--- /dev/null
+/*
+ * 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);
+
+struct scsi_dh_blist {
+ const char *vendor;
+ const char *model;
+ const char *driver;
+};
+
+static const struct scsi_dh_blist scsi_dh_blist[] = {
+ {"DGC", "RAID", "clariion" },
+ {"DGC", "DISK", "clariion" },
+ {"DGC", "VRAID", "clariion" },
+
+ {"COMPAQ", "MSA1000 VOLUME", "hp_sw" },
+ {"COMPAQ", "HSV110", "hp_sw" },
+ {"HP", "HSV100", "hp_sw"},
+ {"DEC", "HSG80", "hp_sw"},
+
+ {"IBM", "1722", "rdac", },
+ {"IBM", "1724", "rdac", },
+ {"IBM", "1726", "rdac", },
+ {"IBM", "1742", "rdac", },
+ {"IBM", "1745", "rdac", },
+ {"IBM", "1746", "rdac", },
+ {"IBM", "1813", "rdac", },
+ {"IBM", "1814", "rdac", },
+ {"IBM", "1815", "rdac", },
+ {"IBM", "1818", "rdac", },
+ {"IBM", "3526", "rdac", },
+ {"SGI", "TP9", "rdac", },
+ {"SGI", "IS", "rdac", },
+ {"STK", "OPENstorage D280", "rdac", },
+ {"STK", "FLEXLINE 380", "rdac", },
+ {"SUN", "CSM", "rdac", },
+ {"SUN", "LCSM100", "rdac", },
+ {"SUN", "STK6580_6780", "rdac", },
+ {"SUN", "SUN_6180", "rdac", },
+ {"SUN", "ArrayStorage", "rdac", },
+ {"DELL", "MD3", "rdac", },
+ {"NETAPP", "INF-01-00", "rdac", },
+ {"LSI", "INF-01-00", "rdac", },
+ {"ENGENIO", "INF-01-00", "rdac", },
+ {NULL, NULL, NULL },
+};
+
+static const char *
+scsi_dh_find_driver(struct scsi_device *sdev)
+{
+ const struct scsi_dh_blist *b;
+
+ if (scsi_device_tpgs(sdev))
+ return "alua";
+
+ for (b = scsi_dh_blist; b->vendor; b++) {
+ if (!strncmp(sdev->vendor, b->vendor, strlen(b->vendor)) &&
+ !strncmp(sdev->model, b->model, strlen(b->model))) {
+ return b->driver;
+ }
+ }
+ return NULL;
+}
+
+
+static struct scsi_device_handler *__scsi_dh_lookup(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;
+}
+
+static struct scsi_device_handler *scsi_dh_lookup(const char *name)
+{
+ struct scsi_device_handler *dh;
+
+ dh = __scsi_dh_lookup(name);
+ if (!dh) {
+ request_module("scsi_dh_%s", name);
+ dh = __scsi_dh_lookup(name);
+ }
+
+ return 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 error;
+
+ if (!try_module_get(scsi_dh->module))
+ return -EINVAL;
+
+ error = scsi_dh->attach(sdev);
+ if (error) {
+ sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n",
+ scsi_dh->name, error);
+ module_put(scsi_dh->module);
+ } else
+ sdev->handler = scsi_dh;
+
+ return error;
+}
+
+/*
+ * scsi_dh_handler_detach - Detach a device handler from a device
+ * @sdev - SCSI device the device handler should be detached from
+ */
+static void scsi_dh_handler_detach(struct scsi_device *sdev)
+{
+ sdev->handler->detach(sdev);
+ sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", sdev->handler->name);
+ module_put(sdev->handler->module);
+}
+
+/*
+ * 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->handler) {
+ /*
+ * Attach to a device handler
+ */
+ scsi_dh = scsi_dh_lookup(buf);
+ if (!scsi_dh)
+ return err;
+ err = scsi_dh_handler_attach(sdev, scsi_dh);
+ } else {
+ if (!strncmp(buf, "detach", 6)) {
+ /*
+ * Detach from a device handler
+ */
+ sdev_printk(KERN_WARNING, sdev,
+ "can't detach handler %s.\n",
+ sdev->handler->name);
+ err = -EINVAL;
+ } else if (!strncmp(buf, "activate", 8)) {
+ /*
+ * Activate a device handler
+ */
+ if (sdev->handler->activate)
+ err = sdev->handler->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->handler)
+ return snprintf(buf, 20, "detached\n");
+
+ return snprintf(buf, 20, "%s\n", sdev->handler->name);
+}
+
+static struct device_attribute scsi_dh_state_attr =
+ __ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state,
+ store_dh_state);
+
+int scsi_dh_add_device(struct scsi_device *sdev)
+{
+ struct scsi_device_handler *devinfo = NULL;
+ const char *drv;
+ int err;
+
+ err = device_create_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
+ if (err)
+ return err;
+
+ drv = scsi_dh_find_driver(sdev);
+ if (drv)
+ devinfo = __scsi_dh_lookup(drv);
+ if (devinfo)
+ err = scsi_dh_handler_attach(sdev, devinfo);
+ return err;
+}
+
+void scsi_dh_release_device(struct scsi_device *sdev)
+{
+ if (sdev->handler)
+ scsi_dh_handler_detach(sdev);
+}
+
+void scsi_dh_remove_device(struct scsi_device *sdev)
+{
+ device_remove_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
+}
+
+/*
+ * 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 (__scsi_dh_lookup(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);
+
+ 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 (!__scsi_dh_lookup(scsi_dh->name))
+ return -ENODEV;
+
+ 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);
+
+static struct scsi_device *get_sdev_from_queue(struct request_queue *q)
+{
+ struct scsi_device *sdev;
+ unsigned long flags;
+
+ 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);
+
+ return sdev;
+}
+
+/*
+ * 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)
+{
+ struct scsi_device *sdev;
+ int err = SCSI_DH_NOSYS;
+
+ sdev = get_sdev_from_queue(q);
+ if (!sdev) {
+ if (fn)
+ fn(data, err);
+ return err;
+ }
+
+ if (!sdev->handler)
+ goto out_fn;
+ err = SCSI_DH_NOTCONN;
+ if (sdev->sdev_state == SDEV_CANCEL ||
+ sdev->sdev_state == SDEV_DEL)
+ goto out_fn;
+
+ err = SCSI_DH_DEV_OFFLINED;
+ if (sdev->sdev_state == SDEV_OFFLINE)
+ goto out_fn;
+
+ if (sdev->handler->activate)
+ err = sdev->handler->activate(sdev, fn, data);
+
+out_put_device:
+ put_device(&sdev->sdev_gendev);
+ return err;
+
+out_fn:
+ if (fn)
+ fn(data, err);
+ goto out_put_device;
+}
+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)
+{
+ struct scsi_device *sdev;
+ int err = -SCSI_DH_NOSYS;
+
+ sdev = get_sdev_from_queue(q);
+ if (!sdev)
+ return err;
+
+ if (sdev->handler && sdev->handler->set_params)
+ err = sdev->handler->set_params(sdev, params);
+ put_device(&sdev->sdev_gendev);
+ return err;
+}
+EXPORT_SYMBOL_GPL(scsi_dh_set_params);
+
+/*
+ * 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)
+{
+ struct scsi_device *sdev;
+ struct scsi_device_handler *scsi_dh;
+ int err = 0;
+
+ sdev = get_sdev_from_queue(q);
+ if (!sdev)
+ return -ENODEV;
+
+ scsi_dh = scsi_dh_lookup(name);
+ if (!scsi_dh) {
+ err = -EINVAL;
+ goto out_put_device;
+ }
+
+ if (sdev->handler) {
+ if (sdev->handler != scsi_dh)
+ err = -EBUSY;
+ goto out_put_device;
+ }
+
+ err = scsi_dh_handler_attach(sdev, scsi_dh);
+
+out_put_device:
+ put_device(&sdev->sdev_gendev);
+ return err;
+}
+EXPORT_SYMBOL_GPL(scsi_dh_attach);
+
+/*
+ * 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)
+{
+ struct scsi_device *sdev;
+ const char *handler_name = NULL;
+
+ sdev = get_sdev_from_queue(q);
+ if (!sdev)
+ return NULL;
+
+ if (sdev->handler)
+ handler_name = kstrdup(sdev->handler->name, gfp);
+ put_device(&sdev->sdev_gendev);
+ return handler_name;
+}
+EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name);
Code Review / kvmfornfv.git / blobdiff