ctl_backend_block.c revision 268151
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: stable/10/sys/cam/ctl/ctl_backend_block.c 268151 2014-07-02 10:45:31Z mav $");
44
45#include <opt_kdtrace.h>
46
47#include <sys/param.h>
48#include <sys/systm.h>
49#include <sys/kernel.h>
50#include <sys/types.h>
51#include <sys/kthread.h>
52#include <sys/bio.h>
53#include <sys/fcntl.h>
54#include <sys/limits.h>
55#include <sys/lock.h>
56#include <sys/mutex.h>
57#include <sys/condvar.h>
58#include <sys/malloc.h>
59#include <sys/conf.h>
60#include <sys/ioccom.h>
61#include <sys/queue.h>
62#include <sys/sbuf.h>
63#include <sys/endian.h>
64#include <sys/uio.h>
65#include <sys/buf.h>
66#include <sys/taskqueue.h>
67#include <sys/vnode.h>
68#include <sys/namei.h>
69#include <sys/mount.h>
70#include <sys/disk.h>
71#include <sys/fcntl.h>
72#include <sys/filedesc.h>
73#include <sys/proc.h>
74#include <sys/pcpu.h>
75#include <sys/module.h>
76#include <sys/sdt.h>
77#include <sys/devicestat.h>
78#include <sys/sysctl.h>
79
80#include <geom/geom.h>
81
82#include <cam/cam.h>
83#include <cam/scsi/scsi_all.h>
84#include <cam/scsi/scsi_da.h>
85#include <cam/ctl/ctl_io.h>
86#include <cam/ctl/ctl.h>
87#include <cam/ctl/ctl_backend.h>
88#include <cam/ctl/ctl_frontend_internal.h>
89#include <cam/ctl/ctl_ioctl.h>
90#include <cam/ctl/ctl_scsi_all.h>
91#include <cam/ctl/ctl_error.h>
92
93/*
94 * The idea here is that we'll allocate enough S/G space to hold a 1MB
95 * I/O.  If we get an I/O larger than that, we'll split it.
96 */
97#define	CTLBLK_HALF_IO_SIZE	(512 * 1024)
98#define	CTLBLK_MAX_IO_SIZE	(CTLBLK_HALF_IO_SIZE * 2)
99#define	CTLBLK_MAX_SEG		MAXPHYS
100#define	CTLBLK_HALF_SEGS	MAX(CTLBLK_HALF_IO_SIZE / CTLBLK_MAX_SEG, 1)
101#define	CTLBLK_MAX_SEGS		(CTLBLK_HALF_SEGS * 2)
102
103#ifdef CTLBLK_DEBUG
104#define DPRINTF(fmt, args...) \
105    printf("cbb(%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
106#else
107#define DPRINTF(fmt, args...) do {} while(0)
108#endif
109
110#define PRIV(io)	\
111    ((struct ctl_ptr_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_BACKEND])
112#define ARGS(io)	\
113    ((struct ctl_lba_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_LBA_LEN])
114
115SDT_PROVIDER_DEFINE(cbb);
116
117typedef enum {
118	CTL_BE_BLOCK_LUN_UNCONFIGURED	= 0x01,
119	CTL_BE_BLOCK_LUN_CONFIG_ERR	= 0x02,
120	CTL_BE_BLOCK_LUN_WAITING	= 0x04,
121	CTL_BE_BLOCK_LUN_MULTI_THREAD	= 0x08
122} ctl_be_block_lun_flags;
123
124typedef enum {
125	CTL_BE_BLOCK_NONE,
126	CTL_BE_BLOCK_DEV,
127	CTL_BE_BLOCK_FILE
128} ctl_be_block_type;
129
130struct ctl_be_block_devdata {
131	struct cdev *cdev;
132	struct cdevsw *csw;
133	int dev_ref;
134};
135
136struct ctl_be_block_filedata {
137	struct ucred *cred;
138};
139
140union ctl_be_block_bedata {
141	struct ctl_be_block_devdata dev;
142	struct ctl_be_block_filedata file;
143};
144
145struct ctl_be_block_io;
146struct ctl_be_block_lun;
147
148typedef void (*cbb_dispatch_t)(struct ctl_be_block_lun *be_lun,
149			       struct ctl_be_block_io *beio);
150
151/*
152 * Backend LUN structure.  There is a 1:1 mapping between a block device
153 * and a backend block LUN, and between a backend block LUN and a CTL LUN.
154 */
155struct ctl_be_block_lun {
156	struct ctl_block_disk *disk;
157	char lunname[32];
158	char *dev_path;
159	ctl_be_block_type dev_type;
160	struct vnode *vn;
161	union ctl_be_block_bedata backend;
162	cbb_dispatch_t dispatch;
163	cbb_dispatch_t lun_flush;
164	cbb_dispatch_t unmap;
165	struct mtx lock;
166	uma_zone_t lun_zone;
167	uint64_t size_blocks;
168	uint64_t size_bytes;
169	uint32_t blocksize;
170	int blocksize_shift;
171	uint16_t pblockexp;
172	uint16_t pblockoff;
173	struct ctl_be_block_softc *softc;
174	struct devstat *disk_stats;
175	ctl_be_block_lun_flags flags;
176	STAILQ_ENTRY(ctl_be_block_lun) links;
177	struct ctl_be_lun ctl_be_lun;
178	struct taskqueue *io_taskqueue;
179	struct task io_task;
180	int num_threads;
181	STAILQ_HEAD(, ctl_io_hdr) input_queue;
182	STAILQ_HEAD(, ctl_io_hdr) config_write_queue;
183	STAILQ_HEAD(, ctl_io_hdr) datamove_queue;
184};
185
186/*
187 * Overall softc structure for the block backend module.
188 */
189struct ctl_be_block_softc {
190	struct mtx			 lock;
191	int				 num_disks;
192	STAILQ_HEAD(, ctl_block_disk)	 disk_list;
193	int				 num_luns;
194	STAILQ_HEAD(, ctl_be_block_lun)	 lun_list;
195};
196
197static struct ctl_be_block_softc backend_block_softc;
198
199/*
200 * Per-I/O information.
201 */
202struct ctl_be_block_io {
203	union ctl_io			*io;
204	struct ctl_sg_entry		sg_segs[CTLBLK_MAX_SEGS];
205	struct iovec			xiovecs[CTLBLK_MAX_SEGS];
206	int				bio_cmd;
207	int				bio_flags;
208	int				num_segs;
209	int				num_bios_sent;
210	int				num_bios_done;
211	int				send_complete;
212	int				num_errors;
213	struct bintime			ds_t0;
214	devstat_tag_type		ds_tag_type;
215	devstat_trans_flags		ds_trans_type;
216	uint64_t			io_len;
217	uint64_t			io_offset;
218	struct ctl_be_block_softc	*softc;
219	struct ctl_be_block_lun		*lun;
220	void (*beio_cont)(struct ctl_be_block_io *beio); /* to continue processing */
221};
222
223static int cbb_num_threads = 14;
224TUNABLE_INT("kern.cam.ctl.block.num_threads", &cbb_num_threads);
225SYSCTL_NODE(_kern_cam_ctl, OID_AUTO, block, CTLFLAG_RD, 0,
226	    "CAM Target Layer Block Backend");
227SYSCTL_INT(_kern_cam_ctl_block, OID_AUTO, num_threads, CTLFLAG_RW,
228           &cbb_num_threads, 0, "Number of threads per backing file");
229
230static struct ctl_be_block_io *ctl_alloc_beio(struct ctl_be_block_softc *softc);
231static void ctl_free_beio(struct ctl_be_block_io *beio);
232static void ctl_complete_beio(struct ctl_be_block_io *beio);
233static int ctl_be_block_move_done(union ctl_io *io);
234static void ctl_be_block_biodone(struct bio *bio);
235static void ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
236				    struct ctl_be_block_io *beio);
237static void ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
238				       struct ctl_be_block_io *beio);
239static void ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
240				   struct ctl_be_block_io *beio);
241static void ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
242				   struct ctl_be_block_io *beio);
243static void ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
244				      struct ctl_be_block_io *beio);
245static void ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
246				    union ctl_io *io);
247static void ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
248				  union ctl_io *io);
249static void ctl_be_block_worker(void *context, int pending);
250static int ctl_be_block_submit(union ctl_io *io);
251static int ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
252				   int flag, struct thread *td);
253static int ctl_be_block_open_file(struct ctl_be_block_lun *be_lun,
254				  struct ctl_lun_req *req);
255static int ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun,
256				 struct ctl_lun_req *req);
257static int ctl_be_block_close(struct ctl_be_block_lun *be_lun);
258static int ctl_be_block_open(struct ctl_be_block_softc *softc,
259			     struct ctl_be_block_lun *be_lun,
260			     struct ctl_lun_req *req);
261static int ctl_be_block_create(struct ctl_be_block_softc *softc,
262			       struct ctl_lun_req *req);
263static int ctl_be_block_rm(struct ctl_be_block_softc *softc,
264			   struct ctl_lun_req *req);
265static int ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
266				  struct ctl_lun_req *req);
267static int ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
268				 struct ctl_lun_req *req);
269static int ctl_be_block_modify(struct ctl_be_block_softc *softc,
270			   struct ctl_lun_req *req);
271static void ctl_be_block_lun_shutdown(void *be_lun);
272static void ctl_be_block_lun_config_status(void *be_lun,
273					   ctl_lun_config_status status);
274static int ctl_be_block_config_write(union ctl_io *io);
275static int ctl_be_block_config_read(union ctl_io *io);
276static int ctl_be_block_lun_info(void *be_lun, struct sbuf *sb);
277int ctl_be_block_init(void);
278
279static struct ctl_backend_driver ctl_be_block_driver =
280{
281	.name = "block",
282	.flags = CTL_BE_FLAG_HAS_CONFIG,
283	.init = ctl_be_block_init,
284	.data_submit = ctl_be_block_submit,
285	.data_move_done = ctl_be_block_move_done,
286	.config_read = ctl_be_block_config_read,
287	.config_write = ctl_be_block_config_write,
288	.ioctl = ctl_be_block_ioctl,
289	.lun_info = ctl_be_block_lun_info
290};
291
292MALLOC_DEFINE(M_CTLBLK, "ctlblk", "Memory used for CTL block backend");
293CTL_BACKEND_DECLARE(cbb, ctl_be_block_driver);
294
295static uma_zone_t beio_zone;
296
297static struct ctl_be_block_io *
298ctl_alloc_beio(struct ctl_be_block_softc *softc)
299{
300	struct ctl_be_block_io *beio;
301
302	beio = uma_zalloc(beio_zone, M_WAITOK | M_ZERO);
303	beio->softc = softc;
304	return (beio);
305}
306
307static void
308ctl_free_beio(struct ctl_be_block_io *beio)
309{
310	int duplicate_free;
311	int i;
312
313	duplicate_free = 0;
314
315	for (i = 0; i < beio->num_segs; i++) {
316		if (beio->sg_segs[i].addr == NULL)
317			duplicate_free++;
318
319		uma_zfree(beio->lun->lun_zone, beio->sg_segs[i].addr);
320		beio->sg_segs[i].addr = NULL;
321
322		/* For compare we had two equal S/G lists. */
323		if (ARGS(beio->io)->flags & CTL_LLF_COMPARE) {
324			uma_zfree(beio->lun->lun_zone,
325			    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr);
326			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr = NULL;
327		}
328	}
329
330	if (duplicate_free > 0) {
331		printf("%s: %d duplicate frees out of %d segments\n", __func__,
332		       duplicate_free, beio->num_segs);
333	}
334
335	uma_zfree(beio_zone, beio);
336}
337
338static void
339ctl_complete_beio(struct ctl_be_block_io *beio)
340{
341	union ctl_io *io;
342	int io_len;
343
344	io = beio->io;
345
346	if ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_SUCCESS)
347		io_len = beio->io_len;
348	else
349		io_len = 0;
350
351	devstat_end_transaction(beio->lun->disk_stats,
352				/*bytes*/ io_len,
353				beio->ds_tag_type,
354				beio->ds_trans_type,
355				/*now*/ NULL,
356				/*then*/&beio->ds_t0);
357
358	if (beio->beio_cont != NULL) {
359		beio->beio_cont(beio);
360	} else {
361		ctl_free_beio(beio);
362		ctl_data_submit_done(io);
363	}
364}
365
366static int
367ctl_be_block_move_done(union ctl_io *io)
368{
369	struct ctl_be_block_io *beio;
370	struct ctl_be_block_lun *be_lun;
371	struct ctl_lba_len_flags *lbalen;
372#ifdef CTL_TIME_IO
373	struct bintime cur_bt;
374#endif
375	int i;
376
377	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
378	be_lun = beio->lun;
379
380	DPRINTF("entered\n");
381
382#ifdef CTL_TIME_IO
383	getbintime(&cur_bt);
384	bintime_sub(&cur_bt, &io->io_hdr.dma_start_bt);
385	bintime_add(&io->io_hdr.dma_bt, &cur_bt);
386	io->io_hdr.num_dmas++;
387#endif
388	io->scsiio.kern_rel_offset += io->scsiio.kern_data_len;
389
390	/*
391	 * We set status at this point for read commands, and write
392	 * commands with errors.
393	 */
394	if ((io->io_hdr.port_status == 0) &&
395	    ((io->io_hdr.flags & CTL_FLAG_ABORT) == 0) &&
396	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
397		lbalen = ARGS(beio->io);
398		if (lbalen->flags & CTL_LLF_READ) {
399			ctl_set_success(&io->scsiio);
400		} else if (lbalen->flags & CTL_LLF_COMPARE) {
401			/* We have two data blocks ready for comparison. */
402			for (i = 0; i < beio->num_segs; i++) {
403				if (memcmp(beio->sg_segs[i].addr,
404				    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr,
405				    beio->sg_segs[i].len) != 0)
406					break;
407			}
408			if (i < beio->num_segs)
409				ctl_set_sense(&io->scsiio,
410				    /*current_error*/ 1,
411				    /*sense_key*/ SSD_KEY_MISCOMPARE,
412				    /*asc*/ 0x1D,
413				    /*ascq*/ 0x00,
414				    SSD_ELEM_NONE);
415			else
416				ctl_set_success(&io->scsiio);
417		}
418	}
419	else if ((io->io_hdr.port_status != 0)
420	      && ((io->io_hdr.flags & CTL_FLAG_ABORT) == 0)
421	      && ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
422		/*
423		 * For hardware error sense keys, the sense key
424		 * specific value is defined to be a retry count,
425		 * but we use it to pass back an internal FETD
426		 * error code.  XXX KDM  Hopefully the FETD is only
427		 * using 16 bits for an error code, since that's
428		 * all the space we have in the sks field.
429		 */
430		ctl_set_internal_failure(&io->scsiio,
431					 /*sks_valid*/ 1,
432					 /*retry_count*/
433					 io->io_hdr.port_status);
434	}
435
436	/*
437	 * If this is a read, or a write with errors, it is done.
438	 */
439	if ((beio->bio_cmd == BIO_READ)
440	 || ((io->io_hdr.flags & CTL_FLAG_ABORT) != 0)
441	 || ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)) {
442		ctl_complete_beio(beio);
443		return (0);
444	}
445
446	/*
447	 * At this point, we have a write and the DMA completed
448	 * successfully.  We now have to queue it to the task queue to
449	 * execute the backend I/O.  That is because we do blocking
450	 * memory allocations, and in the file backing case, blocking I/O.
451	 * This move done routine is generally called in the SIM's
452	 * interrupt context, and therefore we cannot block.
453	 */
454	mtx_lock(&be_lun->lock);
455	/*
456	 * XXX KDM make sure that links is okay to use at this point.
457	 * Otherwise, we either need to add another field to ctl_io_hdr,
458	 * or deal with resource allocation here.
459	 */
460	STAILQ_INSERT_TAIL(&be_lun->datamove_queue, &io->io_hdr, links);
461	mtx_unlock(&be_lun->lock);
462
463	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
464
465	return (0);
466}
467
468static void
469ctl_be_block_biodone(struct bio *bio)
470{
471	struct ctl_be_block_io *beio;
472	struct ctl_be_block_lun *be_lun;
473	union ctl_io *io;
474	int error;
475
476	beio = bio->bio_caller1;
477	be_lun = beio->lun;
478	io = beio->io;
479
480	DPRINTF("entered\n");
481
482	error = bio->bio_error;
483	mtx_lock(&be_lun->lock);
484	if (error != 0)
485		beio->num_errors++;
486
487	beio->num_bios_done++;
488
489	/*
490	 * XXX KDM will this cause WITNESS to complain?  Holding a lock
491	 * during the free might cause it to complain.
492	 */
493	g_destroy_bio(bio);
494
495	/*
496	 * If the send complete bit isn't set, or we aren't the last I/O to
497	 * complete, then we're done.
498	 */
499	if ((beio->send_complete == 0)
500	 || (beio->num_bios_done < beio->num_bios_sent)) {
501		mtx_unlock(&be_lun->lock);
502		return;
503	}
504
505	/*
506	 * At this point, we've verified that we are the last I/O to
507	 * complete, so it's safe to drop the lock.
508	 */
509	mtx_unlock(&be_lun->lock);
510
511	/*
512	 * If there are any errors from the backing device, we fail the
513	 * entire I/O with a medium error.
514	 */
515	if (beio->num_errors > 0) {
516		if (error == EOPNOTSUPP) {
517			ctl_set_invalid_opcode(&io->scsiio);
518		} else if (beio->bio_cmd == BIO_FLUSH) {
519			/* XXX KDM is there is a better error here? */
520			ctl_set_internal_failure(&io->scsiio,
521						 /*sks_valid*/ 1,
522						 /*retry_count*/ 0xbad2);
523		} else
524			ctl_set_medium_error(&io->scsiio);
525		ctl_complete_beio(beio);
526		return;
527	}
528
529	/*
530	 * If this is a write, a flush, a delete or verify, we're all done.
531	 * If this is a read, we can now send the data to the user.
532	 */
533	if ((beio->bio_cmd == BIO_WRITE)
534	 || (beio->bio_cmd == BIO_FLUSH)
535	 || (beio->bio_cmd == BIO_DELETE)
536	 || (ARGS(io)->flags & CTL_LLF_VERIFY)) {
537		ctl_set_success(&io->scsiio);
538		ctl_complete_beio(beio);
539	} else {
540#ifdef CTL_TIME_IO
541        	getbintime(&io->io_hdr.dma_start_bt);
542#endif
543		ctl_datamove(io);
544	}
545}
546
547static void
548ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
549			struct ctl_be_block_io *beio)
550{
551	union ctl_io *io;
552	struct mount *mountpoint;
553	int error, lock_flags;
554
555	DPRINTF("entered\n");
556
557	io = beio->io;
558
559       	(void) vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
560
561	if (MNT_SHARED_WRITES(mountpoint)
562	 || ((mountpoint == NULL)
563	  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
564		lock_flags = LK_SHARED;
565	else
566		lock_flags = LK_EXCLUSIVE;
567
568	vn_lock(be_lun->vn, lock_flags | LK_RETRY);
569
570	binuptime(&beio->ds_t0);
571	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
572
573	error = VOP_FSYNC(be_lun->vn, MNT_WAIT, curthread);
574	VOP_UNLOCK(be_lun->vn, 0);
575
576	vn_finished_write(mountpoint);
577
578	if (error == 0)
579		ctl_set_success(&io->scsiio);
580	else {
581		/* XXX KDM is there is a better error here? */
582		ctl_set_internal_failure(&io->scsiio,
583					 /*sks_valid*/ 1,
584					 /*retry_count*/ 0xbad1);
585	}
586
587	ctl_complete_beio(beio);
588}
589
590SDT_PROBE_DEFINE1(cbb, kernel, read, file_start, "uint64_t");
591SDT_PROBE_DEFINE1(cbb, kernel, write, file_start, "uint64_t");
592SDT_PROBE_DEFINE1(cbb, kernel, read, file_done,"uint64_t");
593SDT_PROBE_DEFINE1(cbb, kernel, write, file_done, "uint64_t");
594
595static void
596ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
597			   struct ctl_be_block_io *beio)
598{
599	struct ctl_be_block_filedata *file_data;
600	union ctl_io *io;
601	struct uio xuio;
602	struct iovec *xiovec;
603	int flags;
604	int error, i;
605
606	DPRINTF("entered\n");
607
608	file_data = &be_lun->backend.file;
609	io = beio->io;
610	flags = beio->bio_flags;
611
612	bzero(&xuio, sizeof(xuio));
613	if (beio->bio_cmd == BIO_READ) {
614		SDT_PROBE(cbb, kernel, read, file_start, 0, 0, 0, 0, 0);
615		xuio.uio_rw = UIO_READ;
616	} else {
617		SDT_PROBE(cbb, kernel, write, file_start, 0, 0, 0, 0, 0);
618		xuio.uio_rw = UIO_WRITE;
619	}
620	xuio.uio_offset = beio->io_offset;
621	xuio.uio_resid = beio->io_len;
622	xuio.uio_segflg = UIO_SYSSPACE;
623	xuio.uio_iov = beio->xiovecs;
624	xuio.uio_iovcnt = beio->num_segs;
625	xuio.uio_td = curthread;
626
627	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
628		xiovec->iov_base = beio->sg_segs[i].addr;
629		xiovec->iov_len = beio->sg_segs[i].len;
630	}
631
632	if (beio->bio_cmd == BIO_READ) {
633		vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
634
635		binuptime(&beio->ds_t0);
636		devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
637
638		/*
639		 * UFS pays attention to IO_DIRECT for reads.  If the
640		 * DIRECTIO option is configured into the kernel, it calls
641		 * ffs_rawread().  But that only works for single-segment
642		 * uios with user space addresses.  In our case, with a
643		 * kernel uio, it still reads into the buffer cache, but it
644		 * will just try to release the buffer from the cache later
645		 * on in ffs_read().
646		 *
647		 * ZFS does not pay attention to IO_DIRECT for reads.
648		 *
649		 * UFS does not pay attention to IO_SYNC for reads.
650		 *
651		 * ZFS pays attention to IO_SYNC (which translates into the
652		 * Solaris define FRSYNC for zfs_read()) for reads.  It
653		 * attempts to sync the file before reading.
654		 *
655		 * So, to attempt to provide some barrier semantics in the
656		 * BIO_ORDERED case, set both IO_DIRECT and IO_SYNC.
657		 */
658		error = VOP_READ(be_lun->vn, &xuio, (flags & BIO_ORDERED) ?
659				 (IO_DIRECT|IO_SYNC) : 0, file_data->cred);
660
661		VOP_UNLOCK(be_lun->vn, 0);
662		SDT_PROBE(cbb, kernel, read, file_done, 0, 0, 0, 0, 0);
663	} else {
664		struct mount *mountpoint;
665		int lock_flags;
666
667		(void)vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
668
669		if (MNT_SHARED_WRITES(mountpoint)
670		 || ((mountpoint == NULL)
671		  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
672			lock_flags = LK_SHARED;
673		else
674			lock_flags = LK_EXCLUSIVE;
675
676		vn_lock(be_lun->vn, lock_flags | LK_RETRY);
677
678		binuptime(&beio->ds_t0);
679		devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
680
681		/*
682		 * UFS pays attention to IO_DIRECT for writes.  The write
683		 * is done asynchronously.  (Normally the write would just
684		 * get put into cache.
685		 *
686		 * UFS pays attention to IO_SYNC for writes.  It will
687		 * attempt to write the buffer out synchronously if that
688		 * flag is set.
689		 *
690		 * ZFS does not pay attention to IO_DIRECT for writes.
691		 *
692		 * ZFS pays attention to IO_SYNC (a.k.a. FSYNC or FRSYNC)
693		 * for writes.  It will flush the transaction from the
694		 * cache before returning.
695		 *
696		 * So if we've got the BIO_ORDERED flag set, we want
697		 * IO_SYNC in either the UFS or ZFS case.
698		 */
699		error = VOP_WRITE(be_lun->vn, &xuio, (flags & BIO_ORDERED) ?
700				  IO_SYNC : 0, file_data->cred);
701		VOP_UNLOCK(be_lun->vn, 0);
702
703		vn_finished_write(mountpoint);
704		SDT_PROBE(cbb, kernel, write, file_done, 0, 0, 0, 0, 0);
705        }
706
707	/*
708	 * If we got an error, set the sense data to "MEDIUM ERROR" and
709	 * return the I/O to the user.
710	 */
711	if (error != 0) {
712		char path_str[32];
713
714		ctl_scsi_path_string(io, path_str, sizeof(path_str));
715		/*
716		 * XXX KDM ZFS returns ENOSPC when the underlying
717		 * filesystem fills up.  What kind of SCSI error should we
718		 * return for that?
719		 */
720		printf("%s%s command returned errno %d\n", path_str,
721		       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE", error);
722		ctl_set_medium_error(&io->scsiio);
723		ctl_complete_beio(beio);
724		return;
725	}
726
727	/*
728	 * If this is a write, we're all done.
729	 * If this is a read, we can now send the data to the user.
730	 */
731	if (ARGS(io)->flags & (CTL_LLF_WRITE | CTL_LLF_VERIFY)) {
732		ctl_set_success(&io->scsiio);
733		ctl_complete_beio(beio);
734	} else {
735#ifdef CTL_TIME_IO
736        	getbintime(&io->io_hdr.dma_start_bt);
737#endif
738		ctl_datamove(io);
739	}
740}
741
742static void
743ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
744		       struct ctl_be_block_io *beio)
745{
746	struct bio *bio;
747	union ctl_io *io;
748	struct ctl_be_block_devdata *dev_data;
749
750	dev_data = &be_lun->backend.dev;
751	io = beio->io;
752
753	DPRINTF("entered\n");
754
755	/* This can't fail, it's a blocking allocation. */
756	bio = g_alloc_bio();
757
758	bio->bio_cmd	    = BIO_FLUSH;
759	bio->bio_flags	   |= BIO_ORDERED;
760	bio->bio_dev	    = dev_data->cdev;
761	bio->bio_offset	    = 0;
762	bio->bio_data	    = 0;
763	bio->bio_done	    = ctl_be_block_biodone;
764	bio->bio_caller1    = beio;
765	bio->bio_pblkno	    = 0;
766
767	/*
768	 * We don't need to acquire the LUN lock here, because we are only
769	 * sending one bio, and so there is no other context to synchronize
770	 * with.
771	 */
772	beio->num_bios_sent = 1;
773	beio->send_complete = 1;
774
775	binuptime(&beio->ds_t0);
776	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
777
778	(*dev_data->csw->d_strategy)(bio);
779}
780
781static void
782ctl_be_block_unmap_dev_range(struct ctl_be_block_lun *be_lun,
783		       struct ctl_be_block_io *beio,
784		       uint64_t off, uint64_t len, int last)
785{
786	struct bio *bio;
787	struct ctl_be_block_devdata *dev_data;
788	uint64_t maxlen;
789
790	dev_data = &be_lun->backend.dev;
791	maxlen = LONG_MAX - (LONG_MAX % be_lun->blocksize);
792	while (len > 0) {
793		bio = g_alloc_bio();
794		bio->bio_cmd	    = BIO_DELETE;
795		bio->bio_flags	   |= beio->bio_flags;
796		bio->bio_dev	    = dev_data->cdev;
797		bio->bio_offset	    = off;
798		bio->bio_length	    = MIN(len, maxlen);
799		bio->bio_data	    = 0;
800		bio->bio_done	    = ctl_be_block_biodone;
801		bio->bio_caller1    = beio;
802		bio->bio_pblkno     = off / be_lun->blocksize;
803
804		off += bio->bio_length;
805		len -= bio->bio_length;
806
807		mtx_lock(&be_lun->lock);
808		beio->num_bios_sent++;
809		if (last && len == 0)
810			beio->send_complete = 1;
811		mtx_unlock(&be_lun->lock);
812
813		(*dev_data->csw->d_strategy)(bio);
814	}
815}
816
817static void
818ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
819		       struct ctl_be_block_io *beio)
820{
821	union ctl_io *io;
822	struct ctl_be_block_devdata *dev_data;
823	struct ctl_ptr_len_flags *ptrlen;
824	struct scsi_unmap_desc *buf, *end;
825	uint64_t len;
826
827	dev_data = &be_lun->backend.dev;
828	io = beio->io;
829
830	DPRINTF("entered\n");
831
832	binuptime(&beio->ds_t0);
833	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
834
835	if (beio->io_offset == -1) {
836		beio->io_len = 0;
837		ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
838		buf = (struct scsi_unmap_desc *)ptrlen->ptr;
839		end = buf + ptrlen->len / sizeof(*buf);
840		for (; buf < end; buf++) {
841			len = (uint64_t)scsi_4btoul(buf->length) *
842			    be_lun->blocksize;
843			beio->io_len += len;
844			ctl_be_block_unmap_dev_range(be_lun, beio,
845			    scsi_8btou64(buf->lba) * be_lun->blocksize, len,
846			    (end - buf < 2) ? TRUE : FALSE);
847		}
848	} else
849		ctl_be_block_unmap_dev_range(be_lun, beio,
850		    beio->io_offset, beio->io_len, TRUE);
851}
852
853static void
854ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
855			  struct ctl_be_block_io *beio)
856{
857	int i;
858	struct bio *bio;
859	struct ctl_be_block_devdata *dev_data;
860	off_t cur_offset;
861	int max_iosize;
862
863	DPRINTF("entered\n");
864
865	dev_data = &be_lun->backend.dev;
866
867	/*
868	 * We have to limit our I/O size to the maximum supported by the
869	 * backend device.  Hopefully it is MAXPHYS.  If the driver doesn't
870	 * set it properly, use DFLTPHYS.
871	 */
872	max_iosize = dev_data->cdev->si_iosize_max;
873	if (max_iosize < PAGE_SIZE)
874		max_iosize = DFLTPHYS;
875
876	cur_offset = beio->io_offset;
877
878	/*
879	 * XXX KDM need to accurately reflect the number of I/Os outstanding
880	 * to a device.
881	 */
882	binuptime(&beio->ds_t0);
883	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
884
885	for (i = 0; i < beio->num_segs; i++) {
886		size_t cur_size;
887		uint8_t *cur_ptr;
888
889		cur_size = beio->sg_segs[i].len;
890		cur_ptr = beio->sg_segs[i].addr;
891
892		while (cur_size > 0) {
893			/* This can't fail, it's a blocking allocation. */
894			bio = g_alloc_bio();
895
896			KASSERT(bio != NULL, ("g_alloc_bio() failed!\n"));
897
898			bio->bio_cmd = beio->bio_cmd;
899			bio->bio_flags |= beio->bio_flags;
900			bio->bio_dev = dev_data->cdev;
901			bio->bio_caller1 = beio;
902			bio->bio_length = min(cur_size, max_iosize);
903			bio->bio_offset = cur_offset;
904			bio->bio_data = cur_ptr;
905			bio->bio_done = ctl_be_block_biodone;
906			bio->bio_pblkno = cur_offset / be_lun->blocksize;
907
908			cur_offset += bio->bio_length;
909			cur_ptr += bio->bio_length;
910			cur_size -= bio->bio_length;
911
912			/*
913			 * Make sure we set the complete bit just before we
914			 * issue the last bio so we don't wind up with a
915			 * race.
916			 *
917			 * Use the LUN mutex here instead of a combination
918			 * of atomic variables for simplicity.
919			 *
920			 * XXX KDM we could have a per-IO lock, but that
921			 * would cause additional per-IO setup and teardown
922			 * overhead.  Hopefully there won't be too much
923			 * contention on the LUN lock.
924			 */
925			mtx_lock(&be_lun->lock);
926
927			beio->num_bios_sent++;
928
929			if ((i == beio->num_segs - 1)
930			 && (cur_size == 0))
931				beio->send_complete = 1;
932
933			mtx_unlock(&be_lun->lock);
934
935			(*dev_data->csw->d_strategy)(bio);
936		}
937	}
938}
939
940static void
941ctl_be_block_cw_done_ws(struct ctl_be_block_io *beio)
942{
943	union ctl_io *io;
944
945	io = beio->io;
946	ctl_free_beio(beio);
947	if (((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)
948	  && ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
949		ctl_config_write_done(io);
950		return;
951	}
952
953	ctl_be_block_config_write(io);
954}
955
956static void
957ctl_be_block_cw_dispatch_ws(struct ctl_be_block_lun *be_lun,
958			    union ctl_io *io)
959{
960	struct ctl_be_block_io *beio;
961	struct ctl_be_block_softc *softc;
962	struct ctl_lba_len_flags *lbalen;
963	uint64_t len_left, lba;
964	int i, seglen;
965	uint8_t *buf, *end;
966
967	DPRINTF("entered\n");
968
969	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
970	softc = be_lun->softc;
971	lbalen = ARGS(beio->io);
972
973	if (lbalen->flags & ~(SWS_LBDATA | SWS_UNMAP) ||
974	    (lbalen->flags & SWS_UNMAP && be_lun->unmap == NULL)) {
975		ctl_free_beio(beio);
976		ctl_set_invalid_field(&io->scsiio,
977				      /*sks_valid*/ 1,
978				      /*command*/ 1,
979				      /*field*/ 1,
980				      /*bit_valid*/ 0,
981				      /*bit*/ 0);
982		ctl_config_write_done(io);
983		return;
984	}
985
986	/*
987	 * If the I/O came down with an ordered or head of queue tag, set
988	 * the BIO_ORDERED attribute.  For head of queue tags, that's
989	 * pretty much the best we can do.
990	 */
991	if ((io->scsiio.tag_type == CTL_TAG_ORDERED)
992	 || (io->scsiio.tag_type == CTL_TAG_HEAD_OF_QUEUE))
993		beio->bio_flags = BIO_ORDERED;
994
995	switch (io->scsiio.tag_type) {
996	case CTL_TAG_ORDERED:
997		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
998		break;
999	case CTL_TAG_HEAD_OF_QUEUE:
1000		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1001		break;
1002	case CTL_TAG_UNTAGGED:
1003	case CTL_TAG_SIMPLE:
1004	case CTL_TAG_ACA:
1005	default:
1006		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1007		break;
1008	}
1009
1010	if (lbalen->flags & SWS_UNMAP) {
1011		beio->io_offset = lbalen->lba * be_lun->blocksize;
1012		beio->io_len = (uint64_t)lbalen->len * be_lun->blocksize;
1013		beio->bio_cmd = BIO_DELETE;
1014		beio->ds_trans_type = DEVSTAT_FREE;
1015
1016		be_lun->unmap(be_lun, beio);
1017		return;
1018	}
1019
1020	beio->bio_cmd = BIO_WRITE;
1021	beio->ds_trans_type = DEVSTAT_WRITE;
1022
1023	DPRINTF("WRITE SAME at LBA %jx len %u\n",
1024	       (uintmax_t)lbalen->lba, lbalen->len);
1025
1026	len_left = (uint64_t)lbalen->len * be_lun->blocksize;
1027	for (i = 0, lba = 0; i < CTLBLK_MAX_SEGS && len_left > 0; i++) {
1028
1029		/*
1030		 * Setup the S/G entry for this chunk.
1031		 */
1032		seglen = MIN(CTLBLK_MAX_SEG, len_left);
1033		seglen -= seglen % be_lun->blocksize;
1034		beio->sg_segs[i].len = seglen;
1035		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1036
1037		DPRINTF("segment %d addr %p len %zd\n", i,
1038			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1039
1040		beio->num_segs++;
1041		len_left -= seglen;
1042
1043		buf = beio->sg_segs[i].addr;
1044		end = buf + seglen;
1045		for (; buf < end; buf += be_lun->blocksize) {
1046			memcpy(buf, io->scsiio.kern_data_ptr, be_lun->blocksize);
1047			if (lbalen->flags & SWS_LBDATA)
1048				scsi_ulto4b(lbalen->lba + lba, buf);
1049			lba++;
1050		}
1051	}
1052
1053	beio->io_offset = lbalen->lba * be_lun->blocksize;
1054	beio->io_len = lba * be_lun->blocksize;
1055
1056	/* We can not do all in one run. Correct and schedule rerun. */
1057	if (len_left > 0) {
1058		lbalen->lba += lba;
1059		lbalen->len -= lba;
1060		beio->beio_cont = ctl_be_block_cw_done_ws;
1061	}
1062
1063	be_lun->dispatch(be_lun, beio);
1064}
1065
1066static void
1067ctl_be_block_cw_dispatch_unmap(struct ctl_be_block_lun *be_lun,
1068			    union ctl_io *io)
1069{
1070	struct ctl_be_block_io *beio;
1071	struct ctl_be_block_softc *softc;
1072	struct ctl_ptr_len_flags *ptrlen;
1073
1074	DPRINTF("entered\n");
1075
1076	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1077	softc = be_lun->softc;
1078	ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1079
1080	if (ptrlen->flags != 0 || be_lun->unmap == NULL) {
1081		ctl_free_beio(beio);
1082		ctl_set_invalid_field(&io->scsiio,
1083				      /*sks_valid*/ 0,
1084				      /*command*/ 1,
1085				      /*field*/ 0,
1086				      /*bit_valid*/ 0,
1087				      /*bit*/ 0);
1088		ctl_config_write_done(io);
1089		return;
1090	}
1091
1092	/*
1093	 * If the I/O came down with an ordered or head of queue tag, set
1094	 * the BIO_ORDERED attribute.  For head of queue tags, that's
1095	 * pretty much the best we can do.
1096	 */
1097	if ((io->scsiio.tag_type == CTL_TAG_ORDERED)
1098	 || (io->scsiio.tag_type == CTL_TAG_HEAD_OF_QUEUE))
1099		beio->bio_flags = BIO_ORDERED;
1100
1101	switch (io->scsiio.tag_type) {
1102	case CTL_TAG_ORDERED:
1103		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1104		break;
1105	case CTL_TAG_HEAD_OF_QUEUE:
1106		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1107		break;
1108	case CTL_TAG_UNTAGGED:
1109	case CTL_TAG_SIMPLE:
1110	case CTL_TAG_ACA:
1111	default:
1112		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1113		break;
1114	}
1115
1116	beio->io_len = 0;
1117	beio->io_offset = -1;
1118
1119	beio->bio_cmd = BIO_DELETE;
1120	beio->ds_trans_type = DEVSTAT_FREE;
1121
1122	DPRINTF("UNMAP\n");
1123
1124	be_lun->unmap(be_lun, beio);
1125}
1126
1127static void
1128ctl_be_block_cw_done(struct ctl_be_block_io *beio)
1129{
1130	union ctl_io *io;
1131
1132	io = beio->io;
1133	ctl_free_beio(beio);
1134	ctl_config_write_done(io);
1135}
1136
1137static void
1138ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
1139			 union ctl_io *io)
1140{
1141	struct ctl_be_block_io *beio;
1142	struct ctl_be_block_softc *softc;
1143
1144	DPRINTF("entered\n");
1145
1146	softc = be_lun->softc;
1147	beio = ctl_alloc_beio(softc);
1148	beio->io = io;
1149	beio->lun = be_lun;
1150	beio->beio_cont = ctl_be_block_cw_done;
1151	PRIV(io)->ptr = (void *)beio;
1152
1153	switch (io->scsiio.cdb[0]) {
1154	case SYNCHRONIZE_CACHE:
1155	case SYNCHRONIZE_CACHE_16:
1156		beio->bio_cmd = BIO_FLUSH;
1157		beio->ds_trans_type = DEVSTAT_NO_DATA;
1158		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1159		beio->io_len = 0;
1160		be_lun->lun_flush(be_lun, beio);
1161		break;
1162	case WRITE_SAME_10:
1163	case WRITE_SAME_16:
1164		ctl_be_block_cw_dispatch_ws(be_lun, io);
1165		break;
1166	case UNMAP:
1167		ctl_be_block_cw_dispatch_unmap(be_lun, io);
1168		break;
1169	default:
1170		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1171		break;
1172	}
1173}
1174
1175SDT_PROBE_DEFINE1(cbb, kernel, read, start, "uint64_t");
1176SDT_PROBE_DEFINE1(cbb, kernel, write, start, "uint64_t");
1177SDT_PROBE_DEFINE1(cbb, kernel, read, alloc_done, "uint64_t");
1178SDT_PROBE_DEFINE1(cbb, kernel, write, alloc_done, "uint64_t");
1179
1180static void
1181ctl_be_block_next(struct ctl_be_block_io *beio)
1182{
1183	struct ctl_be_block_lun *be_lun;
1184	union ctl_io *io;
1185
1186	io = beio->io;
1187	be_lun = beio->lun;
1188	ctl_free_beio(beio);
1189	if (((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)
1190	  && ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1191		ctl_data_submit_done(io);
1192		return;
1193	}
1194
1195	io->io_hdr.status &= ~CTL_STATUS_MASK;
1196	io->io_hdr.status |= CTL_STATUS_NONE;
1197
1198	mtx_lock(&be_lun->lock);
1199	/*
1200	 * XXX KDM make sure that links is okay to use at this point.
1201	 * Otherwise, we either need to add another field to ctl_io_hdr,
1202	 * or deal with resource allocation here.
1203	 */
1204	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1205	mtx_unlock(&be_lun->lock);
1206
1207	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1208}
1209
1210static void
1211ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
1212			   union ctl_io *io)
1213{
1214	struct ctl_be_block_io *beio;
1215	struct ctl_be_block_softc *softc;
1216	struct ctl_lba_len_flags *lbalen;
1217	struct ctl_ptr_len_flags *bptrlen;
1218	uint64_t len_left, lbas;
1219	int i;
1220
1221	softc = be_lun->softc;
1222
1223	DPRINTF("entered\n");
1224
1225	lbalen = ARGS(io);
1226	if (lbalen->flags & CTL_LLF_WRITE) {
1227		SDT_PROBE(cbb, kernel, write, start, 0, 0, 0, 0, 0);
1228	} else {
1229		SDT_PROBE(cbb, kernel, read, start, 0, 0, 0, 0, 0);
1230	}
1231
1232	beio = ctl_alloc_beio(softc);
1233	beio->io = io;
1234	beio->lun = be_lun;
1235	bptrlen = PRIV(io);
1236	bptrlen->ptr = (void *)beio;
1237
1238	/*
1239	 * If the I/O came down with an ordered or head of queue tag, set
1240	 * the BIO_ORDERED attribute.  For head of queue tags, that's
1241	 * pretty much the best we can do.
1242	 *
1243	 * XXX KDM we don't have a great way to easily know about the FUA
1244	 * bit right now (it is decoded in ctl_read_write(), but we don't
1245	 * pass that knowledge to the backend), and in any case we would
1246	 * need to determine how to handle it.
1247	 */
1248	if ((io->scsiio.tag_type == CTL_TAG_ORDERED)
1249	 || (io->scsiio.tag_type == CTL_TAG_HEAD_OF_QUEUE))
1250		beio->bio_flags = BIO_ORDERED;
1251
1252	switch (io->scsiio.tag_type) {
1253	case CTL_TAG_ORDERED:
1254		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1255		break;
1256	case CTL_TAG_HEAD_OF_QUEUE:
1257		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1258		break;
1259	case CTL_TAG_UNTAGGED:
1260	case CTL_TAG_SIMPLE:
1261	case CTL_TAG_ACA:
1262	default:
1263		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1264		break;
1265	}
1266
1267	if (lbalen->flags & CTL_LLF_WRITE) {
1268		beio->bio_cmd = BIO_WRITE;
1269		beio->ds_trans_type = DEVSTAT_WRITE;
1270	} else {
1271		beio->bio_cmd = BIO_READ;
1272		beio->ds_trans_type = DEVSTAT_READ;
1273	}
1274
1275	DPRINTF("%s at LBA %jx len %u @%ju\n",
1276	       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE",
1277	       (uintmax_t)lbalen->lba, lbalen->len, bptrlen->len);
1278	if (lbalen->flags & CTL_LLF_COMPARE)
1279		lbas = CTLBLK_HALF_IO_SIZE;
1280	else
1281		lbas = CTLBLK_MAX_IO_SIZE;
1282	lbas = MIN(lbalen->len - bptrlen->len, lbas / be_lun->blocksize);
1283	beio->io_offset = (lbalen->lba + bptrlen->len) * be_lun->blocksize;
1284	beio->io_len = lbas * be_lun->blocksize;
1285	bptrlen->len += lbas;
1286
1287	for (i = 0, len_left = beio->io_len; len_left > 0; i++) {
1288		KASSERT(i < CTLBLK_MAX_SEGS, ("Too many segs (%d >= %d)",
1289		    i, CTLBLK_MAX_SEGS));
1290
1291		/*
1292		 * Setup the S/G entry for this chunk.
1293		 */
1294		beio->sg_segs[i].len = min(CTLBLK_MAX_SEG, len_left);
1295		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1296
1297		DPRINTF("segment %d addr %p len %zd\n", i,
1298			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1299
1300		/* Set up second segment for compare operation. */
1301		if (lbalen->flags & CTL_LLF_COMPARE) {
1302			beio->sg_segs[i + CTLBLK_HALF_SEGS].len =
1303			    beio->sg_segs[i].len;
1304			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr =
1305			    uma_zalloc(be_lun->lun_zone, M_WAITOK);
1306		}
1307
1308		beio->num_segs++;
1309		len_left -= beio->sg_segs[i].len;
1310	}
1311	if (bptrlen->len < lbalen->len)
1312		beio->beio_cont = ctl_be_block_next;
1313	io->scsiio.be_move_done = ctl_be_block_move_done;
1314	/* For compare we have separate S/G lists for read and datamove. */
1315	if (lbalen->flags & CTL_LLF_COMPARE)
1316		io->scsiio.kern_data_ptr = (uint8_t *)&beio->sg_segs[CTLBLK_HALF_SEGS];
1317	else
1318		io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
1319	io->scsiio.kern_data_len = beio->io_len;
1320	io->scsiio.kern_data_resid = 0;
1321	io->scsiio.kern_sg_entries = beio->num_segs;
1322	io->io_hdr.flags |= CTL_FLAG_ALLOCATED | CTL_FLAG_KDPTR_SGLIST;
1323
1324	/*
1325	 * For the read case, we need to read the data into our buffers and
1326	 * then we can send it back to the user.  For the write case, we
1327	 * need to get the data from the user first.
1328	 */
1329	if (beio->bio_cmd == BIO_READ) {
1330		SDT_PROBE(cbb, kernel, read, alloc_done, 0, 0, 0, 0, 0);
1331		be_lun->dispatch(be_lun, beio);
1332	} else {
1333		SDT_PROBE(cbb, kernel, write, alloc_done, 0, 0, 0, 0, 0);
1334#ifdef CTL_TIME_IO
1335        	getbintime(&io->io_hdr.dma_start_bt);
1336#endif
1337		ctl_datamove(io);
1338	}
1339}
1340
1341static void
1342ctl_be_block_worker(void *context, int pending)
1343{
1344	struct ctl_be_block_lun *be_lun;
1345	struct ctl_be_block_softc *softc;
1346	union ctl_io *io;
1347
1348	be_lun = (struct ctl_be_block_lun *)context;
1349	softc = be_lun->softc;
1350
1351	DPRINTF("entered\n");
1352
1353	mtx_lock(&be_lun->lock);
1354	for (;;) {
1355		io = (union ctl_io *)STAILQ_FIRST(&be_lun->datamove_queue);
1356		if (io != NULL) {
1357			struct ctl_be_block_io *beio;
1358
1359			DPRINTF("datamove queue\n");
1360
1361			STAILQ_REMOVE(&be_lun->datamove_queue, &io->io_hdr,
1362				      ctl_io_hdr, links);
1363
1364			mtx_unlock(&be_lun->lock);
1365
1366			beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1367
1368			be_lun->dispatch(be_lun, beio);
1369
1370			mtx_lock(&be_lun->lock);
1371			continue;
1372		}
1373		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_write_queue);
1374		if (io != NULL) {
1375
1376			DPRINTF("config write queue\n");
1377
1378			STAILQ_REMOVE(&be_lun->config_write_queue, &io->io_hdr,
1379				      ctl_io_hdr, links);
1380
1381			mtx_unlock(&be_lun->lock);
1382
1383			ctl_be_block_cw_dispatch(be_lun, io);
1384
1385			mtx_lock(&be_lun->lock);
1386			continue;
1387		}
1388		io = (union ctl_io *)STAILQ_FIRST(&be_lun->input_queue);
1389		if (io != NULL) {
1390			DPRINTF("input queue\n");
1391
1392			STAILQ_REMOVE(&be_lun->input_queue, &io->io_hdr,
1393				      ctl_io_hdr, links);
1394			mtx_unlock(&be_lun->lock);
1395
1396			/*
1397			 * We must drop the lock, since this routine and
1398			 * its children may sleep.
1399			 */
1400			ctl_be_block_dispatch(be_lun, io);
1401
1402			mtx_lock(&be_lun->lock);
1403			continue;
1404		}
1405
1406		/*
1407		 * If we get here, there is no work left in the queues, so
1408		 * just break out and let the task queue go to sleep.
1409		 */
1410		break;
1411	}
1412	mtx_unlock(&be_lun->lock);
1413}
1414
1415/*
1416 * Entry point from CTL to the backend for I/O.  We queue everything to a
1417 * work thread, so this just puts the I/O on a queue and wakes up the
1418 * thread.
1419 */
1420static int
1421ctl_be_block_submit(union ctl_io *io)
1422{
1423	struct ctl_be_block_lun *be_lun;
1424	struct ctl_be_lun *ctl_be_lun;
1425
1426	DPRINTF("entered\n");
1427
1428	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
1429		CTL_PRIV_BACKEND_LUN].ptr;
1430	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
1431
1432	/*
1433	 * Make sure we only get SCSI I/O.
1434	 */
1435	KASSERT(io->io_hdr.io_type == CTL_IO_SCSI, ("Non-SCSI I/O (type "
1436		"%#x) encountered", io->io_hdr.io_type));
1437
1438	PRIV(io)->len = 0;
1439
1440	mtx_lock(&be_lun->lock);
1441	/*
1442	 * XXX KDM make sure that links is okay to use at this point.
1443	 * Otherwise, we either need to add another field to ctl_io_hdr,
1444	 * or deal with resource allocation here.
1445	 */
1446	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1447	mtx_unlock(&be_lun->lock);
1448	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1449
1450	return (CTL_RETVAL_COMPLETE);
1451}
1452
1453static int
1454ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
1455			int flag, struct thread *td)
1456{
1457	struct ctl_be_block_softc *softc;
1458	int error;
1459
1460	softc = &backend_block_softc;
1461
1462	error = 0;
1463
1464	switch (cmd) {
1465	case CTL_LUN_REQ: {
1466		struct ctl_lun_req *lun_req;
1467
1468		lun_req = (struct ctl_lun_req *)addr;
1469
1470		switch (lun_req->reqtype) {
1471		case CTL_LUNREQ_CREATE:
1472			error = ctl_be_block_create(softc, lun_req);
1473			break;
1474		case CTL_LUNREQ_RM:
1475			error = ctl_be_block_rm(softc, lun_req);
1476			break;
1477		case CTL_LUNREQ_MODIFY:
1478			error = ctl_be_block_modify(softc, lun_req);
1479			break;
1480		default:
1481			lun_req->status = CTL_LUN_ERROR;
1482			snprintf(lun_req->error_str, sizeof(lun_req->error_str),
1483				 "%s: invalid LUN request type %d", __func__,
1484				 lun_req->reqtype);
1485			break;
1486		}
1487		break;
1488	}
1489	default:
1490		error = ENOTTY;
1491		break;
1492	}
1493
1494	return (error);
1495}
1496
1497static int
1498ctl_be_block_open_file(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1499{
1500	struct ctl_be_block_filedata *file_data;
1501	struct ctl_lun_create_params *params;
1502	struct vattr		      vattr;
1503	int			      error;
1504
1505	error = 0;
1506	file_data = &be_lun->backend.file;
1507	params = &req->reqdata.create;
1508
1509	be_lun->dev_type = CTL_BE_BLOCK_FILE;
1510	be_lun->dispatch = ctl_be_block_dispatch_file;
1511	be_lun->lun_flush = ctl_be_block_flush_file;
1512
1513	error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
1514	if (error != 0) {
1515		snprintf(req->error_str, sizeof(req->error_str),
1516			 "error calling VOP_GETATTR() for file %s",
1517			 be_lun->dev_path);
1518		return (error);
1519	}
1520
1521	/*
1522	 * Verify that we have the ability to upgrade to exclusive
1523	 * access on this file so we can trap errors at open instead
1524	 * of reporting them during first access.
1525	 */
1526	if (VOP_ISLOCKED(be_lun->vn) != LK_EXCLUSIVE) {
1527		vn_lock(be_lun->vn, LK_UPGRADE | LK_RETRY);
1528		if (be_lun->vn->v_iflag & VI_DOOMED) {
1529			error = EBADF;
1530			snprintf(req->error_str, sizeof(req->error_str),
1531				 "error locking file %s", be_lun->dev_path);
1532			return (error);
1533		}
1534	}
1535
1536
1537	file_data->cred = crhold(curthread->td_ucred);
1538	if (params->lun_size_bytes != 0)
1539		be_lun->size_bytes = params->lun_size_bytes;
1540	else
1541		be_lun->size_bytes = vattr.va_size;
1542	/*
1543	 * We set the multi thread flag for file operations because all
1544	 * filesystems (in theory) are capable of allowing multiple readers
1545	 * of a file at once.  So we want to get the maximum possible
1546	 * concurrency.
1547	 */
1548	be_lun->flags |= CTL_BE_BLOCK_LUN_MULTI_THREAD;
1549
1550	/*
1551	 * XXX KDM vattr.va_blocksize may be larger than 512 bytes here.
1552	 * With ZFS, it is 131072 bytes.  Block sizes that large don't work
1553	 * with disklabel and UFS on FreeBSD at least.  Large block sizes
1554	 * may not work with other OSes as well.  So just export a sector
1555	 * size of 512 bytes, which should work with any OS or
1556	 * application.  Since our backing is a file, any block size will
1557	 * work fine for the backing store.
1558	 */
1559#if 0
1560	be_lun->blocksize= vattr.va_blocksize;
1561#endif
1562	if (params->blocksize_bytes != 0)
1563		be_lun->blocksize = params->blocksize_bytes;
1564	else
1565		be_lun->blocksize = 512;
1566
1567	/*
1568	 * Sanity check.  The media size has to be at least one
1569	 * sector long.
1570	 */
1571	if (be_lun->size_bytes < be_lun->blocksize) {
1572		error = EINVAL;
1573		snprintf(req->error_str, sizeof(req->error_str),
1574			 "file %s size %ju < block size %u", be_lun->dev_path,
1575			 (uintmax_t)be_lun->size_bytes, be_lun->blocksize);
1576	}
1577	return (error);
1578}
1579
1580static int
1581ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1582{
1583	struct ctl_lun_create_params *params;
1584	struct vattr		      vattr;
1585	struct cdev		     *dev;
1586	struct cdevsw		     *devsw;
1587	int			      error;
1588	off_t			      ps, pss, po, pos;
1589
1590	params = &req->reqdata.create;
1591
1592	be_lun->dev_type = CTL_BE_BLOCK_DEV;
1593	be_lun->dispatch = ctl_be_block_dispatch_dev;
1594	be_lun->lun_flush = ctl_be_block_flush_dev;
1595	be_lun->unmap = ctl_be_block_unmap_dev;
1596	be_lun->backend.dev.cdev = be_lun->vn->v_rdev;
1597	be_lun->backend.dev.csw = dev_refthread(be_lun->backend.dev.cdev,
1598					     &be_lun->backend.dev.dev_ref);
1599	if (be_lun->backend.dev.csw == NULL)
1600		panic("Unable to retrieve device switch");
1601
1602	error = VOP_GETATTR(be_lun->vn, &vattr, NOCRED);
1603	if (error) {
1604		snprintf(req->error_str, sizeof(req->error_str),
1605			 "%s: error getting vnode attributes for device %s",
1606			 __func__, be_lun->dev_path);
1607		return (error);
1608	}
1609
1610	dev = be_lun->vn->v_rdev;
1611	devsw = dev->si_devsw;
1612	if (!devsw->d_ioctl) {
1613		snprintf(req->error_str, sizeof(req->error_str),
1614			 "%s: no d_ioctl for device %s!", __func__,
1615			 be_lun->dev_path);
1616		return (ENODEV);
1617	}
1618
1619	error = devsw->d_ioctl(dev, DIOCGSECTORSIZE,
1620			       (caddr_t)&be_lun->blocksize, FREAD,
1621			       curthread);
1622	if (error) {
1623		snprintf(req->error_str, sizeof(req->error_str),
1624			 "%s: error %d returned for DIOCGSECTORSIZE ioctl "
1625			 "on %s!", __func__, error, be_lun->dev_path);
1626		return (error);
1627	}
1628
1629	/*
1630	 * If the user has asked for a blocksize that is greater than the
1631	 * backing device's blocksize, we can do it only if the blocksize
1632	 * the user is asking for is an even multiple of the underlying
1633	 * device's blocksize.
1634	 */
1635	if ((params->blocksize_bytes != 0)
1636	 && (params->blocksize_bytes > be_lun->blocksize)) {
1637		uint32_t bs_multiple, tmp_blocksize;
1638
1639		bs_multiple = params->blocksize_bytes / be_lun->blocksize;
1640
1641		tmp_blocksize = bs_multiple * be_lun->blocksize;
1642
1643		if (tmp_blocksize == params->blocksize_bytes) {
1644			be_lun->blocksize = params->blocksize_bytes;
1645		} else {
1646			snprintf(req->error_str, sizeof(req->error_str),
1647				 "%s: requested blocksize %u is not an even "
1648				 "multiple of backing device blocksize %u",
1649				 __func__, params->blocksize_bytes,
1650				 be_lun->blocksize);
1651			return (EINVAL);
1652
1653		}
1654	} else if ((params->blocksize_bytes != 0)
1655		&& (params->blocksize_bytes != be_lun->blocksize)) {
1656		snprintf(req->error_str, sizeof(req->error_str),
1657			 "%s: requested blocksize %u < backing device "
1658			 "blocksize %u", __func__, params->blocksize_bytes,
1659			 be_lun->blocksize);
1660		return (EINVAL);
1661	}
1662
1663	error = devsw->d_ioctl(dev, DIOCGMEDIASIZE,
1664			       (caddr_t)&be_lun->size_bytes, FREAD,
1665			       curthread);
1666	if (error) {
1667		snprintf(req->error_str, sizeof(req->error_str),
1668			 "%s: error %d returned for DIOCGMEDIASIZE "
1669			 " ioctl on %s!", __func__, error,
1670			 be_lun->dev_path);
1671		return (error);
1672	}
1673
1674	if (params->lun_size_bytes != 0) {
1675		if (params->lun_size_bytes > be_lun->size_bytes) {
1676			snprintf(req->error_str, sizeof(req->error_str),
1677				 "%s: requested LUN size %ju > backing device "
1678				 "size %ju", __func__,
1679				 (uintmax_t)params->lun_size_bytes,
1680				 (uintmax_t)be_lun->size_bytes);
1681			return (EINVAL);
1682		}
1683
1684		be_lun->size_bytes = params->lun_size_bytes;
1685	}
1686
1687	error = devsw->d_ioctl(dev, DIOCGSTRIPESIZE,
1688			       (caddr_t)&ps, FREAD, curthread);
1689	if (error)
1690		ps = po = 0;
1691	else {
1692		error = devsw->d_ioctl(dev, DIOCGSTRIPEOFFSET,
1693				       (caddr_t)&po, FREAD, curthread);
1694		if (error)
1695			po = 0;
1696	}
1697	pss = ps / be_lun->blocksize;
1698	pos = po / be_lun->blocksize;
1699	if ((pss > 0) && (pss * be_lun->blocksize == ps) && (pss >= pos) &&
1700	    ((pss & (pss - 1)) == 0) && (pos * be_lun->blocksize == po)) {
1701		be_lun->pblockexp = fls(pss) - 1;
1702		be_lun->pblockoff = (pss - pos) % pss;
1703	}
1704
1705	return (0);
1706}
1707
1708static int
1709ctl_be_block_close(struct ctl_be_block_lun *be_lun)
1710{
1711	DROP_GIANT();
1712	if (be_lun->vn) {
1713		int flags = FREAD | FWRITE;
1714
1715		switch (be_lun->dev_type) {
1716		case CTL_BE_BLOCK_DEV:
1717			if (be_lun->backend.dev.csw) {
1718				dev_relthread(be_lun->backend.dev.cdev,
1719					      be_lun->backend.dev.dev_ref);
1720				be_lun->backend.dev.csw  = NULL;
1721				be_lun->backend.dev.cdev = NULL;
1722			}
1723			break;
1724		case CTL_BE_BLOCK_FILE:
1725			break;
1726		case CTL_BE_BLOCK_NONE:
1727			break;
1728		default:
1729			panic("Unexpected backend type.");
1730			break;
1731		}
1732
1733		(void)vn_close(be_lun->vn, flags, NOCRED, curthread);
1734		be_lun->vn = NULL;
1735
1736		switch (be_lun->dev_type) {
1737		case CTL_BE_BLOCK_DEV:
1738			break;
1739		case CTL_BE_BLOCK_FILE:
1740			if (be_lun->backend.file.cred != NULL) {
1741				crfree(be_lun->backend.file.cred);
1742				be_lun->backend.file.cred = NULL;
1743			}
1744			break;
1745		case CTL_BE_BLOCK_NONE:
1746			break;
1747		default:
1748			panic("Unexpected backend type.");
1749			break;
1750		}
1751	}
1752	PICKUP_GIANT();
1753
1754	return (0);
1755}
1756
1757static int
1758ctl_be_block_open(struct ctl_be_block_softc *softc,
1759		       struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1760{
1761	struct nameidata nd;
1762	int		 flags;
1763	int		 error;
1764
1765	/*
1766	 * XXX KDM allow a read-only option?
1767	 */
1768	flags = FREAD | FWRITE;
1769	error = 0;
1770
1771	if (rootvnode == NULL) {
1772		snprintf(req->error_str, sizeof(req->error_str),
1773			 "%s: Root filesystem is not mounted", __func__);
1774		return (1);
1775	}
1776
1777	if (!curthread->td_proc->p_fd->fd_cdir) {
1778		curthread->td_proc->p_fd->fd_cdir = rootvnode;
1779		VREF(rootvnode);
1780	}
1781	if (!curthread->td_proc->p_fd->fd_rdir) {
1782		curthread->td_proc->p_fd->fd_rdir = rootvnode;
1783		VREF(rootvnode);
1784	}
1785	if (!curthread->td_proc->p_fd->fd_jdir) {
1786		curthread->td_proc->p_fd->fd_jdir = rootvnode;
1787		VREF(rootvnode);
1788	}
1789
1790 again:
1791	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, be_lun->dev_path, curthread);
1792	error = vn_open(&nd, &flags, 0, NULL);
1793	if (error) {
1794		/*
1795		 * This is the only reasonable guess we can make as far as
1796		 * path if the user doesn't give us a fully qualified path.
1797		 * If they want to specify a file, they need to specify the
1798		 * full path.
1799		 */
1800		if (be_lun->dev_path[0] != '/') {
1801			char *dev_path = "/dev/";
1802			char *dev_name;
1803
1804			/* Try adding device path at beginning of name */
1805			dev_name = malloc(strlen(be_lun->dev_path)
1806					+ strlen(dev_path) + 1,
1807					  M_CTLBLK, M_WAITOK);
1808			if (dev_name) {
1809				sprintf(dev_name, "%s%s", dev_path,
1810					be_lun->dev_path);
1811				free(be_lun->dev_path, M_CTLBLK);
1812				be_lun->dev_path = dev_name;
1813				goto again;
1814			}
1815		}
1816		snprintf(req->error_str, sizeof(req->error_str),
1817			 "%s: error opening %s", __func__, be_lun->dev_path);
1818		return (error);
1819	}
1820
1821	NDFREE(&nd, NDF_ONLY_PNBUF);
1822
1823	be_lun->vn = nd.ni_vp;
1824
1825	/* We only support disks and files. */
1826	if (vn_isdisk(be_lun->vn, &error)) {
1827		error = ctl_be_block_open_dev(be_lun, req);
1828	} else if (be_lun->vn->v_type == VREG) {
1829		error = ctl_be_block_open_file(be_lun, req);
1830	} else {
1831		error = EINVAL;
1832		snprintf(req->error_str, sizeof(req->error_str),
1833			 "%s is not a disk or plain file", be_lun->dev_path);
1834	}
1835	VOP_UNLOCK(be_lun->vn, 0);
1836
1837	if (error != 0) {
1838		ctl_be_block_close(be_lun);
1839		return (error);
1840	}
1841
1842	be_lun->blocksize_shift = fls(be_lun->blocksize) - 1;
1843	be_lun->size_blocks = be_lun->size_bytes >> be_lun->blocksize_shift;
1844
1845	return (0);
1846}
1847
1848static int
1849ctl_be_block_create(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
1850{
1851	struct ctl_be_block_lun *be_lun;
1852	struct ctl_lun_create_params *params;
1853	char num_thread_str[16];
1854	char tmpstr[32];
1855	char *value;
1856	int retval, num_threads, unmap;
1857	int tmp_num_threads;
1858
1859	params = &req->reqdata.create;
1860	retval = 0;
1861
1862	num_threads = cbb_num_threads;
1863
1864	be_lun = malloc(sizeof(*be_lun), M_CTLBLK, M_ZERO | M_WAITOK);
1865
1866	be_lun->softc = softc;
1867	STAILQ_INIT(&be_lun->input_queue);
1868	STAILQ_INIT(&be_lun->config_write_queue);
1869	STAILQ_INIT(&be_lun->datamove_queue);
1870	sprintf(be_lun->lunname, "cblk%d", softc->num_luns);
1871	mtx_init(&be_lun->lock, be_lun->lunname, NULL, MTX_DEF);
1872	ctl_init_opts(&be_lun->ctl_be_lun, req);
1873
1874	be_lun->lun_zone = uma_zcreate(be_lun->lunname, CTLBLK_MAX_SEG,
1875	    NULL, NULL, NULL, NULL, /*align*/ 0, /*flags*/0);
1876
1877	if (be_lun->lun_zone == NULL) {
1878		snprintf(req->error_str, sizeof(req->error_str),
1879			 "%s: error allocating UMA zone", __func__);
1880		goto bailout_error;
1881	}
1882
1883	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
1884		be_lun->ctl_be_lun.lun_type = params->device_type;
1885	else
1886		be_lun->ctl_be_lun.lun_type = T_DIRECT;
1887
1888	if (be_lun->ctl_be_lun.lun_type == T_DIRECT) {
1889		value = ctl_get_opt(&be_lun->ctl_be_lun, "file");
1890		if (value == NULL) {
1891			snprintf(req->error_str, sizeof(req->error_str),
1892				 "%s: no file argument specified", __func__);
1893			goto bailout_error;
1894		}
1895		be_lun->dev_path = strdup(value, M_CTLBLK);
1896
1897		retval = ctl_be_block_open(softc, be_lun, req);
1898		if (retval != 0) {
1899			retval = 0;
1900			goto bailout_error;
1901		}
1902
1903		/*
1904		 * Tell the user the size of the file/device.
1905		 */
1906		params->lun_size_bytes = be_lun->size_bytes;
1907
1908		/*
1909		 * The maximum LBA is the size - 1.
1910		 */
1911		be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
1912	} else {
1913		/*
1914		 * For processor devices, we don't have any size.
1915		 */
1916		be_lun->blocksize = 0;
1917		be_lun->pblockexp = 0;
1918		be_lun->pblockoff = 0;
1919		be_lun->size_blocks = 0;
1920		be_lun->size_bytes = 0;
1921		be_lun->ctl_be_lun.maxlba = 0;
1922		params->lun_size_bytes = 0;
1923
1924		/*
1925		 * Default to just 1 thread for processor devices.
1926		 */
1927		num_threads = 1;
1928	}
1929
1930	/*
1931	 * XXX This searching loop might be refactored to be combined with
1932	 * the loop above,
1933	 */
1934	value = ctl_get_opt(&be_lun->ctl_be_lun, "num_threads");
1935	if (value != NULL) {
1936		tmp_num_threads = strtol(value, NULL, 0);
1937
1938		/*
1939		 * We don't let the user specify less than one
1940		 * thread, but hope he's clueful enough not to
1941		 * specify 1000 threads.
1942		 */
1943		if (tmp_num_threads < 1) {
1944			snprintf(req->error_str, sizeof(req->error_str),
1945				 "%s: invalid number of threads %s",
1946			         __func__, num_thread_str);
1947			goto bailout_error;
1948		}
1949		num_threads = tmp_num_threads;
1950	}
1951	unmap = 0;
1952	value = ctl_get_opt(&be_lun->ctl_be_lun, "unmap");
1953	if (value != NULL && strcmp(value, "on") == 0)
1954		unmap = 1;
1955
1956	be_lun->flags = CTL_BE_BLOCK_LUN_UNCONFIGURED;
1957	be_lun->ctl_be_lun.flags = CTL_LUN_FLAG_PRIMARY;
1958	if (unmap)
1959		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_UNMAP;
1960	be_lun->ctl_be_lun.be_lun = be_lun;
1961	be_lun->ctl_be_lun.blocksize = be_lun->blocksize;
1962	be_lun->ctl_be_lun.pblockexp = be_lun->pblockexp;
1963	be_lun->ctl_be_lun.pblockoff = be_lun->pblockoff;
1964	/* Tell the user the blocksize we ended up using */
1965	params->blocksize_bytes = be_lun->blocksize;
1966	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
1967		be_lun->ctl_be_lun.req_lun_id = params->req_lun_id;
1968		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_ID_REQ;
1969	} else
1970		be_lun->ctl_be_lun.req_lun_id = 0;
1971
1972	be_lun->ctl_be_lun.lun_shutdown = ctl_be_block_lun_shutdown;
1973	be_lun->ctl_be_lun.lun_config_status =
1974		ctl_be_block_lun_config_status;
1975	be_lun->ctl_be_lun.be = &ctl_be_block_driver;
1976
1977	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
1978		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
1979			 softc->num_luns);
1980		strncpy((char *)be_lun->ctl_be_lun.serial_num, tmpstr,
1981			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
1982			sizeof(tmpstr)));
1983
1984		/* Tell the user what we used for a serial number */
1985		strncpy((char *)params->serial_num, tmpstr,
1986			ctl_min(sizeof(params->serial_num), sizeof(tmpstr)));
1987	} else {
1988		strncpy((char *)be_lun->ctl_be_lun.serial_num,
1989			params->serial_num,
1990			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
1991			sizeof(params->serial_num)));
1992	}
1993	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
1994		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
1995		strncpy((char *)be_lun->ctl_be_lun.device_id, tmpstr,
1996			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
1997			sizeof(tmpstr)));
1998
1999		/* Tell the user what we used for a device ID */
2000		strncpy((char *)params->device_id, tmpstr,
2001			ctl_min(sizeof(params->device_id), sizeof(tmpstr)));
2002	} else {
2003		strncpy((char *)be_lun->ctl_be_lun.device_id,
2004			params->device_id,
2005			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
2006				sizeof(params->device_id)));
2007	}
2008
2009	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_be_block_worker, be_lun);
2010
2011	be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
2012	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
2013
2014	if (be_lun->io_taskqueue == NULL) {
2015		snprintf(req->error_str, sizeof(req->error_str),
2016			 "%s: Unable to create taskqueue", __func__);
2017		goto bailout_error;
2018	}
2019
2020	/*
2021	 * Note that we start the same number of threads by default for
2022	 * both the file case and the block device case.  For the file
2023	 * case, we need multiple threads to allow concurrency, because the
2024	 * vnode interface is designed to be a blocking interface.  For the
2025	 * block device case, ZFS zvols at least will block the caller's
2026	 * context in many instances, and so we need multiple threads to
2027	 * overcome that problem.  Other block devices don't need as many
2028	 * threads, but they shouldn't cause too many problems.
2029	 *
2030	 * If the user wants to just have a single thread for a block
2031	 * device, he can specify that when the LUN is created, or change
2032	 * the tunable/sysctl to alter the default number of threads.
2033	 */
2034	retval = taskqueue_start_threads(&be_lun->io_taskqueue,
2035					 /*num threads*/num_threads,
2036					 /*priority*/PWAIT,
2037					 /*thread name*/
2038					 "%s taskq", be_lun->lunname);
2039
2040	if (retval != 0)
2041		goto bailout_error;
2042
2043	be_lun->num_threads = num_threads;
2044
2045	mtx_lock(&softc->lock);
2046	softc->num_luns++;
2047	STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
2048
2049	mtx_unlock(&softc->lock);
2050
2051	retval = ctl_add_lun(&be_lun->ctl_be_lun);
2052	if (retval != 0) {
2053		mtx_lock(&softc->lock);
2054		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2055			      links);
2056		softc->num_luns--;
2057		mtx_unlock(&softc->lock);
2058		snprintf(req->error_str, sizeof(req->error_str),
2059			 "%s: ctl_add_lun() returned error %d, see dmesg for "
2060			"details", __func__, retval);
2061		retval = 0;
2062		goto bailout_error;
2063	}
2064
2065	mtx_lock(&softc->lock);
2066
2067	/*
2068	 * Tell the config_status routine that we're waiting so it won't
2069	 * clean up the LUN in the event of an error.
2070	 */
2071	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2072
2073	while (be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) {
2074		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2075		if (retval == EINTR)
2076			break;
2077	}
2078	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2079
2080	if (be_lun->flags & CTL_BE_BLOCK_LUN_CONFIG_ERR) {
2081		snprintf(req->error_str, sizeof(req->error_str),
2082			 "%s: LUN configuration error, see dmesg for details",
2083			 __func__);
2084		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2085			      links);
2086		softc->num_luns--;
2087		mtx_unlock(&softc->lock);
2088		goto bailout_error;
2089	} else {
2090		params->req_lun_id = be_lun->ctl_be_lun.lun_id;
2091	}
2092
2093	mtx_unlock(&softc->lock);
2094
2095	be_lun->disk_stats = devstat_new_entry("cbb", params->req_lun_id,
2096					       be_lun->blocksize,
2097					       DEVSTAT_ALL_SUPPORTED,
2098					       be_lun->ctl_be_lun.lun_type
2099					       | DEVSTAT_TYPE_IF_OTHER,
2100					       DEVSTAT_PRIORITY_OTHER);
2101
2102
2103	req->status = CTL_LUN_OK;
2104
2105	return (retval);
2106
2107bailout_error:
2108	req->status = CTL_LUN_ERROR;
2109
2110	if (be_lun->io_taskqueue != NULL)
2111		taskqueue_free(be_lun->io_taskqueue);
2112	ctl_be_block_close(be_lun);
2113	if (be_lun->dev_path != NULL)
2114		free(be_lun->dev_path, M_CTLBLK);
2115	if (be_lun->lun_zone != NULL)
2116		uma_zdestroy(be_lun->lun_zone);
2117	ctl_free_opts(&be_lun->ctl_be_lun);
2118	mtx_destroy(&be_lun->lock);
2119	free(be_lun, M_CTLBLK);
2120
2121	return (retval);
2122}
2123
2124static int
2125ctl_be_block_rm(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2126{
2127	struct ctl_lun_rm_params *params;
2128	struct ctl_be_block_lun *be_lun;
2129	int retval;
2130
2131	params = &req->reqdata.rm;
2132
2133	mtx_lock(&softc->lock);
2134
2135	be_lun = NULL;
2136
2137	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2138		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2139			break;
2140	}
2141	mtx_unlock(&softc->lock);
2142
2143	if (be_lun == NULL) {
2144		snprintf(req->error_str, sizeof(req->error_str),
2145			 "%s: LUN %u is not managed by the block backend",
2146			 __func__, params->lun_id);
2147		goto bailout_error;
2148	}
2149
2150	retval = ctl_disable_lun(&be_lun->ctl_be_lun);
2151
2152	if (retval != 0) {
2153		snprintf(req->error_str, sizeof(req->error_str),
2154			 "%s: error %d returned from ctl_disable_lun() for "
2155			 "LUN %d", __func__, retval, params->lun_id);
2156		goto bailout_error;
2157
2158	}
2159
2160	retval = ctl_invalidate_lun(&be_lun->ctl_be_lun);
2161	if (retval != 0) {
2162		snprintf(req->error_str, sizeof(req->error_str),
2163			 "%s: error %d returned from ctl_invalidate_lun() for "
2164			 "LUN %d", __func__, retval, params->lun_id);
2165		goto bailout_error;
2166	}
2167
2168	mtx_lock(&softc->lock);
2169
2170	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2171
2172	while ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2173                retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2174                if (retval == EINTR)
2175                        break;
2176        }
2177
2178	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2179
2180	if ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2181		snprintf(req->error_str, sizeof(req->error_str),
2182			 "%s: interrupted waiting for LUN to be freed",
2183			 __func__);
2184		mtx_unlock(&softc->lock);
2185		goto bailout_error;
2186	}
2187
2188	STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun, links);
2189
2190	softc->num_luns--;
2191	mtx_unlock(&softc->lock);
2192
2193	taskqueue_drain(be_lun->io_taskqueue, &be_lun->io_task);
2194
2195	taskqueue_free(be_lun->io_taskqueue);
2196
2197	ctl_be_block_close(be_lun);
2198
2199	if (be_lun->disk_stats != NULL)
2200		devstat_remove_entry(be_lun->disk_stats);
2201
2202	uma_zdestroy(be_lun->lun_zone);
2203
2204	ctl_free_opts(&be_lun->ctl_be_lun);
2205	free(be_lun->dev_path, M_CTLBLK);
2206
2207	free(be_lun, M_CTLBLK);
2208
2209	req->status = CTL_LUN_OK;
2210
2211	return (0);
2212
2213bailout_error:
2214
2215	req->status = CTL_LUN_ERROR;
2216
2217	return (0);
2218}
2219
2220static int
2221ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
2222			 struct ctl_lun_req *req)
2223{
2224	struct vattr vattr;
2225	int error;
2226	struct ctl_lun_modify_params *params;
2227
2228	params = &req->reqdata.modify;
2229
2230	if (params->lun_size_bytes != 0) {
2231		be_lun->size_bytes = params->lun_size_bytes;
2232	} else  {
2233		error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
2234		if (error != 0) {
2235			snprintf(req->error_str, sizeof(req->error_str),
2236				 "error calling VOP_GETATTR() for file %s",
2237				 be_lun->dev_path);
2238			return (error);
2239		}
2240
2241		be_lun->size_bytes = vattr.va_size;
2242	}
2243
2244	return (0);
2245}
2246
2247static int
2248ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
2249			struct ctl_lun_req *req)
2250{
2251	struct cdev *dev;
2252	struct cdevsw *devsw;
2253	int error;
2254	struct ctl_lun_modify_params *params;
2255	uint64_t size_bytes;
2256
2257	params = &req->reqdata.modify;
2258
2259	dev = be_lun->vn->v_rdev;
2260	devsw = dev->si_devsw;
2261	if (!devsw->d_ioctl) {
2262		snprintf(req->error_str, sizeof(req->error_str),
2263			 "%s: no d_ioctl for device %s!", __func__,
2264			 be_lun->dev_path);
2265		return (ENODEV);
2266	}
2267
2268	error = devsw->d_ioctl(dev, DIOCGMEDIASIZE,
2269			       (caddr_t)&size_bytes, FREAD,
2270			       curthread);
2271	if (error) {
2272		snprintf(req->error_str, sizeof(req->error_str),
2273			 "%s: error %d returned for DIOCGMEDIASIZE ioctl "
2274			 "on %s!", __func__, error, be_lun->dev_path);
2275		return (error);
2276	}
2277
2278	if (params->lun_size_bytes != 0) {
2279		if (params->lun_size_bytes > size_bytes) {
2280			snprintf(req->error_str, sizeof(req->error_str),
2281				 "%s: requested LUN size %ju > backing device "
2282				 "size %ju", __func__,
2283				 (uintmax_t)params->lun_size_bytes,
2284				 (uintmax_t)size_bytes);
2285			return (EINVAL);
2286		}
2287
2288		be_lun->size_bytes = params->lun_size_bytes;
2289	} else {
2290		be_lun->size_bytes = size_bytes;
2291	}
2292
2293	return (0);
2294}
2295
2296static int
2297ctl_be_block_modify(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2298{
2299	struct ctl_lun_modify_params *params;
2300	struct ctl_be_block_lun *be_lun;
2301	int error;
2302
2303	params = &req->reqdata.modify;
2304
2305	mtx_lock(&softc->lock);
2306
2307	be_lun = NULL;
2308
2309	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2310		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2311			break;
2312	}
2313	mtx_unlock(&softc->lock);
2314
2315	if (be_lun == NULL) {
2316		snprintf(req->error_str, sizeof(req->error_str),
2317			 "%s: LUN %u is not managed by the block backend",
2318			 __func__, params->lun_id);
2319		goto bailout_error;
2320	}
2321
2322	if (params->lun_size_bytes != 0) {
2323		if (params->lun_size_bytes < be_lun->blocksize) {
2324			snprintf(req->error_str, sizeof(req->error_str),
2325				"%s: LUN size %ju < blocksize %u", __func__,
2326				params->lun_size_bytes, be_lun->blocksize);
2327			goto bailout_error;
2328		}
2329	}
2330
2331	vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
2332
2333	if (be_lun->vn->v_type == VREG)
2334		error = ctl_be_block_modify_file(be_lun, req);
2335	else
2336		error = ctl_be_block_modify_dev(be_lun, req);
2337
2338	VOP_UNLOCK(be_lun->vn, 0);
2339
2340	if (error != 0)
2341		goto bailout_error;
2342
2343	be_lun->size_blocks = be_lun->size_bytes >> be_lun->blocksize_shift;
2344
2345	/*
2346	 * The maximum LBA is the size - 1.
2347	 *
2348	 * XXX: Note that this field is being updated without locking,
2349	 * 	which might cause problems on 32-bit architectures.
2350	 */
2351	be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
2352	ctl_lun_capacity_changed(&be_lun->ctl_be_lun);
2353
2354	/* Tell the user the exact size we ended up using */
2355	params->lun_size_bytes = be_lun->size_bytes;
2356
2357	req->status = CTL_LUN_OK;
2358
2359	return (0);
2360
2361bailout_error:
2362	req->status = CTL_LUN_ERROR;
2363
2364	return (0);
2365}
2366
2367static void
2368ctl_be_block_lun_shutdown(void *be_lun)
2369{
2370	struct ctl_be_block_lun *lun;
2371	struct ctl_be_block_softc *softc;
2372
2373	lun = (struct ctl_be_block_lun *)be_lun;
2374
2375	softc = lun->softc;
2376
2377	mtx_lock(&softc->lock);
2378	lun->flags |= CTL_BE_BLOCK_LUN_UNCONFIGURED;
2379	if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2380		wakeup(lun);
2381	mtx_unlock(&softc->lock);
2382
2383}
2384
2385static void
2386ctl_be_block_lun_config_status(void *be_lun, ctl_lun_config_status status)
2387{
2388	struct ctl_be_block_lun *lun;
2389	struct ctl_be_block_softc *softc;
2390
2391	lun = (struct ctl_be_block_lun *)be_lun;
2392	softc = lun->softc;
2393
2394	if (status == CTL_LUN_CONFIG_OK) {
2395		mtx_lock(&softc->lock);
2396		lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2397		if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2398			wakeup(lun);
2399		mtx_unlock(&softc->lock);
2400
2401		/*
2402		 * We successfully added the LUN, attempt to enable it.
2403		 */
2404		if (ctl_enable_lun(&lun->ctl_be_lun) != 0) {
2405			printf("%s: ctl_enable_lun() failed!\n", __func__);
2406			if (ctl_invalidate_lun(&lun->ctl_be_lun) != 0) {
2407				printf("%s: ctl_invalidate_lun() failed!\n",
2408				       __func__);
2409			}
2410		}
2411
2412		return;
2413	}
2414
2415
2416	mtx_lock(&softc->lock);
2417	lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2418	lun->flags |= CTL_BE_BLOCK_LUN_CONFIG_ERR;
2419	wakeup(lun);
2420	mtx_unlock(&softc->lock);
2421}
2422
2423
2424static int
2425ctl_be_block_config_write(union ctl_io *io)
2426{
2427	struct ctl_be_block_lun *be_lun;
2428	struct ctl_be_lun *ctl_be_lun;
2429	int retval;
2430
2431	retval = 0;
2432
2433	DPRINTF("entered\n");
2434
2435	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
2436		CTL_PRIV_BACKEND_LUN].ptr;
2437	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
2438
2439	switch (io->scsiio.cdb[0]) {
2440	case SYNCHRONIZE_CACHE:
2441	case SYNCHRONIZE_CACHE_16:
2442	case WRITE_SAME_10:
2443	case WRITE_SAME_16:
2444	case UNMAP:
2445		/*
2446		 * The upper level CTL code will filter out any CDBs with
2447		 * the immediate bit set and return the proper error.
2448		 *
2449		 * We don't really need to worry about what LBA range the
2450		 * user asked to be synced out.  When they issue a sync
2451		 * cache command, we'll sync out the whole thing.
2452		 */
2453		mtx_lock(&be_lun->lock);
2454		STAILQ_INSERT_TAIL(&be_lun->config_write_queue, &io->io_hdr,
2455				   links);
2456		mtx_unlock(&be_lun->lock);
2457		taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
2458		break;
2459	case START_STOP_UNIT: {
2460		struct scsi_start_stop_unit *cdb;
2461
2462		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
2463
2464		if (cdb->how & SSS_START)
2465			retval = ctl_start_lun(ctl_be_lun);
2466		else {
2467			retval = ctl_stop_lun(ctl_be_lun);
2468			/*
2469			 * XXX KDM Copan-specific offline behavior.
2470			 * Figure out a reasonable way to port this?
2471			 */
2472#ifdef NEEDTOPORT
2473			if ((retval == 0)
2474			 && (cdb->byte2 & SSS_ONOFFLINE))
2475				retval = ctl_lun_offline(ctl_be_lun);
2476#endif
2477		}
2478
2479		/*
2480		 * In general, the above routines should not fail.  They
2481		 * just set state for the LUN.  So we've got something
2482		 * pretty wrong here if we can't start or stop the LUN.
2483		 */
2484		if (retval != 0) {
2485			ctl_set_internal_failure(&io->scsiio,
2486						 /*sks_valid*/ 1,
2487						 /*retry_count*/ 0xf051);
2488			retval = CTL_RETVAL_COMPLETE;
2489		} else {
2490			ctl_set_success(&io->scsiio);
2491		}
2492		ctl_config_write_done(io);
2493		break;
2494	}
2495	default:
2496		ctl_set_invalid_opcode(&io->scsiio);
2497		ctl_config_write_done(io);
2498		retval = CTL_RETVAL_COMPLETE;
2499		break;
2500	}
2501
2502	return (retval);
2503
2504}
2505
2506static int
2507ctl_be_block_config_read(union ctl_io *io)
2508{
2509	return (0);
2510}
2511
2512static int
2513ctl_be_block_lun_info(void *be_lun, struct sbuf *sb)
2514{
2515	struct ctl_be_block_lun *lun;
2516	int retval;
2517
2518	lun = (struct ctl_be_block_lun *)be_lun;
2519	retval = 0;
2520
2521	retval = sbuf_printf(sb, "<num_threads>");
2522
2523	if (retval != 0)
2524		goto bailout;
2525
2526	retval = sbuf_printf(sb, "%d", lun->num_threads);
2527
2528	if (retval != 0)
2529		goto bailout;
2530
2531	retval = sbuf_printf(sb, "</num_threads>");
2532
2533bailout:
2534
2535	return (retval);
2536}
2537
2538int
2539ctl_be_block_init(void)
2540{
2541	struct ctl_be_block_softc *softc;
2542	int retval;
2543
2544	softc = &backend_block_softc;
2545	retval = 0;
2546
2547	mtx_init(&softc->lock, "ctlblk", NULL, MTX_DEF);
2548	beio_zone = uma_zcreate("beio", sizeof(struct ctl_be_block_io),
2549	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
2550	STAILQ_INIT(&softc->disk_list);
2551	STAILQ_INIT(&softc->lun_list);
2552
2553	return (retval);
2554}
2555