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-rw-r--r--src/core/umount.c649
1 files changed, 649 insertions, 0 deletions
diff --git a/src/core/umount.c b/src/core/umount.c
new file mode 100644
index 0000000000..488e1e4a4d
--- /dev/null
+++ b/src/core/umount.c
@@ -0,0 +1,649 @@
+/*-*- 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 Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/swap.h>
+#include <unistd.h>
+#include <linux/loop.h>
+#include <linux/dm-ioctl.h>
+#include <libudev.h>
+
+#include "list.h"
+#include "mount-setup.h"
+#include "umount.h"
+#include "util.h"
+
+typedef struct MountPoint {
+ char *path;
+ dev_t devnum;
+ bool skip_ro;
+ LIST_FIELDS (struct MountPoint, mount_point);
+} MountPoint;
+
+static void mount_point_free(MountPoint **head, MountPoint *m) {
+ assert(head);
+ assert(m);
+
+ LIST_REMOVE(MountPoint, mount_point, *head, m);
+
+ free(m->path);
+ free(m);
+}
+
+static void mount_points_list_free(MountPoint **head) {
+ assert(head);
+
+ while (*head)
+ mount_point_free(head, *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 *m;
+ char *root;
+ bool skip_ro;
+
+ path = p = NULL;
+
+ if ((k = fscanf(proc_self_mountinfo,
+ "%*s " /* (1) mount id */
+ "%*s " /* (2) parent id */
+ "%*s " /* (3) major:minor */
+ "%ms " /* (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 */
+ &root,
+ &path)) != 2) {
+ if (k == EOF)
+ break;
+
+ log_warning("Failed to parse /proc/self/mountinfo:%u.", i);
+
+ free(path);
+ continue;
+ }
+
+ /* If we encounter a bind mount, don't try to remount
+ * the source dir too early */
+ skip_ro = !streq(root, "/");
+ free(root);
+
+ p = cunescape(path);
+ free(path);
+
+ if (!p) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ /* Ignore mount points we can't unmount because they
+ * are API or because we are keeping them open (like
+ * /dev/console) */
+ if (mount_point_is_api(p) ||
+ mount_point_ignore(p) ||
+ path_equal(p, "/dev/console")) {
+ free(p);
+ continue;
+ }
+
+ if (!(m = new0(MountPoint, 1))) {
+ free(p);
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ m->path = p;
+ m->skip_ro = skip_ro;
+ LIST_PREPEND(MountPoint, mount_point, *head, m);
+ }
+
+ r = 0;
+
+finish:
+ fclose(proc_self_mountinfo);
+
+ return r;
+}
+
+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 == ENOENT) ? 0 : -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;
+ }
+
+ if (!(swap = new0(MountPoint, 1))) {
+ free(d);
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ swap->path = d;
+ LIST_PREPEND(MountPoint, mount_point, *head, swap);
+ }
+
+ r = 0;
+
+finish:
+ fclose(proc_swaps);
+
+ return r;
+}
+
+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;
+ }
+
+ if (!(e = udev_enumerate_new(udev))) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ if (udev_enumerate_add_match_subsystem(e, "block") < 0 ||
+ 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;
+ struct udev_device *d;
+ char *loop;
+ const char *dn;
+
+ if (!(d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)))) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ if (!(dn = udev_device_get_devnode(d))) {
+ udev_device_unref(d);
+ continue;
+ }
+
+ loop = strdup(dn);
+ udev_device_unref(d);
+
+ if (!loop) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ if (!(lb = new0(MountPoint, 1))) {
+ free(loop);
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ lb->path = loop;
+ LIST_PREPEND(MountPoint, mount_point, *head, lb);
+ }
+
+ r = 0;
+
+finish:
+ if (e)
+ udev_enumerate_unref(e);
+
+ if (udev)
+ udev_unref(udev);
+
+ return r;
+}
+
+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;
+ }
+
+ if (!(e = udev_enumerate_new(udev))) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ if (udev_enumerate_add_match_subsystem(e, "block") < 0 ||
+ udev_enumerate_add_match_sysname(e, "dm-*") < 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 *m;
+ struct udev_device *d;
+ dev_t devnum;
+ char *node;
+ const char *dn;
+
+ if (!(d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)))) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ devnum = udev_device_get_devnum(d);
+ dn = udev_device_get_devnode(d);
+
+ if (major(devnum) == 0 || !dn) {
+ udev_device_unref(d);
+ continue;
+ }
+
+ node = strdup(dn);
+ udev_device_unref(d);
+
+ if (!node) {
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ if (!(m = new(MountPoint, 1))) {
+ free(node);
+ r = -ENOMEM;
+ goto finish;
+ }
+
+ m->path = node;
+ m->devnum = devnum;
+ LIST_PREPEND(MountPoint, mount_point, *head, m);
+ }
+
+ r = 0;
+
+finish:
+ if (e)
+ udev_enumerate_unref(e);
+
+ if (udev)
+ udev_unref(udev);
+
+ return r;
+}
+
+static int delete_loopback(const char *device) {
+ int fd, r;
+
+ if ((fd = open(device, O_RDONLY|O_CLOEXEC)) < 0)
+ return errno == ENOENT ? 0 : -errno;
+
+ r = ioctl(fd, LOOP_CLR_FD, 0);
+ close_nointr_nofail(fd);
+
+ if (r >= 0)
+ return 1;
+
+ /* ENXIO: not bound, so no error */
+ if (errno == ENXIO)
+ return 0;
+
+ return -errno;
+}
+
+static int delete_dm(dev_t devnum) {
+ int fd, r;
+ struct dm_ioctl dm;
+
+ assert(major(devnum) != 0);
+
+ if ((fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC)) < 0)
+ return -errno;
+
+ zero(dm);
+ dm.version[0] = DM_VERSION_MAJOR;
+ dm.version[1] = DM_VERSION_MINOR;
+ dm.version[2] = DM_VERSION_PATCHLEVEL;
+
+ dm.data_size = sizeof(dm);
+ dm.dev = devnum;
+
+ r = ioctl(fd, DM_DEV_REMOVE, &dm);
+ close_nointr_nofail(fd);
+
+ return r >= 0 ? 0 : -errno;
+}
+
+static int mount_points_list_umount(MountPoint **head, bool *changed, bool log_error) {
+ MountPoint *m, *n;
+ int n_failed = 0;
+
+ assert(head);
+
+ LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+ if (path_equal(m->path, "/")
+#ifndef HAVE_SPLIT_USR
+ || path_equal(m->path, "/usr")
+#endif
+ ) {
+ n_failed++;
+ continue;
+ }
+
+ /* Trying to umount. Forcing to umount if busy (only for NFS mounts) */
+ if (umount2(m->path, MNT_FORCE) == 0) {
+ log_info("Unmounted %s.", m->path);
+ if (changed)
+ *changed = true;
+
+ mount_point_free(head, m);
+ } else if (log_error) {
+ log_warning("Could not unmount %s: %m", m->path);
+ n_failed++;
+ }
+ }
+
+ return n_failed;
+}
+
+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) {
+
+ if (m->skip_ro) {
+ n_failed++;
+ continue;
+ }
+
+ /* Trying to remount read-only */
+ 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 n_failed;
+}
+
+static int swap_points_list_off(MountPoint **head, bool *changed) {
+ MountPoint *m, *n;
+ int n_failed = 0;
+
+ 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 n_failed;
+}
+
+static int loopback_points_list_detach(MountPoint **head, bool *changed) {
+ MountPoint *m, *n;
+ int n_failed = 0, k;
+ struct stat root_st;
+
+ assert(head);
+
+ k = lstat("/", &root_st);
+
+ LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+ int r;
+ struct stat loopback_st;
+
+ if (k >= 0 &&
+ major(root_st.st_dev) != 0 &&
+ lstat(m->path, &loopback_st) >= 0 &&
+ root_st.st_dev == loopback_st.st_rdev) {
+ n_failed ++;
+ continue;
+ }
+
+ 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 n_failed;
+}
+
+static int dm_points_list_detach(MountPoint **head, bool *changed) {
+ MountPoint *m, *n;
+ int n_failed = 0, k;
+ struct stat root_st;
+
+ assert(head);
+
+ k = lstat("/", &root_st);
+
+ LIST_FOREACH_SAFE(mount_point, m, n, *head) {
+ int r;
+
+ if (k >= 0 &&
+ major(root_st.st_dev) != 0 &&
+ root_st.st_dev == m->devnum) {
+ n_failed ++;
+ continue;
+ }
+
+ 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 n_failed;
+}
+
+int umount_all(bool *changed) {
+ int r;
+ bool umount_changed;
+
+ 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;
+
+ /* retry umount, until nothing can be umounted anymore */
+ do {
+ umount_changed = false;
+
+ mount_points_list_umount(&mp_list_head, &umount_changed, false);
+ if (umount_changed)
+ *changed = true;
+
+ } while (umount_changed);
+
+ /* umount one more time with logging enabled */
+ r = mount_points_list_umount(&mp_list_head, &umount_changed, true);
+ if (r <= 0)
+ goto end;
+
+ r = mount_points_list_remount_read_only(&mp_list_head, changed);
+
+ end:
+ mount_points_list_free(&mp_list_head);
+
+ return r;
+}
+
+int swapoff_all(bool *changed) {
+ 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, changed);
+
+ end:
+ mount_points_list_free(&swap_list_head);
+
+ return r;
+}
+
+int loopback_detach_all(bool *changed) {
+ 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, changed);
+
+ end:
+ mount_points_list_free(&loopback_list_head);
+
+ return r;
+}
+
+int dm_detach_all(bool *changed) {
+ int r;
+ LIST_HEAD(MountPoint, dm_list_head);
+
+ LIST_HEAD_INIT(MountPoint, dm_list_head);
+
+ r = dm_list_get(&dm_list_head);
+ if (r < 0)
+ goto end;
+
+ r = dm_points_list_detach(&dm_list_head, changed);
+
+ end:
+ mount_points_list_free(&dm_list_head);
+
+ return r;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-10 16:45:00 +0000