release/src-rt-6.x.4708/linux/linux-2.6.36/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 64
  73
  74 static const char osd_name[] = "osd";
  75 static const char *osd_version_string = "open-osd 0.2.0";
  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 unsigned g_test_ioctl;
 132 do_test_fn *g_do_test;
 133
 134 int osduld_register_test(unsigned ioctl, do_test_fn *do_test)
 135 {
 136         if (g_test_ioctl)
 137                 return -EINVAL;
 138
 139         g_test_ioctl = ioctl;
 140         g_do_test = do_test;
 141         return 0;
 142 }
 143 EXPORT_SYMBOL(osduld_register_test);
 144
 145 void osduld_unregister_test(unsigned ioctl)
 146 {
 147         if (ioctl == g_test_ioctl) {
 148                 g_test_ioctl = 0;
 149                 g_do_test = NULL;
 150         }
 151 }
 152 EXPORT_SYMBOL(osduld_unregister_test);
 153
 154 static do_test_fn *_find_ioctl(unsigned cmd)
 155 {
 156         if (g_test_ioctl == cmd)
 157                 return g_do_test;
 158         else
 159                 return NULL;
 160 }
 161
 162 static long osd_uld_ioctl(struct file *file, unsigned int cmd,
 163         unsigned long arg)
 164 {
 165         struct osd_uld_device *oud = file->private_data;
 166         int ret;
 167         do_test_fn *do_test;
 168
 169         do_test = _find_ioctl(cmd);
 170         if (do_test)
 171                 ret = do_test(&oud->od, cmd, arg);
 172         else {
 173                 OSD_ERR("Unknown ioctl %d: osd_uld_device=%p\n", cmd, oud);
 174                 ret = -ENOIOCTLCMD;
 175         }
 176         return ret;
 177 }
 178
 179 static const struct file_operations osd_fops = {
 180         .owner          = THIS_MODULE,
 181         .open           = osd_uld_open,
 182         .release        = osd_uld_release,
 183         .unlocked_ioctl = osd_uld_ioctl,
 184 };
 185
 186 struct osd_dev *osduld_path_lookup(const char *name)
 187 {
 188         struct osd_uld_device *oud;
 189         struct osd_dev_handle *odh;
 190         struct file *file;
 191         int error;
 192
 193         if (!name || !*name) {
 194                 OSD_ERR("Mount with !path || !*path\n");
 195                 return ERR_PTR(-EINVAL);
 196         }
 197
 198         odh = kzalloc(sizeof(*odh), GFP_KERNEL);
 199         if (unlikely(!odh))
 200                 return ERR_PTR(-ENOMEM);
 201
 202         file = filp_open(name, O_RDWR, 0);
 203         if (IS_ERR(file)) {
 204                 error = PTR_ERR(file);
 205                 goto free_od;
 206         }
 207
 208         if (file->f_op != &osd_fops){
 209                 error = -EINVAL;
 210                 goto close_file;
 211         }
 212
 213         oud = file->private_data;
 214
 215         odh->od = oud->od;
 216         odh->file = file;
 217         odh->oud = oud;
 218
 219         return &odh->od;
 220
 221 close_file:
 222         fput(file);
 223 free_od:
 224         kfree(odh);
 225         return ERR_PTR(error);
 226 }
 227 EXPORT_SYMBOL(osduld_path_lookup);
 228
 229 static inline bool _the_same_or_null(const u8 *a1, unsigned a1_len,
 230                                      const u8 *a2, unsigned a2_len)
 231 {
 232         if (!a2_len) /* User string is Empty means don't care */
 233                 return true;
 234
 235         if (a1_len != a2_len)
 236                 return false;
 237
 238         return 0 == memcmp(a1, a2, a1_len);
 239 }
 240
 241 struct find_oud_t {
 242         const struct osd_dev_info *odi;
 243         struct device *dev;
 244         struct osd_uld_device *oud;
 245 } ;
 246
 247 int _mach_odi(struct device *dev, void *find_data)
 248 {
 249         struct osd_uld_device *oud = container_of(dev, struct osd_uld_device,
 250                                                   class_dev);
 251         struct find_oud_t *fot = find_data;
 252         const struct osd_dev_info *odi = fot->odi;
 253
 254         if (_the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,
 255                               odi->systemid, odi->systemid_len) &&
 256             _the_same_or_null(oud->odi.osdname, oud->odi.osdname_len,
 257                               odi->osdname, odi->osdname_len)) {
 258                 OSD_DEBUG("found device sysid_len=%d osdname=%d\n",
 259                           odi->systemid_len, odi->osdname_len);
 260                 fot->oud = oud;
 261                 return 1;
 262         } else {
 263                 return 0;
 264         }
 265 }
 266
 267 /* osduld_info_lookup - Loop through all devices, return the requested osd_dev.
 268  *
 269  * if @odi->systemid_len and/or @odi->osdname_len are zero, they act as a don't
 270  * care. .e.g if they're both zero /dev/osd0 is returned.
 271  */
 272 struct osd_dev *osduld_info_lookup(const struct osd_dev_info *odi)
 273 {
 274         struct find_oud_t find = {.odi = odi};
 275
 276         find.dev = class_find_device(&osd_uld_class, NULL, &find, _mach_odi);
 277         if (likely(find.dev)) {
 278                 struct osd_dev_handle *odh = kzalloc(sizeof(*odh), GFP_KERNEL);
 279
 280                 if (unlikely(!odh)) {
 281                         put_device(find.dev);
 282                         return ERR_PTR(-ENOMEM);
 283                 }
 284
 285                 odh->od = find.oud->od;
 286                 odh->oud = find.oud;
 287
 288                 return &odh->od;
 289         }
 290
 291         return ERR_PTR(-ENODEV);
 292 }
 293 EXPORT_SYMBOL(osduld_info_lookup);
 294
 295 void osduld_put_device(struct osd_dev *od)
 296 {
 297         if (od && !IS_ERR(od)) {
 298                 struct osd_dev_handle *odh =
 299                                 container_of(od, struct osd_dev_handle, od);
 300                 struct osd_uld_device *oud = odh->oud;
 301
 302                 BUG_ON(od->scsi_device != oud->od.scsi_device);
 303
 304                 /* If scsi has released the device (logout), and exofs has last
 305                  * reference on oud it will be freed by above osd_uld_release
 306                  * within fput below. But this will oops in cdev_release which
 307                  * is called after the fops->release. A get_/put_ pair makes
 308                  * sure we have a cdev for the duration of fput
 309                  */
 310                 if (odh->file) {
 311                         get_device(&oud->class_dev);
 312                         fput(odh->file);
 313                 }
 314                 put_device(&oud->class_dev);
 315                 kfree(odh);
 316         }
 317 }
 318 EXPORT_SYMBOL(osduld_put_device);
 319
 320 const struct osd_dev_info *osduld_device_info(struct osd_dev *od)
 321 {
 322         struct osd_dev_handle *odh =
 323                                 container_of(od, struct osd_dev_handle, od);
 324         return &odh->oud->odi;
 325 }
 326 EXPORT_SYMBOL(osduld_device_info);
 327
 328 bool osduld_device_same(struct osd_dev *od, const struct osd_dev_info *odi)
 329 {
 330         struct osd_dev_handle *odh =
 331                                 container_of(od, struct osd_dev_handle, od);
 332         struct osd_uld_device *oud = odh->oud;
 333
 334         return (oud->odi.systemid_len == odi->systemid_len) &&
 335                 _the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,
 336                                  odi->systemid, odi->systemid_len) &&
 337                 (oud->odi.osdname_len == odi->osdname_len) &&
 338                 _the_same_or_null(oud->odi.osdname, oud->odi.osdname_len,
 339                                   odi->osdname, odi->osdname_len);
 340 }
 341 EXPORT_SYMBOL(osduld_device_same);
 342
 343 /*
 344  * Scsi Device operations
 345  */
 346
 347 static int __detect_osd(struct osd_uld_device *oud)
 348 {
 349         struct scsi_device *scsi_device = oud->od.scsi_device;
 350         char caps[OSD_CAP_LEN];
 351         int error;
 352
 353         /* sending a test_unit_ready as first command seems to be needed
 354          * by some targets
 355          */
 356         OSD_DEBUG("start scsi_test_unit_ready %p %p %p\n",
 357                         oud, scsi_device, scsi_device->request_queue);
 358         error = scsi_test_unit_ready(scsi_device, 10*HZ, 5, NULL);
 359         if (error)
 360                 OSD_ERR("warning: scsi_test_unit_ready failed\n");
 361
 362         osd_sec_init_nosec_doall_caps(caps, &osd_root_object, false, true);
 363         if (osd_auto_detect_ver(&oud->od, caps, &oud->odi))
 364                 return -ENODEV;
 365
 366         return 0;
 367 }
 368
 369 static void __remove(struct device *dev)
 370 {
 371         struct osd_uld_device *oud = container_of(dev, struct osd_uld_device,
 372                                                   class_dev);
 373         struct scsi_device *scsi_device = oud->od.scsi_device;
 374
 375         kfree(oud->odi.osdname);
 376
 377         if (oud->cdev.owner)
 378                 cdev_del(&oud->cdev);
 379
 380         osd_dev_fini(&oud->od);
 381         scsi_device_put(scsi_device);
 382
 383         OSD_INFO("osd_remove %s\n",
 384                  oud->disk ? oud->disk->disk_name : NULL);
 385
 386         if (oud->disk)
 387                 put_disk(oud->disk);
 388         ida_remove(&osd_minor_ida, oud->minor);
 389
 390         kfree(oud);
 391 }
 392
 393 static int osd_probe(struct device *dev)
 394 {
 395         struct scsi_device *scsi_device = to_scsi_device(dev);
 396         struct gendisk *disk;
 397         struct osd_uld_device *oud;
 398         int minor;
 399         int error;
 400
 401         if (scsi_device->type != TYPE_OSD)
 402                 return -ENODEV;
 403
 404         do {
 405                 if (!ida_pre_get(&osd_minor_ida, GFP_KERNEL))
 406                         return -ENODEV;
 407
 408                 error = ida_get_new(&osd_minor_ida, &minor);
 409         } while (error == -EAGAIN);
 410
 411         if (error)
 412                 return error;
 413         if (minor >= SCSI_OSD_MAX_MINOR) {
 414                 error = -EBUSY;
 415                 goto err_retract_minor;
 416         }
 417
 418         error = -ENOMEM;
 419         oud = kzalloc(sizeof(*oud), GFP_KERNEL);
 420         if (NULL == oud)
 421                 goto err_retract_minor;
 422
 423         dev_set_drvdata(dev, oud);
 424         oud->minor = minor;
 425
 426         /* allocate a disk and set it up */
 427         disk = alloc_disk(1);
 428         if (!disk) {
 429                 OSD_ERR("alloc_disk failed\n");
 430                 goto err_free_osd;
 431         }
 432         disk->major = SCSI_OSD_MAJOR;
 433         disk->first_minor = oud->minor;
 434         sprintf(disk->disk_name, "osd%d", oud->minor);
 435         oud->disk = disk;
 436
 437         /* hold one more reference to the scsi_device that will get released
 438          * in __release, in case a logout is happening while fs is mounted
 439          */
 440         scsi_device_get(scsi_device);
 441         osd_dev_init(&oud->od, scsi_device);
 442
 443         /* Detect the OSD Version */
 444         error = __detect_osd(oud);
 445         if (error) {
 446                 OSD_ERR("osd detection failed, non-compatible OSD device\n");
 447                 goto err_put_disk;
 448         }
 449
 450         /* init the char-device for communication with user-mode */
 451         cdev_init(&oud->cdev, &osd_fops);
 452         oud->cdev.owner = THIS_MODULE;
 453         error = cdev_add(&oud->cdev,
 454                          MKDEV(SCSI_OSD_MAJOR, oud->minor), 1);
 455         if (error) {
 456                 OSD_ERR("cdev_add failed\n");
 457                 goto err_put_disk;
 458         }
 459
 460         /* class device member */
 461         oud->class_dev.devt = oud->cdev.dev;
 462         oud->class_dev.class = &osd_uld_class;
 463         oud->class_dev.parent = dev;
 464         oud->class_dev.release = __remove;
 465         error = dev_set_name(&oud->class_dev, disk->disk_name);
 466         if (error) {
 467                 OSD_ERR("dev_set_name failed => %d\n", error);
 468                 goto err_put_cdev;
 469         }
 470
 471         error = device_register(&oud->class_dev);
 472         if (error) {
 473                 OSD_ERR("device_register failed => %d\n", error);
 474                 goto err_put_cdev;
 475         }
 476
 477         get_device(&oud->class_dev);
 478
 479         OSD_INFO("osd_probe %s\n", disk->disk_name);
 480         return 0;
 481
 482 err_put_cdev:
 483         cdev_del(&oud->cdev);
 484 err_put_disk:
 485         scsi_device_put(scsi_device);
 486         put_disk(disk);
 487 err_free_osd:
 488         dev_set_drvdata(dev, NULL);
 489         kfree(oud);
 490 err_retract_minor:
 491         ida_remove(&osd_minor_ida, minor);
 492         return error;
 493 }
 494
 495 static int osd_remove(struct device *dev)
 496 {
 497         struct scsi_device *scsi_device = to_scsi_device(dev);
 498         struct osd_uld_device *oud = dev_get_drvdata(dev);
 499
 500         if (!oud || (oud->od.scsi_device != scsi_device)) {
 501                 OSD_ERR("Half cooked osd-device %p,%p || %p!=%p",
 502                         dev, oud, oud ? oud->od.scsi_device : NULL,
 503                         scsi_device);
 504         }
 505
 506         device_unregister(&oud->class_dev);
 507
 508         put_device(&oud->class_dev);
 509         return 0;
 510 }
 511
 512 /*
 513  * Global driver and scsi registration
 514  */
 515
 516 static struct scsi_driver osd_driver = {
 517         .owner                  = THIS_MODULE,
 518         .gendrv = {
 519                 .name           = osd_name,
 520                 .probe          = osd_probe,
 521                 .remove         = osd_remove,
 522         }
 523 };
 524
 525 static int __init osd_uld_init(void)
 526 {
 527         int err;
 528
 529         err = class_register(&osd_uld_class);
 530         if (err) {
 531                 OSD_ERR("Unable to register sysfs class => %d\n", err);
 532                 return err;
 533         }
 534
 535         err = register_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0),
 536                                      SCSI_OSD_MAX_MINOR, osd_name);
 537         if (err) {
 538                 OSD_ERR("Unable to register major %d for osd ULD => %d\n",
 539                         SCSI_OSD_MAJOR, err);
 540                 goto err_out;
 541         }
 542
 543         err = scsi_register_driver(&osd_driver.gendrv);
 544         if (err) {
 545                 OSD_ERR("scsi_register_driver failed => %d\n", err);
 546                 goto err_out_chrdev;
 547         }
 548
 549         OSD_INFO("LOADED %s\n", osd_version_string);
 550         return 0;
 551
 552 err_out_chrdev:
 553         unregister_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0), SCSI_OSD_MAX_MINOR);
 554 err_out:
 555         class_unregister(&osd_uld_class);
 556         return err;
 557 }
 558
 559 static void __exit osd_uld_exit(void)
 560 {
 561         scsi_unregister_driver(&osd_driver.gendrv);
 562         unregister_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0), SCSI_OSD_MAX_MINOR);
 563         class_unregister(&osd_uld_class);
 564         OSD_INFO("UNLOADED %s\n", osd_version_string);
 565 }
 566
 567 module_init(osd_uld_init);
 568 module_exit(osd_uld_exit);