xref: /freebsd/sys/cam/ctl/ctl_backend_block.c (revision db3cb3640f547c063293e9fdc4db69e9dc120951)
1 /*-
2  * Copyright (c) 2003 Silicon Graphics International Corp.
3  * Copyright (c) 2009-2011 Spectra Logic Corporation
4  * Copyright (c) 2012 The FreeBSD Foundation
5  * All rights reserved.
6  *
7  * Portions of this software were developed by Edward Tomasz Napierala
8  * under sponsorship from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions, and the following disclaimer,
15  *    without modification.
16  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
17  *    substantially similar to the "NO WARRANTY" disclaimer below
18  *    ("Disclaimer") and any redistribution must be conditioned upon
19  *    including a substantially similar Disclaimer requirement for further
20  *    binary redistribution.
21  *
22  * NO WARRANTY
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
31  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
32  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33  * POSSIBILITY OF SUCH DAMAGES.
34  *
35  * $Id: //depot/users/kenm/FreeBSD-test2/sys/cam/ctl/ctl_backend_block.c#5 $
36  */
37 /*
38  * CAM Target Layer driver backend for block devices.
39  *
40  * Author: Ken Merry <ken@FreeBSD.org>
41  */
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/types.h>
49 #include <sys/kthread.h>
50 #include <sys/bio.h>
51 #include <sys/fcntl.h>
52 #include <sys/limits.h>
53 #include <sys/lock.h>
54 #include <sys/mutex.h>
55 #include <sys/condvar.h>
56 #include <sys/malloc.h>
57 #include <sys/conf.h>
58 #include <sys/ioccom.h>
59 #include <sys/queue.h>
60 #include <sys/sbuf.h>
61 #include <sys/endian.h>
62 #include <sys/uio.h>
63 #include <sys/buf.h>
64 #include <sys/taskqueue.h>
65 #include <sys/vnode.h>
66 #include <sys/namei.h>
67 #include <sys/mount.h>
68 #include <sys/disk.h>
69 #include <sys/fcntl.h>
70 #include <sys/filedesc.h>
71 #include <sys/filio.h>
72 #include <sys/proc.h>
73 #include <sys/pcpu.h>
74 #include <sys/module.h>
75 #include <sys/sdt.h>
76 #include <sys/devicestat.h>
77 #include <sys/sysctl.h>
78 
79 #include <geom/geom.h>
80 
81 #include <cam/cam.h>
82 #include <cam/scsi/scsi_all.h>
83 #include <cam/scsi/scsi_da.h>
84 #include <cam/ctl/ctl_io.h>
85 #include <cam/ctl/ctl.h>
86 #include <cam/ctl/ctl_backend.h>
87 #include <cam/ctl/ctl_frontend_internal.h>
88 #include <cam/ctl/ctl_ioctl.h>
89 #include <cam/ctl/ctl_scsi_all.h>
90 #include <cam/ctl/ctl_error.h>
91 
92 /*
93  * The idea here is that we'll allocate enough S/G space to hold a 1MB
94  * I/O.  If we get an I/O larger than that, we'll split it.
95  */
96 #define	CTLBLK_HALF_IO_SIZE	(512 * 1024)
97 #define	CTLBLK_MAX_IO_SIZE	(CTLBLK_HALF_IO_SIZE * 2)
98 #define	CTLBLK_MAX_SEG		MAXPHYS
99 #define	CTLBLK_HALF_SEGS	MAX(CTLBLK_HALF_IO_SIZE / CTLBLK_MAX_SEG, 1)
100 #define	CTLBLK_MAX_SEGS		(CTLBLK_HALF_SEGS * 2)
101 
102 #ifdef CTLBLK_DEBUG
103 #define DPRINTF(fmt, args...) \
104     printf("cbb(%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
105 #else
106 #define DPRINTF(fmt, args...) do {} while(0)
107 #endif
108 
109 #define PRIV(io)	\
110     ((struct ctl_ptr_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_BACKEND])
111 #define ARGS(io)	\
112     ((struct ctl_lba_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_LBA_LEN])
113 
114 SDT_PROVIDER_DEFINE(cbb);
115 
116 typedef enum {
117 	CTL_BE_BLOCK_LUN_UNCONFIGURED	= 0x01,
118 	CTL_BE_BLOCK_LUN_CONFIG_ERR	= 0x02,
119 	CTL_BE_BLOCK_LUN_WAITING	= 0x04,
120 	CTL_BE_BLOCK_LUN_MULTI_THREAD	= 0x08
121 } ctl_be_block_lun_flags;
122 
123 typedef enum {
124 	CTL_BE_BLOCK_NONE,
125 	CTL_BE_BLOCK_DEV,
126 	CTL_BE_BLOCK_FILE
127 } ctl_be_block_type;
128 
129 struct ctl_be_block_devdata {
130 	struct cdev *cdev;
131 	struct cdevsw *csw;
132 	int dev_ref;
133 };
134 
135 struct ctl_be_block_filedata {
136 	struct ucred *cred;
137 };
138 
139 union ctl_be_block_bedata {
140 	struct ctl_be_block_devdata dev;
141 	struct ctl_be_block_filedata file;
142 };
143 
144 struct ctl_be_block_io;
145 struct ctl_be_block_lun;
146 
147 typedef void (*cbb_dispatch_t)(struct ctl_be_block_lun *be_lun,
148 			       struct ctl_be_block_io *beio);
149 typedef uint64_t (*cbb_getattr_t)(struct ctl_be_block_lun *be_lun,
150 				  const char *attrname);
151 
152 /*
153  * Backend LUN structure.  There is a 1:1 mapping between a block device
154  * and a backend block LUN, and between a backend block LUN and a CTL LUN.
155  */
156 struct ctl_be_block_lun {
157 	struct ctl_lun_create_params params;
158 	struct ctl_block_disk *disk;
159 	char lunname[32];
160 	char *dev_path;
161 	ctl_be_block_type dev_type;
162 	struct vnode *vn;
163 	union ctl_be_block_bedata backend;
164 	cbb_dispatch_t dispatch;
165 	cbb_dispatch_t lun_flush;
166 	cbb_dispatch_t unmap;
167 	cbb_dispatch_t get_lba_status;
168 	cbb_getattr_t getattr;
169 	uma_zone_t lun_zone;
170 	uint64_t size_blocks;
171 	uint64_t size_bytes;
172 	uint32_t blocksize;
173 	int blocksize_shift;
174 	uint16_t pblockexp;
175 	uint16_t pblockoff;
176 	uint16_t ublockexp;
177 	uint16_t ublockoff;
178 	uint32_t atomicblock;
179 	uint32_t opttxferlen;
180 	struct ctl_be_block_softc *softc;
181 	struct devstat *disk_stats;
182 	ctl_be_block_lun_flags flags;
183 	STAILQ_ENTRY(ctl_be_block_lun) links;
184 	struct ctl_be_lun ctl_be_lun;
185 	struct taskqueue *io_taskqueue;
186 	struct task io_task;
187 	int num_threads;
188 	STAILQ_HEAD(, ctl_io_hdr) input_queue;
189 	STAILQ_HEAD(, ctl_io_hdr) config_read_queue;
190 	STAILQ_HEAD(, ctl_io_hdr) config_write_queue;
191 	STAILQ_HEAD(, ctl_io_hdr) datamove_queue;
192 	struct mtx_padalign io_lock;
193 	struct mtx_padalign queue_lock;
194 };
195 
196 /*
197  * Overall softc structure for the block backend module.
198  */
199 struct ctl_be_block_softc {
200 	struct mtx			 lock;
201 	int				 num_disks;
202 	STAILQ_HEAD(, ctl_block_disk)	 disk_list;
203 	int				 num_luns;
204 	STAILQ_HEAD(, ctl_be_block_lun)	 lun_list;
205 };
206 
207 static struct ctl_be_block_softc backend_block_softc;
208 
209 /*
210  * Per-I/O information.
211  */
212 struct ctl_be_block_io {
213 	union ctl_io			*io;
214 	struct ctl_sg_entry		sg_segs[CTLBLK_MAX_SEGS];
215 	struct iovec			xiovecs[CTLBLK_MAX_SEGS];
216 	int				bio_cmd;
217 	int				num_segs;
218 	int				num_bios_sent;
219 	int				num_bios_done;
220 	int				send_complete;
221 	int				num_errors;
222 	struct bintime			ds_t0;
223 	devstat_tag_type		ds_tag_type;
224 	devstat_trans_flags		ds_trans_type;
225 	uint64_t			io_len;
226 	uint64_t			io_offset;
227 	struct ctl_be_block_softc	*softc;
228 	struct ctl_be_block_lun		*lun;
229 	void (*beio_cont)(struct ctl_be_block_io *beio); /* to continue processing */
230 };
231 
232 static int cbb_num_threads = 14;
233 SYSCTL_NODE(_kern_cam_ctl, OID_AUTO, block, CTLFLAG_RD, 0,
234 	    "CAM Target Layer Block Backend");
235 SYSCTL_INT(_kern_cam_ctl_block, OID_AUTO, num_threads, CTLFLAG_RWTUN,
236            &cbb_num_threads, 0, "Number of threads per backing file");
237 
238 static struct ctl_be_block_io *ctl_alloc_beio(struct ctl_be_block_softc *softc);
239 static void ctl_free_beio(struct ctl_be_block_io *beio);
240 static void ctl_complete_beio(struct ctl_be_block_io *beio);
241 static int ctl_be_block_move_done(union ctl_io *io);
242 static void ctl_be_block_biodone(struct bio *bio);
243 static void ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
244 				    struct ctl_be_block_io *beio);
245 static void ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
246 				       struct ctl_be_block_io *beio);
247 static void ctl_be_block_gls_file(struct ctl_be_block_lun *be_lun,
248 				  struct ctl_be_block_io *beio);
249 static uint64_t ctl_be_block_getattr_file(struct ctl_be_block_lun *be_lun,
250 					 const char *attrname);
251 static void ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
252 				   struct ctl_be_block_io *beio);
253 static void ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
254 				   struct ctl_be_block_io *beio);
255 static void ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
256 				      struct ctl_be_block_io *beio);
257 static uint64_t ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun,
258 					 const char *attrname);
259 static void ctl_be_block_cr_dispatch(struct ctl_be_block_lun *be_lun,
260 				    union ctl_io *io);
261 static void ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
262 				    union ctl_io *io);
263 static void ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
264 				  union ctl_io *io);
265 static void ctl_be_block_worker(void *context, int pending);
266 static int ctl_be_block_submit(union ctl_io *io);
267 static int ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
268 				   int flag, struct thread *td);
269 static int ctl_be_block_open_file(struct ctl_be_block_lun *be_lun,
270 				  struct ctl_lun_req *req);
271 static int ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun,
272 				 struct ctl_lun_req *req);
273 static int ctl_be_block_close(struct ctl_be_block_lun *be_lun);
274 static int ctl_be_block_open(struct ctl_be_block_softc *softc,
275 			     struct ctl_be_block_lun *be_lun,
276 			     struct ctl_lun_req *req);
277 static int ctl_be_block_create(struct ctl_be_block_softc *softc,
278 			       struct ctl_lun_req *req);
279 static int ctl_be_block_rm(struct ctl_be_block_softc *softc,
280 			   struct ctl_lun_req *req);
281 static int ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
282 				  struct ctl_lun_req *req);
283 static int ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
284 				 struct ctl_lun_req *req);
285 static int ctl_be_block_modify(struct ctl_be_block_softc *softc,
286 			   struct ctl_lun_req *req);
287 static void ctl_be_block_lun_shutdown(void *be_lun);
288 static void ctl_be_block_lun_config_status(void *be_lun,
289 					   ctl_lun_config_status status);
290 static int ctl_be_block_config_write(union ctl_io *io);
291 static int ctl_be_block_config_read(union ctl_io *io);
292 static int ctl_be_block_lun_info(void *be_lun, struct sbuf *sb);
293 static uint64_t ctl_be_block_lun_attr(void *be_lun, const char *attrname);
294 int ctl_be_block_init(void);
295 
296 static struct ctl_backend_driver ctl_be_block_driver =
297 {
298 	.name = "block",
299 	.flags = CTL_BE_FLAG_HAS_CONFIG,
300 	.init = ctl_be_block_init,
301 	.data_submit = ctl_be_block_submit,
302 	.data_move_done = ctl_be_block_move_done,
303 	.config_read = ctl_be_block_config_read,
304 	.config_write = ctl_be_block_config_write,
305 	.ioctl = ctl_be_block_ioctl,
306 	.lun_info = ctl_be_block_lun_info,
307 	.lun_attr = ctl_be_block_lun_attr
308 };
309 
310 MALLOC_DEFINE(M_CTLBLK, "ctlblk", "Memory used for CTL block backend");
311 CTL_BACKEND_DECLARE(cbb, ctl_be_block_driver);
312 
313 static uma_zone_t beio_zone;
314 
315 static struct ctl_be_block_io *
316 ctl_alloc_beio(struct ctl_be_block_softc *softc)
317 {
318 	struct ctl_be_block_io *beio;
319 
320 	beio = uma_zalloc(beio_zone, M_WAITOK | M_ZERO);
321 	beio->softc = softc;
322 	return (beio);
323 }
324 
325 static void
326 ctl_free_beio(struct ctl_be_block_io *beio)
327 {
328 	int duplicate_free;
329 	int i;
330 
331 	duplicate_free = 0;
332 
333 	for (i = 0; i < beio->num_segs; i++) {
334 		if (beio->sg_segs[i].addr == NULL)
335 			duplicate_free++;
336 
337 		uma_zfree(beio->lun->lun_zone, beio->sg_segs[i].addr);
338 		beio->sg_segs[i].addr = NULL;
339 
340 		/* For compare we had two equal S/G lists. */
341 		if (ARGS(beio->io)->flags & CTL_LLF_COMPARE) {
342 			uma_zfree(beio->lun->lun_zone,
343 			    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr);
344 			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr = NULL;
345 		}
346 	}
347 
348 	if (duplicate_free > 0) {
349 		printf("%s: %d duplicate frees out of %d segments\n", __func__,
350 		       duplicate_free, beio->num_segs);
351 	}
352 
353 	uma_zfree(beio_zone, beio);
354 }
355 
356 static void
357 ctl_complete_beio(struct ctl_be_block_io *beio)
358 {
359 	union ctl_io *io = beio->io;
360 
361 	if (beio->beio_cont != NULL) {
362 		beio->beio_cont(beio);
363 	} else {
364 		ctl_free_beio(beio);
365 		ctl_data_submit_done(io);
366 	}
367 }
368 
369 static int
370 ctl_be_block_move_done(union ctl_io *io)
371 {
372 	struct ctl_be_block_io *beio;
373 	struct ctl_be_block_lun *be_lun;
374 	struct ctl_lba_len_flags *lbalen;
375 #ifdef CTL_TIME_IO
376 	struct bintime cur_bt;
377 #endif
378 	int i;
379 
380 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
381 	be_lun = beio->lun;
382 
383 	DPRINTF("entered\n");
384 
385 #ifdef CTL_TIME_IO
386 	getbintime(&cur_bt);
387 	bintime_sub(&cur_bt, &io->io_hdr.dma_start_bt);
388 	bintime_add(&io->io_hdr.dma_bt, &cur_bt);
389 	io->io_hdr.num_dmas++;
390 #endif
391 	io->scsiio.kern_rel_offset += io->scsiio.kern_data_len;
392 
393 	/*
394 	 * We set status at this point for read commands, and write
395 	 * commands with errors.
396 	 */
397 	if (io->io_hdr.flags & CTL_FLAG_ABORT) {
398 		;
399 	} else if ((io->io_hdr.port_status == 0) &&
400 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
401 		lbalen = ARGS(beio->io);
402 		if (lbalen->flags & CTL_LLF_READ) {
403 			ctl_set_success(&io->scsiio);
404 		} else if (lbalen->flags & CTL_LLF_COMPARE) {
405 			/* We have two data blocks ready for comparison. */
406 			for (i = 0; i < beio->num_segs; i++) {
407 				if (memcmp(beio->sg_segs[i].addr,
408 				    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr,
409 				    beio->sg_segs[i].len) != 0)
410 					break;
411 			}
412 			if (i < beio->num_segs)
413 				ctl_set_sense(&io->scsiio,
414 				    /*current_error*/ 1,
415 				    /*sense_key*/ SSD_KEY_MISCOMPARE,
416 				    /*asc*/ 0x1D,
417 				    /*ascq*/ 0x00,
418 				    SSD_ELEM_NONE);
419 			else
420 				ctl_set_success(&io->scsiio);
421 		}
422 	} else if ((io->io_hdr.port_status != 0) &&
423 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE ||
424 	     (io->io_hdr.status & CTL_STATUS_MASK) == CTL_SUCCESS)) {
425 		/*
426 		 * For hardware error sense keys, the sense key
427 		 * specific value is defined to be a retry count,
428 		 * but we use it to pass back an internal FETD
429 		 * error code.  XXX KDM  Hopefully the FETD is only
430 		 * using 16 bits for an error code, since that's
431 		 * all the space we have in the sks field.
432 		 */
433 		ctl_set_internal_failure(&io->scsiio,
434 					 /*sks_valid*/ 1,
435 					 /*retry_count*/
436 					 io->io_hdr.port_status);
437 	}
438 
439 	/*
440 	 * If this is a read, or a write with errors, it is done.
441 	 */
442 	if ((beio->bio_cmd == BIO_READ)
443 	 || ((io->io_hdr.flags & CTL_FLAG_ABORT) != 0)
444 	 || ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)) {
445 		ctl_complete_beio(beio);
446 		return (0);
447 	}
448 
449 	/*
450 	 * At this point, we have a write and the DMA completed
451 	 * successfully.  We now have to queue it to the task queue to
452 	 * execute the backend I/O.  That is because we do blocking
453 	 * memory allocations, and in the file backing case, blocking I/O.
454 	 * This move done routine is generally called in the SIM's
455 	 * interrupt context, and therefore we cannot block.
456 	 */
457 	mtx_lock(&be_lun->queue_lock);
458 	/*
459 	 * XXX KDM make sure that links is okay to use at this point.
460 	 * Otherwise, we either need to add another field to ctl_io_hdr,
461 	 * or deal with resource allocation here.
462 	 */
463 	STAILQ_INSERT_TAIL(&be_lun->datamove_queue, &io->io_hdr, links);
464 	mtx_unlock(&be_lun->queue_lock);
465 
466 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
467 
468 	return (0);
469 }
470 
471 static void
472 ctl_be_block_biodone(struct bio *bio)
473 {
474 	struct ctl_be_block_io *beio;
475 	struct ctl_be_block_lun *be_lun;
476 	union ctl_io *io;
477 	int error;
478 
479 	beio = bio->bio_caller1;
480 	be_lun = beio->lun;
481 	io = beio->io;
482 
483 	DPRINTF("entered\n");
484 
485 	error = bio->bio_error;
486 	mtx_lock(&be_lun->io_lock);
487 	if (error != 0)
488 		beio->num_errors++;
489 
490 	beio->num_bios_done++;
491 
492 	/*
493 	 * XXX KDM will this cause WITNESS to complain?  Holding a lock
494 	 * during the free might cause it to complain.
495 	 */
496 	g_destroy_bio(bio);
497 
498 	/*
499 	 * If the send complete bit isn't set, or we aren't the last I/O to
500 	 * complete, then we're done.
501 	 */
502 	if ((beio->send_complete == 0)
503 	 || (beio->num_bios_done < beio->num_bios_sent)) {
504 		mtx_unlock(&be_lun->io_lock);
505 		return;
506 	}
507 
508 	/*
509 	 * At this point, we've verified that we are the last I/O to
510 	 * complete, so it's safe to drop the lock.
511 	 */
512 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
513 	    beio->ds_tag_type, beio->ds_trans_type,
514 	    /*now*/ NULL, /*then*/&beio->ds_t0);
515 	mtx_unlock(&be_lun->io_lock);
516 
517 	/*
518 	 * If there are any errors from the backing device, we fail the
519 	 * entire I/O with a medium error.
520 	 */
521 	if (beio->num_errors > 0) {
522 		if (error == EOPNOTSUPP) {
523 			ctl_set_invalid_opcode(&io->scsiio);
524 		} else if (error == ENOSPC) {
525 			ctl_set_space_alloc_fail(&io->scsiio);
526 		} else if (beio->bio_cmd == BIO_FLUSH) {
527 			/* XXX KDM is there is a better error here? */
528 			ctl_set_internal_failure(&io->scsiio,
529 						 /*sks_valid*/ 1,
530 						 /*retry_count*/ 0xbad2);
531 		} else
532 			ctl_set_medium_error(&io->scsiio);
533 		ctl_complete_beio(beio);
534 		return;
535 	}
536 
537 	/*
538 	 * If this is a write, a flush, a delete or verify, we're all done.
539 	 * If this is a read, we can now send the data to the user.
540 	 */
541 	if ((beio->bio_cmd == BIO_WRITE)
542 	 || (beio->bio_cmd == BIO_FLUSH)
543 	 || (beio->bio_cmd == BIO_DELETE)
544 	 || (ARGS(io)->flags & CTL_LLF_VERIFY)) {
545 		ctl_set_success(&io->scsiio);
546 		ctl_complete_beio(beio);
547 	} else {
548 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
549 		    beio->beio_cont == NULL)
550 			ctl_set_success(&io->scsiio);
551 #ifdef CTL_TIME_IO
552         	getbintime(&io->io_hdr.dma_start_bt);
553 #endif
554 		ctl_datamove(io);
555 	}
556 }
557 
558 static void
559 ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
560 			struct ctl_be_block_io *beio)
561 {
562 	union ctl_io *io = beio->io;
563 	struct mount *mountpoint;
564 	int error, lock_flags;
565 
566 	DPRINTF("entered\n");
567 
568 	binuptime(&beio->ds_t0);
569 	mtx_lock(&be_lun->io_lock);
570 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
571 	mtx_unlock(&be_lun->io_lock);
572 
573 	(void) vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
574 
575 	if (MNT_SHARED_WRITES(mountpoint)
576 	 || ((mountpoint == NULL)
577 	  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
578 		lock_flags = LK_SHARED;
579 	else
580 		lock_flags = LK_EXCLUSIVE;
581 
582 	vn_lock(be_lun->vn, lock_flags | LK_RETRY);
583 
584 	error = VOP_FSYNC(be_lun->vn, MNT_WAIT, curthread);
585 	VOP_UNLOCK(be_lun->vn, 0);
586 
587 	vn_finished_write(mountpoint);
588 
589 	mtx_lock(&be_lun->io_lock);
590 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
591 	    beio->ds_tag_type, beio->ds_trans_type,
592 	    /*now*/ NULL, /*then*/&beio->ds_t0);
593 	mtx_unlock(&be_lun->io_lock);
594 
595 	if (error == 0)
596 		ctl_set_success(&io->scsiio);
597 	else {
598 		/* XXX KDM is there is a better error here? */
599 		ctl_set_internal_failure(&io->scsiio,
600 					 /*sks_valid*/ 1,
601 					 /*retry_count*/ 0xbad1);
602 	}
603 
604 	ctl_complete_beio(beio);
605 }
606 
607 SDT_PROBE_DEFINE1(cbb, kernel, read, file_start, "uint64_t");
608 SDT_PROBE_DEFINE1(cbb, kernel, write, file_start, "uint64_t");
609 SDT_PROBE_DEFINE1(cbb, kernel, read, file_done,"uint64_t");
610 SDT_PROBE_DEFINE1(cbb, kernel, write, file_done, "uint64_t");
611 
612 static void
613 ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
614 			   struct ctl_be_block_io *beio)
615 {
616 	struct ctl_be_block_filedata *file_data;
617 	union ctl_io *io;
618 	struct uio xuio;
619 	struct iovec *xiovec;
620 	int flags;
621 	int error, i;
622 
623 	DPRINTF("entered\n");
624 
625 	file_data = &be_lun->backend.file;
626 	io = beio->io;
627 	flags = 0;
628 	if (ARGS(io)->flags & CTL_LLF_DPO)
629 		flags |= IO_DIRECT;
630 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
631 		flags |= IO_SYNC;
632 
633 	bzero(&xuio, sizeof(xuio));
634 	if (beio->bio_cmd == BIO_READ) {
635 		SDT_PROBE(cbb, kernel, read, file_start, 0, 0, 0, 0, 0);
636 		xuio.uio_rw = UIO_READ;
637 	} else {
638 		SDT_PROBE(cbb, kernel, write, file_start, 0, 0, 0, 0, 0);
639 		xuio.uio_rw = UIO_WRITE;
640 	}
641 	xuio.uio_offset = beio->io_offset;
642 	xuio.uio_resid = beio->io_len;
643 	xuio.uio_segflg = UIO_SYSSPACE;
644 	xuio.uio_iov = beio->xiovecs;
645 	xuio.uio_iovcnt = beio->num_segs;
646 	xuio.uio_td = curthread;
647 
648 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
649 		xiovec->iov_base = beio->sg_segs[i].addr;
650 		xiovec->iov_len = beio->sg_segs[i].len;
651 	}
652 
653 	binuptime(&beio->ds_t0);
654 	mtx_lock(&be_lun->io_lock);
655 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
656 	mtx_unlock(&be_lun->io_lock);
657 
658 	if (beio->bio_cmd == BIO_READ) {
659 		vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
660 
661 		/*
662 		 * UFS pays attention to IO_DIRECT for reads.  If the
663 		 * DIRECTIO option is configured into the kernel, it calls
664 		 * ffs_rawread().  But that only works for single-segment
665 		 * uios with user space addresses.  In our case, with a
666 		 * kernel uio, it still reads into the buffer cache, but it
667 		 * will just try to release the buffer from the cache later
668 		 * on in ffs_read().
669 		 *
670 		 * ZFS does not pay attention to IO_DIRECT for reads.
671 		 *
672 		 * UFS does not pay attention to IO_SYNC for reads.
673 		 *
674 		 * ZFS pays attention to IO_SYNC (which translates into the
675 		 * Solaris define FRSYNC for zfs_read()) for reads.  It
676 		 * attempts to sync the file before reading.
677 		 *
678 		 * So, to attempt to provide some barrier semantics in the
679 		 * BIO_ORDERED case, set both IO_DIRECT and IO_SYNC.
680 		 */
681 		error = VOP_READ(be_lun->vn, &xuio, flags, file_data->cred);
682 
683 		VOP_UNLOCK(be_lun->vn, 0);
684 		SDT_PROBE(cbb, kernel, read, file_done, 0, 0, 0, 0, 0);
685 	} else {
686 		struct mount *mountpoint;
687 		int lock_flags;
688 
689 		(void)vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
690 
691 		if (MNT_SHARED_WRITES(mountpoint)
692 		 || ((mountpoint == NULL)
693 		  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
694 			lock_flags = LK_SHARED;
695 		else
696 			lock_flags = LK_EXCLUSIVE;
697 
698 		vn_lock(be_lun->vn, lock_flags | LK_RETRY);
699 
700 		/*
701 		 * UFS pays attention to IO_DIRECT for writes.  The write
702 		 * is done asynchronously.  (Normally the write would just
703 		 * get put into cache.
704 		 *
705 		 * UFS pays attention to IO_SYNC for writes.  It will
706 		 * attempt to write the buffer out synchronously if that
707 		 * flag is set.
708 		 *
709 		 * ZFS does not pay attention to IO_DIRECT for writes.
710 		 *
711 		 * ZFS pays attention to IO_SYNC (a.k.a. FSYNC or FRSYNC)
712 		 * for writes.  It will flush the transaction from the
713 		 * cache before returning.
714 		 *
715 		 * So if we've got the BIO_ORDERED flag set, we want
716 		 * IO_SYNC in either the UFS or ZFS case.
717 		 */
718 		error = VOP_WRITE(be_lun->vn, &xuio, flags, file_data->cred);
719 		VOP_UNLOCK(be_lun->vn, 0);
720 
721 		vn_finished_write(mountpoint);
722 		SDT_PROBE(cbb, kernel, write, file_done, 0, 0, 0, 0, 0);
723         }
724 
725 	mtx_lock(&be_lun->io_lock);
726 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
727 	    beio->ds_tag_type, beio->ds_trans_type,
728 	    /*now*/ NULL, /*then*/&beio->ds_t0);
729 	mtx_unlock(&be_lun->io_lock);
730 
731 	/*
732 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
733 	 * return the I/O to the user.
734 	 */
735 	if (error != 0) {
736 		char path_str[32];
737 
738 		ctl_scsi_path_string(io, path_str, sizeof(path_str));
739 		printf("%s%s command returned errno %d\n", path_str,
740 		       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE", error);
741 		if (error == ENOSPC) {
742 			ctl_set_space_alloc_fail(&io->scsiio);
743 		} else
744 			ctl_set_medium_error(&io->scsiio);
745 		ctl_complete_beio(beio);
746 		return;
747 	}
748 
749 	/*
750 	 * If this is a write or a verify, we're all done.
751 	 * If this is a read, we can now send the data to the user.
752 	 */
753 	if ((beio->bio_cmd == BIO_WRITE) ||
754 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
755 		ctl_set_success(&io->scsiio);
756 		ctl_complete_beio(beio);
757 	} else {
758 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
759 		    beio->beio_cont == NULL)
760 			ctl_set_success(&io->scsiio);
761 #ifdef CTL_TIME_IO
762         	getbintime(&io->io_hdr.dma_start_bt);
763 #endif
764 		ctl_datamove(io);
765 	}
766 }
767 
768 static void
769 ctl_be_block_gls_file(struct ctl_be_block_lun *be_lun,
770 			struct ctl_be_block_io *beio)
771 {
772 	union ctl_io *io = beio->io;
773 	struct ctl_lba_len_flags *lbalen = ARGS(io);
774 	struct scsi_get_lba_status_data *data;
775 	off_t roff, off;
776 	int error, status;
777 
778 	DPRINTF("entered\n");
779 
780 	off = roff = ((off_t)lbalen->lba) << be_lun->blocksize_shift;
781 	vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
782 	error = VOP_IOCTL(be_lun->vn, FIOSEEKHOLE, &off,
783 	    0, curthread->td_ucred, curthread);
784 	if (error == 0 && off > roff)
785 		status = 0;	/* mapped up to off */
786 	else {
787 		error = VOP_IOCTL(be_lun->vn, FIOSEEKDATA, &off,
788 		    0, curthread->td_ucred, curthread);
789 		if (error == 0 && off > roff)
790 			status = 1;	/* deallocated up to off */
791 		else {
792 			status = 0;	/* unknown up to the end */
793 			off = be_lun->size_bytes;
794 		}
795 	}
796 	VOP_UNLOCK(be_lun->vn, 0);
797 
798 	off >>= be_lun->blocksize_shift;
799 	data = (struct scsi_get_lba_status_data *)io->scsiio.kern_data_ptr;
800 	scsi_u64to8b(lbalen->lba, data->descr[0].addr);
801 	scsi_ulto4b(MIN(UINT32_MAX, off - lbalen->lba),
802 	    data->descr[0].length);
803 	data->descr[0].status = status;
804 
805 	ctl_complete_beio(beio);
806 }
807 
808 static uint64_t
809 ctl_be_block_getattr_file(struct ctl_be_block_lun *be_lun, const char *attrname)
810 {
811 	struct vattr		vattr;
812 	struct statfs		statfs;
813 	int			error;
814 
815 	if (be_lun->vn == NULL)
816 		return (UINT64_MAX);
817 	if (strcmp(attrname, "blocksused") == 0) {
818 		error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
819 		if (error != 0)
820 			return (UINT64_MAX);
821 		return (vattr.va_bytes >> be_lun->blocksize_shift);
822 	}
823 	if (strcmp(attrname, "blocksavail") == 0) {
824 		error = VFS_STATFS(be_lun->vn->v_mount, &statfs);
825 		if (error != 0)
826 			return (UINT64_MAX);
827 		return ((statfs.f_bavail * statfs.f_bsize) >>
828 		    be_lun->blocksize_shift);
829 	}
830 	return (UINT64_MAX);
831 }
832 
833 static void
834 ctl_be_block_dispatch_zvol(struct ctl_be_block_lun *be_lun,
835 			   struct ctl_be_block_io *beio)
836 {
837 	struct ctl_be_block_devdata *dev_data;
838 	union ctl_io *io;
839 	struct uio xuio;
840 	struct iovec *xiovec;
841 	int flags;
842 	int error, i;
843 
844 	DPRINTF("entered\n");
845 
846 	dev_data = &be_lun->backend.dev;
847 	io = beio->io;
848 	flags = 0;
849 	if (ARGS(io)->flags & CTL_LLF_DPO)
850 		flags |= IO_DIRECT;
851 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
852 		flags |= IO_SYNC;
853 
854 	bzero(&xuio, sizeof(xuio));
855 	if (beio->bio_cmd == BIO_READ) {
856 		SDT_PROBE(cbb, kernel, read, file_start, 0, 0, 0, 0, 0);
857 		xuio.uio_rw = UIO_READ;
858 	} else {
859 		SDT_PROBE(cbb, kernel, write, file_start, 0, 0, 0, 0, 0);
860 		xuio.uio_rw = UIO_WRITE;
861 	}
862 	xuio.uio_offset = beio->io_offset;
863 	xuio.uio_resid = beio->io_len;
864 	xuio.uio_segflg = UIO_SYSSPACE;
865 	xuio.uio_iov = beio->xiovecs;
866 	xuio.uio_iovcnt = beio->num_segs;
867 	xuio.uio_td = curthread;
868 
869 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
870 		xiovec->iov_base = beio->sg_segs[i].addr;
871 		xiovec->iov_len = beio->sg_segs[i].len;
872 	}
873 
874 	binuptime(&beio->ds_t0);
875 	mtx_lock(&be_lun->io_lock);
876 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
877 	mtx_unlock(&be_lun->io_lock);
878 
879 	if (beio->bio_cmd == BIO_READ) {
880 		error = (*dev_data->csw->d_read)(dev_data->cdev, &xuio, flags);
881 		SDT_PROBE(cbb, kernel, read, file_done, 0, 0, 0, 0, 0);
882 	} else {
883 		error = (*dev_data->csw->d_write)(dev_data->cdev, &xuio, flags);
884 		SDT_PROBE(cbb, kernel, write, file_done, 0, 0, 0, 0, 0);
885 	}
886 
887 	mtx_lock(&be_lun->io_lock);
888 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
889 	    beio->ds_tag_type, beio->ds_trans_type,
890 	    /*now*/ NULL, /*then*/&beio->ds_t0);
891 	mtx_unlock(&be_lun->io_lock);
892 
893 	/*
894 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
895 	 * return the I/O to the user.
896 	 */
897 	if (error != 0) {
898 		if (error == ENOSPC) {
899 			ctl_set_space_alloc_fail(&io->scsiio);
900 		} else
901 			ctl_set_medium_error(&io->scsiio);
902 		ctl_complete_beio(beio);
903 		return;
904 	}
905 
906 	/*
907 	 * If this is a write or a verify, we're all done.
908 	 * If this is a read, we can now send the data to the user.
909 	 */
910 	if ((beio->bio_cmd == BIO_WRITE) ||
911 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
912 		ctl_set_success(&io->scsiio);
913 		ctl_complete_beio(beio);
914 	} else {
915 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
916 		    beio->beio_cont == NULL)
917 			ctl_set_success(&io->scsiio);
918 #ifdef CTL_TIME_IO
919         	getbintime(&io->io_hdr.dma_start_bt);
920 #endif
921 		ctl_datamove(io);
922 	}
923 }
924 
925 static void
926 ctl_be_block_gls_zvol(struct ctl_be_block_lun *be_lun,
927 			struct ctl_be_block_io *beio)
928 {
929 	struct ctl_be_block_devdata *dev_data = &be_lun->backend.dev;
930 	union ctl_io *io = beio->io;
931 	struct ctl_lba_len_flags *lbalen = ARGS(io);
932 	struct scsi_get_lba_status_data *data;
933 	off_t roff, off;
934 	int error, status;
935 
936 	DPRINTF("entered\n");
937 
938 	off = roff = ((off_t)lbalen->lba) << be_lun->blocksize_shift;
939 	error = (*dev_data->csw->d_ioctl)(dev_data->cdev, FIOSEEKHOLE,
940 	    (caddr_t)&off, FREAD, curthread);
941 	if (error == 0 && off > roff)
942 		status = 0;	/* mapped up to off */
943 	else {
944 		error = (*dev_data->csw->d_ioctl)(dev_data->cdev, FIOSEEKDATA,
945 		    (caddr_t)&off, FREAD, curthread);
946 		if (error == 0 && off > roff)
947 			status = 1;	/* deallocated up to off */
948 		else {
949 			status = 0;	/* unknown up to the end */
950 			off = be_lun->size_bytes;
951 		}
952 	}
953 
954 	off >>= be_lun->blocksize_shift;
955 	data = (struct scsi_get_lba_status_data *)io->scsiio.kern_data_ptr;
956 	scsi_u64to8b(lbalen->lba, data->descr[0].addr);
957 	scsi_ulto4b(MIN(UINT32_MAX, off - lbalen->lba),
958 	    data->descr[0].length);
959 	data->descr[0].status = status;
960 
961 	ctl_complete_beio(beio);
962 }
963 
964 static void
965 ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
966 		       struct ctl_be_block_io *beio)
967 {
968 	struct bio *bio;
969 	union ctl_io *io;
970 	struct ctl_be_block_devdata *dev_data;
971 
972 	dev_data = &be_lun->backend.dev;
973 	io = beio->io;
974 
975 	DPRINTF("entered\n");
976 
977 	/* This can't fail, it's a blocking allocation. */
978 	bio = g_alloc_bio();
979 
980 	bio->bio_cmd	    = BIO_FLUSH;
981 	bio->bio_flags	   |= BIO_ORDERED;
982 	bio->bio_dev	    = dev_data->cdev;
983 	bio->bio_offset	    = 0;
984 	bio->bio_data	    = 0;
985 	bio->bio_done	    = ctl_be_block_biodone;
986 	bio->bio_caller1    = beio;
987 	bio->bio_pblkno	    = 0;
988 
989 	/*
990 	 * We don't need to acquire the LUN lock here, because we are only
991 	 * sending one bio, and so there is no other context to synchronize
992 	 * with.
993 	 */
994 	beio->num_bios_sent = 1;
995 	beio->send_complete = 1;
996 
997 	binuptime(&beio->ds_t0);
998 	mtx_lock(&be_lun->io_lock);
999 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1000 	mtx_unlock(&be_lun->io_lock);
1001 
1002 	(*dev_data->csw->d_strategy)(bio);
1003 }
1004 
1005 static void
1006 ctl_be_block_unmap_dev_range(struct ctl_be_block_lun *be_lun,
1007 		       struct ctl_be_block_io *beio,
1008 		       uint64_t off, uint64_t len, int last)
1009 {
1010 	struct bio *bio;
1011 	struct ctl_be_block_devdata *dev_data;
1012 	uint64_t maxlen;
1013 
1014 	dev_data = &be_lun->backend.dev;
1015 	maxlen = LONG_MAX - (LONG_MAX % be_lun->blocksize);
1016 	while (len > 0) {
1017 		bio = g_alloc_bio();
1018 		bio->bio_cmd	    = BIO_DELETE;
1019 		bio->bio_dev	    = dev_data->cdev;
1020 		bio->bio_offset	    = off;
1021 		bio->bio_length	    = MIN(len, maxlen);
1022 		bio->bio_data	    = 0;
1023 		bio->bio_done	    = ctl_be_block_biodone;
1024 		bio->bio_caller1    = beio;
1025 		bio->bio_pblkno     = off / be_lun->blocksize;
1026 
1027 		off += bio->bio_length;
1028 		len -= bio->bio_length;
1029 
1030 		mtx_lock(&be_lun->io_lock);
1031 		beio->num_bios_sent++;
1032 		if (last && len == 0)
1033 			beio->send_complete = 1;
1034 		mtx_unlock(&be_lun->io_lock);
1035 
1036 		(*dev_data->csw->d_strategy)(bio);
1037 	}
1038 }
1039 
1040 static void
1041 ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
1042 		       struct ctl_be_block_io *beio)
1043 {
1044 	union ctl_io *io;
1045 	struct ctl_be_block_devdata *dev_data;
1046 	struct ctl_ptr_len_flags *ptrlen;
1047 	struct scsi_unmap_desc *buf, *end;
1048 	uint64_t len;
1049 
1050 	dev_data = &be_lun->backend.dev;
1051 	io = beio->io;
1052 
1053 	DPRINTF("entered\n");
1054 
1055 	binuptime(&beio->ds_t0);
1056 	mtx_lock(&be_lun->io_lock);
1057 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1058 	mtx_unlock(&be_lun->io_lock);
1059 
1060 	if (beio->io_offset == -1) {
1061 		beio->io_len = 0;
1062 		ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1063 		buf = (struct scsi_unmap_desc *)ptrlen->ptr;
1064 		end = buf + ptrlen->len / sizeof(*buf);
1065 		for (; buf < end; buf++) {
1066 			len = (uint64_t)scsi_4btoul(buf->length) *
1067 			    be_lun->blocksize;
1068 			beio->io_len += len;
1069 			ctl_be_block_unmap_dev_range(be_lun, beio,
1070 			    scsi_8btou64(buf->lba) * be_lun->blocksize, len,
1071 			    (end - buf < 2) ? TRUE : FALSE);
1072 		}
1073 	} else
1074 		ctl_be_block_unmap_dev_range(be_lun, beio,
1075 		    beio->io_offset, beio->io_len, TRUE);
1076 }
1077 
1078 static void
1079 ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
1080 			  struct ctl_be_block_io *beio)
1081 {
1082 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
1083 	int i;
1084 	struct bio *bio;
1085 	struct ctl_be_block_devdata *dev_data;
1086 	off_t cur_offset;
1087 	int max_iosize;
1088 
1089 	DPRINTF("entered\n");
1090 
1091 	dev_data = &be_lun->backend.dev;
1092 
1093 	/*
1094 	 * We have to limit our I/O size to the maximum supported by the
1095 	 * backend device.  Hopefully it is MAXPHYS.  If the driver doesn't
1096 	 * set it properly, use DFLTPHYS.
1097 	 */
1098 	max_iosize = dev_data->cdev->si_iosize_max;
1099 	if (max_iosize < PAGE_SIZE)
1100 		max_iosize = DFLTPHYS;
1101 
1102 	cur_offset = beio->io_offset;
1103 	for (i = 0; i < beio->num_segs; i++) {
1104 		size_t cur_size;
1105 		uint8_t *cur_ptr;
1106 
1107 		cur_size = beio->sg_segs[i].len;
1108 		cur_ptr = beio->sg_segs[i].addr;
1109 
1110 		while (cur_size > 0) {
1111 			/* This can't fail, it's a blocking allocation. */
1112 			bio = g_alloc_bio();
1113 
1114 			KASSERT(bio != NULL, ("g_alloc_bio() failed!\n"));
1115 
1116 			bio->bio_cmd = beio->bio_cmd;
1117 			bio->bio_dev = dev_data->cdev;
1118 			bio->bio_caller1 = beio;
1119 			bio->bio_length = min(cur_size, max_iosize);
1120 			bio->bio_offset = cur_offset;
1121 			bio->bio_data = cur_ptr;
1122 			bio->bio_done = ctl_be_block_biodone;
1123 			bio->bio_pblkno = cur_offset / be_lun->blocksize;
1124 
1125 			cur_offset += bio->bio_length;
1126 			cur_ptr += bio->bio_length;
1127 			cur_size -= bio->bio_length;
1128 
1129 			TAILQ_INSERT_TAIL(&queue, bio, bio_queue);
1130 			beio->num_bios_sent++;
1131 		}
1132 	}
1133 	binuptime(&beio->ds_t0);
1134 	mtx_lock(&be_lun->io_lock);
1135 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1136 	beio->send_complete = 1;
1137 	mtx_unlock(&be_lun->io_lock);
1138 
1139 	/*
1140 	 * Fire off all allocated requests!
1141 	 */
1142 	while ((bio = TAILQ_FIRST(&queue)) != NULL) {
1143 		TAILQ_REMOVE(&queue, bio, bio_queue);
1144 		(*dev_data->csw->d_strategy)(bio);
1145 	}
1146 }
1147 
1148 static uint64_t
1149 ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun, const char *attrname)
1150 {
1151 	struct ctl_be_block_devdata	*dev_data = &be_lun->backend.dev;
1152 	struct diocgattr_arg	arg;
1153 	int			error;
1154 
1155 	if (dev_data->csw == NULL || dev_data->csw->d_ioctl == NULL)
1156 		return (UINT64_MAX);
1157 	strlcpy(arg.name, attrname, sizeof(arg.name));
1158 	arg.len = sizeof(arg.value.off);
1159 	error = dev_data->csw->d_ioctl(dev_data->cdev,
1160 	    DIOCGATTR, (caddr_t)&arg, FREAD, curthread);
1161 	if (error != 0)
1162 		return (UINT64_MAX);
1163 	return (arg.value.off);
1164 }
1165 
1166 static void
1167 ctl_be_block_cw_done_ws(struct ctl_be_block_io *beio)
1168 {
1169 	union ctl_io *io;
1170 
1171 	io = beio->io;
1172 	ctl_free_beio(beio);
1173 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1174 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1175 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1176 		ctl_config_write_done(io);
1177 		return;
1178 	}
1179 
1180 	ctl_be_block_config_write(io);
1181 }
1182 
1183 static void
1184 ctl_be_block_cw_dispatch_ws(struct ctl_be_block_lun *be_lun,
1185 			    union ctl_io *io)
1186 {
1187 	struct ctl_be_block_io *beio;
1188 	struct ctl_be_block_softc *softc;
1189 	struct ctl_lba_len_flags *lbalen;
1190 	uint64_t len_left, lba;
1191 	int i, seglen;
1192 	uint8_t *buf, *end;
1193 
1194 	DPRINTF("entered\n");
1195 
1196 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1197 	softc = be_lun->softc;
1198 	lbalen = ARGS(beio->io);
1199 
1200 	if (lbalen->flags & ~(SWS_LBDATA | SWS_UNMAP | SWS_ANCHOR | SWS_NDOB) ||
1201 	    (lbalen->flags & (SWS_UNMAP | SWS_ANCHOR) && be_lun->unmap == NULL)) {
1202 		ctl_free_beio(beio);
1203 		ctl_set_invalid_field(&io->scsiio,
1204 				      /*sks_valid*/ 1,
1205 				      /*command*/ 1,
1206 				      /*field*/ 1,
1207 				      /*bit_valid*/ 0,
1208 				      /*bit*/ 0);
1209 		ctl_config_write_done(io);
1210 		return;
1211 	}
1212 
1213 	switch (io->scsiio.tag_type) {
1214 	case CTL_TAG_ORDERED:
1215 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1216 		break;
1217 	case CTL_TAG_HEAD_OF_QUEUE:
1218 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1219 		break;
1220 	case CTL_TAG_UNTAGGED:
1221 	case CTL_TAG_SIMPLE:
1222 	case CTL_TAG_ACA:
1223 	default:
1224 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1225 		break;
1226 	}
1227 
1228 	if (lbalen->flags & (SWS_UNMAP | SWS_ANCHOR)) {
1229 		beio->io_offset = lbalen->lba * be_lun->blocksize;
1230 		beio->io_len = (uint64_t)lbalen->len * be_lun->blocksize;
1231 		beio->bio_cmd = BIO_DELETE;
1232 		beio->ds_trans_type = DEVSTAT_FREE;
1233 
1234 		be_lun->unmap(be_lun, beio);
1235 		return;
1236 	}
1237 
1238 	beio->bio_cmd = BIO_WRITE;
1239 	beio->ds_trans_type = DEVSTAT_WRITE;
1240 
1241 	DPRINTF("WRITE SAME at LBA %jx len %u\n",
1242 	       (uintmax_t)lbalen->lba, lbalen->len);
1243 
1244 	len_left = (uint64_t)lbalen->len * be_lun->blocksize;
1245 	for (i = 0, lba = 0; i < CTLBLK_MAX_SEGS && len_left > 0; i++) {
1246 
1247 		/*
1248 		 * Setup the S/G entry for this chunk.
1249 		 */
1250 		seglen = MIN(CTLBLK_MAX_SEG, len_left);
1251 		seglen -= seglen % be_lun->blocksize;
1252 		beio->sg_segs[i].len = seglen;
1253 		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1254 
1255 		DPRINTF("segment %d addr %p len %zd\n", i,
1256 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1257 
1258 		beio->num_segs++;
1259 		len_left -= seglen;
1260 
1261 		buf = beio->sg_segs[i].addr;
1262 		end = buf + seglen;
1263 		for (; buf < end; buf += be_lun->blocksize) {
1264 			memcpy(buf, io->scsiio.kern_data_ptr, be_lun->blocksize);
1265 			if (lbalen->flags & SWS_LBDATA)
1266 				scsi_ulto4b(lbalen->lba + lba, buf);
1267 			lba++;
1268 		}
1269 	}
1270 
1271 	beio->io_offset = lbalen->lba * be_lun->blocksize;
1272 	beio->io_len = lba * be_lun->blocksize;
1273 
1274 	/* We can not do all in one run. Correct and schedule rerun. */
1275 	if (len_left > 0) {
1276 		lbalen->lba += lba;
1277 		lbalen->len -= lba;
1278 		beio->beio_cont = ctl_be_block_cw_done_ws;
1279 	}
1280 
1281 	be_lun->dispatch(be_lun, beio);
1282 }
1283 
1284 static void
1285 ctl_be_block_cw_dispatch_unmap(struct ctl_be_block_lun *be_lun,
1286 			    union ctl_io *io)
1287 {
1288 	struct ctl_be_block_io *beio;
1289 	struct ctl_be_block_softc *softc;
1290 	struct ctl_ptr_len_flags *ptrlen;
1291 
1292 	DPRINTF("entered\n");
1293 
1294 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1295 	softc = be_lun->softc;
1296 	ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1297 
1298 	if ((ptrlen->flags & ~SU_ANCHOR) != 0 || be_lun->unmap == NULL) {
1299 		ctl_free_beio(beio);
1300 		ctl_set_invalid_field(&io->scsiio,
1301 				      /*sks_valid*/ 0,
1302 				      /*command*/ 1,
1303 				      /*field*/ 0,
1304 				      /*bit_valid*/ 0,
1305 				      /*bit*/ 0);
1306 		ctl_config_write_done(io);
1307 		return;
1308 	}
1309 
1310 	switch (io->scsiio.tag_type) {
1311 	case CTL_TAG_ORDERED:
1312 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1313 		break;
1314 	case CTL_TAG_HEAD_OF_QUEUE:
1315 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1316 		break;
1317 	case CTL_TAG_UNTAGGED:
1318 	case CTL_TAG_SIMPLE:
1319 	case CTL_TAG_ACA:
1320 	default:
1321 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1322 		break;
1323 	}
1324 
1325 	beio->io_len = 0;
1326 	beio->io_offset = -1;
1327 
1328 	beio->bio_cmd = BIO_DELETE;
1329 	beio->ds_trans_type = DEVSTAT_FREE;
1330 
1331 	DPRINTF("UNMAP\n");
1332 
1333 	be_lun->unmap(be_lun, beio);
1334 }
1335 
1336 static void
1337 ctl_be_block_cr_done(struct ctl_be_block_io *beio)
1338 {
1339 	union ctl_io *io;
1340 
1341 	io = beio->io;
1342 	ctl_free_beio(beio);
1343 	ctl_config_read_done(io);
1344 }
1345 
1346 static void
1347 ctl_be_block_cr_dispatch(struct ctl_be_block_lun *be_lun,
1348 			 union ctl_io *io)
1349 {
1350 	struct ctl_be_block_io *beio;
1351 	struct ctl_be_block_softc *softc;
1352 
1353 	DPRINTF("entered\n");
1354 
1355 	softc = be_lun->softc;
1356 	beio = ctl_alloc_beio(softc);
1357 	beio->io = io;
1358 	beio->lun = be_lun;
1359 	beio->beio_cont = ctl_be_block_cr_done;
1360 	PRIV(io)->ptr = (void *)beio;
1361 
1362 	switch (io->scsiio.cdb[0]) {
1363 	case SERVICE_ACTION_IN:		/* GET LBA STATUS */
1364 		beio->bio_cmd = -1;
1365 		beio->ds_trans_type = DEVSTAT_NO_DATA;
1366 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1367 		beio->io_len = 0;
1368 		if (be_lun->get_lba_status)
1369 			be_lun->get_lba_status(be_lun, beio);
1370 		else
1371 			ctl_be_block_cr_done(beio);
1372 		break;
1373 	default:
1374 		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1375 		break;
1376 	}
1377 }
1378 
1379 static void
1380 ctl_be_block_cw_done(struct ctl_be_block_io *beio)
1381 {
1382 	union ctl_io *io;
1383 
1384 	io = beio->io;
1385 	ctl_free_beio(beio);
1386 	ctl_config_write_done(io);
1387 }
1388 
1389 static void
1390 ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
1391 			 union ctl_io *io)
1392 {
1393 	struct ctl_be_block_io *beio;
1394 	struct ctl_be_block_softc *softc;
1395 
1396 	DPRINTF("entered\n");
1397 
1398 	softc = be_lun->softc;
1399 	beio = ctl_alloc_beio(softc);
1400 	beio->io = io;
1401 	beio->lun = be_lun;
1402 	beio->beio_cont = ctl_be_block_cw_done;
1403 	PRIV(io)->ptr = (void *)beio;
1404 
1405 	switch (io->scsiio.cdb[0]) {
1406 	case SYNCHRONIZE_CACHE:
1407 	case SYNCHRONIZE_CACHE_16:
1408 		beio->bio_cmd = BIO_FLUSH;
1409 		beio->ds_trans_type = DEVSTAT_NO_DATA;
1410 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1411 		beio->io_len = 0;
1412 		be_lun->lun_flush(be_lun, beio);
1413 		break;
1414 	case WRITE_SAME_10:
1415 	case WRITE_SAME_16:
1416 		ctl_be_block_cw_dispatch_ws(be_lun, io);
1417 		break;
1418 	case UNMAP:
1419 		ctl_be_block_cw_dispatch_unmap(be_lun, io);
1420 		break;
1421 	default:
1422 		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1423 		break;
1424 	}
1425 }
1426 
1427 SDT_PROBE_DEFINE1(cbb, kernel, read, start, "uint64_t");
1428 SDT_PROBE_DEFINE1(cbb, kernel, write, start, "uint64_t");
1429 SDT_PROBE_DEFINE1(cbb, kernel, read, alloc_done, "uint64_t");
1430 SDT_PROBE_DEFINE1(cbb, kernel, write, alloc_done, "uint64_t");
1431 
1432 static void
1433 ctl_be_block_next(struct ctl_be_block_io *beio)
1434 {
1435 	struct ctl_be_block_lun *be_lun;
1436 	union ctl_io *io;
1437 
1438 	io = beio->io;
1439 	be_lun = beio->lun;
1440 	ctl_free_beio(beio);
1441 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1442 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1443 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1444 		ctl_data_submit_done(io);
1445 		return;
1446 	}
1447 
1448 	io->io_hdr.status &= ~CTL_STATUS_MASK;
1449 	io->io_hdr.status |= CTL_STATUS_NONE;
1450 
1451 	mtx_lock(&be_lun->queue_lock);
1452 	/*
1453 	 * XXX KDM make sure that links is okay to use at this point.
1454 	 * Otherwise, we either need to add another field to ctl_io_hdr,
1455 	 * or deal with resource allocation here.
1456 	 */
1457 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1458 	mtx_unlock(&be_lun->queue_lock);
1459 
1460 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1461 }
1462 
1463 static void
1464 ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
1465 			   union ctl_io *io)
1466 {
1467 	struct ctl_be_block_io *beio;
1468 	struct ctl_be_block_softc *softc;
1469 	struct ctl_lba_len_flags *lbalen;
1470 	struct ctl_ptr_len_flags *bptrlen;
1471 	uint64_t len_left, lbas;
1472 	int i;
1473 
1474 	softc = be_lun->softc;
1475 
1476 	DPRINTF("entered\n");
1477 
1478 	lbalen = ARGS(io);
1479 	if (lbalen->flags & CTL_LLF_WRITE) {
1480 		SDT_PROBE(cbb, kernel, write, start, 0, 0, 0, 0, 0);
1481 	} else {
1482 		SDT_PROBE(cbb, kernel, read, start, 0, 0, 0, 0, 0);
1483 	}
1484 
1485 	beio = ctl_alloc_beio(softc);
1486 	beio->io = io;
1487 	beio->lun = be_lun;
1488 	bptrlen = PRIV(io);
1489 	bptrlen->ptr = (void *)beio;
1490 
1491 	switch (io->scsiio.tag_type) {
1492 	case CTL_TAG_ORDERED:
1493 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1494 		break;
1495 	case CTL_TAG_HEAD_OF_QUEUE:
1496 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1497 		break;
1498 	case CTL_TAG_UNTAGGED:
1499 	case CTL_TAG_SIMPLE:
1500 	case CTL_TAG_ACA:
1501 	default:
1502 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1503 		break;
1504 	}
1505 
1506 	if (lbalen->flags & CTL_LLF_WRITE) {
1507 		beio->bio_cmd = BIO_WRITE;
1508 		beio->ds_trans_type = DEVSTAT_WRITE;
1509 	} else {
1510 		beio->bio_cmd = BIO_READ;
1511 		beio->ds_trans_type = DEVSTAT_READ;
1512 	}
1513 
1514 	DPRINTF("%s at LBA %jx len %u @%ju\n",
1515 	       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE",
1516 	       (uintmax_t)lbalen->lba, lbalen->len, bptrlen->len);
1517 	if (lbalen->flags & CTL_LLF_COMPARE)
1518 		lbas = CTLBLK_HALF_IO_SIZE;
1519 	else
1520 		lbas = CTLBLK_MAX_IO_SIZE;
1521 	lbas = MIN(lbalen->len - bptrlen->len, lbas / be_lun->blocksize);
1522 	beio->io_offset = (lbalen->lba + bptrlen->len) * be_lun->blocksize;
1523 	beio->io_len = lbas * be_lun->blocksize;
1524 	bptrlen->len += lbas;
1525 
1526 	for (i = 0, len_left = beio->io_len; len_left > 0; i++) {
1527 		KASSERT(i < CTLBLK_MAX_SEGS, ("Too many segs (%d >= %d)",
1528 		    i, CTLBLK_MAX_SEGS));
1529 
1530 		/*
1531 		 * Setup the S/G entry for this chunk.
1532 		 */
1533 		beio->sg_segs[i].len = min(CTLBLK_MAX_SEG, len_left);
1534 		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1535 
1536 		DPRINTF("segment %d addr %p len %zd\n", i,
1537 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1538 
1539 		/* Set up second segment for compare operation. */
1540 		if (lbalen->flags & CTL_LLF_COMPARE) {
1541 			beio->sg_segs[i + CTLBLK_HALF_SEGS].len =
1542 			    beio->sg_segs[i].len;
1543 			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr =
1544 			    uma_zalloc(be_lun->lun_zone, M_WAITOK);
1545 		}
1546 
1547 		beio->num_segs++;
1548 		len_left -= beio->sg_segs[i].len;
1549 	}
1550 	if (bptrlen->len < lbalen->len)
1551 		beio->beio_cont = ctl_be_block_next;
1552 	io->scsiio.be_move_done = ctl_be_block_move_done;
1553 	/* For compare we have separate S/G lists for read and datamove. */
1554 	if (lbalen->flags & CTL_LLF_COMPARE)
1555 		io->scsiio.kern_data_ptr = (uint8_t *)&beio->sg_segs[CTLBLK_HALF_SEGS];
1556 	else
1557 		io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
1558 	io->scsiio.kern_data_len = beio->io_len;
1559 	io->scsiio.kern_data_resid = 0;
1560 	io->scsiio.kern_sg_entries = beio->num_segs;
1561 	io->io_hdr.flags |= CTL_FLAG_ALLOCATED | CTL_FLAG_KDPTR_SGLIST;
1562 
1563 	/*
1564 	 * For the read case, we need to read the data into our buffers and
1565 	 * then we can send it back to the user.  For the write case, we
1566 	 * need to get the data from the user first.
1567 	 */
1568 	if (beio->bio_cmd == BIO_READ) {
1569 		SDT_PROBE(cbb, kernel, read, alloc_done, 0, 0, 0, 0, 0);
1570 		be_lun->dispatch(be_lun, beio);
1571 	} else {
1572 		SDT_PROBE(cbb, kernel, write, alloc_done, 0, 0, 0, 0, 0);
1573 #ifdef CTL_TIME_IO
1574         	getbintime(&io->io_hdr.dma_start_bt);
1575 #endif
1576 		ctl_datamove(io);
1577 	}
1578 }
1579 
1580 static void
1581 ctl_be_block_worker(void *context, int pending)
1582 {
1583 	struct ctl_be_block_lun *be_lun;
1584 	struct ctl_be_block_softc *softc;
1585 	union ctl_io *io;
1586 
1587 	be_lun = (struct ctl_be_block_lun *)context;
1588 	softc = be_lun->softc;
1589 
1590 	DPRINTF("entered\n");
1591 
1592 	mtx_lock(&be_lun->queue_lock);
1593 	for (;;) {
1594 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->datamove_queue);
1595 		if (io != NULL) {
1596 			struct ctl_be_block_io *beio;
1597 
1598 			DPRINTF("datamove queue\n");
1599 
1600 			STAILQ_REMOVE(&be_lun->datamove_queue, &io->io_hdr,
1601 				      ctl_io_hdr, links);
1602 
1603 			mtx_unlock(&be_lun->queue_lock);
1604 
1605 			beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1606 
1607 			be_lun->dispatch(be_lun, beio);
1608 
1609 			mtx_lock(&be_lun->queue_lock);
1610 			continue;
1611 		}
1612 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_write_queue);
1613 		if (io != NULL) {
1614 			DPRINTF("config write queue\n");
1615 			STAILQ_REMOVE(&be_lun->config_write_queue, &io->io_hdr,
1616 				      ctl_io_hdr, links);
1617 			mtx_unlock(&be_lun->queue_lock);
1618 			ctl_be_block_cw_dispatch(be_lun, io);
1619 			mtx_lock(&be_lun->queue_lock);
1620 			continue;
1621 		}
1622 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_read_queue);
1623 		if (io != NULL) {
1624 			DPRINTF("config read queue\n");
1625 			STAILQ_REMOVE(&be_lun->config_read_queue, &io->io_hdr,
1626 				      ctl_io_hdr, links);
1627 			mtx_unlock(&be_lun->queue_lock);
1628 			ctl_be_block_cr_dispatch(be_lun, io);
1629 			mtx_lock(&be_lun->queue_lock);
1630 			continue;
1631 		}
1632 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->input_queue);
1633 		if (io != NULL) {
1634 			DPRINTF("input queue\n");
1635 
1636 			STAILQ_REMOVE(&be_lun->input_queue, &io->io_hdr,
1637 				      ctl_io_hdr, links);
1638 			mtx_unlock(&be_lun->queue_lock);
1639 
1640 			/*
1641 			 * We must drop the lock, since this routine and
1642 			 * its children may sleep.
1643 			 */
1644 			ctl_be_block_dispatch(be_lun, io);
1645 
1646 			mtx_lock(&be_lun->queue_lock);
1647 			continue;
1648 		}
1649 
1650 		/*
1651 		 * If we get here, there is no work left in the queues, so
1652 		 * just break out and let the task queue go to sleep.
1653 		 */
1654 		break;
1655 	}
1656 	mtx_unlock(&be_lun->queue_lock);
1657 }
1658 
1659 /*
1660  * Entry point from CTL to the backend for I/O.  We queue everything to a
1661  * work thread, so this just puts the I/O on a queue and wakes up the
1662  * thread.
1663  */
1664 static int
1665 ctl_be_block_submit(union ctl_io *io)
1666 {
1667 	struct ctl_be_block_lun *be_lun;
1668 	struct ctl_be_lun *ctl_be_lun;
1669 
1670 	DPRINTF("entered\n");
1671 
1672 	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
1673 		CTL_PRIV_BACKEND_LUN].ptr;
1674 	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
1675 
1676 	/*
1677 	 * Make sure we only get SCSI I/O.
1678 	 */
1679 	KASSERT(io->io_hdr.io_type == CTL_IO_SCSI, ("Non-SCSI I/O (type "
1680 		"%#x) encountered", io->io_hdr.io_type));
1681 
1682 	PRIV(io)->len = 0;
1683 
1684 	mtx_lock(&be_lun->queue_lock);
1685 	/*
1686 	 * XXX KDM make sure that links is okay to use at this point.
1687 	 * Otherwise, we either need to add another field to ctl_io_hdr,
1688 	 * or deal with resource allocation here.
1689 	 */
1690 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1691 	mtx_unlock(&be_lun->queue_lock);
1692 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1693 
1694 	return (CTL_RETVAL_COMPLETE);
1695 }
1696 
1697 static int
1698 ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
1699 			int flag, struct thread *td)
1700 {
1701 	struct ctl_be_block_softc *softc;
1702 	int error;
1703 
1704 	softc = &backend_block_softc;
1705 
1706 	error = 0;
1707 
1708 	switch (cmd) {
1709 	case CTL_LUN_REQ: {
1710 		struct ctl_lun_req *lun_req;
1711 
1712 		lun_req = (struct ctl_lun_req *)addr;
1713 
1714 		switch (lun_req->reqtype) {
1715 		case CTL_LUNREQ_CREATE:
1716 			error = ctl_be_block_create(softc, lun_req);
1717 			break;
1718 		case CTL_LUNREQ_RM:
1719 			error = ctl_be_block_rm(softc, lun_req);
1720 			break;
1721 		case CTL_LUNREQ_MODIFY:
1722 			error = ctl_be_block_modify(softc, lun_req);
1723 			break;
1724 		default:
1725 			lun_req->status = CTL_LUN_ERROR;
1726 			snprintf(lun_req->error_str, sizeof(lun_req->error_str),
1727 				 "invalid LUN request type %d",
1728 				 lun_req->reqtype);
1729 			break;
1730 		}
1731 		break;
1732 	}
1733 	default:
1734 		error = ENOTTY;
1735 		break;
1736 	}
1737 
1738 	return (error);
1739 }
1740 
1741 static int
1742 ctl_be_block_open_file(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1743 {
1744 	struct ctl_be_block_filedata *file_data;
1745 	struct ctl_lun_create_params *params;
1746 	char			     *value;
1747 	struct vattr		      vattr;
1748 	off_t			      ps, pss, po, pos, us, uss, uo, uos;
1749 	int			      error;
1750 
1751 	error = 0;
1752 	file_data = &be_lun->backend.file;
1753 	params = &be_lun->params;
1754 
1755 	be_lun->dev_type = CTL_BE_BLOCK_FILE;
1756 	be_lun->dispatch = ctl_be_block_dispatch_file;
1757 	be_lun->lun_flush = ctl_be_block_flush_file;
1758 	be_lun->get_lba_status = ctl_be_block_gls_file;
1759 	be_lun->getattr = ctl_be_block_getattr_file;
1760 
1761 	error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
1762 	if (error != 0) {
1763 		snprintf(req->error_str, sizeof(req->error_str),
1764 			 "error calling VOP_GETATTR() for file %s",
1765 			 be_lun->dev_path);
1766 		return (error);
1767 	}
1768 
1769 	/*
1770 	 * Verify that we have the ability to upgrade to exclusive
1771 	 * access on this file so we can trap errors at open instead
1772 	 * of reporting them during first access.
1773 	 */
1774 	if (VOP_ISLOCKED(be_lun->vn) != LK_EXCLUSIVE) {
1775 		vn_lock(be_lun->vn, LK_UPGRADE | LK_RETRY);
1776 		if (be_lun->vn->v_iflag & VI_DOOMED) {
1777 			error = EBADF;
1778 			snprintf(req->error_str, sizeof(req->error_str),
1779 				 "error locking file %s", be_lun->dev_path);
1780 			return (error);
1781 		}
1782 	}
1783 
1784 
1785 	file_data->cred = crhold(curthread->td_ucred);
1786 	if (params->lun_size_bytes != 0)
1787 		be_lun->size_bytes = params->lun_size_bytes;
1788 	else
1789 		be_lun->size_bytes = vattr.va_size;
1790 	/*
1791 	 * We set the multi thread flag for file operations because all
1792 	 * filesystems (in theory) are capable of allowing multiple readers
1793 	 * of a file at once.  So we want to get the maximum possible
1794 	 * concurrency.
1795 	 */
1796 	be_lun->flags |= CTL_BE_BLOCK_LUN_MULTI_THREAD;
1797 
1798 	/*
1799 	 * For files we can use any logical block size.  Prefer 512 bytes
1800 	 * for compatibility reasons.  If file's vattr.va_blocksize
1801 	 * (preferred I/O block size) is bigger and multiple to chosen
1802 	 * logical block size -- report it as physical block size.
1803 	 */
1804 	if (params->blocksize_bytes != 0)
1805 		be_lun->blocksize = params->blocksize_bytes;
1806 	else
1807 		be_lun->blocksize = 512;
1808 
1809 	us = ps = vattr.va_blocksize;
1810 	uo = po = 0;
1811 
1812 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "pblocksize");
1813 	if (value != NULL)
1814 		ctl_expand_number(value, &ps);
1815 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "pblockoffset");
1816 	if (value != NULL)
1817 		ctl_expand_number(value, &po);
1818 	pss = ps / be_lun->blocksize;
1819 	pos = po / be_lun->blocksize;
1820 	if ((pss > 0) && (pss * be_lun->blocksize == ps) && (pss >= pos) &&
1821 	    ((pss & (pss - 1)) == 0) && (pos * be_lun->blocksize == po)) {
1822 		be_lun->pblockexp = fls(pss) - 1;
1823 		be_lun->pblockoff = (pss - pos) % pss;
1824 	}
1825 
1826 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "ublocksize");
1827 	if (value != NULL)
1828 		ctl_expand_number(value, &us);
1829 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "ublockoffset");
1830 	if (value != NULL)
1831 		ctl_expand_number(value, &uo);
1832 	uss = us / be_lun->blocksize;
1833 	uos = uo / be_lun->blocksize;
1834 	if ((uss > 0) && (uss * be_lun->blocksize == us) && (uss >= uos) &&
1835 	    ((uss & (uss - 1)) == 0) && (uos * be_lun->blocksize == uo)) {
1836 		be_lun->ublockexp = fls(uss) - 1;
1837 		be_lun->ublockoff = (uss - uos) % uss;
1838 	}
1839 
1840 	/*
1841 	 * Sanity check.  The media size has to be at least one
1842 	 * sector long.
1843 	 */
1844 	if (be_lun->size_bytes < be_lun->blocksize) {
1845 		error = EINVAL;
1846 		snprintf(req->error_str, sizeof(req->error_str),
1847 			 "file %s size %ju < block size %u", be_lun->dev_path,
1848 			 (uintmax_t)be_lun->size_bytes, be_lun->blocksize);
1849 	}
1850 
1851 	be_lun->opttxferlen = CTLBLK_MAX_IO_SIZE / be_lun->blocksize;
1852 	return (error);
1853 }
1854 
1855 static int
1856 ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1857 {
1858 	struct ctl_lun_create_params *params;
1859 	struct vattr		      vattr;
1860 	struct cdev		     *dev;
1861 	struct cdevsw		     *devsw;
1862 	char			     *value;
1863 	int			      error, atomic, maxio;
1864 	off_t			      ps, pss, po, pos, us, uss, uo, uos;
1865 
1866 	params = &be_lun->params;
1867 
1868 	be_lun->dev_type = CTL_BE_BLOCK_DEV;
1869 	be_lun->backend.dev.cdev = be_lun->vn->v_rdev;
1870 	be_lun->backend.dev.csw = dev_refthread(be_lun->backend.dev.cdev,
1871 					     &be_lun->backend.dev.dev_ref);
1872 	if (be_lun->backend.dev.csw == NULL)
1873 		panic("Unable to retrieve device switch");
1874 	if (strcmp(be_lun->backend.dev.csw->d_name, "zvol") == 0) {
1875 		be_lun->dispatch = ctl_be_block_dispatch_zvol;
1876 		be_lun->get_lba_status = ctl_be_block_gls_zvol;
1877 		atomic = maxio = CTLBLK_MAX_IO_SIZE;
1878 	} else {
1879 		be_lun->dispatch = ctl_be_block_dispatch_dev;
1880 		atomic = 0;
1881 		maxio = be_lun->backend.dev.cdev->si_iosize_max;
1882 		if (maxio <= 0)
1883 			maxio = DFLTPHYS;
1884 		if (maxio > CTLBLK_MAX_IO_SIZE)
1885 			maxio = CTLBLK_MAX_IO_SIZE;
1886 	}
1887 	be_lun->lun_flush = ctl_be_block_flush_dev;
1888 	be_lun->unmap = ctl_be_block_unmap_dev;
1889 	be_lun->getattr = ctl_be_block_getattr_dev;
1890 
1891 	error = VOP_GETATTR(be_lun->vn, &vattr, NOCRED);
1892 	if (error) {
1893 		snprintf(req->error_str, sizeof(req->error_str),
1894 			 "error getting vnode attributes for device %s",
1895 			 be_lun->dev_path);
1896 		return (error);
1897 	}
1898 
1899 	dev = be_lun->vn->v_rdev;
1900 	devsw = dev->si_devsw;
1901 	if (!devsw->d_ioctl) {
1902 		snprintf(req->error_str, sizeof(req->error_str),
1903 			 "no d_ioctl for device %s!",
1904 			 be_lun->dev_path);
1905 		return (ENODEV);
1906 	}
1907 
1908 	error = devsw->d_ioctl(dev, DIOCGSECTORSIZE,
1909 			       (caddr_t)&be_lun->blocksize, FREAD,
1910 			       curthread);
1911 	if (error) {
1912 		snprintf(req->error_str, sizeof(req->error_str),
1913 			 "error %d returned for DIOCGSECTORSIZE ioctl "
1914 			 "on %s!", error, be_lun->dev_path);
1915 		return (error);
1916 	}
1917 
1918 	/*
1919 	 * If the user has asked for a blocksize that is greater than the
1920 	 * backing device's blocksize, we can do it only if the blocksize
1921 	 * the user is asking for is an even multiple of the underlying
1922 	 * device's blocksize.
1923 	 */
1924 	if ((params->blocksize_bytes != 0)
1925 	 && (params->blocksize_bytes > be_lun->blocksize)) {
1926 		uint32_t bs_multiple, tmp_blocksize;
1927 
1928 		bs_multiple = params->blocksize_bytes / be_lun->blocksize;
1929 
1930 		tmp_blocksize = bs_multiple * be_lun->blocksize;
1931 
1932 		if (tmp_blocksize == params->blocksize_bytes) {
1933 			be_lun->blocksize = params->blocksize_bytes;
1934 		} else {
1935 			snprintf(req->error_str, sizeof(req->error_str),
1936 				 "requested blocksize %u is not an even "
1937 				 "multiple of backing device blocksize %u",
1938 				 params->blocksize_bytes,
1939 				 be_lun->blocksize);
1940 			return (EINVAL);
1941 
1942 		}
1943 	} else if ((params->blocksize_bytes != 0)
1944 		&& (params->blocksize_bytes != be_lun->blocksize)) {
1945 		snprintf(req->error_str, sizeof(req->error_str),
1946 			 "requested blocksize %u < backing device "
1947 			 "blocksize %u", params->blocksize_bytes,
1948 			 be_lun->blocksize);
1949 		return (EINVAL);
1950 	}
1951 
1952 	error = devsw->d_ioctl(dev, DIOCGMEDIASIZE,
1953 			       (caddr_t)&be_lun->size_bytes, FREAD,
1954 			       curthread);
1955 	if (error) {
1956 		snprintf(req->error_str, sizeof(req->error_str),
1957 			 "error %d returned for DIOCGMEDIASIZE "
1958 			 " ioctl on %s!", error,
1959 			 be_lun->dev_path);
1960 		return (error);
1961 	}
1962 
1963 	if (params->lun_size_bytes != 0) {
1964 		if (params->lun_size_bytes > be_lun->size_bytes) {
1965 			snprintf(req->error_str, sizeof(req->error_str),
1966 				 "requested LUN size %ju > backing device "
1967 				 "size %ju",
1968 				 (uintmax_t)params->lun_size_bytes,
1969 				 (uintmax_t)be_lun->size_bytes);
1970 			return (EINVAL);
1971 		}
1972 
1973 		be_lun->size_bytes = params->lun_size_bytes;
1974 	}
1975 
1976 	error = devsw->d_ioctl(dev, DIOCGSTRIPESIZE,
1977 			       (caddr_t)&ps, FREAD, curthread);
1978 	if (error)
1979 		ps = po = 0;
1980 	else {
1981 		error = devsw->d_ioctl(dev, DIOCGSTRIPEOFFSET,
1982 				       (caddr_t)&po, FREAD, curthread);
1983 		if (error)
1984 			po = 0;
1985 	}
1986 	us = ps;
1987 	uo = po;
1988 
1989 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "pblocksize");
1990 	if (value != NULL)
1991 		ctl_expand_number(value, &ps);
1992 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "pblockoffset");
1993 	if (value != NULL)
1994 		ctl_expand_number(value, &po);
1995 	pss = ps / be_lun->blocksize;
1996 	pos = po / be_lun->blocksize;
1997 	if ((pss > 0) && (pss * be_lun->blocksize == ps) && (pss >= pos) &&
1998 	    ((pss & (pss - 1)) == 0) && (pos * be_lun->blocksize == po)) {
1999 		be_lun->pblockexp = fls(pss) - 1;
2000 		be_lun->pblockoff = (pss - pos) % pss;
2001 	}
2002 
2003 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "ublocksize");
2004 	if (value != NULL)
2005 		ctl_expand_number(value, &us);
2006 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "ublockoffset");
2007 	if (value != NULL)
2008 		ctl_expand_number(value, &uo);
2009 	uss = us / be_lun->blocksize;
2010 	uos = uo / be_lun->blocksize;
2011 	if ((uss > 0) && (uss * be_lun->blocksize == us) && (uss >= uos) &&
2012 	    ((uss & (uss - 1)) == 0) && (uos * be_lun->blocksize == uo)) {
2013 		be_lun->ublockexp = fls(uss) - 1;
2014 		be_lun->ublockoff = (uss - uos) % uss;
2015 	}
2016 
2017 	be_lun->atomicblock = atomic / be_lun->blocksize;
2018 	be_lun->opttxferlen = maxio / be_lun->blocksize;
2019 	return (0);
2020 }
2021 
2022 static int
2023 ctl_be_block_close(struct ctl_be_block_lun *be_lun)
2024 {
2025 	DROP_GIANT();
2026 	if (be_lun->vn) {
2027 		int flags = FREAD | FWRITE;
2028 
2029 		switch (be_lun->dev_type) {
2030 		case CTL_BE_BLOCK_DEV:
2031 			if (be_lun->backend.dev.csw) {
2032 				dev_relthread(be_lun->backend.dev.cdev,
2033 					      be_lun->backend.dev.dev_ref);
2034 				be_lun->backend.dev.csw  = NULL;
2035 				be_lun->backend.dev.cdev = NULL;
2036 			}
2037 			break;
2038 		case CTL_BE_BLOCK_FILE:
2039 			break;
2040 		case CTL_BE_BLOCK_NONE:
2041 			break;
2042 		default:
2043 			panic("Unexpected backend type.");
2044 			break;
2045 		}
2046 
2047 		(void)vn_close(be_lun->vn, flags, NOCRED, curthread);
2048 		be_lun->vn = NULL;
2049 
2050 		switch (be_lun->dev_type) {
2051 		case CTL_BE_BLOCK_DEV:
2052 			break;
2053 		case CTL_BE_BLOCK_FILE:
2054 			if (be_lun->backend.file.cred != NULL) {
2055 				crfree(be_lun->backend.file.cred);
2056 				be_lun->backend.file.cred = NULL;
2057 			}
2058 			break;
2059 		case CTL_BE_BLOCK_NONE:
2060 			break;
2061 		default:
2062 			panic("Unexpected backend type.");
2063 			break;
2064 		}
2065 		be_lun->dev_type = CTL_BE_BLOCK_NONE;
2066 	}
2067 	PICKUP_GIANT();
2068 
2069 	return (0);
2070 }
2071 
2072 static int
2073 ctl_be_block_open(struct ctl_be_block_softc *softc,
2074 		       struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
2075 {
2076 	struct nameidata nd;
2077 	int		 flags;
2078 	int		 error;
2079 
2080 	/*
2081 	 * XXX KDM allow a read-only option?
2082 	 */
2083 	flags = FREAD | FWRITE;
2084 	error = 0;
2085 
2086 	if (rootvnode == NULL) {
2087 		snprintf(req->error_str, sizeof(req->error_str),
2088 			 "Root filesystem is not mounted");
2089 		return (1);
2090 	}
2091 
2092 	if (!curthread->td_proc->p_fd->fd_cdir) {
2093 		curthread->td_proc->p_fd->fd_cdir = rootvnode;
2094 		VREF(rootvnode);
2095 	}
2096 	if (!curthread->td_proc->p_fd->fd_rdir) {
2097 		curthread->td_proc->p_fd->fd_rdir = rootvnode;
2098 		VREF(rootvnode);
2099 	}
2100 	if (!curthread->td_proc->p_fd->fd_jdir) {
2101 		curthread->td_proc->p_fd->fd_jdir = rootvnode;
2102 		VREF(rootvnode);
2103 	}
2104 
2105  again:
2106 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, be_lun->dev_path, curthread);
2107 	error = vn_open(&nd, &flags, 0, NULL);
2108 	if (error) {
2109 		/*
2110 		 * This is the only reasonable guess we can make as far as
2111 		 * path if the user doesn't give us a fully qualified path.
2112 		 * If they want to specify a file, they need to specify the
2113 		 * full path.
2114 		 */
2115 		if (be_lun->dev_path[0] != '/') {
2116 			char *dev_path = "/dev/";
2117 			char *dev_name;
2118 
2119 			/* Try adding device path at beginning of name */
2120 			dev_name = malloc(strlen(be_lun->dev_path)
2121 					+ strlen(dev_path) + 1,
2122 					  M_CTLBLK, M_WAITOK);
2123 			if (dev_name) {
2124 				sprintf(dev_name, "%s%s", dev_path,
2125 					be_lun->dev_path);
2126 				free(be_lun->dev_path, M_CTLBLK);
2127 				be_lun->dev_path = dev_name;
2128 				goto again;
2129 			}
2130 		}
2131 		snprintf(req->error_str, sizeof(req->error_str),
2132 		    "error opening %s: %d", be_lun->dev_path, error);
2133 		return (error);
2134 	}
2135 
2136 	NDFREE(&nd, NDF_ONLY_PNBUF);
2137 
2138 	be_lun->vn = nd.ni_vp;
2139 
2140 	/* We only support disks and files. */
2141 	if (vn_isdisk(be_lun->vn, &error)) {
2142 		error = ctl_be_block_open_dev(be_lun, req);
2143 	} else if (be_lun->vn->v_type == VREG) {
2144 		error = ctl_be_block_open_file(be_lun, req);
2145 	} else {
2146 		error = EINVAL;
2147 		snprintf(req->error_str, sizeof(req->error_str),
2148 			 "%s is not a disk or plain file", be_lun->dev_path);
2149 	}
2150 	VOP_UNLOCK(be_lun->vn, 0);
2151 
2152 	if (error != 0) {
2153 		ctl_be_block_close(be_lun);
2154 		return (error);
2155 	}
2156 
2157 	be_lun->blocksize_shift = fls(be_lun->blocksize) - 1;
2158 	be_lun->size_blocks = be_lun->size_bytes >> be_lun->blocksize_shift;
2159 
2160 	return (0);
2161 }
2162 
2163 static int
2164 ctl_be_block_create(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2165 {
2166 	struct ctl_be_block_lun *be_lun;
2167 	struct ctl_lun_create_params *params;
2168 	char num_thread_str[16];
2169 	char tmpstr[32];
2170 	char *value;
2171 	int retval, num_threads, unmap;
2172 	int tmp_num_threads;
2173 
2174 	params = &req->reqdata.create;
2175 	retval = 0;
2176 	req->status = CTL_LUN_OK;
2177 
2178 	num_threads = cbb_num_threads;
2179 
2180 	be_lun = malloc(sizeof(*be_lun), M_CTLBLK, M_ZERO | M_WAITOK);
2181 
2182 	be_lun->params = req->reqdata.create;
2183 	be_lun->softc = softc;
2184 	STAILQ_INIT(&be_lun->input_queue);
2185 	STAILQ_INIT(&be_lun->config_read_queue);
2186 	STAILQ_INIT(&be_lun->config_write_queue);
2187 	STAILQ_INIT(&be_lun->datamove_queue);
2188 	sprintf(be_lun->lunname, "cblk%d", softc->num_luns);
2189 	mtx_init(&be_lun->io_lock, "cblk io lock", NULL, MTX_DEF);
2190 	mtx_init(&be_lun->queue_lock, "cblk queue lock", NULL, MTX_DEF);
2191 	ctl_init_opts(&be_lun->ctl_be_lun.options,
2192 	    req->num_be_args, req->kern_be_args);
2193 
2194 	be_lun->lun_zone = uma_zcreate(be_lun->lunname, CTLBLK_MAX_SEG,
2195 	    NULL, NULL, NULL, NULL, /*align*/ 0, /*flags*/0);
2196 
2197 	if (be_lun->lun_zone == NULL) {
2198 		snprintf(req->error_str, sizeof(req->error_str),
2199 			 "error allocating UMA zone");
2200 		goto bailout_error;
2201 	}
2202 
2203 	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
2204 		be_lun->ctl_be_lun.lun_type = params->device_type;
2205 	else
2206 		be_lun->ctl_be_lun.lun_type = T_DIRECT;
2207 
2208 	if (be_lun->ctl_be_lun.lun_type == T_DIRECT) {
2209 		value = ctl_get_opt(&be_lun->ctl_be_lun.options, "file");
2210 		if (value == NULL) {
2211 			snprintf(req->error_str, sizeof(req->error_str),
2212 				 "no file argument specified");
2213 			goto bailout_error;
2214 		}
2215 		be_lun->dev_path = strdup(value, M_CTLBLK);
2216 		be_lun->blocksize = 512;
2217 		be_lun->blocksize_shift = fls(be_lun->blocksize) - 1;
2218 
2219 		retval = ctl_be_block_open(softc, be_lun, req);
2220 		if (retval != 0) {
2221 			retval = 0;
2222 			req->status = CTL_LUN_WARNING;
2223 		}
2224 	} else {
2225 		/*
2226 		 * For processor devices, we don't have any size.
2227 		 */
2228 		be_lun->blocksize = 0;
2229 		be_lun->pblockexp = 0;
2230 		be_lun->pblockoff = 0;
2231 		be_lun->ublockexp = 0;
2232 		be_lun->ublockoff = 0;
2233 		be_lun->size_blocks = 0;
2234 		be_lun->size_bytes = 0;
2235 		be_lun->ctl_be_lun.maxlba = 0;
2236 
2237 		/*
2238 		 * Default to just 1 thread for processor devices.
2239 		 */
2240 		num_threads = 1;
2241 	}
2242 
2243 	/*
2244 	 * XXX This searching loop might be refactored to be combined with
2245 	 * the loop above,
2246 	 */
2247 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "num_threads");
2248 	if (value != NULL) {
2249 		tmp_num_threads = strtol(value, NULL, 0);
2250 
2251 		/*
2252 		 * We don't let the user specify less than one
2253 		 * thread, but hope he's clueful enough not to
2254 		 * specify 1000 threads.
2255 		 */
2256 		if (tmp_num_threads < 1) {
2257 			snprintf(req->error_str, sizeof(req->error_str),
2258 				 "invalid number of threads %s",
2259 				 num_thread_str);
2260 			goto bailout_error;
2261 		}
2262 		num_threads = tmp_num_threads;
2263 	}
2264 	unmap = (be_lun->dispatch == ctl_be_block_dispatch_zvol);
2265 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "unmap");
2266 	if (value != NULL)
2267 		unmap = (strcmp(value, "on") == 0);
2268 
2269 	be_lun->flags = CTL_BE_BLOCK_LUN_UNCONFIGURED;
2270 	be_lun->ctl_be_lun.flags = CTL_LUN_FLAG_PRIMARY;
2271 	if (be_lun->vn == NULL)
2272 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_OFFLINE;
2273 	if (unmap)
2274 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_UNMAP;
2275 	if (be_lun->dispatch != ctl_be_block_dispatch_dev)
2276 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_SERSEQ_READ;
2277 	be_lun->ctl_be_lun.be_lun = be_lun;
2278 	be_lun->ctl_be_lun.maxlba = (be_lun->size_blocks == 0) ?
2279 	    0 : (be_lun->size_blocks - 1);
2280 	be_lun->ctl_be_lun.blocksize = be_lun->blocksize;
2281 	be_lun->ctl_be_lun.pblockexp = be_lun->pblockexp;
2282 	be_lun->ctl_be_lun.pblockoff = be_lun->pblockoff;
2283 	be_lun->ctl_be_lun.ublockexp = be_lun->ublockexp;
2284 	be_lun->ctl_be_lun.ublockoff = be_lun->ublockoff;
2285 	be_lun->ctl_be_lun.atomicblock = be_lun->atomicblock;
2286 	be_lun->ctl_be_lun.opttxferlen = be_lun->opttxferlen;
2287 	/* Tell the user the blocksize we ended up using */
2288 	params->lun_size_bytes = be_lun->size_bytes;
2289 	params->blocksize_bytes = be_lun->blocksize;
2290 	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
2291 		be_lun->ctl_be_lun.req_lun_id = params->req_lun_id;
2292 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_ID_REQ;
2293 	} else
2294 		be_lun->ctl_be_lun.req_lun_id = 0;
2295 
2296 	be_lun->ctl_be_lun.lun_shutdown = ctl_be_block_lun_shutdown;
2297 	be_lun->ctl_be_lun.lun_config_status =
2298 		ctl_be_block_lun_config_status;
2299 	be_lun->ctl_be_lun.be = &ctl_be_block_driver;
2300 
2301 	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
2302 		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
2303 			 softc->num_luns);
2304 		strncpy((char *)be_lun->ctl_be_lun.serial_num, tmpstr,
2305 			MIN(sizeof(be_lun->ctl_be_lun.serial_num),
2306 			sizeof(tmpstr)));
2307 
2308 		/* Tell the user what we used for a serial number */
2309 		strncpy((char *)params->serial_num, tmpstr,
2310 			MIN(sizeof(params->serial_num), sizeof(tmpstr)));
2311 	} else {
2312 		strncpy((char *)be_lun->ctl_be_lun.serial_num,
2313 			params->serial_num,
2314 			MIN(sizeof(be_lun->ctl_be_lun.serial_num),
2315 			sizeof(params->serial_num)));
2316 	}
2317 	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
2318 		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
2319 		strncpy((char *)be_lun->ctl_be_lun.device_id, tmpstr,
2320 			MIN(sizeof(be_lun->ctl_be_lun.device_id),
2321 			sizeof(tmpstr)));
2322 
2323 		/* Tell the user what we used for a device ID */
2324 		strncpy((char *)params->device_id, tmpstr,
2325 			MIN(sizeof(params->device_id), sizeof(tmpstr)));
2326 	} else {
2327 		strncpy((char *)be_lun->ctl_be_lun.device_id,
2328 			params->device_id,
2329 			MIN(sizeof(be_lun->ctl_be_lun.device_id),
2330 			    sizeof(params->device_id)));
2331 	}
2332 
2333 	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_be_block_worker, be_lun);
2334 
2335 	be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
2336 	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
2337 
2338 	if (be_lun->io_taskqueue == NULL) {
2339 		snprintf(req->error_str, sizeof(req->error_str),
2340 			 "unable to create taskqueue");
2341 		goto bailout_error;
2342 	}
2343 
2344 	/*
2345 	 * Note that we start the same number of threads by default for
2346 	 * both the file case and the block device case.  For the file
2347 	 * case, we need multiple threads to allow concurrency, because the
2348 	 * vnode interface is designed to be a blocking interface.  For the
2349 	 * block device case, ZFS zvols at least will block the caller's
2350 	 * context in many instances, and so we need multiple threads to
2351 	 * overcome that problem.  Other block devices don't need as many
2352 	 * threads, but they shouldn't cause too many problems.
2353 	 *
2354 	 * If the user wants to just have a single thread for a block
2355 	 * device, he can specify that when the LUN is created, or change
2356 	 * the tunable/sysctl to alter the default number of threads.
2357 	 */
2358 	retval = taskqueue_start_threads(&be_lun->io_taskqueue,
2359 					 /*num threads*/num_threads,
2360 					 /*priority*/PWAIT,
2361 					 /*thread name*/
2362 					 "%s taskq", be_lun->lunname);
2363 
2364 	if (retval != 0)
2365 		goto bailout_error;
2366 
2367 	be_lun->num_threads = num_threads;
2368 
2369 	mtx_lock(&softc->lock);
2370 	softc->num_luns++;
2371 	STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
2372 
2373 	mtx_unlock(&softc->lock);
2374 
2375 	retval = ctl_add_lun(&be_lun->ctl_be_lun);
2376 	if (retval != 0) {
2377 		mtx_lock(&softc->lock);
2378 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2379 			      links);
2380 		softc->num_luns--;
2381 		mtx_unlock(&softc->lock);
2382 		snprintf(req->error_str, sizeof(req->error_str),
2383 			 "ctl_add_lun() returned error %d, see dmesg for "
2384 			 "details", retval);
2385 		retval = 0;
2386 		goto bailout_error;
2387 	}
2388 
2389 	mtx_lock(&softc->lock);
2390 
2391 	/*
2392 	 * Tell the config_status routine that we're waiting so it won't
2393 	 * clean up the LUN in the event of an error.
2394 	 */
2395 	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2396 
2397 	while (be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) {
2398 		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2399 		if (retval == EINTR)
2400 			break;
2401 	}
2402 	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2403 
2404 	if (be_lun->flags & CTL_BE_BLOCK_LUN_CONFIG_ERR) {
2405 		snprintf(req->error_str, sizeof(req->error_str),
2406 			 "LUN configuration error, see dmesg for details");
2407 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2408 			      links);
2409 		softc->num_luns--;
2410 		mtx_unlock(&softc->lock);
2411 		goto bailout_error;
2412 	} else {
2413 		params->req_lun_id = be_lun->ctl_be_lun.lun_id;
2414 	}
2415 
2416 	mtx_unlock(&softc->lock);
2417 
2418 	be_lun->disk_stats = devstat_new_entry("cbb", params->req_lun_id,
2419 					       be_lun->blocksize,
2420 					       DEVSTAT_ALL_SUPPORTED,
2421 					       be_lun->ctl_be_lun.lun_type
2422 					       | DEVSTAT_TYPE_IF_OTHER,
2423 					       DEVSTAT_PRIORITY_OTHER);
2424 
2425 	return (retval);
2426 
2427 bailout_error:
2428 	req->status = CTL_LUN_ERROR;
2429 
2430 	if (be_lun->io_taskqueue != NULL)
2431 		taskqueue_free(be_lun->io_taskqueue);
2432 	ctl_be_block_close(be_lun);
2433 	if (be_lun->dev_path != NULL)
2434 		free(be_lun->dev_path, M_CTLBLK);
2435 	if (be_lun->lun_zone != NULL)
2436 		uma_zdestroy(be_lun->lun_zone);
2437 	ctl_free_opts(&be_lun->ctl_be_lun.options);
2438 	mtx_destroy(&be_lun->queue_lock);
2439 	mtx_destroy(&be_lun->io_lock);
2440 	free(be_lun, M_CTLBLK);
2441 
2442 	return (retval);
2443 }
2444 
2445 static int
2446 ctl_be_block_rm(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2447 {
2448 	struct ctl_lun_rm_params *params;
2449 	struct ctl_be_block_lun *be_lun;
2450 	int retval;
2451 
2452 	params = &req->reqdata.rm;
2453 
2454 	mtx_lock(&softc->lock);
2455 
2456 	be_lun = NULL;
2457 
2458 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2459 		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2460 			break;
2461 	}
2462 	mtx_unlock(&softc->lock);
2463 
2464 	if (be_lun == NULL) {
2465 		snprintf(req->error_str, sizeof(req->error_str),
2466 			 "LUN %u is not managed by the block backend",
2467 			 params->lun_id);
2468 		goto bailout_error;
2469 	}
2470 
2471 	retval = ctl_disable_lun(&be_lun->ctl_be_lun);
2472 
2473 	if (retval != 0) {
2474 		snprintf(req->error_str, sizeof(req->error_str),
2475 			 "error %d returned from ctl_disable_lun() for "
2476 			 "LUN %d", retval, params->lun_id);
2477 		goto bailout_error;
2478 
2479 	}
2480 
2481 	retval = ctl_invalidate_lun(&be_lun->ctl_be_lun);
2482 	if (retval != 0) {
2483 		snprintf(req->error_str, sizeof(req->error_str),
2484 			 "error %d returned from ctl_invalidate_lun() for "
2485 			 "LUN %d", retval, params->lun_id);
2486 		goto bailout_error;
2487 	}
2488 
2489 	mtx_lock(&softc->lock);
2490 
2491 	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2492 
2493 	while ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2494                 retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2495                 if (retval == EINTR)
2496                         break;
2497         }
2498 
2499 	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2500 
2501 	if ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2502 		snprintf(req->error_str, sizeof(req->error_str),
2503 			 "interrupted waiting for LUN to be freed");
2504 		mtx_unlock(&softc->lock);
2505 		goto bailout_error;
2506 	}
2507 
2508 	STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun, links);
2509 
2510 	softc->num_luns--;
2511 	mtx_unlock(&softc->lock);
2512 
2513 	taskqueue_drain(be_lun->io_taskqueue, &be_lun->io_task);
2514 
2515 	taskqueue_free(be_lun->io_taskqueue);
2516 
2517 	ctl_be_block_close(be_lun);
2518 
2519 	if (be_lun->disk_stats != NULL)
2520 		devstat_remove_entry(be_lun->disk_stats);
2521 
2522 	uma_zdestroy(be_lun->lun_zone);
2523 
2524 	ctl_free_opts(&be_lun->ctl_be_lun.options);
2525 	free(be_lun->dev_path, M_CTLBLK);
2526 	mtx_destroy(&be_lun->queue_lock);
2527 	mtx_destroy(&be_lun->io_lock);
2528 	free(be_lun, M_CTLBLK);
2529 
2530 	req->status = CTL_LUN_OK;
2531 
2532 	return (0);
2533 
2534 bailout_error:
2535 
2536 	req->status = CTL_LUN_ERROR;
2537 
2538 	return (0);
2539 }
2540 
2541 static int
2542 ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
2543 			 struct ctl_lun_req *req)
2544 {
2545 	struct vattr vattr;
2546 	int error;
2547 	struct ctl_lun_create_params *params = &be_lun->params;
2548 
2549 	if (params->lun_size_bytes != 0) {
2550 		be_lun->size_bytes = params->lun_size_bytes;
2551 	} else  {
2552 		vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
2553 		error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
2554 		VOP_UNLOCK(be_lun->vn, 0);
2555 		if (error != 0) {
2556 			snprintf(req->error_str, sizeof(req->error_str),
2557 				 "error calling VOP_GETATTR() for file %s",
2558 				 be_lun->dev_path);
2559 			return (error);
2560 		}
2561 
2562 		be_lun->size_bytes = vattr.va_size;
2563 	}
2564 
2565 	return (0);
2566 }
2567 
2568 static int
2569 ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
2570 			struct ctl_lun_req *req)
2571 {
2572 	struct ctl_be_block_devdata *dev_data;
2573 	int error;
2574 	struct ctl_lun_create_params *params = &be_lun->params;
2575 	uint64_t size_bytes;
2576 
2577 	dev_data = &be_lun->backend.dev;
2578 	if (!dev_data->csw->d_ioctl) {
2579 		snprintf(req->error_str, sizeof(req->error_str),
2580 			 "no d_ioctl for device %s!", be_lun->dev_path);
2581 		return (ENODEV);
2582 	}
2583 
2584 	error = dev_data->csw->d_ioctl(dev_data->cdev, DIOCGMEDIASIZE,
2585 			       (caddr_t)&size_bytes, FREAD,
2586 			       curthread);
2587 	if (error) {
2588 		snprintf(req->error_str, sizeof(req->error_str),
2589 			 "error %d returned for DIOCGMEDIASIZE ioctl "
2590 			 "on %s!", error, be_lun->dev_path);
2591 		return (error);
2592 	}
2593 
2594 	if (params->lun_size_bytes != 0) {
2595 		if (params->lun_size_bytes > size_bytes) {
2596 			snprintf(req->error_str, sizeof(req->error_str),
2597 				 "requested LUN size %ju > backing device "
2598 				 "size %ju",
2599 				 (uintmax_t)params->lun_size_bytes,
2600 				 (uintmax_t)size_bytes);
2601 			return (EINVAL);
2602 		}
2603 
2604 		be_lun->size_bytes = params->lun_size_bytes;
2605 	} else {
2606 		be_lun->size_bytes = size_bytes;
2607 	}
2608 
2609 	return (0);
2610 }
2611 
2612 static int
2613 ctl_be_block_modify(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2614 {
2615 	struct ctl_lun_modify_params *params;
2616 	struct ctl_be_block_lun *be_lun;
2617 	uint64_t oldsize;
2618 	int error;
2619 
2620 	params = &req->reqdata.modify;
2621 
2622 	mtx_lock(&softc->lock);
2623 	be_lun = NULL;
2624 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2625 		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2626 			break;
2627 	}
2628 	mtx_unlock(&softc->lock);
2629 
2630 	if (be_lun == NULL) {
2631 		snprintf(req->error_str, sizeof(req->error_str),
2632 			 "LUN %u is not managed by the block backend",
2633 			 params->lun_id);
2634 		goto bailout_error;
2635 	}
2636 
2637 	be_lun->params.lun_size_bytes = params->lun_size_bytes;
2638 
2639 	oldsize = be_lun->size_bytes;
2640 	if (be_lun->vn == NULL)
2641 		error = ctl_be_block_open(softc, be_lun, req);
2642 	else if (be_lun->vn->v_type == VREG)
2643 		error = ctl_be_block_modify_file(be_lun, req);
2644 	else
2645 		error = ctl_be_block_modify_dev(be_lun, req);
2646 
2647 	if (error == 0 && be_lun->size_bytes != oldsize) {
2648 		be_lun->size_blocks = be_lun->size_bytes >>
2649 		    be_lun->blocksize_shift;
2650 
2651 		/*
2652 		 * The maximum LBA is the size - 1.
2653 		 *
2654 		 * XXX: Note that this field is being updated without locking,
2655 		 * 	which might cause problems on 32-bit architectures.
2656 		 */
2657 		be_lun->ctl_be_lun.maxlba = (be_lun->size_blocks == 0) ?
2658 		    0 : (be_lun->size_blocks - 1);
2659 		be_lun->ctl_be_lun.blocksize = be_lun->blocksize;
2660 		be_lun->ctl_be_lun.pblockexp = be_lun->pblockexp;
2661 		be_lun->ctl_be_lun.pblockoff = be_lun->pblockoff;
2662 		be_lun->ctl_be_lun.ublockexp = be_lun->ublockexp;
2663 		be_lun->ctl_be_lun.ublockoff = be_lun->ublockoff;
2664 		be_lun->ctl_be_lun.atomicblock = be_lun->atomicblock;
2665 		be_lun->ctl_be_lun.opttxferlen = be_lun->opttxferlen;
2666 		ctl_lun_capacity_changed(&be_lun->ctl_be_lun);
2667 		if (oldsize == 0 && be_lun->size_blocks != 0)
2668 			ctl_lun_online(&be_lun->ctl_be_lun);
2669 	}
2670 
2671 	/* Tell the user the exact size we ended up using */
2672 	params->lun_size_bytes = be_lun->size_bytes;
2673 
2674 	req->status = error ? CTL_LUN_WARNING : CTL_LUN_OK;
2675 
2676 	return (0);
2677 
2678 bailout_error:
2679 	req->status = CTL_LUN_ERROR;
2680 
2681 	return (0);
2682 }
2683 
2684 static void
2685 ctl_be_block_lun_shutdown(void *be_lun)
2686 {
2687 	struct ctl_be_block_lun *lun;
2688 	struct ctl_be_block_softc *softc;
2689 
2690 	lun = (struct ctl_be_block_lun *)be_lun;
2691 
2692 	softc = lun->softc;
2693 
2694 	mtx_lock(&softc->lock);
2695 	lun->flags |= CTL_BE_BLOCK_LUN_UNCONFIGURED;
2696 	if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2697 		wakeup(lun);
2698 	mtx_unlock(&softc->lock);
2699 
2700 }
2701 
2702 static void
2703 ctl_be_block_lun_config_status(void *be_lun, ctl_lun_config_status status)
2704 {
2705 	struct ctl_be_block_lun *lun;
2706 	struct ctl_be_block_softc *softc;
2707 
2708 	lun = (struct ctl_be_block_lun *)be_lun;
2709 	softc = lun->softc;
2710 
2711 	if (status == CTL_LUN_CONFIG_OK) {
2712 		mtx_lock(&softc->lock);
2713 		lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2714 		if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2715 			wakeup(lun);
2716 		mtx_unlock(&softc->lock);
2717 
2718 		/*
2719 		 * We successfully added the LUN, attempt to enable it.
2720 		 */
2721 		if (ctl_enable_lun(&lun->ctl_be_lun) != 0) {
2722 			printf("%s: ctl_enable_lun() failed!\n", __func__);
2723 			if (ctl_invalidate_lun(&lun->ctl_be_lun) != 0) {
2724 				printf("%s: ctl_invalidate_lun() failed!\n",
2725 				       __func__);
2726 			}
2727 		}
2728 
2729 		return;
2730 	}
2731 
2732 
2733 	mtx_lock(&softc->lock);
2734 	lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2735 	lun->flags |= CTL_BE_BLOCK_LUN_CONFIG_ERR;
2736 	wakeup(lun);
2737 	mtx_unlock(&softc->lock);
2738 }
2739 
2740 
2741 static int
2742 ctl_be_block_config_write(union ctl_io *io)
2743 {
2744 	struct ctl_be_block_lun *be_lun;
2745 	struct ctl_be_lun *ctl_be_lun;
2746 	int retval;
2747 
2748 	retval = 0;
2749 
2750 	DPRINTF("entered\n");
2751 
2752 	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
2753 		CTL_PRIV_BACKEND_LUN].ptr;
2754 	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
2755 
2756 	switch (io->scsiio.cdb[0]) {
2757 	case SYNCHRONIZE_CACHE:
2758 	case SYNCHRONIZE_CACHE_16:
2759 	case WRITE_SAME_10:
2760 	case WRITE_SAME_16:
2761 	case UNMAP:
2762 		/*
2763 		 * The upper level CTL code will filter out any CDBs with
2764 		 * the immediate bit set and return the proper error.
2765 		 *
2766 		 * We don't really need to worry about what LBA range the
2767 		 * user asked to be synced out.  When they issue a sync
2768 		 * cache command, we'll sync out the whole thing.
2769 		 */
2770 		mtx_lock(&be_lun->queue_lock);
2771 		STAILQ_INSERT_TAIL(&be_lun->config_write_queue, &io->io_hdr,
2772 				   links);
2773 		mtx_unlock(&be_lun->queue_lock);
2774 		taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
2775 		break;
2776 	case START_STOP_UNIT: {
2777 		struct scsi_start_stop_unit *cdb;
2778 
2779 		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
2780 
2781 		if (cdb->how & SSS_START)
2782 			retval = ctl_start_lun(ctl_be_lun);
2783 		else {
2784 			retval = ctl_stop_lun(ctl_be_lun);
2785 			/*
2786 			 * XXX KDM Copan-specific offline behavior.
2787 			 * Figure out a reasonable way to port this?
2788 			 */
2789 #ifdef NEEDTOPORT
2790 			if ((retval == 0)
2791 			 && (cdb->byte2 & SSS_ONOFFLINE))
2792 				retval = ctl_lun_offline(ctl_be_lun);
2793 #endif
2794 		}
2795 
2796 		/*
2797 		 * In general, the above routines should not fail.  They
2798 		 * just set state for the LUN.  So we've got something
2799 		 * pretty wrong here if we can't start or stop the LUN.
2800 		 */
2801 		if (retval != 0) {
2802 			ctl_set_internal_failure(&io->scsiio,
2803 						 /*sks_valid*/ 1,
2804 						 /*retry_count*/ 0xf051);
2805 			retval = CTL_RETVAL_COMPLETE;
2806 		} else {
2807 			ctl_set_success(&io->scsiio);
2808 		}
2809 		ctl_config_write_done(io);
2810 		break;
2811 	}
2812 	default:
2813 		ctl_set_invalid_opcode(&io->scsiio);
2814 		ctl_config_write_done(io);
2815 		retval = CTL_RETVAL_COMPLETE;
2816 		break;
2817 	}
2818 
2819 	return (retval);
2820 }
2821 
2822 static int
2823 ctl_be_block_config_read(union ctl_io *io)
2824 {
2825 	struct ctl_be_block_lun *be_lun;
2826 	struct ctl_be_lun *ctl_be_lun;
2827 	int retval = 0;
2828 
2829 	DPRINTF("entered\n");
2830 
2831 	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
2832 		CTL_PRIV_BACKEND_LUN].ptr;
2833 	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
2834 
2835 	switch (io->scsiio.cdb[0]) {
2836 	case SERVICE_ACTION_IN:
2837 		if (io->scsiio.cdb[1] == SGLS_SERVICE_ACTION) {
2838 			mtx_lock(&be_lun->queue_lock);
2839 			STAILQ_INSERT_TAIL(&be_lun->config_read_queue,
2840 			    &io->io_hdr, links);
2841 			mtx_unlock(&be_lun->queue_lock);
2842 			taskqueue_enqueue(be_lun->io_taskqueue,
2843 			    &be_lun->io_task);
2844 			retval = CTL_RETVAL_QUEUED;
2845 			break;
2846 		}
2847 		ctl_set_invalid_field(&io->scsiio,
2848 				      /*sks_valid*/ 1,
2849 				      /*command*/ 1,
2850 				      /*field*/ 1,
2851 				      /*bit_valid*/ 1,
2852 				      /*bit*/ 4);
2853 		ctl_config_read_done(io);
2854 		retval = CTL_RETVAL_COMPLETE;
2855 		break;
2856 	default:
2857 		ctl_set_invalid_opcode(&io->scsiio);
2858 		ctl_config_read_done(io);
2859 		retval = CTL_RETVAL_COMPLETE;
2860 		break;
2861 	}
2862 
2863 	return (retval);
2864 }
2865 
2866 static int
2867 ctl_be_block_lun_info(void *be_lun, struct sbuf *sb)
2868 {
2869 	struct ctl_be_block_lun *lun;
2870 	int retval;
2871 
2872 	lun = (struct ctl_be_block_lun *)be_lun;
2873 	retval = 0;
2874 
2875 	retval = sbuf_printf(sb, "\t<num_threads>");
2876 
2877 	if (retval != 0)
2878 		goto bailout;
2879 
2880 	retval = sbuf_printf(sb, "%d", lun->num_threads);
2881 
2882 	if (retval != 0)
2883 		goto bailout;
2884 
2885 	retval = sbuf_printf(sb, "</num_threads>\n");
2886 
2887 bailout:
2888 
2889 	return (retval);
2890 }
2891 
2892 static uint64_t
2893 ctl_be_block_lun_attr(void *be_lun, const char *attrname)
2894 {
2895 	struct ctl_be_block_lun *lun = (struct ctl_be_block_lun *)be_lun;
2896 
2897 	if (lun->getattr == NULL)
2898 		return (UINT64_MAX);
2899 	return (lun->getattr(lun, attrname));
2900 }
2901 
2902 int
2903 ctl_be_block_init(void)
2904 {
2905 	struct ctl_be_block_softc *softc;
2906 	int retval;
2907 
2908 	softc = &backend_block_softc;
2909 	retval = 0;
2910 
2911 	mtx_init(&softc->lock, "ctlblock", NULL, MTX_DEF);
2912 	beio_zone = uma_zcreate("beio", sizeof(struct ctl_be_block_io),
2913 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
2914 	STAILQ_INIT(&softc->disk_list);
2915 	STAILQ_INIT(&softc->lun_list);
2916 
2917 	return (retval);
2918 }
2919