+/*
+ * 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.
#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>
int mon_tid, mgr_tid;
+int sigterm;
+
int run_child(void *v)
{
struct supertype *c = v;
- mon_tid = syscall(SYS_gettid);
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 = 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);
+#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 rv;
+
+ return mon_tid;
}
static struct superswitch *find_metadata_methods(char *vers)
}
-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);
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);
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);
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 supertype *container;
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();
+ }
- if (argc != 2) {
- fprintf(stderr, "Usage: md-manage /device/name/for/container\n");
- exit(2);
+ 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);
- container->device_name = argv[1];
-
- /* 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);
}
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);
-
- if (container->ss->load_super(container, mdfd, argv[1])) {
- fprintf(stderr, "mdmon: Cannot load metadata for %s\n",
- argv[1]);
- exit(3);
- }
- close(mdfd);
- close(mdfd);
-
- mlockall(MCL_FUTURE);
-
/* 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 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",
+ 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);
}
projects / thirdparty / mdadm.git / blobdiff