xref: /freebsd/sys/cam/ctl/ctl_backend_block.c (revision f9fd7337f63698f33239c58c07bf430198235a22)
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				refcnt;
205 	int				bio_cmd;
206 	int				two_sglists;
207 	int				num_segs;
208 	int				num_bios_sent;
209 	int				num_bios_done;
210 	int				send_complete;
211 	int				first_error;
212 	uint64_t			first_error_offset;
213 	struct bintime			ds_t0;
214 	devstat_tag_type		ds_tag_type;
215 	devstat_trans_flags		ds_trans_type;
216 	uint64_t			io_len;
217 	uint64_t			io_offset;
218 	int				io_arg;
219 	struct ctl_be_block_softc	*softc;
220 	struct ctl_be_block_lun		*lun;
221 	void (*beio_cont)(struct ctl_be_block_io *beio); /* to continue processing */
222 };
223 
224 extern struct ctl_softc *control_softc;
225 
226 static int cbb_num_threads = 14;
227 SYSCTL_NODE(_kern_cam_ctl, OID_AUTO, block, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
228 	    "CAM Target Layer Block Backend");
229 SYSCTL_INT(_kern_cam_ctl_block, OID_AUTO, num_threads, CTLFLAG_RWTUN,
230            &cbb_num_threads, 0, "Number of threads per backing file");
231 
232 static struct ctl_be_block_io *ctl_alloc_beio(struct ctl_be_block_softc *softc);
233 static void ctl_free_beio(struct ctl_be_block_io *beio);
234 static void ctl_complete_beio(struct ctl_be_block_io *beio);
235 static int ctl_be_block_move_done(union ctl_io *io);
236 static void ctl_be_block_biodone(struct bio *bio);
237 static void ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
238 				    struct ctl_be_block_io *beio);
239 static void ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
240 				       struct ctl_be_block_io *beio);
241 static void ctl_be_block_gls_file(struct ctl_be_block_lun *be_lun,
242 				  struct ctl_be_block_io *beio);
243 static uint64_t ctl_be_block_getattr_file(struct ctl_be_block_lun *be_lun,
244 					 const char *attrname);
245 static void ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
246 				   struct ctl_be_block_io *beio);
247 static void ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
248 				   struct ctl_be_block_io *beio);
249 static void ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
250 				      struct ctl_be_block_io *beio);
251 static uint64_t ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun,
252 					 const char *attrname);
253 static void ctl_be_block_cr_dispatch(struct ctl_be_block_lun *be_lun,
254 				    union ctl_io *io);
255 static void ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
256 				    union ctl_io *io);
257 static void ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
258 				  union ctl_io *io);
259 static void ctl_be_block_worker(void *context, int pending);
260 static int ctl_be_block_submit(union ctl_io *io);
261 static int ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
262 				   int flag, struct thread *td);
263 static int ctl_be_block_open_file(struct ctl_be_block_lun *be_lun,
264 				  struct ctl_lun_req *req);
265 static int ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun,
266 				 struct ctl_lun_req *req);
267 static int ctl_be_block_close(struct ctl_be_block_lun *be_lun);
268 static int ctl_be_block_open(struct ctl_be_block_lun *be_lun,
269 			     struct ctl_lun_req *req);
270 static int ctl_be_block_create(struct ctl_be_block_softc *softc,
271 			       struct ctl_lun_req *req);
272 static int ctl_be_block_rm(struct ctl_be_block_softc *softc,
273 			   struct ctl_lun_req *req);
274 static int ctl_be_block_modify(struct ctl_be_block_softc *softc,
275 			   struct ctl_lun_req *req);
276 static void ctl_be_block_lun_shutdown(struct ctl_be_lun *cbe_lun);
277 static int ctl_be_block_config_write(union ctl_io *io);
278 static int ctl_be_block_config_read(union ctl_io *io);
279 static int ctl_be_block_lun_info(struct ctl_be_lun *cbe_lun, struct sbuf *sb);
280 static uint64_t ctl_be_block_lun_attr(struct ctl_be_lun *cbe_lun, const char *attrname);
281 static int ctl_be_block_init(void);
282 static int ctl_be_block_shutdown(void);
283 
284 static struct ctl_backend_driver ctl_be_block_driver =
285 {
286 	.name = "block",
287 	.flags = CTL_BE_FLAG_HAS_CONFIG,
288 	.init = ctl_be_block_init,
289 	.shutdown = ctl_be_block_shutdown,
290 	.data_submit = ctl_be_block_submit,
291 	.data_move_done = ctl_be_block_move_done,
292 	.config_read = ctl_be_block_config_read,
293 	.config_write = ctl_be_block_config_write,
294 	.ioctl = ctl_be_block_ioctl,
295 	.lun_info = ctl_be_block_lun_info,
296 	.lun_attr = ctl_be_block_lun_attr
297 };
298 
299 MALLOC_DEFINE(M_CTLBLK, "ctlblock", "Memory used for CTL block backend");
300 CTL_BACKEND_DECLARE(cbb, ctl_be_block_driver);
301 
302 static struct ctl_be_block_io *
303 ctl_alloc_beio(struct ctl_be_block_softc *softc)
304 {
305 	struct ctl_be_block_io *beio;
306 
307 	beio = uma_zalloc(softc->beio_zone, M_WAITOK | M_ZERO);
308 	beio->softc = softc;
309 	beio->refcnt = 1;
310 	return (beio);
311 }
312 
313 static void
314 ctl_real_free_beio(struct ctl_be_block_io *beio)
315 {
316 	struct ctl_be_block_softc *softc = beio->softc;
317 	int i;
318 
319 	for (i = 0; i < beio->num_segs; i++) {
320 		uma_zfree(softc->buf_zone, beio->sg_segs[i].addr);
321 
322 		/* For compare we had two equal S/G lists. */
323 		if (beio->two_sglists) {
324 			uma_zfree(softc->buf_zone,
325 			    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr);
326 		}
327 	}
328 
329 	uma_zfree(softc->beio_zone, beio);
330 }
331 
332 static void
333 ctl_refcnt_beio(void *arg, int diff)
334 {
335 	struct ctl_be_block_io *beio = arg;
336 
337 	if (atomic_fetchadd_int(&beio->refcnt, diff) + diff == 0)
338 		ctl_real_free_beio(beio);
339 }
340 
341 static void
342 ctl_free_beio(struct ctl_be_block_io *beio)
343 {
344 
345 	ctl_refcnt_beio(beio, -1);
346 }
347 
348 static void
349 ctl_complete_beio(struct ctl_be_block_io *beio)
350 {
351 	union ctl_io *io = beio->io;
352 
353 	if (beio->beio_cont != NULL) {
354 		beio->beio_cont(beio);
355 	} else {
356 		ctl_free_beio(beio);
357 		ctl_data_submit_done(io);
358 	}
359 }
360 
361 static size_t
362 cmp(uint8_t *a, uint8_t *b, size_t size)
363 {
364 	size_t i;
365 
366 	for (i = 0; i < size; i++) {
367 		if (a[i] != b[i])
368 			break;
369 	}
370 	return (i);
371 }
372 
373 static void
374 ctl_be_block_compare(union ctl_io *io)
375 {
376 	struct ctl_be_block_io *beio;
377 	uint64_t off, res;
378 	int i;
379 	uint8_t info[8];
380 
381 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
382 	off = 0;
383 	for (i = 0; i < beio->num_segs; i++) {
384 		res = cmp(beio->sg_segs[i].addr,
385 		    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr,
386 		    beio->sg_segs[i].len);
387 		off += res;
388 		if (res < beio->sg_segs[i].len)
389 			break;
390 	}
391 	if (i < beio->num_segs) {
392 		scsi_u64to8b(off, info);
393 		ctl_set_sense(&io->scsiio, /*current_error*/ 1,
394 		    /*sense_key*/ SSD_KEY_MISCOMPARE,
395 		    /*asc*/ 0x1D, /*ascq*/ 0x00,
396 		    /*type*/ SSD_ELEM_INFO,
397 		    /*size*/ sizeof(info), /*data*/ &info,
398 		    /*type*/ SSD_ELEM_NONE);
399 	} else
400 		ctl_set_success(&io->scsiio);
401 }
402 
403 static int
404 ctl_be_block_move_done(union ctl_io *io)
405 {
406 	struct ctl_be_block_io *beio;
407 	struct ctl_be_block_lun *be_lun;
408 	struct ctl_lba_len_flags *lbalen;
409 #ifdef CTL_TIME_IO
410 	struct bintime cur_bt;
411 #endif
412 
413 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
414 	be_lun = beio->lun;
415 
416 	DPRINTF("entered\n");
417 
418 #ifdef CTL_TIME_IO
419 	getbinuptime(&cur_bt);
420 	bintime_sub(&cur_bt, &io->io_hdr.dma_start_bt);
421 	bintime_add(&io->io_hdr.dma_bt, &cur_bt);
422 #endif
423 	io->io_hdr.num_dmas++;
424 	io->scsiio.kern_rel_offset += io->scsiio.kern_data_len;
425 
426 	/*
427 	 * We set status at this point for read commands, and write
428 	 * commands with errors.
429 	 */
430 	if (io->io_hdr.flags & CTL_FLAG_ABORT) {
431 		;
432 	} else if ((io->io_hdr.port_status != 0) &&
433 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE ||
434 	     (io->io_hdr.status & CTL_STATUS_MASK) == CTL_SUCCESS)) {
435 		ctl_set_internal_failure(&io->scsiio, /*sks_valid*/ 1,
436 		    /*retry_count*/ io->io_hdr.port_status);
437 	} else if (io->scsiio.kern_data_resid != 0 &&
438 	    (io->io_hdr.flags & CTL_FLAG_DATA_MASK) == CTL_FLAG_DATA_OUT &&
439 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE ||
440 	     (io->io_hdr.status & CTL_STATUS_MASK) == CTL_SUCCESS)) {
441 		ctl_set_invalid_field_ciu(&io->scsiio);
442 	} else if ((io->io_hdr.port_status == 0) &&
443 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
444 		lbalen = ARGS(beio->io);
445 		if (lbalen->flags & CTL_LLF_READ) {
446 			ctl_set_success(&io->scsiio);
447 		} else if (lbalen->flags & CTL_LLF_COMPARE) {
448 			/* We have two data blocks ready for comparison. */
449 			ctl_be_block_compare(io);
450 		}
451 	}
452 
453 	/*
454 	 * If this is a read, or a write with errors, it is done.
455 	 */
456 	if ((beio->bio_cmd == BIO_READ)
457 	 || ((io->io_hdr.flags & CTL_FLAG_ABORT) != 0)
458 	 || ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)) {
459 		ctl_complete_beio(beio);
460 		return (0);
461 	}
462 
463 	/*
464 	 * At this point, we have a write and the DMA completed
465 	 * successfully.  We now have to queue it to the task queue to
466 	 * execute the backend I/O.  That is because we do blocking
467 	 * memory allocations, and in the file backing case, blocking I/O.
468 	 * This move done routine is generally called in the SIM's
469 	 * interrupt context, and therefore we cannot block.
470 	 */
471 	mtx_lock(&be_lun->queue_lock);
472 	STAILQ_INSERT_TAIL(&be_lun->datamove_queue, &io->io_hdr, links);
473 	mtx_unlock(&be_lun->queue_lock);
474 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
475 
476 	return (0);
477 }
478 
479 static void
480 ctl_be_block_biodone(struct bio *bio)
481 {
482 	struct ctl_be_block_io *beio;
483 	struct ctl_be_block_lun *be_lun;
484 	union ctl_io *io;
485 	int error;
486 
487 	beio = bio->bio_caller1;
488 	be_lun = beio->lun;
489 	io = beio->io;
490 
491 	DPRINTF("entered\n");
492 
493 	error = bio->bio_error;
494 	mtx_lock(&be_lun->io_lock);
495 	if (error != 0 &&
496 	    (beio->first_error == 0 ||
497 	     bio->bio_offset < beio->first_error_offset)) {
498 		beio->first_error = error;
499 		beio->first_error_offset = bio->bio_offset;
500 	}
501 
502 	beio->num_bios_done++;
503 
504 	/*
505 	 * XXX KDM will this cause WITNESS to complain?  Holding a lock
506 	 * during the free might cause it to complain.
507 	 */
508 	g_destroy_bio(bio);
509 
510 	/*
511 	 * If the send complete bit isn't set, or we aren't the last I/O to
512 	 * complete, then we're done.
513 	 */
514 	if ((beio->send_complete == 0)
515 	 || (beio->num_bios_done < beio->num_bios_sent)) {
516 		mtx_unlock(&be_lun->io_lock);
517 		return;
518 	}
519 
520 	/*
521 	 * At this point, we've verified that we are the last I/O to
522 	 * complete, so it's safe to drop the lock.
523 	 */
524 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
525 	    beio->ds_tag_type, beio->ds_trans_type,
526 	    /*now*/ NULL, /*then*/&beio->ds_t0);
527 	mtx_unlock(&be_lun->io_lock);
528 
529 	/*
530 	 * If there are any errors from the backing device, we fail the
531 	 * entire I/O with a medium error.
532 	 */
533 	error = beio->first_error;
534 	if (error != 0) {
535 		if (error == EOPNOTSUPP) {
536 			ctl_set_invalid_opcode(&io->scsiio);
537 		} else if (error == ENOSPC || error == EDQUOT) {
538 			ctl_set_space_alloc_fail(&io->scsiio);
539 		} else if (error == EROFS || error == EACCES) {
540 			ctl_set_hw_write_protected(&io->scsiio);
541 		} else if (beio->bio_cmd == BIO_FLUSH) {
542 			/* XXX KDM is there is a better error here? */
543 			ctl_set_internal_failure(&io->scsiio,
544 						 /*sks_valid*/ 1,
545 						 /*retry_count*/ 0xbad2);
546 		} else {
547 			ctl_set_medium_error(&io->scsiio,
548 			    beio->bio_cmd == BIO_READ);
549 		}
550 		ctl_complete_beio(beio);
551 		return;
552 	}
553 
554 	/*
555 	 * If this is a write, a flush, a delete or verify, we're all done.
556 	 * If this is a read, we can now send the data to the user.
557 	 */
558 	if ((beio->bio_cmd == BIO_WRITE)
559 	 || (beio->bio_cmd == BIO_FLUSH)
560 	 || (beio->bio_cmd == BIO_DELETE)
561 	 || (ARGS(io)->flags & CTL_LLF_VERIFY)) {
562 		ctl_set_success(&io->scsiio);
563 		ctl_complete_beio(beio);
564 	} else {
565 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
566 		    beio->beio_cont == NULL) {
567 			ctl_set_success(&io->scsiio);
568 			ctl_serseq_done(io);
569 		}
570 #ifdef CTL_TIME_IO
571 		getbinuptime(&io->io_hdr.dma_start_bt);
572 #endif
573 		ctl_datamove(io);
574 	}
575 }
576 
577 static void
578 ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
579 			struct ctl_be_block_io *beio)
580 {
581 	union ctl_io *io = beio->io;
582 	struct mount *mountpoint;
583 	int error, lock_flags;
584 
585 	DPRINTF("entered\n");
586 
587 	binuptime(&beio->ds_t0);
588 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
589 
590 	(void) vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
591 
592 	if (MNT_SHARED_WRITES(mountpoint) ||
593 	    ((mountpoint == NULL) && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
594 		lock_flags = LK_SHARED;
595 	else
596 		lock_flags = LK_EXCLUSIVE;
597 	vn_lock(be_lun->vn, lock_flags | LK_RETRY);
598 	error = VOP_FSYNC(be_lun->vn, beio->io_arg ? MNT_NOWAIT : MNT_WAIT,
599 	    curthread);
600 	VOP_UNLOCK(be_lun->vn);
601 
602 	vn_finished_write(mountpoint);
603 
604 	mtx_lock(&be_lun->io_lock);
605 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
606 	    beio->ds_tag_type, beio->ds_trans_type,
607 	    /*now*/ NULL, /*then*/&beio->ds_t0);
608 	mtx_unlock(&be_lun->io_lock);
609 
610 	if (error == 0)
611 		ctl_set_success(&io->scsiio);
612 	else {
613 		/* XXX KDM is there is a better error here? */
614 		ctl_set_internal_failure(&io->scsiio,
615 					 /*sks_valid*/ 1,
616 					 /*retry_count*/ 0xbad1);
617 	}
618 
619 	ctl_complete_beio(beio);
620 }
621 
622 SDT_PROBE_DEFINE1(cbb, , read, file_start, "uint64_t");
623 SDT_PROBE_DEFINE1(cbb, , write, file_start, "uint64_t");
624 SDT_PROBE_DEFINE1(cbb, , read, file_done,"uint64_t");
625 SDT_PROBE_DEFINE1(cbb, , write, file_done, "uint64_t");
626 
627 static void
628 ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
629 			   struct ctl_be_block_io *beio)
630 {
631 	struct ctl_be_block_filedata *file_data;
632 	union ctl_io *io;
633 	struct uio xuio;
634 	struct iovec *xiovec;
635 	size_t s;
636 	int error, flags, i;
637 
638 	DPRINTF("entered\n");
639 
640 	file_data = &be_lun->backend.file;
641 	io = beio->io;
642 	flags = 0;
643 	if (ARGS(io)->flags & CTL_LLF_DPO)
644 		flags |= IO_DIRECT;
645 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
646 		flags |= IO_SYNC;
647 
648 	bzero(&xuio, sizeof(xuio));
649 	if (beio->bio_cmd == BIO_READ) {
650 		SDT_PROBE0(cbb, , read, file_start);
651 		xuio.uio_rw = UIO_READ;
652 	} else {
653 		SDT_PROBE0(cbb, , write, file_start);
654 		xuio.uio_rw = UIO_WRITE;
655 	}
656 	xuio.uio_offset = beio->io_offset;
657 	xuio.uio_resid = beio->io_len;
658 	xuio.uio_segflg = UIO_SYSSPACE;
659 	xuio.uio_iov = beio->xiovecs;
660 	xuio.uio_iovcnt = beio->num_segs;
661 	xuio.uio_td = curthread;
662 
663 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
664 		xiovec->iov_base = beio->sg_segs[i].addr;
665 		xiovec->iov_len = beio->sg_segs[i].len;
666 	}
667 
668 	binuptime(&beio->ds_t0);
669 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
670 
671 	if (beio->bio_cmd == BIO_READ) {
672 		vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
673 
674 		/*
675 		 * UFS pays attention to IO_DIRECT for reads.  If the
676 		 * DIRECTIO option is configured into the kernel, it calls
677 		 * ffs_rawread().  But that only works for single-segment
678 		 * uios with user space addresses.  In our case, with a
679 		 * kernel uio, it still reads into the buffer cache, but it
680 		 * will just try to release the buffer from the cache later
681 		 * on in ffs_read().
682 		 *
683 		 * ZFS does not pay attention to IO_DIRECT for reads.
684 		 *
685 		 * UFS does not pay attention to IO_SYNC for reads.
686 		 *
687 		 * ZFS pays attention to IO_SYNC (which translates into the
688 		 * Solaris define FRSYNC for zfs_read()) for reads.  It
689 		 * attempts to sync the file before reading.
690 		 */
691 		error = VOP_READ(be_lun->vn, &xuio, flags, file_data->cred);
692 
693 		VOP_UNLOCK(be_lun->vn);
694 		SDT_PROBE0(cbb, , read, file_done);
695 		if (error == 0 && xuio.uio_resid > 0) {
696 			/*
697 			 * If we red less then requested (EOF), then
698 			 * we should clean the rest of the buffer.
699 			 */
700 			s = beio->io_len - xuio.uio_resid;
701 			for (i = 0; i < beio->num_segs; i++) {
702 				if (s >= beio->sg_segs[i].len) {
703 					s -= beio->sg_segs[i].len;
704 					continue;
705 				}
706 				bzero((uint8_t *)beio->sg_segs[i].addr + s,
707 				    beio->sg_segs[i].len - s);
708 				s = 0;
709 			}
710 		}
711 	} else {
712 		struct mount *mountpoint;
713 		int lock_flags;
714 
715 		(void)vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
716 
717 		if (MNT_SHARED_WRITES(mountpoint) || ((mountpoint == NULL)
718 		  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
719 			lock_flags = LK_SHARED;
720 		else
721 			lock_flags = LK_EXCLUSIVE;
722 		vn_lock(be_lun->vn, lock_flags | LK_RETRY);
723 
724 		/*
725 		 * UFS pays attention to IO_DIRECT for writes.  The write
726 		 * is done asynchronously.  (Normally the write would just
727 		 * get put into cache.
728 		 *
729 		 * UFS pays attention to IO_SYNC for writes.  It will
730 		 * attempt to write the buffer out synchronously if that
731 		 * flag is set.
732 		 *
733 		 * ZFS does not pay attention to IO_DIRECT for writes.
734 		 *
735 		 * ZFS pays attention to IO_SYNC (a.k.a. FSYNC or FRSYNC)
736 		 * for writes.  It will flush the transaction from the
737 		 * cache before returning.
738 		 */
739 		error = VOP_WRITE(be_lun->vn, &xuio, flags, file_data->cred);
740 		VOP_UNLOCK(be_lun->vn);
741 
742 		vn_finished_write(mountpoint);
743 		SDT_PROBE0(cbb, , write, file_done);
744         }
745 
746 	mtx_lock(&be_lun->io_lock);
747 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
748 	    beio->ds_tag_type, beio->ds_trans_type,
749 	    /*now*/ NULL, /*then*/&beio->ds_t0);
750 	mtx_unlock(&be_lun->io_lock);
751 
752 	/*
753 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
754 	 * return the I/O to the user.
755 	 */
756 	if (error != 0) {
757 		if (error == ENOSPC || error == EDQUOT) {
758 			ctl_set_space_alloc_fail(&io->scsiio);
759 		} else if (error == EROFS || error == EACCES) {
760 			ctl_set_hw_write_protected(&io->scsiio);
761 		} else {
762 			ctl_set_medium_error(&io->scsiio,
763 			    beio->bio_cmd == BIO_READ);
764 		}
765 		ctl_complete_beio(beio);
766 		return;
767 	}
768 
769 	/*
770 	 * If this is a write or a verify, we're all done.
771 	 * If this is a read, we can now send the data to the user.
772 	 */
773 	if ((beio->bio_cmd == BIO_WRITE) ||
774 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
775 		ctl_set_success(&io->scsiio);
776 		ctl_complete_beio(beio);
777 	} else {
778 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
779 		    beio->beio_cont == NULL) {
780 			ctl_set_success(&io->scsiio);
781 			ctl_serseq_done(io);
782 		}
783 #ifdef CTL_TIME_IO
784 		getbinuptime(&io->io_hdr.dma_start_bt);
785 #endif
786 		ctl_datamove(io);
787 	}
788 }
789 
790 static void
791 ctl_be_block_gls_file(struct ctl_be_block_lun *be_lun,
792 			struct ctl_be_block_io *beio)
793 {
794 	union ctl_io *io = beio->io;
795 	struct ctl_lba_len_flags *lbalen = ARGS(io);
796 	struct scsi_get_lba_status_data *data;
797 	off_t roff, off;
798 	int error, status;
799 
800 	DPRINTF("entered\n");
801 
802 	off = roff = ((off_t)lbalen->lba) * be_lun->cbe_lun.blocksize;
803 	vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
804 	error = VOP_IOCTL(be_lun->vn, FIOSEEKHOLE, &off,
805 	    0, curthread->td_ucred, curthread);
806 	if (error == 0 && off > roff)
807 		status = 0;	/* mapped up to off */
808 	else {
809 		error = VOP_IOCTL(be_lun->vn, FIOSEEKDATA, &off,
810 		    0, curthread->td_ucred, curthread);
811 		if (error == 0 && off > roff)
812 			status = 1;	/* deallocated up to off */
813 		else {
814 			status = 0;	/* unknown up to the end */
815 			off = be_lun->size_bytes;
816 		}
817 	}
818 	VOP_UNLOCK(be_lun->vn);
819 
820 	data = (struct scsi_get_lba_status_data *)io->scsiio.kern_data_ptr;
821 	scsi_u64to8b(lbalen->lba, data->descr[0].addr);
822 	scsi_ulto4b(MIN(UINT32_MAX, off / be_lun->cbe_lun.blocksize -
823 	    lbalen->lba), data->descr[0].length);
824 	data->descr[0].status = status;
825 
826 	ctl_complete_beio(beio);
827 }
828 
829 static uint64_t
830 ctl_be_block_getattr_file(struct ctl_be_block_lun *be_lun, const char *attrname)
831 {
832 	struct vattr		vattr;
833 	struct statfs		statfs;
834 	uint64_t		val;
835 	int			error;
836 
837 	val = UINT64_MAX;
838 	if (be_lun->vn == NULL)
839 		return (val);
840 	vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
841 	if (strcmp(attrname, "blocksused") == 0) {
842 		error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
843 		if (error == 0)
844 			val = vattr.va_bytes / be_lun->cbe_lun.blocksize;
845 	}
846 	if (strcmp(attrname, "blocksavail") == 0 &&
847 	    !VN_IS_DOOMED(be_lun->vn)) {
848 		error = VFS_STATFS(be_lun->vn->v_mount, &statfs);
849 		if (error == 0)
850 			val = statfs.f_bavail * statfs.f_bsize /
851 			    be_lun->cbe_lun.blocksize;
852 	}
853 	VOP_UNLOCK(be_lun->vn);
854 	return (val);
855 }
856 
857 static void
858 ctl_be_block_dispatch_zvol(struct ctl_be_block_lun *be_lun,
859 			   struct ctl_be_block_io *beio)
860 {
861 	union ctl_io *io;
862 	struct cdevsw *csw;
863 	struct cdev *dev;
864 	struct uio xuio;
865 	struct iovec *xiovec;
866 	int error, flags, i, ref;
867 
868 	DPRINTF("entered\n");
869 
870 	io = beio->io;
871 	flags = 0;
872 	if (ARGS(io)->flags & CTL_LLF_DPO)
873 		flags |= IO_DIRECT;
874 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
875 		flags |= IO_SYNC;
876 
877 	bzero(&xuio, sizeof(xuio));
878 	if (beio->bio_cmd == BIO_READ) {
879 		SDT_PROBE0(cbb, , read, file_start);
880 		xuio.uio_rw = UIO_READ;
881 	} else {
882 		SDT_PROBE0(cbb, , write, file_start);
883 		xuio.uio_rw = UIO_WRITE;
884 	}
885 	xuio.uio_offset = beio->io_offset;
886 	xuio.uio_resid = beio->io_len;
887 	xuio.uio_segflg = UIO_SYSSPACE;
888 	xuio.uio_iov = beio->xiovecs;
889 	xuio.uio_iovcnt = beio->num_segs;
890 	xuio.uio_td = curthread;
891 
892 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
893 		xiovec->iov_base = beio->sg_segs[i].addr;
894 		xiovec->iov_len = beio->sg_segs[i].len;
895 	}
896 
897 	binuptime(&beio->ds_t0);
898 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
899 
900 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
901 	if (csw) {
902 		if (beio->bio_cmd == BIO_READ)
903 			error = csw->d_read(dev, &xuio, flags);
904 		else
905 			error = csw->d_write(dev, &xuio, flags);
906 		dev_relthread(dev, ref);
907 	} else
908 		error = ENXIO;
909 
910 	if (beio->bio_cmd == BIO_READ)
911 		SDT_PROBE0(cbb, , read, file_done);
912 	else
913 		SDT_PROBE0(cbb, , write, file_done);
914 
915 	mtx_lock(&be_lun->io_lock);
916 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
917 	    beio->ds_tag_type, beio->ds_trans_type,
918 	    /*now*/ NULL, /*then*/&beio->ds_t0);
919 	mtx_unlock(&be_lun->io_lock);
920 
921 	/*
922 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
923 	 * return the I/O to the user.
924 	 */
925 	if (error != 0) {
926 		if (error == ENOSPC || error == EDQUOT) {
927 			ctl_set_space_alloc_fail(&io->scsiio);
928 		} else if (error == EROFS || error == EACCES) {
929 			ctl_set_hw_write_protected(&io->scsiio);
930 		} else {
931 			ctl_set_medium_error(&io->scsiio,
932 			    beio->bio_cmd == BIO_READ);
933 		}
934 		ctl_complete_beio(beio);
935 		return;
936 	}
937 
938 	/*
939 	 * If this is a write or a verify, we're all done.
940 	 * If this is a read, we can now send the data to the user.
941 	 */
942 	if ((beio->bio_cmd == BIO_WRITE) ||
943 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
944 		ctl_set_success(&io->scsiio);
945 		ctl_complete_beio(beio);
946 	} else {
947 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
948 		    beio->beio_cont == NULL) {
949 			ctl_set_success(&io->scsiio);
950 			ctl_serseq_done(io);
951 		}
952 #ifdef CTL_TIME_IO
953 		getbinuptime(&io->io_hdr.dma_start_bt);
954 #endif
955 		ctl_datamove(io);
956 	}
957 }
958 
959 static void
960 ctl_be_block_gls_zvol(struct ctl_be_block_lun *be_lun,
961 			struct ctl_be_block_io *beio)
962 {
963 	union ctl_io *io = beio->io;
964 	struct cdevsw *csw;
965 	struct cdev *dev;
966 	struct ctl_lba_len_flags *lbalen = ARGS(io);
967 	struct scsi_get_lba_status_data *data;
968 	off_t roff, off;
969 	int error, ref, status;
970 
971 	DPRINTF("entered\n");
972 
973 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
974 	if (csw == NULL) {
975 		status = 0;	/* unknown up to the end */
976 		off = be_lun->size_bytes;
977 		goto done;
978 	}
979 	off = roff = ((off_t)lbalen->lba) * be_lun->cbe_lun.blocksize;
980 	error = csw->d_ioctl(dev, FIOSEEKHOLE, (caddr_t)&off, FREAD,
981 	    curthread);
982 	if (error == 0 && off > roff)
983 		status = 0;	/* mapped up to off */
984 	else {
985 		error = csw->d_ioctl(dev, FIOSEEKDATA, (caddr_t)&off, FREAD,
986 		    curthread);
987 		if (error == 0 && off > roff)
988 			status = 1;	/* deallocated up to off */
989 		else {
990 			status = 0;	/* unknown up to the end */
991 			off = be_lun->size_bytes;
992 		}
993 	}
994 	dev_relthread(dev, ref);
995 
996 done:
997 	data = (struct scsi_get_lba_status_data *)io->scsiio.kern_data_ptr;
998 	scsi_u64to8b(lbalen->lba, data->descr[0].addr);
999 	scsi_ulto4b(MIN(UINT32_MAX, off / be_lun->cbe_lun.blocksize -
1000 	    lbalen->lba), data->descr[0].length);
1001 	data->descr[0].status = status;
1002 
1003 	ctl_complete_beio(beio);
1004 }
1005 
1006 static void
1007 ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
1008 		       struct ctl_be_block_io *beio)
1009 {
1010 	struct bio *bio;
1011 	struct cdevsw *csw;
1012 	struct cdev *dev;
1013 	int ref;
1014 
1015 	DPRINTF("entered\n");
1016 
1017 	/* This can't fail, it's a blocking allocation. */
1018 	bio = g_alloc_bio();
1019 
1020 	bio->bio_cmd	    = BIO_FLUSH;
1021 	bio->bio_offset	    = 0;
1022 	bio->bio_data	    = 0;
1023 	bio->bio_done	    = ctl_be_block_biodone;
1024 	bio->bio_caller1    = beio;
1025 	bio->bio_pblkno	    = 0;
1026 
1027 	/*
1028 	 * We don't need to acquire the LUN lock here, because we are only
1029 	 * sending one bio, and so there is no other context to synchronize
1030 	 * with.
1031 	 */
1032 	beio->num_bios_sent = 1;
1033 	beio->send_complete = 1;
1034 
1035 	binuptime(&beio->ds_t0);
1036 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1037 
1038 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1039 	if (csw) {
1040 		bio->bio_dev = dev;
1041 		csw->d_strategy(bio);
1042 		dev_relthread(dev, ref);
1043 	} else {
1044 		bio->bio_error = ENXIO;
1045 		ctl_be_block_biodone(bio);
1046 	}
1047 }
1048 
1049 static void
1050 ctl_be_block_unmap_dev_range(struct ctl_be_block_lun *be_lun,
1051 		       struct ctl_be_block_io *beio,
1052 		       uint64_t off, uint64_t len, int last)
1053 {
1054 	struct bio *bio;
1055 	uint64_t maxlen;
1056 	struct cdevsw *csw;
1057 	struct cdev *dev;
1058 	int ref;
1059 
1060 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1061 	maxlen = LONG_MAX - (LONG_MAX % be_lun->cbe_lun.blocksize);
1062 	while (len > 0) {
1063 		bio = g_alloc_bio();
1064 		bio->bio_cmd	    = BIO_DELETE;
1065 		bio->bio_dev	    = dev;
1066 		bio->bio_offset	    = off;
1067 		bio->bio_length	    = MIN(len, maxlen);
1068 		bio->bio_data	    = 0;
1069 		bio->bio_done	    = ctl_be_block_biodone;
1070 		bio->bio_caller1    = beio;
1071 		bio->bio_pblkno     = off / be_lun->cbe_lun.blocksize;
1072 
1073 		off += bio->bio_length;
1074 		len -= bio->bio_length;
1075 
1076 		mtx_lock(&be_lun->io_lock);
1077 		beio->num_bios_sent++;
1078 		if (last && len == 0)
1079 			beio->send_complete = 1;
1080 		mtx_unlock(&be_lun->io_lock);
1081 
1082 		if (csw) {
1083 			csw->d_strategy(bio);
1084 		} else {
1085 			bio->bio_error = ENXIO;
1086 			ctl_be_block_biodone(bio);
1087 		}
1088 	}
1089 	if (csw)
1090 		dev_relthread(dev, ref);
1091 }
1092 
1093 static void
1094 ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
1095 		       struct ctl_be_block_io *beio)
1096 {
1097 	union ctl_io *io;
1098 	struct ctl_ptr_len_flags *ptrlen;
1099 	struct scsi_unmap_desc *buf, *end;
1100 	uint64_t len;
1101 
1102 	io = beio->io;
1103 
1104 	DPRINTF("entered\n");
1105 
1106 	binuptime(&beio->ds_t0);
1107 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1108 
1109 	if (beio->io_offset == -1) {
1110 		beio->io_len = 0;
1111 		ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1112 		buf = (struct scsi_unmap_desc *)ptrlen->ptr;
1113 		end = buf + ptrlen->len / sizeof(*buf);
1114 		for (; buf < end; buf++) {
1115 			len = (uint64_t)scsi_4btoul(buf->length) *
1116 			    be_lun->cbe_lun.blocksize;
1117 			beio->io_len += len;
1118 			ctl_be_block_unmap_dev_range(be_lun, beio,
1119 			    scsi_8btou64(buf->lba) * be_lun->cbe_lun.blocksize,
1120 			    len, (end - buf < 2) ? TRUE : FALSE);
1121 		}
1122 	} else
1123 		ctl_be_block_unmap_dev_range(be_lun, beio,
1124 		    beio->io_offset, beio->io_len, TRUE);
1125 }
1126 
1127 static void
1128 ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
1129 			  struct ctl_be_block_io *beio)
1130 {
1131 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
1132 	struct bio *bio;
1133 	struct cdevsw *csw;
1134 	struct cdev *dev;
1135 	off_t cur_offset;
1136 	int i, max_iosize, ref;
1137 
1138 	DPRINTF("entered\n");
1139 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1140 
1141 	/*
1142 	 * We have to limit our I/O size to the maximum supported by the
1143 	 * backend device.  Hopefully it is MAXPHYS.  If the driver doesn't
1144 	 * set it properly, use DFLTPHYS.
1145 	 */
1146 	if (csw) {
1147 		max_iosize = dev->si_iosize_max;
1148 		if (max_iosize < PAGE_SIZE)
1149 			max_iosize = DFLTPHYS;
1150 	} else
1151 		max_iosize = DFLTPHYS;
1152 
1153 	cur_offset = beio->io_offset;
1154 	for (i = 0; i < beio->num_segs; i++) {
1155 		size_t cur_size;
1156 		uint8_t *cur_ptr;
1157 
1158 		cur_size = beio->sg_segs[i].len;
1159 		cur_ptr = beio->sg_segs[i].addr;
1160 
1161 		while (cur_size > 0) {
1162 			/* This can't fail, it's a blocking allocation. */
1163 			bio = g_alloc_bio();
1164 
1165 			KASSERT(bio != NULL, ("g_alloc_bio() failed!\n"));
1166 
1167 			bio->bio_cmd = beio->bio_cmd;
1168 			bio->bio_dev = dev;
1169 			bio->bio_caller1 = beio;
1170 			bio->bio_length = min(cur_size, max_iosize);
1171 			bio->bio_offset = cur_offset;
1172 			bio->bio_data = cur_ptr;
1173 			bio->bio_done = ctl_be_block_biodone;
1174 			bio->bio_pblkno = cur_offset / be_lun->cbe_lun.blocksize;
1175 
1176 			cur_offset += bio->bio_length;
1177 			cur_ptr += bio->bio_length;
1178 			cur_size -= bio->bio_length;
1179 
1180 			TAILQ_INSERT_TAIL(&queue, bio, bio_queue);
1181 			beio->num_bios_sent++;
1182 		}
1183 	}
1184 	beio->send_complete = 1;
1185 	binuptime(&beio->ds_t0);
1186 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1187 
1188 	/*
1189 	 * Fire off all allocated requests!
1190 	 */
1191 	while ((bio = TAILQ_FIRST(&queue)) != NULL) {
1192 		TAILQ_REMOVE(&queue, bio, bio_queue);
1193 		if (csw)
1194 			csw->d_strategy(bio);
1195 		else {
1196 			bio->bio_error = ENXIO;
1197 			ctl_be_block_biodone(bio);
1198 		}
1199 	}
1200 	if (csw)
1201 		dev_relthread(dev, ref);
1202 }
1203 
1204 static uint64_t
1205 ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun, const char *attrname)
1206 {
1207 	struct diocgattr_arg	arg;
1208 	struct cdevsw *csw;
1209 	struct cdev *dev;
1210 	int error, ref;
1211 
1212 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1213 	if (csw == NULL)
1214 		return (UINT64_MAX);
1215 	strlcpy(arg.name, attrname, sizeof(arg.name));
1216 	arg.len = sizeof(arg.value.off);
1217 	if (csw->d_ioctl) {
1218 		error = csw->d_ioctl(dev, DIOCGATTR, (caddr_t)&arg, FREAD,
1219 		    curthread);
1220 	} else
1221 		error = ENODEV;
1222 	dev_relthread(dev, ref);
1223 	if (error != 0)
1224 		return (UINT64_MAX);
1225 	return (arg.value.off);
1226 }
1227 
1228 static void
1229 ctl_be_block_cw_dispatch_sync(struct ctl_be_block_lun *be_lun,
1230 			    union ctl_io *io)
1231 {
1232 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1233 	struct ctl_be_block_io *beio;
1234 	struct ctl_lba_len_flags *lbalen;
1235 
1236 	DPRINTF("entered\n");
1237 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1238 	lbalen = (struct ctl_lba_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1239 
1240 	beio->io_len = lbalen->len * cbe_lun->blocksize;
1241 	beio->io_offset = lbalen->lba * cbe_lun->blocksize;
1242 	beio->io_arg = (lbalen->flags & SSC_IMMED) != 0;
1243 	beio->bio_cmd = BIO_FLUSH;
1244 	beio->ds_trans_type = DEVSTAT_NO_DATA;
1245 	DPRINTF("SYNC\n");
1246 	be_lun->lun_flush(be_lun, beio);
1247 }
1248 
1249 static void
1250 ctl_be_block_cw_done_ws(struct ctl_be_block_io *beio)
1251 {
1252 	union ctl_io *io;
1253 
1254 	io = beio->io;
1255 	ctl_free_beio(beio);
1256 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1257 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1258 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1259 		ctl_config_write_done(io);
1260 		return;
1261 	}
1262 
1263 	ctl_be_block_config_write(io);
1264 }
1265 
1266 static void
1267 ctl_be_block_cw_dispatch_ws(struct ctl_be_block_lun *be_lun,
1268 			    union ctl_io *io)
1269 {
1270 	struct ctl_be_block_softc *softc = be_lun->softc;
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 		 * Setup the S/G entry for this chunk.
1322 		 */
1323 		seglen = MIN(CTLBLK_MAX_SEG, len_left);
1324 		if (pb > cbe_lun->blocksize) {
1325 			adj = ((lbalen->lba + lba) * cbe_lun->blocksize +
1326 			    seglen - pbo) % pb;
1327 			if (seglen > adj)
1328 				seglen -= adj;
1329 			else
1330 				seglen -= seglen % cbe_lun->blocksize;
1331 		} else
1332 			seglen -= seglen % cbe_lun->blocksize;
1333 		beio->sg_segs[i].len = seglen;
1334 		beio->sg_segs[i].addr = uma_zalloc(softc->buf_zone, M_WAITOK);
1335 
1336 		DPRINTF("segment %d addr %p len %zd\n", i,
1337 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1338 
1339 		beio->num_segs++;
1340 		len_left -= seglen;
1341 
1342 		buf = beio->sg_segs[i].addr;
1343 		end = buf + seglen;
1344 		for (; buf < end; buf += cbe_lun->blocksize) {
1345 			if (lbalen->flags & SWS_NDOB) {
1346 				memset(buf, 0, cbe_lun->blocksize);
1347 			} else {
1348 				memcpy(buf, io->scsiio.kern_data_ptr,
1349 				    cbe_lun->blocksize);
1350 			}
1351 			if (lbalen->flags & SWS_LBDATA)
1352 				scsi_ulto4b(lbalen->lba + lba, buf);
1353 			lba++;
1354 		}
1355 	}
1356 
1357 	beio->io_offset = lbalen->lba * cbe_lun->blocksize;
1358 	beio->io_len = lba * cbe_lun->blocksize;
1359 
1360 	/* We can not do all in one run. Correct and schedule rerun. */
1361 	if (len_left > 0) {
1362 		lbalen->lba += lba;
1363 		lbalen->len -= lba;
1364 		beio->beio_cont = ctl_be_block_cw_done_ws;
1365 	}
1366 
1367 	be_lun->dispatch(be_lun, beio);
1368 }
1369 
1370 static void
1371 ctl_be_block_cw_dispatch_unmap(struct ctl_be_block_lun *be_lun,
1372 			    union ctl_io *io)
1373 {
1374 	struct ctl_be_block_io *beio;
1375 	struct ctl_ptr_len_flags *ptrlen;
1376 
1377 	DPRINTF("entered\n");
1378 
1379 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1380 	ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1381 
1382 	if ((ptrlen->flags & ~SU_ANCHOR) != 0 || be_lun->unmap == NULL) {
1383 		ctl_free_beio(beio);
1384 		ctl_set_invalid_field(&io->scsiio,
1385 				      /*sks_valid*/ 0,
1386 				      /*command*/ 1,
1387 				      /*field*/ 0,
1388 				      /*bit_valid*/ 0,
1389 				      /*bit*/ 0);
1390 		ctl_config_write_done(io);
1391 		return;
1392 	}
1393 
1394 	beio->io_len = 0;
1395 	beio->io_offset = -1;
1396 	beio->bio_cmd = BIO_DELETE;
1397 	beio->ds_trans_type = DEVSTAT_FREE;
1398 	DPRINTF("UNMAP\n");
1399 	be_lun->unmap(be_lun, beio);
1400 }
1401 
1402 static void
1403 ctl_be_block_cr_done(struct ctl_be_block_io *beio)
1404 {
1405 	union ctl_io *io;
1406 
1407 	io = beio->io;
1408 	ctl_free_beio(beio);
1409 	ctl_config_read_done(io);
1410 }
1411 
1412 static void
1413 ctl_be_block_cr_dispatch(struct ctl_be_block_lun *be_lun,
1414 			 union ctl_io *io)
1415 {
1416 	struct ctl_be_block_io *beio;
1417 	struct ctl_be_block_softc *softc;
1418 
1419 	DPRINTF("entered\n");
1420 
1421 	softc = be_lun->softc;
1422 	beio = ctl_alloc_beio(softc);
1423 	beio->io = io;
1424 	beio->lun = be_lun;
1425 	beio->beio_cont = ctl_be_block_cr_done;
1426 	PRIV(io)->ptr = (void *)beio;
1427 
1428 	switch (io->scsiio.cdb[0]) {
1429 	case SERVICE_ACTION_IN:		/* GET LBA STATUS */
1430 		beio->bio_cmd = -1;
1431 		beio->ds_trans_type = DEVSTAT_NO_DATA;
1432 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1433 		beio->io_len = 0;
1434 		if (be_lun->get_lba_status)
1435 			be_lun->get_lba_status(be_lun, beio);
1436 		else
1437 			ctl_be_block_cr_done(beio);
1438 		break;
1439 	default:
1440 		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1441 		break;
1442 	}
1443 }
1444 
1445 static void
1446 ctl_be_block_cw_done(struct ctl_be_block_io *beio)
1447 {
1448 	union ctl_io *io;
1449 
1450 	io = beio->io;
1451 	ctl_free_beio(beio);
1452 	ctl_config_write_done(io);
1453 }
1454 
1455 static void
1456 ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
1457 			 union ctl_io *io)
1458 {
1459 	struct ctl_be_block_io *beio;
1460 	struct ctl_be_block_softc *softc;
1461 
1462 	DPRINTF("entered\n");
1463 
1464 	softc = be_lun->softc;
1465 	beio = ctl_alloc_beio(softc);
1466 	beio->io = io;
1467 	beio->lun = be_lun;
1468 	beio->beio_cont = ctl_be_block_cw_done;
1469 	switch (io->scsiio.tag_type) {
1470 	case CTL_TAG_ORDERED:
1471 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1472 		break;
1473 	case CTL_TAG_HEAD_OF_QUEUE:
1474 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1475 		break;
1476 	case CTL_TAG_UNTAGGED:
1477 	case CTL_TAG_SIMPLE:
1478 	case CTL_TAG_ACA:
1479 	default:
1480 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1481 		break;
1482 	}
1483 	PRIV(io)->ptr = (void *)beio;
1484 
1485 	switch (io->scsiio.cdb[0]) {
1486 	case SYNCHRONIZE_CACHE:
1487 	case SYNCHRONIZE_CACHE_16:
1488 		ctl_be_block_cw_dispatch_sync(be_lun, io);
1489 		break;
1490 	case WRITE_SAME_10:
1491 	case WRITE_SAME_16:
1492 		ctl_be_block_cw_dispatch_ws(be_lun, io);
1493 		break;
1494 	case UNMAP:
1495 		ctl_be_block_cw_dispatch_unmap(be_lun, io);
1496 		break;
1497 	default:
1498 		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1499 		break;
1500 	}
1501 }
1502 
1503 SDT_PROBE_DEFINE1(cbb, , read, start, "uint64_t");
1504 SDT_PROBE_DEFINE1(cbb, , write, start, "uint64_t");
1505 SDT_PROBE_DEFINE1(cbb, , read, alloc_done, "uint64_t");
1506 SDT_PROBE_DEFINE1(cbb, , write, alloc_done, "uint64_t");
1507 
1508 static void
1509 ctl_be_block_next(struct ctl_be_block_io *beio)
1510 {
1511 	struct ctl_be_block_lun *be_lun;
1512 	union ctl_io *io;
1513 
1514 	io = beio->io;
1515 	be_lun = beio->lun;
1516 	ctl_free_beio(beio);
1517 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1518 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1519 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1520 		ctl_data_submit_done(io);
1521 		return;
1522 	}
1523 
1524 	io->io_hdr.status &= ~CTL_STATUS_MASK;
1525 	io->io_hdr.status |= CTL_STATUS_NONE;
1526 
1527 	mtx_lock(&be_lun->queue_lock);
1528 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1529 	mtx_unlock(&be_lun->queue_lock);
1530 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1531 }
1532 
1533 static void
1534 ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
1535 			   union ctl_io *io)
1536 {
1537 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1538 	struct ctl_be_block_io *beio;
1539 	struct ctl_be_block_softc *softc;
1540 	struct ctl_lba_len_flags *lbalen;
1541 	struct ctl_ptr_len_flags *bptrlen;
1542 	uint64_t len_left, lbas;
1543 	int i;
1544 
1545 	softc = be_lun->softc;
1546 
1547 	DPRINTF("entered\n");
1548 
1549 	lbalen = ARGS(io);
1550 	if (lbalen->flags & CTL_LLF_WRITE) {
1551 		SDT_PROBE0(cbb, , write, start);
1552 	} else {
1553 		SDT_PROBE0(cbb, , read, start);
1554 	}
1555 
1556 	beio = ctl_alloc_beio(softc);
1557 	beio->io = io;
1558 	beio->lun = be_lun;
1559 	bptrlen = PRIV(io);
1560 	bptrlen->ptr = (void *)beio;
1561 
1562 	switch (io->scsiio.tag_type) {
1563 	case CTL_TAG_ORDERED:
1564 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1565 		break;
1566 	case CTL_TAG_HEAD_OF_QUEUE:
1567 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1568 		break;
1569 	case CTL_TAG_UNTAGGED:
1570 	case CTL_TAG_SIMPLE:
1571 	case CTL_TAG_ACA:
1572 	default:
1573 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1574 		break;
1575 	}
1576 
1577 	if (lbalen->flags & CTL_LLF_WRITE) {
1578 		beio->bio_cmd = BIO_WRITE;
1579 		beio->ds_trans_type = DEVSTAT_WRITE;
1580 	} else {
1581 		beio->bio_cmd = BIO_READ;
1582 		beio->ds_trans_type = DEVSTAT_READ;
1583 	}
1584 
1585 	DPRINTF("%s at LBA %jx len %u @%ju\n",
1586 	       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE",
1587 	       (uintmax_t)lbalen->lba, lbalen->len, bptrlen->len);
1588 	if (lbalen->flags & CTL_LLF_COMPARE) {
1589 		beio->two_sglists = 1;
1590 		lbas = CTLBLK_HALF_IO_SIZE;
1591 	} else {
1592 		lbas = CTLBLK_MAX_IO_SIZE;
1593 	}
1594 	lbas = MIN(lbalen->len - bptrlen->len, lbas / cbe_lun->blocksize);
1595 	beio->io_offset = (lbalen->lba + bptrlen->len) * cbe_lun->blocksize;
1596 	beio->io_len = lbas * cbe_lun->blocksize;
1597 	bptrlen->len += lbas;
1598 
1599 	for (i = 0, len_left = beio->io_len; len_left > 0; i++) {
1600 		KASSERT(i < CTLBLK_MAX_SEGS, ("Too many segs (%d >= %d)",
1601 		    i, CTLBLK_MAX_SEGS));
1602 
1603 		/*
1604 		 * Setup the S/G entry for this chunk.
1605 		 */
1606 		beio->sg_segs[i].len = min(CTLBLK_MAX_SEG, len_left);
1607 		beio->sg_segs[i].addr = uma_zalloc(softc->buf_zone, M_WAITOK);
1608 
1609 		DPRINTF("segment %d addr %p len %zd\n", i,
1610 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1611 
1612 		/* Set up second segment for compare operation. */
1613 		if (beio->two_sglists) {
1614 			beio->sg_segs[i + CTLBLK_HALF_SEGS].len =
1615 			    beio->sg_segs[i].len;
1616 			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr =
1617 			    uma_zalloc(softc->buf_zone, M_WAITOK);
1618 		}
1619 
1620 		beio->num_segs++;
1621 		len_left -= beio->sg_segs[i].len;
1622 	}
1623 	if (bptrlen->len < lbalen->len)
1624 		beio->beio_cont = ctl_be_block_next;
1625 	io->scsiio.be_move_done = ctl_be_block_move_done;
1626 	/* For compare we have separate S/G lists for read and datamove. */
1627 	if (beio->two_sglists)
1628 		io->scsiio.kern_data_ptr = (uint8_t *)&beio->sg_segs[CTLBLK_HALF_SEGS];
1629 	else
1630 		io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
1631 	io->scsiio.kern_data_len = beio->io_len;
1632 	io->scsiio.kern_sg_entries = beio->num_segs;
1633 	io->scsiio.kern_data_ref = ctl_refcnt_beio;
1634 	io->scsiio.kern_data_arg = beio;
1635 	io->io_hdr.flags |= CTL_FLAG_ALLOCATED;
1636 
1637 	/*
1638 	 * For the read case, we need to read the data into our buffers and
1639 	 * then we can send it back to the user.  For the write case, we
1640 	 * need to get the data from the user first.
1641 	 */
1642 	if (beio->bio_cmd == BIO_READ) {
1643 		SDT_PROBE0(cbb, , read, alloc_done);
1644 		be_lun->dispatch(be_lun, beio);
1645 	} else {
1646 		SDT_PROBE0(cbb, , write, alloc_done);
1647 #ifdef CTL_TIME_IO
1648 		getbinuptime(&io->io_hdr.dma_start_bt);
1649 #endif
1650 		ctl_datamove(io);
1651 	}
1652 }
1653 
1654 static void
1655 ctl_be_block_worker(void *context, int pending)
1656 {
1657 	struct ctl_be_block_lun *be_lun = (struct ctl_be_block_lun *)context;
1658 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1659 	union ctl_io *io;
1660 	struct ctl_be_block_io *beio;
1661 
1662 	DPRINTF("entered\n");
1663 	/*
1664 	 * Fetch and process I/Os from all queues.  If we detect LUN
1665 	 * CTL_LUN_FLAG_NO_MEDIA status here -- it is result of a race,
1666 	 * so make response maximally opaque to not confuse initiator.
1667 	 */
1668 	for (;;) {
1669 		mtx_lock(&be_lun->queue_lock);
1670 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->datamove_queue);
1671 		if (io != NULL) {
1672 			DPRINTF("datamove queue\n");
1673 			STAILQ_REMOVE(&be_lun->datamove_queue, &io->io_hdr,
1674 				      ctl_io_hdr, links);
1675 			mtx_unlock(&be_lun->queue_lock);
1676 			beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1677 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1678 				ctl_set_busy(&io->scsiio);
1679 				ctl_complete_beio(beio);
1680 				return;
1681 			}
1682 			be_lun->dispatch(be_lun, beio);
1683 			continue;
1684 		}
1685 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_write_queue);
1686 		if (io != NULL) {
1687 			DPRINTF("config write queue\n");
1688 			STAILQ_REMOVE(&be_lun->config_write_queue, &io->io_hdr,
1689 				      ctl_io_hdr, links);
1690 			mtx_unlock(&be_lun->queue_lock);
1691 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1692 				ctl_set_busy(&io->scsiio);
1693 				ctl_config_write_done(io);
1694 				return;
1695 			}
1696 			ctl_be_block_cw_dispatch(be_lun, io);
1697 			continue;
1698 		}
1699 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_read_queue);
1700 		if (io != NULL) {
1701 			DPRINTF("config read queue\n");
1702 			STAILQ_REMOVE(&be_lun->config_read_queue, &io->io_hdr,
1703 				      ctl_io_hdr, links);
1704 			mtx_unlock(&be_lun->queue_lock);
1705 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1706 				ctl_set_busy(&io->scsiio);
1707 				ctl_config_read_done(io);
1708 				return;
1709 			}
1710 			ctl_be_block_cr_dispatch(be_lun, io);
1711 			continue;
1712 		}
1713 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->input_queue);
1714 		if (io != NULL) {
1715 			DPRINTF("input queue\n");
1716 			STAILQ_REMOVE(&be_lun->input_queue, &io->io_hdr,
1717 				      ctl_io_hdr, links);
1718 			mtx_unlock(&be_lun->queue_lock);
1719 			if (cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) {
1720 				ctl_set_busy(&io->scsiio);
1721 				ctl_data_submit_done(io);
1722 				return;
1723 			}
1724 			ctl_be_block_dispatch(be_lun, io);
1725 			continue;
1726 		}
1727 
1728 		/*
1729 		 * If we get here, there is no work left in the queues, so
1730 		 * just break out and let the task queue go to sleep.
1731 		 */
1732 		mtx_unlock(&be_lun->queue_lock);
1733 		break;
1734 	}
1735 }
1736 
1737 /*
1738  * Entry point from CTL to the backend for I/O.  We queue everything to a
1739  * work thread, so this just puts the I/O on a queue and wakes up the
1740  * thread.
1741  */
1742 static int
1743 ctl_be_block_submit(union ctl_io *io)
1744 {
1745 	struct ctl_be_block_lun *be_lun;
1746 
1747 	DPRINTF("entered\n");
1748 
1749 	be_lun = (struct ctl_be_block_lun *)CTL_BACKEND_LUN(io);
1750 
1751 	/*
1752 	 * Make sure we only get SCSI I/O.
1753 	 */
1754 	KASSERT(io->io_hdr.io_type == CTL_IO_SCSI, ("Non-SCSI I/O (type "
1755 		"%#x) encountered", io->io_hdr.io_type));
1756 
1757 	PRIV(io)->len = 0;
1758 
1759 	mtx_lock(&be_lun->queue_lock);
1760 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1761 	mtx_unlock(&be_lun->queue_lock);
1762 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1763 
1764 	return (CTL_RETVAL_COMPLETE);
1765 }
1766 
1767 static int
1768 ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
1769 			int flag, struct thread *td)
1770 {
1771 	struct ctl_be_block_softc *softc = &backend_block_softc;
1772 	int error;
1773 
1774 	error = 0;
1775 	switch (cmd) {
1776 	case CTL_LUN_REQ: {
1777 		struct ctl_lun_req *lun_req;
1778 
1779 		lun_req = (struct ctl_lun_req *)addr;
1780 
1781 		switch (lun_req->reqtype) {
1782 		case CTL_LUNREQ_CREATE:
1783 			error = ctl_be_block_create(softc, lun_req);
1784 			break;
1785 		case CTL_LUNREQ_RM:
1786 			error = ctl_be_block_rm(softc, lun_req);
1787 			break;
1788 		case CTL_LUNREQ_MODIFY:
1789 			error = ctl_be_block_modify(softc, lun_req);
1790 			break;
1791 		default:
1792 			lun_req->status = CTL_LUN_ERROR;
1793 			snprintf(lun_req->error_str, sizeof(lun_req->error_str),
1794 				 "invalid LUN request type %d",
1795 				 lun_req->reqtype);
1796 			break;
1797 		}
1798 		break;
1799 	}
1800 	default:
1801 		error = ENOTTY;
1802 		break;
1803 	}
1804 
1805 	return (error);
1806 }
1807 
1808 static int
1809 ctl_be_block_open_file(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1810 {
1811 	struct ctl_be_lun *cbe_lun;
1812 	struct ctl_be_block_filedata *file_data;
1813 	struct ctl_lun_create_params *params;
1814 	const char		     *value;
1815 	struct vattr		      vattr;
1816 	off_t			      ps, pss, po, pos, us, uss, uo, uos;
1817 	int			      error;
1818 
1819 	cbe_lun = &be_lun->cbe_lun;
1820 	file_data = &be_lun->backend.file;
1821 	params = &be_lun->params;
1822 
1823 	be_lun->dev_type = CTL_BE_BLOCK_FILE;
1824 	be_lun->dispatch = ctl_be_block_dispatch_file;
1825 	be_lun->lun_flush = ctl_be_block_flush_file;
1826 	be_lun->get_lba_status = ctl_be_block_gls_file;
1827 	be_lun->getattr = ctl_be_block_getattr_file;
1828 	be_lun->unmap = NULL;
1829 	cbe_lun->flags &= ~CTL_LUN_FLAG_UNMAP;
1830 
1831 	error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
1832 	if (error != 0) {
1833 		snprintf(req->error_str, sizeof(req->error_str),
1834 			 "error calling VOP_GETATTR() for file %s",
1835 			 be_lun->dev_path);
1836 		return (error);
1837 	}
1838 
1839 	file_data->cred = crhold(curthread->td_ucred);
1840 	if (params->lun_size_bytes != 0)
1841 		be_lun->size_bytes = params->lun_size_bytes;
1842 	else
1843 		be_lun->size_bytes = vattr.va_size;
1844 
1845 	/*
1846 	 * For files we can use any logical block size.  Prefer 512 bytes
1847 	 * for compatibility reasons.  If file's vattr.va_blocksize
1848 	 * (preferred I/O block size) is bigger and multiple to chosen
1849 	 * logical block size -- report it as physical block size.
1850 	 */
1851 	if (params->blocksize_bytes != 0)
1852 		cbe_lun->blocksize = params->blocksize_bytes;
1853 	else if (cbe_lun->lun_type == T_CDROM)
1854 		cbe_lun->blocksize = 2048;
1855 	else
1856 		cbe_lun->blocksize = 512;
1857 	be_lun->size_blocks = be_lun->size_bytes / cbe_lun->blocksize;
1858 	cbe_lun->maxlba = (be_lun->size_blocks == 0) ?
1859 	    0 : (be_lun->size_blocks - 1);
1860 
1861 	us = ps = vattr.va_blocksize;
1862 	uo = po = 0;
1863 
1864 	value = dnvlist_get_string(cbe_lun->options, "pblocksize", NULL);
1865 	if (value != NULL)
1866 		ctl_expand_number(value, &ps);
1867 	value = dnvlist_get_string(cbe_lun->options, "pblockoffset", NULL);
1868 	if (value != NULL)
1869 		ctl_expand_number(value, &po);
1870 	pss = ps / cbe_lun->blocksize;
1871 	pos = po / cbe_lun->blocksize;
1872 	if ((pss > 0) && (pss * cbe_lun->blocksize == ps) && (pss >= pos) &&
1873 	    ((pss & (pss - 1)) == 0) && (pos * cbe_lun->blocksize == po)) {
1874 		cbe_lun->pblockexp = fls(pss) - 1;
1875 		cbe_lun->pblockoff = (pss - pos) % pss;
1876 	}
1877 
1878 	value = dnvlist_get_string(cbe_lun->options, "ublocksize", NULL);
1879 	if (value != NULL)
1880 		ctl_expand_number(value, &us);
1881 	value = dnvlist_get_string(cbe_lun->options, "ublockoffset", NULL);
1882 	if (value != NULL)
1883 		ctl_expand_number(value, &uo);
1884 	uss = us / cbe_lun->blocksize;
1885 	uos = uo / cbe_lun->blocksize;
1886 	if ((uss > 0) && (uss * cbe_lun->blocksize == us) && (uss >= uos) &&
1887 	    ((uss & (uss - 1)) == 0) && (uos * cbe_lun->blocksize == uo)) {
1888 		cbe_lun->ublockexp = fls(uss) - 1;
1889 		cbe_lun->ublockoff = (uss - uos) % uss;
1890 	}
1891 
1892 	/*
1893 	 * Sanity check.  The media size has to be at least one
1894 	 * sector long.
1895 	 */
1896 	if (be_lun->size_bytes < cbe_lun->blocksize) {
1897 		error = EINVAL;
1898 		snprintf(req->error_str, sizeof(req->error_str),
1899 			 "file %s size %ju < block size %u", be_lun->dev_path,
1900 			 (uintmax_t)be_lun->size_bytes, cbe_lun->blocksize);
1901 	}
1902 
1903 	cbe_lun->opttxferlen = CTLBLK_MAX_IO_SIZE / cbe_lun->blocksize;
1904 	return (error);
1905 }
1906 
1907 static int
1908 ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1909 {
1910 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
1911 	struct ctl_lun_create_params *params;
1912 	struct cdevsw		     *csw;
1913 	struct cdev		     *dev;
1914 	const char		     *value;
1915 	int			      error, atomic, maxio, ref, unmap, tmp;
1916 	off_t			      ps, pss, po, pos, us, uss, uo, uos, otmp;
1917 
1918 	params = &be_lun->params;
1919 
1920 	be_lun->dev_type = CTL_BE_BLOCK_DEV;
1921 	csw = devvn_refthread(be_lun->vn, &dev, &ref);
1922 	if (csw == NULL)
1923 		return (ENXIO);
1924 	if (strcmp(csw->d_name, "zvol") == 0) {
1925 		be_lun->dispatch = ctl_be_block_dispatch_zvol;
1926 		be_lun->get_lba_status = ctl_be_block_gls_zvol;
1927 		atomic = maxio = CTLBLK_MAX_IO_SIZE;
1928 	} else {
1929 		be_lun->dispatch = ctl_be_block_dispatch_dev;
1930 		be_lun->get_lba_status = NULL;
1931 		atomic = 0;
1932 		maxio = dev->si_iosize_max;
1933 		if (maxio <= 0)
1934 			maxio = DFLTPHYS;
1935 		if (maxio > CTLBLK_MAX_IO_SIZE)
1936 			maxio = CTLBLK_MAX_IO_SIZE;
1937 	}
1938 	be_lun->lun_flush = ctl_be_block_flush_dev;
1939 	be_lun->getattr = ctl_be_block_getattr_dev;
1940 	be_lun->unmap = ctl_be_block_unmap_dev;
1941 
1942 	if (!csw->d_ioctl) {
1943 		dev_relthread(dev, ref);
1944 		snprintf(req->error_str, sizeof(req->error_str),
1945 			 "no d_ioctl for device %s!", be_lun->dev_path);
1946 		return (ENODEV);
1947 	}
1948 
1949 	error = csw->d_ioctl(dev, DIOCGSECTORSIZE, (caddr_t)&tmp, FREAD,
1950 			       curthread);
1951 	if (error) {
1952 		dev_relthread(dev, ref);
1953 		snprintf(req->error_str, sizeof(req->error_str),
1954 			 "error %d returned for DIOCGSECTORSIZE ioctl "
1955 			 "on %s!", error, be_lun->dev_path);
1956 		return (error);
1957 	}
1958 
1959 	/*
1960 	 * If the user has asked for a blocksize that is greater than the
1961 	 * backing device's blocksize, we can do it only if the blocksize
1962 	 * the user is asking for is an even multiple of the underlying
1963 	 * device's blocksize.
1964 	 */
1965 	if ((params->blocksize_bytes != 0) &&
1966 	    (params->blocksize_bytes >= tmp)) {
1967 		if (params->blocksize_bytes % tmp == 0) {
1968 			cbe_lun->blocksize = params->blocksize_bytes;
1969 		} else {
1970 			dev_relthread(dev, ref);
1971 			snprintf(req->error_str, sizeof(req->error_str),
1972 				 "requested blocksize %u is not an even "
1973 				 "multiple of backing device blocksize %u",
1974 				 params->blocksize_bytes, tmp);
1975 			return (EINVAL);
1976 		}
1977 	} else if (params->blocksize_bytes != 0) {
1978 		dev_relthread(dev, ref);
1979 		snprintf(req->error_str, sizeof(req->error_str),
1980 			 "requested blocksize %u < backing device "
1981 			 "blocksize %u", params->blocksize_bytes, tmp);
1982 		return (EINVAL);
1983 	} else if (cbe_lun->lun_type == T_CDROM)
1984 		cbe_lun->blocksize = MAX(tmp, 2048);
1985 	else
1986 		cbe_lun->blocksize = tmp;
1987 
1988 	error = csw->d_ioctl(dev, DIOCGMEDIASIZE, (caddr_t)&otmp, FREAD,
1989 			     curthread);
1990 	if (error) {
1991 		dev_relthread(dev, ref);
1992 		snprintf(req->error_str, sizeof(req->error_str),
1993 			 "error %d returned for DIOCGMEDIASIZE "
1994 			 " ioctl on %s!", error,
1995 			 be_lun->dev_path);
1996 		return (error);
1997 	}
1998 
1999 	if (params->lun_size_bytes != 0) {
2000 		if (params->lun_size_bytes > otmp) {
2001 			dev_relthread(dev, ref);
2002 			snprintf(req->error_str, sizeof(req->error_str),
2003 				 "requested LUN size %ju > backing device "
2004 				 "size %ju",
2005 				 (uintmax_t)params->lun_size_bytes,
2006 				 (uintmax_t)otmp);
2007 			return (EINVAL);
2008 		}
2009 
2010 		be_lun->size_bytes = params->lun_size_bytes;
2011 	} else
2012 		be_lun->size_bytes = otmp;
2013 	be_lun->size_blocks = be_lun->size_bytes / cbe_lun->blocksize;
2014 	cbe_lun->maxlba = (be_lun->size_blocks == 0) ?
2015 	    0 : (be_lun->size_blocks - 1);
2016 
2017 	error = csw->d_ioctl(dev, DIOCGSTRIPESIZE, (caddr_t)&ps, FREAD,
2018 	    curthread);
2019 	if (error)
2020 		ps = po = 0;
2021 	else {
2022 		error = csw->d_ioctl(dev, DIOCGSTRIPEOFFSET, (caddr_t)&po,
2023 		    FREAD, curthread);
2024 		if (error)
2025 			po = 0;
2026 	}
2027 	us = ps;
2028 	uo = po;
2029 
2030 	value = dnvlist_get_string(cbe_lun->options, "pblocksize", NULL);
2031 	if (value != NULL)
2032 		ctl_expand_number(value, &ps);
2033 	value = dnvlist_get_string(cbe_lun->options, "pblockoffset", NULL);
2034 	if (value != NULL)
2035 		ctl_expand_number(value, &po);
2036 	pss = ps / cbe_lun->blocksize;
2037 	pos = po / cbe_lun->blocksize;
2038 	if ((pss > 0) && (pss * cbe_lun->blocksize == ps) && (pss >= pos) &&
2039 	    ((pss & (pss - 1)) == 0) && (pos * cbe_lun->blocksize == po)) {
2040 		cbe_lun->pblockexp = fls(pss) - 1;
2041 		cbe_lun->pblockoff = (pss - pos) % pss;
2042 	}
2043 
2044 	value = dnvlist_get_string(cbe_lun->options, "ublocksize", NULL);
2045 	if (value != NULL)
2046 		ctl_expand_number(value, &us);
2047 	value = dnvlist_get_string(cbe_lun->options, "ublockoffset", NULL);
2048 	if (value != NULL)
2049 		ctl_expand_number(value, &uo);
2050 	uss = us / cbe_lun->blocksize;
2051 	uos = uo / cbe_lun->blocksize;
2052 	if ((uss > 0) && (uss * cbe_lun->blocksize == us) && (uss >= uos) &&
2053 	    ((uss & (uss - 1)) == 0) && (uos * cbe_lun->blocksize == uo)) {
2054 		cbe_lun->ublockexp = fls(uss) - 1;
2055 		cbe_lun->ublockoff = (uss - uos) % uss;
2056 	}
2057 
2058 	cbe_lun->atomicblock = atomic / cbe_lun->blocksize;
2059 	cbe_lun->opttxferlen = maxio / cbe_lun->blocksize;
2060 
2061 	if (be_lun->dispatch == ctl_be_block_dispatch_zvol) {
2062 		unmap = 1;
2063 	} else {
2064 		struct diocgattr_arg	arg;
2065 
2066 		strlcpy(arg.name, "GEOM::candelete", sizeof(arg.name));
2067 		arg.len = sizeof(arg.value.i);
2068 		error = csw->d_ioctl(dev, DIOCGATTR, (caddr_t)&arg, FREAD,
2069 		    curthread);
2070 		unmap = (error == 0) ? arg.value.i : 0;
2071 	}
2072 	value = dnvlist_get_string(cbe_lun->options, "unmap", NULL);
2073 	if (value != NULL)
2074 		unmap = (strcmp(value, "on") == 0);
2075 	if (unmap)
2076 		cbe_lun->flags |= CTL_LUN_FLAG_UNMAP;
2077 	else
2078 		cbe_lun->flags &= ~CTL_LUN_FLAG_UNMAP;
2079 
2080 	dev_relthread(dev, ref);
2081 	return (0);
2082 }
2083 
2084 static int
2085 ctl_be_block_close(struct ctl_be_block_lun *be_lun)
2086 {
2087 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
2088 	int flags;
2089 
2090 	if (be_lun->vn) {
2091 		flags = FREAD;
2092 		if ((cbe_lun->flags & CTL_LUN_FLAG_READONLY) == 0)
2093 			flags |= FWRITE;
2094 		(void)vn_close(be_lun->vn, flags, NOCRED, curthread);
2095 		be_lun->vn = NULL;
2096 
2097 		switch (be_lun->dev_type) {
2098 		case CTL_BE_BLOCK_DEV:
2099 			break;
2100 		case CTL_BE_BLOCK_FILE:
2101 			if (be_lun->backend.file.cred != NULL) {
2102 				crfree(be_lun->backend.file.cred);
2103 				be_lun->backend.file.cred = NULL;
2104 			}
2105 			break;
2106 		case CTL_BE_BLOCK_NONE:
2107 			break;
2108 		default:
2109 			panic("Unexpected backend type %d", be_lun->dev_type);
2110 			break;
2111 		}
2112 		be_lun->dev_type = CTL_BE_BLOCK_NONE;
2113 	}
2114 	return (0);
2115 }
2116 
2117 static int
2118 ctl_be_block_open(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
2119 {
2120 	struct ctl_be_lun *cbe_lun = &be_lun->cbe_lun;
2121 	struct nameidata nd;
2122 	const char	*value;
2123 	int		 error, flags;
2124 
2125 	error = 0;
2126 	if (rootvnode == NULL) {
2127 		snprintf(req->error_str, sizeof(req->error_str),
2128 			 "Root filesystem is not mounted");
2129 		return (1);
2130 	}
2131 	pwd_ensure_dirs();
2132 
2133 	value = dnvlist_get_string(cbe_lun->options, "file", NULL);
2134 	if (value == NULL) {
2135 		snprintf(req->error_str, sizeof(req->error_str),
2136 			 "no file argument specified");
2137 		return (1);
2138 	}
2139 	free(be_lun->dev_path, M_CTLBLK);
2140 	be_lun->dev_path = strdup(value, M_CTLBLK);
2141 
2142 	flags = FREAD;
2143 	value = dnvlist_get_string(cbe_lun->options, "readonly", NULL);
2144 	if (value != NULL) {
2145 		if (strcmp(value, "on") != 0)
2146 			flags |= FWRITE;
2147 	} else if (cbe_lun->lun_type == T_DIRECT)
2148 		flags |= FWRITE;
2149 
2150 again:
2151 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, be_lun->dev_path, curthread);
2152 	error = vn_open(&nd, &flags, 0, NULL);
2153 	if ((error == EROFS || error == EACCES) && (flags & FWRITE)) {
2154 		flags &= ~FWRITE;
2155 		goto again;
2156 	}
2157 	if (error) {
2158 		/*
2159 		 * This is the only reasonable guess we can make as far as
2160 		 * path if the user doesn't give us a fully qualified path.
2161 		 * If they want to specify a file, they need to specify the
2162 		 * full path.
2163 		 */
2164 		if (be_lun->dev_path[0] != '/') {
2165 			char *dev_name;
2166 
2167 			asprintf(&dev_name, M_CTLBLK, "/dev/%s",
2168 				be_lun->dev_path);
2169 			free(be_lun->dev_path, M_CTLBLK);
2170 			be_lun->dev_path = dev_name;
2171 			goto again;
2172 		}
2173 		snprintf(req->error_str, sizeof(req->error_str),
2174 		    "error opening %s: %d", be_lun->dev_path, error);
2175 		return (error);
2176 	}
2177 	if (flags & FWRITE)
2178 		cbe_lun->flags &= ~CTL_LUN_FLAG_READONLY;
2179 	else
2180 		cbe_lun->flags |= CTL_LUN_FLAG_READONLY;
2181 
2182 	NDFREE(&nd, NDF_ONLY_PNBUF);
2183 	be_lun->vn = nd.ni_vp;
2184 
2185 	/* We only support disks and files. */
2186 	if (vn_isdisk_error(be_lun->vn, &error)) {
2187 		error = ctl_be_block_open_dev(be_lun, req);
2188 	} else if (be_lun->vn->v_type == VREG) {
2189 		error = ctl_be_block_open_file(be_lun, req);
2190 	} else {
2191 		error = EINVAL;
2192 		snprintf(req->error_str, sizeof(req->error_str),
2193 			 "%s is not a disk or plain file", be_lun->dev_path);
2194 	}
2195 	VOP_UNLOCK(be_lun->vn);
2196 
2197 	if (error != 0)
2198 		ctl_be_block_close(be_lun);
2199 	cbe_lun->serseq = CTL_LUN_SERSEQ_OFF;
2200 	if (be_lun->dispatch != ctl_be_block_dispatch_dev)
2201 		cbe_lun->serseq = CTL_LUN_SERSEQ_READ;
2202 	value = dnvlist_get_string(cbe_lun->options, "serseq", NULL);
2203 	if (value != NULL && strcmp(value, "on") == 0)
2204 		cbe_lun->serseq = CTL_LUN_SERSEQ_ON;
2205 	else if (value != NULL && strcmp(value, "read") == 0)
2206 		cbe_lun->serseq = CTL_LUN_SERSEQ_READ;
2207 	else if (value != NULL && strcmp(value, "off") == 0)
2208 		cbe_lun->serseq = CTL_LUN_SERSEQ_OFF;
2209 	return (0);
2210 }
2211 
2212 static int
2213 ctl_be_block_create(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2214 {
2215 	struct ctl_be_lun *cbe_lun;
2216 	struct ctl_be_block_lun *be_lun;
2217 	struct ctl_lun_create_params *params;
2218 	char num_thread_str[16];
2219 	char tmpstr[32];
2220 	const char *value;
2221 	int retval, num_threads;
2222 	int tmp_num_threads;
2223 
2224 	params = &req->reqdata.create;
2225 	retval = 0;
2226 	req->status = CTL_LUN_OK;
2227 
2228 	be_lun = malloc(sizeof(*be_lun), M_CTLBLK, M_ZERO | M_WAITOK);
2229 	cbe_lun = &be_lun->cbe_lun;
2230 	be_lun->params = req->reqdata.create;
2231 	be_lun->softc = softc;
2232 	STAILQ_INIT(&be_lun->input_queue);
2233 	STAILQ_INIT(&be_lun->config_read_queue);
2234 	STAILQ_INIT(&be_lun->config_write_queue);
2235 	STAILQ_INIT(&be_lun->datamove_queue);
2236 	mtx_init(&be_lun->io_lock, "ctlblock io", NULL, MTX_DEF);
2237 	mtx_init(&be_lun->queue_lock, "ctlblock queue", NULL, MTX_DEF);
2238 	cbe_lun->options = nvlist_clone(req->args_nvl);
2239 
2240 	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
2241 		cbe_lun->lun_type = params->device_type;
2242 	else
2243 		cbe_lun->lun_type = T_DIRECT;
2244 	be_lun->flags = 0;
2245 	cbe_lun->flags = 0;
2246 	value = dnvlist_get_string(cbe_lun->options, "ha_role", NULL);
2247 	if (value != NULL) {
2248 		if (strcmp(value, "primary") == 0)
2249 			cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2250 	} else if (control_softc->flags & CTL_FLAG_ACTIVE_SHELF)
2251 		cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2252 
2253 	if (cbe_lun->lun_type == T_DIRECT ||
2254 	    cbe_lun->lun_type == T_CDROM) {
2255 		be_lun->size_bytes = params->lun_size_bytes;
2256 		if (params->blocksize_bytes != 0)
2257 			cbe_lun->blocksize = params->blocksize_bytes;
2258 		else if (cbe_lun->lun_type == T_CDROM)
2259 			cbe_lun->blocksize = 2048;
2260 		else
2261 			cbe_lun->blocksize = 512;
2262 		be_lun->size_blocks = be_lun->size_bytes / cbe_lun->blocksize;
2263 		cbe_lun->maxlba = (be_lun->size_blocks == 0) ?
2264 		    0 : (be_lun->size_blocks - 1);
2265 
2266 		if ((cbe_lun->flags & CTL_LUN_FLAG_PRIMARY) ||
2267 		    control_softc->ha_mode == CTL_HA_MODE_SER_ONLY) {
2268 			retval = ctl_be_block_open(be_lun, req);
2269 			if (retval != 0) {
2270 				retval = 0;
2271 				req->status = CTL_LUN_WARNING;
2272 			}
2273 		}
2274 		num_threads = cbb_num_threads;
2275 	} else {
2276 		num_threads = 1;
2277 	}
2278 
2279 	value = dnvlist_get_string(cbe_lun->options, "num_threads", NULL);
2280 	if (value != NULL) {
2281 		tmp_num_threads = strtol(value, NULL, 0);
2282 
2283 		/*
2284 		 * We don't let the user specify less than one
2285 		 * thread, but hope he's clueful enough not to
2286 		 * specify 1000 threads.
2287 		 */
2288 		if (tmp_num_threads < 1) {
2289 			snprintf(req->error_str, sizeof(req->error_str),
2290 				 "invalid number of threads %s",
2291 				 num_thread_str);
2292 			goto bailout_error;
2293 		}
2294 		num_threads = tmp_num_threads;
2295 	}
2296 
2297 	if (be_lun->vn == NULL)
2298 		cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2299 	/* Tell the user the blocksize we ended up using */
2300 	params->lun_size_bytes = be_lun->size_bytes;
2301 	params->blocksize_bytes = cbe_lun->blocksize;
2302 	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
2303 		cbe_lun->req_lun_id = params->req_lun_id;
2304 		cbe_lun->flags |= CTL_LUN_FLAG_ID_REQ;
2305 	} else
2306 		cbe_lun->req_lun_id = 0;
2307 
2308 	cbe_lun->lun_shutdown = ctl_be_block_lun_shutdown;
2309 	cbe_lun->be = &ctl_be_block_driver;
2310 
2311 	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
2312 		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%04d",
2313 			 softc->num_luns);
2314 		strncpy((char *)cbe_lun->serial_num, tmpstr,
2315 			MIN(sizeof(cbe_lun->serial_num), sizeof(tmpstr)));
2316 
2317 		/* Tell the user what we used for a serial number */
2318 		strncpy((char *)params->serial_num, tmpstr,
2319 			MIN(sizeof(params->serial_num), sizeof(tmpstr)));
2320 	} else {
2321 		strncpy((char *)cbe_lun->serial_num, params->serial_num,
2322 			MIN(sizeof(cbe_lun->serial_num),
2323 			sizeof(params->serial_num)));
2324 	}
2325 	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
2326 		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%04d", softc->num_luns);
2327 		strncpy((char *)cbe_lun->device_id, tmpstr,
2328 			MIN(sizeof(cbe_lun->device_id), sizeof(tmpstr)));
2329 
2330 		/* Tell the user what we used for a device ID */
2331 		strncpy((char *)params->device_id, tmpstr,
2332 			MIN(sizeof(params->device_id), sizeof(tmpstr)));
2333 	} else {
2334 		strncpy((char *)cbe_lun->device_id, params->device_id,
2335 			MIN(sizeof(cbe_lun->device_id),
2336 			    sizeof(params->device_id)));
2337 	}
2338 
2339 	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_be_block_worker, be_lun);
2340 
2341 	be_lun->io_taskqueue = taskqueue_create("ctlblocktq", M_WAITOK,
2342 	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
2343 
2344 	if (be_lun->io_taskqueue == NULL) {
2345 		snprintf(req->error_str, sizeof(req->error_str),
2346 			 "unable to create taskqueue");
2347 		goto bailout_error;
2348 	}
2349 
2350 	/*
2351 	 * Note that we start the same number of threads by default for
2352 	 * both the file case and the block device case.  For the file
2353 	 * case, we need multiple threads to allow concurrency, because the
2354 	 * vnode interface is designed to be a blocking interface.  For the
2355 	 * block device case, ZFS zvols at least will block the caller's
2356 	 * context in many instances, and so we need multiple threads to
2357 	 * overcome that problem.  Other block devices don't need as many
2358 	 * threads, but they shouldn't cause too many problems.
2359 	 *
2360 	 * If the user wants to just have a single thread for a block
2361 	 * device, he can specify that when the LUN is created, or change
2362 	 * the tunable/sysctl to alter the default number of threads.
2363 	 */
2364 	retval = taskqueue_start_threads_in_proc(&be_lun->io_taskqueue,
2365 					 /*num threads*/num_threads,
2366 					 /*priority*/PUSER,
2367 					 /*proc*/control_softc->ctl_proc,
2368 					 /*thread name*/"block");
2369 
2370 	if (retval != 0)
2371 		goto bailout_error;
2372 
2373 	be_lun->num_threads = num_threads;
2374 
2375 	retval = ctl_add_lun(&be_lun->cbe_lun);
2376 	if (retval != 0) {
2377 		snprintf(req->error_str, sizeof(req->error_str),
2378 			 "ctl_add_lun() returned error %d, see dmesg for "
2379 			 "details", retval);
2380 		retval = 0;
2381 		goto bailout_error;
2382 	}
2383 
2384 	be_lun->disk_stats = devstat_new_entry("cbb", cbe_lun->lun_id,
2385 					       cbe_lun->blocksize,
2386 					       DEVSTAT_ALL_SUPPORTED,
2387 					       cbe_lun->lun_type
2388 					       | DEVSTAT_TYPE_IF_OTHER,
2389 					       DEVSTAT_PRIORITY_OTHER);
2390 
2391 	mtx_lock(&softc->lock);
2392 	softc->num_luns++;
2393 	SLIST_INSERT_HEAD(&softc->lun_list, be_lun, links);
2394 	mtx_unlock(&softc->lock);
2395 
2396 	params->req_lun_id = cbe_lun->lun_id;
2397 
2398 	return (retval);
2399 
2400 bailout_error:
2401 	req->status = CTL_LUN_ERROR;
2402 
2403 	if (be_lun->io_taskqueue != NULL)
2404 		taskqueue_free(be_lun->io_taskqueue);
2405 	ctl_be_block_close(be_lun);
2406 	if (be_lun->dev_path != NULL)
2407 		free(be_lun->dev_path, M_CTLBLK);
2408 	nvlist_destroy(cbe_lun->options);
2409 	mtx_destroy(&be_lun->queue_lock);
2410 	mtx_destroy(&be_lun->io_lock);
2411 	free(be_lun, M_CTLBLK);
2412 
2413 	return (retval);
2414 }
2415 
2416 static int
2417 ctl_be_block_rm(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2418 {
2419 	struct ctl_lun_rm_params *params;
2420 	struct ctl_be_block_lun *be_lun;
2421 	struct ctl_be_lun *cbe_lun;
2422 	int retval;
2423 
2424 	params = &req->reqdata.rm;
2425 
2426 	sx_xlock(&softc->modify_lock);
2427 	mtx_lock(&softc->lock);
2428 	SLIST_FOREACH(be_lun, &softc->lun_list, links) {
2429 		if (be_lun->cbe_lun.lun_id == params->lun_id) {
2430 			SLIST_REMOVE(&softc->lun_list, be_lun,
2431 			    ctl_be_block_lun, links);
2432 			softc->num_luns--;
2433 			break;
2434 		}
2435 	}
2436 	mtx_unlock(&softc->lock);
2437 	sx_xunlock(&softc->modify_lock);
2438 	if (be_lun == NULL) {
2439 		snprintf(req->error_str, sizeof(req->error_str),
2440 			 "LUN %u is not managed by the block backend",
2441 			 params->lun_id);
2442 		goto bailout_error;
2443 	}
2444 	cbe_lun = &be_lun->cbe_lun;
2445 
2446 	if (be_lun->vn != NULL) {
2447 		cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2448 		ctl_lun_no_media(cbe_lun);
2449 		taskqueue_drain_all(be_lun->io_taskqueue);
2450 		ctl_be_block_close(be_lun);
2451 	}
2452 
2453 	mtx_lock(&softc->lock);
2454 	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2455 	mtx_unlock(&softc->lock);
2456 
2457 	retval = ctl_remove_lun(cbe_lun);
2458 	if (retval != 0) {
2459 		snprintf(req->error_str, sizeof(req->error_str),
2460 			 "error %d returned from ctl_remove_lun() for "
2461 			 "LUN %d", retval, params->lun_id);
2462 		mtx_lock(&softc->lock);
2463 		be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2464 		mtx_unlock(&softc->lock);
2465 		goto bailout_error;
2466 	}
2467 
2468 	mtx_lock(&softc->lock);
2469 	while ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2470 		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblockrm", 0);
2471 		if (retval == EINTR)
2472 			break;
2473 	}
2474 	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2475 	if (be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) {
2476 		mtx_unlock(&softc->lock);
2477 		free(be_lun, M_CTLBLK);
2478 	} else {
2479 		mtx_unlock(&softc->lock);
2480 		return (EINTR);
2481 	}
2482 
2483 	req->status = CTL_LUN_OK;
2484 	return (0);
2485 
2486 bailout_error:
2487 	req->status = CTL_LUN_ERROR;
2488 	return (0);
2489 }
2490 
2491 static int
2492 ctl_be_block_modify(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2493 {
2494 	struct ctl_lun_modify_params *params;
2495 	struct ctl_be_block_lun *be_lun;
2496 	struct ctl_be_lun *cbe_lun;
2497 	const char *value;
2498 	uint64_t oldsize;
2499 	int error, wasprim;
2500 
2501 	params = &req->reqdata.modify;
2502 
2503 	sx_xlock(&softc->modify_lock);
2504 	mtx_lock(&softc->lock);
2505 	SLIST_FOREACH(be_lun, &softc->lun_list, links) {
2506 		if (be_lun->cbe_lun.lun_id == params->lun_id)
2507 			break;
2508 	}
2509 	mtx_unlock(&softc->lock);
2510 	if (be_lun == NULL) {
2511 		snprintf(req->error_str, sizeof(req->error_str),
2512 			 "LUN %u is not managed by the block backend",
2513 			 params->lun_id);
2514 		goto bailout_error;
2515 	}
2516 	cbe_lun = &be_lun->cbe_lun;
2517 
2518 	if (params->lun_size_bytes != 0)
2519 		be_lun->params.lun_size_bytes = params->lun_size_bytes;
2520 
2521 	if (req->args_nvl != NULL) {
2522 		nvlist_destroy(cbe_lun->options);
2523 		cbe_lun->options = nvlist_clone(req->args_nvl);
2524 	}
2525 
2526 	wasprim = (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY);
2527 	value = dnvlist_get_string(cbe_lun->options, "ha_role", NULL);
2528 	if (value != NULL) {
2529 		if (strcmp(value, "primary") == 0)
2530 			cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2531 		else
2532 			cbe_lun->flags &= ~CTL_LUN_FLAG_PRIMARY;
2533 	} else if (control_softc->flags & CTL_FLAG_ACTIVE_SHELF)
2534 		cbe_lun->flags |= CTL_LUN_FLAG_PRIMARY;
2535 	else
2536 		cbe_lun->flags &= ~CTL_LUN_FLAG_PRIMARY;
2537 	if (wasprim != (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY)) {
2538 		if (cbe_lun->flags & CTL_LUN_FLAG_PRIMARY)
2539 			ctl_lun_primary(cbe_lun);
2540 		else
2541 			ctl_lun_secondary(cbe_lun);
2542 	}
2543 
2544 	oldsize = be_lun->size_blocks;
2545 	if ((cbe_lun->flags & CTL_LUN_FLAG_PRIMARY) ||
2546 	    control_softc->ha_mode == CTL_HA_MODE_SER_ONLY) {
2547 		if (be_lun->vn == NULL)
2548 			error = ctl_be_block_open(be_lun, req);
2549 		else if (vn_isdisk_error(be_lun->vn, &error))
2550 			error = ctl_be_block_open_dev(be_lun, req);
2551 		else if (be_lun->vn->v_type == VREG) {
2552 			vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
2553 			error = ctl_be_block_open_file(be_lun, req);
2554 			VOP_UNLOCK(be_lun->vn);
2555 		} else
2556 			error = EINVAL;
2557 		if ((cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) &&
2558 		    be_lun->vn != NULL) {
2559 			cbe_lun->flags &= ~CTL_LUN_FLAG_NO_MEDIA;
2560 			ctl_lun_has_media(cbe_lun);
2561 		} else if ((cbe_lun->flags & CTL_LUN_FLAG_NO_MEDIA) == 0 &&
2562 		    be_lun->vn == NULL) {
2563 			cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2564 			ctl_lun_no_media(cbe_lun);
2565 		}
2566 		cbe_lun->flags &= ~CTL_LUN_FLAG_EJECTED;
2567 	} else {
2568 		if (be_lun->vn != NULL) {
2569 			cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2570 			ctl_lun_no_media(cbe_lun);
2571 			taskqueue_drain_all(be_lun->io_taskqueue);
2572 			error = ctl_be_block_close(be_lun);
2573 		} else
2574 			error = 0;
2575 	}
2576 	if (be_lun->size_blocks != oldsize)
2577 		ctl_lun_capacity_changed(cbe_lun);
2578 
2579 	/* Tell the user the exact size we ended up using */
2580 	params->lun_size_bytes = be_lun->size_bytes;
2581 
2582 	sx_xunlock(&softc->modify_lock);
2583 	req->status = error ? CTL_LUN_WARNING : CTL_LUN_OK;
2584 	return (0);
2585 
2586 bailout_error:
2587 	sx_xunlock(&softc->modify_lock);
2588 	req->status = CTL_LUN_ERROR;
2589 	return (0);
2590 }
2591 
2592 static void
2593 ctl_be_block_lun_shutdown(struct ctl_be_lun *cbe_lun)
2594 {
2595 	struct ctl_be_block_lun *be_lun = (struct ctl_be_block_lun *)cbe_lun;
2596 	struct ctl_be_block_softc *softc = be_lun->softc;
2597 
2598 	taskqueue_drain_all(be_lun->io_taskqueue);
2599 	taskqueue_free(be_lun->io_taskqueue);
2600 	if (be_lun->disk_stats != NULL)
2601 		devstat_remove_entry(be_lun->disk_stats);
2602 	nvlist_destroy(be_lun->cbe_lun.options);
2603 	free(be_lun->dev_path, M_CTLBLK);
2604 	mtx_destroy(&be_lun->queue_lock);
2605 	mtx_destroy(&be_lun->io_lock);
2606 
2607 	mtx_lock(&softc->lock);
2608 	be_lun->flags |= CTL_BE_BLOCK_LUN_UNCONFIGURED;
2609 	if (be_lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2610 		wakeup(be_lun);
2611 	else
2612 		free(be_lun, M_CTLBLK);
2613 	mtx_unlock(&softc->lock);
2614 }
2615 
2616 static int
2617 ctl_be_block_config_write(union ctl_io *io)
2618 {
2619 	struct ctl_be_block_lun *be_lun;
2620 	struct ctl_be_lun *cbe_lun;
2621 	int retval;
2622 
2623 	DPRINTF("entered\n");
2624 
2625 	cbe_lun = CTL_BACKEND_LUN(io);
2626 	be_lun = (struct ctl_be_block_lun *)cbe_lun;
2627 
2628 	retval = 0;
2629 	switch (io->scsiio.cdb[0]) {
2630 	case SYNCHRONIZE_CACHE:
2631 	case SYNCHRONIZE_CACHE_16:
2632 	case WRITE_SAME_10:
2633 	case WRITE_SAME_16:
2634 	case UNMAP:
2635 		/*
2636 		 * The upper level CTL code will filter out any CDBs with
2637 		 * the immediate bit set and return the proper error.
2638 		 *
2639 		 * We don't really need to worry about what LBA range the
2640 		 * user asked to be synced out.  When they issue a sync
2641 		 * cache command, we'll sync out the whole thing.
2642 		 */
2643 		mtx_lock(&be_lun->queue_lock);
2644 		STAILQ_INSERT_TAIL(&be_lun->config_write_queue, &io->io_hdr,
2645 				   links);
2646 		mtx_unlock(&be_lun->queue_lock);
2647 		taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
2648 		break;
2649 	case START_STOP_UNIT: {
2650 		struct scsi_start_stop_unit *cdb;
2651 		struct ctl_lun_req req;
2652 
2653 		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
2654 		if ((cdb->how & SSS_PC_MASK) != 0) {
2655 			ctl_set_success(&io->scsiio);
2656 			ctl_config_write_done(io);
2657 			break;
2658 		}
2659 		if (cdb->how & SSS_START) {
2660 			if ((cdb->how & SSS_LOEJ) && be_lun->vn == NULL) {
2661 				retval = ctl_be_block_open(be_lun, &req);
2662 				cbe_lun->flags &= ~CTL_LUN_FLAG_EJECTED;
2663 				if (retval == 0) {
2664 					cbe_lun->flags &= ~CTL_LUN_FLAG_NO_MEDIA;
2665 					ctl_lun_has_media(cbe_lun);
2666 				} else {
2667 					cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2668 					ctl_lun_no_media(cbe_lun);
2669 				}
2670 			}
2671 			ctl_start_lun(cbe_lun);
2672 		} else {
2673 			ctl_stop_lun(cbe_lun);
2674 			if (cdb->how & SSS_LOEJ) {
2675 				cbe_lun->flags |= CTL_LUN_FLAG_NO_MEDIA;
2676 				cbe_lun->flags |= CTL_LUN_FLAG_EJECTED;
2677 				ctl_lun_ejected(cbe_lun);
2678 				if (be_lun->vn != NULL)
2679 					ctl_be_block_close(be_lun);
2680 			}
2681 		}
2682 
2683 		ctl_set_success(&io->scsiio);
2684 		ctl_config_write_done(io);
2685 		break;
2686 	}
2687 	case PREVENT_ALLOW:
2688 		ctl_set_success(&io->scsiio);
2689 		ctl_config_write_done(io);
2690 		break;
2691 	default:
2692 		ctl_set_invalid_opcode(&io->scsiio);
2693 		ctl_config_write_done(io);
2694 		retval = CTL_RETVAL_COMPLETE;
2695 		break;
2696 	}
2697 
2698 	return (retval);
2699 }
2700 
2701 static int
2702 ctl_be_block_config_read(union ctl_io *io)
2703 {
2704 	struct ctl_be_block_lun *be_lun;
2705 	int retval = 0;
2706 
2707 	DPRINTF("entered\n");
2708 
2709 	be_lun = (struct ctl_be_block_lun *)CTL_BACKEND_LUN(io);
2710 
2711 	switch (io->scsiio.cdb[0]) {
2712 	case SERVICE_ACTION_IN:
2713 		if (io->scsiio.cdb[1] == SGLS_SERVICE_ACTION) {
2714 			mtx_lock(&be_lun->queue_lock);
2715 			STAILQ_INSERT_TAIL(&be_lun->config_read_queue,
2716 			    &io->io_hdr, links);
2717 			mtx_unlock(&be_lun->queue_lock);
2718 			taskqueue_enqueue(be_lun->io_taskqueue,
2719 			    &be_lun->io_task);
2720 			retval = CTL_RETVAL_QUEUED;
2721 			break;
2722 		}
2723 		ctl_set_invalid_field(&io->scsiio,
2724 				      /*sks_valid*/ 1,
2725 				      /*command*/ 1,
2726 				      /*field*/ 1,
2727 				      /*bit_valid*/ 1,
2728 				      /*bit*/ 4);
2729 		ctl_config_read_done(io);
2730 		retval = CTL_RETVAL_COMPLETE;
2731 		break;
2732 	default:
2733 		ctl_set_invalid_opcode(&io->scsiio);
2734 		ctl_config_read_done(io);
2735 		retval = CTL_RETVAL_COMPLETE;
2736 		break;
2737 	}
2738 
2739 	return (retval);
2740 }
2741 
2742 static int
2743 ctl_be_block_lun_info(struct ctl_be_lun *cbe_lun, struct sbuf *sb)
2744 {
2745 	struct ctl_be_block_lun *lun = (struct ctl_be_block_lun *)cbe_lun;
2746 	int retval;
2747 
2748 	retval = sbuf_printf(sb, "\t<num_threads>");
2749 	if (retval != 0)
2750 		goto bailout;
2751 	retval = sbuf_printf(sb, "%d", lun->num_threads);
2752 	if (retval != 0)
2753 		goto bailout;
2754 	retval = sbuf_printf(sb, "</num_threads>\n");
2755 
2756 bailout:
2757 	return (retval);
2758 }
2759 
2760 static uint64_t
2761 ctl_be_block_lun_attr(struct ctl_be_lun *cbe_lun, const char *attrname)
2762 {
2763 	struct ctl_be_block_lun *lun = (struct ctl_be_block_lun *)cbe_lun;
2764 
2765 	if (lun->getattr == NULL)
2766 		return (UINT64_MAX);
2767 	return (lun->getattr(lun, attrname));
2768 }
2769 
2770 static int
2771 ctl_be_block_init(void)
2772 {
2773 	struct ctl_be_block_softc *softc = &backend_block_softc;
2774 
2775 	sx_init(&softc->modify_lock, "ctlblock modify");
2776 	mtx_init(&softc->lock, "ctlblock", NULL, MTX_DEF);
2777 	softc->beio_zone = uma_zcreate("beio", sizeof(struct ctl_be_block_io),
2778 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
2779 	softc->buf_zone = uma_zcreate("ctlblock", CTLBLK_MAX_SEG,
2780 	    NULL, NULL, NULL, NULL, /*align*/ 0, /*flags*/0);
2781 	SLIST_INIT(&softc->lun_list);
2782 	return (0);
2783 }
2784 
2785 static int
2786 ctl_be_block_shutdown(void)
2787 {
2788 	struct ctl_be_block_softc *softc = &backend_block_softc;
2789 	struct ctl_be_block_lun *lun;
2790 
2791 	mtx_lock(&softc->lock);
2792 	while ((lun = SLIST_FIRST(&softc->lun_list)) != NULL) {
2793 		SLIST_REMOVE_HEAD(&softc->lun_list, links);
2794 		softc->num_luns--;
2795 		/*
2796 		 * Drop our lock here.  Since ctl_remove_lun() can call
2797 		 * back into us, this could potentially lead to a recursive
2798 		 * lock of the same mutex, which would cause a hang.
2799 		 */
2800 		mtx_unlock(&softc->lock);
2801 		ctl_remove_lun(&lun->cbe_lun);
2802 		mtx_lock(&softc->lock);
2803 	}
2804 	mtx_unlock(&softc->lock);
2805 	uma_zdestroy(softc->buf_zone);
2806 	uma_zdestroy(softc->beio_zone);
2807 	mtx_destroy(&softc->lock);
2808 	sx_destroy(&softc->modify_lock);
2809 	return (0);
2810 }
2811