ctl_backend_ramdisk.c revision 269151
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: stable/10/sys/cam/ctl/ctl_backend_ramdisk.c 269151 2014-07-27 08:02:24Z mav $");
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
70typedef 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
76struct 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_padalign queue_lock;
88};
89
90struct 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
103static struct ctl_be_ramdisk_softc rd_softc;
104
105int ctl_backend_ramdisk_init(void);
106void ctl_backend_ramdisk_shutdown(void);
107static int ctl_backend_ramdisk_move_done(union ctl_io *io);
108static int ctl_backend_ramdisk_submit(union ctl_io *io);
109static void ctl_backend_ramdisk_continue(union ctl_io *io);
110static int ctl_backend_ramdisk_ioctl(struct cdev *dev, u_long cmd,
111				     caddr_t addr, int flag, struct thread *td);
112static int ctl_backend_ramdisk_rm(struct ctl_be_ramdisk_softc *softc,
113				  struct ctl_lun_req *req);
114static int ctl_backend_ramdisk_create(struct ctl_be_ramdisk_softc *softc,
115				      struct ctl_lun_req *req, int do_wait);
116static int ctl_backend_ramdisk_modify(struct ctl_be_ramdisk_softc *softc,
117				  struct ctl_lun_req *req);
118static void ctl_backend_ramdisk_worker(void *context, int pending);
119static void ctl_backend_ramdisk_lun_shutdown(void *be_lun);
120static void ctl_backend_ramdisk_lun_config_status(void *be_lun,
121						  ctl_lun_config_status status);
122static int ctl_backend_ramdisk_config_write(union ctl_io *io);
123static int ctl_backend_ramdisk_config_read(union ctl_io *io);
124
125static 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
137MALLOC_DEFINE(M_RAMDISK, "ramdisk", "Memory used for CTL RAMdisk");
138CTL_BACKEND_DECLARE(cbr, ctl_be_ramdisk_driver);
139
140int
141ctl_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, "ctlramdisk", 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
172void
173ctl_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
219static int
220ctl_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->io_hdr.ctl_private[CTL_PRIV_BACKEND].integer > 0) {
245			mtx_lock(&be_lun->queue_lock);
246			STAILQ_INSERT_TAIL(&be_lun->cont_queue,
247			    &io->io_hdr, links);
248			mtx_unlock(&be_lun->queue_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_data_submit_done(io);
271	return(0);
272}
273
274static int
275ctl_backend_ramdisk_submit(union ctl_io *io)
276{
277	struct ctl_be_lun *ctl_be_lun;
278	struct ctl_lba_len_flags *lbalen;
279
280	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
281		CTL_PRIV_BACKEND_LUN].ptr;
282	lbalen = (struct ctl_lba_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
283	if (lbalen->flags & CTL_LLF_VERIFY) {
284		ctl_set_success(&io->scsiio);
285		ctl_data_submit_done(io);
286		return (CTL_RETVAL_COMPLETE);
287	}
288	io->io_hdr.ctl_private[CTL_PRIV_BACKEND].integer =
289	    lbalen->len * ctl_be_lun->blocksize;
290	ctl_backend_ramdisk_continue(io);
291	return (CTL_RETVAL_COMPLETE);
292}
293
294static void
295ctl_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->io_hdr.ctl_private[CTL_PRIV_BACKEND].integer;
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.be_move_done = ctl_backend_ramdisk_move_done;
332	io->scsiio.kern_data_resid = 0;
333	io->scsiio.kern_data_len = len_filled;
334	io->scsiio.kern_sg_entries = sg_filled;
335	io->io_hdr.flags |= CTL_FLAG_ALLOCATED;
336	io->io_hdr.ctl_private[CTL_PRIV_BACKEND].integer -= len_filled;
337#ifdef CTL_TIME_IO
338	getbintime(&io->io_hdr.dma_start_bt);
339#endif
340	ctl_datamove(io);
341}
342
343static void
344ctl_backend_ramdisk_worker(void *context, int pending)
345{
346	struct ctl_be_ramdisk_softc *softc;
347	struct ctl_be_ramdisk_lun *be_lun;
348	union ctl_io *io;
349
350	be_lun = (struct ctl_be_ramdisk_lun *)context;
351	softc = be_lun->softc;
352
353	mtx_lock(&be_lun->queue_lock);
354	for (;;) {
355		io = (union ctl_io *)STAILQ_FIRST(&be_lun->cont_queue);
356		if (io != NULL) {
357			STAILQ_REMOVE(&be_lun->cont_queue, &io->io_hdr,
358				      ctl_io_hdr, links);
359
360			mtx_unlock(&be_lun->queue_lock);
361
362			ctl_backend_ramdisk_continue(io);
363
364			mtx_lock(&be_lun->queue_lock);
365			continue;
366		}
367
368		/*
369		 * If we get here, there is no work left in the queues, so
370		 * just break out and let the task queue go to sleep.
371		 */
372		break;
373	}
374	mtx_unlock(&be_lun->queue_lock);
375}
376
377static int
378ctl_backend_ramdisk_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
379			  int flag, struct thread *td)
380{
381	struct ctl_be_ramdisk_softc *softc;
382	int retval;
383
384	retval = 0;
385	softc = &rd_softc;
386
387	switch (cmd) {
388	case CTL_LUN_REQ: {
389		struct ctl_lun_req *lun_req;
390
391		lun_req = (struct ctl_lun_req *)addr;
392
393		switch (lun_req->reqtype) {
394		case CTL_LUNREQ_CREATE:
395			retval = ctl_backend_ramdisk_create(softc, lun_req,
396							    /*do_wait*/ 1);
397			break;
398		case CTL_LUNREQ_RM:
399			retval = ctl_backend_ramdisk_rm(softc, lun_req);
400			break;
401		case CTL_LUNREQ_MODIFY:
402			retval = ctl_backend_ramdisk_modify(softc, lun_req);
403			break;
404		default:
405			lun_req->status = CTL_LUN_ERROR;
406			snprintf(lun_req->error_str, sizeof(lun_req->error_str),
407				 "%s: invalid LUN request type %d", __func__,
408				 lun_req->reqtype);
409			break;
410		}
411		break;
412	}
413	default:
414		retval = ENOTTY;
415		break;
416	}
417
418	return (retval);
419}
420
421static int
422ctl_backend_ramdisk_rm(struct ctl_be_ramdisk_softc *softc,
423		       struct ctl_lun_req *req)
424{
425	struct ctl_be_ramdisk_lun *be_lun;
426	struct ctl_lun_rm_params *params;
427	int retval;
428
429
430	retval = 0;
431	params = &req->reqdata.rm;
432
433	be_lun = NULL;
434
435	mtx_lock(&softc->lock);
436
437	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
438		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
439			break;
440	}
441	mtx_unlock(&softc->lock);
442
443	if (be_lun == NULL) {
444		snprintf(req->error_str, sizeof(req->error_str),
445			 "%s: LUN %u is not managed by the ramdisk backend",
446			 __func__, params->lun_id);
447		goto bailout_error;
448	}
449
450	retval = ctl_disable_lun(&be_lun->ctl_be_lun);
451
452	if (retval != 0) {
453		snprintf(req->error_str, sizeof(req->error_str),
454			 "%s: error %d returned from ctl_disable_lun() for "
455			 "LUN %d", __func__, retval, params->lun_id);
456		goto bailout_error;
457	}
458
459	/*
460	 * Set the waiting flag before we invalidate the LUN.  Our shutdown
461	 * routine can be called any time after we invalidate the LUN,
462	 * and can be called from our context.
463	 *
464	 * This tells the shutdown routine that we're waiting, or we're
465	 * going to wait for the shutdown to happen.
466	 */
467	mtx_lock(&softc->lock);
468	be_lun->flags |= CTL_BE_RAMDISK_LUN_WAITING;
469	mtx_unlock(&softc->lock);
470
471	retval = ctl_invalidate_lun(&be_lun->ctl_be_lun);
472	if (retval != 0) {
473		snprintf(req->error_str, sizeof(req->error_str),
474			 "%s: error %d returned from ctl_invalidate_lun() for "
475			 "LUN %d", __func__, retval, params->lun_id);
476		mtx_lock(&softc->lock);
477		be_lun->flags &= ~CTL_BE_RAMDISK_LUN_WAITING;
478		mtx_unlock(&softc->lock);
479		goto bailout_error;
480	}
481
482	mtx_lock(&softc->lock);
483
484	while ((be_lun->flags & CTL_BE_RAMDISK_LUN_UNCONFIGURED) == 0) {
485		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlram", 0);
486 		if (retval == EINTR)
487			break;
488	}
489	be_lun->flags &= ~CTL_BE_RAMDISK_LUN_WAITING;
490
491	/*
492	 * We only remove this LUN from the list and free it (below) if
493	 * retval == 0.  If the user interrupted the wait, we just bail out
494	 * without actually freeing the LUN.  We let the shutdown routine
495	 * free the LUN if that happens.
496	 */
497	if (retval == 0) {
498		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
499			      links);
500		softc->num_luns--;
501	}
502
503	mtx_unlock(&softc->lock);
504
505	if (retval == 0) {
506		taskqueue_drain(be_lun->io_taskqueue, &be_lun->io_task);
507		taskqueue_free(be_lun->io_taskqueue);
508		ctl_free_opts(&be_lun->ctl_be_lun.options);
509		mtx_destroy(&be_lun->queue_lock);
510		free(be_lun, M_RAMDISK);
511	}
512
513	req->status = CTL_LUN_OK;
514
515	return (retval);
516
517bailout_error:
518	req->status = CTL_LUN_ERROR;
519
520	return (0);
521}
522
523static int
524ctl_backend_ramdisk_create(struct ctl_be_ramdisk_softc *softc,
525			   struct ctl_lun_req *req, int do_wait)
526{
527	struct ctl_be_ramdisk_lun *be_lun;
528	struct ctl_lun_create_params *params;
529	uint32_t blocksize;
530	char *value;
531	char tmpstr[32];
532	int retval, unmap;
533
534	retval = 0;
535	params = &req->reqdata.create;
536	if (params->blocksize_bytes != 0)
537		blocksize = params->blocksize_bytes;
538	else
539		blocksize = 512;
540
541	be_lun = malloc(sizeof(*be_lun), M_RAMDISK, M_ZERO | (do_wait ?
542			M_WAITOK : M_NOWAIT));
543
544	if (be_lun == NULL) {
545		snprintf(req->error_str, sizeof(req->error_str),
546			 "%s: error allocating %zd bytes", __func__,
547			 sizeof(*be_lun));
548		goto bailout_error;
549	}
550	sprintf(be_lun->lunname, "cram%d", softc->num_luns);
551	ctl_init_opts(&be_lun->ctl_be_lun.options,
552	    req->num_be_args, req->kern_be_args);
553
554	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
555		be_lun->ctl_be_lun.lun_type = params->device_type;
556	else
557		be_lun->ctl_be_lun.lun_type = T_DIRECT;
558
559	if (be_lun->ctl_be_lun.lun_type == T_DIRECT) {
560
561		if (params->lun_size_bytes < blocksize) {
562			snprintf(req->error_str, sizeof(req->error_str),
563				 "%s: LUN size %ju < blocksize %u", __func__,
564				 params->lun_size_bytes, blocksize);
565			goto bailout_error;
566		}
567
568		be_lun->size_blocks = params->lun_size_bytes / blocksize;
569		be_lun->size_bytes = be_lun->size_blocks * blocksize;
570
571		be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
572	} else {
573		be_lun->ctl_be_lun.maxlba = 0;
574		blocksize = 0;
575		be_lun->size_bytes = 0;
576		be_lun->size_blocks = 0;
577	}
578
579	be_lun->ctl_be_lun.blocksize = blocksize;
580
581	/* Tell the user the blocksize we ended up using */
582	params->blocksize_bytes = blocksize;
583
584	/* Tell the user the exact size we ended up using */
585	params->lun_size_bytes = be_lun->size_bytes;
586
587	be_lun->softc = softc;
588
589	unmap = 0;
590	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "unmap");
591	if (value != NULL && strcmp(value, "on") == 0)
592		unmap = 1;
593
594	be_lun->flags = CTL_BE_RAMDISK_LUN_UNCONFIGURED;
595	be_lun->ctl_be_lun.flags = CTL_LUN_FLAG_PRIMARY;
596	if (unmap)
597		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_UNMAP;
598	be_lun->ctl_be_lun.be_lun = be_lun;
599
600	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
601		be_lun->ctl_be_lun.req_lun_id = params->req_lun_id;
602		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_ID_REQ;
603	} else
604		be_lun->ctl_be_lun.req_lun_id = 0;
605
606	be_lun->ctl_be_lun.lun_shutdown = ctl_backend_ramdisk_lun_shutdown;
607	be_lun->ctl_be_lun.lun_config_status =
608		ctl_backend_ramdisk_lun_config_status;
609	be_lun->ctl_be_lun.be = &ctl_be_ramdisk_driver;
610	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
611		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
612			 softc->num_luns);
613		strncpy((char *)be_lun->ctl_be_lun.serial_num, tmpstr,
614			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
615			sizeof(tmpstr)));
616
617		/* Tell the user what we used for a serial number */
618		strncpy((char *)params->serial_num, tmpstr,
619			ctl_min(sizeof(params->serial_num), sizeof(tmpstr)));
620	} else {
621		strncpy((char *)be_lun->ctl_be_lun.serial_num,
622			params->serial_num,
623			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
624			sizeof(params->serial_num)));
625	}
626	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
627		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
628		strncpy((char *)be_lun->ctl_be_lun.device_id, tmpstr,
629			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
630			sizeof(tmpstr)));
631
632		/* Tell the user what we used for a device ID */
633		strncpy((char *)params->device_id, tmpstr,
634			ctl_min(sizeof(params->device_id), sizeof(tmpstr)));
635	} else {
636		strncpy((char *)be_lun->ctl_be_lun.device_id,
637			params->device_id,
638			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
639				sizeof(params->device_id)));
640	}
641
642	STAILQ_INIT(&be_lun->cont_queue);
643	mtx_init(&be_lun->queue_lock, "cram queue lock", NULL, MTX_DEF);
644	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_backend_ramdisk_worker,
645	    be_lun);
646
647	be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
648	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
649	if (be_lun->io_taskqueue == NULL) {
650		snprintf(req->error_str, sizeof(req->error_str),
651			 "%s: Unable to create taskqueue", __func__);
652		goto bailout_error;
653	}
654
655	retval = taskqueue_start_threads(&be_lun->io_taskqueue,
656					 /*num threads*/1,
657					 /*priority*/PWAIT,
658					 /*thread name*/
659					 "%s taskq", be_lun->lunname);
660	if (retval != 0)
661		goto bailout_error;
662
663	mtx_lock(&softc->lock);
664	softc->num_luns++;
665	STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
666
667	mtx_unlock(&softc->lock);
668
669	retval = ctl_add_lun(&be_lun->ctl_be_lun);
670	if (retval != 0) {
671		mtx_lock(&softc->lock);
672		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
673			      links);
674		softc->num_luns--;
675		mtx_unlock(&softc->lock);
676		snprintf(req->error_str, sizeof(req->error_str),
677			 "%s: ctl_add_lun() returned error %d, see dmesg for "
678			"details", __func__, retval);
679		retval = 0;
680		goto bailout_error;
681	}
682
683	if (do_wait == 0)
684		return (retval);
685
686	mtx_lock(&softc->lock);
687
688	/*
689	 * Tell the config_status routine that we're waiting so it won't
690	 * clean up the LUN in the event of an error.
691	 */
692	be_lun->flags |= CTL_BE_RAMDISK_LUN_WAITING;
693
694	while (be_lun->flags & CTL_BE_RAMDISK_LUN_UNCONFIGURED) {
695		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlram", 0);
696		if (retval == EINTR)
697			break;
698	}
699	be_lun->flags &= ~CTL_BE_RAMDISK_LUN_WAITING;
700
701	if (be_lun->flags & CTL_BE_RAMDISK_LUN_CONFIG_ERR) {
702		snprintf(req->error_str, sizeof(req->error_str),
703			 "%s: LUN configuration error, see dmesg for details",
704			 __func__);
705		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
706			      links);
707		softc->num_luns--;
708		mtx_unlock(&softc->lock);
709		goto bailout_error;
710	} else {
711		params->req_lun_id = be_lun->ctl_be_lun.lun_id;
712	}
713	mtx_unlock(&softc->lock);
714
715	req->status = CTL_LUN_OK;
716
717	return (retval);
718
719bailout_error:
720	req->status = CTL_LUN_ERROR;
721	if (be_lun != NULL) {
722		if (be_lun->io_taskqueue != NULL) {
723			taskqueue_free(be_lun->io_taskqueue);
724		}
725		ctl_free_opts(&be_lun->ctl_be_lun.options);
726		mtx_destroy(&be_lun->queue_lock);
727		free(be_lun, M_RAMDISK);
728	}
729
730	return (retval);
731}
732
733static int
734ctl_backend_ramdisk_modify(struct ctl_be_ramdisk_softc *softc,
735		       struct ctl_lun_req *req)
736{
737	struct ctl_be_ramdisk_lun *be_lun;
738	struct ctl_lun_modify_params *params;
739	uint32_t blocksize;
740
741	params = &req->reqdata.modify;
742
743	be_lun = NULL;
744
745	mtx_lock(&softc->lock);
746	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
747		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
748			break;
749	}
750	mtx_unlock(&softc->lock);
751
752	if (be_lun == NULL) {
753		snprintf(req->error_str, sizeof(req->error_str),
754			 "%s: LUN %u is not managed by the ramdisk backend",
755			 __func__, params->lun_id);
756		goto bailout_error;
757	}
758
759	if (params->lun_size_bytes == 0) {
760		snprintf(req->error_str, sizeof(req->error_str),
761			"%s: LUN size \"auto\" not supported "
762			"by the ramdisk backend", __func__);
763		goto bailout_error;
764	}
765
766	blocksize = be_lun->ctl_be_lun.blocksize;
767
768	if (params->lun_size_bytes < blocksize) {
769		snprintf(req->error_str, sizeof(req->error_str),
770			"%s: LUN size %ju < blocksize %u", __func__,
771			params->lun_size_bytes, blocksize);
772		goto bailout_error;
773	}
774
775	be_lun->size_blocks = params->lun_size_bytes / blocksize;
776	be_lun->size_bytes = be_lun->size_blocks * blocksize;
777
778	/*
779	 * The maximum LBA is the size - 1.
780	 *
781	 * XXX: Note that this field is being updated without locking,
782	 * 	which might cause problems on 32-bit architectures.
783	 */
784	be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
785	ctl_lun_capacity_changed(&be_lun->ctl_be_lun);
786
787	/* Tell the user the exact size we ended up using */
788	params->lun_size_bytes = be_lun->size_bytes;
789
790	req->status = CTL_LUN_OK;
791
792	return (0);
793
794bailout_error:
795	req->status = CTL_LUN_ERROR;
796
797	return (0);
798}
799
800static void
801ctl_backend_ramdisk_lun_shutdown(void *be_lun)
802{
803	struct ctl_be_ramdisk_lun *lun;
804	struct ctl_be_ramdisk_softc *softc;
805	int do_free;
806
807	lun = (struct ctl_be_ramdisk_lun *)be_lun;
808	softc = lun->softc;
809	do_free = 0;
810
811	mtx_lock(&softc->lock);
812
813	lun->flags |= CTL_BE_RAMDISK_LUN_UNCONFIGURED;
814
815	if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING) {
816		wakeup(lun);
817	} else {
818		STAILQ_REMOVE(&softc->lun_list, lun, ctl_be_ramdisk_lun,
819			      links);
820		softc->num_luns--;
821		do_free = 1;
822	}
823
824	mtx_unlock(&softc->lock);
825
826	if (do_free != 0)
827		free(be_lun, M_RAMDISK);
828}
829
830static void
831ctl_backend_ramdisk_lun_config_status(void *be_lun,
832				      ctl_lun_config_status status)
833{
834	struct ctl_be_ramdisk_lun *lun;
835	struct ctl_be_ramdisk_softc *softc;
836
837	lun = (struct ctl_be_ramdisk_lun *)be_lun;
838	softc = lun->softc;
839
840	if (status == CTL_LUN_CONFIG_OK) {
841		mtx_lock(&softc->lock);
842		lun->flags &= ~CTL_BE_RAMDISK_LUN_UNCONFIGURED;
843		if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING)
844			wakeup(lun);
845		mtx_unlock(&softc->lock);
846
847		/*
848		 * We successfully added the LUN, attempt to enable it.
849		 */
850		if (ctl_enable_lun(&lun->ctl_be_lun) != 0) {
851			printf("%s: ctl_enable_lun() failed!\n", __func__);
852			if (ctl_invalidate_lun(&lun->ctl_be_lun) != 0) {
853				printf("%s: ctl_invalidate_lun() failed!\n",
854				       __func__);
855			}
856		}
857
858		return;
859	}
860
861
862	mtx_lock(&softc->lock);
863	lun->flags &= ~CTL_BE_RAMDISK_LUN_UNCONFIGURED;
864
865	/*
866	 * If we have a user waiting, let him handle the cleanup.  If not,
867	 * clean things up here.
868	 */
869	if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING) {
870		lun->flags |= CTL_BE_RAMDISK_LUN_CONFIG_ERR;
871		wakeup(lun);
872	} else {
873		STAILQ_REMOVE(&softc->lun_list, lun, ctl_be_ramdisk_lun,
874			      links);
875		softc->num_luns--;
876		free(lun, M_RAMDISK);
877	}
878	mtx_unlock(&softc->lock);
879}
880
881static int
882ctl_backend_ramdisk_config_write(union ctl_io *io)
883{
884	struct ctl_be_ramdisk_softc *softc;
885	int retval;
886
887	retval = 0;
888	softc = &rd_softc;
889
890	switch (io->scsiio.cdb[0]) {
891	case SYNCHRONIZE_CACHE:
892	case SYNCHRONIZE_CACHE_16:
893		/*
894		 * The upper level CTL code will filter out any CDBs with
895		 * the immediate bit set and return the proper error.  It
896		 * will also not allow a sync cache command to go to a LUN
897		 * that is powered down.
898		 *
899		 * We don't really need to worry about what LBA range the
900		 * user asked to be synced out.  When they issue a sync
901		 * cache command, we'll sync out the whole thing.
902		 *
903		 * This is obviously just a stubbed out implementation.
904		 * The real implementation will be in the RAIDCore/CTL
905		 * interface, and can only really happen when RAIDCore
906		 * implements a per-array cache sync.
907		 */
908		ctl_set_success(&io->scsiio);
909		ctl_config_write_done(io);
910		break;
911	case START_STOP_UNIT: {
912		struct scsi_start_stop_unit *cdb;
913		struct ctl_be_lun *ctl_be_lun;
914		struct ctl_be_ramdisk_lun *be_lun;
915
916		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
917
918		ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
919			CTL_PRIV_BACKEND_LUN].ptr;
920		be_lun = (struct ctl_be_ramdisk_lun *)ctl_be_lun->be_lun;
921
922		if (cdb->how & SSS_START)
923			retval = ctl_start_lun(ctl_be_lun);
924		else {
925			retval = ctl_stop_lun(ctl_be_lun);
926#ifdef NEEDTOPORT
927			if ((retval == 0)
928			 && (cdb->byte2 & SSS_ONOFFLINE))
929				retval = ctl_lun_offline(ctl_be_lun);
930#endif
931		}
932
933		/*
934		 * In general, the above routines should not fail.  They
935		 * just set state for the LUN.  So we've got something
936		 * pretty wrong here if we can't start or stop the LUN.
937		 */
938		if (retval != 0) {
939			ctl_set_internal_failure(&io->scsiio,
940						 /*sks_valid*/ 1,
941						 /*retry_count*/ 0xf051);
942			retval = CTL_RETVAL_COMPLETE;
943		} else {
944			ctl_set_success(&io->scsiio);
945		}
946		ctl_config_write_done(io);
947		break;
948	}
949	case WRITE_SAME_10:
950	case WRITE_SAME_16:
951	case UNMAP:
952		ctl_set_success(&io->scsiio);
953		ctl_config_write_done(io);
954		break;
955	default:
956		ctl_set_invalid_opcode(&io->scsiio);
957		ctl_config_write_done(io);
958		retval = CTL_RETVAL_COMPLETE;
959		break;
960	}
961
962	return (retval);
963}
964
965static int
966ctl_backend_ramdisk_config_read(union ctl_io *io)
967{
968	/*
969	 * XXX KDM need to implement!!
970	 */
971	return (0);
972}
973