fs/exofs/ore.c

   1 /*
   2  * Copyright (C) 2005, 2006
   3  * Avishay Traeger (avishay@gmail.com)
   4  * Copyright (C) 2008, 2009
   5  * Boaz Harrosh <bharrosh@panasas.com>
   6  *
   7  * This file is part of exofs.
   8  *
   9  * exofs is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation.  Since it is based on ext2, and the only
  12  * valid version of GPL for the Linux kernel is version 2, the only valid
  13  * version of GPL for exofs is version 2.
  14  *
  15  * exofs is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with exofs; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  23  */
  24
  25 #include <linux/slab.h>
  26 #include <asm/div64.h>
  27 #include <linux/lcm.h>
  28
  29 #include "ore_raid.h"
  30
  31 MODULE_AUTHOR("Boaz Harrosh <bharrosh@panasas.com>");
  32 MODULE_DESCRIPTION("Objects Raid Engine ore.ko");
  33 MODULE_LICENSE("GPL");
  34
  35 /* ore_verify_layout does a couple of things:
  36  * 1. Given a minimum number of needed parameters fixes up the rest of the
  37  *    members to be operatonals for the ore. The needed parameters are those
  38  *    that are defined by the pnfs-objects layout STD.
  39  * 2. Check to see if the current ore code actually supports these parameters
  40  *    for example stripe_unit must be a multple of the system PAGE_SIZE,
  41  *    and etc...
  42  * 3. Cache some havily used calculations that will be needed by users.
  43  */
  44
  45 enum { BIO_MAX_PAGES_KMALLOC =
  46                 (PAGE_SIZE - sizeof(struct bio)) / sizeof(struct bio_vec),};
  47
  48 int ore_verify_layout(unsigned total_comps, struct ore_layout *layout)
  49 {
  50         u64 stripe_length;
  51
  52 /* FIXME: Only raid0 is supported for now. */
  53         if (layout->raid_algorithm != PNFS_OSD_RAID_0) {
  54                 ORE_ERR("Only RAID_0 for now\n");
  55                 return -EINVAL;
  56         }
  57         if (0 != (layout->stripe_unit & ~PAGE_MASK)) {
  58                 ORE_ERR("Stripe Unit(0x%llx)"
  59                           " must be Multples of PAGE_SIZE(0x%lx)\n",
  60                           _LLU(layout->stripe_unit), PAGE_SIZE);
  61                 return -EINVAL;
  62         }
  63         if (layout->group_width) {
  64                 if (!layout->group_depth) {
  65                         ORE_ERR("group_depth == 0 && group_width != 0\n");
  66                         return -EINVAL;
  67                 }
  68                 if (total_comps < (layout->group_width * layout->mirrors_p1)) {
  69                         ORE_ERR("Data Map wrong, "
  70                                 "numdevs=%d < group_width=%d * mirrors=%d\n",
  71                                 total_comps, layout->group_width,
  72                                 layout->mirrors_p1);
  73                         return -EINVAL;
  74                 }
  75                 layout->group_count = total_comps / layout->mirrors_p1 /
  76                                                 layout->group_width;
  77         } else {
  78                 if (layout->group_depth) {
  79                         printk(KERN_NOTICE "Warning: group_depth ignored "
  80                                 "group_width == 0 && group_depth == %lld\n",
  81                                 _LLU(layout->group_depth));
  82                 }
  83                 layout->group_width = total_comps / layout->mirrors_p1;
  84                 layout->group_depth = -1;
  85                 layout->group_count = 1;
  86         }
  87
  88         stripe_length = (u64)layout->group_width * layout->stripe_unit;
  89         if (stripe_length >= (1ULL << 32)) {
  90                 ORE_ERR("Stripe_length(0x%llx) >= 32bit is not supported\n",
  91                         _LLU(stripe_length));
  92                 return -EINVAL;
  93         }
  94
  95         layout->max_io_length =
  96                 (BIO_MAX_PAGES_KMALLOC * PAGE_SIZE - layout->stripe_unit) *
  97                                                         layout->group_width;
  98         if (layout->parity) {
  99                 unsigned stripe_length =
 100                                 (layout->group_width - layout->parity) *
 101                                 layout->stripe_unit;
 102
 103                 layout->max_io_length /= stripe_length;
 104                 layout->max_io_length *= stripe_length;
 105         }
 106         return 0;
 107 }
 108 EXPORT_SYMBOL(ore_verify_layout);
 109
 110 static u8 *_ios_cred(struct ore_io_state *ios, unsigned index)
 111 {
 112         return ios->oc->comps[index & ios->oc->single_comp].cred;
 113 }
 114
 115 static struct osd_obj_id *_ios_obj(struct ore_io_state *ios, unsigned index)
 116 {
 117         return &ios->oc->comps[index & ios->oc->single_comp].obj;
 118 }
 119
 120 static struct osd_dev *_ios_od(struct ore_io_state *ios, unsigned index)
 121 {
 122         ORE_DBGMSG2("oc->first_dev=%d oc->numdevs=%d i=%d oc->ods=%p\n",
 123                     ios->oc->first_dev, ios->oc->numdevs, index,
 124                     ios->oc->ods);
 125
 126         return ore_comp_dev(ios->oc, index);
 127 }
 128
 129 int  _ore_get_io_state(struct ore_layout *layout,
 130                         struct ore_components *oc, unsigned numdevs,
 131                         unsigned sgs_per_dev, unsigned num_par_pages,
 132                         struct ore_io_state **pios)
 133 {
 134         struct ore_io_state *ios;
 135         struct page **pages;
 136         struct osd_sg_entry *sgilist;
 137         struct __alloc_all_io_state {
 138                 struct ore_io_state ios;
 139                 struct ore_per_dev_state per_dev[numdevs];
 140                 union {
 141                         struct osd_sg_entry sglist[sgs_per_dev * numdevs];
 142                         struct page *pages[num_par_pages];
 143                 };
 144         } *_aios;
 145
 146         if (likely(sizeof(*_aios) <= PAGE_SIZE)) {
 147                 _aios = kzalloc(sizeof(*_aios), GFP_KERNEL);
 148                 if (unlikely(!_aios)) {
 149                         ORE_DBGMSG("Failed kzalloc bytes=%zd\n",
 150                                    sizeof(*_aios));
 151                         *pios = NULL;
 152                         return -ENOMEM;
 153                 }
 154                 pages = num_par_pages ? _aios->pages : NULL;
 155                 sgilist = sgs_per_dev ? _aios->sglist : NULL;
 156                 ios = &_aios->ios;
 157         } else {
 158                 struct __alloc_small_io_state {
 159                         struct ore_io_state ios;
 160                         struct ore_per_dev_state per_dev[numdevs];
 161                 } *_aio_small;
 162                 union __extra_part {
 163                         struct osd_sg_entry sglist[sgs_per_dev * numdevs];
 164                         struct page *pages[num_par_pages];
 165                 } *extra_part;
 166
 167                 _aio_small = kzalloc(sizeof(*_aio_small), GFP_KERNEL);
 168                 if (unlikely(!_aio_small)) {
 169                         ORE_DBGMSG("Failed alloc first part bytes=%zd\n",
 170                                    sizeof(*_aio_small));
 171                         *pios = NULL;
 172                         return -ENOMEM;
 173                 }
 174                 extra_part = kzalloc(sizeof(*extra_part), GFP_KERNEL);
 175                 if (unlikely(!extra_part)) {
 176                         ORE_DBGMSG("Failed alloc second part bytes=%zd\n",
 177                                    sizeof(*extra_part));
 178                         kfree(_aio_small);
 179                         *pios = NULL;
 180                         return -ENOMEM;
 181                 }
 182
 183                 pages = num_par_pages ? extra_part->pages : NULL;
 184                 sgilist = sgs_per_dev ? extra_part->sglist : NULL;
 185                 /* In this case the per_dev[0].sgilist holds the pointer to
 186                  * be freed
 187                  */
 188                 ios = &_aio_small->ios;
 189                 ios->extra_part_alloc = true;
 190         }
 191
 192         if (pages) {
 193                 ios->parity_pages = pages;
 194                 ios->max_par_pages = num_par_pages;
 195         }
 196         if (sgilist) {
 197                 unsigned d;
 198
 199                 for (d = 0; d < numdevs; ++d) {
 200                         ios->per_dev[d].sglist = sgilist;
 201                         sgilist += sgs_per_dev;
 202                 }
 203                 ios->sgs_per_dev = sgs_per_dev;
 204         }
 205
 206         ios->layout = layout;
 207         ios->oc = oc;
 208         *pios = ios;
 209         return 0;
 210 }
 211
 212 /* Allocate an io_state for only a single group of devices
 213  *
 214  * If a user needs to call ore_read/write() this version must be used becase it
 215  * allocates extra stuff for striping and raid.
 216  * The ore might decide to only IO less then @length bytes do to alignmets
 217  * and constrains as follows:
 218  * - The IO cannot cross group boundary.
 219  * - In raid5/6 The end of the IO must align at end of a stripe eg.
 220  *   (@offset + @length) % strip_size == 0. Or the complete range is within a
 221  *   single stripe.
 222  * - Memory condition only permitted a shorter IO. (A user can use @length=~0
 223  *   And check the returned ios->length for max_io_size.)
 224  *
 225  * The caller must check returned ios->length (and/or ios->nr_pages) and
 226  * re-issue these pages that fall outside of ios->length
 227  */
 228 int  ore_get_rw_state(struct ore_layout *layout, struct ore_components *oc,
 229                       bool is_reading, u64 offset, u64 length,
 230                       struct ore_io_state **pios)
 231 {
 232         struct ore_io_state *ios;
 233         unsigned numdevs = layout->group_width * layout->mirrors_p1;
 234         unsigned sgs_per_dev = 0, max_par_pages = 0;
 235         int ret;
 236
 237         if (layout->parity && length) {
 238                 unsigned data_devs = layout->group_width - layout->parity;
 239                 unsigned stripe_size = layout->stripe_unit * data_devs;
 240                 unsigned pages_in_unit = layout->stripe_unit / PAGE_SIZE;
 241                 u32 remainder;
 242                 u64 num_stripes;
 243                 u64 num_raid_units;
 244
 245                 num_stripes = div_u64_rem(length, stripe_size, &remainder);
 246                 if (remainder)
 247                         ++num_stripes;
 248
 249                 num_raid_units =  num_stripes * layout->parity;
 250
 251                 if (is_reading) {
 252                         /* For reads add per_dev sglist array */
 253                         /* TODO: Raid 6 we need twice more. Actually:
 254                         *         num_stripes / LCMdP(W,P);
 255                         *         if (W%P != 0) num_stripes *= parity;
 256                         */
 257
 258                         /* first/last seg is split */
 259                         num_raid_units += layout->group_width;
 260                         sgs_per_dev = div_u64(num_raid_units, data_devs);
 261                 } else {
 262                         /* For Writes add parity pages array. */
 263                         max_par_pages = num_raid_units * pages_in_unit *
 264                                                 sizeof(struct page *);
 265                 }
 266         }
 267
 268         ret = _ore_get_io_state(layout, oc, numdevs, sgs_per_dev, max_par_pages,
 269                                 pios);
 270         if (unlikely(ret))
 271                 return ret;
 272
 273         ios = *pios;
 274         ios->reading = is_reading;
 275         ios->offset = offset;
 276
 277         if (length) {
 278                 ore_calc_stripe_info(layout, offset, length, &ios->si);
 279                 ios->length = ios->si.length;
 280                 ios->nr_pages = (ios->length + PAGE_SIZE - 1) / PAGE_SIZE;
 281                 if (layout->parity)
 282                         _ore_post_alloc_raid_stuff(ios);
 283         }
 284
 285         return 0;
 286 }
 287 EXPORT_SYMBOL(ore_get_rw_state);
 288
 289 /* Allocate an io_state for all the devices in the comps array
 290  *
 291  * This version of io_state allocation is used mostly by create/remove
 292  * and trunc where we currently need all the devices. The only wastful
 293  * bit is the read/write_attributes with no IO. Those sites should
 294  * be converted to use ore_get_rw_state() with length=0
 295  */
 296 int  ore_get_io_state(struct ore_layout *layout, struct ore_components *oc,
 297                       struct ore_io_state **pios)
 298 {
 299         return _ore_get_io_state(layout, oc, oc->numdevs, 0, 0, pios);
 300 }
 301 EXPORT_SYMBOL(ore_get_io_state);
 302
 303 void ore_put_io_state(struct ore_io_state *ios)
 304 {
 305         if (ios) {
 306                 unsigned i;
 307
 308                 for (i = 0; i < ios->numdevs; i++) {
 309                         struct ore_per_dev_state *per_dev = &ios->per_dev[i];
 310
 311                         if (per_dev->or)
 312                                 osd_end_request(per_dev->or);
 313                         if (per_dev->bio)
 314                                 bio_put(per_dev->bio);
 315                 }
 316
 317                 _ore_free_raid_stuff(ios);
 318                 kfree(ios);
 319         }
 320 }
 321 EXPORT_SYMBOL(ore_put_io_state);
 322
 323 static void _sync_done(struct ore_io_state *ios, void *p)
 324 {
 325         struct completion *waiting = p;
 326
 327         complete(waiting);
 328 }
 329
 330 static void _last_io(struct kref *kref)
 331 {
 332         struct ore_io_state *ios = container_of(
 333                                         kref, struct ore_io_state, kref);
 334
 335         ios->done(ios, ios->private);
 336 }
 337
 338 static void _done_io(struct osd_request *or, void *p)
 339 {
 340         struct ore_io_state *ios = p;
 341
 342         kref_put(&ios->kref, _last_io);
 343 }
 344
 345 int ore_io_execute(struct ore_io_state *ios)
 346 {
 347         DECLARE_COMPLETION_ONSTACK(wait);
 348         bool sync = (ios->done == NULL);
 349         int i, ret;
 350
 351         if (sync) {
 352                 ios->done = _sync_done;
 353                 ios->private = &wait;
 354         }
 355
 356         for (i = 0; i < ios->numdevs; i++) {
 357                 struct osd_request *or = ios->per_dev[i].or;
 358                 if (unlikely(!or))
 359                         continue;
 360
 361                 ret = osd_finalize_request(or, 0, _ios_cred(ios, i), NULL);
 362                 if (unlikely(ret)) {
 363                         ORE_DBGMSG("Failed to osd_finalize_request() => %d\n",
 364                                      ret);
 365                         return ret;
 366                 }
 367         }
 368
 369         kref_init(&ios->kref);
 370
 371         for (i = 0; i < ios->numdevs; i++) {
 372                 struct osd_request *or = ios->per_dev[i].or;
 373                 if (unlikely(!or))
 374                         continue;
 375
 376                 kref_get(&ios->kref);
 377                 osd_execute_request_async(or, _done_io, ios);
 378         }
 379
 380         kref_put(&ios->kref, _last_io);
 381         ret = 0;
 382
 383         if (sync) {
 384                 wait_for_completion(&wait);
 385                 ret = ore_check_io(ios, NULL);
 386         }
 387         return ret;
 388 }
 389
 390 static void _clear_bio(struct bio *bio)
 391 {
 392         struct bio_vec *bv;
 393         unsigned i;
 394
 395         __bio_for_each_segment(bv, bio, i, 0) {
 396                 unsigned this_count = bv->bv_len;
 397
 398                 if (likely(PAGE_SIZE == this_count))
 399                         clear_highpage(bv->bv_page);
 400                 else
 401                         zero_user(bv->bv_page, bv->bv_offset, this_count);
 402         }
 403 }
 404
 405 int ore_check_io(struct ore_io_state *ios, ore_on_dev_error on_dev_error)
 406 {
 407         enum osd_err_priority acumulated_osd_err = 0;
 408         int acumulated_lin_err = 0;
 409         int i;
 410
 411         for (i = 0; i < ios->numdevs; i++) {
 412                 struct osd_sense_info osi;
 413                 struct ore_per_dev_state *per_dev = &ios->per_dev[i];
 414                 struct osd_request *or = per_dev->or;
 415                 int ret;
 416
 417                 if (unlikely(!or))
 418                         continue;
 419
 420                 ret = osd_req_decode_sense(or, &osi);
 421                 if (likely(!ret))
 422                         continue;
 423
 424                 if (OSD_ERR_PRI_CLEAR_PAGES == osi.osd_err_pri) {
 425                         /* start read offset passed endof file */
 426                         _clear_bio(per_dev->bio);
 427                         ORE_DBGMSG("start read offset passed end of file "
 428                                 "offset=0x%llx, length=0x%llx\n",
 429                                 _LLU(per_dev->offset),
 430                                 _LLU(per_dev->length));
 431
 432                         continue; /* we recovered */
 433                 }
 434
 435                 if (on_dev_error) {
 436                         u64 residual = ios->reading ?
 437                                         or->in.residual : or->out.residual;
 438                         u64 offset = (ios->offset + ios->length) - residual;
 439                         struct ore_dev *od = ios->oc->ods[
 440                                         per_dev->dev - ios->oc->first_dev];
 441
 442                         on_dev_error(ios, od, per_dev->dev, osi.osd_err_pri,
 443                                      offset, residual);
 444                 }
 445                 if (osi.osd_err_pri >= acumulated_osd_err) {
 446                         acumulated_osd_err = osi.osd_err_pri;
 447                         acumulated_lin_err = ret;
 448                 }
 449         }
 450
 451         return acumulated_lin_err;
 452 }
 453 EXPORT_SYMBOL(ore_check_io);
 454
 455 /*
 456  * L - logical offset into the file
 457  *
 458  * D - number of Data devices
 459  *      D = group_width - parity
 460  *
 461  * U - The number of bytes in a stripe within a group
 462  *      U =  stripe_unit * D
 463  *
 464  * T - The number of bytes striped within a group of component objects
 465  *     (before advancing to the next group)
 466  *      T = U * group_depth
 467  *
 468  * S - The number of bytes striped across all component objects
 469  *     before the pattern repeats
 470  *      S = T * group_count
 471  *
 472  * M - The "major" (i.e., across all components) cycle number
 473  *      M = L / S
 474  *
 475  * G - Counts the groups from the beginning of the major cycle
 476  *      G = (L - (M * S)) / T   [or (L % S) / T]
 477  *
 478  * H - The byte offset within the group
 479  *      H = (L - (M * S)) % T   [or (L % S) % T]
 480  *
 481  * N - The "minor" (i.e., across the group) stripe number
 482  *      N = H / U
 483  *
 484  * C - The component index coresponding to L
 485  *
 486  *      C = (H - (N * U)) / stripe_unit + G * D
 487  *      [or (L % U) / stripe_unit + G * D]
 488  *
 489  * O - The component offset coresponding to L
 490  *      O = L % stripe_unit + N * stripe_unit + M * group_depth * stripe_unit
 491  *
 492  * LCMdP – Parity cycle: Lowest Common Multiple of group_width, parity
 493  *          divide by parity
 494  *      LCMdP = lcm(group_width, parity) / parity
 495  *
 496  * R - The parity Rotation stripe
 497  *     (Note parity cycle always starts at a group's boundary)
 498  *      R = N % LCMdP
 499  *
 500  * I = the first parity device index
 501  *      I = (group_width + group_width - R*parity - parity) % group_width
 502  *
 503  * Craid - The component index Rotated
 504  *      Craid = (group_width + C - R*parity) % group_width
 505  *      (We add the group_width to avoid negative numbers modulo math)
 506  */
 507 void ore_calc_stripe_info(struct ore_layout *layout, u64 file_offset,
 508                           u64 length, struct ore_striping_info *si)
 509 {
 510         u32     stripe_unit = layout->stripe_unit;
 511         u32     group_width = layout->group_width;
 512         u64     group_depth = layout->group_depth;
 513         u32     parity      = layout->parity;
 514
 515         u32     D = group_width - parity;
 516         u32     U = D * stripe_unit;
 517         u64     T = U * group_depth;
 518         u64     S = T * layout->group_count;
 519         u64     M = div64_u64(file_offset, S);
 520
 521         /*
 522         G = (L - (M * S)) / T
 523         H = (L - (M * S)) % T
 524         */
 525         u64     LmodS = file_offset - M * S;
 526         u32     G = div64_u64(LmodS, T);
 527         u64     H = LmodS - G * T;
 528
 529         u32     N = div_u64(H, U);
 530
 531         /* "H - (N * U)" is just "H % U" so it's bound to u32 */
 532         u32     C = (u32)(H - (N * U)) / stripe_unit + G * group_width;
 533
 534         div_u64_rem(file_offset, stripe_unit, &si->unit_off);
 535
 536         si->obj_offset = si->unit_off + (N * stripe_unit) +
 537                                   (M * group_depth * stripe_unit);
 538
 539         if (parity) {
 540                 u32 LCMdP = lcm(group_width, parity) / parity;
 541                 /* R     = N % LCMdP; */
 542                 u32 RxP   = (N % LCMdP) * parity;
 543                 u32 first_dev = C - C % group_width;
 544
 545                 si->par_dev = (group_width + group_width - parity - RxP) %
 546                               group_width + first_dev;
 547                 si->dev = (group_width + C - RxP) % group_width + first_dev;
 548                 si->bytes_in_stripe = U;
 549                 si->first_stripe_start = M * S + G * T + N * U;
 550         } else {
 551                 /* Make the math correct see _prepare_one_group */
 552                 si->par_dev = group_width;
 553                 si->dev = C;
 554         }
 555
 556         si->dev *= layout->mirrors_p1;
 557         si->par_dev *= layout->mirrors_p1;
 558         si->offset = file_offset;
 559         si->length = T - H;
 560         if (si->length > length)
 561                 si->length = length;
 562         si->M = M;
 563 }
 564 EXPORT_SYMBOL(ore_calc_stripe_info);
 565
 566 int _ore_add_stripe_unit(struct ore_io_state *ios,  unsigned *cur_pg,
 567                          unsigned pgbase, struct page **pages,
 568                          struct ore_per_dev_state *per_dev, int cur_len)
 569 {
 570         unsigned pg = *cur_pg;
 571         struct request_queue *q =
 572                         osd_request_queue(_ios_od(ios, per_dev->dev));
 573         unsigned len = cur_len;
 574         int ret;
 575
 576         if (per_dev->bio == NULL) {
 577                 unsigned pages_in_stripe = ios->layout->group_width *
 578                                         (ios->layout->stripe_unit / PAGE_SIZE);
 579                 unsigned nr_pages = ios->nr_pages * ios->layout->group_width /
 580                                         (ios->layout->group_width -
 581                                          ios->layout->parity);
 582                 unsigned bio_size = (nr_pages + pages_in_stripe) /
 583                                         ios->layout->group_width;
 584
 585                 per_dev->bio = bio_kmalloc(GFP_KERNEL, bio_size);
 586                 if (unlikely(!per_dev->bio)) {
 587                         ORE_DBGMSG("Failed to allocate BIO size=%u\n",
 588                                      bio_size);
 589                         ret = -ENOMEM;
 590                         goto out;
 591                 }
 592         }
 593
 594         while (cur_len > 0) {
 595                 unsigned pglen = min_t(unsigned, PAGE_SIZE - pgbase, cur_len);
 596                 unsigned added_len;
 597
 598                 cur_len -= pglen;
 599
 600                 added_len = bio_add_pc_page(q, per_dev->bio, pages[pg],
 601                                             pglen, pgbase);
 602                 if (unlikely(pglen != added_len)) {
 603                         ORE_DBGMSG("Failed bio_add_pc_page bi_vcnt=%u\n",
 604                                    per_dev->bio->bi_vcnt);
 605                         ret = -ENOMEM;
 606                         goto out;
 607                 }
 608                 _add_stripe_page(ios->sp2d, &ios->si, pages[pg]);
 609
 610                 pgbase = 0;
 611                 ++pg;
 612         }
 613         BUG_ON(cur_len);
 614
 615         per_dev->length += len;
 616         *cur_pg = pg;
 617         ret = 0;
 618 out:    /* we fail the complete unit on an error eg don't advance
 619          * per_dev->length and cur_pg. This means that we might have a bigger
 620          * bio than the CDB requested length (per_dev->length). That's fine
 621          * only the oposite is fatal.
 622          */
 623         return ret;
 624 }
 625
 626 static int _prepare_for_striping(struct ore_io_state *ios)
 627 {
 628         struct ore_striping_info *si = &ios->si;
 629         unsigned stripe_unit = ios->layout->stripe_unit;
 630         unsigned mirrors_p1 = ios->layout->mirrors_p1;
 631         unsigned group_width = ios->layout->group_width;
 632         unsigned devs_in_group = group_width * mirrors_p1;
 633         unsigned dev = si->dev;
 634         unsigned first_dev = dev - (dev % devs_in_group);
 635         unsigned dev_order;
 636         unsigned cur_pg = ios->pages_consumed;
 637         u64 length = ios->length;
 638         int ret = 0;
 639
 640         if (!ios->pages) {
 641                 ios->numdevs = ios->layout->mirrors_p1;
 642                 return 0;
 643         }
 644
 645         BUG_ON(length > si->length);
 646
 647         dev_order = _dev_order(devs_in_group, mirrors_p1, si->par_dev, dev);
 648         si->cur_comp = dev_order;
 649         si->cur_pg = si->unit_off / PAGE_SIZE;
 650
 651         while (length) {
 652                 unsigned comp = dev - first_dev;
 653                 struct ore_per_dev_state *per_dev = &ios->per_dev[comp];
 654                 unsigned cur_len, page_off = 0;
 655
 656                 if (!per_dev->length) {
 657                         per_dev->dev = dev;
 658                         if (dev == si->dev) {
 659                                 WARN_ON(dev == si->par_dev);
 660                                 per_dev->offset = si->obj_offset;
 661                                 cur_len = stripe_unit - si->unit_off;
 662                                 page_off = si->unit_off & ~PAGE_MASK;
 663                                 BUG_ON(page_off && (page_off != ios->pgbase));
 664                         } else {
 665                                 if (si->cur_comp > dev_order)
 666                                         per_dev->offset =
 667                                                 si->obj_offset - si->unit_off;
 668                                 else /* si->cur_comp < dev_order */
 669                                         per_dev->offset =
 670                                                 si->obj_offset + stripe_unit -
 671                                                                    si->unit_off;
 672                                 cur_len = stripe_unit;
 673                         }
 674                 } else {
 675                         cur_len = stripe_unit;
 676                 }
 677                 if (cur_len >= length)
 678                         cur_len = length;
 679
 680                 ret = _ore_add_stripe_unit(ios, &cur_pg, page_off, ios->pages,
 681                                            per_dev, cur_len);
 682                 if (unlikely(ret))
 683                         goto out;
 684
 685                 dev += mirrors_p1;
 686                 dev = (dev % devs_in_group) + first_dev;
 687
 688                 length -= cur_len;
 689
 690                 si->cur_comp = (si->cur_comp + 1) % group_width;
 691                 if (unlikely((dev == si->par_dev) || (!length && ios->sp2d))) {
 692                         if (!length && ios->sp2d) {
 693                                 /* If we are writing and this is the very last
 694                                  * stripe. then operate on parity dev.
 695                                  */
 696                                 dev = si->par_dev;
 697                         }
 698                         if (ios->sp2d)
 699                                 /* In writes cur_len just means if it's the
 700                                  * last one. See _ore_add_parity_unit.
 701                                  */
 702                                 cur_len = length;
 703                         per_dev = &ios->per_dev[dev - first_dev];
 704                         if (!per_dev->length) {
 705                                 /* Only/always the parity unit of the first
 706                                  * stripe will be empty. So this is a chance to
 707                                  * initialize the per_dev info.
 708                                  */
 709                                 per_dev->dev = dev;
 710                                 per_dev->offset = si->obj_offset - si->unit_off;
 711                         }
 712
 713                         ret = _ore_add_parity_unit(ios, si, per_dev, cur_len);
 714                         if (unlikely(ret))
 715                                         goto out;
 716
 717                         /* Rotate next par_dev backwards with wraping */
 718                         si->par_dev = (devs_in_group + si->par_dev -
 719                                        ios->layout->parity * mirrors_p1) %
 720                                       devs_in_group + first_dev;
 721                         /* Next stripe, start fresh */
 722                         si->cur_comp = 0;
 723                         si->cur_pg = 0;
 724                 }
 725         }
 726 out:
 727         ios->numdevs = devs_in_group;
 728         ios->pages_consumed = cur_pg;
 729         if (unlikely(ret)) {
 730                 if (length == ios->length)
 731                         return ret;
 732                 else
 733                         ios->length -= length;
 734         }
 735         return 0;
 736 }
 737
 738 int ore_create(struct ore_io_state *ios)
 739 {
 740         int i, ret;
 741
 742         for (i = 0; i < ios->oc->numdevs; i++) {
 743                 struct osd_request *or;
 744
 745                 or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
 746                 if (unlikely(!or)) {
 747                         ORE_ERR("%s: osd_start_request failed\n", __func__);
 748                         ret = -ENOMEM;
 749                         goto out;
 750                 }
 751                 ios->per_dev[i].or = or;
 752                 ios->numdevs++;
 753
 754                 osd_req_create_object(or, _ios_obj(ios, i));
 755         }
 756         ret = ore_io_execute(ios);
 757
 758 out:
 759         return ret;
 760 }
 761 EXPORT_SYMBOL(ore_create);
 762
 763 int ore_remove(struct ore_io_state *ios)
 764 {
 765         int i, ret;
 766
 767         for (i = 0; i < ios->oc->numdevs; i++) {
 768                 struct osd_request *or;
 769
 770                 or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
 771                 if (unlikely(!or)) {
 772                         ORE_ERR("%s: osd_start_request failed\n", __func__);
 773                         ret = -ENOMEM;
 774                         goto out;
 775                 }
 776                 ios->per_dev[i].or = or;
 777                 ios->numdevs++;
 778
 779                 osd_req_remove_object(or, _ios_obj(ios, i));
 780         }
 781         ret = ore_io_execute(ios);
 782
 783 out:
 784         return ret;
 785 }
 786 EXPORT_SYMBOL(ore_remove);
 787
 788 static int _write_mirror(struct ore_io_state *ios, int cur_comp)
 789 {
 790         struct ore_per_dev_state *master_dev = &ios->per_dev[cur_comp];
 791         unsigned dev = ios->per_dev[cur_comp].dev;
 792         unsigned last_comp = cur_comp + ios->layout->mirrors_p1;
 793         int ret = 0;
 794
 795         if (ios->pages && !master_dev->length)
 796                 return 0; /* Just an empty slot */
 797
 798         for (; cur_comp < last_comp; ++cur_comp, ++dev) {
 799                 struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
 800                 struct osd_request *or;
 801
 802                 or = osd_start_request(_ios_od(ios, dev), GFP_KERNEL);
 803                 if (unlikely(!or)) {
 804                         ORE_ERR("%s: osd_start_request failed\n", __func__);
 805                         ret = -ENOMEM;
 806                         goto out;
 807                 }
 808                 per_dev->or = or;
 809
 810                 if (ios->pages) {
 811                         struct bio *bio;
 812
 813                         if (per_dev != master_dev) {
 814                                 bio = bio_kmalloc(GFP_KERNEL,
 815                                                   master_dev->bio->bi_max_vecs);
 816                                 if (unlikely(!bio)) {
 817                                         ORE_DBGMSG(
 818                                               "Failed to allocate BIO size=%u\n",
 819                                               master_dev->bio->bi_max_vecs);
 820                                         ret = -ENOMEM;
 821                                         goto out;
 822                                 }
 823
 824                                 __bio_clone(bio, master_dev->bio);
 825                                 bio->bi_bdev = NULL;
 826                                 bio->bi_next = NULL;
 827                                 per_dev->offset = master_dev->offset;
 828                                 per_dev->length = master_dev->length;
 829                                 per_dev->bio =  bio;
 830                                 per_dev->dev = dev;
 831                         } else {
 832                                 bio = master_dev->bio;
 833                                 /* FIXME: bio_set_dir() */
 834                                 bio->bi_rw |= REQ_WRITE;
 835                         }
 836
 837                         osd_req_write(or, _ios_obj(ios, dev), per_dev->offset,
 838                                       bio, per_dev->length);
 839                         ORE_DBGMSG("write(0x%llx) offset=0x%llx "
 840                                       "length=0x%llx dev=%d\n",
 841                                      _LLU(_ios_obj(ios, dev)->id),
 842                                      _LLU(per_dev->offset),
 843                                      _LLU(per_dev->length), dev);
 844                 } else if (ios->kern_buff) {
 845                         per_dev->offset = ios->si.obj_offset;
 846                         per_dev->dev = ios->si.dev + dev;
 847
 848                         /* no cross device without page array */
 849                         BUG_ON((ios->layout->group_width > 1) &&
 850                                (ios->si.unit_off + ios->length >
 851                                 ios->layout->stripe_unit));
 852
 853                         ret = osd_req_write_kern(or, _ios_obj(ios, per_dev->dev),
 854                                                  per_dev->offset,
 855                                                  ios->kern_buff, ios->length);
 856                         if (unlikely(ret))
 857                                 goto out;
 858                         ORE_DBGMSG2("write_kern(0x%llx) offset=0x%llx "
 859                                       "length=0x%llx dev=%d\n",
 860                                      _LLU(_ios_obj(ios, dev)->id),
 861                                      _LLU(per_dev->offset),
 862                                      _LLU(ios->length), per_dev->dev);
 863                 } else {
 864                         osd_req_set_attributes(or, _ios_obj(ios, dev));
 865                         ORE_DBGMSG2("obj(0x%llx) set_attributes=%d dev=%d\n",
 866                                      _LLU(_ios_obj(ios, dev)->id),
 867                                      ios->out_attr_len, dev);
 868                 }
 869
 870                 if (ios->out_attr)
 871                         osd_req_add_set_attr_list(or, ios->out_attr,
 872                                                   ios->out_attr_len);
 873
 874                 if (ios->in_attr)
 875                         osd_req_add_get_attr_list(or, ios->in_attr,
 876                                                   ios->in_attr_len);
 877         }
 878
 879 out:
 880         return ret;
 881 }
 882
 883 int ore_write(struct ore_io_state *ios)
 884 {
 885         int i;
 886         int ret;
 887
 888         if (unlikely(ios->sp2d && !ios->r4w)) {
 889                 /* A library is attempting a RAID-write without providing
 890                  * a pages lock interface.
 891                  */
 892                 WARN_ON_ONCE(1);
 893                 return -ENOTSUPP;
 894         }
 895
 896         ret = _prepare_for_striping(ios);
 897         if (unlikely(ret))
 898                 return ret;
 899
 900         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
 901                 ret = _write_mirror(ios, i);
 902                 if (unlikely(ret))
 903                         return ret;
 904         }
 905
 906         ret = ore_io_execute(ios);
 907         return ret;
 908 }
 909 EXPORT_SYMBOL(ore_write);
 910
 911 int _ore_read_mirror(struct ore_io_state *ios, unsigned cur_comp)
 912 {
 913         struct osd_request *or;
 914         struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
 915         struct osd_obj_id *obj = _ios_obj(ios, cur_comp);
 916         unsigned first_dev = (unsigned)obj->id;
 917
 918         if (ios->pages && !per_dev->length)
 919                 return 0; /* Just an empty slot */
 920
 921         first_dev = per_dev->dev + first_dev % ios->layout->mirrors_p1;
 922         or = osd_start_request(_ios_od(ios, first_dev), GFP_KERNEL);
 923         if (unlikely(!or)) {
 924                 ORE_ERR("%s: osd_start_request failed\n", __func__);
 925                 return -ENOMEM;
 926         }
 927         per_dev->or = or;
 928
 929         if (ios->pages) {
 930                 if (per_dev->cur_sg) {
 931                         /* finalize the last sg_entry */
 932                         _ore_add_sg_seg(per_dev, 0, false);
 933                         if (unlikely(!per_dev->cur_sg))
 934                                 return 0; /* Skip parity only device */
 935
 936                         osd_req_read_sg(or, obj, per_dev->bio,
 937                                         per_dev->sglist, per_dev->cur_sg);
 938                 } else {
 939                         /* The no raid case */
 940                         osd_req_read(or, obj, per_dev->offset,
 941                                      per_dev->bio, per_dev->length);
 942                 }
 943
 944                 ORE_DBGMSG("read(0x%llx) offset=0x%llx length=0x%llx"
 945                              " dev=%d sg_len=%d\n", _LLU(obj->id),
 946                              _LLU(per_dev->offset), _LLU(per_dev->length),
 947                              first_dev, per_dev->cur_sg);
 948         } else {
 949                 BUG_ON(ios->kern_buff);
 950
 951                 osd_req_get_attributes(or, obj);
 952                 ORE_DBGMSG2("obj(0x%llx) get_attributes=%d dev=%d\n",
 953                               _LLU(obj->id),
 954                               ios->in_attr_len, first_dev);
 955         }
 956         if (ios->out_attr)
 957                 osd_req_add_set_attr_list(or, ios->out_attr, ios->out_attr_len);
 958
 959         if (ios->in_attr)
 960                 osd_req_add_get_attr_list(or, ios->in_attr, ios->in_attr_len);
 961
 962         return 0;
 963 }
 964
 965 int ore_read(struct ore_io_state *ios)
 966 {
 967         int i;
 968         int ret;
 969
 970         ret = _prepare_for_striping(ios);
 971         if (unlikely(ret))
 972                 return ret;
 973
 974         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
 975                 ret = _ore_read_mirror(ios, i);
 976                 if (unlikely(ret))
 977                         return ret;
 978         }
 979
 980         ret = ore_io_execute(ios);
 981         return ret;
 982 }
 983 EXPORT_SYMBOL(ore_read);
 984
 985 int extract_attr_from_ios(struct ore_io_state *ios, struct osd_attr *attr)
 986 {
 987         struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
 988         void *iter = NULL;
 989         int nelem;
 990
 991         do {
 992                 nelem = 1;
 993                 osd_req_decode_get_attr_list(ios->per_dev[0].or,
 994                                              &cur_attr, &nelem, &iter);
 995                 if ((cur_attr.attr_page == attr->attr_page) &&
 996                     (cur_attr.attr_id == attr->attr_id)) {
 997                         attr->len = cur_attr.len;
 998                         attr->val_ptr = cur_attr.val_ptr;
 999                         return 0;
1000                 }
1001         } while (iter);
1002
1003         return -EIO;
1004 }
1005 EXPORT_SYMBOL(extract_attr_from_ios);
1006
1007 static int _truncate_mirrors(struct ore_io_state *ios, unsigned cur_comp,
1008                              struct osd_attr *attr)
1009 {
1010         int last_comp = cur_comp + ios->layout->mirrors_p1;
1011
1012         for (; cur_comp < last_comp; ++cur_comp) {
1013                 struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
1014                 struct osd_request *or;
1015
1016                 or = osd_start_request(_ios_od(ios, cur_comp), GFP_KERNEL);
1017                 if (unlikely(!or)) {
1018                         ORE_ERR("%s: osd_start_request failed\n", __func__);
1019                         return -ENOMEM;
1020                 }
1021                 per_dev->or = or;
1022
1023                 osd_req_set_attributes(or, _ios_obj(ios, cur_comp));
1024                 osd_req_add_set_attr_list(or, attr, 1);
1025         }
1026
1027         return 0;
1028 }
1029
1030 struct _trunc_info {
1031         struct ore_striping_info si;
1032         u64 prev_group_obj_off;
1033         u64 next_group_obj_off;
1034
1035         unsigned first_group_dev;
1036         unsigned nex_group_dev;
1037 };
1038
1039 static void _calc_trunk_info(struct ore_layout *layout, u64 file_offset,
1040                              struct _trunc_info *ti)
1041 {
1042         unsigned stripe_unit = layout->stripe_unit;
1043
1044         ore_calc_stripe_info(layout, file_offset, 0, &ti->si);
1045
1046         ti->prev_group_obj_off = ti->si.M * stripe_unit;
1047         ti->next_group_obj_off = ti->si.M ? (ti->si.M - 1) * stripe_unit : 0;
1048
1049         ti->first_group_dev = ti->si.dev - (ti->si.dev % layout->group_width);
1050         ti->nex_group_dev = ti->first_group_dev + layout->group_width;
1051 }
1052
1053 int ore_truncate(struct ore_layout *layout, struct ore_components *oc,
1054                    u64 size)
1055 {
1056         struct ore_io_state *ios;
1057         struct exofs_trunc_attr {
1058                 struct osd_attr attr;
1059                 __be64 newsize;
1060         } *size_attrs;
1061         struct _trunc_info ti;
1062         int i, ret;
1063
1064         ret = ore_get_io_state(layout, oc, &ios);
1065         if (unlikely(ret))
1066                 return ret;
1067
1068         _calc_trunk_info(ios->layout, size, &ti);
1069
1070         size_attrs = kcalloc(ios->oc->numdevs, sizeof(*size_attrs),
1071                              GFP_KERNEL);
1072         if (unlikely(!size_attrs)) {
1073                 ret = -ENOMEM;
1074                 goto out;
1075         }
1076
1077         ios->numdevs = ios->oc->numdevs;
1078
1079         for (i = 0; i < ios->numdevs; ++i) {
1080                 struct exofs_trunc_attr *size_attr = &size_attrs[i];
1081                 u64 obj_size;
1082
1083                 if (i < ti.first_group_dev)
1084                         obj_size = ti.prev_group_obj_off;
1085                 else if (i >= ti.nex_group_dev)
1086                         obj_size = ti.next_group_obj_off;
1087                 else if (i < ti.si.dev) /* dev within this group */
1088                         obj_size = ti.si.obj_offset +
1089                                       ios->layout->stripe_unit - ti.si.unit_off;
1090                 else if (i == ti.si.dev)
1091                         obj_size = ti.si.obj_offset;
1092                 else /* i > ti.dev */
1093                         obj_size = ti.si.obj_offset - ti.si.unit_off;
1094
1095                 size_attr->newsize = cpu_to_be64(obj_size);
1096                 size_attr->attr = g_attr_logical_length;
1097                 size_attr->attr.val_ptr = &size_attr->newsize;
1098
1099                 ORE_DBGMSG("trunc(0x%llx) obj_offset=0x%llx dev=%d\n",
1100                              _LLU(oc->comps->obj.id), _LLU(obj_size), i);
1101                 ret = _truncate_mirrors(ios, i * ios->layout->mirrors_p1,
1102                                         &size_attr->attr);
1103                 if (unlikely(ret))
1104                         goto out;
1105         }
1106         ret = ore_io_execute(ios);
1107
1108 out:
1109         kfree(size_attrs);
1110         ore_put_io_state(ios);
1111         return ret;
1112 }
1113 EXPORT_SYMBOL(ore_truncate);
1114
1115 const struct osd_attr g_attr_logical_length = ATTR_DEF(
1116         OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
1117 EXPORT_SYMBOL(g_attr_logical_length);