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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/***
Copyright © 2010 ProFUSION embedded systems
***/
#include <linux/dm-ioctl.h>
#include <sys/ioctl.h>
#include "sd-device.h"
#include "alloc-util.h"
#include "blockdev-util.h"
#include "detach-dm.h"
#include "device-util.h"
#include "devnum-util.h"
#include "errno-util.h"
#include "fd-util.h"
#include "sync-util.h"
typedef struct DeviceMapper {
char *path;
dev_t devnum;
LIST_FIELDS(struct DeviceMapper, device_mapper);
} DeviceMapper;
static void device_mapper_free(DeviceMapper **head, DeviceMapper *m) {
assert(head);
assert(m);
LIST_REMOVE(device_mapper, *head, m);
free(m->path);
free(m);
}
static void device_mapper_list_free(DeviceMapper **head) {
assert(head);
while (*head)
device_mapper_free(head, *head);
}
static int dm_list_get(DeviceMapper **head) {
_cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
int r;
assert(head);
r = sd_device_enumerator_new(&e);
if (r < 0)
return r;
r = sd_device_enumerator_allow_uninitialized(e);
if (r < 0)
return r;
r = sd_device_enumerator_add_match_subsystem(e, "block", true);
if (r < 0)
return r;
r = sd_device_enumerator_add_match_sysname(e, "dm-*");
if (r < 0)
return r;
FOREACH_DEVICE(e, d) {
_cleanup_free_ char *p = NULL;
const char *dn;
DeviceMapper *m;
dev_t devnum;
if (sd_device_get_devnum(d, &devnum) < 0 ||
sd_device_get_devname(d, &dn) < 0)
continue;
p = strdup(dn);
if (!p)
return -ENOMEM;
m = new(DeviceMapper, 1);
if (!m)
return -ENOMEM;
*m = (DeviceMapper) {
.path = TAKE_PTR(p),
.devnum = devnum,
};
LIST_PREPEND(device_mapper, *head, m);
}
return 0;
}
static int delete_dm(DeviceMapper *m) {
_cleanup_close_ int fd = -EBADF;
int r;
assert(m);
assert(major(m->devnum) != 0);
assert(m->path);
fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC);
if (fd < 0)
return -errno;
r = fsync_path_at(AT_FDCWD, m->path);
if (r < 0)
log_debug_errno(r, "Failed to sync DM block device %s, ignoring: %m", m->path);
return RET_NERRNO(ioctl(fd, DM_DEV_REMOVE, &(struct dm_ioctl) {
.version = {
DM_VERSION_MAJOR,
DM_VERSION_MINOR,
DM_VERSION_PATCHLEVEL
},
.data_size = sizeof(struct dm_ioctl),
.dev = m->devnum,
}));
}
static int dm_points_list_detach(DeviceMapper **head, bool *changed, bool last_try) {
int n_failed = 0, r;
dev_t rootdev = 0, usrdev = 0;
assert(head);
assert(changed);
(void) get_block_device("/", &rootdev);
(void) get_block_device("/usr", &usrdev);
LIST_FOREACH(device_mapper, m, *head) {
if ((major(rootdev) != 0 && rootdev == m->devnum) ||
(major(usrdev) != 0 && usrdev == m->devnum)) {
log_debug("Not detaching DM %s that backs the OS itself, skipping.", m->path);
n_failed ++;
continue;
}
log_info("Detaching DM %s (" DEVNUM_FORMAT_STR ").", m->path, DEVNUM_FORMAT_VAL(m->devnum));
r = delete_dm(m);
if (r < 0) {
log_full_errno(last_try ? LOG_ERR : LOG_INFO, r, "Could not detach DM %s: %m", m->path);
n_failed++;
continue;
}
*changed = true;
device_mapper_free(head, m);
}
return n_failed;
}
int dm_detach_all(bool *changed, bool last_try) {
_cleanup_(device_mapper_list_free) LIST_HEAD(DeviceMapper, dm_list_head);
int r;
assert(changed);
LIST_HEAD_INIT(dm_list_head);
r = dm_list_get(&dm_list_head);
if (r < 0)
return r;
return dm_points_list_detach(&dm_list_head, changed, last_try);
}
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