static void backend_changed(struct xenbus_watch *watch,
const char **vec, unsigned int len)
{
int err;
long instance;
struct backend_info *be
= container_of(watch, struct backend_info, backend_watch);
struct xenbus_device *dev = be->dev;
err = xenbus_scanf(XBT_NULL, dev->nodename,
"instance","%li", &instance);
if (XENBUS_EXIST_ERR(err)) {
return;
}
if (err != 1) {
xenbus_dev_fatal(dev, err, "reading instance");
return;
}
if (be->is_instance_set == 0) {
be->instance = instance;
be->is_instance_set = 1;
}
}
/**
* Callback received when the hotplug scripts have placed the handle node.
* Read it, and create a netif structure. If the frontend is ready, connect.
*/
static void backend_changed(struct xenbus_watch *watch,
const char **vec, unsigned int len)
{
int err;
long handle;
struct backend_info *be
= container_of(watch, struct backend_info, backend_watch);
struct xenbus_device *dev = be->dev;
DPRINTK("");
err = xenbus_scanf(XBT_NULL, dev->nodename, "handle", "%li", &handle);
if (XENBUS_EXIST_ERR(err)) {
/* Since this watch will fire once immediately after it is
registered, we expect this. Ignore it, and wait for the
hotplug scripts. */
return;
}
if (err != 1) {
xenbus_dev_fatal(dev, err, "reading handle");
return;
}
if (be->netif == NULL) {
u8 be_mac[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 };
be->netif = netif_alloc(dev->otherend_id, handle, be_mac);
if (IS_ERR(be->netif)) {
err = PTR_ERR(be->netif);
be->netif = NULL;
xenbus_dev_fatal(dev, err, "creating interface");
return;
}
kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
maybe_connect(be);
}
}
/*
* Callback received when the hotplug scripts have placed the physical-device
* node. Read it and the mode node, and create a vbd. If the frontend is
* ready, connect.
*/
static void backend_changed(struct xenbus_watch *watch,
const char **vec, unsigned int len)
{
int err;
unsigned major;
unsigned minor;
struct backend_info *be
= container_of(watch, struct backend_info, backend_watch);
struct xenbus_device *dev = be->dev;
int cdrom = 0;
unsigned long handle;
char *device_type;
DPRINTK("");
err = xenbus_scanf(XBT_NIL, dev->nodename, "physical-device", "%x:%x",
&major, &minor);
if (XENBUS_EXIST_ERR(err)) {
/*
* Since this watch will fire once immediately after it is
* registered, we expect this. Ignore it, and wait for the
* hotplug scripts.
*/
return;
}
if (err != 2) {
xenbus_dev_fatal(dev, err, "reading physical-device");
return;
}
if (be->major | be->minor) {
if (be->major != major || be->minor != minor)
pr_warn(DRV_PFX "changing physical device (from %x:%x to %x:%x) not supported.\n",
be->major, be->minor, major, minor);
return;
}
be->mode = xenbus_read(XBT_NIL, dev->nodename, "mode", NULL);
if (IS_ERR(be->mode)) {
err = PTR_ERR(be->mode);
be->mode = NULL;
xenbus_dev_fatal(dev, err, "reading mode");
return;
}
device_type = xenbus_read(XBT_NIL, dev->otherend, "device-type", NULL);
if (!IS_ERR(device_type)) {
cdrom = strcmp(device_type, "cdrom") == 0;
kfree(device_type);
}
/* Front end dir is a number, which is used as the handle. */
err = strict_strtoul(strrchr(dev->otherend, '/') + 1, 0, &handle);
if (err)
return;
be->major = major;
be->minor = minor;
err = xen_vbd_create(be->blkif, handle, major, minor,
!strchr(be->mode, 'w'), cdrom);
if (err)
xenbus_dev_fatal(dev, err, "creating vbd structure");
else {
err = xenvbd_sysfs_addif(dev);
if (err) {
xen_vbd_free(&be->blkif->vbd);
xenbus_dev_fatal(dev, err, "creating sysfs entries");
}
}
if (err) {
kfree(be->mode);
be->mode = NULL;
be->major = 0;
be->minor = 0;
} else {
/* We're potentially connected now */
xen_update_blkif_status(be->blkif);
}
}
/**
* Callback received when the hotplug scripts have placed the physical-device
* node. Read it and the mode node, and create a vbd. If the frontend is
* ready, connect.
*/
static void backend_changed(struct xenbus_watch *watch,
const char **vec, unsigned int len)
{
int err;
unsigned major;
unsigned minor;
struct backend_info *be
= container_of(watch, struct backend_info, backend_watch);
struct xenbus_device *dev = be->dev;
DPRINTK("");
err = xenbus_scanf(XBT_NULL, dev->nodename, "physical-device", "%x:%x",
&major, &minor);
if (XENBUS_EXIST_ERR(err)) {
/* Since this watch will fire once immediately after it is
registered, we expect this. Ignore it, and wait for the
hotplug scripts. */
return;
}
if (err != 2) {
xenbus_dev_fatal(dev, err, "reading physical-device");
return;
}
if ((be->major || be->minor) &&
((be->major != major) || (be->minor != minor))) {
printk(KERN_WARNING
"blkback: changing physical device (from %x:%x to "
"%x:%x) not supported.\n", be->major, be->minor,
major, minor);
return;
}
be->mode = xenbus_read(XBT_NULL, dev->nodename, "mode", NULL);
if (IS_ERR(be->mode)) {
err = PTR_ERR(be->mode);
be->mode = NULL;
xenbus_dev_fatal(dev, err, "reading mode");
return;
}
if (be->major == 0 && be->minor == 0) {
/* Front end dir is a number, which is used as the handle. */
char *p = strrchr(dev->otherend, '/') + 1;
long handle = simple_strtoul(p, NULL, 0);
be->major = major;
be->minor = minor;
err = vbd_create(be->blkif, handle, major, minor,
(NULL == strchr(be->mode, 'w')));
if (err) {
be->major = 0;
be->minor = 0;
xenbus_dev_fatal(dev, err, "creating vbd structure");
return;
}
device_create_file(&dev->dev, &dev_attr_physical_device);
device_create_file(&dev->dev, &dev_attr_mode);
/* We're potentially connected now */
update_blkif_status(be->blkif);
}
}
static void scsifront_free(struct vscsifrnt_info *info)
{
struct Scsi_Host *host = info->host;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,14)
if (host->shost_state != SHOST_DEL) {
#else
if (!test_bit(SHOST_DEL, &host->shost_state)) {
#endif
scsi_remove_host(info->host);
}
if (info->ring_ref != GRANT_INVALID_REF) {
gnttab_end_foreign_access(info->ring_ref,
(unsigned long)info->ring.sring);
info->ring_ref = GRANT_INVALID_REF;
info->ring.sring = NULL;
}
if (info->irq)
unbind_from_irqhandler(info->irq, info);
info->irq = 0;
scsi_host_put(info->host);
}
static int scsifront_alloc_ring(struct vscsifrnt_info *info)
{
struct xenbus_device *dev = info->dev;
struct vscsiif_sring *sring;
int err = -ENOMEM;
info->ring_ref = GRANT_INVALID_REF;
/***** Frontend to Backend ring start *****/
sring = (struct vscsiif_sring *) __get_free_page(GFP_KERNEL);
if (!sring) {
xenbus_dev_fatal(dev, err, "fail to allocate shared ring (Front to Back)");
return err;
}
SHARED_RING_INIT(sring);
FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
err = xenbus_grant_ring(dev, virt_to_mfn(sring));
if (err < 0) {
free_page((unsigned long) sring);
info->ring.sring = NULL;
xenbus_dev_fatal(dev, err, "fail to grant shared ring (Front to Back)");
goto free_sring;
}
info->ring_ref = err;
err = bind_listening_port_to_irqhandler(
dev->otherend_id, scsifront_intr,
SA_SAMPLE_RANDOM, "scsifront", info);
if (err <= 0) {
xenbus_dev_fatal(dev, err, "bind_listening_port_to_irqhandler");
goto free_sring;
}
info->irq = err;
return 0;
/* free resource */
free_sring:
scsifront_free(info);
return err;
}
static int scsifront_init_ring(struct vscsifrnt_info *info)
{
struct xenbus_device *dev = info->dev;
struct xenbus_transaction xbt;
int err;
DPRINTK("%s\n",__FUNCTION__);
err = scsifront_alloc_ring(info);
if (err)
return err;
DPRINTK("%u %u\n", info->ring_ref, info->evtchn);
again:
err = xenbus_transaction_start(&xbt);
if (err) {
xenbus_dev_fatal(dev, err, "starting transaction");
}
err = xenbus_printf(xbt, dev->nodename, "ring-ref", "%u",
info->ring_ref);
if (err) {
xenbus_dev_fatal(dev, err, "%s", "writing ring-ref");
goto fail;
}
err = xenbus_printf(xbt, dev->nodename, "event-channel", "%u",
irq_to_evtchn_port(info->irq));
if (err) {
xenbus_dev_fatal(dev, err, "%s", "writing event-channel");
goto fail;
}
err = xenbus_transaction_end(xbt, 0);
if (err) {
if (err == -EAGAIN)
goto again;
xenbus_dev_fatal(dev, err, "completing transaction");
goto free_sring;
}
return 0;
fail:
xenbus_transaction_end(xbt, 1);
free_sring:
/* free resource */
scsifront_free(info);
return err;
}
static int scsifront_probe(struct xenbus_device *dev,
const struct xenbus_device_id *id)
{
struct vscsifrnt_info *info;
struct Scsi_Host *host;
int i, err = -ENOMEM;
char name[DEFAULT_TASK_COMM_LEN];
host = scsi_host_alloc(&scsifront_sht, sizeof(*info));
if (!host) {
xenbus_dev_fatal(dev, err, "fail to allocate scsi host");
return err;
}
info = (struct vscsifrnt_info *) host->hostdata;
info->host = host;
dev->dev.driver_data = info;
info->dev = dev;
for (i = 0; i < VSCSIIF_MAX_REQS; i++) {
info->shadow[i].next_free = i + 1;
init_waitqueue_head(&(info->shadow[i].wq_reset));
info->shadow[i].wait_reset = 0;
}
info->shadow[VSCSIIF_MAX_REQS - 1].next_free = 0x0fff;
err = scsifront_init_ring(info);
if (err) {
scsi_host_put(host);
return err;
}
init_waitqueue_head(&info->wq);
spin_lock_init(&info->io_lock);
spin_lock_init(&info->shadow_lock);
snprintf(name, DEFAULT_TASK_COMM_LEN, "vscsiif.%d", info->host->host_no);
info->kthread = kthread_run(scsifront_schedule, info, name);
if (IS_ERR(info->kthread)) {
err = PTR_ERR(info->kthread);
info->kthread = NULL;
printk(KERN_ERR "scsifront: kthread start err %d\n", err);
goto free_sring;
}
host->max_id = VSCSIIF_MAX_TARGET;
host->max_channel = 0;
host->max_lun = VSCSIIF_MAX_LUN;
host->max_sectors = (VSCSIIF_SG_TABLESIZE - 1) * PAGE_SIZE / 512;
err = scsi_add_host(host, &dev->dev);
if (err) {
printk(KERN_ERR "scsifront: fail to add scsi host %d\n", err);
goto free_sring;
}
xenbus_switch_state(dev, XenbusStateInitialised);
return 0;
free_sring:
/* free resource */
scsifront_free(info);
return err;
}
static int scsifront_remove(struct xenbus_device *dev)
{
struct vscsifrnt_info *info = dev->dev.driver_data;
DPRINTK("%s: %s removed\n",__FUNCTION__ ,dev->nodename);
if (info->kthread) {
kthread_stop(info->kthread);
info->kthread = NULL;
}
scsifront_free(info);
return 0;
}
static int scsifront_disconnect(struct vscsifrnt_info *info)
{
struct xenbus_device *dev = info->dev;
struct Scsi_Host *host = info->host;
DPRINTK("%s: %s disconnect\n",__FUNCTION__ ,dev->nodename);
/*
When this function is executed, all devices of
Frontend have been deleted.
Therefore, it need not block I/O before remove_host.
*/
scsi_remove_host(host);
xenbus_frontend_closed(dev);
return 0;
}
#define VSCSIFRONT_OP_ADD_LUN 1
#define VSCSIFRONT_OP_DEL_LUN 2
static void scsifront_do_lun_hotplug(struct vscsifrnt_info *info, int op)
{
struct xenbus_device *dev = info->dev;
int i, err = 0;
char str[64], state_str[64];
char **dir;
unsigned int dir_n = 0;
unsigned int device_state;
unsigned int hst, chn, tgt, lun;
struct scsi_device *sdev;
dir = xenbus_directory(XBT_NIL, dev->otherend, "vscsi-devs", &dir_n);
if (IS_ERR(dir))
return;
for (i = 0; i < dir_n; i++) {
/* read status */
snprintf(str, sizeof(str), "vscsi-devs/%s/state", dir[i]);
err = xenbus_scanf(XBT_NIL, dev->otherend, str, "%u",
&device_state);
if (XENBUS_EXIST_ERR(err))
continue;
/* virtual SCSI device */
snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", dir[i]);
err = xenbus_scanf(XBT_NIL, dev->otherend, str,
"%u:%u:%u:%u", &hst, &chn, &tgt, &lun);
if (XENBUS_EXIST_ERR(err))
continue;
/* front device state path */
snprintf(state_str, sizeof(state_str), "vscsi-devs/%s/state", dir[i]);
switch (op) {
case VSCSIFRONT_OP_ADD_LUN:
if (device_state == XenbusStateInitialised) {
sdev = scsi_device_lookup(info->host, chn, tgt, lun);
if (sdev) {
printk(KERN_ERR "scsifront: Device already in use.\n");
scsi_device_put(sdev);
xenbus_printf(XBT_NIL, dev->nodename,
state_str, "%d", XenbusStateClosed);
} else {
scsi_add_device(info->host, chn, tgt, lun);
xenbus_printf(XBT_NIL, dev->nodename,
state_str, "%d", XenbusStateConnected);
}
}
break;
case VSCSIFRONT_OP_DEL_LUN:
if (device_state == XenbusStateClosing) {
sdev = scsi_device_lookup(info->host, chn, tgt, lun);
if (sdev) {
scsi_remove_device(sdev);
scsi_device_put(sdev);
xenbus_printf(XBT_NIL, dev->nodename,
state_str, "%d", XenbusStateClosed);
}
}
break;
default:
break;
}
}
kfree(dir);
return;
}
static void scsifront_backend_changed(struct xenbus_device *dev,
enum xenbus_state backend_state)
{
struct vscsifrnt_info *info = dev->dev.driver_data;
DPRINTK("%p %u %u\n", dev, dev->state, backend_state);
switch (backend_state) {
case XenbusStateUnknown:
case XenbusStateInitialising:
case XenbusStateInitWait:
case XenbusStateClosed:
break;
case XenbusStateInitialised:
break;
case XenbusStateConnected:
if (xenbus_read_driver_state(dev->nodename) ==
XenbusStateInitialised) {
scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_ADD_LUN);
}
if (dev->state == XenbusStateConnected)
break;
xenbus_switch_state(dev, XenbusStateConnected);
break;
case XenbusStateClosing:
scsifront_disconnect(info);
break;
case XenbusStateReconfiguring:
scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_DEL_LUN);
xenbus_switch_state(dev, XenbusStateReconfiguring);
break;
case XenbusStateReconfigured:
scsifront_do_lun_hotplug(info, VSCSIFRONT_OP_ADD_LUN);
xenbus_switch_state(dev, XenbusStateConnected);
break;
}
}
static struct xenbus_device_id scsifront_ids[] = {
{ "vscsi" },
{ "" }
};
MODULE_ALIAS("xen:vscsi");
static struct xenbus_driver scsifront_driver = {
.name = "vscsi",
.owner = THIS_MODULE,
.ids = scsifront_ids,
.probe = scsifront_probe,
.remove = scsifront_remove,
/* .resume = scsifront_resume, */
.otherend_changed = scsifront_backend_changed,
};
int scsifront_xenbus_init(void)
{
return xenbus_register_frontend(&scsifront_driver);
}
void scsifront_xenbus_unregister(void)
{
xenbus_unregister_driver(&scsifront_driver);
}