xref: /freebsd/sys/cam/ctl/ctl_backend_ramdisk.c (revision 0572ccaa4543b0abef8ef81e384c1d04de9f3da1)
1 /*-
2  * Copyright (c) 2003, 2008 Silicon Graphics International Corp.
3  * Copyright (c) 2012 The FreeBSD Foundation
4  * All rights reserved.
5  *
6  * Portions of this software were developed by Edward Tomasz Napierala
7  * under sponsorship from the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions, and the following disclaimer,
14  *    without modification.
15  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
16  *    substantially similar to the "NO WARRANTY" disclaimer below
17  *    ("Disclaimer") and any redistribution must be conditioned upon
18  *    including a substantially similar Disclaimer requirement for further
19  *    binary redistribution.
20  *
21  * NO WARRANTY
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
25  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
26  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
30  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
31  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGES.
33  *
34  * $Id: //depot/users/kenm/FreeBSD-test2/sys/cam/ctl/ctl_backend_ramdisk.c#3 $
35  */
36 /*
37  * CAM Target Layer backend for a "fake" ramdisk.
38  *
39  * Author: Ken Merry <ken@FreeBSD.org>
40  */
41 
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/condvar.h>
49 #include <sys/types.h>
50 #include <sys/lock.h>
51 #include <sys/mutex.h>
52 #include <sys/malloc.h>
53 #include <sys/taskqueue.h>
54 #include <sys/time.h>
55 #include <sys/queue.h>
56 #include <sys/conf.h>
57 #include <sys/ioccom.h>
58 #include <sys/module.h>
59 
60 #include <cam/scsi/scsi_all.h>
61 #include <cam/ctl/ctl_io.h>
62 #include <cam/ctl/ctl.h>
63 #include <cam/ctl/ctl_util.h>
64 #include <cam/ctl/ctl_backend.h>
65 #include <cam/ctl/ctl_frontend_internal.h>
66 #include <cam/ctl/ctl_debug.h>
67 #include <cam/ctl/ctl_ioctl.h>
68 #include <cam/ctl/ctl_error.h>
69 
70 typedef enum {
71 	CTL_BE_RAMDISK_LUN_UNCONFIGURED	= 0x01,
72 	CTL_BE_RAMDISK_LUN_CONFIG_ERR	= 0x02,
73 	CTL_BE_RAMDISK_LUN_WAITING	= 0x04
74 } ctl_be_ramdisk_lun_flags;
75 
76 struct ctl_be_ramdisk_lun {
77 	char lunname[32];
78 	uint64_t size_bytes;
79 	uint64_t size_blocks;
80 	struct ctl_be_ramdisk_softc *softc;
81 	ctl_be_ramdisk_lun_flags flags;
82 	STAILQ_ENTRY(ctl_be_ramdisk_lun) links;
83 	struct ctl_be_lun ctl_be_lun;
84 	struct taskqueue *io_taskqueue;
85 	struct task io_task;
86 	STAILQ_HEAD(, ctl_io_hdr) cont_queue;
87 	struct mtx lock;
88 };
89 
90 struct ctl_be_ramdisk_softc {
91 	struct mtx lock;
92 	int rd_size;
93 #ifdef CTL_RAMDISK_PAGES
94 	uint8_t **ramdisk_pages;
95 	int num_pages;
96 #else
97 	uint8_t *ramdisk_buffer;
98 #endif
99 	int num_luns;
100 	STAILQ_HEAD(, ctl_be_ramdisk_lun) lun_list;
101 };
102 
103 static struct ctl_be_ramdisk_softc rd_softc;
104 
105 int ctl_backend_ramdisk_init(void);
106 void ctl_backend_ramdisk_shutdown(void);
107 static int ctl_backend_ramdisk_move_done(union ctl_io *io);
108 static int ctl_backend_ramdisk_submit(union ctl_io *io);
109 static void ctl_backend_ramdisk_continue(union ctl_io *io);
110 static int ctl_backend_ramdisk_ioctl(struct cdev *dev, u_long cmd,
111 				     caddr_t addr, int flag, struct thread *td);
112 static int ctl_backend_ramdisk_rm(struct ctl_be_ramdisk_softc *softc,
113 				  struct ctl_lun_req *req);
114 static int ctl_backend_ramdisk_create(struct ctl_be_ramdisk_softc *softc,
115 				      struct ctl_lun_req *req, int do_wait);
116 static int ctl_backend_ramdisk_modify(struct ctl_be_ramdisk_softc *softc,
117 				  struct ctl_lun_req *req);
118 static void ctl_backend_ramdisk_worker(void *context, int pending);
119 static void ctl_backend_ramdisk_lun_shutdown(void *be_lun);
120 static void ctl_backend_ramdisk_lun_config_status(void *be_lun,
121 						  ctl_lun_config_status status);
122 static int ctl_backend_ramdisk_config_write(union ctl_io *io);
123 static int ctl_backend_ramdisk_config_read(union ctl_io *io);
124 
125 static struct ctl_backend_driver ctl_be_ramdisk_driver =
126 {
127 	.name = "ramdisk",
128 	.flags = CTL_BE_FLAG_HAS_CONFIG,
129 	.init = ctl_backend_ramdisk_init,
130 	.data_submit = ctl_backend_ramdisk_submit,
131 	.data_move_done = ctl_backend_ramdisk_move_done,
132 	.config_read = ctl_backend_ramdisk_config_read,
133 	.config_write = ctl_backend_ramdisk_config_write,
134 	.ioctl = ctl_backend_ramdisk_ioctl
135 };
136 
137 MALLOC_DEFINE(M_RAMDISK, "ramdisk", "Memory used for CTL RAMdisk");
138 CTL_BACKEND_DECLARE(cbr, ctl_be_ramdisk_driver);
139 
140 int
141 ctl_backend_ramdisk_init(void)
142 {
143 	struct ctl_be_ramdisk_softc *softc;
144 #ifdef CTL_RAMDISK_PAGES
145 	int i;
146 #endif
147 
148 
149 	softc = &rd_softc;
150 
151 	memset(softc, 0, sizeof(*softc));
152 
153 	mtx_init(&softc->lock, "ramdisk", NULL, MTX_DEF);
154 
155 	STAILQ_INIT(&softc->lun_list);
156 	softc->rd_size = 1024 * 1024;
157 #ifdef CTL_RAMDISK_PAGES
158 	softc->num_pages = softc->rd_size / PAGE_SIZE;
159 	softc->ramdisk_pages = (uint8_t **)malloc(sizeof(uint8_t *) *
160 						  softc->num_pages, M_RAMDISK,
161 						  M_WAITOK);
162 	for (i = 0; i < softc->num_pages; i++)
163 		softc->ramdisk_pages[i] = malloc(PAGE_SIZE, M_RAMDISK,M_WAITOK);
164 #else
165 	softc->ramdisk_buffer = (uint8_t *)malloc(softc->rd_size, M_RAMDISK,
166 						  M_WAITOK);
167 #endif
168 
169 	return (0);
170 }
171 
172 void
173 ctl_backend_ramdisk_shutdown(void)
174 {
175 	struct ctl_be_ramdisk_softc *softc;
176 	struct ctl_be_ramdisk_lun *lun, *next_lun;
177 #ifdef CTL_RAMDISK_PAGES
178 	int i;
179 #endif
180 
181 	softc = &rd_softc;
182 
183 	mtx_lock(&softc->lock);
184 	for (lun = STAILQ_FIRST(&softc->lun_list); lun != NULL; lun = next_lun){
185 		/*
186 		 * Grab the next LUN.  The current LUN may get removed by
187 		 * ctl_invalidate_lun(), which will call our LUN shutdown
188 		 * routine, if there is no outstanding I/O for this LUN.
189 		 */
190 		next_lun = STAILQ_NEXT(lun, links);
191 
192 		/*
193 		 * Drop our lock here.  Since ctl_invalidate_lun() can call
194 		 * back into us, this could potentially lead to a recursive
195 		 * lock of the same mutex, which would cause a hang.
196 		 */
197 		mtx_unlock(&softc->lock);
198 		ctl_disable_lun(&lun->ctl_be_lun);
199 		ctl_invalidate_lun(&lun->ctl_be_lun);
200 		mtx_lock(&softc->lock);
201 	}
202 	mtx_unlock(&softc->lock);
203 
204 #ifdef CTL_RAMDISK_PAGES
205 	for (i = 0; i < softc->num_pages; i++)
206 		free(softc->ramdisk_pages[i], M_RAMDISK);
207 
208 	free(softc->ramdisk_pages, M_RAMDISK);
209 #else
210 	free(softc->ramdisk_buffer, M_RAMDISK);
211 #endif
212 
213 	if (ctl_backend_deregister(&ctl_be_ramdisk_driver) != 0) {
214 		printf("ctl_backend_ramdisk_shutdown: "
215 		       "ctl_backend_deregister() failed!\n");
216 	}
217 }
218 
219 static int
220 ctl_backend_ramdisk_move_done(union ctl_io *io)
221 {
222 	struct ctl_be_lun *ctl_be_lun;
223 	struct ctl_be_ramdisk_lun *be_lun;
224 #ifdef CTL_TIME_IO
225 	struct bintime cur_bt;
226 #endif
227 
228 	CTL_DEBUG_PRINT(("ctl_backend_ramdisk_move_done\n"));
229 	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
230 		CTL_PRIV_BACKEND_LUN].ptr;
231 	be_lun = (struct ctl_be_ramdisk_lun *)ctl_be_lun->be_lun;
232 #ifdef CTL_TIME_IO
233 	getbintime(&cur_bt);
234 	bintime_sub(&cur_bt, &io->io_hdr.dma_start_bt);
235 	bintime_add(&io->io_hdr.dma_bt, &cur_bt);
236 	io->io_hdr.num_dmas++;
237 #endif
238 	if (io->scsiio.kern_sg_entries > 0)
239 		free(io->scsiio.kern_data_ptr, M_RAMDISK);
240 	io->scsiio.kern_rel_offset += io->scsiio.kern_data_len;
241 	if ((io->io_hdr.port_status == 0)
242 	 && ((io->io_hdr.flags & CTL_FLAG_ABORT) == 0)
243 	 && ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
244 		if (io->scsiio.kern_rel_offset < io->scsiio.kern_total_len) {
245 			mtx_lock(&be_lun->lock);
246 			STAILQ_INSERT_TAIL(&be_lun->cont_queue,
247 			    &io->io_hdr, links);
248 			mtx_unlock(&be_lun->lock);
249 			taskqueue_enqueue(be_lun->io_taskqueue,
250 			    &be_lun->io_task);
251 			return (0);
252 		}
253 		io->io_hdr.status = CTL_SUCCESS;
254 	} else if ((io->io_hdr.port_status != 0)
255 	      && ((io->io_hdr.flags & CTL_FLAG_ABORT) == 0)
256 	      && ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)){
257 		/*
258 		 * For hardware error sense keys, the sense key
259 		 * specific value is defined to be a retry count,
260 		 * but we use it to pass back an internal FETD
261 		 * error code.  XXX KDM  Hopefully the FETD is only
262 		 * using 16 bits for an error code, since that's
263 		 * all the space we have in the sks field.
264 		 */
265 		ctl_set_internal_failure(&io->scsiio,
266 					 /*sks_valid*/ 1,
267 					 /*retry_count*/
268 					 io->io_hdr.port_status);
269 	}
270 	ctl_done(io);
271 	return(0);
272 }
273 
274 static int
275 ctl_backend_ramdisk_submit(union ctl_io *io)
276 {
277 	struct ctl_lba_len lbalen;
278 	struct ctl_be_lun *ctl_be_lun;
279 
280 	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
281 		CTL_PRIV_BACKEND_LUN].ptr;
282 
283 	memcpy(&lbalen, io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN].bytes,
284 	       sizeof(lbalen));
285 	io->scsiio.be_move_done = ctl_backend_ramdisk_move_done;
286 	io->scsiio.kern_total_len = lbalen.len * ctl_be_lun->blocksize;
287 	io->scsiio.kern_rel_offset = 0;
288 	io->scsiio.kern_data_resid = 0;
289 	ctl_backend_ramdisk_continue(io);
290 
291 	return (CTL_RETVAL_COMPLETE);
292 }
293 
294 static void
295 ctl_backend_ramdisk_continue(union ctl_io *io)
296 {
297 	struct ctl_be_ramdisk_softc *softc;
298 	int len, len_filled, sg_filled;
299 #ifdef CTL_RAMDISK_PAGES
300 	struct ctl_sg_entry *sg_entries;
301 	int i;
302 #endif
303 
304 	softc = &rd_softc;
305 	len = io->scsiio.kern_total_len - io->scsiio.kern_rel_offset;
306 #ifdef CTL_RAMDISK_PAGES
307 	sg_filled = min(btoc(len), softc->num_pages);
308 	if (sg_filled > 1) {
309 		io->scsiio.kern_data_ptr = malloc(sizeof(struct ctl_sg_entry) *
310 						  sg_filled, M_RAMDISK,
311 						  M_WAITOK);
312 		sg_entries = (struct ctl_sg_entry *)io->scsiio.kern_data_ptr;
313 		for (i = 0, len_filled = 0; i < sg_filled; i++) {
314 			sg_entries[i].addr = softc->ramdisk_pages[i];
315 			sg_entries[i].len = ctl_min(PAGE_SIZE,
316 						    len - len_filled);
317 			len_filled += sg_entries[i].len;
318 		}
319 		io->io_hdr.flags |= CTL_FLAG_KDPTR_SGLIST;
320 	} else {
321 		sg_filled = 0;
322 		len_filled = len;
323 		io->scsiio.kern_data_ptr = softc->ramdisk_pages[0];
324 	}
325 #else
326 	sg_filled = 0;
327 	len_filled = min(len, softc->rd_size);
328 	io->scsiio.kern_data_ptr = softc->ramdisk_buffer;
329 #endif /* CTL_RAMDISK_PAGES */
330 
331 	io->scsiio.kern_data_len = len_filled;
332 	io->scsiio.kern_sg_entries = sg_filled;
333 	io->io_hdr.flags |= CTL_FLAG_ALLOCATED;
334 #ifdef CTL_TIME_IO
335 	getbintime(&io->io_hdr.dma_start_bt);
336 #endif
337 	ctl_datamove(io);
338 }
339 
340 static void
341 ctl_backend_ramdisk_worker(void *context, int pending)
342 {
343 	struct ctl_be_ramdisk_softc *softc;
344 	struct ctl_be_ramdisk_lun *be_lun;
345 	union ctl_io *io;
346 
347 	be_lun = (struct ctl_be_ramdisk_lun *)context;
348 	softc = be_lun->softc;
349 
350 	mtx_lock(&be_lun->lock);
351 	for (;;) {
352 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->cont_queue);
353 		if (io != NULL) {
354 			STAILQ_REMOVE(&be_lun->cont_queue, &io->io_hdr,
355 				      ctl_io_hdr, links);
356 
357 			mtx_unlock(&be_lun->lock);
358 
359 			ctl_backend_ramdisk_continue(io);
360 
361 			mtx_lock(&be_lun->lock);
362 			continue;
363 		}
364 
365 		/*
366 		 * If we get here, there is no work left in the queues, so
367 		 * just break out and let the task queue go to sleep.
368 		 */
369 		break;
370 	}
371 	mtx_unlock(&be_lun->lock);
372 }
373 
374 static int
375 ctl_backend_ramdisk_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
376 			  int flag, struct thread *td)
377 {
378 	struct ctl_be_ramdisk_softc *softc;
379 	int retval;
380 
381 	retval = 0;
382 	softc = &rd_softc;
383 
384 	switch (cmd) {
385 	case CTL_LUN_REQ: {
386 		struct ctl_lun_req *lun_req;
387 
388 		lun_req = (struct ctl_lun_req *)addr;
389 
390 		switch (lun_req->reqtype) {
391 		case CTL_LUNREQ_CREATE:
392 			retval = ctl_backend_ramdisk_create(softc, lun_req,
393 							    /*do_wait*/ 1);
394 			break;
395 		case CTL_LUNREQ_RM:
396 			retval = ctl_backend_ramdisk_rm(softc, lun_req);
397 			break;
398 		case CTL_LUNREQ_MODIFY:
399 			retval = ctl_backend_ramdisk_modify(softc, lun_req);
400 			break;
401 		default:
402 			lun_req->status = CTL_LUN_ERROR;
403 			snprintf(lun_req->error_str, sizeof(lun_req->error_str),
404 				 "%s: invalid LUN request type %d", __func__,
405 				 lun_req->reqtype);
406 			break;
407 		}
408 		break;
409 	}
410 	default:
411 		retval = ENOTTY;
412 		break;
413 	}
414 
415 	return (retval);
416 }
417 
418 static int
419 ctl_backend_ramdisk_rm(struct ctl_be_ramdisk_softc *softc,
420 		       struct ctl_lun_req *req)
421 {
422 	struct ctl_be_ramdisk_lun *be_lun;
423 	struct ctl_lun_rm_params *params;
424 	int retval;
425 
426 
427 	retval = 0;
428 	params = &req->reqdata.rm;
429 
430 	be_lun = NULL;
431 
432 	mtx_lock(&softc->lock);
433 
434 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
435 		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
436 			break;
437 	}
438 	mtx_unlock(&softc->lock);
439 
440 	if (be_lun == NULL) {
441 		snprintf(req->error_str, sizeof(req->error_str),
442 			 "%s: LUN %u is not managed by the ramdisk backend",
443 			 __func__, params->lun_id);
444 		goto bailout_error;
445 	}
446 
447 	retval = ctl_disable_lun(&be_lun->ctl_be_lun);
448 
449 	if (retval != 0) {
450 		snprintf(req->error_str, sizeof(req->error_str),
451 			 "%s: error %d returned from ctl_disable_lun() for "
452 			 "LUN %d", __func__, retval, params->lun_id);
453 		goto bailout_error;
454 	}
455 
456 	/*
457 	 * Set the waiting flag before we invalidate the LUN.  Our shutdown
458 	 * routine can be called any time after we invalidate the LUN,
459 	 * and can be called from our context.
460 	 *
461 	 * This tells the shutdown routine that we're waiting, or we're
462 	 * going to wait for the shutdown to happen.
463 	 */
464 	mtx_lock(&softc->lock);
465 	be_lun->flags |= CTL_BE_RAMDISK_LUN_WAITING;
466 	mtx_unlock(&softc->lock);
467 
468 	retval = ctl_invalidate_lun(&be_lun->ctl_be_lun);
469 	if (retval != 0) {
470 		snprintf(req->error_str, sizeof(req->error_str),
471 			 "%s: error %d returned from ctl_invalidate_lun() for "
472 			 "LUN %d", __func__, retval, params->lun_id);
473 		mtx_lock(&softc->lock);
474 		be_lun->flags &= ~CTL_BE_RAMDISK_LUN_WAITING;
475 		mtx_unlock(&softc->lock);
476 		goto bailout_error;
477 	}
478 
479 	mtx_lock(&softc->lock);
480 
481 	while ((be_lun->flags & CTL_BE_RAMDISK_LUN_UNCONFIGURED) == 0) {
482 		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlram", 0);
483  		if (retval == EINTR)
484 			break;
485 	}
486 	be_lun->flags &= ~CTL_BE_RAMDISK_LUN_WAITING;
487 
488 	/*
489 	 * We only remove this LUN from the list and free it (below) if
490 	 * retval == 0.  If the user interrupted the wait, we just bail out
491 	 * without actually freeing the LUN.  We let the shutdown routine
492 	 * free the LUN if that happens.
493 	 */
494 	if (retval == 0) {
495 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
496 			      links);
497 		softc->num_luns--;
498 	}
499 
500 	mtx_unlock(&softc->lock);
501 
502 	if (retval == 0) {
503 		taskqueue_drain(be_lun->io_taskqueue, &be_lun->io_task);
504 		taskqueue_free(be_lun->io_taskqueue);
505 		mtx_destroy(&be_lun->lock);
506 		free(be_lun, M_RAMDISK);
507 	}
508 
509 	req->status = CTL_LUN_OK;
510 
511 	return (retval);
512 
513 bailout_error:
514 	req->status = CTL_LUN_ERROR;
515 
516 	return (0);
517 }
518 
519 static int
520 ctl_backend_ramdisk_create(struct ctl_be_ramdisk_softc *softc,
521 			   struct ctl_lun_req *req, int do_wait)
522 {
523 	struct ctl_be_ramdisk_lun *be_lun;
524 	struct ctl_lun_create_params *params;
525 	uint32_t blocksize;
526 	char tmpstr[32];
527 	int i, retval, unmap;
528 
529 	retval = 0;
530 	params = &req->reqdata.create;
531 	if (params->blocksize_bytes != 0)
532 		blocksize = params->blocksize_bytes;
533 	else
534 		blocksize = 512;
535 
536 	be_lun = malloc(sizeof(*be_lun), M_RAMDISK, M_ZERO | (do_wait ?
537 			M_WAITOK : M_NOWAIT));
538 
539 	if (be_lun == NULL) {
540 		snprintf(req->error_str, sizeof(req->error_str),
541 			 "%s: error allocating %zd bytes", __func__,
542 			 sizeof(*be_lun));
543 		goto bailout_error;
544 	}
545 	sprintf(be_lun->lunname, "cram%d", softc->num_luns);
546 	STAILQ_INIT(&be_lun->ctl_be_lun.options);
547 
548 	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
549 		be_lun->ctl_be_lun.lun_type = params->device_type;
550 	else
551 		be_lun->ctl_be_lun.lun_type = T_DIRECT;
552 
553 	if (be_lun->ctl_be_lun.lun_type == T_DIRECT) {
554 
555 		if (params->lun_size_bytes < blocksize) {
556 			snprintf(req->error_str, sizeof(req->error_str),
557 				 "%s: LUN size %ju < blocksize %u", __func__,
558 				 params->lun_size_bytes, blocksize);
559 			goto bailout_error;
560 		}
561 
562 		be_lun->size_blocks = params->lun_size_bytes / blocksize;
563 		be_lun->size_bytes = be_lun->size_blocks * blocksize;
564 
565 		be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
566 	} else {
567 		be_lun->ctl_be_lun.maxlba = 0;
568 		blocksize = 0;
569 		be_lun->size_bytes = 0;
570 		be_lun->size_blocks = 0;
571 	}
572 
573 	be_lun->ctl_be_lun.blocksize = blocksize;
574 
575 	/* Tell the user the blocksize we ended up using */
576 	params->blocksize_bytes = blocksize;
577 
578 	/* Tell the user the exact size we ended up using */
579 	params->lun_size_bytes = be_lun->size_bytes;
580 
581 	be_lun->softc = softc;
582 
583 	unmap = 0;
584 	for (i = 0; i < req->num_be_args; i++) {
585 		if (strcmp(req->kern_be_args[i].kname, "unmap") == 0 &&
586 		    strcmp(req->kern_be_args[i].kvalue, "on") == 0) {
587 			unmap = 1;
588 		} else {
589 			struct ctl_be_lun_option *opt;
590 
591 			opt = malloc(sizeof(*opt), M_RAMDISK, M_WAITOK);
592 			opt->name = malloc(strlen(req->kern_be_args[i].kname) + 1, M_RAMDISK, M_WAITOK);
593 			strcpy(opt->name, req->kern_be_args[i].kname);
594 			opt->value = malloc(strlen(req->kern_be_args[i].kvalue) + 1, M_RAMDISK, M_WAITOK);
595 			strcpy(opt->value, req->kern_be_args[i].kvalue);
596 			STAILQ_INSERT_TAIL(&be_lun->ctl_be_lun.options, opt, links);
597 		}
598 	}
599 
600 	be_lun->flags = CTL_BE_RAMDISK_LUN_UNCONFIGURED;
601 	be_lun->ctl_be_lun.flags = CTL_LUN_FLAG_PRIMARY;
602 	if (unmap)
603 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_UNMAP;
604 	be_lun->ctl_be_lun.be_lun = be_lun;
605 
606 	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
607 		be_lun->ctl_be_lun.req_lun_id = params->req_lun_id;
608 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_ID_REQ;
609 	} else
610 		be_lun->ctl_be_lun.req_lun_id = 0;
611 
612 	be_lun->ctl_be_lun.lun_shutdown = ctl_backend_ramdisk_lun_shutdown;
613 	be_lun->ctl_be_lun.lun_config_status =
614 		ctl_backend_ramdisk_lun_config_status;
615 	be_lun->ctl_be_lun.be = &ctl_be_ramdisk_driver;
616 	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
617 		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
618 			 softc->num_luns);
619 		strncpy((char *)be_lun->ctl_be_lun.serial_num, tmpstr,
620 			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
621 			sizeof(tmpstr)));
622 
623 		/* Tell the user what we used for a serial number */
624 		strncpy((char *)params->serial_num, tmpstr,
625 			ctl_min(sizeof(params->serial_num), sizeof(tmpstr)));
626 	} else {
627 		strncpy((char *)be_lun->ctl_be_lun.serial_num,
628 			params->serial_num,
629 			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
630 			sizeof(params->serial_num)));
631 	}
632 	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
633 		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
634 		strncpy((char *)be_lun->ctl_be_lun.device_id, tmpstr,
635 			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
636 			sizeof(tmpstr)));
637 
638 		/* Tell the user what we used for a device ID */
639 		strncpy((char *)params->device_id, tmpstr,
640 			ctl_min(sizeof(params->device_id), sizeof(tmpstr)));
641 	} else {
642 		strncpy((char *)be_lun->ctl_be_lun.device_id,
643 			params->device_id,
644 			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
645 				sizeof(params->device_id)));
646 	}
647 
648 	STAILQ_INIT(&be_lun->cont_queue);
649 	mtx_init(&be_lun->lock, "CTL ramdisk", NULL, MTX_DEF);
650 	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_backend_ramdisk_worker,
651 	    be_lun);
652 
653 	be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
654 	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
655 	if (be_lun->io_taskqueue == NULL) {
656 		snprintf(req->error_str, sizeof(req->error_str),
657 			 "%s: Unable to create taskqueue", __func__);
658 		goto bailout_error;
659 	}
660 
661 	retval = taskqueue_start_threads(&be_lun->io_taskqueue,
662 					 /*num threads*/1,
663 					 /*priority*/PWAIT,
664 					 /*thread name*/
665 					 "%s taskq", be_lun->lunname);
666 	if (retval != 0)
667 		goto bailout_error;
668 
669 	mtx_lock(&softc->lock);
670 	softc->num_luns++;
671 	STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
672 
673 	mtx_unlock(&softc->lock);
674 
675 	retval = ctl_add_lun(&be_lun->ctl_be_lun);
676 	if (retval != 0) {
677 		mtx_lock(&softc->lock);
678 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
679 			      links);
680 		softc->num_luns--;
681 		mtx_unlock(&softc->lock);
682 		snprintf(req->error_str, sizeof(req->error_str),
683 			 "%s: ctl_add_lun() returned error %d, see dmesg for "
684 			"details", __func__, retval);
685 		retval = 0;
686 		goto bailout_error;
687 	}
688 
689 	if (do_wait == 0)
690 		return (retval);
691 
692 	mtx_lock(&softc->lock);
693 
694 	/*
695 	 * Tell the config_status routine that we're waiting so it won't
696 	 * clean up the LUN in the event of an error.
697 	 */
698 	be_lun->flags |= CTL_BE_RAMDISK_LUN_WAITING;
699 
700 	while (be_lun->flags & CTL_BE_RAMDISK_LUN_UNCONFIGURED) {
701 		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlram", 0);
702 		if (retval == EINTR)
703 			break;
704 	}
705 	be_lun->flags &= ~CTL_BE_RAMDISK_LUN_WAITING;
706 
707 	if (be_lun->flags & CTL_BE_RAMDISK_LUN_CONFIG_ERR) {
708 		snprintf(req->error_str, sizeof(req->error_str),
709 			 "%s: LUN configuration error, see dmesg for details",
710 			 __func__);
711 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
712 			      links);
713 		softc->num_luns--;
714 		mtx_unlock(&softc->lock);
715 		goto bailout_error;
716 	} else {
717 		params->req_lun_id = be_lun->ctl_be_lun.lun_id;
718 	}
719 	mtx_unlock(&softc->lock);
720 
721 	req->status = CTL_LUN_OK;
722 
723 	return (retval);
724 
725 bailout_error:
726 	req->status = CTL_LUN_ERROR;
727 	if (be_lun != NULL) {
728 		if (be_lun->io_taskqueue != NULL) {
729 			taskqueue_free(be_lun->io_taskqueue);
730 		}
731 		mtx_destroy(&be_lun->lock);
732 		free(be_lun, M_RAMDISK);
733 	}
734 
735 	return (retval);
736 }
737 
738 static int
739 ctl_backend_ramdisk_modify(struct ctl_be_ramdisk_softc *softc,
740 		       struct ctl_lun_req *req)
741 {
742 	struct ctl_be_ramdisk_lun *be_lun;
743 	struct ctl_lun_modify_params *params;
744 	uint32_t blocksize;
745 
746 	params = &req->reqdata.modify;
747 
748 	be_lun = NULL;
749 
750 	mtx_lock(&softc->lock);
751 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
752 		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
753 			break;
754 	}
755 	mtx_unlock(&softc->lock);
756 
757 	if (be_lun == NULL) {
758 		snprintf(req->error_str, sizeof(req->error_str),
759 			 "%s: LUN %u is not managed by the ramdisk backend",
760 			 __func__, params->lun_id);
761 		goto bailout_error;
762 	}
763 
764 	if (params->lun_size_bytes == 0) {
765 		snprintf(req->error_str, sizeof(req->error_str),
766 			"%s: LUN size \"auto\" not supported "
767 			"by the ramdisk backend", __func__);
768 		goto bailout_error;
769 	}
770 
771 	blocksize = be_lun->ctl_be_lun.blocksize;
772 
773 	if (params->lun_size_bytes < blocksize) {
774 		snprintf(req->error_str, sizeof(req->error_str),
775 			"%s: LUN size %ju < blocksize %u", __func__,
776 			params->lun_size_bytes, blocksize);
777 		goto bailout_error;
778 	}
779 
780 	be_lun->size_blocks = params->lun_size_bytes / blocksize;
781 	be_lun->size_bytes = be_lun->size_blocks * blocksize;
782 
783 	/*
784 	 * The maximum LBA is the size - 1.
785 	 *
786 	 * XXX: Note that this field is being updated without locking,
787 	 * 	which might cause problems on 32-bit architectures.
788 	 */
789 	be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
790 	ctl_lun_capacity_changed(&be_lun->ctl_be_lun);
791 
792 	/* Tell the user the exact size we ended up using */
793 	params->lun_size_bytes = be_lun->size_bytes;
794 
795 	req->status = CTL_LUN_OK;
796 
797 	return (0);
798 
799 bailout_error:
800 	req->status = CTL_LUN_ERROR;
801 
802 	return (0);
803 }
804 
805 static void
806 ctl_backend_ramdisk_lun_shutdown(void *be_lun)
807 {
808 	struct ctl_be_ramdisk_lun *lun;
809 	struct ctl_be_ramdisk_softc *softc;
810 	int do_free;
811 
812 	lun = (struct ctl_be_ramdisk_lun *)be_lun;
813 	softc = lun->softc;
814 	do_free = 0;
815 
816 	mtx_lock(&softc->lock);
817 
818 	lun->flags |= CTL_BE_RAMDISK_LUN_UNCONFIGURED;
819 
820 	if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING) {
821 		wakeup(lun);
822 	} else {
823 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
824 			      links);
825 		softc->num_luns--;
826 		do_free = 1;
827 	}
828 
829 	mtx_unlock(&softc->lock);
830 
831 	if (do_free != 0)
832 		free(be_lun, M_RAMDISK);
833 }
834 
835 static void
836 ctl_backend_ramdisk_lun_config_status(void *be_lun,
837 				      ctl_lun_config_status status)
838 {
839 	struct ctl_be_ramdisk_lun *lun;
840 	struct ctl_be_ramdisk_softc *softc;
841 
842 	lun = (struct ctl_be_ramdisk_lun *)be_lun;
843 	softc = lun->softc;
844 
845 	if (status == CTL_LUN_CONFIG_OK) {
846 		mtx_lock(&softc->lock);
847 		lun->flags &= ~CTL_BE_RAMDISK_LUN_UNCONFIGURED;
848 		if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING)
849 			wakeup(lun);
850 		mtx_unlock(&softc->lock);
851 
852 		/*
853 		 * We successfully added the LUN, attempt to enable it.
854 		 */
855 		if (ctl_enable_lun(&lun->ctl_be_lun) != 0) {
856 			printf("%s: ctl_enable_lun() failed!\n", __func__);
857 			if (ctl_invalidate_lun(&lun->ctl_be_lun) != 0) {
858 				printf("%s: ctl_invalidate_lun() failed!\n",
859 				       __func__);
860 			}
861 		}
862 
863 		return;
864 	}
865 
866 
867 	mtx_lock(&softc->lock);
868 	lun->flags &= ~CTL_BE_RAMDISK_LUN_UNCONFIGURED;
869 
870 	/*
871 	 * If we have a user waiting, let him handle the cleanup.  If not,
872 	 * clean things up here.
873 	 */
874 	if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING) {
875 		lun->flags |= CTL_BE_RAMDISK_LUN_CONFIG_ERR;
876 		wakeup(lun);
877 	} else {
878 		STAILQ_REMOVE(&softc->lun_list, lun, ctl_be_ramdisk_lun,
879 			      links);
880 		softc->num_luns--;
881 		free(lun, M_RAMDISK);
882 	}
883 	mtx_unlock(&softc->lock);
884 }
885 
886 static int
887 ctl_backend_ramdisk_config_write(union ctl_io *io)
888 {
889 	struct ctl_be_ramdisk_softc *softc;
890 	int retval;
891 
892 	retval = 0;
893 	softc = &rd_softc;
894 
895 	switch (io->scsiio.cdb[0]) {
896 	case SYNCHRONIZE_CACHE:
897 	case SYNCHRONIZE_CACHE_16:
898 		/*
899 		 * The upper level CTL code will filter out any CDBs with
900 		 * the immediate bit set and return the proper error.  It
901 		 * will also not allow a sync cache command to go to a LUN
902 		 * that is powered down.
903 		 *
904 		 * We don't really need to worry about what LBA range the
905 		 * user asked to be synced out.  When they issue a sync
906 		 * cache command, we'll sync out the whole thing.
907 		 *
908 		 * This is obviously just a stubbed out implementation.
909 		 * The real implementation will be in the RAIDCore/CTL
910 		 * interface, and can only really happen when RAIDCore
911 		 * implements a per-array cache sync.
912 		 */
913 		ctl_set_success(&io->scsiio);
914 		ctl_config_write_done(io);
915 		break;
916 	case START_STOP_UNIT: {
917 		struct scsi_start_stop_unit *cdb;
918 		struct ctl_be_lun *ctl_be_lun;
919 		struct ctl_be_ramdisk_lun *be_lun;
920 
921 		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
922 
923 		ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
924 			CTL_PRIV_BACKEND_LUN].ptr;
925 		be_lun = (struct ctl_be_ramdisk_lun *)ctl_be_lun->be_lun;
926 
927 		if (cdb->how & SSS_START)
928 			retval = ctl_start_lun(ctl_be_lun);
929 		else {
930 			retval = ctl_stop_lun(ctl_be_lun);
931 #ifdef NEEDTOPORT
932 			if ((retval == 0)
933 			 && (cdb->byte2 & SSS_ONOFFLINE))
934 				retval = ctl_lun_offline(ctl_be_lun);
935 #endif
936 		}
937 
938 		/*
939 		 * In general, the above routines should not fail.  They
940 		 * just set state for the LUN.  So we've got something
941 		 * pretty wrong here if we can't start or stop the LUN.
942 		 */
943 		if (retval != 0) {
944 			ctl_set_internal_failure(&io->scsiio,
945 						 /*sks_valid*/ 1,
946 						 /*retry_count*/ 0xf051);
947 			retval = CTL_RETVAL_COMPLETE;
948 		} else {
949 			ctl_set_success(&io->scsiio);
950 		}
951 		ctl_config_write_done(io);
952 		break;
953 	}
954 	case WRITE_SAME_10:
955 	case WRITE_SAME_16:
956 	case UNMAP:
957 		ctl_set_success(&io->scsiio);
958 		ctl_config_write_done(io);
959 		break;
960 	default:
961 		ctl_set_invalid_opcode(&io->scsiio);
962 		ctl_config_write_done(io);
963 		retval = CTL_RETVAL_COMPLETE;
964 		break;
965 	}
966 
967 	return (retval);
968 }
969 
970 static int
971 ctl_backend_ramdisk_config_read(union ctl_io *io)
972 {
973 	/*
974 	 * XXX KDM need to implement!!
975 	 */
976 	return (0);
977 }
978