ctl_backend_block.c revision 267537
1/*-
2 * Copyright (c) 2003 Silicon Graphics International Corp.
3 * Copyright (c) 2009-2011 Spectra Logic Corporation
4 * Copyright (c) 2012 The FreeBSD Foundation
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_block.c#5 $
36 */
37/*
38 * CAM Target Layer driver backend for block devices.
39 *
40 * Author: Ken Merry <ken@FreeBSD.org>
41 */
42#include <sys/cdefs.h>
43__FBSDID("$FreeBSD: head/sys/cam/ctl/ctl_backend_block.c 267537 2014-06-16 11:00:14Z mav $");
44
45#include <sys/param.h>
46#include <sys/systm.h>
47#include <sys/kernel.h>
48#include <sys/types.h>
49#include <sys/kthread.h>
50#include <sys/bio.h>
51#include <sys/fcntl.h>
52#include <sys/limits.h>
53#include <sys/lock.h>
54#include <sys/mutex.h>
55#include <sys/condvar.h>
56#include <sys/malloc.h>
57#include <sys/conf.h>
58#include <sys/ioccom.h>
59#include <sys/queue.h>
60#include <sys/sbuf.h>
61#include <sys/endian.h>
62#include <sys/uio.h>
63#include <sys/buf.h>
64#include <sys/taskqueue.h>
65#include <sys/vnode.h>
66#include <sys/namei.h>
67#include <sys/mount.h>
68#include <sys/disk.h>
69#include <sys/fcntl.h>
70#include <sys/filedesc.h>
71#include <sys/proc.h>
72#include <sys/pcpu.h>
73#include <sys/module.h>
74#include <sys/sdt.h>
75#include <sys/devicestat.h>
76#include <sys/sysctl.h>
77
78#include <geom/geom.h>
79
80#include <cam/cam.h>
81#include <cam/scsi/scsi_all.h>
82#include <cam/scsi/scsi_da.h>
83#include <cam/ctl/ctl_io.h>
84#include <cam/ctl/ctl.h>
85#include <cam/ctl/ctl_backend.h>
86#include <cam/ctl/ctl_frontend_internal.h>
87#include <cam/ctl/ctl_ioctl.h>
88#include <cam/ctl/ctl_scsi_all.h>
89#include <cam/ctl/ctl_error.h>
90
91/*
92 * The idea here is that we'll allocate enough S/G space to hold a 1MB
93 * I/O.  If we get an I/O larger than that, we'll split it.
94 */
95#define	CTLBLK_HALF_IO_SIZE	(512 * 1024)
96#define	CTLBLK_MAX_IO_SIZE	(CTLBLK_HALF_IO_SIZE * 2)
97#define	CTLBLK_MAX_SEG		MAXPHYS
98#define	CTLBLK_HALF_SEGS	MAX(CTLBLK_HALF_IO_SIZE / CTLBLK_MAX_SEG, 1)
99#define	CTLBLK_MAX_SEGS		(CTLBLK_HALF_SEGS * 2)
100
101#ifdef CTLBLK_DEBUG
102#define DPRINTF(fmt, args...) \
103    printf("cbb(%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
104#else
105#define DPRINTF(fmt, args...) do {} while(0)
106#endif
107
108#define PRIV(io)	\
109    ((struct ctl_ptr_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_BACKEND])
110#define ARGS(io)	\
111    ((struct ctl_lba_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_LBA_LEN])
112
113SDT_PROVIDER_DEFINE(cbb);
114
115typedef enum {
116	CTL_BE_BLOCK_LUN_UNCONFIGURED	= 0x01,
117	CTL_BE_BLOCK_LUN_CONFIG_ERR	= 0x02,
118	CTL_BE_BLOCK_LUN_WAITING	= 0x04,
119	CTL_BE_BLOCK_LUN_MULTI_THREAD	= 0x08
120} ctl_be_block_lun_flags;
121
122typedef enum {
123	CTL_BE_BLOCK_NONE,
124	CTL_BE_BLOCK_DEV,
125	CTL_BE_BLOCK_FILE
126} ctl_be_block_type;
127
128struct ctl_be_block_devdata {
129	struct cdev *cdev;
130	struct cdevsw *csw;
131	int dev_ref;
132};
133
134struct ctl_be_block_filedata {
135	struct ucred *cred;
136};
137
138union ctl_be_block_bedata {
139	struct ctl_be_block_devdata dev;
140	struct ctl_be_block_filedata file;
141};
142
143struct ctl_be_block_io;
144struct ctl_be_block_lun;
145
146typedef void (*cbb_dispatch_t)(struct ctl_be_block_lun *be_lun,
147			       struct ctl_be_block_io *beio);
148
149/*
150 * Backend LUN structure.  There is a 1:1 mapping between a block device
151 * and a backend block LUN, and between a backend block LUN and a CTL LUN.
152 */
153struct ctl_be_block_lun {
154	struct ctl_block_disk *disk;
155	char lunname[32];
156	char *dev_path;
157	ctl_be_block_type dev_type;
158	struct vnode *vn;
159	union ctl_be_block_bedata backend;
160	cbb_dispatch_t dispatch;
161	cbb_dispatch_t lun_flush;
162	cbb_dispatch_t unmap;
163	struct mtx lock;
164	uma_zone_t lun_zone;
165	uint64_t size_blocks;
166	uint64_t size_bytes;
167	uint32_t blocksize;
168	int blocksize_shift;
169	uint16_t pblockexp;
170	uint16_t pblockoff;
171	struct ctl_be_block_softc *softc;
172	struct devstat *disk_stats;
173	ctl_be_block_lun_flags flags;
174	STAILQ_ENTRY(ctl_be_block_lun) links;
175	struct ctl_be_lun ctl_be_lun;
176	struct taskqueue *io_taskqueue;
177	struct task io_task;
178	int num_threads;
179	STAILQ_HEAD(, ctl_io_hdr) input_queue;
180	STAILQ_HEAD(, ctl_io_hdr) config_write_queue;
181	STAILQ_HEAD(, ctl_io_hdr) datamove_queue;
182};
183
184/*
185 * Overall softc structure for the block backend module.
186 */
187struct ctl_be_block_softc {
188	struct mtx			 lock;
189	int				 num_disks;
190	STAILQ_HEAD(, ctl_block_disk)	 disk_list;
191	int				 num_luns;
192	STAILQ_HEAD(, ctl_be_block_lun)	 lun_list;
193};
194
195static struct ctl_be_block_softc backend_block_softc;
196
197/*
198 * Per-I/O information.
199 */
200struct ctl_be_block_io {
201	union ctl_io			*io;
202	struct ctl_sg_entry		sg_segs[CTLBLK_MAX_SEGS];
203	struct iovec			xiovecs[CTLBLK_MAX_SEGS];
204	int				bio_cmd;
205	int				bio_flags;
206	int				num_segs;
207	int				num_bios_sent;
208	int				num_bios_done;
209	int				send_complete;
210	int				num_errors;
211	struct bintime			ds_t0;
212	devstat_tag_type		ds_tag_type;
213	devstat_trans_flags		ds_trans_type;
214	uint64_t			io_len;
215	uint64_t			io_offset;
216	struct ctl_be_block_softc	*softc;
217	struct ctl_be_block_lun		*lun;
218	void (*beio_cont)(struct ctl_be_block_io *beio); /* to continue processing */
219};
220
221static int cbb_num_threads = 14;
222TUNABLE_INT("kern.cam.ctl.block.num_threads", &cbb_num_threads);
223SYSCTL_NODE(_kern_cam_ctl, OID_AUTO, block, CTLFLAG_RD, 0,
224	    "CAM Target Layer Block Backend");
225SYSCTL_INT(_kern_cam_ctl_block, OID_AUTO, num_threads, CTLFLAG_RW,
226           &cbb_num_threads, 0, "Number of threads per backing file");
227
228static struct ctl_be_block_io *ctl_alloc_beio(struct ctl_be_block_softc *softc);
229static void ctl_free_beio(struct ctl_be_block_io *beio);
230static void ctl_complete_beio(struct ctl_be_block_io *beio);
231static int ctl_be_block_move_done(union ctl_io *io);
232static void ctl_be_block_biodone(struct bio *bio);
233static void ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
234				    struct ctl_be_block_io *beio);
235static void ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
236				       struct ctl_be_block_io *beio);
237static void ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
238				   struct ctl_be_block_io *beio);
239static void ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
240				   struct ctl_be_block_io *beio);
241static void ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
242				      struct ctl_be_block_io *beio);
243static void ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
244				    union ctl_io *io);
245static void ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
246				  union ctl_io *io);
247static void ctl_be_block_worker(void *context, int pending);
248static int ctl_be_block_submit(union ctl_io *io);
249static int ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
250				   int flag, struct thread *td);
251static int ctl_be_block_open_file(struct ctl_be_block_lun *be_lun,
252				  struct ctl_lun_req *req);
253static int ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun,
254				 struct ctl_lun_req *req);
255static int ctl_be_block_close(struct ctl_be_block_lun *be_lun);
256static int ctl_be_block_open(struct ctl_be_block_softc *softc,
257			     struct ctl_be_block_lun *be_lun,
258			     struct ctl_lun_req *req);
259static int ctl_be_block_create(struct ctl_be_block_softc *softc,
260			       struct ctl_lun_req *req);
261static int ctl_be_block_rm(struct ctl_be_block_softc *softc,
262			   struct ctl_lun_req *req);
263static int ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
264				  struct ctl_lun_req *req);
265static int ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
266				 struct ctl_lun_req *req);
267static int ctl_be_block_modify(struct ctl_be_block_softc *softc,
268			   struct ctl_lun_req *req);
269static void ctl_be_block_lun_shutdown(void *be_lun);
270static void ctl_be_block_lun_config_status(void *be_lun,
271					   ctl_lun_config_status status);
272static int ctl_be_block_config_write(union ctl_io *io);
273static int ctl_be_block_config_read(union ctl_io *io);
274static int ctl_be_block_lun_info(void *be_lun, struct sbuf *sb);
275int ctl_be_block_init(void);
276
277static struct ctl_backend_driver ctl_be_block_driver =
278{
279	.name = "block",
280	.flags = CTL_BE_FLAG_HAS_CONFIG,
281	.init = ctl_be_block_init,
282	.data_submit = ctl_be_block_submit,
283	.data_move_done = ctl_be_block_move_done,
284	.config_read = ctl_be_block_config_read,
285	.config_write = ctl_be_block_config_write,
286	.ioctl = ctl_be_block_ioctl,
287	.lun_info = ctl_be_block_lun_info
288};
289
290MALLOC_DEFINE(M_CTLBLK, "ctlblk", "Memory used for CTL block backend");
291CTL_BACKEND_DECLARE(cbb, ctl_be_block_driver);
292
293static uma_zone_t beio_zone;
294
295static struct ctl_be_block_io *
296ctl_alloc_beio(struct ctl_be_block_softc *softc)
297{
298	struct ctl_be_block_io *beio;
299
300	beio = uma_zalloc(beio_zone, M_WAITOK | M_ZERO);
301	beio->softc = softc;
302	return (beio);
303}
304
305static void
306ctl_free_beio(struct ctl_be_block_io *beio)
307{
308	int duplicate_free;
309	int i;
310
311	duplicate_free = 0;
312
313	for (i = 0; i < beio->num_segs; i++) {
314		if (beio->sg_segs[i].addr == NULL)
315			duplicate_free++;
316
317		uma_zfree(beio->lun->lun_zone, beio->sg_segs[i].addr);
318		beio->sg_segs[i].addr = NULL;
319
320		/* For compare we had two equal S/G lists. */
321		if (ARGS(beio->io)->flags & CTL_LLF_COMPARE) {
322			uma_zfree(beio->lun->lun_zone,
323			    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr);
324			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr = NULL;
325		}
326	}
327
328	if (duplicate_free > 0) {
329		printf("%s: %d duplicate frees out of %d segments\n", __func__,
330		       duplicate_free, beio->num_segs);
331	}
332
333	uma_zfree(beio_zone, beio);
334}
335
336static void
337ctl_complete_beio(struct ctl_be_block_io *beio)
338{
339	union ctl_io *io;
340	int io_len;
341
342	io = beio->io;
343
344	if ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_SUCCESS)
345		io_len = beio->io_len;
346	else
347		io_len = 0;
348
349	devstat_end_transaction(beio->lun->disk_stats,
350				/*bytes*/ io_len,
351				beio->ds_tag_type,
352				beio->ds_trans_type,
353				/*now*/ NULL,
354				/*then*/&beio->ds_t0);
355
356	if (beio->beio_cont != NULL) {
357		beio->beio_cont(beio);
358	} else {
359		ctl_free_beio(beio);
360		ctl_data_submit_done(io);
361	}
362}
363
364static int
365ctl_be_block_move_done(union ctl_io *io)
366{
367	struct ctl_be_block_io *beio;
368	struct ctl_be_block_lun *be_lun;
369	struct ctl_lba_len_flags *lbalen;
370#ifdef CTL_TIME_IO
371	struct bintime cur_bt;
372#endif
373	int i;
374
375	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
376	be_lun = beio->lun;
377
378	DPRINTF("entered\n");
379
380#ifdef CTL_TIME_IO
381	getbintime(&cur_bt);
382	bintime_sub(&cur_bt, &io->io_hdr.dma_start_bt);
383	bintime_add(&io->io_hdr.dma_bt, &cur_bt);
384	io->io_hdr.num_dmas++;
385#endif
386	io->scsiio.kern_rel_offset += io->scsiio.kern_data_len;
387
388	/*
389	 * We set status at this point for read commands, and write
390	 * commands with errors.
391	 */
392	if ((io->io_hdr.port_status == 0) &&
393	    ((io->io_hdr.flags & CTL_FLAG_ABORT) == 0) &&
394	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
395		lbalen = ARGS(beio->io);
396		if (lbalen->flags & CTL_LLF_READ) {
397			ctl_set_success(&io->scsiio);
398		} else if (lbalen->flags & CTL_LLF_COMPARE) {
399			/* We have two data blocks ready for comparison. */
400			for (i = 0; i < beio->num_segs; i++) {
401				if (memcmp(beio->sg_segs[i].addr,
402				    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr,
403				    beio->sg_segs[i].len) != 0)
404					break;
405			}
406			if (i < beio->num_segs)
407				ctl_set_sense(&io->scsiio,
408				    /*current_error*/ 1,
409				    /*sense_key*/ SSD_KEY_MISCOMPARE,
410				    /*asc*/ 0x1D,
411				    /*ascq*/ 0x00,
412				    SSD_ELEM_NONE);
413			else
414				ctl_set_success(&io->scsiio);
415		}
416	}
417	else if ((io->io_hdr.port_status != 0)
418	      && ((io->io_hdr.flags & CTL_FLAG_ABORT) == 0)
419	      && ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
420		/*
421		 * For hardware error sense keys, the sense key
422		 * specific value is defined to be a retry count,
423		 * but we use it to pass back an internal FETD
424		 * error code.  XXX KDM  Hopefully the FETD is only
425		 * using 16 bits for an error code, since that's
426		 * all the space we have in the sks field.
427		 */
428		ctl_set_internal_failure(&io->scsiio,
429					 /*sks_valid*/ 1,
430					 /*retry_count*/
431					 io->io_hdr.port_status);
432	}
433
434	/*
435	 * If this is a read, or a write with errors, it is done.
436	 */
437	if ((beio->bio_cmd == BIO_READ)
438	 || ((io->io_hdr.flags & CTL_FLAG_ABORT) != 0)
439	 || ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)) {
440		ctl_complete_beio(beio);
441		return (0);
442	}
443
444	/*
445	 * At this point, we have a write and the DMA completed
446	 * successfully.  We now have to queue it to the task queue to
447	 * execute the backend I/O.  That is because we do blocking
448	 * memory allocations, and in the file backing case, blocking I/O.
449	 * This move done routine is generally called in the SIM's
450	 * interrupt context, and therefore we cannot block.
451	 */
452	mtx_lock(&be_lun->lock);
453	/*
454	 * XXX KDM make sure that links is okay to use at this point.
455	 * Otherwise, we either need to add another field to ctl_io_hdr,
456	 * or deal with resource allocation here.
457	 */
458	STAILQ_INSERT_TAIL(&be_lun->datamove_queue, &io->io_hdr, links);
459	mtx_unlock(&be_lun->lock);
460
461	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
462
463	return (0);
464}
465
466static void
467ctl_be_block_biodone(struct bio *bio)
468{
469	struct ctl_be_block_io *beio;
470	struct ctl_be_block_lun *be_lun;
471	union ctl_io *io;
472	int error;
473
474	beio = bio->bio_caller1;
475	be_lun = beio->lun;
476	io = beio->io;
477
478	DPRINTF("entered\n");
479
480	error = bio->bio_error;
481	mtx_lock(&be_lun->lock);
482	if (error != 0)
483		beio->num_errors++;
484
485	beio->num_bios_done++;
486
487	/*
488	 * XXX KDM will this cause WITNESS to complain?  Holding a lock
489	 * during the free might cause it to complain.
490	 */
491	g_destroy_bio(bio);
492
493	/*
494	 * If the send complete bit isn't set, or we aren't the last I/O to
495	 * complete, then we're done.
496	 */
497	if ((beio->send_complete == 0)
498	 || (beio->num_bios_done < beio->num_bios_sent)) {
499		mtx_unlock(&be_lun->lock);
500		return;
501	}
502
503	/*
504	 * At this point, we've verified that we are the last I/O to
505	 * complete, so it's safe to drop the lock.
506	 */
507	mtx_unlock(&be_lun->lock);
508
509	/*
510	 * If there are any errors from the backing device, we fail the
511	 * entire I/O with a medium error.
512	 */
513	if (beio->num_errors > 0) {
514		if (error == EOPNOTSUPP) {
515			ctl_set_invalid_opcode(&io->scsiio);
516		} else if (beio->bio_cmd == BIO_FLUSH) {
517			/* XXX KDM is there is a better error here? */
518			ctl_set_internal_failure(&io->scsiio,
519						 /*sks_valid*/ 1,
520						 /*retry_count*/ 0xbad2);
521		} else
522			ctl_set_medium_error(&io->scsiio);
523		ctl_complete_beio(beio);
524		return;
525	}
526
527	/*
528	 * If this is a write, a flush, a delete or verify, we're all done.
529	 * If this is a read, we can now send the data to the user.
530	 */
531	if ((beio->bio_cmd == BIO_WRITE)
532	 || (beio->bio_cmd == BIO_FLUSH)
533	 || (beio->bio_cmd == BIO_DELETE)
534	 || (ARGS(io)->flags & CTL_LLF_VERIFY)) {
535		ctl_set_success(&io->scsiio);
536		ctl_complete_beio(beio);
537	} else {
538#ifdef CTL_TIME_IO
539        	getbintime(&io->io_hdr.dma_start_bt);
540#endif
541		ctl_datamove(io);
542	}
543}
544
545static void
546ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
547			struct ctl_be_block_io *beio)
548{
549	union ctl_io *io;
550	struct mount *mountpoint;
551	int error, lock_flags;
552
553	DPRINTF("entered\n");
554
555	io = beio->io;
556
557       	(void) vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
558
559	if (MNT_SHARED_WRITES(mountpoint)
560	 || ((mountpoint == NULL)
561	  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
562		lock_flags = LK_SHARED;
563	else
564		lock_flags = LK_EXCLUSIVE;
565
566	vn_lock(be_lun->vn, lock_flags | LK_RETRY);
567
568	binuptime(&beio->ds_t0);
569	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
570
571	error = VOP_FSYNC(be_lun->vn, MNT_WAIT, curthread);
572	VOP_UNLOCK(be_lun->vn, 0);
573
574	vn_finished_write(mountpoint);
575
576	if (error == 0)
577		ctl_set_success(&io->scsiio);
578	else {
579		/* XXX KDM is there is a better error here? */
580		ctl_set_internal_failure(&io->scsiio,
581					 /*sks_valid*/ 1,
582					 /*retry_count*/ 0xbad1);
583	}
584
585	ctl_complete_beio(beio);
586}
587
588SDT_PROBE_DEFINE1(cbb, kernel, read, file_start, "uint64_t");
589SDT_PROBE_DEFINE1(cbb, kernel, write, file_start, "uint64_t");
590SDT_PROBE_DEFINE1(cbb, kernel, read, file_done,"uint64_t");
591SDT_PROBE_DEFINE1(cbb, kernel, write, file_done, "uint64_t");
592
593static void
594ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
595			   struct ctl_be_block_io *beio)
596{
597	struct ctl_be_block_filedata *file_data;
598	union ctl_io *io;
599	struct uio xuio;
600	struct iovec *xiovec;
601	int flags;
602	int error, i;
603
604	DPRINTF("entered\n");
605
606	file_data = &be_lun->backend.file;
607	io = beio->io;
608	flags = beio->bio_flags;
609
610	bzero(&xuio, sizeof(xuio));
611	if (beio->bio_cmd == BIO_READ) {
612		SDT_PROBE(cbb, kernel, read, file_start, 0, 0, 0, 0, 0);
613		xuio.uio_rw = UIO_READ;
614	} else {
615		SDT_PROBE(cbb, kernel, write, file_start, 0, 0, 0, 0, 0);
616		xuio.uio_rw = UIO_WRITE;
617	}
618	xuio.uio_offset = beio->io_offset;
619	xuio.uio_resid = beio->io_len;
620	xuio.uio_segflg = UIO_SYSSPACE;
621	xuio.uio_iov = beio->xiovecs;
622	xuio.uio_iovcnt = beio->num_segs;
623	xuio.uio_td = curthread;
624
625	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
626		xiovec->iov_base = beio->sg_segs[i].addr;
627		xiovec->iov_len = beio->sg_segs[i].len;
628	}
629
630	if (beio->bio_cmd == BIO_READ) {
631		vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
632
633		binuptime(&beio->ds_t0);
634		devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
635
636		/*
637		 * UFS pays attention to IO_DIRECT for reads.  If the
638		 * DIRECTIO option is configured into the kernel, it calls
639		 * ffs_rawread().  But that only works for single-segment
640		 * uios with user space addresses.  In our case, with a
641		 * kernel uio, it still reads into the buffer cache, but it
642		 * will just try to release the buffer from the cache later
643		 * on in ffs_read().
644		 *
645		 * ZFS does not pay attention to IO_DIRECT for reads.
646		 *
647		 * UFS does not pay attention to IO_SYNC for reads.
648		 *
649		 * ZFS pays attention to IO_SYNC (which translates into the
650		 * Solaris define FRSYNC for zfs_read()) for reads.  It
651		 * attempts to sync the file before reading.
652		 *
653		 * So, to attempt to provide some barrier semantics in the
654		 * BIO_ORDERED case, set both IO_DIRECT and IO_SYNC.
655		 */
656		error = VOP_READ(be_lun->vn, &xuio, (flags & BIO_ORDERED) ?
657				 (IO_DIRECT|IO_SYNC) : 0, file_data->cred);
658
659		VOP_UNLOCK(be_lun->vn, 0);
660		SDT_PROBE(cbb, kernel, read, file_done, 0, 0, 0, 0, 0);
661	} else {
662		struct mount *mountpoint;
663		int lock_flags;
664
665		(void)vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
666
667		if (MNT_SHARED_WRITES(mountpoint)
668		 || ((mountpoint == NULL)
669		  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
670			lock_flags = LK_SHARED;
671		else
672			lock_flags = LK_EXCLUSIVE;
673
674		vn_lock(be_lun->vn, lock_flags | LK_RETRY);
675
676		binuptime(&beio->ds_t0);
677		devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
678
679		/*
680		 * UFS pays attention to IO_DIRECT for writes.  The write
681		 * is done asynchronously.  (Normally the write would just
682		 * get put into cache.
683		 *
684		 * UFS pays attention to IO_SYNC for writes.  It will
685		 * attempt to write the buffer out synchronously if that
686		 * flag is set.
687		 *
688		 * ZFS does not pay attention to IO_DIRECT for writes.
689		 *
690		 * ZFS pays attention to IO_SYNC (a.k.a. FSYNC or FRSYNC)
691		 * for writes.  It will flush the transaction from the
692		 * cache before returning.
693		 *
694		 * So if we've got the BIO_ORDERED flag set, we want
695		 * IO_SYNC in either the UFS or ZFS case.
696		 */
697		error = VOP_WRITE(be_lun->vn, &xuio, (flags & BIO_ORDERED) ?
698				  IO_SYNC : 0, file_data->cred);
699		VOP_UNLOCK(be_lun->vn, 0);
700
701		vn_finished_write(mountpoint);
702		SDT_PROBE(cbb, kernel, write, file_done, 0, 0, 0, 0, 0);
703        }
704
705	/*
706	 * If we got an error, set the sense data to "MEDIUM ERROR" and
707	 * return the I/O to the user.
708	 */
709	if (error != 0) {
710		char path_str[32];
711
712		ctl_scsi_path_string(io, path_str, sizeof(path_str));
713		/*
714		 * XXX KDM ZFS returns ENOSPC when the underlying
715		 * filesystem fills up.  What kind of SCSI error should we
716		 * return for that?
717		 */
718		printf("%s%s command returned errno %d\n", path_str,
719		       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE", error);
720		ctl_set_medium_error(&io->scsiio);
721		ctl_complete_beio(beio);
722		return;
723	}
724
725	/*
726	 * If this is a write, we're all done.
727	 * If this is a read, we can now send the data to the user.
728	 */
729	if (ARGS(io)->flags & (CTL_LLF_WRITE | CTL_LLF_VERIFY)) {
730		ctl_set_success(&io->scsiio);
731		ctl_complete_beio(beio);
732	} else {
733#ifdef CTL_TIME_IO
734        	getbintime(&io->io_hdr.dma_start_bt);
735#endif
736		ctl_datamove(io);
737	}
738}
739
740static void
741ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
742		       struct ctl_be_block_io *beio)
743{
744	struct bio *bio;
745	union ctl_io *io;
746	struct ctl_be_block_devdata *dev_data;
747
748	dev_data = &be_lun->backend.dev;
749	io = beio->io;
750
751	DPRINTF("entered\n");
752
753	/* This can't fail, it's a blocking allocation. */
754	bio = g_alloc_bio();
755
756	bio->bio_cmd	    = BIO_FLUSH;
757	bio->bio_flags	   |= BIO_ORDERED;
758	bio->bio_dev	    = dev_data->cdev;
759	bio->bio_offset	    = 0;
760	bio->bio_data	    = 0;
761	bio->bio_done	    = ctl_be_block_biodone;
762	bio->bio_caller1    = beio;
763	bio->bio_pblkno	    = 0;
764
765	/*
766	 * We don't need to acquire the LUN lock here, because we are only
767	 * sending one bio, and so there is no other context to synchronize
768	 * with.
769	 */
770	beio->num_bios_sent = 1;
771	beio->send_complete = 1;
772
773	binuptime(&beio->ds_t0);
774	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
775
776	(*dev_data->csw->d_strategy)(bio);
777}
778
779static void
780ctl_be_block_unmap_dev_range(struct ctl_be_block_lun *be_lun,
781		       struct ctl_be_block_io *beio,
782		       uint64_t off, uint64_t len, int last)
783{
784	struct bio *bio;
785	struct ctl_be_block_devdata *dev_data;
786	uint64_t maxlen;
787
788	dev_data = &be_lun->backend.dev;
789	maxlen = LONG_MAX - (LONG_MAX % be_lun->blocksize);
790	while (len > 0) {
791		bio = g_alloc_bio();
792		bio->bio_cmd	    = BIO_DELETE;
793		bio->bio_flags	   |= beio->bio_flags;
794		bio->bio_dev	    = dev_data->cdev;
795		bio->bio_offset	    = off;
796		bio->bio_length	    = MIN(len, maxlen);
797		bio->bio_data	    = 0;
798		bio->bio_done	    = ctl_be_block_biodone;
799		bio->bio_caller1    = beio;
800		bio->bio_pblkno     = off / be_lun->blocksize;
801
802		off += bio->bio_length;
803		len -= bio->bio_length;
804
805		mtx_lock(&be_lun->lock);
806		beio->num_bios_sent++;
807		if (last && len == 0)
808			beio->send_complete = 1;
809		mtx_unlock(&be_lun->lock);
810
811		(*dev_data->csw->d_strategy)(bio);
812	}
813}
814
815static void
816ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
817		       struct ctl_be_block_io *beio)
818{
819	union ctl_io *io;
820	struct ctl_be_block_devdata *dev_data;
821	struct ctl_ptr_len_flags *ptrlen;
822	struct scsi_unmap_desc *buf, *end;
823	uint64_t len;
824
825	dev_data = &be_lun->backend.dev;
826	io = beio->io;
827
828	DPRINTF("entered\n");
829
830	binuptime(&beio->ds_t0);
831	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
832
833	if (beio->io_offset == -1) {
834		beio->io_len = 0;
835		ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
836		buf = (struct scsi_unmap_desc *)ptrlen->ptr;
837		end = buf + ptrlen->len / sizeof(*buf);
838		for (; buf < end; buf++) {
839			len = (uint64_t)scsi_4btoul(buf->length) *
840			    be_lun->blocksize;
841			beio->io_len += len;
842			ctl_be_block_unmap_dev_range(be_lun, beio,
843			    scsi_8btou64(buf->lba) * be_lun->blocksize, len,
844			    (end - buf < 2) ? TRUE : FALSE);
845		}
846	} else
847		ctl_be_block_unmap_dev_range(be_lun, beio,
848		    beio->io_offset, beio->io_len, TRUE);
849}
850
851static void
852ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
853			  struct ctl_be_block_io *beio)
854{
855	int i;
856	struct bio *bio;
857	struct ctl_be_block_devdata *dev_data;
858	off_t cur_offset;
859	int max_iosize;
860
861	DPRINTF("entered\n");
862
863	dev_data = &be_lun->backend.dev;
864
865	/*
866	 * We have to limit our I/O size to the maximum supported by the
867	 * backend device.  Hopefully it is MAXPHYS.  If the driver doesn't
868	 * set it properly, use DFLTPHYS.
869	 */
870	max_iosize = dev_data->cdev->si_iosize_max;
871	if (max_iosize < PAGE_SIZE)
872		max_iosize = DFLTPHYS;
873
874	cur_offset = beio->io_offset;
875
876	/*
877	 * XXX KDM need to accurately reflect the number of I/Os outstanding
878	 * to a device.
879	 */
880	binuptime(&beio->ds_t0);
881	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
882
883	for (i = 0; i < beio->num_segs; i++) {
884		size_t cur_size;
885		uint8_t *cur_ptr;
886
887		cur_size = beio->sg_segs[i].len;
888		cur_ptr = beio->sg_segs[i].addr;
889
890		while (cur_size > 0) {
891			/* This can't fail, it's a blocking allocation. */
892			bio = g_alloc_bio();
893
894			KASSERT(bio != NULL, ("g_alloc_bio() failed!\n"));
895
896			bio->bio_cmd = beio->bio_cmd;
897			bio->bio_flags |= beio->bio_flags;
898			bio->bio_dev = dev_data->cdev;
899			bio->bio_caller1 = beio;
900			bio->bio_length = min(cur_size, max_iosize);
901			bio->bio_offset = cur_offset;
902			bio->bio_data = cur_ptr;
903			bio->bio_done = ctl_be_block_biodone;
904			bio->bio_pblkno = cur_offset / be_lun->blocksize;
905
906			cur_offset += bio->bio_length;
907			cur_ptr += bio->bio_length;
908			cur_size -= bio->bio_length;
909
910			/*
911			 * Make sure we set the complete bit just before we
912			 * issue the last bio so we don't wind up with a
913			 * race.
914			 *
915			 * Use the LUN mutex here instead of a combination
916			 * of atomic variables for simplicity.
917			 *
918			 * XXX KDM we could have a per-IO lock, but that
919			 * would cause additional per-IO setup and teardown
920			 * overhead.  Hopefully there won't be too much
921			 * contention on the LUN lock.
922			 */
923			mtx_lock(&be_lun->lock);
924
925			beio->num_bios_sent++;
926
927			if ((i == beio->num_segs - 1)
928			 && (cur_size == 0))
929				beio->send_complete = 1;
930
931			mtx_unlock(&be_lun->lock);
932
933			(*dev_data->csw->d_strategy)(bio);
934		}
935	}
936}
937
938static void
939ctl_be_block_cw_done_ws(struct ctl_be_block_io *beio)
940{
941	union ctl_io *io;
942
943	io = beio->io;
944	ctl_free_beio(beio);
945	if (((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)
946	  && ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
947		ctl_config_write_done(io);
948		return;
949	}
950
951	ctl_be_block_config_write(io);
952}
953
954static void
955ctl_be_block_cw_dispatch_ws(struct ctl_be_block_lun *be_lun,
956			    union ctl_io *io)
957{
958	struct ctl_be_block_io *beio;
959	struct ctl_be_block_softc *softc;
960	struct ctl_lba_len_flags *lbalen;
961	uint64_t len_left, lba;
962	int i, seglen;
963	uint8_t *buf, *end;
964
965	DPRINTF("entered\n");
966
967	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
968	softc = be_lun->softc;
969	lbalen = ARGS(beio->io);
970
971	if (lbalen->flags & ~(SWS_LBDATA | SWS_UNMAP) ||
972	    (lbalen->flags & SWS_UNMAP && be_lun->unmap == NULL)) {
973		ctl_free_beio(beio);
974		ctl_set_invalid_field(&io->scsiio,
975				      /*sks_valid*/ 1,
976				      /*command*/ 1,
977				      /*field*/ 1,
978				      /*bit_valid*/ 0,
979				      /*bit*/ 0);
980		ctl_config_write_done(io);
981		return;
982	}
983
984	/*
985	 * If the I/O came down with an ordered or head of queue tag, set
986	 * the BIO_ORDERED attribute.  For head of queue tags, that's
987	 * pretty much the best we can do.
988	 */
989	if ((io->scsiio.tag_type == CTL_TAG_ORDERED)
990	 || (io->scsiio.tag_type == CTL_TAG_HEAD_OF_QUEUE))
991		beio->bio_flags = BIO_ORDERED;
992
993	switch (io->scsiio.tag_type) {
994	case CTL_TAG_ORDERED:
995		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
996		break;
997	case CTL_TAG_HEAD_OF_QUEUE:
998		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
999		break;
1000	case CTL_TAG_UNTAGGED:
1001	case CTL_TAG_SIMPLE:
1002	case CTL_TAG_ACA:
1003	default:
1004		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1005		break;
1006	}
1007
1008	if (lbalen->flags & SWS_UNMAP) {
1009		beio->io_offset = lbalen->lba * be_lun->blocksize;
1010		beio->io_len = (uint64_t)lbalen->len * be_lun->blocksize;
1011		beio->bio_cmd = BIO_DELETE;
1012		beio->ds_trans_type = DEVSTAT_FREE;
1013
1014		be_lun->unmap(be_lun, beio);
1015		return;
1016	}
1017
1018	beio->bio_cmd = BIO_WRITE;
1019	beio->ds_trans_type = DEVSTAT_WRITE;
1020
1021	DPRINTF("WRITE SAME at LBA %jx len %u\n",
1022	       (uintmax_t)lbalen->lba, lbalen->len);
1023
1024	len_left = (uint64_t)lbalen->len * be_lun->blocksize;
1025	for (i = 0, lba = 0; i < CTLBLK_MAX_SEGS && len_left > 0; i++) {
1026
1027		/*
1028		 * Setup the S/G entry for this chunk.
1029		 */
1030		seglen = MIN(CTLBLK_MAX_SEG, len_left);
1031		seglen -= seglen % be_lun->blocksize;
1032		beio->sg_segs[i].len = seglen;
1033		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1034
1035		DPRINTF("segment %d addr %p len %zd\n", i,
1036			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1037
1038		beio->num_segs++;
1039		len_left -= seglen;
1040
1041		buf = beio->sg_segs[i].addr;
1042		end = buf + seglen;
1043		for (; buf < end; buf += be_lun->blocksize) {
1044			memcpy(buf, io->scsiio.kern_data_ptr, be_lun->blocksize);
1045			if (lbalen->flags & SWS_LBDATA)
1046				scsi_ulto4b(lbalen->lba + lba, buf);
1047			lba++;
1048		}
1049	}
1050
1051	beio->io_offset = lbalen->lba * be_lun->blocksize;
1052	beio->io_len = lba * be_lun->blocksize;
1053
1054	/* We can not do all in one run. Correct and schedule rerun. */
1055	if (len_left > 0) {
1056		lbalen->lba += lba;
1057		lbalen->len -= lba;
1058		beio->beio_cont = ctl_be_block_cw_done_ws;
1059	}
1060
1061	be_lun->dispatch(be_lun, beio);
1062}
1063
1064static void
1065ctl_be_block_cw_dispatch_unmap(struct ctl_be_block_lun *be_lun,
1066			    union ctl_io *io)
1067{
1068	struct ctl_be_block_io *beio;
1069	struct ctl_be_block_softc *softc;
1070	struct ctl_ptr_len_flags *ptrlen;
1071
1072	DPRINTF("entered\n");
1073
1074	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1075	softc = be_lun->softc;
1076	ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1077
1078	if (ptrlen->flags != 0 || be_lun->unmap == NULL) {
1079		ctl_free_beio(beio);
1080		ctl_set_invalid_field(&io->scsiio,
1081				      /*sks_valid*/ 0,
1082				      /*command*/ 1,
1083				      /*field*/ 0,
1084				      /*bit_valid*/ 0,
1085				      /*bit*/ 0);
1086		ctl_config_write_done(io);
1087		return;
1088	}
1089
1090	/*
1091	 * If the I/O came down with an ordered or head of queue tag, set
1092	 * the BIO_ORDERED attribute.  For head of queue tags, that's
1093	 * pretty much the best we can do.
1094	 */
1095	if ((io->scsiio.tag_type == CTL_TAG_ORDERED)
1096	 || (io->scsiio.tag_type == CTL_TAG_HEAD_OF_QUEUE))
1097		beio->bio_flags = BIO_ORDERED;
1098
1099	switch (io->scsiio.tag_type) {
1100	case CTL_TAG_ORDERED:
1101		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1102		break;
1103	case CTL_TAG_HEAD_OF_QUEUE:
1104		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1105		break;
1106	case CTL_TAG_UNTAGGED:
1107	case CTL_TAG_SIMPLE:
1108	case CTL_TAG_ACA:
1109	default:
1110		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1111		break;
1112	}
1113
1114	beio->io_len = 0;
1115	beio->io_offset = -1;
1116
1117	beio->bio_cmd = BIO_DELETE;
1118	beio->ds_trans_type = DEVSTAT_FREE;
1119
1120	DPRINTF("UNMAP\n");
1121
1122	be_lun->unmap(be_lun, beio);
1123}
1124
1125static void
1126ctl_be_block_cw_done(struct ctl_be_block_io *beio)
1127{
1128	union ctl_io *io;
1129
1130	io = beio->io;
1131	ctl_free_beio(beio);
1132	ctl_config_write_done(io);
1133}
1134
1135static void
1136ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
1137			 union ctl_io *io)
1138{
1139	struct ctl_be_block_io *beio;
1140	struct ctl_be_block_softc *softc;
1141
1142	DPRINTF("entered\n");
1143
1144	softc = be_lun->softc;
1145	beio = ctl_alloc_beio(softc);
1146	beio->io = io;
1147	beio->lun = be_lun;
1148	beio->beio_cont = ctl_be_block_cw_done;
1149	PRIV(io)->ptr = (void *)beio;
1150
1151	switch (io->scsiio.cdb[0]) {
1152	case SYNCHRONIZE_CACHE:
1153	case SYNCHRONIZE_CACHE_16:
1154		beio->bio_cmd = BIO_FLUSH;
1155		beio->ds_trans_type = DEVSTAT_NO_DATA;
1156		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1157		beio->io_len = 0;
1158		be_lun->lun_flush(be_lun, beio);
1159		break;
1160	case WRITE_SAME_10:
1161	case WRITE_SAME_16:
1162		ctl_be_block_cw_dispatch_ws(be_lun, io);
1163		break;
1164	case UNMAP:
1165		ctl_be_block_cw_dispatch_unmap(be_lun, io);
1166		break;
1167	default:
1168		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1169		break;
1170	}
1171}
1172
1173SDT_PROBE_DEFINE1(cbb, kernel, read, start, "uint64_t");
1174SDT_PROBE_DEFINE1(cbb, kernel, write, start, "uint64_t");
1175SDT_PROBE_DEFINE1(cbb, kernel, read, alloc_done, "uint64_t");
1176SDT_PROBE_DEFINE1(cbb, kernel, write, alloc_done, "uint64_t");
1177
1178static void
1179ctl_be_block_next(struct ctl_be_block_io *beio)
1180{
1181	struct ctl_be_block_lun *be_lun;
1182	union ctl_io *io;
1183
1184	io = beio->io;
1185	be_lun = beio->lun;
1186	ctl_free_beio(beio);
1187	if (((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)
1188	  && ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1189		ctl_data_submit_done(io);
1190		return;
1191	}
1192
1193	io->io_hdr.status &= ~CTL_STATUS_MASK;
1194	io->io_hdr.status |= CTL_STATUS_NONE;
1195
1196	mtx_lock(&be_lun->lock);
1197	/*
1198	 * XXX KDM make sure that links is okay to use at this point.
1199	 * Otherwise, we either need to add another field to ctl_io_hdr,
1200	 * or deal with resource allocation here.
1201	 */
1202	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1203	mtx_unlock(&be_lun->lock);
1204
1205	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1206}
1207
1208static void
1209ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
1210			   union ctl_io *io)
1211{
1212	struct ctl_be_block_io *beio;
1213	struct ctl_be_block_softc *softc;
1214	struct ctl_lba_len_flags *lbalen;
1215	struct ctl_ptr_len_flags *bptrlen;
1216	uint64_t len_left, lbas;
1217	int i;
1218
1219	softc = be_lun->softc;
1220
1221	DPRINTF("entered\n");
1222
1223	lbalen = ARGS(io);
1224	if (lbalen->flags & CTL_LLF_WRITE) {
1225		SDT_PROBE(cbb, kernel, write, start, 0, 0, 0, 0, 0);
1226	} else {
1227		SDT_PROBE(cbb, kernel, read, start, 0, 0, 0, 0, 0);
1228	}
1229
1230	beio = ctl_alloc_beio(softc);
1231	beio->io = io;
1232	beio->lun = be_lun;
1233	bptrlen = PRIV(io);
1234	bptrlen->ptr = (void *)beio;
1235
1236	/*
1237	 * If the I/O came down with an ordered or head of queue tag, set
1238	 * the BIO_ORDERED attribute.  For head of queue tags, that's
1239	 * pretty much the best we can do.
1240	 *
1241	 * XXX KDM we don't have a great way to easily know about the FUA
1242	 * bit right now (it is decoded in ctl_read_write(), but we don't
1243	 * pass that knowledge to the backend), and in any case we would
1244	 * need to determine how to handle it.
1245	 */
1246	if ((io->scsiio.tag_type == CTL_TAG_ORDERED)
1247	 || (io->scsiio.tag_type == CTL_TAG_HEAD_OF_QUEUE))
1248		beio->bio_flags = BIO_ORDERED;
1249
1250	switch (io->scsiio.tag_type) {
1251	case CTL_TAG_ORDERED:
1252		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1253		break;
1254	case CTL_TAG_HEAD_OF_QUEUE:
1255		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1256		break;
1257	case CTL_TAG_UNTAGGED:
1258	case CTL_TAG_SIMPLE:
1259	case CTL_TAG_ACA:
1260	default:
1261		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1262		break;
1263	}
1264
1265	if (lbalen->flags & CTL_LLF_WRITE) {
1266		beio->bio_cmd = BIO_WRITE;
1267		beio->ds_trans_type = DEVSTAT_WRITE;
1268	} else {
1269		beio->bio_cmd = BIO_READ;
1270		beio->ds_trans_type = DEVSTAT_READ;
1271	}
1272
1273	DPRINTF("%s at LBA %jx len %u @%ju\n",
1274	       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE",
1275	       (uintmax_t)lbalen->lba, lbalen->len, bptrlen->len);
1276	if (lbalen->flags & CTL_LLF_COMPARE)
1277		lbas = CTLBLK_HALF_IO_SIZE;
1278	else
1279		lbas = CTLBLK_MAX_IO_SIZE;
1280	lbas = MIN(lbalen->len - bptrlen->len, lbas / be_lun->blocksize);
1281	beio->io_offset = (lbalen->lba + bptrlen->len) * be_lun->blocksize;
1282	beio->io_len = lbas * be_lun->blocksize;
1283	bptrlen->len += lbas;
1284
1285	for (i = 0, len_left = beio->io_len; len_left > 0; i++) {
1286		KASSERT(i < CTLBLK_MAX_SEGS, ("Too many segs (%d >= %d)",
1287		    i, CTLBLK_MAX_SEGS));
1288
1289		/*
1290		 * Setup the S/G entry for this chunk.
1291		 */
1292		beio->sg_segs[i].len = min(CTLBLK_MAX_SEG, len_left);
1293		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1294
1295		DPRINTF("segment %d addr %p len %zd\n", i,
1296			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1297
1298		/* Set up second segment for compare operation. */
1299		if (lbalen->flags & CTL_LLF_COMPARE) {
1300			beio->sg_segs[i + CTLBLK_HALF_SEGS].len =
1301			    beio->sg_segs[i].len;
1302			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr =
1303			    uma_zalloc(be_lun->lun_zone, M_WAITOK);
1304		}
1305
1306		beio->num_segs++;
1307		len_left -= beio->sg_segs[i].len;
1308	}
1309	if (bptrlen->len < lbalen->len)
1310		beio->beio_cont = ctl_be_block_next;
1311	io->scsiio.be_move_done = ctl_be_block_move_done;
1312	/* For compare we have separate S/G lists for read and datamove. */
1313	if (lbalen->flags & CTL_LLF_COMPARE)
1314		io->scsiio.kern_data_ptr = (uint8_t *)&beio->sg_segs[CTLBLK_HALF_SEGS];
1315	else
1316		io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
1317	io->scsiio.kern_data_len = beio->io_len;
1318	io->scsiio.kern_data_resid = 0;
1319	io->scsiio.kern_sg_entries = beio->num_segs;
1320	io->io_hdr.flags |= CTL_FLAG_ALLOCATED | CTL_FLAG_KDPTR_SGLIST;
1321
1322	/*
1323	 * For the read case, we need to read the data into our buffers and
1324	 * then we can send it back to the user.  For the write case, we
1325	 * need to get the data from the user first.
1326	 */
1327	if (beio->bio_cmd == BIO_READ) {
1328		SDT_PROBE(cbb, kernel, read, alloc_done, 0, 0, 0, 0, 0);
1329		be_lun->dispatch(be_lun, beio);
1330	} else {
1331		SDT_PROBE(cbb, kernel, write, alloc_done, 0, 0, 0, 0, 0);
1332#ifdef CTL_TIME_IO
1333        	getbintime(&io->io_hdr.dma_start_bt);
1334#endif
1335		ctl_datamove(io);
1336	}
1337}
1338
1339static void
1340ctl_be_block_worker(void *context, int pending)
1341{
1342	struct ctl_be_block_lun *be_lun;
1343	struct ctl_be_block_softc *softc;
1344	union ctl_io *io;
1345
1346	be_lun = (struct ctl_be_block_lun *)context;
1347	softc = be_lun->softc;
1348
1349	DPRINTF("entered\n");
1350
1351	mtx_lock(&be_lun->lock);
1352	for (;;) {
1353		io = (union ctl_io *)STAILQ_FIRST(&be_lun->datamove_queue);
1354		if (io != NULL) {
1355			struct ctl_be_block_io *beio;
1356
1357			DPRINTF("datamove queue\n");
1358
1359			STAILQ_REMOVE(&be_lun->datamove_queue, &io->io_hdr,
1360				      ctl_io_hdr, links);
1361
1362			mtx_unlock(&be_lun->lock);
1363
1364			beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1365
1366			be_lun->dispatch(be_lun, beio);
1367
1368			mtx_lock(&be_lun->lock);
1369			continue;
1370		}
1371		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_write_queue);
1372		if (io != NULL) {
1373
1374			DPRINTF("config write queue\n");
1375
1376			STAILQ_REMOVE(&be_lun->config_write_queue, &io->io_hdr,
1377				      ctl_io_hdr, links);
1378
1379			mtx_unlock(&be_lun->lock);
1380
1381			ctl_be_block_cw_dispatch(be_lun, io);
1382
1383			mtx_lock(&be_lun->lock);
1384			continue;
1385		}
1386		io = (union ctl_io *)STAILQ_FIRST(&be_lun->input_queue);
1387		if (io != NULL) {
1388			DPRINTF("input queue\n");
1389
1390			STAILQ_REMOVE(&be_lun->input_queue, &io->io_hdr,
1391				      ctl_io_hdr, links);
1392			mtx_unlock(&be_lun->lock);
1393
1394			/*
1395			 * We must drop the lock, since this routine and
1396			 * its children may sleep.
1397			 */
1398			ctl_be_block_dispatch(be_lun, io);
1399
1400			mtx_lock(&be_lun->lock);
1401			continue;
1402		}
1403
1404		/*
1405		 * If we get here, there is no work left in the queues, so
1406		 * just break out and let the task queue go to sleep.
1407		 */
1408		break;
1409	}
1410	mtx_unlock(&be_lun->lock);
1411}
1412
1413/*
1414 * Entry point from CTL to the backend for I/O.  We queue everything to a
1415 * work thread, so this just puts the I/O on a queue and wakes up the
1416 * thread.
1417 */
1418static int
1419ctl_be_block_submit(union ctl_io *io)
1420{
1421	struct ctl_be_block_lun *be_lun;
1422	struct ctl_be_lun *ctl_be_lun;
1423
1424	DPRINTF("entered\n");
1425
1426	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
1427		CTL_PRIV_BACKEND_LUN].ptr;
1428	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
1429
1430	/*
1431	 * Make sure we only get SCSI I/O.
1432	 */
1433	KASSERT(io->io_hdr.io_type == CTL_IO_SCSI, ("Non-SCSI I/O (type "
1434		"%#x) encountered", io->io_hdr.io_type));
1435
1436	PRIV(io)->len = 0;
1437
1438	mtx_lock(&be_lun->lock);
1439	/*
1440	 * XXX KDM make sure that links is okay to use at this point.
1441	 * Otherwise, we either need to add another field to ctl_io_hdr,
1442	 * or deal with resource allocation here.
1443	 */
1444	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1445	mtx_unlock(&be_lun->lock);
1446	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1447
1448	return (CTL_RETVAL_COMPLETE);
1449}
1450
1451static int
1452ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
1453			int flag, struct thread *td)
1454{
1455	struct ctl_be_block_softc *softc;
1456	int error;
1457
1458	softc = &backend_block_softc;
1459
1460	error = 0;
1461
1462	switch (cmd) {
1463	case CTL_LUN_REQ: {
1464		struct ctl_lun_req *lun_req;
1465
1466		lun_req = (struct ctl_lun_req *)addr;
1467
1468		switch (lun_req->reqtype) {
1469		case CTL_LUNREQ_CREATE:
1470			error = ctl_be_block_create(softc, lun_req);
1471			break;
1472		case CTL_LUNREQ_RM:
1473			error = ctl_be_block_rm(softc, lun_req);
1474			break;
1475		case CTL_LUNREQ_MODIFY:
1476			error = ctl_be_block_modify(softc, lun_req);
1477			break;
1478		default:
1479			lun_req->status = CTL_LUN_ERROR;
1480			snprintf(lun_req->error_str, sizeof(lun_req->error_str),
1481				 "%s: invalid LUN request type %d", __func__,
1482				 lun_req->reqtype);
1483			break;
1484		}
1485		break;
1486	}
1487	default:
1488		error = ENOTTY;
1489		break;
1490	}
1491
1492	return (error);
1493}
1494
1495static int
1496ctl_be_block_open_file(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1497{
1498	struct ctl_be_block_filedata *file_data;
1499	struct ctl_lun_create_params *params;
1500	struct vattr		      vattr;
1501	int			      error;
1502
1503	error = 0;
1504	file_data = &be_lun->backend.file;
1505	params = &req->reqdata.create;
1506
1507	be_lun->dev_type = CTL_BE_BLOCK_FILE;
1508	be_lun->dispatch = ctl_be_block_dispatch_file;
1509	be_lun->lun_flush = ctl_be_block_flush_file;
1510
1511	error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
1512	if (error != 0) {
1513		snprintf(req->error_str, sizeof(req->error_str),
1514			 "error calling VOP_GETATTR() for file %s",
1515			 be_lun->dev_path);
1516		return (error);
1517	}
1518
1519	/*
1520	 * Verify that we have the ability to upgrade to exclusive
1521	 * access on this file so we can trap errors at open instead
1522	 * of reporting them during first access.
1523	 */
1524	if (VOP_ISLOCKED(be_lun->vn) != LK_EXCLUSIVE) {
1525		vn_lock(be_lun->vn, LK_UPGRADE | LK_RETRY);
1526		if (be_lun->vn->v_iflag & VI_DOOMED) {
1527			error = EBADF;
1528			snprintf(req->error_str, sizeof(req->error_str),
1529				 "error locking file %s", be_lun->dev_path);
1530			return (error);
1531		}
1532	}
1533
1534
1535	file_data->cred = crhold(curthread->td_ucred);
1536	if (params->lun_size_bytes != 0)
1537		be_lun->size_bytes = params->lun_size_bytes;
1538	else
1539		be_lun->size_bytes = vattr.va_size;
1540	/*
1541	 * We set the multi thread flag for file operations because all
1542	 * filesystems (in theory) are capable of allowing multiple readers
1543	 * of a file at once.  So we want to get the maximum possible
1544	 * concurrency.
1545	 */
1546	be_lun->flags |= CTL_BE_BLOCK_LUN_MULTI_THREAD;
1547
1548	/*
1549	 * XXX KDM vattr.va_blocksize may be larger than 512 bytes here.
1550	 * With ZFS, it is 131072 bytes.  Block sizes that large don't work
1551	 * with disklabel and UFS on FreeBSD at least.  Large block sizes
1552	 * may not work with other OSes as well.  So just export a sector
1553	 * size of 512 bytes, which should work with any OS or
1554	 * application.  Since our backing is a file, any block size will
1555	 * work fine for the backing store.
1556	 */
1557#if 0
1558	be_lun->blocksize= vattr.va_blocksize;
1559#endif
1560	if (params->blocksize_bytes != 0)
1561		be_lun->blocksize = params->blocksize_bytes;
1562	else
1563		be_lun->blocksize = 512;
1564
1565	/*
1566	 * Sanity check.  The media size has to be at least one
1567	 * sector long.
1568	 */
1569	if (be_lun->size_bytes < be_lun->blocksize) {
1570		error = EINVAL;
1571		snprintf(req->error_str, sizeof(req->error_str),
1572			 "file %s size %ju < block size %u", be_lun->dev_path,
1573			 (uintmax_t)be_lun->size_bytes, be_lun->blocksize);
1574	}
1575	return (error);
1576}
1577
1578static int
1579ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1580{
1581	struct ctl_lun_create_params *params;
1582	struct vattr		      vattr;
1583	struct cdev		     *dev;
1584	struct cdevsw		     *devsw;
1585	int			      error;
1586	off_t			      ps, pss, po, pos;
1587
1588	params = &req->reqdata.create;
1589
1590	be_lun->dev_type = CTL_BE_BLOCK_DEV;
1591	be_lun->dispatch = ctl_be_block_dispatch_dev;
1592	be_lun->lun_flush = ctl_be_block_flush_dev;
1593	be_lun->unmap = ctl_be_block_unmap_dev;
1594	be_lun->backend.dev.cdev = be_lun->vn->v_rdev;
1595	be_lun->backend.dev.csw = dev_refthread(be_lun->backend.dev.cdev,
1596					     &be_lun->backend.dev.dev_ref);
1597	if (be_lun->backend.dev.csw == NULL)
1598		panic("Unable to retrieve device switch");
1599
1600	error = VOP_GETATTR(be_lun->vn, &vattr, NOCRED);
1601	if (error) {
1602		snprintf(req->error_str, sizeof(req->error_str),
1603			 "%s: error getting vnode attributes for device %s",
1604			 __func__, be_lun->dev_path);
1605		return (error);
1606	}
1607
1608	dev = be_lun->vn->v_rdev;
1609	devsw = dev->si_devsw;
1610	if (!devsw->d_ioctl) {
1611		snprintf(req->error_str, sizeof(req->error_str),
1612			 "%s: no d_ioctl for device %s!", __func__,
1613			 be_lun->dev_path);
1614		return (ENODEV);
1615	}
1616
1617	error = devsw->d_ioctl(dev, DIOCGSECTORSIZE,
1618			       (caddr_t)&be_lun->blocksize, FREAD,
1619			       curthread);
1620	if (error) {
1621		snprintf(req->error_str, sizeof(req->error_str),
1622			 "%s: error %d returned for DIOCGSECTORSIZE ioctl "
1623			 "on %s!", __func__, error, be_lun->dev_path);
1624		return (error);
1625	}
1626
1627	/*
1628	 * If the user has asked for a blocksize that is greater than the
1629	 * backing device's blocksize, we can do it only if the blocksize
1630	 * the user is asking for is an even multiple of the underlying
1631	 * device's blocksize.
1632	 */
1633	if ((params->blocksize_bytes != 0)
1634	 && (params->blocksize_bytes > be_lun->blocksize)) {
1635		uint32_t bs_multiple, tmp_blocksize;
1636
1637		bs_multiple = params->blocksize_bytes / be_lun->blocksize;
1638
1639		tmp_blocksize = bs_multiple * be_lun->blocksize;
1640
1641		if (tmp_blocksize == params->blocksize_bytes) {
1642			be_lun->blocksize = params->blocksize_bytes;
1643		} else {
1644			snprintf(req->error_str, sizeof(req->error_str),
1645				 "%s: requested blocksize %u is not an even "
1646				 "multiple of backing device blocksize %u",
1647				 __func__, params->blocksize_bytes,
1648				 be_lun->blocksize);
1649			return (EINVAL);
1650
1651		}
1652	} else if ((params->blocksize_bytes != 0)
1653		&& (params->blocksize_bytes != be_lun->blocksize)) {
1654		snprintf(req->error_str, sizeof(req->error_str),
1655			 "%s: requested blocksize %u < backing device "
1656			 "blocksize %u", __func__, params->blocksize_bytes,
1657			 be_lun->blocksize);
1658		return (EINVAL);
1659	}
1660
1661	error = devsw->d_ioctl(dev, DIOCGMEDIASIZE,
1662			       (caddr_t)&be_lun->size_bytes, FREAD,
1663			       curthread);
1664	if (error) {
1665		snprintf(req->error_str, sizeof(req->error_str),
1666			 "%s: error %d returned for DIOCGMEDIASIZE "
1667			 " ioctl on %s!", __func__, error,
1668			 be_lun->dev_path);
1669		return (error);
1670	}
1671
1672	if (params->lun_size_bytes != 0) {
1673		if (params->lun_size_bytes > be_lun->size_bytes) {
1674			snprintf(req->error_str, sizeof(req->error_str),
1675				 "%s: requested LUN size %ju > backing device "
1676				 "size %ju", __func__,
1677				 (uintmax_t)params->lun_size_bytes,
1678				 (uintmax_t)be_lun->size_bytes);
1679			return (EINVAL);
1680		}
1681
1682		be_lun->size_bytes = params->lun_size_bytes;
1683	}
1684
1685	error = devsw->d_ioctl(dev, DIOCGSTRIPESIZE,
1686			       (caddr_t)&ps, FREAD, curthread);
1687	if (error)
1688		ps = po = 0;
1689	else {
1690		error = devsw->d_ioctl(dev, DIOCGSTRIPEOFFSET,
1691				       (caddr_t)&po, FREAD, curthread);
1692		if (error)
1693			po = 0;
1694	}
1695	pss = ps / be_lun->blocksize;
1696	pos = po / be_lun->blocksize;
1697	if ((pss > 0) && (pss * be_lun->blocksize == ps) && (pss >= pos) &&
1698	    ((pss & (pss - 1)) == 0) && (pos * be_lun->blocksize == po)) {
1699		be_lun->pblockexp = fls(pss) - 1;
1700		be_lun->pblockoff = (pss - pos) % pss;
1701	}
1702
1703	return (0);
1704}
1705
1706static int
1707ctl_be_block_close(struct ctl_be_block_lun *be_lun)
1708{
1709	DROP_GIANT();
1710	if (be_lun->vn) {
1711		int flags = FREAD | FWRITE;
1712
1713		switch (be_lun->dev_type) {
1714		case CTL_BE_BLOCK_DEV:
1715			if (be_lun->backend.dev.csw) {
1716				dev_relthread(be_lun->backend.dev.cdev,
1717					      be_lun->backend.dev.dev_ref);
1718				be_lun->backend.dev.csw  = NULL;
1719				be_lun->backend.dev.cdev = NULL;
1720			}
1721			break;
1722		case CTL_BE_BLOCK_FILE:
1723			break;
1724		case CTL_BE_BLOCK_NONE:
1725			break;
1726		default:
1727			panic("Unexpected backend type.");
1728			break;
1729		}
1730
1731		(void)vn_close(be_lun->vn, flags, NOCRED, curthread);
1732		be_lun->vn = NULL;
1733
1734		switch (be_lun->dev_type) {
1735		case CTL_BE_BLOCK_DEV:
1736			break;
1737		case CTL_BE_BLOCK_FILE:
1738			if (be_lun->backend.file.cred != NULL) {
1739				crfree(be_lun->backend.file.cred);
1740				be_lun->backend.file.cred = NULL;
1741			}
1742			break;
1743		case CTL_BE_BLOCK_NONE:
1744			break;
1745		default:
1746			panic("Unexpected backend type.");
1747			break;
1748		}
1749	}
1750	PICKUP_GIANT();
1751
1752	return (0);
1753}
1754
1755static int
1756ctl_be_block_open(struct ctl_be_block_softc *softc,
1757		       struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1758{
1759	struct nameidata nd;
1760	int		 flags;
1761	int		 error;
1762
1763	/*
1764	 * XXX KDM allow a read-only option?
1765	 */
1766	flags = FREAD | FWRITE;
1767	error = 0;
1768
1769	if (rootvnode == NULL) {
1770		snprintf(req->error_str, sizeof(req->error_str),
1771			 "%s: Root filesystem is not mounted", __func__);
1772		return (1);
1773	}
1774
1775	if (!curthread->td_proc->p_fd->fd_cdir) {
1776		curthread->td_proc->p_fd->fd_cdir = rootvnode;
1777		VREF(rootvnode);
1778	}
1779	if (!curthread->td_proc->p_fd->fd_rdir) {
1780		curthread->td_proc->p_fd->fd_rdir = rootvnode;
1781		VREF(rootvnode);
1782	}
1783	if (!curthread->td_proc->p_fd->fd_jdir) {
1784		curthread->td_proc->p_fd->fd_jdir = rootvnode;
1785		VREF(rootvnode);
1786	}
1787
1788 again:
1789	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, be_lun->dev_path, curthread);
1790	error = vn_open(&nd, &flags, 0, NULL);
1791	if (error) {
1792		/*
1793		 * This is the only reasonable guess we can make as far as
1794		 * path if the user doesn't give us a fully qualified path.
1795		 * If they want to specify a file, they need to specify the
1796		 * full path.
1797		 */
1798		if (be_lun->dev_path[0] != '/') {
1799			char *dev_path = "/dev/";
1800			char *dev_name;
1801
1802			/* Try adding device path at beginning of name */
1803			dev_name = malloc(strlen(be_lun->dev_path)
1804					+ strlen(dev_path) + 1,
1805					  M_CTLBLK, M_WAITOK);
1806			if (dev_name) {
1807				sprintf(dev_name, "%s%s", dev_path,
1808					be_lun->dev_path);
1809				free(be_lun->dev_path, M_CTLBLK);
1810				be_lun->dev_path = dev_name;
1811				goto again;
1812			}
1813		}
1814		snprintf(req->error_str, sizeof(req->error_str),
1815			 "%s: error opening %s", __func__, be_lun->dev_path);
1816		return (error);
1817	}
1818
1819	NDFREE(&nd, NDF_ONLY_PNBUF);
1820
1821	be_lun->vn = nd.ni_vp;
1822
1823	/* We only support disks and files. */
1824	if (vn_isdisk(be_lun->vn, &error)) {
1825		error = ctl_be_block_open_dev(be_lun, req);
1826	} else if (be_lun->vn->v_type == VREG) {
1827		error = ctl_be_block_open_file(be_lun, req);
1828	} else {
1829		error = EINVAL;
1830		snprintf(req->error_str, sizeof(req->error_str),
1831			 "%s is not a disk or plain file", be_lun->dev_path);
1832	}
1833	VOP_UNLOCK(be_lun->vn, 0);
1834
1835	if (error != 0) {
1836		ctl_be_block_close(be_lun);
1837		return (error);
1838	}
1839
1840	be_lun->blocksize_shift = fls(be_lun->blocksize) - 1;
1841	be_lun->size_blocks = be_lun->size_bytes >> be_lun->blocksize_shift;
1842
1843	return (0);
1844}
1845
1846static int
1847ctl_be_block_create(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
1848{
1849	struct ctl_be_block_lun *be_lun;
1850	struct ctl_lun_create_params *params;
1851	char num_thread_str[16];
1852	char tmpstr[32];
1853	char *value;
1854	int retval, num_threads, unmap;
1855	int tmp_num_threads;
1856
1857	params = &req->reqdata.create;
1858	retval = 0;
1859
1860	num_threads = cbb_num_threads;
1861
1862	be_lun = malloc(sizeof(*be_lun), M_CTLBLK, M_ZERO | M_WAITOK);
1863
1864	be_lun->softc = softc;
1865	STAILQ_INIT(&be_lun->input_queue);
1866	STAILQ_INIT(&be_lun->config_write_queue);
1867	STAILQ_INIT(&be_lun->datamove_queue);
1868	sprintf(be_lun->lunname, "cblk%d", softc->num_luns);
1869	mtx_init(&be_lun->lock, be_lun->lunname, NULL, MTX_DEF);
1870	ctl_init_opts(&be_lun->ctl_be_lun, req);
1871
1872	be_lun->lun_zone = uma_zcreate(be_lun->lunname, CTLBLK_MAX_SEG,
1873	    NULL, NULL, NULL, NULL, /*align*/ 0, /*flags*/0);
1874
1875	if (be_lun->lun_zone == NULL) {
1876		snprintf(req->error_str, sizeof(req->error_str),
1877			 "%s: error allocating UMA zone", __func__);
1878		goto bailout_error;
1879	}
1880
1881	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
1882		be_lun->ctl_be_lun.lun_type = params->device_type;
1883	else
1884		be_lun->ctl_be_lun.lun_type = T_DIRECT;
1885
1886	if (be_lun->ctl_be_lun.lun_type == T_DIRECT) {
1887		value = ctl_get_opt(&be_lun->ctl_be_lun, "file");
1888		if (value == NULL) {
1889			snprintf(req->error_str, sizeof(req->error_str),
1890				 "%s: no file argument specified", __func__);
1891			goto bailout_error;
1892		}
1893		be_lun->dev_path = strdup(value, M_CTLBLK);
1894
1895		retval = ctl_be_block_open(softc, be_lun, req);
1896		if (retval != 0) {
1897			retval = 0;
1898			goto bailout_error;
1899		}
1900
1901		/*
1902		 * Tell the user the size of the file/device.
1903		 */
1904		params->lun_size_bytes = be_lun->size_bytes;
1905
1906		/*
1907		 * The maximum LBA is the size - 1.
1908		 */
1909		be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
1910	} else {
1911		/*
1912		 * For processor devices, we don't have any size.
1913		 */
1914		be_lun->blocksize = 0;
1915		be_lun->pblockexp = 0;
1916		be_lun->pblockoff = 0;
1917		be_lun->size_blocks = 0;
1918		be_lun->size_bytes = 0;
1919		be_lun->ctl_be_lun.maxlba = 0;
1920		params->lun_size_bytes = 0;
1921
1922		/*
1923		 * Default to just 1 thread for processor devices.
1924		 */
1925		num_threads = 1;
1926	}
1927
1928	/*
1929	 * XXX This searching loop might be refactored to be combined with
1930	 * the loop above,
1931	 */
1932	value = ctl_get_opt(&be_lun->ctl_be_lun, "num_threads");
1933	if (value != NULL) {
1934		tmp_num_threads = strtol(value, NULL, 0);
1935
1936		/*
1937		 * We don't let the user specify less than one
1938		 * thread, but hope he's clueful enough not to
1939		 * specify 1000 threads.
1940		 */
1941		if (tmp_num_threads < 1) {
1942			snprintf(req->error_str, sizeof(req->error_str),
1943				 "%s: invalid number of threads %s",
1944			         __func__, num_thread_str);
1945			goto bailout_error;
1946		}
1947		num_threads = tmp_num_threads;
1948	}
1949	unmap = 0;
1950	value = ctl_get_opt(&be_lun->ctl_be_lun, "unmap");
1951	if (value != NULL && strcmp(value, "on") == 0)
1952		unmap = 1;
1953
1954	be_lun->flags = CTL_BE_BLOCK_LUN_UNCONFIGURED;
1955	be_lun->ctl_be_lun.flags = CTL_LUN_FLAG_PRIMARY;
1956	if (unmap)
1957		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_UNMAP;
1958	be_lun->ctl_be_lun.be_lun = be_lun;
1959	be_lun->ctl_be_lun.blocksize = be_lun->blocksize;
1960	be_lun->ctl_be_lun.pblockexp = be_lun->pblockexp;
1961	be_lun->ctl_be_lun.pblockoff = be_lun->pblockoff;
1962	/* Tell the user the blocksize we ended up using */
1963	params->blocksize_bytes = be_lun->blocksize;
1964	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
1965		be_lun->ctl_be_lun.req_lun_id = params->req_lun_id;
1966		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_ID_REQ;
1967	} else
1968		be_lun->ctl_be_lun.req_lun_id = 0;
1969
1970	be_lun->ctl_be_lun.lun_shutdown = ctl_be_block_lun_shutdown;
1971	be_lun->ctl_be_lun.lun_config_status =
1972		ctl_be_block_lun_config_status;
1973	be_lun->ctl_be_lun.be = &ctl_be_block_driver;
1974
1975	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
1976		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
1977			 softc->num_luns);
1978		strncpy((char *)be_lun->ctl_be_lun.serial_num, tmpstr,
1979			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
1980			sizeof(tmpstr)));
1981
1982		/* Tell the user what we used for a serial number */
1983		strncpy((char *)params->serial_num, tmpstr,
1984			ctl_min(sizeof(params->serial_num), sizeof(tmpstr)));
1985	} else {
1986		strncpy((char *)be_lun->ctl_be_lun.serial_num,
1987			params->serial_num,
1988			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
1989			sizeof(params->serial_num)));
1990	}
1991	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
1992		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
1993		strncpy((char *)be_lun->ctl_be_lun.device_id, tmpstr,
1994			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
1995			sizeof(tmpstr)));
1996
1997		/* Tell the user what we used for a device ID */
1998		strncpy((char *)params->device_id, tmpstr,
1999			ctl_min(sizeof(params->device_id), sizeof(tmpstr)));
2000	} else {
2001		strncpy((char *)be_lun->ctl_be_lun.device_id,
2002			params->device_id,
2003			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
2004				sizeof(params->device_id)));
2005	}
2006
2007	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_be_block_worker, be_lun);
2008
2009	be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
2010	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
2011
2012	if (be_lun->io_taskqueue == NULL) {
2013		snprintf(req->error_str, sizeof(req->error_str),
2014			 "%s: Unable to create taskqueue", __func__);
2015		goto bailout_error;
2016	}
2017
2018	/*
2019	 * Note that we start the same number of threads by default for
2020	 * both the file case and the block device case.  For the file
2021	 * case, we need multiple threads to allow concurrency, because the
2022	 * vnode interface is designed to be a blocking interface.  For the
2023	 * block device case, ZFS zvols at least will block the caller's
2024	 * context in many instances, and so we need multiple threads to
2025	 * overcome that problem.  Other block devices don't need as many
2026	 * threads, but they shouldn't cause too many problems.
2027	 *
2028	 * If the user wants to just have a single thread for a block
2029	 * device, he can specify that when the LUN is created, or change
2030	 * the tunable/sysctl to alter the default number of threads.
2031	 */
2032	retval = taskqueue_start_threads(&be_lun->io_taskqueue,
2033					 /*num threads*/num_threads,
2034					 /*priority*/PWAIT,
2035					 /*thread name*/
2036					 "%s taskq", be_lun->lunname);
2037
2038	if (retval != 0)
2039		goto bailout_error;
2040
2041	be_lun->num_threads = num_threads;
2042
2043	mtx_lock(&softc->lock);
2044	softc->num_luns++;
2045	STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
2046
2047	mtx_unlock(&softc->lock);
2048
2049	retval = ctl_add_lun(&be_lun->ctl_be_lun);
2050	if (retval != 0) {
2051		mtx_lock(&softc->lock);
2052		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2053			      links);
2054		softc->num_luns--;
2055		mtx_unlock(&softc->lock);
2056		snprintf(req->error_str, sizeof(req->error_str),
2057			 "%s: ctl_add_lun() returned error %d, see dmesg for "
2058			"details", __func__, retval);
2059		retval = 0;
2060		goto bailout_error;
2061	}
2062
2063	mtx_lock(&softc->lock);
2064
2065	/*
2066	 * Tell the config_status routine that we're waiting so it won't
2067	 * clean up the LUN in the event of an error.
2068	 */
2069	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2070
2071	while (be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) {
2072		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2073		if (retval == EINTR)
2074			break;
2075	}
2076	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2077
2078	if (be_lun->flags & CTL_BE_BLOCK_LUN_CONFIG_ERR) {
2079		snprintf(req->error_str, sizeof(req->error_str),
2080			 "%s: LUN configuration error, see dmesg for details",
2081			 __func__);
2082		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2083			      links);
2084		softc->num_luns--;
2085		mtx_unlock(&softc->lock);
2086		goto bailout_error;
2087	} else {
2088		params->req_lun_id = be_lun->ctl_be_lun.lun_id;
2089	}
2090
2091	mtx_unlock(&softc->lock);
2092
2093	be_lun->disk_stats = devstat_new_entry("cbb", params->req_lun_id,
2094					       be_lun->blocksize,
2095					       DEVSTAT_ALL_SUPPORTED,
2096					       be_lun->ctl_be_lun.lun_type
2097					       | DEVSTAT_TYPE_IF_OTHER,
2098					       DEVSTAT_PRIORITY_OTHER);
2099
2100
2101	req->status = CTL_LUN_OK;
2102
2103	return (retval);
2104
2105bailout_error:
2106	req->status = CTL_LUN_ERROR;
2107
2108	if (be_lun->io_taskqueue != NULL)
2109		taskqueue_free(be_lun->io_taskqueue);
2110	ctl_be_block_close(be_lun);
2111	if (be_lun->dev_path != NULL)
2112		free(be_lun->dev_path, M_CTLBLK);
2113	if (be_lun->lun_zone != NULL)
2114		uma_zdestroy(be_lun->lun_zone);
2115	ctl_free_opts(&be_lun->ctl_be_lun);
2116	mtx_destroy(&be_lun->lock);
2117	free(be_lun, M_CTLBLK);
2118
2119	return (retval);
2120}
2121
2122static int
2123ctl_be_block_rm(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2124{
2125	struct ctl_lun_rm_params *params;
2126	struct ctl_be_block_lun *be_lun;
2127	int retval;
2128
2129	params = &req->reqdata.rm;
2130
2131	mtx_lock(&softc->lock);
2132
2133	be_lun = NULL;
2134
2135	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2136		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2137			break;
2138	}
2139	mtx_unlock(&softc->lock);
2140
2141	if (be_lun == NULL) {
2142		snprintf(req->error_str, sizeof(req->error_str),
2143			 "%s: LUN %u is not managed by the block backend",
2144			 __func__, params->lun_id);
2145		goto bailout_error;
2146	}
2147
2148	retval = ctl_disable_lun(&be_lun->ctl_be_lun);
2149
2150	if (retval != 0) {
2151		snprintf(req->error_str, sizeof(req->error_str),
2152			 "%s: error %d returned from ctl_disable_lun() for "
2153			 "LUN %d", __func__, retval, params->lun_id);
2154		goto bailout_error;
2155
2156	}
2157
2158	retval = ctl_invalidate_lun(&be_lun->ctl_be_lun);
2159	if (retval != 0) {
2160		snprintf(req->error_str, sizeof(req->error_str),
2161			 "%s: error %d returned from ctl_invalidate_lun() for "
2162			 "LUN %d", __func__, retval, params->lun_id);
2163		goto bailout_error;
2164	}
2165
2166	mtx_lock(&softc->lock);
2167
2168	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2169
2170	while ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2171                retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2172                if (retval == EINTR)
2173                        break;
2174        }
2175
2176	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2177
2178	if ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2179		snprintf(req->error_str, sizeof(req->error_str),
2180			 "%s: interrupted waiting for LUN to be freed",
2181			 __func__);
2182		mtx_unlock(&softc->lock);
2183		goto bailout_error;
2184	}
2185
2186	STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun, links);
2187
2188	softc->num_luns--;
2189	mtx_unlock(&softc->lock);
2190
2191	taskqueue_drain(be_lun->io_taskqueue, &be_lun->io_task);
2192
2193	taskqueue_free(be_lun->io_taskqueue);
2194
2195	ctl_be_block_close(be_lun);
2196
2197	if (be_lun->disk_stats != NULL)
2198		devstat_remove_entry(be_lun->disk_stats);
2199
2200	uma_zdestroy(be_lun->lun_zone);
2201
2202	ctl_free_opts(&be_lun->ctl_be_lun);
2203	free(be_lun->dev_path, M_CTLBLK);
2204
2205	free(be_lun, M_CTLBLK);
2206
2207	req->status = CTL_LUN_OK;
2208
2209	return (0);
2210
2211bailout_error:
2212
2213	req->status = CTL_LUN_ERROR;
2214
2215	return (0);
2216}
2217
2218static int
2219ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
2220			 struct ctl_lun_req *req)
2221{
2222	struct vattr vattr;
2223	int error;
2224	struct ctl_lun_modify_params *params;
2225
2226	params = &req->reqdata.modify;
2227
2228	if (params->lun_size_bytes != 0) {
2229		be_lun->size_bytes = params->lun_size_bytes;
2230	} else  {
2231		error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
2232		if (error != 0) {
2233			snprintf(req->error_str, sizeof(req->error_str),
2234				 "error calling VOP_GETATTR() for file %s",
2235				 be_lun->dev_path);
2236			return (error);
2237		}
2238
2239		be_lun->size_bytes = vattr.va_size;
2240	}
2241
2242	return (0);
2243}
2244
2245static int
2246ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
2247			struct ctl_lun_req *req)
2248{
2249	struct cdev *dev;
2250	struct cdevsw *devsw;
2251	int error;
2252	struct ctl_lun_modify_params *params;
2253	uint64_t size_bytes;
2254
2255	params = &req->reqdata.modify;
2256
2257	dev = be_lun->vn->v_rdev;
2258	devsw = dev->si_devsw;
2259	if (!devsw->d_ioctl) {
2260		snprintf(req->error_str, sizeof(req->error_str),
2261			 "%s: no d_ioctl for device %s!", __func__,
2262			 be_lun->dev_path);
2263		return (ENODEV);
2264	}
2265
2266	error = devsw->d_ioctl(dev, DIOCGMEDIASIZE,
2267			       (caddr_t)&size_bytes, FREAD,
2268			       curthread);
2269	if (error) {
2270		snprintf(req->error_str, sizeof(req->error_str),
2271			 "%s: error %d returned for DIOCGMEDIASIZE ioctl "
2272			 "on %s!", __func__, error, be_lun->dev_path);
2273		return (error);
2274	}
2275
2276	if (params->lun_size_bytes != 0) {
2277		if (params->lun_size_bytes > size_bytes) {
2278			snprintf(req->error_str, sizeof(req->error_str),
2279				 "%s: requested LUN size %ju > backing device "
2280				 "size %ju", __func__,
2281				 (uintmax_t)params->lun_size_bytes,
2282				 (uintmax_t)size_bytes);
2283			return (EINVAL);
2284		}
2285
2286		be_lun->size_bytes = params->lun_size_bytes;
2287	} else {
2288		be_lun->size_bytes = size_bytes;
2289	}
2290
2291	return (0);
2292}
2293
2294static int
2295ctl_be_block_modify(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2296{
2297	struct ctl_lun_modify_params *params;
2298	struct ctl_be_block_lun *be_lun;
2299	int error;
2300
2301	params = &req->reqdata.modify;
2302
2303	mtx_lock(&softc->lock);
2304
2305	be_lun = NULL;
2306
2307	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2308		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2309			break;
2310	}
2311	mtx_unlock(&softc->lock);
2312
2313	if (be_lun == NULL) {
2314		snprintf(req->error_str, sizeof(req->error_str),
2315			 "%s: LUN %u is not managed by the block backend",
2316			 __func__, params->lun_id);
2317		goto bailout_error;
2318	}
2319
2320	if (params->lun_size_bytes != 0) {
2321		if (params->lun_size_bytes < be_lun->blocksize) {
2322			snprintf(req->error_str, sizeof(req->error_str),
2323				"%s: LUN size %ju < blocksize %u", __func__,
2324				params->lun_size_bytes, be_lun->blocksize);
2325			goto bailout_error;
2326		}
2327	}
2328
2329	vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
2330
2331	if (be_lun->vn->v_type == VREG)
2332		error = ctl_be_block_modify_file(be_lun, req);
2333	else
2334		error = ctl_be_block_modify_dev(be_lun, req);
2335
2336	VOP_UNLOCK(be_lun->vn, 0);
2337
2338	if (error != 0)
2339		goto bailout_error;
2340
2341	be_lun->size_blocks = be_lun->size_bytes >> be_lun->blocksize_shift;
2342
2343	/*
2344	 * The maximum LBA is the size - 1.
2345	 *
2346	 * XXX: Note that this field is being updated without locking,
2347	 * 	which might cause problems on 32-bit architectures.
2348	 */
2349	be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
2350	ctl_lun_capacity_changed(&be_lun->ctl_be_lun);
2351
2352	/* Tell the user the exact size we ended up using */
2353	params->lun_size_bytes = be_lun->size_bytes;
2354
2355	req->status = CTL_LUN_OK;
2356
2357	return (0);
2358
2359bailout_error:
2360	req->status = CTL_LUN_ERROR;
2361
2362	return (0);
2363}
2364
2365static void
2366ctl_be_block_lun_shutdown(void *be_lun)
2367{
2368	struct ctl_be_block_lun *lun;
2369	struct ctl_be_block_softc *softc;
2370
2371	lun = (struct ctl_be_block_lun *)be_lun;
2372
2373	softc = lun->softc;
2374
2375	mtx_lock(&softc->lock);
2376	lun->flags |= CTL_BE_BLOCK_LUN_UNCONFIGURED;
2377	if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2378		wakeup(lun);
2379	mtx_unlock(&softc->lock);
2380
2381}
2382
2383static void
2384ctl_be_block_lun_config_status(void *be_lun, ctl_lun_config_status status)
2385{
2386	struct ctl_be_block_lun *lun;
2387	struct ctl_be_block_softc *softc;
2388
2389	lun = (struct ctl_be_block_lun *)be_lun;
2390	softc = lun->softc;
2391
2392	if (status == CTL_LUN_CONFIG_OK) {
2393		mtx_lock(&softc->lock);
2394		lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2395		if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2396			wakeup(lun);
2397		mtx_unlock(&softc->lock);
2398
2399		/*
2400		 * We successfully added the LUN, attempt to enable it.
2401		 */
2402		if (ctl_enable_lun(&lun->ctl_be_lun) != 0) {
2403			printf("%s: ctl_enable_lun() failed!\n", __func__);
2404			if (ctl_invalidate_lun(&lun->ctl_be_lun) != 0) {
2405				printf("%s: ctl_invalidate_lun() failed!\n",
2406				       __func__);
2407			}
2408		}
2409
2410		return;
2411	}
2412
2413
2414	mtx_lock(&softc->lock);
2415	lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2416	lun->flags |= CTL_BE_BLOCK_LUN_CONFIG_ERR;
2417	wakeup(lun);
2418	mtx_unlock(&softc->lock);
2419}
2420
2421
2422static int
2423ctl_be_block_config_write(union ctl_io *io)
2424{
2425	struct ctl_be_block_lun *be_lun;
2426	struct ctl_be_lun *ctl_be_lun;
2427	int retval;
2428
2429	retval = 0;
2430
2431	DPRINTF("entered\n");
2432
2433	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
2434		CTL_PRIV_BACKEND_LUN].ptr;
2435	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
2436
2437	switch (io->scsiio.cdb[0]) {
2438	case SYNCHRONIZE_CACHE:
2439	case SYNCHRONIZE_CACHE_16:
2440	case WRITE_SAME_10:
2441	case WRITE_SAME_16:
2442	case UNMAP:
2443		/*
2444		 * The upper level CTL code will filter out any CDBs with
2445		 * the immediate bit set and return the proper error.
2446		 *
2447		 * We don't really need to worry about what LBA range the
2448		 * user asked to be synced out.  When they issue a sync
2449		 * cache command, we'll sync out the whole thing.
2450		 */
2451		mtx_lock(&be_lun->lock);
2452		STAILQ_INSERT_TAIL(&be_lun->config_write_queue, &io->io_hdr,
2453				   links);
2454		mtx_unlock(&be_lun->lock);
2455		taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
2456		break;
2457	case START_STOP_UNIT: {
2458		struct scsi_start_stop_unit *cdb;
2459
2460		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
2461
2462		if (cdb->how & SSS_START)
2463			retval = ctl_start_lun(ctl_be_lun);
2464		else {
2465			retval = ctl_stop_lun(ctl_be_lun);
2466			/*
2467			 * XXX KDM Copan-specific offline behavior.
2468			 * Figure out a reasonable way to port this?
2469			 */
2470#ifdef NEEDTOPORT
2471			if ((retval == 0)
2472			 && (cdb->byte2 & SSS_ONOFFLINE))
2473				retval = ctl_lun_offline(ctl_be_lun);
2474#endif
2475		}
2476
2477		/*
2478		 * In general, the above routines should not fail.  They
2479		 * just set state for the LUN.  So we've got something
2480		 * pretty wrong here if we can't start or stop the LUN.
2481		 */
2482		if (retval != 0) {
2483			ctl_set_internal_failure(&io->scsiio,
2484						 /*sks_valid*/ 1,
2485						 /*retry_count*/ 0xf051);
2486			retval = CTL_RETVAL_COMPLETE;
2487		} else {
2488			ctl_set_success(&io->scsiio);
2489		}
2490		ctl_config_write_done(io);
2491		break;
2492	}
2493	default:
2494		ctl_set_invalid_opcode(&io->scsiio);
2495		ctl_config_write_done(io);
2496		retval = CTL_RETVAL_COMPLETE;
2497		break;
2498	}
2499
2500	return (retval);
2501
2502}
2503
2504static int
2505ctl_be_block_config_read(union ctl_io *io)
2506{
2507	return (0);
2508}
2509
2510static int
2511ctl_be_block_lun_info(void *be_lun, struct sbuf *sb)
2512{
2513	struct ctl_be_block_lun *lun;
2514	int retval;
2515
2516	lun = (struct ctl_be_block_lun *)be_lun;
2517	retval = 0;
2518
2519	retval = sbuf_printf(sb, "<num_threads>");
2520
2521	if (retval != 0)
2522		goto bailout;
2523
2524	retval = sbuf_printf(sb, "%d", lun->num_threads);
2525
2526	if (retval != 0)
2527		goto bailout;
2528
2529	retval = sbuf_printf(sb, "</num_threads>");
2530
2531bailout:
2532
2533	return (retval);
2534}
2535
2536int
2537ctl_be_block_init(void)
2538{
2539	struct ctl_be_block_softc *softc;
2540	int retval;
2541
2542	softc = &backend_block_softc;
2543	retval = 0;
2544
2545	mtx_init(&softc->lock, "ctlblk", NULL, MTX_DEF);
2546	beio_zone = uma_zcreate("beio", sizeof(struct ctl_be_block_io),
2547	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
2548	STAILQ_INIT(&softc->disk_list);
2549	STAILQ_INIT(&softc->lun_list);
2550
2551	return (retval);
2552}
2553