driver-core: constify data for class_find_device()
[deliverable/linux.git] / drivers / scsi / osd / osd_uld.c
CommitLineData
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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>
021e2230 52#include <linux/file.h>
5a0e3ad6 53#include <linux/slab.h>
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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
41f8ad76 72#define SCSI_OSD_MAX_MINOR MINORMASK
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73
74static const char osd_name[] = "osd";
41f8ad76 75static const char *osd_version_string = "open-osd 0.2.1";
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76
77MODULE_AUTHOR("Boaz Harrosh <bharrosh@panasas.com>");
78MODULE_DESCRIPTION("open-osd Upper-Layer-Driver osd.ko");
79MODULE_LICENSE("GPL");
80MODULE_ALIAS_CHARDEV_MAJOR(SCSI_OSD_MAJOR);
81MODULE_ALIAS_SCSI_DEVICE(TYPE_OSD);
82
83struct osd_uld_device {
84 int minor;
d6ae4333 85 struct device class_dev;
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86 struct cdev cdev;
87 struct osd_dev od;
2cdd6410 88 struct osd_dev_info odi;
95b05a7d 89 struct gendisk *disk;
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90};
91
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92struct osd_dev_handle {
93 struct osd_dev od;
94 struct file *file;
95 struct osd_uld_device *oud;
96} ;
97
98static DEFINE_IDA(osd_minor_ida);
99
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100/*
101 * scsi sysfs attribute operations
102 */
103static ssize_t osdname_show(struct device *dev, struct device_attribute *attr,
104 char *buf)
105{
106 struct osd_uld_device *ould = container_of(dev, struct osd_uld_device,
107 class_dev);
108 return sprintf(buf, "%s\n", ould->odi.osdname);
109}
110
111static ssize_t systemid_show(struct device *dev, struct device_attribute *attr,
112 char *buf)
113{
114 struct osd_uld_device *ould = container_of(dev, struct osd_uld_device,
115 class_dev);
116
117 memcpy(buf, ould->odi.systemid, ould->odi.systemid_len);
118 return ould->odi.systemid_len;
119}
120
121static struct device_attribute osd_uld_attrs[] = {
122 __ATTR(osdname, S_IRUGO, osdname_show, NULL),
123 __ATTR(systemid, S_IRUGO, systemid_show, NULL),
124 __ATTR_NULL,
125};
126
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127static struct class osd_uld_class = {
128 .owner = THIS_MODULE,
129 .name = "scsi_osd",
51976a8c 130 .dev_attrs = osd_uld_attrs,
d6ae4333 131};
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132
133/*
134 * Char Device operations
135 */
136
137static int osd_uld_open(struct inode *inode, struct file *file)
138{
139 struct osd_uld_device *oud = container_of(inode->i_cdev,
140 struct osd_uld_device, cdev);
141
d6ae4333 142 get_device(&oud->class_dev);
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143 /* cache osd_uld_device on file handle */
144 file->private_data = oud;
145 OSD_DEBUG("osd_uld_open %p\n", oud);
146 return 0;
147}
148
149static int osd_uld_release(struct inode *inode, struct file *file)
150{
151 struct osd_uld_device *oud = file->private_data;
152
153 OSD_DEBUG("osd_uld_release %p\n", file->private_data);
154 file->private_data = NULL;
d6ae4333 155 put_device(&oud->class_dev);
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156 return 0;
157}
158
159/* FIXME: Only one vector for now */
160unsigned g_test_ioctl;
161do_test_fn *g_do_test;
162
163int osduld_register_test(unsigned ioctl, do_test_fn *do_test)
164{
165 if (g_test_ioctl)
166 return -EINVAL;
167
168 g_test_ioctl = ioctl;
169 g_do_test = do_test;
170 return 0;
171}
172EXPORT_SYMBOL(osduld_register_test);
173
174void osduld_unregister_test(unsigned ioctl)
175{
176 if (ioctl == g_test_ioctl) {
177 g_test_ioctl = 0;
178 g_do_test = NULL;
179 }
180}
181EXPORT_SYMBOL(osduld_unregister_test);
182
183static do_test_fn *_find_ioctl(unsigned cmd)
184{
185 if (g_test_ioctl == cmd)
186 return g_do_test;
187 else
188 return NULL;
189}
190
191static long osd_uld_ioctl(struct file *file, unsigned int cmd,
192 unsigned long arg)
193{
194 struct osd_uld_device *oud = file->private_data;
195 int ret;
196 do_test_fn *do_test;
197
198 do_test = _find_ioctl(cmd);
199 if (do_test)
200 ret = do_test(&oud->od, cmd, arg);
201 else {
202 OSD_ERR("Unknown ioctl %d: osd_uld_device=%p\n", cmd, oud);
203 ret = -ENOIOCTLCMD;
204 }
205 return ret;
206}
207
208static const struct file_operations osd_fops = {
209 .owner = THIS_MODULE,
210 .open = osd_uld_open,
211 .release = osd_uld_release,
212 .unlocked_ioctl = osd_uld_ioctl,
6038f373 213 .llseek = noop_llseek,
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214};
215
e24977d4 216struct osd_dev *osduld_path_lookup(const char *name)
b799bc7d 217{
021e2230 218 struct osd_uld_device *oud;
d6ae4333 219 struct osd_dev_handle *odh;
021e2230 220 struct file *file;
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221 int error;
222
e24977d4 223 if (!name || !*name) {
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224 OSD_ERR("Mount with !path || !*path\n");
225 return ERR_PTR(-EINVAL);
226 }
227
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228 odh = kzalloc(sizeof(*odh), GFP_KERNEL);
229 if (unlikely(!odh))
021e2230 230 return ERR_PTR(-ENOMEM);
b799bc7d 231
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232 file = filp_open(name, O_RDWR, 0);
233 if (IS_ERR(file)) {
234 error = PTR_ERR(file);
235 goto free_od;
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236 }
237
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238 if (file->f_op != &osd_fops){
239 error = -EINVAL;
240 goto close_file;
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241 }
242
021e2230 243 oud = file->private_data;
b799bc7d 244
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245 odh->od = oud->od;
246 odh->file = file;
247 odh->oud = oud;
b799bc7d 248
d6ae4333 249 return &odh->od;
b799bc7d 250
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251close_file:
252 fput(file);
253free_od:
d6ae4333 254 kfree(odh);
021e2230 255 return ERR_PTR(error);
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256}
257EXPORT_SYMBOL(osduld_path_lookup);
258
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259static inline bool _the_same_or_null(const u8 *a1, unsigned a1_len,
260 const u8 *a2, unsigned a2_len)
261{
262 if (!a2_len) /* User string is Empty means don't care */
263 return true;
264
265 if (a1_len != a2_len)
266 return false;
267
268 return 0 == memcmp(a1, a2, a1_len);
269}
270
9f3b795a 271static int _match_odi(struct device *dev, const void *find_data)
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272{
273 struct osd_uld_device *oud = container_of(dev, struct osd_uld_device,
274 class_dev);
9f3b795a 275 const struct osd_dev_info *odi = find_data;
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276
277 if (_the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,
278 odi->systemid, odi->systemid_len) &&
279 _the_same_or_null(oud->odi.osdname, oud->odi.osdname_len,
280 odi->osdname, odi->osdname_len)) {
281 OSD_DEBUG("found device sysid_len=%d osdname=%d\n",
282 odi->systemid_len, odi->osdname_len);
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283 return 1;
284 } else {
285 return 0;
286 }
287}
288
289/* osduld_info_lookup - Loop through all devices, return the requested osd_dev.
290 *
291 * if @odi->systemid_len and/or @odi->osdname_len are zero, they act as a don't
292 * care. .e.g if they're both zero /dev/osd0 is returned.
293 */
294struct osd_dev *osduld_info_lookup(const struct osd_dev_info *odi)
295{
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296 struct device *dev = class_find_device(&osd_uld_class, NULL, odi, _match_odi);
297 if (likely(dev)) {
2cdd6410 298 struct osd_dev_handle *odh = kzalloc(sizeof(*odh), GFP_KERNEL);
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299 struct osd_uld_device *oud = container_of(dev,
300 struct osd_uld_device, class_dev);
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301
302 if (unlikely(!odh)) {
9f3b795a 303 put_device(dev);
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304 return ERR_PTR(-ENOMEM);
305 }
306
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307 odh->od = oud->od;
308 odh->oud = oud;
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309
310 return &odh->od;
311 }
312
313 return ERR_PTR(-ENODEV);
314}
315EXPORT_SYMBOL(osduld_info_lookup);
316
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317void osduld_put_device(struct osd_dev *od)
318{
021e2230 319 if (od && !IS_ERR(od)) {
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320 struct osd_dev_handle *odh =
321 container_of(od, struct osd_dev_handle, od);
322 struct osd_uld_device *oud = odh->oud;
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323
324 BUG_ON(od->scsi_device != oud->od.scsi_device);
325
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326 /* If scsi has released the device (logout), and exofs has last
327 * reference on oud it will be freed by above osd_uld_release
328 * within fput below. But this will oops in cdev_release which
d6ae4333 329 * is called after the fops->release. A get_/put_ pair makes
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330 * sure we have a cdev for the duration of fput
331 */
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332 if (odh->file) {
333 get_device(&oud->class_dev);
334 fput(odh->file);
335 }
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336 put_device(&oud->class_dev);
337 kfree(odh);
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338 }
339}
340EXPORT_SYMBOL(osduld_put_device);
341
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342const struct osd_dev_info *osduld_device_info(struct osd_dev *od)
343{
344 struct osd_dev_handle *odh =
345 container_of(od, struct osd_dev_handle, od);
346 return &odh->oud->odi;
347}
348EXPORT_SYMBOL(osduld_device_info);
349
350bool osduld_device_same(struct osd_dev *od, const struct osd_dev_info *odi)
351{
352 struct osd_dev_handle *odh =
353 container_of(od, struct osd_dev_handle, od);
354 struct osd_uld_device *oud = odh->oud;
355
356 return (oud->odi.systemid_len == odi->systemid_len) &&
357 _the_same_or_null(oud->odi.systemid, oud->odi.systemid_len,
358 odi->systemid, odi->systemid_len) &&
359 (oud->odi.osdname_len == odi->osdname_len) &&
360 _the_same_or_null(oud->odi.osdname, oud->odi.osdname_len,
361 odi->osdname, odi->osdname_len);
362}
363EXPORT_SYMBOL(osduld_device_same);
364
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365/*
366 * Scsi Device operations
367 */
368
369static int __detect_osd(struct osd_uld_device *oud)
370{
371 struct scsi_device *scsi_device = oud->od.scsi_device;
1b9dce94 372 char caps[OSD_CAP_LEN];
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373 int error;
374
375 /* sending a test_unit_ready as first command seems to be needed
376 * by some targets
377 */
378 OSD_DEBUG("start scsi_test_unit_ready %p %p %p\n",
379 oud, scsi_device, scsi_device->request_queue);
380 error = scsi_test_unit_ready(scsi_device, 10*HZ, 5, NULL);
381 if (error)
382 OSD_ERR("warning: scsi_test_unit_ready failed\n");
383
1b9dce94 384 osd_sec_init_nosec_doall_caps(caps, &osd_root_object, false, true);
2cdd6410 385 if (osd_auto_detect_ver(&oud->od, caps, &oud->odi))
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386 return -ENODEV;
387
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388 return 0;
389}
390
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391static void __remove(struct device *dev)
392{
393 struct osd_uld_device *oud = container_of(dev, struct osd_uld_device,
394 class_dev);
395 struct scsi_device *scsi_device = oud->od.scsi_device;
396
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397 kfree(oud->odi.osdname);
398
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399 if (oud->cdev.owner)
400 cdev_del(&oud->cdev);
401
402 osd_dev_fini(&oud->od);
403 scsi_device_put(scsi_device);
404
405 OSD_INFO("osd_remove %s\n",
406 oud->disk ? oud->disk->disk_name : NULL);
407
408 if (oud->disk)
409 put_disk(oud->disk);
410 ida_remove(&osd_minor_ida, oud->minor);
411
412 kfree(oud);
413}
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414
415static int osd_probe(struct device *dev)
416{
417 struct scsi_device *scsi_device = to_scsi_device(dev);
418 struct gendisk *disk;
419 struct osd_uld_device *oud;
420 int minor;
421 int error;
422
423 if (scsi_device->type != TYPE_OSD)
424 return -ENODEV;
425
426 do {
427 if (!ida_pre_get(&osd_minor_ida, GFP_KERNEL))
428 return -ENODEV;
429
430 error = ida_get_new(&osd_minor_ida, &minor);
431 } while (error == -EAGAIN);
432
433 if (error)
434 return error;
435 if (minor >= SCSI_OSD_MAX_MINOR) {
436 error = -EBUSY;
437 goto err_retract_minor;
438 }
439
440 error = -ENOMEM;
441 oud = kzalloc(sizeof(*oud), GFP_KERNEL);
442 if (NULL == oud)
443 goto err_retract_minor;
444
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445 dev_set_drvdata(dev, oud);
446 oud->minor = minor;
447
448 /* allocate a disk and set it up */
449 /* FIXME: do we need this since sg has already done that */
450 disk = alloc_disk(1);
451 if (!disk) {
452 OSD_ERR("alloc_disk failed\n");
453 goto err_free_osd;
454 }
455 disk->major = SCSI_OSD_MAJOR;
456 disk->first_minor = oud->minor;
457 sprintf(disk->disk_name, "osd%d", oud->minor);
458 oud->disk = disk;
459
460 /* hold one more reference to the scsi_device that will get released
461 * in __release, in case a logout is happening while fs is mounted
462 */
463 scsi_device_get(scsi_device);
464 osd_dev_init(&oud->od, scsi_device);
465
466 /* Detect the OSD Version */
467 error = __detect_osd(oud);
468 if (error) {
469 OSD_ERR("osd detection failed, non-compatible OSD device\n");
470 goto err_put_disk;
471 }
472
473 /* init the char-device for communication with user-mode */
474 cdev_init(&oud->cdev, &osd_fops);
475 oud->cdev.owner = THIS_MODULE;
476 error = cdev_add(&oud->cdev,
477 MKDEV(SCSI_OSD_MAJOR, oud->minor), 1);
478 if (error) {
479 OSD_ERR("cdev_add failed\n");
480 goto err_put_disk;
481 }
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482
483 /* class device member */
484 oud->class_dev.devt = oud->cdev.dev;
485 oud->class_dev.class = &osd_uld_class;
486 oud->class_dev.parent = dev;
487 oud->class_dev.release = __remove;
488 error = dev_set_name(&oud->class_dev, disk->disk_name);
489 if (error) {
490 OSD_ERR("dev_set_name failed => %d\n", error);
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491 goto err_put_cdev;
492 }
493
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494 error = device_register(&oud->class_dev);
495 if (error) {
496 OSD_ERR("device_register failed => %d\n", error);
497 goto err_put_cdev;
498 }
499
500 get_device(&oud->class_dev);
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501
502 OSD_INFO("osd_probe %s\n", disk->disk_name);
503 return 0;
504
505err_put_cdev:
506 cdev_del(&oud->cdev);
507err_put_disk:
508 scsi_device_put(scsi_device);
509 put_disk(disk);
510err_free_osd:
511 dev_set_drvdata(dev, NULL);
512 kfree(oud);
513err_retract_minor:
514 ida_remove(&osd_minor_ida, minor);
515 return error;
516}
517
518static int osd_remove(struct device *dev)
519{
520 struct scsi_device *scsi_device = to_scsi_device(dev);
521 struct osd_uld_device *oud = dev_get_drvdata(dev);
522
523 if (!oud || (oud->od.scsi_device != scsi_device)) {
524 OSD_ERR("Half cooked osd-device %p,%p || %p!=%p",
525 dev, oud, oud ? oud->od.scsi_device : NULL,
526 scsi_device);
527 }
528
d6ae4333 529 device_unregister(&oud->class_dev);
95b05a7d 530
d6ae4333 531 put_device(&oud->class_dev);
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532 return 0;
533}
534
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535/*
536 * Global driver and scsi registration
537 */
538
539static struct scsi_driver osd_driver = {
540 .owner = THIS_MODULE,
541 .gendrv = {
542 .name = osd_name,
543 .probe = osd_probe,
544 .remove = osd_remove,
545 }
546};
547
548static int __init osd_uld_init(void)
549{
550 int err;
551
d6ae4333
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552 err = class_register(&osd_uld_class);
553 if (err) {
554 OSD_ERR("Unable to register sysfs class => %d\n", err);
555 return err;
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556 }
557
558 err = register_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0),
559 SCSI_OSD_MAX_MINOR, osd_name);
560 if (err) {
561 OSD_ERR("Unable to register major %d for osd ULD => %d\n",
562 SCSI_OSD_MAJOR, err);
563 goto err_out;
564 }
565
566 err = scsi_register_driver(&osd_driver.gendrv);
567 if (err) {
568 OSD_ERR("scsi_register_driver failed => %d\n", err);
569 goto err_out_chrdev;
570 }
571
572 OSD_INFO("LOADED %s\n", osd_version_string);
573 return 0;
574
575err_out_chrdev:
576 unregister_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0), SCSI_OSD_MAX_MINOR);
577err_out:
d6ae4333 578 class_unregister(&osd_uld_class);
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579 return err;
580}
581
582static void __exit osd_uld_exit(void)
583{
584 scsi_unregister_driver(&osd_driver.gendrv);
585 unregister_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0), SCSI_OSD_MAX_MINOR);
d6ae4333 586 class_unregister(&osd_uld_class);
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587 OSD_INFO("UNLOADED %s\n", osd_version_string);
588}
589
590module_init(osd_uld_init);
591module_exit(osd_uld_exit);
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