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shutdown: loop only as long as we manage to unmount/detach devices, give up immediately when we are stuck

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This commit is contained in:
Lennart Poettering 2010-10-14 18:55:04 +02:00
parent 6f3f9deb0b
commit 12aad1d075
3 changed files with 179 additions and 115 deletions
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76
src/shutdown.c
View File

@ -38,7 +38,6 @@
#define TIMEOUT_USEC (5 * USEC_PER_SEC)
#define FINALIZE_ATTEMPTS 50
#define FINALIZE_CRITICAL_ATTEMPTS 10
static bool ignore_proc(pid_t pid) {
if (pid == 1)
@ -69,7 +68,7 @@ static bool is_kernel_thread(pid_t pid)
static int killall(int sign) {
DIR *dir;
struct dirent *d;
unsigned int processes = 0;
unsigned int n_processes = 0;
if ((dir = opendir("/proc")) == NULL)
return -errno;
@ -87,20 +86,20 @@ static int killall(int sign) {
continue;
if (kill(pid, sign) == 0)
processes++;
n_processes++;
else
log_warning("Could not kill %d: %m", pid);
}
closedir(dir);
return processes;
return n_processes;
}
static int send_signal(int sign) {
sigset_t mask, oldmask;
usec_t until;
int processes;
int n_processes;
struct timespec ts;
assert_se(sigemptyset(&mask) == 0);
@ -111,12 +110,12 @@ static int send_signal(int sign) {
if (kill(-1, SIGSTOP) < 0)
log_warning("Failed kill(-1, SIGSTOP): %m");
processes = killall(sign);
n_processes = killall(sign);
if (kill(-1, SIGCONT) < 0)
log_warning("Failed kill(-1, SIGCONT): %m");
if (processes <= 0)
if (n_processes <= 0)
goto finish;
until = now(CLOCK_MONOTONIC) + TIMEOUT_USEC;
@ -124,14 +123,15 @@ static int send_signal(int sign) {
usec_t n = now(CLOCK_MONOTONIC);
for (;;) {
pid_t pid = waitpid(-1, NULL, WNOHANG);
if (pid == 0)
break;
else if (pid < 0 && errno == ECHILD) {
processes = 0;
n_processes = 0;
goto finish;
}
if (--processes == 0)
if (--n_processes == 0)
goto finish;
}
@ -146,7 +146,7 @@ static int send_signal(int sign) {
finish:
sigprocmask(SIG_SETMASK, &oldmask, NULL);
return processes;
return n_processes;
}
static int rescue_send_signal(int sign) {
@ -199,8 +199,10 @@ finish:
}
int main(int argc, char *argv[]) {
int cmd, r, retries;
int cmd, r;
unsigned retries;
bool need_umount = true, need_swapoff = true, need_loop_detach = true, need_dm_detach = true;
bool killed_everbody = false;
log_parse_environment();
log_set_target(LOG_TARGET_CONSOLE); /* syslog will die if not gone yet */
@ -247,11 +249,12 @@ int main(int argc, char *argv[]) {
log_warning("Cannot send SIGKILL to all process: %s", strerror(r));
/* Unmount all mountpoints, swaps, and loopback devices */
retries = FINALIZE_ATTEMPTS;
for (;;) {
for (retries = 0; retries < FINALIZE_ATTEMPTS; retries++) {
bool changed = false;
if (need_umount) {
log_info("Unmounting filesystems.");
r = umount_all();
r = umount_all(&changed);
if (r == 0)
need_umount = false;
else if (r > 0)
@ -262,7 +265,7 @@ int main(int argc, char *argv[]) {
if (need_swapoff) {
log_info("Disabling swaps.");
r = swapoff_all();
r = swapoff_all(&changed);
if (r == 0)
need_swapoff = false;
else if (r > 0)
@ -273,7 +276,7 @@ int main(int argc, char *argv[]) {
if (need_loop_detach) {
log_info("Detaching loop devices.");
r = loopback_detach_all();
r = loopback_detach_all(&changed);
if (r == 0)
need_loop_detach = false;
else if (r > 0)
@ -284,7 +287,7 @@ int main(int argc, char *argv[]) {
if (need_dm_detach) {
log_info("Detaching DM devices.");
r = dm_detach_all();
r = dm_detach_all(&changed);
if (r == 0)
need_dm_detach = false;
else if (r > 0)
@ -293,31 +296,40 @@ int main(int argc, char *argv[]) {
log_error("Error detaching dm devices: %s", strerror(-r));
}
if (need_umount || need_swapoff || need_loop_detach || need_dm_detach) {
retries--;
if (!need_umount && !need_swapoff && !need_loop_detach && !need_dm_detach)
/* Yay, done */
break;
if (retries == FINALIZE_CRITICAL_ATTEMPTS) {
log_warning("Approaching critical level to finalize filesystem and devices, try to kill all processes.");
rescue_send_signal(SIGTERM);
rescue_send_signal(SIGKILL);
}
/* If in this iteration we didn't manage to
* unmount/deactivate anything, we either kill more
* processes, or simply give up */
if (!changed) {
if (retries > 0)
log_info("Action still required, %d tries left.", retries);
else {
log_error("Giving up. Actions left: Umount=%s, Swap off=%s, Loop detach=%s, dm detach=%s",
yes_no(need_umount), yes_no(need_swapoff), yes_no(need_loop_detach), yes_no(need_dm_detach));
if (killed_everbody) {
/* Hmm, we already killed everybody,
* let's just give up */
log_error("Cannot finalize all filesystems and devices, giving up.");
break;
}
} else
break;
log_warning("Cannot finalize filesystems and devices, trying to kill remaining processes.");
rescue_send_signal(SIGTERM);
rescue_send_signal(SIGKILL);
killed_everbody = true;
}
log_debug("Couldn't finalize filesystems and devices after %u retries, trying again.", retries+1);
}
if (retries >= FINALIZE_ATTEMPTS)
log_error("Too many interations, giving up.");
sync();
if (cmd == LINUX_REBOOT_CMD_KEXEC) {
/* we cheat and exec kexec to avoid doing all its work */
/* We cheat and exec kexec to avoid doing all its work */
pid_t pid = fork();
if (pid < 0)
log_error("Could not fork: %m. Falling back to normal reboot.");
else if (pid > 0) {

210
src/umount.c
View File

@ -40,30 +40,37 @@ typedef struct MountPoint {
LIST_FIELDS (struct MountPoint, mount_point);
} MountPoint;
static void mount_point_remove_and_free(MountPoint *mount_point, MountPoint **mount_point_list_head) {
LIST_REMOVE(MountPoint, mount_point, *mount_point_list_head, mount_point);
static void mount_point_free(MountPoint **head, MountPoint *m) {
assert(head);
assert(m);
free(mount_point->path);
free(mount_point);
LIST_REMOVE(MountPoint, mount_point, *head, m);
free(m->path);
free(m);
}
static void mount_points_list_free(MountPoint **mount_point_list_head) {
while (*mount_point_list_head)
mount_point_remove_and_free(*mount_point_list_head, mount_point_list_head);
static void mount_points_list_free(MountPoint **head) {
assert(head);
while (*head)
mount_point_free(head, *head);
}
static int mount_points_list_get(MountPoint **mount_point_list_head) {
static int mount_points_list_get(MountPoint **head) {
FILE *proc_self_mountinfo;
char *path, *p;
unsigned int i;
int r;
assert(head);
if (!(proc_self_mountinfo = fopen("/proc/self/mountinfo", "re")))
return -errno;
for (i = 1;; i++) {
int k;
MountPoint *mp;
MountPoint *m;
path = p = NULL;
@ -103,14 +110,14 @@ static int mount_points_list_get(MountPoint **mount_point_list_head) {
continue;
}
if (!(mp = new0(MountPoint, 1))) {
if (!(m = new0(MountPoint, 1))) {
free(p);
r = -ENOMEM;
goto finish;
}
mp->path = p;
LIST_PREPEND(MountPoint, mount_point, *mount_point_list_head, mp);
m->path = p;
LIST_PREPEND(MountPoint, mount_point, *head, m);
}
r = 0;
@ -121,11 +128,13 @@ finish:
return r;
}
static int swap_list_get(MountPoint **swap_list_head) {
static int swap_list_get(MountPoint **head) {
FILE *proc_swaps;
unsigned int i;
int r;
assert(head);
if (!(proc_swaps = fopen("/proc/swaps", "re")))
return -errno;
@ -173,7 +182,7 @@ static int swap_list_get(MountPoint **swap_list_head) {
}
swap->path = d;
LIST_PREPEND(MountPoint, mount_point, *swap_list_head, swap);
LIST_PREPEND(MountPoint, mount_point, *head, swap);
}
r = 0;
@ -184,12 +193,14 @@ finish:
return r;
}
static int loopback_list_get(MountPoint **loopback_list_head) {
static int loopback_list_get(MountPoint **head) {
int r;
struct udev *udev;
struct udev_enumerate *e = NULL;
struct udev_list_entry *item = NULL, *first = NULL;
assert(head);
if (!(udev = udev_new())) {
r = -ENOMEM;
goto finish;
@ -244,7 +255,7 @@ static int loopback_list_get(MountPoint **loopback_list_head) {
}
lb->path = loop;
LIST_PREPEND(MountPoint, mount_point, *loopback_list_head, lb);
LIST_PREPEND(MountPoint, mount_point, *head, lb);
}
r = 0;
@ -259,12 +270,14 @@ finish:
return r;
}
static int dm_list_get(MountPoint **dm_list_head) {
static int dm_list_get(MountPoint **head) {
int r;
struct udev *udev;
struct udev_enumerate *e = NULL;
struct udev_list_entry *item = NULL, *first = NULL;
assert(head);
if (!(udev = udev_new())) {
r = -ENOMEM;
goto finish;
@ -324,7 +337,7 @@ static int dm_list_get(MountPoint **dm_list_head) {
m->path = node;
m->devnum = devnum;
LIST_PREPEND(MountPoint, mount_point, *dm_list_head, m);
LIST_PREPEND(MountPoint, mount_point, *head, m);
}
r = 0;
@ -348,8 +361,14 @@ static int delete_loopback(const char *device) {
r = ioctl(fd, LOOP_CLR_FD, 0);
close_nointr_nofail(fd);
if (r >= 0)
return 1;
/* ENXIO: not bound, so no error */
return (r >= 0 || errno == ENXIO) ? 0 : -errno;
if (errno == ENXIO)
return 0;
return -errno;
}
static int delete_dm(dev_t devnum) {
@ -375,92 +394,125 @@ static int delete_dm(dev_t devnum) {
return r >= 0 ? 0 : -errno;
}
static int mount_points_list_umount(MountPoint **mount_point_list_head) {
MountPoint *mp, *mp_next;
int failed = 0;
static int mount_points_list_umount(MountPoint **head, bool *changed) {
MountPoint *m, *n;
int n_failed = 0;
LIST_FOREACH_SAFE(mount_point, mp, mp_next, *mount_point_list_head) {
if (streq(mp->path, "/"))
assert(head);
LIST_FOREACH_SAFE(mount_point, m, n, *head) {
if (streq(m->path, "/"))
continue;
/* Trying to umount. Forcing to umount if busy (only for NFS mounts) */
if (umount2(mp->path, MNT_FORCE) == 0)
mount_point_remove_and_free(mp, mount_point_list_head);
else {
log_warning("Could not unmount %s: %m", mp->path);
failed++;
if (umount2(m->path, MNT_FORCE) == 0) {
if (changed)
*changed = true;
mount_point_free(head, m);
} else {
log_warning("Could not unmount %s: %m", m->path);
n_failed++;
}
}
return failed;
return n_failed;
}
static int mount_points_list_remount_read_only(MountPoint **mount_point_list_head) {
MountPoint *mp, *mp_next;
int failed = 0;
static int mount_points_list_remount_read_only(MountPoint **head, bool *changed) {
MountPoint *m, *n;
int n_failed = 0;
assert(head);
LIST_FOREACH_SAFE(mount_point, m, n, *head) {
LIST_FOREACH_SAFE(mount_point, mp, mp_next, *mount_point_list_head) {
/* Trying to remount read-only */
if (mount(NULL, mp->path, NULL, MS_MGC_VAL|MS_REMOUNT|MS_RDONLY, NULL) == 0)
mount_point_remove_and_free(mp, mount_point_list_head);
else {
log_warning("Could not remount as read-only %s: %m", mp->path);
failed++;
if (mount(NULL, m->path, NULL, MS_MGC_VAL|MS_REMOUNT|MS_RDONLY, NULL) == 0) {
if (changed)
*changed = true;
mount_point_free(head, m);
} else {
log_warning("Could not remount as read-only %s: %m", m->path);
n_failed++;
}
}
return failed;
return n_failed;
}
static int swap_points_list_off(MountPoint **swap_list_head) {
MountPoint *swap, *swap_next;
int failed = 0;
static int swap_points_list_off(MountPoint **head, bool *changed) {
MountPoint *m, *n;
int n_failed = 0;
LIST_FOREACH_SAFE(mount_point, swap, swap_next, *swap_list_head) {
if (swapoff(swap->path) == 0)
mount_point_remove_and_free(swap, swap_list_head);
else {
log_warning("Could not deactivate swap %s: %m", swap->path);
failed++;
assert(head);
LIST_FOREACH_SAFE(mount_point, m, n, *head) {
if (swapoff(m->path) == 0) {
if (changed)
*changed = true;
mount_point_free(head, m);
} else {
log_warning("Could not deactivate swap %s: %m", m->path);
n_failed++;
}
}
return failed;
return n_failed;
}
static int loopback_points_list_detach(MountPoint **loopback_list_head) {
MountPoint *loopback, *loopback_next;
int failed = 0;
static int loopback_points_list_detach(MountPoint **head, bool *changed) {
MountPoint *m, *n;
int n_failed = 0;
LIST_FOREACH_SAFE(mount_point, loopback, loopback_next, *loopback_list_head) {
if (delete_loopback(loopback->path) == 0)
mount_point_remove_and_free(loopback, loopback_list_head);
else {
log_warning("Could not delete loopback %s: %m", loopback->path);
failed++;
assert(head);
LIST_FOREACH_SAFE(mount_point, m, n, *head) {
int r;
if ((r = delete_loopback(m->path)) >= 0) {
if (r > 0 && changed)
*changed = true;
mount_point_free(head, m);
} else {
log_warning("Could not delete loopback %s: %m", m->path);
n_failed++;
}
}
return failed;
return n_failed;
}
static int dm_points_list_detach(MountPoint **dm_list_head) {
MountPoint *dm, *dm_next;
int failed = 0;
static int dm_points_list_detach(MountPoint **head, bool *changed) {
MountPoint *m, *n;
int n_failed = 0;
LIST_FOREACH_SAFE(mount_point, dm, dm_next, *dm_list_head) {
if (delete_dm(dm->devnum) == 0)
mount_point_remove_and_free(dm, dm_list_head);
else {
log_warning("Could not delete dm %s: %m", dm->path);
failed++;
assert(head);
LIST_FOREACH_SAFE(mount_point, m, n, *head) {
int r;
if ((r = delete_dm(m->devnum)) >= 0) {
if (r > 0 && changed)
*changed = true;
mount_point_free(head, m);
} else {
log_warning("Could not delete dm %s: %m", m->path);
n_failed++;
}
}
return failed;
return n_failed;
}
int umount_all(void) {
int umount_all(bool *changed) {
int r;
LIST_HEAD(MountPoint, mp_list_head);
@ -470,11 +522,11 @@ int umount_all(void) {
if (r < 0)
goto end;
r = mount_points_list_umount(&mp_list_head);
r = mount_points_list_umount(&mp_list_head, changed);
if (r <= 0)
goto end;
r = mount_points_list_remount_read_only(&mp_list_head);
r = mount_points_list_remount_read_only(&mp_list_head, changed);
end:
mount_points_list_free(&mp_list_head);
@ -482,7 +534,7 @@ int umount_all(void) {
return r;
}
int swapoff_all(void) {
int swapoff_all(bool *changed) {
int r;
LIST_HEAD(MountPoint, swap_list_head);
@ -492,7 +544,7 @@ int swapoff_all(void) {
if (r < 0)
goto end;
r = swap_points_list_off(&swap_list_head);
r = swap_points_list_off(&swap_list_head, changed);
end:
mount_points_list_free(&swap_list_head);
@ -500,7 +552,7 @@ int swapoff_all(void) {
return r;
}
int loopback_detach_all(void) {
int loopback_detach_all(bool *changed) {
int r;
LIST_HEAD(MountPoint, loopback_list_head);
@ -510,7 +562,7 @@ int loopback_detach_all(void) {
if (r < 0)
goto end;
r = loopback_points_list_detach(&loopback_list_head);
r = loopback_points_list_detach(&loopback_list_head, changed);
end:
mount_points_list_free(&loopback_list_head);
@ -518,7 +570,7 @@ int loopback_detach_all(void) {
return r;
}
int dm_detach_all(void) {
int dm_detach_all(bool *changed) {
int r;
LIST_HEAD(MountPoint, dm_list_head);
@ -528,7 +580,7 @@ int dm_detach_all(void) {
if (r < 0)
goto end;
r = dm_points_list_detach(&dm_list_head);
r = dm_points_list_detach(&dm_list_head, changed);
end:
mount_points_list_free(&dm_list_head);

8
src/umount.h
View File

@ -22,12 +22,12 @@
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
int umount_all(void);
int umount_all(bool *changed);
int swapoff_all(void);
int swapoff_all(bool *changed);
int loopback_detach_all(void);
int loopback_detach_all(bool *changed);
int dm_detach_all(void);
int dm_detach_all(bool *changed);
#endif