sys/cam/ctl/ctl_backend_block.c

   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 <opt_kdtrace.h>
  46
  47 #include <sys/param.h>
  48 #include <sys/systm.h>
  49 #include <sys/kernel.h>
  50 #include <sys/types.h>
  51 #include <sys/kthread.h>
  52 #include <sys/bio.h>
  53 #include <sys/fcntl.h>
  54 #include <sys/lock.h>
  55 #include <sys/mutex.h>
  56 #include <sys/condvar.h>
  57 #include <sys/malloc.h>
  58 #include <sys/conf.h>
  59 #include <sys/ioccom.h>
  60 #include <sys/queue.h>
  61 #include <sys/sbuf.h>
  62 #include <sys/endian.h>
  63 #include <sys/uio.h>
  64 #include <sys/buf.h>
  65 #include <sys/taskqueue.h>
  66 #include <sys/vnode.h>
  67 #include <sys/namei.h>
  68 #include <sys/mount.h>
  69 #include <sys/disk.h>
  70 #include <sys/fcntl.h>
  71 #include <sys/filedesc.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 16MB
  94  * I/O.  If we get an I/O larger than that, we'll reject it.
  95  */
  96 #define CTLBLK_MAX_IO_SIZE      (16 * 1024 * 1024)
  97 #define CTLBLK_MAX_SEGS         (CTLBLK_MAX_IO_SIZE / MAXPHYS) + 1
  98
  99 #ifdef CTLBLK_DEBUG
 100 #define DPRINTF(fmt, args...) \
 101     printf("cbb(%s:%d): " fmt, __FUNCTION__, __LINE__, ##args)
 102 #else
 103 #define DPRINTF(fmt, args...) do {} while(0)
 104 #endif
 105
 106 SDT_PROVIDER_DEFINE(cbb);
 107
 108 typedef enum {
 109         CTL_BE_BLOCK_LUN_UNCONFIGURED   = 0x01,
 110         CTL_BE_BLOCK_LUN_CONFIG_ERR     = 0x02,
 111         CTL_BE_BLOCK_LUN_WAITING        = 0x04,
 112         CTL_BE_BLOCK_LUN_MULTI_THREAD   = 0x08
 113 } ctl_be_block_lun_flags;
 114
 115 typedef enum {
 116         CTL_BE_BLOCK_NONE,
 117         CTL_BE_BLOCK_DEV,
 118         CTL_BE_BLOCK_FILE
 119 } ctl_be_block_type;
 120
 121 struct ctl_be_block_devdata {
 122         struct cdev *cdev;
 123         struct cdevsw *csw;
 124         int dev_ref;
 125 };
 126
 127 struct ctl_be_block_filedata {
 128         struct ucred *cred;
 129 };
 130
 131 union ctl_be_block_bedata {
 132         struct ctl_be_block_devdata dev;
 133         struct ctl_be_block_filedata file;
 134 };
 135
 136 struct ctl_be_block_io;
 137 struct ctl_be_block_lun;
 138
 139 typedef void (*cbb_dispatch_t)(struct ctl_be_block_lun *be_lun,
 140                                struct ctl_be_block_io *beio);
 141
 142 /*
 143  * Backend LUN structure.  There is a 1:1 mapping between a block device
 144  * and a backend block LUN, and between a backend block LUN and a CTL LUN.
 145  */
 146 struct ctl_be_block_lun {
 147         struct ctl_block_disk *disk;
 148         char lunname[32];
 149         char *dev_path;
 150         ctl_be_block_type dev_type;
 151         struct vnode *vn;
 152         union ctl_be_block_bedata backend;
 153         cbb_dispatch_t dispatch;
 154         cbb_dispatch_t lun_flush;
 155         struct mtx lock;
 156         uma_zone_t lun_zone;
 157         uint64_t size_blocks;
 158         uint64_t size_bytes;
 159         uint32_t blocksize;
 160         int blocksize_shift;
 161         struct ctl_be_block_softc *softc;
 162         struct devstat *disk_stats;
 163         ctl_be_block_lun_flags flags;
 164         STAILQ_ENTRY(ctl_be_block_lun) links;
 165         struct ctl_be_lun ctl_be_lun;
 166         struct taskqueue *io_taskqueue;
 167         struct task io_task;
 168         int num_threads;
 169         STAILQ_HEAD(, ctl_io_hdr) input_queue;
 170         STAILQ_HEAD(, ctl_io_hdr) config_write_queue;
 171         STAILQ_HEAD(, ctl_io_hdr) datamove_queue;
 172 };
 173
 174 /*
 175  * Overall softc structure for the block backend module.
 176  */
 177 struct ctl_be_block_softc {
 178         STAILQ_HEAD(, ctl_be_block_io)   beio_free_queue;
 179         struct mtx                       lock;
 180         int                              prealloc_beio;
 181         int                              num_disks;
 182         STAILQ_HEAD(, ctl_block_disk)    disk_list;
 183         int                              num_luns;
 184         STAILQ_HEAD(, ctl_be_block_lun)  lun_list;
 185 };
 186
 187 static struct ctl_be_block_softc backend_block_softc;
 188
 189 /*
 190  * Per-I/O information.
 191  */
 192 struct ctl_be_block_io {
 193         union ctl_io                    *io;
 194         struct ctl_sg_entry             sg_segs[CTLBLK_MAX_SEGS];
 195         struct iovec                    xiovecs[CTLBLK_MAX_SEGS];
 196         int                             bio_cmd;
 197         int                             bio_flags;
 198         int                             num_segs;
 199         int                             num_bios_sent;
 200         int                             num_bios_done;
 201         int                             send_complete;
 202         int                             num_errors;
 203         struct bintime                  ds_t0;
 204         devstat_tag_type                ds_tag_type;
 205         devstat_trans_flags             ds_trans_type;
 206         uint64_t                        io_len;
 207         uint64_t                        io_offset;
 208         struct ctl_be_block_softc       *softc;
 209         struct ctl_be_block_lun         *lun;
 210         STAILQ_ENTRY(ctl_be_block_io)   links;
 211 };
 212
 213 static int cbb_num_threads = 14;
 214 TUNABLE_INT("kern.cam.ctl.block.num_threads", &cbb_num_threads);
 215 SYSCTL_NODE(_kern_cam_ctl, OID_AUTO, block, CTLFLAG_RD, 0,
 216             "CAM Target Layer Block Backend");
 217 SYSCTL_INT(_kern_cam_ctl_block, OID_AUTO, num_threads, CTLFLAG_RW,
 218            &cbb_num_threads, 0, "Number of threads per backing file");
 219
 220 static struct ctl_be_block_io *ctl_alloc_beio(struct ctl_be_block_softc *softc);
 221 static void ctl_free_beio(struct ctl_be_block_io *beio);
 222 static int ctl_grow_beio(struct ctl_be_block_softc *softc, int count);
 223 #if 0
 224 static void ctl_shrink_beio(struct ctl_be_block_softc *softc);
 225 #endif
 226 static void ctl_complete_beio(struct ctl_be_block_io *beio);
 227 static int ctl_be_block_move_done(union ctl_io *io);
 228 static void ctl_be_block_biodone(struct bio *bio);
 229 static void ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
 230                                     struct ctl_be_block_io *beio);
 231 static void ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
 232                                        struct ctl_be_block_io *beio);
 233 static void ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
 234                                    struct ctl_be_block_io *beio);
 235 static void ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
 236                                       struct ctl_be_block_io *beio);
 237 static void ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
 238                                     union ctl_io *io);
 239 static void ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
 240                                   union ctl_io *io);
 241 static void ctl_be_block_worker(void *context, int pending);
 242 static int ctl_be_block_submit(union ctl_io *io);
 243 static int ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
 244                                    int flag, struct thread *td);
 245 static int ctl_be_block_open_file(struct ctl_be_block_lun *be_lun,
 246                                   struct ctl_lun_req *req);
 247 static int ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun,
 248                                  struct ctl_lun_req *req);
 249 static int ctl_be_block_close(struct ctl_be_block_lun *be_lun);
 250 static int ctl_be_block_open(struct ctl_be_block_softc *softc,
 251                              struct ctl_be_block_lun *be_lun,
 252                              struct ctl_lun_req *req);
 253 static int ctl_be_block_create(struct ctl_be_block_softc *softc,
 254                                struct ctl_lun_req *req);
 255 static int ctl_be_block_rm(struct ctl_be_block_softc *softc,
 256                            struct ctl_lun_req *req);
 257 static int ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
 258                                   struct ctl_lun_req *req);
 259 static int ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
 260                                  struct ctl_lun_req *req);
 261 static int ctl_be_block_modify(struct ctl_be_block_softc *softc,
 262                            struct ctl_lun_req *req);
 263 static void ctl_be_block_lun_shutdown(void *be_lun);
 264 static void ctl_be_block_lun_config_status(void *be_lun,
 265                                            ctl_lun_config_status status);
 266 static int ctl_be_block_config_write(union ctl_io *io);
 267 static int ctl_be_block_config_read(union ctl_io *io);
 268 static int ctl_be_block_lun_info(void *be_lun, struct sbuf *sb);
 269 int ctl_be_block_init(void);
 270
 271 static struct ctl_backend_driver ctl_be_block_driver =
 272 {
 273         .name = "block",
 274         .flags = CTL_BE_FLAG_HAS_CONFIG,
 275         .init = ctl_be_block_init,
 276         .data_submit = ctl_be_block_submit,
 277         .data_move_done = ctl_be_block_move_done,
 278         .config_read = ctl_be_block_config_read,
 279         .config_write = ctl_be_block_config_write,
 280         .ioctl = ctl_be_block_ioctl,
 281         .lun_info = ctl_be_block_lun_info
 282 };
 283
 284 MALLOC_DEFINE(M_CTLBLK, "ctlblk", "Memory used for CTL block backend");
 285 CTL_BACKEND_DECLARE(cbb, ctl_be_block_driver);
 286
 287 static struct ctl_be_block_io *
 288 ctl_alloc_beio(struct ctl_be_block_softc *softc)
 289 {
 290         struct ctl_be_block_io *beio;
 291         int count;
 292
 293         mtx_lock(&softc->lock);
 294
 295         beio = STAILQ_FIRST(&softc->beio_free_queue);
 296         if (beio != NULL) {
 297                 STAILQ_REMOVE(&softc->beio_free_queue, beio,
 298                               ctl_be_block_io, links);
 299         }
 300         mtx_unlock(&softc->lock);
 301
 302         if (beio != NULL) {
 303                 bzero(beio, sizeof(*beio));
 304                 beio->softc = softc;
 305                 return (beio);
 306         }
 307
 308         for (;;) {
 309
 310                 count = ctl_grow_beio(softc, /*count*/ 10);
 311
 312                 /*
 313                  * This shouldn't be possible, since ctl_grow_beio() uses a
 314                  * blocking malloc.
 315                  */
 316                 if (count == 0)
 317                         return (NULL);
 318
 319                 /*
 320                  * Since we have to drop the lock when we're allocating beio
 321                  * structures, it's possible someone else can come along and
 322                  * allocate the beio's we've just allocated.
 323                  */
 324                 mtx_lock(&softc->lock);
 325                 beio = STAILQ_FIRST(&softc->beio_free_queue);
 326                 if (beio != NULL) {
 327                         STAILQ_REMOVE(&softc->beio_free_queue, beio,
 328                                       ctl_be_block_io, links);
 329                 }
 330                 mtx_unlock(&softc->lock);
 331
 332                 if (beio != NULL) {
 333                         bzero(beio, sizeof(*beio));
 334                         beio->softc = softc;
 335                         break;
 336                 }
 337         }
 338         return (beio);
 339 }
 340
 341 static void
 342 ctl_free_beio(struct ctl_be_block_io *beio)
 343 {
 344         struct ctl_be_block_softc *softc;
 345         int duplicate_free;
 346         int i;
 347
 348         softc = beio->softc;
 349         duplicate_free = 0;
 350
 351         for (i = 0; i < beio->num_segs; i++) {
 352                 if (beio->sg_segs[i].addr == NULL)
 353                         duplicate_free++;
 354
 355                 uma_zfree(beio->lun->lun_zone, beio->sg_segs[i].addr);
 356                 beio->sg_segs[i].addr = NULL;
 357         }
 358
 359         if (duplicate_free > 0) {
 360                 printf("%s: %d duplicate frees out of %d segments\n", __func__,
 361                        duplicate_free, beio->num_segs);
 362         }
 363         mtx_lock(&softc->lock);
 364         STAILQ_INSERT_TAIL(&softc->beio_free_queue, beio, links);
 365         mtx_unlock(&softc->lock);
 366 }
 367
 368 static int
 369 ctl_grow_beio(struct ctl_be_block_softc *softc, int count)
 370 {
 371         int i;
 372
 373         for (i = 0; i < count; i++) {
 374                 struct ctl_be_block_io *beio;
 375
 376                 beio = (struct ctl_be_block_io *)malloc(sizeof(*beio),
 377                                                            M_CTLBLK,
 378                                                            M_WAITOK | M_ZERO);
 379                 beio->softc = softc;
 380                 mtx_lock(&softc->lock);
 381                 STAILQ_INSERT_TAIL(&softc->beio_free_queue, beio, links);
 382                 mtx_unlock(&softc->lock);
 383         }
 384
 385         return (i);
 386 }
 387
 388 #if 0
 389 static void
 390 ctl_shrink_beio(struct ctl_be_block_softc *softc)
 391 {
 392         struct ctl_be_block_io *beio, *beio_tmp;
 393
 394         mtx_lock(&softc->lock);
 395         STAILQ_FOREACH_SAFE(beio, &softc->beio_free_queue, links, beio_tmp) {
 396                 STAILQ_REMOVE(&softc->beio_free_queue, beio,
 397                               ctl_be_block_io, links);
 398                 free(beio, M_CTLBLK);
 399         }
 400         mtx_unlock(&softc->lock);
 401 }
 402 #endif
 403
 404 static void
 405 ctl_complete_beio(struct ctl_be_block_io *beio)
 406 {
 407         union ctl_io *io;
 408         int io_len;
 409
 410         io = beio->io;
 411
 412         if ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_SUCCESS)
 413                 io_len = beio->io_len;
 414         else
 415                 io_len = 0;
 416
 417         devstat_end_transaction(beio->lun->disk_stats,
 418                                 /*bytes*/ io_len,
 419                                 beio->ds_tag_type,
 420                                 beio->ds_trans_type,
 421                                 /*now*/ NULL,
 422                                 /*then*/&beio->ds_t0);
 423
 424         ctl_free_beio(beio);
 425         ctl_done(io);
 426 }
 427
 428 static int
 429 ctl_be_block_move_done(union ctl_io *io)
 430 {
 431         struct ctl_be_block_io *beio;
 432         struct ctl_be_block_lun *be_lun;
 433 #ifdef CTL_TIME_IO
 434         struct bintime cur_bt;
 435 #endif
 436
 437         beio = (struct ctl_be_block_io *)
 438                 io->io_hdr.ctl_private[CTL_PRIV_BACKEND].ptr;
 439
 440         be_lun = beio->lun;
 441
 442         DPRINTF("entered\n");
 443
 444 #ifdef CTL_TIME_IO
 445         getbintime(&cur_bt);
 446         bintime_sub(&cur_bt, &io->io_hdr.dma_start_bt);
 447         bintime_add(&io->io_hdr.dma_bt, &cur_bt);
 448         io->io_hdr.num_dmas++;
 449 #endif
 450
 451         /*
 452          * We set status at this point for read commands, and write
 453          * commands with errors.
 454          */
 455         if ((beio->bio_cmd == BIO_READ)
 456          && (io->io_hdr.port_status == 0)
 457          && ((io->io_hdr.flags & CTL_FLAG_ABORT) == 0)
 458          && ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE))
 459                 ctl_set_success(&io->scsiio);
 460         else if ((io->io_hdr.port_status != 0)
 461               && ((io->io_hdr.flags & CTL_FLAG_ABORT) == 0)
 462               && ((io->io_hdr.status & CTL_STATUS_MASK) == CTL_STATUS_NONE)) {
 463                 /*
 464                  * For hardware error sense keys, the sense key
 465                  * specific value is defined to be a retry count,
 466                  * but we use it to pass back an internal FETD
 467                  * error code.  XXX KDM  Hopefully the FETD is only
 468                  * using 16 bits for an error code, since that's
 469                  * all the space we have in the sks field.
 470                  */
 471                 ctl_set_internal_failure(&io->scsiio,
 472                                          /*sks_valid*/ 1,
 473                                          /*retry_count*/
 474                                          io->io_hdr.port_status);
 475         }
 476
 477         /*
 478          * If this is a read, or a write with errors, it is done.
 479          */
 480         if ((beio->bio_cmd == BIO_READ)
 481          || ((io->io_hdr.flags & CTL_FLAG_ABORT) != 0)
 482          || ((io->io_hdr.status & CTL_STATUS_MASK) != CTL_STATUS_NONE)) {
 483                 ctl_complete_beio(beio);
 484                 return (0);
 485         }
 486
 487         /*
 488          * At this point, we have a write and the DMA completed
 489          * successfully.  We now have to queue it to the task queue to
 490          * execute the backend I/O.  That is because we do blocking
 491          * memory allocations, and in the file backing case, blocking I/O.
 492          * This move done routine is generally called in the SIM's
 493          * interrupt context, and therefore we cannot block.
 494          */
 495         mtx_lock(&be_lun->lock);
 496         /*
 497          * XXX KDM make sure that links is okay to use at this point.
 498          * Otherwise, we either need to add another field to ctl_io_hdr,
 499          * or deal with resource allocation here.
 500          */
 501         STAILQ_INSERT_TAIL(&be_lun->datamove_queue, &io->io_hdr, links);
 502         mtx_unlock(&be_lun->lock);
 503
 504         taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
 505
 506         return (0);
 507 }
 508
 509 static void
 510 ctl_be_block_biodone(struct bio *bio)
 511 {
 512         struct ctl_be_block_io *beio;
 513         struct ctl_be_block_lun *be_lun;
 514         union ctl_io *io;
 515
 516         beio = bio->bio_caller1;
 517         be_lun = beio->lun;
 518         io = beio->io;
 519
 520         DPRINTF("entered\n");
 521
 522         mtx_lock(&be_lun->lock);
 523         if (bio->bio_error != 0)
 524                 beio->num_errors++;
 525
 526         beio->num_bios_done++;
 527
 528         /*
 529          * XXX KDM will this cause WITNESS to complain?  Holding a lock
 530          * during the free might cause it to complain.
 531          */
 532         g_destroy_bio(bio);
 533
 534         /*
 535          * If the send complete bit isn't set, or we aren't the last I/O to
 536          * complete, then we're done.
 537          */
 538         if ((beio->send_complete == 0)
 539          || (beio->num_bios_done < beio->num_bios_sent)) {
 540                 mtx_unlock(&be_lun->lock);
 541                 return;
 542         }
 543
 544         /*
 545          * At this point, we've verified that we are the last I/O to
 546          * complete, so it's safe to drop the lock.
 547          */
 548         mtx_unlock(&be_lun->lock);
 549
 550         /*
 551          * If there are any errors from the backing device, we fail the
 552          * entire I/O with a medium error.
 553          */
 554         if (beio->num_errors > 0) {
 555                 if (beio->bio_cmd == BIO_FLUSH) {
 556                         /* XXX KDM is there is a better error here? */
 557                         ctl_set_internal_failure(&io->scsiio,
 558                                                  /*sks_valid*/ 1,
 559                                                  /*retry_count*/ 0xbad2);
 560                 } else
 561                         ctl_set_medium_error(&io->scsiio);
 562                 ctl_complete_beio(beio);
 563                 return;
 564         }
 565
 566         /*
 567          * If this is a write or a flush, we're all done.
 568          * If this is a read, we can now send the data to the user.
 569          */
 570         if ((beio->bio_cmd == BIO_WRITE)
 571          || (beio->bio_cmd == BIO_FLUSH)) {
 572                 ctl_set_success(&io->scsiio);
 573                 ctl_complete_beio(beio);
 574         } else {
 575                 io->scsiio.be_move_done = ctl_be_block_move_done;
 576                 io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
 577                 io->scsiio.kern_data_len = beio->io_len;
 578                 io->scsiio.kern_total_len = beio->io_len;
 579                 io->scsiio.kern_rel_offset = 0;
 580                 io->scsiio.kern_data_resid = 0;
 581                 io->scsiio.kern_sg_entries = beio->num_segs;
 582                 io->io_hdr.flags |= CTL_FLAG_ALLOCATED | CTL_FLAG_KDPTR_SGLIST;
 583 #ifdef CTL_TIME_IO
 584                 getbintime(&io->io_hdr.dma_start_bt);
 585 #endif
 586                 ctl_datamove(io);
 587         }
 588 }
 589
 590 static void
 591 ctl_be_block_flush_file(struct ctl_be_block_lun *be_lun,
 592                         struct ctl_be_block_io *beio)
 593 {
 594         union ctl_io *io;
 595         struct mount *mountpoint;
 596         int vfs_is_locked, error, lock_flags;
 597
 598         DPRINTF("entered\n");
 599
 600         io = beio->io;
 601
 602         vfs_is_locked = VFS_LOCK_GIANT(be_lun->vn->v_mount);
 603
 604         (void) vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
 605
 606         if (MNT_SHARED_WRITES(mountpoint)
 607          || ((mountpoint == NULL)
 608           && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
 609                 lock_flags = LK_SHARED;
 610         else
 611                 lock_flags = LK_EXCLUSIVE;
 612
 613         vn_lock(be_lun->vn, lock_flags | LK_RETRY);
 614
 615         binuptime(&beio->ds_t0);
 616         devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
 617
 618         error = VOP_FSYNC(be_lun->vn, MNT_WAIT, curthread);
 619         VOP_UNLOCK(be_lun->vn, 0);
 620
 621         vn_finished_write(mountpoint);
 622
 623         VFS_UNLOCK_GIANT(vfs_is_locked);
 624
 625         if (error == 0)
 626                 ctl_set_success(&io->scsiio);
 627         else {
 628                 /* XXX KDM is there is a better error here? */
 629                 ctl_set_internal_failure(&io->scsiio,
 630                                          /*sks_valid*/ 1,
 631                                          /*retry_count*/ 0xbad1);
 632         }
 633
 634         ctl_complete_beio(beio);
 635 }
 636
 637 SDT_PROBE_DEFINE1(cbb, kernel, read, file_start, file_start, "uint64_t");
 638 SDT_PROBE_DEFINE1(cbb, kernel, write, file_start, file_start, "uint64_t");
 639 SDT_PROBE_DEFINE1(cbb, kernel, read, file_done, file_done,"uint64_t");
 640 SDT_PROBE_DEFINE1(cbb, kernel, write, file_done, file_done, "uint64_t");
 641
 642 static void
 643 ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
 644                            struct ctl_be_block_io *beio)
 645 {
 646         struct ctl_be_block_filedata *file_data;
 647         union ctl_io *io;
 648         struct uio xuio;
 649         struct iovec *xiovec;
 650         int vfs_is_locked, flags;
 651         int error, i;
 652
 653         DPRINTF("entered\n");
 654
 655         file_data = &be_lun->backend.file;
 656         io = beio->io;
 657         flags = beio->bio_flags;
 658
 659         if (beio->bio_cmd == BIO_READ) {
 660                 SDT_PROBE(cbb, kernel, read, file_start, 0, 0, 0, 0, 0);
 661         } else {
 662                 SDT_PROBE(cbb, kernel, write, file_start, 0, 0, 0, 0, 0);
 663         }
 664
 665         bzero(&xuio, sizeof(xuio));
 666         if (beio->bio_cmd == BIO_READ)
 667                 xuio.uio_rw = UIO_READ;
 668         else
 669                 xuio.uio_rw = UIO_WRITE;
 670
 671         xuio.uio_offset = beio->io_offset;
 672         xuio.uio_resid = beio->io_len;
 673         xuio.uio_segflg = UIO_SYSSPACE;
 674         xuio.uio_iov = beio->xiovecs;
 675         xuio.uio_iovcnt = beio->num_segs;
 676         xuio.uio_td = curthread;
 677
 678         for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
 679                 xiovec->iov_base = beio->sg_segs[i].addr;
 680                 xiovec->iov_len = beio->sg_segs[i].len;
 681         }
 682
 683         vfs_is_locked = VFS_LOCK_GIANT(be_lun->vn->v_mount);
 684         if (beio->bio_cmd == BIO_READ) {
 685                 vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
 686
 687                 binuptime(&beio->ds_t0);
 688                 devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
 689
 690                 /*
 691                  * UFS pays attention to IO_DIRECT for reads.  If the
 692                  * DIRECTIO option is configured into the kernel, it calls
 693                  * ffs_rawread().  But that only works for single-segment
 694                  * uios with user space addresses.  In our case, with a
 695                  * kernel uio, it still reads into the buffer cache, but it
 696                  * will just try to release the buffer from the cache later
 697                  * on in ffs_read().
 698                  *
 699                  * ZFS does not pay attention to IO_DIRECT for reads.
 700                  *
 701                  * UFS does not pay attention to IO_SYNC for reads.
 702                  *
 703                  * ZFS pays attention to IO_SYNC (which translates into the
 704                  * Solaris define FRSYNC for zfs_read()) for reads.  It
 705                  * attempts to sync the file before reading.
 706                  *
 707                  * So, to attempt to provide some barrier semantics in the
 708                  * BIO_ORDERED case, set both IO_DIRECT and IO_SYNC.
 709                  */
 710                 error = VOP_READ(be_lun->vn, &xuio, (flags & BIO_ORDERED) ?
 711                                  (IO_DIRECT|IO_SYNC) : 0, file_data->cred);
 712
 713                 VOP_UNLOCK(be_lun->vn, 0);
 714         } else {
 715                 struct mount *mountpoint;
 716                 int lock_flags;
 717
 718                 (void)vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
 719
 720                 if (MNT_SHARED_WRITES(mountpoint)
 721                  || ((mountpoint == NULL)
 722                   && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
 723                         lock_flags = LK_SHARED;
 724                 else
 725                         lock_flags = LK_EXCLUSIVE;
 726
 727                 vn_lock(be_lun->vn, lock_flags | LK_RETRY);
 728
 729                 binuptime(&beio->ds_t0);
 730                 devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
 731
 732                 /*
 733                  * UFS pays attention to IO_DIRECT for writes.  The write
 734                  * is done asynchronously.  (Normally the write would just
 735                  * get put into cache.
 736                  *
 737                  * UFS pays attention to IO_SYNC for writes.  It will
 738                  * attempt to write the buffer out synchronously if that
 739                  * flag is set.
 740                  *
 741                  * ZFS does not pay attention to IO_DIRECT for writes.
 742                  *
 743                  * ZFS pays attention to IO_SYNC (a.k.a. FSYNC or FRSYNC)
 744                  * for writes.  It will flush the transaction from the
 745                  * cache before returning.
 746                  *
 747                  * So if we've got the BIO_ORDERED flag set, we want
 748                  * IO_SYNC in either the UFS or ZFS case.
 749                  */
 750                 error = VOP_WRITE(be_lun->vn, &xuio, (flags & BIO_ORDERED) ?
 751                                   IO_SYNC : 0, file_data->cred);
 752                 VOP_UNLOCK(be_lun->vn, 0);
 753
 754                 vn_finished_write(mountpoint);
 755         }
 756         VFS_UNLOCK_GIANT(vfs_is_locked);
 757
 758         /*
 759          * If we got an error, set the sense data to "MEDIUM ERROR" and
 760          * return the I/O to the user.
 761          */
 762         if (error != 0) {
 763                 char path_str[32];
 764
 765                 ctl_scsi_path_string(io, path_str, sizeof(path_str));
 766                 /*
 767                  * XXX KDM ZFS returns ENOSPC when the underlying
 768                  * filesystem fills up.  What kind of SCSI error should we
 769                  * return for that?
 770                  */
 771                 printf("%s%s command returned errno %d\n", path_str,
 772                        (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE", error);
 773                 ctl_set_medium_error(&io->scsiio);
 774                 ctl_complete_beio(beio);
 775                 return;
 776         }
 777
 778         /*
 779          * If this is a write, we're all done.
 780          * If this is a read, we can now send the data to the user.
 781          */
 782         if (beio->bio_cmd == BIO_WRITE) {
 783                 ctl_set_success(&io->scsiio);
 784                 SDT_PROBE(cbb, kernel, write, file_done, 0, 0, 0, 0, 0);
 785                 ctl_complete_beio(beio);
 786         } else {
 787                 SDT_PROBE(cbb, kernel, read, file_done, 0, 0, 0, 0, 0);
 788                 io->scsiio.be_move_done = ctl_be_block_move_done;
 789                 io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
 790                 io->scsiio.kern_data_len = beio->io_len;
 791                 io->scsiio.kern_total_len = beio->io_len;
 792                 io->scsiio.kern_rel_offset = 0;
 793                 io->scsiio.kern_data_resid = 0;
 794                 io->scsiio.kern_sg_entries = beio->num_segs;
 795                 io->io_hdr.flags |= CTL_FLAG_ALLOCATED | CTL_FLAG_KDPTR_SGLIST;
 796 #ifdef CTL_TIME_IO
 797                 getbintime(&io->io_hdr.dma_start_bt);
 798 #endif
 799                 ctl_datamove(io);
 800         }
 801 }
 802
 803 static void
 804 ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
 805                        struct ctl_be_block_io *beio)
 806 {
 807         struct bio *bio;
 808         union ctl_io *io;
 809         struct ctl_be_block_devdata *dev_data;
 810
 811         dev_data = &be_lun->backend.dev;
 812         io = beio->io;
 813
 814         DPRINTF("entered\n");
 815
 816         /* This can't fail, it's a blocking allocation. */
 817         bio = g_alloc_bio();
 818
 819         bio->bio_cmd        = BIO_FLUSH;
 820         bio->bio_flags     |= BIO_ORDERED;
 821         bio->bio_dev        = dev_data->cdev;
 822         bio->bio_offset     = 0;
 823         bio->bio_data       = 0;
 824         bio->bio_done       = ctl_be_block_biodone;
 825         bio->bio_caller1    = beio;
 826         bio->bio_pblkno     = 0;
 827
 828         /*
 829          * We don't need to acquire the LUN lock here, because we are only
 830          * sending one bio, and so there is no other context to synchronize
 831          * with.
 832          */
 833         beio->num_bios_sent = 1;
 834         beio->send_complete = 1;
 835
 836         binuptime(&beio->ds_t0);
 837         devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
 838
 839         (*dev_data->csw->d_strategy)(bio);
 840 }
 841
 842 static void
 843 ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
 844                           struct ctl_be_block_io *beio)
 845 {
 846         int i;
 847         struct bio *bio;
 848         struct ctl_be_block_devdata *dev_data;
 849         off_t cur_offset;
 850         int max_iosize;
 851
 852         DPRINTF("entered\n");
 853
 854         dev_data = &be_lun->backend.dev;
 855
 856         /*
 857          * We have to limit our I/O size to the maximum supported by the
 858          * backend device.  Hopefully it is MAXPHYS.  If the driver doesn't
 859          * set it properly, use DFLTPHYS.
 860          */
 861         max_iosize = dev_data->cdev->si_iosize_max;
 862         if (max_iosize < PAGE_SIZE)
 863                 max_iosize = DFLTPHYS;
 864
 865         cur_offset = beio->io_offset;
 866
 867         /*
 868          * XXX KDM need to accurately reflect the number of I/Os outstanding
 869          * to a device.
 870          */
 871         binuptime(&beio->ds_t0);
 872         devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
 873
 874         for (i = 0; i < beio->num_segs; i++) {
 875                 size_t cur_size;
 876                 uint8_t *cur_ptr;
 877
 878                 cur_size = beio->sg_segs[i].len;
 879                 cur_ptr = beio->sg_segs[i].addr;
 880
 881                 while (cur_size > 0) {
 882                         /* This can't fail, it's a blocking allocation. */
 883                         bio = g_alloc_bio();
 884
 885                         KASSERT(bio != NULL, ("g_alloc_bio() failed!\n"));
 886
 887                         bio->bio_cmd = beio->bio_cmd;
 888                         bio->bio_flags |= beio->bio_flags;
 889                         bio->bio_dev = dev_data->cdev;
 890                         bio->bio_caller1 = beio;
 891                         bio->bio_length = min(cur_size, max_iosize);
 892                         bio->bio_offset = cur_offset;
 893                         bio->bio_data = cur_ptr;
 894                         bio->bio_done = ctl_be_block_biodone;
 895                         bio->bio_pblkno = cur_offset / be_lun->blocksize;
 896
 897                         cur_offset += bio->bio_length;
 898                         cur_ptr += bio->bio_length;
 899                         cur_size -= bio->bio_length;
 900
 901                         /*
 902                          * Make sure we set the complete bit just before we
 903                          * issue the last bio so we don't wind up with a
 904                          * race.
 905                          *
 906                          * Use the LUN mutex here instead of a combination
 907                          * of atomic variables for simplicity.
 908                          *
 909                          * XXX KDM we could have a per-IO lock, but that
 910                          * would cause additional per-IO setup and teardown
 911                          * overhead.  Hopefully there won't be too much
 912                          * contention on the LUN lock.
 913                          */
 914                         mtx_lock(&be_lun->lock);
 915
 916                         beio->num_bios_sent++;
 917
 918                         if ((i == beio->num_segs - 1)
 919                          && (cur_size == 0))
 920                                 beio->send_complete = 1;
 921
 922                         mtx_unlock(&be_lun->lock);
 923
 924                         (*dev_data->csw->d_strategy)(bio);
 925                 }
 926         }
 927 }
 928
 929 static void
 930 ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
 931                          union ctl_io *io)
 932 {
 933         struct ctl_be_block_io *beio;
 934         struct ctl_be_block_softc *softc;
 935
 936         DPRINTF("entered\n");
 937
 938         softc = be_lun->softc;
 939         beio = ctl_alloc_beio(softc);
 940         if (beio == NULL) {
 941                 /*
 942                  * This should not happen.  ctl_alloc_beio() will call
 943                  * ctl_grow_beio() with a blocking malloc as needed.
 944                  * A malloc with M_WAITOK should not fail.
 945                  */
 946                 ctl_set_busy(&io->scsiio);
 947                 ctl_done(io);
 948                 return;
 949         }
 950
 951         beio->io = io;
 952         beio->softc = softc;
 953         beio->lun = be_lun;
 954         io->io_hdr.ctl_private[CTL_PRIV_BACKEND].ptr = beio;
 955
 956         switch (io->scsiio.cdb[0]) {
 957         case SYNCHRONIZE_CACHE:
 958         case SYNCHRONIZE_CACHE_16:
 959                 beio->bio_cmd = BIO_FLUSH;
 960                 beio->ds_trans_type = DEVSTAT_NO_DATA;
 961                 beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
 962                 beio->io_len = 0;
 963                 be_lun->lun_flush(be_lun, beio);
 964                 break;
 965         default:
 966                 panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
 967                 break;
 968         }
 969 }
 970
 971 SDT_PROBE_DEFINE1(cbb, kernel, read, start, start, "uint64_t");
 972 SDT_PROBE_DEFINE1(cbb, kernel, write, start, start, "uint64_t");
 973 SDT_PROBE_DEFINE1(cbb, kernel, read, alloc_done, alloc_done, "uint64_t");
 974 SDT_PROBE_DEFINE1(cbb, kernel, write, alloc_done, alloc_done, "uint64_t");
 975
 976 static void
 977 ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
 978                            union ctl_io *io)
 979 {
 980         struct ctl_be_block_io *beio;
 981         struct ctl_be_block_softc *softc;
 982         struct ctl_lba_len lbalen;
 983         uint64_t len_left, io_size_bytes;
 984         int i;
 985
 986         softc = be_lun->softc;
 987
 988         DPRINTF("entered\n");
 989
 990         if ((io->io_hdr.flags & CTL_FLAG_DATA_MASK) == CTL_FLAG_DATA_IN) {
 991                 SDT_PROBE(cbb, kernel, read, start, 0, 0, 0, 0, 0);
 992         } else {
 993                 SDT_PROBE(cbb, kernel, write, start, 0, 0, 0, 0, 0);
 994         }
 995
 996         memcpy(&lbalen, io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN].bytes,
 997                sizeof(lbalen));
 998
 999         io_size_bytes = lbalen.len * be_lun->blocksize;
1000
1001         /*
1002          * XXX KDM this is temporary, until we implement chaining of beio
1003          * structures and multiple datamove calls to move all the data in
1004          * or out.
1005          */
1006         if (io_size_bytes > CTLBLK_MAX_IO_SIZE) {
1007                 printf("%s: IO length %ju > max io size %u\n", __func__,
1008                        io_size_bytes, CTLBLK_MAX_IO_SIZE);
1009                 ctl_set_invalid_field(&io->scsiio,
1010                                       /*sks_valid*/ 0,
1011                                       /*command*/ 1,
1012                                       /*field*/ 0,
1013                                       /*bit_valid*/ 0,
1014                                       /*bit*/ 0);
1015                 ctl_done(io);
1016                 return;
1017         }
1018
1019         beio = ctl_alloc_beio(softc);
1020         if (beio == NULL) {
1021                 /*
1022                  * This should not happen.  ctl_alloc_beio() will call
1023                  * ctl_grow_beio() with a blocking malloc as needed.
1024                  * A malloc with M_WAITOK should not fail.
1025                  */
1026                 ctl_set_busy(&io->scsiio);
1027                 ctl_done(io);
1028                 return;
1029         }
1030
1031         beio->io = io;
1032         beio->softc = softc;
1033         beio->lun = be_lun;
1034         io->io_hdr.ctl_private[CTL_PRIV_BACKEND].ptr = beio;
1035
1036         /*
1037          * If the I/O came down with an ordered or head of queue tag, set
1038          * the BIO_ORDERED attribute.  For head of queue tags, that's
1039          * pretty much the best we can do.
1040          *
1041          * XXX KDM we don't have a great way to easily know about the FUA
1042          * bit right now (it is decoded in ctl_read_write(), but we don't
1043          * pass that knowledge to the backend), and in any case we would
1044          * need to determine how to handle it.
1045          */
1046         if ((io->scsiio.tag_type == CTL_TAG_ORDERED)
1047          || (io->scsiio.tag_type == CTL_TAG_HEAD_OF_QUEUE))
1048                 beio->bio_flags = BIO_ORDERED;
1049
1050         switch (io->scsiio.tag_type) {
1051         case CTL_TAG_ORDERED:
1052                 beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1053                 break;
1054         case CTL_TAG_HEAD_OF_QUEUE:
1055                 beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1056                 break;
1057         case CTL_TAG_UNTAGGED:
1058         case CTL_TAG_SIMPLE:
1059         case CTL_TAG_ACA:
1060         default:
1061                 beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1062                 break;
1063         }
1064
1065         /*
1066          * This path handles read and write only.  The config write path
1067          * handles flush operations.
1068          */
1069         if ((io->io_hdr.flags & CTL_FLAG_DATA_MASK) == CTL_FLAG_DATA_IN) {
1070                 beio->bio_cmd = BIO_READ;
1071                 beio->ds_trans_type = DEVSTAT_READ;
1072         } else {
1073                 beio->bio_cmd = BIO_WRITE;
1074                 beio->ds_trans_type = DEVSTAT_WRITE;
1075         }
1076
1077         beio->io_len = lbalen.len * be_lun->blocksize;
1078         beio->io_offset = lbalen.lba * be_lun->blocksize;
1079
1080         DPRINTF("%s at LBA %jx len %u\n",
1081                (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE",
1082                (uintmax_t)lbalen.lba, lbalen.len);
1083
1084         for (i = 0, len_left = io_size_bytes; i < CTLBLK_MAX_SEGS &&
1085              len_left > 0; i++) {
1086
1087                 /*
1088                  * Setup the S/G entry for this chunk.
1089                  */
1090                 beio->sg_segs[i].len = min(MAXPHYS, len_left);
1091                 beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1092
1093                 DPRINTF("segment %d addr %p len %zd\n", i,
1094                         beio->sg_segs[i].addr, beio->sg_segs[i].len);
1095
1096                 beio->num_segs++;
1097                 len_left -= beio->sg_segs[i].len;
1098         }
1099
1100         /*
1101          * For the read case, we need to read the data into our buffers and
1102          * then we can send it back to the user.  For the write case, we
1103          * need to get the data from the user first.
1104          */
1105         if (beio->bio_cmd == BIO_READ) {
1106                 SDT_PROBE(cbb, kernel, read, alloc_done, 0, 0, 0, 0, 0);
1107                 be_lun->dispatch(be_lun, beio);
1108         } else {
1109                 SDT_PROBE(cbb, kernel, write, alloc_done, 0, 0, 0, 0, 0);
1110                 io->scsiio.be_move_done = ctl_be_block_move_done;
1111                 io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
1112                 io->scsiio.kern_data_len = beio->io_len;
1113                 io->scsiio.kern_total_len = beio->io_len;
1114                 io->scsiio.kern_rel_offset = 0;
1115                 io->scsiio.kern_data_resid = 0;
1116                 io->scsiio.kern_sg_entries = beio->num_segs;
1117                 io->io_hdr.flags |= CTL_FLAG_ALLOCATED | CTL_FLAG_KDPTR_SGLIST;
1118 #ifdef CTL_TIME_IO
1119                 getbintime(&io->io_hdr.dma_start_bt);
1120 #endif
1121                 ctl_datamove(io);
1122         }
1123 }
1124
1125 static void
1126 ctl_be_block_worker(void *context, int pending)
1127 {
1128         struct ctl_be_block_lun *be_lun;
1129         struct ctl_be_block_softc *softc;
1130         union ctl_io *io;
1131
1132         be_lun = (struct ctl_be_block_lun *)context;
1133         softc = be_lun->softc;
1134
1135         DPRINTF("entered\n");
1136
1137         mtx_lock(&be_lun->lock);
1138         for (;;) {
1139                 io = (union ctl_io *)STAILQ_FIRST(&be_lun->datamove_queue);
1140                 if (io != NULL) {
1141                         struct ctl_be_block_io *beio;
1142
1143                         DPRINTF("datamove queue\n");
1144
1145                         STAILQ_REMOVE(&be_lun->datamove_queue, &io->io_hdr,
1146                                       ctl_io_hdr, links);
1147
1148                         mtx_unlock(&be_lun->lock);
1149
1150                         beio = (struct ctl_be_block_io *)
1151                             io->io_hdr.ctl_private[CTL_PRIV_BACKEND].ptr;
1152
1153                         be_lun->dispatch(be_lun, beio);
1154
1155                         mtx_lock(&be_lun->lock);
1156                         continue;
1157                 }
1158                 io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_write_queue);
1159                 if (io != NULL) {
1160
1161                         DPRINTF("config write queue\n");
1162
1163                         STAILQ_REMOVE(&be_lun->config_write_queue, &io->io_hdr,
1164                                       ctl_io_hdr, links);
1165
1166                         mtx_unlock(&be_lun->lock);
1167
1168                         ctl_be_block_cw_dispatch(be_lun, io);
1169
1170                         mtx_lock(&be_lun->lock);
1171                         continue;
1172                 }
1173                 io = (union ctl_io *)STAILQ_FIRST(&be_lun->input_queue);
1174                 if (io != NULL) {
1175                         DPRINTF("input queue\n");
1176
1177                         STAILQ_REMOVE(&be_lun->input_queue, &io->io_hdr,
1178                                       ctl_io_hdr, links);
1179                         mtx_unlock(&be_lun->lock);
1180
1181                         /*
1182                          * We must drop the lock, since this routine and
1183                          * its children may sleep.
1184                          */
1185                         ctl_be_block_dispatch(be_lun, io);
1186
1187                         mtx_lock(&be_lun->lock);
1188                         continue;
1189                 }
1190
1191                 /*
1192                  * If we get here, there is no work left in the queues, so
1193                  * just break out and let the task queue go to sleep.
1194                  */
1195                 break;
1196         }
1197         mtx_unlock(&be_lun->lock);
1198 }
1199
1200 /*
1201  * Entry point from CTL to the backend for I/O.  We queue everything to a
1202  * work thread, so this just puts the I/O on a queue and wakes up the
1203  * thread.
1204  */
1205 static int
1206 ctl_be_block_submit(union ctl_io *io)
1207 {
1208         struct ctl_be_block_lun *be_lun;
1209         struct ctl_be_lun *ctl_be_lun;
1210         int retval;
1211
1212         DPRINTF("entered\n");
1213
1214         retval = CTL_RETVAL_COMPLETE;
1215
1216         ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
1217                 CTL_PRIV_BACKEND_LUN].ptr;
1218         be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
1219
1220         /*
1221          * Make sure we only get SCSI I/O.
1222          */
1223         KASSERT(io->io_hdr.io_type == CTL_IO_SCSI, ("Non-SCSI I/O (type "
1224                 "%#x) encountered", io->io_hdr.io_type));
1225
1226         mtx_lock(&be_lun->lock);
1227         /*
1228          * XXX KDM make sure that links is okay to use at this point.
1229          * Otherwise, we either need to add another field to ctl_io_hdr,
1230          * or deal with resource allocation here.
1231          */
1232         STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1233         mtx_unlock(&be_lun->lock);
1234
1235         taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1236
1237         return (retval);
1238 }
1239
1240 static int
1241 ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
1242                         int flag, struct thread *td)
1243 {
1244         struct ctl_be_block_softc *softc;
1245         int error;
1246
1247         softc = &backend_block_softc;
1248
1249         error = 0;
1250
1251         switch (cmd) {
1252         case CTL_LUN_REQ: {
1253                 struct ctl_lun_req *lun_req;
1254
1255                 lun_req = (struct ctl_lun_req *)addr;
1256
1257                 switch (lun_req->reqtype) {
1258                 case CTL_LUNREQ_CREATE:
1259                         error = ctl_be_block_create(softc, lun_req);
1260                         break;
1261                 case CTL_LUNREQ_RM:
1262                         error = ctl_be_block_rm(softc, lun_req);
1263                         break;
1264                 case CTL_LUNREQ_MODIFY:
1265                         error = ctl_be_block_modify(softc, lun_req);
1266                         break;
1267                 default:
1268                         lun_req->status = CTL_LUN_ERROR;
1269                         snprintf(lun_req->error_str, sizeof(lun_req->error_str),
1270                                  "%s: invalid LUN request type %d", __func__,
1271                                  lun_req->reqtype);
1272                         break;
1273                 }
1274                 break;
1275         }
1276         default:
1277                 error = ENOTTY;
1278                 break;
1279         }
1280
1281         return (error);
1282 }
1283
1284 static int
1285 ctl_be_block_open_file(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1286 {
1287         struct ctl_be_block_filedata *file_data;
1288         struct ctl_lun_create_params *params;
1289         struct vattr                  vattr;
1290         int                           error;
1291
1292         error = 0;
1293         file_data = &be_lun->backend.file;
1294         params = &req->reqdata.create;
1295
1296         be_lun->dev_type = CTL_BE_BLOCK_FILE;
1297         be_lun->dispatch = ctl_be_block_dispatch_file;
1298         be_lun->lun_flush = ctl_be_block_flush_file;
1299
1300         error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
1301         if (error != 0) {
1302                 snprintf(req->error_str, sizeof(req->error_str),
1303                          "error calling VOP_GETATTR() for file %s",
1304                          be_lun->dev_path);
1305                 return (error);
1306         }
1307
1308         /*
1309          * Verify that we have the ability to upgrade to exclusive
1310          * access on this file so we can trap errors at open instead
1311          * of reporting them during first access.
1312          */
1313         if (VOP_ISLOCKED(be_lun->vn) != LK_EXCLUSIVE) {
1314                 vn_lock(be_lun->vn, LK_UPGRADE | LK_RETRY);
1315                 if (be_lun->vn->v_iflag & VI_DOOMED) {
1316                         error = EBADF;
1317                         snprintf(req->error_str, sizeof(req->error_str),
1318                                  "error locking file %s", be_lun->dev_path);
1319                         return (error);
1320                 }
1321         }
1322
1323
1324         file_data->cred = crhold(curthread->td_ucred);
1325         if (params->lun_size_bytes != 0)
1326                 be_lun->size_bytes = params->lun_size_bytes;
1327         else
1328                 be_lun->size_bytes = vattr.va_size;
1329         /*
1330          * We set the multi thread flag for file operations because all
1331          * filesystems (in theory) are capable of allowing multiple readers
1332          * of a file at once.  So we want to get the maximum possible
1333          * concurrency.
1334          */
1335         be_lun->flags |= CTL_BE_BLOCK_LUN_MULTI_THREAD;
1336
1337         /*
1338          * XXX KDM vattr.va_blocksize may be larger than 512 bytes here.
1339          * With ZFS, it is 131072 bytes.  Block sizes that large don't work
1340          * with disklabel and UFS on FreeBSD at least.  Large block sizes
1341          * may not work with other OSes as well.  So just export a sector
1342          * size of 512 bytes, which should work with any OS or
1343          * application.  Since our backing is a file, any block size will
1344          * work fine for the backing store.
1345          */
1346 #if 0
1347         be_lun->blocksize= vattr.va_blocksize;
1348 #endif
1349         if (params->blocksize_bytes != 0)
1350                 be_lun->blocksize = params->blocksize_bytes;
1351         else
1352                 be_lun->blocksize = 512;
1353
1354         /*
1355          * Sanity check.  The media size has to be at least one
1356          * sector long.
1357          */
1358         if (be_lun->size_bytes < be_lun->blocksize) {
1359                 error = EINVAL;
1360                 snprintf(req->error_str, sizeof(req->error_str),
1361                          "file %s size %ju < block size %u", be_lun->dev_path,
1362                          (uintmax_t)be_lun->size_bytes, be_lun->blocksize);
1363         }
1364         return (error);
1365 }
1366
1367 static int
1368 ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1369 {
1370         struct ctl_lun_create_params *params;
1371         struct vattr                  vattr;
1372         struct cdev                  *dev;
1373         struct cdevsw                *devsw;
1374         int                           error;
1375
1376         params = &req->reqdata.create;
1377
1378         be_lun->dev_type = CTL_BE_BLOCK_DEV;
1379         be_lun->dispatch = ctl_be_block_dispatch_dev;
1380         be_lun->lun_flush = ctl_be_block_flush_dev;
1381         be_lun->backend.dev.cdev = be_lun->vn->v_rdev;
1382         be_lun->backend.dev.csw = dev_refthread(be_lun->backend.dev.cdev,
1383                                              &be_lun->backend.dev.dev_ref);
1384         if (be_lun->backend.dev.csw == NULL)
1385                 panic("Unable to retrieve device switch");
1386
1387         error = VOP_GETATTR(be_lun->vn, &vattr, NOCRED);
1388         if (error) {
1389                 snprintf(req->error_str, sizeof(req->error_str),
1390                          "%s: error getting vnode attributes for device %s",
1391                          __func__, be_lun->dev_path);
1392                 return (error);
1393         }
1394
1395         dev = be_lun->vn->v_rdev;
1396         devsw = dev->si_devsw;
1397         if (!devsw->d_ioctl) {
1398                 snprintf(req->error_str, sizeof(req->error_str),
1399                          "%s: no d_ioctl for device %s!", __func__,
1400                          be_lun->dev_path);
1401                 return (ENODEV);
1402         }
1403
1404         error = devsw->d_ioctl(dev, DIOCGSECTORSIZE,
1405                                (caddr_t)&be_lun->blocksize, FREAD,
1406                                curthread);
1407         if (error) {
1408                 snprintf(req->error_str, sizeof(req->error_str),
1409                          "%s: error %d returned for DIOCGSECTORSIZE ioctl "
1410                          "on %s!", __func__, error, be_lun->dev_path);
1411                 return (error);
1412         }
1413
1414         /*
1415          * If the user has asked for a blocksize that is greater than the
1416          * backing device's blocksize, we can do it only if the blocksize
1417          * the user is asking for is an even multiple of the underlying
1418          * device's blocksize.
1419          */
1420         if ((params->blocksize_bytes != 0)
1421          && (params->blocksize_bytes > be_lun->blocksize)) {
1422                 uint32_t bs_multiple, tmp_blocksize;
1423
1424                 bs_multiple = params->blocksize_bytes / be_lun->blocksize;
1425
1426                 tmp_blocksize = bs_multiple * be_lun->blocksize;
1427
1428                 if (tmp_blocksize == params->blocksize_bytes) {
1429                         be_lun->blocksize = params->blocksize_bytes;
1430                 } else {
1431                         snprintf(req->error_str, sizeof(req->error_str),
1432                                  "%s: requested blocksize %u is not an even "
1433                                  "multiple of backing device blocksize %u",
1434                                  __func__, params->blocksize_bytes,
1435                                  be_lun->blocksize);
1436                         return (EINVAL);
1437
1438                 }
1439         } else if ((params->blocksize_bytes != 0)
1440                 && (params->blocksize_bytes != be_lun->blocksize)) {
1441                 snprintf(req->error_str, sizeof(req->error_str),
1442                          "%s: requested blocksize %u < backing device "
1443                          "blocksize %u", __func__, params->blocksize_bytes,
1444                          be_lun->blocksize);
1445                 return (EINVAL);
1446         }
1447
1448         error = devsw->d_ioctl(dev, DIOCGMEDIASIZE,
1449                                (caddr_t)&be_lun->size_bytes, FREAD,
1450                                curthread);
1451         if (error) {
1452                 snprintf(req->error_str, sizeof(req->error_str),
1453                          "%s: error %d returned for DIOCGMEDIASIZE "
1454                          " ioctl on %s!", __func__, error,
1455                          be_lun->dev_path);
1456                 return (error);
1457         }
1458
1459         if (params->lun_size_bytes != 0) {
1460                 if (params->lun_size_bytes > be_lun->size_bytes) {
1461                         snprintf(req->error_str, sizeof(req->error_str),
1462                                  "%s: requested LUN size %ju > backing device "
1463                                  "size %ju", __func__,
1464                                  (uintmax_t)params->lun_size_bytes,
1465                                  (uintmax_t)be_lun->size_bytes);
1466                         return (EINVAL);
1467                 }
1468
1469                 be_lun->size_bytes = params->lun_size_bytes;
1470         }
1471
1472         return (0);
1473 }
1474
1475 static int
1476 ctl_be_block_close(struct ctl_be_block_lun *be_lun)
1477 {
1478         DROP_GIANT();
1479         if (be_lun->vn) {
1480                 int flags = FREAD | FWRITE;
1481                 int vfs_is_locked = 0;
1482
1483                 switch (be_lun->dev_type) {
1484                 case CTL_BE_BLOCK_DEV:
1485                         if (be_lun->backend.dev.csw) {
1486                                 dev_relthread(be_lun->backend.dev.cdev,
1487                                               be_lun->backend.dev.dev_ref);
1488                                 be_lun->backend.dev.csw  = NULL;
1489                                 be_lun->backend.dev.cdev = NULL;
1490                         }
1491                         break;
1492                 case CTL_BE_BLOCK_FILE:
1493                         vfs_is_locked = VFS_LOCK_GIANT(be_lun->vn->v_mount);
1494                         break;
1495                 case CTL_BE_BLOCK_NONE:
1496                 default:
1497                         panic("Unexpected backend type.");
1498                         break;
1499                 }
1500
1501                 (void)vn_close(be_lun->vn, flags, NOCRED, curthread);
1502                 be_lun->vn = NULL;
1503
1504                 switch (be_lun->dev_type) {
1505                 case CTL_BE_BLOCK_DEV:
1506                         break;
1507                 case CTL_BE_BLOCK_FILE:
1508                         VFS_UNLOCK_GIANT(vfs_is_locked);
1509                         if (be_lun->backend.file.cred != NULL) {
1510                                 crfree(be_lun->backend.file.cred);
1511                                 be_lun->backend.file.cred = NULL;
1512                         }
1513                         break;
1514                 case CTL_BE_BLOCK_NONE:
1515                 default:
1516                         panic("Unexpected backend type.");
1517                         break;
1518                 }
1519         }
1520         PICKUP_GIANT();
1521
1522         return (0);
1523 }
1524
1525 static int
1526 ctl_be_block_open(struct ctl_be_block_softc *softc,
1527                        struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1528 {
1529         struct nameidata nd;
1530         int              flags;
1531         int              error;
1532         int              vfs_is_locked;
1533
1534         /*
1535          * XXX KDM allow a read-only option?
1536          */
1537         flags = FREAD | FWRITE;
1538         error = 0;
1539
1540         if (rootvnode == NULL) {
1541                 snprintf(req->error_str, sizeof(req->error_str),
1542                          "%s: Root filesystem is not mounted", __func__);
1543                 return (1);
1544         }
1545
1546         if (!curthread->td_proc->p_fd->fd_cdir) {
1547                 curthread->td_proc->p_fd->fd_cdir = rootvnode;
1548                 VREF(rootvnode);
1549         }
1550         if (!curthread->td_proc->p_fd->fd_rdir) {
1551                 curthread->td_proc->p_fd->fd_rdir = rootvnode;
1552                 VREF(rootvnode);
1553         }
1554         if (!curthread->td_proc->p_fd->fd_jdir) {
1555                 curthread->td_proc->p_fd->fd_jdir = rootvnode;
1556                 VREF(rootvnode);
1557         }
1558
1559  again:
1560         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, be_lun->dev_path, curthread);
1561         error = vn_open(&nd, &flags, 0, NULL);
1562         if (error) {
1563                 /*
1564                  * This is the only reasonable guess we can make as far as
1565                  * path if the user doesn't give us a fully qualified path.
1566                  * If they want to specify a file, they need to specify the
1567                  * full path.
1568                  */
1569                 if (be_lun->dev_path[0] != '/') {
1570                         char *dev_path = "/dev/";
1571                         char *dev_name;
1572
1573                         /* Try adding device path at beginning of name */
1574                         dev_name = malloc(strlen(be_lun->dev_path)
1575                                         + strlen(dev_path) + 1,
1576                                           M_CTLBLK, M_WAITOK);
1577                         if (dev_name) {
1578                                 sprintf(dev_name, "%s%s", dev_path,
1579                                         be_lun->dev_path);
1580                                 free(be_lun->dev_path, M_CTLBLK);
1581                                 be_lun->dev_path = dev_name;
1582                                 goto again;
1583                         }
1584                 }
1585                 snprintf(req->error_str, sizeof(req->error_str),
1586                          "%s: error opening %s", __func__, be_lun->dev_path);
1587                 return (error);
1588         }
1589
1590         vfs_is_locked = NDHASGIANT(&nd);
1591
1592         NDFREE(&nd, NDF_ONLY_PNBUF);
1593
1594         be_lun->vn = nd.ni_vp;
1595
1596         /* We only support disks and files. */
1597         if (vn_isdisk(be_lun->vn, &error)) {
1598                 error = ctl_be_block_open_dev(be_lun, req);
1599         } else if (be_lun->vn->v_type == VREG) {
1600                 error = ctl_be_block_open_file(be_lun, req);
1601         } else {
1602                 error = EINVAL;
1603                 snprintf(req->error_str, sizeof(req->error_str),
1604                          "%s is not a disk or file", be_lun->dev_path);
1605         }
1606         VOP_UNLOCK(be_lun->vn, 0);
1607         VFS_UNLOCK_GIANT(vfs_is_locked);
1608
1609         if (error != 0) {
1610                 ctl_be_block_close(be_lun);
1611                 return (error);
1612         }
1613
1614         be_lun->blocksize_shift = fls(be_lun->blocksize) - 1;
1615         be_lun->size_blocks = be_lun->size_bytes >> be_lun->blocksize_shift;
1616
1617         return (0);
1618 }
1619
1620 static int
1621 ctl_be_block_mem_ctor(void *mem, int size, void *arg, int flags)
1622 {
1623         return (0);
1624 }
1625
1626 static void
1627 ctl_be_block_mem_dtor(void *mem, int size, void *arg)
1628 {
1629         bzero(mem, size);
1630 }
1631
1632 static int
1633 ctl_be_block_create(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
1634 {
1635         struct ctl_be_block_lun *be_lun;
1636         struct ctl_lun_create_params *params;
1637         struct ctl_be_arg *file_arg;
1638         char tmpstr[32];
1639         int retval, num_threads;
1640         int i;
1641
1642         params = &req->reqdata.create;
1643         retval = 0;
1644
1645         num_threads = cbb_num_threads;
1646
1647         file_arg = NULL;
1648
1649         be_lun = malloc(sizeof(*be_lun), M_CTLBLK, M_ZERO | M_WAITOK);
1650
1651         be_lun->softc = softc;
1652         STAILQ_INIT(&be_lun->input_queue);
1653         STAILQ_INIT(&be_lun->config_write_queue);
1654         STAILQ_INIT(&be_lun->datamove_queue);
1655         sprintf(be_lun->lunname, "cblk%d", softc->num_luns);
1656         mtx_init(&be_lun->lock, be_lun->lunname, NULL, MTX_DEF);
1657
1658         be_lun->lun_zone = uma_zcreate(be_lun->lunname, MAXPHYS,
1659             ctl_be_block_mem_ctor, ctl_be_block_mem_dtor, NULL, NULL,
1660             /*align*/ 0, /*flags*/0);
1661
1662         if (be_lun->lun_zone == NULL) {
1663                 snprintf(req->error_str, sizeof(req->error_str),
1664                          "%s: error allocating UMA zone", __func__);
1665                 goto bailout_error;
1666         }
1667
1668         if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
1669                 be_lun->ctl_be_lun.lun_type = params->device_type;
1670         else
1671                 be_lun->ctl_be_lun.lun_type = T_DIRECT;
1672
1673         if (be_lun->ctl_be_lun.lun_type == T_DIRECT) {
1674                 for (i = 0; i < req->num_be_args; i++) {
1675                         if (strcmp(req->kern_be_args[i].kname, "file") == 0) {
1676                                 file_arg = &req->kern_be_args[i];
1677                                 break;
1678                         }
1679                 }
1680
1681                 if (file_arg == NULL) {
1682                         snprintf(req->error_str, sizeof(req->error_str),
1683                                  "%s: no file argument specified", __func__);
1684                         goto bailout_error;
1685                 }
1686
1687                 be_lun->dev_path = malloc(file_arg->vallen, M_CTLBLK,
1688                                           M_WAITOK | M_ZERO);
1689
1690                 strlcpy(be_lun->dev_path, (char *)file_arg->kvalue,
1691                         file_arg->vallen);
1692
1693                 retval = ctl_be_block_open(softc, be_lun, req);
1694                 if (retval != 0) {
1695                         retval = 0;
1696                         goto bailout_error;
1697                 }
1698
1699                 /*
1700                  * Tell the user the size of the file/device.
1701                  */
1702                 params->lun_size_bytes = be_lun->size_bytes;
1703
1704                 /*
1705                  * The maximum LBA is the size - 1.
1706                  */
1707                 be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
1708         } else {
1709                 /*
1710                  * For processor devices, we don't have any size.
1711                  */
1712                 be_lun->blocksize = 0;
1713                 be_lun->size_blocks = 0;
1714                 be_lun->size_bytes = 0;
1715                 be_lun->ctl_be_lun.maxlba = 0;
1716                 params->lun_size_bytes = 0;
1717
1718                 /*
1719                  * Default to just 1 thread for processor devices.
1720                  */
1721                 num_threads = 1;
1722         }
1723
1724         /*
1725          * XXX This searching loop might be refactored to be combined with
1726          * the loop above,
1727          */
1728         for (i = 0; i < req->num_be_args; i++) {
1729                 if (strcmp(req->kern_be_args[i].kname, "num_threads") == 0) {
1730                         struct ctl_be_arg *thread_arg;
1731                         char num_thread_str[16];
1732                         int tmp_num_threads;
1733
1734
1735                         thread_arg = &req->kern_be_args[i];
1736
1737                         strlcpy(num_thread_str, (char *)thread_arg->kvalue,
1738                                 min(thread_arg->vallen,
1739                                 sizeof(num_thread_str)));
1740
1741                         tmp_num_threads = strtol(num_thread_str, NULL, 0);
1742
1743                         /*
1744                          * We don't let the user specify less than one
1745                          * thread, but hope he's clueful enough not to
1746                          * specify 1000 threads.
1747                          */
1748                         if (tmp_num_threads < 1) {
1749                                 snprintf(req->error_str, sizeof(req->error_str),
1750                                          "%s: invalid number of threads %s",
1751                                          __func__, num_thread_str);
1752                                 goto bailout_error;
1753                         }
1754
1755                         num_threads = tmp_num_threads;
1756                 }
1757         }
1758
1759         be_lun->flags = CTL_BE_BLOCK_LUN_UNCONFIGURED;
1760         be_lun->ctl_be_lun.flags = CTL_LUN_FLAG_PRIMARY;
1761         be_lun->ctl_be_lun.be_lun = be_lun;
1762         be_lun->ctl_be_lun.blocksize = be_lun->blocksize;
1763         /* Tell the user the blocksize we ended up using */
1764         params->blocksize_bytes = be_lun->blocksize;
1765         if (params->flags & CTL_LUN_FLAG_ID_REQ) {
1766                 be_lun->ctl_be_lun.req_lun_id = params->req_lun_id;
1767                 be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_ID_REQ;
1768         } else
1769                 be_lun->ctl_be_lun.req_lun_id = 0;
1770
1771         be_lun->ctl_be_lun.lun_shutdown = ctl_be_block_lun_shutdown;
1772         be_lun->ctl_be_lun.lun_config_status =
1773                 ctl_be_block_lun_config_status;
1774         be_lun->ctl_be_lun.be = &ctl_be_block_driver;
1775
1776         if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
1777                 snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
1778                          softc->num_luns);
1779                 strncpy((char *)be_lun->ctl_be_lun.serial_num, tmpstr,
1780                         ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
1781                         sizeof(tmpstr)));
1782
1783                 /* Tell the user what we used for a serial number */
1784                 strncpy((char *)params->serial_num, tmpstr,
1785                         ctl_min(sizeof(params->serial_num), sizeof(tmpstr)));
1786         } else {
1787                 strncpy((char *)be_lun->ctl_be_lun.serial_num,
1788                         params->serial_num,
1789                         ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
1790                         sizeof(params->serial_num)));
1791         }
1792         if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
1793                 snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
1794                 strncpy((char *)be_lun->ctl_be_lun.device_id, tmpstr,
1795                         ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
1796                         sizeof(tmpstr)));
1797
1798                 /* Tell the user what we used for a device ID */
1799                 strncpy((char *)params->device_id, tmpstr,
1800                         ctl_min(sizeof(params->device_id), sizeof(tmpstr)));
1801         } else {
1802                 strncpy((char *)be_lun->ctl_be_lun.device_id,
1803                         params->device_id,
1804                         ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
1805                                 sizeof(params->device_id)));
1806         }
1807
1808         TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_be_block_worker, be_lun);
1809
1810         be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
1811             taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
1812
1813         if (be_lun->io_taskqueue == NULL) {
1814                 snprintf(req->error_str, sizeof(req->error_str),
1815                          "%s: Unable to create taskqueue", __func__);
1816                 goto bailout_error;
1817         }
1818
1819         /*
1820          * Note that we start the same number of threads by default for
1821          * both the file case and the block device case.  For the file
1822          * case, we need multiple threads to allow concurrency, because the
1823          * vnode interface is designed to be a blocking interface.  For the
1824          * block device case, ZFS zvols at least will block the caller's
1825          * context in many instances, and so we need multiple threads to
1826          * overcome that problem.  Other block devices don't need as many
1827          * threads, but they shouldn't cause too many problems.
1828          *
1829          * If the user wants to just have a single thread for a block
1830          * device, he can specify that when the LUN is created, or change
1831          * the tunable/sysctl to alter the default number of threads.
1832          */
1833         retval = taskqueue_start_threads(&be_lun->io_taskqueue,
1834                                          /*num threads*/num_threads,
1835                                          /*priority*/PWAIT,
1836                                          /*thread name*/
1837                                          "%s taskq", be_lun->lunname);
1838
1839         if (retval != 0)
1840                 goto bailout_error;
1841
1842         be_lun->num_threads = num_threads;
1843
1844         mtx_lock(&softc->lock);
1845         softc->num_luns++;
1846         STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
1847
1848         mtx_unlock(&softc->lock);
1849
1850         retval = ctl_add_lun(&be_lun->ctl_be_lun);
1851         if (retval != 0) {
1852                 mtx_lock(&softc->lock);
1853                 STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
1854                               links);
1855                 softc->num_luns--;
1856                 mtx_unlock(&softc->lock);
1857                 snprintf(req->error_str, sizeof(req->error_str),
1858                          "%s: ctl_add_lun() returned error %d, see dmesg for "
1859                         "details", __func__, retval);
1860                 retval = 0;
1861                 goto bailout_error;
1862         }
1863
1864         mtx_lock(&softc->lock);
1865
1866         /*
1867          * Tell the config_status routine that we're waiting so it won't
1868          * clean up the LUN in the event of an error.
1869          */
1870         be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
1871
1872         while (be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) {
1873                 retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
1874                 if (retval == EINTR)
1875                         break;
1876         }
1877         be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
1878
1879         if (be_lun->flags & CTL_BE_BLOCK_LUN_CONFIG_ERR) {
1880                 snprintf(req->error_str, sizeof(req->error_str),
1881                          "%s: LUN configuration error, see dmesg for details",
1882                          __func__);
1883                 STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
1884                               links);
1885                 softc->num_luns--;
1886                 mtx_unlock(&softc->lock);
1887                 goto bailout_error;
1888         } else {
1889                 params->req_lun_id = be_lun->ctl_be_lun.lun_id;
1890         }
1891
1892         mtx_unlock(&softc->lock);
1893
1894         be_lun->disk_stats = devstat_new_entry("cbb", params->req_lun_id,
1895                                                be_lun->blocksize,
1896                                                DEVSTAT_ALL_SUPPORTED,
1897                                                be_lun->ctl_be_lun.lun_type
1898                                                | DEVSTAT_TYPE_IF_OTHER,
1899                                                DEVSTAT_PRIORITY_OTHER);
1900
1901
1902         req->status = CTL_LUN_OK;
1903
1904         return (retval);
1905
1906 bailout_error:
1907         req->status = CTL_LUN_ERROR;
1908
1909         ctl_be_block_close(be_lun);
1910
1911         free(be_lun->dev_path, M_CTLBLK);
1912         free(be_lun, M_CTLBLK);
1913
1914         return (retval);
1915 }
1916
1917 static int
1918 ctl_be_block_rm(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
1919 {
1920         struct ctl_lun_rm_params *params;
1921         struct ctl_be_block_lun *be_lun;
1922         int retval;
1923
1924         params = &req->reqdata.rm;
1925
1926         mtx_lock(&softc->lock);
1927
1928         be_lun = NULL;
1929
1930         STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
1931                 if (be_lun->ctl_be_lun.lun_id == params->lun_id)
1932                         break;
1933         }
1934         mtx_unlock(&softc->lock);
1935
1936         if (be_lun == NULL) {
1937                 snprintf(req->error_str, sizeof(req->error_str),
1938                          "%s: LUN %u is not managed by the block backend",
1939                          __func__, params->lun_id);
1940                 goto bailout_error;
1941         }
1942
1943         retval = ctl_disable_lun(&be_lun->ctl_be_lun);
1944
1945         if (retval != 0) {
1946                 snprintf(req->error_str, sizeof(req->error_str),
1947                          "%s: error %d returned from ctl_disable_lun() for "
1948                          "LUN %d", __func__, retval, params->lun_id);
1949                 goto bailout_error;
1950
1951         }
1952
1953         retval = ctl_invalidate_lun(&be_lun->ctl_be_lun);
1954         if (retval != 0) {
1955                 snprintf(req->error_str, sizeof(req->error_str),
1956                          "%s: error %d returned from ctl_invalidate_lun() for "
1957                          "LUN %d", __func__, retval, params->lun_id);
1958                 goto bailout_error;
1959         }
1960
1961         mtx_lock(&softc->lock);
1962
1963         be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
1964
1965         while ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
1966                 retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
1967                 if (retval == EINTR)
1968                         break;
1969         }
1970
1971         be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
1972
1973         if ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
1974                 snprintf(req->error_str, sizeof(req->error_str),
1975                          "%s: interrupted waiting for LUN to be freed",
1976                          __func__);
1977                 mtx_unlock(&softc->lock);
1978                 goto bailout_error;
1979         }
1980
1981         STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun, links);
1982
1983         softc->num_luns--;
1984         mtx_unlock(&softc->lock);
1985
1986         taskqueue_drain(be_lun->io_taskqueue, &be_lun->io_task);
1987
1988         taskqueue_free(be_lun->io_taskqueue);
1989
1990         ctl_be_block_close(be_lun);
1991
1992         if (be_lun->disk_stats != NULL)
1993                 devstat_remove_entry(be_lun->disk_stats);
1994
1995         uma_zdestroy(be_lun->lun_zone);
1996
1997         free(be_lun->dev_path, M_CTLBLK);
1998
1999         free(be_lun, M_CTLBLK);
2000
2001         req->status = CTL_LUN_OK;
2002
2003         return (0);
2004
2005 bailout_error:
2006
2007         req->status = CTL_LUN_ERROR;
2008
2009         return (0);
2010 }
2011
2012 static int
2013 ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
2014                          struct ctl_lun_req *req)
2015 {
2016         struct vattr vattr;
2017         int error;
2018         struct ctl_lun_modify_params *params;
2019
2020         params = &req->reqdata.modify;
2021
2022         if (params->lun_size_bytes != 0) {
2023                 be_lun->size_bytes = params->lun_size_bytes;
2024         } else  {
2025                 error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
2026                 if (error != 0) {
2027                         snprintf(req->error_str, sizeof(req->error_str),
2028                                  "error calling VOP_GETATTR() for file %s",
2029                                  be_lun->dev_path);
2030                         return (error);
2031                 }
2032
2033                 be_lun->size_bytes = vattr.va_size;
2034         }
2035
2036         return (0);
2037 }
2038
2039 static int
2040 ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
2041                         struct ctl_lun_req *req)
2042 {
2043         struct cdev *dev;
2044         struct cdevsw *devsw;
2045         int error;
2046         struct ctl_lun_modify_params *params;
2047         uint64_t size_bytes;
2048
2049         params = &req->reqdata.modify;
2050
2051         dev = be_lun->vn->v_rdev;
2052         devsw = dev->si_devsw;
2053         if (!devsw->d_ioctl) {
2054                 snprintf(req->error_str, sizeof(req->error_str),
2055                          "%s: no d_ioctl for device %s!", __func__,
2056                          be_lun->dev_path);
2057                 return (ENODEV);
2058         }
2059
2060         error = devsw->d_ioctl(dev, DIOCGMEDIASIZE,
2061                                (caddr_t)&size_bytes, FREAD,
2062                                curthread);
2063         if (error) {
2064                 snprintf(req->error_str, sizeof(req->error_str),
2065                          "%s: error %d returned for DIOCGMEDIASIZE ioctl "
2066                          "on %s!", __func__, error, be_lun->dev_path);
2067                 return (error);
2068         }
2069
2070         if (params->lun_size_bytes != 0) {
2071                 if (params->lun_size_bytes > size_bytes) {
2072                         snprintf(req->error_str, sizeof(req->error_str),
2073                                  "%s: requested LUN size %ju > backing device "
2074                                  "size %ju", __func__,
2075                                  (uintmax_t)params->lun_size_bytes,
2076                                  (uintmax_t)size_bytes);
2077                         return (EINVAL);
2078                 }
2079
2080                 be_lun->size_bytes = params->lun_size_bytes;
2081         } else {
2082                 be_lun->size_bytes = size_bytes;
2083         }
2084
2085         return (0);
2086 }
2087
2088 static int
2089 ctl_be_block_modify(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2090 {
2091         struct ctl_lun_modify_params *params;
2092         struct ctl_be_block_lun *be_lun;
2093         int vfs_is_locked, error;
2094
2095         params = &req->reqdata.modify;
2096
2097         mtx_lock(&softc->lock);
2098
2099         be_lun = NULL;
2100
2101         STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2102                 if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2103                         break;
2104         }
2105         mtx_unlock(&softc->lock);
2106
2107         if (be_lun == NULL) {
2108                 snprintf(req->error_str, sizeof(req->error_str),
2109                          "%s: LUN %u is not managed by the block backend",
2110                          __func__, params->lun_id);
2111                 goto bailout_error;
2112         }
2113
2114         if (params->lun_size_bytes != 0) {
2115                 if (params->lun_size_bytes < be_lun->blocksize) {
2116                         snprintf(req->error_str, sizeof(req->error_str),
2117                                 "%s: LUN size %ju < blocksize %u", __func__,
2118                                 params->lun_size_bytes, be_lun->blocksize);
2119                         goto bailout_error;
2120                 }
2121         }
2122
2123         vfs_is_locked = VFS_LOCK_GIANT(be_lun->vn->v_mount);
2124         vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
2125
2126         if (be_lun->vn->v_type == VREG)
2127                 error = ctl_be_block_modify_file(be_lun, req);
2128         else
2129                 error = ctl_be_block_modify_dev(be_lun, req);
2130
2131         VOP_UNLOCK(be_lun->vn, 0);
2132         VFS_UNLOCK_GIANT(vfs_is_locked);
2133
2134         if (error != 0)
2135                 goto bailout_error;
2136
2137         be_lun->size_blocks = be_lun->size_bytes >> be_lun->blocksize_shift;
2138
2139         /*
2140          * The maximum LBA is the size - 1.
2141          *
2142          * XXX: Note that this field is being updated without locking,
2143          *      which might cause problems on 32-bit architectures.
2144          */
2145         be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
2146         ctl_lun_capacity_changed(&be_lun->ctl_be_lun);
2147
2148         /* Tell the user the exact size we ended up using */
2149         params->lun_size_bytes = be_lun->size_bytes;
2150
2151         req->status = CTL_LUN_OK;
2152
2153         return (0);
2154
2155 bailout_error:
2156         req->status = CTL_LUN_ERROR;
2157
2158         return (0);
2159 }
2160
2161 static void
2162 ctl_be_block_lun_shutdown(void *be_lun)
2163 {
2164         struct ctl_be_block_lun *lun;
2165         struct ctl_be_block_softc *softc;
2166
2167         lun = (struct ctl_be_block_lun *)be_lun;
2168
2169         softc = lun->softc;
2170
2171         mtx_lock(&softc->lock);
2172         lun->flags |= CTL_BE_BLOCK_LUN_UNCONFIGURED;
2173         if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2174                 wakeup(lun);
2175         mtx_unlock(&softc->lock);
2176
2177 }
2178
2179 static void
2180 ctl_be_block_lun_config_status(void *be_lun, ctl_lun_config_status status)
2181 {
2182         struct ctl_be_block_lun *lun;
2183         struct ctl_be_block_softc *softc;
2184
2185         lun = (struct ctl_be_block_lun *)be_lun;
2186         softc = lun->softc;
2187
2188         if (status == CTL_LUN_CONFIG_OK) {
2189                 mtx_lock(&softc->lock);
2190                 lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2191                 if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2192                         wakeup(lun);
2193                 mtx_unlock(&softc->lock);
2194
2195                 /*
2196                  * We successfully added the LUN, attempt to enable it.
2197                  */
2198                 if (ctl_enable_lun(&lun->ctl_be_lun) != 0) {
2199                         printf("%s: ctl_enable_lun() failed!\n", __func__);
2200                         if (ctl_invalidate_lun(&lun->ctl_be_lun) != 0) {
2201                                 printf("%s: ctl_invalidate_lun() failed!\n",
2202                                        __func__);
2203                         }
2204                 }
2205
2206                 return;
2207         }
2208
2209
2210         mtx_lock(&softc->lock);
2211         lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2212         lun->flags |= CTL_BE_BLOCK_LUN_CONFIG_ERR;
2213         wakeup(lun);
2214         mtx_unlock(&softc->lock);
2215 }
2216
2217
2218 static int
2219 ctl_be_block_config_write(union ctl_io *io)
2220 {
2221         struct ctl_be_block_lun *be_lun;
2222         struct ctl_be_lun *ctl_be_lun;
2223         int retval;
2224
2225         retval = 0;
2226
2227         DPRINTF("entered\n");
2228
2229         ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
2230                 CTL_PRIV_BACKEND_LUN].ptr;
2231         be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
2232
2233         switch (io->scsiio.cdb[0]) {
2234         case SYNCHRONIZE_CACHE:
2235         case SYNCHRONIZE_CACHE_16:
2236                 /*
2237                  * The upper level CTL code will filter out any CDBs with
2238                  * the immediate bit set and return the proper error.
2239                  *
2240                  * We don't really need to worry about what LBA range the
2241                  * user asked to be synced out.  When they issue a sync
2242                  * cache command, we'll sync out the whole thing.
2243                  */
2244                 mtx_lock(&be_lun->lock);
2245                 STAILQ_INSERT_TAIL(&be_lun->config_write_queue, &io->io_hdr,
2246                                    links);
2247                 mtx_unlock(&be_lun->lock);
2248                 taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
2249                 break;
2250         case START_STOP_UNIT: {
2251                 struct scsi_start_stop_unit *cdb;
2252
2253                 cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
2254
2255                 if (cdb->how & SSS_START)
2256                         retval = ctl_start_lun(ctl_be_lun);
2257                 else {
2258                         retval = ctl_stop_lun(ctl_be_lun);
2259                         /*
2260                          * XXX KDM Copan-specific offline behavior.
2261                          * Figure out a reasonable way to port this?
2262                          */
2263 #ifdef NEEDTOPORT
2264                         if ((retval == 0)
2265                          && (cdb->byte2 & SSS_ONOFFLINE))
2266                                 retval = ctl_lun_offline(ctl_be_lun);
2267 #endif
2268                 }
2269
2270                 /*
2271                  * In general, the above routines should not fail.  They
2272                  * just set state for the LUN.  So we've got something
2273                  * pretty wrong here if we can't start or stop the LUN.
2274                  */
2275                 if (retval != 0) {
2276                         ctl_set_internal_failure(&io->scsiio,
2277                                                  /*sks_valid*/ 1,
2278                                                  /*retry_count*/ 0xf051);
2279                         retval = CTL_RETVAL_COMPLETE;
2280                 } else {
2281                         ctl_set_success(&io->scsiio);
2282                 }
2283                 ctl_config_write_done(io);
2284                 break;
2285         }
2286         default:
2287                 ctl_set_invalid_opcode(&io->scsiio);
2288                 ctl_config_write_done(io);
2289                 retval = CTL_RETVAL_COMPLETE;
2290                 break;
2291         }
2292
2293         return (retval);
2294
2295 }
2296
2297 static int
2298 ctl_be_block_config_read(union ctl_io *io)
2299 {
2300         return (0);
2301 }
2302
2303 static int
2304 ctl_be_block_lun_info(void *be_lun, struct sbuf *sb)
2305 {
2306         struct ctl_be_block_lun *lun;
2307         int retval;
2308
2309         lun = (struct ctl_be_block_lun *)be_lun;
2310         retval = 0;
2311
2312         retval = sbuf_printf(sb, "<num_threads>");
2313
2314         if (retval != 0)
2315                 goto bailout;
2316
2317         retval = sbuf_printf(sb, "%d", lun->num_threads);
2318
2319         if (retval != 0)
2320                 goto bailout;
2321
2322         retval = sbuf_printf(sb, "</num_threads>");
2323
2324         /*
2325          * For processor devices, we don't have a path variable.
2326          */
2327         if ((retval != 0)
2328          || (lun->dev_path == NULL))
2329                 goto bailout;
2330
2331         retval = sbuf_printf(sb, "<file>");
2332
2333         if (retval != 0)
2334                 goto bailout;
2335
2336         retval = ctl_sbuf_printf_esc(sb, lun->dev_path);
2337
2338         if (retval != 0)
2339                 goto bailout;
2340
2341         retval = sbuf_printf(sb, "</file>\n");
2342
2343 bailout:
2344
2345         return (retval);
2346 }
2347
2348 int
2349 ctl_be_block_init(void)
2350 {
2351         struct ctl_be_block_softc *softc;
2352         int retval;
2353
2354         softc = &backend_block_softc;
2355         retval = 0;
2356
2357         mtx_init(&softc->lock, "ctlblk", NULL, MTX_DEF);
2358         STAILQ_INIT(&softc->beio_free_queue);
2359         STAILQ_INIT(&softc->disk_list);
2360         STAILQ_INIT(&softc->lun_list);
2361         ctl_grow_beio(softc, 200);
2362
2363         return (retval);
2364 }