xref: /freebsd/sys/cam/ctl/ctl_backend_ramdisk.c (revision a0ee8cc636cd5c2374ec44ca71226564ea0bca95)
1 /*-
2  * Copyright (c) 2003, 2008 Silicon Graphics International Corp.
3  * Copyright (c) 2012 The FreeBSD Foundation
4  * Copyright (c) 2014-2015 Alexander Motin <mav@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Portions of this software were developed by Edward Tomasz Napierala
8  * under sponsorship from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions, and the following disclaimer,
15  *    without modification.
16  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
17  *    substantially similar to the "NO WARRANTY" disclaimer below
18  *    ("Disclaimer") and any redistribution must be conditioned upon
19  *    including a substantially similar Disclaimer requirement for further
20  *    binary redistribution.
21  *
22  * NO WARRANTY
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
32  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33  * POSSIBILITY OF SUCH DAMAGES.
34  *
35  * $Id: //depot/users/kenm/FreeBSD-test2/sys/cam/ctl/ctl_backend_ramdisk.c#3 $
36  */
37 /*
38  * CAM Target Layer backend for a "fake" ramdisk.
39  *
40  * Author: Ken Merry <ken@FreeBSD.org>
41  */
42 
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/condvar.h>
50 #include <sys/types.h>
51 #include <sys/lock.h>
52 #include <sys/mutex.h>
53 #include <sys/malloc.h>
54 #include <sys/taskqueue.h>
55 #include <sys/time.h>
56 #include <sys/queue.h>
57 #include <sys/conf.h>
58 #include <sys/ioccom.h>
59 #include <sys/module.h>
60 #include <sys/sysctl.h>
61 
62 #include <cam/scsi/scsi_all.h>
63 #include <cam/scsi/scsi_da.h>
64 #include <cam/ctl/ctl_io.h>
65 #include <cam/ctl/ctl.h>
66 #include <cam/ctl/ctl_util.h>
67 #include <cam/ctl/ctl_backend.h>
68 #include <cam/ctl/ctl_debug.h>
69 #include <cam/ctl/ctl_ioctl.h>
70 #include <cam/ctl/ctl_ha.h>
71 #include <cam/ctl/ctl_private.h>
72 #include <cam/ctl/ctl_error.h>
73 
74 typedef enum {
75 	CTL_BE_RAMDISK_LUN_UNCONFIGURED	= 0x01,
76 	CTL_BE_RAMDISK_LUN_CONFIG_ERR	= 0x02,
77 	CTL_BE_RAMDISK_LUN_WAITING	= 0x04
78 } ctl_be_ramdisk_lun_flags;
79 
80 struct ctl_be_ramdisk_lun {
81 	struct ctl_lun_create_params params;
82 	char lunname[32];
83 	uint64_t size_bytes;
84 	uint64_t size_blocks;
85 	struct ctl_be_ramdisk_softc *softc;
86 	ctl_be_ramdisk_lun_flags flags;
87 	STAILQ_ENTRY(ctl_be_ramdisk_lun) links;
88 	struct ctl_be_lun cbe_lun;
89 	struct taskqueue *io_taskqueue;
90 	struct task io_task;
91 	STAILQ_HEAD(, ctl_io_hdr) cont_queue;
92 	struct mtx_padalign queue_lock;
93 };
94 
95 struct ctl_be_ramdisk_softc {
96 	struct mtx lock;
97 	int rd_size;
98 #ifdef CTL_RAMDISK_PAGES
99 	uint8_t **ramdisk_pages;
100 	int num_pages;
101 #else
102 	uint8_t *ramdisk_buffer;
103 #endif
104 	int num_luns;
105 	STAILQ_HEAD(, ctl_be_ramdisk_lun) lun_list;
106 };
107 
108 static struct ctl_be_ramdisk_softc rd_softc;
109 extern struct ctl_softc *control_softc;
110 
111 int ctl_backend_ramdisk_init(void);
112 void ctl_backend_ramdisk_shutdown(void);
113 static int ctl_backend_ramdisk_move_done(union ctl_io *io);
114 static int ctl_backend_ramdisk_submit(union ctl_io *io);
115 static void ctl_backend_ramdisk_continue(union ctl_io *io);
116 static int ctl_backend_ramdisk_ioctl(struct cdev *dev, u_long cmd,
117 				     caddr_t addr, int flag, struct thread *td);
118 static int ctl_backend_ramdisk_rm(struct ctl_be_ramdisk_softc *softc,
119 				  struct ctl_lun_req *req);
120 static int ctl_backend_ramdisk_create(struct ctl_be_ramdisk_softc *softc,
121 				      struct ctl_lun_req *req);
122 static int ctl_backend_ramdisk_modify(struct ctl_be_ramdisk_softc *softc,
123 				  struct ctl_lun_req *req);
124 static void ctl_backend_ramdisk_worker(void *context, int pending);
125 static void ctl_backend_ramdisk_lun_shutdown(void *be_lun);
126 static void ctl_backend_ramdisk_lun_config_status(void *be_lun,
127 						  ctl_lun_config_status status);
128 static int ctl_backend_ramdisk_config_write(union ctl_io *io);
129 static int ctl_backend_ramdisk_config_read(union ctl_io *io);
130 
131 static struct ctl_backend_driver ctl_be_ramdisk_driver =
132 {
133 	.name = "ramdisk",
134 	.flags = CTL_BE_FLAG_HAS_CONFIG,
135 	.init = ctl_backend_ramdisk_init,
136 	.data_submit = ctl_backend_ramdisk_submit,
137 	.data_move_done = ctl_backend_ramdisk_move_done,
138 	.config_read = ctl_backend_ramdisk_config_read,
139 	.config_write = ctl_backend_ramdisk_config_write,
140 	.ioctl = ctl_backend_ramdisk_ioctl
141 };
142 
143 MALLOC_DEFINE(M_RAMDISK, "ramdisk", "Memory used for CTL RAMdisk");
144 CTL_BACKEND_DECLARE(cbr, ctl_be_ramdisk_driver);
145 
146 int
147 ctl_backend_ramdisk_init(void)
148 {
149 	struct ctl_be_ramdisk_softc *softc = &rd_softc;
150 #ifdef CTL_RAMDISK_PAGES
151 	int i;
152 #endif
153 
154 	memset(softc, 0, sizeof(*softc));
155 	mtx_init(&softc->lock, "ctlramdisk", NULL, MTX_DEF);
156 	STAILQ_INIT(&softc->lun_list);
157 	softc->rd_size = 1024 * 1024;
158 #ifdef CTL_RAMDISK_PAGES
159 	softc->num_pages = softc->rd_size / PAGE_SIZE;
160 	softc->ramdisk_pages = (uint8_t **)malloc(sizeof(uint8_t *) *
161 						  softc->num_pages, M_RAMDISK,
162 						  M_WAITOK);
163 	for (i = 0; i < softc->num_pages; i++)
164 		softc->ramdisk_pages[i] = malloc(PAGE_SIZE, M_RAMDISK,M_WAITOK);
165 #else
166 	softc->ramdisk_buffer = (uint8_t *)malloc(softc->rd_size, M_RAMDISK,
167 						  M_WAITOK);
168 #endif
169 
170 	return (0);
171 }
172 
173 void
174 ctl_backend_ramdisk_shutdown(void)
175 {
176 	struct ctl_be_ramdisk_softc *softc = &rd_softc;
177 	struct ctl_be_ramdisk_lun *lun, *next_lun;
178 #ifdef CTL_RAMDISK_PAGES
179 	int i;
180 #endif
181 
182 	mtx_lock(&softc->lock);
183 	STAILQ_FOREACH_SAFE(lun, &softc->lun_list, links, next_lun) {
184 		/*
185 		 * Drop our lock here.  Since ctl_invalidate_lun() can call
186 		 * back into us, this could potentially lead to a recursive
187 		 * lock of the same mutex, which would cause a hang.
188 		 */
189 		mtx_unlock(&softc->lock);
190 		ctl_disable_lun(&lun->cbe_lun);
191 		ctl_invalidate_lun(&lun->cbe_lun);
192 		mtx_lock(&softc->lock);
193 	}
194 	mtx_unlock(&softc->lock);
195 
196 #ifdef CTL_RAMDISK_PAGES
197 	for (i = 0; i < softc->num_pages; i++)
198 		free(softc->ramdisk_pages[i], M_RAMDISK);
199 
200 	free(softc->ramdisk_pages, M_RAMDISK);
201 #else
202 	free(softc->ramdisk_buffer, M_RAMDISK);
203 #endif
204 
205 	if (ctl_backend_deregister(&ctl_be_ramdisk_driver) != 0) {
206 		printf("ctl_backend_ramdisk_shutdown: "
207 		       "ctl_backend_deregister() failed!\n");
208 	}
209 }
210 
211 static int
212 ctl_backend_ramdisk_move_done(union ctl_io *io)
213 {
214 	struct ctl_be_lun *cbe_lun;
215 	struct ctl_be_ramdisk_lun *be_lun;
216 #ifdef CTL_TIME_IO
217 	struct bintime cur_bt;
218 #endif
219 
220 	CTL_DEBUG_PRINT(("ctl_backend_ramdisk_move_done\n"));
221 	cbe_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
222 		CTL_PRIV_BACKEND_LUN].ptr;
223 	be_lun = (struct ctl_be_ramdisk_lun *)cbe_lun->be_lun;
224 #ifdef CTL_TIME_IO
225 	getbinuptime(&cur_bt);
226 	bintime_sub(&cur_bt, &io->io_hdr.dma_start_bt);
227 	bintime_add(&io->io_hdr.dma_bt, &cur_bt);
228 #endif
229 	io->io_hdr.num_dmas++;
230 	if (io->scsiio.kern_sg_entries > 0)
231 		free(io->scsiio.kern_data_ptr, M_RAMDISK);
232 	io->scsiio.kern_rel_offset += io->scsiio.kern_data_len;
233 	if (io->io_hdr.flags & CTL_FLAG_ABORT) {
234 		;
235 	} else if ((io->io_hdr.port_status == 0) &&
236 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
237 		if (io->io_hdr.ctl_private[CTL_PRIV_BACKEND].integer > 0) {
238 			mtx_lock(&be_lun->queue_lock);
239 			STAILQ_INSERT_TAIL(&be_lun->cont_queue,
240 			    &io->io_hdr, links);
241 			mtx_unlock(&be_lun->queue_lock);
242 			taskqueue_enqueue(be_lun->io_taskqueue,
243 			    &be_lun->io_task);
244 			return (0);
245 		}
246 		ctl_set_success(&io->scsiio);
247 	} else if ((io->io_hdr.port_status != 0) &&
248 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE ||
249 	     (io->io_hdr.status & CTL_STATUS_MASK) == CTL_SUCCESS)) {
250 		/*
251 		 * For hardware error sense keys, the sense key
252 		 * specific value is defined to be a retry count,
253 		 * but we use it to pass back an internal FETD
254 		 * error code.  XXX KDM  Hopefully the FETD is only
255 		 * using 16 bits for an error code, since that's
256 		 * all the space we have in the sks field.
257 		 */
258 		ctl_set_internal_failure(&io->scsiio,
259 					 /*sks_valid*/ 1,
260 					 /*retry_count*/
261 					 io->io_hdr.port_status);
262 	}
263 	ctl_data_submit_done(io);
264 	return(0);
265 }
266 
267 static int
268 ctl_backend_ramdisk_submit(union ctl_io *io)
269 {
270 	struct ctl_be_lun *cbe_lun;
271 	struct ctl_lba_len_flags *lbalen;
272 
273 	cbe_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
274 		CTL_PRIV_BACKEND_LUN].ptr;
275 	lbalen = (struct ctl_lba_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
276 	if (lbalen->flags & CTL_LLF_VERIFY) {
277 		ctl_set_success(&io->scsiio);
278 		ctl_data_submit_done(io);
279 		return (CTL_RETVAL_COMPLETE);
280 	}
281 	io->io_hdr.ctl_private[CTL_PRIV_BACKEND].integer =
282 	    lbalen->len * cbe_lun->blocksize;
283 	ctl_backend_ramdisk_continue(io);
284 	return (CTL_RETVAL_COMPLETE);
285 }
286 
287 static void
288 ctl_backend_ramdisk_continue(union ctl_io *io)
289 {
290 	struct ctl_be_ramdisk_softc *softc;
291 	int len, len_filled, sg_filled;
292 #ifdef CTL_RAMDISK_PAGES
293 	struct ctl_sg_entry *sg_entries;
294 	int i;
295 #endif
296 
297 	softc = &rd_softc;
298 	len = io->io_hdr.ctl_private[CTL_PRIV_BACKEND].integer;
299 #ifdef CTL_RAMDISK_PAGES
300 	sg_filled = min(btoc(len), softc->num_pages);
301 	if (sg_filled > 1) {
302 		io->scsiio.kern_data_ptr = malloc(sizeof(struct ctl_sg_entry) *
303 						  sg_filled, M_RAMDISK,
304 						  M_WAITOK);
305 		sg_entries = (struct ctl_sg_entry *)io->scsiio.kern_data_ptr;
306 		for (i = 0, len_filled = 0; i < sg_filled; i++) {
307 			sg_entries[i].addr = softc->ramdisk_pages[i];
308 			sg_entries[i].len = MIN(PAGE_SIZE, len - len_filled);
309 			len_filled += sg_entries[i].len;
310 		}
311 	} else {
312 		sg_filled = 0;
313 		len_filled = len;
314 		io->scsiio.kern_data_ptr = softc->ramdisk_pages[0];
315 	}
316 #else
317 	sg_filled = 0;
318 	len_filled = min(len, softc->rd_size);
319 	io->scsiio.kern_data_ptr = softc->ramdisk_buffer;
320 #endif /* CTL_RAMDISK_PAGES */
321 
322 	io->scsiio.be_move_done = ctl_backend_ramdisk_move_done;
323 	io->scsiio.kern_data_resid = 0;
324 	io->scsiio.kern_data_len = len_filled;
325 	io->scsiio.kern_sg_entries = sg_filled;
326 	io->io_hdr.flags |= CTL_FLAG_ALLOCATED;
327 	io->io_hdr.ctl_private[CTL_PRIV_BACKEND].integer -= len_filled;
328 #ifdef CTL_TIME_IO
329 	getbinuptime(&io->io_hdr.dma_start_bt);
330 #endif
331 	ctl_datamove(io);
332 }
333 
334 static void
335 ctl_backend_ramdisk_worker(void *context, int pending)
336 {
337 	struct ctl_be_ramdisk_lun *be_lun;
338 	union ctl_io *io;
339 
340 	be_lun = (struct ctl_be_ramdisk_lun *)context;
341 
342 	mtx_lock(&be_lun->queue_lock);
343 	for (;;) {
344 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->cont_queue);
345 		if (io != NULL) {
346 			STAILQ_REMOVE(&be_lun->cont_queue, &io->io_hdr,
347 				      ctl_io_hdr, links);
348 			mtx_unlock(&be_lun->queue_lock);
349 			ctl_backend_ramdisk_continue(io);
350 			mtx_lock(&be_lun->queue_lock);
351 			continue;
352 		}
353 
354 		/*
355 		 * If we get here, there is no work left in the queues, so
356 		 * just break out and let the task queue go to sleep.
357 		 */
358 		break;
359 	}
360 	mtx_unlock(&be_lun->queue_lock);
361 }
362 
363 static int
364 ctl_backend_ramdisk_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
365 			  int flag, struct thread *td)
366 {
367 	struct ctl_be_ramdisk_softc *softc = &rd_softc;
368 	struct ctl_lun_req *lun_req;
369 	int retval;
370 
371 	retval = 0;
372 	switch (cmd) {
373 	case CTL_LUN_REQ:
374 		lun_req = (struct ctl_lun_req *)addr;
375 		switch (lun_req->reqtype) {
376 		case CTL_LUNREQ_CREATE:
377 			retval = ctl_backend_ramdisk_create(softc, lun_req);
378 			break;
379 		case CTL_LUNREQ_RM:
380 			retval = ctl_backend_ramdisk_rm(softc, lun_req);
381 			break;
382 		case CTL_LUNREQ_MODIFY:
383 			retval = ctl_backend_ramdisk_modify(softc, lun_req);
384 			break;
385 		default:
386 			lun_req->status = CTL_LUN_ERROR;
387 			snprintf(lun_req->error_str, sizeof(lun_req->error_str),
388 				 "%s: invalid LUN request type %d", __func__,
389 				 lun_req->reqtype);
390 			break;
391 		}
392 		break;
393 	default:
394 		retval = ENOTTY;
395 		break;
396 	}
397 
398 	return (retval);
399 }
400 
401 static int
402 ctl_backend_ramdisk_rm(struct ctl_be_ramdisk_softc *softc,
403 		       struct ctl_lun_req *req)
404 {
405 	struct ctl_be_ramdisk_lun *be_lun;
406 	struct ctl_lun_rm_params *params;
407 	int retval;
408 
409 	params = &req->reqdata.rm;
410 	mtx_lock(&softc->lock);
411 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
412 		if (be_lun->cbe_lun.lun_id == params->lun_id)
413 			break;
414 	}
415 	mtx_unlock(&softc->lock);
416 	if (be_lun == NULL) {
417 		snprintf(req->error_str, sizeof(req->error_str),
418 			 "%s: LUN %u is not managed by the ramdisk backend",
419 			 __func__, params->lun_id);
420 		goto bailout_error;
421 	}
422 
423 	retval = ctl_disable_lun(&be_lun->cbe_lun);
424 	if (retval != 0) {
425 		snprintf(req->error_str, sizeof(req->error_str),
426 			 "%s: error %d returned from ctl_disable_lun() for "
427 			 "LUN %d", __func__, retval, params->lun_id);
428 		goto bailout_error;
429 	}
430 
431 	/*
432 	 * Set the waiting flag before we invalidate the LUN.  Our shutdown
433 	 * routine can be called any time after we invalidate the LUN,
434 	 * and can be called from our context.
435 	 *
436 	 * This tells the shutdown routine that we're waiting, or we're
437 	 * going to wait for the shutdown to happen.
438 	 */
439 	mtx_lock(&softc->lock);
440 	be_lun->flags |= CTL_BE_RAMDISK_LUN_WAITING;
441 	mtx_unlock(&softc->lock);
442 
443 	retval = ctl_invalidate_lun(&be_lun->cbe_lun);
444 	if (retval != 0) {
445 		snprintf(req->error_str, sizeof(req->error_str),
446 			 "%s: error %d returned from ctl_invalidate_lun() for "
447 			 "LUN %d", __func__, retval, params->lun_id);
448 		mtx_lock(&softc->lock);
449 		be_lun->flags &= ~CTL_BE_RAMDISK_LUN_WAITING;
450 		mtx_unlock(&softc->lock);
451 		goto bailout_error;
452 	}
453 
454 	mtx_lock(&softc->lock);
455 	while ((be_lun->flags & CTL_BE_RAMDISK_LUN_UNCONFIGURED) == 0) {
456 		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlram", 0);
457 		if (retval == EINTR)
458 			break;
459 	}
460 	be_lun->flags &= ~CTL_BE_RAMDISK_LUN_WAITING;
461 
462 	/*
463 	 * We only remove this LUN from the list and free it (below) if
464 	 * retval == 0.  If the user interrupted the wait, we just bail out
465 	 * without actually freeing the LUN.  We let the shutdown routine
466 	 * free the LUN if that happens.
467 	 */
468 	if (retval == 0) {
469 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
470 			      links);
471 		softc->num_luns--;
472 	}
473 
474 	mtx_unlock(&softc->lock);
475 
476 	if (retval == 0) {
477 		taskqueue_drain_all(be_lun->io_taskqueue);
478 		taskqueue_free(be_lun->io_taskqueue);
479 		ctl_free_opts(&be_lun->cbe_lun.options);
480 		mtx_destroy(&be_lun->queue_lock);
481 		free(be_lun, M_RAMDISK);
482 	}
483 
484 	req->status = CTL_LUN_OK;
485 	return (retval);
486 
487 bailout_error:
488 	req->status = CTL_LUN_ERROR;
489 	return (0);
490 }
491 
492 static int
493 ctl_backend_ramdisk_create(struct ctl_be_ramdisk_softc *softc,
494 			   struct ctl_lun_req *req)
495 {
496 	struct ctl_be_ramdisk_lun *be_lun;
497 	struct ctl_be_lun *cbe_lun;
498 	struct ctl_lun_create_params *params;
499 	char *value;
500 	char tmpstr[32];
501 	int retval;
502 
503 	retval = 0;
504 	params = &req->reqdata.create;
505 
506 	be_lun = malloc(sizeof(*be_lun), M_RAMDISK, M_ZERO | M_WAITOK);
507 	cbe_lun = &be_lun->cbe_lun;
508 	cbe_lun->be_lun = be_lun;
509 	be_lun->params = req->reqdata.create;
510 	be_lun->softc = softc;
511 	sprintf(be_lun->lunname, "cram%d", softc->num_luns);
512 	ctl_init_opts(&cbe_lun->options, req->num_be_args, req->kern_be_args);
513 
514 	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
515 		cbe_lun->lun_type = params->device_type;
516 	else
517 		cbe_lun->lun_type = T_DIRECT;
518 	be_lun->flags = CTL_BE_RAMDISK_LUN_UNCONFIGURED;
519 	cbe_lun->flags = 0;
520 	value = ctl_get_opt(&cbe_lun->options, "ha_role");
521 	if (value != NULL) {
522 		if (strcmp(value, "primary") == 0)
523 			cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
524 	} else if (control_softc->flags & CTL_FLAG_ACTIVE_SHELF)
525 		cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
526 
527 	if (cbe_lun->lun_type == T_DIRECT ||
528 	    cbe_lun->lun_type == T_CDROM) {
529 		if (params->blocksize_bytes != 0)
530 			cbe_lun->blocksize = params->blocksize_bytes;
531 		else if (cbe_lun->lun_type == T_CDROM)
532 			cbe_lun->blocksize = 2048;
533 		else
534 			cbe_lun->blocksize = 512;
535 		if (params->lun_size_bytes < cbe_lun->blocksize) {
536 			snprintf(req->error_str, sizeof(req->error_str),
537 				 "%s: LUN size %ju < blocksize %u", __func__,
538 				 params->lun_size_bytes, cbe_lun->blocksize);
539 			goto bailout_error;
540 		}
541 		be_lun->size_blocks = params->lun_size_bytes / cbe_lun->blocksize;
542 		be_lun->size_bytes = be_lun->size_blocks * cbe_lun->blocksize;
543 		cbe_lun->maxlba = be_lun->size_blocks - 1;
544 		cbe_lun->atomicblock = UINT32_MAX;
545 		cbe_lun->opttxferlen = softc->rd_size / cbe_lun->blocksize;
546 	}
547 
548 	/* Tell the user the blocksize we ended up using */
549 	params->blocksize_bytes = cbe_lun->blocksize;
550 	params->lun_size_bytes = be_lun->size_bytes;
551 
552 	value = ctl_get_opt(&cbe_lun->options, "unmap");
553 	if (value != NULL && strcmp(value, "on") == 0)
554 		cbe_lun->flags |= CTL_LUN_FLAG_UNMAP;
555 	value = ctl_get_opt(&cbe_lun->options, "readonly");
556 	if (value != NULL) {
557 		if (strcmp(value, "on") == 0)
558 			cbe_lun->flags |= CTL_LUN_FLAG_READONLY;
559 	} else if (cbe_lun->lun_type != T_DIRECT)
560 		cbe_lun->flags |= CTL_LUN_FLAG_READONLY;
561 	cbe_lun->serseq = CTL_LUN_SERSEQ_OFF;
562 	value = ctl_get_opt(&cbe_lun->options, "serseq");
563 	if (value != NULL && strcmp(value, "on") == 0)
564 		cbe_lun->serseq = CTL_LUN_SERSEQ_ON;
565 	else if (value != NULL && strcmp(value, "read") == 0)
566 		cbe_lun->serseq = CTL_LUN_SERSEQ_READ;
567 	else if (value != NULL && strcmp(value, "off") == 0)
568 		cbe_lun->serseq = CTL_LUN_SERSEQ_OFF;
569 
570 	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
571 		cbe_lun->req_lun_id = params->req_lun_id;
572 		cbe_lun->flags |= CTL_LUN_FLAG_ID_REQ;
573 	} else
574 		cbe_lun->req_lun_id = 0;
575 
576 	cbe_lun->lun_shutdown = ctl_backend_ramdisk_lun_shutdown;
577 	cbe_lun->lun_config_status = ctl_backend_ramdisk_lun_config_status;
578 	cbe_lun->be = &ctl_be_ramdisk_driver;
579 	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
580 		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
581 			 softc->num_luns);
582 		strncpy((char *)cbe_lun->serial_num, tmpstr,
583 			MIN(sizeof(cbe_lun->serial_num), sizeof(tmpstr)));
584 
585 		/* Tell the user what we used for a serial number */
586 		strncpy((char *)params->serial_num, tmpstr,
587 			MIN(sizeof(params->serial_num), sizeof(tmpstr)));
588 	} else {
589 		strncpy((char *)cbe_lun->serial_num, params->serial_num,
590 			MIN(sizeof(cbe_lun->serial_num),
591 			    sizeof(params->serial_num)));
592 	}
593 	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
594 		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
595 		strncpy((char *)cbe_lun->device_id, tmpstr,
596 			MIN(sizeof(cbe_lun->device_id), sizeof(tmpstr)));
597 
598 		/* Tell the user what we used for a device ID */
599 		strncpy((char *)params->device_id, tmpstr,
600 			MIN(sizeof(params->device_id), sizeof(tmpstr)));
601 	} else {
602 		strncpy((char *)cbe_lun->device_id, params->device_id,
603 			MIN(sizeof(cbe_lun->device_id),
604 			    sizeof(params->device_id)));
605 	}
606 
607 	STAILQ_INIT(&be_lun->cont_queue);
608 	mtx_init(&be_lun->queue_lock, "cram queue lock", NULL, MTX_DEF);
609 	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_backend_ramdisk_worker,
610 	    be_lun);
611 
612 	be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
613 	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
614 	if (be_lun->io_taskqueue == NULL) {
615 		snprintf(req->error_str, sizeof(req->error_str),
616 			 "%s: Unable to create taskqueue", __func__);
617 		goto bailout_error;
618 	}
619 
620 	retval = taskqueue_start_threads(&be_lun->io_taskqueue,
621 					 /*num threads*/1,
622 					 /*priority*/PWAIT,
623 					 /*thread name*/
624 					 "%s taskq", be_lun->lunname);
625 	if (retval != 0)
626 		goto bailout_error;
627 
628 	mtx_lock(&softc->lock);
629 	softc->num_luns++;
630 	STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
631 	mtx_unlock(&softc->lock);
632 
633 	retval = ctl_add_lun(&be_lun->cbe_lun);
634 	if (retval != 0) {
635 		mtx_lock(&softc->lock);
636 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
637 			      links);
638 		softc->num_luns--;
639 		mtx_unlock(&softc->lock);
640 		snprintf(req->error_str, sizeof(req->error_str),
641 			 "%s: ctl_add_lun() returned error %d, see dmesg for "
642 			"details", __func__, retval);
643 		retval = 0;
644 		goto bailout_error;
645 	}
646 
647 	mtx_lock(&softc->lock);
648 
649 	/*
650 	 * Tell the config_status routine that we're waiting so it won't
651 	 * clean up the LUN in the event of an error.
652 	 */
653 	be_lun->flags |= CTL_BE_RAMDISK_LUN_WAITING;
654 
655 	while (be_lun->flags & CTL_BE_RAMDISK_LUN_UNCONFIGURED) {
656 		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlram", 0);
657 		if (retval == EINTR)
658 			break;
659 	}
660 	be_lun->flags &= ~CTL_BE_RAMDISK_LUN_WAITING;
661 
662 	if (be_lun->flags & CTL_BE_RAMDISK_LUN_CONFIG_ERR) {
663 		snprintf(req->error_str, sizeof(req->error_str),
664 			 "%s: LUN configuration error, see dmesg for details",
665 			 __func__);
666 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
667 			      links);
668 		softc->num_luns--;
669 		mtx_unlock(&softc->lock);
670 		goto bailout_error;
671 	} else {
672 		params->req_lun_id = cbe_lun->lun_id;
673 	}
674 	mtx_unlock(&softc->lock);
675 
676 	req->status = CTL_LUN_OK;
677 	return (retval);
678 
679 bailout_error:
680 	req->status = CTL_LUN_ERROR;
681 	if (be_lun != NULL) {
682 		if (be_lun->io_taskqueue != NULL) {
683 			taskqueue_free(be_lun->io_taskqueue);
684 		}
685 		ctl_free_opts(&cbe_lun->options);
686 		mtx_destroy(&be_lun->queue_lock);
687 		free(be_lun, M_RAMDISK);
688 	}
689 	return (retval);
690 }
691 
692 static int
693 ctl_backend_ramdisk_modify(struct ctl_be_ramdisk_softc *softc,
694 		       struct ctl_lun_req *req)
695 {
696 	struct ctl_be_ramdisk_lun *be_lun;
697 	struct ctl_be_lun *cbe_lun;
698 	struct ctl_lun_modify_params *params;
699 	char *value;
700 	uint32_t blocksize;
701 	int wasprim;
702 
703 	params = &req->reqdata.modify;
704 
705 	mtx_lock(&softc->lock);
706 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
707 		if (be_lun->cbe_lun.lun_id == params->lun_id)
708 			break;
709 	}
710 	mtx_unlock(&softc->lock);
711 	if (be_lun == NULL) {
712 		snprintf(req->error_str, sizeof(req->error_str),
713 			 "%s: LUN %u is not managed by the ramdisk backend",
714 			 __func__, params->lun_id);
715 		goto bailout_error;
716 	}
717 	cbe_lun = &be_lun->cbe_lun;
718 
719 	if (params->lun_size_bytes != 0)
720 		be_lun->params.lun_size_bytes = params->lun_size_bytes;
721 	ctl_update_opts(&cbe_lun->options, req->num_be_args, req->kern_be_args);
722 
723 	wasprim = (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY);
724 	value = ctl_get_opt(&cbe_lun->options, "ha_role");
725 	if (value != NULL) {
726 		if (strcmp(value, "primary") == 0)
727 			cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
728 		else
729 			cbe_lun->flags &= ~CTL_LUN_FLAG_PRIMARY;
730 	} else if (control_softc->flags & CTL_FLAG_ACTIVE_SHELF)
731 		cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
732 	else
733 		cbe_lun->flags &= ~CTL_LUN_FLAG_PRIMARY;
734 	if (wasprim != (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY)) {
735 		if (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY)
736 			ctl_lun_primary(cbe_lun);
737 		else
738 			ctl_lun_secondary(cbe_lun);
739 	}
740 
741 	blocksize = be_lun->cbe_lun.blocksize;
742 	if (be_lun->params.lun_size_bytes < blocksize) {
743 		snprintf(req->error_str, sizeof(req->error_str),
744 			"%s: LUN size %ju < blocksize %u", __func__,
745 			be_lun->params.lun_size_bytes, blocksize);
746 		goto bailout_error;
747 	}
748 	be_lun->size_blocks = be_lun->params.lun_size_bytes / blocksize;
749 	be_lun->size_bytes = be_lun->size_blocks * blocksize;
750 	be_lun->cbe_lun.maxlba = be_lun->size_blocks - 1;
751 	ctl_lun_capacity_changed(&be_lun->cbe_lun);
752 
753 	/* Tell the user the exact size we ended up using */
754 	params->lun_size_bytes = be_lun->size_bytes;
755 
756 	req->status = CTL_LUN_OK;
757 	return (0);
758 
759 bailout_error:
760 	req->status = CTL_LUN_ERROR;
761 	return (0);
762 }
763 
764 static void
765 ctl_backend_ramdisk_lun_shutdown(void *be_lun)
766 {
767 	struct ctl_be_ramdisk_lun *lun;
768 	struct ctl_be_ramdisk_softc *softc;
769 	int do_free;
770 
771 	lun = (struct ctl_be_ramdisk_lun *)be_lun;
772 	softc = lun->softc;
773 	do_free = 0;
774 
775 	mtx_lock(&softc->lock);
776 	lun->flags |= CTL_BE_RAMDISK_LUN_UNCONFIGURED;
777 	if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING) {
778 		wakeup(lun);
779 	} else {
780 		STAILQ_REMOVE(&softc->lun_list, lun, ctl_be_ramdisk_lun,
781 			      links);
782 		softc->num_luns--;
783 		do_free = 1;
784 	}
785 	mtx_unlock(&softc->lock);
786 
787 	if (do_free != 0)
788 		free(be_lun, M_RAMDISK);
789 }
790 
791 static void
792 ctl_backend_ramdisk_lun_config_status(void *be_lun,
793 				      ctl_lun_config_status status)
794 {
795 	struct ctl_be_ramdisk_lun *lun;
796 	struct ctl_be_ramdisk_softc *softc;
797 
798 	lun = (struct ctl_be_ramdisk_lun *)be_lun;
799 	softc = lun->softc;
800 
801 	if (status == CTL_LUN_CONFIG_OK) {
802 		mtx_lock(&softc->lock);
803 		lun->flags &= ~CTL_BE_RAMDISK_LUN_UNCONFIGURED;
804 		if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING)
805 			wakeup(lun);
806 		mtx_unlock(&softc->lock);
807 
808 		/*
809 		 * We successfully added the LUN, attempt to enable it.
810 		 */
811 		if (ctl_enable_lun(&lun->cbe_lun) != 0) {
812 			printf("%s: ctl_enable_lun() failed!\n", __func__);
813 			if (ctl_invalidate_lun(&lun->cbe_lun) != 0) {
814 				printf("%s: ctl_invalidate_lun() failed!\n",
815 				       __func__);
816 			}
817 		}
818 
819 		return;
820 	}
821 
822 
823 	mtx_lock(&softc->lock);
824 	lun->flags &= ~CTL_BE_RAMDISK_LUN_UNCONFIGURED;
825 
826 	/*
827 	 * If we have a user waiting, let him handle the cleanup.  If not,
828 	 * clean things up here.
829 	 */
830 	if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING) {
831 		lun->flags |= CTL_BE_RAMDISK_LUN_CONFIG_ERR;
832 		wakeup(lun);
833 	} else {
834 		STAILQ_REMOVE(&softc->lun_list, lun, ctl_be_ramdisk_lun,
835 			      links);
836 		softc->num_luns--;
837 		free(lun, M_RAMDISK);
838 	}
839 	mtx_unlock(&softc->lock);
840 }
841 
842 static int
843 ctl_backend_ramdisk_config_write(union ctl_io *io)
844 {
845 	struct ctl_be_lun *cbe_lun;
846 	int retval;
847 
848 	cbe_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
849 	    CTL_PRIV_BACKEND_LUN].ptr;
850 	retval = 0;
851 	switch (io->scsiio.cdb[0]) {
852 	case SYNCHRONIZE_CACHE:
853 	case SYNCHRONIZE_CACHE_16:
854 		/*
855 		 * The upper level CTL code will filter out any CDBs with
856 		 * the immediate bit set and return the proper error.  It
857 		 * will also not allow a sync cache command to go to a LUN
858 		 * that is powered down.
859 		 *
860 		 * We don't really need to worry about what LBA range the
861 		 * user asked to be synced out.  When they issue a sync
862 		 * cache command, we'll sync out the whole thing.
863 		 *
864 		 * This is obviously just a stubbed out implementation.
865 		 * The real implementation will be in the RAIDCore/CTL
866 		 * interface, and can only really happen when RAIDCore
867 		 * implements a per-array cache sync.
868 		 */
869 		ctl_set_success(&io->scsiio);
870 		ctl_config_write_done(io);
871 		break;
872 	case START_STOP_UNIT: {
873 		struct scsi_start_stop_unit *cdb;
874 
875 		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
876 		if ((cdb->how & SSS_PC_MASK) != 0) {
877 			ctl_set_success(&io->scsiio);
878 			ctl_config_write_done(io);
879 			break;
880 		}
881 		if (cdb->how & SSS_START) {
882 			if (cdb->how & SSS_LOEJ)
883 				ctl_lun_has_media(cbe_lun);
884 			ctl_start_lun(cbe_lun);
885 		} else {
886 			ctl_stop_lun(cbe_lun);
887 			if (cdb->how & SSS_LOEJ)
888 				ctl_lun_ejected(cbe_lun);
889 		}
890 		ctl_set_success(&io->scsiio);
891 		ctl_config_write_done(io);
892 		break;
893 	}
894 	case PREVENT_ALLOW:
895 	case WRITE_SAME_10:
896 	case WRITE_SAME_16:
897 	case UNMAP:
898 		ctl_set_success(&io->scsiio);
899 		ctl_config_write_done(io);
900 		break;
901 	default:
902 		ctl_set_invalid_opcode(&io->scsiio);
903 		ctl_config_write_done(io);
904 		retval = CTL_RETVAL_COMPLETE;
905 		break;
906 	}
907 
908 	return (retval);
909 }
910 
911 static int
912 ctl_backend_ramdisk_config_read(union ctl_io *io)
913 {
914 	int retval = 0;
915 
916 	switch (io->scsiio.cdb[0]) {
917 	case SERVICE_ACTION_IN:
918 		if (io->scsiio.cdb[1] == SGLS_SERVICE_ACTION) {
919 			/* We have nothing to tell, leave default data. */
920 			ctl_config_read_done(io);
921 			retval = CTL_RETVAL_COMPLETE;
922 			break;
923 		}
924 		ctl_set_invalid_field(&io->scsiio,
925 				      /*sks_valid*/ 1,
926 				      /*command*/ 1,
927 				      /*field*/ 1,
928 				      /*bit_valid*/ 1,
929 				      /*bit*/ 4);
930 		ctl_config_read_done(io);
931 		retval = CTL_RETVAL_COMPLETE;
932 		break;
933 	default:
934 		ctl_set_invalid_opcode(&io->scsiio);
935 		ctl_config_read_done(io);
936 		retval = CTL_RETVAL_COMPLETE;
937 		break;
938 	}
939 
940 	return (retval);
941 }
942