635 lines
19 KiB
C
635 lines
19 KiB
C
/***
|
|
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 <linux/loop.h>
|
|
#include <string.h>
|
|
#include <sys/mount.h>
|
|
#include <sys/swap.h>
|
|
|
|
#include "libudev.h"
|
|
|
|
#include "alloc-util.h"
|
|
#include "escape.h"
|
|
#include "fd-util.h"
|
|
#include "fstab-util.h"
|
|
#include "linux-3.13/dm-ioctl.h"
|
|
#include "list.h"
|
|
#include "mount-setup.h"
|
|
#include "path-util.h"
|
|
#include "string-util.h"
|
|
#include "udev-util.h"
|
|
#include "umount.h"
|
|
#include "mount-util.h"
|
|
#include "util.h"
|
|
#include "virt.h"
|
|
|
|
typedef struct MountPoint {
|
|
char *path;
|
|
char *options;
|
|
char *type;
|
|
dev_t devnum;
|
|
LIST_FIELDS(struct MountPoint, mount_point);
|
|
} MountPoint;
|
|
|
|
static void mount_point_free(MountPoint **head, MountPoint *m) {
|
|
assert(head);
|
|
assert(m);
|
|
|
|
LIST_REMOVE(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) {
|
|
_cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
|
|
unsigned int i;
|
|
int r;
|
|
|
|
assert(head);
|
|
|
|
proc_self_mountinfo = fopen("/proc/self/mountinfo", "re");
|
|
if (!proc_self_mountinfo)
|
|
return -errno;
|
|
|
|
for (i = 1;; i++) {
|
|
_cleanup_free_ char *path = NULL, *options = NULL, *type = NULL;
|
|
char *p = NULL;
|
|
MountPoint *m;
|
|
int k;
|
|
|
|
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 flags */
|
|
"%*[^-]" /* (7) optional fields */
|
|
"- " /* (8) separator */
|
|
"%ms " /* (9) file system type */
|
|
"%*s" /* (10) mount source */
|
|
"%ms" /* (11) mount options */
|
|
"%*[^\n]", /* some rubbish at the end */
|
|
&path, &type, &options);
|
|
if (k != 3) {
|
|
if (k == EOF)
|
|
break;
|
|
|
|
log_warning("Failed to parse /proc/self/mountinfo:%u.", i);
|
|
continue;
|
|
}
|
|
|
|
r = cunescape(path, UNESCAPE_RELAX, &p);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
/* Ignore mount points we can't unmount because they
|
|
* are API or because we are keeping them open (like
|
|
* /dev/console). Also, ignore all mounts below API
|
|
* file systems, since they are likely virtual too,
|
|
* and hence not worth spending time on. Also, in
|
|
* unprivileged containers we might lack the rights to
|
|
* unmount these things, hence don't bother. */
|
|
if (mount_point_is_api(p) ||
|
|
mount_point_ignore(p) ||
|
|
path_startswith(p, "/dev") ||
|
|
path_startswith(p, "/sys") ||
|
|
path_startswith(p, "/proc")) {
|
|
free(p);
|
|
continue;
|
|
}
|
|
|
|
m = new0(MountPoint, 1);
|
|
if (!m) {
|
|
free(p);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
m->path = p;
|
|
m->options = options;
|
|
options = NULL;
|
|
m->type = type;
|
|
type = NULL;
|
|
|
|
LIST_PREPEND(mount_point, *head, m);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int swap_list_get(MountPoint **head) {
|
|
_cleanup_fclose_ FILE *proc_swaps = NULL;
|
|
unsigned int i;
|
|
int r;
|
|
|
|
assert(head);
|
|
|
|
proc_swaps = fopen("/proc/swaps", "re");
|
|
if (!proc_swaps)
|
|
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;
|
|
|
|
k = fscanf(proc_swaps,
|
|
"%ms " /* device/file */
|
|
"%*s " /* type of swap */
|
|
"%*s " /* swap size */
|
|
"%*s " /* used */
|
|
"%*s\n", /* priority */
|
|
&dev);
|
|
|
|
if (k != 1) {
|
|
if (k == EOF)
|
|
break;
|
|
|
|
log_warning("Failed to parse /proc/swaps:%u.", i);
|
|
free(dev);
|
|
continue;
|
|
}
|
|
|
|
if (endswith(dev, " (deleted)")) {
|
|
free(dev);
|
|
continue;
|
|
}
|
|
|
|
r = cunescape(dev, UNESCAPE_RELAX, &d);
|
|
free(dev);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
swap = new0(MountPoint, 1);
|
|
if (!swap) {
|
|
free(d);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
swap->path = d;
|
|
LIST_PREPEND(mount_point, *head, swap);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int loopback_list_get(MountPoint **head) {
|
|
_cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
|
|
struct udev_list_entry *item = NULL, *first = NULL;
|
|
_cleanup_udev_unref_ struct udev *udev = NULL;
|
|
int r;
|
|
|
|
assert(head);
|
|
|
|
udev = udev_new();
|
|
if (!udev)
|
|
return -ENOMEM;
|
|
|
|
e = udev_enumerate_new(udev);
|
|
if (!e)
|
|
return -ENOMEM;
|
|
|
|
r = udev_enumerate_add_match_subsystem(e, "block");
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = udev_enumerate_add_match_sysname(e, "loop*");
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = udev_enumerate_add_match_sysattr(e, "loop/backing_file", NULL);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = udev_enumerate_scan_devices(e);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
first = udev_enumerate_get_list_entry(e);
|
|
udev_list_entry_foreach(item, first) {
|
|
MountPoint *lb;
|
|
_cleanup_udev_device_unref_ struct udev_device *d;
|
|
char *loop;
|
|
const char *dn;
|
|
|
|
d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
|
|
if (!d)
|
|
return -ENOMEM;
|
|
|
|
dn = udev_device_get_devnode(d);
|
|
if (!dn)
|
|
continue;
|
|
|
|
loop = strdup(dn);
|
|
if (!loop)
|
|
return -ENOMEM;
|
|
|
|
lb = new0(MountPoint, 1);
|
|
if (!lb) {
|
|
free(loop);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
lb->path = loop;
|
|
LIST_PREPEND(mount_point, *head, lb);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dm_list_get(MountPoint **head) {
|
|
_cleanup_udev_enumerate_unref_ struct udev_enumerate *e = NULL;
|
|
struct udev_list_entry *item = NULL, *first = NULL;
|
|
_cleanup_udev_unref_ struct udev *udev = NULL;
|
|
int r;
|
|
|
|
assert(head);
|
|
|
|
udev = udev_new();
|
|
if (!udev)
|
|
return -ENOMEM;
|
|
|
|
e = udev_enumerate_new(udev);
|
|
if (!e)
|
|
return -ENOMEM;
|
|
|
|
r = udev_enumerate_add_match_subsystem(e, "block");
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = udev_enumerate_add_match_sysname(e, "dm-*");
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = udev_enumerate_scan_devices(e);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
first = udev_enumerate_get_list_entry(e);
|
|
udev_list_entry_foreach(item, first) {
|
|
MountPoint *m;
|
|
_cleanup_udev_device_unref_ struct udev_device *d;
|
|
dev_t devnum;
|
|
char *node;
|
|
const char *dn;
|
|
|
|
d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item));
|
|
if (!d)
|
|
return -ENOMEM;
|
|
|
|
devnum = udev_device_get_devnum(d);
|
|
dn = udev_device_get_devnode(d);
|
|
if (major(devnum) == 0 || !dn)
|
|
continue;
|
|
|
|
node = strdup(dn);
|
|
if (!node)
|
|
return -ENOMEM;
|
|
|
|
m = new(MountPoint, 1);
|
|
if (!m) {
|
|
free(node);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
m->path = node;
|
|
m->devnum = devnum;
|
|
LIST_PREPEND(mount_point, *head, m);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int delete_loopback(const char *device) {
|
|
_cleanup_close_ int fd = -1;
|
|
int r;
|
|
|
|
fd = open(device, O_RDONLY|O_CLOEXEC);
|
|
if (fd < 0)
|
|
return errno == ENOENT ? 0 : -errno;
|
|
|
|
r = ioctl(fd, LOOP_CLR_FD, 0);
|
|
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) {
|
|
|
|
struct dm_ioctl dm = {
|
|
.version = {
|
|
DM_VERSION_MAJOR,
|
|
DM_VERSION_MINOR,
|
|
DM_VERSION_PATCHLEVEL
|
|
},
|
|
.data_size = sizeof(dm),
|
|
.dev = devnum,
|
|
};
|
|
|
|
_cleanup_close_ int fd = -1;
|
|
|
|
assert(major(devnum) != 0);
|
|
|
|
fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC);
|
|
if (fd < 0)
|
|
return -errno;
|
|
|
|
if (ioctl(fd, DM_DEV_REMOVE, &dm) < 0)
|
|
return -errno;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool nonunmountable_path(const char *path) {
|
|
return path_equal(path, "/")
|
|
#if ! HAVE_SPLIT_USR
|
|
|| path_equal(path, "/usr")
|
|
#endif
|
|
|| path_startswith(path, "/run/initramfs");
|
|
}
|
|
|
|
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 we are in a container, don't attempt to
|
|
read-only mount anything as that brings no real
|
|
benefits, but might confuse the host, as we remount
|
|
the superblock here, not the bind mount.
|
|
If the filesystem is a network fs, also skip the
|
|
remount. It brings no value (we cannot leave
|
|
a "dirty fs") and could hang if the network is down. */
|
|
if (detect_container() <= 0 &&
|
|
!fstype_is_network(m->type)) {
|
|
_cleanup_free_ char *options = NULL;
|
|
/* MS_REMOUNT requires that the data parameter
|
|
* should be the same from the original mount
|
|
* except for the desired changes. Since we want
|
|
* to remount read-only, we should filter out
|
|
* rw (and ro too, because it confuses the kernel) */
|
|
(void) fstab_filter_options(m->options, "rw\0ro\0", NULL, NULL, &options);
|
|
|
|
/* We always try to remount directories
|
|
* read-only first, before we go on and umount
|
|
* them.
|
|
*
|
|
* Mount points can be stacked. If a mount
|
|
* point is stacked below / or /usr, we
|
|
* cannot umount or remount it directly,
|
|
* since there is no way to refer to the
|
|
* underlying mount. There's nothing we can do
|
|
* about it for the general case, but we can
|
|
* do something about it if it is aliased
|
|
* somehwere else via a bind mount. If we
|
|
* explicitly remount the super block of that
|
|
* alias read-only we hence should be
|
|
* relatively safe regarding keeping dirty an fs
|
|
* we cannot otherwise see. */
|
|
log_info("Remounting '%s' read-only with options '%s'.", m->path, options);
|
|
if (mount(NULL, m->path, NULL, MS_REMOUNT|MS_RDONLY, options) < 0) {
|
|
if (log_error)
|
|
log_notice_errno(errno, "Failed to remount '%s' read-only: %m", m->path);
|
|
if (nonunmountable_path(m->path))
|
|
n_failed++;
|
|
}
|
|
}
|
|
|
|
/* Skip / and /usr since we cannot unmount that
|
|
* anyway, since we are running from it. They have
|
|
* already been remounted ro. */
|
|
if (nonunmountable_path(m->path))
|
|
continue;
|
|
|
|
/* Trying to umount. We don't force here since we rely
|
|
* on busy NFS and FUSE file systems to return EBUSY
|
|
* until we closed everything on top of them. */
|
|
log_info("Unmounting %s.", m->path);
|
|
if (umount2(m->path, 0) == 0) {
|
|
if (changed)
|
|
*changed = true;
|
|
|
|
mount_point_free(head, m);
|
|
} else {
|
|
if (log_error)
|
|
log_warning_errno(errno, "Could not unmount %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) {
|
|
log_info("Deactivating swap %s.", m->path);
|
|
if (swapoff(m->path) == 0) {
|
|
if (changed)
|
|
*changed = true;
|
|
|
|
mount_point_free(head, m);
|
|
} else {
|
|
log_warning_errno(errno, "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;
|
|
}
|
|
|
|
log_info("Detaching loopback %s.", m->path);
|
|
r = delete_loopback(m->path);
|
|
if (r >= 0) {
|
|
if (r > 0 && changed)
|
|
*changed = true;
|
|
|
|
mount_point_free(head, m);
|
|
} else {
|
|
log_warning_errno(errno, "Could not detach 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, r;
|
|
dev_t rootdev;
|
|
|
|
assert(head);
|
|
|
|
r = get_block_device("/", &rootdev);
|
|
if (r <= 0)
|
|
rootdev = 0;
|
|
|
|
LIST_FOREACH_SAFE(mount_point, m, n, *head) {
|
|
|
|
if (major(rootdev) != 0)
|
|
if (rootdev == m->devnum) {
|
|
n_failed ++;
|
|
continue;
|
|
}
|
|
|
|
log_info("Detaching DM %u:%u.", major(m->devnum), minor(m->devnum));
|
|
r = delete_dm(m->devnum);
|
|
if (r >= 0) {
|
|
if (changed)
|
|
*changed = true;
|
|
|
|
mount_point_free(head, m);
|
|
} else {
|
|
log_warning_errno(errno, "Could not detach 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(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);
|
|
|
|
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(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(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(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;
|
|
}
|