aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/scsi/osd/osd_uld.c
blob: f8b1a749958b1f7cbfea0c095af5fdbee599da1e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
/*
 * 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);
	error = sysfs_create_link(&scsi_device->sdev_gendev.kobj,
				  &oud->class_member->kobj, osd_symlink);
	if (error)
		OSD_ERR("warning: unable to make symlink\n");

	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);
	}

	sysfs_remove_link(&oud->od.scsi_device->sdev_gendev.kobj, osd_symlink);

	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);