fs/exofs/ios.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 <scsi/scsi_device.h>
  27 #include <asm/div64.h>
  28
  29 #include "exofs.h"
  30
  31 #define EXOFS_DBGMSG2(M...) do {} while (0)
  32 /* #define EXOFS_DBGMSG2 EXOFS_DBGMSG */
  33
  34 void exofs_make_credential(u8 cred_a[OSD_CAP_LEN], const struct osd_obj_id *obj)
  35 {
  36         osd_sec_init_nosec_doall_caps(cred_a, obj, false, true);
  37 }
  38
  39 int exofs_read_kern(struct osd_dev *od, u8 *cred, struct osd_obj_id *obj,
  40                     u64 offset, void *p, unsigned length)
  41 {
  42         struct osd_request *or = osd_start_request(od, GFP_KERNEL);
  43 /*      struct osd_sense_info osi = {.key = 0};*/
  44         int ret;
  45
  46         if (unlikely(!or)) {
  47                 EXOFS_DBGMSG("%s: osd_start_request failed.\n", __func__);
  48                 return -ENOMEM;
  49         }
  50         ret = osd_req_read_kern(or, obj, offset, p, length);
  51         if (unlikely(ret)) {
  52                 EXOFS_DBGMSG("%s: osd_req_read_kern failed.\n", __func__);
  53                 goto out;
  54         }
  55
  56         ret = osd_finalize_request(or, 0, cred, NULL);
  57         if (unlikely(ret)) {
  58                 EXOFS_DBGMSG("Faild to osd_finalize_request() => %d\n", ret);
  59                 goto out;
  60         }
  61
  62         ret = osd_execute_request(or);
  63         if (unlikely(ret))
  64                 EXOFS_DBGMSG("osd_execute_request() => %d\n", ret);
  65         /* osd_req_decode_sense(or, ret); */
  66
  67 out:
  68         osd_end_request(or);
  69         return ret;
  70 }
  71
  72 int exofs_get_io_state(struct exofs_layout *layout,
  73                        struct exofs_io_state **pios)
  74 {
  75         struct exofs_io_state *ios;
  76
  77         /*TODO: Maybe use kmem_cach per sbi of size
  78          * exofs_io_state_size(layout->s_numdevs)
  79          */
  80         ios = kzalloc(exofs_io_state_size(layout->s_numdevs), GFP_KERNEL);
  81         if (unlikely(!ios)) {
  82                 EXOFS_DBGMSG("Faild kzalloc bytes=%d\n",
  83                              exofs_io_state_size(layout->s_numdevs));
  84                 *pios = NULL;
  85                 return -ENOMEM;
  86         }
  87
  88         ios->layout = layout;
  89         ios->obj.partition = layout->s_pid;
  90         *pios = ios;
  91         return 0;
  92 }
  93
  94 void exofs_put_io_state(struct exofs_io_state *ios)
  95 {
  96         if (ios) {
  97                 unsigned i;
  98
  99                 for (i = 0; i < ios->numdevs; i++) {
 100                         struct exofs_per_dev_state *per_dev = &ios->per_dev[i];
 101
 102                         if (per_dev->or)
 103                                 osd_end_request(per_dev->or);
 104                         if (per_dev->bio)
 105                                 bio_put(per_dev->bio);
 106                 }
 107
 108                 kfree(ios);
 109         }
 110 }
 111
 112 unsigned exofs_layout_od_id(struct exofs_layout *layout,
 113                             osd_id obj_no, unsigned layout_index)
 114 {
 115 /*      switch (layout->lay_func) {
 116         case LAYOUT_MOVING_WINDOW:
 117         {*/
 118                 unsigned dev_mod = obj_no;
 119
 120                 return (layout_index + dev_mod * layout->mirrors_p1) %
 121                                                               layout->s_numdevs;
 122 /*      }
 123         case LAYOUT_FUNC_IMPLICT:
 124                 return layout->devs[layout_index];
 125         }*/
 126 }
 127
 128 static inline struct osd_dev *exofs_ios_od(struct exofs_io_state *ios,
 129                                            unsigned layout_index)
 130 {
 131         return ios->layout->s_ods[
 132                 exofs_layout_od_id(ios->layout, ios->obj.id, layout_index)];
 133 }
 134
 135 static void _sync_done(struct exofs_io_state *ios, void *p)
 136 {
 137         struct completion *waiting = p;
 138
 139         complete(waiting);
 140 }
 141
 142 static void _last_io(struct kref *kref)
 143 {
 144         struct exofs_io_state *ios = container_of(
 145                                         kref, struct exofs_io_state, kref);
 146
 147         ios->done(ios, ios->private);
 148 }
 149
 150 static void _done_io(struct osd_request *or, void *p)
 151 {
 152         struct exofs_io_state *ios = p;
 153
 154         kref_put(&ios->kref, _last_io);
 155 }
 156
 157 static int exofs_io_execute(struct exofs_io_state *ios)
 158 {
 159         DECLARE_COMPLETION_ONSTACK(wait);
 160         bool sync = (ios->done == NULL);
 161         int i, ret;
 162
 163         if (sync) {
 164                 ios->done = _sync_done;
 165                 ios->private = &wait;
 166         }
 167
 168         for (i = 0; i < ios->numdevs; i++) {
 169                 struct osd_request *or = ios->per_dev[i].or;
 170                 if (unlikely(!or))
 171                         continue;
 172
 173                 ret = osd_finalize_request(or, 0, ios->cred, NULL);
 174                 if (unlikely(ret)) {
 175                         EXOFS_DBGMSG("Faild to osd_finalize_request() => %d\n",
 176                                      ret);
 177                         return ret;
 178                 }
 179         }
 180
 181         kref_init(&ios->kref);
 182
 183         for (i = 0; i < ios->numdevs; i++) {
 184                 struct osd_request *or = ios->per_dev[i].or;
 185                 if (unlikely(!or))
 186                         continue;
 187
 188                 kref_get(&ios->kref);
 189                 osd_execute_request_async(or, _done_io, ios);
 190         }
 191
 192         kref_put(&ios->kref, _last_io);
 193         ret = 0;
 194
 195         if (sync) {
 196                 wait_for_completion(&wait);
 197                 ret = exofs_check_io(ios, NULL);
 198         }
 199         return ret;
 200 }
 201
 202 static void _clear_bio(struct bio *bio)
 203 {
 204         struct bio_vec *bv;
 205         unsigned i;
 206
 207         __bio_for_each_segment(bv, bio, i, 0) {
 208                 unsigned this_count = bv->bv_len;
 209
 210                 if (likely(PAGE_SIZE == this_count))
 211                         clear_highpage(bv->bv_page);
 212                 else
 213                         zero_user(bv->bv_page, bv->bv_offset, this_count);
 214         }
 215 }
 216
 217 int exofs_check_io(struct exofs_io_state *ios, u64 *resid)
 218 {
 219         enum osd_err_priority acumulated_osd_err = 0;
 220         int acumulated_lin_err = 0;
 221         int i;
 222
 223         for (i = 0; i < ios->numdevs; i++) {
 224                 struct osd_sense_info osi;
 225                 struct osd_request *or = ios->per_dev[i].or;
 226                 int ret;
 227
 228                 if (unlikely(!or))
 229                         continue;
 230
 231                 ret = osd_req_decode_sense(or, &osi);
 232                 if (likely(!ret))
 233                         continue;
 234
 235                 if (OSD_ERR_PRI_CLEAR_PAGES == osi.osd_err_pri) {
 236                         /* start read offset passed endof file */
 237                         _clear_bio(ios->per_dev[i].bio);
 238                         EXOFS_DBGMSG("start read offset passed end of file "
 239                                 "offset=0x%llx, length=0x%llx\n",
 240                                 _LLU(ios->per_dev[i].offset),
 241                                 _LLU(ios->per_dev[i].length));
 242
 243                         continue; /* we recovered */
 244                 }
 245
 246                 if (osi.osd_err_pri >= acumulated_osd_err) {
 247                         acumulated_osd_err = osi.osd_err_pri;
 248                         acumulated_lin_err = ret;
 249                 }
 250         }
 251
 252         /* TODO: raid specific residual calculations */
 253         if (resid) {
 254                 if (likely(!acumulated_lin_err))
 255                         *resid = 0;
 256                 else
 257                         *resid = ios->length;
 258         }
 259
 260         return acumulated_lin_err;
 261 }
 262
 263 /*
 264  * L - logical offset into the file
 265  *
 266  * U - The number of bytes in a stripe within a group
 267  *
 268  *      U = stripe_unit * group_width
 269  *
 270  * T - The number of bytes striped within a group of component objects
 271  *     (before advancing to the next group)
 272  *
 273  *      T = stripe_unit * group_width * group_depth
 274  *
 275  * S - The number of bytes striped across all component objects
 276  *     before the pattern repeats
 277  *
 278  *      S = stripe_unit * group_width * group_depth * group_count
 279  *
 280  * M - The "major" (i.e., across all components) stripe number
 281  *
 282  *      M = L / S
 283  *
 284  * G - Counts the groups from the beginning of the major stripe
 285  *
 286  *      G = (L - (M * S)) / T   [or (L % S) / T]
 287  *
 288  * H - The byte offset within the group
 289  *
 290  *      H = (L - (M * S)) % T   [or (L % S) % T]
 291  *
 292  * N - The "minor" (i.e., across the group) stripe number
 293  *
 294  *      N = H / U
 295  *
 296  * C - The component index coresponding to L
 297  *
 298  *      C = (H - (N * U)) / stripe_unit + G * group_width
 299  *      [or (L % U) / stripe_unit + G * group_width]
 300  *
 301  * O - The component offset coresponding to L
 302  *
 303  *      O = L % stripe_unit + N * stripe_unit + M * group_depth * stripe_unit
 304  */
 305 struct _striping_info {
 306         u64 obj_offset;
 307         u64 group_length;
 308         u64 total_group_length;
 309         u64 Major;
 310         unsigned dev;
 311         unsigned unit_off;
 312 };
 313
 314 static void _calc_stripe_info(struct exofs_io_state *ios, u64 file_offset,
 315                               struct _striping_info *si)
 316 {
 317         u32     stripe_unit = ios->layout->stripe_unit;
 318         u32     group_width = ios->layout->group_width;
 319         u64     group_depth = ios->layout->group_depth;
 320
 321         u32     U = stripe_unit * group_width;
 322         u64     T = U * group_depth;
 323         u64     S = T * ios->layout->group_count;
 324         u64     M = div64_u64(file_offset, S);
 325
 326         /*
 327         G = (L - (M * S)) / T
 328         H = (L - (M * S)) % T
 329         */
 330         u64     LmodS = file_offset - M * S;
 331         u32     G = div64_u64(LmodS, T);
 332         u64     H = LmodS - G * T;
 333
 334         u32     N = div_u64(H, U);
 335
 336         /* "H - (N * U)" is just "H % U" so it's bound to u32 */
 337         si->dev = (u32)(H - (N * U)) / stripe_unit + G * group_width;
 338         si->dev *= ios->layout->mirrors_p1;
 339
 340         div_u64_rem(file_offset, stripe_unit, &si->unit_off);
 341
 342         si->obj_offset = si->unit_off + (N * stripe_unit) +
 343                                   (M * group_depth * stripe_unit);
 344
 345         si->group_length = T - H;
 346         si->total_group_length = T;
 347         si->Major = M;
 348 }
 349
 350 static int _add_stripe_unit(struct exofs_io_state *ios,  unsigned *cur_pg,
 351                 unsigned pgbase, struct exofs_per_dev_state *per_dev,
 352                 int cur_len)
 353 {
 354         unsigned pg = *cur_pg;
 355         struct request_queue *q =
 356                         osd_request_queue(exofs_ios_od(ios, per_dev->dev));
 357
 358         per_dev->length += cur_len;
 359
 360         if (per_dev->bio == NULL) {
 361                 unsigned pages_in_stripe = ios->layout->group_width *
 362                                         (ios->layout->stripe_unit / PAGE_SIZE);
 363                 unsigned bio_size = (ios->nr_pages + pages_in_stripe) /
 364                                                 ios->layout->group_width;
 365
 366                 per_dev->bio = bio_kmalloc(GFP_KERNEL, bio_size);
 367                 if (unlikely(!per_dev->bio)) {
 368                         EXOFS_DBGMSG("Faild to allocate BIO size=%u\n",
 369                                      bio_size);
 370                         return -ENOMEM;
 371                 }
 372         }
 373
 374         while (cur_len > 0) {
 375                 unsigned pglen = min_t(unsigned, PAGE_SIZE - pgbase, cur_len);
 376                 unsigned added_len;
 377
 378                 BUG_ON(ios->nr_pages <= pg);
 379                 cur_len -= pglen;
 380
 381                 added_len = bio_add_pc_page(q, per_dev->bio, ios->pages[pg],
 382                                             pglen, pgbase);
 383                 if (unlikely(pglen != added_len))
 384                         return -ENOMEM;
 385                 pgbase = 0;
 386                 ++pg;
 387         }
 388         BUG_ON(cur_len);
 389
 390         *cur_pg = pg;
 391         return 0;
 392 }
 393
 394 static int _prepare_one_group(struct exofs_io_state *ios, u64 length,
 395                               struct _striping_info *si, unsigned first_comp)
 396 {
 397         unsigned stripe_unit = ios->layout->stripe_unit;
 398         unsigned mirrors_p1 = ios->layout->mirrors_p1;
 399         unsigned devs_in_group = ios->layout->group_width * mirrors_p1;
 400         unsigned dev = si->dev;
 401         unsigned first_dev = dev - (dev % devs_in_group);
 402         unsigned comp = first_comp + (dev - first_dev);
 403         unsigned max_comp = ios->numdevs ? ios->numdevs - mirrors_p1 : 0;
 404         unsigned cur_pg = ios->pages_consumed;
 405         int ret = 0;
 406
 407         while (length) {
 408                 struct exofs_per_dev_state *per_dev = &ios->per_dev[comp];
 409                 unsigned cur_len, page_off = 0;
 410
 411                 if (!per_dev->length) {
 412                         per_dev->dev = dev;
 413                         if (dev < si->dev) {
 414                                 per_dev->offset = si->obj_offset + stripe_unit -
 415                                                                    si->unit_off;
 416                                 cur_len = stripe_unit;
 417                         } else if (dev == si->dev) {
 418                                 per_dev->offset = si->obj_offset;
 419                                 cur_len = stripe_unit - si->unit_off;
 420                                 page_off = si->unit_off & ~PAGE_MASK;
 421                                 BUG_ON(page_off && (page_off != ios->pgbase));
 422                         } else { /* dev > si->dev */
 423                                 per_dev->offset = si->obj_offset - si->unit_off;
 424                                 cur_len = stripe_unit;
 425                         }
 426
 427                         if (max_comp < comp)
 428                                 max_comp = comp;
 429
 430                         dev += mirrors_p1;
 431                         dev = (dev % devs_in_group) + first_dev;
 432                 } else {
 433                         cur_len = stripe_unit;
 434                 }
 435                 if (cur_len >= length)
 436                         cur_len = length;
 437
 438                 ret = _add_stripe_unit(ios, &cur_pg, page_off , per_dev,
 439                                        cur_len);
 440                 if (unlikely(ret))
 441                         goto out;
 442
 443                 comp += mirrors_p1;
 444                 comp = (comp % devs_in_group) + first_comp;
 445
 446                 length -= cur_len;
 447         }
 448 out:
 449         ios->numdevs = max_comp + mirrors_p1;
 450         ios->pages_consumed = cur_pg;
 451         return ret;
 452 }
 453
 454 static int _prepare_for_striping(struct exofs_io_state *ios)
 455 {
 456         u64 length = ios->length;
 457         struct _striping_info si;
 458         unsigned devs_in_group = ios->layout->group_width *
 459                                  ios->layout->mirrors_p1;
 460         unsigned first_comp = 0;
 461         int ret = 0;
 462
 463         _calc_stripe_info(ios, ios->offset, &si);
 464
 465         if (!ios->pages) {
 466                 if (ios->kern_buff) {
 467                         struct exofs_per_dev_state *per_dev = &ios->per_dev[0];
 468
 469                         per_dev->offset = si.obj_offset;
 470                         per_dev->dev = si.dev;
 471
 472                         /* no cross device without page array */
 473                         BUG_ON((ios->layout->group_width > 1) &&
 474                                (si.unit_off + ios->length >
 475                                 ios->layout->stripe_unit));
 476                 }
 477                 ios->numdevs = ios->layout->mirrors_p1;
 478                 return 0;
 479         }
 480
 481         while (length) {
 482                 if (length < si.group_length)
 483                         si.group_length = length;
 484
 485                 ret = _prepare_one_group(ios, si.group_length, &si, first_comp);
 486                 if (unlikely(ret))
 487                         goto out;
 488
 489                 length -= si.group_length;
 490
 491                 si.group_length = si.total_group_length;
 492                 si.unit_off = 0;
 493                 ++si.Major;
 494                 si.obj_offset = si.Major * ios->layout->stripe_unit *
 495                                                 ios->layout->group_depth;
 496
 497                 si.dev = (si.dev - (si.dev % devs_in_group)) + devs_in_group;
 498                 si.dev %= ios->layout->s_numdevs;
 499
 500                 first_comp += devs_in_group;
 501                 first_comp %= ios->layout->s_numdevs;
 502         }
 503
 504 out:
 505         return ret;
 506 }
 507
 508 int exofs_sbi_create(struct exofs_io_state *ios)
 509 {
 510         int i, ret;
 511
 512         for (i = 0; i < ios->layout->s_numdevs; i++) {
 513                 struct osd_request *or;
 514
 515                 or = osd_start_request(exofs_ios_od(ios, i), GFP_KERNEL);
 516                 if (unlikely(!or)) {
 517                         EXOFS_ERR("%s: osd_start_request failed\n", __func__);
 518                         ret = -ENOMEM;
 519                         goto out;
 520                 }
 521                 ios->per_dev[i].or = or;
 522                 ios->numdevs++;
 523
 524                 osd_req_create_object(or, &ios->obj);
 525         }
 526         ret = exofs_io_execute(ios);
 527
 528 out:
 529         return ret;
 530 }
 531
 532 int exofs_sbi_remove(struct exofs_io_state *ios)
 533 {
 534         int i, ret;
 535
 536         for (i = 0; i < ios->layout->s_numdevs; i++) {
 537                 struct osd_request *or;
 538
 539                 or = osd_start_request(exofs_ios_od(ios, i), GFP_KERNEL);
 540                 if (unlikely(!or)) {
 541                         EXOFS_ERR("%s: osd_start_request failed\n", __func__);
 542                         ret = -ENOMEM;
 543                         goto out;
 544                 }
 545                 ios->per_dev[i].or = or;
 546                 ios->numdevs++;
 547
 548                 osd_req_remove_object(or, &ios->obj);
 549         }
 550         ret = exofs_io_execute(ios);
 551
 552 out:
 553         return ret;
 554 }
 555
 556 static int _sbi_write_mirror(struct exofs_io_state *ios, int cur_comp)
 557 {
 558         struct exofs_per_dev_state *master_dev = &ios->per_dev[cur_comp];
 559         unsigned dev = ios->per_dev[cur_comp].dev;
 560         unsigned last_comp = cur_comp + ios->layout->mirrors_p1;
 561         int ret = 0;
 562
 563         if (ios->pages && !master_dev->length)
 564                 return 0; /* Just an empty slot */
 565
 566         for (; cur_comp < last_comp; ++cur_comp, ++dev) {
 567                 struct exofs_per_dev_state *per_dev = &ios->per_dev[cur_comp];
 568                 struct osd_request *or;
 569
 570                 or = osd_start_request(exofs_ios_od(ios, dev), GFP_KERNEL);
 571                 if (unlikely(!or)) {
 572                         EXOFS_ERR("%s: osd_start_request failed\n", __func__);
 573                         ret = -ENOMEM;
 574                         goto out;
 575                 }
 576                 per_dev->or = or;
 577                 per_dev->offset = master_dev->offset;
 578
 579                 if (ios->pages) {
 580                         struct bio *bio;
 581
 582                         if (per_dev != master_dev) {
 583                                 bio = bio_kmalloc(GFP_KERNEL,
 584                                                   master_dev->bio->bi_max_vecs);
 585                                 if (unlikely(!bio)) {
 586                                         EXOFS_DBGMSG(
 587                                               "Faild to allocate BIO size=%u\n",
 588                                               master_dev->bio->bi_max_vecs);
 589                                         ret = -ENOMEM;
 590                                         goto out;
 591                                 }
 592
 593                                 __bio_clone(bio, master_dev->bio);
 594                                 bio->bi_bdev = NULL;
 595                                 bio->bi_next = NULL;
 596                                 per_dev->length = master_dev->length;
 597                                 per_dev->bio =  bio;
 598                                 per_dev->dev = dev;
 599                         } else {
 600                                 bio = master_dev->bio;
 601                                 /* FIXME: bio_set_dir() */
 602                                 bio->bi_rw |= (1 << BIO_RW);
 603                         }
 604
 605                         osd_req_write(or, &ios->obj, per_dev->offset, bio,
 606                                       per_dev->length);
 607                         EXOFS_DBGMSG("write(0x%llx) offset=0x%llx "
 608                                       "length=0x%llx dev=%d\n",
 609                                      _LLU(ios->obj.id), _LLU(per_dev->offset),
 610                                      _LLU(per_dev->length), dev);
 611                 } else if (ios->kern_buff) {
 612                         ret = osd_req_write_kern(or, &ios->obj, per_dev->offset,
 613                                            ios->kern_buff, ios->length);
 614                         if (unlikely(ret))
 615                                 goto out;
 616                         EXOFS_DBGMSG2("write_kern(0x%llx) offset=0x%llx "
 617                                       "length=0x%llx dev=%d\n",
 618                                      _LLU(ios->obj.id), _LLU(per_dev->offset),
 619                                      _LLU(ios->length), dev);
 620                 } else {
 621                         osd_req_set_attributes(or, &ios->obj);
 622                         EXOFS_DBGMSG2("obj(0x%llx) set_attributes=%d dev=%d\n",
 623                                      _LLU(ios->obj.id), ios->out_attr_len, dev);
 624                 }
 625
 626                 if (ios->out_attr)
 627                         osd_req_add_set_attr_list(or, ios->out_attr,
 628                                                   ios->out_attr_len);
 629
 630                 if (ios->in_attr)
 631                         osd_req_add_get_attr_list(or, ios->in_attr,
 632                                                   ios->in_attr_len);
 633         }
 634
 635 out:
 636         return ret;
 637 }
 638
 639 int exofs_sbi_write(struct exofs_io_state *ios)
 640 {
 641         int i;
 642         int ret;
 643
 644         ret = _prepare_for_striping(ios);
 645         if (unlikely(ret))
 646                 return ret;
 647
 648         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
 649                 ret = _sbi_write_mirror(ios, i);
 650                 if (unlikely(ret))
 651                         return ret;
 652         }
 653
 654         ret = exofs_io_execute(ios);
 655         return ret;
 656 }
 657
 658 static int _sbi_read_mirror(struct exofs_io_state *ios, unsigned cur_comp)
 659 {
 660         struct osd_request *or;
 661         struct exofs_per_dev_state *per_dev = &ios->per_dev[cur_comp];
 662         unsigned first_dev = (unsigned)ios->obj.id;
 663
 664         if (ios->pages && !per_dev->length)
 665                 return 0; /* Just an empty slot */
 666
 667         first_dev = per_dev->dev + first_dev % ios->layout->mirrors_p1;
 668         or = osd_start_request(exofs_ios_od(ios, first_dev), GFP_KERNEL);
 669         if (unlikely(!or)) {
 670                 EXOFS_ERR("%s: osd_start_request failed\n", __func__);
 671                 return -ENOMEM;
 672         }
 673         per_dev->or = or;
 674
 675         if (ios->pages) {
 676                 osd_req_read(or, &ios->obj, per_dev->offset,
 677                                 per_dev->bio, per_dev->length);
 678                 EXOFS_DBGMSG("read(0x%llx) offset=0x%llx length=0x%llx"
 679                              " dev=%d\n", _LLU(ios->obj.id),
 680                              _LLU(per_dev->offset), _LLU(per_dev->length),
 681                              first_dev);
 682         } else if (ios->kern_buff) {
 683                 int ret = osd_req_read_kern(or, &ios->obj, per_dev->offset,
 684                                             ios->kern_buff, ios->length);
 685                 EXOFS_DBGMSG2("read_kern(0x%llx) offset=0x%llx "
 686                               "length=0x%llx dev=%d ret=>%d\n",
 687                               _LLU(ios->obj.id), _LLU(per_dev->offset),
 688                               _LLU(ios->length), first_dev, ret);
 689                 if (unlikely(ret))
 690                         return ret;
 691         } else {
 692                 osd_req_get_attributes(or, &ios->obj);
 693                 EXOFS_DBGMSG2("obj(0x%llx) get_attributes=%d dev=%d\n",
 694                               _LLU(ios->obj.id), ios->in_attr_len, first_dev);
 695         }
 696         if (ios->out_attr)
 697                 osd_req_add_set_attr_list(or, ios->out_attr, ios->out_attr_len);
 698
 699         if (ios->in_attr)
 700                 osd_req_add_get_attr_list(or, ios->in_attr, ios->in_attr_len);
 701
 702         return 0;
 703 }
 704
 705 int exofs_sbi_read(struct exofs_io_state *ios)
 706 {
 707         int i;
 708         int ret;
 709
 710         ret = _prepare_for_striping(ios);
 711         if (unlikely(ret))
 712                 return ret;
 713
 714         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
 715                 ret = _sbi_read_mirror(ios, i);
 716                 if (unlikely(ret))
 717                         return ret;
 718         }
 719
 720         ret = exofs_io_execute(ios);
 721         return ret;
 722 }
 723
 724 int extract_attr_from_ios(struct exofs_io_state *ios, struct osd_attr *attr)
 725 {
 726         struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
 727         void *iter = NULL;
 728         int nelem;
 729
 730         do {
 731                 nelem = 1;
 732                 osd_req_decode_get_attr_list(ios->per_dev[0].or,
 733                                              &cur_attr, &nelem, &iter);
 734                 if ((cur_attr.attr_page == attr->attr_page) &&
 735                     (cur_attr.attr_id == attr->attr_id)) {
 736                         attr->len = cur_attr.len;
 737                         attr->val_ptr = cur_attr.val_ptr;
 738                         return 0;
 739                 }
 740         } while (iter);
 741
 742         return -EIO;
 743 }
 744
 745 static int _truncate_mirrors(struct exofs_io_state *ios, unsigned cur_comp,
 746                              struct osd_attr *attr)
 747 {
 748         int last_comp = cur_comp + ios->layout->mirrors_p1;
 749
 750         for (; cur_comp < last_comp; ++cur_comp) {
 751                 struct exofs_per_dev_state *per_dev = &ios->per_dev[cur_comp];
 752                 struct osd_request *or;
 753
 754                 or = osd_start_request(exofs_ios_od(ios, cur_comp), GFP_KERNEL);
 755                 if (unlikely(!or)) {
 756                         EXOFS_ERR("%s: osd_start_request failed\n", __func__);
 757                         return -ENOMEM;
 758                 }
 759                 per_dev->or = or;
 760
 761                 osd_req_set_attributes(or, &ios->obj);
 762                 osd_req_add_set_attr_list(or, attr, 1);
 763         }
 764
 765         return 0;
 766 }
 767
 768 int exofs_oi_truncate(struct exofs_i_info *oi, u64 size)
 769 {
 770         struct exofs_sb_info *sbi = oi->vfs_inode.i_sb->s_fs_info;
 771         struct exofs_io_state *ios;
 772         struct exofs_trunc_attr {
 773                 struct osd_attr attr;
 774                 __be64 newsize;
 775         } *size_attrs;
 776         struct _striping_info si;
 777         int i, ret;
 778
 779         ret = exofs_get_io_state(&sbi->layout, &ios);
 780         if (unlikely(ret))
 781                 return ret;
 782
 783         size_attrs = kcalloc(ios->layout->group_width, sizeof(*size_attrs),
 784                              GFP_KERNEL);
 785         if (unlikely(!size_attrs)) {
 786                 ret = -ENOMEM;
 787                 goto out;
 788         }
 789
 790         ios->obj.id = exofs_oi_objno(oi);
 791         ios->cred = oi->i_cred;
 792
 793         ios->numdevs = ios->layout->s_numdevs;
 794         _calc_stripe_info(ios, size, &si);
 795
 796         for (i = 0; i < ios->layout->group_width; ++i) {
 797                 struct exofs_trunc_attr *size_attr = &size_attrs[i];
 798                 u64 obj_size;
 799
 800                 if (i < si.dev)
 801                         obj_size = si.obj_offset +
 802                                         ios->layout->stripe_unit - si.unit_off;
 803                 else if (i == si.dev)
 804                         obj_size = si.obj_offset;
 805                 else /* i > si.dev */
 806                         obj_size = si.obj_offset - si.unit_off;
 807
 808                 size_attr->newsize = cpu_to_be64(obj_size);
 809                 size_attr->attr = g_attr_logical_length;
 810                 size_attr->attr.val_ptr = &size_attr->newsize;
 811
 812                 ret = _truncate_mirrors(ios, i * ios->layout->mirrors_p1,
 813                                         &size_attr->attr);
 814                 if (unlikely(ret))
 815                         goto out;
 816         }
 817         ret = exofs_io_execute(ios);
 818
 819 out:
 820         kfree(size_attrs);
 821         exofs_put_io_state(ios);
 822         return ret;
 823 }