ctl_backend_ramdisk.c revision 268143
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 268143 2014-07-02 10:35:06Z 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 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, "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
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->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
274static int
275ctl_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
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->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
340static void
341ctl_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
374static int
375ctl_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
418static int
419ctl_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		ctl_free_opts(&be_lun->ctl_be_lun);
506		mtx_destroy(&be_lun->lock);
507		free(be_lun, M_RAMDISK);
508	}
509
510	req->status = CTL_LUN_OK;
511
512	return (retval);
513
514bailout_error:
515	req->status = CTL_LUN_ERROR;
516
517	return (0);
518}
519
520static int
521ctl_backend_ramdisk_create(struct ctl_be_ramdisk_softc *softc,
522			   struct ctl_lun_req *req, int do_wait)
523{
524	struct ctl_be_ramdisk_lun *be_lun;
525	struct ctl_lun_create_params *params;
526	uint32_t blocksize;
527	char *value;
528	char tmpstr[32];
529	int retval, unmap;
530
531	retval = 0;
532	params = &req->reqdata.create;
533	if (params->blocksize_bytes != 0)
534		blocksize = params->blocksize_bytes;
535	else
536		blocksize = 512;
537
538	be_lun = malloc(sizeof(*be_lun), M_RAMDISK, M_ZERO | (do_wait ?
539			M_WAITOK : M_NOWAIT));
540
541	if (be_lun == NULL) {
542		snprintf(req->error_str, sizeof(req->error_str),
543			 "%s: error allocating %zd bytes", __func__,
544			 sizeof(*be_lun));
545		goto bailout_error;
546	}
547	sprintf(be_lun->lunname, "cram%d", softc->num_luns);
548	ctl_init_opts(&be_lun->ctl_be_lun, req);
549
550	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
551		be_lun->ctl_be_lun.lun_type = params->device_type;
552	else
553		be_lun->ctl_be_lun.lun_type = T_DIRECT;
554
555	if (be_lun->ctl_be_lun.lun_type == T_DIRECT) {
556
557		if (params->lun_size_bytes < blocksize) {
558			snprintf(req->error_str, sizeof(req->error_str),
559				 "%s: LUN size %ju < blocksize %u", __func__,
560				 params->lun_size_bytes, blocksize);
561			goto bailout_error;
562		}
563
564		be_lun->size_blocks = params->lun_size_bytes / blocksize;
565		be_lun->size_bytes = be_lun->size_blocks * blocksize;
566
567		be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
568	} else {
569		be_lun->ctl_be_lun.maxlba = 0;
570		blocksize = 0;
571		be_lun->size_bytes = 0;
572		be_lun->size_blocks = 0;
573	}
574
575	be_lun->ctl_be_lun.blocksize = blocksize;
576
577	/* Tell the user the blocksize we ended up using */
578	params->blocksize_bytes = blocksize;
579
580	/* Tell the user the exact size we ended up using */
581	params->lun_size_bytes = be_lun->size_bytes;
582
583	be_lun->softc = softc;
584
585	unmap = 0;
586	value = ctl_get_opt(&be_lun->ctl_be_lun, "unmap");
587	if (value != NULL && strcmp(value, "on") == 0)
588		unmap = 1;
589
590	be_lun->flags = CTL_BE_RAMDISK_LUN_UNCONFIGURED;
591	be_lun->ctl_be_lun.flags = CTL_LUN_FLAG_PRIMARY;
592	if (unmap)
593		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_UNMAP;
594	be_lun->ctl_be_lun.be_lun = be_lun;
595
596	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
597		be_lun->ctl_be_lun.req_lun_id = params->req_lun_id;
598		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_ID_REQ;
599	} else
600		be_lun->ctl_be_lun.req_lun_id = 0;
601
602	be_lun->ctl_be_lun.lun_shutdown = ctl_backend_ramdisk_lun_shutdown;
603	be_lun->ctl_be_lun.lun_config_status =
604		ctl_backend_ramdisk_lun_config_status;
605	be_lun->ctl_be_lun.be = &ctl_be_ramdisk_driver;
606	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
607		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
608			 softc->num_luns);
609		strncpy((char *)be_lun->ctl_be_lun.serial_num, tmpstr,
610			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
611			sizeof(tmpstr)));
612
613		/* Tell the user what we used for a serial number */
614		strncpy((char *)params->serial_num, tmpstr,
615			ctl_min(sizeof(params->serial_num), sizeof(tmpstr)));
616	} else {
617		strncpy((char *)be_lun->ctl_be_lun.serial_num,
618			params->serial_num,
619			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
620			sizeof(params->serial_num)));
621	}
622	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
623		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
624		strncpy((char *)be_lun->ctl_be_lun.device_id, tmpstr,
625			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
626			sizeof(tmpstr)));
627
628		/* Tell the user what we used for a device ID */
629		strncpy((char *)params->device_id, tmpstr,
630			ctl_min(sizeof(params->device_id), sizeof(tmpstr)));
631	} else {
632		strncpy((char *)be_lun->ctl_be_lun.device_id,
633			params->device_id,
634			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
635				sizeof(params->device_id)));
636	}
637
638	STAILQ_INIT(&be_lun->cont_queue);
639	mtx_init(&be_lun->lock, "CTL ramdisk", NULL, MTX_DEF);
640	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_backend_ramdisk_worker,
641	    be_lun);
642
643	be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
644	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
645	if (be_lun->io_taskqueue == NULL) {
646		snprintf(req->error_str, sizeof(req->error_str),
647			 "%s: Unable to create taskqueue", __func__);
648		goto bailout_error;
649	}
650
651	retval = taskqueue_start_threads(&be_lun->io_taskqueue,
652					 /*num threads*/1,
653					 /*priority*/PWAIT,
654					 /*thread name*/
655					 "%s taskq", be_lun->lunname);
656	if (retval != 0)
657		goto bailout_error;
658
659	mtx_lock(&softc->lock);
660	softc->num_luns++;
661	STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
662
663	mtx_unlock(&softc->lock);
664
665	retval = ctl_add_lun(&be_lun->ctl_be_lun);
666	if (retval != 0) {
667		mtx_lock(&softc->lock);
668		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
669			      links);
670		softc->num_luns--;
671		mtx_unlock(&softc->lock);
672		snprintf(req->error_str, sizeof(req->error_str),
673			 "%s: ctl_add_lun() returned error %d, see dmesg for "
674			"details", __func__, retval);
675		retval = 0;
676		goto bailout_error;
677	}
678
679	if (do_wait == 0)
680		return (retval);
681
682	mtx_lock(&softc->lock);
683
684	/*
685	 * Tell the config_status routine that we're waiting so it won't
686	 * clean up the LUN in the event of an error.
687	 */
688	be_lun->flags |= CTL_BE_RAMDISK_LUN_WAITING;
689
690	while (be_lun->flags & CTL_BE_RAMDISK_LUN_UNCONFIGURED) {
691		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlram", 0);
692		if (retval == EINTR)
693			break;
694	}
695	be_lun->flags &= ~CTL_BE_RAMDISK_LUN_WAITING;
696
697	if (be_lun->flags & CTL_BE_RAMDISK_LUN_CONFIG_ERR) {
698		snprintf(req->error_str, sizeof(req->error_str),
699			 "%s: LUN configuration error, see dmesg for details",
700			 __func__);
701		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
702			      links);
703		softc->num_luns--;
704		mtx_unlock(&softc->lock);
705		goto bailout_error;
706	} else {
707		params->req_lun_id = be_lun->ctl_be_lun.lun_id;
708	}
709	mtx_unlock(&softc->lock);
710
711	req->status = CTL_LUN_OK;
712
713	return (retval);
714
715bailout_error:
716	req->status = CTL_LUN_ERROR;
717	if (be_lun != NULL) {
718		if (be_lun->io_taskqueue != NULL) {
719			taskqueue_free(be_lun->io_taskqueue);
720		}
721		ctl_free_opts(&be_lun->ctl_be_lun);
722		mtx_destroy(&be_lun->lock);
723		free(be_lun, M_RAMDISK);
724	}
725
726	return (retval);
727}
728
729static int
730ctl_backend_ramdisk_modify(struct ctl_be_ramdisk_softc *softc,
731		       struct ctl_lun_req *req)
732{
733	struct ctl_be_ramdisk_lun *be_lun;
734	struct ctl_lun_modify_params *params;
735	uint32_t blocksize;
736
737	params = &req->reqdata.modify;
738
739	be_lun = NULL;
740
741	mtx_lock(&softc->lock);
742	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
743		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
744			break;
745	}
746	mtx_unlock(&softc->lock);
747
748	if (be_lun == NULL) {
749		snprintf(req->error_str, sizeof(req->error_str),
750			 "%s: LUN %u is not managed by the ramdisk backend",
751			 __func__, params->lun_id);
752		goto bailout_error;
753	}
754
755	if (params->lun_size_bytes == 0) {
756		snprintf(req->error_str, sizeof(req->error_str),
757			"%s: LUN size \"auto\" not supported "
758			"by the ramdisk backend", __func__);
759		goto bailout_error;
760	}
761
762	blocksize = be_lun->ctl_be_lun.blocksize;
763
764	if (params->lun_size_bytes < blocksize) {
765		snprintf(req->error_str, sizeof(req->error_str),
766			"%s: LUN size %ju < blocksize %u", __func__,
767			params->lun_size_bytes, blocksize);
768		goto bailout_error;
769	}
770
771	be_lun->size_blocks = params->lun_size_bytes / blocksize;
772	be_lun->size_bytes = be_lun->size_blocks * blocksize;
773
774	/*
775	 * The maximum LBA is the size - 1.
776	 *
777	 * XXX: Note that this field is being updated without locking,
778	 * 	which might cause problems on 32-bit architectures.
779	 */
780	be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
781	ctl_lun_capacity_changed(&be_lun->ctl_be_lun);
782
783	/* Tell the user the exact size we ended up using */
784	params->lun_size_bytes = be_lun->size_bytes;
785
786	req->status = CTL_LUN_OK;
787
788	return (0);
789
790bailout_error:
791	req->status = CTL_LUN_ERROR;
792
793	return (0);
794}
795
796static void
797ctl_backend_ramdisk_lun_shutdown(void *be_lun)
798{
799	struct ctl_be_ramdisk_lun *lun;
800	struct ctl_be_ramdisk_softc *softc;
801	int do_free;
802
803	lun = (struct ctl_be_ramdisk_lun *)be_lun;
804	softc = lun->softc;
805	do_free = 0;
806
807	mtx_lock(&softc->lock);
808
809	lun->flags |= CTL_BE_RAMDISK_LUN_UNCONFIGURED;
810
811	if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING) {
812		wakeup(lun);
813	} else {
814		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_ramdisk_lun,
815			      links);
816		softc->num_luns--;
817		do_free = 1;
818	}
819
820	mtx_unlock(&softc->lock);
821
822	if (do_free != 0)
823		free(be_lun, M_RAMDISK);
824}
825
826static void
827ctl_backend_ramdisk_lun_config_status(void *be_lun,
828				      ctl_lun_config_status status)
829{
830	struct ctl_be_ramdisk_lun *lun;
831	struct ctl_be_ramdisk_softc *softc;
832
833	lun = (struct ctl_be_ramdisk_lun *)be_lun;
834	softc = lun->softc;
835
836	if (status == CTL_LUN_CONFIG_OK) {
837		mtx_lock(&softc->lock);
838		lun->flags &= ~CTL_BE_RAMDISK_LUN_UNCONFIGURED;
839		if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING)
840			wakeup(lun);
841		mtx_unlock(&softc->lock);
842
843		/*
844		 * We successfully added the LUN, attempt to enable it.
845		 */
846		if (ctl_enable_lun(&lun->ctl_be_lun) != 0) {
847			printf("%s: ctl_enable_lun() failed!\n", __func__);
848			if (ctl_invalidate_lun(&lun->ctl_be_lun) != 0) {
849				printf("%s: ctl_invalidate_lun() failed!\n",
850				       __func__);
851			}
852		}
853
854		return;
855	}
856
857
858	mtx_lock(&softc->lock);
859	lun->flags &= ~CTL_BE_RAMDISK_LUN_UNCONFIGURED;
860
861	/*
862	 * If we have a user waiting, let him handle the cleanup.  If not,
863	 * clean things up here.
864	 */
865	if (lun->flags & CTL_BE_RAMDISK_LUN_WAITING) {
866		lun->flags |= CTL_BE_RAMDISK_LUN_CONFIG_ERR;
867		wakeup(lun);
868	} else {
869		STAILQ_REMOVE(&softc->lun_list, lun, ctl_be_ramdisk_lun,
870			      links);
871		softc->num_luns--;
872		free(lun, M_RAMDISK);
873	}
874	mtx_unlock(&softc->lock);
875}
876
877static int
878ctl_backend_ramdisk_config_write(union ctl_io *io)
879{
880	struct ctl_be_ramdisk_softc *softc;
881	int retval;
882
883	retval = 0;
884	softc = &rd_softc;
885
886	switch (io->scsiio.cdb[0]) {
887	case SYNCHRONIZE_CACHE:
888	case SYNCHRONIZE_CACHE_16:
889		/*
890		 * The upper level CTL code will filter out any CDBs with
891		 * the immediate bit set and return the proper error.  It
892		 * will also not allow a sync cache command to go to a LUN
893		 * that is powered down.
894		 *
895		 * We don't really need to worry about what LBA range the
896		 * user asked to be synced out.  When they issue a sync
897		 * cache command, we'll sync out the whole thing.
898		 *
899		 * This is obviously just a stubbed out implementation.
900		 * The real implementation will be in the RAIDCore/CTL
901		 * interface, and can only really happen when RAIDCore
902		 * implements a per-array cache sync.
903		 */
904		ctl_set_success(&io->scsiio);
905		ctl_config_write_done(io);
906		break;
907	case START_STOP_UNIT: {
908		struct scsi_start_stop_unit *cdb;
909		struct ctl_be_lun *ctl_be_lun;
910		struct ctl_be_ramdisk_lun *be_lun;
911
912		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
913
914		ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
915			CTL_PRIV_BACKEND_LUN].ptr;
916		be_lun = (struct ctl_be_ramdisk_lun *)ctl_be_lun->be_lun;
917
918		if (cdb->how & SSS_START)
919			retval = ctl_start_lun(ctl_be_lun);
920		else {
921			retval = ctl_stop_lun(ctl_be_lun);
922#ifdef NEEDTOPORT
923			if ((retval == 0)
924			 && (cdb->byte2 & SSS_ONOFFLINE))
925				retval = ctl_lun_offline(ctl_be_lun);
926#endif
927		}
928
929		/*
930		 * In general, the above routines should not fail.  They
931		 * just set state for the LUN.  So we've got something
932		 * pretty wrong here if we can't start or stop the LUN.
933		 */
934		if (retval != 0) {
935			ctl_set_internal_failure(&io->scsiio,
936						 /*sks_valid*/ 1,
937						 /*retry_count*/ 0xf051);
938			retval = CTL_RETVAL_COMPLETE;
939		} else {
940			ctl_set_success(&io->scsiio);
941		}
942		ctl_config_write_done(io);
943		break;
944	}
945	case WRITE_SAME_10:
946	case WRITE_SAME_16:
947	case UNMAP:
948		ctl_set_success(&io->scsiio);
949		ctl_config_write_done(io);
950		break;
951	default:
952		ctl_set_invalid_opcode(&io->scsiio);
953		ctl_config_write_done(io);
954		retval = CTL_RETVAL_COMPLETE;
955		break;
956	}
957
958	return (retval);
959}
960
961static int
962ctl_backend_ramdisk_config_read(union ctl_io *io)
963{
964	/*
965	 * XXX KDM need to implement!!
966	 */
967	return (0);
968}
969