X-Git-Url: http://git.ipfire.org/?p=thirdparty%2Fmdadm.git;a=blobdiff_plain;f=mdmon.c;h=d20bb3e490c01bbde2067bffb70c31ae50dcab04;hp=877cf1a16762315b6378fa62061cb155f4aed3bb;hb=24f6f99b3630b1a89aaa57930c5c9de8a3df9ded;hpb=13047e4c0708ad06a6c0a07e79a080dade94df38

diff --git a/mdmon.c b/mdmon.c
index 877cf1a1..d20bb3e4 100644
--- a/mdmon.c
+++ b/mdmon.c
@@ -1,3 +1,22 @@
+/*
+ * mdmon - monitor external metadata arrays
+ *
+ * Copyright (C) 2007-2009 Neil Brown <neilb@suse.de>
+ * Copyright (C) 2007-2009 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
 
 /*
  * md array manager.
@@ -60,13 +79,25 @@ int run_child(void *v)
 	return 0;
 }
 
-int clone_monitor(struct supertype *container)
+#ifdef __ia64__
+int __clone2(int (*fn)(void *),
+	    void *child_stack_base, size_t stack_size,
+	    int flags, void *arg, ...
+	 /* pid_t *pid, struct user_desc *tls, pid_t *ctid */ );
+#endif
+ int clone_monitor(struct supertype *container)
 {
 	static char stack[4096];
 
+#ifdef __ia64__
+	mon_tid = __clone2(run_child, stack, sizeof(stack),
+		   CLONE_FS|CLONE_FILES|CLONE_VM|CLONE_SIGHAND|CLONE_THREAD,
+		   container);
+#else
 	mon_tid = clone(run_child, stack+4096-64,
 		   CLONE_FS|CLONE_FILES|CLONE_VM|CLONE_SIGHAND|CLONE_THREAD,
 		   container);
+#endif
 
 	mgr_tid = syscall(SYS_gettid);
 
@@ -82,7 +113,6 @@ static struct superswitch *find_metadata_methods(char *vers)
 	return NULL;
 }
 
-
 int make_pidfile(char *devname, int o_excl)
 {
 	char path[100];
@@ -118,26 +148,16 @@ int is_container_member(struct mdstat_ent *mdstat, char *container)
 	return 1;
 }
 
-void remove_pidfile(char *devname);
-static void try_kill_monitor(char *devname)
+static void try_kill_monitor(pid_t pid, char *devname, int sock)
 {
 	char buf[100];
 	int fd;
-	pid_t pid;
-	struct mdstat_ent *mdstat;
-
-	sprintf(buf, "/var/run/mdadm/%s.pid", devname);
-	fd = open(buf, O_RDONLY);
-	if (fd < 0)
-		return;
+	int n;
+	long fl;
 
-	if (read(fd, buf, sizeof(buf)) < 0) {
-		close(fd);
+	/* first rule of survival... don't off yourself */
+	if (pid == getpid())
 		return;
-	}
-
-	close(fd);
-	pid = strtoul(buf, NULL, 10);
 
 	/* kill this process if it is mdmon */
 	sprintf(buf, "/proc/%lu/cmdline", (unsigned long) pid);
@@ -145,24 +165,21 @@ static void try_kill_monitor(char *devname)
 	if (fd < 0)
 		return;
 
-	if (read(fd, buf, sizeof(buf)) < 0) {
-		close(fd);
-		return;
-	}
+	n = read(fd, buf, sizeof(buf)-1);
+	buf[sizeof(buf)-1] = 0;
+	close(fd);
 
-	if (!strstr(buf, "mdmon"))
+	if (n < 0 || !strstr(buf, "mdmon"))
 		return;
 
 	kill(pid, SIGTERM);
 
-	mdstat = mdstat_read(0, 0);
-	for ( ; mdstat; mdstat = mdstat->next)
-		if (is_container_member(mdstat, devname)) {
-			sprintf(buf, "/dev/%s", mdstat->dev);
-			WaitClean(buf);
-		}
-	free_mdstat(mdstat);
-	remove_pidfile(devname);
+	/* Wait for monitor to exit by reading from the socket, after
+	 * clearing the non-blocking flag */
+	fl = fcntl(sock, F_GETFL, 0);
+	fl &= ~O_NONBLOCK;
+	fcntl(sock, F_SETFL, fl);
+	read(sock, buf, 100);
 }
 
 void remove_pidfile(char *devname)
@@ -227,7 +244,7 @@ static void wake_me(int sig)
 static int do_fork(void)
 {
 	#ifdef DEBUG
-	if (env_no_mdmon())
+	if (check_env("MDADM_NO_MDMON"))
 		return 0;
 	#endif
 
@@ -236,11 +253,79 @@ static int do_fork(void)
 
 void usage(void)
 {
-	fprintf(stderr, "Usage: mdmon [--switch-root dir] /device/name/for/container\n");
+	fprintf(stderr, "Usage: mdmon /device/name/for/container [target_dir]\n");
 	exit(2);
 }
 
+static int mdmon(char *devname, int devnum, int must_fork, char *switchroot);
+
 int main(int argc, char *argv[])
+{
+	char *container_name = NULL;
+	char *switchroot = NULL;
+	int devnum;
+	char *devname;
+	int status = 0;
+
+	switch (argc) {
+	case 3:
+		switchroot = argv[2];
+	case 2:
+		container_name = argv[1];
+		break;
+	default:
+		usage();
+	}
+
+	if (strcmp(container_name, "/proc/mdstat") == 0) {
+		struct mdstat_ent *mdstat, *e;
+
+		/* launch an mdmon instance for each container found */
+		mdstat = mdstat_read(0, 0);
+		for (e = mdstat; e; e = e->next) {
+			if (strncmp(e->metadata_version, "external:", 9) == 0 &&
+			    !is_subarray(&e->metadata_version[9])) {
+				devname = devnum2devname(e->devnum);
+				/* update cmdline so this mdmon instance can be
+				 * distinguished from others in a call to ps(1)
+				 */
+				if (strlen(devname) <= strlen(container_name)) {
+					memset(container_name, 0, strlen(container_name));
+					sprintf(container_name, "%s", devname);
+				}
+				status |= mdmon(devname, e->devnum, 1,
+						switchroot);
+			}
+		}
+		free_mdstat(mdstat);
+
+		return status;
+	} else if (strncmp(container_name, "md", 2) == 0) {
+		devnum = devname2devnum(container_name);
+		devname = devnum2devname(devnum);
+		if (strcmp(container_name, devname) != 0)
+			devname = NULL;
+	} else {
+		struct stat st;
+
+		devnum = NoMdDev;
+		if (stat(container_name, &st) == 0)
+			devnum = stat2devnum(&st);
+		if (devnum == NoMdDev)
+			devname = NULL;
+		else
+			devname = devnum2devname(devnum);
+	}
+
+	if (!devname) {
+		fprintf(stderr, "mdmon: %s is not a valid md device name\n",
+			container_name);
+		exit(1);
+	}
+	return mdmon(devname, devnum, do_fork(), switchroot);
+}
+
+static int mdmon(char *devname, int devnum, int must_fork, char *switchroot)
 {
 	int mdfd;
 	struct mdinfo *mdi, *di;
@@ -250,48 +335,77 @@ int main(int argc, char *argv[])
 	int pfd[2];
 	int status;
 	int ignore;
-	char *container_name = NULL;
-	char *switchroot = NULL;
+	pid_t victim = -1;
+	int victim_sock = -1;
 
-	switch (argc) {
-	case 2:
-		container_name = argv[1];
-		break;
-	case 4:
-		if (strcmp(argv[1], "--switch-root") != 0) {
-			fprintf(stderr, "mdmon: unknown argument %s\n", argv[1]);
-			usage();
+	dprintf("starting mdmon for %s in %s\n",
+		devname, switchroot ? : "/");
+
+	/* switchroot is either a path name starting with '/', or a
+	 * pid of the original mdmon (we have already done the chroot).
+	 * In the latter case, stdin is a socket connected to the original
+	 * mdmon.
+	 */
+
+	/* try to spawn mdmon instances from the target file system */
+	if (switchroot && switchroot[0] == '/' &&
+	    strcmp(switchroot, "/") != 0) {
+		pid_t pid;
+		char buf[20];
+
+		switch (fork()) {
+		case 0:
+			victim = mdmon_pid(devnum);
+			victim_sock = connect_monitor(devname);
+			if (chroot(switchroot) != 0) {
+				fprintf(stderr, "mdmon: failed to chroot to '%s': %s\n",
+					switchroot, strerror(errno));
+				exit(4);
+			}
+			ignore = chdir("/");
+			sprintf(buf, "%d", victim);
+			if (victim_sock) {
+				close(0);
+				dup(victim_sock);
+				close(victim_sock);
+			}
+			execl("/sbin/mdmon", "mdmon", devname, buf, NULL);
+			exit(1);
+		case -1:
+			return 1;
+		default:
+			pid = wait(&status);
+			if (pid > -1 && WIFEXITED(status) &&
+			    WEXITSTATUS(status) == 0)
+				return 0;
+			else
+				return 1;
 		}
-		switchroot = argv[2];
-		container_name = argv[3];
-		break;
-	default:
-		usage();
 	}
 
-	mdfd = open(container_name, O_RDWR);
+	mdfd = open_dev(devnum);
 	if (mdfd < 0) {
-		fprintf(stderr, "mdmon: %s: %s\n", container_name,
+		fprintf(stderr, "mdmon: %s: %s\n", devname,
 			strerror(errno));
-		exit(1);
+		return 1;
 	}
 	if (md_get_version(mdfd) < 0) {
 		fprintf(stderr, "mdmon: %s: Not an md device\n",
-			container_name);
-		exit(1);
+			devname);
+		return 1;
 	}
 
 	/* Fork, and have the child tell us when they are ready */
-	if (do_fork()) {
+	if (must_fork) {
 		if (pipe(pfd) != 0) {
 			fprintf(stderr, "mdmon: failed to create pipe\n");
-			exit(1);
+			return 1;
 		}
 		switch(fork()) {
 		case -1:
 			fprintf(stderr, "mdmon: failed to fork: %s\n",
 				strerror(errno));
-			exit(1);
+			return 1;
 		case 0: /* child */
 			close(pfd[0]);
 			break;
@@ -301,16 +415,17 @@ int main(int argc, char *argv[])
 				wait(&status);
 				status = WEXITSTATUS(status);
 			}
-			exit(status);
+			return status;
 		}
 	} else
 		pfd[0] = pfd[1] = -1;
 
-	container = malloc(sizeof(*container));
-	container->devnum = fd2devnum(mdfd);
-	container->devname = devnum2devname(container->devnum);
-	container->device_name = container_name;
+	container = calloc(1, sizeof(*container));
+	container->devnum = devnum;
+	container->devname = devname;
 	container->arrays = NULL;
+	container->subarray[0] = 0;
+	container->sock = -1;
 
 	if (!container->devname) {
 		fprintf(stderr, "mdmon: failed to allocate container name string\n");
@@ -318,7 +433,7 @@ int main(int argc, char *argv[])
 	}
 
 	mdi = sysfs_read(mdfd, container->devnum,
-			 GET_VERSION|GET_LEVEL|GET_DEVS);
+			 GET_VERSION|GET_LEVEL|GET_DEVS|SKIP_GONE_DEVS);
 
 	if (!mdi) {
 		fprintf(stderr, "mdmon: failed to load sysfs info for %s\n",
@@ -327,20 +442,20 @@ int main(int argc, char *argv[])
 	}
 	if (mdi->array.level != UnSet) {
 		fprintf(stderr, "mdmon: %s is not a container - cannot monitor\n",
-			container_name);
+			devname);
 		exit(3);
 	}
 	if (mdi->array.major_version != -1 ||
 	    mdi->array.minor_version != -2) {
 		fprintf(stderr, "mdmon: %s does not use external metadata - cannot monitor\n",
-			container_name);
+			devname);
 		exit(3);
 	}
 
 	container->ss = find_metadata_methods(mdi->text_version);
 	if (container->ss == NULL) {
 		fprintf(stderr, "mdmon: %s uses unknown metadata: %s\n",
-			container_name, mdi->text_version);
+			devname, mdi->text_version);
 		exit(3);
 	}
 
@@ -375,58 +490,33 @@ int main(int argc, char *argv[])
 
 	if (switchroot) {
 		/* we assume we assume that /sys /proc /dev are available in
-		 * the new root (see nash:setuproot)
-		 *
-		 * kill any monitors in the current namespace and change
-		 * to the new one
+		 * the new root
 		 */
-		try_kill_monitor(container->devname);
-		if (chroot(switchroot) != 0) {
-			fprintf(stderr, "mdmon: failed to chroot to '%s': %s\n",
-				switchroot, strerror(errno));
-			exit(4);
+		if (switchroot[0] == '/') {
+			victim = mdmon_pid(container->devnum);
+			victim_sock = connect_monitor(container->devname);
+		} else {
+			victim = atoi(switchroot);
+			victim_sock = 0;
 		}
 	}
 
-	/* If this fails, we hope it already exists 
-	 * pid file lives in /var/run/mdadm/mdXX.pid
-	 */
-	mkdir("/var", 0600);
-	mkdir("/var/run", 0600);
-	mkdir("/var/run/mdadm", 0600);
 	ignore = chdir("/");
-	if (make_pidfile(container->devname, O_EXCL) < 0) {
+	if (victim < 0) {
 		if (ping_monitor(container->devname) == 0) {
 			fprintf(stderr, "mdmon: %s already managed\n",
 				container->devname);
 			exit(3);
-		} else {
-			int err;
-
-			/* cleanup the old monitor, this one is taking over */
-			try_kill_monitor(container->devname);
-			err = make_pidfile(container->devname, 0);
-			if (err < 0) {
-				fprintf(stderr, "mdmon: %s Cannot create pidfile\n",
-					container->devname);
-				if (err == -EROFS) {
-					/* FIXME implement a mechanism to
-					 * prevent duplicate monitor instances
-					 */
-					fprintf(stderr,
-						"mdmon: continuing on read-only file system\n");
-				} else
-					exit(3);
-			}
 		}
+		/* if there is a pid file, kill whoever is there just in case */
+		victim = mdmon_pid(container->devnum);
 	}
-	container->sock = make_control_sock(container->devname);
-
-	if (container->ss->load_super(container, mdfd, container_name)) {
+	if (container->ss->load_super(container, mdfd, devname)) {
 		fprintf(stderr, "mdmon: Cannot load metadata for %s\n",
-			container_name);
+			devname);
 		exit(3);
 	}
+	close(mdfd);
 
 	/* Ok, this is close enough.  We can say goodbye to our parent now.
 	 */
@@ -436,6 +526,19 @@ int main(int argc, char *argv[])
 			getppid());
 	close(pfd[1]);
 
+	mlockall(MCL_CURRENT | MCL_FUTURE);
+
+	if (clone_monitor(container) < 0) {
+		fprintf(stderr, "mdmon: failed to start monitor process: %s\n",
+			strerror(errno));
+		exit(2);
+	}
+
+	if (victim > -1) {
+		try_kill_monitor(victim, container->devname, victim_sock);
+		close(victim_sock);
+	}
+
 	setsid();
 	close(0);
 	open("/dev/null", O_RDWR);
@@ -446,14 +549,6 @@ int main(int argc, char *argv[])
 	ignore = dup(0);
 #endif
 
-	mlockall(MCL_FUTURE);
-
-	if (clone_monitor(container) < 0) {
-		fprintf(stderr, "mdmon: failed to start monitor process: %s\n",
-			strerror(errno));
-		exit(2);
-	}
-
 	do_manager(container);
 
 	exit(0);