h>     /* for ESHRC */
-#include <stdio.h>     /* for f...() */
-#include <string.h>    /* for memset() */
-#include <stdlib.h>    /* for atoi() */
-#include <unistd.h>    /* for unlink() */
-#include <fcntl.h>     /* for fcntl() */
-
-#include <debug.h>
-
-#include "pidfile.h"
-
-int pidfile_create(const char *pidFile, pid_t pid)
-{
-	char buf[20];
-	struct flock lock;
-	int fd, value;
-
-	if((fd = open(pidFile, O_WRONLY | O_CREAT,
-		       (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH))) < 0) {
-		condlog(0, "Cannot open pidfile [%s], error was [%s]",
-			pidFile, strerror(errno));
-		return 1;
-	}
-	lock.l_type = F_WRLCK;
-	lock.l_start = 0;
-	lock.l_whence = SEEK_SET;
-	lock.l_len = 0;
-
-	if (fcntl(fd, F_SETLK, &lock) < 0) {
-		if (errno != EACCES && errno != EAGAIN)
-			condlog(0, "Cannot lock pidfile [%s], error was [%s]",
-				pidFile, strerror(errno));
-		else
-			condlog(0, "process is already running");
-		goto fail;
-	}
-	if (ftruncate(fd, 0) < 0) {
-		condlog(0, "Cannot truncate pidfile [%s], error was [%s]",
-			pidFile, strerror(errno));
-		goto fail;
-	}
-	memset(buf, 0, sizeof(buf));
-	snprintf(buf, sizeof(buf)-1, "%u", pid);
-	if (write(fd, buf, strlen(buf)) != strlen(buf)) {
-		condlog(0, "Cannot write pid to pidfile [%s], error was [%s]",
-			pidFile, strerror(errno));
-		goto fail;
-	}
-	if ((value = fcntl(fd, F_GETFD, 0)) < 0) {
-		condlog(0, "Cannot get close-on-exec flag from pidfile [%s], "
-			"error was [%s]", pidFile, strerror(errno));
-		goto fail;
-	}
-	value |= FD_CLOEXEC;
-	if (fcntl(fd, F_SETFD, value) < 0) {
-		condlog(0, "Cannot set close-on-exec flag from pidfile [%s], "
-			"error was [%s]", pidFile, strerror(errno));
-		goto fail;
-	}
-	return 0;
-fail:
-	close(fd);
-	return 1;
-}
Index: multipath-tools-110916/multipathd/pidfile.h
===================================================================
--- multipath-tools-110916.orig/multipathd/pidfile.h
+++ /dev/null
@@ -1 +0,0 @@
-int pidfile_create(const char *pidFile, pid_t pid);
Index: multipath-tools-110916/libmultipath/Makefile
===================================================================
--- multipath-tools-110916.orig/libmultipath/Makefile
+++ multipath-tools-110916/libmultipath/Makefile
@@ -15,7 +15,7 @@ OBJS = memory.o parser.o vector.o devmap
        pgpolicies.o debug.o regex.o defaults.o uevent.o \
        switchgroup.o uxsock.o print.o alias.o log_pthread.o \
        log.o configure.o structs_vec.o sysfs.o prio.o checkers.o \
-       lock.o waiter.o
+       lock.o waiter.o pidfile.o
 
 LIBDM_API_FLUSH = $(shell grep -Ecs '^[a-z]*[[:space:]]+dm_task_no_flush' /usr/include/libdevmapper.h)
 
Index: multipath-tools-110916/libmultipath/pidfile.c
===================================================================
--- /dev/null
+++ multipath-tools-110916/libmultipath/pidfile.c
@@ -0,0 +1,95 @@
+#include <sys/types.h> /* for pid_t */
+#include <sys/stat.h>  /* for open */
+#include <signal.h>    /* for kill() */
+#include <errno.h>     /* for ESHRC */
+#include <stdio.h>     /* for f...() */
+#include <string.h>    /* for memset() */
+#include <stdlib.h>    /* for atoi() */
+#include <unistd.h>    /* for unlink() */
+#include <fcntl.h>     /* for fcntl() */
+
+#include "debug.h"
+#include "pidfile.h"
+
+int pidfile_create(const char *pidFile, pid_t pid)
+{
+	char buf[20];
+	struct flock lock;
+	int fd, value;
+
+	if((fd = open(pidFile, O_WRONLY | O_CREAT,
+		       (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH))) < 0) {
+		condlog(0, "Cannot open pidfile [%s], error was [%s]",
+			pidFile, strerror(errno));
+		return 1;
+	}
+	lock.l_type = F_WRLCK;
+	lock.l_start = 0;
+	lock.l_whence = SEEK_SET;
+	lock.l_len = 0;
+
+	if (fcntl(fd, F_SETLK, &lock) < 0) {
+		if (errno != EACCES && errno != EAGAIN)
+			condlog(0, "Cannot lock pidfile [%s], error was [%s]",
+				pidFile, strerror(errno));
+		else
+			condlog(0, "process is already running");
+		goto fail;
+	}
+	if (ftruncate(fd, 0) < 0) {
+		condlog(0, "Cannot truncate pidfile [%s], error was [%s]",
+			pidFile, strerror(errno));
+		goto fail;
+	}
+	memset(buf, 0, sizeof(buf));
+	snprintf(buf, sizeof(buf)-1, "%u", pid);
+	if (write(fd, buf, strlen(buf)) != strlen(buf)) {
+		condlog(0, "Cannot write pid to pidfile [%s], error was [%s]",
+			pidFile, strerror(errno));
+		goto fail;
+	}
+	if ((value = fcntl(fd, F_GETFD, 0)) < 0) {
+		condlog(0, "Cannot get close-on-exec flag from pidfile [%s], "
+			"error was [%s]", pidFile, strerror(errno));
+		goto fail;
+	}
+	value |= FD_CLOEXEC;
+	if (fcntl(fd, F_SETFD, value) < 0) {
+		condlog(0, "Cannot set close-on-exec flag from pidfile [%s], "
+			"error was [%s]", pidFile, strerror(errno));
+		goto fail;
+	}
+	return 0;
+fail:
+	close(fd);
+	return 1;
+}
+
+int pidfile_check(const char *file)
+{
+	int fd;
+	struct flock lock;
+
+	fd = open(file, O_RDONLY);
+	if (fd < 0) {
+		if (errno == ENOENT)
+			return 0;
+		condlog(0, "Cannot open pidfile, %s : %s", file,
+				strerror(errno));
+		return -1;
+	}
+	lock.l_type = F_WRLCK;
+	lock.l_start = 0;
+	lock.l_whence = SEEK_SET;
+	lock.l_len = 0;
+
+	if (fcntl(fd, F_GETLK, &lock) < 0) {
+		condlog(0, "Cannot check lock on pidfile, %s : %s", file,
+				strerror(errno));
+		return -1;
+	}
+	close(fd);
+	if (lock.l_type == F_UNLCK)
+		return 0;
+	return 1;
+}
Index: multipath-tools-110916/libmultipath/pidfile.h
===================================================================
--- /dev/null
+++ multipath-tools-110916/libmultipath/pidfile.h
@@ -0,0 +1,2 @@
+int pidfile_create(const char *pidFile, pid_t pid);
+int pidfile_check(const char *file);
Index: multipath-tools-110916/multipathd/Makefile
===================================================================
--- multipath-tools-110916.orig/multipathd/Makefile
+++ multipath-tools-110916/multipathd/Makefile
@@ -19,7 +19,7 @@ LDFLAGS += -lpthread -ldevmapper -lreadl
 #
 # object files
 #
-OBJS = main.o pidfile.o uxlsnr.o uxclnt.o cli.o cli_handlers.o
+OBJS = main.o uxlsnr.o uxclnt.o cli.o cli_handlers.o
 
 
 #
Index: multipath-tools-110916/multipathd/main.c
===================================================================
--- multipath-tools-110916.orig/multipathd/main.c
+++ multipath-tools-110916/multipathd/main.c
@@ -49,9 +49,9 @@
 #include <prio.h>
 #include <pgpolicies.h>
 #include <uevent.h>
+#include <pidfile.h>
 
 #include "main.h"
-#include "pidfile.h"
 #include "uxlsnr.h"
 #include "uxclnt.h"
 #include "cli.h"




More information about the dm-devel mailing list