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
74static const char osd_name[] = "osd";
75static const char *osd_version_string = "open-osd 0.2.1";
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;
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
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
100static struct class osd_uld_class = {
101	.owner		= THIS_MODULE,
102	.name		= "scsi_osd",
103};
104
105/*
106 * Char Device operations
107 */
108
109static 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
121static 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 */
132unsigned g_test_ioctl;
133do_test_fn *g_do_test;
134
135int 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}
144EXPORT_SYMBOL(osduld_register_test);
145
146void osduld_unregister_test(unsigned ioctl)
147{
148	if (ioctl == g_test_ioctl) {
149		g_test_ioctl = 0;
150		g_do_test = NULL;
151	}
152}
153EXPORT_SYMBOL(osduld_unregister_test);
154
155static 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
163static 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
180static 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
188struct 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
223close_file:
224	fput(file);
225free_od:
226	kfree(odh);
227	return ERR_PTR(error);
228}
229EXPORT_SYMBOL(osduld_path_lookup);
230
231static 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
243struct find_oud_t {
244	const struct osd_dev_info *odi;
245	struct device *dev;
246	struct osd_uld_device *oud;
247} ;
248
249int _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 */
274struct 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}
295EXPORT_SYMBOL(osduld_info_lookup);
296
297void 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}
320EXPORT_SYMBOL(osduld_put_device);
321
322const 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}
328EXPORT_SYMBOL(osduld_device_info);
329
330bool 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}
343EXPORT_SYMBOL(osduld_device_same);
344
345/*
346 * Scsi Device operations
347 */
348
349static 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
371static 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
395static 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
485err_put_cdev:
486	cdev_del(&oud->cdev);
487err_put_disk:
488	scsi_device_put(scsi_device);
489	put_disk(disk);
490err_free_osd:
491	dev_set_drvdata(dev, NULL);
492	kfree(oud);
493err_retract_minor:
494	ida_remove(&osd_minor_ida, minor);
495	return error;
496}
497
498static 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
519static 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
528static 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
555err_out_chrdev:
556	unregister_chrdev_region(MKDEV(SCSI_OSD_MAJOR, 0), SCSI_OSD_MAX_MINOR);
557err_out:
558	class_unregister(&osd_uld_class);
559	return err;
560}
561
562static 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
570module_init(osd_uld_init);
571module_exit(osd_uld_exit);
572