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 error, lock_flags;
 597
 598         DPRINTF("entered\n");
 599
 600         io = beio->io;
 601
 602         (void) vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
 603
 604         if (MNT_SHARED_WRITES(mountpoint)
 605          || ((mountpoint == NULL)
 606           && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
 607                 lock_flags = LK_SHARED;
 608         else
 609                 lock_flags = LK_EXCLUSIVE;
 610
 611         vn_lock(be_lun->vn, lock_flags | LK_RETRY);
 612
 613         binuptime(&beio->ds_t0);
 614         devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
 615
 616         error = VOP_FSYNC(be_lun->vn, MNT_WAIT, curthread);
 617         VOP_UNLOCK(be_lun->vn, 0);
 618
 619         vn_finished_write(mountpoint);
 620
 621         if (error == 0)
 622                 ctl_set_success(&io->scsiio);
 623         else {
 624                 /* XXX KDM is there is a better error here? */
 625                 ctl_set_internal_failure(&io->scsiio,
 626                                          /*sks_valid*/ 1,
 627                                          /*retry_count*/ 0xbad1);
 628         }
 629
 630         ctl_complete_beio(beio);
 631 }
 632
 633 SDT_PROBE_DEFINE1(cbb, kernel, read, file_start, file_start, "uint64_t");
 634 SDT_PROBE_DEFINE1(cbb, kernel, write, file_start, file_start, "uint64_t");
 635 SDT_PROBE_DEFINE1(cbb, kernel, read, file_done, file_done,"uint64_t");
 636 SDT_PROBE_DEFINE1(cbb, kernel, write, file_done, file_done, "uint64_t");
 637
 638 static void
 639 ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
 640                            struct ctl_be_block_io *beio)
 641 {
 642         struct ctl_be_block_filedata *file_data;
 643         union ctl_io *io;
 644         struct uio xuio;
 645         struct iovec *xiovec;
 646         int flags;
 647         int error, i;
 648
 649         DPRINTF("entered\n");
 650
 651         file_data = &be_lun->backend.file;
 652         io = beio->io;
 653         flags = beio->bio_flags;
 654
 655         if (beio->bio_cmd == BIO_READ) {
 656                 SDT_PROBE(cbb, kernel, read, file_start, 0, 0, 0, 0, 0);
 657         } else {
 658                 SDT_PROBE(cbb, kernel, write, file_start, 0, 0, 0, 0, 0);
 659         }
 660
 661         bzero(&xuio, sizeof(xuio));
 662         if (beio->bio_cmd == BIO_READ)
 663                 xuio.uio_rw = UIO_READ;
 664         else
 665                 xuio.uio_rw = UIO_WRITE;
 666
 667         xuio.uio_offset = beio->io_offset;
 668         xuio.uio_resid = beio->io_len;
 669         xuio.uio_segflg = UIO_SYSSPACE;
 670         xuio.uio_iov = beio->xiovecs;
 671         xuio.uio_iovcnt = beio->num_segs;
 672         xuio.uio_td = curthread;
 673
 674         for (i = 0, xiovec = xuio.uio_iov; i < xuio.uio_iovcnt; i++, xiovec++) {
 675                 xiovec->iov_base = beio->sg_segs[i].addr;
 676                 xiovec->iov_len = beio->sg_segs[i].len;
 677         }
 678
 679         if (beio->bio_cmd == BIO_READ) {
 680                 vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
 681
 682                 binuptime(&beio->ds_t0);
 683                 devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
 684
 685                 /*
 686                  * UFS pays attention to IO_DIRECT for reads.  If the
 687                  * DIRECTIO option is configured into the kernel, it calls
 688                  * ffs_rawread().  But that only works for single-segment
 689                  * uios with user space addresses.  In our case, with a
 690                  * kernel uio, it still reads into the buffer cache, but it
 691                  * will just try to release the buffer from the cache later
 692                  * on in ffs_read().
 693                  *
 694                  * ZFS does not pay attention to IO_DIRECT for reads.
 695                  *
 696                  * UFS does not pay attention to IO_SYNC for reads.
 697                  *
 698                  * ZFS pays attention to IO_SYNC (which translates into the
 699                  * Solaris define FRSYNC for zfs_read()) for reads.  It
 700                  * attempts to sync the file before reading.
 701                  *
 702                  * So, to attempt to provide some barrier semantics in the
 703                  * BIO_ORDERED case, set both IO_DIRECT and IO_SYNC.
 704                  */
 705                 error = VOP_READ(be_lun->vn, &xuio, (flags & BIO_ORDERED) ?
 706                                  (IO_DIRECT|IO_SYNC) : 0, file_data->cred);
 707
 708                 VOP_UNLOCK(be_lun->vn, 0);
 709         } else {
 710                 struct mount *mountpoint;
 711                 int lock_flags;
 712
 713                 (void)vn_start_write(be_lun->vn, &mountpoint, V_WAIT);
 714
 715                 if (MNT_SHARED_WRITES(mountpoint)
 716                  || ((mountpoint == NULL)
 717                   && MNT_SHARED_WRITES(be_lun->vn->v_mount)))
 718                         lock_flags = LK_SHARED;
 719                 else
 720                         lock_flags = LK_EXCLUSIVE;
 721
 722                 vn_lock(be_lun->vn, lock_flags | LK_RETRY);
 723
 724                 binuptime(&beio->ds_t0);
 725                 devstat_start_transaction(beio->lun->disk_stats, &beio->ds_t0);
 726
 727                 /*
 728                  * UFS pays attention to IO_DIRECT for writes.  The write
 729                  * is done asynchronously.  (Normally the write would just
 730                  * get put into cache.
 731                  *
 732                  * UFS pays attention to IO_SYNC for writes.  It will
 733                  * attempt to write the buffer out synchronously if that
 734                  * flag is set.
 735                  *
 736                  * ZFS does not pay attention to IO_DIRECT for writes.
 737                  *
 738                  * ZFS pays attention to IO_SYNC (a.k.a. FSYNC or FRSYNC)
 739                  * for writes.  It will flush the transaction from the
 740                  * cache before returning.
 741                  *
 742                  * So if we've got the BIO_ORDERED flag set, we want
 743                  * IO_SYNC in either the UFS or ZFS case.
 744                  */
 745                 error = VOP_WRITE(be_lun->vn, &xuio, (flags & BIO_ORDERED) ?
 746                                   IO_SYNC : 0, file_data->cred);
 747                 VOP_UNLOCK(be_lun->vn, 0);
 748
 749                 vn_finished_write(mountpoint);
 750         }
 751
 752         /*
 753          * If we got an error, set the sense data to "MEDIUM ERROR" and
 754          * return the I/O to the user.
 755          */
 756         if (error != 0) {
 757                 char path_str[32];
 758
 759                 ctl_scsi_path_string(io, path_str, sizeof(path_str));
 760                 /*
 761                  * XXX KDM ZFS returns ENOSPC when the underlying
 762                  * filesystem fills up.  What kind of SCSI error should we
 763                  * return for that?
 764                  */
 765                 printf("%s%s command returned errno %d\n", path_str,
 766                        (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE", error);
 767                 ctl_set_medium_error(&io->scsiio);
 768                 ctl_complete_beio(beio);
 769                 return;
 770         }
 771
 772         /*
 773          * If this is a write, we're all done.
 774          * If this is a read, we can now send the data to the user.
 775          */
 776         if (beio->bio_cmd == BIO_WRITE) {
 777                 ctl_set_success(&io->scsiio);
 778                 SDT_PROBE(cbb, kernel, write, file_done, 0, 0, 0, 0, 0);
 779                 ctl_complete_beio(beio);
 780         } else {
 781                 SDT_PROBE(cbb, kernel, read, file_done, 0, 0, 0, 0, 0);
 782                 io->scsiio.be_move_done = ctl_be_block_move_done;
 783                 io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
 784                 io->scsiio.kern_data_len = beio->io_len;
 785                 io->scsiio.kern_total_len = beio->io_len;
 786                 io->scsiio.kern_rel_offset = 0;
 787                 io->scsiio.kern_data_resid = 0;
 788                 io->scsiio.kern_sg_entries = beio->num_segs;
 789                 io->io_hdr.flags |= CTL_FLAG_ALLOCATED | CTL_FLAG_KDPTR_SGLIST;
 790 #ifdef CTL_TIME_IO
 791                 getbintime(&io->io_hdr.dma_start_bt);
 792 #endif
 793                 ctl_datamove(io);
 794         }
 795 }
 796
 797 static void
 798 ctl_be_block_flush_dev(struct ctl_be_block_lun *be_lun,
 799                        struct ctl_be_block_io *beio)
 800 {
 801         struct bio *bio;
 802         union ctl_io *io;
 803         struct ctl_be_block_devdata *dev_data;
 804
 805         dev_data = &be_lun->backend.dev;
 806         io = beio->io;
 807
 808         DPRINTF("entered\n");
 809
 810         /* This can't fail, it's a blocking allocation. */
 811         bio = g_alloc_bio();
 812
 813         bio->bio_cmd        = BIO_FLUSH;
 814         bio->bio_flags     |= BIO_ORDERED;
 815         bio->bio_dev        = dev_data->cdev;
 816         bio->bio_offset     = 0;
 817         bio->bio_data       = 0;
 818         bio->bio_done       = ctl_be_block_biodone;
 819         bio->bio_caller1    = beio;
 820         bio->bio_pblkno     = 0;
 821
 822         /*
 823          * We don't need to acquire the LUN lock here, because we are only
 824          * sending one bio, and so there is no other context to synchronize
 825          * with.
 826          */
 827         beio->num_bios_sent = 1;
 828         beio->send_complete = 1;
 829
 830         binuptime(&beio->ds_t0);
 831         devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
 832
 833         (*dev_data->csw->d_strategy)(bio);
 834 }
 835
 836 static void
 837 ctl_be_block_dispatch_dev(struct ctl_be_block_lun *be_lun,
 838                           struct ctl_be_block_io *beio)
 839 {
 840         int i;
 841         struct bio *bio;
 842         struct ctl_be_block_devdata *dev_data;
 843         off_t cur_offset;
 844         int max_iosize;
 845
 846         DPRINTF("entered\n");
 847
 848         dev_data = &be_lun->backend.dev;
 849
 850         /*
 851          * We have to limit our I/O size to the maximum supported by the
 852          * backend device.  Hopefully it is MAXPHYS.  If the driver doesn't
 853          * set it properly, use DFLTPHYS.
 854          */
 855         max_iosize = dev_data->cdev->si_iosize_max;
 856         if (max_iosize < PAGE_SIZE)
 857                 max_iosize = DFLTPHYS;
 858
 859         cur_offset = beio->io_offset;
 860
 861         /*
 862          * XXX KDM need to accurately reflect the number of I/Os outstanding
 863          * to a device.
 864          */
 865         binuptime(&beio->ds_t0);
 866         devstat_start_transaction(be_lun->disk_stats, &beio->ds_t0);
 867
 868         for (i = 0; i < beio->num_segs; i++) {
 869                 size_t cur_size;
 870                 uint8_t *cur_ptr;
 871
 872                 cur_size = beio->sg_segs[i].len;
 873                 cur_ptr = beio->sg_segs[i].addr;
 874
 875                 while (cur_size > 0) {
 876                         /* This can't fail, it's a blocking allocation. */
 877                         bio = g_alloc_bio();
 878
 879                         KASSERT(bio != NULL, ("g_alloc_bio() failed!\n"));
 880
 881                         bio->bio_cmd = beio->bio_cmd;
 882                         bio->bio_flags |= beio->bio_flags;
 883                         bio->bio_dev = dev_data->cdev;
 884                         bio->bio_caller1 = beio;
 885                         bio->bio_length = min(cur_size, max_iosize);
 886                         bio->bio_offset = cur_offset;
 887                         bio->bio_data = cur_ptr;
 888                         bio->bio_done = ctl_be_block_biodone;
 889                         bio->bio_pblkno = cur_offset / be_lun->blocksize;
 890
 891                         cur_offset += bio->bio_length;
 892                         cur_ptr += bio->bio_length;
 893                         cur_size -= bio->bio_length;
 894
 895                         /*
 896                          * Make sure we set the complete bit just before we
 897                          * issue the last bio so we don't wind up with a
 898                          * race.
 899                          *
 900                          * Use the LUN mutex here instead of a combination
 901                          * of atomic variables for simplicity.
 902                          *
 903                          * XXX KDM we could have a per-IO lock, but that
 904                          * would cause additional per-IO setup and teardown
 905                          * overhead.  Hopefully there won't be too much
 906                          * contention on the LUN lock.
 907                          */
 908                         mtx_lock(&be_lun->lock);
 909
 910                         beio->num_bios_sent++;
 911
 912                         if ((i == beio->num_segs - 1)
 913                          && (cur_size == 0))
 914                                 beio->send_complete = 1;
 915
 916                         mtx_unlock(&be_lun->lock);
 917
 918                         (*dev_data->csw->d_strategy)(bio);
 919                 }
 920         }
 921 }
 922
 923 static void
 924 ctl_be_block_cw_dispatch(struct ctl_be_block_lun *be_lun,
 925                          union ctl_io *io)
 926 {
 927         struct ctl_be_block_io *beio;
 928         struct ctl_be_block_softc *softc;
 929
 930         DPRINTF("entered\n");
 931
 932         softc = be_lun->softc;
 933         beio = ctl_alloc_beio(softc);
 934         if (beio == NULL) {
 935                 /*
 936                  * This should not happen.  ctl_alloc_beio() will call
 937                  * ctl_grow_beio() with a blocking malloc as needed.
 938                  * A malloc with M_WAITOK should not fail.
 939                  */
 940                 ctl_set_busy(&io->scsiio);
 941                 ctl_done(io);
 942                 return;
 943         }
 944
 945         beio->io = io;
 946         beio->softc = softc;
 947         beio->lun = be_lun;
 948         io->io_hdr.ctl_private[CTL_PRIV_BACKEND].ptr = beio;
 949
 950         switch (io->scsiio.cdb[0]) {
 951         case SYNCHRONIZE_CACHE:
 952         case SYNCHRONIZE_CACHE_16:
 953                 beio->bio_cmd = BIO_FLUSH;
 954                 beio->ds_trans_type = DEVSTAT_NO_DATA;
 955                 beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
 956                 beio->io_len = 0;
 957                 be_lun->lun_flush(be_lun, beio);
 958                 break;
 959         default:
 960                 panic("Unhandled CDB type %#x", io->scsiio.cdb[0]);
 961                 break;
 962         }
 963 }
 964
 965 SDT_PROBE_DEFINE1(cbb, kernel, read, start, start, "uint64_t");
 966 SDT_PROBE_DEFINE1(cbb, kernel, write, start, start, "uint64_t");
 967 SDT_PROBE_DEFINE1(cbb, kernel, read, alloc_done, alloc_done, "uint64_t");
 968 SDT_PROBE_DEFINE1(cbb, kernel, write, alloc_done, alloc_done, "uint64_t");
 969
 970 static void
 971 ctl_be_block_dispatch(struct ctl_be_block_lun *be_lun,
 972                            union ctl_io *io)
 973 {
 974         struct ctl_be_block_io *beio;
 975         struct ctl_be_block_softc *softc;
 976         struct ctl_lba_len lbalen;
 977         uint64_t len_left, io_size_bytes;
 978         int i;
 979
 980         softc = be_lun->softc;
 981
 982         DPRINTF("entered\n");
 983
 984         if ((io->io_hdr.flags & CTL_FLAG_DATA_MASK) == CTL_FLAG_DATA_IN) {
 985                 SDT_PROBE(cbb, kernel, read, start, 0, 0, 0, 0, 0);
 986         } else {
 987                 SDT_PROBE(cbb, kernel, write, start, 0, 0, 0, 0, 0);
 988         }
 989
 990         memcpy(&lbalen, io->io_hdr.ctl_private[CTL_PRIV_LBA_LEN].bytes,
 991                sizeof(lbalen));
 992
 993         io_size_bytes = lbalen.len * be_lun->blocksize;
 994
 995         /*
 996          * XXX KDM this is temporary, until we implement chaining of beio
 997          * structures and multiple datamove calls to move all the data in
 998          * or out.
 999          */
1000         if (io_size_bytes > CTLBLK_MAX_IO_SIZE) {
1001                 printf("%s: IO length %ju > max io size %u\n", __func__,
1002                        io_size_bytes, CTLBLK_MAX_IO_SIZE);
1003                 ctl_set_invalid_field(&io->scsiio,
1004                                       /*sks_valid*/ 0,
1005                                       /*command*/ 1,
1006                                       /*field*/ 0,
1007                                       /*bit_valid*/ 0,
1008                                       /*bit*/ 0);
1009                 ctl_done(io);
1010                 return;
1011         }
1012
1013         beio = ctl_alloc_beio(softc);
1014         if (beio == NULL) {
1015                 /*
1016                  * This should not happen.  ctl_alloc_beio() will call
1017                  * ctl_grow_beio() with a blocking malloc as needed.
1018                  * A malloc with M_WAITOK should not fail.
1019                  */
1020                 ctl_set_busy(&io->scsiio);
1021                 ctl_done(io);
1022                 return;
1023         }
1024
1025         beio->io = io;
1026         beio->softc = softc;
1027         beio->lun = be_lun;
1028         io->io_hdr.ctl_private[CTL_PRIV_BACKEND].ptr = beio;
1029
1030         /*
1031          * If the I/O came down with an ordered or head of queue tag, set
1032          * the BIO_ORDERED attribute.  For head of queue tags, that's
1033          * pretty much the best we can do.
1034          *
1035          * XXX KDM we don't have a great way to easily know about the FUA
1036          * bit right now (it is decoded in ctl_read_write(), but we don't
1037          * pass that knowledge to the backend), and in any case we would
1038          * need to determine how to handle it.
1039          */
1040         if ((io->scsiio.tag_type == CTL_TAG_ORDERED)
1041          || (io->scsiio.tag_type == CTL_TAG_HEAD_OF_QUEUE))
1042                 beio->bio_flags = BIO_ORDERED;
1043
1044         switch (io->scsiio.tag_type) {
1045         case CTL_TAG_ORDERED:
1046                 beio->ds_tag_type = DEVSTAT_TAG_ORDERED;
1047                 break;
1048         case CTL_TAG_HEAD_OF_QUEUE:
1049                 beio->ds_tag_type = DEVSTAT_TAG_HEAD;
1050                 break;
1051         case CTL_TAG_UNTAGGED:
1052         case CTL_TAG_SIMPLE:
1053         case CTL_TAG_ACA:
1054         default:
1055                 beio->ds_tag_type = DEVSTAT_TAG_SIMPLE;
1056                 break;
1057         }
1058
1059         /*
1060          * This path handles read and write only.  The config write path
1061          * handles flush operations.
1062          */
1063         if ((io->io_hdr.flags & CTL_FLAG_DATA_MASK) == CTL_FLAG_DATA_IN) {
1064                 beio->bio_cmd = BIO_READ;
1065                 beio->ds_trans_type = DEVSTAT_READ;
1066         } else {
1067                 beio->bio_cmd = BIO_WRITE;
1068                 beio->ds_trans_type = DEVSTAT_WRITE;
1069         }
1070
1071         beio->io_len = lbalen.len * be_lun->blocksize;
1072         beio->io_offset = lbalen.lba * be_lun->blocksize;
1073
1074         DPRINTF("%s at LBA %jx len %u\n",
1075                (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE",
1076                (uintmax_t)lbalen.lba, lbalen.len);
1077
1078         for (i = 0, len_left = io_size_bytes; i < CTLBLK_MAX_SEGS &&
1079              len_left > 0; i++) {
1080
1081                 /*
1082                  * Setup the S/G entry for this chunk.
1083                  */
1084                 beio->sg_segs[i].len = min(MAXPHYS, len_left);
1085                 beio->sg_segs[i].addr = uma_zalloc(be_lun->lun_zone, M_WAITOK);
1086
1087                 DPRINTF("segment %d addr %p len %zd\n", i,
1088                         beio->sg_segs[i].addr, beio->sg_segs[i].len);
1089
1090                 beio->num_segs++;
1091                 len_left -= beio->sg_segs[i].len;
1092         }
1093
1094         /*
1095          * For the read case, we need to read the data into our buffers and
1096          * then we can send it back to the user.  For the write case, we
1097          * need to get the data from the user first.
1098          */
1099         if (beio->bio_cmd == BIO_READ) {
1100                 SDT_PROBE(cbb, kernel, read, alloc_done, 0, 0, 0, 0, 0);
1101                 be_lun->dispatch(be_lun, beio);
1102         } else {
1103                 SDT_PROBE(cbb, kernel, write, alloc_done, 0, 0, 0, 0, 0);
1104                 io->scsiio.be_move_done = ctl_be_block_move_done;
1105                 io->scsiio.kern_data_ptr = (uint8_t *)beio->sg_segs;
1106                 io->scsiio.kern_data_len = beio->io_len;
1107                 io->scsiio.kern_total_len = beio->io_len;
1108                 io->scsiio.kern_rel_offset = 0;
1109                 io->scsiio.kern_data_resid = 0;
1110                 io->scsiio.kern_sg_entries = beio->num_segs;
1111                 io->io_hdr.flags |= CTL_FLAG_ALLOCATED | CTL_FLAG_KDPTR_SGLIST;
1112 #ifdef CTL_TIME_IO
1113                 getbintime(&io->io_hdr.dma_start_bt);
1114 #endif
1115                 ctl_datamove(io);
1116         }
1117 }
1118
1119 static void
1120 ctl_be_block_worker(void *context, int pending)
1121 {
1122         struct ctl_be_block_lun *be_lun;
1123         struct ctl_be_block_softc *softc;
1124         union ctl_io *io;
1125
1126         be_lun = (struct ctl_be_block_lun *)context;
1127         softc = be_lun->softc;
1128
1129         DPRINTF("entered\n");
1130
1131         mtx_lock(&be_lun->lock);
1132         for (;;) {
1133                 io = (union ctl_io *)STAILQ_FIRST(&be_lun->datamove_queue);
1134                 if (io != NULL) {
1135                         struct ctl_be_block_io *beio;
1136
1137                         DPRINTF("datamove queue\n");
1138
1139                         STAILQ_REMOVE(&be_lun->datamove_queue, &io->io_hdr,
1140                                       ctl_io_hdr, links);
1141
1142                         mtx_unlock(&be_lun->lock);
1143
1144                         beio = (struct ctl_be_block_io *)
1145                             io->io_hdr.ctl_private[CTL_PRIV_BACKEND].ptr;
1146
1147                         be_lun->dispatch(be_lun, beio);
1148
1149                         mtx_lock(&be_lun->lock);
1150                         continue;
1151                 }
1152                 io = (union ctl_io *)STAILQ_FIRST(&be_lun->config_write_queue);
1153                 if (io != NULL) {
1154
1155                         DPRINTF("config write queue\n");
1156
1157                         STAILQ_REMOVE(&be_lun->config_write_queue, &io->io_hdr,
1158                                       ctl_io_hdr, links);
1159
1160                         mtx_unlock(&be_lun->lock);
1161
1162                         ctl_be_block_cw_dispatch(be_lun, io);
1163
1164                         mtx_lock(&be_lun->lock);
1165                         continue;
1166                 }
1167                 io = (union ctl_io *)STAILQ_FIRST(&be_lun->input_queue);
1168                 if (io != NULL) {
1169                         DPRINTF("input queue\n");
1170
1171                         STAILQ_REMOVE(&be_lun->input_queue, &io->io_hdr,
1172                                       ctl_io_hdr, links);
1173                         mtx_unlock(&be_lun->lock);
1174
1175                         /*
1176                          * We must drop the lock, since this routine and
1177                          * its children may sleep.
1178                          */
1179                         ctl_be_block_dispatch(be_lun, io);
1180
1181                         mtx_lock(&be_lun->lock);
1182                         continue;
1183                 }
1184
1185                 /*
1186                  * If we get here, there is no work left in the queues, so
1187                  * just break out and let the task queue go to sleep.
1188                  */
1189                 break;
1190         }
1191         mtx_unlock(&be_lun->lock);
1192 }
1193
1194 /*
1195  * Entry point from CTL to the backend for I/O.  We queue everything to a
1196  * work thread, so this just puts the I/O on a queue and wakes up the
1197  * thread.
1198  */
1199 static int
1200 ctl_be_block_submit(union ctl_io *io)
1201 {
1202         struct ctl_be_block_lun *be_lun;
1203         struct ctl_be_lun *ctl_be_lun;
1204         int retval;
1205
1206         DPRINTF("entered\n");
1207
1208         retval = CTL_RETVAL_COMPLETE;
1209
1210         ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
1211                 CTL_PRIV_BACKEND_LUN].ptr;
1212         be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
1213
1214         /*
1215          * Make sure we only get SCSI I/O.
1216          */
1217         KASSERT(io->io_hdr.io_type == CTL_IO_SCSI, ("Non-SCSI I/O (type "
1218                 "%#x) encountered", io->io_hdr.io_type));
1219
1220         mtx_lock(&be_lun->lock);
1221         /*
1222          * XXX KDM make sure that links is okay to use at this point.
1223          * Otherwise, we either need to add another field to ctl_io_hdr,
1224          * or deal with resource allocation here.
1225          */
1226         STAILQ_INSERT_TAIL(&be_lun->input_queue, &io->io_hdr, links);
1227         mtx_unlock(&be_lun->lock);
1228
1229         taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
1230
1231         return (retval);
1232 }
1233
1234 static int
1235 ctl_be_block_ioctl(struct cdev *dev, u_long cmd, caddr_t addr,
1236                         int flag, struct thread *td)
1237 {
1238         struct ctl_be_block_softc *softc;
1239         int error;
1240
1241         softc = &backend_block_softc;
1242
1243         error = 0;
1244
1245         switch (cmd) {
1246         case CTL_LUN_REQ: {
1247                 struct ctl_lun_req *lun_req;
1248
1249                 lun_req = (struct ctl_lun_req *)addr;
1250
1251                 switch (lun_req->reqtype) {
1252                 case CTL_LUNREQ_CREATE:
1253                         error = ctl_be_block_create(softc, lun_req);
1254                         break;
1255                 case CTL_LUNREQ_RM:
1256                         error = ctl_be_block_rm(softc, lun_req);
1257                         break;
1258                 case CTL_LUNREQ_MODIFY:
1259                         error = ctl_be_block_modify(softc, lun_req);
1260                         break;
1261                 default:
1262                         lun_req->status = CTL_LUN_ERROR;
1263                         snprintf(lun_req->error_str, sizeof(lun_req->error_str),
1264                                  "%s: invalid LUN request type %d", __func__,
1265                                  lun_req->reqtype);
1266                         break;
1267                 }
1268                 break;
1269         }
1270         default:
1271                 error = ENOTTY;
1272                 break;
1273         }
1274
1275         return (error);
1276 }
1277
1278 static int
1279 ctl_be_block_open_file(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1280 {
1281         struct ctl_be_block_filedata *file_data;
1282         struct ctl_lun_create_params *params;
1283         struct vattr                  vattr;
1284         int                           error;
1285
1286         error = 0;
1287         file_data = &be_lun->backend.file;
1288         params = &req->reqdata.create;
1289
1290         be_lun->dev_type = CTL_BE_BLOCK_FILE;
1291         be_lun->dispatch = ctl_be_block_dispatch_file;
1292         be_lun->lun_flush = ctl_be_block_flush_file;
1293
1294         error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
1295         if (error != 0) {
1296                 snprintf(req->error_str, sizeof(req->error_str),
1297                          "error calling VOP_GETATTR() for file %s",
1298                          be_lun->dev_path);
1299                 return (error);
1300         }
1301
1302         /*
1303          * Verify that we have the ability to upgrade to exclusive
1304          * access on this file so we can trap errors at open instead
1305          * of reporting them during first access.
1306          */
1307         if (VOP_ISLOCKED(be_lun->vn) != LK_EXCLUSIVE) {
1308                 vn_lock(be_lun->vn, LK_UPGRADE | LK_RETRY);
1309                 if (be_lun->vn->v_iflag & VI_DOOMED) {
1310                         error = EBADF;
1311                         snprintf(req->error_str, sizeof(req->error_str),
1312                                  "error locking file %s", be_lun->dev_path);
1313                         return (error);
1314                 }
1315         }
1316
1317
1318         file_data->cred = crhold(curthread->td_ucred);
1319         if (params->lun_size_bytes != 0)
1320                 be_lun->size_bytes = params->lun_size_bytes;
1321         else
1322                 be_lun->size_bytes = vattr.va_size;
1323         /*
1324          * We set the multi thread flag for file operations because all
1325          * filesystems (in theory) are capable of allowing multiple readers
1326          * of a file at once.  So we want to get the maximum possible
1327          * concurrency.
1328          */
1329         be_lun->flags |= CTL_BE_BLOCK_LUN_MULTI_THREAD;
1330
1331         /*
1332          * XXX KDM vattr.va_blocksize may be larger than 512 bytes here.
1333          * With ZFS, it is 131072 bytes.  Block sizes that large don't work
1334          * with disklabel and UFS on FreeBSD at least.  Large block sizes
1335          * may not work with other OSes as well.  So just export a sector
1336          * size of 512 bytes, which should work with any OS or
1337          * application.  Since our backing is a file, any block size will
1338          * work fine for the backing store.
1339          */
1340 #if 0
1341         be_lun->blocksize= vattr.va_blocksize;
1342 #endif
1343         if (params->blocksize_bytes != 0)
1344                 be_lun->blocksize = params->blocksize_bytes;
1345         else
1346                 be_lun->blocksize = 512;
1347
1348         /*
1349          * Sanity check.  The media size has to be at least one
1350          * sector long.
1351          */
1352         if (be_lun->size_bytes < be_lun->blocksize) {
1353                 error = EINVAL;
1354                 snprintf(req->error_str, sizeof(req->error_str),
1355                          "file %s size %ju < block size %u", be_lun->dev_path,
1356                          (uintmax_t)be_lun->size_bytes, be_lun->blocksize);
1357         }
1358         return (error);
1359 }
1360
1361 static int
1362 ctl_be_block_open_dev(struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1363 {
1364         struct ctl_lun_create_params *params;
1365         struct vattr                  vattr;
1366         struct cdev                  *dev;
1367         struct cdevsw                *devsw;
1368         int                           error;
1369
1370         params = &req->reqdata.create;
1371
1372         be_lun->dev_type = CTL_BE_BLOCK_DEV;
1373         be_lun->dispatch = ctl_be_block_dispatch_dev;
1374         be_lun->lun_flush = ctl_be_block_flush_dev;
1375         be_lun->backend.dev.cdev = be_lun->vn->v_rdev;
1376         be_lun->backend.dev.csw = dev_refthread(be_lun->backend.dev.cdev,
1377                                              &be_lun->backend.dev.dev_ref);
1378         if (be_lun->backend.dev.csw == NULL)
1379                 panic("Unable to retrieve device switch");
1380
1381         error = VOP_GETATTR(be_lun->vn, &vattr, NOCRED);
1382         if (error) {
1383                 snprintf(req->error_str, sizeof(req->error_str),
1384                          "%s: error getting vnode attributes for device %s",
1385                          __func__, be_lun->dev_path);
1386                 return (error);
1387         }
1388
1389         dev = be_lun->vn->v_rdev;
1390         devsw = dev->si_devsw;
1391         if (!devsw->d_ioctl) {
1392                 snprintf(req->error_str, sizeof(req->error_str),
1393                          "%s: no d_ioctl for device %s!", __func__,
1394                          be_lun->dev_path);
1395                 return (ENODEV);
1396         }
1397
1398         error = devsw->d_ioctl(dev, DIOCGSECTORSIZE,
1399                                (caddr_t)&be_lun->blocksize, FREAD,
1400                                curthread);
1401         if (error) {
1402                 snprintf(req->error_str, sizeof(req->error_str),
1403                          "%s: error %d returned for DIOCGSECTORSIZE ioctl "
1404                          "on %s!", __func__, error, be_lun->dev_path);
1405                 return (error);
1406         }
1407
1408         /*
1409          * If the user has asked for a blocksize that is greater than the
1410          * backing device's blocksize, we can do it only if the blocksize
1411          * the user is asking for is an even multiple of the underlying
1412          * device's blocksize.
1413          */
1414         if ((params->blocksize_bytes != 0)
1415          && (params->blocksize_bytes > be_lun->blocksize)) {
1416                 uint32_t bs_multiple, tmp_blocksize;
1417
1418                 bs_multiple = params->blocksize_bytes / be_lun->blocksize;
1419
1420                 tmp_blocksize = bs_multiple * be_lun->blocksize;
1421
1422                 if (tmp_blocksize == params->blocksize_bytes) {
1423                         be_lun->blocksize = params->blocksize_bytes;
1424                 } else {
1425                         snprintf(req->error_str, sizeof(req->error_str),
1426                                  "%s: requested blocksize %u is not an even "
1427                                  "multiple of backing device blocksize %u",
1428                                  __func__, params->blocksize_bytes,
1429                                  be_lun->blocksize);
1430                         return (EINVAL);
1431
1432                 }
1433         } else if ((params->blocksize_bytes != 0)
1434                 && (params->blocksize_bytes != be_lun->blocksize)) {
1435                 snprintf(req->error_str, sizeof(req->error_str),
1436                          "%s: requested blocksize %u < backing device "
1437                          "blocksize %u", __func__, params->blocksize_bytes,
1438                          be_lun->blocksize);
1439                 return (EINVAL);
1440         }
1441
1442         error = devsw->d_ioctl(dev, DIOCGMEDIASIZE,
1443                                (caddr_t)&be_lun->size_bytes, FREAD,
1444                                curthread);
1445         if (error) {
1446                 snprintf(req->error_str, sizeof(req->error_str),
1447                          "%s: error %d returned for DIOCGMEDIASIZE "
1448                          " ioctl on %s!", __func__, error,
1449                          be_lun->dev_path);
1450                 return (error);
1451         }
1452
1453         if (params->lun_size_bytes != 0) {
1454                 if (params->lun_size_bytes > be_lun->size_bytes) {
1455                         snprintf(req->error_str, sizeof(req->error_str),
1456                                  "%s: requested LUN size %ju > backing device "
1457                                  "size %ju", __func__,
1458                                  (uintmax_t)params->lun_size_bytes,
1459                                  (uintmax_t)be_lun->size_bytes);
1460                         return (EINVAL);
1461                 }
1462
1463                 be_lun->size_bytes = params->lun_size_bytes;
1464         }
1465
1466         return (0);
1467 }
1468
1469 static int
1470 ctl_be_block_close(struct ctl_be_block_lun *be_lun)
1471 {
1472         DROP_GIANT();
1473         if (be_lun->vn) {
1474                 int flags = FREAD | FWRITE;
1475
1476                 switch (be_lun->dev_type) {
1477                 case CTL_BE_BLOCK_DEV:
1478                         if (be_lun->backend.dev.csw) {
1479                                 dev_relthread(be_lun->backend.dev.cdev,
1480                                               be_lun->backend.dev.dev_ref);
1481                                 be_lun->backend.dev.csw  = NULL;
1482                                 be_lun->backend.dev.cdev = NULL;
1483                         }
1484                         break;
1485                 case CTL_BE_BLOCK_FILE:
1486                         break;
1487                 case CTL_BE_BLOCK_NONE:
1488                 default:
1489                         panic("Unexpected backend type.");
1490                         break;
1491                 }
1492
1493                 (void)vn_close(be_lun->vn, flags, NOCRED, curthread);
1494                 be_lun->vn = NULL;
1495
1496                 switch (be_lun->dev_type) {
1497                 case CTL_BE_BLOCK_DEV:
1498                         break;
1499                 case CTL_BE_BLOCK_FILE:
1500                         if (be_lun->backend.file.cred != NULL) {
1501                                 crfree(be_lun->backend.file.cred);
1502                                 be_lun->backend.file.cred = NULL;
1503                         }
1504                         break;
1505                 case CTL_BE_BLOCK_NONE:
1506                 default:
1507                         panic("Unexpected backend type.");
1508                         break;
1509                 }
1510         }
1511         PICKUP_GIANT();
1512
1513         return (0);
1514 }
1515
1516 static int
1517 ctl_be_block_open(struct ctl_be_block_softc *softc,
1518                        struct ctl_be_block_lun *be_lun, struct ctl_lun_req *req)
1519 {
1520         struct nameidata nd;
1521         int              flags;
1522         int              error;
1523
1524         /*
1525          * XXX KDM allow a read-only option?
1526          */
1527         flags = FREAD | FWRITE;
1528         error = 0;
1529
1530         if (rootvnode == NULL) {
1531                 snprintf(req->error_str, sizeof(req->error_str),
1532                          "%s: Root filesystem is not mounted", __func__);
1533                 return (1);
1534         }
1535
1536         if (!curthread->td_proc->p_fd->fd_cdir) {
1537                 curthread->td_proc->p_fd->fd_cdir = rootvnode;
1538                 VREF(rootvnode);
1539         }
1540         if (!curthread->td_proc->p_fd->fd_rdir) {
1541                 curthread->td_proc->p_fd->fd_rdir = rootvnode;
1542                 VREF(rootvnode);
1543         }
1544         if (!curthread->td_proc->p_fd->fd_jdir) {
1545                 curthread->td_proc->p_fd->fd_jdir = rootvnode;
1546                 VREF(rootvnode);
1547         }
1548
1549  again:
1550         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, be_lun->dev_path, curthread);
1551         error = vn_open(&nd, &flags, 0, NULL);
1552         if (error) {
1553                 /*
1554                  * This is the only reasonable guess we can make as far as
1555                  * path if the user doesn't give us a fully qualified path.
1556                  * If they want to specify a file, they need to specify the
1557                  * full path.
1558                  */
1559                 if (be_lun->dev_path[0] != '/') {
1560                         char *dev_path = "/dev/";
1561                         char *dev_name;
1562
1563                         /* Try adding device path at beginning of name */
1564                         dev_name = malloc(strlen(be_lun->dev_path)
1565                                         + strlen(dev_path) + 1,
1566                                           M_CTLBLK, M_WAITOK);
1567                         if (dev_name) {
1568                                 sprintf(dev_name, "%s%s", dev_path,
1569                                         be_lun->dev_path);
1570                                 free(be_lun->dev_path, M_CTLBLK);
1571                                 be_lun->dev_path = dev_name;
1572                                 goto again;
1573                         }
1574                 }
1575                 snprintf(req->error_str, sizeof(req->error_str),
1576                          "%s: error opening %s", __func__, be_lun->dev_path);
1577                 return (error);
1578         }
1579
1580         NDFREE(&nd, NDF_ONLY_PNBUF);
1581
1582         be_lun->vn = nd.ni_vp;
1583
1584         /* We only support disks and files. */
1585         if (vn_isdisk(be_lun->vn, &error)) {
1586                 error = ctl_be_block_open_dev(be_lun, req);
1587         } else if (be_lun->vn->v_type == VREG) {
1588                 error = ctl_be_block_open_file(be_lun, req);
1589         } else {
1590                 error = EINVAL;
1591                 snprintf(req->error_str, sizeof(req->error_str),
1592                          "%s is not a disk or file", be_lun->dev_path);
1593         }
1594         VOP_UNLOCK(be_lun->vn, 0);
1595
1596         if (error != 0) {
1597                 ctl_be_block_close(be_lun);
1598                 return (error);
1599         }
1600
1601         be_lun->blocksize_shift = fls(be_lun->blocksize) - 1;
1602         be_lun->size_blocks = be_lun->size_bytes >> be_lun->blocksize_shift;
1603
1604         return (0);
1605 }
1606
1607 static int
1608 ctl_be_block_mem_ctor(void *mem, int size, void *arg, int flags)
1609 {
1610         return (0);
1611 }
1612
1613 static void
1614 ctl_be_block_mem_dtor(void *mem, int size, void *arg)
1615 {
1616         bzero(mem, size);
1617 }
1618
1619 static int
1620 ctl_be_block_create(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
1621 {
1622         struct ctl_be_block_lun *be_lun;
1623         struct ctl_lun_create_params *params;
1624         struct ctl_be_arg *file_arg;
1625         char tmpstr[32];
1626         int retval, num_threads;
1627         int i;
1628
1629         params = &req->reqdata.create;
1630         retval = 0;
1631
1632         num_threads = cbb_num_threads;
1633
1634         file_arg = NULL;
1635
1636         be_lun = malloc(sizeof(*be_lun), M_CTLBLK, M_ZERO | M_WAITOK);
1637
1638         be_lun->softc = softc;
1639         STAILQ_INIT(&be_lun->input_queue);
1640         STAILQ_INIT(&be_lun->config_write_queue);
1641         STAILQ_INIT(&be_lun->datamove_queue);
1642         STAILQ_INIT(&be_lun->ctl_be_lun.options);
1643         sprintf(be_lun->lunname, "cblk%d", softc->num_luns);
1644         mtx_init(&be_lun->lock, be_lun->lunname, NULL, MTX_DEF);
1645
1646         be_lun->lun_zone = uma_zcreate(be_lun->lunname, MAXPHYS,
1647             ctl_be_block_mem_ctor, ctl_be_block_mem_dtor, NULL, NULL,
1648             /*align*/ 0, /*flags*/0);
1649
1650         if (be_lun->lun_zone == NULL) {
1651                 snprintf(req->error_str, sizeof(req->error_str),
1652                          "%s: error allocating UMA zone", __func__);
1653                 goto bailout_error;
1654         }
1655
1656         if (params->flags & CTL_LUN_FLAG_DEV_TYPE)
1657                 be_lun->ctl_be_lun.lun_type = params->device_type;
1658         else
1659                 be_lun->ctl_be_lun.lun_type = T_DIRECT;
1660
1661         if (be_lun->ctl_be_lun.lun_type == T_DIRECT) {
1662                 for (i = 0; i < req->num_be_args; i++) {
1663                         if (strcmp(req->kern_be_args[i].kname, "file") == 0) {
1664                                 file_arg = &req->kern_be_args[i];
1665                                 break;
1666                         }
1667                 }
1668
1669                 if (file_arg == NULL) {
1670                         snprintf(req->error_str, sizeof(req->error_str),
1671                                  "%s: no file argument specified", __func__);
1672                         goto bailout_error;
1673                 }
1674
1675                 be_lun->dev_path = malloc(file_arg->vallen, M_CTLBLK,
1676                                           M_WAITOK | M_ZERO);
1677
1678                 strlcpy(be_lun->dev_path, (char *)file_arg->kvalue,
1679                         file_arg->vallen);
1680
1681                 retval = ctl_be_block_open(softc, be_lun, req);
1682                 if (retval != 0) {
1683                         retval = 0;
1684                         goto bailout_error;
1685                 }
1686
1687                 /*
1688                  * Tell the user the size of the file/device.
1689                  */
1690                 params->lun_size_bytes = be_lun->size_bytes;
1691
1692                 /*
1693                  * The maximum LBA is the size - 1.
1694                  */
1695                 be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
1696         } else {
1697                 /*
1698                  * For processor devices, we don't have any size.
1699                  */
1700                 be_lun->blocksize = 0;
1701                 be_lun->size_blocks = 0;
1702                 be_lun->size_bytes = 0;
1703                 be_lun->ctl_be_lun.maxlba = 0;
1704                 params->lun_size_bytes = 0;
1705
1706                 /*
1707                  * Default to just 1 thread for processor devices.
1708                  */
1709                 num_threads = 1;
1710         }
1711
1712         /*
1713          * XXX This searching loop might be refactored to be combined with
1714          * the loop above,
1715          */
1716         for (i = 0; i < req->num_be_args; i++) {
1717                 if (strcmp(req->kern_be_args[i].kname, "num_threads") == 0) {
1718                         struct ctl_be_arg *thread_arg;
1719                         char num_thread_str[16];
1720                         int tmp_num_threads;
1721
1722
1723                         thread_arg = &req->kern_be_args[i];
1724
1725                         strlcpy(num_thread_str, (char *)thread_arg->kvalue,
1726                                 min(thread_arg->vallen,
1727                                 sizeof(num_thread_str)));
1728
1729                         tmp_num_threads = strtol(num_thread_str, NULL, 0);
1730
1731                         /*
1732                          * We don't let the user specify less than one
1733                          * thread, but hope he's clueful enough not to
1734                          * specify 1000 threads.
1735                          */
1736                         if (tmp_num_threads < 1) {
1737                                 snprintf(req->error_str, sizeof(req->error_str),
1738                                          "%s: invalid number of threads %s",
1739                                          __func__, num_thread_str);
1740                                 goto bailout_error;
1741                         }
1742
1743                         num_threads = tmp_num_threads;
1744                 } else if (strcmp(req->kern_be_args[i].kname, "file") != 0 &&
1745                     strcmp(req->kern_be_args[i].kname, "dev") != 0) {
1746                         struct ctl_be_lun_option *opt;
1747
1748                         opt = malloc(sizeof(*opt), M_CTLBLK, M_WAITOK);
1749                         opt->name = malloc(strlen(req->kern_be_args[i].kname) + 1, M_CTLBLK, M_WAITOK);
1750                         strcpy(opt->name, req->kern_be_args[i].kname);
1751                         opt->value = malloc(strlen(req->kern_be_args[i].kvalue) + 1, M_CTLBLK, M_WAITOK);
1752                         strcpy(opt->value, req->kern_be_args[i].kvalue);
1753                         STAILQ_INSERT_TAIL(&be_lun->ctl_be_lun.options, opt, links);
1754                 }
1755         }
1756
1757         be_lun->flags = CTL_BE_BLOCK_LUN_UNCONFIGURED;
1758         be_lun->ctl_be_lun.flags = CTL_LUN_FLAG_PRIMARY;
1759         be_lun->ctl_be_lun.be_lun = be_lun;
1760         be_lun->ctl_be_lun.blocksize = be_lun->blocksize;
1761         /* Tell the user the blocksize we ended up using */
1762         params->blocksize_bytes = be_lun->blocksize;
1763         if (params->flags & CTL_LUN_FLAG_ID_REQ) {
1764                 be_lun->ctl_be_lun.req_lun_id = params->req_lun_id;
1765                 be_lun->ctl_be_lun.flags |= CTL_LUN_FLAG_ID_REQ;
1766         } else
1767                 be_lun->ctl_be_lun.req_lun_id = 0;
1768
1769         be_lun->ctl_be_lun.lun_shutdown = ctl_be_block_lun_shutdown;
1770         be_lun->ctl_be_lun.lun_config_status =
1771                 ctl_be_block_lun_config_status;
1772         be_lun->ctl_be_lun.be = &ctl_be_block_driver;
1773
1774         if ((params->flags & CTL_LUN_FLAG_SERIAL_NUM) == 0) {
1775                 snprintf(tmpstr, sizeof(tmpstr), "MYSERIAL%4d",
1776                          softc->num_luns);
1777                 strncpy((char *)be_lun->ctl_be_lun.serial_num, tmpstr,
1778                         ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
1779                         sizeof(tmpstr)));
1780
1781                 /* Tell the user what we used for a serial number */
1782                 strncpy((char *)params->serial_num, tmpstr,
1783                         ctl_min(sizeof(params->serial_num), sizeof(tmpstr)));
1784         } else {
1785                 strncpy((char *)be_lun->ctl_be_lun.serial_num,
1786                         params->serial_num,
1787                         ctl_min(sizeof(be_lun->ctl_be_lun.serial_num),
1788                         sizeof(params->serial_num)));
1789         }
1790         if ((params->flags & CTL_LUN_FLAG_DEVID) == 0) {
1791                 snprintf(tmpstr, sizeof(tmpstr), "MYDEVID%4d", softc->num_luns);
1792                 strncpy((char *)be_lun->ctl_be_lun.device_id, tmpstr,
1793                         ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
1794                         sizeof(tmpstr)));
1795
1796                 /* Tell the user what we used for a device ID */
1797                 strncpy((char *)params->device_id, tmpstr,
1798                         ctl_min(sizeof(params->device_id), sizeof(tmpstr)));
1799         } else {
1800                 strncpy((char *)be_lun->ctl_be_lun.device_id,
1801                         params->device_id,
1802                         ctl_min(sizeof(be_lun->ctl_be_lun.device_id),
1803                                 sizeof(params->device_id)));
1804         }
1805
1806         TASK_INIT(&be_lun->io_task, /*priority*/0, ctl_be_block_worker, be_lun);
1807
1808         be_lun->io_taskqueue = taskqueue_create(be_lun->lunname, M_WAITOK,
1809             taskqueue_thread_enqueue, /*context*/&be_lun->io_taskqueue);
1810
1811         if (be_lun->io_taskqueue == NULL) {
1812                 snprintf(req->error_str, sizeof(req->error_str),
1813                          "%s: Unable to create taskqueue", __func__);
1814                 goto bailout_error;
1815         }
1816
1817         /*
1818          * Note that we start the same number of threads by default for
1819          * both the file case and the block device case.  For the file
1820          * case, we need multiple threads to allow concurrency, because the
1821          * vnode interface is designed to be a blocking interface.  For the
1822          * block device case, ZFS zvols at least will block the caller's
1823          * context in many instances, and so we need multiple threads to
1824          * overcome that problem.  Other block devices don't need as many
1825          * threads, but they shouldn't cause too many problems.
1826          *
1827          * If the user wants to just have a single thread for a block
1828          * device, he can specify that when the LUN is created, or change
1829          * the tunable/sysctl to alter the default number of threads.
1830          */
1831         retval = taskqueue_start_threads(&be_lun->io_taskqueue,
1832                                          /*num threads*/num_threads,
1833                                          /*priority*/PWAIT,
1834                                          /*thread name*/
1835                                          "%s taskq", be_lun->lunname);
1836
1837         if (retval != 0)
1838                 goto bailout_error;
1839
1840         be_lun->num_threads = num_threads;
1841
1842         mtx_lock(&softc->lock);
1843         softc->num_luns++;
1844         STAILQ_INSERT_TAIL(&softc->lun_list, be_lun, links);
1845
1846         mtx_unlock(&softc->lock);
1847
1848         retval = ctl_add_lun(&be_lun->ctl_be_lun);
1849         if (retval != 0) {
1850                 mtx_lock(&softc->lock);
1851                 STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
1852                               links);
1853                 softc->num_luns--;
1854                 mtx_unlock(&softc->lock);
1855                 snprintf(req->error_str, sizeof(req->error_str),
1856                          "%s: ctl_add_lun() returned error %d, see dmesg for "
1857                         "details", __func__, retval);
1858                 retval = 0;
1859                 goto bailout_error;
1860         }
1861
1862         mtx_lock(&softc->lock);
1863
1864         /*
1865          * Tell the config_status routine that we're waiting so it won't
1866          * clean up the LUN in the event of an error.
1867          */
1868         be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
1869
1870         while (be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) {
1871                 retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
1872                 if (retval == EINTR)
1873                         break;
1874         }
1875         be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
1876
1877         if (be_lun->flags & CTL_BE_BLOCK_LUN_CONFIG_ERR) {
1878                 snprintf(req->error_str, sizeof(req->error_str),
1879                          "%s: LUN configuration error, see dmesg for details",
1880                          __func__);
1881                 STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun,
1882                               links);
1883                 softc->num_luns--;
1884                 mtx_unlock(&softc->lock);
1885                 goto bailout_error;
1886         } else {
1887                 params->req_lun_id = be_lun->ctl_be_lun.lun_id;
1888         }
1889
1890         mtx_unlock(&softc->lock);
1891
1892         be_lun->disk_stats = devstat_new_entry("cbb", params->req_lun_id,
1893                                                be_lun->blocksize,
1894                                                DEVSTAT_ALL_SUPPORTED,
1895                                                be_lun->ctl_be_lun.lun_type
1896                                                | DEVSTAT_TYPE_IF_OTHER,
1897                                                DEVSTAT_PRIORITY_OTHER);
1898
1899
1900         req->status = CTL_LUN_OK;
1901
1902         return (retval);
1903
1904 bailout_error:
1905         req->status = CTL_LUN_ERROR;
1906
1907         ctl_be_block_close(be_lun);
1908
1909         free(be_lun->dev_path, M_CTLBLK);
1910         free(be_lun, M_CTLBLK);
1911
1912         return (retval);
1913 }
1914
1915 static int
1916 ctl_be_block_rm(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
1917 {
1918         struct ctl_lun_rm_params *params;
1919         struct ctl_be_block_lun *be_lun;
1920         int retval;
1921
1922         params = &req->reqdata.rm;
1923
1924         mtx_lock(&softc->lock);
1925
1926         be_lun = NULL;
1927
1928         STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
1929                 if (be_lun->ctl_be_lun.lun_id == params->lun_id)
1930                         break;
1931         }
1932         mtx_unlock(&softc->lock);
1933
1934         if (be_lun == NULL) {
1935                 snprintf(req->error_str, sizeof(req->error_str),
1936                          "%s: LUN %u is not managed by the block backend",
1937                          __func__, params->lun_id);
1938                 goto bailout_error;
1939         }
1940
1941         retval = ctl_disable_lun(&be_lun->ctl_be_lun);
1942
1943         if (retval != 0) {
1944                 snprintf(req->error_str, sizeof(req->error_str),
1945                          "%s: error %d returned from ctl_disable_lun() for "
1946                          "LUN %d", __func__, retval, params->lun_id);
1947                 goto bailout_error;
1948
1949         }
1950
1951         retval = ctl_invalidate_lun(&be_lun->ctl_be_lun);
1952         if (retval != 0) {
1953                 snprintf(req->error_str, sizeof(req->error_str),
1954                          "%s: error %d returned from ctl_invalidate_lun() for "
1955                          "LUN %d", __func__, retval, params->lun_id);
1956                 goto bailout_error;
1957         }
1958
1959         mtx_lock(&softc->lock);
1960
1961         be_lun->flags |= CTL_BE_BLOCK_LUN_WAITING;
1962
1963         while ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
1964                 retval = msleep(be_lun, &softc->lock, PCATCH, "ctlblk", 0);
1965                 if (retval == EINTR)
1966                         break;
1967         }
1968
1969         be_lun->flags &= ~CTL_BE_BLOCK_LUN_WAITING;
1970
1971         if ((be_lun->flags & CTL_BE_BLOCK_LUN_UNCONFIGURED) == 0) {
1972                 snprintf(req->error_str, sizeof(req->error_str),
1973                          "%s: interrupted waiting for LUN to be freed",
1974                          __func__);
1975                 mtx_unlock(&softc->lock);
1976                 goto bailout_error;
1977         }
1978
1979         STAILQ_REMOVE(&softc->lun_list, be_lun, ctl_be_block_lun, links);
1980
1981         softc->num_luns--;
1982         mtx_unlock(&softc->lock);
1983
1984         taskqueue_drain(be_lun->io_taskqueue, &be_lun->io_task);
1985
1986         taskqueue_free(be_lun->io_taskqueue);
1987
1988         ctl_be_block_close(be_lun);
1989
1990         if (be_lun->disk_stats != NULL)
1991                 devstat_remove_entry(be_lun->disk_stats);
1992
1993         uma_zdestroy(be_lun->lun_zone);
1994
1995         free(be_lun->dev_path, M_CTLBLK);
1996
1997         free(be_lun, M_CTLBLK);
1998
1999         req->status = CTL_LUN_OK;
2000
2001         return (0);
2002
2003 bailout_error:
2004
2005         req->status = CTL_LUN_ERROR;
2006
2007         return (0);
2008 }
2009
2010 static int
2011 ctl_be_block_modify_file(struct ctl_be_block_lun *be_lun,
2012                          struct ctl_lun_req *req)
2013 {
2014         struct vattr vattr;
2015         int error;
2016         struct ctl_lun_modify_params *params;
2017
2018         params = &req->reqdata.modify;
2019
2020         if (params->lun_size_bytes != 0) {
2021                 be_lun->size_bytes = params->lun_size_bytes;
2022         } else  {
2023                 error = VOP_GETATTR(be_lun->vn, &vattr, curthread->td_ucred);
2024                 if (error != 0) {
2025                         snprintf(req->error_str, sizeof(req->error_str),
2026                                  "error calling VOP_GETATTR() for file %s",
2027                                  be_lun->dev_path);
2028                         return (error);
2029                 }
2030
2031                 be_lun->size_bytes = vattr.va_size;
2032         }
2033
2034         return (0);
2035 }
2036
2037 static int
2038 ctl_be_block_modify_dev(struct ctl_be_block_lun *be_lun,
2039                         struct ctl_lun_req *req)
2040 {
2041         struct cdev *dev;
2042         struct cdevsw *devsw;
2043         int error;
2044         struct ctl_lun_modify_params *params;
2045         uint64_t size_bytes;
2046
2047         params = &req->reqdata.modify;
2048
2049         dev = be_lun->vn->v_rdev;
2050         devsw = dev->si_devsw;
2051         if (!devsw->d_ioctl) {
2052                 snprintf(req->error_str, sizeof(req->error_str),
2053                          "%s: no d_ioctl for device %s!", __func__,
2054                          be_lun->dev_path);
2055                 return (ENODEV);
2056         }
2057
2058         error = devsw->d_ioctl(dev, DIOCGMEDIASIZE,
2059                                (caddr_t)&size_bytes, FREAD,
2060                                curthread);
2061         if (error) {
2062                 snprintf(req->error_str, sizeof(req->error_str),
2063                          "%s: error %d returned for DIOCGMEDIASIZE ioctl "
2064                          "on %s!", __func__, error, be_lun->dev_path);
2065                 return (error);
2066         }
2067
2068         if (params->lun_size_bytes != 0) {
2069                 if (params->lun_size_bytes > size_bytes) {
2070                         snprintf(req->error_str, sizeof(req->error_str),
2071                                  "%s: requested LUN size %ju > backing device "
2072                                  "size %ju", __func__,
2073                                  (uintmax_t)params->lun_size_bytes,
2074                                  (uintmax_t)size_bytes);
2075                         return (EINVAL);
2076                 }
2077
2078                 be_lun->size_bytes = params->lun_size_bytes;
2079         } else {
2080                 be_lun->size_bytes = size_bytes;
2081         }
2082
2083         return (0);
2084 }
2085
2086 static int
2087 ctl_be_block_modify(struct ctl_be_block_softc *softc, struct ctl_lun_req *req)
2088 {
2089         struct ctl_lun_modify_params *params;
2090         struct ctl_be_block_lun *be_lun;
2091         int error;
2092
2093         params = &req->reqdata.modify;
2094
2095         mtx_lock(&softc->lock);
2096
2097         be_lun = NULL;
2098
2099         STAILQ_FOREACH(be_lun, &softc->lun_list, links) {
2100                 if (be_lun->ctl_be_lun.lun_id == params->lun_id)
2101                         break;
2102         }
2103         mtx_unlock(&softc->lock);
2104
2105         if (be_lun == NULL) {
2106                 snprintf(req->error_str, sizeof(req->error_str),
2107                          "%s: LUN %u is not managed by the block backend",
2108                          __func__, params->lun_id);
2109                 goto bailout_error;
2110         }
2111
2112         if (params->lun_size_bytes != 0) {
2113                 if (params->lun_size_bytes < be_lun->blocksize) {
2114                         snprintf(req->error_str, sizeof(req->error_str),
2115                                 "%s: LUN size %ju < blocksize %u", __func__,
2116                                 params->lun_size_bytes, be_lun->blocksize);
2117                         goto bailout_error;
2118                 }
2119         }
2120
2121         vn_lock(be_lun->vn, LK_SHARED | LK_RETRY);
2122
2123         if (be_lun->vn->v_type == VREG)
2124                 error = ctl_be_block_modify_file(be_lun, req);
2125         else
2126                 error = ctl_be_block_modify_dev(be_lun, req);
2127
2128         VOP_UNLOCK(be_lun->vn, 0);
2129
2130         if (error != 0)
2131                 goto bailout_error;
2132
2133         be_lun->size_blocks = be_lun->size_bytes >> be_lun->blocksize_shift;
2134
2135         /*
2136          * The maximum LBA is the size - 1.
2137          *
2138          * XXX: Note that this field is being updated without locking,
2139          *      which might cause problems on 32-bit architectures.
2140          */
2141         be_lun->ctl_be_lun.maxlba = be_lun->size_blocks - 1;
2142         ctl_lun_capacity_changed(&be_lun->ctl_be_lun);
2143
2144         /* Tell the user the exact size we ended up using */
2145         params->lun_size_bytes = be_lun->size_bytes;
2146
2147         req->status = CTL_LUN_OK;
2148
2149         return (0);
2150
2151 bailout_error:
2152         req->status = CTL_LUN_ERROR;
2153
2154         return (0);
2155 }
2156
2157 static void
2158 ctl_be_block_lun_shutdown(void *be_lun)
2159 {
2160         struct ctl_be_block_lun *lun;
2161         struct ctl_be_block_softc *softc;
2162
2163         lun = (struct ctl_be_block_lun *)be_lun;
2164
2165         softc = lun->softc;
2166
2167         mtx_lock(&softc->lock);
2168         lun->flags |= CTL_BE_BLOCK_LUN_UNCONFIGURED;
2169         if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2170                 wakeup(lun);
2171         mtx_unlock(&softc->lock);
2172
2173 }
2174
2175 static void
2176 ctl_be_block_lun_config_status(void *be_lun, ctl_lun_config_status status)
2177 {
2178         struct ctl_be_block_lun *lun;
2179         struct ctl_be_block_softc *softc;
2180
2181         lun = (struct ctl_be_block_lun *)be_lun;
2182         softc = lun->softc;
2183
2184         if (status == CTL_LUN_CONFIG_OK) {
2185                 mtx_lock(&softc->lock);
2186                 lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2187                 if (lun->flags & CTL_BE_BLOCK_LUN_WAITING)
2188                         wakeup(lun);
2189                 mtx_unlock(&softc->lock);
2190
2191                 /*
2192                  * We successfully added the LUN, attempt to enable it.
2193                  */
2194                 if (ctl_enable_lun(&lun->ctl_be_lun) != 0) {
2195                         printf("%s: ctl_enable_lun() failed!\n", __func__);
2196                         if (ctl_invalidate_lun(&lun->ctl_be_lun) != 0) {
2197                                 printf("%s: ctl_invalidate_lun() failed!\n",
2198                                        __func__);
2199                         }
2200                 }
2201
2202                 return;
2203         }
2204
2205
2206         mtx_lock(&softc->lock);
2207         lun->flags &= ~CTL_BE_BLOCK_LUN_UNCONFIGURED;
2208         lun->flags |= CTL_BE_BLOCK_LUN_CONFIG_ERR;
2209         wakeup(lun);
2210         mtx_unlock(&softc->lock);
2211 }
2212
2213
2214 static int
2215 ctl_be_block_config_write(union ctl_io *io)
2216 {
2217         struct ctl_be_block_lun *be_lun;
2218         struct ctl_be_lun *ctl_be_lun;
2219         int retval;
2220
2221         retval = 0;
2222
2223         DPRINTF("entered\n");
2224
2225         ctl_be_lun = (struct ctl_be_lun *)io->io_hdr.ctl_private[
2226                 CTL_PRIV_BACKEND_LUN].ptr;
2227         be_lun = (struct ctl_be_block_lun *)ctl_be_lun->be_lun;
2228
2229         switch (io->scsiio.cdb[0]) {
2230         case SYNCHRONIZE_CACHE:
2231         case SYNCHRONIZE_CACHE_16:
2232                 /*
2233                  * The upper level CTL code will filter out any CDBs with
2234                  * the immediate bit set and return the proper error.
2235                  *
2236                  * We don't really need to worry about what LBA range the
2237                  * user asked to be synced out.  When they issue a sync
2238                  * cache command, we'll sync out the whole thing.
2239                  */
2240                 mtx_lock(&be_lun->lock);
2241                 STAILQ_INSERT_TAIL(&be_lun->config_write_queue, &io->io_hdr,
2242                                    links);
2243                 mtx_unlock(&be_lun->lock);
2244                 taskqueue_enqueue(be_lun->io_taskqueue, &be_lun->io_task);
2245                 break;
2246         case START_STOP_UNIT: {
2247                 struct scsi_start_stop_unit *cdb;
2248
2249                 cdb = (struct scsi_start_stop_unit *)io->scsiio.cdb;
2250
2251                 if (cdb->how & SSS_START)
2252                         retval = ctl_start_lun(ctl_be_lun);
2253                 else {
2254                         retval = ctl_stop_lun(ctl_be_lun);
2255                         /*
2256                          * XXX KDM Copan-specific offline behavior.
2257                          * Figure out a reasonable way to port this?
2258                          */
2259 #ifdef NEEDTOPORT
2260                         if ((retval == 0)
2261                          && (cdb->byte2 & SSS_ONOFFLINE))
2262                                 retval = ctl_lun_offline(ctl_be_lun);
2263 #endif
2264                 }
2265
2266                 /*
2267                  * In general, the above routines should not fail.  They
2268                  * just set state for the LUN.  So we've got something
2269                  * pretty wrong here if we can't start or stop the LUN.
2270                  */
2271                 if (retval != 0) {
2272                         ctl_set_internal_failure(&io->scsiio,
2273                                                  /*sks_valid*/ 1,
2274                                                  /*retry_count*/ 0xf051);
2275                         retval = CTL_RETVAL_COMPLETE;
2276                 } else {
2277                         ctl_set_success(&io->scsiio);
2278                 }
2279                 ctl_config_write_done(io);
2280                 break;
2281         }
2282         default:
2283                 ctl_set_invalid_opcode(&io->scsiio);
2284                 ctl_config_write_done(io);
2285                 retval = CTL_RETVAL_COMPLETE;
2286                 break;
2287         }
2288
2289         return (retval);
2290
2291 }
2292
2293 static int
2294 ctl_be_block_config_read(union ctl_io *io)
2295 {
2296         return (0);
2297 }
2298
2299 static int
2300 ctl_be_block_lun_info(void *be_lun, struct sbuf *sb)
2301 {
2302         struct ctl_be_block_lun *lun;
2303         int retval;
2304
2305         lun = (struct ctl_be_block_lun *)be_lun;
2306         retval = 0;
2307
2308         retval = sbuf_printf(sb, "<num_threads>");
2309
2310         if (retval != 0)
2311                 goto bailout;
2312
2313         retval = sbuf_printf(sb, "%d", lun->num_threads);
2314
2315         if (retval != 0)
2316                 goto bailout;
2317
2318         retval = sbuf_printf(sb, "</num_threads>");
2319
2320         /*
2321          * For processor devices, we don't have a path variable.
2322          */
2323         if ((retval != 0)
2324          || (lun->dev_path == NULL))
2325                 goto bailout;
2326
2327         retval = sbuf_printf(sb, "<file>");
2328
2329         if (retval != 0)
2330                 goto bailout;
2331
2332         retval = ctl_sbuf_printf_esc(sb, lun->dev_path);
2333
2334         if (retval != 0)
2335                 goto bailout;
2336
2337         retval = sbuf_printf(sb, "</file>\n");
2338
2339 bailout:
2340
2341         return (retval);
2342 }
2343
2344 int
2345 ctl_be_block_init(void)
2346 {
2347         struct ctl_be_block_softc *softc;
2348         int retval;
2349
2350         softc = &backend_block_softc;
2351         retval = 0;
2352
2353         mtx_init(&softc->lock, "ctlblk", NULL, MTX_DEF);
2354         STAILQ_INIT(&softc->beio_free_queue);
2355         STAILQ_INIT(&softc->disk_list);
2356         STAILQ_INIT(&softc->lun_list);
2357         ctl_grow_beio(softc, 200);
2358
2359         return (retval);
2360 }