From 12aad1d075a6cfa23920b977146e79d8154f2540 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 14 Oct 2010 18:55:04 +0200 Subject: [PATCH] shutdown: loop only as long as we manage to unmount/detach devices, give up immediately when we are stuck --- src/shutdown.c | 76 ++++++++++-------- src/umount.c | 210 ++++++++++++++++++++++++++++++------------------- src/umount.h | 8 +- 3 files changed, 179 insertions(+), 115 deletions(-) diff --git a/src/shutdown.c b/src/shutdown.c index 2c14371df..bd4b69bbe 100644 --- a/src/shutdown.c +++ b/src/shutdown.c @@ -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) { diff --git a/src/umount.c b/src/umount.c index c95f72760..c7f62081d 100644 --- a/src/umount.c +++ b/src/umount.c @@ -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; + + assert(head); - 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++; + 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; + + assert(head); + + LIST_FOREACH_SAFE(mount_point, m, n, *head) { + int r; - 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++; + 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; + + 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; - 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++; + 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); diff --git a/src/umount.h b/src/umount.h index c06ca867a..acdf09acf 100644 --- a/src/umount.h +++ b/src/umount.h @@ -22,12 +22,12 @@ along with systemd; If not, see . ***/ -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 -- 2.30.2