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_stripe", "Device Mapper Target Stripe");
  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  * Table routine called to get params string.
 146  */
 147 static char *
 148 dm_target_stripe_table(void *target_config)
 149 {
 150         dm_target_stripe_config_t *tsc;
 151         char *params;
 152         char *ptr;
 153         size_t len;
 154         size_t nlen;
 155         int n;
 156
 157         tsc = target_config;
 158
 159         /* caller expects use of M_DM for returned params */
 160         nlen = DM_MAX_PARAMS_SIZE;
 161         params = kmalloc(nlen, M_DM, M_WAITOK);
 162         ptr = params;
 163
 164         ksnprintf(ptr, nlen, "%d %jd",
 165                   tsc->stripe_num, (intmax_t)tsc->stripe_chunksize);
 166         len = strlen(params);
 167         ptr += len;
 168         nlen -= len;
 169
 170         for (n = 0; n < tsc->stripe_num; ++n) {
 171                 ksnprintf(ptr, nlen, " %s %jd",
 172                           tsc->stripe_devs[n].pdev->name,
 173                           (intmax_t)tsc->stripe_devs[n].offset);
 174                 len = strlen(ptr);
 175                 ptr += len;
 176                 nlen -= len;
 177         }
 178
 179         return params;
 180 }
 181
 182 /*
 183  * Strategy routine called from dm_strategy.
 184  */
 185 static int
 186 dm_target_stripe_strategy(dm_table_entry_t *table_en, struct buf *bp)
 187 {
 188         dm_target_stripe_config_t *tsc;
 189         struct bio *bio = &bp->b_bio1;
 190         struct buf *nestbuf;
 191         uint64_t blkno, blkoff;
 192         uint64_t stripe, blknr;
 193         uint32_t stripe_off, stripe_rest, num_blks, issue_blks;
 194         int devnr;
 195
 196         tsc = table_en->target_config;
 197         if (tsc == NULL)
 198                 return 0;
 199
 200         /* calculate extent of request */
 201         KKASSERT(bp->b_resid % DEV_BSIZE == 0);
 202
 203         switch(bp->b_cmd) {
 204         case BUF_CMD_READ:
 205         case BUF_CMD_WRITE:
 206         case BUF_CMD_FREEBLKS:
 207                 /*
 208                  * Loop through to individual operations
 209                  */
 210                 blkno = bp->b_bio1.bio_offset / DEV_BSIZE;
 211                 blkoff = 0;
 212                 num_blks = bp->b_resid / DEV_BSIZE;
 213                 nestiobuf_init(bio);
 214
 215                 while (num_blks > 0) {
 216                         /* blockno to strip piece nr */
 217                         stripe = blkno / tsc->stripe_chunksize;
 218                         stripe_off = blkno % tsc->stripe_chunksize;
 219
 220                         /* where we are inside the strip */
 221                         devnr = stripe % tsc->stripe_num;
 222                         blknr = stripe / tsc->stripe_num;
 223
 224                         /* how much is left before we hit a boundary */
 225                         stripe_rest = tsc->stripe_chunksize - stripe_off;
 226
 227                         /* issue this piece on stripe `stripe' */
 228                         issue_blks = MIN(stripe_rest, num_blks);
 229                         nestbuf = getpbuf(NULL);
 230                         nestbuf->b_flags |= bio->bio_buf->b_flags & B_HASBOGUS;
 231
 232                         nestiobuf_add(bio, nestbuf, blkoff,
 233                                         issue_blks * DEV_BSIZE, NULL);
 234
 235                         /* I need number of bytes. */
 236                         nestbuf->b_bio1.bio_offset =
 237                                 blknr * tsc->stripe_chunksize + stripe_off;
 238                         nestbuf->b_bio1.bio_offset +=
 239                                 tsc->stripe_devs[devnr].offset;
 240                         nestbuf->b_bio1.bio_offset *= DEV_BSIZE;
 241
 242                         vn_strategy(tsc->stripe_devs[devnr].pdev->pdev_vnode,
 243                                     &nestbuf->b_bio1);
 244
 245                         blkno += issue_blks;
 246                         blkoff += issue_blks * DEV_BSIZE;
 247                         num_blks -= issue_blks;
 248                 }
 249                 nestiobuf_start(bio);
 250                 break;
 251         case BUF_CMD_FLUSH:
 252                 nestiobuf_init(bio);
 253                 for (devnr = 0; devnr < tsc->stripe_num; ++devnr) {
 254                         nestbuf = getpbuf(NULL);
 255                         nestbuf->b_flags |= bio->bio_buf->b_flags & B_HASBOGUS;
 256
 257                         nestiobuf_add(bio, nestbuf, 0, 0, NULL);
 258                         nestbuf->b_bio1.bio_offset = 0;
 259                         vn_strategy(tsc->stripe_devs[devnr].pdev->pdev_vnode,
 260                                     &nestbuf->b_bio1);
 261                 }
 262                 nestiobuf_start(bio);
 263                 break;
 264         default:
 265                 bp->b_flags |= B_ERROR;
 266                 bp->b_error = EIO;
 267                 biodone(bio);
 268                 break;
 269         }
 270         return 0;
 271 }
 272
 273
 274 static int
 275 dm_target_stripe_dump(dm_table_entry_t *table_en, void *data, size_t length, off_t offset)
 276 {
 277         dm_target_stripe_config_t *tsc;
 278         uint64_t blkno, blkoff;
 279         uint64_t stripe, blknr;
 280         uint32_t stripe_off, stripe_rest, num_blks, issue_blks;
 281         uint64_t off2, len2;
 282         int devnr;
 283
 284         tsc = table_en->target_config;
 285         if (tsc == NULL)
 286                 return 0;
 287
 288         /* calculate extent of request */
 289         KKASSERT(length % DEV_BSIZE == 0);
 290
 291         blkno = offset / DEV_BSIZE;
 292         blkoff = 0;
 293         num_blks = length / DEV_BSIZE;
 294
 295         /*
 296          * 0 length means flush buffers and return
 297          */
 298         if (length == 0) {
 299                 for (devnr = 0; devnr < tsc->stripe_num; ++devnr) {
 300                         if (tsc->stripe_devs[devnr].pdev->pdev_vnode->v_rdev == NULL)
 301                                 return ENXIO;
 302
 303                         dev_ddump(tsc->stripe_devs[devnr].pdev->pdev_vnode->v_rdev,
 304                             data, 0, offset, 0);
 305                 }
 306                 return 0;
 307         }
 308
 309         while (num_blks > 0) {
 310                 /* blockno to strip piece nr */
 311                 stripe = blkno / tsc->stripe_chunksize;
 312                 stripe_off = blkno % tsc->stripe_chunksize;
 313
 314                 /* where we are inside the strip */
 315                 devnr = stripe % tsc->stripe_num;
 316                 blknr = stripe / tsc->stripe_num;
 317
 318                 /* how much is left before we hit a boundary */
 319                 stripe_rest = tsc->stripe_chunksize - stripe_off;
 320
 321                 /* issue this piece on stripe `stripe' */
 322                 issue_blks = MIN(stripe_rest, num_blks);
 323
 324 #if 0
 325                 nestiobuf_add(bio, nestbuf, blkoff,
 326                                 issue_blks * DEV_BSIZE);
 327 #endif
 328                 len2 = issue_blks * DEV_BSIZE;
 329
 330                 /* I need number of bytes. */
 331                 off2 = blknr * tsc->stripe_chunksize + stripe_off;
 332                 off2 += tsc->stripe_devs[devnr].offset;
 333                 off2 *= DEV_BSIZE;
 334                 off2 = dm_pdev_correct_dump_offset(tsc->stripe_devs[devnr].pdev,
 335                     off2);
 336
 337                 if (tsc->stripe_devs[devnr].pdev->pdev_vnode->v_rdev == NULL)
 338                         return ENXIO;
 339
 340                 dev_ddump(tsc->stripe_devs[devnr].pdev->pdev_vnode->v_rdev,
 341                     (char *)data + blkoff, 0, off2, len2);
 342
 343                 blkno += issue_blks;
 344                 blkoff += issue_blks * DEV_BSIZE;
 345                 num_blks -= issue_blks;
 346         }
 347
 348         return 0;
 349 }
 350
 351 /*
 352  * Destroy a dm table entry for stripes.
 353  */
 354 static int
 355 dm_target_stripe_destroy(dm_table_entry_t *table_en)
 356 {
 357         dm_target_stripe_config_t *tsc;
 358
 359         if ((tsc = table_en->target_config) != NULL) {
 360                 table_en->target_config = NULL;
 361                 dm_target_stripe_destroy_config(tsc);
 362         }
 363
 364         return 0;
 365 }
 366
 367 static void
 368 dm_target_stripe_destroy_config(dm_target_stripe_config_t *tsc)
 369 {
 370         int n;
 371
 372         for (n = 0; n < tsc->stripe_num; ++n) {
 373                 if (tsc->stripe_devs[n].pdev) {
 374                         dm_pdev_decr(tsc->stripe_devs[n].pdev);
 375                         tsc->stripe_devs[n].pdev = NULL;
 376                 }
 377         }
 378         kfree(tsc, M_DMSTRIPE);
 379 }
 380
 381 /*
 382  * Unsupported for this target.
 383  */
 384 static int
 385 dm_target_stripe_upcall(dm_table_entry_t *table_en, struct buf *bp)
 386 {
 387         return 0;
 388 }
 389
 390 static int
 391 dmts_mod_handler(module_t mod, int type, void *unused)
 392 {
 393         dm_target_t *dmt = NULL;
 394         int err = 0;
 395
 396         switch(type) {
 397         case MOD_LOAD:
 398                 if ((dmt = dm_target_lookup("striped")) != NULL) {
 399                         dm_target_unbusy(dmt);
 400                         return EEXIST;
 401                 }
 402                 dmt = dm_target_alloc("striped");
 403                 dmt->version[0] = 1;
 404                 dmt->version[1] = 0;
 405                 dmt->version[2] = 3;
 406                 strlcpy(dmt->name, "striped", DM_MAX_TYPE_NAME);
 407                 dmt->init = &dm_target_stripe_init;
 408                 dmt->table = &dm_target_stripe_table;
 409                 dmt->strategy = &dm_target_stripe_strategy;
 410                 dmt->destroy = &dm_target_stripe_destroy;
 411                 dmt->upcall = &dm_target_stripe_upcall;
 412                 dmt->dump = &dm_target_stripe_dump;
 413
 414                 err = dm_target_insert(dmt);
 415                 if (err == 0)
 416                         kprintf("dm_target_stripe: Successfully initialized\n");
 417                 break;
 418
 419         case MOD_UNLOAD:
 420                 err = dm_target_rem("striped");
 421                 if (err == 0)
 422                         kprintf("dm_target_stripe: unloaded\n");
 423                 break;
 424
 425         default:
 426                 break;
 427         }
 428
 429         return err;
 430 }
 431
 432 DM_TARGET_MODULE(dm_target_striped, dmts_mod_handler);