drivers/scsi/osd/osd_uld.c

   1 /*
   2  * osd_uld.c - OSD Upper Layer Driver
   3  *
   4  * A Linux driver module that registers as a SCSI ULD and probes
   5  * for OSD type SCSI devices.
   6  * It's main function is to export osd devices to in-kernel users like
   7  * osdfs and pNFS-objects-LD. It also provides one ioctl for running
   8  * in Kernel tests.
   9  *
  10  * Copyright (C) 2008 Panasas Inc.  All rights reserved.
  11  *
  12  * Authors:
  13  *   Boaz Harrosh <bharrosh@panasas.com>
  14  *   Benny Halevy <bhalevy@panasas.com>
  15  *
  16  * This program is free software; you can redistribute it and/or modify
  17  * it under the terms of the GNU General Public License version 2
  18  *
  19  * Redistribution and use in source and binary forms, with or without
  20  * modification, are permitted provided that the following conditions
  21  * are met:
  22  *
  23  *  1. Redistributions of source code must retain the above copyright
  24  *     notice, this list of conditions and the following disclaimer.
  25  *  2. Redistributions in binary form must reproduce the above copyright
  26  *     notice, this list of conditions and the following disclaimer in the
  27  *     documentation and/or other materials provided with the distribution.
  28  *  3. Neither the name of the Panasas company nor the names of its
  29  *     contributors may be used to endorse or promote products derived
  30  *     from this software without specific prior written permission.
  31  *
  32  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  33  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  34  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  35  * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  36  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  37  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  38  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  39  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  40  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  41  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  42  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  43  */
  44
  45 #include <linux/namei.h>
  46 #include <linux/cdev.h>
  47 #include <linux/fs.h>
  48 #include <linux/module.h>
  49 #include <linux/device.h>
  50 #include <linux/idr.h>
  51 #include <linux/major.h>
  52 #include <linux/file.h>
  53
  54 #include <scsi/scsi.h>
  55 #include <scsi/scsi_driver.h>
  56 #include <scsi/scsi_device.h>
  57 #include <scsi/scsi_ioctl.h>
  58
  59 #include <scsi/osd_initiator.h>
  60 #include <scsi/osd_sec.h>
  61
  62 #include "osd_debug.h"
  63
  64 #ifndef TYPE_OSD
  65 #  define TYPE_OSD 0x11
  66 #endif
  67
  68 #ifndef SCSI_OSD_MAJOR
  69 #  define SCSI_OSD_MAJOR 260
  70 #endif
  71 #define SCSI_OSD_MAX_MINOR 64
  72
  73 static const char osd_name[] = "osd";
  74 static const char *osd_version_string = "open-osd 0.1.0";
  75 const char osd_symlink[] = "scsi_osd";
  76
  77 MODULE_AUTHOR("Boaz Harrosh <bharrosh@panasas.com>");
  78 MODULE_DESCRIPTION("open-osd Upper-Layer-Driver osd.ko");
  79 MODULE_LICENSE("GPL");
  80 MODULE_ALIAS_CHARDEV_MAJOR(SCSI_OSD_MAJOR);
  81 MODULE_ALIAS_SCSI_DEVICE(TYPE_OSD);
  82
  83 struct osd_uld_device {
  84         int minor;
  85         struct kref kref;
  86         struct cdev cdev;
  87         struct osd_dev od;
  88         struct gendisk *disk;
  89         struct device *class_member;
  90 };
  91
  92 static void __uld_get(struct osd_uld_device *oud);
  93 static void __uld_put(struct osd_uld_device *oud);
  94
  95 /*
  96  * Char Device operations
  97  */
  98
  99 static int osd_uld_open(struct inode *inode, struct file *file)
 100 {
 101         struct osd_uld_device *oud = container_of(inode->i_cdev,
 102                                         struct osd_uld_device, cdev);
 103
 104         __uld_get(oud);
 105         /* cache osd_uld_device on file handle */
 106         file->private_data = oud;
 107         OSD_DEBUG("osd_uld_open %p\n", oud);
 108         return 0;
 109 }
 110
 111 static int osd_uld_release(struct inode *inode, struct file *file)
 112 {
 113         struct osd_uld_device *oud = file->private_data;
 114
 115         OSD_DEBUG("osd_uld_release %p\n", file->private_data);
 116         file->private_data = NULL;
 117         __uld_put(oud);
 118         return 0;
 119 }
 120
 121 /* FIXME: Only one vector for now */
 122 unsigned g_test_ioctl;
 123 do_test_fn *g_do_test;
 124
 125 int osduld_register_test(unsigned ioctl, do_test_fn *do_test)
 126 {
 127         if (g_test_ioctl)
 128                 return -EINVAL;
 129
 130         g_test_ioctl = ioctl;
 131         g_do_test = do_test;
 132         return 0;
 133 }
 134 EXPORT_SYMBOL(osduld_register_test);
 135
 136 void osduld_unregister_test(unsigned ioctl)
 137 {
 138         if (ioctl == g_test_ioctl) {
 139                 g_test_ioctl = 0;
 140                 g_do_test = NULL;
 141         }
 142 }
 143 EXPORT_SYMBOL(osduld_unregister_test);
 144
 145 static do_test_fn *_find_ioctl(unsigned cmd)
 146 {
 147         if (g_test_ioctl == cmd)
 148                 return g_do_test;
 149         else
 150                 return NULL;
 151 }
 152
 153 static long osd_uld_ioctl(struct file *file, unsigned int cmd,
 154         unsigned long arg)
 155 {
 156         struct osd_uld_device *oud = file->private_data;
 157         int ret;
 158         do_test_fn *do_test;
 159
 160         do_test = _find_ioctl(cmd);
 161         if (do_test)
 162                 ret = do_test(&oud->od, cmd, arg);
 163         else {
 164                 OSD_ERR("Unknown ioctl %d: osd_uld_device=%p\n", cmd, oud);
 165                 ret = -ENOIOCTLCMD;
 166         }
 167         return ret;
 168 }
 169
 170 static const struct file_operations osd_fops = {
 171         .owner          = THIS_MODULE,
 172         .open           = osd_uld_open,
 173         .release        = osd_uld_release,
 174         .unlocked_ioctl = osd_uld_ioctl,
 175 };
 176
 177 struct osd_dev *osduld_path_lookup(const char *name)
 178 {
 179         struct osd_uld_device *oud;
 180         struct osd_dev *od;
 181         struct file *file;
 182         int error;
 183
 184         if (!name || !*name) {
 185                 OSD_ERR("Mount with !path || !*path\n");
 186                 return ERR_PTR(-EINVAL);
 187         }
 188
 189         od = kzalloc(sizeof(*od), GFP_KERNEL);
 190         if (!od)
 191                 return ERR_PTR(-ENOMEM);
 192
 193         file = filp_open(name, O_RDWR, 0);
 194         if (IS_ERR(file)) {
 195                 error = PTR_ERR(file);
 196                 goto free_od;
 197         }
 198
 199         if (file->f_op != &osd_fops){
 200                 error = -EINVAL;
 201                 goto close_file;
 202         }
 203
 204         oud = file->private_data;
 205
 206         *od = oud->od;
 207         od->file = file;
 208
 209         return od;
 210
 211 close_file:
 212         fput(file);
 213 free_od:
 214         kfree(od);
 215         return ERR_PTR(error);
 216 }
 217 EXPORT_SYMBOL(osduld_path_lookup);
 218
 219 void osduld_put_device(struct osd_dev *od)
 220 {
 221
 222         if (od && !IS_ERR(od)) {
 223                 struct osd_uld_device *oud = od->file->private_data;
 224
 225                 BUG_ON(od->scsi_device != oud->od.scsi_device);
 226
 227                 fput(od->file);
 228                 kfree(od);
 229         }
 230 }
 231 EXPORT_SYMBOL(osduld_put_device);
 232
 233 /*
 234  * Scsi Device operations
 235  */
 236
 237 static int __detect_osd(struct osd_uld_device *oud)
 238 {
 239         struct scsi_device *scsi_device = oud->od.scsi_device;
 240         char caps[OSD_CAP_LEN];
 241         int error;
 242
 243         /* sending a test_unit_ready as first command seems to be needed
 244          * by some targets
 245          */
 246         OSD_DEBUG("start scsi_test_unit_ready %p %p %p\n",
 247                         oud, scsi_device, scsi_device->request_queue);
 248         error = scsi_test_unit_ready(scsi_device, 10*HZ, 5, NULL);
 249         if (error)
 250                 OSD_ERR("warning: scsi_test_unit_ready failed\n");
 251
 252         osd_sec_init_nosec_doall_caps(caps, &osd_root_object, false, true);
 253         if (osd_auto_detect_ver(&oud->od, caps))
 254                 return -ENODEV;
 255
 256         return 0;
 257 }
 258
 259 static struct class *osd_sysfs_class;
 260 static DEFINE_IDA(osd_minor_ida);
 261
 262 static int osd_probe(struct device *dev)
 263 {
 264         struct scsi_device *scsi_device = to_scsi_device(dev);
 265         struct gendisk *disk;
 266         struct osd_uld_device *oud;
 267         int minor;
 268         int error;
 269
 270         if (scsi_device->type != TYPE_OSD)
 271                 return -ENODEV;
 272
 273         do {
 274                 if (!ida_pre_get(&osd_minor_ida, GFP_KERNEL))
 275                         return -ENODEV;
 276
 277                 error = ida_get_new(&osd_minor_ida, &minor);
 278         } while (error == -EAGAIN);
 279
 280         if (error)
 281                 return error;
 282         if (minor >= SCSI_OSD_MAX_MINOR) {
 283                 error = -EBUSY;
 284                 goto err_retract_minor;
 285         }
 286
 287         error = -ENOMEM;
 288         oud = kzalloc(sizeof(*oud), GFP_KERNEL);
 289         if (NULL == oud)
 290                 goto err_retract_minor;
 291
 292         kref_init(&oud->kref);
 293         dev_set_drvdata(dev, oud);
 294         oud->minor = minor;
 295
 296         /* allocate a disk and set it up */
 297         /* FIXME: do we need this since sg has already done that */
 298         disk = alloc_disk(1);
 299         if (!disk) {
 300                 OSD_ERR("alloc_disk failed\n");
 301                 goto err_free_osd;
 302         }
 303         disk->major = SCSI_OSD_MAJOR;
 304         disk->first_minor = oud->minor;
 305         sprintf(disk->disk_name, "osd%d", oud->minor);
 306         oud->disk = disk;
 307
 308         /* hold one more reference to the scsi_device that will get released
 309          * in __release, in case a logout is happening while fs is mounted
 310          */
 311         scsi_device_get(scsi_device);
 312         osd_dev_init(&oud->od, scsi_device);
 313
 314         /* Detect the OSD Version */
 315         error = __detect_osd(oud);
 316         if (error) {
 317                 OSD_ERR("osd detection failed, non-compatible OSD device\n");
 318                 goto err_put_disk;
 319         }
 320
 321         /* init the char-device for communication with user-mode */
 322         cdev_init(&oud->cdev, &osd_fops);
 323         oud->cdev.owner = THIS_MODULE;
 324         error = cdev_add(&oud->cdev,
 325                          MKDEV(SCSI_OSD_MAJOR, oud->minor), 1);
 326         if (error) {
 327                 OSD_ERR("cdev_add failed\n");
 328                 goto err_put_disk;
 329         }
 330         kobject_get(&oud->cdev.kobj); /* 2nd ref see osd_remove() */
 331
 332         /* class_member */
 333         oud->class_member = device_create(osd_sysfs_class, dev,
 334                 MKDEV(SCSI_OSD_MAJOR, oud->minor), "%s", disk->disk_name);
 335         if (IS_ERR(oud->class_member)) {
 336                 OSD_ERR("class_device_create failed\n");
 337                 error = PTR_ERR(oud->class_member);
 338                 goto err_put_cdev;
 339         }
 340
 341         dev_set_drvdata(oud->class_member, oud);
 342
 343         OSD_INFO("osd_probe %s\n", disk->disk_name);
 344         return 0;
 345
 346 err_put_cdev:
 347         cdev_del(&oud->cdev);
 348 err_put_disk:
 349         scsi_device_put(scsi_device);
 350         put_disk(disk);
 351 err_free_osd:
 352         dev_set_drvdata(dev, NULL);
 353         kfree(oud);
 354 err_retract_minor:
 355         ida_remove(&osd_minor_ida, minor);
 356         return error;
 357 }
 358
 359 static int osd_remove(struct device *dev)
 360 {
 361         struct scsi_device *scsi_device = to_scsi_device(dev);
 362         struct osd_uld_device *oud = dev_get_drvdata(dev);
 363
 364         if (!oud || (oud->od.scsi_device != scsi_device)) {
 365                 OSD_ERR("Half cooked osd-device %p,%p || %p!=%p",
 366                         dev, oud, oud ? oud->od.scsi_device : NULL,
 367                         scsi_device);
 368         }
 369
 370         if (oud->class_member)
 371                 device_destroy(osd_sysfs_class,
 372                                MKDEV(SCSI_OSD_MAJOR, oud->minor));
 373
 374         /* We have 2 references to the cdev. One is released here
 375          * and also takes down the /dev/osdX mapping. The second
 376          * Will be released in __remove() after all users have released
 377          * the osd_uld_device.
 378          */
 379         if (oud->cdev.owner)
 380                 cdev_del(&oud->cdev);
 381
 382         __uld_put(oud);
 383         return 0;
 384 }
 385
 386 static void __remove(struct kref *kref)
 387 {
 388         struct osd_uld_device *oud = container_of(kref,
 389                                         struct osd_uld_device, kref);
 390         struct scsi_device *scsi_device = oud->od.scsi_device;
 391
 392         /* now let delete the char_dev */
 393         kobject_put(&oud->cdev.kobj);
 394
 395         osd_dev_fini(&oud->od);
 396         scsi_device_put(scsi_device);
 397
 398         OSD_INFO("osd_remove %s\n",
 399                  oud->disk ? oud->disk->disk_name : NULL);
 400
 401         if (oud->disk)
 402                 put_disk(oud->disk);
 403
 404         ida_remove(&osd_minor_ida, oud->minor);
 405         kfree(oud);
 406 }
 407
 408 static void __uld_get(struct osd_uld_device *oud)
 409 {
 410         kref_get(&oud->kref);
 411 }
 412
 413 static void __uld_put(struct osd_uld_device *oud)
 414 {
 415         kref_put(&oud->kref, __remove);
 416 }
 417
 418 /*
 419  * Global driver and scsi registration
 420  */
 421
 422 static struct scsi_driver osd_driver = {
 423         .owner                  = THIS_MODULE,
 424         .gendrv = {
 425                 .name           = osd_name,
 426                 .probe          = osd_probe,
 427                 .remove         = osd_remove,
 428         }
 429 };
 430
 431 static int __init osd_uld_init(void)
 432 {
 433         int err;
 434
 435         osd_sysfs_class = class_create(THIS_MODULE, osd_symlink);
 436         if (IS_ERR(osd_sysfs_class)) {
 437                 OSD_ERR("Unable to register sysfs class => %ld\n",
 438                         PTR_ERR(osd_sysfs_class));
 439                 return PTR_ERR(osd_sysfs_class);
 440         }
 441
 442         err = register_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0),
 443                                      SCSI_OSD_MAX_MINOR, osd_name);
 444         if (err) {
 445                 OSD_ERR("Unable to register major %d for osd ULD => %d\n",
 446                         SCSI_OSD_MAJOR, err);
 447                 goto err_out;
 448         }
 449
 450         err = scsi_register_driver(&osd_driver.gendrv);
 451         if (err) {
 452                 OSD_ERR("scsi_register_driver failed => %d\n", err);
 453                 goto err_out_chrdev;
 454         }
 455
 456         OSD_INFO("LOADED %s\n", osd_version_string);
 457         return 0;
 458
 459 err_out_chrdev:
 460         unregister_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0), SCSI_OSD_MAX_MINOR);
 461 err_out:
 462         class_destroy(osd_sysfs_class);
 463         return err;
 464 }
 465
 466 static void __exit osd_uld_exit(void)
 467 {
 468         scsi_unregister_driver(&osd_driver.gendrv);
 469         unregister_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0), SCSI_OSD_MAX_MINOR);
 470         class_destroy(osd_sysfs_class);
 471         OSD_INFO("UNLOADED %s\n", osd_version_string);
 472 }
 473
 474 module_init(osd_uld_init);
 475 module_exit(osd_uld_exit);