diff options
Diffstat (limited to 'drivers/scsi/device_handler/scsi_dh.c')
| -rw-r--r-- | drivers/scsi/device_handler/scsi_dh.c | 621 |
1 files changed, 0 insertions, 621 deletions
diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c deleted file mode 100644 index 1efebc9eedfb..000000000000 --- a/drivers/scsi/device_handler/scsi_dh.c +++ /dev/null @@ -1,621 +0,0 @@ -/* - * SCSI device handler infrastruture. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License as published by the - * Free Software Foundation; either version 2 of the License, or (at your - * option) any later version. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License along - * with this program; if not, write to the Free Software Foundation, Inc., - * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - * - * Copyright IBM Corporation, 2007 - * Authors: - * Chandra Seetharaman <sekharan@us.ibm.com> - * Mike Anderson <andmike@linux.vnet.ibm.com> - */ - -#include <linux/slab.h> -#include <linux/module.h> -#include <scsi/scsi_dh.h> -#include "../scsi_priv.h" - -static DEFINE_SPINLOCK(list_lock); -static LIST_HEAD(scsi_dh_list); - -static struct scsi_device_handler *get_device_handler(const char *name) -{ - struct scsi_device_handler *tmp, *found = NULL; - - spin_lock(&list_lock); - list_for_each_entry(tmp, &scsi_dh_list, list) { - if (!strncmp(tmp->name, name, strlen(tmp->name))) { - found = tmp; - break; - } - } - spin_unlock(&list_lock); - return found; -} - -/* - * device_handler_match_function - Match a device handler to a device - * @sdev - SCSI device to be tested - * - * Tests @sdev against the match function of all registered device_handler. - * Returns the found device handler or NULL if not found. - */ -static struct scsi_device_handler * -device_handler_match_function(struct scsi_device *sdev) -{ - struct scsi_device_handler *tmp_dh, *found_dh = NULL; - - spin_lock(&list_lock); - list_for_each_entry(tmp_dh, &scsi_dh_list, list) { - if (tmp_dh->match && tmp_dh->match(sdev)) { - found_dh = tmp_dh; - break; - } - } - spin_unlock(&list_lock); - return found_dh; -} - -/* - * 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; - - found_dh = device_handler_match_function(sdev); - - if (scsi_dh && found_dh != scsi_dh) - 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) -{ - struct scsi_dh_data *d; - - if (sdev->scsi_dh_data) { - if (sdev->scsi_dh_data->scsi_dh != scsi_dh) - return -EBUSY; - - kref_get(&sdev->scsi_dh_data->kref); - return 0; - } - - if (!try_module_get(scsi_dh->module)) - return -EINVAL; - - d = scsi_dh->attach(sdev); - if (IS_ERR(d)) { - sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%ld)\n", - scsi_dh->name, PTR_ERR(d)); - module_put(scsi_dh->module); - return PTR_ERR(d); - } - - d->scsi_dh = scsi_dh; - kref_init(&d->kref); - d->sdev = sdev; - - spin_lock_irq(sdev->request_queue->queue_lock); - sdev->scsi_dh_data = d; - spin_unlock_irq(sdev->request_queue->queue_lock); - return 0; -} - -static void __detach_handler (struct kref *kref) -{ - struct scsi_dh_data *scsi_dh_data = - container_of(kref, struct scsi_dh_data, kref); - struct scsi_device_handler *scsi_dh = scsi_dh_data->scsi_dh; - struct scsi_device *sdev = scsi_dh_data->sdev; - - scsi_dh->detach(sdev); - - spin_lock_irq(sdev->request_queue->queue_lock); - sdev->scsi_dh_data = NULL; - spin_unlock_irq(sdev->request_queue->queue_lock); - - sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", scsi_dh->name); - module_put(scsi_dh->module); -} - -/* - * 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) - kref_put(&sdev->scsi_dh_data->kref, __detach_handler); -} - -/* - * 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->sdev_state == SDEV_CANCEL || - sdev->sdev_state == SDEV_DEL) - return -ENODEV; - - 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, NULL, NULL); - 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) { - err = device_create_file(dev, &scsi_dh_state_attr); - /* don't care about err */ - devinfo = device_handler_match(NULL, sdev); - if (devinfo) - err = scsi_dh_handler_attach(sdev, devinfo); - } else if (action == BUS_NOTIFY_DEL_DEVICE) { - device_remove_file(dev, &scsi_dh_state_attr); - scsi_dh_handler_detach(sdev, NULL); - } - 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); - - return 0; -} - -/* - * scsi_register_device_handler - register a device handler personality - * module. - * @scsi_dh - device handler to be registered. - * - * Returns 0 on success, -EBUSY if handler already registered. - */ -int scsi_register_device_handler(struct scsi_device_handler *scsi_dh) -{ - - if (get_device_handler(scsi_dh->name)) - return -EBUSY; - - if (!scsi_dh->attach || !scsi_dh->detach) - return -EINVAL; - - 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); - - return SCSI_DH_OK; -} -EXPORT_SYMBOL_GPL(scsi_register_device_handler); - -/* - * scsi_unregister_device_handler - register a device handler personality - * module. - * @scsi_dh - device handler to be unregistered. - * - * Returns 0 on success, -ENODEV if handler not registered. - */ -int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh) -{ - - if (!get_device_handler(scsi_dh->name)) - return -ENODEV; - - bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, - scsi_dh_notifier_remove); - - spin_lock(&list_lock); - list_del(&scsi_dh->list); - spin_unlock(&list_lock); - printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name); - - return SCSI_DH_OK; -} -EXPORT_SYMBOL_GPL(scsi_unregister_device_handler); - -/* - * scsi_dh_activate - activate the path associated with the scsi_device - * corresponding to the given request queue. - * Returns immediately without waiting for activation to be completed. - * @q - Request queue that is associated with the scsi_device to be - * activated. - * @fn - Function to be called upon completion of the activation. - * Function fn is called with data (below) and the error code. - * Function fn may be called from the same calling context. So, - * do not hold the lock in the caller which may be needed in fn. - * @data - data passed to the function fn upon completion. - * - */ -int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data) -{ - int err = 0; - unsigned long flags; - struct scsi_device *sdev; - struct scsi_device_handler *scsi_dh = NULL; - struct device *dev = NULL; - - spin_lock_irqsave(q->queue_lock, flags); - sdev = q->queuedata; - if (!sdev) { - spin_unlock_irqrestore(q->queue_lock, flags); - err = SCSI_DH_NOSYS; - if (fn) - fn(data, err); - return err; - } - - if (sdev->scsi_dh_data) - scsi_dh = sdev->scsi_dh_data->scsi_dh; - dev = get_device(&sdev->sdev_gendev); - if (!scsi_dh || !dev || - sdev->sdev_state == SDEV_CANCEL || - sdev->sdev_state == SDEV_DEL) - err = SCSI_DH_NOSYS; - if (sdev->sdev_state == SDEV_OFFLINE) - err = SCSI_DH_DEV_OFFLINED; - spin_unlock_irqrestore(q->queue_lock, flags); - - if (err) { - if (fn) - fn(data, err); - goto out; - } - - if (scsi_dh->activate) - err = scsi_dh->activate(sdev, fn, data); -out: - put_device(dev); - return err; -} -EXPORT_SYMBOL_GPL(scsi_dh_activate); - -/* - * scsi_dh_set_params - set the parameters for the device as per the - * string specified in params. - * @q - Request queue that is associated with the scsi_device for - * which the parameters to be set. - * @params - parameters in the following format - * "no_of_params\0param1\0param2\0param3\0...\0" - * for example, string for 2 parameters with value 10 and 21 - * is specified as "2\010\021\0". - */ -int scsi_dh_set_params(struct request_queue *q, const char *params) -{ - int err = -SCSI_DH_NOSYS; - 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 && sdev->scsi_dh_data) - scsi_dh = sdev->scsi_dh_data->scsi_dh; - if (scsi_dh && scsi_dh->set_params && get_device(&sdev->sdev_gendev)) - err = 0; - spin_unlock_irqrestore(q->queue_lock, flags); - - if (err) - return err; - err = scsi_dh->set_params(sdev, params); - put_device(&sdev->sdev_gendev); - return err; -} -EXPORT_SYMBOL_GPL(scsi_dh_set_params); - -/* - * scsi_dh_handler_exist - Return TRUE(1) if a device handler exists for - * the given name. FALSE(0) otherwise. - * @name - name of the device handler. - */ -int scsi_dh_handler_exist(const char *name) -{ - return (get_device_handler(name) != NULL); -} -EXPORT_SYMBOL_GPL(scsi_dh_handler_exist); - -/* - * scsi_dh_attach - Attach device handler - * @q - Request queue that is associated with the scsi_device - * 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_detach - Detach device handler - * @q - Request queue that is associated with the scsi_device - * 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) { - scsi_dh = sdev->scsi_dh_data->scsi_dh; - scsi_dh_handler_detach(sdev, scsi_dh); - } - put_device(&sdev->sdev_gendev); -} -EXPORT_SYMBOL_GPL(scsi_dh_detach); - -/* - * scsi_dh_attached_handler_name - Get attached device handler's name - * @q - Request queue that is associated with the scsi_device - * that may have a device handler attached - * @gfp - the GFP mask used in the kmalloc() call when allocating memory - * - * Returns name of attached handler, NULL if no handler is attached. - * Caller must take care to free the returned string. - */ -const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp) -{ - unsigned long flags; - struct scsi_device *sdev; - const char *handler_name = 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 NULL; - - if (sdev->scsi_dh_data) - handler_name = kstrdup(sdev->scsi_dh_data->scsi_dh->name, gfp); - - put_device(&sdev->sdev_gendev); - return handler_name; -} -EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name); - -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"); |