![Hannes Reinecke](/assets/img/avatar_default.png)
When calling scsi_dh_activate() we should be returning SCSI_DH_NOTCONN if the device handler couldn't be attached. Reviewed-by: Bart van Assche <bart.vanassche@sandisk.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: James Bottomley <JBottomley@Odin.com>
438 lines
11 KiB
C
438 lines
11 KiB
C
/*
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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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struct scsi_dh_blist {
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const char *vendor;
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const char *model;
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const char *driver;
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};
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static const struct scsi_dh_blist scsi_dh_blist[] = {
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{"DGC", "RAID", "clariion" },
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{"DGC", "DISK", "clariion" },
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{"DGC", "VRAID", "clariion" },
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{"COMPAQ", "MSA1000 VOLUME", "hp_sw" },
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{"COMPAQ", "HSV110", "hp_sw" },
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{"HP", "HSV100", "hp_sw"},
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{"DEC", "HSG80", "hp_sw"},
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{"IBM", "1722", "rdac", },
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{"IBM", "1724", "rdac", },
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{"IBM", "1726", "rdac", },
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{"IBM", "1742", "rdac", },
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{"IBM", "1745", "rdac", },
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{"IBM", "1746", "rdac", },
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{"IBM", "1813", "rdac", },
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{"IBM", "1814", "rdac", },
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{"IBM", "1815", "rdac", },
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{"IBM", "1818", "rdac", },
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{"IBM", "3526", "rdac", },
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{"SGI", "TP9", "rdac", },
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{"SGI", "IS", "rdac", },
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{"STK", "OPENstorage D280", "rdac", },
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{"STK", "FLEXLINE 380", "rdac", },
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{"SUN", "CSM", "rdac", },
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{"SUN", "LCSM100", "rdac", },
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{"SUN", "STK6580_6780", "rdac", },
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{"SUN", "SUN_6180", "rdac", },
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{"SUN", "ArrayStorage", "rdac", },
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{"DELL", "MD3", "rdac", },
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{"NETAPP", "INF-01-00", "rdac", },
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{"LSI", "INF-01-00", "rdac", },
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{"ENGENIO", "INF-01-00", "rdac", },
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{NULL, NULL, NULL },
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};
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static const char *
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scsi_dh_find_driver(struct scsi_device *sdev)
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{
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const struct scsi_dh_blist *b;
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if (scsi_device_tpgs(sdev))
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return "alua";
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for (b = scsi_dh_blist; b->vendor; b++) {
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if (!strncmp(sdev->vendor, b->vendor, strlen(b->vendor)) &&
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!strncmp(sdev->model, b->model, strlen(b->model))) {
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return b->driver;
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}
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}
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return NULL;
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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 *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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* 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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int error;
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if (!try_module_get(scsi_dh->module))
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return -EINVAL;
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error = scsi_dh->attach(sdev);
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if (error) {
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sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%d)\n",
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scsi_dh->name, error);
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module_put(scsi_dh->module);
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} else
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sdev->handler = scsi_dh;
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return error;
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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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sdev->handler->detach(sdev);
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sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", sdev->handler->name);
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module_put(sdev->handler->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->handler) {
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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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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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sdev_printk(KERN_WARNING, sdev,
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"can't detach handler %s.\n",
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sdev->handler->name);
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err = -EINVAL;
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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 (sdev->handler->activate)
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err = sdev->handler->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->handler)
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return snprintf(buf, 20, "detached\n");
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return snprintf(buf, 20, "%s\n", sdev->handler->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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int scsi_dh_add_device(struct scsi_device *sdev)
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{
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struct scsi_device_handler *devinfo = NULL;
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const char *drv;
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int err;
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err = device_create_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
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if (err)
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return err;
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drv = scsi_dh_find_driver(sdev);
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if (drv)
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devinfo = scsi_dh_lookup(drv);
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if (devinfo)
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err = scsi_dh_handler_attach(sdev, devinfo);
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return err;
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}
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void scsi_dh_remove_device(struct scsi_device *sdev)
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{
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if (sdev->handler)
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scsi_dh_handler_detach(sdev);
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device_remove_file(&sdev->sdev_gendev, &scsi_dh_state_attr);
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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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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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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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static struct scsi_device *get_sdev_from_queue(struct request_queue *q)
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{
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struct scsi_device *sdev;
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unsigned long flags;
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spin_lock_irqsave(q->queue_lock, flags);
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sdev = q->queuedata;
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if (!sdev || !get_device(&sdev->sdev_gendev))
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sdev = NULL;
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spin_unlock_irqrestore(q->queue_lock, flags);
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return sdev;
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}
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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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struct scsi_device *sdev;
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int err = SCSI_DH_NOSYS;
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sdev = get_sdev_from_queue(q);
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if (!sdev) {
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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->handler)
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goto out_fn;
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err = SCSI_DH_NOTCONN;
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if (sdev->sdev_state == SDEV_CANCEL ||
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sdev->sdev_state == SDEV_DEL)
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goto out_fn;
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err = SCSI_DH_DEV_OFFLINED;
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if (sdev->sdev_state == SDEV_OFFLINE)
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goto out_fn;
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if (sdev->handler->activate)
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err = sdev->handler->activate(sdev, fn, data);
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out_put_device:
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put_device(&sdev->sdev_gendev);
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return err;
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out_fn:
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if (fn)
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fn(data, err);
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goto out_put_device;
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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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struct scsi_device *sdev;
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int err = -SCSI_DH_NOSYS;
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sdev = get_sdev_from_queue(q);
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if (!sdev)
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return err;
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if (sdev->handler && sdev->handler->set_params)
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err = sdev->handler->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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*/
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int scsi_dh_attach(struct request_queue *q, const char *name)
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{
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struct scsi_device *sdev;
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struct scsi_device_handler *scsi_dh;
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int err = 0;
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sdev = get_sdev_from_queue(q);
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if (!sdev)
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return -ENODEV;
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scsi_dh = scsi_dh_lookup(name);
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if (!scsi_dh) {
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err = -EINVAL;
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goto out_put_device;
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}
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if (sdev->handler) {
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if (sdev->handler != scsi_dh)
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err = -EBUSY;
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goto out_put_device;
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}
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err = scsi_dh_handler_attach(sdev, scsi_dh);
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out_put_device:
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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_attach);
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/*
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* scsi_dh_attached_handler_name - Get attached device handler's name
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* @q - Request queue that is associated with the scsi_device
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* that may have a device handler attached
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* @gfp - the GFP mask used in the kmalloc() call when allocating memory
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*
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* Returns name of attached handler, NULL if no handler is attached.
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* Caller must take care to free the returned string.
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*/
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const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp)
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{
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struct scsi_device *sdev;
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const char *handler_name = NULL;
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sdev = get_sdev_from_queue(q);
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if (!sdev)
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return NULL;
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if (sdev->handler)
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handler_name = kstrdup(sdev->handler->name, gfp);
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put_device(&sdev->sdev_gendev);
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return handler_name;
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}
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EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name);
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