linux/fs/exofs/ore.c
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   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 <linux/module.h>
  27#include <asm/div64.h>
  28#include <linux/lcm.h>
  29
  30#include "ore_raid.h"
  31
  32MODULE_AUTHOR("Boaz Harrosh <bharrosh@panasas.com>");
  33MODULE_DESCRIPTION("Objects Raid Engine ore.ko");
  34MODULE_LICENSE("GPL");
  35
  36/* ore_verify_layout does a couple of things:
  37 * 1. Given a minimum number of needed parameters fixes up the rest of the
  38 *    members to be operatonals for the ore. The needed parameters are those
  39 *    that are defined by the pnfs-objects layout STD.
  40 * 2. Check to see if the current ore code actually supports these parameters
  41 *    for example stripe_unit must be a multple of the system PAGE_SIZE,
  42 *    and etc...
  43 * 3. Cache some havily used calculations that will be needed by users.
  44 */
  45
  46enum { BIO_MAX_PAGES_KMALLOC =
  47                (PAGE_SIZE - sizeof(struct bio)) / sizeof(struct bio_vec),};
  48
  49int ore_verify_layout(unsigned total_comps, struct ore_layout *layout)
  50{
  51        u64 stripe_length;
  52
  53        switch (layout->raid_algorithm) {
  54        case PNFS_OSD_RAID_0:
  55                layout->parity = 0;
  56                break;
  57        case PNFS_OSD_RAID_5:
  58                layout->parity = 1;
  59                break;
  60        case PNFS_OSD_RAID_PQ:
  61        case PNFS_OSD_RAID_4:
  62        default:
  63                ORE_ERR("Only RAID_0/5 for now\n");
  64                return -EINVAL;
  65        }
  66        if (0 != (layout->stripe_unit & ~PAGE_MASK)) {
  67                ORE_ERR("Stripe Unit(0x%llx)"
  68                          " must be Multples of PAGE_SIZE(0x%lx)\n",
  69                          _LLU(layout->stripe_unit), PAGE_SIZE);
  70                return -EINVAL;
  71        }
  72        if (layout->group_width) {
  73                if (!layout->group_depth) {
  74                        ORE_ERR("group_depth == 0 && group_width != 0\n");
  75                        return -EINVAL;
  76                }
  77                if (total_comps < (layout->group_width * layout->mirrors_p1)) {
  78                        ORE_ERR("Data Map wrong, "
  79                                "numdevs=%d < group_width=%d * mirrors=%d\n",
  80                                total_comps, layout->group_width,
  81                                layout->mirrors_p1);
  82                        return -EINVAL;
  83                }
  84                layout->group_count = total_comps / layout->mirrors_p1 /
  85                                                layout->group_width;
  86        } else {
  87                if (layout->group_depth) {
  88                        printk(KERN_NOTICE "Warning: group_depth ignored "
  89                                "group_width == 0 && group_depth == %lld\n",
  90                                _LLU(layout->group_depth));
  91                }
  92                layout->group_width = total_comps / layout->mirrors_p1;
  93                layout->group_depth = -1;
  94                layout->group_count = 1;
  95        }
  96
  97        stripe_length = (u64)layout->group_width * layout->stripe_unit;
  98        if (stripe_length >= (1ULL << 32)) {
  99                ORE_ERR("Stripe_length(0x%llx) >= 32bit is not supported\n",
 100                        _LLU(stripe_length));
 101                return -EINVAL;
 102        }
 103
 104        layout->max_io_length =
 105                (BIO_MAX_PAGES_KMALLOC * PAGE_SIZE - layout->stripe_unit) *
 106                                                        layout->group_width;
 107        if (layout->parity) {
 108                unsigned stripe_length =
 109                                (layout->group_width - layout->parity) *
 110                                layout->stripe_unit;
 111
 112                layout->max_io_length /= stripe_length;
 113                layout->max_io_length *= stripe_length;
 114        }
 115        return 0;
 116}
 117EXPORT_SYMBOL(ore_verify_layout);
 118
 119static u8 *_ios_cred(struct ore_io_state *ios, unsigned index)
 120{
 121        return ios->oc->comps[index & ios->oc->single_comp].cred;
 122}
 123
 124static struct osd_obj_id *_ios_obj(struct ore_io_state *ios, unsigned index)
 125{
 126        return &ios->oc->comps[index & ios->oc->single_comp].obj;
 127}
 128
 129static struct osd_dev *_ios_od(struct ore_io_state *ios, unsigned index)
 130{
 131        ORE_DBGMSG2("oc->first_dev=%d oc->numdevs=%d i=%d oc->ods=%p\n",
 132                    ios->oc->first_dev, ios->oc->numdevs, index,
 133                    ios->oc->ods);
 134
 135        return ore_comp_dev(ios->oc, index);
 136}
 137
 138int  _ore_get_io_state(struct ore_layout *layout,
 139                        struct ore_components *oc, unsigned numdevs,
 140                        unsigned sgs_per_dev, unsigned num_par_pages,
 141                        struct ore_io_state **pios)
 142{
 143        struct ore_io_state *ios;
 144        struct page **pages;
 145        struct osd_sg_entry *sgilist;
 146        struct __alloc_all_io_state {
 147                struct ore_io_state ios;
 148                struct ore_per_dev_state per_dev[numdevs];
 149                union {
 150                        struct osd_sg_entry sglist[sgs_per_dev * numdevs];
 151                        struct page *pages[num_par_pages];
 152                };
 153        } *_aios;
 154
 155        if (likely(sizeof(*_aios) <= PAGE_SIZE)) {
 156                _aios = kzalloc(sizeof(*_aios), GFP_KERNEL);
 157                if (unlikely(!_aios)) {
 158                        ORE_DBGMSG("Failed kzalloc bytes=%zd\n",
 159                                   sizeof(*_aios));
 160                        *pios = NULL;
 161                        return -ENOMEM;
 162                }
 163                pages = num_par_pages ? _aios->pages : NULL;
 164                sgilist = sgs_per_dev ? _aios->sglist : NULL;
 165                ios = &_aios->ios;
 166        } else {
 167                struct __alloc_small_io_state {
 168                        struct ore_io_state ios;
 169                        struct ore_per_dev_state per_dev[numdevs];
 170                } *_aio_small;
 171                union __extra_part {
 172                        struct osd_sg_entry sglist[sgs_per_dev * numdevs];
 173                        struct page *pages[num_par_pages];
 174                } *extra_part;
 175
 176                _aio_small = kzalloc(sizeof(*_aio_small), GFP_KERNEL);
 177                if (unlikely(!_aio_small)) {
 178                        ORE_DBGMSG("Failed alloc first part bytes=%zd\n",
 179                                   sizeof(*_aio_small));
 180                        *pios = NULL;
 181                        return -ENOMEM;
 182                }
 183                extra_part = kzalloc(sizeof(*extra_part), GFP_KERNEL);
 184                if (unlikely(!extra_part)) {
 185                        ORE_DBGMSG("Failed alloc second part bytes=%zd\n",
 186                                   sizeof(*extra_part));
 187                        kfree(_aio_small);
 188                        *pios = NULL;
 189                        return -ENOMEM;
 190                }
 191
 192                pages = num_par_pages ? extra_part->pages : NULL;
 193                sgilist = sgs_per_dev ? extra_part->sglist : NULL;
 194                /* In this case the per_dev[0].sgilist holds the pointer to
 195                 * be freed
 196                 */
 197                ios = &_aio_small->ios;
 198                ios->extra_part_alloc = true;
 199        }
 200
 201        if (pages) {
 202                ios->parity_pages = pages;
 203                ios->max_par_pages = num_par_pages;
 204        }
 205        if (sgilist) {
 206                unsigned d;
 207
 208                for (d = 0; d < numdevs; ++d) {
 209                        ios->per_dev[d].sglist = sgilist;
 210                        sgilist += sgs_per_dev;
 211                }
 212                ios->sgs_per_dev = sgs_per_dev;
 213        }
 214
 215        ios->layout = layout;
 216        ios->oc = oc;
 217        *pios = ios;
 218        return 0;
 219}
 220
 221/* Allocate an io_state for only a single group of devices
 222 *
 223 * If a user needs to call ore_read/write() this version must be used becase it
 224 * allocates extra stuff for striping and raid.
 225 * The ore might decide to only IO less then @length bytes do to alignmets
 226 * and constrains as follows:
 227 * - The IO cannot cross group boundary.
 228 * - In raid5/6 The end of the IO must align at end of a stripe eg.
 229 *   (@offset + @length) % strip_size == 0. Or the complete range is within a
 230 *   single stripe.
 231 * - Memory condition only permitted a shorter IO. (A user can use @length=~0
 232 *   And check the returned ios->length for max_io_size.)
 233 *
 234 * The caller must check returned ios->length (and/or ios->nr_pages) and
 235 * re-issue these pages that fall outside of ios->length
 236 */
 237int  ore_get_rw_state(struct ore_layout *layout, struct ore_components *oc,
 238                      bool is_reading, u64 offset, u64 length,
 239                      struct ore_io_state **pios)
 240{
 241        struct ore_io_state *ios;
 242        unsigned numdevs = layout->group_width * layout->mirrors_p1;
 243        unsigned sgs_per_dev = 0, max_par_pages = 0;
 244        int ret;
 245
 246        if (layout->parity && length) {
 247                unsigned data_devs = layout->group_width - layout->parity;
 248                unsigned stripe_size = layout->stripe_unit * data_devs;
 249                unsigned pages_in_unit = layout->stripe_unit / PAGE_SIZE;
 250                u32 remainder;
 251                u64 num_stripes;
 252                u64 num_raid_units;
 253
 254                num_stripes = div_u64_rem(length, stripe_size, &remainder);
 255                if (remainder)
 256                        ++num_stripes;
 257
 258                num_raid_units =  num_stripes * layout->parity;
 259
 260                if (is_reading) {
 261                        /* For reads add per_dev sglist array */
 262                        /* TODO: Raid 6 we need twice more. Actually:
 263                        *         num_stripes / LCMdP(W,P);
 264                        *         if (W%P != 0) num_stripes *= parity;
 265                        */
 266
 267                        /* first/last seg is split */
 268                        num_raid_units += layout->group_width;
 269                        sgs_per_dev = div_u64(num_raid_units, data_devs) + 2;
 270                } else {
 271                        /* For Writes add parity pages array. */
 272                        max_par_pages = num_raid_units * pages_in_unit *
 273                                                sizeof(struct page *);
 274                }
 275        }
 276
 277        ret = _ore_get_io_state(layout, oc, numdevs, sgs_per_dev, max_par_pages,
 278                                pios);
 279        if (unlikely(ret))
 280                return ret;
 281
 282        ios = *pios;
 283        ios->reading = is_reading;
 284        ios->offset = offset;
 285
 286        if (length) {
 287                ore_calc_stripe_info(layout, offset, length, &ios->si);
 288                ios->length = ios->si.length;
 289                ios->nr_pages = (ios->length + PAGE_SIZE - 1) / PAGE_SIZE;
 290                if (layout->parity)
 291                        _ore_post_alloc_raid_stuff(ios);
 292        }
 293
 294        return 0;
 295}
 296EXPORT_SYMBOL(ore_get_rw_state);
 297
 298/* Allocate an io_state for all the devices in the comps array
 299 *
 300 * This version of io_state allocation is used mostly by create/remove
 301 * and trunc where we currently need all the devices. The only wastful
 302 * bit is the read/write_attributes with no IO. Those sites should
 303 * be converted to use ore_get_rw_state() with length=0
 304 */
 305int  ore_get_io_state(struct ore_layout *layout, struct ore_components *oc,
 306                      struct ore_io_state **pios)
 307{
 308        return _ore_get_io_state(layout, oc, oc->numdevs, 0, 0, pios);
 309}
 310EXPORT_SYMBOL(ore_get_io_state);
 311
 312void ore_put_io_state(struct ore_io_state *ios)
 313{
 314        if (ios) {
 315                unsigned i;
 316
 317                for (i = 0; i < ios->numdevs; i++) {
 318                        struct ore_per_dev_state *per_dev = &ios->per_dev[i];
 319
 320                        if (per_dev->or)
 321                                osd_end_request(per_dev->or);
 322                        if (per_dev->bio)
 323                                bio_put(per_dev->bio);
 324                }
 325
 326                _ore_free_raid_stuff(ios);
 327                kfree(ios);
 328        }
 329}
 330EXPORT_SYMBOL(ore_put_io_state);
 331
 332static void _sync_done(struct ore_io_state *ios, void *p)
 333{
 334        struct completion *waiting = p;
 335
 336        complete(waiting);
 337}
 338
 339static void _last_io(struct kref *kref)
 340{
 341        struct ore_io_state *ios = container_of(
 342                                        kref, struct ore_io_state, kref);
 343
 344        ios->done(ios, ios->private);
 345}
 346
 347static void _done_io(struct osd_request *or, void *p)
 348{
 349        struct ore_io_state *ios = p;
 350
 351        kref_put(&ios->kref, _last_io);
 352}
 353
 354int ore_io_execute(struct ore_io_state *ios)
 355{
 356        DECLARE_COMPLETION_ONSTACK(wait);
 357        bool sync = (ios->done == NULL);
 358        int i, ret;
 359
 360        if (sync) {
 361                ios->done = _sync_done;
 362                ios->private = &wait;
 363        }
 364
 365        for (i = 0; i < ios->numdevs; i++) {
 366                struct osd_request *or = ios->per_dev[i].or;
 367                if (unlikely(!or))
 368                        continue;
 369
 370                ret = osd_finalize_request(or, 0, _ios_cred(ios, i), NULL);
 371                if (unlikely(ret)) {
 372                        ORE_DBGMSG("Failed to osd_finalize_request() => %d\n",
 373                                     ret);
 374                        return ret;
 375                }
 376        }
 377
 378        kref_init(&ios->kref);
 379
 380        for (i = 0; i < ios->numdevs; i++) {
 381                struct osd_request *or = ios->per_dev[i].or;
 382                if (unlikely(!or))
 383                        continue;
 384
 385                kref_get(&ios->kref);
 386                osd_execute_request_async(or, _done_io, ios);
 387        }
 388
 389        kref_put(&ios->kref, _last_io);
 390        ret = 0;
 391
 392        if (sync) {
 393                wait_for_completion(&wait);
 394                ret = ore_check_io(ios, NULL);
 395        }
 396        return ret;
 397}
 398
 399static void _clear_bio(struct bio *bio)
 400{
 401        struct bio_vec *bv;
 402        unsigned i;
 403
 404        __bio_for_each_segment(bv, bio, i, 0) {
 405                unsigned this_count = bv->bv_len;
 406
 407                if (likely(PAGE_SIZE == this_count))
 408                        clear_highpage(bv->bv_page);
 409                else
 410                        zero_user(bv->bv_page, bv->bv_offset, this_count);
 411        }
 412}
 413
 414int ore_check_io(struct ore_io_state *ios, ore_on_dev_error on_dev_error)
 415{
 416        enum osd_err_priority acumulated_osd_err = 0;
 417        int acumulated_lin_err = 0;
 418        int i;
 419
 420        for (i = 0; i < ios->numdevs; i++) {
 421                struct osd_sense_info osi;
 422                struct ore_per_dev_state *per_dev = &ios->per_dev[i];
 423                struct osd_request *or = per_dev->or;
 424                int ret;
 425
 426                if (unlikely(!or))
 427                        continue;
 428
 429                ret = osd_req_decode_sense(or, &osi);
 430                if (likely(!ret))
 431                        continue;
 432
 433                if (OSD_ERR_PRI_CLEAR_PAGES == osi.osd_err_pri) {
 434                        /* start read offset passed endof file */
 435                        _clear_bio(per_dev->bio);
 436                        ORE_DBGMSG("start read offset passed end of file "
 437                                "offset=0x%llx, length=0x%llx\n",
 438                                _LLU(per_dev->offset),
 439                                _LLU(per_dev->length));
 440
 441                        continue; /* we recovered */
 442                }
 443
 444                if (on_dev_error) {
 445                        u64 residual = ios->reading ?
 446                                        or->in.residual : or->out.residual;
 447                        u64 offset = (ios->offset + ios->length) - residual;
 448                        unsigned dev = per_dev->dev - ios->oc->first_dev;
 449                        struct ore_dev *od = ios->oc->ods[dev];
 450
 451                        on_dev_error(ios, od, dev, osi.osd_err_pri,
 452                                     offset, residual);
 453                }
 454                if (osi.osd_err_pri >= acumulated_osd_err) {
 455                        acumulated_osd_err = osi.osd_err_pri;
 456                        acumulated_lin_err = ret;
 457                }
 458        }
 459
 460        return acumulated_lin_err;
 461}
 462EXPORT_SYMBOL(ore_check_io);
 463
 464/*
 465 * L - logical offset into the file
 466 *
 467 * D - number of Data devices
 468 *      D = group_width - parity
 469 *
 470 * U - The number of bytes in a stripe within a group
 471 *      U =  stripe_unit * D
 472 *
 473 * T - The number of bytes striped within a group of component objects
 474 *     (before advancing to the next group)
 475 *      T = U * group_depth
 476 *
 477 * S - The number of bytes striped across all component objects
 478 *     before the pattern repeats
 479 *      S = T * group_count
 480 *
 481 * M - The "major" (i.e., across all components) cycle number
 482 *      M = L / S
 483 *
 484 * G - Counts the groups from the beginning of the major cycle
 485 *      G = (L - (M * S)) / T   [or (L % S) / T]
 486 *
 487 * H - The byte offset within the group
 488 *      H = (L - (M * S)) % T   [or (L % S) % T]
 489 *
 490 * N - The "minor" (i.e., across the group) stripe number
 491 *      N = H / U
 492 *
 493 * C - The component index coresponding to L
 494 *
 495 *      C = (H - (N * U)) / stripe_unit + G * D
 496 *      [or (L % U) / stripe_unit + G * D]
 497 *
 498 * O - The component offset coresponding to L
 499 *      O = L % stripe_unit + N * stripe_unit + M * group_depth * stripe_unit
 500 *
 501 * LCMdP – Parity cycle: Lowest Common Multiple of group_width, parity
 502 *          divide by parity
 503 *      LCMdP = lcm(group_width, parity) / parity
 504 *
 505 * R - The parity Rotation stripe
 506 *     (Note parity cycle always starts at a group's boundary)
 507 *      R = N % LCMdP
 508 *
 509 * I = the first parity device index
 510 *      I = (group_width + group_width - R*parity - parity) % group_width
 511 *
 512 * Craid - The component index Rotated
 513 *      Craid = (group_width + C - R*parity) % group_width
 514 *      (We add the group_width to avoid negative numbers modulo math)
 515 */
 516void ore_calc_stripe_info(struct ore_layout *layout, u64 file_offset,
 517                          u64 length, struct ore_striping_info *si)
 518{
 519        u32     stripe_unit = layout->stripe_unit;
 520        u32     group_width = layout->group_width;
 521        u64     group_depth = layout->group_depth;
 522        u32     parity      = layout->parity;
 523
 524        u32     D = group_width - parity;
 525        u32     U = D * stripe_unit;
 526        u64     T = U * group_depth;
 527        u64     S = T * layout->group_count;
 528        u64     M = div64_u64(file_offset, S);
 529
 530        /*
 531        G = (L - (M * S)) / T
 532        H = (L - (M * S)) % T
 533        */
 534        u64     LmodS = file_offset - M * S;
 535        u32     G = div64_u64(LmodS, T);
 536        u64     H = LmodS - G * T;
 537
 538        u32     N = div_u64(H, U);
 539
 540        /* "H - (N * U)" is just "H % U" so it's bound to u32 */
 541        u32     C = (u32)(H - (N * U)) / stripe_unit + G * group_width;
 542
 543        div_u64_rem(file_offset, stripe_unit, &si->unit_off);
 544
 545        si->obj_offset = si->unit_off + (N * stripe_unit) +
 546                                  (M * group_depth * stripe_unit);
 547
 548        if (parity) {
 549                u32 LCMdP = lcm(group_width, parity) / parity;
 550                /* R     = N % LCMdP; */
 551                u32 RxP   = (N % LCMdP) * parity;
 552                u32 first_dev = C - C % group_width;
 553
 554                si->par_dev = (group_width + group_width - parity - RxP) %
 555                              group_width + first_dev;
 556                si->dev = (group_width + C - RxP) % group_width + first_dev;
 557                si->bytes_in_stripe = U;
 558                si->first_stripe_start = M * S + G * T + N * U;
 559        } else {
 560                /* Make the math correct see _prepare_one_group */
 561                si->par_dev = group_width;
 562                si->dev = C;
 563        }
 564
 565        si->dev *= layout->mirrors_p1;
 566        si->par_dev *= layout->mirrors_p1;
 567        si->offset = file_offset;
 568        si->length = T - H;
 569        if (si->length > length)
 570                si->length = length;
 571        si->M = M;
 572}
 573EXPORT_SYMBOL(ore_calc_stripe_info);
 574
 575int _ore_add_stripe_unit(struct ore_io_state *ios,  unsigned *cur_pg,
 576                         unsigned pgbase, struct page **pages,
 577                         struct ore_per_dev_state *per_dev, int cur_len)
 578{
 579        unsigned pg = *cur_pg;
 580        struct request_queue *q =
 581                        osd_request_queue(_ios_od(ios, per_dev->dev));
 582        unsigned len = cur_len;
 583        int ret;
 584
 585        if (per_dev->bio == NULL) {
 586                unsigned pages_in_stripe = ios->layout->group_width *
 587                                        (ios->layout->stripe_unit / PAGE_SIZE);
 588                unsigned nr_pages = ios->nr_pages * ios->layout->group_width /
 589                                        (ios->layout->group_width -
 590                                         ios->layout->parity);
 591                unsigned bio_size = (nr_pages + pages_in_stripe) /
 592                                        ios->layout->group_width;
 593
 594                per_dev->bio = bio_kmalloc(GFP_KERNEL, bio_size);
 595                if (unlikely(!per_dev->bio)) {
 596                        ORE_DBGMSG("Failed to allocate BIO size=%u\n",
 597                                     bio_size);
 598                        ret = -ENOMEM;
 599                        goto out;
 600                }
 601        }
 602
 603        while (cur_len > 0) {
 604                unsigned pglen = min_t(unsigned, PAGE_SIZE - pgbase, cur_len);
 605                unsigned added_len;
 606
 607                cur_len -= pglen;
 608
 609                added_len = bio_add_pc_page(q, per_dev->bio, pages[pg],
 610                                            pglen, pgbase);
 611                if (unlikely(pglen != added_len)) {
 612                        ORE_DBGMSG("Failed bio_add_pc_page bi_vcnt=%u\n",
 613                                   per_dev->bio->bi_vcnt);
 614                        ret = -ENOMEM;
 615                        goto out;
 616                }
 617                _add_stripe_page(ios->sp2d, &ios->si, pages[pg]);
 618
 619                pgbase = 0;
 620                ++pg;
 621        }
 622        BUG_ON(cur_len);
 623
 624        per_dev->length += len;
 625        *cur_pg = pg;
 626        ret = 0;
 627out:    /* we fail the complete unit on an error eg don't advance
 628         * per_dev->length and cur_pg. This means that we might have a bigger
 629         * bio than the CDB requested length (per_dev->length). That's fine
 630         * only the oposite is fatal.
 631         */
 632        return ret;
 633}
 634
 635static int _prepare_for_striping(struct ore_io_state *ios)
 636{
 637        struct ore_striping_info *si = &ios->si;
 638        unsigned stripe_unit = ios->layout->stripe_unit;
 639        unsigned mirrors_p1 = ios->layout->mirrors_p1;
 640        unsigned group_width = ios->layout->group_width;
 641        unsigned devs_in_group = group_width * mirrors_p1;
 642        unsigned dev = si->dev;
 643        unsigned first_dev = dev - (dev % devs_in_group);
 644        unsigned dev_order;
 645        unsigned cur_pg = ios->pages_consumed;
 646        u64 length = ios->length;
 647        int ret = 0;
 648
 649        if (!ios->pages) {
 650                ios->numdevs = ios->layout->mirrors_p1;
 651                return 0;
 652        }
 653
 654        BUG_ON(length > si->length);
 655
 656        dev_order = _dev_order(devs_in_group, mirrors_p1, si->par_dev, dev);
 657        si->cur_comp = dev_order;
 658        si->cur_pg = si->unit_off / PAGE_SIZE;
 659
 660        while (length) {
 661                unsigned comp = dev - first_dev;
 662                struct ore_per_dev_state *per_dev = &ios->per_dev[comp];
 663                unsigned cur_len, page_off = 0;
 664
 665                if (!per_dev->length) {
 666                        per_dev->dev = dev;
 667                        if (dev == si->dev) {
 668                                WARN_ON(dev == si->par_dev);
 669                                per_dev->offset = si->obj_offset;
 670                                cur_len = stripe_unit - si->unit_off;
 671                                page_off = si->unit_off & ~PAGE_MASK;
 672                                BUG_ON(page_off && (page_off != ios->pgbase));
 673                        } else {
 674                                if (si->cur_comp > dev_order)
 675                                        per_dev->offset =
 676                                                si->obj_offset - si->unit_off;
 677                                else /* si->cur_comp < dev_order */
 678                                        per_dev->offset =
 679                                                si->obj_offset + stripe_unit -
 680                                                                   si->unit_off;
 681                                cur_len = stripe_unit;
 682                        }
 683                } else {
 684                        cur_len = stripe_unit;
 685                }
 686                if (cur_len >= length)
 687                        cur_len = length;
 688
 689                ret = _ore_add_stripe_unit(ios, &cur_pg, page_off, ios->pages,
 690                                           per_dev, cur_len);
 691                if (unlikely(ret))
 692                        goto out;
 693
 694                dev += mirrors_p1;
 695                dev = (dev % devs_in_group) + first_dev;
 696
 697                length -= cur_len;
 698
 699                si->cur_comp = (si->cur_comp + 1) % group_width;
 700                if (unlikely((dev == si->par_dev) || (!length && ios->sp2d))) {
 701                        if (!length && ios->sp2d) {
 702                                /* If we are writing and this is the very last
 703                                 * stripe. then operate on parity dev.
 704                                 */
 705                                dev = si->par_dev;
 706                        }
 707                        if (ios->sp2d)
 708                                /* In writes cur_len just means if it's the
 709                                 * last one. See _ore_add_parity_unit.
 710                                 */
 711                                cur_len = length;
 712                        per_dev = &ios->per_dev[dev - first_dev];
 713                        if (!per_dev->length) {
 714                                /* Only/always the parity unit of the first
 715                                 * stripe will be empty. So this is a chance to
 716                                 * initialize the per_dev info.
 717                                 */
 718                                per_dev->dev = dev;
 719                                per_dev->offset = si->obj_offset - si->unit_off;
 720                        }
 721
 722                        ret = _ore_add_parity_unit(ios, si, per_dev, cur_len);
 723                        if (unlikely(ret))
 724                                        goto out;
 725
 726                        /* Rotate next par_dev backwards with wraping */
 727                        si->par_dev = (devs_in_group + si->par_dev -
 728                                       ios->layout->parity * mirrors_p1) %
 729                                      devs_in_group + first_dev;
 730                        /* Next stripe, start fresh */
 731                        si->cur_comp = 0;
 732                        si->cur_pg = 0;
 733                }
 734        }
 735out:
 736        ios->numdevs = devs_in_group;
 737        ios->pages_consumed = cur_pg;
 738        return ret;
 739}
 740
 741int ore_create(struct ore_io_state *ios)
 742{
 743        int i, ret;
 744
 745        for (i = 0; i < ios->oc->numdevs; i++) {
 746                struct osd_request *or;
 747
 748                or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
 749                if (unlikely(!or)) {
 750                        ORE_ERR("%s: osd_start_request failed\n", __func__);
 751                        ret = -ENOMEM;
 752                        goto out;
 753                }
 754                ios->per_dev[i].or = or;
 755                ios->numdevs++;
 756
 757                osd_req_create_object(or, _ios_obj(ios, i));
 758        }
 759        ret = ore_io_execute(ios);
 760
 761out:
 762        return ret;
 763}
 764EXPORT_SYMBOL(ore_create);
 765
 766int ore_remove(struct ore_io_state *ios)
 767{
 768        int i, ret;
 769
 770        for (i = 0; i < ios->oc->numdevs; i++) {
 771                struct osd_request *or;
 772
 773                or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
 774                if (unlikely(!or)) {
 775                        ORE_ERR("%s: osd_start_request failed\n", __func__);
 776                        ret = -ENOMEM;
 777                        goto out;
 778                }
 779                ios->per_dev[i].or = or;
 780                ios->numdevs++;
 781
 782                osd_req_remove_object(or, _ios_obj(ios, i));
 783        }
 784        ret = ore_io_execute(ios);
 785
 786out:
 787        return ret;
 788}
 789EXPORT_SYMBOL(ore_remove);
 790
 791static int _write_mirror(struct ore_io_state *ios, int cur_comp)
 792{
 793        struct ore_per_dev_state *master_dev = &ios->per_dev[cur_comp];
 794        unsigned dev = ios->per_dev[cur_comp].dev;
 795        unsigned last_comp = cur_comp + ios->layout->mirrors_p1;
 796        int ret = 0;
 797
 798        if (ios->pages && !master_dev->length)
 799                return 0; /* Just an empty slot */
 800
 801        for (; cur_comp < last_comp; ++cur_comp, ++dev) {
 802                struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
 803                struct osd_request *or;
 804
 805                or = osd_start_request(_ios_od(ios, dev), GFP_KERNEL);
 806                if (unlikely(!or)) {
 807                        ORE_ERR("%s: osd_start_request failed\n", __func__);
 808                        ret = -ENOMEM;
 809                        goto out;
 810                }
 811                per_dev->or = or;
 812
 813                if (ios->pages) {
 814                        struct bio *bio;
 815
 816                        if (per_dev != master_dev) {
 817                                bio = bio_clone_kmalloc(master_dev->bio,
 818                                                        GFP_KERNEL);
 819                                if (unlikely(!bio)) {
 820                                        ORE_DBGMSG(
 821                                              "Failed to allocate BIO size=%u\n",
 822                                              master_dev->bio->bi_max_vecs);
 823                                        ret = -ENOMEM;
 824                                        goto out;
 825                                }
 826
 827                                bio->bi_bdev = NULL;
 828                                bio->bi_next = NULL;
 829                                per_dev->offset = master_dev->offset;
 830                                per_dev->length = master_dev->length;
 831                                per_dev->bio =  bio;
 832                                per_dev->dev = dev;
 833                        } else {
 834                                bio = master_dev->bio;
 835                                /* FIXME: bio_set_dir() */
 836                                bio->bi_rw |= REQ_WRITE;
 837                        }
 838
 839                        osd_req_write(or, _ios_obj(ios, cur_comp),
 840                                      per_dev->offset, bio, per_dev->length);
 841                        ORE_DBGMSG("write(0x%llx) offset=0x%llx "
 842                                      "length=0x%llx dev=%d\n",
 843                                     _LLU(_ios_obj(ios, cur_comp)->id),
 844                                     _LLU(per_dev->offset),
 845                                     _LLU(per_dev->length), dev);
 846                } else if (ios->kern_buff) {
 847                        per_dev->offset = ios->si.obj_offset;
 848                        per_dev->dev = ios->si.dev + dev;
 849
 850                        /* no cross device without page array */
 851                        BUG_ON((ios->layout->group_width > 1) &&
 852                               (ios->si.unit_off + ios->length >
 853                                ios->layout->stripe_unit));
 854
 855                        ret = osd_req_write_kern(or, _ios_obj(ios, cur_comp),
 856                                                 per_dev->offset,
 857                                                 ios->kern_buff, ios->length);
 858                        if (unlikely(ret))
 859                                goto out;
 860                        ORE_DBGMSG2("write_kern(0x%llx) offset=0x%llx "
 861                                      "length=0x%llx dev=%d\n",
 862                                     _LLU(_ios_obj(ios, cur_comp)->id),
 863                                     _LLU(per_dev->offset),
 864                                     _LLU(ios->length), per_dev->dev);
 865                } else {
 866                        osd_req_set_attributes(or, _ios_obj(ios, cur_comp));
 867                        ORE_DBGMSG2("obj(0x%llx) set_attributes=%d dev=%d\n",
 868                                     _LLU(_ios_obj(ios, cur_comp)->id),
 869                                     ios->out_attr_len, dev);
 870                }
 871
 872                if (ios->out_attr)
 873                        osd_req_add_set_attr_list(or, ios->out_attr,
 874                                                  ios->out_attr_len);
 875
 876                if (ios->in_attr)
 877                        osd_req_add_get_attr_list(or, ios->in_attr,
 878                                                  ios->in_attr_len);
 879        }
 880
 881out:
 882        return ret;
 883}
 884
 885int ore_write(struct ore_io_state *ios)
 886{
 887        int i;
 888        int ret;
 889
 890        if (unlikely(ios->sp2d && !ios->r4w)) {
 891                /* A library is attempting a RAID-write without providing
 892                 * a pages lock interface.
 893                 */
 894                WARN_ON_ONCE(1);
 895                return -ENOTSUPP;
 896        }
 897
 898        ret = _prepare_for_striping(ios);
 899        if (unlikely(ret))
 900                return ret;
 901
 902        for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
 903                ret = _write_mirror(ios, i);
 904                if (unlikely(ret))
 905                        return ret;
 906        }
 907
 908        ret = ore_io_execute(ios);
 909        return ret;
 910}
 911EXPORT_SYMBOL(ore_write);
 912
 913int _ore_read_mirror(struct ore_io_state *ios, unsigned cur_comp)
 914{
 915        struct osd_request *or;
 916        struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
 917        struct osd_obj_id *obj = _ios_obj(ios, cur_comp);
 918        unsigned first_dev = (unsigned)obj->id;
 919
 920        if (ios->pages && !per_dev->length)
 921                return 0; /* Just an empty slot */
 922
 923        first_dev = per_dev->dev + first_dev % ios->layout->mirrors_p1;
 924        or = osd_start_request(_ios_od(ios, first_dev), GFP_KERNEL);
 925        if (unlikely(!or)) {
 926                ORE_ERR("%s: osd_start_request failed\n", __func__);
 927                return -ENOMEM;
 928        }
 929        per_dev->or = or;
 930
 931        if (ios->pages) {
 932                if (per_dev->cur_sg) {
 933                        /* finalize the last sg_entry */
 934                        _ore_add_sg_seg(per_dev, 0, false);
 935                        if (unlikely(!per_dev->cur_sg))
 936                                return 0; /* Skip parity only device */
 937
 938                        osd_req_read_sg(or, obj, per_dev->bio,
 939                                        per_dev->sglist, per_dev->cur_sg);
 940                } else {
 941                        /* The no raid case */
 942                        osd_req_read(or, obj, per_dev->offset,
 943                                     per_dev->bio, per_dev->length);
 944                }
 945
 946                ORE_DBGMSG("read(0x%llx) offset=0x%llx length=0x%llx"
 947                             " dev=%d sg_len=%d\n", _LLU(obj->id),
 948                             _LLU(per_dev->offset), _LLU(per_dev->length),
 949                             first_dev, per_dev->cur_sg);
 950        } else {
 951                BUG_ON(ios->kern_buff);
 952
 953                osd_req_get_attributes(or, obj);
 954                ORE_DBGMSG2("obj(0x%llx) get_attributes=%d dev=%d\n",
 955                              _LLU(obj->id),
 956                              ios->in_attr_len, first_dev);
 957        }
 958        if (ios->out_attr)
 959                osd_req_add_set_attr_list(or, ios->out_attr, ios->out_attr_len);
 960
 961        if (ios->in_attr)
 962                osd_req_add_get_attr_list(or, ios->in_attr, ios->in_attr_len);
 963
 964        return 0;
 965}
 966
 967int ore_read(struct ore_io_state *ios)
 968{
 969        int i;
 970        int ret;
 971
 972        ret = _prepare_for_striping(ios);
 973        if (unlikely(ret))
 974                return ret;
 975
 976        for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
 977                ret = _ore_read_mirror(ios, i);
 978                if (unlikely(ret))
 979                        return ret;
 980        }
 981
 982        ret = ore_io_execute(ios);
 983        return ret;
 984}
 985EXPORT_SYMBOL(ore_read);
 986
 987int extract_attr_from_ios(struct ore_io_state *ios, struct osd_attr *attr)
 988{
 989        struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
 990        void *iter = NULL;
 991        int nelem;
 992
 993        do {
 994                nelem = 1;
 995                osd_req_decode_get_attr_list(ios->per_dev[0].or,
 996                                             &cur_attr, &nelem, &iter);
 997                if ((cur_attr.attr_page == attr->attr_page) &&
 998                    (cur_attr.attr_id == attr->attr_id)) {
 999                        attr->len = cur_attr.len;
1000                        attr->val_ptr = cur_attr.val_ptr;
1001                        return 0;
1002                }
1003        } while (iter);
1004
1005        return -EIO;
1006}
1007EXPORT_SYMBOL(extract_attr_from_ios);
1008
1009static int _truncate_mirrors(struct ore_io_state *ios, unsigned cur_comp,
1010                             struct osd_attr *attr)
1011{
1012        int last_comp = cur_comp + ios->layout->mirrors_p1;
1013
1014        for (; cur_comp < last_comp; ++cur_comp) {
1015                struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
1016                struct osd_request *or;
1017
1018                or = osd_start_request(_ios_od(ios, cur_comp), GFP_KERNEL);
1019                if (unlikely(!or)) {
1020                        ORE_ERR("%s: osd_start_request failed\n", __func__);
1021                        return -ENOMEM;
1022                }
1023                per_dev->or = or;
1024
1025                osd_req_set_attributes(or, _ios_obj(ios, cur_comp));
1026                osd_req_add_set_attr_list(or, attr, 1);
1027        }
1028
1029        return 0;
1030}
1031
1032struct _trunc_info {
1033        struct ore_striping_info si;
1034        u64 prev_group_obj_off;
1035        u64 next_group_obj_off;
1036
1037        unsigned first_group_dev;
1038        unsigned nex_group_dev;
1039};
1040
1041static void _calc_trunk_info(struct ore_layout *layout, u64 file_offset,
1042                             struct _trunc_info *ti)
1043{
1044        unsigned stripe_unit = layout->stripe_unit;
1045
1046        ore_calc_stripe_info(layout, file_offset, 0, &ti->si);
1047
1048        ti->prev_group_obj_off = ti->si.M * stripe_unit;
1049        ti->next_group_obj_off = ti->si.M ? (ti->si.M - 1) * stripe_unit : 0;
1050
1051        ti->first_group_dev = ti->si.dev - (ti->si.dev % layout->group_width);
1052        ti->nex_group_dev = ti->first_group_dev + layout->group_width;
1053}
1054
1055int ore_truncate(struct ore_layout *layout, struct ore_components *oc,
1056                   u64 size)
1057{
1058        struct ore_io_state *ios;
1059        struct exofs_trunc_attr {
1060                struct osd_attr attr;
1061                __be64 newsize;
1062        } *size_attrs;
1063        struct _trunc_info ti;
1064        int i, ret;
1065
1066        ret = ore_get_io_state(layout, oc, &ios);
1067        if (unlikely(ret))
1068                return ret;
1069
1070        _calc_trunk_info(ios->layout, size, &ti);
1071
1072        size_attrs = kcalloc(ios->oc->numdevs, sizeof(*size_attrs),
1073                             GFP_KERNEL);
1074        if (unlikely(!size_attrs)) {
1075                ret = -ENOMEM;
1076                goto out;
1077        }
1078
1079        ios->numdevs = ios->oc->numdevs;
1080
1081        for (i = 0; i < ios->numdevs; ++i) {
1082                struct exofs_trunc_attr *size_attr = &size_attrs[i];
1083                u64 obj_size;
1084
1085                if (i < ti.first_group_dev)
1086                        obj_size = ti.prev_group_obj_off;
1087                else if (i >= ti.nex_group_dev)
1088                        obj_size = ti.next_group_obj_off;
1089                else if (i < ti.si.dev) /* dev within this group */
1090                        obj_size = ti.si.obj_offset +
1091                                      ios->layout->stripe_unit - ti.si.unit_off;
1092                else if (i == ti.si.dev)
1093                        obj_size = ti.si.obj_offset;
1094                else /* i > ti.dev */
1095                        obj_size = ti.si.obj_offset - ti.si.unit_off;
1096
1097                size_attr->newsize = cpu_to_be64(obj_size);
1098                size_attr->attr = g_attr_logical_length;
1099                size_attr->attr.val_ptr = &size_attr->newsize;
1100
1101                ORE_DBGMSG("trunc(0x%llx) obj_offset=0x%llx dev=%d\n",
1102                             _LLU(oc->comps->obj.id), _LLU(obj_size), i);
1103                ret = _truncate_mirrors(ios, i * ios->layout->mirrors_p1,
1104                                        &size_attr->attr);
1105                if (unlikely(ret))
1106                        goto out;
1107        }
1108        ret = ore_io_execute(ios);
1109
1110out:
1111        kfree(size_attrs);
1112        ore_put_io_state(ios);
1113        return ret;
1114}
1115EXPORT_SYMBOL(ore_truncate);
1116
1117const struct osd_attr g_attr_logical_length = ATTR_DEF(
1118        OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
1119EXPORT_SYMBOL(g_attr_logical_length);
1120
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