xref: /freebsd/sys/cam/ctl/ctl_backend_block.c (revision 4e99f45480598189d49d45a825533a6c9e12f02c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2003 Silicon Graphics International Corp.
5  * Copyright (c) 2009-2011 Spectra Logic Corporation
6  * Copyright (c) 2012 The FreeBSD Foundation
7  * Copyright (c) 2014-2015 Alexander Motin <mav@FreeBSD.org>
8  * All rights reserved.
9  *
10  * Portions of this software were developed by Edward Tomasz Napierala
11  * under sponsorship from the FreeBSD Foundation.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions, and the following disclaimer,
18  *    without modification.
19  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
20  *    substantially similar to the "NO WARRANTY" disclaimer below
21  *    ("Disclaimer") and any redistribution must be conditioned upon
22  *    including a substantially similar Disclaimer requirement for further
23  *    binary redistribution.
24  *
25  * NO WARRANTY
26  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
27  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
28  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
29  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
30  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
34  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
35  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGES.
37  *
38  * $Id: //depot/users/kenm/FreeBSD-test2/sys/cam/ctl/ctl_backend_block.c#5 $
39  */
40 /*
41  * CAM Target Layer driver backend for block devices.
42  *
43  * Author: Ken Merry <ken@FreeBSD.org>
44  */
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
47 
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
51 #include <sys/types.h>
52 #include <sys/kthread.h>
53 #include <sys/bio.h>
54 #include <sys/fcntl.h>
55 #include <sys/limits.h>
56 #include <sys/lock.h>
57 #include <sys/mutex.h>
58 #include <sys/condvar.h>
59 #include <sys/malloc.h>
60 #include <sys/conf.h>
61 #include <sys/ioccom.h>
62 #include <sys/queue.h>
63 #include <sys/sbuf.h>
64 #include <sys/endian.h>
65 #include <sys/uio.h>
66 #include <sys/buf.h>
67 #include <sys/taskqueue.h>
68 #include <sys/vnode.h>
69 #include <sys/namei.h>
70 #include <sys/mount.h>
71 #include <sys/disk.h>
72 #include <sys/fcntl.h>
73 #include <sys/filedesc.h>
74 #include <sys/filio.h>
75 #include <sys/proc.h>
76 #include <sys/pcpu.h>
77 #include <sys/module.h>
78 #include <sys/sdt.h>
79 #include <sys/devicestat.h>
80 #include <sys/sysctl.h>
81 #include <sys/nv.h>
82 #include <sys/dnv.h>
83 #include <sys/sx.h>
84 
85 #include <geom/geom.h>
86 
87 #include <cam/cam.h>
88 #include <cam/scsi/scsi_all.h>
89 #include <cam/scsi/scsi_da.h>
90 #include <cam/ctl/ctl_io.h>
91 #include <cam/ctl/ctl.h>
92 #include <cam/ctl/ctl_backend.h>
93 #include <cam/ctl/ctl_ioctl.h>
94 #include <cam/ctl/ctl_ha.h>
95 #include <cam/ctl/ctl_scsi_all.h>
96 #include <cam/ctl/ctl_private.h>
97 #include <cam/ctl/ctl_error.h>
98 
99 /*
100  * The idea here is that we'll allocate enough S/G space to hold a 1MB
101  * I/O.  If we get an I/O larger than that, we'll split it.
102  */
103 #define	CTLBLK_HALF_IO_SIZE	(512 * 1024)
104 #define	CTLBLK_MAX_IO_SIZE	(CTLBLK_HALF_IO_SIZE * 2)
105 #define	CTLBLK_MAX_SEG		MAXPHYS
106 #define	CTLBLK_HALF_SEGS	MAX(CTLBLK_HALF_IO_SIZE / CTLBLK_MAX_SEG, 1)
107 #define	CTLBLK_MAX_SEGS		(CTLBLK_HALF_SEGS * 2)
108 
109 #ifdef CTLBLK_DEBUG
110 #define DPRINTF(fmt, args...) \
111     printf("cbb(%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
112 #else
113 #define DPRINTF(fmt, args...) do {} while(0)
114 #endif
115 
116 #define PRIV(io)	\
117     ((struct ctl_ptr_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_BACKEND])
118 #define ARGS(io)	\
119     ((struct ctl_lba_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_LBA_LEN])
120 
121 SDT_PROVIDER_DEFINE(cbb);
122 
123 typedef enum {
124 	CTL_BE_BLOCK_LUN_UNCONFIGURED	= 0x01,
125 	CTL_BE_BLOCK_LUN_WAITING	= 0x04,
126 } ctl_be_block_lun_flags;
127 
128 typedef enum {
129 	CTL_BE_BLOCK_NONE,
130 	CTL_BE_BLOCK_DEV,
131 	CTL_BE_BLOCK_FILE
132 } ctl_be_block_type;
133 
134 struct ctl_be_block_filedata {
135 	struct ucred *cred;
136 };
137 
138 union ctl_be_block_bedata {
139 	struct ctl_be_block_filedata file;
140 };
141 
142 struct ctl_be_block_io;
143 struct ctl_be_block_lun;
144 
145 typedef void (*cbb_dispatch_t)(struct ctl_be_block_lun *be_lun,
146 			       struct ctl_be_block_io *beio);
147 typedef uint64_t (*cbb_getattr_t)(struct ctl_be_block_lun *be_lun,
148 				  const char *attrname);
149 
150 /*
151  * Backend LUN structure.  There is a 1:1 mapping between a block device
152  * and a backend block LUN, and between a backend block LUN and a CTL LUN.
153  */
154 struct ctl_be_block_lun {
155 	struct ctl_be_lun cbe_lun;		/* Must be first element. */
156 	struct ctl_lun_create_params params;
157 	char *dev_path;
158 	ctl_be_block_type dev_type;
159 	struct vnode *vn;
160 	union ctl_be_block_bedata backend;
161 	cbb_dispatch_t dispatch;
162 	cbb_dispatch_t lun_flush;
163 	cbb_dispatch_t unmap;
164 	cbb_dispatch_t get_lba_status;
165 	cbb_getattr_t getattr;
166 	uint64_t size_blocks;
167 	uint64_t size_bytes;
168 	struct ctl_be_block_softc *softc;
169 	struct devstat *disk_stats;
170 	ctl_be_block_lun_flags flags;
171 	SLIST_ENTRY(ctl_be_block_lun) links;
172 	struct taskqueue *io_taskqueue;
173 	struct task io_task;
174 	int num_threads;
175 	STAILQ_HEAD(, ctl_io_hdr) input_queue;
176 	STAILQ_HEAD(, ctl_io_hdr) config_read_queue;
177 	STAILQ_HEAD(, ctl_io_hdr) config_write_queue;
178 	STAILQ_HEAD(, ctl_io_hdr) datamove_queue;
179 	struct mtx_padalign io_lock;
180 	struct mtx_padalign queue_lock;
181 };
182 
183 /*
184  * Overall softc structure for the block backend module.
185  */
186 struct ctl_be_block_softc {
187 	struct sx			 modify_lock;
188 	struct mtx			 lock;
189 	int				 num_luns;
190 	SLIST_HEAD(, ctl_be_block_lun)	 lun_list;
191 	uma_zone_t			 beio_zone;
192 	uma_zone_t			 buf_zone;
193 };
194 
195 static struct ctl_be_block_softc backend_block_softc;
196 
197 /*
198  * Per-I/O information.
199  */
200 struct ctl_be_block_io {
201 	union ctl_io			*io;
202 	struct ctl_sg_entry		sg_segs[CTLBLK_MAX_SEGS];
203 	struct iovec			xiovecs[CTLBLK_MAX_SEGS];
204 	int				bio_cmd;
205 	int				two_sglists;
206 	int				num_segs;
207 	int				num_bios_sent;
208 	int				num_bios_done;
209 	int				send_complete;
210 	int				first_error;
211 	uint64_t			first_error_offset;
212 	struct bintime			ds_t0;
213 	devstat_tag_type		ds_tag_type;
214 	devstat_trans_flags		ds_trans_type;
215 	uint64_t			io_len;
216 	uint64_t			io_offset;
217 	int				io_arg;
218 	struct ctl_be_block_softc	*softc;
219 	struct ctl_be_block_lun		*lun;
220 	void (*beio_cont)(struct ctl_be_block_io *beio); /* to continue processing */
221 };
222 
223 extern struct ctl_softc *control_softc;
224 
225 static int cbb_num_threads = 14;
226 SYSCTL_NODE(_kern_cam_ctl, OID_AUTO, block, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
227 	    "CAM Target Layer Block Backend");
228 SYSCTL_INT(_kern_cam_ctl_block, OID_AUTO, num_threads, CTLFLAG_RWTUN,
229            &cbb_num_threads, 0, "Number of threads per backing file");
230 
231 static struct ctl_be_block_io *ctl_alloc_beio(struct ctl_be_block_softc *softc);
232 static void ctl_free_beio(struct ctl_be_block_io *beio);
233 static void ctl_complete_beio(struct ctl_be_block_io *beio);
234 static int ctl_be_block_move_done(union ctl_io *io);
235 static void ctl_be_block_biodone(struct bio *bio);
236 static void ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
237 				    struct ctl_be_block_io *beio);
238 static void ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
239 				       struct ctl_be_block_io *beio);
240 static void ctl_be_block_gls_file(struct ctl_be_block_lun *be_lun,
241 				  struct ctl_be_block_io *beio);
242 static uint64_t ctl_be_block_getattr_file(struct ctl_be_block_lun *be_lun,
243 					 const char *attrname);
244 static void ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
245 				   struct ctl_be_block_io *beio);
246 static void ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
247 				   struct ctl_be_block_io *beio);
248 static void ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
249 				      struct ctl_be_block_io *beio);
250 static uint64_t ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun,
251 					 const char *attrname);
252 static void ctl_be_block_cr_dispatch(struct ctl_be_block_lun *be_lun,
253 				    union ctl_io *io);
254 static void ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
255 				    union ctl_io *io);
256 static void ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
257 				  union ctl_io *io);
258 static void ctl_be_block_worker(void *context, int pending);
259 static int ctl_be_block_submit(union ctl_io *io);
260 static int ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
261 				   int flag, struct thread *td);
262 static int ctl_be_block_open_file(struct ctl_be_block_lun *be_lun,
263 				  struct ctl_lun_req *req);
264 static int ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun,
265 				 struct ctl_lun_req *req);
266 static int ctl_be_block_close(struct ctl_be_block_lun *be_lun);
267 static int ctl_be_block_open(struct ctl_be_block_lun *be_lun,
268 			     struct ctl_lun_req *req);
269 static int ctl_be_block_create(struct ctl_be_block_softc *softc,
270 			       struct ctl_lun_req *req);
271 static int ctl_be_block_rm(struct ctl_be_block_softc *softc,
272 			   struct ctl_lun_req *req);
273 static int ctl_be_block_modify(struct ctl_be_block_softc *softc,
274 			   struct ctl_lun_req *req);
275 static void ctl_be_block_lun_shutdown(struct ctl_be_lun *cbe_lun);
276 static int ctl_be_block_config_write(union ctl_io *io);
277 static int ctl_be_block_config_read(union ctl_io *io);
278 static int ctl_be_block_lun_info(struct ctl_be_lun *cbe_lun, struct sbuf *sb);
279 static uint64_t ctl_be_block_lun_attr(struct ctl_be_lun *cbe_lun, const char *attrname);
280 static int ctl_be_block_init(void);
281 static int ctl_be_block_shutdown(void);
282 
283 static struct ctl_backend_driver ctl_be_block_driver =
284 {
285 	.name = "block",
286 	.flags = CTL_BE_FLAG_HAS_CONFIG,
287 	.init = ctl_be_block_init,
288 	.shutdown = ctl_be_block_shutdown,
289 	.data_submit = ctl_be_block_submit,
290 	.data_move_done = ctl_be_block_move_done,
291 	.config_read = ctl_be_block_config_read,
292 	.config_write = ctl_be_block_config_write,
293 	.ioctl = ctl_be_block_ioctl,
294 	.lun_info = ctl_be_block_lun_info,
295 	.lun_attr = ctl_be_block_lun_attr
296 };
297 
298 MALLOC_DEFINE(M_CTLBLK, "ctlblock", "Memory used for CTL block backend");
299 CTL_BACKEND_DECLARE(cbb, ctl_be_block_driver);
300 
301 static struct ctl_be_block_io *
302 ctl_alloc_beio(struct ctl_be_block_softc *softc)
303 {
304 	struct ctl_be_block_io *beio;
305 
306 	beio = uma_zalloc(softc->beio_zone, M_WAITOK | M_ZERO);
307 	beio->softc = softc;
308 	return (beio);
309 }
310 
311 static void
312 ctl_free_beio(struct ctl_be_block_io *beio)
313 {
314 	struct ctl_be_block_softc *softc = beio->softc;
315 	int i;
316 
317 	for (i = 0; i < beio->num_segs; i++) {
318 		uma_zfree(softc->buf_zone, beio->sg_segs[i].addr);
319 
320 		/* For compare we had two equal S/G lists. */
321 		if (beio->two_sglists) {
322 			uma_zfree(softc->buf_zone,
323 			    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr);
324 		}
325 	}
326 
327 	uma_zfree(softc->beio_zone, beio);
328 }
329 
330 static void
331 ctl_complete_beio(struct ctl_be_block_io *beio)
332 {
333 	union ctl_io *io = beio->io;
334 
335 	if (beio->beio_cont != NULL) {
336 		beio->beio_cont(beio);
337 	} else {
338 		ctl_free_beio(beio);
339 		ctl_data_submit_done(io);
340 	}
341 }
342 
343 static size_t
344 cmp(uint8_t *a, uint8_t *b, size_t size)
345 {
346 	size_t i;
347 
348 	for (i = 0; i < size; i++) {
349 		if (a[i] != b[i])
350 			break;
351 	}
352 	return (i);
353 }
354 
355 static void
356 ctl_be_block_compare(union ctl_io *io)
357 {
358 	struct ctl_be_block_io *beio;
359 	uint64_t off, res;
360 	int i;
361 	uint8_t info[8];
362 
363 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
364 	off = 0;
365 	for (i = 0; i < beio->num_segs; i++) {
366 		res = cmp(beio->sg_segs[i].addr,
367 		    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr,
368 		    beio->sg_segs[i].len);
369 		off += res;
370 		if (res < beio->sg_segs[i].len)
371 			break;
372 	}
373 	if (i < beio->num_segs) {
374 		scsi_u64to8b(off, info);
375 		ctl_set_sense(&io->scsiio, /*current_error*/ 1,
376 		    /*sense_key*/ SSD_KEY_MISCOMPARE,
377 		    /*asc*/ 0x1D, /*ascq*/ 0x00,
378 		    /*type*/ SSD_ELEM_INFO,
379 		    /*size*/ sizeof(info), /*data*/ &info,
380 		    /*type*/ SSD_ELEM_NONE);
381 	} else
382 		ctl_set_success(&io->scsiio);
383 }
384 
385 static int
386 ctl_be_block_move_done(union ctl_io *io)
387 {
388 	struct ctl_be_block_io *beio;
389 	struct ctl_be_block_lun *be_lun;
390 	struct ctl_lba_len_flags *lbalen;
391 #ifdef CTL_TIME_IO
392 	struct bintime cur_bt;
393 #endif
394 
395 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
396 	be_lun = beio->lun;
397 
398 	DPRINTF("entered\n");
399 
400 #ifdef CTL_TIME_IO
401 	getbinuptime(&cur_bt);
402 	bintime_sub(&cur_bt, &io->io_hdr.dma_start_bt);
403 	bintime_add(&io->io_hdr.dma_bt, &cur_bt);
404 #endif
405 	io->io_hdr.num_dmas++;
406 	io->scsiio.kern_rel_offset += io->scsiio.kern_data_len;
407 
408 	/*
409 	 * We set status at this point for read commands, and write
410 	 * commands with errors.
411 	 */
412 	if (io->io_hdr.flags & CTL_FLAG_ABORT) {
413 		;
414 	} else if ((io->io_hdr.port_status != 0) &&
415 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE ||
416 	     (io->io_hdr.status & CTL_STATUS_MASK) == CTL_SUCCESS)) {
417 		ctl_set_internal_failure(&io->scsiio, /*sks_valid*/ 1,
418 		    /*retry_count*/ io->io_hdr.port_status);
419 	} else if (io->scsiio.kern_data_resid != 0 &&
420 	    (io->io_hdr.flags & CTL_FLAG_DATA_MASK) == CTL_FLAG_DATA_OUT &&
421 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE ||
422 	     (io->io_hdr.status & CTL_STATUS_MASK) == CTL_SUCCESS)) {
423 		ctl_set_invalid_field_ciu(&io->scsiio);
424 	} else if ((io->io_hdr.port_status == 0) &&
425 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
426 		lbalen = ARGS(beio->io);
427 		if (lbalen->flags & CTL_LLF_READ) {
428 			ctl_set_success(&io->scsiio);
429 		} else if (lbalen->flags & CTL_LLF_COMPARE) {
430 			/* We have two data blocks ready for comparison. */
431 			ctl_be_block_compare(io);
432 		}
433 	}
434 
435 	/*
436 	 * If this is a read, or a write with errors, it is done.
437 	 */
438 	if ((beio->bio_cmd == BIO_READ)
439 	 || ((io->io_hdr.flags & CTL_FLAG_ABORT) != 0)
440 	 || ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)) {
441 		ctl_complete_beio(beio);
442 		return (0);
443 	}
444 
445 	/*
446 	 * At this point, we have a write and the DMA completed
447 	 * successfully.  We now have to queue it to the task queue to
448 	 * execute the backend I/O.  That is because we do blocking
449 	 * memory allocations, and in the file backing case, blocking I/O.
450 	 * This move done routine is generally called in the SIM's
451 	 * interrupt context, and therefore we cannot block.
452 	 */
453 	mtx_lock(&be_lun->queue_lock);
454 	STAILQ_INSERT_TAIL(&be_lun->datamove_queue, &io->io_hdr, links);
455 	mtx_unlock(&be_lun->queue_lock);
456 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
457 
458 	return (0);
459 }
460 
461 static void
462 ctl_be_block_biodone(struct bio *bio)
463 {
464 	struct ctl_be_block_io *beio;
465 	struct ctl_be_block_lun *be_lun;
466 	union ctl_io *io;
467 	int error;
468 
469 	beio = bio->bio_caller1;
470 	be_lun = beio->lun;
471 	io = beio->io;
472 
473 	DPRINTF("entered\n");
474 
475 	error = bio->bio_error;
476 	mtx_lock(&be_lun->io_lock);
477 	if (error != 0 &&
478 	    (beio->first_error == 0 ||
479 	     bio->bio_offset < beio->first_error_offset)) {
480 		beio->first_error = error;
481 		beio->first_error_offset = bio->bio_offset;
482 	}
483 
484 	beio->num_bios_done++;
485 
486 	/*
487 	 * XXX KDM will this cause WITNESS to complain?  Holding a lock
488 	 * during the free might cause it to complain.
489 	 */
490 	g_destroy_bio(bio);
491 
492 	/*
493 	 * If the send complete bit isn't set, or we aren't the last I/O to
494 	 * complete, then we're done.
495 	 */
496 	if ((beio->send_complete == 0)
497 	 || (beio->num_bios_done < beio->num_bios_sent)) {
498 		mtx_unlock(&be_lun->io_lock);
499 		return;
500 	}
501 
502 	/*
503 	 * At this point, we've verified that we are the last I/O to
504 	 * complete, so it's safe to drop the lock.
505 	 */
506 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
507 	    beio->ds_tag_type, beio->ds_trans_type,
508 	    /*now*/ NULL, /*then*/&beio->ds_t0);
509 	mtx_unlock(&be_lun->io_lock);
510 
511 	/*
512 	 * If there are any errors from the backing device, we fail the
513 	 * entire I/O with a medium error.
514 	 */
515 	error = beio->first_error;
516 	if (error != 0) {
517 		if (error == EOPNOTSUPP) {
518 			ctl_set_invalid_opcode(&io->scsiio);
519 		} else if (error == ENOSPC || error == EDQUOT) {
520 			ctl_set_space_alloc_fail(&io->scsiio);
521 		} else if (error == EROFS || error == EACCES) {
522 			ctl_set_hw_write_protected(&io->scsiio);
523 		} else if (beio->bio_cmd == BIO_FLUSH) {
524 			/* XXX KDM is there is a better error here? */
525 			ctl_set_internal_failure(&io->scsiio,
526 						 /*sks_valid*/ 1,
527 						 /*retry_count*/ 0xbad2);
528 		} else {
529 			ctl_set_medium_error(&io->scsiio,
530 			    beio->bio_cmd == BIO_READ);
531 		}
532 		ctl_complete_beio(beio);
533 		return;
534 	}
535 
536 	/*
537 	 * If this is a write, a flush, a delete or verify, we're all done.
538 	 * If this is a read, we can now send the data to the user.
539 	 */
540 	if ((beio->bio_cmd == BIO_WRITE)
541 	 || (beio->bio_cmd == BIO_FLUSH)
542 	 || (beio->bio_cmd == BIO_DELETE)
543 	 || (ARGS(io)->flags & CTL_LLF_VERIFY)) {
544 		ctl_set_success(&io->scsiio);
545 		ctl_complete_beio(beio);
546 	} else {
547 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
548 		    beio->beio_cont == NULL) {
549 			ctl_set_success(&io->scsiio);
550 			ctl_serseq_done(io);
551 		}
552 #ifdef CTL_TIME_IO
553 		getbinuptime(&io->io_hdr.dma_start_bt);
554 #endif
555 		ctl_datamove(io);
556 	}
557 }
558 
559 static void
560 ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
561 			struct ctl_be_block_io *beio)
562 {
563 	union ctl_io *io = beio->io;
564 	struct mount *mountpoint;
565 	int error, lock_flags;
566 
567 	DPRINTF("entered\n");
568 
569 	binuptime(&beio->ds_t0);
570 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
571 
572 	(void) vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
573 
574 	if (MNT_SHARED_WRITES(mountpoint) ||
575 	    ((mountpoint == NULL) && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
576 		lock_flags = LK_SHARED;
577 	else
578 		lock_flags = LK_EXCLUSIVE;
579 	vn_lock(be_lun->vn, lock_flags | LK_RETRY);
580 	error = VOP_FSYNC(be_lun->vn, beio->io_arg ? MNT_NOWAIT : MNT_WAIT,
581 	    curthread);
582 	VOP_UNLOCK(be_lun->vn);
583 
584 	vn_finished_write(mountpoint);
585 
586 	mtx_lock(&be_lun->io_lock);
587 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
588 	    beio->ds_tag_type, beio->ds_trans_type,
589 	    /*now*/ NULL, /*then*/&beio->ds_t0);
590 	mtx_unlock(&be_lun->io_lock);
591 
592 	if (error == 0)
593 		ctl_set_success(&io->scsiio);
594 	else {
595 		/* XXX KDM is there is a better error here? */
596 		ctl_set_internal_failure(&io->scsiio,
597 					 /*sks_valid*/ 1,
598 					 /*retry_count*/ 0xbad1);
599 	}
600 
601 	ctl_complete_beio(beio);
602 }
603 
604 SDT_PROBE_DEFINE1(cbb, , read, file_start, "uint64_t");
605 SDT_PROBE_DEFINE1(cbb, , write, file_start, "uint64_t");
606 SDT_PROBE_DEFINE1(cbb, , read, file_done,"uint64_t");
607 SDT_PROBE_DEFINE1(cbb, , write, file_done, "uint64_t");
608 
609 static void
610 ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
611 			   struct ctl_be_block_io *beio)
612 {
613 	struct ctl_be_block_filedata *file_data;
614 	union ctl_io *io;
615 	struct uio xuio;
616 	struct iovec *xiovec;
617 	size_t s;
618 	int error, flags, i;
619 
620 	DPRINTF("entered\n");
621 
622 	file_data = &be_lun->backend.file;
623 	io = beio->io;
624 	flags = 0;
625 	if (ARGS(io)->flags & CTL_LLF_DPO)
626 		flags |= IO_DIRECT;
627 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
628 		flags |= IO_SYNC;
629 
630 	bzero(&xuio, sizeof(xuio));
631 	if (beio->bio_cmd == BIO_READ) {
632 		SDT_PROBE0(cbb, , read, file_start);
633 		xuio.uio_rw = UIO_READ;
634 	} else {
635 		SDT_PROBE0(cbb, , write, file_start);
636 		xuio.uio_rw = UIO_WRITE;
637 	}
638 	xuio.uio_offset = beio->io_offset;
639 	xuio.uio_resid = beio->io_len;
640 	xuio.uio_segflg = UIO_SYSSPACE;
641 	xuio.uio_iov = beio->xiovecs;
642 	xuio.uio_iovcnt = beio->num_segs;
643 	xuio.uio_td = curthread;
644 
645 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
646 		xiovec->iov_base = beio->sg_segs[i].addr;
647 		xiovec->iov_len = beio->sg_segs[i].len;
648 	}
649 
650 	binuptime(&beio->ds_t0);
651 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
652 
653 	if (beio->bio_cmd == BIO_READ) {
654 		vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
655 
656 		/*
657 		 * UFS pays attention to IO_DIRECT for reads.  If the
658 		 * DIRECTIO option is configured into the kernel, it calls
659 		 * ffs_rawread().  But that only works for single-segment
660 		 * uios with user space addresses.  In our case, with a
661 		 * kernel uio, it still reads into the buffer cache, but it
662 		 * will just try to release the buffer from the cache later
663 		 * on in ffs_read().
664 		 *
665 		 * ZFS does not pay attention to IO_DIRECT for reads.
666 		 *
667 		 * UFS does not pay attention to IO_SYNC for reads.
668 		 *
669 		 * ZFS pays attention to IO_SYNC (which translates into the
670 		 * Solaris define FRSYNC for zfs_read()) for reads.  It
671 		 * attempts to sync the file before reading.
672 		 */
673 		error = VOP_READ(be_lun->vn, &xuio, flags, file_data->cred);
674 
675 		VOP_UNLOCK(be_lun->vn);
676 		SDT_PROBE0(cbb, , read, file_done);
677 		if (error == 0 && xuio.uio_resid > 0) {
678 			/*
679 			 * If we red less then requested (EOF), then
680 			 * we should clean the rest of the buffer.
681 			 */
682 			s = beio->io_len - xuio.uio_resid;
683 			for (i = 0; i < beio->num_segs; i++) {
684 				if (s >= beio->sg_segs[i].len) {
685 					s -= beio->sg_segs[i].len;
686 					continue;
687 				}
688 				bzero((uint8_t *)beio->sg_segs[i].addr + s,
689 				    beio->sg_segs[i].len - s);
690 				s = 0;
691 			}
692 		}
693 	} else {
694 		struct mount *mountpoint;
695 		int lock_flags;
696 
697 		(void)vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
698 
699 		if (MNT_SHARED_WRITES(mountpoint) || ((mountpoint == NULL)
700 		  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
701 			lock_flags = LK_SHARED;
702 		else
703 			lock_flags = LK_EXCLUSIVE;
704 		vn_lock(be_lun->vn, lock_flags | LK_RETRY);
705 
706 		/*
707 		 * UFS pays attention to IO_DIRECT for writes.  The write
708 		 * is done asynchronously.  (Normally the write would just
709 		 * get put into cache.
710 		 *
711 		 * UFS pays attention to IO_SYNC for writes.  It will
712 		 * attempt to write the buffer out synchronously if that
713 		 * flag is set.
714 		 *
715 		 * ZFS does not pay attention to IO_DIRECT for writes.
716 		 *
717 		 * ZFS pays attention to IO_SYNC (a.k.a. FSYNC or FRSYNC)
718 		 * for writes.  It will flush the transaction from the
719 		 * cache before returning.
720 		 */
721 		error = VOP_WRITE(be_lun->vn, &xuio, flags, file_data->cred);
722 		VOP_UNLOCK(be_lun->vn);
723 
724 		vn_finished_write(mountpoint);
725 		SDT_PROBE0(cbb, , write, file_done);
726         }
727 
728 	mtx_lock(&be_lun->io_lock);
729 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
730 	    beio->ds_tag_type, beio->ds_trans_type,
731 	    /*now*/ NULL, /*then*/&beio->ds_t0);
732 	mtx_unlock(&be_lun->io_lock);
733 
734 	/*
735 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
736 	 * return the I/O to the user.
737 	 */
738 	if (error != 0) {
739 		if (error == ENOSPC || error == EDQUOT) {
740 			ctl_set_space_alloc_fail(&io->scsiio);
741 		} else if (error == EROFS || error == EACCES) {
742 			ctl_set_hw_write_protected(&io->scsiio);
743 		} else {
744 			ctl_set_medium_error(&io->scsiio,
745 			    beio->bio_cmd == BIO_READ);
746 		}
747 		ctl_complete_beio(beio);
748 		return;
749 	}
750 
751 	/*
752 	 * If this is a write or a verify, we're all done.
753 	 * If this is a read, we can now send the data to the user.
754 	 */
755 	if ((beio->bio_cmd == BIO_WRITE) ||
756 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
757 		ctl_set_success(&io->scsiio);
758 		ctl_complete_beio(beio);
759 	} else {
760 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
761 		    beio->beio_cont == NULL) {
762 			ctl_set_success(&io->scsiio);
763 			ctl_serseq_done(io);
764 		}
765 #ifdef CTL_TIME_IO
766 		getbinuptime(&io->io_hdr.dma_start_bt);
767 #endif
768 		ctl_datamove(io);
769 	}
770 }
771 
772 static void
773 ctl_be_block_gls_file(struct ctl_be_block_lun *be_lun,
774 			struct ctl_be_block_io *beio)
775 {
776 	union ctl_io *io = beio->io;
777 	struct ctl_lba_len_flags *lbalen = ARGS(io);
778 	struct scsi_get_lba_status_data *data;
779 	off_t roff, off;
780 	int error, status;
781 
782 	DPRINTF("entered\n");
783 
784 	off = roff = ((off_t)lbalen->lba) * be_lun->cbe_lun.blocksize;
785 	vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
786 	error = VOP_IOCTL(be_lun->vn, FIOSEEKHOLE, &off,
787 	    0, curthread->td_ucred, curthread);
788 	if (error == 0 && off > roff)
789 		status = 0;	/* mapped up to off */
790 	else {
791 		error = VOP_IOCTL(be_lun->vn, FIOSEEKDATA, &off,
792 		    0, curthread->td_ucred, curthread);
793 		if (error == 0 && off > roff)
794 			status = 1;	/* deallocated up to off */
795 		else {
796 			status = 0;	/* unknown up to the end */
797 			off = be_lun->size_bytes;
798 		}
799 	}
800 	VOP_UNLOCK(be_lun->vn);
801 
802 	data = (struct scsi_get_lba_status_data *)io->scsiio.kern_data_ptr;
803 	scsi_u64to8b(lbalen->lba, data->descr[0].addr);
804 	scsi_ulto4b(MIN(UINT32_MAX, off / be_lun->cbe_lun.blocksize -
805 	    lbalen->lba), data->descr[0].length);
806 	data->descr[0].status = status;
807 
808 	ctl_complete_beio(beio);
809 }
810 
811 static uint64_t
812 ctl_be_block_getattr_file(struct ctl_be_block_lun *be_lun, const char *attrname)
813 {
814 	struct vattr		vattr;
815 	struct statfs		statfs;
816 	uint64_t		val;
817 	int			error;
818 
819 	val = UINT64_MAX;
820 	if (be_lun->vn == NULL)
821 		return (val);
822 	vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
823 	if (strcmp(attrname, "blocksused") == 0) {
824 		error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
825 		if (error == 0)
826 			val = vattr.va_bytes / be_lun->cbe_lun.blocksize;
827 	}
828 	if (strcmp(attrname, "blocksavail") == 0 &&
829 	    !VN_IS_DOOMED(be_lun->vn)) {
830 		error = VFS_STATFS(be_lun->vn->v_mount, &statfs);
831 		if (error == 0)
832 			val = statfs.f_bavail * statfs.f_bsize /
833 			    be_lun->cbe_lun.blocksize;
834 	}
835 	VOP_UNLOCK(be_lun->vn);
836 	return (val);
837 }
838 
839 static void
840 ctl_be_block_dispatch_zvol(struct ctl_be_block_lun *be_lun,
841 			   struct ctl_be_block_io *beio)
842 {
843 	union ctl_io *io;
844 	struct cdevsw *csw;
845 	struct cdev *dev;
846 	struct uio xuio;
847 	struct iovec *xiovec;
848 	int error, flags, i, ref;
849 
850 	DPRINTF("entered\n");
851 
852 	io = beio->io;
853 	flags = 0;
854 	if (ARGS(io)->flags & CTL_LLF_DPO)
855 		flags |= IO_DIRECT;
856 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
857 		flags |= IO_SYNC;
858 
859 	bzero(&xuio, sizeof(xuio));
860 	if (beio->bio_cmd == BIO_READ) {
861 		SDT_PROBE0(cbb, , read, file_start);
862 		xuio.uio_rw = UIO_READ;
863 	} else {
864 		SDT_PROBE0(cbb, , write, file_start);
865 		xuio.uio_rw = UIO_WRITE;
866 	}
867 	xuio.uio_offset = beio->io_offset;
868 	xuio.uio_resid = beio->io_len;
869 	xuio.uio_segflg = UIO_SYSSPACE;
870 	xuio.uio_iov = beio->xiovecs;
871 	xuio.uio_iovcnt = beio->num_segs;
872 	xuio.uio_td = curthread;
873 
874 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
875 		xiovec->iov_base = beio->sg_segs[i].addr;
876 		xiovec->iov_len = beio->sg_segs[i].len;
877 	}
878 
879 	binuptime(&beio->ds_t0);
880 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
881 
882 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
883 	if (csw) {
884 		if (beio->bio_cmd == BIO_READ)
885 			error = csw->d_read(dev, &xuio, flags);
886 		else
887 			error = csw->d_write(dev, &xuio, flags);
888 		dev_relthread(dev, ref);
889 	} else
890 		error = ENXIO;
891 
892 	if (beio->bio_cmd == BIO_READ)
893 		SDT_PROBE0(cbb, , read, file_done);
894 	else
895 		SDT_PROBE0(cbb, , write, file_done);
896 
897 	mtx_lock(&be_lun->io_lock);
898 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
899 	    beio->ds_tag_type, beio->ds_trans_type,
900 	    /*now*/ NULL, /*then*/&beio->ds_t0);
901 	mtx_unlock(&be_lun->io_lock);
902 
903 	/*
904 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
905 	 * return the I/O to the user.
906 	 */
907 	if (error != 0) {
908 		if (error == ENOSPC || error == EDQUOT) {
909 			ctl_set_space_alloc_fail(&io->scsiio);
910 		} else if (error == EROFS || error == EACCES) {
911 			ctl_set_hw_write_protected(&io->scsiio);
912 		} else {
913 			ctl_set_medium_error(&io->scsiio,
914 			    beio->bio_cmd == BIO_READ);
915 		}
916 		ctl_complete_beio(beio);
917 		return;
918 	}
919 
920 	/*
921 	 * If this is a write or a verify, we're all done.
922 	 * If this is a read, we can now send the data to the user.
923 	 */
924 	if ((beio->bio_cmd == BIO_WRITE) ||
925 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
926 		ctl_set_success(&io->scsiio);
927 		ctl_complete_beio(beio);
928 	} else {
929 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
930 		    beio->beio_cont == NULL) {
931 			ctl_set_success(&io->scsiio);
932 			ctl_serseq_done(io);
933 		}
934 #ifdef CTL_TIME_IO
935 		getbinuptime(&io->io_hdr.dma_start_bt);
936 #endif
937 		ctl_datamove(io);
938 	}
939 }
940 
941 static void
942 ctl_be_block_gls_zvol(struct ctl_be_block_lun *be_lun,
943 			struct ctl_be_block_io *beio)
944 {
945 	union ctl_io *io = beio->io;
946 	struct cdevsw *csw;
947 	struct cdev *dev;
948 	struct ctl_lba_len_flags *lbalen = ARGS(io);
949 	struct scsi_get_lba_status_data *data;
950 	off_t roff, off;
951 	int error, ref, status;
952 
953 	DPRINTF("entered\n");
954 
955 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
956 	if (csw == NULL) {
957 		status = 0;	/* unknown up to the end */
958 		off = be_lun->size_bytes;
959 		goto done;
960 	}
961 	off = roff = ((off_t)lbalen->lba) * be_lun->cbe_lun.blocksize;
962 	error = csw->d_ioctl(dev, FIOSEEKHOLE, (caddr_t)&off, FREAD,
963 	    curthread);
964 	if (error == 0 && off > roff)
965 		status = 0;	/* mapped up to off */
966 	else {
967 		error = csw->d_ioctl(dev, FIOSEEKDATA, (caddr_t)&off, FREAD,
968 		    curthread);
969 		if (error == 0 && off > roff)
970 			status = 1;	/* deallocated up to off */
971 		else {
972 			status = 0;	/* unknown up to the end */
973 			off = be_lun->size_bytes;
974 		}
975 	}
976 	dev_relthread(dev, ref);
977 
978 done:
979 	data = (struct scsi_get_lba_status_data *)io->scsiio.kern_data_ptr;
980 	scsi_u64to8b(lbalen->lba, data->descr[0].addr);
981 	scsi_ulto4b(MIN(UINT32_MAX, off / be_lun->cbe_lun.blocksize -
982 	    lbalen->lba), data->descr[0].length);
983 	data->descr[0].status = status;
984 
985 	ctl_complete_beio(beio);
986 }
987 
988 static void
989 ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
990 		       struct ctl_be_block_io *beio)
991 {
992 	struct bio *bio;
993 	struct cdevsw *csw;
994 	struct cdev *dev;
995 	int ref;
996 
997 	DPRINTF("entered\n");
998 
999 	/* This can't fail, it's a blocking allocation. */
1000 	bio = g_alloc_bio();
1001 
1002 	bio->bio_cmd	    = BIO_FLUSH;
1003 	bio->bio_offset	    = 0;
1004 	bio->bio_data	    = 0;
1005 	bio->bio_done	    = ctl_be_block_biodone;
1006 	bio->bio_caller1    = beio;
1007 	bio->bio_pblkno	    = 0;
1008 
1009 	/*
1010 	 * We don't need to acquire the LUN lock here, because we are only
1011 	 * sending one bio, and so there is no other context to synchronize
1012 	 * with.
1013 	 */
1014 	beio->num_bios_sent = 1;
1015 	beio->send_complete = 1;
1016 
1017 	binuptime(&beio->ds_t0);
1018 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1019 
1020 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1021 	if (csw) {
1022 		bio->bio_dev = dev;
1023 		csw->d_strategy(bio);
1024 		dev_relthread(dev, ref);
1025 	} else {
1026 		bio->bio_error = ENXIO;
1027 		ctl_be_block_biodone(bio);
1028 	}
1029 }
1030 
1031 static void
1032 ctl_be_block_unmap_dev_range(struct ctl_be_block_lun *be_lun,
1033 		       struct ctl_be_block_io *beio,
1034 		       uint64_t off, uint64_t len, int last)
1035 {
1036 	struct bio *bio;
1037 	uint64_t maxlen;
1038 	struct cdevsw *csw;
1039 	struct cdev *dev;
1040 	int ref;
1041 
1042 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1043 	maxlen = LONG_MAX - (LONG_MAX % be_lun->cbe_lun.blocksize);
1044 	while (len > 0) {
1045 		bio = g_alloc_bio();
1046 		bio->bio_cmd	    = BIO_DELETE;
1047 		bio->bio_dev	    = dev;
1048 		bio->bio_offset	    = off;
1049 		bio->bio_length	    = MIN(len, maxlen);
1050 		bio->bio_data	    = 0;
1051 		bio->bio_done	    = ctl_be_block_biodone;
1052 		bio->bio_caller1    = beio;
1053 		bio->bio_pblkno     = off / be_lun->cbe_lun.blocksize;
1054 
1055 		off += bio->bio_length;
1056 		len -= bio->bio_length;
1057 
1058 		mtx_lock(&be_lun->io_lock);
1059 		beio->num_bios_sent++;
1060 		if (last && len == 0)
1061 			beio->send_complete = 1;
1062 		mtx_unlock(&be_lun->io_lock);
1063 
1064 		if (csw) {
1065 			csw->d_strategy(bio);
1066 		} else {
1067 			bio->bio_error = ENXIO;
1068 			ctl_be_block_biodone(bio);
1069 		}
1070 	}
1071 	if (csw)
1072 		dev_relthread(dev, ref);
1073 }
1074 
1075 static void
1076 ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
1077 		       struct ctl_be_block_io *beio)
1078 {
1079 	union ctl_io *io;
1080 	struct ctl_ptr_len_flags *ptrlen;
1081 	struct scsi_unmap_desc *buf, *end;
1082 	uint64_t len;
1083 
1084 	io = beio->io;
1085 
1086 	DPRINTF("entered\n");
1087 
1088 	binuptime(&beio->ds_t0);
1089 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1090 
1091 	if (beio->io_offset == -1) {
1092 		beio->io_len = 0;
1093 		ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1094 		buf = (struct scsi_unmap_desc *)ptrlen->ptr;
1095 		end = buf + ptrlen->len / sizeof(*buf);
1096 		for (; buf < end; buf++) {
1097 			len = (uint64_t)scsi_4btoul(buf->length) *
1098 			    be_lun->cbe_lun.blocksize;
1099 			beio->io_len += len;
1100 			ctl_be_block_unmap_dev_range(be_lun, beio,
1101 			    scsi_8btou64(buf->lba) * be_lun->cbe_lun.blocksize,
1102 			    len, (end - buf < 2) ? TRUE : FALSE);
1103 		}
1104 	} else
1105 		ctl_be_block_unmap_dev_range(be_lun, beio,
1106 		    beio->io_offset, beio->io_len, TRUE);
1107 }
1108 
1109 static void
1110 ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
1111 			  struct ctl_be_block_io *beio)
1112 {
1113 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
1114 	struct bio *bio;
1115 	struct cdevsw *csw;
1116 	struct cdev *dev;
1117 	off_t cur_offset;
1118 	int i, max_iosize, ref;
1119 
1120 	DPRINTF("entered\n");
1121 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1122 
1123 	/*
1124 	 * We have to limit our I/O size to the maximum supported by the
1125 	 * backend device.  Hopefully it is MAXPHYS.  If the driver doesn't
1126 	 * set it properly, use DFLTPHYS.
1127 	 */
1128 	if (csw) {
1129 		max_iosize = dev->si_iosize_max;
1130 		if (max_iosize < PAGE_SIZE)
1131 			max_iosize = DFLTPHYS;
1132 	} else
1133 		max_iosize = DFLTPHYS;
1134 
1135 	cur_offset = beio->io_offset;
1136 	for (i = 0; i < beio->num_segs; i++) {
1137 		size_t cur_size;
1138 		uint8_t *cur_ptr;
1139 
1140 		cur_size = beio->sg_segs[i].len;
1141 		cur_ptr = beio->sg_segs[i].addr;
1142 
1143 		while (cur_size > 0) {
1144 			/* This can't fail, it's a blocking allocation. */
1145 			bio = g_alloc_bio();
1146 
1147 			KASSERT(bio != NULL, ("g_alloc_bio() failed!\n"));
1148 
1149 			bio->bio_cmd = beio->bio_cmd;
1150 			bio->bio_dev = dev;
1151 			bio->bio_caller1 = beio;
1152 			bio->bio_length = min(cur_size, max_iosize);
1153 			bio->bio_offset = cur_offset;
1154 			bio->bio_data = cur_ptr;
1155 			bio->bio_done = ctl_be_block_biodone;
1156 			bio->bio_pblkno = cur_offset / be_lun->cbe_lun.blocksize;
1157 
1158 			cur_offset += bio->bio_length;
1159 			cur_ptr += bio->bio_length;
1160 			cur_size -= bio->bio_length;
1161 
1162 			TAILQ_INSERT_TAIL(&queue, bio, bio_queue);
1163 			beio->num_bios_sent++;
1164 		}
1165 	}
1166 	beio->send_complete = 1;
1167 	binuptime(&beio->ds_t0);
1168 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1169 
1170 	/*
1171 	 * Fire off all allocated requests!
1172 	 */
1173 	while ((bio = TAILQ_FIRST(&queue)) != NULL) {
1174 		TAILQ_REMOVE(&queue, bio, bio_queue);
1175 		if (csw)
1176 			csw->d_strategy(bio);
1177 		else {
1178 			bio->bio_error = ENXIO;
1179 			ctl_be_block_biodone(bio);
1180 		}
1181 	}
1182 	if (csw)
1183 		dev_relthread(dev, ref);
1184 }
1185 
1186 static uint64_t
1187 ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun, const char *attrname)
1188 {
1189 	struct diocgattr_arg	arg;
1190 	struct cdevsw *csw;
1191 	struct cdev *dev;
1192 	int error, ref;
1193 
1194 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1195 	if (csw == NULL)
1196 		return (UINT64_MAX);
1197 	strlcpy(arg.name, attrname, sizeof(arg.name));
1198 	arg.len = sizeof(arg.value.off);
1199 	if (csw->d_ioctl) {
1200 		error = csw->d_ioctl(dev, DIOCGATTR, (caddr_t)&arg, FREAD,
1201 		    curthread);
1202 	} else
1203 		error = ENODEV;
1204 	dev_relthread(dev, ref);
1205 	if (error != 0)
1206 		return (UINT64_MAX);
1207 	return (arg.value.off);
1208 }
1209 
1210 static void
1211 ctl_be_block_cw_dispatch_sync(struct ctl_be_block_lun *be_lun,
1212 			    union ctl_io *io)
1213 {
1214 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1215 	struct ctl_be_block_io *beio;
1216 	struct ctl_lba_len_flags *lbalen;
1217 
1218 	DPRINTF("entered\n");
1219 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1220 	lbalen = (struct ctl_lba_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1221 
1222 	beio->io_len = lbalen->len * cbe_lun->blocksize;
1223 	beio->io_offset = lbalen->lba * cbe_lun->blocksize;
1224 	beio->io_arg = (lbalen->flags & SSC_IMMED) != 0;
1225 	beio->bio_cmd = BIO_FLUSH;
1226 	beio->ds_trans_type = DEVSTAT_NO_DATA;
1227 	DPRINTF("SYNC\n");
1228 	be_lun->lun_flush(be_lun, beio);
1229 }
1230 
1231 static void
1232 ctl_be_block_cw_done_ws(struct ctl_be_block_io *beio)
1233 {
1234 	union ctl_io *io;
1235 
1236 	io = beio->io;
1237 	ctl_free_beio(beio);
1238 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1239 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1240 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1241 		ctl_config_write_done(io);
1242 		return;
1243 	}
1244 
1245 	ctl_be_block_config_write(io);
1246 }
1247 
1248 static void
1249 ctl_be_block_cw_dispatch_ws(struct ctl_be_block_lun *be_lun,
1250 			    union ctl_io *io)
1251 {
1252 	struct ctl_be_block_softc *softc = be_lun->softc;
1253 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1254 	struct ctl_be_block_io *beio;
1255 	struct ctl_lba_len_flags *lbalen;
1256 	uint64_t len_left, lba;
1257 	uint32_t pb, pbo, adj;
1258 	int i, seglen;
1259 	uint8_t *buf, *end;
1260 
1261 	DPRINTF("entered\n");
1262 
1263 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1264 	lbalen = ARGS(beio->io);
1265 
1266 	if (lbalen->flags & ~(SWS_LBDATA | SWS_UNMAP | SWS_ANCHOR | SWS_NDOB) ||
1267 	    (lbalen->flags & (SWS_UNMAP | SWS_ANCHOR) && be_lun->unmap == NULL)) {
1268 		ctl_free_beio(beio);
1269 		ctl_set_invalid_field(&io->scsiio,
1270 				      /*sks_valid*/ 1,
1271 				      /*command*/ 1,
1272 				      /*field*/ 1,
1273 				      /*bit_valid*/ 0,
1274 				      /*bit*/ 0);
1275 		ctl_config_write_done(io);
1276 		return;
1277 	}
1278 
1279 	if (lbalen->flags & (SWS_UNMAP | SWS_ANCHOR)) {
1280 		beio->io_offset = lbalen->lba * cbe_lun->blocksize;
1281 		beio->io_len = (uint64_t)lbalen->len * cbe_lun->blocksize;
1282 		beio->bio_cmd = BIO_DELETE;
1283 		beio->ds_trans_type = DEVSTAT_FREE;
1284 
1285 		be_lun->unmap(be_lun, beio);
1286 		return;
1287 	}
1288 
1289 	beio->bio_cmd = BIO_WRITE;
1290 	beio->ds_trans_type = DEVSTAT_WRITE;
1291 
1292 	DPRINTF("WRITE SAME at LBA %jx len %u\n",
1293 	       (uintmax_t)lbalen->lba, lbalen->len);
1294 
1295 	pb = cbe_lun->blocksize << be_lun->cbe_lun.pblockexp;
1296 	if (be_lun->cbe_lun.pblockoff > 0)
1297 		pbo = pb - cbe_lun->blocksize * be_lun->cbe_lun.pblockoff;
1298 	else
1299 		pbo = 0;
1300 	len_left = (uint64_t)lbalen->len * cbe_lun->blocksize;
1301 	for (i = 0, lba = 0; i < CTLBLK_MAX_SEGS && len_left > 0; i++) {
1302 
1303 		/*
1304 		 * Setup the S/G entry for this chunk.
1305 		 */
1306 		seglen = MIN(CTLBLK_MAX_SEG, len_left);
1307 		if (pb > cbe_lun->blocksize) {
1308 			adj = ((lbalen->lba + lba) * cbe_lun->blocksize +
1309 			    seglen - pbo) % pb;
1310 			if (seglen > adj)
1311 				seglen -= adj;
1312 			else
1313 				seglen -= seglen % cbe_lun->blocksize;
1314 		} else
1315 			seglen -= seglen % cbe_lun->blocksize;
1316 		beio->sg_segs[i].len = seglen;
1317 		beio->sg_segs[i].addr = uma_zalloc(softc->buf_zone, M_WAITOK);
1318 
1319 		DPRINTF("segment %d addr %p len %zd\n", i,
1320 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1321 
1322 		beio->num_segs++;
1323 		len_left -= seglen;
1324 
1325 		buf = beio->sg_segs[i].addr;
1326 		end = buf + seglen;
1327 		for (; buf < end; buf += cbe_lun->blocksize) {
1328 			if (lbalen->flags & SWS_NDOB) {
1329 				memset(buf, 0, cbe_lun->blocksize);
1330 			} else {
1331 				memcpy(buf, io->scsiio.kern_data_ptr,
1332 				    cbe_lun->blocksize);
1333 			}
1334 			if (lbalen->flags & SWS_LBDATA)
1335 				scsi_ulto4b(lbalen->lba + lba, buf);
1336 			lba++;
1337 		}
1338 	}
1339 
1340 	beio->io_offset = lbalen->lba * cbe_lun->blocksize;
1341 	beio->io_len = lba * cbe_lun->blocksize;
1342 
1343 	/* We can not do all in one run. Correct and schedule rerun. */
1344 	if (len_left > 0) {
1345 		lbalen->lba += lba;
1346 		lbalen->len -= lba;
1347 		beio->beio_cont = ctl_be_block_cw_done_ws;
1348 	}
1349 
1350 	be_lun->dispatch(be_lun, beio);
1351 }
1352 
1353 static void
1354 ctl_be_block_cw_dispatch_unmap(struct ctl_be_block_lun *be_lun,
1355 			    union ctl_io *io)
1356 {
1357 	struct ctl_be_block_io *beio;
1358 	struct ctl_ptr_len_flags *ptrlen;
1359 
1360 	DPRINTF("entered\n");
1361 
1362 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1363 	ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1364 
1365 	if ((ptrlen->flags & ~SU_ANCHOR) != 0 || be_lun->unmap == NULL) {
1366 		ctl_free_beio(beio);
1367 		ctl_set_invalid_field(&io->scsiio,
1368 				      /*sks_valid*/ 0,
1369 				      /*command*/ 1,
1370 				      /*field*/ 0,
1371 				      /*bit_valid*/ 0,
1372 				      /*bit*/ 0);
1373 		ctl_config_write_done(io);
1374 		return;
1375 	}
1376 
1377 	beio->io_len = 0;
1378 	beio->io_offset = -1;
1379 	beio->bio_cmd = BIO_DELETE;
1380 	beio->ds_trans_type = DEVSTAT_FREE;
1381 	DPRINTF("UNMAP\n");
1382 	be_lun->unmap(be_lun, beio);
1383 }
1384 
1385 static void
1386 ctl_be_block_cr_done(struct ctl_be_block_io *beio)
1387 {
1388 	union ctl_io *io;
1389 
1390 	io = beio->io;
1391 	ctl_free_beio(beio);
1392 	ctl_config_read_done(io);
1393 }
1394 
1395 static void
1396 ctl_be_block_cr_dispatch(struct ctl_be_block_lun *be_lun,
1397 			 union ctl_io *io)
1398 {
1399 	struct ctl_be_block_io *beio;
1400 	struct ctl_be_block_softc *softc;
1401 
1402 	DPRINTF("entered\n");
1403 
1404 	softc = be_lun->softc;
1405 	beio = ctl_alloc_beio(softc);
1406 	beio->io = io;
1407 	beio->lun = be_lun;
1408 	beio->beio_cont = ctl_be_block_cr_done;
1409 	PRIV(io)->ptr = (void *)beio;
1410 
1411 	switch (io->scsiio.cdb[0]) {
1412 	case SERVICE_ACTION_IN:		/* GET LBA STATUS */
1413 		beio->bio_cmd = -1;
1414 		beio->ds_trans_type = DEVSTAT_NO_DATA;
1415 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1416 		beio->io_len = 0;
1417 		if (be_lun->get_lba_status)
1418 			be_lun->get_lba_status(be_lun, beio);
1419 		else
1420 			ctl_be_block_cr_done(beio);
1421 		break;
1422 	default:
1423 		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1424 		break;
1425 	}
1426 }
1427 
1428 static void
1429 ctl_be_block_cw_done(struct ctl_be_block_io *beio)
1430 {
1431 	union ctl_io *io;
1432 
1433 	io = beio->io;
1434 	ctl_free_beio(beio);
1435 	ctl_config_write_done(io);
1436 }
1437 
1438 static void
1439 ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
1440 			 union ctl_io *io)
1441 {
1442 	struct ctl_be_block_io *beio;
1443 	struct ctl_be_block_softc *softc;
1444 
1445 	DPRINTF("entered\n");
1446 
1447 	softc = be_lun->softc;
1448 	beio = ctl_alloc_beio(softc);
1449 	beio->io = io;
1450 	beio->lun = be_lun;
1451 	beio->beio_cont = ctl_be_block_cw_done;
1452 	switch (io->scsiio.tag_type) {
1453 	case CTL_TAG_ORDERED:
1454 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1455 		break;
1456 	case CTL_TAG_HEAD_OF_QUEUE:
1457 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1458 		break;
1459 	case CTL_TAG_UNTAGGED:
1460 	case CTL_TAG_SIMPLE:
1461 	case CTL_TAG_ACA:
1462 	default:
1463 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1464 		break;
1465 	}
1466 	PRIV(io)->ptr = (void *)beio;
1467 
1468 	switch (io->scsiio.cdb[0]) {
1469 	case SYNCHRONIZE_CACHE:
1470 	case SYNCHRONIZE_CACHE_16:
1471 		ctl_be_block_cw_dispatch_sync(be_lun, io);
1472 		break;
1473 	case WRITE_SAME_10:
1474 	case WRITE_SAME_16:
1475 		ctl_be_block_cw_dispatch_ws(be_lun, io);
1476 		break;
1477 	case UNMAP:
1478 		ctl_be_block_cw_dispatch_unmap(be_lun, io);
1479 		break;
1480 	default:
1481 		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1482 		break;
1483 	}
1484 }
1485 
1486 SDT_PROBE_DEFINE1(cbb, , read, start, "uint64_t");
1487 SDT_PROBE_DEFINE1(cbb, , write, start, "uint64_t");
1488 SDT_PROBE_DEFINE1(cbb, , read, alloc_done, "uint64_t");
1489 SDT_PROBE_DEFINE1(cbb, , write, alloc_done, "uint64_t");
1490 
1491 static void
1492 ctl_be_block_next(struct ctl_be_block_io *beio)
1493 {
1494 	struct ctl_be_block_lun *be_lun;
1495 	union ctl_io *io;
1496 
1497 	io = beio->io;
1498 	be_lun = beio->lun;
1499 	ctl_free_beio(beio);
1500 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1501 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1502 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1503 		ctl_data_submit_done(io);
1504 		return;
1505 	}
1506 
1507 	io->io_hdr.status &= ~CTL_STATUS_MASK;
1508 	io->io_hdr.status |= CTL_STATUS_NONE;
1509 
1510 	mtx_lock(&be_lun->queue_lock);
1511 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1512 	mtx_unlock(&be_lun->queue_lock);
1513 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1514 }
1515 
1516 static void
1517 ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
1518 			   union ctl_io *io)
1519 {
1520 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1521 	struct ctl_be_block_io *beio;
1522 	struct ctl_be_block_softc *softc;
1523 	struct ctl_lba_len_flags *lbalen;
1524 	struct ctl_ptr_len_flags *bptrlen;
1525 	uint64_t len_left, lbas;
1526 	int i;
1527 
1528 	softc = be_lun->softc;
1529 
1530 	DPRINTF("entered\n");
1531 
1532 	lbalen = ARGS(io);
1533 	if (lbalen->flags & CTL_LLF_WRITE) {
1534 		SDT_PROBE0(cbb, , write, start);
1535 	} else {
1536 		SDT_PROBE0(cbb, , read, start);
1537 	}
1538 
1539 	beio = ctl_alloc_beio(softc);
1540 	beio->io = io;
1541 	beio->lun = be_lun;
1542 	bptrlen = PRIV(io);
1543 	bptrlen->ptr = (void *)beio;
1544 
1545 	switch (io->scsiio.tag_type) {
1546 	case CTL_TAG_ORDERED:
1547 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1548 		break;
1549 	case CTL_TAG_HEAD_OF_QUEUE:
1550 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1551 		break;
1552 	case CTL_TAG_UNTAGGED:
1553 	case CTL_TAG_SIMPLE:
1554 	case CTL_TAG_ACA:
1555 	default:
1556 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1557 		break;
1558 	}
1559 
1560 	if (lbalen->flags & CTL_LLF_WRITE) {
1561 		beio->bio_cmd = BIO_WRITE;
1562 		beio->ds_trans_type = DEVSTAT_WRITE;
1563 	} else {
1564 		beio->bio_cmd = BIO_READ;
1565 		beio->ds_trans_type = DEVSTAT_READ;
1566 	}
1567 
1568 	DPRINTF("%s at LBA %jx len %u @%ju\n",
1569 	       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE",
1570 	       (uintmax_t)lbalen->lba, lbalen->len, bptrlen->len);
1571 	if (lbalen->flags & CTL_LLF_COMPARE) {
1572 		beio->two_sglists = 1;
1573 		lbas = CTLBLK_HALF_IO_SIZE;
1574 	} else {
1575 		lbas = CTLBLK_MAX_IO_SIZE;
1576 	}
1577 	lbas = MIN(lbalen->len - bptrlen->len, lbas / cbe_lun->blocksize);
1578 	beio->io_offset = (lbalen->lba + bptrlen->len) * cbe_lun->blocksize;
1579 	beio->io_len = lbas * cbe_lun->blocksize;
1580 	bptrlen->len += lbas;
1581 
1582 	for (i = 0, len_left = beio->io_len; len_left > 0; i++) {
1583 		KASSERT(i < CTLBLK_MAX_SEGS, ("Too many segs (%d >= %d)",
1584 		    i, CTLBLK_MAX_SEGS));
1585 
1586 		/*
1587 		 * Setup the S/G entry for this chunk.
1588 		 */
1589 		beio->sg_segs[i].len = min(CTLBLK_MAX_SEG, len_left);
1590 		beio->sg_segs[i].addr = uma_zalloc(softc->buf_zone, M_WAITOK);
1591 
1592 		DPRINTF("segment %d addr %p len %zd\n", i,
1593 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1594 
1595 		/* Set up second segment for compare operation. */
1596 		if (beio->two_sglists) {
1597 			beio->sg_segs[i + CTLBLK_HALF_SEGS].len =
1598 			    beio->sg_segs[i].len;
1599 			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr =
1600 			    uma_zalloc(softc->buf_zone, M_WAITOK);
1601 		}
1602 
1603 		beio->num_segs++;
1604 		len_left -= beio->sg_segs[i].len;
1605 	}
1606 	if (bptrlen->len < lbalen->len)
1607 		beio->beio_cont = ctl_be_block_next;
1608 	io->scsiio.be_move_done = ctl_be_block_move_done;
1609 	/* For compare we have separate S/G lists for read and datamove. */
1610 	if (beio->two_sglists)
1611 		io->scsiio.kern_data_ptr = (uint8_t *)&beio->sg_segs[CTLBLK_HALF_SEGS];
1612 	else
1613 		io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
1614 	io->scsiio.kern_data_len = beio->io_len;
1615 	io->scsiio.kern_sg_entries = beio->num_segs;
1616 	io->io_hdr.flags |= CTL_FLAG_ALLOCATED;
1617 
1618 	/*
1619 	 * For the read case, we need to read the data into our buffers and
1620 	 * then we can send it back to the user.  For the write case, we
1621 	 * need to get the data from the user first.
1622 	 */
1623 	if (beio->bio_cmd == BIO_READ) {
1624 		SDT_PROBE0(cbb, , read, alloc_done);
1625 		be_lun->dispatch(be_lun, beio);
1626 	} else {
1627 		SDT_PROBE0(cbb, , write, alloc_done);
1628 #ifdef CTL_TIME_IO
1629 		getbinuptime(&io->io_hdr.dma_start_bt);
1630 #endif
1631 		ctl_datamove(io);
1632 	}
1633 }
1634 
1635 static void
1636 ctl_be_block_worker(void *context, int pending)
1637 {
1638 	struct ctl_be_block_lun *be_lun = (struct ctl_be_block_lun *)context;
1639 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1640 	union ctl_io *io;
1641 	struct ctl_be_block_io *beio;
1642 
1643 	DPRINTF("entered\n");
1644 	/*
1645 	 * Fetch and process I/Os from all queues.  If we detect LUN
1646 	 * CTL_LUN_FLAG_NO_MEDIA status here -- it is result of a race,
1647 	 * so make response maximally opaque to not confuse initiator.
1648 	 */
1649 	for (;;) {
1650 		mtx_lock(&be_lun->queue_lock);
1651 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->datamove_queue);
1652 		if (io != NULL) {
1653 			DPRINTF("datamove queue\n");
1654 			STAILQ_REMOVE(&be_lun->datamove_queue, &io->io_hdr,
1655 				      ctl_io_hdr, links);
1656 			mtx_unlock(&be_lun->queue_lock);
1657 			beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1658 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1659 				ctl_set_busy(&io->scsiio);
1660 				ctl_complete_beio(beio);
1661 				return;
1662 			}
1663 			be_lun->dispatch(be_lun, beio);
1664 			continue;
1665 		}
1666 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_write_queue);
1667 		if (io != NULL) {
1668 			DPRINTF("config write queue\n");
1669 			STAILQ_REMOVE(&be_lun->config_write_queue, &io->io_hdr,
1670 				      ctl_io_hdr, links);
1671 			mtx_unlock(&be_lun->queue_lock);
1672 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1673 				ctl_set_busy(&io->scsiio);
1674 				ctl_config_write_done(io);
1675 				return;
1676 			}
1677 			ctl_be_block_cw_dispatch(be_lun, io);
1678 			continue;
1679 		}
1680 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_read_queue);
1681 		if (io != NULL) {
1682 			DPRINTF("config read queue\n");
1683 			STAILQ_REMOVE(&be_lun->config_read_queue, &io->io_hdr,
1684 				      ctl_io_hdr, links);
1685 			mtx_unlock(&be_lun->queue_lock);
1686 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1687 				ctl_set_busy(&io->scsiio);
1688 				ctl_config_read_done(io);
1689 				return;
1690 			}
1691 			ctl_be_block_cr_dispatch(be_lun, io);
1692 			continue;
1693 		}
1694 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->input_queue);
1695 		if (io != NULL) {
1696 			DPRINTF("input queue\n");
1697 			STAILQ_REMOVE(&be_lun->input_queue, &io->io_hdr,
1698 				      ctl_io_hdr, links);
1699 			mtx_unlock(&be_lun->queue_lock);
1700 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1701 				ctl_set_busy(&io->scsiio);
1702 				ctl_data_submit_done(io);
1703 				return;
1704 			}
1705 			ctl_be_block_dispatch(be_lun, io);
1706 			continue;
1707 		}
1708 
1709 		/*
1710 		 * If we get here, there is no work left in the queues, so
1711 		 * just break out and let the task queue go to sleep.
1712 		 */
1713 		mtx_unlock(&be_lun->queue_lock);
1714 		break;
1715 	}
1716 }
1717 
1718 /*
1719  * Entry point from CTL to the backend for I/O.  We queue everything to a
1720  * work thread, so this just puts the I/O on a queue and wakes up the
1721  * thread.
1722  */
1723 static int
1724 ctl_be_block_submit(union ctl_io *io)
1725 {
1726 	struct ctl_be_block_lun *be_lun;
1727 
1728 	DPRINTF("entered\n");
1729 
1730 	be_lun = (struct ctl_be_block_lun *)CTL_BACKEND_LUN(io);
1731 
1732 	/*
1733 	 * Make sure we only get SCSI I/O.
1734 	 */
1735 	KASSERT(io->io_hdr.io_type == CTL_IO_SCSI, ("Non-SCSI I/O (type "
1736 		"%#x) encountered", io->io_hdr.io_type));
1737 
1738 	PRIV(io)->len = 0;
1739 
1740 	mtx_lock(&be_lun->queue_lock);
1741 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1742 	mtx_unlock(&be_lun->queue_lock);
1743 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1744 
1745 	return (CTL_RETVAL_COMPLETE);
1746 }
1747 
1748 static int
1749 ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
1750 			int flag, struct thread *td)
1751 {
1752 	struct ctl_be_block_softc *softc = &backend_block_softc;
1753 	int error;
1754 
1755 	error = 0;
1756 	switch (cmd) {
1757 	case CTL_LUN_REQ: {
1758 		struct ctl_lun_req *lun_req;
1759 
1760 		lun_req = (struct ctl_lun_req *)addr;
1761 
1762 		switch (lun_req->reqtype) {
1763 		case CTL_LUNREQ_CREATE:
1764 			error = ctl_be_block_create(softc, lun_req);
1765 			break;
1766 		case CTL_LUNREQ_RM:
1767 			error = ctl_be_block_rm(softc, lun_req);
1768 			break;
1769 		case CTL_LUNREQ_MODIFY:
1770 			error = ctl_be_block_modify(softc, lun_req);
1771 			break;
1772 		default:
1773 			lun_req->status = CTL_LUN_ERROR;
1774 			snprintf(lun_req->error_str, sizeof(lun_req->error_str),
1775 				 "invalid LUN request type %d",
1776 				 lun_req->reqtype);
1777 			break;
1778 		}
1779 		break;
1780 	}
1781 	default:
1782 		error = ENOTTY;
1783 		break;
1784 	}
1785 
1786 	return (error);
1787 }
1788 
1789 static int
1790 ctl_be_block_open_file(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1791 {
1792 	struct ctl_be_lun *cbe_lun;
1793 	struct ctl_be_block_filedata *file_data;
1794 	struct ctl_lun_create_params *params;
1795 	const char		     *value;
1796 	struct vattr		      vattr;
1797 	off_t			      ps, pss, po, pos, us, uss, uo, uos;
1798 	int			      error;
1799 
1800 	cbe_lun = &be_lun->cbe_lun;
1801 	file_data = &be_lun->backend.file;
1802 	params = &be_lun->params;
1803 
1804 	be_lun->dev_type = CTL_BE_BLOCK_FILE;
1805 	be_lun->dispatch = ctl_be_block_dispatch_file;
1806 	be_lun->lun_flush = ctl_be_block_flush_file;
1807 	be_lun->get_lba_status = ctl_be_block_gls_file;
1808 	be_lun->getattr = ctl_be_block_getattr_file;
1809 	be_lun->unmap = NULL;
1810 	cbe_lun->flags &= ~CTL_LUN_FLAG_UNMAP;
1811 
1812 	error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
1813 	if (error != 0) {
1814 		snprintf(req->error_str, sizeof(req->error_str),
1815 			 "error calling VOP_GETATTR() for file %s",
1816 			 be_lun->dev_path);
1817 		return (error);
1818 	}
1819 
1820 	file_data->cred = crhold(curthread->td_ucred);
1821 	if (params->lun_size_bytes != 0)
1822 		be_lun->size_bytes = params->lun_size_bytes;
1823 	else
1824 		be_lun->size_bytes = vattr.va_size;
1825 
1826 	/*
1827 	 * For files we can use any logical block size.  Prefer 512 bytes
1828 	 * for compatibility reasons.  If file's vattr.va_blocksize
1829 	 * (preferred I/O block size) is bigger and multiple to chosen
1830 	 * logical block size -- report it as physical block size.
1831 	 */
1832 	if (params->blocksize_bytes != 0)
1833 		cbe_lun->blocksize = params->blocksize_bytes;
1834 	else if (cbe_lun->lun_type == T_CDROM)
1835 		cbe_lun->blocksize = 2048;
1836 	else
1837 		cbe_lun->blocksize = 512;
1838 	be_lun->size_blocks = be_lun->size_bytes / cbe_lun->blocksize;
1839 	cbe_lun->maxlba = (be_lun->size_blocks == 0) ?
1840 	    0 : (be_lun->size_blocks - 1);
1841 
1842 	us = ps = vattr.va_blocksize;
1843 	uo = po = 0;
1844 
1845 	value = dnvlist_get_string(cbe_lun->options, "pblocksize", NULL);
1846 	if (value != NULL)
1847 		ctl_expand_number(value, &ps);
1848 	value = dnvlist_get_string(cbe_lun->options, "pblockoffset", NULL);
1849 	if (value != NULL)
1850 		ctl_expand_number(value, &po);
1851 	pss = ps / cbe_lun->blocksize;
1852 	pos = po / cbe_lun->blocksize;
1853 	if ((pss > 0) && (pss * cbe_lun->blocksize == ps) && (pss >= pos) &&
1854 	    ((pss & (pss - 1)) == 0) && (pos * cbe_lun->blocksize == po)) {
1855 		cbe_lun->pblockexp = fls(pss) - 1;
1856 		cbe_lun->pblockoff = (pss - pos) % pss;
1857 	}
1858 
1859 	value = dnvlist_get_string(cbe_lun->options, "ublocksize", NULL);
1860 	if (value != NULL)
1861 		ctl_expand_number(value, &us);
1862 	value = dnvlist_get_string(cbe_lun->options, "ublockoffset", NULL);
1863 	if (value != NULL)
1864 		ctl_expand_number(value, &uo);
1865 	uss = us / cbe_lun->blocksize;
1866 	uos = uo / cbe_lun->blocksize;
1867 	if ((uss > 0) && (uss * cbe_lun->blocksize == us) && (uss >= uos) &&
1868 	    ((uss & (uss - 1)) == 0) && (uos * cbe_lun->blocksize == uo)) {
1869 		cbe_lun->ublockexp = fls(uss) - 1;
1870 		cbe_lun->ublockoff = (uss - uos) % uss;
1871 	}
1872 
1873 	/*
1874 	 * Sanity check.  The media size has to be at least one
1875 	 * sector long.
1876 	 */
1877 	if (be_lun->size_bytes < cbe_lun->blocksize) {
1878 		error = EINVAL;
1879 		snprintf(req->error_str, sizeof(req->error_str),
1880 			 "file %s size %ju < block size %u", be_lun->dev_path,
1881 			 (uintmax_t)be_lun->size_bytes, cbe_lun->blocksize);
1882 	}
1883 
1884 	cbe_lun->opttxferlen = CTLBLK_MAX_IO_SIZE / cbe_lun->blocksize;
1885 	return (error);
1886 }
1887 
1888 static int
1889 ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1890 {
1891 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1892 	struct ctl_lun_create_params *params;
1893 	struct cdevsw		     *csw;
1894 	struct cdev		     *dev;
1895 	const char		     *value;
1896 	int			      error, atomic, maxio, ref, unmap, tmp;
1897 	off_t			      ps, pss, po, pos, us, uss, uo, uos, otmp;
1898 
1899 	params = &be_lun->params;
1900 
1901 	be_lun->dev_type = CTL_BE_BLOCK_DEV;
1902 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1903 	if (csw == NULL)
1904 		return (ENXIO);
1905 	if (strcmp(csw->d_name, "zvol") == 0) {
1906 		be_lun->dispatch = ctl_be_block_dispatch_zvol;
1907 		be_lun->get_lba_status = ctl_be_block_gls_zvol;
1908 		atomic = maxio = CTLBLK_MAX_IO_SIZE;
1909 	} else {
1910 		be_lun->dispatch = ctl_be_block_dispatch_dev;
1911 		be_lun->get_lba_status = NULL;
1912 		atomic = 0;
1913 		maxio = dev->si_iosize_max;
1914 		if (maxio <= 0)
1915 			maxio = DFLTPHYS;
1916 		if (maxio > CTLBLK_MAX_IO_SIZE)
1917 			maxio = CTLBLK_MAX_IO_SIZE;
1918 	}
1919 	be_lun->lun_flush = ctl_be_block_flush_dev;
1920 	be_lun->getattr = ctl_be_block_getattr_dev;
1921 	be_lun->unmap = ctl_be_block_unmap_dev;
1922 
1923 	if (!csw->d_ioctl) {
1924 		dev_relthread(dev, ref);
1925 		snprintf(req->error_str, sizeof(req->error_str),
1926 			 "no d_ioctl for device %s!", be_lun->dev_path);
1927 		return (ENODEV);
1928 	}
1929 
1930 	error = csw->d_ioctl(dev, DIOCGSECTORSIZE, (caddr_t)&tmp, FREAD,
1931 			       curthread);
1932 	if (error) {
1933 		dev_relthread(dev, ref);
1934 		snprintf(req->error_str, sizeof(req->error_str),
1935 			 "error %d returned for DIOCGSECTORSIZE ioctl "
1936 			 "on %s!", error, be_lun->dev_path);
1937 		return (error);
1938 	}
1939 
1940 	/*
1941 	 * If the user has asked for a blocksize that is greater than the
1942 	 * backing device's blocksize, we can do it only if the blocksize
1943 	 * the user is asking for is an even multiple of the underlying
1944 	 * device's blocksize.
1945 	 */
1946 	if ((params->blocksize_bytes != 0) &&
1947 	    (params->blocksize_bytes >= tmp)) {
1948 		if (params->blocksize_bytes % tmp == 0) {
1949 			cbe_lun->blocksize = params->blocksize_bytes;
1950 		} else {
1951 			dev_relthread(dev, ref);
1952 			snprintf(req->error_str, sizeof(req->error_str),
1953 				 "requested blocksize %u is not an even "
1954 				 "multiple of backing device blocksize %u",
1955 				 params->blocksize_bytes, tmp);
1956 			return (EINVAL);
1957 		}
1958 	} else if (params->blocksize_bytes != 0) {
1959 		dev_relthread(dev, ref);
1960 		snprintf(req->error_str, sizeof(req->error_str),
1961 			 "requested blocksize %u < backing device "
1962 			 "blocksize %u", params->blocksize_bytes, tmp);
1963 		return (EINVAL);
1964 	} else if (cbe_lun->lun_type == T_CDROM)
1965 		cbe_lun->blocksize = MAX(tmp, 2048);
1966 	else
1967 		cbe_lun->blocksize = tmp;
1968 
1969 	error = csw->d_ioctl(dev, DIOCGMEDIASIZE, (caddr_t)&otmp, FREAD,
1970 			     curthread);
1971 	if (error) {
1972 		dev_relthread(dev, ref);
1973 		snprintf(req->error_str, sizeof(req->error_str),
1974 			 "error %d returned for DIOCGMEDIASIZE "
1975 			 " ioctl on %s!", error,
1976 			 be_lun->dev_path);
1977 		return (error);
1978 	}
1979 
1980 	if (params->lun_size_bytes != 0) {
1981 		if (params->lun_size_bytes > otmp) {
1982 			dev_relthread(dev, ref);
1983 			snprintf(req->error_str, sizeof(req->error_str),
1984 				 "requested LUN size %ju > backing device "
1985 				 "size %ju",
1986 				 (uintmax_t)params->lun_size_bytes,
1987 				 (uintmax_t)otmp);
1988 			return (EINVAL);
1989 		}
1990 
1991 		be_lun->size_bytes = params->lun_size_bytes;
1992 	} else
1993 		be_lun->size_bytes = otmp;
1994 	be_lun->size_blocks = be_lun->size_bytes / cbe_lun->blocksize;
1995 	cbe_lun->maxlba = (be_lun->size_blocks == 0) ?
1996 	    0 : (be_lun->size_blocks - 1);
1997 
1998 	error = csw->d_ioctl(dev, DIOCGSTRIPESIZE, (caddr_t)&ps, FREAD,
1999 	    curthread);
2000 	if (error)
2001 		ps = po = 0;
2002 	else {
2003 		error = csw->d_ioctl(dev, DIOCGSTRIPEOFFSET, (caddr_t)&po,
2004 		    FREAD, curthread);
2005 		if (error)
2006 			po = 0;
2007 	}
2008 	us = ps;
2009 	uo = po;
2010 
2011 	value = dnvlist_get_string(cbe_lun->options, "pblocksize", NULL);
2012 	if (value != NULL)
2013 		ctl_expand_number(value, &ps);
2014 	value = dnvlist_get_string(cbe_lun->options, "pblockoffset", NULL);
2015 	if (value != NULL)
2016 		ctl_expand_number(value, &po);
2017 	pss = ps / cbe_lun->blocksize;
2018 	pos = po / cbe_lun->blocksize;
2019 	if ((pss > 0) && (pss * cbe_lun->blocksize == ps) && (pss >= pos) &&
2020 	    ((pss & (pss - 1)) == 0) && (pos * cbe_lun->blocksize == po)) {
2021 		cbe_lun->pblockexp = fls(pss) - 1;
2022 		cbe_lun->pblockoff = (pss - pos) % pss;
2023 	}
2024 
2025 	value = dnvlist_get_string(cbe_lun->options, "ublocksize", NULL);
2026 	if (value != NULL)
2027 		ctl_expand_number(value, &us);
2028 	value = dnvlist_get_string(cbe_lun->options, "ublockoffset", NULL);
2029 	if (value != NULL)
2030 		ctl_expand_number(value, &uo);
2031 	uss = us / cbe_lun->blocksize;
2032 	uos = uo / cbe_lun->blocksize;
2033 	if ((uss > 0) && (uss * cbe_lun->blocksize == us) && (uss >= uos) &&
2034 	    ((uss & (uss - 1)) == 0) && (uos * cbe_lun->blocksize == uo)) {
2035 		cbe_lun->ublockexp = fls(uss) - 1;
2036 		cbe_lun->ublockoff = (uss - uos) % uss;
2037 	}
2038 
2039 	cbe_lun->atomicblock = atomic / cbe_lun->blocksize;
2040 	cbe_lun->opttxferlen = maxio / cbe_lun->blocksize;
2041 
2042 	if (be_lun->dispatch == ctl_be_block_dispatch_zvol) {
2043 		unmap = 1;
2044 	} else {
2045 		struct diocgattr_arg	arg;
2046 
2047 		strlcpy(arg.name, "GEOM::candelete", sizeof(arg.name));
2048 		arg.len = sizeof(arg.value.i);
2049 		error = csw->d_ioctl(dev, DIOCGATTR, (caddr_t)&arg, FREAD,
2050 		    curthread);
2051 		unmap = (error == 0) ? arg.value.i : 0;
2052 	}
2053 	value = dnvlist_get_string(cbe_lun->options, "unmap", NULL);
2054 	if (value != NULL)
2055 		unmap = (strcmp(value, "on") == 0);
2056 	if (unmap)
2057 		cbe_lun->flags |= CTL_LUN_FLAG_UNMAP;
2058 	else
2059 		cbe_lun->flags &= ~CTL_LUN_FLAG_UNMAP;
2060 
2061 	dev_relthread(dev, ref);
2062 	return (0);
2063 }
2064 
2065 static int
2066 ctl_be_block_close(struct ctl_be_block_lun *be_lun)
2067 {
2068 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
2069 	int flags;
2070 
2071 	if (be_lun->vn) {
2072 		flags = FREAD;
2073 		if ((cbe_lun->flags & CTL_LUN_FLAG_READONLY) == 0)
2074 			flags |= FWRITE;
2075 		(void)vn_close(be_lun->vn, flags, NOCRED, curthread);
2076 		be_lun->vn = NULL;
2077 
2078 		switch (be_lun->dev_type) {
2079 		case CTL_BE_BLOCK_DEV:
2080 			break;
2081 		case CTL_BE_BLOCK_FILE:
2082 			if (be_lun->backend.file.cred != NULL) {
2083 				crfree(be_lun->backend.file.cred);
2084 				be_lun->backend.file.cred = NULL;
2085 			}
2086 			break;
2087 		case CTL_BE_BLOCK_NONE:
2088 			break;
2089 		default:
2090 			panic("Unexpected backend type %d", be_lun->dev_type);
2091 			break;
2092 		}
2093 		be_lun->dev_type = CTL_BE_BLOCK_NONE;
2094 	}
2095 	return (0);
2096 }
2097 
2098 static int
2099 ctl_be_block_open(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
2100 {
2101 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
2102 	struct nameidata nd;
2103 	const char	*value;
2104 	int		 error, flags;
2105 
2106 	error = 0;
2107 	if (rootvnode == NULL) {
2108 		snprintf(req->error_str, sizeof(req->error_str),
2109 			 "Root filesystem is not mounted");
2110 		return (1);
2111 	}
2112 	pwd_ensure_dirs();
2113 
2114 	value = dnvlist_get_string(cbe_lun->options, "file", NULL);
2115 	if (value == NULL) {
2116 		snprintf(req->error_str, sizeof(req->error_str),
2117 			 "no file argument specified");
2118 		return (1);
2119 	}
2120 	free(be_lun->dev_path, M_CTLBLK);
2121 	be_lun->dev_path = strdup(value, M_CTLBLK);
2122 
2123 	flags = FREAD;
2124 	value = dnvlist_get_string(cbe_lun->options, "readonly", NULL);
2125 	if (value != NULL) {
2126 		if (strcmp(value, "on") != 0)
2127 			flags |= FWRITE;
2128 	} else if (cbe_lun->lun_type == T_DIRECT)
2129 		flags |= FWRITE;
2130 
2131 again:
2132 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, be_lun->dev_path, curthread);
2133 	error = vn_open(&nd, &flags, 0, NULL);
2134 	if ((error == EROFS || error == EACCES) && (flags & FWRITE)) {
2135 		flags &= ~FWRITE;
2136 		goto again;
2137 	}
2138 	if (error) {
2139 		/*
2140 		 * This is the only reasonable guess we can make as far as
2141 		 * path if the user doesn't give us a fully qualified path.
2142 		 * If they want to specify a file, they need to specify the
2143 		 * full path.
2144 		 */
2145 		if (be_lun->dev_path[0] != '/') {
2146 			char *dev_name;
2147 
2148 			asprintf(&dev_name, M_CTLBLK, "/dev/%s",
2149 				be_lun->dev_path);
2150 			free(be_lun->dev_path, M_CTLBLK);
2151 			be_lun->dev_path = dev_name;
2152 			goto again;
2153 		}
2154 		snprintf(req->error_str, sizeof(req->error_str),
2155 		    "error opening %s: %d", be_lun->dev_path, error);
2156 		return (error);
2157 	}
2158 	if (flags & FWRITE)
2159 		cbe_lun->flags &= ~CTL_LUN_FLAG_READONLY;
2160 	else
2161 		cbe_lun->flags |= CTL_LUN_FLAG_READONLY;
2162 
2163 	NDFREE(&nd, NDF_ONLY_PNBUF);
2164 	be_lun->vn = nd.ni_vp;
2165 
2166 	/* We only support disks and files. */
2167 	if (vn_isdisk(be_lun->vn, &error)) {
2168 		error = ctl_be_block_open_dev(be_lun, req);
2169 	} else if (be_lun->vn->v_type == VREG) {
2170 		error = ctl_be_block_open_file(be_lun, req);
2171 	} else {
2172 		error = EINVAL;
2173 		snprintf(req->error_str, sizeof(req->error_str),
2174 			 "%s is not a disk or plain file", be_lun->dev_path);
2175 	}
2176 	VOP_UNLOCK(be_lun->vn);
2177 
2178 	if (error != 0)
2179 		ctl_be_block_close(be_lun);
2180 	cbe_lun->serseq = CTL_LUN_SERSEQ_OFF;
2181 	if (be_lun->dispatch != ctl_be_block_dispatch_dev)
2182 		cbe_lun->serseq = CTL_LUN_SERSEQ_READ;
2183 	value = dnvlist_get_string(cbe_lun->options, "serseq", NULL);
2184 	if (value != NULL && strcmp(value, "on") == 0)
2185 		cbe_lun->serseq = CTL_LUN_SERSEQ_ON;
2186 	else if (value != NULL && strcmp(value, "read") == 0)
2187 		cbe_lun->serseq = CTL_LUN_SERSEQ_READ;
2188 	else if (value != NULL && strcmp(value, "off") == 0)
2189 		cbe_lun->serseq = CTL_LUN_SERSEQ_OFF;
2190 	return (0);
2191 }
2192 
2193 static int
2194 ctl_be_block_create(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2195 {
2196 	struct ctl_be_lun *cbe_lun;
2197 	struct ctl_be_block_lun *be_lun;
2198 	struct ctl_lun_create_params *params;
2199 	char num_thread_str[16];
2200 	char tmpstr[32];
2201 	const char *value;
2202 	int retval, num_threads;
2203 	int tmp_num_threads;
2204 
2205 	params = &req->reqdata.create;
2206 	retval = 0;
2207 	req->status = CTL_LUN_OK;
2208 
2209 	be_lun = malloc(sizeof(*be_lun), M_CTLBLK, M_ZERO | M_WAITOK);
2210 	cbe_lun = &be_lun->cbe_lun;
2211 	be_lun->params = req->reqdata.create;
2212 	be_lun->softc = softc;
2213 	STAILQ_INIT(&be_lun->input_queue);
2214 	STAILQ_INIT(&be_lun->config_read_queue);
2215 	STAILQ_INIT(&be_lun->config_write_queue);
2216 	STAILQ_INIT(&be_lun->datamove_queue);
2217 	mtx_init(&be_lun->io_lock, "ctlblock io", NULL, MTX_DEF);
2218 	mtx_init(&be_lun->queue_lock, "ctlblock queue", NULL, MTX_DEF);
2219 	cbe_lun->options = nvlist_clone(req->args_nvl);
2220 
2221 	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
2222 		cbe_lun->lun_type = params->device_type;
2223 	else
2224 		cbe_lun->lun_type = T_DIRECT;
2225 	be_lun->flags = 0;
2226 	cbe_lun->flags = 0;
2227 	value = dnvlist_get_string(cbe_lun->options, "ha_role", NULL);
2228 	if (value != NULL) {
2229 		if (strcmp(value, "primary") == 0)
2230 			cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2231 	} else if (control_softc->flags & CTL_FLAG_ACTIVE_SHELF)
2232 		cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2233 
2234 	if (cbe_lun->lun_type == T_DIRECT ||
2235 	    cbe_lun->lun_type == T_CDROM) {
2236 		be_lun->size_bytes = params->lun_size_bytes;
2237 		if (params->blocksize_bytes != 0)
2238 			cbe_lun->blocksize = params->blocksize_bytes;
2239 		else if (cbe_lun->lun_type == T_CDROM)
2240 			cbe_lun->blocksize = 2048;
2241 		else
2242 			cbe_lun->blocksize = 512;
2243 		be_lun->size_blocks = be_lun->size_bytes / cbe_lun->blocksize;
2244 		cbe_lun->maxlba = (be_lun->size_blocks == 0) ?
2245 		    0 : (be_lun->size_blocks - 1);
2246 
2247 		if ((cbe_lun->flags & CTL_LUN_FLAG_PRIMARY) ||
2248 		    control_softc->ha_mode == CTL_HA_MODE_SER_ONLY) {
2249 			retval = ctl_be_block_open(be_lun, req);
2250 			if (retval != 0) {
2251 				retval = 0;
2252 				req->status = CTL_LUN_WARNING;
2253 			}
2254 		}
2255 		num_threads = cbb_num_threads;
2256 	} else {
2257 		num_threads = 1;
2258 	}
2259 
2260 	value = dnvlist_get_string(cbe_lun->options, "num_threads", NULL);
2261 	if (value != NULL) {
2262 		tmp_num_threads = strtol(value, NULL, 0);
2263 
2264 		/*
2265 		 * We don't let the user specify less than one
2266 		 * thread, but hope he's clueful enough not to
2267 		 * specify 1000 threads.
2268 		 */
2269 		if (tmp_num_threads < 1) {
2270 			snprintf(req->error_str, sizeof(req->error_str),
2271 				 "invalid number of threads %s",
2272 				 num_thread_str);
2273 			goto bailout_error;
2274 		}
2275 		num_threads = tmp_num_threads;
2276 	}
2277 
2278 	if (be_lun->vn == NULL)
2279 		cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2280 	/* Tell the user the blocksize we ended up using */
2281 	params->lun_size_bytes = be_lun->size_bytes;
2282 	params->blocksize_bytes = cbe_lun->blocksize;
2283 	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
2284 		cbe_lun->req_lun_id = params->req_lun_id;
2285 		cbe_lun->flags |= CTL_LUN_FLAG_ID_REQ;
2286 	} else
2287 		cbe_lun->req_lun_id = 0;
2288 
2289 	cbe_lun->lun_shutdown = ctl_be_block_lun_shutdown;
2290 	cbe_lun->be = &ctl_be_block_driver;
2291 
2292 	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
2293 		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%04d",
2294 			 softc->num_luns);
2295 		strncpy((char *)cbe_lun->serial_num, tmpstr,
2296 			MIN(sizeof(cbe_lun->serial_num), sizeof(tmpstr)));
2297 
2298 		/* Tell the user what we used for a serial number */
2299 		strncpy((char *)params->serial_num, tmpstr,
2300 			MIN(sizeof(params->serial_num), sizeof(tmpstr)));
2301 	} else {
2302 		strncpy((char *)cbe_lun->serial_num, params->serial_num,
2303 			MIN(sizeof(cbe_lun->serial_num),
2304 			sizeof(params->serial_num)));
2305 	}
2306 	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
2307 		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%04d", softc->num_luns);
2308 		strncpy((char *)cbe_lun->device_id, tmpstr,
2309 			MIN(sizeof(cbe_lun->device_id), sizeof(tmpstr)));
2310 
2311 		/* Tell the user what we used for a device ID */
2312 		strncpy((char *)params->device_id, tmpstr,
2313 			MIN(sizeof(params->device_id), sizeof(tmpstr)));
2314 	} else {
2315 		strncpy((char *)cbe_lun->device_id, params->device_id,
2316 			MIN(sizeof(cbe_lun->device_id),
2317 			    sizeof(params->device_id)));
2318 	}
2319 
2320 	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_be_block_worker, be_lun);
2321 
2322 	be_lun->io_taskqueue = taskqueue_create("ctlblocktq", M_WAITOK,
2323 	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
2324 
2325 	if (be_lun->io_taskqueue == NULL) {
2326 		snprintf(req->error_str, sizeof(req->error_str),
2327 			 "unable to create taskqueue");
2328 		goto bailout_error;
2329 	}
2330 
2331 	/*
2332 	 * Note that we start the same number of threads by default for
2333 	 * both the file case and the block device case.  For the file
2334 	 * case, we need multiple threads to allow concurrency, because the
2335 	 * vnode interface is designed to be a blocking interface.  For the
2336 	 * block device case, ZFS zvols at least will block the caller's
2337 	 * context in many instances, and so we need multiple threads to
2338 	 * overcome that problem.  Other block devices don't need as many
2339 	 * threads, but they shouldn't cause too many problems.
2340 	 *
2341 	 * If the user wants to just have a single thread for a block
2342 	 * device, he can specify that when the LUN is created, or change
2343 	 * the tunable/sysctl to alter the default number of threads.
2344 	 */
2345 	retval = taskqueue_start_threads_in_proc(&be_lun->io_taskqueue,
2346 					 /*num threads*/num_threads,
2347 					 /*priority*/PUSER,
2348 					 /*proc*/control_softc->ctl_proc,
2349 					 /*thread name*/"block");
2350 
2351 	if (retval != 0)
2352 		goto bailout_error;
2353 
2354 	be_lun->num_threads = num_threads;
2355 
2356 	retval = ctl_add_lun(&be_lun->cbe_lun);
2357 	if (retval != 0) {
2358 		snprintf(req->error_str, sizeof(req->error_str),
2359 			 "ctl_add_lun() returned error %d, see dmesg for "
2360 			 "details", retval);
2361 		retval = 0;
2362 		goto bailout_error;
2363 	}
2364 
2365 	be_lun->disk_stats = devstat_new_entry("cbb", cbe_lun->lun_id,
2366 					       cbe_lun->blocksize,
2367 					       DEVSTAT_ALL_SUPPORTED,
2368 					       cbe_lun->lun_type
2369 					       | DEVSTAT_TYPE_IF_OTHER,
2370 					       DEVSTAT_PRIORITY_OTHER);
2371 
2372 	mtx_lock(&softc->lock);
2373 	softc->num_luns++;
2374 	SLIST_INSERT_HEAD(&softc->lun_list, be_lun, links);
2375 	mtx_unlock(&softc->lock);
2376 
2377 	params->req_lun_id = cbe_lun->lun_id;
2378 
2379 	return (retval);
2380 
2381 bailout_error:
2382 	req->status = CTL_LUN_ERROR;
2383 
2384 	if (be_lun->io_taskqueue != NULL)
2385 		taskqueue_free(be_lun->io_taskqueue);
2386 	ctl_be_block_close(be_lun);
2387 	if (be_lun->dev_path != NULL)
2388 		free(be_lun->dev_path, M_CTLBLK);
2389 	nvlist_destroy(cbe_lun->options);
2390 	mtx_destroy(&be_lun->queue_lock);
2391 	mtx_destroy(&be_lun->io_lock);
2392 	free(be_lun, M_CTLBLK);
2393 
2394 	return (retval);
2395 }
2396 
2397 static int
2398 ctl_be_block_rm(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2399 {
2400 	struct ctl_lun_rm_params *params;
2401 	struct ctl_be_block_lun *be_lun;
2402 	struct ctl_be_lun *cbe_lun;
2403 	int retval;
2404 
2405 	params = &req->reqdata.rm;
2406 
2407 	sx_xlock(&softc->modify_lock);
2408 	mtx_lock(&softc->lock);
2409 	SLIST_FOREACH(be_lun, &softc->lun_list, links) {
2410 		if (be_lun->cbe_lun.lun_id == params->lun_id) {
2411 			SLIST_REMOVE(&softc->lun_list, be_lun,
2412 			    ctl_be_block_lun, links);
2413 			softc->num_luns--;
2414 			break;
2415 		}
2416 	}
2417 	mtx_unlock(&softc->lock);
2418 	sx_xunlock(&softc->modify_lock);
2419 	if (be_lun == NULL) {
2420 		snprintf(req->error_str, sizeof(req->error_str),
2421 			 "LUN %u is not managed by the block backend",
2422 			 params->lun_id);
2423 		goto bailout_error;
2424 	}
2425 	cbe_lun = &be_lun->cbe_lun;
2426 
2427 	if (be_lun->vn != NULL) {
2428 		cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2429 		ctl_lun_no_media(cbe_lun);
2430 		taskqueue_drain_all(be_lun->io_taskqueue);
2431 		ctl_be_block_close(be_lun);
2432 	}
2433 
2434 	mtx_lock(&softc->lock);
2435 	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2436 	mtx_unlock(&softc->lock);
2437 
2438 	retval = ctl_remove_lun(cbe_lun);
2439 	if (retval != 0) {
2440 		snprintf(req->error_str, sizeof(req->error_str),
2441 			 "error %d returned from ctl_remove_lun() for "
2442 			 "LUN %d", retval, params->lun_id);
2443 		mtx_lock(&softc->lock);
2444 		be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2445 		mtx_unlock(&softc->lock);
2446 		goto bailout_error;
2447 	}
2448 
2449 	mtx_lock(&softc->lock);
2450 	while ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2451 		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblockrm", 0);
2452 		if (retval == EINTR)
2453 			break;
2454 	}
2455 	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2456 	if (be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) {
2457 		mtx_unlock(&softc->lock);
2458 		free(be_lun, M_CTLBLK);
2459 	} else {
2460 		mtx_unlock(&softc->lock);
2461 		return (EINTR);
2462 	}
2463 
2464 	req->status = CTL_LUN_OK;
2465 	return (0);
2466 
2467 bailout_error:
2468 	req->status = CTL_LUN_ERROR;
2469 	return (0);
2470 }
2471 
2472 static int
2473 ctl_be_block_modify(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2474 {
2475 	struct ctl_lun_modify_params *params;
2476 	struct ctl_be_block_lun *be_lun;
2477 	struct ctl_be_lun *cbe_lun;
2478 	const char *value;
2479 	uint64_t oldsize;
2480 	int error, wasprim;
2481 
2482 	params = &req->reqdata.modify;
2483 
2484 	sx_xlock(&softc->modify_lock);
2485 	mtx_lock(&softc->lock);
2486 	SLIST_FOREACH(be_lun, &softc->lun_list, links) {
2487 		if (be_lun->cbe_lun.lun_id == params->lun_id)
2488 			break;
2489 	}
2490 	mtx_unlock(&softc->lock);
2491 	if (be_lun == NULL) {
2492 		snprintf(req->error_str, sizeof(req->error_str),
2493 			 "LUN %u is not managed by the block backend",
2494 			 params->lun_id);
2495 		goto bailout_error;
2496 	}
2497 	cbe_lun = &be_lun->cbe_lun;
2498 
2499 	if (params->lun_size_bytes != 0)
2500 		be_lun->params.lun_size_bytes = params->lun_size_bytes;
2501 
2502 	if (req->args_nvl != NULL) {
2503 		nvlist_destroy(cbe_lun->options);
2504 		cbe_lun->options = nvlist_clone(req->args_nvl);
2505 	}
2506 
2507 	wasprim = (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY);
2508 	value = dnvlist_get_string(cbe_lun->options, "ha_role", NULL);
2509 	if (value != NULL) {
2510 		if (strcmp(value, "primary") == 0)
2511 			cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2512 		else
2513 			cbe_lun->flags &= ~CTL_LUN_FLAG_PRIMARY;
2514 	} else if (control_softc->flags & CTL_FLAG_ACTIVE_SHELF)
2515 		cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2516 	else
2517 		cbe_lun->flags &= ~CTL_LUN_FLAG_PRIMARY;
2518 	if (wasprim != (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY)) {
2519 		if (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY)
2520 			ctl_lun_primary(cbe_lun);
2521 		else
2522 			ctl_lun_secondary(cbe_lun);
2523 	}
2524 
2525 	oldsize = be_lun->size_blocks;
2526 	if ((cbe_lun->flags & CTL_LUN_FLAG_PRIMARY) ||
2527 	    control_softc->ha_mode == CTL_HA_MODE_SER_ONLY) {
2528 		if (be_lun->vn == NULL)
2529 			error = ctl_be_block_open(be_lun, req);
2530 		else if (vn_isdisk(be_lun->vn, &error))
2531 			error = ctl_be_block_open_dev(be_lun, req);
2532 		else if (be_lun->vn->v_type == VREG) {
2533 			vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
2534 			error = ctl_be_block_open_file(be_lun, req);
2535 			VOP_UNLOCK(be_lun->vn);
2536 		} else
2537 			error = EINVAL;
2538 		if ((cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) &&
2539 		    be_lun->vn != NULL) {
2540 			cbe_lun->flags &= ~CTL_LUN_FLAG_NO_MEDIA;
2541 			ctl_lun_has_media(cbe_lun);
2542 		} else if ((cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) == 0 &&
2543 		    be_lun->vn == NULL) {
2544 			cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2545 			ctl_lun_no_media(cbe_lun);
2546 		}
2547 		cbe_lun->flags &= ~CTL_LUN_FLAG_EJECTED;
2548 	} else {
2549 		if (be_lun->vn != NULL) {
2550 			cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2551 			ctl_lun_no_media(cbe_lun);
2552 			taskqueue_drain_all(be_lun->io_taskqueue);
2553 			error = ctl_be_block_close(be_lun);
2554 		} else
2555 			error = 0;
2556 	}
2557 	if (be_lun->size_blocks != oldsize)
2558 		ctl_lun_capacity_changed(cbe_lun);
2559 
2560 	/* Tell the user the exact size we ended up using */
2561 	params->lun_size_bytes = be_lun->size_bytes;
2562 
2563 	sx_xunlock(&softc->modify_lock);
2564 	req->status = error ? CTL_LUN_WARNING : CTL_LUN_OK;
2565 	return (0);
2566 
2567 bailout_error:
2568 	sx_xunlock(&softc->modify_lock);
2569 	req->status = CTL_LUN_ERROR;
2570 	return (0);
2571 }
2572 
2573 static void
2574 ctl_be_block_lun_shutdown(struct ctl_be_lun *cbe_lun)
2575 {
2576 	struct ctl_be_block_lun *be_lun = (struct ctl_be_block_lun *)cbe_lun;
2577 	struct ctl_be_block_softc *softc = be_lun->softc;
2578 
2579 	taskqueue_drain_all(be_lun->io_taskqueue);
2580 	taskqueue_free(be_lun->io_taskqueue);
2581 	if (be_lun->disk_stats != NULL)
2582 		devstat_remove_entry(be_lun->disk_stats);
2583 	nvlist_destroy(be_lun->cbe_lun.options);
2584 	free(be_lun->dev_path, M_CTLBLK);
2585 	mtx_destroy(&be_lun->queue_lock);
2586 	mtx_destroy(&be_lun->io_lock);
2587 
2588 	mtx_lock(&softc->lock);
2589 	be_lun->flags |= CTL_BE_BLOCK_LUN_UNCONFIGURED;
2590 	if (be_lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2591 		wakeup(be_lun);
2592 	else
2593 		free(be_lun, M_CTLBLK);
2594 	mtx_unlock(&softc->lock);
2595 }
2596 
2597 static int
2598 ctl_be_block_config_write(union ctl_io *io)
2599 {
2600 	struct ctl_be_block_lun *be_lun;
2601 	struct ctl_be_lun *cbe_lun;
2602 	int retval;
2603 
2604 	DPRINTF("entered\n");
2605 
2606 	cbe_lun = CTL_BACKEND_LUN(io);
2607 	be_lun = (struct ctl_be_block_lun *)cbe_lun;
2608 
2609 	retval = 0;
2610 	switch (io->scsiio.cdb[0]) {
2611 	case SYNCHRONIZE_CACHE:
2612 	case SYNCHRONIZE_CACHE_16:
2613 	case WRITE_SAME_10:
2614 	case WRITE_SAME_16:
2615 	case UNMAP:
2616 		/*
2617 		 * The upper level CTL code will filter out any CDBs with
2618 		 * the immediate bit set and return the proper error.
2619 		 *
2620 		 * We don't really need to worry about what LBA range the
2621 		 * user asked to be synced out.  When they issue a sync
2622 		 * cache command, we'll sync out the whole thing.
2623 		 */
2624 		mtx_lock(&be_lun->queue_lock);
2625 		STAILQ_INSERT_TAIL(&be_lun->config_write_queue, &io->io_hdr,
2626 				   links);
2627 		mtx_unlock(&be_lun->queue_lock);
2628 		taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
2629 		break;
2630 	case START_STOP_UNIT: {
2631 		struct scsi_start_stop_unit *cdb;
2632 		struct ctl_lun_req req;
2633 
2634 		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
2635 		if ((cdb->how & SSS_PC_MASK) != 0) {
2636 			ctl_set_success(&io->scsiio);
2637 			ctl_config_write_done(io);
2638 			break;
2639 		}
2640 		if (cdb->how & SSS_START) {
2641 			if ((cdb->how & SSS_LOEJ) && be_lun->vn == NULL) {
2642 				retval = ctl_be_block_open(be_lun, &req);
2643 				cbe_lun->flags &= ~CTL_LUN_FLAG_EJECTED;
2644 				if (retval == 0) {
2645 					cbe_lun->flags &= ~CTL_LUN_FLAG_NO_MEDIA;
2646 					ctl_lun_has_media(cbe_lun);
2647 				} else {
2648 					cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2649 					ctl_lun_no_media(cbe_lun);
2650 				}
2651 			}
2652 			ctl_start_lun(cbe_lun);
2653 		} else {
2654 			ctl_stop_lun(cbe_lun);
2655 			if (cdb->how & SSS_LOEJ) {
2656 				cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2657 				cbe_lun->flags |= CTL_LUN_FLAG_EJECTED;
2658 				ctl_lun_ejected(cbe_lun);
2659 				if (be_lun->vn != NULL)
2660 					ctl_be_block_close(be_lun);
2661 			}
2662 		}
2663 
2664 		ctl_set_success(&io->scsiio);
2665 		ctl_config_write_done(io);
2666 		break;
2667 	}
2668 	case PREVENT_ALLOW:
2669 		ctl_set_success(&io->scsiio);
2670 		ctl_config_write_done(io);
2671 		break;
2672 	default:
2673 		ctl_set_invalid_opcode(&io->scsiio);
2674 		ctl_config_write_done(io);
2675 		retval = CTL_RETVAL_COMPLETE;
2676 		break;
2677 	}
2678 
2679 	return (retval);
2680 }
2681 
2682 static int
2683 ctl_be_block_config_read(union ctl_io *io)
2684 {
2685 	struct ctl_be_block_lun *be_lun;
2686 	int retval = 0;
2687 
2688 	DPRINTF("entered\n");
2689 
2690 	be_lun = (struct ctl_be_block_lun *)CTL_BACKEND_LUN(io);
2691 
2692 	switch (io->scsiio.cdb[0]) {
2693 	case SERVICE_ACTION_IN:
2694 		if (io->scsiio.cdb[1] == SGLS_SERVICE_ACTION) {
2695 			mtx_lock(&be_lun->queue_lock);
2696 			STAILQ_INSERT_TAIL(&be_lun->config_read_queue,
2697 			    &io->io_hdr, links);
2698 			mtx_unlock(&be_lun->queue_lock);
2699 			taskqueue_enqueue(be_lun->io_taskqueue,
2700 			    &be_lun->io_task);
2701 			retval = CTL_RETVAL_QUEUED;
2702 			break;
2703 		}
2704 		ctl_set_invalid_field(&io->scsiio,
2705 				      /*sks_valid*/ 1,
2706 				      /*command*/ 1,
2707 				      /*field*/ 1,
2708 				      /*bit_valid*/ 1,
2709 				      /*bit*/ 4);
2710 		ctl_config_read_done(io);
2711 		retval = CTL_RETVAL_COMPLETE;
2712 		break;
2713 	default:
2714 		ctl_set_invalid_opcode(&io->scsiio);
2715 		ctl_config_read_done(io);
2716 		retval = CTL_RETVAL_COMPLETE;
2717 		break;
2718 	}
2719 
2720 	return (retval);
2721 }
2722 
2723 static int
2724 ctl_be_block_lun_info(struct ctl_be_lun *cbe_lun, struct sbuf *sb)
2725 {
2726 	struct ctl_be_block_lun *lun = (struct ctl_be_block_lun *)cbe_lun;
2727 	int retval;
2728 
2729 	retval = sbuf_printf(sb, "\t<num_threads>");
2730 	if (retval != 0)
2731 		goto bailout;
2732 	retval = sbuf_printf(sb, "%d", lun->num_threads);
2733 	if (retval != 0)
2734 		goto bailout;
2735 	retval = sbuf_printf(sb, "</num_threads>\n");
2736 
2737 bailout:
2738 	return (retval);
2739 }
2740 
2741 static uint64_t
2742 ctl_be_block_lun_attr(struct ctl_be_lun *cbe_lun, const char *attrname)
2743 {
2744 	struct ctl_be_block_lun *lun = (struct ctl_be_block_lun *)cbe_lun;
2745 
2746 	if (lun->getattr == NULL)
2747 		return (UINT64_MAX);
2748 	return (lun->getattr(lun, attrname));
2749 }
2750 
2751 static int
2752 ctl_be_block_init(void)
2753 {
2754 	struct ctl_be_block_softc *softc = &backend_block_softc;
2755 
2756 	sx_init(&softc->modify_lock, "ctlblock modify");
2757 	mtx_init(&softc->lock, "ctlblock", NULL, MTX_DEF);
2758 	softc->beio_zone = uma_zcreate("beio", sizeof(struct ctl_be_block_io),
2759 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
2760 	softc->buf_zone = uma_zcreate("ctlblock", CTLBLK_MAX_SEG,
2761 	    NULL, NULL, NULL, NULL, /*align*/ 0, /*flags*/0);
2762 	SLIST_INIT(&softc->lun_list);
2763 	return (0);
2764 }
2765 
2766 
2767 static int
2768 ctl_be_block_shutdown(void)
2769 {
2770 	struct ctl_be_block_softc *softc = &backend_block_softc;
2771 	struct ctl_be_block_lun *lun;
2772 
2773 	mtx_lock(&softc->lock);
2774 	while ((lun = SLIST_FIRST(&softc->lun_list)) != NULL) {
2775 		SLIST_REMOVE_HEAD(&softc->lun_list, links);
2776 		softc->num_luns--;
2777 		/*
2778 		 * Drop our lock here.  Since ctl_remove_lun() can call
2779 		 * back into us, this could potentially lead to a recursive
2780 		 * lock of the same mutex, which would cause a hang.
2781 		 */
2782 		mtx_unlock(&softc->lock);
2783 		ctl_remove_lun(&lun->cbe_lun);
2784 		mtx_lock(&softc->lock);
2785 	}
2786 	mtx_unlock(&softc->lock);
2787 	uma_zdestroy(softc->buf_zone);
2788 	uma_zdestroy(softc->beio_zone);
2789 	mtx_destroy(&softc->lock);
2790 	sx_destroy(&softc->modify_lock);
2791 	return (0);
2792 }
2793