thin-provisioning-tools/ft-lib/dm-ioctl.c

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#include <linux/dm-ioctl.h>
#include <linux/kdev_t.h>
#include <linux/fs.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
2017-10-23 15:08:11 +05:30
#include <sys/sysmacros.h>
#include <fcntl.h>
#include <unistd.h>
//----------------------------------------------------------------
// assuming div is a power of 2
static size_t round_up(size_t n, size_t div)
{
size_t mask = div - 1;
return (n + mask) & ~mask;
}
//----------------------------------------------------------------
static void *zalloc(size_t len)
{
void *ptr = malloc(len);
if (ptr)
memset(ptr, 0, len);
return ptr;
}
static void *payload(struct dm_ioctl *ctl)
{
return ((unsigned char *) ctl) + ctl->data_start;
}
static struct dm_ioctl *alloc_ctl(size_t payload_size)
{
size_t len = sizeof(struct dm_ioctl) + payload_size;
struct dm_ioctl *ctl = zalloc(len);
if (ctl) {
ctl->version[0] = DM_VERSION_MAJOR;
ctl->version[1] = DM_VERSION_MINOR;
ctl->version[2] = DM_VERSION_PATCHLEVEL;
ctl->data_size = len;
ctl->data_start = sizeof(*ctl);
}
return ctl;
}
static void free_ctl(struct dm_ioctl *ctl)
{
free(ctl);
}
// realloc only copies the dm_ioctl struct, not the payload.
// old is always freed, even in case of error.
static struct dm_ioctl *realloc_ctl(struct dm_ioctl *old, size_t extra_payload)
{
struct dm_ioctl *ctl;
size_t old_payload_size = old->data_size - sizeof(struct dm_ioctl);
size_t new_payload_size = old_payload_size + extra_payload;
ctl = alloc_ctl(new_payload_size);
if (ctl)
memcpy(payload(ctl), payload(old), sizeof(*ctl));
free_ctl(old);
return ctl;
}
//----------------------------------------------------------------
struct dm_interface {
int fd;
};
// FIXME: pass in some form of log object?
struct dm_interface *dm_open()
{
int fd;
char path[1024];
struct dm_interface *dmi;
snprintf(path, sizeof(path), "/dev/%s/%s", DM_DIR, DM_CONTROL_NODE);
fd = open(path, O_RDWR | O_EXCL);
if (fd < 0)
return NULL;
dmi = zalloc(sizeof(*dmi));
if (dmi)
dmi->fd = fd;
else
close(fd);
return dmi;
}
void dm_close(struct dm_interface *dmi)
{
close(dmi->fd);
free(dmi);
}
//----------------------------------------------------------------
struct dev_list {
struct dev_list *next;
unsigned major;
unsigned minor;
char *name;
};
void free_dev_list(struct dev_list *dl)
{
struct dev_list *next;
while (dl) {
next = dl->next;
free(dl->name);
free(dl);
dl = next;
}
}
struct dev_list_builder {
struct dev_list *head, *tail;
};
static void dlb_init(struct dev_list_builder *dlb)
{
dlb->head = dlb->tail = NULL;
}
static int dlb_append(struct dev_list_builder *dlb,
unsigned major, unsigned minor, const char *name)
{
struct dev_list *dl = malloc(sizeof(*dl));
if (!dl)
return -ENOMEM;
dl->next = NULL;
dl->major = major;
dl->minor = minor;
dl->name = strdup(name);
if (dlb->head) {
dlb->tail->next = dl;
dlb->tail = dl;
} else
dlb->head = dlb->tail = dl;
return 0;
}
static struct dev_list *dlb_get(struct dev_list_builder *dlb)
{
return dlb->head;
}
//----------------------------------------------------------------
static int copy_string(char *dest, const char *src, size_t max)
{
if (strlen(src) + 1 > max)
return -ENOMEM;
strcpy(dest, src);
return 0;
}
static int copy_name(struct dm_ioctl *ctl, const char *name)
{
return copy_string(ctl->name, name, DM_NAME_LEN);
}
static int copy_uuid(struct dm_ioctl *ctl, const char *uuid)
{
return copy_string(ctl->uuid, uuid, DM_UUID_LEN);
}
//----------------------------------------------------------------
int dm_version(struct dm_interface *dmi, uint32_t *major, uint32_t *minor, uint32_t *patch)
{
int r;
struct dm_ioctl *ctl = alloc_ctl(0);
if (!ctl)
return -ENOMEM;
r = ioctl(dmi->fd, DM_VERSION, ctl);
*major = ctl->version[0];
*minor = ctl->version[1];
*patch = ctl->version[2];
free_ctl(ctl);
return r;
}
int dm_remove_all(struct dm_interface *dmi)
{
int r;
struct dm_ioctl *ctl = alloc_ctl(0);
if (!ctl)
return -ENOMEM;
r = ioctl(dmi->fd, DM_REMOVE_ALL, ctl);
free_ctl(ctl);
return r;
}
static bool list_devices(struct dm_interface *dmi, struct dm_ioctl *ctl,
size_t payload_size, struct dev_list **devs,
int *r)
{
struct dm_name_list *nl;
struct dev_list_builder dlb;
*r = ioctl(dmi->fd, DM_LIST_DEVICES, ctl);
if (*r < 0)
return true;
if (ctl->flags & DM_BUFFER_FULL_FLAG) {
free_ctl(ctl);
return false;
}
dlb_init(&dlb);
nl = (struct dm_name_list *) payload(ctl);
if (nl->dev) {
for (;;) {
dlb_append(&dlb, MAJOR(nl->dev), MINOR(nl->dev), nl->name);
if (!nl->next)
break;
nl = (struct dm_name_list *) (((unsigned char *) nl) + nl->next);
}
}
*devs = dlb_get(&dlb);
return true;
}
int dm_list_devices(struct dm_interface *dmi, struct dev_list **devs)
{
int r;
struct dm_ioctl *ctl;
size_t payload_size = 8192;
ctl = alloc_ctl(payload_size);
if (!ctl)
return -ENOMEM;
while (!list_devices(dmi, ctl, payload_size, devs, &r)) {
payload_size *= 2;
ctl = realloc_ctl(ctl, payload_size);
if (!ctl)
return -ENOMEM;
}
free_ctl(ctl);
return r;
}
// Obviously major and minor are only valid if successful.
int dm_create_device(struct dm_interface *dmi, const char *name, const char *uuid,
uint32_t *major_result, uint32_t *minor_result)
{
int r;
struct dm_ioctl *ctl = alloc_ctl(0);
if (!ctl)
return -ENOMEM;
r = copy_name(ctl, name);
if (r) {
free_ctl(ctl);
return r;
}
r = copy_uuid(ctl, name);
if (r) {
free_ctl(ctl);
return r;
}
r = ioctl(dmi->fd, DM_DEV_CREATE, ctl);
if (!r) {
*major_result = MAJOR(ctl->dev);
*minor_result = MINOR(ctl->dev);
}
free_ctl(ctl);
return r;
}
static int dev_cmd(struct dm_interface *dmi, const char *name, int request, unsigned flags)
{
int r;
struct dm_ioctl *ctl = alloc_ctl(0);
if (!ctl)
return -ENOMEM;
ctl->flags = flags;
r = copy_name(ctl, name);
if (r) {
free_ctl(ctl);
return -ENOMEM;
}
r = ioctl(dmi->fd, request, ctl);
free_ctl(ctl);
return r;
}
int dm_remove_device(struct dm_interface *dmi, const char *name)
{
return dev_cmd(dmi, name, DM_DEV_REMOVE, 0);
}
int dm_suspend_device(struct dm_interface *dmi, const char *name)
{
return dev_cmd(dmi, name, DM_DEV_SUSPEND, DM_SUSPEND_FLAG);
}
int dm_resume_device(struct dm_interface *dmi, const char *name)
{
return dev_cmd(dmi, name, DM_DEV_SUSPEND, 0);
}
int dm_clear_device(struct dm_interface *dmi, const char *name)
{
return dev_cmd(dmi, name, DM_TABLE_CLEAR, 0);
}
//----------------------------------------------------------------
struct target {
struct target *next;
uint64_t len;
char *type;
char *args;
};
void free_targets(struct target *t)
{
while (t) {
struct target *next = t->next;
free(t->type);
free(t->args);
t = next;
}
}
struct target_builder {
struct target *head, *tail;
};
static void tb_init(struct target_builder *tb)
{
tb->head = tb->tail = NULL;
}
static int tb_append(struct target_builder *tb, uint64_t len, char *type, char *args)
{
struct target *t = malloc(sizeof(*t));
if (!t)
return -ENOMEM;
t->next = NULL;
t->len = len;
t->type = strdup(type);
if (!t->type) {
free(t);
return -ENOMEM;
}
t->args = strdup(args);
if (!t->args) {
free(t->type);
free(t);
return -ENOMEM;
}
if (tb->head) {
tb->tail->next = t;
tb->tail = t;
} else
tb->head = tb->tail = t;
return 0;
}
static struct target *tb_get(struct target_builder *tb)
{
return tb->head;
}
//----------------------------------------------------------------
static size_t calc_load_payload(struct target *t)
{
size_t space = 0;
while (t) {
space += sizeof(struct dm_target_spec);
space += strlen(t->args) + 16;
t = t->next;
}
return space + 128;
}
static int prep_load(struct dm_ioctl *ctl, size_t payload_size,
const char *name, struct target *t)
{
int r;
uint64_t current_sector = 0;
struct dm_target_spec *spec;
ctl->target_count = 0;
spec = payload(ctl);
while (t) {
spec->sector_start = current_sector;
current_sector += t->len;
spec->length = t->len;
spec->status = 0;
r = copy_string(spec->target_type, t->type, DM_MAX_TYPE_NAME);
if (r)
return r;
r = copy_string((char *) (spec + 1), t->args, payload_size);
if (r)
return r;
spec->next = sizeof(*spec) + round_up(strlen(t->args) + 1, 8);
payload_size -= spec->next;
spec = (struct dm_target_spec *) (((char *) spec) + spec->next);
ctl->target_count++;
t = t->next;
}
return 0;
}
int dm_load(struct dm_interface *dmi, const char *name,
struct target *targets)
{
int r;
size_t payload_size = calc_load_payload(targets);
struct dm_ioctl *ctl = alloc_ctl(payload_size);
if (!ctl)
return -ENOMEM;
r = prep_load(ctl, payload_size, name, targets);
if (r) {
free_ctl(ctl);
return r;
}
r = copy_name(ctl, name);
if (r) {
free_ctl(ctl);
return -ENOMEM;
}
r = ioctl(dmi->fd, DM_TABLE_LOAD, ctl);
free_ctl(ctl);
return r;
}
//----------------------------------------------------------------
// returns false if control buffer too small.
static bool get_status(struct dm_interface *dmi, struct dm_ioctl *ctl,
const char *name, unsigned flags,
int *result)
{
*result = copy_name(ctl, name);
if (*result) {
free_ctl(ctl);
return true;
}
ctl->flags = flags;
ctl->target_count = 0;
*result = ioctl(dmi->fd, DM_TABLE_STATUS, ctl);
if (*result)
return true;
if (ctl->flags & DM_BUFFER_FULL_FLAG)
return false;
return true;
}
static int unpack_status(struct dm_ioctl *ctl, struct target **result)
{
unsigned i;
struct target_builder tb;
struct dm_target_spec *spec = payload(ctl);
char *spec_start = (char *) spec;
tb_init(&tb);
for (i = 0; i < ctl->target_count; i++) {
tb_append(&tb, spec->length, spec->target_type, (char *) (spec + 1));
spec = (struct dm_target_spec *) (spec_start + spec->next);
}
*result = tb_get(&tb);
return 0;
}
static int status_cmd(struct dm_interface *dmi, const char *name,
struct target **targets, unsigned flags)
{
int r;
size_t payload_size = 8192;
struct dm_ioctl *ctl = NULL;
ctl = alloc_ctl(payload_size);
if (!ctl)
return -ENOMEM;
retry:
if (!get_status(dmi, ctl, name, flags, &r)) {
payload_size *= 2;
ctl = realloc_ctl(ctl, payload_size);
if (!ctl)
return -ENOMEM;
goto retry;
}
if (r)
return r;
r = unpack_status(ctl, targets);
free_ctl(ctl);
return r;
}
int dm_status(struct dm_interface *dmi, const char *name, struct target **targets)
{
return status_cmd(dmi, name, targets, 0);
}
int dm_table(struct dm_interface *dmi, const char *name, struct target **targets)
{
return status_cmd(dmi, name, targets, DM_STATUS_TABLE_FLAG);
}
#if 0
int dm_info(struct dm_interface *dmi, const char *name, struct target **targets)
{
return status_cmd(dmi, name, targets, DM_STATUS_INFO_FLAG);
}
#endif
int dm_message(struct dm_interface *dmi, const char *name, uint64_t sector,
const char *msg_str)
{
int r;
size_t msg_len = strlen(msg_str) + 1;
size_t payload_size = msg_len + 32;
struct dm_ioctl *ctl = alloc_ctl(payload_size);
struct dm_target_msg *msg;
if (!ctl)
return -ENOMEM;
msg = payload(ctl);
copy_name(ctl, name);
msg->sector = sector;
memcpy(msg->message, msg_str, msg_len);
r = ioctl(dmi->fd, DM_TARGET_MSG, ctl);
free_ctl(ctl);
return r;
}
int get_dev_size(const char *path, uint64_t *sectors)
{
int r, fd;
fd = open(path, O_RDONLY);
if (fd < 0)
return -EINVAL;
r = ioctl(fd, BLKGETSIZE64, sectors);
(*sectors) /= 512;
close(fd);
return r;
}
//----------------------------------------------------------------