From patchwork Wed Jul 8 08:30:20 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 6742711 Return-Path: X-Original-To: patchwork-linux-scsi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id A2625C05AD for ; Wed, 8 Jul 2015 08:31:12 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 55F2B207B7 for ; Wed, 8 Jul 2015 08:31:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B11C6207B2 for ; Wed, 8 Jul 2015 08:31:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933755AbbGHIbF (ORCPT ); Wed, 8 Jul 2015 04:31:05 -0400 Received: from cantor2.suse.de ([195.135.220.15]:33387 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935380AbbGHIaf (ORCPT ); Wed, 8 Jul 2015 04:30:35 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 3843BAAB2; Wed, 8 Jul 2015 08:30:28 +0000 (UTC) From: Hannes Reinecke To: James Bottomley Cc: Christoph Hellwig , linux-scsi@vger.kernel.org, "Martin K. Petersen" , Mike Snitzer , Hannes Reinecke Subject: [PATCH 03/10] scsi_dh: move to drivers/scsi Date: Wed, 8 Jul 2015 10:30:20 +0200 Message-Id: <1436344226-94765-4-git-send-email-hare@suse.de> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1436344226-94765-1-git-send-email-hare@suse.de> References: <1436344226-94765-1-git-send-email-hare@suse.de> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Christoph Hellwig Prepare for building scsi_dh.c into the core SCSI module by moving it to drivers/scsi. Signed-off-by: Christoph Hellwig Signed-off-by: Hannes Reinecke --- drivers/scsi/Makefile | 1 + drivers/scsi/device_handler/Makefile | 1 - drivers/scsi/device_handler/scsi_dh.c | 570 ---------------------------------- drivers/scsi/scsi_dh.c | 570 ++++++++++++++++++++++++++++++++++ 4 files changed, 571 insertions(+), 571 deletions(-) delete mode 100644 drivers/scsi/device_handler/scsi_dh.c create mode 100644 drivers/scsi/scsi_dh.c diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile index 91209e3..22f54b0 100644 --- a/drivers/scsi/Makefile +++ b/drivers/scsi/Makefile @@ -171,6 +171,7 @@ scsi_mod-$(CONFIG_SYSCTL) += scsi_sysctl.o scsi_mod-$(CONFIG_SCSI_PROC_FS) += scsi_proc.o scsi_mod-y += scsi_trace.o scsi_logging.o scsi_mod-$(CONFIG_PM) += scsi_pm.o +obj-$(CONFIG_SCSI_DH) += scsi_dh.o hv_storvsc-y := storvsc_drv.o diff --git a/drivers/scsi/device_handler/Makefile b/drivers/scsi/device_handler/Makefile index e1d2ea0..09866c5 100644 --- a/drivers/scsi/device_handler/Makefile +++ b/drivers/scsi/device_handler/Makefile @@ -1,7 +1,6 @@ # # SCSI Device Handler # -obj-$(CONFIG_SCSI_DH) += scsi_dh.o obj-$(CONFIG_SCSI_DH_RDAC) += scsi_dh_rdac.o obj-$(CONFIG_SCSI_DH_HP_SW) += scsi_dh_hp_sw.o obj-$(CONFIG_SCSI_DH_EMC) += scsi_dh_emc.o diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c deleted file mode 100644 index 5bd0af6..0000000 --- a/drivers/scsi/device_handler/scsi_dh.c +++ /dev/null @@ -1,570 +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 - * Mike Anderson - */ - -#include -#include -#include -#include "../scsi_priv.h" - -static DEFINE_SPINLOCK(list_lock); -static LIST_HEAD(scsi_dh_list); - -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(name); - dh = __scsi_dh_lookup(name); - } - - return dh; -} - -/* - * 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 (!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; - 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; -} - -/* - * 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) -{ - struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data; - struct scsi_device_handler *scsi_dh = scsi_dh_data->scsi_dh; - - 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); -} - -/* - * 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 = scsi_dh_lookup(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); - 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); - if (sdev->scsi_dh_data) - scsi_dh_handler_detach(sdev); - } - 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); - - if (sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh == scsi_dh) - scsi_dh_handler_detach(sdev); - - 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 (__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); - - 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 (!__scsi_dh_lookup(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_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 = scsi_dh_lookup(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) - return err; - - if (sdev->scsi_dh_data) { - if (sdev->scsi_dh_data->scsi_dh != 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) -{ - 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 "); -MODULE_LICENSE("GPL"); diff --git a/drivers/scsi/scsi_dh.c b/drivers/scsi/scsi_dh.c new file mode 100644 index 0000000..3c06c72 --- /dev/null +++ b/drivers/scsi/scsi_dh.c @@ -0,0 +1,570 @@ +/* + * 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 + * Mike Anderson + */ + +#include +#include +#include +#include "scsi_priv.h" + +static DEFINE_SPINLOCK(list_lock); +static LIST_HEAD(scsi_dh_list); + +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(name); + dh = __scsi_dh_lookup(name); + } + + return dh; +} + +/* + * 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 (!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; + 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; +} + +/* + * 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) +{ + struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data; + struct scsi_device_handler *scsi_dh = scsi_dh_data->scsi_dh; + + 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); +} + +/* + * 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 = scsi_dh_lookup(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); + 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); + if (sdev->scsi_dh_data) + scsi_dh_handler_detach(sdev); + } + 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); + + if (sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh == scsi_dh) + scsi_dh_handler_detach(sdev); + + 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 (__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); + + 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 (!__scsi_dh_lookup(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_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 = scsi_dh_lookup(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) + return err; + + if (sdev->scsi_dh_data) { + if (sdev->scsi_dh_data->scsi_dh != 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) +{ + 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 "); +MODULE_LICENSE("GPL");