X-Git-Url: http://git.ipfire.org/?p=thirdparty%2Fmdadm.git;a=blobdiff_plain;f=mdmon.c;h=73c244af91bcbd92a657f250b8f8ba55b3af7b55;hp=2919a02f4e98f73fa5a8e9993ba95abfdacd6d4a;hb=e8a70c89585ddca2bcb4160808f64506c64df13b;hpb=5869a76c90aa0725e665d3c7bd6c7ab021d24fd4

diff --git a/mdmon.c b/mdmon.c
index 2919a02f..73c244af 100644
--- a/mdmon.c
+++ b/mdmon.c
@@ -1,3 +1,22 @@
+/*
+ * mdmon - monitor external metadata arrays
+ *
+ * Copyright (C) 2007-2008 Neil Brown <neilb@suse.de>
+ * Copyright (C) 2007-2008 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.
@@ -26,15 +45,19 @@
 
 #include	<unistd.h>
 #include	<stdlib.h>
+#include	<sys/types.h>
 #include	<sys/stat.h>
 #include	<sys/socket.h>
 #include	<sys/un.h>
 #include	<sys/mman.h>
+#include	<sys/syscall.h>
+#include	<sys/wait.h>
 #include	<stdio.h>
 #include	<errno.h>
 #include	<string.h>
 #include	<fcntl.h>
 #include	<signal.h>
+#include	<dirent.h>
 
 #include	<sched.h>
 
@@ -43,80 +66,96 @@
 
 struct active_array *discard_this;
 struct active_array *pending_discard;
-struct md_generic_cmd *active_cmd;
+
+int mon_tid, mgr_tid;
+
+int sigterm;
 
 int run_child(void *v)
 {
 	struct supertype *c = v;
-	sigset_t set;
-	/* SIGUSR is sent from child to parent,  So child must block it */
-	sigemptyset(&set);
-	sigaddset(&set, SIGUSR1);
-	sigprocmask(SIG_BLOCK, &set, NULL);
 
 	do_monitor(c);
 	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];
-	int rv;
-
-	rv = pipe(container->mgr_pipe);
-	if (rv < 0)
-		return rv;
-	rv = pipe(container->mon_pipe);
-	if (rv < 0)
-		goto err_mon_pipe;
 
-	rv = clone(run_child, stack+4096-64,
+#ifdef __ia64__
+	mon_tid = __clone2(run_child, stack, sizeof(stack),
 		   CLONE_FS|CLONE_FILES|CLONE_VM|CLONE_SIGHAND|CLONE_THREAD,
 		   container);
-	if (rv < 0)
-		goto err_clone;
-	else
-		return rv;
-
- err_clone:
-	close(container->mon_pipe[0]);
-	close(container->mon_pipe[1]);
- err_mon_pipe:
-	close(container->mgr_pipe[0]);
-	close(container->mgr_pipe[1]);
-
-	return rv;
+#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);
+
+	return mon_tid;
 }
 
 static struct superswitch *find_metadata_methods(char *vers)
 {
 	if (strcmp(vers, "ddf") == 0)
 		return &super_ddf;
+	if (strcmp(vers, "imsm") == 0)
+		return &super_imsm;
 	return NULL;
 }
 
 
-static int make_pidfile(char *devname, int o_excl)
+int make_pidfile(char *devname, int o_excl)
 {
 	char path[100];
 	char pid[10];
 	int fd;
+	int n;
+
+	if (sigterm)
+		return -1;
+
 	sprintf(path, "/var/run/mdadm/%s.pid", devname);
 
 	fd = open(path, O_RDWR|O_CREAT|o_excl, 0600);
 	if (fd < 0)
-		return -1;
+		return -errno;
 	sprintf(pid, "%d\n", getpid());
-	write(fd, pid, strlen(pid));
+	n = write(fd, pid, strlen(pid));
 	close(fd);
+	if (n < 0)
+		return -errno;
 	return 0;
 }
 
+int is_container_member(struct mdstat_ent *mdstat, char *container)
+{
+	if (mdstat->metadata_version == NULL ||
+	    strncmp(mdstat->metadata_version, "external:", 9) != 0 ||
+	    !is_subarray(mdstat->metadata_version+9) ||
+	    strncmp(mdstat->metadata_version+10, container, strlen(container)) != 0 ||
+	    mdstat->metadata_version[10+strlen(container)] != '/')
+		return 0;
+
+	return 1;
+}
+
+void remove_pidfile(char *devname);
 static void try_kill_monitor(char *devname)
 {
 	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);
@@ -131,6 +170,10 @@ static void try_kill_monitor(char *devname)
 	close(fd);
 	pid = strtoul(buf, NULL, 10);
 
+	/* first rule of survival... don't off yourself */
+	if (pid == getpid())
+		return;
+
 	/* kill this process if it is mdmon */
 	sprintf(buf, "/proc/%lu/cmdline", (unsigned long) pid);
 	fd = open(buf, O_RDONLY);
@@ -142,17 +185,44 @@ static void try_kill_monitor(char *devname)
 		return;
 	}
 
-	if (strstr(buf, "mdmon") != NULL)
-		kill(pid, SIGTERM);
+	if (!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, 0);
+		}
+	free_mdstat(mdstat);
+	remove_pidfile(devname);
+}
+
+void remove_pidfile(char *devname)
+{
+	char buf[100];
+
+	if (sigterm)
+		return;
+
+	sprintf(buf, "/var/run/mdadm/%s.pid", devname);
+	unlink(buf);
+	sprintf(buf, "/var/run/mdadm/%s.sock", devname);
+	unlink(buf);
 }
 
-static int make_control_sock(char *devname)
+int make_control_sock(char *devname)
 {
 	char path[100];
 	int sfd;
 	long fl;
 	struct sockaddr_un addr;
 
+	if (sigterm)
+		return -1;
+
 	sprintf(path, "/var/run/mdadm/%s.sock", devname);
 	unlink(path);
 	sfd = socket(PF_LOCAL, SOCK_STREAM, 0);
@@ -172,58 +242,123 @@ static int make_control_sock(char *devname)
 	return sfd;
 }
 
+int socket_hup_requested;
+static void hup(int sig)
+{
+	socket_hup_requested = 1;
+}
+
+static void term(int sig)
+{
+	sigterm = 1;
+}
+
+static void wake_me(int sig)
+{
+
+}
+
+/* if we are debugging and starting mdmon by hand then don't fork */
+static int do_fork(void)
+{
+	#ifdef DEBUG
+	if (check_env("MDADM_NO_MDMON"))
+		return 0;
+	#endif
+
+	return 1;
+}
+
+void usage(void)
+{
+	fprintf(stderr, "Usage: mdmon [--switch-root dir] /device/name/for/container\n");
+	exit(2);
+}
+
 int main(int argc, char *argv[])
 {
 	int mdfd;
 	struct mdinfo *mdi, *di;
 	struct supertype *container;
-	if (argc != 2) {
-		fprintf(stderr, "Usage: md-manage /device/name/for/container\n");
-		exit(2);
+	sigset_t set;
+	struct sigaction act;
+	int pfd[2];
+	int status;
+	int ignore;
+	char *container_name = NULL;
+	char *switchroot = NULL;
+	int devnum;
+	char *devname;
+
+	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();
+		}
+		switchroot = argv[2];
+		container_name = argv[3];
+		break;
+	default:
+		usage();
+	}
+
+	devnum = devname2devnum(container_name);
+	devname = devnum2devname(devnum);
+	if (strcmp(container_name, devname) != 0) {
+		fprintf(stderr, "mdmon: %s is not a valid md device name\n",
+			container_name);
+		exit(1);
 	}
-	mdfd = open(argv[1], O_RDWR);
+	mdfd = open_dev(devnum);
 	if (mdfd < 0) {
-		fprintf(stderr, "md-manage: %s: %s\n", argv[1],
+		fprintf(stderr, "mdmon: %s: %s\n", container_name,
 			strerror(errno));
 		exit(1);
 	}
 	if (md_get_version(mdfd) < 0) {
-		fprintf(stderr, "md-manage: %s: Not an md device\n",
-			argv[1]);
+		fprintf(stderr, "mdmon: %s: Not an md device\n",
+			container_name);
 		exit(1);
 	}
 
-	/* hopefully it is a container - we'll check later */
-
-	container = malloc(sizeof(*container));
-	container->devnum = fd2devnum(mdfd);
-	container->devname = devnum2devname(container->devnum);
-
-	/* If this fails, we hope it already exists */
-	mkdir("/var/run/mdadm", 0600);
-	/* pid file lives in /var/run/mdadm/mdXX.pid */
-	if (make_pidfile(container->devname, O_EXCL) < 0) {
-		if (ping_monitor(container->devname) == 0) {
-			fprintf(stderr, "mdmon: %s already managed\n",
-				container->devname);
-			exit(3);
-		} else {
-			/* cleanup the old monitor, this one is taking over */
-			try_kill_monitor(container->devname);
-			if (make_pidfile(container->devname, 0) < 0) {
-				fprintf(stderr, "mdmon: %s Cannot create pidfile\n",
-					container->devname);
-				exit(3);
+	/* Fork, and have the child tell us when they are ready */
+	if (do_fork()) {
+		if (pipe(pfd) != 0) {
+			fprintf(stderr, "mdmon: failed to create pipe\n");
+			exit(1);
+		}
+		switch(fork()) {
+		case -1:
+			fprintf(stderr, "mdmon: failed to fork: %s\n",
+				strerror(errno));
+			exit(1);
+		case 0: /* child */
+			close(pfd[0]);
+			break;
+		default: /* parent */
+			close(pfd[1]);
+			if (read(pfd[0], &status, sizeof(status)) != sizeof(status)) {
+				wait(&status);
+				status = WEXITSTATUS(status);
 			}
+			exit(status);
 		}
-	}
+	} else
+		pfd[0] = pfd[1] = -1;
 
-	container->sock = make_control_sock(container->devname);
-	if (container->sock < 0) {
-		fprintf(stderr, "mdmon: Cannot create socket in /var/run/mdadm\n");
+	container = malloc(sizeof(*container));
+	container->devnum = devnum;
+	container->devname = devname;
+	container->arrays = NULL;
+
+	if (!container->devname) {
+		fprintf(stderr, "mdmon: failed to allocate container name string\n");
 		exit(3);
 	}
-	container->arrays = NULL;
 
 	mdi = sysfs_read(mdfd, container->devnum,
 			 GET_VERSION|GET_LEVEL|GET_DEVS);
@@ -235,45 +370,130 @@ int main(int argc, char *argv[])
 	}
 	if (mdi->array.level != UnSet) {
 		fprintf(stderr, "mdmon: %s is not a container - cannot monitor\n",
-			argv[1]);
+			container_name);
 		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",
-			argv[1]);
+			container_name);
 		exit(3);
 	}
 
 	container->ss = find_metadata_methods(mdi->text_version);
 	if (container->ss == NULL) {
 		fprintf(stderr, "mdmon: %s uses unknown metadata: %s\n",
-			argv[1], mdi->text_version);
+			container_name, mdi->text_version);
 		exit(3);
 	}
 
 	container->devs = NULL;
 	for (di = mdi->devs; di; di = di->next) {
 		struct mdinfo *cd = malloc(sizeof(*cd));
-		cd = di;
+		*cd = *di;
 		cd->next = container->devs;
 		container->devs = cd;
 	}
 	sysfs_free(mdi);
 
+	/* SIGUSR is sent between parent and child.  So both block it
+	 * and enable it only with pselect.
+	 */
+	sigemptyset(&set);
+	sigaddset(&set, SIGUSR1);
+	sigaddset(&set, SIGHUP);
+	sigaddset(&set, SIGALRM);
+	sigaddset(&set, SIGTERM);
+	sigprocmask(SIG_BLOCK, &set, NULL);
+	act.sa_handler = wake_me;
+	act.sa_flags = 0;
+	sigaction(SIGUSR1, &act, NULL);
+	sigaction(SIGALRM, &act, NULL);
+	act.sa_handler = hup;
+	sigaction(SIGHUP, &act, NULL);
+	act.sa_handler = term;
+	sigaction(SIGTERM, &act, NULL);
+	act.sa_handler = SIG_IGN;
+	sigaction(SIGPIPE, &act, NULL);
+
+	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
+		 */
+		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 (container->ss->load_super(container, mdfd, argv[1])) {
+	/* 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 (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);
+			}
+		}
+	}
+	container->sock = make_control_sock(container->devname);
+
+	if (container->ss->load_super(container, mdfd, container_name)) {
 		fprintf(stderr, "mdmon: Cannot load metadata for %s\n",
-			argv[1]);
+			container_name);
 		exit(3);
 	}
-
 	close(mdfd);
 
+	/* Ok, this is close enough.  We can say goodbye to our parent now.
+	 */
+	status = 0;
+	if (write(pfd[1], &status, sizeof(status)) < 0)
+		fprintf(stderr, "mdmon: failed to notify our parent: %d\n",
+			getppid());
+	close(pfd[1]);
+
+	setsid();
+	close(0);
+	open("/dev/null", O_RDWR);
+	close(1);
+	ignore = dup(0);
+#ifndef DEBUG
+	close(2);
+	ignore = dup(0);
+#endif
+
 	mlockall(MCL_FUTURE);
 
 	if (clone_monitor(container) < 0) {
-		fprintf(stderr, "md-manage: failed to start monitor process: %s\n",
+		fprintf(stderr, "mdmon: failed to start monitor process: %s\n",
 			strerror(errno));
 		exit(2);
 	}