#include <scsi/scsi_dh.h>
#include "../scsi_priv.h"
+struct scsi_dh_devinfo_list {
+ struct list_head node;
+ char vendor[9];
+ char model[17];
+ struct scsi_device_handler *handler;
+};
+
static DEFINE_SPINLOCK(list_lock);
static LIST_HEAD(scsi_dh_list);
+static LIST_HEAD(scsi_dh_dev_list);
static struct scsi_device_handler *get_device_handler(const char *name)
{
spin_lock(&list_lock);
list_for_each_entry(tmp, &scsi_dh_list, list) {
- if (!strcmp(tmp->name, name)) {
+ if (!strncmp(tmp->name, name, strlen(tmp->name))) {
found = tmp;
break;
}
return found;
}
+
+static struct scsi_device_handler *
+scsi_dh_cache_lookup(struct scsi_device *sdev)
+{
+ struct scsi_dh_devinfo_list *tmp;
+ struct scsi_device_handler *found_dh = NULL;
+
+ spin_lock(&list_lock);
+ list_for_each_entry(tmp, &scsi_dh_dev_list, node) {
+ if (!strncmp(sdev->vendor, tmp->vendor, strlen(tmp->vendor)) &&
+ !strncmp(sdev->model, tmp->model, strlen(tmp->model))) {
+ found_dh = tmp->handler;
+ break;
+ }
+ }
+ spin_unlock(&list_lock);
+
+ return found_dh;
+}
+
+static int scsi_dh_handler_lookup(struct scsi_device_handler *scsi_dh,
+ struct scsi_device *sdev)
+{
+ int i, found = 0;
+
+ for(i = 0; scsi_dh->devlist[i].vendor; i++) {
+ if (!strncmp(sdev->vendor, scsi_dh->devlist[i].vendor,
+ strlen(scsi_dh->devlist[i].vendor)) &&
+ !strncmp(sdev->model, scsi_dh->devlist[i].model,
+ strlen(scsi_dh->devlist[i].model))) {
+ found = 1;
+ break;
+ }
+ }
+ return found;
+}
+
+/*
+ * device_handler_match - Attach a device handler to a device
+ * @scsi_dh - The device handler to match against or NULL
+ * @sdev - SCSI device to be tested against @scsi_dh
+ *
+ * Tests @sdev against the device handler @scsi_dh or against
+ * all registered device_handler if @scsi_dh == NULL.
+ * Returns the found device handler or NULL if not found.
+ */
+static struct scsi_device_handler *
+device_handler_match(struct scsi_device_handler *scsi_dh,
+ struct scsi_device *sdev)
+{
+ struct scsi_device_handler *found_dh = NULL;
+ struct scsi_dh_devinfo_list *tmp;
+
+ found_dh = scsi_dh_cache_lookup(sdev);
+ if (found_dh)
+ return found_dh;
+
+ if (scsi_dh) {
+ if (scsi_dh_handler_lookup(scsi_dh, sdev))
+ found_dh = scsi_dh;
+ } else {
+ struct scsi_device_handler *tmp_dh;
+
+ spin_lock(&list_lock);
+ list_for_each_entry(tmp_dh, &scsi_dh_list, list) {
+ if (scsi_dh_handler_lookup(tmp_dh, sdev))
+ found_dh = tmp_dh;
+ }
+ spin_unlock(&list_lock);
+ }
+
+ if (found_dh) { /* If device is found, add it to the cache */
+ tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
+ if (tmp) {
+ strncpy(tmp->vendor, sdev->vendor, 8);
+ strncpy(tmp->model, sdev->model, 16);
+ tmp->vendor[8] = '\0';
+ tmp->model[16] = '\0';
+ tmp->handler = found_dh;
+ spin_lock(&list_lock);
+ list_add(&tmp->node, &scsi_dh_dev_list);
+ spin_unlock(&list_lock);
+ } else {
+ found_dh = NULL;
+ }
+ }
+
+ return found_dh;
+}
+
+/*
+ * scsi_dh_handler_attach - Attach a device handler to a device
+ * @sdev - SCSI device the device handler should attach to
+ * @scsi_dh - The device handler to attach
+ */
+static int scsi_dh_handler_attach(struct scsi_device *sdev,
+ struct scsi_device_handler *scsi_dh)
+{
+ int err = 0;
+
+ if (sdev->scsi_dh_data) {
+ if (sdev->scsi_dh_data->scsi_dh != scsi_dh)
+ err = -EBUSY;
+ } else if (scsi_dh->attach)
+ err = scsi_dh->attach(sdev);
+
+ return err;
+}
+
+/*
+ * scsi_dh_handler_detach - Detach a device handler from a device
+ * @sdev - SCSI device the device handler should be detached from
+ * @scsi_dh - Device handler to be detached
+ *
+ * Detach from a device handler. If a device handler is specified,
+ * only detach if the currently attached handler matches @scsi_dh.
+ */
+static void scsi_dh_handler_detach(struct scsi_device *sdev,
+ struct scsi_device_handler *scsi_dh)
+{
+ if (!sdev->scsi_dh_data)
+ return;
+
+ if (scsi_dh && scsi_dh != sdev->scsi_dh_data->scsi_dh)
+ return;
+
+ if (!scsi_dh)
+ scsi_dh = sdev->scsi_dh_data->scsi_dh;
+
+ if (scsi_dh && scsi_dh->detach)
+ scsi_dh->detach(sdev);
+}
+
+/*
+ * Functions for sysfs attribute 'dh_state'
+ */
+static ssize_t
+store_dh_state(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+ struct scsi_device_handler *scsi_dh;
+ int err = -EINVAL;
+
+ if (!sdev->scsi_dh_data) {
+ /*
+ * Attach to a device handler
+ */
+ if (!(scsi_dh = get_device_handler(buf)))
+ return err;
+ err = scsi_dh_handler_attach(sdev, scsi_dh);
+ } else {
+ scsi_dh = sdev->scsi_dh_data->scsi_dh;
+ if (!strncmp(buf, "detach", 6)) {
+ /*
+ * Detach from a device handler
+ */
+ scsi_dh_handler_detach(sdev, scsi_dh);
+ err = 0;
+ } else if (!strncmp(buf, "activate", 8)) {
+ /*
+ * Activate a device handler
+ */
+ if (scsi_dh->activate)
+ err = scsi_dh->activate(sdev);
+ else
+ err = 0;
+ }
+ }
+
+ return err<0?err:count;
+}
+
+static ssize_t
+show_dh_state(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct scsi_device *sdev = to_scsi_device(dev);
+
+ if (!sdev->scsi_dh_data)
+ return snprintf(buf, 20, "detached\n");
+
+ return snprintf(buf, 20, "%s\n", sdev->scsi_dh_data->scsi_dh->name);
+}
+
+static struct device_attribute scsi_dh_state_attr =
+ __ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state,
+ store_dh_state);
+
+/*
+ * scsi_dh_sysfs_attr_add - Callback for scsi_init_dh
+ */
+static int scsi_dh_sysfs_attr_add(struct device *dev, void *data)
+{
+ struct scsi_device *sdev;
+ int err;
+
+ if (!scsi_is_sdev_device(dev))
+ return 0;
+
+ sdev = to_scsi_device(dev);
+
+ err = device_create_file(&sdev->sdev_gendev,
+ &scsi_dh_state_attr);
+
+ return 0;
+}
+
+/*
+ * scsi_dh_sysfs_attr_remove - Callback for scsi_exit_dh
+ */
+static int scsi_dh_sysfs_attr_remove(struct device *dev, void *data)
+{
+ struct scsi_device *sdev;
+
+ if (!scsi_is_sdev_device(dev))
+ return 0;
+
+ sdev = to_scsi_device(dev);
+
+ device_remove_file(&sdev->sdev_gendev,
+ &scsi_dh_state_attr);
+
+ return 0;
+}
+
+/*
+ * scsi_dh_notifier - notifier chain callback
+ */
+static int scsi_dh_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct device *dev = data;
+ struct scsi_device *sdev;
+ int err = 0;
+ struct scsi_device_handler *devinfo = NULL;
+
+ if (!scsi_is_sdev_device(dev))
+ return 0;
+
+ sdev = to_scsi_device(dev);
+
+ if (action == BUS_NOTIFY_ADD_DEVICE) {
+ devinfo = device_handler_match(NULL, sdev);
+ if (!devinfo)
+ goto out;
+
+ err = scsi_dh_handler_attach(sdev, devinfo);
+ if (!err)
+ err = device_create_file(dev, &scsi_dh_state_attr);
+ } else if (action == BUS_NOTIFY_DEL_DEVICE) {
+ device_remove_file(dev, &scsi_dh_state_attr);
+ scsi_dh_handler_detach(sdev, NULL);
+ }
+out:
+ return err;
+}
+
+/*
+ * scsi_dh_notifier_add - Callback for scsi_register_device_handler
+ */
static int scsi_dh_notifier_add(struct device *dev, void *data)
{
struct scsi_device_handler *scsi_dh = data;
+ struct scsi_device *sdev;
+
+ if (!scsi_is_sdev_device(dev))
+ return 0;
+
+ if (!get_device(dev))
+ return 0;
+
+ sdev = to_scsi_device(dev);
+
+ if (device_handler_match(scsi_dh, sdev))
+ scsi_dh_handler_attach(sdev, scsi_dh);
+
+ put_device(dev);
+
+ return 0;
+}
+
+/*
+ * scsi_dh_notifier_remove - Callback for scsi_unregister_device_handler
+ */
+static int scsi_dh_notifier_remove(struct device *dev, void *data)
+{
+ struct scsi_device_handler *scsi_dh = data;
+ struct scsi_device *sdev;
+
+ if (!scsi_is_sdev_device(dev))
+ return 0;
+
+ if (!get_device(dev))
+ return 0;
+
+ sdev = to_scsi_device(dev);
+
+ scsi_dh_handler_detach(sdev, scsi_dh);
+
+ put_device(dev);
- scsi_dh->nb.notifier_call(&scsi_dh->nb, BUS_NOTIFY_ADD_DEVICE, dev);
return 0;
}
*/
int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
{
- int ret = -EBUSY;
- struct scsi_device_handler *tmp;
+ if (get_device_handler(scsi_dh->name))
+ return -EBUSY;
- tmp = get_device_handler(scsi_dh->name);
- if (tmp)
- goto done;
-
- ret = bus_register_notifier(&scsi_bus_type, &scsi_dh->nb);
-
- bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, scsi_dh_notifier_add);
spin_lock(&list_lock);
list_add(&scsi_dh->list, &scsi_dh_list);
spin_unlock(&list_lock);
+ bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, scsi_dh_notifier_add);
+ printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name);
-done:
- return ret;
+ return SCSI_DH_OK;
}
EXPORT_SYMBOL_GPL(scsi_register_device_handler);
-static int scsi_dh_notifier_remove(struct device *dev, void *data)
-{
- struct scsi_device_handler *scsi_dh = data;
-
- scsi_dh->nb.notifier_call(&scsi_dh->nb, BUS_NOTIFY_DEL_DEVICE, dev);
- return 0;
-}
-
/*
* scsi_unregister_device_handler - register a device handler personality
* module.
*/
int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
{
- int ret = -ENODEV;
- struct scsi_device_handler *tmp;
-
- tmp = get_device_handler(scsi_dh->name);
- if (!tmp)
- goto done;
+ struct scsi_dh_devinfo_list *tmp, *pos;
- ret = bus_unregister_notifier(&scsi_bus_type, &scsi_dh->nb);
+ if (!get_device_handler(scsi_dh->name))
+ return -ENODEV;
bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh,
- scsi_dh_notifier_remove);
+ scsi_dh_notifier_remove);
+
spin_lock(&list_lock);
list_del(&scsi_dh->list);
+ list_for_each_entry_safe(pos, tmp, &scsi_dh_dev_list, node) {
+ if (pos->handler == scsi_dh) {
+ list_del(&pos->node);
+ kfree(pos);
+ }
+ }
spin_unlock(&list_lock);
+ printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name);
-done:
- return ret;
+ return SCSI_DH_OK;
}
EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);
}
EXPORT_SYMBOL_GPL(scsi_dh_handler_exist);
+/*
+ * scsi_dh_handler_attach - Attach device handler
+ * @sdev - sdev the handler should be attached to
+ * @name - name of the handler to attach
+ */
+int scsi_dh_attach(struct request_queue *q, const char *name)
+{
+ unsigned long flags;
+ struct scsi_device *sdev;
+ struct scsi_device_handler *scsi_dh;
+ int err = 0;
+
+ scsi_dh = get_device_handler(name);
+ if (!scsi_dh)
+ return -EINVAL;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ sdev = q->queuedata;
+ if (!sdev || !get_device(&sdev->sdev_gendev))
+ err = -ENODEV;
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ if (!err) {
+ err = scsi_dh_handler_attach(sdev, scsi_dh);
+
+ put_device(&sdev->sdev_gendev);
+ }
+ return err;
+}
+EXPORT_SYMBOL_GPL(scsi_dh_attach);
+
+/*
+ * scsi_dh_handler_detach - Detach device handler
+ * @sdev - sdev the handler should be detached from
+ *
+ * This function will detach the device handler only
+ * if the sdev is not part of the internal list, ie
+ * if it has been attached manually.
+ */
+void scsi_dh_detach(struct request_queue *q)
+{
+ unsigned long flags;
+ struct scsi_device *sdev;
+ struct scsi_device_handler *scsi_dh = NULL;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ sdev = q->queuedata;
+ if (!sdev || !get_device(&sdev->sdev_gendev))
+ sdev = NULL;
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ if (!sdev)
+ return;
+
+ if (sdev->scsi_dh_data) {
+ /* if sdev is not on internal list, detach */
+ scsi_dh = sdev->scsi_dh_data->scsi_dh;
+ if (!device_handler_match(scsi_dh, sdev))
+ scsi_dh_handler_detach(sdev, scsi_dh);
+ }
+ put_device(&sdev->sdev_gendev);
+}
+EXPORT_SYMBOL_GPL(scsi_dh_detach);
+
+static struct notifier_block scsi_dh_nb = {
+ .notifier_call = scsi_dh_notifier
+};
+
+static int __init scsi_dh_init(void)
+{
+ int r;
+
+ r = bus_register_notifier(&scsi_bus_type, &scsi_dh_nb);
+
+ if (!r)
+ bus_for_each_dev(&scsi_bus_type, NULL, NULL,
+ scsi_dh_sysfs_attr_add);
+
+ return r;
+}
+
+static void __exit scsi_dh_exit(void)
+{
+ bus_for_each_dev(&scsi_bus_type, NULL, NULL,
+ scsi_dh_sysfs_attr_remove);
+ bus_unregister_notifier(&scsi_bus_type, &scsi_dh_nb);
+}
+
+module_init(scsi_dh_init);
+module_exit(scsi_dh_exit);
+
MODULE_DESCRIPTION("SCSI device handler");
MODULE_AUTHOR("Chandra Seetharaman <sekharan@us.ibm.com>");
MODULE_LICENSE("GPL");
projects / linux-2.6-omap-h63xx.git / blobdiff