sys/dev/disk/dm/targets/striped/dm_target_striped.c

   1 /*
   2  * Copyright (c) 2009 The NetBSD Foundation, Inc.
   3  * All rights reserved.
   4  *
   5  * This code is derived from software contributed to The NetBSD Foundation
   6  * by Adam Hamsik.
   7  *
   8  * This code is further derived from software contributed to the
   9  * DragonFly project by Alex Hornung and Matthew Dillon
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
  21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
  22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
  24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  30  * POSSIBILITY OF SUCH DAMAGE.
  31  *
  32  * $NetBSD: dm_target_stripe.c,v 1.9 2010/01/04 00:14:41 haad Exp $
  33  */
  34
  35 /*
  36  * This file implements initial version of device-mapper stripe target.
  37  *
  38  * DragonFly changes: Increase to an unlimited number of stripes
  39  */
  40 #include <sys/types.h>
  41
  42 #include <sys/buf.h>
  43 #include <sys/malloc.h>
  44 #include <sys/vnode.h>
  45
  46 #include <dev/disk/dm/dm.h>
  47 MALLOC_DEFINE(M_DMSTRIPE, "dm_striped", "Device Mapper Target Striped");
  48
  49 #define MAX_STRIPES 32
  50
  51 struct target_stripe_dev {
  52         dm_pdev_t *pdev;
  53         uint64_t offset;
  54 };
  55
  56 typedef struct target_stripe_config {
  57         struct target_stripe_dev stripe_devs[MAX_STRIPES];
  58         int stripe_num;
  59         uint64_t stripe_chunksize;
  60 } dm_target_stripe_config_t;
  61
  62 static void dm_target_stripe_destroy_config(dm_target_stripe_config_t *tsc);
  63
  64 /*
  65  * Init function called from dm_table_load_ioctl.
  66  *
  67  * Example line sent to dm from lvm tools when using striped target.
  68  * start length striped #stripes chunk_size device1 offset1 ... deviceN offsetN
  69  * 0 65536 striped 2 512 /dev/hda 0 /dev/hdb 0
  70  */
  71 static int
  72 dm_target_stripe_init(dm_table_entry_t *table_en, char *params)
  73 {
  74         dm_target_stripe_config_t *tsc;
  75         int n;
  76         char *ap;
  77
  78         if (params == NULL)
  79                 return EINVAL;
  80
  81         /*
  82          * nstripes
  83          */
  84         ap = strsep(&params, " \t");
  85         if (ap == NULL)
  86                 return EINVAL;
  87         n = (int)atoi64(ap);
  88         if (n < 0 || n > MAX_STRIPES) {
  89                 kprintf("dm: Error %d stripes not supported (%d max)\n",
  90                         n, MAX_STRIPES);
  91                 return ENOTSUP;
  92         }
  93
  94         tsc = kmalloc(sizeof(dm_target_stripe_config_t),
  95                       M_DMSTRIPE, M_WAITOK | M_ZERO);
  96         tsc->stripe_num = n;
  97
  98         ap = strsep(&params, " \t");
  99         if (ap == NULL) {
 100                 dm_target_stripe_destroy_config(tsc);
 101                 return EINVAL;
 102         }
 103         tsc->stripe_chunksize = atoi64(ap);
 104         if (tsc->stripe_chunksize < 1 ||
 105             tsc->stripe_chunksize * DEV_BSIZE > MAXPHYS) {
 106                 kprintf("dm: Error unsupported chunk size %jdKB\n",
 107                         (intmax_t)tsc->stripe_chunksize * DEV_BSIZE / 1024);
 108                 dm_target_stripe_destroy_config(tsc);
 109                 return EINVAL;
 110         }
 111
 112         /*
 113          * Parse the devices
 114          */
 115
 116         kprintf("dm: Stripe %d devices chunk size %dKB\n",
 117                 (int)tsc->stripe_num,
 118                 (int)tsc->stripe_chunksize
 119         );
 120
 121         for (n = 0; n < tsc->stripe_num; ++n) {
 122                 ap = strsep(&params, " \t");
 123                 if (ap == NULL)
 124                         break;
 125                 tsc->stripe_devs[n].pdev = dm_pdev_insert(ap);
 126                 if (tsc->stripe_devs[n].pdev == NULL)
 127                         break;
 128                 ap = strsep(&params, " \t");
 129                 if (ap == NULL)
 130                         break;
 131                 tsc->stripe_devs[n].offset = atoi64(ap);
 132                 dm_table_add_deps(table_en, tsc->stripe_devs[n].pdev);
 133         }
 134         if (n != tsc->stripe_num) {
 135                 dm_target_stripe_destroy_config(tsc);
 136                 return (ENOENT);
 137         }
 138
 139         dm_table_init_target(table_en, DM_STRIPE_DEV, tsc);
 140
 141         return 0;
 142 }
 143
 144 /*
 145  * Info routine called to get params string.
 146  */
 147 static char *
 148 dm_target_stripe_info(void *target_config)
 149 {
 150         dm_target_stripe_config_t *tsc;
 151         char *params;
 152         char *ptr;
 153         size_t len;
 154         int ret;
 155         int i;
 156
 157         tsc = target_config;
 158
 159         len = DM_MAX_PARAMS_SIZE;
 160         params = kmalloc(len, M_DM, M_WAITOK | M_ZERO);
 161         ptr = params;
 162
 163         ret = ksnprintf(ptr, len, "%d ", tsc->stripe_num);
 164         ptr += ret;
 165         len -= ret;
 166
 167         for (i = 0; i < tsc->stripe_num; i++) {
 168                 ret = ksnprintf(ptr, len, "%s ",
 169                         tsc->stripe_devs[i].pdev->udev_name);
 170                 ptr += ret;
 171                 len -= ret;
 172         }
 173
 174         ret = ksnprintf(ptr, len, "1 ");
 175         ptr += ret;
 176         len -= ret;
 177
 178         /*
 179          * stripe target currently has no error_count.
 180          */
 181         for (i = 0; i < tsc->stripe_num; i++) {
 182                 ret = ksnprintf(ptr, len, "A");
 183                 ptr += ret;
 184                 len -= ret;
 185         }
 186
 187         return params;
 188 }
 189
 190 /*
 191  * Table routine called to get params string.
 192  */
 193 static char *
 194 dm_target_stripe_table(void *target_config)
 195 {
 196         dm_target_stripe_config_t *tsc;
 197         char *params;
 198         char *ptr;
 199         size_t len;
 200         int ret;
 201         int i;
 202
 203         tsc = target_config;
 204
 205         len = DM_MAX_PARAMS_SIZE;
 206         params = kmalloc(len, M_DM, M_WAITOK | M_ZERO);
 207         ptr = params;
 208
 209         ret = ksnprintf(ptr, len, "%d %jd",
 210                 tsc->stripe_num,
 211                 (intmax_t)tsc->stripe_chunksize);
 212         ptr += ret;
 213         len -= ret;
 214
 215         for (i = 0; i < tsc->stripe_num; i++) {
 216                 ret = ksnprintf(ptr, len, " %s %jd",
 217                         tsc->stripe_devs[i].pdev->udev_name,
 218                         (intmax_t)tsc->stripe_devs[i].offset);
 219                 ptr += ret;
 220                 len -= ret;
 221         }
 222
 223         return params;
 224 }
 225
 226 /*
 227  * Strategy routine called from dm_strategy.
 228  */
 229 static int
 230 dm_target_stripe_strategy(dm_table_entry_t *table_en, struct buf *bp)
 231 {
 232         dm_target_stripe_config_t *tsc;
 233         struct bio *bio = &bp->b_bio1;
 234         struct buf *nestbuf;
 235         uint64_t blkno, blkoff;
 236         uint64_t stripe, blknr;
 237         uint32_t stripe_off, stripe_rest, num_blks, issue_blks;
 238         int devnr;
 239
 240         tsc = table_en->target_config;
 241         if (tsc == NULL)
 242                 return 0;
 243
 244         /* calculate extent of request */
 245         KKASSERT(bp->b_resid % DEV_BSIZE == 0);
 246
 247         switch(bp->b_cmd) {
 248         case BUF_CMD_READ:
 249         case BUF_CMD_WRITE:
 250         case BUF_CMD_FREEBLKS:
 251                 /*
 252                  * Loop through to individual operations
 253                  */
 254                 blkno = bp->b_bio1.bio_offset / DEV_BSIZE;
 255                 blkoff = 0;
 256                 num_blks = bp->b_resid / DEV_BSIZE;
 257                 nestiobuf_init(bio);
 258
 259                 while (num_blks > 0) {
 260                         /* blockno to strip piece nr */
 261                         stripe = blkno / tsc->stripe_chunksize;
 262                         stripe_off = blkno % tsc->stripe_chunksize;
 263
 264                         /* where we are inside the strip */
 265                         devnr = stripe % tsc->stripe_num;
 266                         blknr = stripe / tsc->stripe_num;
 267
 268                         /* how much is left before we hit a boundary */
 269                         stripe_rest = tsc->stripe_chunksize - stripe_off;
 270
 271                         /* issue this piece on stripe `stripe' */
 272                         issue_blks = MIN(stripe_rest, num_blks);
 273                         nestbuf = getpbuf(NULL);
 274                         nestbuf->b_flags |= bio->bio_buf->b_flags & B_HASBOGUS;
 275
 276                         nestiobuf_add(bio, nestbuf, blkoff,
 277                                         issue_blks * DEV_BSIZE, NULL);
 278
 279                         /* I need number of bytes. */
 280                         nestbuf->b_bio1.bio_offset =
 281                                 blknr * tsc->stripe_chunksize + stripe_off;
 282                         nestbuf->b_bio1.bio_offset +=
 283                                 tsc->stripe_devs[devnr].offset;
 284                         nestbuf->b_bio1.bio_offset *= DEV_BSIZE;
 285
 286                         vn_strategy(tsc->stripe_devs[devnr].pdev->pdev_vnode,
 287                                     &nestbuf->b_bio1);
 288
 289                         blkno += issue_blks;
 290                         blkoff += issue_blks * DEV_BSIZE;
 291                         num_blks -= issue_blks;
 292                 }
 293                 nestiobuf_start(bio);
 294                 break;
 295         case BUF_CMD_FLUSH:
 296                 nestiobuf_init(bio);
 297                 for (devnr = 0; devnr < tsc->stripe_num; ++devnr) {
 298                         nestbuf = getpbuf(NULL);
 299                         nestbuf->b_flags |= bio->bio_buf->b_flags & B_HASBOGUS;
 300
 301                         nestiobuf_add(bio, nestbuf, 0, 0, NULL);
 302                         nestbuf->b_bio1.bio_offset = 0;
 303                         vn_strategy(tsc->stripe_devs[devnr].pdev->pdev_vnode,
 304                                     &nestbuf->b_bio1);
 305                 }
 306                 nestiobuf_start(bio);
 307                 break;
 308         default:
 309                 bp->b_flags |= B_ERROR;
 310                 bp->b_error = EIO;
 311                 biodone(bio);
 312                 break;
 313         }
 314         return 0;
 315 }
 316
 317
 318 static int
 319 dm_target_stripe_dump(dm_table_entry_t *table_en, void *data, size_t length, off_t offset)
 320 {
 321         dm_target_stripe_config_t *tsc;
 322         uint64_t blkno, blkoff;
 323         uint64_t stripe, blknr;
 324         uint32_t stripe_off, stripe_rest, num_blks, issue_blks;
 325         uint64_t off2, len2;
 326         int devnr;
 327
 328         tsc = table_en->target_config;
 329         if (tsc == NULL)
 330                 return 0;
 331
 332         /* calculate extent of request */
 333         KKASSERT(length % DEV_BSIZE == 0);
 334
 335         blkno = offset / DEV_BSIZE;
 336         blkoff = 0;
 337         num_blks = length / DEV_BSIZE;
 338
 339         /*
 340          * 0 length means flush buffers and return
 341          */
 342         if (length == 0) {
 343                 for (devnr = 0; devnr < tsc->stripe_num; ++devnr) {
 344                         if (tsc->stripe_devs[devnr].pdev->pdev_vnode->v_rdev == NULL)
 345                                 return ENXIO;
 346
 347                         dev_ddump(tsc->stripe_devs[devnr].pdev->pdev_vnode->v_rdev,
 348                             data, 0, offset, 0);
 349                 }
 350                 return 0;
 351         }
 352
 353         while (num_blks > 0) {
 354                 /* blockno to strip piece nr */
 355                 stripe = blkno / tsc->stripe_chunksize;
 356                 stripe_off = blkno % tsc->stripe_chunksize;
 357
 358                 /* where we are inside the strip */
 359                 devnr = stripe % tsc->stripe_num;
 360                 blknr = stripe / tsc->stripe_num;
 361
 362                 /* how much is left before we hit a boundary */
 363                 stripe_rest = tsc->stripe_chunksize - stripe_off;
 364
 365                 /* issue this piece on stripe `stripe' */
 366                 issue_blks = MIN(stripe_rest, num_blks);
 367
 368 #if 0
 369                 nestiobuf_add(bio, nestbuf, blkoff,
 370                                 issue_blks * DEV_BSIZE);
 371 #endif
 372                 len2 = issue_blks * DEV_BSIZE;
 373
 374                 /* I need number of bytes. */
 375                 off2 = blknr * tsc->stripe_chunksize + stripe_off;
 376                 off2 += tsc->stripe_devs[devnr].offset;
 377                 off2 *= DEV_BSIZE;
 378                 off2 = dm_pdev_correct_dump_offset(tsc->stripe_devs[devnr].pdev,
 379                     off2);
 380
 381                 if (tsc->stripe_devs[devnr].pdev->pdev_vnode->v_rdev == NULL)
 382                         return ENXIO;
 383
 384                 dev_ddump(tsc->stripe_devs[devnr].pdev->pdev_vnode->v_rdev,
 385                     (char *)data + blkoff, 0, off2, len2);
 386
 387                 blkno += issue_blks;
 388                 blkoff += issue_blks * DEV_BSIZE;
 389                 num_blks -= issue_blks;
 390         }
 391
 392         return 0;
 393 }
 394
 395 /*
 396  * Destroy a dm table entry for stripes.
 397  */
 398 static int
 399 dm_target_stripe_destroy(dm_table_entry_t *table_en)
 400 {
 401         dm_target_stripe_config_t *tsc;
 402
 403         if ((tsc = table_en->target_config) != NULL) {
 404                 table_en->target_config = NULL;
 405                 dm_target_stripe_destroy_config(tsc);
 406         }
 407
 408         return 0;
 409 }
 410
 411 static void
 412 dm_target_stripe_destroy_config(dm_target_stripe_config_t *tsc)
 413 {
 414         int n;
 415
 416         for (n = 0; n < tsc->stripe_num; ++n) {
 417                 if (tsc->stripe_devs[n].pdev) {
 418                         dm_pdev_decr(tsc->stripe_devs[n].pdev);
 419                         tsc->stripe_devs[n].pdev = NULL;
 420                 }
 421         }
 422         kfree(tsc, M_DMSTRIPE);
 423 }
 424
 425 /*
 426  * Unsupported for this target.
 427  */
 428 static int
 429 dm_target_stripe_upcall(dm_table_entry_t *table_en, struct buf *bp)
 430 {
 431         return 0;
 432 }
 433
 434 static int
 435 dmts_mod_handler(module_t mod, int type, void *unused)
 436 {
 437         dm_target_t *dmt = NULL;
 438         int err = 0;
 439
 440         switch(type) {
 441         case MOD_LOAD:
 442                 if ((dmt = dm_target_lookup("striped")) != NULL) {
 443                         dm_target_unbusy(dmt);
 444                         return EEXIST;
 445                 }
 446                 dmt = dm_target_alloc("striped");
 447                 dmt->version[0] = 1;
 448                 dmt->version[1] = 0;
 449                 dmt->version[2] = 3;
 450                 strlcpy(dmt->name, "striped", DM_MAX_TYPE_NAME);
 451                 dmt->init = &dm_target_stripe_init;
 452                 dmt->info = &dm_target_stripe_info;
 453                 dmt->table = &dm_target_stripe_table;
 454                 dmt->strategy = &dm_target_stripe_strategy;
 455                 dmt->destroy = &dm_target_stripe_destroy;
 456                 dmt->upcall = &dm_target_stripe_upcall;
 457                 dmt->dump = &dm_target_stripe_dump;
 458
 459                 err = dm_target_insert(dmt);
 460                 if (err == 0)
 461                         kprintf("dm_target_striped: Successfully initialized\n");
 462                 break;
 463
 464         case MOD_UNLOAD:
 465                 err = dm_target_rem("striped");
 466                 if (err == 0)
 467                         kprintf("dm_target_striped: unloaded\n");
 468                 break;
 469
 470         default:
 471                 break;
 472         }
 473
 474         return err;
 475 }
 476
 477 DM_TARGET_MODULE(dm_target_striped, dmts_mod_handler);