xref: /freebsd/sys/cam/ctl/ctl_backend_block.c (revision 5ec9cb893bd22bf2d47ab2fef29aae6ee5e1d131)
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 	int				io_arg;
228 	struct ctl_be_block_softc	*softc;
229 	struct ctl_be_block_lun		*lun;
230 	void (*beio_cont)(struct ctl_be_block_io *beio); /* to continue processing */
231 };
232 
233 static int cbb_num_threads = 14;
234 SYSCTL_NODE(_kern_cam_ctl, OID_AUTO, block, CTLFLAG_RD, 0,
235 	    "CAM Target Layer Block Backend");
236 SYSCTL_INT(_kern_cam_ctl_block, OID_AUTO, num_threads, CTLFLAG_RWTUN,
237            &cbb_num_threads, 0, "Number of threads per backing file");
238 
239 static struct ctl_be_block_io *ctl_alloc_beio(struct ctl_be_block_softc *softc);
240 static void ctl_free_beio(struct ctl_be_block_io *beio);
241 static void ctl_complete_beio(struct ctl_be_block_io *beio);
242 static int ctl_be_block_move_done(union ctl_io *io);
243 static void ctl_be_block_biodone(struct bio *bio);
244 static void ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
245 				    struct ctl_be_block_io *beio);
246 static void ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
247 				       struct ctl_be_block_io *beio);
248 static void ctl_be_block_gls_file(struct ctl_be_block_lun *be_lun,
249 				  struct ctl_be_block_io *beio);
250 static uint64_t ctl_be_block_getattr_file(struct ctl_be_block_lun *be_lun,
251 					 const char *attrname);
252 static void ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
253 				   struct ctl_be_block_io *beio);
254 static void ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
255 				   struct ctl_be_block_io *beio);
256 static void ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
257 				      struct ctl_be_block_io *beio);
258 static uint64_t ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun,
259 					 const char *attrname);
260 static void ctl_be_block_cr_dispatch(struct ctl_be_block_lun *be_lun,
261 				    union ctl_io *io);
262 static void ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
263 				    union ctl_io *io);
264 static void ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
265 				  union ctl_io *io);
266 static void ctl_be_block_worker(void *context, int pending);
267 static int ctl_be_block_submit(union ctl_io *io);
268 static int ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
269 				   int flag, struct thread *td);
270 static int ctl_be_block_open_file(struct ctl_be_block_lun *be_lun,
271 				  struct ctl_lun_req *req);
272 static int ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun,
273 				 struct ctl_lun_req *req);
274 static int ctl_be_block_close(struct ctl_be_block_lun *be_lun);
275 static int ctl_be_block_open(struct ctl_be_block_softc *softc,
276 			     struct ctl_be_block_lun *be_lun,
277 			     struct ctl_lun_req *req);
278 static int ctl_be_block_create(struct ctl_be_block_softc *softc,
279 			       struct ctl_lun_req *req);
280 static int ctl_be_block_rm(struct ctl_be_block_softc *softc,
281 			   struct ctl_lun_req *req);
282 static int ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
283 				  struct ctl_lun_req *req);
284 static int ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
285 				 struct ctl_lun_req *req);
286 static int ctl_be_block_modify(struct ctl_be_block_softc *softc,
287 			   struct ctl_lun_req *req);
288 static void ctl_be_block_lun_shutdown(void *be_lun);
289 static void ctl_be_block_lun_config_status(void *be_lun,
290 					   ctl_lun_config_status status);
291 static int ctl_be_block_config_write(union ctl_io *io);
292 static int ctl_be_block_config_read(union ctl_io *io);
293 static int ctl_be_block_lun_info(void *be_lun, struct sbuf *sb);
294 static uint64_t ctl_be_block_lun_attr(void *be_lun, const char *attrname);
295 int ctl_be_block_init(void);
296 
297 static struct ctl_backend_driver ctl_be_block_driver =
298 {
299 	.name = "block",
300 	.flags = CTL_BE_FLAG_HAS_CONFIG,
301 	.init = ctl_be_block_init,
302 	.data_submit = ctl_be_block_submit,
303 	.data_move_done = ctl_be_block_move_done,
304 	.config_read = ctl_be_block_config_read,
305 	.config_write = ctl_be_block_config_write,
306 	.ioctl = ctl_be_block_ioctl,
307 	.lun_info = ctl_be_block_lun_info,
308 	.lun_attr = ctl_be_block_lun_attr
309 };
310 
311 MALLOC_DEFINE(M_CTLBLK, "ctlblk", "Memory used for CTL block backend");
312 CTL_BACKEND_DECLARE(cbb, ctl_be_block_driver);
313 
314 static uma_zone_t beio_zone;
315 
316 static struct ctl_be_block_io *
317 ctl_alloc_beio(struct ctl_be_block_softc *softc)
318 {
319 	struct ctl_be_block_io *beio;
320 
321 	beio = uma_zalloc(beio_zone, M_WAITOK | M_ZERO);
322 	beio->softc = softc;
323 	return (beio);
324 }
325 
326 static void
327 ctl_free_beio(struct ctl_be_block_io *beio)
328 {
329 	int duplicate_free;
330 	int i;
331 
332 	duplicate_free = 0;
333 
334 	for (i = 0; i < beio->num_segs; i++) {
335 		if (beio->sg_segs[i].addr == NULL)
336 			duplicate_free++;
337 
338 		uma_zfree(beio->lun->lun_zone, beio->sg_segs[i].addr);
339 		beio->sg_segs[i].addr = NULL;
340 
341 		/* For compare we had two equal S/G lists. */
342 		if (ARGS(beio->io)->flags & CTL_LLF_COMPARE) {
343 			uma_zfree(beio->lun->lun_zone,
344 			    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr);
345 			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr = NULL;
346 		}
347 	}
348 
349 	if (duplicate_free > 0) {
350 		printf("%s: %d duplicate frees out of %d segments\n", __func__,
351 		       duplicate_free, beio->num_segs);
352 	}
353 
354 	uma_zfree(beio_zone, beio);
355 }
356 
357 static void
358 ctl_complete_beio(struct ctl_be_block_io *beio)
359 {
360 	union ctl_io *io = beio->io;
361 
362 	if (beio->beio_cont != NULL) {
363 		beio->beio_cont(beio);
364 	} else {
365 		ctl_free_beio(beio);
366 		ctl_data_submit_done(io);
367 	}
368 }
369 
370 static int
371 ctl_be_block_move_done(union ctl_io *io)
372 {
373 	struct ctl_be_block_io *beio;
374 	struct ctl_be_block_lun *be_lun;
375 	struct ctl_lba_len_flags *lbalen;
376 #ifdef CTL_TIME_IO
377 	struct bintime cur_bt;
378 #endif
379 	int i;
380 
381 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
382 	be_lun = beio->lun;
383 
384 	DPRINTF("entered\n");
385 
386 #ifdef CTL_TIME_IO
387 	getbintime(&cur_bt);
388 	bintime_sub(&cur_bt, &io->io_hdr.dma_start_bt);
389 	bintime_add(&io->io_hdr.dma_bt, &cur_bt);
390 	io->io_hdr.num_dmas++;
391 #endif
392 	io->scsiio.kern_rel_offset += io->scsiio.kern_data_len;
393 
394 	/*
395 	 * We set status at this point for read commands, and write
396 	 * commands with errors.
397 	 */
398 	if (io->io_hdr.flags & CTL_FLAG_ABORT) {
399 		;
400 	} else if ((io->io_hdr.port_status == 0) &&
401 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
402 		lbalen = ARGS(beio->io);
403 		if (lbalen->flags & CTL_LLF_READ) {
404 			ctl_set_success(&io->scsiio);
405 		} else if (lbalen->flags & CTL_LLF_COMPARE) {
406 			/* We have two data blocks ready for comparison. */
407 			for (i = 0; i < beio->num_segs; i++) {
408 				if (memcmp(beio->sg_segs[i].addr,
409 				    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr,
410 				    beio->sg_segs[i].len) != 0)
411 					break;
412 			}
413 			if (i < beio->num_segs)
414 				ctl_set_sense(&io->scsiio,
415 				    /*current_error*/ 1,
416 				    /*sense_key*/ SSD_KEY_MISCOMPARE,
417 				    /*asc*/ 0x1D,
418 				    /*ascq*/ 0x00,
419 				    SSD_ELEM_NONE);
420 			else
421 				ctl_set_success(&io->scsiio);
422 		}
423 	} else if ((io->io_hdr.port_status != 0) &&
424 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE ||
425 	     (io->io_hdr.status & CTL_STATUS_MASK) == CTL_SUCCESS)) {
426 		/*
427 		 * For hardware error sense keys, the sense key
428 		 * specific value is defined to be a retry count,
429 		 * but we use it to pass back an internal FETD
430 		 * error code.  XXX KDM  Hopefully the FETD is only
431 		 * using 16 bits for an error code, since that's
432 		 * all the space we have in the sks field.
433 		 */
434 		ctl_set_internal_failure(&io->scsiio,
435 					 /*sks_valid*/ 1,
436 					 /*retry_count*/
437 					 io->io_hdr.port_status);
438 	}
439 
440 	/*
441 	 * If this is a read, or a write with errors, it is done.
442 	 */
443 	if ((beio->bio_cmd == BIO_READ)
444 	 || ((io->io_hdr.flags & CTL_FLAG_ABORT) != 0)
445 	 || ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)) {
446 		ctl_complete_beio(beio);
447 		return (0);
448 	}
449 
450 	/*
451 	 * At this point, we have a write and the DMA completed
452 	 * successfully.  We now have to queue it to the task queue to
453 	 * execute the backend I/O.  That is because we do blocking
454 	 * memory allocations, and in the file backing case, blocking I/O.
455 	 * This move done routine is generally called in the SIM's
456 	 * interrupt context, and therefore we cannot block.
457 	 */
458 	mtx_lock(&be_lun->queue_lock);
459 	/*
460 	 * XXX KDM make sure that links is okay to use at this point.
461 	 * Otherwise, we either need to add another field to ctl_io_hdr,
462 	 * or deal with resource allocation here.
463 	 */
464 	STAILQ_INSERT_TAIL(&be_lun->datamove_queue, &io->io_hdr, links);
465 	mtx_unlock(&be_lun->queue_lock);
466 
467 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
468 
469 	return (0);
470 }
471 
472 static void
473 ctl_be_block_biodone(struct bio *bio)
474 {
475 	struct ctl_be_block_io *beio;
476 	struct ctl_be_block_lun *be_lun;
477 	union ctl_io *io;
478 	int error;
479 
480 	beio = bio->bio_caller1;
481 	be_lun = beio->lun;
482 	io = beio->io;
483 
484 	DPRINTF("entered\n");
485 
486 	error = bio->bio_error;
487 	mtx_lock(&be_lun->io_lock);
488 	if (error != 0)
489 		beio->num_errors++;
490 
491 	beio->num_bios_done++;
492 
493 	/*
494 	 * XXX KDM will this cause WITNESS to complain?  Holding a lock
495 	 * during the free might cause it to complain.
496 	 */
497 	g_destroy_bio(bio);
498 
499 	/*
500 	 * If the send complete bit isn't set, or we aren't the last I/O to
501 	 * complete, then we're done.
502 	 */
503 	if ((beio->send_complete == 0)
504 	 || (beio->num_bios_done < beio->num_bios_sent)) {
505 		mtx_unlock(&be_lun->io_lock);
506 		return;
507 	}
508 
509 	/*
510 	 * At this point, we've verified that we are the last I/O to
511 	 * complete, so it's safe to drop the lock.
512 	 */
513 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
514 	    beio->ds_tag_type, beio->ds_trans_type,
515 	    /*now*/ NULL, /*then*/&beio->ds_t0);
516 	mtx_unlock(&be_lun->io_lock);
517 
518 	/*
519 	 * If there are any errors from the backing device, we fail the
520 	 * entire I/O with a medium error.
521 	 */
522 	if (beio->num_errors > 0) {
523 		if (error == EOPNOTSUPP) {
524 			ctl_set_invalid_opcode(&io->scsiio);
525 		} else if (error == ENOSPC || error == EDQUOT) {
526 			ctl_set_space_alloc_fail(&io->scsiio);
527 		} else if (beio->bio_cmd == BIO_FLUSH) {
528 			/* XXX KDM is there is a better error here? */
529 			ctl_set_internal_failure(&io->scsiio,
530 						 /*sks_valid*/ 1,
531 						 /*retry_count*/ 0xbad2);
532 		} else
533 			ctl_set_medium_error(&io->scsiio);
534 		ctl_complete_beio(beio);
535 		return;
536 	}
537 
538 	/*
539 	 * If this is a write, a flush, a delete or verify, we're all done.
540 	 * If this is a read, we can now send the data to the user.
541 	 */
542 	if ((beio->bio_cmd == BIO_WRITE)
543 	 || (beio->bio_cmd == BIO_FLUSH)
544 	 || (beio->bio_cmd == BIO_DELETE)
545 	 || (ARGS(io)->flags & CTL_LLF_VERIFY)) {
546 		ctl_set_success(&io->scsiio);
547 		ctl_complete_beio(beio);
548 	} else {
549 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
550 		    beio->beio_cont == NULL)
551 			ctl_set_success(&io->scsiio);
552 #ifdef CTL_TIME_IO
553         	getbintime(&io->io_hdr.dma_start_bt);
554 #endif
555 		ctl_datamove(io);
556 	}
557 }
558 
559 static void
560 ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
561 			struct ctl_be_block_io *beio)
562 {
563 	union ctl_io *io = beio->io;
564 	struct mount *mountpoint;
565 	int error, lock_flags;
566 
567 	DPRINTF("entered\n");
568 
569 	binuptime(&beio->ds_t0);
570 	mtx_lock(&be_lun->io_lock);
571 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
572 	mtx_unlock(&be_lun->io_lock);
573 
574 	(void) vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
575 
576 	if (MNT_SHARED_WRITES(mountpoint)
577 	 || ((mountpoint == NULL)
578 	  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
579 		lock_flags = LK_SHARED;
580 	else
581 		lock_flags = LK_EXCLUSIVE;
582 
583 	vn_lock(be_lun->vn, lock_flags | LK_RETRY);
584 
585 	error = VOP_FSYNC(be_lun->vn, beio->io_arg ? MNT_NOWAIT : MNT_WAIT,
586 	    curthread);
587 	VOP_UNLOCK(be_lun->vn, 0);
588 
589 	vn_finished_write(mountpoint);
590 
591 	mtx_lock(&be_lun->io_lock);
592 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
593 	    beio->ds_tag_type, beio->ds_trans_type,
594 	    /*now*/ NULL, /*then*/&beio->ds_t0);
595 	mtx_unlock(&be_lun->io_lock);
596 
597 	if (error == 0)
598 		ctl_set_success(&io->scsiio);
599 	else {
600 		/* XXX KDM is there is a better error here? */
601 		ctl_set_internal_failure(&io->scsiio,
602 					 /*sks_valid*/ 1,
603 					 /*retry_count*/ 0xbad1);
604 	}
605 
606 	ctl_complete_beio(beio);
607 }
608 
609 SDT_PROBE_DEFINE1(cbb, kernel, read, file_start, "uint64_t");
610 SDT_PROBE_DEFINE1(cbb, kernel, write, file_start, "uint64_t");
611 SDT_PROBE_DEFINE1(cbb, kernel, read, file_done,"uint64_t");
612 SDT_PROBE_DEFINE1(cbb, kernel, write, file_done, "uint64_t");
613 
614 static void
615 ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
616 			   struct ctl_be_block_io *beio)
617 {
618 	struct ctl_be_block_filedata *file_data;
619 	union ctl_io *io;
620 	struct uio xuio;
621 	struct iovec *xiovec;
622 	int flags;
623 	int error, i;
624 
625 	DPRINTF("entered\n");
626 
627 	file_data = &be_lun->backend.file;
628 	io = beio->io;
629 	flags = 0;
630 	if (ARGS(io)->flags & CTL_LLF_DPO)
631 		flags |= IO_DIRECT;
632 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
633 		flags |= IO_SYNC;
634 
635 	bzero(&xuio, sizeof(xuio));
636 	if (beio->bio_cmd == BIO_READ) {
637 		SDT_PROBE(cbb, kernel, read, file_start, 0, 0, 0, 0, 0);
638 		xuio.uio_rw = UIO_READ;
639 	} else {
640 		SDT_PROBE(cbb, kernel, write, file_start, 0, 0, 0, 0, 0);
641 		xuio.uio_rw = UIO_WRITE;
642 	}
643 	xuio.uio_offset = beio->io_offset;
644 	xuio.uio_resid = beio->io_len;
645 	xuio.uio_segflg = UIO_SYSSPACE;
646 	xuio.uio_iov = beio->xiovecs;
647 	xuio.uio_iovcnt = beio->num_segs;
648 	xuio.uio_td = curthread;
649 
650 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
651 		xiovec->iov_base = beio->sg_segs[i].addr;
652 		xiovec->iov_len = beio->sg_segs[i].len;
653 	}
654 
655 	binuptime(&beio->ds_t0);
656 	mtx_lock(&be_lun->io_lock);
657 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
658 	mtx_unlock(&be_lun->io_lock);
659 
660 	if (beio->bio_cmd == BIO_READ) {
661 		vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
662 
663 		/*
664 		 * UFS pays attention to IO_DIRECT for reads.  If the
665 		 * DIRECTIO option is configured into the kernel, it calls
666 		 * ffs_rawread().  But that only works for single-segment
667 		 * uios with user space addresses.  In our case, with a
668 		 * kernel uio, it still reads into the buffer cache, but it
669 		 * will just try to release the buffer from the cache later
670 		 * on in ffs_read().
671 		 *
672 		 * ZFS does not pay attention to IO_DIRECT for reads.
673 		 *
674 		 * UFS does not pay attention to IO_SYNC for reads.
675 		 *
676 		 * ZFS pays attention to IO_SYNC (which translates into the
677 		 * Solaris define FRSYNC for zfs_read()) for reads.  It
678 		 * attempts to sync the file before reading.
679 		 */
680 		error = VOP_READ(be_lun->vn, &xuio, flags, file_data->cred);
681 
682 		VOP_UNLOCK(be_lun->vn, 0);
683 		SDT_PROBE(cbb, kernel, read, file_done, 0, 0, 0, 0, 0);
684 	} else {
685 		struct mount *mountpoint;
686 		int lock_flags;
687 
688 		(void)vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
689 
690 		if (MNT_SHARED_WRITES(mountpoint)
691 		 || ((mountpoint == NULL)
692 		  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
693 			lock_flags = LK_SHARED;
694 		else
695 			lock_flags = LK_EXCLUSIVE;
696 
697 		vn_lock(be_lun->vn, lock_flags | LK_RETRY);
698 
699 		/*
700 		 * UFS pays attention to IO_DIRECT for writes.  The write
701 		 * is done asynchronously.  (Normally the write would just
702 		 * get put into cache.
703 		 *
704 		 * UFS pays attention to IO_SYNC for writes.  It will
705 		 * attempt to write the buffer out synchronously if that
706 		 * flag is set.
707 		 *
708 		 * ZFS does not pay attention to IO_DIRECT for writes.
709 		 *
710 		 * ZFS pays attention to IO_SYNC (a.k.a. FSYNC or FRSYNC)
711 		 * for writes.  It will flush the transaction from the
712 		 * cache before returning.
713 		 */
714 		error = VOP_WRITE(be_lun->vn, &xuio, flags, file_data->cred);
715 		VOP_UNLOCK(be_lun->vn, 0);
716 
717 		vn_finished_write(mountpoint);
718 		SDT_PROBE(cbb, kernel, write, file_done, 0, 0, 0, 0, 0);
719         }
720 
721 	mtx_lock(&be_lun->io_lock);
722 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
723 	    beio->ds_tag_type, beio->ds_trans_type,
724 	    /*now*/ NULL, /*then*/&beio->ds_t0);
725 	mtx_unlock(&be_lun->io_lock);
726 
727 	/*
728 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
729 	 * return the I/O to the user.
730 	 */
731 	if (error != 0) {
732 		char path_str[32];
733 
734 		ctl_scsi_path_string(io, path_str, sizeof(path_str));
735 		printf("%s%s command returned errno %d\n", path_str,
736 		       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE", error);
737 		if (error == ENOSPC || error == EDQUOT) {
738 			ctl_set_space_alloc_fail(&io->scsiio);
739 		} else
740 			ctl_set_medium_error(&io->scsiio);
741 		ctl_complete_beio(beio);
742 		return;
743 	}
744 
745 	/*
746 	 * If this is a write or a verify, we're all done.
747 	 * If this is a read, we can now send the data to the user.
748 	 */
749 	if ((beio->bio_cmd == BIO_WRITE) ||
750 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
751 		ctl_set_success(&io->scsiio);
752 		ctl_complete_beio(beio);
753 	} else {
754 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
755 		    beio->beio_cont == NULL)
756 			ctl_set_success(&io->scsiio);
757 #ifdef CTL_TIME_IO
758         	getbintime(&io->io_hdr.dma_start_bt);
759 #endif
760 		ctl_datamove(io);
761 	}
762 }
763 
764 static void
765 ctl_be_block_gls_file(struct ctl_be_block_lun *be_lun,
766 			struct ctl_be_block_io *beio)
767 {
768 	union ctl_io *io = beio->io;
769 	struct ctl_lba_len_flags *lbalen = ARGS(io);
770 	struct scsi_get_lba_status_data *data;
771 	off_t roff, off;
772 	int error, status;
773 
774 	DPRINTF("entered\n");
775 
776 	off = roff = ((off_t)lbalen->lba) << be_lun->blocksize_shift;
777 	vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
778 	error = VOP_IOCTL(be_lun->vn, FIOSEEKHOLE, &off,
779 	    0, curthread->td_ucred, curthread);
780 	if (error == 0 && off > roff)
781 		status = 0;	/* mapped up to off */
782 	else {
783 		error = VOP_IOCTL(be_lun->vn, FIOSEEKDATA, &off,
784 		    0, curthread->td_ucred, curthread);
785 		if (error == 0 && off > roff)
786 			status = 1;	/* deallocated up to off */
787 		else {
788 			status = 0;	/* unknown up to the end */
789 			off = be_lun->size_bytes;
790 		}
791 	}
792 	VOP_UNLOCK(be_lun->vn, 0);
793 
794 	off >>= be_lun->blocksize_shift;
795 	data = (struct scsi_get_lba_status_data *)io->scsiio.kern_data_ptr;
796 	scsi_u64to8b(lbalen->lba, data->descr[0].addr);
797 	scsi_ulto4b(MIN(UINT32_MAX, off - lbalen->lba),
798 	    data->descr[0].length);
799 	data->descr[0].status = status;
800 
801 	ctl_complete_beio(beio);
802 }
803 
804 static uint64_t
805 ctl_be_block_getattr_file(struct ctl_be_block_lun *be_lun, const char *attrname)
806 {
807 	struct vattr		vattr;
808 	struct statfs		statfs;
809 	uint64_t		val;
810 	int			error;
811 
812 	val = UINT64_MAX;
813 	if (be_lun->vn == NULL)
814 		return (val);
815 	vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
816 	if (strcmp(attrname, "blocksused") == 0) {
817 		error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
818 		if (error == 0)
819 			val = vattr.va_bytes >> be_lun->blocksize_shift;
820 	}
821 	if (strcmp(attrname, "blocksavail") == 0 &&
822 	    (be_lun->vn->v_iflag & VI_DOOMED) == 0) {
823 		error = VFS_STATFS(be_lun->vn->v_mount, &statfs);
824 		if (error == 0)
825 			val = (statfs.f_bavail * statfs.f_bsize) >>
826 			    be_lun->blocksize_shift;
827 	}
828 	VOP_UNLOCK(be_lun->vn, 0);
829 	return (val);
830 }
831 
832 static void
833 ctl_be_block_dispatch_zvol(struct ctl_be_block_lun *be_lun,
834 			   struct ctl_be_block_io *beio)
835 {
836 	struct ctl_be_block_devdata *dev_data;
837 	union ctl_io *io;
838 	struct uio xuio;
839 	struct iovec *xiovec;
840 	int flags;
841 	int error, i;
842 
843 	DPRINTF("entered\n");
844 
845 	dev_data = &be_lun->backend.dev;
846 	io = beio->io;
847 	flags = 0;
848 	if (ARGS(io)->flags & CTL_LLF_DPO)
849 		flags |= IO_DIRECT;
850 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
851 		flags |= IO_SYNC;
852 
853 	bzero(&xuio, sizeof(xuio));
854 	if (beio->bio_cmd == BIO_READ) {
855 		SDT_PROBE(cbb, kernel, read, file_start, 0, 0, 0, 0, 0);
856 		xuio.uio_rw = UIO_READ;
857 	} else {
858 		SDT_PROBE(cbb, kernel, write, file_start, 0, 0, 0, 0, 0);
859 		xuio.uio_rw = UIO_WRITE;
860 	}
861 	xuio.uio_offset = beio->io_offset;
862 	xuio.uio_resid = beio->io_len;
863 	xuio.uio_segflg = UIO_SYSSPACE;
864 	xuio.uio_iov = beio->xiovecs;
865 	xuio.uio_iovcnt = beio->num_segs;
866 	xuio.uio_td = curthread;
867 
868 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
869 		xiovec->iov_base = beio->sg_segs[i].addr;
870 		xiovec->iov_len = beio->sg_segs[i].len;
871 	}
872 
873 	binuptime(&beio->ds_t0);
874 	mtx_lock(&be_lun->io_lock);
875 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
876 	mtx_unlock(&be_lun->io_lock);
877 
878 	if (beio->bio_cmd == BIO_READ) {
879 		error = (*dev_data->csw->d_read)(dev_data->cdev, &xuio, flags);
880 		SDT_PROBE(cbb, kernel, read, file_done, 0, 0, 0, 0, 0);
881 	} else {
882 		error = (*dev_data->csw->d_write)(dev_data->cdev, &xuio, flags);
883 		SDT_PROBE(cbb, kernel, write, file_done, 0, 0, 0, 0, 0);
884 	}
885 
886 	mtx_lock(&be_lun->io_lock);
887 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
888 	    beio->ds_tag_type, beio->ds_trans_type,
889 	    /*now*/ NULL, /*then*/&beio->ds_t0);
890 	mtx_unlock(&be_lun->io_lock);
891 
892 	/*
893 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
894 	 * return the I/O to the user.
895 	 */
896 	if (error != 0) {
897 		if (error == ENOSPC || error == EDQUOT) {
898 			ctl_set_space_alloc_fail(&io->scsiio);
899 		} else
900 			ctl_set_medium_error(&io->scsiio);
901 		ctl_complete_beio(beio);
902 		return;
903 	}
904 
905 	/*
906 	 * If this is a write or a verify, we're all done.
907 	 * If this is a read, we can now send the data to the user.
908 	 */
909 	if ((beio->bio_cmd == BIO_WRITE) ||
910 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
911 		ctl_set_success(&io->scsiio);
912 		ctl_complete_beio(beio);
913 	} else {
914 		if ((ARGS(io)->flags & CTL_LLF_READ) &&
915 		    beio->beio_cont == NULL)
916 			ctl_set_success(&io->scsiio);
917 #ifdef CTL_TIME_IO
918         	getbintime(&io->io_hdr.dma_start_bt);
919 #endif
920 		ctl_datamove(io);
921 	}
922 }
923 
924 static void
925 ctl_be_block_gls_zvol(struct ctl_be_block_lun *be_lun,
926 			struct ctl_be_block_io *beio)
927 {
928 	struct ctl_be_block_devdata *dev_data = &be_lun->backend.dev;
929 	union ctl_io *io = beio->io;
930 	struct ctl_lba_len_flags *lbalen = ARGS(io);
931 	struct scsi_get_lba_status_data *data;
932 	off_t roff, off;
933 	int error, status;
934 
935 	DPRINTF("entered\n");
936 
937 	off = roff = ((off_t)lbalen->lba) << be_lun->blocksize_shift;
938 	error = (*dev_data->csw->d_ioctl)(dev_data->cdev, FIOSEEKHOLE,
939 	    (caddr_t)&off, FREAD, curthread);
940 	if (error == 0 && off > roff)
941 		status = 0;	/* mapped up to off */
942 	else {
943 		error = (*dev_data->csw->d_ioctl)(dev_data->cdev, FIOSEEKDATA,
944 		    (caddr_t)&off, FREAD, curthread);
945 		if (error == 0 && off > roff)
946 			status = 1;	/* deallocated up to off */
947 		else {
948 			status = 0;	/* unknown up to the end */
949 			off = be_lun->size_bytes;
950 		}
951 	}
952 
953 	off >>= be_lun->blocksize_shift;
954 	data = (struct scsi_get_lba_status_data *)io->scsiio.kern_data_ptr;
955 	scsi_u64to8b(lbalen->lba, data->descr[0].addr);
956 	scsi_ulto4b(MIN(UINT32_MAX, off - lbalen->lba),
957 	    data->descr[0].length);
958 	data->descr[0].status = status;
959 
960 	ctl_complete_beio(beio);
961 }
962 
963 static void
964 ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
965 		       struct ctl_be_block_io *beio)
966 {
967 	struct bio *bio;
968 	union ctl_io *io;
969 	struct ctl_be_block_devdata *dev_data;
970 
971 	dev_data = &be_lun->backend.dev;
972 	io = beio->io;
973 
974 	DPRINTF("entered\n");
975 
976 	/* This can't fail, it's a blocking allocation. */
977 	bio = g_alloc_bio();
978 
979 	bio->bio_cmd	    = BIO_FLUSH;
980 	bio->bio_dev	    = dev_data->cdev;
981 	bio->bio_offset	    = 0;
982 	bio->bio_data	    = 0;
983 	bio->bio_done	    = ctl_be_block_biodone;
984 	bio->bio_caller1    = beio;
985 	bio->bio_pblkno	    = 0;
986 
987 	/*
988 	 * We don't need to acquire the LUN lock here, because we are only
989 	 * sending one bio, and so there is no other context to synchronize
990 	 * with.
991 	 */
992 	beio->num_bios_sent = 1;
993 	beio->send_complete = 1;
994 
995 	binuptime(&beio->ds_t0);
996 	mtx_lock(&be_lun->io_lock);
997 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
998 	mtx_unlock(&be_lun->io_lock);
999 
1000 	(*dev_data->csw->d_strategy)(bio);
1001 }
1002 
1003 static void
1004 ctl_be_block_unmap_dev_range(struct ctl_be_block_lun *be_lun,
1005 		       struct ctl_be_block_io *beio,
1006 		       uint64_t off, uint64_t len, int last)
1007 {
1008 	struct bio *bio;
1009 	struct ctl_be_block_devdata *dev_data;
1010 	uint64_t maxlen;
1011 
1012 	dev_data = &be_lun->backend.dev;
1013 	maxlen = LONG_MAX - (LONG_MAX % be_lun->blocksize);
1014 	while (len > 0) {
1015 		bio = g_alloc_bio();
1016 		bio->bio_cmd	    = BIO_DELETE;
1017 		bio->bio_dev	    = dev_data->cdev;
1018 		bio->bio_offset	    = off;
1019 		bio->bio_length	    = MIN(len, maxlen);
1020 		bio->bio_data	    = 0;
1021 		bio->bio_done	    = ctl_be_block_biodone;
1022 		bio->bio_caller1    = beio;
1023 		bio->bio_pblkno     = off / be_lun->blocksize;
1024 
1025 		off += bio->bio_length;
1026 		len -= bio->bio_length;
1027 
1028 		mtx_lock(&be_lun->io_lock);
1029 		beio->num_bios_sent++;
1030 		if (last && len == 0)
1031 			beio->send_complete = 1;
1032 		mtx_unlock(&be_lun->io_lock);
1033 
1034 		(*dev_data->csw->d_strategy)(bio);
1035 	}
1036 }
1037 
1038 static void
1039 ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
1040 		       struct ctl_be_block_io *beio)
1041 {
1042 	union ctl_io *io;
1043 	struct ctl_be_block_devdata *dev_data;
1044 	struct ctl_ptr_len_flags *ptrlen;
1045 	struct scsi_unmap_desc *buf, *end;
1046 	uint64_t len;
1047 
1048 	dev_data = &be_lun->backend.dev;
1049 	io = beio->io;
1050 
1051 	DPRINTF("entered\n");
1052 
1053 	binuptime(&beio->ds_t0);
1054 	mtx_lock(&be_lun->io_lock);
1055 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1056 	mtx_unlock(&be_lun->io_lock);
1057 
1058 	if (beio->io_offset == -1) {
1059 		beio->io_len = 0;
1060 		ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1061 		buf = (struct scsi_unmap_desc *)ptrlen->ptr;
1062 		end = buf + ptrlen->len / sizeof(*buf);
1063 		for (; buf < end; buf++) {
1064 			len = (uint64_t)scsi_4btoul(buf->length) *
1065 			    be_lun->blocksize;
1066 			beio->io_len += len;
1067 			ctl_be_block_unmap_dev_range(be_lun, beio,
1068 			    scsi_8btou64(buf->lba) * be_lun->blocksize, len,
1069 			    (end - buf < 2) ? TRUE : FALSE);
1070 		}
1071 	} else
1072 		ctl_be_block_unmap_dev_range(be_lun, beio,
1073 		    beio->io_offset, beio->io_len, TRUE);
1074 }
1075 
1076 static void
1077 ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
1078 			  struct ctl_be_block_io *beio)
1079 {
1080 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
1081 	int i;
1082 	struct bio *bio;
1083 	struct ctl_be_block_devdata *dev_data;
1084 	off_t cur_offset;
1085 	int max_iosize;
1086 
1087 	DPRINTF("entered\n");
1088 
1089 	dev_data = &be_lun->backend.dev;
1090 
1091 	/*
1092 	 * We have to limit our I/O size to the maximum supported by the
1093 	 * backend device.  Hopefully it is MAXPHYS.  If the driver doesn't
1094 	 * set it properly, use DFLTPHYS.
1095 	 */
1096 	max_iosize = dev_data->cdev->si_iosize_max;
1097 	if (max_iosize < PAGE_SIZE)
1098 		max_iosize = DFLTPHYS;
1099 
1100 	cur_offset = beio->io_offset;
1101 	for (i = 0; i < beio->num_segs; i++) {
1102 		size_t cur_size;
1103 		uint8_t *cur_ptr;
1104 
1105 		cur_size = beio->sg_segs[i].len;
1106 		cur_ptr = beio->sg_segs[i].addr;
1107 
1108 		while (cur_size > 0) {
1109 			/* This can't fail, it's a blocking allocation. */
1110 			bio = g_alloc_bio();
1111 
1112 			KASSERT(bio != NULL, ("g_alloc_bio() failed!\n"));
1113 
1114 			bio->bio_cmd = beio->bio_cmd;
1115 			bio->bio_dev = dev_data->cdev;
1116 			bio->bio_caller1 = beio;
1117 			bio->bio_length = min(cur_size, max_iosize);
1118 			bio->bio_offset = cur_offset;
1119 			bio->bio_data = cur_ptr;
1120 			bio->bio_done = ctl_be_block_biodone;
1121 			bio->bio_pblkno = cur_offset / be_lun->blocksize;
1122 
1123 			cur_offset += bio->bio_length;
1124 			cur_ptr += bio->bio_length;
1125 			cur_size -= bio->bio_length;
1126 
1127 			TAILQ_INSERT_TAIL(&queue, bio, bio_queue);
1128 			beio->num_bios_sent++;
1129 		}
1130 	}
1131 	binuptime(&beio->ds_t0);
1132 	mtx_lock(&be_lun->io_lock);
1133 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1134 	beio->send_complete = 1;
1135 	mtx_unlock(&be_lun->io_lock);
1136 
1137 	/*
1138 	 * Fire off all allocated requests!
1139 	 */
1140 	while ((bio = TAILQ_FIRST(&queue)) != NULL) {
1141 		TAILQ_REMOVE(&queue, bio, bio_queue);
1142 		(*dev_data->csw->d_strategy)(bio);
1143 	}
1144 }
1145 
1146 static uint64_t
1147 ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun, const char *attrname)
1148 {
1149 	struct ctl_be_block_devdata	*dev_data = &be_lun->backend.dev;
1150 	struct diocgattr_arg	arg;
1151 	int			error;
1152 
1153 	if (dev_data->csw == NULL || dev_data->csw->d_ioctl == NULL)
1154 		return (UINT64_MAX);
1155 	strlcpy(arg.name, attrname, sizeof(arg.name));
1156 	arg.len = sizeof(arg.value.off);
1157 	error = dev_data->csw->d_ioctl(dev_data->cdev,
1158 	    DIOCGATTR, (caddr_t)&arg, FREAD, curthread);
1159 	if (error != 0)
1160 		return (UINT64_MAX);
1161 	return (arg.value.off);
1162 }
1163 
1164 static void
1165 ctl_be_block_cw_dispatch_sync(struct ctl_be_block_lun *be_lun,
1166 			    union ctl_io *io)
1167 {
1168 	struct ctl_be_block_io *beio;
1169 	struct ctl_lba_len_flags *lbalen;
1170 
1171 	DPRINTF("entered\n");
1172 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1173 	lbalen = (struct ctl_lba_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1174 
1175 	beio->io_len = lbalen->len * be_lun->blocksize;
1176 	beio->io_offset = lbalen->lba * be_lun->blocksize;
1177 	beio->io_arg = (lbalen->flags & SSC_IMMED) != 0;
1178 	beio->bio_cmd = BIO_FLUSH;
1179 	beio->ds_trans_type = DEVSTAT_NO_DATA;
1180 	DPRINTF("SYNC\n");
1181 	be_lun->lun_flush(be_lun, beio);
1182 }
1183 
1184 static void
1185 ctl_be_block_cw_done_ws(struct ctl_be_block_io *beio)
1186 {
1187 	union ctl_io *io;
1188 
1189 	io = beio->io;
1190 	ctl_free_beio(beio);
1191 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1192 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1193 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1194 		ctl_config_write_done(io);
1195 		return;
1196 	}
1197 
1198 	ctl_be_block_config_write(io);
1199 }
1200 
1201 static void
1202 ctl_be_block_cw_dispatch_ws(struct ctl_be_block_lun *be_lun,
1203 			    union ctl_io *io)
1204 {
1205 	struct ctl_be_block_io *beio;
1206 	struct ctl_lba_len_flags *lbalen;
1207 	uint64_t len_left, lba;
1208 	uint32_t pb, pbo, adj;
1209 	int i, seglen;
1210 	uint8_t *buf, *end;
1211 
1212 	DPRINTF("entered\n");
1213 
1214 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1215 	lbalen = ARGS(beio->io);
1216 
1217 	if (lbalen->flags & ~(SWS_LBDATA | SWS_UNMAP | SWS_ANCHOR | SWS_NDOB) ||
1218 	    (lbalen->flags & (SWS_UNMAP | SWS_ANCHOR) && be_lun->unmap == NULL)) {
1219 		ctl_free_beio(beio);
1220 		ctl_set_invalid_field(&io->scsiio,
1221 				      /*sks_valid*/ 1,
1222 				      /*command*/ 1,
1223 				      /*field*/ 1,
1224 				      /*bit_valid*/ 0,
1225 				      /*bit*/ 0);
1226 		ctl_config_write_done(io);
1227 		return;
1228 	}
1229 
1230 	if (lbalen->flags & (SWS_UNMAP | SWS_ANCHOR)) {
1231 		beio->io_offset = lbalen->lba * be_lun->blocksize;
1232 		beio->io_len = (uint64_t)lbalen->len * be_lun->blocksize;
1233 		beio->bio_cmd = BIO_DELETE;
1234 		beio->ds_trans_type = DEVSTAT_FREE;
1235 
1236 		be_lun->unmap(be_lun, beio);
1237 		return;
1238 	}
1239 
1240 	beio->bio_cmd = BIO_WRITE;
1241 	beio->ds_trans_type = DEVSTAT_WRITE;
1242 
1243 	DPRINTF("WRITE SAME at LBA %jx len %u\n",
1244 	       (uintmax_t)lbalen->lba, lbalen->len);
1245 
1246 	pb = be_lun->blocksize << be_lun->pblockexp;
1247 	if (be_lun->pblockoff > 0)
1248 		pbo = pb - be_lun->blocksize * be_lun->pblockoff;
1249 	else
1250 		pbo = 0;
1251 	len_left = (uint64_t)lbalen->len * be_lun->blocksize;
1252 	for (i = 0, lba = 0; i < CTLBLK_MAX_SEGS && len_left > 0; i++) {
1253 
1254 		/*
1255 		 * Setup the S/G entry for this chunk.
1256 		 */
1257 		seglen = MIN(CTLBLK_MAX_SEG, len_left);
1258 		if (pb > be_lun->blocksize) {
1259 			adj = ((lbalen->lba + lba) * be_lun->blocksize +
1260 			    seglen - pbo) % pb;
1261 			if (seglen > adj)
1262 				seglen -= adj;
1263 			else
1264 				seglen -= seglen % be_lun->blocksize;
1265 		} else
1266 			seglen -= seglen % be_lun->blocksize;
1267 		beio->sg_segs[i].len = seglen;
1268 		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1269 
1270 		DPRINTF("segment %d addr %p len %zd\n", i,
1271 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1272 
1273 		beio->num_segs++;
1274 		len_left -= seglen;
1275 
1276 		buf = beio->sg_segs[i].addr;
1277 		end = buf + seglen;
1278 		for (; buf < end; buf += be_lun->blocksize) {
1279 			memcpy(buf, io->scsiio.kern_data_ptr, be_lun->blocksize);
1280 			if (lbalen->flags & SWS_LBDATA)
1281 				scsi_ulto4b(lbalen->lba + lba, buf);
1282 			lba++;
1283 		}
1284 	}
1285 
1286 	beio->io_offset = lbalen->lba * be_lun->blocksize;
1287 	beio->io_len = lba * be_lun->blocksize;
1288 
1289 	/* We can not do all in one run. Correct and schedule rerun. */
1290 	if (len_left > 0) {
1291 		lbalen->lba += lba;
1292 		lbalen->len -= lba;
1293 		beio->beio_cont = ctl_be_block_cw_done_ws;
1294 	}
1295 
1296 	be_lun->dispatch(be_lun, beio);
1297 }
1298 
1299 static void
1300 ctl_be_block_cw_dispatch_unmap(struct ctl_be_block_lun *be_lun,
1301 			    union ctl_io *io)
1302 {
1303 	struct ctl_be_block_io *beio;
1304 	struct ctl_ptr_len_flags *ptrlen;
1305 
1306 	DPRINTF("entered\n");
1307 
1308 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1309 	ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1310 
1311 	if ((ptrlen->flags & ~SU_ANCHOR) != 0 || be_lun->unmap == NULL) {
1312 		ctl_free_beio(beio);
1313 		ctl_set_invalid_field(&io->scsiio,
1314 				      /*sks_valid*/ 0,
1315 				      /*command*/ 1,
1316 				      /*field*/ 0,
1317 				      /*bit_valid*/ 0,
1318 				      /*bit*/ 0);
1319 		ctl_config_write_done(io);
1320 		return;
1321 	}
1322 
1323 	beio->io_len = 0;
1324 	beio->io_offset = -1;
1325 	beio->bio_cmd = BIO_DELETE;
1326 	beio->ds_trans_type = DEVSTAT_FREE;
1327 	DPRINTF("UNMAP\n");
1328 	be_lun->unmap(be_lun, beio);
1329 }
1330 
1331 static void
1332 ctl_be_block_cr_done(struct ctl_be_block_io *beio)
1333 {
1334 	union ctl_io *io;
1335 
1336 	io = beio->io;
1337 	ctl_free_beio(beio);
1338 	ctl_config_read_done(io);
1339 }
1340 
1341 static void
1342 ctl_be_block_cr_dispatch(struct ctl_be_block_lun *be_lun,
1343 			 union ctl_io *io)
1344 {
1345 	struct ctl_be_block_io *beio;
1346 	struct ctl_be_block_softc *softc;
1347 
1348 	DPRINTF("entered\n");
1349 
1350 	softc = be_lun->softc;
1351 	beio = ctl_alloc_beio(softc);
1352 	beio->io = io;
1353 	beio->lun = be_lun;
1354 	beio->beio_cont = ctl_be_block_cr_done;
1355 	PRIV(io)->ptr = (void *)beio;
1356 
1357 	switch (io->scsiio.cdb[0]) {
1358 	case SERVICE_ACTION_IN:		/* GET LBA STATUS */
1359 		beio->bio_cmd = -1;
1360 		beio->ds_trans_type = DEVSTAT_NO_DATA;
1361 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1362 		beio->io_len = 0;
1363 		if (be_lun->get_lba_status)
1364 			be_lun->get_lba_status(be_lun, beio);
1365 		else
1366 			ctl_be_block_cr_done(beio);
1367 		break;
1368 	default:
1369 		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1370 		break;
1371 	}
1372 }
1373 
1374 static void
1375 ctl_be_block_cw_done(struct ctl_be_block_io *beio)
1376 {
1377 	union ctl_io *io;
1378 
1379 	io = beio->io;
1380 	ctl_free_beio(beio);
1381 	ctl_config_write_done(io);
1382 }
1383 
1384 static void
1385 ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
1386 			 union ctl_io *io)
1387 {
1388 	struct ctl_be_block_io *beio;
1389 	struct ctl_be_block_softc *softc;
1390 
1391 	DPRINTF("entered\n");
1392 
1393 	softc = be_lun->softc;
1394 	beio = ctl_alloc_beio(softc);
1395 	beio->io = io;
1396 	beio->lun = be_lun;
1397 	beio->beio_cont = ctl_be_block_cw_done;
1398 	switch (io->scsiio.tag_type) {
1399 	case CTL_TAG_ORDERED:
1400 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1401 		break;
1402 	case CTL_TAG_HEAD_OF_QUEUE:
1403 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1404 		break;
1405 	case CTL_TAG_UNTAGGED:
1406 	case CTL_TAG_SIMPLE:
1407 	case CTL_TAG_ACA:
1408 	default:
1409 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1410 		break;
1411 	}
1412 	PRIV(io)->ptr = (void *)beio;
1413 
1414 	switch (io->scsiio.cdb[0]) {
1415 	case SYNCHRONIZE_CACHE:
1416 	case SYNCHRONIZE_CACHE_16:
1417 		ctl_be_block_cw_dispatch_sync(be_lun, io);
1418 		break;
1419 	case WRITE_SAME_10:
1420 	case WRITE_SAME_16:
1421 		ctl_be_block_cw_dispatch_ws(be_lun, io);
1422 		break;
1423 	case UNMAP:
1424 		ctl_be_block_cw_dispatch_unmap(be_lun, io);
1425 		break;
1426 	default:
1427 		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1428 		break;
1429 	}
1430 }
1431 
1432 SDT_PROBE_DEFINE1(cbb, kernel, read, start, "uint64_t");
1433 SDT_PROBE_DEFINE1(cbb, kernel, write, start, "uint64_t");
1434 SDT_PROBE_DEFINE1(cbb, kernel, read, alloc_done, "uint64_t");
1435 SDT_PROBE_DEFINE1(cbb, kernel, write, alloc_done, "uint64_t");
1436 
1437 static void
1438 ctl_be_block_next(struct ctl_be_block_io *beio)
1439 {
1440 	struct ctl_be_block_lun *be_lun;
1441 	union ctl_io *io;
1442 
1443 	io = beio->io;
1444 	be_lun = beio->lun;
1445 	ctl_free_beio(beio);
1446 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1447 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1448 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1449 		ctl_data_submit_done(io);
1450 		return;
1451 	}
1452 
1453 	io->io_hdr.status &= ~CTL_STATUS_MASK;
1454 	io->io_hdr.status |= CTL_STATUS_NONE;
1455 
1456 	mtx_lock(&be_lun->queue_lock);
1457 	/*
1458 	 * XXX KDM make sure that links is okay to use at this point.
1459 	 * Otherwise, we either need to add another field to ctl_io_hdr,
1460 	 * or deal with resource allocation here.
1461 	 */
1462 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1463 	mtx_unlock(&be_lun->queue_lock);
1464 
1465 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1466 }
1467 
1468 static void
1469 ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
1470 			   union ctl_io *io)
1471 {
1472 	struct ctl_be_block_io *beio;
1473 	struct ctl_be_block_softc *softc;
1474 	struct ctl_lba_len_flags *lbalen;
1475 	struct ctl_ptr_len_flags *bptrlen;
1476 	uint64_t len_left, lbas;
1477 	int i;
1478 
1479 	softc = be_lun->softc;
1480 
1481 	DPRINTF("entered\n");
1482 
1483 	lbalen = ARGS(io);
1484 	if (lbalen->flags & CTL_LLF_WRITE) {
1485 		SDT_PROBE(cbb, kernel, write, start, 0, 0, 0, 0, 0);
1486 	} else {
1487 		SDT_PROBE(cbb, kernel, read, start, 0, 0, 0, 0, 0);
1488 	}
1489 
1490 	beio = ctl_alloc_beio(softc);
1491 	beio->io = io;
1492 	beio->lun = be_lun;
1493 	bptrlen = PRIV(io);
1494 	bptrlen->ptr = (void *)beio;
1495 
1496 	switch (io->scsiio.tag_type) {
1497 	case CTL_TAG_ORDERED:
1498 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1499 		break;
1500 	case CTL_TAG_HEAD_OF_QUEUE:
1501 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1502 		break;
1503 	case CTL_TAG_UNTAGGED:
1504 	case CTL_TAG_SIMPLE:
1505 	case CTL_TAG_ACA:
1506 	default:
1507 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1508 		break;
1509 	}
1510 
1511 	if (lbalen->flags & CTL_LLF_WRITE) {
1512 		beio->bio_cmd = BIO_WRITE;
1513 		beio->ds_trans_type = DEVSTAT_WRITE;
1514 	} else {
1515 		beio->bio_cmd = BIO_READ;
1516 		beio->ds_trans_type = DEVSTAT_READ;
1517 	}
1518 
1519 	DPRINTF("%s at LBA %jx len %u @%ju\n",
1520 	       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE",
1521 	       (uintmax_t)lbalen->lba, lbalen->len, bptrlen->len);
1522 	if (lbalen->flags & CTL_LLF_COMPARE)
1523 		lbas = CTLBLK_HALF_IO_SIZE;
1524 	else
1525 		lbas = CTLBLK_MAX_IO_SIZE;
1526 	lbas = MIN(lbalen->len - bptrlen->len, lbas / be_lun->blocksize);
1527 	beio->io_offset = (lbalen->lba + bptrlen->len) * be_lun->blocksize;
1528 	beio->io_len = lbas * be_lun->blocksize;
1529 	bptrlen->len += lbas;
1530 
1531 	for (i = 0, len_left = beio->io_len; len_left > 0; i++) {
1532 		KASSERT(i < CTLBLK_MAX_SEGS, ("Too many segs (%d >= %d)",
1533 		    i, CTLBLK_MAX_SEGS));
1534 
1535 		/*
1536 		 * Setup the S/G entry for this chunk.
1537 		 */
1538 		beio->sg_segs[i].len = min(CTLBLK_MAX_SEG, len_left);
1539 		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1540 
1541 		DPRINTF("segment %d addr %p len %zd\n", i,
1542 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1543 
1544 		/* Set up second segment for compare operation. */
1545 		if (lbalen->flags & CTL_LLF_COMPARE) {
1546 			beio->sg_segs[i + CTLBLK_HALF_SEGS].len =
1547 			    beio->sg_segs[i].len;
1548 			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr =
1549 			    uma_zalloc(be_lun->lun_zone, M_WAITOK);
1550 		}
1551 
1552 		beio->num_segs++;
1553 		len_left -= beio->sg_segs[i].len;
1554 	}
1555 	if (bptrlen->len < lbalen->len)
1556 		beio->beio_cont = ctl_be_block_next;
1557 	io->scsiio.be_move_done = ctl_be_block_move_done;
1558 	/* For compare we have separate S/G lists for read and datamove. */
1559 	if (lbalen->flags & CTL_LLF_COMPARE)
1560 		io->scsiio.kern_data_ptr = (uint8_t *)&beio->sg_segs[CTLBLK_HALF_SEGS];
1561 	else
1562 		io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
1563 	io->scsiio.kern_data_len = beio->io_len;
1564 	io->scsiio.kern_data_resid = 0;
1565 	io->scsiio.kern_sg_entries = beio->num_segs;
1566 	io->io_hdr.flags |= CTL_FLAG_ALLOCATED | CTL_FLAG_KDPTR_SGLIST;
1567 
1568 	/*
1569 	 * For the read case, we need to read the data into our buffers and
1570 	 * then we can send it back to the user.  For the write case, we
1571 	 * need to get the data from the user first.
1572 	 */
1573 	if (beio->bio_cmd == BIO_READ) {
1574 		SDT_PROBE(cbb, kernel, read, alloc_done, 0, 0, 0, 0, 0);
1575 		be_lun->dispatch(be_lun, beio);
1576 	} else {
1577 		SDT_PROBE(cbb, kernel, write, alloc_done, 0, 0, 0, 0, 0);
1578 #ifdef CTL_TIME_IO
1579         	getbintime(&io->io_hdr.dma_start_bt);
1580 #endif
1581 		ctl_datamove(io);
1582 	}
1583 }
1584 
1585 static void
1586 ctl_be_block_worker(void *context, int pending)
1587 {
1588 	struct ctl_be_block_lun *be_lun;
1589 	struct ctl_be_block_softc *softc;
1590 	union ctl_io *io;
1591 
1592 	be_lun = (struct ctl_be_block_lun *)context;
1593 	softc = be_lun->softc;
1594 
1595 	DPRINTF("entered\n");
1596 
1597 	mtx_lock(&be_lun->queue_lock);
1598 	for (;;) {
1599 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->datamove_queue);
1600 		if (io != NULL) {
1601 			struct ctl_be_block_io *beio;
1602 
1603 			DPRINTF("datamove queue\n");
1604 
1605 			STAILQ_REMOVE(&be_lun->datamove_queue, &io->io_hdr,
1606 				      ctl_io_hdr, links);
1607 
1608 			mtx_unlock(&be_lun->queue_lock);
1609 
1610 			beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1611 
1612 			be_lun->dispatch(be_lun, beio);
1613 
1614 			mtx_lock(&be_lun->queue_lock);
1615 			continue;
1616 		}
1617 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_write_queue);
1618 		if (io != NULL) {
1619 			DPRINTF("config write queue\n");
1620 			STAILQ_REMOVE(&be_lun->config_write_queue, &io->io_hdr,
1621 				      ctl_io_hdr, links);
1622 			mtx_unlock(&be_lun->queue_lock);
1623 			ctl_be_block_cw_dispatch(be_lun, io);
1624 			mtx_lock(&be_lun->queue_lock);
1625 			continue;
1626 		}
1627 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_read_queue);
1628 		if (io != NULL) {
1629 			DPRINTF("config read queue\n");
1630 			STAILQ_REMOVE(&be_lun->config_read_queue, &io->io_hdr,
1631 				      ctl_io_hdr, links);
1632 			mtx_unlock(&be_lun->queue_lock);
1633 			ctl_be_block_cr_dispatch(be_lun, io);
1634 			mtx_lock(&be_lun->queue_lock);
1635 			continue;
1636 		}
1637 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->input_queue);
1638 		if (io != NULL) {
1639 			DPRINTF("input queue\n");
1640 
1641 			STAILQ_REMOVE(&be_lun->input_queue, &io->io_hdr,
1642 				      ctl_io_hdr, links);
1643 			mtx_unlock(&be_lun->queue_lock);
1644 
1645 			/*
1646 			 * We must drop the lock, since this routine and
1647 			 * its children may sleep.
1648 			 */
1649 			ctl_be_block_dispatch(be_lun, io);
1650 
1651 			mtx_lock(&be_lun->queue_lock);
1652 			continue;
1653 		}
1654 
1655 		/*
1656 		 * If we get here, there is no work left in the queues, so
1657 		 * just break out and let the task queue go to sleep.
1658 		 */
1659 		break;
1660 	}
1661 	mtx_unlock(&be_lun->queue_lock);
1662 }
1663 
1664 /*
1665  * Entry point from CTL to the backend for I/O.  We queue everything to a
1666  * work thread, so this just puts the I/O on a queue and wakes up the
1667  * thread.
1668  */
1669 static int
1670 ctl_be_block_submit(union ctl_io *io)
1671 {
1672 	struct ctl_be_block_lun *be_lun;
1673 	struct ctl_be_lun *ctl_be_lun;
1674 
1675 	DPRINTF("entered\n");
1676 
1677 	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
1678 		CTL_PRIV_BACKEND_LUN].ptr;
1679 	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
1680 
1681 	/*
1682 	 * Make sure we only get SCSI I/O.
1683 	 */
1684 	KASSERT(io->io_hdr.io_type == CTL_IO_SCSI, ("Non-SCSI I/O (type "
1685 		"%#x) encountered", io->io_hdr.io_type));
1686 
1687 	PRIV(io)->len = 0;
1688 
1689 	mtx_lock(&be_lun->queue_lock);
1690 	/*
1691 	 * XXX KDM make sure that links is okay to use at this point.
1692 	 * Otherwise, we either need to add another field to ctl_io_hdr,
1693 	 * or deal with resource allocation here.
1694 	 */
1695 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1696 	mtx_unlock(&be_lun->queue_lock);
1697 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1698 
1699 	return (CTL_RETVAL_COMPLETE);
1700 }
1701 
1702 static int
1703 ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
1704 			int flag, struct thread *td)
1705 {
1706 	struct ctl_be_block_softc *softc;
1707 	int error;
1708 
1709 	softc = &backend_block_softc;
1710 
1711 	error = 0;
1712 
1713 	switch (cmd) {
1714 	case CTL_LUN_REQ: {
1715 		struct ctl_lun_req *lun_req;
1716 
1717 		lun_req = (struct ctl_lun_req *)addr;
1718 
1719 		switch (lun_req->reqtype) {
1720 		case CTL_LUNREQ_CREATE:
1721 			error = ctl_be_block_create(softc, lun_req);
1722 			break;
1723 		case CTL_LUNREQ_RM:
1724 			error = ctl_be_block_rm(softc, lun_req);
1725 			break;
1726 		case CTL_LUNREQ_MODIFY:
1727 			error = ctl_be_block_modify(softc, lun_req);
1728 			break;
1729 		default:
1730 			lun_req->status = CTL_LUN_ERROR;
1731 			snprintf(lun_req->error_str, sizeof(lun_req->error_str),
1732 				 "invalid LUN request type %d",
1733 				 lun_req->reqtype);
1734 			break;
1735 		}
1736 		break;
1737 	}
1738 	default:
1739 		error = ENOTTY;
1740 		break;
1741 	}
1742 
1743 	return (error);
1744 }
1745 
1746 static int
1747 ctl_be_block_open_file(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1748 {
1749 	struct ctl_be_block_filedata *file_data;
1750 	struct ctl_lun_create_params *params;
1751 	char			     *value;
1752 	struct vattr		      vattr;
1753 	off_t			      ps, pss, po, pos, us, uss, uo, uos;
1754 	int			      error;
1755 
1756 	error = 0;
1757 	file_data = &be_lun->backend.file;
1758 	params = &be_lun->params;
1759 
1760 	be_lun->dev_type = CTL_BE_BLOCK_FILE;
1761 	be_lun->dispatch = ctl_be_block_dispatch_file;
1762 	be_lun->lun_flush = ctl_be_block_flush_file;
1763 	be_lun->get_lba_status = ctl_be_block_gls_file;
1764 	be_lun->getattr = ctl_be_block_getattr_file;
1765 
1766 	error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
1767 	if (error != 0) {
1768 		snprintf(req->error_str, sizeof(req->error_str),
1769 			 "error calling VOP_GETATTR() for file %s",
1770 			 be_lun->dev_path);
1771 		return (error);
1772 	}
1773 
1774 	/*
1775 	 * Verify that we have the ability to upgrade to exclusive
1776 	 * access on this file so we can trap errors at open instead
1777 	 * of reporting them during first access.
1778 	 */
1779 	if (VOP_ISLOCKED(be_lun->vn) != LK_EXCLUSIVE) {
1780 		vn_lock(be_lun->vn, LK_UPGRADE | LK_RETRY);
1781 		if (be_lun->vn->v_iflag & VI_DOOMED) {
1782 			error = EBADF;
1783 			snprintf(req->error_str, sizeof(req->error_str),
1784 				 "error locking file %s", be_lun->dev_path);
1785 			return (error);
1786 		}
1787 	}
1788 
1789 
1790 	file_data->cred = crhold(curthread->td_ucred);
1791 	if (params->lun_size_bytes != 0)
1792 		be_lun->size_bytes = params->lun_size_bytes;
1793 	else
1794 		be_lun->size_bytes = vattr.va_size;
1795 	/*
1796 	 * We set the multi thread flag for file operations because all
1797 	 * filesystems (in theory) are capable of allowing multiple readers
1798 	 * of a file at once.  So we want to get the maximum possible
1799 	 * concurrency.
1800 	 */
1801 	be_lun->flags |= CTL_BE_BLOCK_LUN_MULTI_THREAD;
1802 
1803 	/*
1804 	 * For files we can use any logical block size.  Prefer 512 bytes
1805 	 * for compatibility reasons.  If file's vattr.va_blocksize
1806 	 * (preferred I/O block size) is bigger and multiple to chosen
1807 	 * logical block size -- report it as physical block size.
1808 	 */
1809 	if (params->blocksize_bytes != 0)
1810 		be_lun->blocksize = params->blocksize_bytes;
1811 	else
1812 		be_lun->blocksize = 512;
1813 
1814 	us = ps = vattr.va_blocksize;
1815 	uo = po = 0;
1816 
1817 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "pblocksize");
1818 	if (value != NULL)
1819 		ctl_expand_number(value, &ps);
1820 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "pblockoffset");
1821 	if (value != NULL)
1822 		ctl_expand_number(value, &po);
1823 	pss = ps / be_lun->blocksize;
1824 	pos = po / be_lun->blocksize;
1825 	if ((pss > 0) && (pss * be_lun->blocksize == ps) && (pss >= pos) &&
1826 	    ((pss & (pss - 1)) == 0) && (pos * be_lun->blocksize == po)) {
1827 		be_lun->pblockexp = fls(pss) - 1;
1828 		be_lun->pblockoff = (pss - pos) % pss;
1829 	}
1830 
1831 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "ublocksize");
1832 	if (value != NULL)
1833 		ctl_expand_number(value, &us);
1834 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "ublockoffset");
1835 	if (value != NULL)
1836 		ctl_expand_number(value, &uo);
1837 	uss = us / be_lun->blocksize;
1838 	uos = uo / be_lun->blocksize;
1839 	if ((uss > 0) && (uss * be_lun->blocksize == us) && (uss >= uos) &&
1840 	    ((uss & (uss - 1)) == 0) && (uos * be_lun->blocksize == uo)) {
1841 		be_lun->ublockexp = fls(uss) - 1;
1842 		be_lun->ublockoff = (uss - uos) % uss;
1843 	}
1844 
1845 	/*
1846 	 * Sanity check.  The media size has to be at least one
1847 	 * sector long.
1848 	 */
1849 	if (be_lun->size_bytes < be_lun->blocksize) {
1850 		error = EINVAL;
1851 		snprintf(req->error_str, sizeof(req->error_str),
1852 			 "file %s size %ju < block size %u", be_lun->dev_path,
1853 			 (uintmax_t)be_lun->size_bytes, be_lun->blocksize);
1854 	}
1855 
1856 	be_lun->opttxferlen = CTLBLK_MAX_IO_SIZE / be_lun->blocksize;
1857 	return (error);
1858 }
1859 
1860 static int
1861 ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1862 {
1863 	struct ctl_lun_create_params *params;
1864 	struct vattr		      vattr;
1865 	struct cdev		     *dev;
1866 	struct cdevsw		     *devsw;
1867 	char			     *value;
1868 	int			      error, atomic, maxio, unmap;
1869 	off_t			      ps, pss, po, pos, us, uss, uo, uos;
1870 
1871 	params = &be_lun->params;
1872 
1873 	be_lun->dev_type = CTL_BE_BLOCK_DEV;
1874 	be_lun->backend.dev.cdev = be_lun->vn->v_rdev;
1875 	be_lun->backend.dev.csw = dev_refthread(be_lun->backend.dev.cdev,
1876 					     &be_lun->backend.dev.dev_ref);
1877 	if (be_lun->backend.dev.csw == NULL)
1878 		panic("Unable to retrieve device switch");
1879 	if (strcmp(be_lun->backend.dev.csw->d_name, "zvol") == 0) {
1880 		be_lun->dispatch = ctl_be_block_dispatch_zvol;
1881 		be_lun->get_lba_status = ctl_be_block_gls_zvol;
1882 		atomic = maxio = CTLBLK_MAX_IO_SIZE;
1883 	} else {
1884 		be_lun->dispatch = ctl_be_block_dispatch_dev;
1885 		atomic = 0;
1886 		maxio = be_lun->backend.dev.cdev->si_iosize_max;
1887 		if (maxio <= 0)
1888 			maxio = DFLTPHYS;
1889 		if (maxio > CTLBLK_MAX_IO_SIZE)
1890 			maxio = CTLBLK_MAX_IO_SIZE;
1891 	}
1892 	be_lun->lun_flush = ctl_be_block_flush_dev;
1893 	be_lun->getattr = ctl_be_block_getattr_dev;
1894 
1895 	error = VOP_GETATTR(be_lun->vn, &vattr, NOCRED);
1896 	if (error) {
1897 		snprintf(req->error_str, sizeof(req->error_str),
1898 			 "error getting vnode attributes for device %s",
1899 			 be_lun->dev_path);
1900 		return (error);
1901 	}
1902 
1903 	dev = be_lun->vn->v_rdev;
1904 	devsw = dev->si_devsw;
1905 	if (!devsw->d_ioctl) {
1906 		snprintf(req->error_str, sizeof(req->error_str),
1907 			 "no d_ioctl for device %s!",
1908 			 be_lun->dev_path);
1909 		return (ENODEV);
1910 	}
1911 
1912 	error = devsw->d_ioctl(dev, DIOCGSECTORSIZE,
1913 			       (caddr_t)&be_lun->blocksize, FREAD,
1914 			       curthread);
1915 	if (error) {
1916 		snprintf(req->error_str, sizeof(req->error_str),
1917 			 "error %d returned for DIOCGSECTORSIZE ioctl "
1918 			 "on %s!", error, be_lun->dev_path);
1919 		return (error);
1920 	}
1921 
1922 	/*
1923 	 * If the user has asked for a blocksize that is greater than the
1924 	 * backing device's blocksize, we can do it only if the blocksize
1925 	 * the user is asking for is an even multiple of the underlying
1926 	 * device's blocksize.
1927 	 */
1928 	if ((params->blocksize_bytes != 0)
1929 	 && (params->blocksize_bytes > be_lun->blocksize)) {
1930 		uint32_t bs_multiple, tmp_blocksize;
1931 
1932 		bs_multiple = params->blocksize_bytes / be_lun->blocksize;
1933 
1934 		tmp_blocksize = bs_multiple * be_lun->blocksize;
1935 
1936 		if (tmp_blocksize == params->blocksize_bytes) {
1937 			be_lun->blocksize = params->blocksize_bytes;
1938 		} else {
1939 			snprintf(req->error_str, sizeof(req->error_str),
1940 				 "requested blocksize %u is not an even "
1941 				 "multiple of backing device blocksize %u",
1942 				 params->blocksize_bytes,
1943 				 be_lun->blocksize);
1944 			return (EINVAL);
1945 
1946 		}
1947 	} else if ((params->blocksize_bytes != 0)
1948 		&& (params->blocksize_bytes != be_lun->blocksize)) {
1949 		snprintf(req->error_str, sizeof(req->error_str),
1950 			 "requested blocksize %u < backing device "
1951 			 "blocksize %u", params->blocksize_bytes,
1952 			 be_lun->blocksize);
1953 		return (EINVAL);
1954 	}
1955 
1956 	error = devsw->d_ioctl(dev, DIOCGMEDIASIZE,
1957 			       (caddr_t)&be_lun->size_bytes, FREAD,
1958 			       curthread);
1959 	if (error) {
1960 		snprintf(req->error_str, sizeof(req->error_str),
1961 			 "error %d returned for DIOCGMEDIASIZE "
1962 			 " ioctl on %s!", error,
1963 			 be_lun->dev_path);
1964 		return (error);
1965 	}
1966 
1967 	if (params->lun_size_bytes != 0) {
1968 		if (params->lun_size_bytes > be_lun->size_bytes) {
1969 			snprintf(req->error_str, sizeof(req->error_str),
1970 				 "requested LUN size %ju > backing device "
1971 				 "size %ju",
1972 				 (uintmax_t)params->lun_size_bytes,
1973 				 (uintmax_t)be_lun->size_bytes);
1974 			return (EINVAL);
1975 		}
1976 
1977 		be_lun->size_bytes = params->lun_size_bytes;
1978 	}
1979 
1980 	error = devsw->d_ioctl(dev, DIOCGSTRIPESIZE,
1981 			       (caddr_t)&ps, FREAD, curthread);
1982 	if (error)
1983 		ps = po = 0;
1984 	else {
1985 		error = devsw->d_ioctl(dev, DIOCGSTRIPEOFFSET,
1986 				       (caddr_t)&po, FREAD, curthread);
1987 		if (error)
1988 			po = 0;
1989 	}
1990 	us = ps;
1991 	uo = po;
1992 
1993 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "pblocksize");
1994 	if (value != NULL)
1995 		ctl_expand_number(value, &ps);
1996 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "pblockoffset");
1997 	if (value != NULL)
1998 		ctl_expand_number(value, &po);
1999 	pss = ps / be_lun->blocksize;
2000 	pos = po / be_lun->blocksize;
2001 	if ((pss > 0) && (pss * be_lun->blocksize == ps) && (pss >= pos) &&
2002 	    ((pss & (pss - 1)) == 0) && (pos * be_lun->blocksize == po)) {
2003 		be_lun->pblockexp = fls(pss) - 1;
2004 		be_lun->pblockoff = (pss - pos) % pss;
2005 	}
2006 
2007 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "ublocksize");
2008 	if (value != NULL)
2009 		ctl_expand_number(value, &us);
2010 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "ublockoffset");
2011 	if (value != NULL)
2012 		ctl_expand_number(value, &uo);
2013 	uss = us / be_lun->blocksize;
2014 	uos = uo / be_lun->blocksize;
2015 	if ((uss > 0) && (uss * be_lun->blocksize == us) && (uss >= uos) &&
2016 	    ((uss & (uss - 1)) == 0) && (uos * be_lun->blocksize == uo)) {
2017 		be_lun->ublockexp = fls(uss) - 1;
2018 		be_lun->ublockoff = (uss - uos) % uss;
2019 	}
2020 
2021 	be_lun->atomicblock = atomic / be_lun->blocksize;
2022 	be_lun->opttxferlen = maxio / be_lun->blocksize;
2023 
2024 	if (be_lun->dispatch == ctl_be_block_dispatch_zvol) {
2025 		unmap = 1;
2026 	} else {
2027 		struct diocgattr_arg	arg;
2028 
2029 		strlcpy(arg.name, "GEOM::candelete", sizeof(arg.name));
2030 		arg.len = sizeof(arg.value.i);
2031 		error = devsw->d_ioctl(dev, DIOCGATTR,
2032 		    (caddr_t)&arg, FREAD, curthread);
2033 		unmap = (error == 0) ? arg.value.i : 0;
2034 	}
2035 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "unmap");
2036 	if (value != NULL)
2037 		unmap = (strcmp(value, "on") == 0);
2038 	if (unmap)
2039 		be_lun->unmap = ctl_be_block_unmap_dev;
2040 
2041 	return (0);
2042 }
2043 
2044 static int
2045 ctl_be_block_close(struct ctl_be_block_lun *be_lun)
2046 {
2047 	DROP_GIANT();
2048 	if (be_lun->vn) {
2049 		int flags = FREAD | FWRITE;
2050 
2051 		switch (be_lun->dev_type) {
2052 		case CTL_BE_BLOCK_DEV:
2053 			if (be_lun->backend.dev.csw) {
2054 				dev_relthread(be_lun->backend.dev.cdev,
2055 					      be_lun->backend.dev.dev_ref);
2056 				be_lun->backend.dev.csw  = NULL;
2057 				be_lun->backend.dev.cdev = NULL;
2058 			}
2059 			break;
2060 		case CTL_BE_BLOCK_FILE:
2061 			break;
2062 		case CTL_BE_BLOCK_NONE:
2063 			break;
2064 		default:
2065 			panic("Unexpected backend type.");
2066 			break;
2067 		}
2068 
2069 		(void)vn_close(be_lun->vn, flags, NOCRED, curthread);
2070 		be_lun->vn = NULL;
2071 
2072 		switch (be_lun->dev_type) {
2073 		case CTL_BE_BLOCK_DEV:
2074 			break;
2075 		case CTL_BE_BLOCK_FILE:
2076 			if (be_lun->backend.file.cred != NULL) {
2077 				crfree(be_lun->backend.file.cred);
2078 				be_lun->backend.file.cred = NULL;
2079 			}
2080 			break;
2081 		case CTL_BE_BLOCK_NONE:
2082 			break;
2083 		default:
2084 			panic("Unexpected backend type.");
2085 			break;
2086 		}
2087 		be_lun->dev_type = CTL_BE_BLOCK_NONE;
2088 	}
2089 	PICKUP_GIANT();
2090 
2091 	return (0);
2092 }
2093 
2094 static int
2095 ctl_be_block_open(struct ctl_be_block_softc *softc,
2096 		       struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
2097 {
2098 	struct nameidata nd;
2099 	int		 flags;
2100 	int		 error;
2101 
2102 	/*
2103 	 * XXX KDM allow a read-only option?
2104 	 */
2105 	flags = FREAD | FWRITE;
2106 	error = 0;
2107 
2108 	if (rootvnode == NULL) {
2109 		snprintf(req->error_str, sizeof(req->error_str),
2110 			 "Root filesystem is not mounted");
2111 		return (1);
2112 	}
2113 
2114 	pwd_ensure_dirs();
2115 
2116  again:
2117 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, be_lun->dev_path, curthread);
2118 	error = vn_open(&nd, &flags, 0, NULL);
2119 	if (error) {
2120 		/*
2121 		 * This is the only reasonable guess we can make as far as
2122 		 * path if the user doesn't give us a fully qualified path.
2123 		 * If they want to specify a file, they need to specify the
2124 		 * full path.
2125 		 */
2126 		if (be_lun->dev_path[0] != '/') {
2127 			char *dev_path = "/dev/";
2128 			char *dev_name;
2129 
2130 			/* Try adding device path at beginning of name */
2131 			dev_name = malloc(strlen(be_lun->dev_path)
2132 					+ strlen(dev_path) + 1,
2133 					  M_CTLBLK, M_WAITOK);
2134 			if (dev_name) {
2135 				sprintf(dev_name, "%s%s", dev_path,
2136 					be_lun->dev_path);
2137 				free(be_lun->dev_path, M_CTLBLK);
2138 				be_lun->dev_path = dev_name;
2139 				goto again;
2140 			}
2141 		}
2142 		snprintf(req->error_str, sizeof(req->error_str),
2143 		    "error opening %s: %d", be_lun->dev_path, error);
2144 		return (error);
2145 	}
2146 
2147 	NDFREE(&nd, NDF_ONLY_PNBUF);
2148 
2149 	be_lun->vn = nd.ni_vp;
2150 
2151 	/* We only support disks and files. */
2152 	if (vn_isdisk(be_lun->vn, &error)) {
2153 		error = ctl_be_block_open_dev(be_lun, req);
2154 	} else if (be_lun->vn->v_type == VREG) {
2155 		error = ctl_be_block_open_file(be_lun, req);
2156 	} else {
2157 		error = EINVAL;
2158 		snprintf(req->error_str, sizeof(req->error_str),
2159 			 "%s is not a disk or plain file", be_lun->dev_path);
2160 	}
2161 	VOP_UNLOCK(be_lun->vn, 0);
2162 
2163 	if (error != 0) {
2164 		ctl_be_block_close(be_lun);
2165 		return (error);
2166 	}
2167 
2168 	be_lun->blocksize_shift = fls(be_lun->blocksize) - 1;
2169 	be_lun->size_blocks = be_lun->size_bytes >> be_lun->blocksize_shift;
2170 
2171 	return (0);
2172 }
2173 
2174 static int
2175 ctl_be_block_create(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2176 {
2177 	struct ctl_be_block_lun *be_lun;
2178 	struct ctl_lun_create_params *params;
2179 	char num_thread_str[16];
2180 	char tmpstr[32];
2181 	char *value;
2182 	int retval, num_threads;
2183 	int tmp_num_threads;
2184 
2185 	params = &req->reqdata.create;
2186 	retval = 0;
2187 	req->status = CTL_LUN_OK;
2188 
2189 	num_threads = cbb_num_threads;
2190 
2191 	be_lun = malloc(sizeof(*be_lun), M_CTLBLK, M_ZERO | M_WAITOK);
2192 
2193 	be_lun->params = req->reqdata.create;
2194 	be_lun->softc = softc;
2195 	STAILQ_INIT(&be_lun->input_queue);
2196 	STAILQ_INIT(&be_lun->config_read_queue);
2197 	STAILQ_INIT(&be_lun->config_write_queue);
2198 	STAILQ_INIT(&be_lun->datamove_queue);
2199 	sprintf(be_lun->lunname, "cblk%d", softc->num_luns);
2200 	mtx_init(&be_lun->io_lock, "cblk io lock", NULL, MTX_DEF);
2201 	mtx_init(&be_lun->queue_lock, "cblk queue lock", NULL, MTX_DEF);
2202 	ctl_init_opts(&be_lun->ctl_be_lun.options,
2203 	    req->num_be_args, req->kern_be_args);
2204 
2205 	be_lun->lun_zone = uma_zcreate(be_lun->lunname, CTLBLK_MAX_SEG,
2206 	    NULL, NULL, NULL, NULL, /*align*/ 0, /*flags*/0);
2207 
2208 	if (be_lun->lun_zone == NULL) {
2209 		snprintf(req->error_str, sizeof(req->error_str),
2210 			 "error allocating UMA zone");
2211 		goto bailout_error;
2212 	}
2213 
2214 	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
2215 		be_lun->ctl_be_lun.lun_type = params->device_type;
2216 	else
2217 		be_lun->ctl_be_lun.lun_type = T_DIRECT;
2218 
2219 	if (be_lun->ctl_be_lun.lun_type == T_DIRECT) {
2220 		value = ctl_get_opt(&be_lun->ctl_be_lun.options, "file");
2221 		if (value == NULL) {
2222 			snprintf(req->error_str, sizeof(req->error_str),
2223 				 "no file argument specified");
2224 			goto bailout_error;
2225 		}
2226 		be_lun->dev_path = strdup(value, M_CTLBLK);
2227 		be_lun->blocksize = 512;
2228 		be_lun->blocksize_shift = fls(be_lun->blocksize) - 1;
2229 
2230 		retval = ctl_be_block_open(softc, be_lun, req);
2231 		if (retval != 0) {
2232 			retval = 0;
2233 			req->status = CTL_LUN_WARNING;
2234 		}
2235 	} else {
2236 		/*
2237 		 * For processor devices, we don't have any size.
2238 		 */
2239 		be_lun->blocksize = 0;
2240 		be_lun->pblockexp = 0;
2241 		be_lun->pblockoff = 0;
2242 		be_lun->ublockexp = 0;
2243 		be_lun->ublockoff = 0;
2244 		be_lun->size_blocks = 0;
2245 		be_lun->size_bytes = 0;
2246 		be_lun->ctl_be_lun.maxlba = 0;
2247 
2248 		/*
2249 		 * Default to just 1 thread for processor devices.
2250 		 */
2251 		num_threads = 1;
2252 	}
2253 
2254 	/*
2255 	 * XXX This searching loop might be refactored to be combined with
2256 	 * the loop above,
2257 	 */
2258 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "num_threads");
2259 	if (value != NULL) {
2260 		tmp_num_threads = strtol(value, NULL, 0);
2261 
2262 		/*
2263 		 * We don't let the user specify less than one
2264 		 * thread, but hope he's clueful enough not to
2265 		 * specify 1000 threads.
2266 		 */
2267 		if (tmp_num_threads < 1) {
2268 			snprintf(req->error_str, sizeof(req->error_str),
2269 				 "invalid number of threads %s",
2270 				 num_thread_str);
2271 			goto bailout_error;
2272 		}
2273 		num_threads = tmp_num_threads;
2274 	}
2275 
2276 	be_lun->flags = CTL_BE_BLOCK_LUN_UNCONFIGURED;
2277 	be_lun->ctl_be_lun.flags = CTL_LUN_FLAG_PRIMARY;
2278 	if (be_lun->vn == NULL)
2279 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_OFFLINE;
2280 	if (be_lun->unmap != NULL)
2281 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_UNMAP;
2282 	if (be_lun->dispatch != ctl_be_block_dispatch_dev)
2283 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_SERSEQ_READ;
2284 	be_lun->ctl_be_lun.be_lun = be_lun;
2285 	be_lun->ctl_be_lun.maxlba = (be_lun->size_blocks == 0) ?
2286 	    0 : (be_lun->size_blocks - 1);
2287 	be_lun->ctl_be_lun.blocksize = be_lun->blocksize;
2288 	be_lun->ctl_be_lun.pblockexp = be_lun->pblockexp;
2289 	be_lun->ctl_be_lun.pblockoff = be_lun->pblockoff;
2290 	be_lun->ctl_be_lun.ublockexp = be_lun->ublockexp;
2291 	be_lun->ctl_be_lun.ublockoff = be_lun->ublockoff;
2292 	be_lun->ctl_be_lun.atomicblock = be_lun->atomicblock;
2293 	be_lun->ctl_be_lun.opttxferlen = be_lun->opttxferlen;
2294 	/* Tell the user the blocksize we ended up using */
2295 	params->lun_size_bytes = be_lun->size_bytes;
2296 	params->blocksize_bytes = be_lun->blocksize;
2297 	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
2298 		be_lun->ctl_be_lun.req_lun_id = params->req_lun_id;
2299 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_ID_REQ;
2300 	} else
2301 		be_lun->ctl_be_lun.req_lun_id = 0;
2302 
2303 	be_lun->ctl_be_lun.lun_shutdown = ctl_be_block_lun_shutdown;
2304 	be_lun->ctl_be_lun.lun_config_status =
2305 		ctl_be_block_lun_config_status;
2306 	be_lun->ctl_be_lun.be = &ctl_be_block_driver;
2307 
2308 	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
2309 		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
2310 			 softc->num_luns);
2311 		strncpy((char *)be_lun->ctl_be_lun.serial_num, tmpstr,
2312 			MIN(sizeof(be_lun->ctl_be_lun.serial_num),
2313 			sizeof(tmpstr)));
2314 
2315 		/* Tell the user what we used for a serial number */
2316 		strncpy((char *)params->serial_num, tmpstr,
2317 			MIN(sizeof(params->serial_num), sizeof(tmpstr)));
2318 	} else {
2319 		strncpy((char *)be_lun->ctl_be_lun.serial_num,
2320 			params->serial_num,
2321 			MIN(sizeof(be_lun->ctl_be_lun.serial_num),
2322 			sizeof(params->serial_num)));
2323 	}
2324 	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
2325 		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
2326 		strncpy((char *)be_lun->ctl_be_lun.device_id, tmpstr,
2327 			MIN(sizeof(be_lun->ctl_be_lun.device_id),
2328 			sizeof(tmpstr)));
2329 
2330 		/* Tell the user what we used for a device ID */
2331 		strncpy((char *)params->device_id, tmpstr,
2332 			MIN(sizeof(params->device_id), sizeof(tmpstr)));
2333 	} else {
2334 		strncpy((char *)be_lun->ctl_be_lun.device_id,
2335 			params->device_id,
2336 			MIN(sizeof(be_lun->ctl_be_lun.device_id),
2337 			    sizeof(params->device_id)));
2338 	}
2339 
2340 	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_be_block_worker, be_lun);
2341 
2342 	be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
2343 	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
2344 
2345 	if (be_lun->io_taskqueue == NULL) {
2346 		snprintf(req->error_str, sizeof(req->error_str),
2347 			 "unable to create taskqueue");
2348 		goto bailout_error;
2349 	}
2350 
2351 	/*
2352 	 * Note that we start the same number of threads by default for
2353 	 * both the file case and the block device case.  For the file
2354 	 * case, we need multiple threads to allow concurrency, because the
2355 	 * vnode interface is designed to be a blocking interface.  For the
2356 	 * block device case, ZFS zvols at least will block the caller's
2357 	 * context in many instances, and so we need multiple threads to
2358 	 * overcome that problem.  Other block devices don't need as many
2359 	 * threads, but they shouldn't cause too many problems.
2360 	 *
2361 	 * If the user wants to just have a single thread for a block
2362 	 * device, he can specify that when the LUN is created, or change
2363 	 * the tunable/sysctl to alter the default number of threads.
2364 	 */
2365 	retval = taskqueue_start_threads(&be_lun->io_taskqueue,
2366 					 /*num threads*/num_threads,
2367 					 /*priority*/PWAIT,
2368 					 /*thread name*/
2369 					 "%s taskq", be_lun->lunname);
2370 
2371 	if (retval != 0)
2372 		goto bailout_error;
2373 
2374 	be_lun->num_threads = num_threads;
2375 
2376 	mtx_lock(&softc->lock);
2377 	softc->num_luns++;
2378 	STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
2379 
2380 	mtx_unlock(&softc->lock);
2381 
2382 	retval = ctl_add_lun(&be_lun->ctl_be_lun);
2383 	if (retval != 0) {
2384 		mtx_lock(&softc->lock);
2385 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2386 			      links);
2387 		softc->num_luns--;
2388 		mtx_unlock(&softc->lock);
2389 		snprintf(req->error_str, sizeof(req->error_str),
2390 			 "ctl_add_lun() returned error %d, see dmesg for "
2391 			 "details", retval);
2392 		retval = 0;
2393 		goto bailout_error;
2394 	}
2395 
2396 	mtx_lock(&softc->lock);
2397 
2398 	/*
2399 	 * Tell the config_status routine that we're waiting so it won't
2400 	 * clean up the LUN in the event of an error.
2401 	 */
2402 	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2403 
2404 	while (be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) {
2405 		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2406 		if (retval == EINTR)
2407 			break;
2408 	}
2409 	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2410 
2411 	if (be_lun->flags & CTL_BE_BLOCK_LUN_CONFIG_ERR) {
2412 		snprintf(req->error_str, sizeof(req->error_str),
2413 			 "LUN configuration error, see dmesg for details");
2414 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2415 			      links);
2416 		softc->num_luns--;
2417 		mtx_unlock(&softc->lock);
2418 		goto bailout_error;
2419 	} else {
2420 		params->req_lun_id = be_lun->ctl_be_lun.lun_id;
2421 	}
2422 
2423 	mtx_unlock(&softc->lock);
2424 
2425 	be_lun->disk_stats = devstat_new_entry("cbb", params->req_lun_id,
2426 					       be_lun->blocksize,
2427 					       DEVSTAT_ALL_SUPPORTED,
2428 					       be_lun->ctl_be_lun.lun_type
2429 					       | DEVSTAT_TYPE_IF_OTHER,
2430 					       DEVSTAT_PRIORITY_OTHER);
2431 
2432 	return (retval);
2433 
2434 bailout_error:
2435 	req->status = CTL_LUN_ERROR;
2436 
2437 	if (be_lun->io_taskqueue != NULL)
2438 		taskqueue_free(be_lun->io_taskqueue);
2439 	ctl_be_block_close(be_lun);
2440 	if (be_lun->dev_path != NULL)
2441 		free(be_lun->dev_path, M_CTLBLK);
2442 	if (be_lun->lun_zone != NULL)
2443 		uma_zdestroy(be_lun->lun_zone);
2444 	ctl_free_opts(&be_lun->ctl_be_lun.options);
2445 	mtx_destroy(&be_lun->queue_lock);
2446 	mtx_destroy(&be_lun->io_lock);
2447 	free(be_lun, M_CTLBLK);
2448 
2449 	return (retval);
2450 }
2451 
2452 static int
2453 ctl_be_block_rm(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2454 {
2455 	struct ctl_lun_rm_params *params;
2456 	struct ctl_be_block_lun *be_lun;
2457 	int retval;
2458 
2459 	params = &req->reqdata.rm;
2460 
2461 	mtx_lock(&softc->lock);
2462 
2463 	be_lun = NULL;
2464 
2465 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2466 		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2467 			break;
2468 	}
2469 	mtx_unlock(&softc->lock);
2470 
2471 	if (be_lun == NULL) {
2472 		snprintf(req->error_str, sizeof(req->error_str),
2473 			 "LUN %u is not managed by the block backend",
2474 			 params->lun_id);
2475 		goto bailout_error;
2476 	}
2477 
2478 	retval = ctl_disable_lun(&be_lun->ctl_be_lun);
2479 
2480 	if (retval != 0) {
2481 		snprintf(req->error_str, sizeof(req->error_str),
2482 			 "error %d returned from ctl_disable_lun() for "
2483 			 "LUN %d", retval, params->lun_id);
2484 		goto bailout_error;
2485 
2486 	}
2487 
2488 	retval = ctl_invalidate_lun(&be_lun->ctl_be_lun);
2489 	if (retval != 0) {
2490 		snprintf(req->error_str, sizeof(req->error_str),
2491 			 "error %d returned from ctl_invalidate_lun() for "
2492 			 "LUN %d", retval, params->lun_id);
2493 		goto bailout_error;
2494 	}
2495 
2496 	mtx_lock(&softc->lock);
2497 
2498 	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2499 
2500 	while ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2501                 retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2502                 if (retval == EINTR)
2503                         break;
2504         }
2505 
2506 	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2507 
2508 	if ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2509 		snprintf(req->error_str, sizeof(req->error_str),
2510 			 "interrupted waiting for LUN to be freed");
2511 		mtx_unlock(&softc->lock);
2512 		goto bailout_error;
2513 	}
2514 
2515 	STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun, links);
2516 
2517 	softc->num_luns--;
2518 	mtx_unlock(&softc->lock);
2519 
2520 	taskqueue_drain(be_lun->io_taskqueue, &be_lun->io_task);
2521 
2522 	taskqueue_free(be_lun->io_taskqueue);
2523 
2524 	ctl_be_block_close(be_lun);
2525 
2526 	if (be_lun->disk_stats != NULL)
2527 		devstat_remove_entry(be_lun->disk_stats);
2528 
2529 	uma_zdestroy(be_lun->lun_zone);
2530 
2531 	ctl_free_opts(&be_lun->ctl_be_lun.options);
2532 	free(be_lun->dev_path, M_CTLBLK);
2533 	mtx_destroy(&be_lun->queue_lock);
2534 	mtx_destroy(&be_lun->io_lock);
2535 	free(be_lun, M_CTLBLK);
2536 
2537 	req->status = CTL_LUN_OK;
2538 
2539 	return (0);
2540 
2541 bailout_error:
2542 
2543 	req->status = CTL_LUN_ERROR;
2544 
2545 	return (0);
2546 }
2547 
2548 static int
2549 ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
2550 			 struct ctl_lun_req *req)
2551 {
2552 	struct vattr vattr;
2553 	int error;
2554 	struct ctl_lun_create_params *params = &be_lun->params;
2555 
2556 	if (params->lun_size_bytes != 0) {
2557 		be_lun->size_bytes = params->lun_size_bytes;
2558 	} else  {
2559 		vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
2560 		error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
2561 		VOP_UNLOCK(be_lun->vn, 0);
2562 		if (error != 0) {
2563 			snprintf(req->error_str, sizeof(req->error_str),
2564 				 "error calling VOP_GETATTR() for file %s",
2565 				 be_lun->dev_path);
2566 			return (error);
2567 		}
2568 
2569 		be_lun->size_bytes = vattr.va_size;
2570 	}
2571 
2572 	return (0);
2573 }
2574 
2575 static int
2576 ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
2577 			struct ctl_lun_req *req)
2578 {
2579 	struct ctl_be_block_devdata *dev_data;
2580 	int error;
2581 	struct ctl_lun_create_params *params = &be_lun->params;
2582 	uint64_t size_bytes;
2583 
2584 	dev_data = &be_lun->backend.dev;
2585 	if (!dev_data->csw->d_ioctl) {
2586 		snprintf(req->error_str, sizeof(req->error_str),
2587 			 "no d_ioctl for device %s!", be_lun->dev_path);
2588 		return (ENODEV);
2589 	}
2590 
2591 	error = dev_data->csw->d_ioctl(dev_data->cdev, DIOCGMEDIASIZE,
2592 			       (caddr_t)&size_bytes, FREAD,
2593 			       curthread);
2594 	if (error) {
2595 		snprintf(req->error_str, sizeof(req->error_str),
2596 			 "error %d returned for DIOCGMEDIASIZE ioctl "
2597 			 "on %s!", error, be_lun->dev_path);
2598 		return (error);
2599 	}
2600 
2601 	if (params->lun_size_bytes != 0) {
2602 		if (params->lun_size_bytes > size_bytes) {
2603 			snprintf(req->error_str, sizeof(req->error_str),
2604 				 "requested LUN size %ju > backing device "
2605 				 "size %ju",
2606 				 (uintmax_t)params->lun_size_bytes,
2607 				 (uintmax_t)size_bytes);
2608 			return (EINVAL);
2609 		}
2610 
2611 		be_lun->size_bytes = params->lun_size_bytes;
2612 	} else {
2613 		be_lun->size_bytes = size_bytes;
2614 	}
2615 
2616 	return (0);
2617 }
2618 
2619 static int
2620 ctl_be_block_modify(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2621 {
2622 	struct ctl_lun_modify_params *params;
2623 	struct ctl_be_block_lun *be_lun;
2624 	uint64_t oldsize;
2625 	int error;
2626 
2627 	params = &req->reqdata.modify;
2628 
2629 	mtx_lock(&softc->lock);
2630 	be_lun = NULL;
2631 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2632 		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2633 			break;
2634 	}
2635 	mtx_unlock(&softc->lock);
2636 
2637 	if (be_lun == NULL) {
2638 		snprintf(req->error_str, sizeof(req->error_str),
2639 			 "LUN %u is not managed by the block backend",
2640 			 params->lun_id);
2641 		goto bailout_error;
2642 	}
2643 
2644 	be_lun->params.lun_size_bytes = params->lun_size_bytes;
2645 
2646 	oldsize = be_lun->size_bytes;
2647 	if (be_lun->vn == NULL)
2648 		error = ctl_be_block_open(softc, be_lun, req);
2649 	else if (vn_isdisk(be_lun->vn, &error))
2650 		error = ctl_be_block_modify_dev(be_lun, req);
2651 	else if (be_lun->vn->v_type == VREG)
2652 		error = ctl_be_block_modify_file(be_lun, req);
2653 	else
2654 		error = EINVAL;
2655 
2656 	if (error == 0 && be_lun->size_bytes != oldsize) {
2657 		be_lun->size_blocks = be_lun->size_bytes >>
2658 		    be_lun->blocksize_shift;
2659 
2660 		/*
2661 		 * The maximum LBA is the size - 1.
2662 		 *
2663 		 * XXX: Note that this field is being updated without locking,
2664 		 * 	which might cause problems on 32-bit architectures.
2665 		 */
2666 		if (be_lun->unmap != NULL)
2667 			be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_UNMAP;
2668 		be_lun->ctl_be_lun.maxlba = (be_lun->size_blocks == 0) ?
2669 		    0 : (be_lun->size_blocks - 1);
2670 		be_lun->ctl_be_lun.blocksize = be_lun->blocksize;
2671 		be_lun->ctl_be_lun.pblockexp = be_lun->pblockexp;
2672 		be_lun->ctl_be_lun.pblockoff = be_lun->pblockoff;
2673 		be_lun->ctl_be_lun.ublockexp = be_lun->ublockexp;
2674 		be_lun->ctl_be_lun.ublockoff = be_lun->ublockoff;
2675 		be_lun->ctl_be_lun.atomicblock = be_lun->atomicblock;
2676 		be_lun->ctl_be_lun.opttxferlen = be_lun->opttxferlen;
2677 		ctl_lun_capacity_changed(&be_lun->ctl_be_lun);
2678 		if (oldsize == 0 && be_lun->size_blocks != 0)
2679 			ctl_lun_online(&be_lun->ctl_be_lun);
2680 	}
2681 
2682 	/* Tell the user the exact size we ended up using */
2683 	params->lun_size_bytes = be_lun->size_bytes;
2684 
2685 	req->status = error ? CTL_LUN_WARNING : CTL_LUN_OK;
2686 
2687 	return (0);
2688 
2689 bailout_error:
2690 	req->status = CTL_LUN_ERROR;
2691 
2692 	return (0);
2693 }
2694 
2695 static void
2696 ctl_be_block_lun_shutdown(void *be_lun)
2697 {
2698 	struct ctl_be_block_lun *lun;
2699 	struct ctl_be_block_softc *softc;
2700 
2701 	lun = (struct ctl_be_block_lun *)be_lun;
2702 
2703 	softc = lun->softc;
2704 
2705 	mtx_lock(&softc->lock);
2706 	lun->flags |= CTL_BE_BLOCK_LUN_UNCONFIGURED;
2707 	if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2708 		wakeup(lun);
2709 	mtx_unlock(&softc->lock);
2710 
2711 }
2712 
2713 static void
2714 ctl_be_block_lun_config_status(void *be_lun, ctl_lun_config_status status)
2715 {
2716 	struct ctl_be_block_lun *lun;
2717 	struct ctl_be_block_softc *softc;
2718 
2719 	lun = (struct ctl_be_block_lun *)be_lun;
2720 	softc = lun->softc;
2721 
2722 	if (status == CTL_LUN_CONFIG_OK) {
2723 		mtx_lock(&softc->lock);
2724 		lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2725 		if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2726 			wakeup(lun);
2727 		mtx_unlock(&softc->lock);
2728 
2729 		/*
2730 		 * We successfully added the LUN, attempt to enable it.
2731 		 */
2732 		if (ctl_enable_lun(&lun->ctl_be_lun) != 0) {
2733 			printf("%s: ctl_enable_lun() failed!\n", __func__);
2734 			if (ctl_invalidate_lun(&lun->ctl_be_lun) != 0) {
2735 				printf("%s: ctl_invalidate_lun() failed!\n",
2736 				       __func__);
2737 			}
2738 		}
2739 
2740 		return;
2741 	}
2742 
2743 
2744 	mtx_lock(&softc->lock);
2745 	lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2746 	lun->flags |= CTL_BE_BLOCK_LUN_CONFIG_ERR;
2747 	wakeup(lun);
2748 	mtx_unlock(&softc->lock);
2749 }
2750 
2751 
2752 static int
2753 ctl_be_block_config_write(union ctl_io *io)
2754 {
2755 	struct ctl_be_block_lun *be_lun;
2756 	struct ctl_be_lun *ctl_be_lun;
2757 	int retval;
2758 
2759 	retval = 0;
2760 
2761 	DPRINTF("entered\n");
2762 
2763 	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
2764 		CTL_PRIV_BACKEND_LUN].ptr;
2765 	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
2766 
2767 	switch (io->scsiio.cdb[0]) {
2768 	case SYNCHRONIZE_CACHE:
2769 	case SYNCHRONIZE_CACHE_16:
2770 	case WRITE_SAME_10:
2771 	case WRITE_SAME_16:
2772 	case UNMAP:
2773 		/*
2774 		 * The upper level CTL code will filter out any CDBs with
2775 		 * the immediate bit set and return the proper error.
2776 		 *
2777 		 * We don't really need to worry about what LBA range the
2778 		 * user asked to be synced out.  When they issue a sync
2779 		 * cache command, we'll sync out the whole thing.
2780 		 */
2781 		mtx_lock(&be_lun->queue_lock);
2782 		STAILQ_INSERT_TAIL(&be_lun->config_write_queue, &io->io_hdr,
2783 				   links);
2784 		mtx_unlock(&be_lun->queue_lock);
2785 		taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
2786 		break;
2787 	case START_STOP_UNIT: {
2788 		struct scsi_start_stop_unit *cdb;
2789 
2790 		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
2791 
2792 		if (cdb->how & SSS_START)
2793 			retval = ctl_start_lun(ctl_be_lun);
2794 		else {
2795 			retval = ctl_stop_lun(ctl_be_lun);
2796 			/*
2797 			 * XXX KDM Copan-specific offline behavior.
2798 			 * Figure out a reasonable way to port this?
2799 			 */
2800 #ifdef NEEDTOPORT
2801 			if ((retval == 0)
2802 			 && (cdb->byte2 & SSS_ONOFFLINE))
2803 				retval = ctl_lun_offline(ctl_be_lun);
2804 #endif
2805 		}
2806 
2807 		/*
2808 		 * In general, the above routines should not fail.  They
2809 		 * just set state for the LUN.  So we've got something
2810 		 * pretty wrong here if we can't start or stop the LUN.
2811 		 */
2812 		if (retval != 0) {
2813 			ctl_set_internal_failure(&io->scsiio,
2814 						 /*sks_valid*/ 1,
2815 						 /*retry_count*/ 0xf051);
2816 			retval = CTL_RETVAL_COMPLETE;
2817 		} else {
2818 			ctl_set_success(&io->scsiio);
2819 		}
2820 		ctl_config_write_done(io);
2821 		break;
2822 	}
2823 	default:
2824 		ctl_set_invalid_opcode(&io->scsiio);
2825 		ctl_config_write_done(io);
2826 		retval = CTL_RETVAL_COMPLETE;
2827 		break;
2828 	}
2829 
2830 	return (retval);
2831 }
2832 
2833 static int
2834 ctl_be_block_config_read(union ctl_io *io)
2835 {
2836 	struct ctl_be_block_lun *be_lun;
2837 	struct ctl_be_lun *ctl_be_lun;
2838 	int retval = 0;
2839 
2840 	DPRINTF("entered\n");
2841 
2842 	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
2843 		CTL_PRIV_BACKEND_LUN].ptr;
2844 	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
2845 
2846 	switch (io->scsiio.cdb[0]) {
2847 	case SERVICE_ACTION_IN:
2848 		if (io->scsiio.cdb[1] == SGLS_SERVICE_ACTION) {
2849 			mtx_lock(&be_lun->queue_lock);
2850 			STAILQ_INSERT_TAIL(&be_lun->config_read_queue,
2851 			    &io->io_hdr, links);
2852 			mtx_unlock(&be_lun->queue_lock);
2853 			taskqueue_enqueue(be_lun->io_taskqueue,
2854 			    &be_lun->io_task);
2855 			retval = CTL_RETVAL_QUEUED;
2856 			break;
2857 		}
2858 		ctl_set_invalid_field(&io->scsiio,
2859 				      /*sks_valid*/ 1,
2860 				      /*command*/ 1,
2861 				      /*field*/ 1,
2862 				      /*bit_valid*/ 1,
2863 				      /*bit*/ 4);
2864 		ctl_config_read_done(io);
2865 		retval = CTL_RETVAL_COMPLETE;
2866 		break;
2867 	default:
2868 		ctl_set_invalid_opcode(&io->scsiio);
2869 		ctl_config_read_done(io);
2870 		retval = CTL_RETVAL_COMPLETE;
2871 		break;
2872 	}
2873 
2874 	return (retval);
2875 }
2876 
2877 static int
2878 ctl_be_block_lun_info(void *be_lun, struct sbuf *sb)
2879 {
2880 	struct ctl_be_block_lun *lun;
2881 	int retval;
2882 
2883 	lun = (struct ctl_be_block_lun *)be_lun;
2884 	retval = 0;
2885 
2886 	retval = sbuf_printf(sb, "\t<num_threads>");
2887 
2888 	if (retval != 0)
2889 		goto bailout;
2890 
2891 	retval = sbuf_printf(sb, "%d", lun->num_threads);
2892 
2893 	if (retval != 0)
2894 		goto bailout;
2895 
2896 	retval = sbuf_printf(sb, "</num_threads>\n");
2897 
2898 bailout:
2899 
2900 	return (retval);
2901 }
2902 
2903 static uint64_t
2904 ctl_be_block_lun_attr(void *be_lun, const char *attrname)
2905 {
2906 	struct ctl_be_block_lun *lun = (struct ctl_be_block_lun *)be_lun;
2907 
2908 	if (lun->getattr == NULL)
2909 		return (UINT64_MAX);
2910 	return (lun->getattr(lun, attrname));
2911 }
2912 
2913 int
2914 ctl_be_block_init(void)
2915 {
2916 	struct ctl_be_block_softc *softc;
2917 	int retval;
2918 
2919 	softc = &backend_block_softc;
2920 	retval = 0;
2921 
2922 	mtx_init(&softc->lock, "ctlblock", NULL, MTX_DEF);
2923 	beio_zone = uma_zcreate("beio", sizeof(struct ctl_be_block_io),
2924 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
2925 	STAILQ_INIT(&softc->disk_list);
2926 	STAILQ_INIT(&softc->lun_list);
2927 
2928 	return (retval);
2929 }
2930