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scsi_dh: move to drivers/scsi
Prepare for building scsi_dh.c into the core SCSI module by moving it to drivers/scsi. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Odin.com>
This commit is contained in:
Christoph Hellwig
committed by
James Bottomley
James Bottomley
parent
566079c849
commit
daaa858b7a
@@ -1,571 +0,0 @@
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/*
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* SCSI device handler infrastruture.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* Copyright IBM Corporation, 2007
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* Authors:
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* Chandra Seetharaman <sekharan@us.ibm.com>
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* Mike Anderson <andmike@linux.vnet.ibm.com>
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*/
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <scsi/scsi_dh.h>
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#include "../scsi_priv.h"
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static DEFINE_SPINLOCK(list_lock);
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static LIST_HEAD(scsi_dh_list);
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static struct scsi_device_handler *__scsi_dh_lookup(const char *name)
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{
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struct scsi_device_handler *tmp, *found = NULL;
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spin_lock(&list_lock);
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list_for_each_entry(tmp, &scsi_dh_list, list) {
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if (!strncmp(tmp->name, name, strlen(tmp->name))) {
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found = tmp;
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break;
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}
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}
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spin_unlock(&list_lock);
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return found;
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}
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static struct scsi_device_handler *scsi_dh_lookup(const char *name)
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{
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struct scsi_device_handler *dh;
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dh = __scsi_dh_lookup(name);
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if (!dh) {
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request_module(name);
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dh = __scsi_dh_lookup(name);
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}
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return dh;
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}
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/*
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* device_handler_match_function - Match a device handler to a device
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* @sdev - SCSI device to be tested
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*
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* Tests @sdev against the match function of all registered device_handler.
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* Returns the found device handler or NULL if not found.
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*/
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static struct scsi_device_handler *
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device_handler_match_function(struct scsi_device *sdev)
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{
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struct scsi_device_handler *tmp_dh, *found_dh = NULL;
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spin_lock(&list_lock);
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list_for_each_entry(tmp_dh, &scsi_dh_list, list) {
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if (tmp_dh->match && tmp_dh->match(sdev)) {
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found_dh = tmp_dh;
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break;
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}
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}
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spin_unlock(&list_lock);
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return found_dh;
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}
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/*
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* device_handler_match - Attach a device handler to a device
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* @scsi_dh - The device handler to match against or NULL
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* @sdev - SCSI device to be tested against @scsi_dh
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*
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* Tests @sdev against the device handler @scsi_dh or against
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* all registered device_handler if @scsi_dh == NULL.
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* Returns the found device handler or NULL if not found.
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*/
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static struct scsi_device_handler *
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device_handler_match(struct scsi_device_handler *scsi_dh,
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struct scsi_device *sdev)
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{
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struct scsi_device_handler *found_dh;
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found_dh = device_handler_match_function(sdev);
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if (scsi_dh && found_dh != scsi_dh)
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found_dh = NULL;
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return found_dh;
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}
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/*
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* scsi_dh_handler_attach - Attach a device handler to a device
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* @sdev - SCSI device the device handler should attach to
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* @scsi_dh - The device handler to attach
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*/
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static int scsi_dh_handler_attach(struct scsi_device *sdev,
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struct scsi_device_handler *scsi_dh)
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{
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struct scsi_dh_data *d;
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if (!try_module_get(scsi_dh->module))
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return -EINVAL;
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d = scsi_dh->attach(sdev);
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if (IS_ERR(d)) {
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sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%ld)\n",
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scsi_dh->name, PTR_ERR(d));
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module_put(scsi_dh->module);
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return PTR_ERR(d);
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}
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d->scsi_dh = scsi_dh;
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d->sdev = sdev;
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spin_lock_irq(sdev->request_queue->queue_lock);
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sdev->scsi_dh_data = d;
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spin_unlock_irq(sdev->request_queue->queue_lock);
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return 0;
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}
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/*
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* scsi_dh_handler_detach - Detach a device handler from a device
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* @sdev - SCSI device the device handler should be detached from
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*/
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static void scsi_dh_handler_detach(struct scsi_device *sdev)
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{
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struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data;
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struct scsi_device_handler *scsi_dh = scsi_dh_data->scsi_dh;
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scsi_dh->detach(sdev);
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spin_lock_irq(sdev->request_queue->queue_lock);
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sdev->scsi_dh_data = NULL;
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spin_unlock_irq(sdev->request_queue->queue_lock);
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sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", scsi_dh->name);
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module_put(scsi_dh->module);
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}
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/*
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* Functions for sysfs attribute 'dh_state'
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*/
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static ssize_t
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store_dh_state(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct scsi_device *sdev = to_scsi_device(dev);
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struct scsi_device_handler *scsi_dh;
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int err = -EINVAL;
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if (sdev->sdev_state == SDEV_CANCEL ||
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sdev->sdev_state == SDEV_DEL)
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return -ENODEV;
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if (!sdev->scsi_dh_data) {
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/*
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* Attach to a device handler
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*/
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scsi_dh = scsi_dh_lookup(buf);
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if (!scsi_dh)
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return err;
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err = scsi_dh_handler_attach(sdev, scsi_dh);
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} else {
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scsi_dh = sdev->scsi_dh_data->scsi_dh;
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if (!strncmp(buf, "detach", 6)) {
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/*
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* Detach from a device handler
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*/
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scsi_dh_handler_detach(sdev);
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err = 0;
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} else if (!strncmp(buf, "activate", 8)) {
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/*
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* Activate a device handler
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*/
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if (scsi_dh->activate)
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err = scsi_dh->activate(sdev, NULL, NULL);
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else
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err = 0;
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}
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}
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return err<0?err:count;
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}
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static ssize_t
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show_dh_state(struct device *dev, struct device_attribute *attr, char *buf)
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{
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struct scsi_device *sdev = to_scsi_device(dev);
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if (!sdev->scsi_dh_data)
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return snprintf(buf, 20, "detached\n");
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return snprintf(buf, 20, "%s\n", sdev->scsi_dh_data->scsi_dh->name);
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}
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static struct device_attribute scsi_dh_state_attr =
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__ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state,
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store_dh_state);
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/*
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* scsi_dh_sysfs_attr_add - Callback for scsi_init_dh
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*/
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static int scsi_dh_sysfs_attr_add(struct device *dev, void *data)
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{
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struct scsi_device *sdev;
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int err;
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if (!scsi_is_sdev_device(dev))
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return 0;
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sdev = to_scsi_device(dev);
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err = device_create_file(&sdev->sdev_gendev,
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&scsi_dh_state_attr);
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return 0;
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}
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/*
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* scsi_dh_sysfs_attr_remove - Callback for scsi_exit_dh
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*/
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static int scsi_dh_sysfs_attr_remove(struct device *dev, void *data)
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{
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struct scsi_device *sdev;
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if (!scsi_is_sdev_device(dev))
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return 0;
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sdev = to_scsi_device(dev);
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device_remove_file(&sdev->sdev_gendev,
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&scsi_dh_state_attr);
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return 0;
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}
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/*
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* scsi_dh_notifier - notifier chain callback
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*/
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static int scsi_dh_notifier(struct notifier_block *nb,
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unsigned long action, void *data)
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{
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struct device *dev = data;
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struct scsi_device *sdev;
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int err = 0;
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struct scsi_device_handler *devinfo = NULL;
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if (!scsi_is_sdev_device(dev))
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return 0;
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sdev = to_scsi_device(dev);
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if (action == BUS_NOTIFY_ADD_DEVICE) {
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err = device_create_file(dev, &scsi_dh_state_attr);
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/* don't care about err */
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devinfo = device_handler_match(NULL, sdev);
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if (devinfo)
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err = scsi_dh_handler_attach(sdev, devinfo);
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} else if (action == BUS_NOTIFY_DEL_DEVICE) {
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device_remove_file(dev, &scsi_dh_state_attr);
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if (sdev->scsi_dh_data)
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scsi_dh_handler_detach(sdev);
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}
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return err;
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}
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/*
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* scsi_dh_notifier_add - Callback for scsi_register_device_handler
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*/
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static int scsi_dh_notifier_add(struct device *dev, void *data)
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{
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struct scsi_device_handler *scsi_dh = data;
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struct scsi_device *sdev;
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if (!scsi_is_sdev_device(dev))
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return 0;
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if (!get_device(dev))
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return 0;
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sdev = to_scsi_device(dev);
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if (device_handler_match(scsi_dh, sdev))
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scsi_dh_handler_attach(sdev, scsi_dh);
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put_device(dev);
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return 0;
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}
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/*
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* scsi_dh_notifier_remove - Callback for scsi_unregister_device_handler
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*/
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static int scsi_dh_notifier_remove(struct device *dev, void *data)
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{
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struct scsi_device_handler *scsi_dh = data;
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struct scsi_device *sdev;
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if (!scsi_is_sdev_device(dev))
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return 0;
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if (!get_device(dev))
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return 0;
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sdev = to_scsi_device(dev);
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if (sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh == scsi_dh)
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scsi_dh_handler_detach(sdev);
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put_device(dev);
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return 0;
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}
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/*
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* scsi_register_device_handler - register a device handler personality
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* module.
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* @scsi_dh - device handler to be registered.
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*
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* Returns 0 on success, -EBUSY if handler already registered.
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*/
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int scsi_register_device_handler(struct scsi_device_handler *scsi_dh)
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{
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if (__scsi_dh_lookup(scsi_dh->name))
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return -EBUSY;
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if (!scsi_dh->attach || !scsi_dh->detach)
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return -EINVAL;
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spin_lock(&list_lock);
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list_add(&scsi_dh->list, &scsi_dh_list);
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spin_unlock(&list_lock);
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bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh, scsi_dh_notifier_add);
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printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name);
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return SCSI_DH_OK;
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}
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EXPORT_SYMBOL_GPL(scsi_register_device_handler);
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/*
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* scsi_unregister_device_handler - register a device handler personality
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* module.
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* @scsi_dh - device handler to be unregistered.
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*
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* Returns 0 on success, -ENODEV if handler not registered.
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*/
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int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh)
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{
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if (!__scsi_dh_lookup(scsi_dh->name))
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return -ENODEV;
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bus_for_each_dev(&scsi_bus_type, NULL, scsi_dh,
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scsi_dh_notifier_remove);
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spin_lock(&list_lock);
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list_del(&scsi_dh->list);
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spin_unlock(&list_lock);
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printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name);
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return SCSI_DH_OK;
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}
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EXPORT_SYMBOL_GPL(scsi_unregister_device_handler);
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/*
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* scsi_dh_activate - activate the path associated with the scsi_device
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* corresponding to the given request queue.
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* Returns immediately without waiting for activation to be completed.
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* @q - Request queue that is associated with the scsi_device to be
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* activated.
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* @fn - Function to be called upon completion of the activation.
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* Function fn is called with data (below) and the error code.
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* Function fn may be called from the same calling context. So,
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* do not hold the lock in the caller which may be needed in fn.
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* @data - data passed to the function fn upon completion.
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*
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*/
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int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data)
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{
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int err = 0;
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unsigned long flags;
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struct scsi_device *sdev;
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struct scsi_device_handler *scsi_dh = NULL;
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struct device *dev = NULL;
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spin_lock_irqsave(q->queue_lock, flags);
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sdev = q->queuedata;
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if (!sdev) {
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spin_unlock_irqrestore(q->queue_lock, flags);
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err = SCSI_DH_NOSYS;
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if (fn)
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fn(data, err);
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return err;
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}
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if (sdev->scsi_dh_data)
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scsi_dh = sdev->scsi_dh_data->scsi_dh;
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dev = get_device(&sdev->sdev_gendev);
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if (!scsi_dh || !dev ||
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sdev->sdev_state == SDEV_CANCEL ||
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sdev->sdev_state == SDEV_DEL)
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err = SCSI_DH_NOSYS;
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if (sdev->sdev_state == SDEV_OFFLINE)
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err = SCSI_DH_DEV_OFFLINED;
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spin_unlock_irqrestore(q->queue_lock, flags);
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if (err) {
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if (fn)
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fn(data, err);
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goto out;
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}
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if (scsi_dh->activate)
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err = scsi_dh->activate(sdev, fn, data);
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out:
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put_device(dev);
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return err;
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}
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EXPORT_SYMBOL_GPL(scsi_dh_activate);
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/*
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* scsi_dh_set_params - set the parameters for the device as per the
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* string specified in params.
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* @q - Request queue that is associated with the scsi_device for
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* which the parameters to be set.
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* @params - parameters in the following format
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* "no_of_params\0param1\0param2\0param3\0...\0"
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* for example, string for 2 parameters with value 10 and 21
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* is specified as "2\010\021\0".
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*/
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int scsi_dh_set_params(struct request_queue *q, const char *params)
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{
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int err = -SCSI_DH_NOSYS;
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unsigned long flags;
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struct scsi_device *sdev;
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struct scsi_device_handler *scsi_dh = NULL;
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spin_lock_irqsave(q->queue_lock, flags);
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sdev = q->queuedata;
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if (sdev && sdev->scsi_dh_data)
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scsi_dh = sdev->scsi_dh_data->scsi_dh;
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if (scsi_dh && scsi_dh->set_params && get_device(&sdev->sdev_gendev))
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err = 0;
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spin_unlock_irqrestore(q->queue_lock, flags);
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if (err)
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return err;
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err = scsi_dh->set_params(sdev, params);
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put_device(&sdev->sdev_gendev);
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return err;
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}
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EXPORT_SYMBOL_GPL(scsi_dh_set_params);
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/*
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* scsi_dh_attach - Attach device handler
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* @q - Request queue that is associated with the scsi_device
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* the handler should be attached to
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* @name - name of the handler to attach
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*/
|
||||
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 <sekharan@us.ibm.com>");
|
||||
MODULE_LICENSE("GPL");
|
||||
Reference in New Issue
Block a user