/*
* osd_uld.c - OSD Upper Layer Driver
*
* A Linux driver module that registers as a SCSI ULD and probes
* for OSD type SCSI devices.
* It's main function is to export osd devices to in-kernel users like
* osdfs and pNFS-objects-LD. It also provides one ioctl for running
* in Kernel tests.
*
* Copyright (C) 2008 Panasas Inc. All rights reserved.
*
* Authors:
* Boaz Harrosh <bharrosh@panasas.com>
* Benny Halevy <bhalevy@panasas.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Panasas company nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/namei.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/idr.h>
#include <linux/major.h>
#include <scsi/scsi.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/osd_initiator.h>
#include <scsi/osd_sec.h>
#include "osd_debug.h"
#ifndef TYPE_OSD
# define TYPE_OSD 0x11
#endif
#ifndef SCSI_OSD_MAJOR
# define SCSI_OSD_MAJOR 260
#endif
#define SCSI_OSD_MAX_MINOR 64
static const char osd_name[] = "osd";
static const char *osd_version_string = "open-osd 0.1.0";
const char osd_symlink[] = "scsi_osd";
MODULE_AUTHOR("Boaz Harrosh <bharrosh@panasas.com>");
MODULE_DESCRIPTION("open-osd Upper-Layer-Driver osd.ko");
MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(SCSI_OSD_MAJOR);
MODULE_ALIAS_SCSI_DEVICE(TYPE_OSD);
struct osd_uld_device {
int minor;
struct kref kref;
struct cdev cdev;
struct osd_dev od;
struct gendisk *disk;
struct device *class_member;
};
static void __uld_get(struct osd_uld_device *oud);
static void __uld_put(struct osd_uld_device *oud);
/*
* Char Device operations
*/
static int osd_uld_open(struct inode *inode, struct file *file)
{
struct osd_uld_device *oud = container_of(inode->i_cdev,
struct osd_uld_device, cdev);
__uld_get(oud);
/* cache osd_uld_device on file handle */
file->private_data = oud;
OSD_DEBUG("osd_uld_open %p\n", oud);
return 0;
}
static int osd_uld_release(struct inode *inode, struct file *file)
{
struct osd_uld_device *oud = file->private_data;
OSD_DEBUG("osd_uld_release %p\n", file->private_data);
file->private_data = NULL;
__uld_put(oud);
return 0;
}
/* FIXME: Only one vector for now */
unsigned g_test_ioctl;
do_test_fn *g_do_test;
int osduld_register_test(unsigned ioctl, do_test_fn *do_test)
{
if (g_test_ioctl)
return -EINVAL;
g_test_ioctl = ioctl;
g_do_test = do_test;
return 0;
}
EXPORT_SYMBOL(osduld_register_test);
void osduld_unregister_test(unsigned ioctl)
{
if (ioctl == g_test_ioctl) {
g_test_ioctl = 0;
g_do_test = NULL;
}
}
EXPORT_SYMBOL(osduld_unregister_test);
static do_test_fn *_find_ioctl(unsigned cmd)
{
if (g_test_ioctl == cmd)
return g_do_test;
else
return NULL;
}
static long osd_uld_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct osd_uld_device *oud = file->private_data;
int ret;
do_test_fn *do_test;
do_test = _find_ioctl(cmd);
if (do_test)
ret = do_test(&oud->od, cmd, arg);
else {
OSD_ERR("Unknown ioctl %d: osd_uld_device=%p\n", cmd, oud);
ret = -ENOIOCTLCMD;
}
return ret;
}
static const struct file_operations osd_fops = {
.owner = THIS_MODULE,
.open = osd_uld_open,
.release = osd_uld_release,
.unlocked_ioctl = osd_uld_ioctl,
};
struct osd_dev *osduld_path_lookup(const char *path)
{
struct nameidata nd;
struct inode *inode;
struct cdev *cdev;
struct osd_uld_device *uninitialized_var(oud);
int error;
if (!path || !*path) {
OSD_ERR("Mount with !path || !*path\n");
return ERR_PTR(-EINVAL);
}
error = path_lookup(path, LOOKUP_FOLLOW, &nd);
if (error) {
OSD_ERR("path_lookup of %s faild=>%d\n", path, error);
return ERR_PTR(error);
}
inode = nd.path.dentry->d_inode;
error = -EINVAL; /* Not the right device e.g osd_uld_device */
if (!S_ISCHR(inode->i_mode)) {
OSD_DEBUG("!S_ISCHR()\n");
goto out;
}
cdev = inode->i_cdev;
if (!cdev) {
OSD_ERR("Before mounting an OSD Based filesystem\n");
OSD_ERR(" user-mode must open+close the %s device\n", path);
OSD_ERR(" Example: bash: echo < %s\n", path);
goto out;
}
/* The Magic wand. Is it our char-dev */
/* TODO: Support sg devices */
if (cdev->owner != THIS_MODULE) {
OSD_ERR("Error mounting %s - is not an OSD device\n", path);
goto out;
}
oud = container_of(cdev, struct osd_uld_device, cdev);
__uld_get(oud);
error = 0;
out:
path_put(&nd.path);
return error ? ERR_PTR(error) : &oud->od;
}
EXPORT_SYMBOL(osduld_path_lookup);
void osduld_put_device(struct osd_dev *od)
{
if (od) {
struct osd_uld_device *oud = container_of(od,
struct osd_uld_device, od);
__uld_put(oud);
}
}
EXPORT_SYMBOL(osduld_put_device);
/*
* Scsi Device operations
*/
static int __detect_osd(struct osd_uld_device *oud)
{
struct scsi_device *scsi_device = oud->od.scsi_device;
char caps[OSD_CAP_LEN];
int error;
/* sending a test_unit_ready as first command seems to be needed
* by some targets
*/
OSD_DEBUG("start scsi_test_unit_ready %p %p %p\n",
oud, scsi_device, scsi_device->request_queue);
error = scsi_test_unit_ready(scsi_device, 10*HZ, 5, NULL);
if (error)
OSD_ERR("warning: scsi_test_unit_ready failed\n");
osd_sec_init_nosec_doall_caps(caps, &osd_root_object, false, true);
if (osd_auto_detect_ver(&oud->od, caps))
return -ENODEV;
return 0;
}
static struct class *osd_sysfs_class;
static DEFINE_IDA(osd_minor_ida);
static int osd_probe(struct device *dev)
{
struct scsi_device *scsi_device = to_scsi_device(dev);
struct gendisk *disk;
struct osd_uld_device *oud;
int minor;
int error;
if (scsi_device->type != TYPE_OSD)
return -ENODEV;
do {
if (!ida_pre_get(&osd_minor_ida, GFP_KERNEL))
return -ENODEV;
error = ida_get_new(&osd_minor_ida, &minor);
} while (error == -EAGAIN);
if (error)
return error;
if (minor >= SCSI_OSD_MAX_MINOR) {
error = -EBUSY;
goto err_retract_minor;
}
error = -ENOMEM;
oud = kzalloc(sizeof(*oud), GFP_KERNEL);
if (NULL == oud)
goto err_retract_minor;
kref_init(&oud->kref);
dev_set_drvdata(dev, oud);
oud->minor = minor;
/* allocate a disk and set it up */
/* FIXME: do we need this since sg has already done that */
disk = alloc_disk(1);
if (!disk) {
OSD_ERR("alloc_disk failed\n");
goto err_free_osd;
}
disk->major = SCSI_OSD_MAJOR;
disk->first_minor = oud->minor;
sprintf(disk->disk_name, "osd%d", oud->minor);
oud->disk = disk;
/* hold one more reference to the scsi_device that will get released
* in __release, in case a logout is happening while fs is mounted
*/
scsi_device_get(scsi_device);
osd_dev_init(&oud->od, scsi_device);
/* Detect the OSD Version */
error = __detect_osd(oud);
if (error) {
OSD_ERR("osd detection failed, non-compatible OSD device\n");
goto err_put_disk;
}
/* init the char-device for communication with user-mode */
cdev_init(&oud->cdev, &osd_fops);
oud->cdev.owner = THIS_MODULE;
error = cdev_add(&oud->cdev,
MKDEV(SCSI_OSD_MAJOR, oud->minor), 1);
if (error) {
OSD_ERR("cdev_add failed\n");
goto err_put_disk;
}
kobject_get(&oud->cdev.kobj); /* 2nd ref see osd_remove() */
/* class_member */
oud->class_member = device_create(osd_sysfs_class, dev,
MKDEV(SCSI_OSD_MAJOR, oud->minor), "%s", disk->disk_name);
if (IS_ERR(oud->class_member)) {
OSD_ERR("class_device_create failed\n");
error = PTR_ERR(oud->class_member);
goto err_put_cdev;
}
dev_set_drvdata(oud->class_member, oud);
OSD_INFO("osd_probe %s\n", disk->disk_name);
return 0;
err_put_cdev:
cdev_del(&oud->cdev);
err_put_disk:
scsi_device_put(scsi_device);
put_disk(disk);
err_free_osd:
dev_set_drvdata(dev, NULL);
kfree(oud);
err_retract_minor:
ida_remove(&osd_minor_ida, minor);
return error;
}
static int osd_remove(struct device *dev)
{
struct scsi_device *scsi_device = to_scsi_device(dev);
struct osd_uld_device *oud = dev_get_drvdata(dev);
if (!oud || (oud->od.scsi_device != scsi_device)) {
OSD_ERR("Half cooked osd-device %p,%p || %p!=%p",
dev, oud, oud ? oud->od.scsi_device : NULL,
scsi_device);
}
if (oud->class_member)
device_destroy(osd_sysfs_class,
MKDEV(SCSI_OSD_MAJOR, oud->minor));
/* We have 2 references to the cdev. One is released here
* and also takes down the /dev/osdX mapping. The second
* Will be released in __remove() after all users have released
* the osd_uld_device.
*/
if (oud->cdev.owner)
cdev_del(&oud->cdev);
__uld_put(oud);
return 0;
}
static void __remove(struct kref *kref)
{
struct osd_uld_device *oud = container_of(kref,
struct osd_uld_device, kref);
struct scsi_device *scsi_device = oud->od.scsi_device;
/* now let delete the char_dev */
kobject_put(&oud->cdev.kobj);
osd_dev_fini(&oud->od);
scsi_device_put(scsi_device);
OSD_INFO("osd_remove %s\n",
oud->disk ? oud->disk->disk_name : NULL);
if (oud->disk)
put_disk(oud->disk);
ida_remove(&osd_minor_ida, oud->minor);
kfree(oud);
}
static void __uld_get(struct osd_uld_device *oud)
{
kref_get(&oud->kref);
}
static void __uld_put(struct osd_uld_device *oud)
{
kref_put(&oud->kref, __remove);
}
/*
* Global driver and scsi registration
*/
static struct scsi_driver osd_driver = {
.owner = THIS_MODULE,
.gendrv = {
.name = osd_name,
.probe = osd_probe,
.remove = osd_remove,
}
};
static int __init osd_uld_init(void)
{
int err;
osd_sysfs_class = class_create(THIS_MODULE, osd_symlink);
if (IS_ERR(osd_sysfs_class)) {
OSD_ERR("Unable to register sysfs class => %ld\n",
PTR_ERR(osd_sysfs_class));
return PTR_ERR(osd_sysfs_class);
}
err = register_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0),
SCSI_OSD_MAX_MINOR, osd_name);
if (err) {
OSD_ERR("Unable to register major %d for osd ULD => %d\n",
SCSI_OSD_MAJOR, err);
goto err_out;
}
err = scsi_register_driver(&osd_driver.gendrv);
if (err) {
OSD_ERR("scsi_register_driver failed => %d\n", err);
goto err_out_chrdev;
}
OSD_INFO("LOADED %s\n", osd_version_string);
return 0;
err_out_chrdev:
unregister_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0), SCSI_OSD_MAX_MINOR);
err_out:
class_destroy(osd_sysfs_class);
return err;
}
static void __exit osd_uld_exit(void)
{
scsi_unregister_driver(&osd_driver.gendrv);
unregister_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0), SCSI_OSD_MAX_MINOR);
class_destroy(osd_sysfs_class);
OSD_INFO("UNLOADED %s\n", osd_version_string);
}
module_init(osd_uld_init);
module_exit(osd_uld_exit);
