xref: /freebsd/sys/cam/ctl/ctl_backend_block.c (revision 6b129086dcee14496517fae085b448e3edc69bc7)
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/proc.h>
72 #include <sys/pcpu.h>
73 #include <sys/module.h>
74 #include <sys/sdt.h>
75 #include <sys/devicestat.h>
76 #include <sys/sysctl.h>
77 
78 #include <geom/geom.h>
79 
80 #include <cam/cam.h>
81 #include <cam/scsi/scsi_all.h>
82 #include <cam/scsi/scsi_da.h>
83 #include <cam/ctl/ctl_io.h>
84 #include <cam/ctl/ctl.h>
85 #include <cam/ctl/ctl_backend.h>
86 #include <cam/ctl/ctl_frontend_internal.h>
87 #include <cam/ctl/ctl_ioctl.h>
88 #include <cam/ctl/ctl_scsi_all.h>
89 #include <cam/ctl/ctl_error.h>
90 
91 /*
92  * The idea here is that we'll allocate enough S/G space to hold a 1MB
93  * I/O.  If we get an I/O larger than that, we'll split it.
94  */
95 #define	CTLBLK_HALF_IO_SIZE	(512 * 1024)
96 #define	CTLBLK_MAX_IO_SIZE	(CTLBLK_HALF_IO_SIZE * 2)
97 #define	CTLBLK_MAX_SEG		MAXPHYS
98 #define	CTLBLK_HALF_SEGS	MAX(CTLBLK_HALF_IO_SIZE / CTLBLK_MAX_SEG, 1)
99 #define	CTLBLK_MAX_SEGS		(CTLBLK_HALF_SEGS * 2)
100 
101 #ifdef CTLBLK_DEBUG
102 #define DPRINTF(fmt, args...) \
103     printf("cbb(%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
104 #else
105 #define DPRINTF(fmt, args...) do {} while(0)
106 #endif
107 
108 #define PRIV(io)	\
109     ((struct ctl_ptr_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_BACKEND])
110 #define ARGS(io)	\
111     ((struct ctl_lba_len_flags *)&(io)->io_hdr.ctl_private[CTL_PRIV_LBA_LEN])
112 
113 SDT_PROVIDER_DEFINE(cbb);
114 
115 typedef enum {
116 	CTL_BE_BLOCK_LUN_UNCONFIGURED	= 0x01,
117 	CTL_BE_BLOCK_LUN_CONFIG_ERR	= 0x02,
118 	CTL_BE_BLOCK_LUN_WAITING	= 0x04,
119 	CTL_BE_BLOCK_LUN_MULTI_THREAD	= 0x08
120 } ctl_be_block_lun_flags;
121 
122 typedef enum {
123 	CTL_BE_BLOCK_NONE,
124 	CTL_BE_BLOCK_DEV,
125 	CTL_BE_BLOCK_FILE
126 } ctl_be_block_type;
127 
128 struct ctl_be_block_devdata {
129 	struct cdev *cdev;
130 	struct cdevsw *csw;
131 	int dev_ref;
132 };
133 
134 struct ctl_be_block_filedata {
135 	struct ucred *cred;
136 };
137 
138 union ctl_be_block_bedata {
139 	struct ctl_be_block_devdata dev;
140 	struct ctl_be_block_filedata file;
141 };
142 
143 struct ctl_be_block_io;
144 struct ctl_be_block_lun;
145 
146 typedef void (*cbb_dispatch_t)(struct ctl_be_block_lun *be_lun,
147 			       struct ctl_be_block_io *beio);
148 typedef uint64_t (*cbb_getattr_t)(struct ctl_be_block_lun *be_lun,
149 				  const char *attrname);
150 
151 /*
152  * Backend LUN structure.  There is a 1:1 mapping between a block device
153  * and a backend block LUN, and between a backend block LUN and a CTL LUN.
154  */
155 struct ctl_be_block_lun {
156 	struct ctl_lun_create_params params;
157 	struct ctl_block_disk *disk;
158 	char lunname[32];
159 	char *dev_path;
160 	ctl_be_block_type dev_type;
161 	struct vnode *vn;
162 	union ctl_be_block_bedata backend;
163 	cbb_dispatch_t dispatch;
164 	cbb_dispatch_t lun_flush;
165 	cbb_dispatch_t unmap;
166 	cbb_getattr_t getattr;
167 	uma_zone_t lun_zone;
168 	uint64_t size_blocks;
169 	uint64_t size_bytes;
170 	uint32_t blocksize;
171 	int blocksize_shift;
172 	uint16_t pblockexp;
173 	uint16_t pblockoff;
174 	struct ctl_be_block_softc *softc;
175 	struct devstat *disk_stats;
176 	ctl_be_block_lun_flags flags;
177 	STAILQ_ENTRY(ctl_be_block_lun) links;
178 	struct ctl_be_lun ctl_be_lun;
179 	struct taskqueue *io_taskqueue;
180 	struct task io_task;
181 	int num_threads;
182 	STAILQ_HEAD(, ctl_io_hdr) input_queue;
183 	STAILQ_HEAD(, ctl_io_hdr) config_write_queue;
184 	STAILQ_HEAD(, ctl_io_hdr) datamove_queue;
185 	struct mtx_padalign io_lock;
186 	struct mtx_padalign queue_lock;
187 };
188 
189 /*
190  * Overall softc structure for the block backend module.
191  */
192 struct ctl_be_block_softc {
193 	struct mtx			 lock;
194 	int				 num_disks;
195 	STAILQ_HEAD(, ctl_block_disk)	 disk_list;
196 	int				 num_luns;
197 	STAILQ_HEAD(, ctl_be_block_lun)	 lun_list;
198 };
199 
200 static struct ctl_be_block_softc backend_block_softc;
201 
202 /*
203  * Per-I/O information.
204  */
205 struct ctl_be_block_io {
206 	union ctl_io			*io;
207 	struct ctl_sg_entry		sg_segs[CTLBLK_MAX_SEGS];
208 	struct iovec			xiovecs[CTLBLK_MAX_SEGS];
209 	int				bio_cmd;
210 	int				num_segs;
211 	int				num_bios_sent;
212 	int				num_bios_done;
213 	int				send_complete;
214 	int				num_errors;
215 	struct bintime			ds_t0;
216 	devstat_tag_type		ds_tag_type;
217 	devstat_trans_flags		ds_trans_type;
218 	uint64_t			io_len;
219 	uint64_t			io_offset;
220 	struct ctl_be_block_softc	*softc;
221 	struct ctl_be_block_lun		*lun;
222 	void (*beio_cont)(struct ctl_be_block_io *beio); /* to continue processing */
223 };
224 
225 static int cbb_num_threads = 14;
226 SYSCTL_NODE(_kern_cam_ctl, OID_AUTO, block, CTLFLAG_RD, 0,
227 	    "CAM Target Layer Block Backend");
228 SYSCTL_INT(_kern_cam_ctl_block, OID_AUTO, num_threads, CTLFLAG_RWTUN,
229            &cbb_num_threads, 0, "Number of threads per backing file");
230 
231 static struct ctl_be_block_io *ctl_alloc_beio(struct ctl_be_block_softc *softc);
232 static void ctl_free_beio(struct ctl_be_block_io *beio);
233 static void ctl_complete_beio(struct ctl_be_block_io *beio);
234 static int ctl_be_block_move_done(union ctl_io *io);
235 static void ctl_be_block_biodone(struct bio *bio);
236 static void ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
237 				    struct ctl_be_block_io *beio);
238 static void ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
239 				       struct ctl_be_block_io *beio);
240 static void ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
241 				   struct ctl_be_block_io *beio);
242 static void ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
243 				   struct ctl_be_block_io *beio);
244 static void ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
245 				      struct ctl_be_block_io *beio);
246 static uint64_t ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun,
247 					 const char *attrname);
248 static void ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
249 				    union ctl_io *io);
250 static void ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
251 				  union ctl_io *io);
252 static void ctl_be_block_worker(void *context, int pending);
253 static int ctl_be_block_submit(union ctl_io *io);
254 static int ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
255 				   int flag, struct thread *td);
256 static int ctl_be_block_open_file(struct ctl_be_block_lun *be_lun,
257 				  struct ctl_lun_req *req);
258 static int ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun,
259 				 struct ctl_lun_req *req);
260 static int ctl_be_block_close(struct ctl_be_block_lun *be_lun);
261 static int ctl_be_block_open(struct ctl_be_block_softc *softc,
262 			     struct ctl_be_block_lun *be_lun,
263 			     struct ctl_lun_req *req);
264 static int ctl_be_block_create(struct ctl_be_block_softc *softc,
265 			       struct ctl_lun_req *req);
266 static int ctl_be_block_rm(struct ctl_be_block_softc *softc,
267 			   struct ctl_lun_req *req);
268 static int ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
269 				  struct ctl_lun_req *req);
270 static int ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
271 				 struct ctl_lun_req *req);
272 static int ctl_be_block_modify(struct ctl_be_block_softc *softc,
273 			   struct ctl_lun_req *req);
274 static void ctl_be_block_lun_shutdown(void *be_lun);
275 static void ctl_be_block_lun_config_status(void *be_lun,
276 					   ctl_lun_config_status status);
277 static int ctl_be_block_config_write(union ctl_io *io);
278 static int ctl_be_block_config_read(union ctl_io *io);
279 static int ctl_be_block_lun_info(void *be_lun, struct sbuf *sb);
280 static uint64_t ctl_be_block_lun_attr(void *be_lun, const char *attrname);
281 int ctl_be_block_init(void);
282 
283 static struct ctl_backend_driver ctl_be_block_driver =
284 {
285 	.name = "block",
286 	.flags = CTL_BE_FLAG_HAS_CONFIG,
287 	.init = ctl_be_block_init,
288 	.data_submit = ctl_be_block_submit,
289 	.data_move_done = ctl_be_block_move_done,
290 	.config_read = ctl_be_block_config_read,
291 	.config_write = ctl_be_block_config_write,
292 	.ioctl = ctl_be_block_ioctl,
293 	.lun_info = ctl_be_block_lun_info,
294 	.lun_attr = ctl_be_block_lun_attr
295 };
296 
297 MALLOC_DEFINE(M_CTLBLK, "ctlblk", "Memory used for CTL block backend");
298 CTL_BACKEND_DECLARE(cbb, ctl_be_block_driver);
299 
300 static uma_zone_t beio_zone;
301 
302 static struct ctl_be_block_io *
303 ctl_alloc_beio(struct ctl_be_block_softc *softc)
304 {
305 	struct ctl_be_block_io *beio;
306 
307 	beio = uma_zalloc(beio_zone, M_WAITOK | M_ZERO);
308 	beio->softc = softc;
309 	return (beio);
310 }
311 
312 static void
313 ctl_free_beio(struct ctl_be_block_io *beio)
314 {
315 	int duplicate_free;
316 	int i;
317 
318 	duplicate_free = 0;
319 
320 	for (i = 0; i < beio->num_segs; i++) {
321 		if (beio->sg_segs[i].addr == NULL)
322 			duplicate_free++;
323 
324 		uma_zfree(beio->lun->lun_zone, beio->sg_segs[i].addr);
325 		beio->sg_segs[i].addr = NULL;
326 
327 		/* For compare we had two equal S/G lists. */
328 		if (ARGS(beio->io)->flags & CTL_LLF_COMPARE) {
329 			uma_zfree(beio->lun->lun_zone,
330 			    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr);
331 			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr = NULL;
332 		}
333 	}
334 
335 	if (duplicate_free > 0) {
336 		printf("%s: %d duplicate frees out of %d segments\n", __func__,
337 		       duplicate_free, beio->num_segs);
338 	}
339 
340 	uma_zfree(beio_zone, beio);
341 }
342 
343 static void
344 ctl_complete_beio(struct ctl_be_block_io *beio)
345 {
346 	union ctl_io *io = beio->io;
347 
348 	if (beio->beio_cont != NULL) {
349 		beio->beio_cont(beio);
350 	} else {
351 		ctl_free_beio(beio);
352 		ctl_data_submit_done(io);
353 	}
354 }
355 
356 static int
357 ctl_be_block_move_done(union ctl_io *io)
358 {
359 	struct ctl_be_block_io *beio;
360 	struct ctl_be_block_lun *be_lun;
361 	struct ctl_lba_len_flags *lbalen;
362 #ifdef CTL_TIME_IO
363 	struct bintime cur_bt;
364 #endif
365 	int i;
366 
367 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
368 	be_lun = beio->lun;
369 
370 	DPRINTF("entered\n");
371 
372 #ifdef CTL_TIME_IO
373 	getbintime(&cur_bt);
374 	bintime_sub(&cur_bt, &io->io_hdr.dma_start_bt);
375 	bintime_add(&io->io_hdr.dma_bt, &cur_bt);
376 	io->io_hdr.num_dmas++;
377 #endif
378 	io->scsiio.kern_rel_offset += io->scsiio.kern_data_len;
379 
380 	/*
381 	 * We set status at this point for read commands, and write
382 	 * commands with errors.
383 	 */
384 	if ((io->io_hdr.port_status == 0) &&
385 	    ((io->io_hdr.flags & CTL_FLAG_ABORT) == 0) &&
386 	    ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
387 		lbalen = ARGS(beio->io);
388 		if (lbalen->flags & CTL_LLF_READ) {
389 			ctl_set_success(&io->scsiio);
390 		} else if (lbalen->flags & CTL_LLF_COMPARE) {
391 			/* We have two data blocks ready for comparison. */
392 			for (i = 0; i < beio->num_segs; i++) {
393 				if (memcmp(beio->sg_segs[i].addr,
394 				    beio->sg_segs[i + CTLBLK_HALF_SEGS].addr,
395 				    beio->sg_segs[i].len) != 0)
396 					break;
397 			}
398 			if (i < beio->num_segs)
399 				ctl_set_sense(&io->scsiio,
400 				    /*current_error*/ 1,
401 				    /*sense_key*/ SSD_KEY_MISCOMPARE,
402 				    /*asc*/ 0x1D,
403 				    /*ascq*/ 0x00,
404 				    SSD_ELEM_NONE);
405 			else
406 				ctl_set_success(&io->scsiio);
407 		}
408 	}
409 	else if ((io->io_hdr.port_status != 0)
410 	      && ((io->io_hdr.flags & CTL_FLAG_ABORT) == 0)
411 	      && ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
412 		/*
413 		 * For hardware error sense keys, the sense key
414 		 * specific value is defined to be a retry count,
415 		 * but we use it to pass back an internal FETD
416 		 * error code.  XXX KDM  Hopefully the FETD is only
417 		 * using 16 bits for an error code, since that's
418 		 * all the space we have in the sks field.
419 		 */
420 		ctl_set_internal_failure(&io->scsiio,
421 					 /*sks_valid*/ 1,
422 					 /*retry_count*/
423 					 io->io_hdr.port_status);
424 	}
425 
426 	/*
427 	 * If this is a read, or a write with errors, it is done.
428 	 */
429 	if ((beio->bio_cmd == BIO_READ)
430 	 || ((io->io_hdr.flags & CTL_FLAG_ABORT) != 0)
431 	 || ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)) {
432 		ctl_complete_beio(beio);
433 		return (0);
434 	}
435 
436 	/*
437 	 * At this point, we have a write and the DMA completed
438 	 * successfully.  We now have to queue it to the task queue to
439 	 * execute the backend I/O.  That is because we do blocking
440 	 * memory allocations, and in the file backing case, blocking I/O.
441 	 * This move done routine is generally called in the SIM's
442 	 * interrupt context, and therefore we cannot block.
443 	 */
444 	mtx_lock(&be_lun->queue_lock);
445 	/*
446 	 * XXX KDM make sure that links is okay to use at this point.
447 	 * Otherwise, we either need to add another field to ctl_io_hdr,
448 	 * or deal with resource allocation here.
449 	 */
450 	STAILQ_INSERT_TAIL(&be_lun->datamove_queue, &io->io_hdr, links);
451 	mtx_unlock(&be_lun->queue_lock);
452 
453 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
454 
455 	return (0);
456 }
457 
458 static void
459 ctl_be_block_biodone(struct bio *bio)
460 {
461 	struct ctl_be_block_io *beio;
462 	struct ctl_be_block_lun *be_lun;
463 	union ctl_io *io;
464 	int error;
465 
466 	beio = bio->bio_caller1;
467 	be_lun = beio->lun;
468 	io = beio->io;
469 
470 	DPRINTF("entered\n");
471 
472 	error = bio->bio_error;
473 	mtx_lock(&be_lun->io_lock);
474 	if (error != 0)
475 		beio->num_errors++;
476 
477 	beio->num_bios_done++;
478 
479 	/*
480 	 * XXX KDM will this cause WITNESS to complain?  Holding a lock
481 	 * during the free might cause it to complain.
482 	 */
483 	g_destroy_bio(bio);
484 
485 	/*
486 	 * If the send complete bit isn't set, or we aren't the last I/O to
487 	 * complete, then we're done.
488 	 */
489 	if ((beio->send_complete == 0)
490 	 || (beio->num_bios_done < beio->num_bios_sent)) {
491 		mtx_unlock(&be_lun->io_lock);
492 		return;
493 	}
494 
495 	/*
496 	 * At this point, we've verified that we are the last I/O to
497 	 * complete, so it's safe to drop the lock.
498 	 */
499 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
500 	    beio->ds_tag_type, beio->ds_trans_type,
501 	    /*now*/ NULL, /*then*/&beio->ds_t0);
502 	mtx_unlock(&be_lun->io_lock);
503 
504 	/*
505 	 * If there are any errors from the backing device, we fail the
506 	 * entire I/O with a medium error.
507 	 */
508 	if (beio->num_errors > 0) {
509 		if (error == EOPNOTSUPP) {
510 			ctl_set_invalid_opcode(&io->scsiio);
511 		} else if (error == ENOSPC) {
512 			ctl_set_space_alloc_fail(&io->scsiio);
513 		} else if (beio->bio_cmd == BIO_FLUSH) {
514 			/* XXX KDM is there is a better error here? */
515 			ctl_set_internal_failure(&io->scsiio,
516 						 /*sks_valid*/ 1,
517 						 /*retry_count*/ 0xbad2);
518 		} else
519 			ctl_set_medium_error(&io->scsiio);
520 		ctl_complete_beio(beio);
521 		return;
522 	}
523 
524 	/*
525 	 * If this is a write, a flush, a delete or verify, we're all done.
526 	 * If this is a read, we can now send the data to the user.
527 	 */
528 	if ((beio->bio_cmd == BIO_WRITE)
529 	 || (beio->bio_cmd == BIO_FLUSH)
530 	 || (beio->bio_cmd == BIO_DELETE)
531 	 || (ARGS(io)->flags & CTL_LLF_VERIFY)) {
532 		ctl_set_success(&io->scsiio);
533 		ctl_complete_beio(beio);
534 	} else {
535 #ifdef CTL_TIME_IO
536         	getbintime(&io->io_hdr.dma_start_bt);
537 #endif
538 		ctl_datamove(io);
539 	}
540 }
541 
542 static void
543 ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
544 			struct ctl_be_block_io *beio)
545 {
546 	union ctl_io *io = beio->io;
547 	struct mount *mountpoint;
548 	int error, lock_flags;
549 
550 	DPRINTF("entered\n");
551 
552 	binuptime(&beio->ds_t0);
553 	mtx_lock(&be_lun->io_lock);
554 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
555 	mtx_unlock(&be_lun->io_lock);
556 
557 	(void) vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
558 
559 	if (MNT_SHARED_WRITES(mountpoint)
560 	 || ((mountpoint == NULL)
561 	  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
562 		lock_flags = LK_SHARED;
563 	else
564 		lock_flags = LK_EXCLUSIVE;
565 
566 	vn_lock(be_lun->vn, lock_flags | LK_RETRY);
567 
568 	error = VOP_FSYNC(be_lun->vn, MNT_WAIT, curthread);
569 	VOP_UNLOCK(be_lun->vn, 0);
570 
571 	vn_finished_write(mountpoint);
572 
573 	mtx_lock(&be_lun->io_lock);
574 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
575 	    beio->ds_tag_type, beio->ds_trans_type,
576 	    /*now*/ NULL, /*then*/&beio->ds_t0);
577 	mtx_unlock(&be_lun->io_lock);
578 
579 	if (error == 0)
580 		ctl_set_success(&io->scsiio);
581 	else {
582 		/* XXX KDM is there is a better error here? */
583 		ctl_set_internal_failure(&io->scsiio,
584 					 /*sks_valid*/ 1,
585 					 /*retry_count*/ 0xbad1);
586 	}
587 
588 	ctl_complete_beio(beio);
589 }
590 
591 SDT_PROBE_DEFINE1(cbb, kernel, read, file_start, "uint64_t");
592 SDT_PROBE_DEFINE1(cbb, kernel, write, file_start, "uint64_t");
593 SDT_PROBE_DEFINE1(cbb, kernel, read, file_done,"uint64_t");
594 SDT_PROBE_DEFINE1(cbb, kernel, write, file_done, "uint64_t");
595 
596 static void
597 ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
598 			   struct ctl_be_block_io *beio)
599 {
600 	struct ctl_be_block_filedata *file_data;
601 	union ctl_io *io;
602 	struct uio xuio;
603 	struct iovec *xiovec;
604 	int flags;
605 	int error, i;
606 
607 	DPRINTF("entered\n");
608 
609 	file_data = &be_lun->backend.file;
610 	io = beio->io;
611 	flags = 0;
612 	if (ARGS(io)->flags & CTL_LLF_DPO)
613 		flags |= IO_DIRECT;
614 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
615 		flags |= IO_SYNC;
616 
617 	bzero(&xuio, sizeof(xuio));
618 	if (beio->bio_cmd == BIO_READ) {
619 		SDT_PROBE(cbb, kernel, read, file_start, 0, 0, 0, 0, 0);
620 		xuio.uio_rw = UIO_READ;
621 	} else {
622 		SDT_PROBE(cbb, kernel, write, file_start, 0, 0, 0, 0, 0);
623 		xuio.uio_rw = UIO_WRITE;
624 	}
625 	xuio.uio_offset = beio->io_offset;
626 	xuio.uio_resid = beio->io_len;
627 	xuio.uio_segflg = UIO_SYSSPACE;
628 	xuio.uio_iov = beio->xiovecs;
629 	xuio.uio_iovcnt = beio->num_segs;
630 	xuio.uio_td = curthread;
631 
632 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
633 		xiovec->iov_base = beio->sg_segs[i].addr;
634 		xiovec->iov_len = beio->sg_segs[i].len;
635 	}
636 
637 	binuptime(&beio->ds_t0);
638 	mtx_lock(&be_lun->io_lock);
639 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
640 	mtx_unlock(&be_lun->io_lock);
641 
642 	if (beio->bio_cmd == BIO_READ) {
643 		vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
644 
645 		/*
646 		 * UFS pays attention to IO_DIRECT for reads.  If the
647 		 * DIRECTIO option is configured into the kernel, it calls
648 		 * ffs_rawread().  But that only works for single-segment
649 		 * uios with user space addresses.  In our case, with a
650 		 * kernel uio, it still reads into the buffer cache, but it
651 		 * will just try to release the buffer from the cache later
652 		 * on in ffs_read().
653 		 *
654 		 * ZFS does not pay attention to IO_DIRECT for reads.
655 		 *
656 		 * UFS does not pay attention to IO_SYNC for reads.
657 		 *
658 		 * ZFS pays attention to IO_SYNC (which translates into the
659 		 * Solaris define FRSYNC for zfs_read()) for reads.  It
660 		 * attempts to sync the file before reading.
661 		 *
662 		 * So, to attempt to provide some barrier semantics in the
663 		 * BIO_ORDERED case, set both IO_DIRECT and IO_SYNC.
664 		 */
665 		error = VOP_READ(be_lun->vn, &xuio, flags, file_data->cred);
666 
667 		VOP_UNLOCK(be_lun->vn, 0);
668 		SDT_PROBE(cbb, kernel, read, file_done, 0, 0, 0, 0, 0);
669 	} else {
670 		struct mount *mountpoint;
671 		int lock_flags;
672 
673 		(void)vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
674 
675 		if (MNT_SHARED_WRITES(mountpoint)
676 		 || ((mountpoint == NULL)
677 		  && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
678 			lock_flags = LK_SHARED;
679 		else
680 			lock_flags = LK_EXCLUSIVE;
681 
682 		vn_lock(be_lun->vn, lock_flags | LK_RETRY);
683 
684 		/*
685 		 * UFS pays attention to IO_DIRECT for writes.  The write
686 		 * is done asynchronously.  (Normally the write would just
687 		 * get put into cache.
688 		 *
689 		 * UFS pays attention to IO_SYNC for writes.  It will
690 		 * attempt to write the buffer out synchronously if that
691 		 * flag is set.
692 		 *
693 		 * ZFS does not pay attention to IO_DIRECT for writes.
694 		 *
695 		 * ZFS pays attention to IO_SYNC (a.k.a. FSYNC or FRSYNC)
696 		 * for writes.  It will flush the transaction from the
697 		 * cache before returning.
698 		 *
699 		 * So if we've got the BIO_ORDERED flag set, we want
700 		 * IO_SYNC in either the UFS or ZFS case.
701 		 */
702 		error = VOP_WRITE(be_lun->vn, &xuio, flags, file_data->cred);
703 		VOP_UNLOCK(be_lun->vn, 0);
704 
705 		vn_finished_write(mountpoint);
706 		SDT_PROBE(cbb, kernel, write, file_done, 0, 0, 0, 0, 0);
707         }
708 
709 	mtx_lock(&be_lun->io_lock);
710 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
711 	    beio->ds_tag_type, beio->ds_trans_type,
712 	    /*now*/ NULL, /*then*/&beio->ds_t0);
713 	mtx_unlock(&be_lun->io_lock);
714 
715 	/*
716 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
717 	 * return the I/O to the user.
718 	 */
719 	if (error != 0) {
720 		char path_str[32];
721 
722 		ctl_scsi_path_string(io, path_str, sizeof(path_str));
723 		printf("%s%s command returned errno %d\n", path_str,
724 		       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE", error);
725 		if (error == ENOSPC) {
726 			ctl_set_space_alloc_fail(&io->scsiio);
727 		} else
728 			ctl_set_medium_error(&io->scsiio);
729 		ctl_complete_beio(beio);
730 		return;
731 	}
732 
733 	/*
734 	 * If this is a write or a verify, we're all done.
735 	 * If this is a read, we can now send the data to the user.
736 	 */
737 	if ((beio->bio_cmd == BIO_WRITE) ||
738 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
739 		ctl_set_success(&io->scsiio);
740 		ctl_complete_beio(beio);
741 	} else {
742 #ifdef CTL_TIME_IO
743         	getbintime(&io->io_hdr.dma_start_bt);
744 #endif
745 		ctl_datamove(io);
746 	}
747 }
748 
749 static void
750 ctl_be_block_dispatch_zvol(struct ctl_be_block_lun *be_lun,
751 			   struct ctl_be_block_io *beio)
752 {
753 	struct ctl_be_block_devdata *dev_data;
754 	union ctl_io *io;
755 	struct uio xuio;
756 	struct iovec *xiovec;
757 	int flags;
758 	int error, i;
759 
760 	DPRINTF("entered\n");
761 
762 	dev_data = &be_lun->backend.dev;
763 	io = beio->io;
764 	flags = 0;
765 	if (ARGS(io)->flags & CTL_LLF_DPO)
766 		flags |= IO_DIRECT;
767 	if (beio->bio_cmd == BIO_WRITE && ARGS(io)->flags & CTL_LLF_FUA)
768 		flags |= IO_SYNC;
769 
770 	bzero(&xuio, sizeof(xuio));
771 	if (beio->bio_cmd == BIO_READ) {
772 		SDT_PROBE(cbb, kernel, read, file_start, 0, 0, 0, 0, 0);
773 		xuio.uio_rw = UIO_READ;
774 	} else {
775 		SDT_PROBE(cbb, kernel, write, file_start, 0, 0, 0, 0, 0);
776 		xuio.uio_rw = UIO_WRITE;
777 	}
778 	xuio.uio_offset = beio->io_offset;
779 	xuio.uio_resid = beio->io_len;
780 	xuio.uio_segflg = UIO_SYSSPACE;
781 	xuio.uio_iov = beio->xiovecs;
782 	xuio.uio_iovcnt = beio->num_segs;
783 	xuio.uio_td = curthread;
784 
785 	for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
786 		xiovec->iov_base = beio->sg_segs[i].addr;
787 		xiovec->iov_len = beio->sg_segs[i].len;
788 	}
789 
790 	binuptime(&beio->ds_t0);
791 	mtx_lock(&be_lun->io_lock);
792 	devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
793 	mtx_unlock(&be_lun->io_lock);
794 
795 	if (beio->bio_cmd == BIO_READ) {
796 		error = (*dev_data->csw->d_read)(dev_data->cdev, &xuio, flags);
797 		SDT_PROBE(cbb, kernel, read, file_done, 0, 0, 0, 0, 0);
798 	} else {
799 		error = (*dev_data->csw->d_write)(dev_data->cdev, &xuio, flags);
800 		SDT_PROBE(cbb, kernel, write, file_done, 0, 0, 0, 0, 0);
801 	}
802 
803 	mtx_lock(&be_lun->io_lock);
804 	devstat_end_transaction(beio->lun->disk_stats, beio->io_len,
805 	    beio->ds_tag_type, beio->ds_trans_type,
806 	    /*now*/ NULL, /*then*/&beio->ds_t0);
807 	mtx_unlock(&be_lun->io_lock);
808 
809 	/*
810 	 * If we got an error, set the sense data to "MEDIUM ERROR" and
811 	 * return the I/O to the user.
812 	 */
813 	if (error != 0) {
814 		if (error == ENOSPC) {
815 			ctl_set_space_alloc_fail(&io->scsiio);
816 		} else
817 			ctl_set_medium_error(&io->scsiio);
818 		ctl_complete_beio(beio);
819 		return;
820 	}
821 
822 	/*
823 	 * If this is a write or a verify, we're all done.
824 	 * If this is a read, we can now send the data to the user.
825 	 */
826 	if ((beio->bio_cmd == BIO_WRITE) ||
827 	    (ARGS(io)->flags & CTL_LLF_VERIFY)) {
828 		ctl_set_success(&io->scsiio);
829 		ctl_complete_beio(beio);
830 	} else {
831 #ifdef CTL_TIME_IO
832         	getbintime(&io->io_hdr.dma_start_bt);
833 #endif
834 		ctl_datamove(io);
835 	}
836 }
837 
838 static void
839 ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
840 		       struct ctl_be_block_io *beio)
841 {
842 	struct bio *bio;
843 	union ctl_io *io;
844 	struct ctl_be_block_devdata *dev_data;
845 
846 	dev_data = &be_lun->backend.dev;
847 	io = beio->io;
848 
849 	DPRINTF("entered\n");
850 
851 	/* This can't fail, it's a blocking allocation. */
852 	bio = g_alloc_bio();
853 
854 	bio->bio_cmd	    = BIO_FLUSH;
855 	bio->bio_flags	   |= BIO_ORDERED;
856 	bio->bio_dev	    = dev_data->cdev;
857 	bio->bio_offset	    = 0;
858 	bio->bio_data	    = 0;
859 	bio->bio_done	    = ctl_be_block_biodone;
860 	bio->bio_caller1    = beio;
861 	bio->bio_pblkno	    = 0;
862 
863 	/*
864 	 * We don't need to acquire the LUN lock here, because we are only
865 	 * sending one bio, and so there is no other context to synchronize
866 	 * with.
867 	 */
868 	beio->num_bios_sent = 1;
869 	beio->send_complete = 1;
870 
871 	binuptime(&beio->ds_t0);
872 	mtx_lock(&be_lun->io_lock);
873 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
874 	mtx_unlock(&be_lun->io_lock);
875 
876 	(*dev_data->csw->d_strategy)(bio);
877 }
878 
879 static void
880 ctl_be_block_unmap_dev_range(struct ctl_be_block_lun *be_lun,
881 		       struct ctl_be_block_io *beio,
882 		       uint64_t off, uint64_t len, int last)
883 {
884 	struct bio *bio;
885 	struct ctl_be_block_devdata *dev_data;
886 	uint64_t maxlen;
887 
888 	dev_data = &be_lun->backend.dev;
889 	maxlen = LONG_MAX - (LONG_MAX % be_lun->blocksize);
890 	while (len > 0) {
891 		bio = g_alloc_bio();
892 		bio->bio_cmd	    = BIO_DELETE;
893 		bio->bio_dev	    = dev_data->cdev;
894 		bio->bio_offset	    = off;
895 		bio->bio_length	    = MIN(len, maxlen);
896 		bio->bio_data	    = 0;
897 		bio->bio_done	    = ctl_be_block_biodone;
898 		bio->bio_caller1    = beio;
899 		bio->bio_pblkno     = off / be_lun->blocksize;
900 
901 		off += bio->bio_length;
902 		len -= bio->bio_length;
903 
904 		mtx_lock(&be_lun->io_lock);
905 		beio->num_bios_sent++;
906 		if (last && len == 0)
907 			beio->send_complete = 1;
908 		mtx_unlock(&be_lun->io_lock);
909 
910 		(*dev_data->csw->d_strategy)(bio);
911 	}
912 }
913 
914 static void
915 ctl_be_block_unmap_dev(struct ctl_be_block_lun *be_lun,
916 		       struct ctl_be_block_io *beio)
917 {
918 	union ctl_io *io;
919 	struct ctl_be_block_devdata *dev_data;
920 	struct ctl_ptr_len_flags *ptrlen;
921 	struct scsi_unmap_desc *buf, *end;
922 	uint64_t len;
923 
924 	dev_data = &be_lun->backend.dev;
925 	io = beio->io;
926 
927 	DPRINTF("entered\n");
928 
929 	binuptime(&beio->ds_t0);
930 	mtx_lock(&be_lun->io_lock);
931 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
932 	mtx_unlock(&be_lun->io_lock);
933 
934 	if (beio->io_offset == -1) {
935 		beio->io_len = 0;
936 		ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
937 		buf = (struct scsi_unmap_desc *)ptrlen->ptr;
938 		end = buf + ptrlen->len / sizeof(*buf);
939 		for (; buf < end; buf++) {
940 			len = (uint64_t)scsi_4btoul(buf->length) *
941 			    be_lun->blocksize;
942 			beio->io_len += len;
943 			ctl_be_block_unmap_dev_range(be_lun, beio,
944 			    scsi_8btou64(buf->lba) * be_lun->blocksize, len,
945 			    (end - buf < 2) ? TRUE : FALSE);
946 		}
947 	} else
948 		ctl_be_block_unmap_dev_range(be_lun, beio,
949 		    beio->io_offset, beio->io_len, TRUE);
950 }
951 
952 static void
953 ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
954 			  struct ctl_be_block_io *beio)
955 {
956 	TAILQ_HEAD(, bio) queue = TAILQ_HEAD_INITIALIZER(queue);
957 	int i;
958 	struct bio *bio;
959 	struct ctl_be_block_devdata *dev_data;
960 	off_t cur_offset;
961 	int max_iosize;
962 
963 	DPRINTF("entered\n");
964 
965 	dev_data = &be_lun->backend.dev;
966 
967 	/*
968 	 * We have to limit our I/O size to the maximum supported by the
969 	 * backend device.  Hopefully it is MAXPHYS.  If the driver doesn't
970 	 * set it properly, use DFLTPHYS.
971 	 */
972 	max_iosize = dev_data->cdev->si_iosize_max;
973 	if (max_iosize < PAGE_SIZE)
974 		max_iosize = DFLTPHYS;
975 
976 	cur_offset = beio->io_offset;
977 	for (i = 0; i < beio->num_segs; i++) {
978 		size_t cur_size;
979 		uint8_t *cur_ptr;
980 
981 		cur_size = beio->sg_segs[i].len;
982 		cur_ptr = beio->sg_segs[i].addr;
983 
984 		while (cur_size > 0) {
985 			/* This can't fail, it's a blocking allocation. */
986 			bio = g_alloc_bio();
987 
988 			KASSERT(bio != NULL, ("g_alloc_bio() failed!\n"));
989 
990 			bio->bio_cmd = beio->bio_cmd;
991 			bio->bio_dev = dev_data->cdev;
992 			bio->bio_caller1 = beio;
993 			bio->bio_length = min(cur_size, max_iosize);
994 			bio->bio_offset = cur_offset;
995 			bio->bio_data = cur_ptr;
996 			bio->bio_done = ctl_be_block_biodone;
997 			bio->bio_pblkno = cur_offset / be_lun->blocksize;
998 
999 			cur_offset += bio->bio_length;
1000 			cur_ptr += bio->bio_length;
1001 			cur_size -= bio->bio_length;
1002 
1003 			TAILQ_INSERT_TAIL(&queue, bio, bio_queue);
1004 			beio->num_bios_sent++;
1005 		}
1006 	}
1007 	binuptime(&beio->ds_t0);
1008 	mtx_lock(&be_lun->io_lock);
1009 	devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
1010 	beio->send_complete = 1;
1011 	mtx_unlock(&be_lun->io_lock);
1012 
1013 	/*
1014 	 * Fire off all allocated requests!
1015 	 */
1016 	while ((bio = TAILQ_FIRST(&queue)) != NULL) {
1017 		TAILQ_REMOVE(&queue, bio, bio_queue);
1018 		(*dev_data->csw->d_strategy)(bio);
1019 	}
1020 }
1021 
1022 static uint64_t
1023 ctl_be_block_getattr_dev(struct ctl_be_block_lun *be_lun, const char *attrname)
1024 {
1025 	struct ctl_be_block_devdata	*dev_data = &be_lun->backend.dev;
1026 	struct diocgattr_arg	arg;
1027 	int			error;
1028 
1029 	if (dev_data->csw == NULL || dev_data->csw->d_ioctl == NULL)
1030 		return (UINT64_MAX);
1031 	strlcpy(arg.name, attrname, sizeof(arg.name));
1032 	arg.len = sizeof(arg.value.off);
1033 	error = dev_data->csw->d_ioctl(dev_data->cdev,
1034 	    DIOCGATTR, (caddr_t)&arg, FREAD, curthread);
1035 	if (error != 0)
1036 		return (UINT64_MAX);
1037 	return (arg.value.off);
1038 }
1039 
1040 static void
1041 ctl_be_block_cw_done_ws(struct ctl_be_block_io *beio)
1042 {
1043 	union ctl_io *io;
1044 
1045 	io = beio->io;
1046 	ctl_free_beio(beio);
1047 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1048 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1049 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1050 		ctl_config_write_done(io);
1051 		return;
1052 	}
1053 
1054 	ctl_be_block_config_write(io);
1055 }
1056 
1057 static void
1058 ctl_be_block_cw_dispatch_ws(struct ctl_be_block_lun *be_lun,
1059 			    union ctl_io *io)
1060 {
1061 	struct ctl_be_block_io *beio;
1062 	struct ctl_be_block_softc *softc;
1063 	struct ctl_lba_len_flags *lbalen;
1064 	uint64_t len_left, lba;
1065 	int i, seglen;
1066 	uint8_t *buf, *end;
1067 
1068 	DPRINTF("entered\n");
1069 
1070 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1071 	softc = be_lun->softc;
1072 	lbalen = ARGS(beio->io);
1073 
1074 	if (lbalen->flags & ~(SWS_LBDATA | SWS_UNMAP | SWS_ANCHOR | SWS_NDOB) ||
1075 	    (lbalen->flags & (SWS_UNMAP | SWS_ANCHOR) && be_lun->unmap == NULL)) {
1076 		ctl_free_beio(beio);
1077 		ctl_set_invalid_field(&io->scsiio,
1078 				      /*sks_valid*/ 1,
1079 				      /*command*/ 1,
1080 				      /*field*/ 1,
1081 				      /*bit_valid*/ 0,
1082 				      /*bit*/ 0);
1083 		ctl_config_write_done(io);
1084 		return;
1085 	}
1086 
1087 	switch (io->scsiio.tag_type) {
1088 	case CTL_TAG_ORDERED:
1089 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1090 		break;
1091 	case CTL_TAG_HEAD_OF_QUEUE:
1092 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1093 		break;
1094 	case CTL_TAG_UNTAGGED:
1095 	case CTL_TAG_SIMPLE:
1096 	case CTL_TAG_ACA:
1097 	default:
1098 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1099 		break;
1100 	}
1101 
1102 	if (lbalen->flags & (SWS_UNMAP | SWS_ANCHOR)) {
1103 		beio->io_offset = lbalen->lba * be_lun->blocksize;
1104 		beio->io_len = (uint64_t)lbalen->len * be_lun->blocksize;
1105 		beio->bio_cmd = BIO_DELETE;
1106 		beio->ds_trans_type = DEVSTAT_FREE;
1107 
1108 		be_lun->unmap(be_lun, beio);
1109 		return;
1110 	}
1111 
1112 	beio->bio_cmd = BIO_WRITE;
1113 	beio->ds_trans_type = DEVSTAT_WRITE;
1114 
1115 	DPRINTF("WRITE SAME at LBA %jx len %u\n",
1116 	       (uintmax_t)lbalen->lba, lbalen->len);
1117 
1118 	len_left = (uint64_t)lbalen->len * be_lun->blocksize;
1119 	for (i = 0, lba = 0; i < CTLBLK_MAX_SEGS && len_left > 0; i++) {
1120 
1121 		/*
1122 		 * Setup the S/G entry for this chunk.
1123 		 */
1124 		seglen = MIN(CTLBLK_MAX_SEG, len_left);
1125 		seglen -= seglen % be_lun->blocksize;
1126 		beio->sg_segs[i].len = seglen;
1127 		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1128 
1129 		DPRINTF("segment %d addr %p len %zd\n", i,
1130 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1131 
1132 		beio->num_segs++;
1133 		len_left -= seglen;
1134 
1135 		buf = beio->sg_segs[i].addr;
1136 		end = buf + seglen;
1137 		for (; buf < end; buf += be_lun->blocksize) {
1138 			memcpy(buf, io->scsiio.kern_data_ptr, be_lun->blocksize);
1139 			if (lbalen->flags & SWS_LBDATA)
1140 				scsi_ulto4b(lbalen->lba + lba, buf);
1141 			lba++;
1142 		}
1143 	}
1144 
1145 	beio->io_offset = lbalen->lba * be_lun->blocksize;
1146 	beio->io_len = lba * be_lun->blocksize;
1147 
1148 	/* We can not do all in one run. Correct and schedule rerun. */
1149 	if (len_left > 0) {
1150 		lbalen->lba += lba;
1151 		lbalen->len -= lba;
1152 		beio->beio_cont = ctl_be_block_cw_done_ws;
1153 	}
1154 
1155 	be_lun->dispatch(be_lun, beio);
1156 }
1157 
1158 static void
1159 ctl_be_block_cw_dispatch_unmap(struct ctl_be_block_lun *be_lun,
1160 			    union ctl_io *io)
1161 {
1162 	struct ctl_be_block_io *beio;
1163 	struct ctl_be_block_softc *softc;
1164 	struct ctl_ptr_len_flags *ptrlen;
1165 
1166 	DPRINTF("entered\n");
1167 
1168 	beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1169 	softc = be_lun->softc;
1170 	ptrlen = (struct ctl_ptr_len_flags *)&io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN];
1171 
1172 	if ((ptrlen->flags & ~SU_ANCHOR) != 0 || be_lun->unmap == NULL) {
1173 		ctl_free_beio(beio);
1174 		ctl_set_invalid_field(&io->scsiio,
1175 				      /*sks_valid*/ 0,
1176 				      /*command*/ 1,
1177 				      /*field*/ 0,
1178 				      /*bit_valid*/ 0,
1179 				      /*bit*/ 0);
1180 		ctl_config_write_done(io);
1181 		return;
1182 	}
1183 
1184 	switch (io->scsiio.tag_type) {
1185 	case CTL_TAG_ORDERED:
1186 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1187 		break;
1188 	case CTL_TAG_HEAD_OF_QUEUE:
1189 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1190 		break;
1191 	case CTL_TAG_UNTAGGED:
1192 	case CTL_TAG_SIMPLE:
1193 	case CTL_TAG_ACA:
1194 	default:
1195 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1196 		break;
1197 	}
1198 
1199 	beio->io_len = 0;
1200 	beio->io_offset = -1;
1201 
1202 	beio->bio_cmd = BIO_DELETE;
1203 	beio->ds_trans_type = DEVSTAT_FREE;
1204 
1205 	DPRINTF("UNMAP\n");
1206 
1207 	be_lun->unmap(be_lun, beio);
1208 }
1209 
1210 static void
1211 ctl_be_block_cw_done(struct ctl_be_block_io *beio)
1212 {
1213 	union ctl_io *io;
1214 
1215 	io = beio->io;
1216 	ctl_free_beio(beio);
1217 	ctl_config_write_done(io);
1218 }
1219 
1220 static void
1221 ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
1222 			 union ctl_io *io)
1223 {
1224 	struct ctl_be_block_io *beio;
1225 	struct ctl_be_block_softc *softc;
1226 
1227 	DPRINTF("entered\n");
1228 
1229 	softc = be_lun->softc;
1230 	beio = ctl_alloc_beio(softc);
1231 	beio->io = io;
1232 	beio->lun = be_lun;
1233 	beio->beio_cont = ctl_be_block_cw_done;
1234 	PRIV(io)->ptr = (void *)beio;
1235 
1236 	switch (io->scsiio.cdb[0]) {
1237 	case SYNCHRONIZE_CACHE:
1238 	case SYNCHRONIZE_CACHE_16:
1239 		beio->bio_cmd = BIO_FLUSH;
1240 		beio->ds_trans_type = DEVSTAT_NO_DATA;
1241 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1242 		beio->io_len = 0;
1243 		be_lun->lun_flush(be_lun, beio);
1244 		break;
1245 	case WRITE_SAME_10:
1246 	case WRITE_SAME_16:
1247 		ctl_be_block_cw_dispatch_ws(be_lun, io);
1248 		break;
1249 	case UNMAP:
1250 		ctl_be_block_cw_dispatch_unmap(be_lun, io);
1251 		break;
1252 	default:
1253 		panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
1254 		break;
1255 	}
1256 }
1257 
1258 SDT_PROBE_DEFINE1(cbb, kernel, read, start, "uint64_t");
1259 SDT_PROBE_DEFINE1(cbb, kernel, write, start, "uint64_t");
1260 SDT_PROBE_DEFINE1(cbb, kernel, read, alloc_done, "uint64_t");
1261 SDT_PROBE_DEFINE1(cbb, kernel, write, alloc_done, "uint64_t");
1262 
1263 static void
1264 ctl_be_block_next(struct ctl_be_block_io *beio)
1265 {
1266 	struct ctl_be_block_lun *be_lun;
1267 	union ctl_io *io;
1268 
1269 	io = beio->io;
1270 	be_lun = beio->lun;
1271 	ctl_free_beio(beio);
1272 	if ((io->io_hdr.flags & CTL_FLAG_ABORT) ||
1273 	    ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE &&
1274 	     (io->io_hdr.status & CTL_STATUS_MASK) != CTL_SUCCESS)) {
1275 		ctl_data_submit_done(io);
1276 		return;
1277 	}
1278 
1279 	io->io_hdr.status &= ~CTL_STATUS_MASK;
1280 	io->io_hdr.status |= CTL_STATUS_NONE;
1281 
1282 	mtx_lock(&be_lun->queue_lock);
1283 	/*
1284 	 * XXX KDM make sure that links is okay to use at this point.
1285 	 * Otherwise, we either need to add another field to ctl_io_hdr,
1286 	 * or deal with resource allocation here.
1287 	 */
1288 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1289 	mtx_unlock(&be_lun->queue_lock);
1290 
1291 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1292 }
1293 
1294 static void
1295 ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
1296 			   union ctl_io *io)
1297 {
1298 	struct ctl_be_block_io *beio;
1299 	struct ctl_be_block_softc *softc;
1300 	struct ctl_lba_len_flags *lbalen;
1301 	struct ctl_ptr_len_flags *bptrlen;
1302 	uint64_t len_left, lbas;
1303 	int i;
1304 
1305 	softc = be_lun->softc;
1306 
1307 	DPRINTF("entered\n");
1308 
1309 	lbalen = ARGS(io);
1310 	if (lbalen->flags & CTL_LLF_WRITE) {
1311 		SDT_PROBE(cbb, kernel, write, start, 0, 0, 0, 0, 0);
1312 	} else {
1313 		SDT_PROBE(cbb, kernel, read, start, 0, 0, 0, 0, 0);
1314 	}
1315 
1316 	beio = ctl_alloc_beio(softc);
1317 	beio->io = io;
1318 	beio->lun = be_lun;
1319 	bptrlen = PRIV(io);
1320 	bptrlen->ptr = (void *)beio;
1321 
1322 	switch (io->scsiio.tag_type) {
1323 	case CTL_TAG_ORDERED:
1324 		beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1325 		break;
1326 	case CTL_TAG_HEAD_OF_QUEUE:
1327 		beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1328 		break;
1329 	case CTL_TAG_UNTAGGED:
1330 	case CTL_TAG_SIMPLE:
1331 	case CTL_TAG_ACA:
1332 	default:
1333 		beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1334 		break;
1335 	}
1336 
1337 	if (lbalen->flags & CTL_LLF_WRITE) {
1338 		beio->bio_cmd = BIO_WRITE;
1339 		beio->ds_trans_type = DEVSTAT_WRITE;
1340 	} else {
1341 		beio->bio_cmd = BIO_READ;
1342 		beio->ds_trans_type = DEVSTAT_READ;
1343 	}
1344 
1345 	DPRINTF("%s at LBA %jx len %u @%ju\n",
1346 	       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE",
1347 	       (uintmax_t)lbalen->lba, lbalen->len, bptrlen->len);
1348 	if (lbalen->flags & CTL_LLF_COMPARE)
1349 		lbas = CTLBLK_HALF_IO_SIZE;
1350 	else
1351 		lbas = CTLBLK_MAX_IO_SIZE;
1352 	lbas = MIN(lbalen->len - bptrlen->len, lbas / be_lun->blocksize);
1353 	beio->io_offset = (lbalen->lba + bptrlen->len) * be_lun->blocksize;
1354 	beio->io_len = lbas * be_lun->blocksize;
1355 	bptrlen->len += lbas;
1356 
1357 	for (i = 0, len_left = beio->io_len; len_left > 0; i++) {
1358 		KASSERT(i < CTLBLK_MAX_SEGS, ("Too many segs (%d >= %d)",
1359 		    i, CTLBLK_MAX_SEGS));
1360 
1361 		/*
1362 		 * Setup the S/G entry for this chunk.
1363 		 */
1364 		beio->sg_segs[i].len = min(CTLBLK_MAX_SEG, len_left);
1365 		beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1366 
1367 		DPRINTF("segment %d addr %p len %zd\n", i,
1368 			beio->sg_segs[i].addr, beio->sg_segs[i].len);
1369 
1370 		/* Set up second segment for compare operation. */
1371 		if (lbalen->flags & CTL_LLF_COMPARE) {
1372 			beio->sg_segs[i + CTLBLK_HALF_SEGS].len =
1373 			    beio->sg_segs[i].len;
1374 			beio->sg_segs[i + CTLBLK_HALF_SEGS].addr =
1375 			    uma_zalloc(be_lun->lun_zone, M_WAITOK);
1376 		}
1377 
1378 		beio->num_segs++;
1379 		len_left -= beio->sg_segs[i].len;
1380 	}
1381 	if (bptrlen->len < lbalen->len)
1382 		beio->beio_cont = ctl_be_block_next;
1383 	io->scsiio.be_move_done = ctl_be_block_move_done;
1384 	/* For compare we have separate S/G lists for read and datamove. */
1385 	if (lbalen->flags & CTL_LLF_COMPARE)
1386 		io->scsiio.kern_data_ptr = (uint8_t *)&beio->sg_segs[CTLBLK_HALF_SEGS];
1387 	else
1388 		io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
1389 	io->scsiio.kern_data_len = beio->io_len;
1390 	io->scsiio.kern_data_resid = 0;
1391 	io->scsiio.kern_sg_entries = beio->num_segs;
1392 	io->io_hdr.flags |= CTL_FLAG_ALLOCATED | CTL_FLAG_KDPTR_SGLIST;
1393 
1394 	/*
1395 	 * For the read case, we need to read the data into our buffers and
1396 	 * then we can send it back to the user.  For the write case, we
1397 	 * need to get the data from the user first.
1398 	 */
1399 	if (beio->bio_cmd == BIO_READ) {
1400 		SDT_PROBE(cbb, kernel, read, alloc_done, 0, 0, 0, 0, 0);
1401 		be_lun->dispatch(be_lun, beio);
1402 	} else {
1403 		SDT_PROBE(cbb, kernel, write, alloc_done, 0, 0, 0, 0, 0);
1404 #ifdef CTL_TIME_IO
1405         	getbintime(&io->io_hdr.dma_start_bt);
1406 #endif
1407 		ctl_datamove(io);
1408 	}
1409 }
1410 
1411 static void
1412 ctl_be_block_worker(void *context, int pending)
1413 {
1414 	struct ctl_be_block_lun *be_lun;
1415 	struct ctl_be_block_softc *softc;
1416 	union ctl_io *io;
1417 
1418 	be_lun = (struct ctl_be_block_lun *)context;
1419 	softc = be_lun->softc;
1420 
1421 	DPRINTF("entered\n");
1422 
1423 	mtx_lock(&be_lun->queue_lock);
1424 	for (;;) {
1425 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->datamove_queue);
1426 		if (io != NULL) {
1427 			struct ctl_be_block_io *beio;
1428 
1429 			DPRINTF("datamove queue\n");
1430 
1431 			STAILQ_REMOVE(&be_lun->datamove_queue, &io->io_hdr,
1432 				      ctl_io_hdr, links);
1433 
1434 			mtx_unlock(&be_lun->queue_lock);
1435 
1436 			beio = (struct ctl_be_block_io *)PRIV(io)->ptr;
1437 
1438 			be_lun->dispatch(be_lun, beio);
1439 
1440 			mtx_lock(&be_lun->queue_lock);
1441 			continue;
1442 		}
1443 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_write_queue);
1444 		if (io != NULL) {
1445 
1446 			DPRINTF("config write queue\n");
1447 
1448 			STAILQ_REMOVE(&be_lun->config_write_queue, &io->io_hdr,
1449 				      ctl_io_hdr, links);
1450 
1451 			mtx_unlock(&be_lun->queue_lock);
1452 
1453 			ctl_be_block_cw_dispatch(be_lun, io);
1454 
1455 			mtx_lock(&be_lun->queue_lock);
1456 			continue;
1457 		}
1458 		io = (union ctl_io *)STAILQ_FIRST(&be_lun->input_queue);
1459 		if (io != NULL) {
1460 			DPRINTF("input queue\n");
1461 
1462 			STAILQ_REMOVE(&be_lun->input_queue, &io->io_hdr,
1463 				      ctl_io_hdr, links);
1464 			mtx_unlock(&be_lun->queue_lock);
1465 
1466 			/*
1467 			 * We must drop the lock, since this routine and
1468 			 * its children may sleep.
1469 			 */
1470 			ctl_be_block_dispatch(be_lun, io);
1471 
1472 			mtx_lock(&be_lun->queue_lock);
1473 			continue;
1474 		}
1475 
1476 		/*
1477 		 * If we get here, there is no work left in the queues, so
1478 		 * just break out and let the task queue go to sleep.
1479 		 */
1480 		break;
1481 	}
1482 	mtx_unlock(&be_lun->queue_lock);
1483 }
1484 
1485 /*
1486  * Entry point from CTL to the backend for I/O.  We queue everything to a
1487  * work thread, so this just puts the I/O on a queue and wakes up the
1488  * thread.
1489  */
1490 static int
1491 ctl_be_block_submit(union ctl_io *io)
1492 {
1493 	struct ctl_be_block_lun *be_lun;
1494 	struct ctl_be_lun *ctl_be_lun;
1495 
1496 	DPRINTF("entered\n");
1497 
1498 	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
1499 		CTL_PRIV_BACKEND_LUN].ptr;
1500 	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
1501 
1502 	/*
1503 	 * Make sure we only get SCSI I/O.
1504 	 */
1505 	KASSERT(io->io_hdr.io_type == CTL_IO_SCSI, ("Non-SCSI I/O (type "
1506 		"%#x) encountered", io->io_hdr.io_type));
1507 
1508 	PRIV(io)->len = 0;
1509 
1510 	mtx_lock(&be_lun->queue_lock);
1511 	/*
1512 	 * XXX KDM make sure that links is okay to use at this point.
1513 	 * Otherwise, we either need to add another field to ctl_io_hdr,
1514 	 * or deal with resource allocation here.
1515 	 */
1516 	STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1517 	mtx_unlock(&be_lun->queue_lock);
1518 	taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1519 
1520 	return (CTL_RETVAL_COMPLETE);
1521 }
1522 
1523 static int
1524 ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
1525 			int flag, struct thread *td)
1526 {
1527 	struct ctl_be_block_softc *softc;
1528 	int error;
1529 
1530 	softc = &backend_block_softc;
1531 
1532 	error = 0;
1533 
1534 	switch (cmd) {
1535 	case CTL_LUN_REQ: {
1536 		struct ctl_lun_req *lun_req;
1537 
1538 		lun_req = (struct ctl_lun_req *)addr;
1539 
1540 		switch (lun_req->reqtype) {
1541 		case CTL_LUNREQ_CREATE:
1542 			error = ctl_be_block_create(softc, lun_req);
1543 			break;
1544 		case CTL_LUNREQ_RM:
1545 			error = ctl_be_block_rm(softc, lun_req);
1546 			break;
1547 		case CTL_LUNREQ_MODIFY:
1548 			error = ctl_be_block_modify(softc, lun_req);
1549 			break;
1550 		default:
1551 			lun_req->status = CTL_LUN_ERROR;
1552 			snprintf(lun_req->error_str, sizeof(lun_req->error_str),
1553 				 "invalid LUN request type %d",
1554 				 lun_req->reqtype);
1555 			break;
1556 		}
1557 		break;
1558 	}
1559 	default:
1560 		error = ENOTTY;
1561 		break;
1562 	}
1563 
1564 	return (error);
1565 }
1566 
1567 static int
1568 ctl_be_block_open_file(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1569 {
1570 	struct ctl_be_block_filedata *file_data;
1571 	struct ctl_lun_create_params *params;
1572 	struct vattr		      vattr;
1573 	off_t			      pss;
1574 	int			      error;
1575 
1576 	error = 0;
1577 	file_data = &be_lun->backend.file;
1578 	params = &be_lun->params;
1579 
1580 	be_lun->dev_type = CTL_BE_BLOCK_FILE;
1581 	be_lun->dispatch = ctl_be_block_dispatch_file;
1582 	be_lun->lun_flush = ctl_be_block_flush_file;
1583 
1584 	error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
1585 	if (error != 0) {
1586 		snprintf(req->error_str, sizeof(req->error_str),
1587 			 "error calling VOP_GETATTR() for file %s",
1588 			 be_lun->dev_path);
1589 		return (error);
1590 	}
1591 
1592 	/*
1593 	 * Verify that we have the ability to upgrade to exclusive
1594 	 * access on this file so we can trap errors at open instead
1595 	 * of reporting them during first access.
1596 	 */
1597 	if (VOP_ISLOCKED(be_lun->vn) != LK_EXCLUSIVE) {
1598 		vn_lock(be_lun->vn, LK_UPGRADE | LK_RETRY);
1599 		if (be_lun->vn->v_iflag & VI_DOOMED) {
1600 			error = EBADF;
1601 			snprintf(req->error_str, sizeof(req->error_str),
1602 				 "error locking file %s", be_lun->dev_path);
1603 			return (error);
1604 		}
1605 	}
1606 
1607 
1608 	file_data->cred = crhold(curthread->td_ucred);
1609 	if (params->lun_size_bytes != 0)
1610 		be_lun->size_bytes = params->lun_size_bytes;
1611 	else
1612 		be_lun->size_bytes = vattr.va_size;
1613 	/*
1614 	 * We set the multi thread flag for file operations because all
1615 	 * filesystems (in theory) are capable of allowing multiple readers
1616 	 * of a file at once.  So we want to get the maximum possible
1617 	 * concurrency.
1618 	 */
1619 	be_lun->flags |= CTL_BE_BLOCK_LUN_MULTI_THREAD;
1620 
1621 	/*
1622 	 * For files we can use any logical block size.  Prefer 512 bytes
1623 	 * for compatibility reasons.  If file's vattr.va_blocksize
1624 	 * (preferred I/O block size) is bigger and multiple to chosen
1625 	 * logical block size -- report it as physical block size.
1626 	 */
1627 	if (params->blocksize_bytes != 0)
1628 		be_lun->blocksize = params->blocksize_bytes;
1629 	else
1630 		be_lun->blocksize = 512;
1631 	pss = vattr.va_blocksize / be_lun->blocksize;
1632 	if ((pss > 0) && (pss * be_lun->blocksize == vattr.va_blocksize) &&
1633 	    ((pss & (pss - 1)) == 0)) {
1634 		be_lun->pblockexp = fls(pss) - 1;
1635 		be_lun->pblockoff = 0;
1636 	}
1637 
1638 	/*
1639 	 * Sanity check.  The media size has to be at least one
1640 	 * sector long.
1641 	 */
1642 	if (be_lun->size_bytes < be_lun->blocksize) {
1643 		error = EINVAL;
1644 		snprintf(req->error_str, sizeof(req->error_str),
1645 			 "file %s size %ju < block size %u", be_lun->dev_path,
1646 			 (uintmax_t)be_lun->size_bytes, be_lun->blocksize);
1647 	}
1648 	return (error);
1649 }
1650 
1651 static int
1652 ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1653 {
1654 	struct ctl_lun_create_params *params;
1655 	struct vattr		      vattr;
1656 	struct cdev		     *dev;
1657 	struct cdevsw		     *devsw;
1658 	int			      error;
1659 	off_t			      ps, pss, po, pos;
1660 
1661 	params = &be_lun->params;
1662 
1663 	be_lun->dev_type = CTL_BE_BLOCK_DEV;
1664 	be_lun->backend.dev.cdev = be_lun->vn->v_rdev;
1665 	be_lun->backend.dev.csw = dev_refthread(be_lun->backend.dev.cdev,
1666 					     &be_lun->backend.dev.dev_ref);
1667 	if (be_lun->backend.dev.csw == NULL)
1668 		panic("Unable to retrieve device switch");
1669 	if (strcmp(be_lun->backend.dev.csw->d_name, "zvol") == 0)
1670 		be_lun->dispatch = ctl_be_block_dispatch_zvol;
1671 	else
1672 		be_lun->dispatch = ctl_be_block_dispatch_dev;
1673 	be_lun->lun_flush = ctl_be_block_flush_dev;
1674 	be_lun->unmap = ctl_be_block_unmap_dev;
1675 	be_lun->getattr = ctl_be_block_getattr_dev;
1676 
1677 	error = VOP_GETATTR(be_lun->vn, &vattr, NOCRED);
1678 	if (error) {
1679 		snprintf(req->error_str, sizeof(req->error_str),
1680 			 "error getting vnode attributes for device %s",
1681 			 be_lun->dev_path);
1682 		return (error);
1683 	}
1684 
1685 	dev = be_lun->vn->v_rdev;
1686 	devsw = dev->si_devsw;
1687 	if (!devsw->d_ioctl) {
1688 		snprintf(req->error_str, sizeof(req->error_str),
1689 			 "no d_ioctl for device %s!",
1690 			 be_lun->dev_path);
1691 		return (ENODEV);
1692 	}
1693 
1694 	error = devsw->d_ioctl(dev, DIOCGSECTORSIZE,
1695 			       (caddr_t)&be_lun->blocksize, FREAD,
1696 			       curthread);
1697 	if (error) {
1698 		snprintf(req->error_str, sizeof(req->error_str),
1699 			 "error %d returned for DIOCGSECTORSIZE ioctl "
1700 			 "on %s!", error, be_lun->dev_path);
1701 		return (error);
1702 	}
1703 
1704 	/*
1705 	 * If the user has asked for a blocksize that is greater than the
1706 	 * backing device's blocksize, we can do it only if the blocksize
1707 	 * the user is asking for is an even multiple of the underlying
1708 	 * device's blocksize.
1709 	 */
1710 	if ((params->blocksize_bytes != 0)
1711 	 && (params->blocksize_bytes > be_lun->blocksize)) {
1712 		uint32_t bs_multiple, tmp_blocksize;
1713 
1714 		bs_multiple = params->blocksize_bytes / be_lun->blocksize;
1715 
1716 		tmp_blocksize = bs_multiple * be_lun->blocksize;
1717 
1718 		if (tmp_blocksize == params->blocksize_bytes) {
1719 			be_lun->blocksize = params->blocksize_bytes;
1720 		} else {
1721 			snprintf(req->error_str, sizeof(req->error_str),
1722 				 "requested blocksize %u is not an even "
1723 				 "multiple of backing device blocksize %u",
1724 				 params->blocksize_bytes,
1725 				 be_lun->blocksize);
1726 			return (EINVAL);
1727 
1728 		}
1729 	} else if ((params->blocksize_bytes != 0)
1730 		&& (params->blocksize_bytes != be_lun->blocksize)) {
1731 		snprintf(req->error_str, sizeof(req->error_str),
1732 			 "requested blocksize %u < backing device "
1733 			 "blocksize %u", params->blocksize_bytes,
1734 			 be_lun->blocksize);
1735 		return (EINVAL);
1736 	}
1737 
1738 	error = devsw->d_ioctl(dev, DIOCGMEDIASIZE,
1739 			       (caddr_t)&be_lun->size_bytes, FREAD,
1740 			       curthread);
1741 	if (error) {
1742 		snprintf(req->error_str, sizeof(req->error_str),
1743 			 "error %d returned for DIOCGMEDIASIZE "
1744 			 " ioctl on %s!", error,
1745 			 be_lun->dev_path);
1746 		return (error);
1747 	}
1748 
1749 	if (params->lun_size_bytes != 0) {
1750 		if (params->lun_size_bytes > be_lun->size_bytes) {
1751 			snprintf(req->error_str, sizeof(req->error_str),
1752 				 "requested LUN size %ju > backing device "
1753 				 "size %ju",
1754 				 (uintmax_t)params->lun_size_bytes,
1755 				 (uintmax_t)be_lun->size_bytes);
1756 			return (EINVAL);
1757 		}
1758 
1759 		be_lun->size_bytes = params->lun_size_bytes;
1760 	}
1761 
1762 	error = devsw->d_ioctl(dev, DIOCGSTRIPESIZE,
1763 			       (caddr_t)&ps, FREAD, curthread);
1764 	if (error)
1765 		ps = po = 0;
1766 	else {
1767 		error = devsw->d_ioctl(dev, DIOCGSTRIPEOFFSET,
1768 				       (caddr_t)&po, FREAD, curthread);
1769 		if (error)
1770 			po = 0;
1771 	}
1772 	pss = ps / be_lun->blocksize;
1773 	pos = po / be_lun->blocksize;
1774 	if ((pss > 0) && (pss * be_lun->blocksize == ps) && (pss >= pos) &&
1775 	    ((pss & (pss - 1)) == 0) && (pos * be_lun->blocksize == po)) {
1776 		be_lun->pblockexp = fls(pss) - 1;
1777 		be_lun->pblockoff = (pss - pos) % pss;
1778 	}
1779 
1780 	return (0);
1781 }
1782 
1783 static int
1784 ctl_be_block_close(struct ctl_be_block_lun *be_lun)
1785 {
1786 	DROP_GIANT();
1787 	if (be_lun->vn) {
1788 		int flags = FREAD | FWRITE;
1789 
1790 		switch (be_lun->dev_type) {
1791 		case CTL_BE_BLOCK_DEV:
1792 			if (be_lun->backend.dev.csw) {
1793 				dev_relthread(be_lun->backend.dev.cdev,
1794 					      be_lun->backend.dev.dev_ref);
1795 				be_lun->backend.dev.csw  = NULL;
1796 				be_lun->backend.dev.cdev = NULL;
1797 			}
1798 			break;
1799 		case CTL_BE_BLOCK_FILE:
1800 			break;
1801 		case CTL_BE_BLOCK_NONE:
1802 			break;
1803 		default:
1804 			panic("Unexpected backend type.");
1805 			break;
1806 		}
1807 
1808 		(void)vn_close(be_lun->vn, flags, NOCRED, curthread);
1809 		be_lun->vn = NULL;
1810 
1811 		switch (be_lun->dev_type) {
1812 		case CTL_BE_BLOCK_DEV:
1813 			break;
1814 		case CTL_BE_BLOCK_FILE:
1815 			if (be_lun->backend.file.cred != NULL) {
1816 				crfree(be_lun->backend.file.cred);
1817 				be_lun->backend.file.cred = NULL;
1818 			}
1819 			break;
1820 		case CTL_BE_BLOCK_NONE:
1821 			break;
1822 		default:
1823 			panic("Unexpected backend type.");
1824 			break;
1825 		}
1826 		be_lun->dev_type = CTL_BE_BLOCK_NONE;
1827 	}
1828 	PICKUP_GIANT();
1829 
1830 	return (0);
1831 }
1832 
1833 static int
1834 ctl_be_block_open(struct ctl_be_block_softc *softc,
1835 		       struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1836 {
1837 	struct nameidata nd;
1838 	int		 flags;
1839 	int		 error;
1840 
1841 	/*
1842 	 * XXX KDM allow a read-only option?
1843 	 */
1844 	flags = FREAD | FWRITE;
1845 	error = 0;
1846 
1847 	if (rootvnode == NULL) {
1848 		snprintf(req->error_str, sizeof(req->error_str),
1849 			 "Root filesystem is not mounted");
1850 		return (1);
1851 	}
1852 
1853 	if (!curthread->td_proc->p_fd->fd_cdir) {
1854 		curthread->td_proc->p_fd->fd_cdir = rootvnode;
1855 		VREF(rootvnode);
1856 	}
1857 	if (!curthread->td_proc->p_fd->fd_rdir) {
1858 		curthread->td_proc->p_fd->fd_rdir = rootvnode;
1859 		VREF(rootvnode);
1860 	}
1861 	if (!curthread->td_proc->p_fd->fd_jdir) {
1862 		curthread->td_proc->p_fd->fd_jdir = rootvnode;
1863 		VREF(rootvnode);
1864 	}
1865 
1866  again:
1867 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, be_lun->dev_path, curthread);
1868 	error = vn_open(&nd, &flags, 0, NULL);
1869 	if (error) {
1870 		/*
1871 		 * This is the only reasonable guess we can make as far as
1872 		 * path if the user doesn't give us a fully qualified path.
1873 		 * If they want to specify a file, they need to specify the
1874 		 * full path.
1875 		 */
1876 		if (be_lun->dev_path[0] != '/') {
1877 			char *dev_path = "/dev/";
1878 			char *dev_name;
1879 
1880 			/* Try adding device path at beginning of name */
1881 			dev_name = malloc(strlen(be_lun->dev_path)
1882 					+ strlen(dev_path) + 1,
1883 					  M_CTLBLK, M_WAITOK);
1884 			if (dev_name) {
1885 				sprintf(dev_name, "%s%s", dev_path,
1886 					be_lun->dev_path);
1887 				free(be_lun->dev_path, M_CTLBLK);
1888 				be_lun->dev_path = dev_name;
1889 				goto again;
1890 			}
1891 		}
1892 		snprintf(req->error_str, sizeof(req->error_str),
1893 		    "error opening %s: %d", be_lun->dev_path, error);
1894 		return (error);
1895 	}
1896 
1897 	NDFREE(&nd, NDF_ONLY_PNBUF);
1898 
1899 	be_lun->vn = nd.ni_vp;
1900 
1901 	/* We only support disks and files. */
1902 	if (vn_isdisk(be_lun->vn, &error)) {
1903 		error = ctl_be_block_open_dev(be_lun, req);
1904 	} else if (be_lun->vn->v_type == VREG) {
1905 		error = ctl_be_block_open_file(be_lun, req);
1906 	} else {
1907 		error = EINVAL;
1908 		snprintf(req->error_str, sizeof(req->error_str),
1909 			 "%s is not a disk or plain file", be_lun->dev_path);
1910 	}
1911 	VOP_UNLOCK(be_lun->vn, 0);
1912 
1913 	if (error != 0) {
1914 		ctl_be_block_close(be_lun);
1915 		return (error);
1916 	}
1917 
1918 	be_lun->blocksize_shift = fls(be_lun->blocksize) - 1;
1919 	be_lun->size_blocks = be_lun->size_bytes >> be_lun->blocksize_shift;
1920 
1921 	return (0);
1922 }
1923 
1924 static int
1925 ctl_be_block_create(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
1926 {
1927 	struct ctl_be_block_lun *be_lun;
1928 	struct ctl_lun_create_params *params;
1929 	char num_thread_str[16];
1930 	char tmpstr[32];
1931 	char *value;
1932 	int retval, num_threads, unmap;
1933 	int tmp_num_threads;
1934 
1935 	params = &req->reqdata.create;
1936 	retval = 0;
1937 	req->status = CTL_LUN_OK;
1938 
1939 	num_threads = cbb_num_threads;
1940 
1941 	be_lun = malloc(sizeof(*be_lun), M_CTLBLK, M_ZERO | M_WAITOK);
1942 
1943 	be_lun->params = req->reqdata.create;
1944 	be_lun->softc = softc;
1945 	STAILQ_INIT(&be_lun->input_queue);
1946 	STAILQ_INIT(&be_lun->config_write_queue);
1947 	STAILQ_INIT(&be_lun->datamove_queue);
1948 	sprintf(be_lun->lunname, "cblk%d", softc->num_luns);
1949 	mtx_init(&be_lun->io_lock, "cblk io lock", NULL, MTX_DEF);
1950 	mtx_init(&be_lun->queue_lock, "cblk queue lock", NULL, MTX_DEF);
1951 	ctl_init_opts(&be_lun->ctl_be_lun.options,
1952 	    req->num_be_args, req->kern_be_args);
1953 
1954 	be_lun->lun_zone = uma_zcreate(be_lun->lunname, CTLBLK_MAX_SEG,
1955 	    NULL, NULL, NULL, NULL, /*align*/ 0, /*flags*/0);
1956 
1957 	if (be_lun->lun_zone == NULL) {
1958 		snprintf(req->error_str, sizeof(req->error_str),
1959 			 "error allocating UMA zone");
1960 		goto bailout_error;
1961 	}
1962 
1963 	if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
1964 		be_lun->ctl_be_lun.lun_type = params->device_type;
1965 	else
1966 		be_lun->ctl_be_lun.lun_type = T_DIRECT;
1967 
1968 	if (be_lun->ctl_be_lun.lun_type == T_DIRECT) {
1969 		value = ctl_get_opt(&be_lun->ctl_be_lun.options, "file");
1970 		if (value == NULL) {
1971 			snprintf(req->error_str, sizeof(req->error_str),
1972 				 "no file argument specified");
1973 			goto bailout_error;
1974 		}
1975 		be_lun->dev_path = strdup(value, M_CTLBLK);
1976 		be_lun->blocksize = 512;
1977 		be_lun->blocksize_shift = fls(be_lun->blocksize) - 1;
1978 
1979 		retval = ctl_be_block_open(softc, be_lun, req);
1980 		if (retval != 0) {
1981 			retval = 0;
1982 			req->status = CTL_LUN_WARNING;
1983 		}
1984 	} else {
1985 		/*
1986 		 * For processor devices, we don't have any size.
1987 		 */
1988 		be_lun->blocksize = 0;
1989 		be_lun->pblockexp = 0;
1990 		be_lun->pblockoff = 0;
1991 		be_lun->size_blocks = 0;
1992 		be_lun->size_bytes = 0;
1993 		be_lun->ctl_be_lun.maxlba = 0;
1994 
1995 		/*
1996 		 * Default to just 1 thread for processor devices.
1997 		 */
1998 		num_threads = 1;
1999 	}
2000 
2001 	/*
2002 	 * XXX This searching loop might be refactored to be combined with
2003 	 * the loop above,
2004 	 */
2005 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "num_threads");
2006 	if (value != NULL) {
2007 		tmp_num_threads = strtol(value, NULL, 0);
2008 
2009 		/*
2010 		 * We don't let the user specify less than one
2011 		 * thread, but hope he's clueful enough not to
2012 		 * specify 1000 threads.
2013 		 */
2014 		if (tmp_num_threads < 1) {
2015 			snprintf(req->error_str, sizeof(req->error_str),
2016 				 "invalid number of threads %s",
2017 				 num_thread_str);
2018 			goto bailout_error;
2019 		}
2020 		num_threads = tmp_num_threads;
2021 	}
2022 	unmap = (be_lun->dispatch == ctl_be_block_dispatch_zvol);
2023 	value = ctl_get_opt(&be_lun->ctl_be_lun.options, "unmap");
2024 	if (value != NULL)
2025 		unmap = (strcmp(value, "on") == 0);
2026 
2027 	be_lun->flags = CTL_BE_BLOCK_LUN_UNCONFIGURED;
2028 	be_lun->ctl_be_lun.flags = CTL_LUN_FLAG_PRIMARY;
2029 	if (be_lun->vn == NULL)
2030 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_OFFLINE;
2031 	if (unmap)
2032 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_UNMAP;
2033 	be_lun->ctl_be_lun.be_lun = be_lun;
2034 	be_lun->ctl_be_lun.maxlba = (be_lun->size_blocks == 0) ?
2035 	    0 : (be_lun->size_blocks - 1);
2036 	be_lun->ctl_be_lun.blocksize = be_lun->blocksize;
2037 	be_lun->ctl_be_lun.pblockexp = be_lun->pblockexp;
2038 	be_lun->ctl_be_lun.pblockoff = be_lun->pblockoff;
2039 	if (be_lun->dispatch == ctl_be_block_dispatch_zvol &&
2040 	    be_lun->blocksize != 0)
2041 		be_lun->ctl_be_lun.atomicblock = CTLBLK_MAX_IO_SIZE /
2042 		    be_lun->blocksize;
2043 	/* Tell the user the blocksize we ended up using */
2044 	params->lun_size_bytes = be_lun->size_bytes;
2045 	params->blocksize_bytes = be_lun->blocksize;
2046 	if (params->flags & CTL_LUN_FLAG_ID_REQ) {
2047 		be_lun->ctl_be_lun.req_lun_id = params->req_lun_id;
2048 		be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_ID_REQ;
2049 	} else
2050 		be_lun->ctl_be_lun.req_lun_id = 0;
2051 
2052 	be_lun->ctl_be_lun.lun_shutdown = ctl_be_block_lun_shutdown;
2053 	be_lun->ctl_be_lun.lun_config_status =
2054 		ctl_be_block_lun_config_status;
2055 	be_lun->ctl_be_lun.be = &ctl_be_block_driver;
2056 
2057 	if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
2058 		snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
2059 			 softc->num_luns);
2060 		strncpy((char *)be_lun->ctl_be_lun.serial_num, tmpstr,
2061 			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
2062 			sizeof(tmpstr)));
2063 
2064 		/* Tell the user what we used for a serial number */
2065 		strncpy((char *)params->serial_num, tmpstr,
2066 			ctl_min(sizeof(params->serial_num), sizeof(tmpstr)));
2067 	} else {
2068 		strncpy((char *)be_lun->ctl_be_lun.serial_num,
2069 			params->serial_num,
2070 			ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
2071 			sizeof(params->serial_num)));
2072 	}
2073 	if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
2074 		snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
2075 		strncpy((char *)be_lun->ctl_be_lun.device_id, tmpstr,
2076 			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
2077 			sizeof(tmpstr)));
2078 
2079 		/* Tell the user what we used for a device ID */
2080 		strncpy((char *)params->device_id, tmpstr,
2081 			ctl_min(sizeof(params->device_id), sizeof(tmpstr)));
2082 	} else {
2083 		strncpy((char *)be_lun->ctl_be_lun.device_id,
2084 			params->device_id,
2085 			ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
2086 				sizeof(params->device_id)));
2087 	}
2088 
2089 	TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_be_block_worker, be_lun);
2090 
2091 	be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
2092 	    taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
2093 
2094 	if (be_lun->io_taskqueue == NULL) {
2095 		snprintf(req->error_str, sizeof(req->error_str),
2096 			 "unable to create taskqueue");
2097 		goto bailout_error;
2098 	}
2099 
2100 	/*
2101 	 * Note that we start the same number of threads by default for
2102 	 * both the file case and the block device case.  For the file
2103 	 * case, we need multiple threads to allow concurrency, because the
2104 	 * vnode interface is designed to be a blocking interface.  For the
2105 	 * block device case, ZFS zvols at least will block the caller's
2106 	 * context in many instances, and so we need multiple threads to
2107 	 * overcome that problem.  Other block devices don't need as many
2108 	 * threads, but they shouldn't cause too many problems.
2109 	 *
2110 	 * If the user wants to just have a single thread for a block
2111 	 * device, he can specify that when the LUN is created, or change
2112 	 * the tunable/sysctl to alter the default number of threads.
2113 	 */
2114 	retval = taskqueue_start_threads(&be_lun->io_taskqueue,
2115 					 /*num threads*/num_threads,
2116 					 /*priority*/PWAIT,
2117 					 /*thread name*/
2118 					 "%s taskq", be_lun->lunname);
2119 
2120 	if (retval != 0)
2121 		goto bailout_error;
2122 
2123 	be_lun->num_threads = num_threads;
2124 
2125 	mtx_lock(&softc->lock);
2126 	softc->num_luns++;
2127 	STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
2128 
2129 	mtx_unlock(&softc->lock);
2130 
2131 	retval = ctl_add_lun(&be_lun->ctl_be_lun);
2132 	if (retval != 0) {
2133 		mtx_lock(&softc->lock);
2134 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2135 			      links);
2136 		softc->num_luns--;
2137 		mtx_unlock(&softc->lock);
2138 		snprintf(req->error_str, sizeof(req->error_str),
2139 			 "ctl_add_lun() returned error %d, see dmesg for "
2140 			 "details", retval);
2141 		retval = 0;
2142 		goto bailout_error;
2143 	}
2144 
2145 	mtx_lock(&softc->lock);
2146 
2147 	/*
2148 	 * Tell the config_status routine that we're waiting so it won't
2149 	 * clean up the LUN in the event of an error.
2150 	 */
2151 	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2152 
2153 	while (be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) {
2154 		retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2155 		if (retval == EINTR)
2156 			break;
2157 	}
2158 	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2159 
2160 	if (be_lun->flags & CTL_BE_BLOCK_LUN_CONFIG_ERR) {
2161 		snprintf(req->error_str, sizeof(req->error_str),
2162 			 "LUN configuration error, see dmesg for details");
2163 		STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
2164 			      links);
2165 		softc->num_luns--;
2166 		mtx_unlock(&softc->lock);
2167 		goto bailout_error;
2168 	} else {
2169 		params->req_lun_id = be_lun->ctl_be_lun.lun_id;
2170 	}
2171 
2172 	mtx_unlock(&softc->lock);
2173 
2174 	be_lun->disk_stats = devstat_new_entry("cbb", params->req_lun_id,
2175 					       be_lun->blocksize,
2176 					       DEVSTAT_ALL_SUPPORTED,
2177 					       be_lun->ctl_be_lun.lun_type
2178 					       | DEVSTAT_TYPE_IF_OTHER,
2179 					       DEVSTAT_PRIORITY_OTHER);
2180 
2181 	return (retval);
2182 
2183 bailout_error:
2184 	req->status = CTL_LUN_ERROR;
2185 
2186 	if (be_lun->io_taskqueue != NULL)
2187 		taskqueue_free(be_lun->io_taskqueue);
2188 	ctl_be_block_close(be_lun);
2189 	if (be_lun->dev_path != NULL)
2190 		free(be_lun->dev_path, M_CTLBLK);
2191 	if (be_lun->lun_zone != NULL)
2192 		uma_zdestroy(be_lun->lun_zone);
2193 	ctl_free_opts(&be_lun->ctl_be_lun.options);
2194 	mtx_destroy(&be_lun->queue_lock);
2195 	mtx_destroy(&be_lun->io_lock);
2196 	free(be_lun, M_CTLBLK);
2197 
2198 	return (retval);
2199 }
2200 
2201 static int
2202 ctl_be_block_rm(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2203 {
2204 	struct ctl_lun_rm_params *params;
2205 	struct ctl_be_block_lun *be_lun;
2206 	int retval;
2207 
2208 	params = &req->reqdata.rm;
2209 
2210 	mtx_lock(&softc->lock);
2211 
2212 	be_lun = NULL;
2213 
2214 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2215 		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2216 			break;
2217 	}
2218 	mtx_unlock(&softc->lock);
2219 
2220 	if (be_lun == NULL) {
2221 		snprintf(req->error_str, sizeof(req->error_str),
2222 			 "LUN %u is not managed by the block backend",
2223 			 params->lun_id);
2224 		goto bailout_error;
2225 	}
2226 
2227 	retval = ctl_disable_lun(&be_lun->ctl_be_lun);
2228 
2229 	if (retval != 0) {
2230 		snprintf(req->error_str, sizeof(req->error_str),
2231 			 "error %d returned from ctl_disable_lun() for "
2232 			 "LUN %d", retval, params->lun_id);
2233 		goto bailout_error;
2234 
2235 	}
2236 
2237 	retval = ctl_invalidate_lun(&be_lun->ctl_be_lun);
2238 	if (retval != 0) {
2239 		snprintf(req->error_str, sizeof(req->error_str),
2240 			 "error %d returned from ctl_invalidate_lun() for "
2241 			 "LUN %d", retval, params->lun_id);
2242 		goto bailout_error;
2243 	}
2244 
2245 	mtx_lock(&softc->lock);
2246 
2247 	be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
2248 
2249 	while ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2250                 retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
2251                 if (retval == EINTR)
2252                         break;
2253         }
2254 
2255 	be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
2256 
2257 	if ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
2258 		snprintf(req->error_str, sizeof(req->error_str),
2259 			 "interrupted waiting for LUN to be freed");
2260 		mtx_unlock(&softc->lock);
2261 		goto bailout_error;
2262 	}
2263 
2264 	STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun, links);
2265 
2266 	softc->num_luns--;
2267 	mtx_unlock(&softc->lock);
2268 
2269 	taskqueue_drain(be_lun->io_taskqueue, &be_lun->io_task);
2270 
2271 	taskqueue_free(be_lun->io_taskqueue);
2272 
2273 	ctl_be_block_close(be_lun);
2274 
2275 	if (be_lun->disk_stats != NULL)
2276 		devstat_remove_entry(be_lun->disk_stats);
2277 
2278 	uma_zdestroy(be_lun->lun_zone);
2279 
2280 	ctl_free_opts(&be_lun->ctl_be_lun.options);
2281 	free(be_lun->dev_path, M_CTLBLK);
2282 	mtx_destroy(&be_lun->queue_lock);
2283 	mtx_destroy(&be_lun->io_lock);
2284 	free(be_lun, M_CTLBLK);
2285 
2286 	req->status = CTL_LUN_OK;
2287 
2288 	return (0);
2289 
2290 bailout_error:
2291 
2292 	req->status = CTL_LUN_ERROR;
2293 
2294 	return (0);
2295 }
2296 
2297 static int
2298 ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
2299 			 struct ctl_lun_req *req)
2300 {
2301 	struct vattr vattr;
2302 	int error;
2303 	struct ctl_lun_create_params *params = &be_lun->params;
2304 
2305 	if (params->lun_size_bytes != 0) {
2306 		be_lun->size_bytes = params->lun_size_bytes;
2307 	} else  {
2308 		vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
2309 		error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
2310 		VOP_UNLOCK(be_lun->vn, 0);
2311 		if (error != 0) {
2312 			snprintf(req->error_str, sizeof(req->error_str),
2313 				 "error calling VOP_GETATTR() for file %s",
2314 				 be_lun->dev_path);
2315 			return (error);
2316 		}
2317 
2318 		be_lun->size_bytes = vattr.va_size;
2319 	}
2320 
2321 	return (0);
2322 }
2323 
2324 static int
2325 ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
2326 			struct ctl_lun_req *req)
2327 {
2328 	struct ctl_be_block_devdata *dev_data;
2329 	int error;
2330 	struct ctl_lun_create_params *params = &be_lun->params;
2331 	uint64_t size_bytes;
2332 
2333 	dev_data = &be_lun->backend.dev;
2334 	if (!dev_data->csw->d_ioctl) {
2335 		snprintf(req->error_str, sizeof(req->error_str),
2336 			 "no d_ioctl for device %s!", be_lun->dev_path);
2337 		return (ENODEV);
2338 	}
2339 
2340 	error = dev_data->csw->d_ioctl(dev_data->cdev, DIOCGMEDIASIZE,
2341 			       (caddr_t)&size_bytes, FREAD,
2342 			       curthread);
2343 	if (error) {
2344 		snprintf(req->error_str, sizeof(req->error_str),
2345 			 "error %d returned for DIOCGMEDIASIZE ioctl "
2346 			 "on %s!", error, be_lun->dev_path);
2347 		return (error);
2348 	}
2349 
2350 	if (params->lun_size_bytes != 0) {
2351 		if (params->lun_size_bytes > size_bytes) {
2352 			snprintf(req->error_str, sizeof(req->error_str),
2353 				 "requested LUN size %ju > backing device "
2354 				 "size %ju",
2355 				 (uintmax_t)params->lun_size_bytes,
2356 				 (uintmax_t)size_bytes);
2357 			return (EINVAL);
2358 		}
2359 
2360 		be_lun->size_bytes = params->lun_size_bytes;
2361 	} else {
2362 		be_lun->size_bytes = size_bytes;
2363 	}
2364 
2365 	return (0);
2366 }
2367 
2368 static int
2369 ctl_be_block_modify(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2370 {
2371 	struct ctl_lun_modify_params *params;
2372 	struct ctl_be_block_lun *be_lun;
2373 	uint64_t oldsize;
2374 	int error;
2375 
2376 	params = &req->reqdata.modify;
2377 
2378 	mtx_lock(&softc->lock);
2379 	be_lun = NULL;
2380 	STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2381 		if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2382 			break;
2383 	}
2384 	mtx_unlock(&softc->lock);
2385 
2386 	if (be_lun == NULL) {
2387 		snprintf(req->error_str, sizeof(req->error_str),
2388 			 "LUN %u is not managed by the block backend",
2389 			 params->lun_id);
2390 		goto bailout_error;
2391 	}
2392 
2393 	be_lun->params.lun_size_bytes = params->lun_size_bytes;
2394 
2395 	oldsize = be_lun->size_bytes;
2396 	if (be_lun->vn == NULL)
2397 		error = ctl_be_block_open(softc, be_lun, req);
2398 	else if (be_lun->vn->v_type == VREG)
2399 		error = ctl_be_block_modify_file(be_lun, req);
2400 	else
2401 		error = ctl_be_block_modify_dev(be_lun, req);
2402 
2403 	if (error == 0 && be_lun->size_bytes != oldsize) {
2404 		be_lun->size_blocks = be_lun->size_bytes >>
2405 		    be_lun->blocksize_shift;
2406 
2407 		/*
2408 		 * The maximum LBA is the size - 1.
2409 		 *
2410 		 * XXX: Note that this field is being updated without locking,
2411 		 * 	which might cause problems on 32-bit architectures.
2412 		 */
2413 		be_lun->ctl_be_lun.maxlba = (be_lun->size_blocks == 0) ?
2414 		    0 : (be_lun->size_blocks - 1);
2415 		be_lun->ctl_be_lun.blocksize = be_lun->blocksize;
2416 		be_lun->ctl_be_lun.pblockexp = be_lun->pblockexp;
2417 		be_lun->ctl_be_lun.pblockoff = be_lun->pblockoff;
2418 		if (be_lun->dispatch == ctl_be_block_dispatch_zvol &&
2419 		    be_lun->blocksize != 0)
2420 			be_lun->ctl_be_lun.atomicblock = CTLBLK_MAX_IO_SIZE /
2421 			    be_lun->blocksize;
2422 		ctl_lun_capacity_changed(&be_lun->ctl_be_lun);
2423 		if (oldsize == 0 && be_lun->size_blocks != 0)
2424 			ctl_lun_online(&be_lun->ctl_be_lun);
2425 	}
2426 
2427 	/* Tell the user the exact size we ended up using */
2428 	params->lun_size_bytes = be_lun->size_bytes;
2429 
2430 	req->status = error ? CTL_LUN_WARNING : CTL_LUN_OK;
2431 
2432 	return (0);
2433 
2434 bailout_error:
2435 	req->status = CTL_LUN_ERROR;
2436 
2437 	return (0);
2438 }
2439 
2440 static void
2441 ctl_be_block_lun_shutdown(void *be_lun)
2442 {
2443 	struct ctl_be_block_lun *lun;
2444 	struct ctl_be_block_softc *softc;
2445 
2446 	lun = (struct ctl_be_block_lun *)be_lun;
2447 
2448 	softc = lun->softc;
2449 
2450 	mtx_lock(&softc->lock);
2451 	lun->flags |= CTL_BE_BLOCK_LUN_UNCONFIGURED;
2452 	if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2453 		wakeup(lun);
2454 	mtx_unlock(&softc->lock);
2455 
2456 }
2457 
2458 static void
2459 ctl_be_block_lun_config_status(void *be_lun, ctl_lun_config_status status)
2460 {
2461 	struct ctl_be_block_lun *lun;
2462 	struct ctl_be_block_softc *softc;
2463 
2464 	lun = (struct ctl_be_block_lun *)be_lun;
2465 	softc = lun->softc;
2466 
2467 	if (status == CTL_LUN_CONFIG_OK) {
2468 		mtx_lock(&softc->lock);
2469 		lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2470 		if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2471 			wakeup(lun);
2472 		mtx_unlock(&softc->lock);
2473 
2474 		/*
2475 		 * We successfully added the LUN, attempt to enable it.
2476 		 */
2477 		if (ctl_enable_lun(&lun->ctl_be_lun) != 0) {
2478 			printf("%s: ctl_enable_lun() failed!\n", __func__);
2479 			if (ctl_invalidate_lun(&lun->ctl_be_lun) != 0) {
2480 				printf("%s: ctl_invalidate_lun() failed!\n",
2481 				       __func__);
2482 			}
2483 		}
2484 
2485 		return;
2486 	}
2487 
2488 
2489 	mtx_lock(&softc->lock);
2490 	lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2491 	lun->flags |= CTL_BE_BLOCK_LUN_CONFIG_ERR;
2492 	wakeup(lun);
2493 	mtx_unlock(&softc->lock);
2494 }
2495 
2496 
2497 static int
2498 ctl_be_block_config_write(union ctl_io *io)
2499 {
2500 	struct ctl_be_block_lun *be_lun;
2501 	struct ctl_be_lun *ctl_be_lun;
2502 	int retval;
2503 
2504 	retval = 0;
2505 
2506 	DPRINTF("entered\n");
2507 
2508 	ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
2509 		CTL_PRIV_BACKEND_LUN].ptr;
2510 	be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
2511 
2512 	switch (io->scsiio.cdb[0]) {
2513 	case SYNCHRONIZE_CACHE:
2514 	case SYNCHRONIZE_CACHE_16:
2515 	case WRITE_SAME_10:
2516 	case WRITE_SAME_16:
2517 	case UNMAP:
2518 		/*
2519 		 * The upper level CTL code will filter out any CDBs with
2520 		 * the immediate bit set and return the proper error.
2521 		 *
2522 		 * We don't really need to worry about what LBA range the
2523 		 * user asked to be synced out.  When they issue a sync
2524 		 * cache command, we'll sync out the whole thing.
2525 		 */
2526 		mtx_lock(&be_lun->queue_lock);
2527 		STAILQ_INSERT_TAIL(&be_lun->config_write_queue, &io->io_hdr,
2528 				   links);
2529 		mtx_unlock(&be_lun->queue_lock);
2530 		taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
2531 		break;
2532 	case START_STOP_UNIT: {
2533 		struct scsi_start_stop_unit *cdb;
2534 
2535 		cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
2536 
2537 		if (cdb->how & SSS_START)
2538 			retval = ctl_start_lun(ctl_be_lun);
2539 		else {
2540 			retval = ctl_stop_lun(ctl_be_lun);
2541 			/*
2542 			 * XXX KDM Copan-specific offline behavior.
2543 			 * Figure out a reasonable way to port this?
2544 			 */
2545 #ifdef NEEDTOPORT
2546 			if ((retval == 0)
2547 			 && (cdb->byte2 & SSS_ONOFFLINE))
2548 				retval = ctl_lun_offline(ctl_be_lun);
2549 #endif
2550 		}
2551 
2552 		/*
2553 		 * In general, the above routines should not fail.  They
2554 		 * just set state for the LUN.  So we've got something
2555 		 * pretty wrong here if we can't start or stop the LUN.
2556 		 */
2557 		if (retval != 0) {
2558 			ctl_set_internal_failure(&io->scsiio,
2559 						 /*sks_valid*/ 1,
2560 						 /*retry_count*/ 0xf051);
2561 			retval = CTL_RETVAL_COMPLETE;
2562 		} else {
2563 			ctl_set_success(&io->scsiio);
2564 		}
2565 		ctl_config_write_done(io);
2566 		break;
2567 	}
2568 	default:
2569 		ctl_set_invalid_opcode(&io->scsiio);
2570 		ctl_config_write_done(io);
2571 		retval = CTL_RETVAL_COMPLETE;
2572 		break;
2573 	}
2574 
2575 	return (retval);
2576 
2577 }
2578 
2579 static int
2580 ctl_be_block_config_read(union ctl_io *io)
2581 {
2582 	return (0);
2583 }
2584 
2585 static int
2586 ctl_be_block_lun_info(void *be_lun, struct sbuf *sb)
2587 {
2588 	struct ctl_be_block_lun *lun;
2589 	int retval;
2590 
2591 	lun = (struct ctl_be_block_lun *)be_lun;
2592 	retval = 0;
2593 
2594 	retval = sbuf_printf(sb, "\t<num_threads>");
2595 
2596 	if (retval != 0)
2597 		goto bailout;
2598 
2599 	retval = sbuf_printf(sb, "%d", lun->num_threads);
2600 
2601 	if (retval != 0)
2602 		goto bailout;
2603 
2604 	retval = sbuf_printf(sb, "</num_threads>\n");
2605 
2606 bailout:
2607 
2608 	return (retval);
2609 }
2610 
2611 static uint64_t
2612 ctl_be_block_lun_attr(void *be_lun, const char *attrname)
2613 {
2614 	struct ctl_be_block_lun *lun = (struct ctl_be_block_lun *)be_lun;
2615 
2616 	if (lun->getattr == NULL)
2617 		return (UINT64_MAX);
2618 	return (lun->getattr(lun, attrname));
2619 }
2620 
2621 int
2622 ctl_be_block_init(void)
2623 {
2624 	struct ctl_be_block_softc *softc;
2625 	int retval;
2626 
2627 	softc = &backend_block_softc;
2628 	retval = 0;
2629 
2630 	mtx_init(&softc->lock, "ctlblock", NULL, MTX_DEF);
2631 	beio_zone = uma_zcreate("beio", sizeof(struct ctl_be_block_io),
2632 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
2633 	STAILQ_INIT(&softc->disk_list);
2634 	STAILQ_INIT(&softc->lun_list);
2635 
2636 	return (retval);
2637 }
2638