static int
zvol_open(struct block_device *bdev, fmode_t flag)
{
zvol_state_t *zv;
int error = 0, drop_mutex = 0;
/*
* If the caller is already holding the mutex do not take it
* again, this will happen as part of zvol_create_minor_impl().
* Once add_disk() is called the device is live and the kernel
* will attempt to open it to read the partition information.
*/
if (!mutex_owned(&zvol_state_lock)) {
mutex_enter(&zvol_state_lock);
drop_mutex = 1;
}
/*
* Obtain a copy of private_data under the lock to make sure
* that either the result of zvol_freeg() setting
* bdev->bd_disk->private_data to NULL is observed, or zvol_free()
* is not called on this zv because of the positive zv_open_count.
*/
zv = bdev->bd_disk->private_data;
if (zv == NULL) {
error = -ENXIO;
goto out_mutex;
}
if (zv->zv_open_count == 0) {
error = zvol_first_open(zv);
if (error)
goto out_mutex;
}
if ((flag & FMODE_WRITE) && (zv->zv_flags & ZVOL_RDONLY)) {
error = -EROFS;
goto out_open_count;
}
zv->zv_open_count++;
check_disk_change(bdev);
out_open_count:
if (zv->zv_open_count == 0)
zvol_last_close(zv);
out_mutex:
if (drop_mutex)
mutex_exit(&zvol_state_lock);
return (SET_ERROR(error));
}
static int
zvol_open(struct block_device *bdev, fmode_t flag)
{
zvol_state_t *zv = bdev->bd_disk->private_data;
int error = 0, drop_mutex = 0;
/*
* If the caller is already holding the mutex do not take it
* again, this will happen as part of zvol_create_minor().
* Once add_disk() is called the device is live and the kernel
* will attempt to open it to read the partition information.
*/
if (!mutex_owned(&zvol_state_lock)) {
mutex_enter(&zvol_state_lock);
drop_mutex = 1;
}
ASSERT3P(zv, !=, NULL);
if (zv->zv_open_count == 0) {
error = zvol_first_open(zv);
if (error)
goto out_mutex;
}
if ((flag & FMODE_WRITE) &&
(get_disk_ro(zv->zv_disk) || (zv->zv_flags & ZVOL_RDONLY))) {
error = -EROFS;
goto out_open_count;
}
zv->zv_open_count++;
out_open_count:
if (zv->zv_open_count == 0)
zvol_last_close(zv);
out_mutex:
if (drop_mutex)
mutex_exit(&zvol_state_lock);
check_disk_change(bdev);
return (error);
}
