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 #include <linux/slab.h>
  54
  55 #include <scsi/scsi.h>
  56 #include <scsi/scsi_driver.h>
  57 #include <scsi/scsi_device.h>
  58 #include <scsi/scsi_ioctl.h>
  59
  60 #include <scsi/osd_initiator.h>
  61 #include <scsi/osd_sec.h>
  62
  63 #include "osd_debug.h"
  64
  65 #ifndef TYPE_OSD
  66 #  define TYPE_OSD 0x11
  67 #endif
  68
  69 #ifndef SCSI_OSD_MAJOR
  70 #  define SCSI_OSD_MAJOR 260
  71 #endif
  72 #define SCSI_OSD_MAX_MINOR MINORMASK
  73
  74 static const char osd_name[] = "osd";
  75 static const char *osd_version_string = "open-osd 0.2.1";
  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 device class_dev;
  86         struct cdev cdev;
  87         struct osd_dev od;
  88         struct osd_dev_info odi;
  89         struct gendisk *disk;
  90 };
  91
  92 struct osd_dev_handle {
  93         struct osd_dev od;
  94         struct file *file;
  95         struct osd_uld_device *oud;
  96 } ;
  97
  98 static DEFINE_IDA(osd_minor_ida);
  99
 100 static struct class osd_uld_class = {
 101         .owner          = THIS_MODULE,
 102         .name           = "scsi_osd",
 103 };
 104
 105 /*
 106  * Char Device operations
 107  */
 108
 109 static int osd_uld_open(struct inode *inode, struct file *file)
 110 {
 111         struct osd_uld_device *oud = container_of(inode->i_cdev,
 112                                         struct osd_uld_device, cdev);
 113
 114         get_device(&oud->class_dev);
 115         /* cache osd_uld_device on file handle */
 116         file->private_data = oud;
 117         OSD_DEBUG("osd_uld_open %p\n", oud);
 118         return 0;
 119 }
 120
 121 static int osd_uld_release(struct inode *inode, struct file *file)
 122 {
 123         struct osd_uld_device *oud = file->private_data;
 124
 125         OSD_DEBUG("osd_uld_release %p\n", file->private_data);
 126         file->private_data = NULL;
 127         put_device(&oud->class_dev);
 128         return 0;
 129 }
 130
 131 /* FIXME: Only one vector for now */
 132 unsigned g_test_ioctl;
 133 do_test_fn *g_do_test;
 134
 135 int osduld_register_test(unsigned ioctl, do_test_fn *do_test)
 136 {
 137         if (g_test_ioctl)
 138                 return -EINVAL;
 139
 140         g_test_ioctl = ioctl;
 141         g_do_test = do_test;
 142         return 0;
 143 }
 144 EXPORT_SYMBOL(osduld_register_test);
 145
 146 void osduld_unregister_test(unsigned ioctl)
 147 {
 148         if (ioctl == g_test_ioctl) {
 149                 g_test_ioctl = 0;
 150                 g_do_test = NULL;
 151         }
 152 }
 153 EXPORT_SYMBOL(osduld_unregister_test);
 154
 155 static do_test_fn *_find_ioctl(unsigned cmd)
 156 {
 157         if (g_test_ioctl == cmd)
 158                 return g_do_test;
 159         else
 160                 return NULL;
 161 }
 162
 163 static long osd_uld_ioctl(struct file *file, unsigned int cmd,
 164         unsigned long arg)
 165 {
 166         struct osd_uld_device *oud = file->private_data;
 167         int ret;
 168         do_test_fn *do_test;
 169
 170         do_test = _find_ioctl(cmd);
 171         if (do_test)
 172                 ret = do_test(&oud->od, cmd, arg);
 173         else {
 174                 OSD_ERR("Unknown ioctl %d: osd_uld_device=%p\n", cmd, oud);
 175                 ret = -ENOIOCTLCMD;
 176         }
 177         return ret;
 178 }
 179
 180 static const struct file_operations osd_fops = {
 181         .owner          = THIS_MODULE,
 182         .open           = osd_uld_open,
 183         .release        = osd_uld_release,
 184         .unlocked_ioctl = osd_uld_ioctl,
 185         .llseek         = noop_llseek,
 186 };
 187
 188 struct osd_dev *osduld_path_lookup(const char *name)
 189 {
 190         struct osd_uld_device *oud;
 191         struct osd_dev_handle *odh;
 192         struct file *file;
 193         int error;
 194
 195         if (!name || !*name) {
 196                 OSD_ERR("Mount with !path || !*path\n");
 197                 return ERR_PTR(-EINVAL);
 198         }
 199
 200         odh = kzalloc(sizeof(*odh), GFP_KERNEL);
 201         if (unlikely(!odh))
 202                 return ERR_PTR(-ENOMEM);
 203
 204         file = filp_open(name, O_RDWR, 0);
 205         if (IS_ERR(file)) {
 206                 error = PTR_ERR(file);
 207                 goto free_od;
 208         }
 209
 210         if (file->f_op != &osd_fops){
 211                 error = -EINVAL;
 212                 goto close_file;
 213         }
 214
 215         oud = file->private_data;
 216
 217         odh->od = oud->od;
 218         odh->file = file;
 219         odh->oud = oud;
 220
 221         return &odh->od;
 222
 223 close_file:
 224         fput(file);
 225 free_od:
 226         kfree(odh);
 227         return ERR_PTR(error);
 228 }
 229 EXPORT_SYMBOL(osduld_path_lookup);
 230
 231 static inline bool _the_same_or_null(const u8 *a1, unsigned a1_len,
 232                                      const u8 *a2, unsigned a2_len)
 233 {
 234         if (!a2_len) /* User string is Empty means don't care */
 235                 return true;
 236
 237         if (a1_len != a2_len)
 238                 return false;
 239
 240         return 0 == memcmp(a1, a2, a1_len);
 241 }
 242
 243 struct find_oud_t {
 244         const struct osd_dev_info *odi;
 245         struct device *dev;
 246         struct osd_uld_device *oud;
 247 } ;
 248
 249 int _mach_odi(struct device *dev, void *find_data)
 250 {
 251         struct osd_uld_device *oud = container_of(dev, struct osd_uld_device,
 252                                                   class_dev);
 253         struct find_oud_t *fot = find_data;
 254         const struct osd_dev_info *odi = fot->odi;
 255
 256         if (_the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,
 257                               odi->systemid, odi->systemid_len) &&
 258             _the_same_or_null(oud->odi.osdname, oud->odi.osdname_len,
 259                               odi->osdname, odi->osdname_len)) {
 260                 OSD_DEBUG("found device sysid_len=%d osdname=%d\n",
 261                           odi->systemid_len, odi->osdname_len);
 262                 fot->oud = oud;
 263                 return 1;
 264         } else {
 265                 return 0;
 266         }
 267 }
 268
 269 /* osduld_info_lookup - Loop through all devices, return the requested osd_dev.
 270  *
 271  * if @odi->systemid_len and/or @odi->osdname_len are zero, they act as a don't
 272  * care. .e.g if they're both zero /dev/osd0 is returned.
 273  */
 274 struct osd_dev *osduld_info_lookup(const struct osd_dev_info *odi)
 275 {
 276         struct find_oud_t find = {.odi = odi};
 277
 278         find.dev = class_find_device(&osd_uld_class, NULL, &find, _mach_odi);
 279         if (likely(find.dev)) {
 280                 struct osd_dev_handle *odh = kzalloc(sizeof(*odh), GFP_KERNEL);
 281
 282                 if (unlikely(!odh)) {
 283                         put_device(find.dev);
 284                         return ERR_PTR(-ENOMEM);
 285                 }
 286
 287                 odh->od = find.oud->od;
 288                 odh->oud = find.oud;
 289
 290                 return &odh->od;
 291         }
 292
 293         return ERR_PTR(-ENODEV);
 294 }
 295 EXPORT_SYMBOL(osduld_info_lookup);
 296
 297 void osduld_put_device(struct osd_dev *od)
 298 {
 299         if (od && !IS_ERR(od)) {
 300                 struct osd_dev_handle *odh =
 301                                 container_of(od, struct osd_dev_handle, od);
 302                 struct osd_uld_device *oud = odh->oud;
 303
 304                 BUG_ON(od->scsi_device != oud->od.scsi_device);
 305
 306                 /* If scsi has released the device (logout), and exofs has last
 307                  * reference on oud it will be freed by above osd_uld_release
 308                  * within fput below. But this will oops in cdev_release which
 309                  * is called after the fops->release. A get_/put_ pair makes
 310                  * sure we have a cdev for the duration of fput
 311                  */
 312                 if (odh->file) {
 313                         get_device(&oud->class_dev);
 314                         fput(odh->file);
 315                 }
 316                 put_device(&oud->class_dev);
 317                 kfree(odh);
 318         }
 319 }
 320 EXPORT_SYMBOL(osduld_put_device);
 321
 322 const struct osd_dev_info *osduld_device_info(struct osd_dev *od)
 323 {
 324         struct osd_dev_handle *odh =
 325                                 container_of(od, struct osd_dev_handle, od);
 326         return &odh->oud->odi;
 327 }
 328 EXPORT_SYMBOL(osduld_device_info);
 329
 330 bool osduld_device_same(struct osd_dev *od, const struct osd_dev_info *odi)
 331 {
 332         struct osd_dev_handle *odh =
 333                                 container_of(od, struct osd_dev_handle, od);
 334         struct osd_uld_device *oud = odh->oud;
 335
 336         return (oud->odi.systemid_len == odi->systemid_len) &&
 337                 _the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,
 338                                  odi->systemid, odi->systemid_len) &&
 339                 (oud->odi.osdname_len == odi->osdname_len) &&
 340                 _the_same_or_null(oud->odi.osdname, oud->odi.osdname_len,
 341                                   odi->osdname, odi->osdname_len);
 342 }
 343 EXPORT_SYMBOL(osduld_device_same);
 344
 345 /*
 346  * Scsi Device operations
 347  */
 348
 349 static int __detect_osd(struct osd_uld_device *oud)
 350 {
 351         struct scsi_device *scsi_device = oud->od.scsi_device;
 352         char caps[OSD_CAP_LEN];
 353         int error;
 354
 355         /* sending a test_unit_ready as first command seems to be needed
 356          * by some targets
 357          */
 358         OSD_DEBUG("start scsi_test_unit_ready %p %p %p\n",
 359                         oud, scsi_device, scsi_device->request_queue);
 360         error = scsi_test_unit_ready(scsi_device, 10*HZ, 5, NULL);
 361         if (error)
 362                 OSD_ERR("warning: scsi_test_unit_ready failed\n");
 363
 364         osd_sec_init_nosec_doall_caps(caps, &osd_root_object, false, true);
 365         if (osd_auto_detect_ver(&oud->od, caps, &oud->odi))
 366                 return -ENODEV;
 367
 368         return 0;
 369 }
 370
 371 static void __remove(struct device *dev)
 372 {
 373         struct osd_uld_device *oud = container_of(dev, struct osd_uld_device,
 374                                                   class_dev);
 375         struct scsi_device *scsi_device = oud->od.scsi_device;
 376
 377         kfree(oud->odi.osdname);
 378
 379         if (oud->cdev.owner)
 380                 cdev_del(&oud->cdev);
 381
 382         osd_dev_fini(&oud->od);
 383         scsi_device_put(scsi_device);
 384
 385         OSD_INFO("osd_remove %s\n",
 386                  oud->disk ? oud->disk->disk_name : NULL);
 387
 388         if (oud->disk)
 389                 put_disk(oud->disk);
 390         ida_remove(&osd_minor_ida, oud->minor);
 391
 392         kfree(oud);
 393 }
 394
 395 static int osd_probe(struct device *dev)
 396 {
 397         struct scsi_device *scsi_device = to_scsi_device(dev);
 398         struct gendisk *disk;
 399         struct osd_uld_device *oud;
 400         int minor;
 401         int error;
 402
 403         if (scsi_device->type != TYPE_OSD)
 404                 return -ENODEV;
 405
 406         do {
 407                 if (!ida_pre_get(&osd_minor_ida, GFP_KERNEL))
 408                         return -ENODEV;
 409
 410                 error = ida_get_new(&osd_minor_ida, &minor);
 411         } while (error == -EAGAIN);
 412
 413         if (error)
 414                 return error;
 415         if (minor >= SCSI_OSD_MAX_MINOR) {
 416                 error = -EBUSY;
 417                 goto err_retract_minor;
 418         }
 419
 420         error = -ENOMEM;
 421         oud = kzalloc(sizeof(*oud), GFP_KERNEL);
 422         if (NULL == oud)
 423                 goto err_retract_minor;
 424
 425         dev_set_drvdata(dev, oud);
 426         oud->minor = minor;
 427
 428         /* allocate a disk and set it up */
 429         /* FIXME: do we need this since sg has already done that */
 430         disk = alloc_disk(1);
 431         if (!disk) {
 432                 OSD_ERR("alloc_disk failed\n");
 433                 goto err_free_osd;
 434         }
 435         disk->major = SCSI_OSD_MAJOR;
 436         disk->first_minor = oud->minor;
 437         sprintf(disk->disk_name, "osd%d", oud->minor);
 438         oud->disk = disk;
 439
 440         /* hold one more reference to the scsi_device that will get released
 441          * in __release, in case a logout is happening while fs is mounted
 442          */
 443         scsi_device_get(scsi_device);
 444         osd_dev_init(&oud->od, scsi_device);
 445
 446         /* Detect the OSD Version */
 447         error = __detect_osd(oud);
 448         if (error) {
 449                 OSD_ERR("osd detection failed, non-compatible OSD device\n");
 450                 goto err_put_disk;
 451         }
 452
 453         /* init the char-device for communication with user-mode */
 454         cdev_init(&oud->cdev, &osd_fops);
 455         oud->cdev.owner = THIS_MODULE;
 456         error = cdev_add(&oud->cdev,
 457                          MKDEV(SCSI_OSD_MAJOR, oud->minor), 1);
 458         if (error) {
 459                 OSD_ERR("cdev_add failed\n");
 460                 goto err_put_disk;
 461         }
 462
 463         /* class device member */
 464         oud->class_dev.devt = oud->cdev.dev;
 465         oud->class_dev.class = &osd_uld_class;
 466         oud->class_dev.parent = dev;
 467         oud->class_dev.release = __remove;
 468         error = dev_set_name(&oud->class_dev, disk->disk_name);
 469         if (error) {
 470                 OSD_ERR("dev_set_name failed => %d\n", error);
 471                 goto err_put_cdev;
 472         }
 473
 474         error = device_register(&oud->class_dev);
 475         if (error) {
 476                 OSD_ERR("device_register failed => %d\n", error);
 477                 goto err_put_cdev;
 478         }
 479
 480         get_device(&oud->class_dev);
 481
 482         OSD_INFO("osd_probe %s\n", disk->disk_name);
 483         return 0;
 484
 485 err_put_cdev:
 486         cdev_del(&oud->cdev);
 487 err_put_disk:
 488         scsi_device_put(scsi_device);
 489         put_disk(disk);
 490 err_free_osd:
 491         dev_set_drvdata(dev, NULL);
 492         kfree(oud);
 493 err_retract_minor:
 494         ida_remove(&osd_minor_ida, minor);
 495         return error;
 496 }
 497
 498 static int osd_remove(struct device *dev)
 499 {
 500         struct scsi_device *scsi_device = to_scsi_device(dev);
 501         struct osd_uld_device *oud = dev_get_drvdata(dev);
 502
 503         if (!oud || (oud->od.scsi_device != scsi_device)) {
 504                 OSD_ERR("Half cooked osd-device %p,%p || %p!=%p",
 505                         dev, oud, oud ? oud->od.scsi_device : NULL,
 506                         scsi_device);
 507         }
 508
 509         device_unregister(&oud->class_dev);
 510
 511         put_device(&oud->class_dev);
 512         return 0;
 513 }
 514
 515 /*
 516  * Global driver and scsi registration
 517  */
 518
 519 static struct scsi_driver osd_driver = {
 520         .owner                  = THIS_MODULE,
 521         .gendrv = {
 522                 .name           = osd_name,
 523                 .probe          = osd_probe,
 524                 .remove         = osd_remove,
 525         }
 526 };
 527
 528 static int __init osd_uld_init(void)
 529 {
 530         int err;
 531
 532         err = class_register(&osd_uld_class);
 533         if (err) {
 534                 OSD_ERR("Unable to register sysfs class => %d\n", err);
 535                 return err;
 536         }
 537
 538         err = register_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0),
 539                                      SCSI_OSD_MAX_MINOR, osd_name);
 540         if (err) {
 541                 OSD_ERR("Unable to register major %d for osd ULD => %d\n",
 542                         SCSI_OSD_MAJOR, err);
 543                 goto err_out;
 544         }
 545
 546         err = scsi_register_driver(&osd_driver.gendrv);
 547         if (err) {
 548                 OSD_ERR("scsi_register_driver failed => %d\n", err);
 549                 goto err_out_chrdev;
 550         }
 551
 552         OSD_INFO("LOADED %s\n", osd_version_string);
 553         return 0;
 554
 555 err_out_chrdev:
 556         unregister_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0), SCSI_OSD_MAX_MINOR);
 557 err_out:
 558         class_unregister(&osd_uld_class);
 559         return err;
 560 }
 561
 562 static void __exit osd_uld_exit(void)
 563 {
 564         scsi_unregister_driver(&osd_driver.gendrv);
 565         unregister_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0), SCSI_OSD_MAX_MINOR);
 566         class_unregister(&osd_uld_class);
 567         OSD_INFO("UNLOADED %s\n", osd_version_string);
 568 }
 569
 570 module_init(osd_uld_init);
 571 module_exit(osd_uld_exit);