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