xref: /freebsd/sys/cam/ctl/ctl_backend_block.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
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  * Copyright (c) 2014-2015 Alexander Motin <mav@FreeBSD.org>
6  * All rights reserved.
7  *
8  * Portions of this software were developed by Edward Tomasz Napierala
9  * under sponsorship from the FreeBSD Foundation.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  *
23  * NO WARRANTY
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
27  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
28  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
32  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
33  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34  * POSSIBILITY OF SUCH DAMAGES.
35  *
36  * $Id: //depot/users/kenm/FreeBSD-test2/sys/cam/ctl/ctl_backend_block.c#5 $
37  */
38 /*
39  * CAM Target Layer driver backend for block devices.
40  *
41  * Author: Ken Merry <ken@FreeBSD.org>
42  */
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD$");
45 
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/types.h>
50 #include <sys/kthread.h>
51 #include <sys/bio.h>
52 #include <sys/fcntl.h>
53 #include <sys/limits.h>
54 #include <sys/lock.h>
55 #include <sys/mutex.h>
56 #include <sys/condvar.h>
57 #include <sys/malloc.h>
58 #include <sys/conf.h>
59 #include <sys/ioccom.h>
60 #include <sys/queue.h>
61 #include <sys/sbuf.h>
62 #include <sys/endian.h>
63 #include <sys/uio.h>
64 #include <sys/buf.h>
65 #include <sys/taskqueue.h>
66 #include <sys/vnode.h>
67 #include <sys/namei.h>
68 #include <sys/mount.h>
69 #include <sys/disk.h>
70 #include <sys/fcntl.h>
71 #include <sys/filedesc.h>
72 #include <sys/filio.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_ioctl.h>
89 #include <cam/ctl/ctl_ha.h>
90 #include <cam/ctl/ctl_scsi_all.h>
91 #include <cam/ctl/ctl_private.h>
92 #include <cam/ctl/ctl_error.h>
93 
94 /*
95  * The idea here is that we'll allocate enough S/G space to hold a 1MB
96  * I/O.  If we get an I/O larger than that, we'll split it.
97  */
98 #define	CTLBLK_HALF_IO_SIZE	(512 * 1024)
99 #define	CTLBLK_MAX_IO_SIZE	(CTLBLK_HALF_IO_SIZE * 2)
100 #define	CTLBLK_MAX_SEG		MAXPHYS
101 #define	CTLBLK_HALF_SEGS	MAX(CTLBLK_HALF_IO_SIZE / CTLBLK_MAX_SEG, 1)
102 #define	CTLBLK_MAX_SEGS		(CTLBLK_HALF_SEGS * 2)
103 
104 #ifdef CTLBLK_DEBUG
105 #define DPRINTF(fmt, args...) \
106     printf("cbb(%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
107 #else
108 #define DPRINTF(fmt, args...) do {} while(0)
109 #endif
110 
111 #define PRIV(io)	\
112     ((struct ctl_ptr_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_BACKEND])
113 #define ARGS(io)	\
114     ((struct ctl_lba_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_LBA_LEN])
115 
116 SDT_PROVIDER_DEFINE(cbb);
117 
118 typedef enum {
119 	CTL_BE_BLOCK_LUN_UNCONFIGURED	= 0x01,
120 	CTL_BE_BLOCK_LUN_CONFIG_ERR	= 0x02,
121 	CTL_BE_BLOCK_LUN_WAITING	= 0x04,
122 } ctl_be_block_lun_flags;
123 
124 typedef enum {
125 	CTL_BE_BLOCK_NONE,
126 	CTL_BE_BLOCK_DEV,
127 	CTL_BE_BLOCK_FILE
128 } ctl_be_block_type;
129 
130 struct ctl_be_block_filedata {
131 	struct ucred *cred;
132 };
133 
134 union ctl_be_block_bedata {
135 	struct ctl_be_block_filedata file;
136 };
137 
138 struct ctl_be_block_io;
139 struct ctl_be_block_lun;
140 
141 typedef void (*cbb_dispatch_t)(struct ctl_be_block_lun *be_lun,
142 			       struct ctl_be_block_io *beio);
143 typedef uint64_t (*cbb_getattr_t)(struct ctl_be_block_lun *be_lun,
144 				  const char *attrname);
145 
146 /*
147  * Backend LUN structure.  There is a 1:1 mapping between a block device
148  * and a backend block LUN, and between a backend block LUN and a CTL LUN.
149  */
150 struct ctl_be_block_lun {
151 	struct ctl_lun_create_params params;
152 	char lunname[32];
153 	char *dev_path;
154 	ctl_be_block_type dev_type;
155 	struct vnode *vn;
156 	union ctl_be_block_bedata backend;
157 	cbb_dispatch_t dispatch;
158 	cbb_dispatch_t lun_flush;
159 	cbb_dispatch_t unmap;
160 	cbb_dispatch_t get_lba_status;
161 	cbb_getattr_t getattr;
162 	uma_zone_t lun_zone;
163 	uint64_t size_blocks;
164 	uint64_t size_bytes;
165 	struct ctl_be_block_softc *softc;
166 	struct devstat *disk_stats;
167 	ctl_be_block_lun_flags flags;
168 	STAILQ_ENTRY(ctl_be_block_lun) links;
169 	struct ctl_be_lun cbe_lun;
170 	struct taskqueue *io_taskqueue;
171 	struct task io_task;
172 	int num_threads;
173 	STAILQ_HEAD(, ctl_io_hdr) input_queue;
174 	STAILQ_HEAD(, ctl_io_hdr) config_read_queue;
175 	STAILQ_HEAD(, ctl_io_hdr) config_write_queue;
176 	STAILQ_HEAD(, ctl_io_hdr) datamove_queue;
177 	struct mtx_padalign io_lock;
178 	struct mtx_padalign queue_lock;
179 };
180 
181 /*
182  * Overall softc structure for the block backend module.
183  */
184 struct ctl_be_block_softc {
185 	struct mtx			 lock;
186 	int				 num_luns;
187 	STAILQ_HEAD(, ctl_be_block_lun)	 lun_list;
188 };
189 
190 static struct ctl_be_block_softc backend_block_softc;
191 
192 /*
193  * Per-I/O information.
194  */
195 struct ctl_be_block_io {
196 	union ctl_io			*io;
197 	struct ctl_sg_entry		sg_segs[CTLBLK_MAX_SEGS];
198 	struct iovec			xiovecs[CTLBLK_MAX_SEGS];
199 	int				bio_cmd;
200 	int				num_segs;
201 	int				num_bios_sent;
202 	int				num_bios_done;
203 	int				send_complete;
204 	int				num_errors;
205 	struct bintime			ds_t0;
206 	devstat_tag_type		ds_tag_type;
207 	devstat_trans_flags		ds_trans_type;
208 	uint64_t			io_len;
209 	uint64_t			io_offset;
210 	int				io_arg;
211 	struct ctl_be_block_softc	*softc;
212 	struct ctl_be_block_lun		*lun;
213 	void (*beio_cont)(struct ctl_be_block_io *beio); /* to continue processing */
214 };
215 
216 extern struct ctl_softc *control_softc;
217 
218 static int cbb_num_threads = 14;
219 SYSCTL_NODE(_kern_cam_ctl, OID_AUTO, block, CTLFLAG_RD, 0,
220 	    "CAM Target Layer Block Backend");
221 SYSCTL_INT(_kern_cam_ctl_block, OID_AUTO, num_threads, CTLFLAG_RWTUN,
222            &cbb_num_threads, 0, "Number of threads per backing file");
223 
224 static struct ctl_be_block_io *ctl_alloc_beio(struct ctl_be_block_softc *softc);
225 static void ctl_free_beio(struct ctl_be_block_io *beio);
226 static void ctl_complete_beio(struct ctl_be_block_io *beio);
227 static int ctl_be_block_move_done(union ctl_io *io);
228 static void ctl_be_block_biodone(struct bio *bio);
229 static void ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
230 				    struct ctl_be_block_io *beio);
231 static void ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
232 				       struct ctl_be_block_io *beio);
233 static void ctl_be_block_gls_file(struct ctl_be_block_lun *be_lun,
234 				  struct ctl_be_block_io *beio);
235 static uint64_t ctl_be_block_getattr_file(struct ctl_be_block_lun *be_lun,
236 					 const char *attrname);
237 static void ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
238 				   struct ctl_be_block_io *beio);
239 static void ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
240 				   struct ctl_be_block_io *beio);
241 static void ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
242 				      struct ctl_be_block_io *beio);
243 static uint64_t ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun,
244 					 const char *attrname);
245 static void ctl_be_block_cr_dispatch(struct ctl_be_block_lun *be_lun,
246 				    union ctl_io *io);
247 static void ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
248 				    union ctl_io *io);
249 static void ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
250 				  union ctl_io *io);
251 static void ctl_be_block_worker(void *context, int pending);
252 static int ctl_be_block_submit(union ctl_io *io);
253 static int ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
254 				   int flag, struct thread *td);
255 static int ctl_be_block_open_file(struct ctl_be_block_lun *be_lun,
256 				  struct ctl_lun_req *req);
257 static int ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun,
258 				 struct ctl_lun_req *req);
259 static int ctl_be_block_close(struct ctl_be_block_lun *be_lun);
260 static int ctl_be_block_open(struct ctl_be_block_lun *be_lun,
261 			     struct ctl_lun_req *req);
262 static int ctl_be_block_create(struct ctl_be_block_softc *softc,
263 			       struct ctl_lun_req *req);
264 static int ctl_be_block_rm(struct ctl_be_block_softc *softc,
265 			   struct ctl_lun_req *req);
266 static int ctl_be_block_modify(struct ctl_be_block_softc *softc,
267 			   struct ctl_lun_req *req);
268 static void ctl_be_block_lun_shutdown(void *be_lun);
269 static void ctl_be_block_lun_config_status(void *be_lun,
270 					   ctl_lun_config_status status);
271 static int ctl_be_block_config_write(union ctl_io *io);
272 static int ctl_be_block_config_read(union ctl_io *io);
273 static int ctl_be_block_lun_info(void *be_lun, struct sbuf *sb);
274 static uint64_t ctl_be_block_lun_attr(void *be_lun, const char *attrname);
275 int ctl_be_block_init(void);
276 
277 static 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 	.lun_attr = ctl_be_block_lun_attr
289 };
290 
291 MALLOC_DEFINE(M_CTLBLK, "ctlblk", "Memory used for CTL block backend");
292 CTL_BACKEND_DECLARE(cbb, ctl_be_block_driver);
293 
294 static uma_zone_t beio_zone;
295 
296 static struct ctl_be_block_io *
297 ctl_alloc_beio(struct ctl_be_block_softc *softc)
298 {
299 	struct ctl_be_block_io *beio;
300 
301 	beio = uma_zalloc(beio_zone, M_WAITOK | M_ZERO);
302 	beio->softc = softc;
303 	return (beio);
304 }
305 
306 static void
307 ctl_free_beio(struct ctl_be_block_io *beio)
308 {
309 	int duplicate_free;
310 	int i;
311 
312 	duplicate_free = 0;
313 
314 	for (i = 0; i < beio->num_segs; i++) {
315 		if (beio->sg_segs[i].addr == NULL)
316 			duplicate_free++;
317 
318 		uma_zfree(beio->lun->lun_zone, beio->sg_segs[i].addr);
319 		beio->sg_segs[i].addr = NULL;
320 
321 		/* For compare we had two equal S/G lists. */
322 		if (ARGS(beio->io)->flags & CTL_LLF_COMPARE) {
323 			uma_zfree(beio->lun->lun_zone,
324 			    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr);
325 			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr = NULL;
326 		}
327 	}
328 
329 	if (duplicate_free > 0) {
330 		printf("%s: %d duplicate frees out of %d segments\n", __func__,
331 		       duplicate_free, beio->num_segs);
332 	}
333 
334 	uma_zfree(beio_zone, beio);
335 }
336 
337 static void
338 ctl_complete_beio(struct ctl_be_block_io *beio)
339 {
340 	union ctl_io *io = beio->io;
341 
342 	if (beio->beio_cont != NULL) {
343 		beio->beio_cont(beio);
344 	} else {
345 		ctl_free_beio(beio);
346 		ctl_data_submit_done(io);
347 	}
348 }
349 
350 static size_t
351 cmp(uint8_t *a, uint8_t *b, size_t size)
352 {
353 	size_t i;
354 
355 	for (i = 0; i < size; i++) {
356 		if (a[i] != b[i])
357 			break;
358 	}
359 	return (i);
360 }
361 
362 static void
363 ctl_be_block_compare(union ctl_io *io)
364 {
365 	struct ctl_be_block_io *beio;
366 	uint64_t off, res;
367 	int i;
368 	uint8_t info[8];
369 
370 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
371 	off = 0;
372 	for (i = 0; i < beio->num_segs; i++) {
373 		res = cmp(beio->sg_segs[i].addr,
374 		    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr,
375 		    beio->sg_segs[i].len);
376 		off += res;
377 		if (res < beio->sg_segs[i].len)
378 			break;
379 	}
380 	if (i < beio->num_segs) {
381 		scsi_u64to8b(off, info);
382 		ctl_set_sense(&io->scsiio, /*current_error*/ 1,
383 		    /*sense_key*/ SSD_KEY_MISCOMPARE,
384 		    /*asc*/ 0x1D, /*ascq*/ 0x00,
385 		    /*type*/ SSD_ELEM_INFO,
386 		    /*size*/ sizeof(info), /*data*/ &info,
387 		    /*type*/ SSD_ELEM_NONE);
388 	} else
389 		ctl_set_success(&io->scsiio);
390 }
391 
392 static int
393 ctl_be_block_move_done(union ctl_io *io)
394 {
395 	struct ctl_be_block_io *beio;
396 	struct ctl_be_block_lun *be_lun;
397 	struct ctl_lba_len_flags *lbalen;
398 #ifdef CTL_TIME_IO
399 	struct bintime cur_bt;
400 #endif
401 
402 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
403 	be_lun = beio->lun;
404 
405 	DPRINTF("entered\n");
406 
407 #ifdef CTL_TIME_IO
408 	getbinuptime(&cur_bt);
409 	bintime_sub(&cur_bt, &io->io_hdr.dma_start_bt);
410 	bintime_add(&io->io_hdr.dma_bt, &cur_bt);
411 #endif
412 	io->io_hdr.num_dmas++;
413 	io->scsiio.kern_rel_offset += io->scsiio.kern_data_len;
414 
415 	/*
416 	 * We set status at this point for read commands, and write
417 	 * commands with errors.
418 	 */
419 	if (io->io_hdr.flags & CTL_FLAG_ABORT) {
420 		;
421 	} else if ((io->io_hdr.port_status == 0) &&
422 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
423 		lbalen = ARGS(beio->io);
424 		if (lbalen->flags & CTL_LLF_READ) {
425 			ctl_set_success(&io->scsiio);
426 		} else if (lbalen->flags & CTL_LLF_COMPARE) {
427 			/* We have two data blocks ready for comparison. */
428 			ctl_be_block_compare(io);
429 		}
430 	} else if ((io->io_hdr.port_status != 0) &&
431 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE ||
432 	     (io->io_hdr.status & CTL_STATUS_MASK) == CTL_SUCCESS)) {
433 		/*
434 		 * For hardware error sense keys, the sense key
435 		 * specific value is defined to be a retry count,
436 		 * but we use it to pass back an internal FETD
437 		 * error code.  XXX KDM  Hopefully the FETD is only
438 		 * using 16 bits for an error code, since that's
439 		 * all the space we have in the sks field.
440 		 */
441 		ctl_set_internal_failure(&io->scsiio,
442 					 /*sks_valid*/ 1,
443 					 /*retry_count*/
444 					 io->io_hdr.port_status);
445 	}
446 
447 	/*
448 	 * If this is a read, or a write with errors, it is done.
449 	 */
450 	if ((beio->bio_cmd == BIO_READ)
451 	 || ((io->io_hdr.flags & CTL_FLAG_ABORT) != 0)
452 	 || ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)) {
453 		ctl_complete_beio(beio);
454 		return (0);
455 	}
456 
457 	/*
458 	 * At this point, we have a write and the DMA completed
459 	 * successfully.  We now have to queue it to the task queue to
460 	 * execute the backend I/O.  That is because we do blocking
461 	 * memory allocations, and in the file backing case, blocking I/O.
462 	 * This move done routine is generally called in the SIM's
463 	 * interrupt context, and therefore we cannot block.
464 	 */
465 	mtx_lock(&be_lun->queue_lock);
466 	STAILQ_INSERT_TAIL(&be_lun->datamove_queue, &io->io_hdr, links);
467 	mtx_unlock(&be_lun->queue_lock);
468 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
469 
470 	return (0);
471 }
472 
473 static void
474 ctl_be_block_biodone(struct bio *bio)
475 {
476 	struct ctl_be_block_io *beio;
477 	struct ctl_be_block_lun *be_lun;
478 	union ctl_io *io;
479 	int error;
480 
481 	beio = bio->bio_caller1;
482 	be_lun = beio->lun;
483 	io = beio->io;
484 
485 	DPRINTF("entered\n");
486 
487 	error = bio->bio_error;
488 	mtx_lock(&be_lun->io_lock);
489 	if (error != 0)
490 		beio->num_errors++;
491 
492 	beio->num_bios_done++;
493 
494 	/*
495 	 * XXX KDM will this cause WITNESS to complain?  Holding a lock
496 	 * during the free might cause it to complain.
497 	 */
498 	g_destroy_bio(bio);
499 
500 	/*
501 	 * If the send complete bit isn't set, or we aren't the last I/O to
502 	 * complete, then we're done.
503 	 */
504 	if ((beio->send_complete == 0)
505 	 || (beio->num_bios_done < beio->num_bios_sent)) {
506 		mtx_unlock(&be_lun->io_lock);
507 		return;
508 	}
509 
510 	/*
511 	 * At this point, we've verified that we are the last I/O to
512 	 * complete, so it's safe to drop the lock.
513 	 */
514 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
515 	    beio->ds_tag_type, beio->ds_trans_type,
516 	    /*now*/ NULL, /*then*/&beio->ds_t0);
517 	mtx_unlock(&be_lun->io_lock);
518 
519 	/*
520 	 * If there are any errors from the backing device, we fail the
521 	 * entire I/O with a medium error.
522 	 */
523 	if (beio->num_errors > 0) {
524 		if (error == EOPNOTSUPP) {
525 			ctl_set_invalid_opcode(&io->scsiio);
526 		} else if (error == ENOSPC || error == EDQUOT) {
527 			ctl_set_space_alloc_fail(&io->scsiio);
528 		} else if (error == EROFS || error == EACCES) {
529 			ctl_set_hw_write_protected(&io->scsiio);
530 		} else if (beio->bio_cmd == BIO_FLUSH) {
531 			/* XXX KDM is there is a better error here? */
532 			ctl_set_internal_failure(&io->scsiio,
533 						 /*sks_valid*/ 1,
534 						 /*retry_count*/ 0xbad2);
535 		} else {
536 			ctl_set_medium_error(&io->scsiio,
537 			    beio->bio_cmd == BIO_READ);
538 		}
539 		ctl_complete_beio(beio);
540 		return;
541 	}
542 
543 	/*
544 	 * If this is a write, a flush, a delete or verify, we're all done.
545 	 * If this is a read, we can now send the data to the user.
546 	 */
547 	if ((beio->bio_cmd == BIO_WRITE)
548 	 || (beio->bio_cmd == BIO_FLUSH)
549 	 || (beio->bio_cmd == BIO_DELETE)
550 	 || (ARGS(io)->flags & CTL_LLF_VERIFY)) {
551 		ctl_set_success(&io->scsiio);
552 		ctl_complete_beio(beio);
553 	} else {
554 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
555 		    beio->beio_cont == NULL) {
556 			ctl_set_success(&io->scsiio);
557 			ctl_serseq_done(io);
558 		}
559 #ifdef CTL_TIME_IO
560 		getbinuptime(&io->io_hdr.dma_start_bt);
561 #endif
562 		ctl_datamove(io);
563 	}
564 }
565 
566 static void
567 ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
568 			struct ctl_be_block_io *beio)
569 {
570 	union ctl_io *io = beio->io;
571 	struct mount *mountpoint;
572 	int error, lock_flags;
573 
574 	DPRINTF("entered\n");
575 
576 	binuptime(&beio->ds_t0);
577 	mtx_lock(&be_lun->io_lock);
578 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
579 	mtx_unlock(&be_lun->io_lock);
580 
581 	(void) vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
582 
583 	if (MNT_SHARED_WRITES(mountpoint) ||
584 	    ((mountpoint == NULL) && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
585 		lock_flags = LK_SHARED;
586 	else
587 		lock_flags = LK_EXCLUSIVE;
588 	vn_lock(be_lun->vn, lock_flags | LK_RETRY);
589 	error = VOP_FSYNC(be_lun->vn, beio->io_arg ? MNT_NOWAIT : MNT_WAIT,
590 	    curthread);
591 	VOP_UNLOCK(be_lun->vn, 0);
592 
593 	vn_finished_write(mountpoint);
594 
595 	mtx_lock(&be_lun->io_lock);
596 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
597 	    beio->ds_tag_type, beio->ds_trans_type,
598 	    /*now*/ NULL, /*then*/&beio->ds_t0);
599 	mtx_unlock(&be_lun->io_lock);
600 
601 	if (error == 0)
602 		ctl_set_success(&io->scsiio);
603 	else {
604 		/* XXX KDM is there is a better error here? */
605 		ctl_set_internal_failure(&io->scsiio,
606 					 /*sks_valid*/ 1,
607 					 /*retry_count*/ 0xbad1);
608 	}
609 
610 	ctl_complete_beio(beio);
611 }
612 
613 SDT_PROBE_DEFINE1(cbb, , read, file_start, "uint64_t");
614 SDT_PROBE_DEFINE1(cbb, , write, file_start, "uint64_t");
615 SDT_PROBE_DEFINE1(cbb, , read, file_done,"uint64_t");
616 SDT_PROBE_DEFINE1(cbb, , write, file_done, "uint64_t");
617 
618 static void
619 ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
620 			   struct ctl_be_block_io *beio)
621 {
622 	struct ctl_be_block_filedata *file_data;
623 	union ctl_io *io;
624 	struct uio xuio;
625 	struct iovec *xiovec;
626 	size_t s;
627 	int error, flags, i;
628 
629 	DPRINTF("entered\n");
630 
631 	file_data = &be_lun->backend.file;
632 	io = beio->io;
633 	flags = 0;
634 	if (ARGS(io)->flags & CTL_LLF_DPO)
635 		flags |= IO_DIRECT;
636 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
637 		flags |= IO_SYNC;
638 
639 	bzero(&xuio, sizeof(xuio));
640 	if (beio->bio_cmd == BIO_READ) {
641 		SDT_PROBE0(cbb, , read, file_start);
642 		xuio.uio_rw = UIO_READ;
643 	} else {
644 		SDT_PROBE0(cbb, , write, file_start);
645 		xuio.uio_rw = UIO_WRITE;
646 	}
647 	xuio.uio_offset = beio->io_offset;
648 	xuio.uio_resid = beio->io_len;
649 	xuio.uio_segflg = UIO_SYSSPACE;
650 	xuio.uio_iov = beio->xiovecs;
651 	xuio.uio_iovcnt = beio->num_segs;
652 	xuio.uio_td = curthread;
653 
654 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
655 		xiovec->iov_base = beio->sg_segs[i].addr;
656 		xiovec->iov_len = beio->sg_segs[i].len;
657 	}
658 
659 	binuptime(&beio->ds_t0);
660 	mtx_lock(&be_lun->io_lock);
661 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
662 	mtx_unlock(&be_lun->io_lock);
663 
664 	if (beio->bio_cmd == BIO_READ) {
665 		vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
666 
667 		/*
668 		 * UFS pays attention to IO_DIRECT for reads.  If the
669 		 * DIRECTIO option is configured into the kernel, it calls
670 		 * ffs_rawread().  But that only works for single-segment
671 		 * uios with user space addresses.  In our case, with a
672 		 * kernel uio, it still reads into the buffer cache, but it
673 		 * will just try to release the buffer from the cache later
674 		 * on in ffs_read().
675 		 *
676 		 * ZFS does not pay attention to IO_DIRECT for reads.
677 		 *
678 		 * UFS does not pay attention to IO_SYNC for reads.
679 		 *
680 		 * ZFS pays attention to IO_SYNC (which translates into the
681 		 * Solaris define FRSYNC for zfs_read()) for reads.  It
682 		 * attempts to sync the file before reading.
683 		 */
684 		error = VOP_READ(be_lun->vn, &xuio, flags, file_data->cred);
685 
686 		VOP_UNLOCK(be_lun->vn, 0);
687 		SDT_PROBE0(cbb, , read, file_done);
688 		if (error == 0 && xuio.uio_resid > 0) {
689 			/*
690 			 * If we red less then requested (EOF), then
691 			 * we should clean the rest of the buffer.
692 			 */
693 			s = beio->io_len - xuio.uio_resid;
694 			for (i = 0; i < beio->num_segs; i++) {
695 				if (s >= beio->sg_segs[i].len) {
696 					s -= beio->sg_segs[i].len;
697 					continue;
698 				}
699 				bzero((uint8_t *)beio->sg_segs[i].addr + s,
700 				    beio->sg_segs[i].len - s);
701 				s = 0;
702 			}
703 		}
704 	} else {
705 		struct mount *mountpoint;
706 		int lock_flags;
707 
708 		(void)vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
709 
710 		if (MNT_SHARED_WRITES(mountpoint) || ((mountpoint == NULL)
711 		  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
712 			lock_flags = LK_SHARED;
713 		else
714 			lock_flags = LK_EXCLUSIVE;
715 		vn_lock(be_lun->vn, lock_flags | LK_RETRY);
716 
717 		/*
718 		 * UFS pays attention to IO_DIRECT for writes.  The write
719 		 * is done asynchronously.  (Normally the write would just
720 		 * get put into cache.
721 		 *
722 		 * UFS pays attention to IO_SYNC for writes.  It will
723 		 * attempt to write the buffer out synchronously if that
724 		 * flag is set.
725 		 *
726 		 * ZFS does not pay attention to IO_DIRECT for writes.
727 		 *
728 		 * ZFS pays attention to IO_SYNC (a.k.a. FSYNC or FRSYNC)
729 		 * for writes.  It will flush the transaction from the
730 		 * cache before returning.
731 		 */
732 		error = VOP_WRITE(be_lun->vn, &xuio, flags, file_data->cred);
733 		VOP_UNLOCK(be_lun->vn, 0);
734 
735 		vn_finished_write(mountpoint);
736 		SDT_PROBE0(cbb, , write, file_done);
737         }
738 
739 	mtx_lock(&be_lun->io_lock);
740 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
741 	    beio->ds_tag_type, beio->ds_trans_type,
742 	    /*now*/ NULL, /*then*/&beio->ds_t0);
743 	mtx_unlock(&be_lun->io_lock);
744 
745 	/*
746 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
747 	 * return the I/O to the user.
748 	 */
749 	if (error != 0) {
750 		if (error == ENOSPC || error == EDQUOT) {
751 			ctl_set_space_alloc_fail(&io->scsiio);
752 		} else if (error == EROFS || error == EACCES) {
753 			ctl_set_hw_write_protected(&io->scsiio);
754 		} else {
755 			ctl_set_medium_error(&io->scsiio,
756 			    beio->bio_cmd == BIO_READ);
757 		}
758 		ctl_complete_beio(beio);
759 		return;
760 	}
761 
762 	/*
763 	 * If this is a write or a verify, we're all done.
764 	 * If this is a read, we can now send the data to the user.
765 	 */
766 	if ((beio->bio_cmd == BIO_WRITE) ||
767 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
768 		ctl_set_success(&io->scsiio);
769 		ctl_complete_beio(beio);
770 	} else {
771 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
772 		    beio->beio_cont == NULL) {
773 			ctl_set_success(&io->scsiio);
774 			ctl_serseq_done(io);
775 		}
776 #ifdef CTL_TIME_IO
777 		getbinuptime(&io->io_hdr.dma_start_bt);
778 #endif
779 		ctl_datamove(io);
780 	}
781 }
782 
783 static void
784 ctl_be_block_gls_file(struct ctl_be_block_lun *be_lun,
785 			struct ctl_be_block_io *beio)
786 {
787 	union ctl_io *io = beio->io;
788 	struct ctl_lba_len_flags *lbalen = ARGS(io);
789 	struct scsi_get_lba_status_data *data;
790 	off_t roff, off;
791 	int error, status;
792 
793 	DPRINTF("entered\n");
794 
795 	off = roff = ((off_t)lbalen->lba) * be_lun->cbe_lun.blocksize;
796 	vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
797 	error = VOP_IOCTL(be_lun->vn, FIOSEEKHOLE, &off,
798 	    0, curthread->td_ucred, curthread);
799 	if (error == 0 && off > roff)
800 		status = 0;	/* mapped up to off */
801 	else {
802 		error = VOP_IOCTL(be_lun->vn, FIOSEEKDATA, &off,
803 		    0, curthread->td_ucred, curthread);
804 		if (error == 0 && off > roff)
805 			status = 1;	/* deallocated up to off */
806 		else {
807 			status = 0;	/* unknown up to the end */
808 			off = be_lun->size_bytes;
809 		}
810 	}
811 	VOP_UNLOCK(be_lun->vn, 0);
812 
813 	data = (struct scsi_get_lba_status_data *)io->scsiio.kern_data_ptr;
814 	scsi_u64to8b(lbalen->lba, data->descr[0].addr);
815 	scsi_ulto4b(MIN(UINT32_MAX, off / be_lun->cbe_lun.blocksize -
816 	    lbalen->lba), data->descr[0].length);
817 	data->descr[0].status = status;
818 
819 	ctl_complete_beio(beio);
820 }
821 
822 static uint64_t
823 ctl_be_block_getattr_file(struct ctl_be_block_lun *be_lun, const char *attrname)
824 {
825 	struct vattr		vattr;
826 	struct statfs		statfs;
827 	uint64_t		val;
828 	int			error;
829 
830 	val = UINT64_MAX;
831 	if (be_lun->vn == NULL)
832 		return (val);
833 	vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
834 	if (strcmp(attrname, "blocksused") == 0) {
835 		error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
836 		if (error == 0)
837 			val = vattr.va_bytes / be_lun->cbe_lun.blocksize;
838 	}
839 	if (strcmp(attrname, "blocksavail") == 0 &&
840 	    (be_lun->vn->v_iflag & VI_DOOMED) == 0) {
841 		error = VFS_STATFS(be_lun->vn->v_mount, &statfs);
842 		if (error == 0)
843 			val = statfs.f_bavail * statfs.f_bsize /
844 			    be_lun->cbe_lun.blocksize;
845 	}
846 	VOP_UNLOCK(be_lun->vn, 0);
847 	return (val);
848 }
849 
850 static void
851 ctl_be_block_dispatch_zvol(struct ctl_be_block_lun *be_lun,
852 			   struct ctl_be_block_io *beio)
853 {
854 	union ctl_io *io;
855 	struct cdevsw *csw;
856 	struct cdev *dev;
857 	struct uio xuio;
858 	struct iovec *xiovec;
859 	int error, flags, i, ref;
860 
861 	DPRINTF("entered\n");
862 
863 	io = beio->io;
864 	flags = 0;
865 	if (ARGS(io)->flags & CTL_LLF_DPO)
866 		flags |= IO_DIRECT;
867 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
868 		flags |= IO_SYNC;
869 
870 	bzero(&xuio, sizeof(xuio));
871 	if (beio->bio_cmd == BIO_READ) {
872 		SDT_PROBE0(cbb, , read, file_start);
873 		xuio.uio_rw = UIO_READ;
874 	} else {
875 		SDT_PROBE0(cbb, , write, file_start);
876 		xuio.uio_rw = UIO_WRITE;
877 	}
878 	xuio.uio_offset = beio->io_offset;
879 	xuio.uio_resid = beio->io_len;
880 	xuio.uio_segflg = UIO_SYSSPACE;
881 	xuio.uio_iov = beio->xiovecs;
882 	xuio.uio_iovcnt = beio->num_segs;
883 	xuio.uio_td = curthread;
884 
885 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
886 		xiovec->iov_base = beio->sg_segs[i].addr;
887 		xiovec->iov_len = beio->sg_segs[i].len;
888 	}
889 
890 	binuptime(&beio->ds_t0);
891 	mtx_lock(&be_lun->io_lock);
892 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
893 	mtx_unlock(&be_lun->io_lock);
894 
895 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
896 	if (csw) {
897 		if (beio->bio_cmd == BIO_READ)
898 			error = csw->d_read(dev, &xuio, flags);
899 		else
900 			error = csw->d_write(dev, &xuio, flags);
901 		dev_relthread(dev, ref);
902 	} else
903 		error = ENXIO;
904 
905 	if (beio->bio_cmd == BIO_READ)
906 		SDT_PROBE0(cbb, , read, file_done);
907 	else
908 		SDT_PROBE0(cbb, , write, file_done);
909 
910 	mtx_lock(&be_lun->io_lock);
911 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
912 	    beio->ds_tag_type, beio->ds_trans_type,
913 	    /*now*/ NULL, /*then*/&beio->ds_t0);
914 	mtx_unlock(&be_lun->io_lock);
915 
916 	/*
917 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
918 	 * return the I/O to the user.
919 	 */
920 	if (error != 0) {
921 		if (error == ENOSPC || error == EDQUOT) {
922 			ctl_set_space_alloc_fail(&io->scsiio);
923 		} else if (error == EROFS || error == EACCES) {
924 			ctl_set_hw_write_protected(&io->scsiio);
925 		} else {
926 			ctl_set_medium_error(&io->scsiio,
927 			    beio->bio_cmd == BIO_READ);
928 		}
929 		ctl_complete_beio(beio);
930 		return;
931 	}
932 
933 	/*
934 	 * If this is a write or a verify, we're all done.
935 	 * If this is a read, we can now send the data to the user.
936 	 */
937 	if ((beio->bio_cmd == BIO_WRITE) ||
938 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
939 		ctl_set_success(&io->scsiio);
940 		ctl_complete_beio(beio);
941 	} else {
942 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
943 		    beio->beio_cont == NULL) {
944 			ctl_set_success(&io->scsiio);
945 			ctl_serseq_done(io);
946 		}
947 #ifdef CTL_TIME_IO
948 		getbinuptime(&io->io_hdr.dma_start_bt);
949 #endif
950 		ctl_datamove(io);
951 	}
952 }
953 
954 static void
955 ctl_be_block_gls_zvol(struct ctl_be_block_lun *be_lun,
956 			struct ctl_be_block_io *beio)
957 {
958 	union ctl_io *io = beio->io;
959 	struct cdevsw *csw;
960 	struct cdev *dev;
961 	struct ctl_lba_len_flags *lbalen = ARGS(io);
962 	struct scsi_get_lba_status_data *data;
963 	off_t roff, off;
964 	int error, ref, status;
965 
966 	DPRINTF("entered\n");
967 
968 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
969 	if (csw == NULL) {
970 		status = 0;	/* unknown up to the end */
971 		off = be_lun->size_bytes;
972 		goto done;
973 	}
974 	off = roff = ((off_t)lbalen->lba) * be_lun->cbe_lun.blocksize;
975 	error = csw->d_ioctl(dev, FIOSEEKHOLE, (caddr_t)&off, FREAD,
976 	    curthread);
977 	if (error == 0 && off > roff)
978 		status = 0;	/* mapped up to off */
979 	else {
980 		error = csw->d_ioctl(dev, FIOSEEKDATA, (caddr_t)&off, FREAD,
981 		    curthread);
982 		if (error == 0 && off > roff)
983 			status = 1;	/* deallocated up to off */
984 		else {
985 			status = 0;	/* unknown up to the end */
986 			off = be_lun->size_bytes;
987 		}
988 	}
989 	dev_relthread(dev, ref);
990 
991 done:
992 	data = (struct scsi_get_lba_status_data *)io->scsiio.kern_data_ptr;
993 	scsi_u64to8b(lbalen->lba, data->descr[0].addr);
994 	scsi_ulto4b(MIN(UINT32_MAX, off / be_lun->cbe_lun.blocksize -
995 	    lbalen->lba), data->descr[0].length);
996 	data->descr[0].status = status;
997 
998 	ctl_complete_beio(beio);
999 }
1000 
1001 static void
1002 ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
1003 		       struct ctl_be_block_io *beio)
1004 {
1005 	struct bio *bio;
1006 	struct cdevsw *csw;
1007 	struct cdev *dev;
1008 	int ref;
1009 
1010 	DPRINTF("entered\n");
1011 
1012 	/* This can't fail, it's a blocking allocation. */
1013 	bio = g_alloc_bio();
1014 
1015 	bio->bio_cmd	    = BIO_FLUSH;
1016 	bio->bio_offset	    = 0;
1017 	bio->bio_data	    = 0;
1018 	bio->bio_done	    = ctl_be_block_biodone;
1019 	bio->bio_caller1    = beio;
1020 	bio->bio_pblkno	    = 0;
1021 
1022 	/*
1023 	 * We don't need to acquire the LUN lock here, because we are only
1024 	 * sending one bio, and so there is no other context to synchronize
1025 	 * with.
1026 	 */
1027 	beio->num_bios_sent = 1;
1028 	beio->send_complete = 1;
1029 
1030 	binuptime(&beio->ds_t0);
1031 	mtx_lock(&be_lun->io_lock);
1032 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1033 	mtx_unlock(&be_lun->io_lock);
1034 
1035 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1036 	if (csw) {
1037 		bio->bio_dev = dev;
1038 		csw->d_strategy(bio);
1039 		dev_relthread(dev, ref);
1040 	} else {
1041 		bio->bio_error = ENXIO;
1042 		ctl_be_block_biodone(bio);
1043 	}
1044 }
1045 
1046 static void
1047 ctl_be_block_unmap_dev_range(struct ctl_be_block_lun *be_lun,
1048 		       struct ctl_be_block_io *beio,
1049 		       uint64_t off, uint64_t len, int last)
1050 {
1051 	struct bio *bio;
1052 	uint64_t maxlen;
1053 	struct cdevsw *csw;
1054 	struct cdev *dev;
1055 	int ref;
1056 
1057 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1058 	maxlen = LONG_MAX - (LONG_MAX % be_lun->cbe_lun.blocksize);
1059 	while (len > 0) {
1060 		bio = g_alloc_bio();
1061 		bio->bio_cmd	    = BIO_DELETE;
1062 		bio->bio_dev	    = dev;
1063 		bio->bio_offset	    = off;
1064 		bio->bio_length	    = MIN(len, maxlen);
1065 		bio->bio_data	    = 0;
1066 		bio->bio_done	    = ctl_be_block_biodone;
1067 		bio->bio_caller1    = beio;
1068 		bio->bio_pblkno     = off / be_lun->cbe_lun.blocksize;
1069 
1070 		off += bio->bio_length;
1071 		len -= bio->bio_length;
1072 
1073 		mtx_lock(&be_lun->io_lock);
1074 		beio->num_bios_sent++;
1075 		if (last && len == 0)
1076 			beio->send_complete = 1;
1077 		mtx_unlock(&be_lun->io_lock);
1078 
1079 		if (csw) {
1080 			csw->d_strategy(bio);
1081 		} else {
1082 			bio->bio_error = ENXIO;
1083 			ctl_be_block_biodone(bio);
1084 		}
1085 	}
1086 	if (csw)
1087 		dev_relthread(dev, ref);
1088 }
1089 
1090 static void
1091 ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
1092 		       struct ctl_be_block_io *beio)
1093 {
1094 	union ctl_io *io;
1095 	struct ctl_ptr_len_flags *ptrlen;
1096 	struct scsi_unmap_desc *buf, *end;
1097 	uint64_t len;
1098 
1099 	io = beio->io;
1100 
1101 	DPRINTF("entered\n");
1102 
1103 	binuptime(&beio->ds_t0);
1104 	mtx_lock(&be_lun->io_lock);
1105 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1106 	mtx_unlock(&be_lun->io_lock);
1107 
1108 	if (beio->io_offset == -1) {
1109 		beio->io_len = 0;
1110 		ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1111 		buf = (struct scsi_unmap_desc *)ptrlen->ptr;
1112 		end = buf + ptrlen->len / sizeof(*buf);
1113 		for (; buf < end; buf++) {
1114 			len = (uint64_t)scsi_4btoul(buf->length) *
1115 			    be_lun->cbe_lun.blocksize;
1116 			beio->io_len += len;
1117 			ctl_be_block_unmap_dev_range(be_lun, beio,
1118 			    scsi_8btou64(buf->lba) * be_lun->cbe_lun.blocksize,
1119 			    len, (end - buf < 2) ? TRUE : FALSE);
1120 		}
1121 	} else
1122 		ctl_be_block_unmap_dev_range(be_lun, beio,
1123 		    beio->io_offset, beio->io_len, TRUE);
1124 }
1125 
1126 static void
1127 ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
1128 			  struct ctl_be_block_io *beio)
1129 {
1130 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
1131 	struct bio *bio;
1132 	struct cdevsw *csw;
1133 	struct cdev *dev;
1134 	off_t cur_offset;
1135 	int i, max_iosize, ref;
1136 
1137 	DPRINTF("entered\n");
1138 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1139 
1140 	/*
1141 	 * We have to limit our I/O size to the maximum supported by the
1142 	 * backend device.  Hopefully it is MAXPHYS.  If the driver doesn't
1143 	 * set it properly, use DFLTPHYS.
1144 	 */
1145 	if (csw) {
1146 		max_iosize = dev->si_iosize_max;
1147 		if (max_iosize < PAGE_SIZE)
1148 			max_iosize = DFLTPHYS;
1149 	} else
1150 		max_iosize = DFLTPHYS;
1151 
1152 	cur_offset = beio->io_offset;
1153 	for (i = 0; i < beio->num_segs; i++) {
1154 		size_t cur_size;
1155 		uint8_t *cur_ptr;
1156 
1157 		cur_size = beio->sg_segs[i].len;
1158 		cur_ptr = beio->sg_segs[i].addr;
1159 
1160 		while (cur_size > 0) {
1161 			/* This can't fail, it's a blocking allocation. */
1162 			bio = g_alloc_bio();
1163 
1164 			KASSERT(bio != NULL, ("g_alloc_bio() failed!\n"));
1165 
1166 			bio->bio_cmd = beio->bio_cmd;
1167 			bio->bio_dev = dev;
1168 			bio->bio_caller1 = beio;
1169 			bio->bio_length = min(cur_size, max_iosize);
1170 			bio->bio_offset = cur_offset;
1171 			bio->bio_data = cur_ptr;
1172 			bio->bio_done = ctl_be_block_biodone;
1173 			bio->bio_pblkno = cur_offset / be_lun->cbe_lun.blocksize;
1174 
1175 			cur_offset += bio->bio_length;
1176 			cur_ptr += bio->bio_length;
1177 			cur_size -= bio->bio_length;
1178 
1179 			TAILQ_INSERT_TAIL(&queue, bio, bio_queue);
1180 			beio->num_bios_sent++;
1181 		}
1182 	}
1183 	binuptime(&beio->ds_t0);
1184 	mtx_lock(&be_lun->io_lock);
1185 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1186 	beio->send_complete = 1;
1187 	mtx_unlock(&be_lun->io_lock);
1188 
1189 	/*
1190 	 * Fire off all allocated requests!
1191 	 */
1192 	while ((bio = TAILQ_FIRST(&queue)) != NULL) {
1193 		TAILQ_REMOVE(&queue, bio, bio_queue);
1194 		if (csw)
1195 			csw->d_strategy(bio);
1196 		else {
1197 			bio->bio_error = ENXIO;
1198 			ctl_be_block_biodone(bio);
1199 		}
1200 	}
1201 	if (csw)
1202 		dev_relthread(dev, ref);
1203 }
1204 
1205 static uint64_t
1206 ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun, const char *attrname)
1207 {
1208 	struct diocgattr_arg	arg;
1209 	struct cdevsw *csw;
1210 	struct cdev *dev;
1211 	int error, ref;
1212 
1213 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1214 	if (csw == NULL)
1215 		return (UINT64_MAX);
1216 	strlcpy(arg.name, attrname, sizeof(arg.name));
1217 	arg.len = sizeof(arg.value.off);
1218 	if (csw->d_ioctl) {
1219 		error = csw->d_ioctl(dev, DIOCGATTR, (caddr_t)&arg, FREAD,
1220 		    curthread);
1221 	} else
1222 		error = ENODEV;
1223 	dev_relthread(dev, ref);
1224 	if (error != 0)
1225 		return (UINT64_MAX);
1226 	return (arg.value.off);
1227 }
1228 
1229 static void
1230 ctl_be_block_cw_dispatch_sync(struct ctl_be_block_lun *be_lun,
1231 			    union ctl_io *io)
1232 {
1233 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1234 	struct ctl_be_block_io *beio;
1235 	struct ctl_lba_len_flags *lbalen;
1236 
1237 	DPRINTF("entered\n");
1238 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1239 	lbalen = (struct ctl_lba_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1240 
1241 	beio->io_len = lbalen->len * cbe_lun->blocksize;
1242 	beio->io_offset = lbalen->lba * cbe_lun->blocksize;
1243 	beio->io_arg = (lbalen->flags & SSC_IMMED) != 0;
1244 	beio->bio_cmd = BIO_FLUSH;
1245 	beio->ds_trans_type = DEVSTAT_NO_DATA;
1246 	DPRINTF("SYNC\n");
1247 	be_lun->lun_flush(be_lun, beio);
1248 }
1249 
1250 static void
1251 ctl_be_block_cw_done_ws(struct ctl_be_block_io *beio)
1252 {
1253 	union ctl_io *io;
1254 
1255 	io = beio->io;
1256 	ctl_free_beio(beio);
1257 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1258 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1259 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1260 		ctl_config_write_done(io);
1261 		return;
1262 	}
1263 
1264 	ctl_be_block_config_write(io);
1265 }
1266 
1267 static void
1268 ctl_be_block_cw_dispatch_ws(struct ctl_be_block_lun *be_lun,
1269 			    union ctl_io *io)
1270 {
1271 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1272 	struct ctl_be_block_io *beio;
1273 	struct ctl_lba_len_flags *lbalen;
1274 	uint64_t len_left, lba;
1275 	uint32_t pb, pbo, adj;
1276 	int i, seglen;
1277 	uint8_t *buf, *end;
1278 
1279 	DPRINTF("entered\n");
1280 
1281 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1282 	lbalen = ARGS(beio->io);
1283 
1284 	if (lbalen->flags & ~(SWS_LBDATA | SWS_UNMAP | SWS_ANCHOR | SWS_NDOB) ||
1285 	    (lbalen->flags & (SWS_UNMAP | SWS_ANCHOR) && be_lun->unmap == NULL)) {
1286 		ctl_free_beio(beio);
1287 		ctl_set_invalid_field(&io->scsiio,
1288 				      /*sks_valid*/ 1,
1289 				      /*command*/ 1,
1290 				      /*field*/ 1,
1291 				      /*bit_valid*/ 0,
1292 				      /*bit*/ 0);
1293 		ctl_config_write_done(io);
1294 		return;
1295 	}
1296 
1297 	if (lbalen->flags & (SWS_UNMAP | SWS_ANCHOR)) {
1298 		beio->io_offset = lbalen->lba * cbe_lun->blocksize;
1299 		beio->io_len = (uint64_t)lbalen->len * cbe_lun->blocksize;
1300 		beio->bio_cmd = BIO_DELETE;
1301 		beio->ds_trans_type = DEVSTAT_FREE;
1302 
1303 		be_lun->unmap(be_lun, beio);
1304 		return;
1305 	}
1306 
1307 	beio->bio_cmd = BIO_WRITE;
1308 	beio->ds_trans_type = DEVSTAT_WRITE;
1309 
1310 	DPRINTF("WRITE SAME at LBA %jx len %u\n",
1311 	       (uintmax_t)lbalen->lba, lbalen->len);
1312 
1313 	pb = cbe_lun->blocksize << be_lun->cbe_lun.pblockexp;
1314 	if (be_lun->cbe_lun.pblockoff > 0)
1315 		pbo = pb - cbe_lun->blocksize * be_lun->cbe_lun.pblockoff;
1316 	else
1317 		pbo = 0;
1318 	len_left = (uint64_t)lbalen->len * cbe_lun->blocksize;
1319 	for (i = 0, lba = 0; i < CTLBLK_MAX_SEGS && len_left > 0; i++) {
1320 
1321 		/*
1322 		 * Setup the S/G entry for this chunk.
1323 		 */
1324 		seglen = MIN(CTLBLK_MAX_SEG, len_left);
1325 		if (pb > cbe_lun->blocksize) {
1326 			adj = ((lbalen->lba + lba) * cbe_lun->blocksize +
1327 			    seglen - pbo) % pb;
1328 			if (seglen > adj)
1329 				seglen -= adj;
1330 			else
1331 				seglen -= seglen % cbe_lun->blocksize;
1332 		} else
1333 			seglen -= seglen % cbe_lun->blocksize;
1334 		beio->sg_segs[i].len = seglen;
1335 		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1336 
1337 		DPRINTF("segment %d addr %p len %zd\n", i,
1338 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1339 
1340 		beio->num_segs++;
1341 		len_left -= seglen;
1342 
1343 		buf = beio->sg_segs[i].addr;
1344 		end = buf + seglen;
1345 		for (; buf < end; buf += cbe_lun->blocksize) {
1346 			if (lbalen->flags & SWS_NDOB) {
1347 				memset(buf, 0, cbe_lun->blocksize);
1348 			} else {
1349 				memcpy(buf, io->scsiio.kern_data_ptr,
1350 				    cbe_lun->blocksize);
1351 			}
1352 			if (lbalen->flags & SWS_LBDATA)
1353 				scsi_ulto4b(lbalen->lba + lba, buf);
1354 			lba++;
1355 		}
1356 	}
1357 
1358 	beio->io_offset = lbalen->lba * cbe_lun->blocksize;
1359 	beio->io_len = lba * cbe_lun->blocksize;
1360 
1361 	/* We can not do all in one run. Correct and schedule rerun. */
1362 	if (len_left > 0) {
1363 		lbalen->lba += lba;
1364 		lbalen->len -= lba;
1365 		beio->beio_cont = ctl_be_block_cw_done_ws;
1366 	}
1367 
1368 	be_lun->dispatch(be_lun, beio);
1369 }
1370 
1371 static void
1372 ctl_be_block_cw_dispatch_unmap(struct ctl_be_block_lun *be_lun,
1373 			    union ctl_io *io)
1374 {
1375 	struct ctl_be_block_io *beio;
1376 	struct ctl_ptr_len_flags *ptrlen;
1377 
1378 	DPRINTF("entered\n");
1379 
1380 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1381 	ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1382 
1383 	if ((ptrlen->flags & ~SU_ANCHOR) != 0 || be_lun->unmap == NULL) {
1384 		ctl_free_beio(beio);
1385 		ctl_set_invalid_field(&io->scsiio,
1386 				      /*sks_valid*/ 0,
1387 				      /*command*/ 1,
1388 				      /*field*/ 0,
1389 				      /*bit_valid*/ 0,
1390 				      /*bit*/ 0);
1391 		ctl_config_write_done(io);
1392 		return;
1393 	}
1394 
1395 	beio->io_len = 0;
1396 	beio->io_offset = -1;
1397 	beio->bio_cmd = BIO_DELETE;
1398 	beio->ds_trans_type = DEVSTAT_FREE;
1399 	DPRINTF("UNMAP\n");
1400 	be_lun->unmap(be_lun, beio);
1401 }
1402 
1403 static void
1404 ctl_be_block_cr_done(struct ctl_be_block_io *beio)
1405 {
1406 	union ctl_io *io;
1407 
1408 	io = beio->io;
1409 	ctl_free_beio(beio);
1410 	ctl_config_read_done(io);
1411 }
1412 
1413 static void
1414 ctl_be_block_cr_dispatch(struct ctl_be_block_lun *be_lun,
1415 			 union ctl_io *io)
1416 {
1417 	struct ctl_be_block_io *beio;
1418 	struct ctl_be_block_softc *softc;
1419 
1420 	DPRINTF("entered\n");
1421 
1422 	softc = be_lun->softc;
1423 	beio = ctl_alloc_beio(softc);
1424 	beio->io = io;
1425 	beio->lun = be_lun;
1426 	beio->beio_cont = ctl_be_block_cr_done;
1427 	PRIV(io)->ptr = (void *)beio;
1428 
1429 	switch (io->scsiio.cdb[0]) {
1430 	case SERVICE_ACTION_IN:		/* GET LBA STATUS */
1431 		beio->bio_cmd = -1;
1432 		beio->ds_trans_type = DEVSTAT_NO_DATA;
1433 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1434 		beio->io_len = 0;
1435 		if (be_lun->get_lba_status)
1436 			be_lun->get_lba_status(be_lun, beio);
1437 		else
1438 			ctl_be_block_cr_done(beio);
1439 		break;
1440 	default:
1441 		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1442 		break;
1443 	}
1444 }
1445 
1446 static void
1447 ctl_be_block_cw_done(struct ctl_be_block_io *beio)
1448 {
1449 	union ctl_io *io;
1450 
1451 	io = beio->io;
1452 	ctl_free_beio(beio);
1453 	ctl_config_write_done(io);
1454 }
1455 
1456 static void
1457 ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
1458 			 union ctl_io *io)
1459 {
1460 	struct ctl_be_block_io *beio;
1461 	struct ctl_be_block_softc *softc;
1462 
1463 	DPRINTF("entered\n");
1464 
1465 	softc = be_lun->softc;
1466 	beio = ctl_alloc_beio(softc);
1467 	beio->io = io;
1468 	beio->lun = be_lun;
1469 	beio->beio_cont = ctl_be_block_cw_done;
1470 	switch (io->scsiio.tag_type) {
1471 	case CTL_TAG_ORDERED:
1472 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1473 		break;
1474 	case CTL_TAG_HEAD_OF_QUEUE:
1475 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1476 		break;
1477 	case CTL_TAG_UNTAGGED:
1478 	case CTL_TAG_SIMPLE:
1479 	case CTL_TAG_ACA:
1480 	default:
1481 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1482 		break;
1483 	}
1484 	PRIV(io)->ptr = (void *)beio;
1485 
1486 	switch (io->scsiio.cdb[0]) {
1487 	case SYNCHRONIZE_CACHE:
1488 	case SYNCHRONIZE_CACHE_16:
1489 		ctl_be_block_cw_dispatch_sync(be_lun, io);
1490 		break;
1491 	case WRITE_SAME_10:
1492 	case WRITE_SAME_16:
1493 		ctl_be_block_cw_dispatch_ws(be_lun, io);
1494 		break;
1495 	case UNMAP:
1496 		ctl_be_block_cw_dispatch_unmap(be_lun, io);
1497 		break;
1498 	default:
1499 		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1500 		break;
1501 	}
1502 }
1503 
1504 SDT_PROBE_DEFINE1(cbb, , read, start, "uint64_t");
1505 SDT_PROBE_DEFINE1(cbb, , write, start, "uint64_t");
1506 SDT_PROBE_DEFINE1(cbb, , read, alloc_done, "uint64_t");
1507 SDT_PROBE_DEFINE1(cbb, , write, alloc_done, "uint64_t");
1508 
1509 static void
1510 ctl_be_block_next(struct ctl_be_block_io *beio)
1511 {
1512 	struct ctl_be_block_lun *be_lun;
1513 	union ctl_io *io;
1514 
1515 	io = beio->io;
1516 	be_lun = beio->lun;
1517 	ctl_free_beio(beio);
1518 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1519 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1520 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1521 		ctl_data_submit_done(io);
1522 		return;
1523 	}
1524 
1525 	io->io_hdr.status &= ~CTL_STATUS_MASK;
1526 	io->io_hdr.status |= CTL_STATUS_NONE;
1527 
1528 	mtx_lock(&be_lun->queue_lock);
1529 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1530 	mtx_unlock(&be_lun->queue_lock);
1531 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1532 }
1533 
1534 static void
1535 ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
1536 			   union ctl_io *io)
1537 {
1538 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1539 	struct ctl_be_block_io *beio;
1540 	struct ctl_be_block_softc *softc;
1541 	struct ctl_lba_len_flags *lbalen;
1542 	struct ctl_ptr_len_flags *bptrlen;
1543 	uint64_t len_left, lbas;
1544 	int i;
1545 
1546 	softc = be_lun->softc;
1547 
1548 	DPRINTF("entered\n");
1549 
1550 	lbalen = ARGS(io);
1551 	if (lbalen->flags & CTL_LLF_WRITE) {
1552 		SDT_PROBE0(cbb, , write, start);
1553 	} else {
1554 		SDT_PROBE0(cbb, , read, start);
1555 	}
1556 
1557 	beio = ctl_alloc_beio(softc);
1558 	beio->io = io;
1559 	beio->lun = be_lun;
1560 	bptrlen = PRIV(io);
1561 	bptrlen->ptr = (void *)beio;
1562 
1563 	switch (io->scsiio.tag_type) {
1564 	case CTL_TAG_ORDERED:
1565 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1566 		break;
1567 	case CTL_TAG_HEAD_OF_QUEUE:
1568 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1569 		break;
1570 	case CTL_TAG_UNTAGGED:
1571 	case CTL_TAG_SIMPLE:
1572 	case CTL_TAG_ACA:
1573 	default:
1574 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1575 		break;
1576 	}
1577 
1578 	if (lbalen->flags & CTL_LLF_WRITE) {
1579 		beio->bio_cmd = BIO_WRITE;
1580 		beio->ds_trans_type = DEVSTAT_WRITE;
1581 	} else {
1582 		beio->bio_cmd = BIO_READ;
1583 		beio->ds_trans_type = DEVSTAT_READ;
1584 	}
1585 
1586 	DPRINTF("%s at LBA %jx len %u @%ju\n",
1587 	       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE",
1588 	       (uintmax_t)lbalen->lba, lbalen->len, bptrlen->len);
1589 	if (lbalen->flags & CTL_LLF_COMPARE)
1590 		lbas = CTLBLK_HALF_IO_SIZE;
1591 	else
1592 		lbas = CTLBLK_MAX_IO_SIZE;
1593 	lbas = MIN(lbalen->len - bptrlen->len, lbas / cbe_lun->blocksize);
1594 	beio->io_offset = (lbalen->lba + bptrlen->len) * cbe_lun->blocksize;
1595 	beio->io_len = lbas * cbe_lun->blocksize;
1596 	bptrlen->len += lbas;
1597 
1598 	for (i = 0, len_left = beio->io_len; len_left > 0; i++) {
1599 		KASSERT(i < CTLBLK_MAX_SEGS, ("Too many segs (%d >= %d)",
1600 		    i, CTLBLK_MAX_SEGS));
1601 
1602 		/*
1603 		 * Setup the S/G entry for this chunk.
1604 		 */
1605 		beio->sg_segs[i].len = min(CTLBLK_MAX_SEG, len_left);
1606 		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1607 
1608 		DPRINTF("segment %d addr %p len %zd\n", i,
1609 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1610 
1611 		/* Set up second segment for compare operation. */
1612 		if (lbalen->flags & CTL_LLF_COMPARE) {
1613 			beio->sg_segs[i + CTLBLK_HALF_SEGS].len =
1614 			    beio->sg_segs[i].len;
1615 			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr =
1616 			    uma_zalloc(be_lun->lun_zone, M_WAITOK);
1617 		}
1618 
1619 		beio->num_segs++;
1620 		len_left -= beio->sg_segs[i].len;
1621 	}
1622 	if (bptrlen->len < lbalen->len)
1623 		beio->beio_cont = ctl_be_block_next;
1624 	io->scsiio.be_move_done = ctl_be_block_move_done;
1625 	/* For compare we have separate S/G lists for read and datamove. */
1626 	if (lbalen->flags & CTL_LLF_COMPARE)
1627 		io->scsiio.kern_data_ptr = (uint8_t *)&beio->sg_segs[CTLBLK_HALF_SEGS];
1628 	else
1629 		io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
1630 	io->scsiio.kern_data_len = beio->io_len;
1631 	io->scsiio.kern_data_resid = 0;
1632 	io->scsiio.kern_sg_entries = beio->num_segs;
1633 	io->io_hdr.flags |= CTL_FLAG_ALLOCATED;
1634 
1635 	/*
1636 	 * For the read case, we need to read the data into our buffers and
1637 	 * then we can send it back to the user.  For the write case, we
1638 	 * need to get the data from the user first.
1639 	 */
1640 	if (beio->bio_cmd == BIO_READ) {
1641 		SDT_PROBE0(cbb, , read, alloc_done);
1642 		be_lun->dispatch(be_lun, beio);
1643 	} else {
1644 		SDT_PROBE0(cbb, , write, alloc_done);
1645 #ifdef CTL_TIME_IO
1646 		getbinuptime(&io->io_hdr.dma_start_bt);
1647 #endif
1648 		ctl_datamove(io);
1649 	}
1650 }
1651 
1652 static void
1653 ctl_be_block_worker(void *context, int pending)
1654 {
1655 	struct ctl_be_block_lun *be_lun = (struct ctl_be_block_lun *)context;
1656 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1657 	union ctl_io *io;
1658 	struct ctl_be_block_io *beio;
1659 
1660 	DPRINTF("entered\n");
1661 	/*
1662 	 * Fetch and process I/Os from all queues.  If we detect LUN
1663 	 * CTL_LUN_FLAG_NO_MEDIA status here -- it is result of a race,
1664 	 * so make response maximally opaque to not confuse initiator.
1665 	 */
1666 	for (;;) {
1667 		mtx_lock(&be_lun->queue_lock);
1668 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->datamove_queue);
1669 		if (io != NULL) {
1670 			DPRINTF("datamove queue\n");
1671 			STAILQ_REMOVE(&be_lun->datamove_queue, &io->io_hdr,
1672 				      ctl_io_hdr, links);
1673 			mtx_unlock(&be_lun->queue_lock);
1674 			beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1675 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1676 				ctl_set_busy(&io->scsiio);
1677 				ctl_complete_beio(beio);
1678 				return;
1679 			}
1680 			be_lun->dispatch(be_lun, beio);
1681 			continue;
1682 		}
1683 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_write_queue);
1684 		if (io != NULL) {
1685 			DPRINTF("config write queue\n");
1686 			STAILQ_REMOVE(&be_lun->config_write_queue, &io->io_hdr,
1687 				      ctl_io_hdr, links);
1688 			mtx_unlock(&be_lun->queue_lock);
1689 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1690 				ctl_set_busy(&io->scsiio);
1691 				ctl_config_write_done(io);
1692 				return;
1693 			}
1694 			ctl_be_block_cw_dispatch(be_lun, io);
1695 			continue;
1696 		}
1697 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_read_queue);
1698 		if (io != NULL) {
1699 			DPRINTF("config read queue\n");
1700 			STAILQ_REMOVE(&be_lun->config_read_queue, &io->io_hdr,
1701 				      ctl_io_hdr, links);
1702 			mtx_unlock(&be_lun->queue_lock);
1703 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1704 				ctl_set_busy(&io->scsiio);
1705 				ctl_config_read_done(io);
1706 				return;
1707 			}
1708 			ctl_be_block_cr_dispatch(be_lun, io);
1709 			continue;
1710 		}
1711 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->input_queue);
1712 		if (io != NULL) {
1713 			DPRINTF("input queue\n");
1714 			STAILQ_REMOVE(&be_lun->input_queue, &io->io_hdr,
1715 				      ctl_io_hdr, links);
1716 			mtx_unlock(&be_lun->queue_lock);
1717 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1718 				ctl_set_busy(&io->scsiio);
1719 				ctl_data_submit_done(io);
1720 				return;
1721 			}
1722 			ctl_be_block_dispatch(be_lun, io);
1723 			continue;
1724 		}
1725 
1726 		/*
1727 		 * If we get here, there is no work left in the queues, so
1728 		 * just break out and let the task queue go to sleep.
1729 		 */
1730 		mtx_unlock(&be_lun->queue_lock);
1731 		break;
1732 	}
1733 }
1734 
1735 /*
1736  * Entry point from CTL to the backend for I/O.  We queue everything to a
1737  * work thread, so this just puts the I/O on a queue and wakes up the
1738  * thread.
1739  */
1740 static int
1741 ctl_be_block_submit(union ctl_io *io)
1742 {
1743 	struct ctl_be_block_lun *be_lun;
1744 	struct ctl_be_lun *cbe_lun;
1745 
1746 	DPRINTF("entered\n");
1747 
1748 	cbe_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
1749 		CTL_PRIV_BACKEND_LUN].ptr;
1750 	be_lun = (struct ctl_be_block_lun *)cbe_lun->be_lun;
1751 
1752 	/*
1753 	 * Make sure we only get SCSI I/O.
1754 	 */
1755 	KASSERT(io->io_hdr.io_type == CTL_IO_SCSI, ("Non-SCSI I/O (type "
1756 		"%#x) encountered", io->io_hdr.io_type));
1757 
1758 	PRIV(io)->len = 0;
1759 
1760 	mtx_lock(&be_lun->queue_lock);
1761 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1762 	mtx_unlock(&be_lun->queue_lock);
1763 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1764 
1765 	return (CTL_RETVAL_COMPLETE);
1766 }
1767 
1768 static int
1769 ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
1770 			int flag, struct thread *td)
1771 {
1772 	struct ctl_be_block_softc *softc;
1773 	int error;
1774 
1775 	softc = &backend_block_softc;
1776 
1777 	error = 0;
1778 
1779 	switch (cmd) {
1780 	case CTL_LUN_REQ: {
1781 		struct ctl_lun_req *lun_req;
1782 
1783 		lun_req = (struct ctl_lun_req *)addr;
1784 
1785 		switch (lun_req->reqtype) {
1786 		case CTL_LUNREQ_CREATE:
1787 			error = ctl_be_block_create(softc, lun_req);
1788 			break;
1789 		case CTL_LUNREQ_RM:
1790 			error = ctl_be_block_rm(softc, lun_req);
1791 			break;
1792 		case CTL_LUNREQ_MODIFY:
1793 			error = ctl_be_block_modify(softc, lun_req);
1794 			break;
1795 		default:
1796 			lun_req->status = CTL_LUN_ERROR;
1797 			snprintf(lun_req->error_str, sizeof(lun_req->error_str),
1798 				 "invalid LUN request type %d",
1799 				 lun_req->reqtype);
1800 			break;
1801 		}
1802 		break;
1803 	}
1804 	default:
1805 		error = ENOTTY;
1806 		break;
1807 	}
1808 
1809 	return (error);
1810 }
1811 
1812 static int
1813 ctl_be_block_open_file(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1814 {
1815 	struct ctl_be_lun *cbe_lun;
1816 	struct ctl_be_block_filedata *file_data;
1817 	struct ctl_lun_create_params *params;
1818 	char			     *value;
1819 	struct vattr		      vattr;
1820 	off_t			      ps, pss, po, pos, us, uss, uo, uos;
1821 	int			      error;
1822 
1823 	cbe_lun = &be_lun->cbe_lun;
1824 	file_data = &be_lun->backend.file;
1825 	params = &be_lun->params;
1826 
1827 	be_lun->dev_type = CTL_BE_BLOCK_FILE;
1828 	be_lun->dispatch = ctl_be_block_dispatch_file;
1829 	be_lun->lun_flush = ctl_be_block_flush_file;
1830 	be_lun->get_lba_status = ctl_be_block_gls_file;
1831 	be_lun->getattr = ctl_be_block_getattr_file;
1832 	be_lun->unmap = NULL;
1833 	cbe_lun->flags &= ~CTL_LUN_FLAG_UNMAP;
1834 
1835 	error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
1836 	if (error != 0) {
1837 		snprintf(req->error_str, sizeof(req->error_str),
1838 			 "error calling VOP_GETATTR() for file %s",
1839 			 be_lun->dev_path);
1840 		return (error);
1841 	}
1842 
1843 	file_data->cred = crhold(curthread->td_ucred);
1844 	if (params->lun_size_bytes != 0)
1845 		be_lun->size_bytes = params->lun_size_bytes;
1846 	else
1847 		be_lun->size_bytes = vattr.va_size;
1848 
1849 	/*
1850 	 * For files we can use any logical block size.  Prefer 512 bytes
1851 	 * for compatibility reasons.  If file's vattr.va_blocksize
1852 	 * (preferred I/O block size) is bigger and multiple to chosen
1853 	 * logical block size -- report it as physical block size.
1854 	 */
1855 	if (params->blocksize_bytes != 0)
1856 		cbe_lun->blocksize = params->blocksize_bytes;
1857 	else if (cbe_lun->lun_type == T_CDROM)
1858 		cbe_lun->blocksize = 2048;
1859 	else
1860 		cbe_lun->blocksize = 512;
1861 	be_lun->size_blocks = be_lun->size_bytes / cbe_lun->blocksize;
1862 	cbe_lun->maxlba = (be_lun->size_blocks == 0) ?
1863 	    0 : (be_lun->size_blocks - 1);
1864 
1865 	us = ps = vattr.va_blocksize;
1866 	uo = po = 0;
1867 
1868 	value = ctl_get_opt(&cbe_lun->options, "pblocksize");
1869 	if (value != NULL)
1870 		ctl_expand_number(value, &ps);
1871 	value = ctl_get_opt(&cbe_lun->options, "pblockoffset");
1872 	if (value != NULL)
1873 		ctl_expand_number(value, &po);
1874 	pss = ps / cbe_lun->blocksize;
1875 	pos = po / cbe_lun->blocksize;
1876 	if ((pss > 0) && (pss * cbe_lun->blocksize == ps) && (pss >= pos) &&
1877 	    ((pss & (pss - 1)) == 0) && (pos * cbe_lun->blocksize == po)) {
1878 		cbe_lun->pblockexp = fls(pss) - 1;
1879 		cbe_lun->pblockoff = (pss - pos) % pss;
1880 	}
1881 
1882 	value = ctl_get_opt(&cbe_lun->options, "ublocksize");
1883 	if (value != NULL)
1884 		ctl_expand_number(value, &us);
1885 	value = ctl_get_opt(&cbe_lun->options, "ublockoffset");
1886 	if (value != NULL)
1887 		ctl_expand_number(value, &uo);
1888 	uss = us / cbe_lun->blocksize;
1889 	uos = uo / cbe_lun->blocksize;
1890 	if ((uss > 0) && (uss * cbe_lun->blocksize == us) && (uss >= uos) &&
1891 	    ((uss & (uss - 1)) == 0) && (uos * cbe_lun->blocksize == uo)) {
1892 		cbe_lun->ublockexp = fls(uss) - 1;
1893 		cbe_lun->ublockoff = (uss - uos) % uss;
1894 	}
1895 
1896 	/*
1897 	 * Sanity check.  The media size has to be at least one
1898 	 * sector long.
1899 	 */
1900 	if (be_lun->size_bytes < cbe_lun->blocksize) {
1901 		error = EINVAL;
1902 		snprintf(req->error_str, sizeof(req->error_str),
1903 			 "file %s size %ju < block size %u", be_lun->dev_path,
1904 			 (uintmax_t)be_lun->size_bytes, cbe_lun->blocksize);
1905 	}
1906 
1907 	cbe_lun->opttxferlen = CTLBLK_MAX_IO_SIZE / cbe_lun->blocksize;
1908 	return (error);
1909 }
1910 
1911 static int
1912 ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1913 {
1914 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1915 	struct ctl_lun_create_params *params;
1916 	struct cdevsw		     *csw;
1917 	struct cdev		     *dev;
1918 	char			     *value;
1919 	int			      error, atomic, maxio, ref, unmap, tmp;
1920 	off_t			      ps, pss, po, pos, us, uss, uo, uos, otmp;
1921 
1922 	params = &be_lun->params;
1923 
1924 	be_lun->dev_type = CTL_BE_BLOCK_DEV;
1925 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1926 	if (csw == NULL)
1927 		return (ENXIO);
1928 	if (strcmp(csw->d_name, "zvol") == 0) {
1929 		be_lun->dispatch = ctl_be_block_dispatch_zvol;
1930 		be_lun->get_lba_status = ctl_be_block_gls_zvol;
1931 		atomic = maxio = CTLBLK_MAX_IO_SIZE;
1932 	} else {
1933 		be_lun->dispatch = ctl_be_block_dispatch_dev;
1934 		be_lun->get_lba_status = NULL;
1935 		atomic = 0;
1936 		maxio = dev->si_iosize_max;
1937 		if (maxio <= 0)
1938 			maxio = DFLTPHYS;
1939 		if (maxio > CTLBLK_MAX_IO_SIZE)
1940 			maxio = CTLBLK_MAX_IO_SIZE;
1941 	}
1942 	be_lun->lun_flush = ctl_be_block_flush_dev;
1943 	be_lun->getattr = ctl_be_block_getattr_dev;
1944 	be_lun->unmap = ctl_be_block_unmap_dev;
1945 
1946 	if (!csw->d_ioctl) {
1947 		dev_relthread(dev, ref);
1948 		snprintf(req->error_str, sizeof(req->error_str),
1949 			 "no d_ioctl for device %s!", be_lun->dev_path);
1950 		return (ENODEV);
1951 	}
1952 
1953 	error = csw->d_ioctl(dev, DIOCGSECTORSIZE, (caddr_t)&tmp, FREAD,
1954 			       curthread);
1955 	if (error) {
1956 		dev_relthread(dev, ref);
1957 		snprintf(req->error_str, sizeof(req->error_str),
1958 			 "error %d returned for DIOCGSECTORSIZE ioctl "
1959 			 "on %s!", error, be_lun->dev_path);
1960 		return (error);
1961 	}
1962 
1963 	/*
1964 	 * If the user has asked for a blocksize that is greater than the
1965 	 * backing device's blocksize, we can do it only if the blocksize
1966 	 * the user is asking for is an even multiple of the underlying
1967 	 * device's blocksize.
1968 	 */
1969 	if ((params->blocksize_bytes != 0) &&
1970 	    (params->blocksize_bytes >= tmp)) {
1971 		if (params->blocksize_bytes % tmp == 0) {
1972 			cbe_lun->blocksize = params->blocksize_bytes;
1973 		} else {
1974 			dev_relthread(dev, ref);
1975 			snprintf(req->error_str, sizeof(req->error_str),
1976 				 "requested blocksize %u is not an even "
1977 				 "multiple of backing device blocksize %u",
1978 				 params->blocksize_bytes, tmp);
1979 			return (EINVAL);
1980 		}
1981 	} else if (params->blocksize_bytes != 0) {
1982 		dev_relthread(dev, ref);
1983 		snprintf(req->error_str, sizeof(req->error_str),
1984 			 "requested blocksize %u < backing device "
1985 			 "blocksize %u", params->blocksize_bytes, tmp);
1986 		return (EINVAL);
1987 	} else if (cbe_lun->lun_type == T_CDROM)
1988 		cbe_lun->blocksize = MAX(tmp, 2048);
1989 	else
1990 		cbe_lun->blocksize = tmp;
1991 
1992 	error = csw->d_ioctl(dev, DIOCGMEDIASIZE, (caddr_t)&otmp, FREAD,
1993 			     curthread);
1994 	if (error) {
1995 		dev_relthread(dev, ref);
1996 		snprintf(req->error_str, sizeof(req->error_str),
1997 			 "error %d returned for DIOCGMEDIASIZE "
1998 			 " ioctl on %s!", error,
1999 			 be_lun->dev_path);
2000 		return (error);
2001 	}
2002 
2003 	if (params->lun_size_bytes != 0) {
2004 		if (params->lun_size_bytes > otmp) {
2005 			dev_relthread(dev, ref);
2006 			snprintf(req->error_str, sizeof(req->error_str),
2007 				 "requested LUN size %ju > backing device "
2008 				 "size %ju",
2009 				 (uintmax_t)params->lun_size_bytes,
2010 				 (uintmax_t)otmp);
2011 			return (EINVAL);
2012 		}
2013 
2014 		be_lun->size_bytes = params->lun_size_bytes;
2015 	} else
2016 		be_lun->size_bytes = otmp;
2017 	be_lun->size_blocks = be_lun->size_bytes / cbe_lun->blocksize;
2018 	cbe_lun->maxlba = (be_lun->size_blocks == 0) ?
2019 	    0 : (be_lun->size_blocks - 1);
2020 
2021 	error = csw->d_ioctl(dev, DIOCGSTRIPESIZE, (caddr_t)&ps, FREAD,
2022 	    curthread);
2023 	if (error)
2024 		ps = po = 0;
2025 	else {
2026 		error = csw->d_ioctl(dev, DIOCGSTRIPEOFFSET, (caddr_t)&po,
2027 		    FREAD, curthread);
2028 		if (error)
2029 			po = 0;
2030 	}
2031 	us = ps;
2032 	uo = po;
2033 
2034 	value = ctl_get_opt(&cbe_lun->options, "pblocksize");
2035 	if (value != NULL)
2036 		ctl_expand_number(value, &ps);
2037 	value = ctl_get_opt(&cbe_lun->options, "pblockoffset");
2038 	if (value != NULL)
2039 		ctl_expand_number(value, &po);
2040 	pss = ps / cbe_lun->blocksize;
2041 	pos = po / cbe_lun->blocksize;
2042 	if ((pss > 0) && (pss * cbe_lun->blocksize == ps) && (pss >= pos) &&
2043 	    ((pss & (pss - 1)) == 0) && (pos * cbe_lun->blocksize == po)) {
2044 		cbe_lun->pblockexp = fls(pss) - 1;
2045 		cbe_lun->pblockoff = (pss - pos) % pss;
2046 	}
2047 
2048 	value = ctl_get_opt(&cbe_lun->options, "ublocksize");
2049 	if (value != NULL)
2050 		ctl_expand_number(value, &us);
2051 	value = ctl_get_opt(&cbe_lun->options, "ublockoffset");
2052 	if (value != NULL)
2053 		ctl_expand_number(value, &uo);
2054 	uss = us / cbe_lun->blocksize;
2055 	uos = uo / cbe_lun->blocksize;
2056 	if ((uss > 0) && (uss * cbe_lun->blocksize == us) && (uss >= uos) &&
2057 	    ((uss & (uss - 1)) == 0) && (uos * cbe_lun->blocksize == uo)) {
2058 		cbe_lun->ublockexp = fls(uss) - 1;
2059 		cbe_lun->ublockoff = (uss - uos) % uss;
2060 	}
2061 
2062 	cbe_lun->atomicblock = atomic / cbe_lun->blocksize;
2063 	cbe_lun->opttxferlen = maxio / cbe_lun->blocksize;
2064 
2065 	if (be_lun->dispatch == ctl_be_block_dispatch_zvol) {
2066 		unmap = 1;
2067 	} else {
2068 		struct diocgattr_arg	arg;
2069 
2070 		strlcpy(arg.name, "GEOM::candelete", sizeof(arg.name));
2071 		arg.len = sizeof(arg.value.i);
2072 		error = csw->d_ioctl(dev, DIOCGATTR, (caddr_t)&arg, FREAD,
2073 		    curthread);
2074 		unmap = (error == 0) ? arg.value.i : 0;
2075 	}
2076 	value = ctl_get_opt(&cbe_lun->options, "unmap");
2077 	if (value != NULL)
2078 		unmap = (strcmp(value, "on") == 0);
2079 	if (unmap)
2080 		cbe_lun->flags |= CTL_LUN_FLAG_UNMAP;
2081 	else
2082 		cbe_lun->flags &= ~CTL_LUN_FLAG_UNMAP;
2083 
2084 	dev_relthread(dev, ref);
2085 	return (0);
2086 }
2087 
2088 static int
2089 ctl_be_block_close(struct ctl_be_block_lun *be_lun)
2090 {
2091 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
2092 	int flags;
2093 
2094 	if (be_lun->vn) {
2095 		flags = FREAD;
2096 		if ((cbe_lun->flags & CTL_LUN_FLAG_READONLY) == 0)
2097 			flags |= FWRITE;
2098 		(void)vn_close(be_lun->vn, flags, NOCRED, curthread);
2099 		be_lun->vn = NULL;
2100 
2101 		switch (be_lun->dev_type) {
2102 		case CTL_BE_BLOCK_DEV:
2103 			break;
2104 		case CTL_BE_BLOCK_FILE:
2105 			if (be_lun->backend.file.cred != NULL) {
2106 				crfree(be_lun->backend.file.cred);
2107 				be_lun->backend.file.cred = NULL;
2108 			}
2109 			break;
2110 		case CTL_BE_BLOCK_NONE:
2111 			break;
2112 		default:
2113 			panic("Unexpected backend type %d", be_lun->dev_type);
2114 			break;
2115 		}
2116 		be_lun->dev_type = CTL_BE_BLOCK_NONE;
2117 	}
2118 	return (0);
2119 }
2120 
2121 static int
2122 ctl_be_block_open(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
2123 {
2124 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
2125 	struct nameidata nd;
2126 	char		*value;
2127 	int		 error, flags;
2128 
2129 	error = 0;
2130 	if (rootvnode == NULL) {
2131 		snprintf(req->error_str, sizeof(req->error_str),
2132 			 "Root filesystem is not mounted");
2133 		return (1);
2134 	}
2135 	pwd_ensure_dirs();
2136 
2137 	value = ctl_get_opt(&cbe_lun->options, "file");
2138 	if (value == NULL) {
2139 		snprintf(req->error_str, sizeof(req->error_str),
2140 			 "no file argument specified");
2141 		return (1);
2142 	}
2143 	free(be_lun->dev_path, M_CTLBLK);
2144 	be_lun->dev_path = strdup(value, M_CTLBLK);
2145 
2146 	flags = FREAD;
2147 	value = ctl_get_opt(&cbe_lun->options, "readonly");
2148 	if (value != NULL) {
2149 		if (strcmp(value, "on") != 0)
2150 			flags |= FWRITE;
2151 	} else if (cbe_lun->lun_type == T_DIRECT)
2152 		flags |= FWRITE;
2153 
2154 again:
2155 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, be_lun->dev_path, curthread);
2156 	error = vn_open(&nd, &flags, 0, NULL);
2157 	if ((error == EROFS || error == EACCES) && (flags & FWRITE)) {
2158 		flags &= ~FWRITE;
2159 		goto again;
2160 	}
2161 	if (error) {
2162 		/*
2163 		 * This is the only reasonable guess we can make as far as
2164 		 * path if the user doesn't give us a fully qualified path.
2165 		 * If they want to specify a file, they need to specify the
2166 		 * full path.
2167 		 */
2168 		if (be_lun->dev_path[0] != '/') {
2169 			char *dev_name;
2170 
2171 			asprintf(&dev_name, M_CTLBLK, "/dev/%s",
2172 				be_lun->dev_path);
2173 			free(be_lun->dev_path, M_CTLBLK);
2174 			be_lun->dev_path = dev_name;
2175 			goto again;
2176 		}
2177 		snprintf(req->error_str, sizeof(req->error_str),
2178 		    "error opening %s: %d", be_lun->dev_path, error);
2179 		return (error);
2180 	}
2181 	if (flags & FWRITE)
2182 		cbe_lun->flags &= ~CTL_LUN_FLAG_READONLY;
2183 	else
2184 		cbe_lun->flags |= CTL_LUN_FLAG_READONLY;
2185 
2186 	NDFREE(&nd, NDF_ONLY_PNBUF);
2187 	be_lun->vn = nd.ni_vp;
2188 
2189 	/* We only support disks and files. */
2190 	if (vn_isdisk(be_lun->vn, &error)) {
2191 		error = ctl_be_block_open_dev(be_lun, req);
2192 	} else if (be_lun->vn->v_type == VREG) {
2193 		error = ctl_be_block_open_file(be_lun, req);
2194 	} else {
2195 		error = EINVAL;
2196 		snprintf(req->error_str, sizeof(req->error_str),
2197 			 "%s is not a disk or plain file", be_lun->dev_path);
2198 	}
2199 	VOP_UNLOCK(be_lun->vn, 0);
2200 
2201 	if (error != 0)
2202 		ctl_be_block_close(be_lun);
2203 	cbe_lun->serseq = CTL_LUN_SERSEQ_OFF;
2204 	if (be_lun->dispatch != ctl_be_block_dispatch_dev)
2205 		cbe_lun->serseq = CTL_LUN_SERSEQ_READ;
2206 	value = ctl_get_opt(&cbe_lun->options, "serseq");
2207 	if (value != NULL && strcmp(value, "on") == 0)
2208 		cbe_lun->serseq = CTL_LUN_SERSEQ_ON;
2209 	else if (value != NULL && strcmp(value, "read") == 0)
2210 		cbe_lun->serseq = CTL_LUN_SERSEQ_READ;
2211 	else if (value != NULL && strcmp(value, "off") == 0)
2212 		cbe_lun->serseq = CTL_LUN_SERSEQ_OFF;
2213 	return (0);
2214 }
2215 
2216 static int
2217 ctl_be_block_create(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2218 {
2219 	struct ctl_be_lun *cbe_lun;
2220 	struct ctl_be_block_lun *be_lun;
2221 	struct ctl_lun_create_params *params;
2222 	char num_thread_str[16];
2223 	char tmpstr[32];
2224 	char *value;
2225 	int retval, num_threads;
2226 	int tmp_num_threads;
2227 
2228 	params = &req->reqdata.create;
2229 	retval = 0;
2230 	req->status = CTL_LUN_OK;
2231 
2232 	be_lun = malloc(sizeof(*be_lun), M_CTLBLK, M_ZERO | M_WAITOK);
2233 	cbe_lun = &be_lun->cbe_lun;
2234 	cbe_lun->be_lun = be_lun;
2235 	be_lun->params = req->reqdata.create;
2236 	be_lun->softc = softc;
2237 	STAILQ_INIT(&be_lun->input_queue);
2238 	STAILQ_INIT(&be_lun->config_read_queue);
2239 	STAILQ_INIT(&be_lun->config_write_queue);
2240 	STAILQ_INIT(&be_lun->datamove_queue);
2241 	sprintf(be_lun->lunname, "cblk%d", softc->num_luns);
2242 	mtx_init(&be_lun->io_lock, "cblk io lock", NULL, MTX_DEF);
2243 	mtx_init(&be_lun->queue_lock, "cblk queue lock", NULL, MTX_DEF);
2244 	ctl_init_opts(&cbe_lun->options,
2245 	    req->num_be_args, req->kern_be_args);
2246 	be_lun->lun_zone = uma_zcreate(be_lun->lunname, CTLBLK_MAX_SEG,
2247 	    NULL, NULL, NULL, NULL, /*align*/ 0, /*flags*/0);
2248 	if (be_lun->lun_zone == NULL) {
2249 		snprintf(req->error_str, sizeof(req->error_str),
2250 			 "error allocating UMA zone");
2251 		goto bailout_error;
2252 	}
2253 
2254 	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
2255 		cbe_lun->lun_type = params->device_type;
2256 	else
2257 		cbe_lun->lun_type = T_DIRECT;
2258 	be_lun->flags = CTL_BE_BLOCK_LUN_UNCONFIGURED;
2259 	cbe_lun->flags = 0;
2260 	value = ctl_get_opt(&cbe_lun->options, "ha_role");
2261 	if (value != NULL) {
2262 		if (strcmp(value, "primary") == 0)
2263 			cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2264 	} else if (control_softc->flags & CTL_FLAG_ACTIVE_SHELF)
2265 		cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2266 
2267 	if (cbe_lun->lun_type == T_DIRECT ||
2268 	    cbe_lun->lun_type == T_CDROM) {
2269 		be_lun->size_bytes = params->lun_size_bytes;
2270 		if (params->blocksize_bytes != 0)
2271 			cbe_lun->blocksize = params->blocksize_bytes;
2272 		else if (cbe_lun->lun_type == T_CDROM)
2273 			cbe_lun->blocksize = 2048;
2274 		else
2275 			cbe_lun->blocksize = 512;
2276 		be_lun->size_blocks = be_lun->size_bytes / cbe_lun->blocksize;
2277 		cbe_lun->maxlba = (be_lun->size_blocks == 0) ?
2278 		    0 : (be_lun->size_blocks - 1);
2279 
2280 		if ((cbe_lun->flags & CTL_LUN_FLAG_PRIMARY) ||
2281 		    control_softc->ha_mode == CTL_HA_MODE_SER_ONLY) {
2282 			retval = ctl_be_block_open(be_lun, req);
2283 			if (retval != 0) {
2284 				retval = 0;
2285 				req->status = CTL_LUN_WARNING;
2286 			}
2287 		}
2288 		num_threads = cbb_num_threads;
2289 	} else {
2290 		num_threads = 1;
2291 	}
2292 
2293 	value = ctl_get_opt(&cbe_lun->options, "num_threads");
2294 	if (value != NULL) {
2295 		tmp_num_threads = strtol(value, NULL, 0);
2296 
2297 		/*
2298 		 * We don't let the user specify less than one
2299 		 * thread, but hope he's clueful enough not to
2300 		 * specify 1000 threads.
2301 		 */
2302 		if (tmp_num_threads < 1) {
2303 			snprintf(req->error_str, sizeof(req->error_str),
2304 				 "invalid number of threads %s",
2305 				 num_thread_str);
2306 			goto bailout_error;
2307 		}
2308 		num_threads = tmp_num_threads;
2309 	}
2310 
2311 	if (be_lun->vn == NULL)
2312 		cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2313 	/* Tell the user the blocksize we ended up using */
2314 	params->lun_size_bytes = be_lun->size_bytes;
2315 	params->blocksize_bytes = cbe_lun->blocksize;
2316 	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
2317 		cbe_lun->req_lun_id = params->req_lun_id;
2318 		cbe_lun->flags |= CTL_LUN_FLAG_ID_REQ;
2319 	} else
2320 		cbe_lun->req_lun_id = 0;
2321 
2322 	cbe_lun->lun_shutdown = ctl_be_block_lun_shutdown;
2323 	cbe_lun->lun_config_status = ctl_be_block_lun_config_status;
2324 	cbe_lun->be = &ctl_be_block_driver;
2325 
2326 	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
2327 		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
2328 			 softc->num_luns);
2329 		strncpy((char *)cbe_lun->serial_num, tmpstr,
2330 			MIN(sizeof(cbe_lun->serial_num), sizeof(tmpstr)));
2331 
2332 		/* Tell the user what we used for a serial number */
2333 		strncpy((char *)params->serial_num, tmpstr,
2334 			MIN(sizeof(params->serial_num), sizeof(tmpstr)));
2335 	} else {
2336 		strncpy((char *)cbe_lun->serial_num, params->serial_num,
2337 			MIN(sizeof(cbe_lun->serial_num),
2338 			sizeof(params->serial_num)));
2339 	}
2340 	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
2341 		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
2342 		strncpy((char *)cbe_lun->device_id, tmpstr,
2343 			MIN(sizeof(cbe_lun->device_id), sizeof(tmpstr)));
2344 
2345 		/* Tell the user what we used for a device ID */
2346 		strncpy((char *)params->device_id, tmpstr,
2347 			MIN(sizeof(params->device_id), sizeof(tmpstr)));
2348 	} else {
2349 		strncpy((char *)cbe_lun->device_id, params->device_id,
2350 			MIN(sizeof(cbe_lun->device_id),
2351 			    sizeof(params->device_id)));
2352 	}
2353 
2354 	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_be_block_worker, be_lun);
2355 
2356 	be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
2357 	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
2358 
2359 	if (be_lun->io_taskqueue == NULL) {
2360 		snprintf(req->error_str, sizeof(req->error_str),
2361 			 "unable to create taskqueue");
2362 		goto bailout_error;
2363 	}
2364 
2365 	/*
2366 	 * Note that we start the same number of threads by default for
2367 	 * both the file case and the block device case.  For the file
2368 	 * case, we need multiple threads to allow concurrency, because the
2369 	 * vnode interface is designed to be a blocking interface.  For the
2370 	 * block device case, ZFS zvols at least will block the caller's
2371 	 * context in many instances, and so we need multiple threads to
2372 	 * overcome that problem.  Other block devices don't need as many
2373 	 * threads, but they shouldn't cause too many problems.
2374 	 *
2375 	 * If the user wants to just have a single thread for a block
2376 	 * device, he can specify that when the LUN is created, or change
2377 	 * the tunable/sysctl to alter the default number of threads.
2378 	 */
2379 	retval = taskqueue_start_threads(&be_lun->io_taskqueue,
2380 					 /*num threads*/num_threads,
2381 					 /*priority*/PWAIT,
2382 					 /*thread name*/
2383 					 "%s taskq", be_lun->lunname);
2384 
2385 	if (retval != 0)
2386 		goto bailout_error;
2387 
2388 	be_lun->num_threads = num_threads;
2389 
2390 	mtx_lock(&softc->lock);
2391 	softc->num_luns++;
2392 	STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
2393 
2394 	mtx_unlock(&softc->lock);
2395 
2396 	retval = ctl_add_lun(&be_lun->cbe_lun);
2397 	if (retval != 0) {
2398 		mtx_lock(&softc->lock);
2399 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2400 			      links);
2401 		softc->num_luns--;
2402 		mtx_unlock(&softc->lock);
2403 		snprintf(req->error_str, sizeof(req->error_str),
2404 			 "ctl_add_lun() returned error %d, see dmesg for "
2405 			 "details", retval);
2406 		retval = 0;
2407 		goto bailout_error;
2408 	}
2409 
2410 	mtx_lock(&softc->lock);
2411 
2412 	/*
2413 	 * Tell the config_status routine that we're waiting so it won't
2414 	 * clean up the LUN in the event of an error.
2415 	 */
2416 	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2417 
2418 	while (be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) {
2419 		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2420 		if (retval == EINTR)
2421 			break;
2422 	}
2423 	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2424 
2425 	if (be_lun->flags & CTL_BE_BLOCK_LUN_CONFIG_ERR) {
2426 		snprintf(req->error_str, sizeof(req->error_str),
2427 			 "LUN configuration error, see dmesg for details");
2428 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2429 			      links);
2430 		softc->num_luns--;
2431 		mtx_unlock(&softc->lock);
2432 		goto bailout_error;
2433 	} else {
2434 		params->req_lun_id = cbe_lun->lun_id;
2435 	}
2436 
2437 	mtx_unlock(&softc->lock);
2438 
2439 	be_lun->disk_stats = devstat_new_entry("cbb", params->req_lun_id,
2440 					       cbe_lun->blocksize,
2441 					       DEVSTAT_ALL_SUPPORTED,
2442 					       cbe_lun->lun_type
2443 					       | DEVSTAT_TYPE_IF_OTHER,
2444 					       DEVSTAT_PRIORITY_OTHER);
2445 
2446 	return (retval);
2447 
2448 bailout_error:
2449 	req->status = CTL_LUN_ERROR;
2450 
2451 	if (be_lun->io_taskqueue != NULL)
2452 		taskqueue_free(be_lun->io_taskqueue);
2453 	ctl_be_block_close(be_lun);
2454 	if (be_lun->dev_path != NULL)
2455 		free(be_lun->dev_path, M_CTLBLK);
2456 	if (be_lun->lun_zone != NULL)
2457 		uma_zdestroy(be_lun->lun_zone);
2458 	ctl_free_opts(&cbe_lun->options);
2459 	mtx_destroy(&be_lun->queue_lock);
2460 	mtx_destroy(&be_lun->io_lock);
2461 	free(be_lun, M_CTLBLK);
2462 
2463 	return (retval);
2464 }
2465 
2466 static int
2467 ctl_be_block_rm(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2468 {
2469 	struct ctl_lun_rm_params *params;
2470 	struct ctl_be_block_lun *be_lun;
2471 	struct ctl_be_lun *cbe_lun;
2472 	int retval;
2473 
2474 	params = &req->reqdata.rm;
2475 
2476 	mtx_lock(&softc->lock);
2477 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2478 		if (be_lun->cbe_lun.lun_id == params->lun_id)
2479 			break;
2480 	}
2481 	mtx_unlock(&softc->lock);
2482 	if (be_lun == NULL) {
2483 		snprintf(req->error_str, sizeof(req->error_str),
2484 			 "LUN %u is not managed by the block backend",
2485 			 params->lun_id);
2486 		goto bailout_error;
2487 	}
2488 	cbe_lun = &be_lun->cbe_lun;
2489 
2490 	retval = ctl_disable_lun(cbe_lun);
2491 	if (retval != 0) {
2492 		snprintf(req->error_str, sizeof(req->error_str),
2493 			 "error %d returned from ctl_disable_lun() for "
2494 			 "LUN %d", retval, params->lun_id);
2495 		goto bailout_error;
2496 	}
2497 
2498 	if (be_lun->vn != NULL) {
2499 		cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2500 		ctl_lun_no_media(cbe_lun);
2501 		taskqueue_drain_all(be_lun->io_taskqueue);
2502 		ctl_be_block_close(be_lun);
2503 	}
2504 
2505 	retval = ctl_invalidate_lun(cbe_lun);
2506 	if (retval != 0) {
2507 		snprintf(req->error_str, sizeof(req->error_str),
2508 			 "error %d returned from ctl_invalidate_lun() for "
2509 			 "LUN %d", retval, params->lun_id);
2510 		goto bailout_error;
2511 	}
2512 
2513 	mtx_lock(&softc->lock);
2514 	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2515 	while ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2516                 retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2517                 if (retval == EINTR)
2518                         break;
2519         }
2520 	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2521 
2522 	if ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2523 		snprintf(req->error_str, sizeof(req->error_str),
2524 			 "interrupted waiting for LUN to be freed");
2525 		mtx_unlock(&softc->lock);
2526 		goto bailout_error;
2527 	}
2528 
2529 	STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun, links);
2530 
2531 	softc->num_luns--;
2532 	mtx_unlock(&softc->lock);
2533 
2534 	taskqueue_drain_all(be_lun->io_taskqueue);
2535 	taskqueue_free(be_lun->io_taskqueue);
2536 
2537 	if (be_lun->disk_stats != NULL)
2538 		devstat_remove_entry(be_lun->disk_stats);
2539 
2540 	uma_zdestroy(be_lun->lun_zone);
2541 
2542 	ctl_free_opts(&cbe_lun->options);
2543 	free(be_lun->dev_path, M_CTLBLK);
2544 	mtx_destroy(&be_lun->queue_lock);
2545 	mtx_destroy(&be_lun->io_lock);
2546 	free(be_lun, M_CTLBLK);
2547 
2548 	req->status = CTL_LUN_OK;
2549 	return (0);
2550 
2551 bailout_error:
2552 	req->status = CTL_LUN_ERROR;
2553 	return (0);
2554 }
2555 
2556 static int
2557 ctl_be_block_modify(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2558 {
2559 	struct ctl_lun_modify_params *params;
2560 	struct ctl_be_block_lun *be_lun;
2561 	struct ctl_be_lun *cbe_lun;
2562 	char *value;
2563 	uint64_t oldsize;
2564 	int error, wasprim;
2565 
2566 	params = &req->reqdata.modify;
2567 
2568 	mtx_lock(&softc->lock);
2569 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2570 		if (be_lun->cbe_lun.lun_id == params->lun_id)
2571 			break;
2572 	}
2573 	mtx_unlock(&softc->lock);
2574 	if (be_lun == NULL) {
2575 		snprintf(req->error_str, sizeof(req->error_str),
2576 			 "LUN %u is not managed by the block backend",
2577 			 params->lun_id);
2578 		goto bailout_error;
2579 	}
2580 	cbe_lun = &be_lun->cbe_lun;
2581 
2582 	if (params->lun_size_bytes != 0)
2583 		be_lun->params.lun_size_bytes = params->lun_size_bytes;
2584 	ctl_update_opts(&cbe_lun->options, req->num_be_args, req->kern_be_args);
2585 
2586 	wasprim = (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY);
2587 	value = ctl_get_opt(&cbe_lun->options, "ha_role");
2588 	if (value != NULL) {
2589 		if (strcmp(value, "primary") == 0)
2590 			cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2591 		else
2592 			cbe_lun->flags &= ~CTL_LUN_FLAG_PRIMARY;
2593 	} else if (control_softc->flags & CTL_FLAG_ACTIVE_SHELF)
2594 		cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2595 	else
2596 		cbe_lun->flags &= ~CTL_LUN_FLAG_PRIMARY;
2597 	if (wasprim != (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY)) {
2598 		if (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY)
2599 			ctl_lun_primary(cbe_lun);
2600 		else
2601 			ctl_lun_secondary(cbe_lun);
2602 	}
2603 
2604 	oldsize = be_lun->size_blocks;
2605 	if ((cbe_lun->flags & CTL_LUN_FLAG_PRIMARY) ||
2606 	    control_softc->ha_mode == CTL_HA_MODE_SER_ONLY) {
2607 		if (be_lun->vn == NULL)
2608 			error = ctl_be_block_open(be_lun, req);
2609 		else if (vn_isdisk(be_lun->vn, &error))
2610 			error = ctl_be_block_open_dev(be_lun, req);
2611 		else if (be_lun->vn->v_type == VREG) {
2612 			vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
2613 			error = ctl_be_block_open_file(be_lun, req);
2614 			VOP_UNLOCK(be_lun->vn, 0);
2615 		} else
2616 			error = EINVAL;
2617 		if ((cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) &&
2618 		    be_lun->vn != NULL) {
2619 			cbe_lun->flags &= ~CTL_LUN_FLAG_NO_MEDIA;
2620 			ctl_lun_has_media(cbe_lun);
2621 		} else if ((cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) == 0 &&
2622 		    be_lun->vn == NULL) {
2623 			cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2624 			ctl_lun_no_media(cbe_lun);
2625 		}
2626 		cbe_lun->flags &= ~CTL_LUN_FLAG_EJECTED;
2627 	} else {
2628 		if (be_lun->vn != NULL) {
2629 			cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2630 			ctl_lun_no_media(cbe_lun);
2631 			taskqueue_drain_all(be_lun->io_taskqueue);
2632 			error = ctl_be_block_close(be_lun);
2633 		} else
2634 			error = 0;
2635 	}
2636 	if (be_lun->size_blocks != oldsize)
2637 		ctl_lun_capacity_changed(cbe_lun);
2638 
2639 	/* Tell the user the exact size we ended up using */
2640 	params->lun_size_bytes = be_lun->size_bytes;
2641 
2642 	req->status = error ? CTL_LUN_WARNING : CTL_LUN_OK;
2643 	return (0);
2644 
2645 bailout_error:
2646 	req->status = CTL_LUN_ERROR;
2647 	return (0);
2648 }
2649 
2650 static void
2651 ctl_be_block_lun_shutdown(void *be_lun)
2652 {
2653 	struct ctl_be_block_lun *lun;
2654 	struct ctl_be_block_softc *softc;
2655 
2656 	lun = (struct ctl_be_block_lun *)be_lun;
2657 	softc = lun->softc;
2658 
2659 	mtx_lock(&softc->lock);
2660 	lun->flags |= CTL_BE_BLOCK_LUN_UNCONFIGURED;
2661 	if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2662 		wakeup(lun);
2663 	mtx_unlock(&softc->lock);
2664 }
2665 
2666 static void
2667 ctl_be_block_lun_config_status(void *be_lun, ctl_lun_config_status status)
2668 {
2669 	struct ctl_be_block_lun *lun;
2670 	struct ctl_be_block_softc *softc;
2671 
2672 	lun = (struct ctl_be_block_lun *)be_lun;
2673 	softc = lun->softc;
2674 
2675 	if (status == CTL_LUN_CONFIG_OK) {
2676 		mtx_lock(&softc->lock);
2677 		lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2678 		if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2679 			wakeup(lun);
2680 		mtx_unlock(&softc->lock);
2681 
2682 		/*
2683 		 * We successfully added the LUN, attempt to enable it.
2684 		 */
2685 		if (ctl_enable_lun(&lun->cbe_lun) != 0) {
2686 			printf("%s: ctl_enable_lun() failed!\n", __func__);
2687 			if (ctl_invalidate_lun(&lun->cbe_lun) != 0) {
2688 				printf("%s: ctl_invalidate_lun() failed!\n",
2689 				       __func__);
2690 			}
2691 		}
2692 
2693 		return;
2694 	}
2695 
2696 
2697 	mtx_lock(&softc->lock);
2698 	lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2699 	lun->flags |= CTL_BE_BLOCK_LUN_CONFIG_ERR;
2700 	wakeup(lun);
2701 	mtx_unlock(&softc->lock);
2702 }
2703 
2704 
2705 static int
2706 ctl_be_block_config_write(union ctl_io *io)
2707 {
2708 	struct ctl_be_block_lun *be_lun;
2709 	struct ctl_be_lun *cbe_lun;
2710 	int retval;
2711 
2712 	DPRINTF("entered\n");
2713 
2714 	cbe_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
2715 		CTL_PRIV_BACKEND_LUN].ptr;
2716 	be_lun = (struct ctl_be_block_lun *)cbe_lun->be_lun;
2717 
2718 	retval = 0;
2719 	switch (io->scsiio.cdb[0]) {
2720 	case SYNCHRONIZE_CACHE:
2721 	case SYNCHRONIZE_CACHE_16:
2722 	case WRITE_SAME_10:
2723 	case WRITE_SAME_16:
2724 	case UNMAP:
2725 		/*
2726 		 * The upper level CTL code will filter out any CDBs with
2727 		 * the immediate bit set and return the proper error.
2728 		 *
2729 		 * We don't really need to worry about what LBA range the
2730 		 * user asked to be synced out.  When they issue a sync
2731 		 * cache command, we'll sync out the whole thing.
2732 		 */
2733 		mtx_lock(&be_lun->queue_lock);
2734 		STAILQ_INSERT_TAIL(&be_lun->config_write_queue, &io->io_hdr,
2735 				   links);
2736 		mtx_unlock(&be_lun->queue_lock);
2737 		taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
2738 		break;
2739 	case START_STOP_UNIT: {
2740 		struct scsi_start_stop_unit *cdb;
2741 		struct ctl_lun_req req;
2742 
2743 		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
2744 		if ((cdb->how & SSS_PC_MASK) != 0) {
2745 			ctl_set_success(&io->scsiio);
2746 			ctl_config_write_done(io);
2747 			break;
2748 		}
2749 		if (cdb->how & SSS_START) {
2750 			if ((cdb->how & SSS_LOEJ) && be_lun->vn == NULL) {
2751 				retval = ctl_be_block_open(be_lun, &req);
2752 				cbe_lun->flags &= ~CTL_LUN_FLAG_EJECTED;
2753 				if (retval == 0) {
2754 					cbe_lun->flags &= ~CTL_LUN_FLAG_NO_MEDIA;
2755 					ctl_lun_has_media(cbe_lun);
2756 				} else {
2757 					cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2758 					ctl_lun_no_media(cbe_lun);
2759 				}
2760 			}
2761 			ctl_start_lun(cbe_lun);
2762 		} else {
2763 			ctl_stop_lun(cbe_lun);
2764 			if (cdb->how & SSS_LOEJ) {
2765 				cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2766 				cbe_lun->flags |= CTL_LUN_FLAG_EJECTED;
2767 				ctl_lun_ejected(cbe_lun);
2768 				if (be_lun->vn != NULL)
2769 					ctl_be_block_close(be_lun);
2770 			}
2771 		}
2772 
2773 		ctl_set_success(&io->scsiio);
2774 		ctl_config_write_done(io);
2775 		break;
2776 	}
2777 	case PREVENT_ALLOW:
2778 		ctl_set_success(&io->scsiio);
2779 		ctl_config_write_done(io);
2780 		break;
2781 	default:
2782 		ctl_set_invalid_opcode(&io->scsiio);
2783 		ctl_config_write_done(io);
2784 		retval = CTL_RETVAL_COMPLETE;
2785 		break;
2786 	}
2787 
2788 	return (retval);
2789 }
2790 
2791 static int
2792 ctl_be_block_config_read(union ctl_io *io)
2793 {
2794 	struct ctl_be_block_lun *be_lun;
2795 	struct ctl_be_lun *cbe_lun;
2796 	int retval = 0;
2797 
2798 	DPRINTF("entered\n");
2799 
2800 	cbe_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
2801 		CTL_PRIV_BACKEND_LUN].ptr;
2802 	be_lun = (struct ctl_be_block_lun *)cbe_lun->be_lun;
2803 
2804 	switch (io->scsiio.cdb[0]) {
2805 	case SERVICE_ACTION_IN:
2806 		if (io->scsiio.cdb[1] == SGLS_SERVICE_ACTION) {
2807 			mtx_lock(&be_lun->queue_lock);
2808 			STAILQ_INSERT_TAIL(&be_lun->config_read_queue,
2809 			    &io->io_hdr, links);
2810 			mtx_unlock(&be_lun->queue_lock);
2811 			taskqueue_enqueue(be_lun->io_taskqueue,
2812 			    &be_lun->io_task);
2813 			retval = CTL_RETVAL_QUEUED;
2814 			break;
2815 		}
2816 		ctl_set_invalid_field(&io->scsiio,
2817 				      /*sks_valid*/ 1,
2818 				      /*command*/ 1,
2819 				      /*field*/ 1,
2820 				      /*bit_valid*/ 1,
2821 				      /*bit*/ 4);
2822 		ctl_config_read_done(io);
2823 		retval = CTL_RETVAL_COMPLETE;
2824 		break;
2825 	default:
2826 		ctl_set_invalid_opcode(&io->scsiio);
2827 		ctl_config_read_done(io);
2828 		retval = CTL_RETVAL_COMPLETE;
2829 		break;
2830 	}
2831 
2832 	return (retval);
2833 }
2834 
2835 static int
2836 ctl_be_block_lun_info(void *be_lun, struct sbuf *sb)
2837 {
2838 	struct ctl_be_block_lun *lun;
2839 	int retval;
2840 
2841 	lun = (struct ctl_be_block_lun *)be_lun;
2842 
2843 	retval = sbuf_printf(sb, "\t<num_threads>");
2844 	if (retval != 0)
2845 		goto bailout;
2846 	retval = sbuf_printf(sb, "%d", lun->num_threads);
2847 	if (retval != 0)
2848 		goto bailout;
2849 	retval = sbuf_printf(sb, "</num_threads>\n");
2850 
2851 bailout:
2852 	return (retval);
2853 }
2854 
2855 static uint64_t
2856 ctl_be_block_lun_attr(void *be_lun, const char *attrname)
2857 {
2858 	struct ctl_be_block_lun *lun = (struct ctl_be_block_lun *)be_lun;
2859 
2860 	if (lun->getattr == NULL)
2861 		return (UINT64_MAX);
2862 	return (lun->getattr(lun, attrname));
2863 }
2864 
2865 int
2866 ctl_be_block_init(void)
2867 {
2868 	struct ctl_be_block_softc *softc;
2869 	int retval;
2870 
2871 	softc = &backend_block_softc;
2872 	retval = 0;
2873 
2874 	mtx_init(&softc->lock, "ctlblock", NULL, MTX_DEF);
2875 	beio_zone = uma_zcreate("beio", sizeof(struct ctl_be_block_io),
2876 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
2877 	STAILQ_INIT(&softc->lun_list);
2878 
2879 	return (retval);
2880 }
2881