From e3478379751fda30316204c68112b5a2b9ffd5a7 Mon Sep 17 00:00:00 2001 From: Fabiano Fidencio Date: Thu, 7 Oct 2010 05:43:57 -0700 Subject: [PATCH] umount: Adding unmount functions to be used in shutdown This functions will: - umount all mount points that aren't API - remount read-only all mount points that can't be umounted - umount all swap devices. - detach all loopback devices TODO: - umount dms Mountpoints are being read from /proc/self/mountinfo. Swaps are being read from /proc/swaps. Loop devices from /sys/class/block/loop*. --- .gitignore | 1 + src/umount.c | 410 +++++++++++++++++++++++++++++++++++++++++++++++++++ src/umount.h | 31 ++++ 3 files changed, 442 insertions(+) create mode 100644 src/umount.c create mode 100644 src/umount.h diff --git a/.gitignore b/.gitignore index 9ba0758a1..2ba000c0b 100644 --- a/.gitignore +++ b/.gitignore @@ -1,3 +1,4 @@ +systemd-shutdown systemd-tmpfiles systemd-readahead-collect systemd-readahead-replay diff --git a/src/umount.c b/src/umount.c new file mode 100644 index 000000000..4842d403a --- /dev/null +++ b/src/umount.c @@ -0,0 +1,410 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2010 ProFUSION embedded systems + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that 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 systemd; If not, see . +***/ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "list.h" +#include "mount-setup.h" +#include "umount.h" +#include "util.h" + +typedef struct MountPoint { + char *path; + bool read_only; + LIST_FIELDS (struct MountPoint, mount_point); +} MountPoint; + +static MountPoint *mount_point_alloc(char *path) { + MountPoint *mp; + + if (!(mp = new(MountPoint, 1))) + return NULL; + + mp->path = path; + mp->read_only = false; + + return mp; +} + +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); + + free(mount_point->path); + free(mount_point); +} + +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 int mount_points_list_get(MountPoint **mount_point_list_head) { + FILE *proc_self_mountinfo; + char *path, *p; + unsigned int i; + int r; + + if (!(proc_self_mountinfo = fopen("/proc/self/mountinfo", "re"))) + return -errno; + + for (i = 1;; i++) { + int k; + MountPoint *mp; + + path = p = NULL; + + if ((k = fscanf(proc_self_mountinfo, + "%*s " /* (1) mount id */ + "%*s " /* (2) parent id */ + "%*s " /* (3) major:minor */ + "%*s " /* (4) root */ + "%ms " /* (5) mount point */ + "%*s" /* (6) mount options */ + "%*[^-]" /* (7) optional fields */ + "- " /* (8) separator */ + "%*s " /* (9) file system type */ + "%*s" /* (10) mount source */ + "%*s" /* (11) mount options 2 */ + "%*[^\n]", /* some rubbish at the end */ + &path)) != 1) { + if (k == EOF) + break; + + log_warning("Failed to parse /proc/self/mountinfo:%u.", i); + + free(path); + continue; + } + + if (mount_point_is_api(path)) { + free(path); + continue; + } + + if (!(p = cunescape(path))) { + r = -ENOMEM; + goto finish; + } + + if (!(mp = mount_point_alloc(p))) { + r = -ENOMEM; + goto finish; + } + LIST_PREPEND(MountPoint, mount_point, *mount_point_list_head, mp); + + free(path); + } + + r = 0; + +finish: + fclose(proc_self_mountinfo); + + free(path); + + return r; +} + +static int swap_list_get(MountPoint **swap_list_head) { + FILE *proc_swaps; + unsigned int i; + int r; + + if (!(proc_swaps = fopen("/proc/swaps", "re"))) + return -errno; + + (void) fscanf(proc_swaps, "%*s %*s %*s %*s %*s\n"); + + for (i = 2;; i++) { + MountPoint *swap; + char *dev = NULL, *d; + int k; + + if ((k = fscanf(proc_swaps, + "%ms " /* device/file */ + "%*s " /* type of swap */ + "%*s " /* swap size */ + "%*s " /* used */ + "%*s\n", /* priority */ + &dev)) != 1) { + + if (k == EOF) + break; + + log_warning("Failed to parse /proc/swaps:%u.", i); + + free(dev); + continue; + } + + if (endswith(dev, "(deleted)")) { + free(dev); + continue; + } + + d = cunescape(dev); + free(dev); + + if (!d) { + r = -ENOMEM; + goto finish; + } + + swap = mount_point_alloc(d); + if (!swap) { + free(d); + r = -ENOMEM; + goto finish; + } + + LIST_PREPEND(MountPoint, mount_point, *swap_list_head, swap); + } + + r = 0; + +finish: + fclose(proc_swaps); + + return r; +} + +static int loopback_list_get(MountPoint **loopback_list_head) { + int r; + struct udev *udev; + struct udev_enumerate *e = NULL; + struct udev_list_entry *item = NULL, *first = NULL; + + if (!(udev = udev_new())) { + r = -ENOMEM; + goto finish; + } + + if (!(e = udev_enumerate_new(udev))) { + r = -ENOMEM; + goto finish; + } + + if (udev_enumerate_add_match_subsystem(e, "block") < 0) { + r = -EIO; + goto finish; + } + + if (udev_enumerate_add_match_sysname(e, "loop*") < 0) { + r = -EIO; + goto finish; + } + + if (udev_enumerate_scan_devices(e) < 0) { + r = -EIO; + goto finish; + } + + first = udev_enumerate_get_list_entry(e); + + udev_list_entry_foreach(item, first) { + MountPoint *lb; + char *loop; + + loop = cunescape(udev_list_entry_get_name(item)); + if (!loop) { + r = -ENOMEM; + goto finish; + } + + lb = mount_point_alloc(loop); + if (!lb) { + free(loop); + r = -ENOMEM; + goto finish; + } + + LIST_PREPEND(MountPoint, mount_point, *loopback_list_head, lb); + } + + r = 0; + +finish: + if (e) + udev_enumerate_unref(e); + + free(udev); + return r; +} + +static int delete_loopback(const char *device) { + int fd, r; + + if ((fd = open(device, O_RDONLY|O_CLOEXEC)) < 0) { + if (errno == ENOENT) { + log_debug("Loop device %s does not exist.", device); + errno = 0; + return 0; + } + return -errno; + } + + ioctl(fd, LOOP_CLR_FD, 0); + r = errno; + close_nointr(fd); + + if (r == ENXIO) /* not bound, so no error */ + r = 0; + errno = r; + return -errno; +} + +static int mount_points_list_umount(MountPoint **mount_point_list_head) { + MountPoint *mp, *mp_next; + int failed = 0; + + LIST_FOREACH_SAFE(mount_point, mp, mp_next, *mount_point_list_head) { + if (streq(mp->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_debug("Could not unmount %s: %m", mp->path); + failed++; + } + } + + return failed; +} + +static int mount_points_list_remount_read_only(MountPoint **mount_point_list_head) { + MountPoint *mp, *mp_next; + int failed = 0; + + LIST_FOREACH_SAFE(mount_point, mp, mp_next, *mount_point_list_head) { + if (mp->read_only) + continue; + + /* Trying to remount read-only */ + if (mount(NULL, mp->path, NULL, MS_MGC_VAL|MS_REMOUNT|MS_RDONLY, NULL) == 0) { + mp->read_only = true; + mount_point_remove_and_free(mp, mount_point_list_head); + } else { + log_debug("Could not remount as read-only %s: %m", mp->path); + failed++; + } + } + + return failed; +} + +static int swap_points_list_off(MountPoint **swap_list_head) { + MountPoint *swap, *swap_next; + int 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_debug("Could not swapoff %s: %m", swap->path); + failed++; + } + } + + return failed; +} + +static int loopback_points_list_detach(MountPoint **loopback_list_head) { + MountPoint *loopback, *loopback_next; + int 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_debug("Could not delete loopback %s: %m", loopback->path); + failed++; + } + } + + return failed; +} + +int umount_all(void) { + int r; + LIST_HEAD(MountPoint, mp_list_head); + + LIST_HEAD_INIT(MountPoint, mp_list_head); + + r = mount_points_list_get(&mp_list_head); + if (r < 0) + goto end; + + r = mount_points_list_umount(&mp_list_head); + if (r <= 0) + goto end; + + r = mount_points_list_remount_read_only(&mp_list_head); + + end: + mount_points_list_free(&mp_list_head); + + return r; +} + +int swapoff_all(void) { + int r; + LIST_HEAD(MountPoint, swap_list_head); + + LIST_HEAD_INIT(MountPoint, swap_list_head); + + r = swap_list_get(&swap_list_head); + if (r < 0) + goto end; + + r = swap_points_list_off(&swap_list_head); + + end: + mount_points_list_free(&swap_list_head); + + return r; +} + +int loopback_detach_all(void) { + int r; + LIST_HEAD(MountPoint, loopback_list_head); + + LIST_HEAD_INIT(MountPoint, loopback_list_head); + + r = loopback_list_get(&loopback_list_head); + if (r < 0) + goto end; + + r = loopback_points_list_detach(&loopback_list_head); + + end: + mount_points_list_free(&loopback_list_head); + + return r; +} diff --git a/src/umount.h b/src/umount.h new file mode 100644 index 000000000..aeccc00f1 --- /dev/null +++ b/src/umount.h @@ -0,0 +1,31 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#ifndef fooumounthfoo +#define fooumounthfoo + +/*** + This file is part of systemd. + + Copyright 2010 ProFUSION embedded systems + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that 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 systemd; If not, see . +***/ + +int umount_all(void); + +int swapoff_all(void); + +int loopback_detach_all(void); + +#endif -- 2.30.2