static int
zvol_first_open(zvol_state_t *zv)
{
objset_t *os;
uint64_t volsize;
int error;
uint64_t ro;
/* lie and say we're read-only */
error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, 1, zvol_tag, &os);
if (error)
return (SET_ERROR(-error));
zv->zv_objset = os;
error = dsl_prop_get_integer(zv->zv_name, "readonly", &ro, NULL);
if (error)
goto out_owned;
error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
if (error)
goto out_owned;
error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf);
if (error)
goto out_owned;
set_capacity(zv->zv_disk, volsize >> 9);
zv->zv_volsize = volsize;
zv->zv_zilog = zil_open(os, zvol_get_data);
if (ro || dmu_objset_is_snapshot(os) ||
!spa_writeable(dmu_objset_spa(os))) {
set_disk_ro(zv->zv_disk, 1);
zv->zv_flags |= ZVOL_RDONLY;
} else {
set_disk_ro(zv->zv_disk, 0);
zv->zv_flags &= ~ZVOL_RDONLY;
}
out_owned:
if (error) {
dmu_objset_disown(os, zvol_tag);
zv->zv_objset = NULL;
}
return (SET_ERROR(-error));
}
/*
* Set read only
*/
static int
dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
{
struct dasd_device *base;
int intval, rc;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (bdev != bdev->bd_contains)
// ro setting is not allowed for partitions
return -EINVAL;
if (get_user(intval, (int __user *)argp))
return -EFAULT;
base = dasd_device_from_gendisk(bdev->bd_disk);
if (!base)
return -ENODEV;
if (!intval && test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
dasd_put_device(base);
return -EROFS;
}
set_disk_ro(bdev->bd_disk, intval);
rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, intval);
dasd_put_device(base);
return rc;
}
static int ide_floppy_get_flexible_disk_page(ide_drive_t *drive,
struct ide_atapi_pc *pc)
{
struct ide_disk_obj *floppy = drive->driver_data;
struct gendisk *disk = floppy->disk;
u8 *page, buf[40];
int capacity, lba_capacity;
u16 transfer_rate, sector_size, cyls, rpm;
u8 heads, sectors;
ide_floppy_create_mode_sense_cmd(pc, IDEFLOPPY_FLEXIBLE_DISK_PAGE);
if (ide_queue_pc_tail(drive, disk, pc, buf, pc->req_xfer)) {
printk(KERN_ERR PFX "Can't get flexible disk page params\n");
return 1;
}
if (buf[3] & 0x80)
drive->dev_flags |= IDE_DFLAG_WP;
else
drive->dev_flags &= ~IDE_DFLAG_WP;
set_disk_ro(disk, !!(drive->dev_flags & IDE_DFLAG_WP));
page = &buf[8];
transfer_rate = be16_to_cpup((__be16 *)&buf[8 + 2]);
sector_size = be16_to_cpup((__be16 *)&buf[8 + 6]);
cyls = be16_to_cpup((__be16 *)&buf[8 + 8]);
rpm = be16_to_cpup((__be16 *)&buf[8 + 28]);
heads = buf[8 + 4];
sectors = buf[8 + 5];
capacity = cyls * heads * sectors * sector_size;
if (memcmp(page, &floppy->flexible_disk_page, 32))
printk(KERN_INFO PFX "%s: %dkB, %d/%d/%d CHS, %d kBps, "
"%d sector size, %d rpm\n",
drive->name, capacity / 1024, cyls, heads,
sectors, transfer_rate / 8, sector_size, rpm);
memcpy(&floppy->flexible_disk_page, page, 32);
drive->bios_cyl = cyls;
drive->bios_head = heads;
drive->bios_sect = sectors;
lba_capacity = floppy->blocks * floppy->block_size;
if (capacity < lba_capacity) {
printk(KERN_NOTICE PFX "%s: The disk reports a capacity of %d "
"bytes, but the drive only handles %d\n",
drive->name, lba_capacity, capacity);
floppy->blocks = floppy->block_size ?
capacity / floppy->block_size : 0;
drive->capacity64 = floppy->blocks * floppy->bs_factor;
}
return 0;
}
/*
* Rename a block device minor mode for the specified volume.
*/
static void
zvol_rename_minor(zvol_state_t *zv, const char *newname)
{
int readonly = get_disk_ro(zv->zv_disk);
ASSERT(MUTEX_HELD(&zvol_state_lock));
strlcpy(zv->zv_name, newname, sizeof (zv->zv_name));
/*
* The block device's read-only state is briefly changed causing
* a KOBJ_CHANGE uevent to be issued. This ensures udev detects
* the name change and fixes the symlinks. This does not change
* ZVOL_RDONLY in zv->zv_flags so the actual read-only state never
* changes. This would normally be done using kobject_uevent() but
* that is a GPL-only symbol which is why we need this workaround.
*/
set_disk_ro(zv->zv_disk, !readonly);
set_disk_ro(zv->zv_disk, readonly);
}
/*
* Allocate and register gendisk structure for device.
*/
int dasd_gendisk_alloc(struct dasd_block *block)
{
struct gendisk *gdp;
struct dasd_device *base;
int len;
/* Make sure the minor for this device exists. */
base = block->base;
if (base->devindex >= DASD_PER_MAJOR)
return -EBUSY;
gdp = alloc_disk(1 << DASD_PARTN_BITS);
if (!gdp)
return -ENOMEM;
/* Initialize gendisk structure. */
gdp->major = DASD_MAJOR;
gdp->first_minor = base->devindex << DASD_PARTN_BITS;
gdp->fops = &dasd_device_operations;
gdp->driverfs_dev = &base->cdev->dev;
/*
* Set device name.
* dasda - dasdz : 26 devices
* dasdaa - dasdzz : 676 devices, added up = 702
* dasdaaa - dasdzzz : 17576 devices, added up = 18278
* dasdaaaa - dasdzzzz : 456976 devices, added up = 475252
*/
len = sprintf(gdp->disk_name, "dasd");
if (base->devindex > 25) {
if (base->devindex > 701) {
if (base->devindex > 18277)
len += sprintf(gdp->disk_name + len, "%c",
'a'+(((base->devindex-18278)
/17576)%26));
len += sprintf(gdp->disk_name + len, "%c",
'a'+(((base->devindex-702)/676)%26));
}
len += sprintf(gdp->disk_name + len, "%c",
'a'+(((base->devindex-26)/26)%26));
}
len += sprintf(gdp->disk_name + len, "%c", 'a'+(base->devindex%26));
if (base->features & DASD_FEATURE_READONLY ||
test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
set_disk_ro(gdp, 1);
gdp->private_data = block;
gdp->queue = block->request_queue;
block->gdp = gdp;
set_capacity(block->gdp, 0);
add_disk(block->gdp);
return 0;
}
/*
* Allocate and register gendisk structure for device.
*/
int
dasd_gendisk_alloc(struct dasd_device *device)
{
struct gendisk *gdp;
int len;
/* Make sure the minor for this device exists. */
if (device->devindex >= DASD_PER_MAJOR)
return -EBUSY;
gdp = alloc_disk(1 << DASD_PARTN_BITS);
if (!gdp)
return -ENOMEM;
/* Initialize gendisk structure. */
gdp->major = DASD_MAJOR;
gdp->first_minor = device->devindex << DASD_PARTN_BITS;
gdp->fops = &dasd_device_operations;
gdp->driverfs_dev = &device->cdev->dev;
/*
* Set device name.
* dasda - dasdz : 26 devices
* dasdaa - dasdzz : 676 devices, added up = 702
* dasdaaa - dasdzzz : 17576 devices, added up = 18278
* dasdaaaa - dasdzzzz : 456976 devices, added up = 475252
*/
len = sprintf(gdp->disk_name, "dasd");
if (device->devindex > 25) {
if (device->devindex > 701) {
if (device->devindex > 18277)
len += sprintf(gdp->disk_name + len, "%c",
'a'+(((device->devindex-18278)
/17576)%26));
len += sprintf(gdp->disk_name + len, "%c",
'a'+(((device->devindex-702)/676)%26));
}
len += sprintf(gdp->disk_name + len, "%c",
'a'+(((device->devindex-26)/26)%26));
}
len += sprintf(gdp->disk_name + len, "%c", 'a'+(device->devindex%26));
sprintf(gdp->devfs_name, "dasd/%s", device->cdev->dev.bus_id);
if (test_bit(DASD_FLAG_RO, &device->flags))
set_disk_ro(gdp, 1);
gdp->private_data = device;
gdp->queue = device->request_queue;
device->gdp = gdp;
set_capacity(device->gdp, 0);
add_disk(device->gdp);
return 0;
}
/*
* Set read only
*/
static int
dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
{
struct dasd_block *block = bdev->bd_disk->private_data;
int intval;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (bdev != bdev->bd_contains)
// ro setting is not allowed for partitions
return -EINVAL;
if (get_user(intval, (int __user *)argp))
return -EFAULT;
set_disk_ro(bdev->bd_disk, intval);
return dasd_set_feature(block->base->cdev, DASD_FEATURE_READONLY, intval);
}
static int
zvol_first_open(zvol_state_t *zv)
{
objset_t *os;
uint64_t volsize;
int locked = 0;
int error;
uint64_t ro;
/*
* In all other cases the spa_namespace_lock is taken before the
* bdev->bd_mutex lock. But in this case the Linux __blkdev_get()
* function calls fops->open() with the bdev->bd_mutex lock held.
*
* To avoid a potential lock inversion deadlock we preemptively
* try to take the spa_namespace_lock(). Normally it will not
* be contended and this is safe because spa_open_common() handles
* the case where the caller already holds the spa_namespace_lock.
*
* When it is contended we risk a lock inversion if we were to
* block waiting for the lock. Luckily, the __blkdev_get()
* function allows us to return -ERESTARTSYS which will result in
* bdev->bd_mutex being dropped, reacquired, and fops->open() being
* called again. This process can be repeated safely until both
* locks are acquired.
*/
if (!mutex_owned(&spa_namespace_lock)) {
locked = mutex_tryenter(&spa_namespace_lock);
if (!locked)
return (-ERESTARTSYS);
}
/* lie and say we're read-only */
error = dmu_objset_own(zv->zv_name, DMU_OST_ZVOL, 1, zvol_tag, &os);
if (error)
goto out_mutex;
error = zap_lookup(os, ZVOL_ZAP_OBJ, "size", 8, 1, &volsize);
if (error) {
dmu_objset_disown(os, zvol_tag);
goto out_mutex;
}
zv->zv_objset = os;
error = dmu_bonus_hold(os, ZVOL_OBJ, zvol_tag, &zv->zv_dbuf);
if (error) {
dmu_objset_disown(os, zvol_tag);
goto out_mutex;
}
set_capacity(zv->zv_disk, volsize >> 9);
zv->zv_volsize = volsize;
zv->zv_zilog = zil_open(os, zvol_get_data);
VERIFY(dsl_prop_get_integer(zv->zv_name, "readonly", &ro, NULL) == 0);
if (ro || dmu_objset_is_snapshot(os) ||
!spa_writeable(dmu_objset_spa(os))) {
set_disk_ro(zv->zv_disk, 1);
zv->zv_flags |= ZVOL_RDONLY;
} else {
set_disk_ro(zv->zv_disk, 0);
zv->zv_flags &= ~ZVOL_RDONLY;
}
out_mutex:
if (locked)
mutex_exit(&spa_namespace_lock);
return (-error);
}
static void __init dm_setup_drive(void)
{
struct mapped_device *md = NULL;
struct dm_table *table = NULL;
struct dm_setup_target *target;
char *uuid = dm_setup_args.uuid;
fmode_t fmode = FMODE_READ;
/* Finish parsing the targets. */
if (dm_setup_parse_targets(dm_setup_args.targets))
goto parse_fail;
if (dm_create(dm_setup_args.minor, &md)) {
DMDEBUG("failed to create the device");
goto dm_create_fail;
}
DMDEBUG("created device '%s'", dm_device_name(md));
/* In addition to flagging the table below, the disk must be
* set explicitly ro/rw. */
set_disk_ro(dm_disk(md), dm_setup_args.ro);
if (!dm_setup_args.ro)
fmode |= FMODE_WRITE;
if (dm_table_create(&table, fmode, dm_setup_args.target_count, md)) {
DMDEBUG("failed to create the table");
goto dm_table_create_fail;
}
target = dm_setup_args.target;
while (target) {
DMINFO("adding target '%llu %llu %s %s'",
(unsigned long long) target->begin,
(unsigned long long) target->length, target->type,
target->params);
if (dm_table_add_target(table, target->type, target->begin,
target->length, target->params)) {
DMDEBUG("failed to add the target to the table");
goto add_target_fail;
}
target = target->next;
}
if (dm_table_complete(table)) {
DMDEBUG("failed to complete the table");
goto table_complete_fail;
}
/* Suspend the device so that we can bind it to the table. */
if (dm_suspend(md, 0)) {
DMDEBUG("failed to suspend the device pre-bind");
goto suspend_fail;
}
/* Bind the table to the device. This is the only way to associate
* md->map with the table and set the disk capacity directly. */
if (dm_swap_table(md, table)) { /* should return NULL. */
DMDEBUG("failed to bind the device to the table");
goto table_bind_fail;
}
/* Finally, resume and the device should be ready. */
if (dm_resume(md)) {
DMDEBUG("failed to resume the device");
goto resume_fail;
}
/* Export the dm device via the ioctl interface */
if (!strcmp(DM_NO_UUID, dm_setup_args.uuid))
uuid = NULL;
if (dm_ioctl_export(md, dm_setup_args.name, uuid)) {
DMDEBUG("failed to export device with given name and uuid");
goto export_fail;
}
printk(KERN_INFO "dm: dm-%d is ready\n", dm_setup_args.minor);
dm_setup_cleanup();
return;
export_fail:
resume_fail:
table_bind_fail:
suspend_fail:
table_complete_fail:
add_target_fail:
dm_table_put(table);
dm_table_create_fail:
dm_put(md);
dm_create_fail:
dm_setup_cleanup();
parse_fail:
printk(KERN_WARNING "dm: starting dm-%d (%s) failed\n",
dm_setup_args.minor, dm_setup_args.name);
}