lustre/lov/lov_pack.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * Copyright (c) 2011 Whamcloud, Inc.
  34  */
  35 /*
  36  * This file is part of Lustre, http://www.lustre.org/
  37  * Lustre is a trademark of Sun Microsystems, Inc.
  38  *
  39  * lustre/lov/lov_pack.c
  40  *
  41  * (Un)packing of OST/MDS requests
  42  *
  43  * Author: Andreas Dilger <adilger@clusterfs.com>
  44  */
  45
  46 #define DEBUG_SUBSYSTEM S_LOV
  47 #ifndef __KERNEL__
  48 #include <liblustre.h>
  49 #endif
  50
  51 #include <lustre_net.h>
  52 #include <obd.h>
  53 #include <obd_lov.h>
  54 #include <obd_class.h>
  55 #include <obd_support.h>
  56 #include <lustre/lustre_user.h>
  57
  58 #include "lov_internal.h"
  59
  60 static void lov_dump_lmm_common(int level, void *lmmp)
  61 {
  62         struct lov_mds_md *lmm = lmmp;
  63
  64         CDEBUG(level, "objid "LPX64", magic 0x%08x, pattern %#x\n",
  65                (__u64)le64_to_cpu(lmm->lmm_object_id),
  66                le32_to_cpu(lmm->lmm_magic),
  67                le32_to_cpu(lmm->lmm_pattern));
  68         CDEBUG(level,"stripe_size %u, stripe_count %u\n",
  69                le32_to_cpu(lmm->lmm_stripe_size),
  70                le32_to_cpu(lmm->lmm_stripe_count));
  71 }
  72
  73 static void lov_dump_lmm_objects(int level, struct lov_ost_data *lod,
  74                                  int stripe_count)
  75 {
  76         int i;
  77
  78         if (stripe_count > LOV_V1_INSANE_STRIPE_COUNT) {
  79                 CDEBUG(level, "bad stripe_count %u > max_stripe_count %u\n",
  80                        stripe_count, LOV_V1_INSANE_STRIPE_COUNT);
  81         }
  82
  83         for (i = 0; i < stripe_count; ++i, ++lod) {
  84                 CDEBUG(level, "stripe %u idx %u subobj "LPX64"/"LPX64"\n", i,
  85                        le32_to_cpu(lod->l_ost_idx),
  86                        (__u64)le64_to_cpu(lod->l_object_seq),
  87                        (__u64)le64_to_cpu(lod->l_object_id));
  88         }
  89 }
  90
  91 void lov_dump_lmm_v1(int level, struct lov_mds_md_v1 *lmm)
  92 {
  93         lov_dump_lmm_common(level, lmm);
  94         lov_dump_lmm_objects(level, lmm->lmm_objects,
  95                              le32_to_cpu(lmm->lmm_stripe_count));
  96 }
  97
  98 void lov_dump_lmm_v3(int level, struct lov_mds_md_v3 *lmm)
  99 {
 100         lov_dump_lmm_common(level, lmm);
 101         CDEBUG(level,"pool_name "LOV_POOLNAMEF"\n", lmm->lmm_pool_name);
 102         lov_dump_lmm_objects(level, lmm->lmm_objects,
 103                              le32_to_cpu(lmm->lmm_stripe_count));
 104 }
 105
 106 void lov_dump_lmm(int level, void *lmm)
 107 {
 108         int magic;
 109
 110         magic = ((struct lov_mds_md_v1 *)(lmm))->lmm_magic;
 111         switch (magic) {
 112         case LOV_MAGIC_V1:
 113                 return lov_dump_lmm_v1(level, (struct lov_mds_md_v1 *)(lmm));
 114         case LOV_MAGIC_V3:
 115                 return lov_dump_lmm_v3(level, (struct lov_mds_md_v3 *)(lmm));
 116         default:
 117                 CERROR("Cannot recognize lmm_magic %x", magic);
 118         }
 119         return;
 120 }
 121
 122 #define LMM_ASSERT(test)                                                \
 123 do {                                                                    \
 124         if (!(test)) lov_dump_lmm(D_ERROR, lmm);                        \
 125         LASSERT(test); /* so we know what assertion failed */           \
 126 } while(0)
 127
 128 /* Pack LOV object metadata for disk storage.  It is packed in LE byte
 129  * order and is opaque to the networking layer.
 130  *
 131  * XXX In the future, this will be enhanced to get the EA size from the
 132  *     underlying OSC device(s) to get their EA sizes so we can stack
 133  *     LOVs properly.  For now lov_mds_md_size() just assumes one obd_id
 134  *     per stripe.
 135  */
 136 int lov_packmd(struct obd_export *exp, struct lov_mds_md **lmmp,
 137                struct lov_stripe_md *lsm)
 138 {
 139         struct obd_device *obd = class_exp2obd(exp);
 140         struct lov_obd *lov = &obd->u.lov;
 141         struct lov_mds_md_v1 *lmmv1;
 142         struct lov_mds_md_v3 *lmmv3;
 143         int stripe_count;
 144         struct lov_ost_data_v1 *lmm_objects;
 145         int lmm_size, lmm_magic;
 146         int i;
 147         ENTRY;
 148
 149         if (lsm) {
 150                 lmm_magic = lsm->lsm_magic;
 151         } else {
 152                 if (lmmp && *lmmp)
 153                         lmm_magic = le32_to_cpu((*lmmp)->lmm_magic);
 154                 else
 155                         /* lsm == NULL and lmmp == NULL */
 156                         lmm_magic = LOV_MAGIC;
 157         }
 158
 159         if ((lmm_magic != LOV_MAGIC_V1) &&
 160             (lmm_magic != LOV_MAGIC_V3)) {
 161                 CERROR("bad mem LOV MAGIC: 0x%08X != 0x%08X nor 0x%08X\n",
 162                         lmm_magic, LOV_MAGIC_V1, LOV_MAGIC_V3);
 163                 RETURN(-EINVAL);
 164
 165         }
 166
 167         if (lsm) {
 168                 /* If we are just sizing the EA, limit the stripe count
 169                  * to the actual number of OSTs in this filesystem. */
 170                 if (!lmmp) {
 171                         stripe_count = lov_get_stripecnt(lov, lmm_magic,
 172                                                          lsm->lsm_stripe_count);
 173                         lsm->lsm_stripe_count = stripe_count;
 174                 } else {
 175                         stripe_count = lsm->lsm_stripe_count;
 176                 }
 177         } else {
 178                 /* No need to allocate more than maximum supported stripes.
 179                  * Anyway, this is pretty inaccurate since ld_tgt_count now
 180                  * represents max index and we should rely on the actual number
 181                  * of OSTs instead */
 182                 stripe_count = lov_mds_md_stripecnt(lov->lov_ocd.ocd_max_easize,
 183                                                     lmm_magic);
 184                 if (stripe_count > lov->desc.ld_tgt_count)
 185                         stripe_count = lov->desc.ld_tgt_count;
 186         }
 187
 188         /* XXX LOV STACKING call into osc for sizes */
 189         lmm_size = lov_mds_md_size(stripe_count, lmm_magic);
 190
 191         if (!lmmp)
 192                 RETURN(lmm_size);
 193
 194         if (*lmmp && !lsm) {
 195                 stripe_count = le32_to_cpu((*lmmp)->lmm_stripe_count);
 196                 lmm_size = lov_mds_md_size(stripe_count, lmm_magic);
 197                 OBD_FREE_LARGE(*lmmp, lmm_size);
 198                 *lmmp = NULL;
 199                 RETURN(0);
 200         }
 201
 202         if (!*lmmp) {
 203                 OBD_ALLOC_LARGE(*lmmp, lmm_size);
 204                 if (!*lmmp)
 205                         RETURN(-ENOMEM);
 206         }
 207
 208         CDEBUG(D_INFO, "lov_packmd: LOV_MAGIC 0x%08X, lmm_size = %d \n",
 209                lmm_magic, lmm_size);
 210
 211         lmmv1 = *lmmp;
 212         lmmv3 = (struct lov_mds_md_v3 *)*lmmp;
 213         if (lmm_magic == LOV_MAGIC_V3)
 214                 lmmv3->lmm_magic = cpu_to_le32(LOV_MAGIC_V3);
 215         else
 216                 lmmv1->lmm_magic = cpu_to_le32(LOV_MAGIC_V1);
 217
 218         if (!lsm)
 219                 RETURN(lmm_size);
 220
 221         /* lmmv1 and lmmv3 point to the same struct and have the
 222          * same first fields
 223          */
 224         lmmv1->lmm_object_id = cpu_to_le64(lsm->lsm_object_id);
 225         lmmv1->lmm_object_seq = cpu_to_le64(lsm->lsm_object_seq);
 226         lmmv1->lmm_stripe_size = cpu_to_le32(lsm->lsm_stripe_size);
 227         lmmv1->lmm_stripe_count = cpu_to_le32(stripe_count);
 228         lmmv1->lmm_pattern = cpu_to_le32(lsm->lsm_pattern);
 229         if (lsm->lsm_magic == LOV_MAGIC_V3) {
 230                 strncpy(lmmv3->lmm_pool_name, lsm->lsm_pool_name,
 231                         LOV_MAXPOOLNAME);
 232                 lmm_objects = lmmv3->lmm_objects;
 233         } else {
 234                 lmm_objects = lmmv1->lmm_objects;
 235         }
 236
 237         for (i = 0; i < stripe_count; i++) {
 238                 struct lov_oinfo *loi = lsm->lsm_oinfo[i];
 239                 /* XXX LOV STACKING call down to osc_packmd() to do packing */
 240                 LASSERTF(loi->loi_id, "lmm_oid "LPU64" stripe %u/%u idx %u\n",
 241                          lmmv1->lmm_object_id, i, stripe_count, loi->loi_ost_idx);
 242                 lmm_objects[i].l_object_id = cpu_to_le64(loi->loi_id);
 243                 lmm_objects[i].l_object_seq = cpu_to_le64(loi->loi_seq);
 244                 lmm_objects[i].l_ost_gen = cpu_to_le32(loi->loi_ost_gen);
 245                 lmm_objects[i].l_ost_idx = cpu_to_le32(loi->loi_ost_idx);
 246         }
 247
 248         RETURN(lmm_size);
 249 }
 250
 251 /* Find the max stripecount we should use */
 252 __u32 lov_get_stripecnt(struct lov_obd *lov, __u32 magic, __u32 stripe_count)
 253 {
 254         __u32 max_stripes = LOV_MAX_STRIPE_COUNT_OLD;
 255
 256         if (!stripe_count)
 257                 stripe_count = lov->desc.ld_default_stripe_count;
 258         if (stripe_count > lov->desc.ld_active_tgt_count)
 259                 stripe_count = lov->desc.ld_active_tgt_count;
 260         if (!stripe_count)
 261                 stripe_count = 1;
 262
 263         /* stripe count is based on whether ldiskfs can handle
 264          * larger EA sizes */
 265         if (lov->lov_ocd.ocd_connect_flags & OBD_CONNECT_MAX_EASIZE &&
 266             lov->lov_ocd.ocd_max_easize)
 267                 max_stripes = lov_mds_md_stripecnt(lov->lov_ocd.ocd_max_easize,
 268                                                    magic);
 269
 270         if (stripe_count > max_stripes)
 271                 stripe_count = max_stripes;
 272
 273         return stripe_count;
 274 }
 275
 276
 277 static int lov_verify_lmm(void *lmm, int lmm_bytes, int *stripe_count)
 278 {
 279         int rc;
 280
 281         if (lsm_op_find(le32_to_cpu(*(__u32 *)lmm)) == NULL) {
 282                 char *buffer;
 283                 int sz;
 284
 285                 CERROR("bad disk LOV MAGIC: 0x%08X; dumping LMM (size=%d):\n",
 286                        le32_to_cpu(*(__u32 *)lmm), lmm_bytes);
 287                 sz = lmm_bytes * 2 + 1;
 288                 OBD_ALLOC_LARGE(buffer, sz);
 289                 if (buffer != NULL) {
 290                         int i;
 291
 292                         for (i = 0; i < lmm_bytes; i++)
 293                                 sprintf(buffer+2*i, "%.2X", ((char *)lmm)[i]);
 294                         buffer[sz] = '\0';
 295                         CERROR("%s\n", buffer);
 296                         OBD_FREE_LARGE(buffer, sz);
 297                 }
 298                 return -EINVAL;
 299         }
 300         rc = lsm_op_find(le32_to_cpu(*(__u32 *)lmm))->lsm_lmm_verify(lmm,
 301                                      lmm_bytes, stripe_count);
 302         return rc;
 303 }
 304
 305 int lov_alloc_memmd(struct lov_stripe_md **lsmp, int stripe_count,
 306                     int pattern, int magic)
 307 {
 308         int i, lsm_size;
 309         ENTRY;
 310
 311         CDEBUG(D_INFO, "alloc lsm, stripe_count %d\n", stripe_count);
 312
 313         *lsmp = lsm_alloc_plain(stripe_count, &lsm_size);
 314         if (!*lsmp) {
 315                 CERROR("can't allocate lsmp stripe_count %d\n", stripe_count);
 316                 RETURN(-ENOMEM);
 317         }
 318
 319         cfs_spin_lock_init(&(*lsmp)->lsm_lock);
 320         (*lsmp)->lsm_magic = magic;
 321         (*lsmp)->lsm_stripe_count = stripe_count;
 322         (*lsmp)->lsm_maxbytes = LUSTRE_STRIPE_MAXBYTES * stripe_count;
 323         (*lsmp)->lsm_pattern = pattern;
 324         (*lsmp)->lsm_pool_name[0] = '\0';
 325         (*lsmp)->lsm_oinfo[0]->loi_ost_idx = ~0;
 326
 327         for (i = 0; i < stripe_count; i++)
 328                 loi_init((*lsmp)->lsm_oinfo[i]);
 329
 330         RETURN(lsm_size);
 331 }
 332
 333 void lov_free_memmd(struct lov_stripe_md **lsmp)
 334 {
 335         struct lov_stripe_md *lsm = *lsmp;
 336
 337         LASSERT(lsm_op_find(lsm->lsm_magic) != NULL);
 338         lsm_op_find(lsm->lsm_magic)->lsm_free(lsm);
 339
 340         *lsmp = NULL;
 341 }
 342
 343
 344 /* Unpack LOV object metadata from disk storage.  It is packed in LE byte
 345  * order and is opaque to the networking layer.
 346  */
 347 int lov_unpackmd(struct obd_export *exp,  struct lov_stripe_md **lsmp,
 348                  struct lov_mds_md *lmm, int lmm_bytes)
 349 {
 350         struct obd_device *obd = class_exp2obd(exp);
 351         struct lov_obd *lov = &obd->u.lov;
 352         int rc = 0, stripe_count, lsm_size;
 353         __u32 magic;
 354         ENTRY;
 355
 356         /* If passed an MDS struct use values from there, otherwise defaults */
 357         if (lmm) {
 358                 rc = lov_verify_lmm(lmm, lmm_bytes, &stripe_count);
 359                 if (rc)
 360                         RETURN(rc);
 361                 magic = le32_to_cpu(lmm->lmm_magic);
 362         } else {
 363                 magic = LOV_MAGIC;
 364                 stripe_count = lov_get_stripecnt(lov, magic, 0);
 365         }
 366
 367         /* If we aren't passed an lsmp struct, we just want the size */
 368         if (!lsmp) {
 369                 /* XXX LOV STACKING call into osc for sizes */
 370                 LBUG();
 371                 RETURN(lov_stripe_md_size(stripe_count));
 372         }
 373         /* If we are passed an allocated struct but nothing to unpack, free */
 374         if (*lsmp && !lmm) {
 375                 lov_free_memmd(lsmp);
 376                 RETURN(0);
 377         }
 378
 379         lsm_size = lov_alloc_memmd(lsmp, stripe_count, LOV_PATTERN_RAID0,
 380                                    magic);
 381         if (lsm_size < 0)
 382                 RETURN(lsm_size);
 383
 384         /* If we are passed a pointer but nothing to unpack, we only alloc */
 385         if (!lmm)
 386                 RETURN(lsm_size);
 387
 388         LASSERT(lsm_op_find(magic) != NULL);
 389         rc = lsm_op_find(magic)->lsm_unpackmd(lov, *lsmp, lmm);
 390         if (rc) {
 391                 lov_free_memmd(lsmp);
 392                 RETURN(rc);
 393         }
 394
 395         RETURN(lsm_size);
 396 }
 397
 398 static int __lov_setstripe(struct obd_export *exp, int max_lmm_size,
 399                            struct lov_stripe_md **lsmp,
 400                            struct lov_user_md *lump)
 401 {
 402         struct obd_device *obd = class_exp2obd(exp);
 403         struct lov_obd *lov = &obd->u.lov;
 404         char buffer[sizeof(struct lov_user_md_v3)];
 405         struct lov_user_md_v3 *lumv3 = (struct lov_user_md_v3 *)&buffer[0];
 406         struct lov_user_md_v1 *lumv1 = (struct lov_user_md_v1 *)&buffer[0];
 407         int lmm_magic;
 408         int stripe_count;
 409         int rc;
 410         ENTRY;
 411
 412         if (cfs_copy_from_user(lumv3, lump, sizeof(struct lov_user_md_v1)))
 413                 RETURN(-EFAULT);
 414
 415         lmm_magic = lumv1->lmm_magic;
 416
 417         if (lmm_magic == __swab32(LOV_USER_MAGIC_V1)) {
 418                 lustre_swab_lov_user_md_v1(lumv1);
 419                 lmm_magic = LOV_USER_MAGIC_V1;
 420         } else if (lmm_magic == LOV_USER_MAGIC_V3) {
 421                 if (cfs_copy_from_user(lumv3, lump, sizeof(*lumv3)))
 422                         RETURN(-EFAULT);
 423         } else if (lmm_magic == __swab32(LOV_USER_MAGIC_V3)) {
 424                 if (cfs_copy_from_user(lumv3, lump, sizeof(*lumv3)))
 425                         RETURN(-EFAULT);
 426                 lustre_swab_lov_user_md_v3(lumv3);
 427                 lmm_magic = LOV_USER_MAGIC_V3;
 428         } else if (lmm_magic != LOV_USER_MAGIC_V1) {
 429                 CDEBUG(D_IOCTL,
 430                        "bad userland LOV MAGIC: %#08x != %#08x nor %#08x\n",
 431                        lmm_magic, LOV_USER_MAGIC_V1, LOV_USER_MAGIC_V3);
 432                        RETURN(-EINVAL);
 433         }
 434
 435         /* in the rest of the tests, as *lumv1 and lumv3 have the same
 436          * fields, we use lumv1 to avoid code duplication */
 437
 438         if (lumv1->lmm_pattern == 0) {
 439                 lumv1->lmm_pattern = lov->desc.ld_pattern ?
 440                         lov->desc.ld_pattern : LOV_PATTERN_RAID0;
 441         }
 442
 443         if (lumv1->lmm_pattern != LOV_PATTERN_RAID0) {
 444                 CDEBUG(D_IOCTL, "bad userland stripe pattern: %#x\n",
 445                        lumv1->lmm_pattern);
 446                 RETURN(-EINVAL);
 447         }
 448
 449         /* 64kB is the largest common page size we see (ia64), and matches the
 450          * check in lfs */
 451         if (lumv1->lmm_stripe_size & (LOV_MIN_STRIPE_SIZE - 1)) {
 452                 CDEBUG(D_IOCTL, "stripe size %u not multiple of %u, fixing\n",
 453                        lumv1->lmm_stripe_size, LOV_MIN_STRIPE_SIZE);
 454                 lumv1->lmm_stripe_size = LOV_MIN_STRIPE_SIZE;
 455         }
 456
 457         if ((lumv1->lmm_stripe_offset >= lov->desc.ld_tgt_count) &&
 458             (lumv1->lmm_stripe_offset !=
 459              (typeof(lumv1->lmm_stripe_offset))(-1))) {
 460                 CDEBUG(D_IOCTL, "stripe offset %u > number of OSTs %u\n",
 461                        lumv1->lmm_stripe_offset, lov->desc.ld_tgt_count);
 462                 RETURN(-EINVAL);
 463         }
 464         stripe_count = lov_get_stripecnt(lov, lmm_magic,
 465                                          lumv1->lmm_stripe_count);
 466
 467         if (max_lmm_size) {
 468                 int max_stripes = (max_lmm_size -
 469                                    lov_mds_md_size(0, lmm_magic)) /
 470                                    sizeof(struct lov_ost_data_v1);
 471                 if (unlikely(max_stripes < stripe_count)) {
 472                         CDEBUG(D_IOCTL, "stripe count reset from %d to %d\n",
 473                                stripe_count, max_stripes);
 474                         stripe_count = max_stripes;
 475                 }
 476         }
 477
 478         if (lmm_magic == LOV_USER_MAGIC_V3) {
 479                 struct pool_desc *pool;
 480
 481                 pool = lov_find_pool(lov, lumv3->lmm_pool_name);
 482                 if (pool != NULL) {
 483                         if (lumv3->lmm_stripe_offset !=
 484                             (typeof(lumv3->lmm_stripe_offset))(-1)) {
 485                                 rc = lov_check_index_in_pool(
 486                                         lumv3->lmm_stripe_offset, pool);
 487                                 if (rc < 0) {
 488                                         lov_pool_putref(pool);
 489                                         RETURN(-EINVAL);
 490                                 }
 491                         }
 492
 493                         if (stripe_count > pool_tgt_count(pool))
 494                                 stripe_count = pool_tgt_count(pool);
 495
 496                         lov_pool_putref(pool);
 497                 }
 498         }
 499
 500         rc = lov_alloc_memmd(lsmp, stripe_count, lumv1->lmm_pattern, lmm_magic);
 501
 502         if (rc >= 0) {
 503                 (*lsmp)->lsm_oinfo[0]->loi_ost_idx = lumv1->lmm_stripe_offset;
 504                 (*lsmp)->lsm_stripe_size = lumv1->lmm_stripe_size;
 505                 if (lmm_magic == LOV_USER_MAGIC_V3)
 506                         strncpy((*lsmp)->lsm_pool_name, lumv3->lmm_pool_name,
 507                                 LOV_MAXPOOLNAME);
 508                 rc = 0;
 509         }
 510
 511         RETURN(rc);
 512 }
 513
 514 /* Configure object striping information on a new file.
 515  *
 516  * @lmmu is a pointer to a user struct with one or more of the fields set to
 517  * indicate the application preference: lmm_stripe_count, lmm_stripe_size,
 518  * lmm_stripe_offset, and lmm_stripe_pattern.  lmm_magic must be LOV_MAGIC.
 519  * @lsmp is a pointer to an in-core stripe MD that needs to be filled in.
 520  */
 521 int lov_setstripe(struct obd_export *exp, int max_lmm_size,
 522                   struct lov_stripe_md **lsmp, struct lov_user_md *lump)
 523 {
 524         int rc;
 525         mm_segment_t seg;
 526
 527         seg = get_fs();
 528         set_fs(KERNEL_DS);
 529
 530         rc = __lov_setstripe(exp, max_lmm_size, lsmp, lump);
 531         set_fs(seg);
 532         RETURN(rc);
 533 }
 534
 535 int lov_setea(struct obd_export *exp, struct lov_stripe_md **lsmp,
 536               struct lov_user_md *lump)
 537 {
 538         int i;
 539         int rc;
 540         struct obd_export *oexp;
 541         struct lov_obd *lov = &exp->exp_obd->u.lov;
 542         obd_id last_id = 0;
 543         struct lov_user_ost_data_v1 *lmm_objects;
 544
 545         ENTRY;
 546
 547         if (lump->lmm_magic == LOV_USER_MAGIC_V3)
 548                 lmm_objects = ((struct lov_user_md_v3 *)lump)->lmm_objects;
 549         else
 550                 lmm_objects = lump->lmm_objects;
 551
 552         for (i = 0; i < lump->lmm_stripe_count; i++) {
 553                 __u32 len = sizeof(last_id);
 554                 oexp = lov->lov_tgts[lmm_objects[i].l_ost_idx]->ltd_exp;
 555                 rc = obd_get_info(oexp, sizeof(KEY_LAST_ID), KEY_LAST_ID,
 556                                   &len, &last_id, NULL);
 557                 if (rc)
 558                         RETURN(rc);
 559                 if (lmm_objects[i].l_object_id > last_id) {
 560                         CERROR("Setting EA for object > than last id on "
 561                                "ost idx %d "LPD64" > "LPD64" \n",
 562                                lmm_objects[i].l_ost_idx,
 563                                lmm_objects[i].l_object_id, last_id);
 564                         RETURN(-EINVAL);
 565                 }
 566         }
 567
 568         rc = lov_setstripe(exp, 0, lsmp, lump);
 569         if (rc)
 570                 RETURN(rc);
 571
 572         for (i = 0; i < lump->lmm_stripe_count; i++) {
 573                 (*lsmp)->lsm_oinfo[i]->loi_ost_idx =
 574                         lmm_objects[i].l_ost_idx;
 575                 (*lsmp)->lsm_oinfo[i]->loi_id = lmm_objects[i].l_object_id;
 576                 (*lsmp)->lsm_oinfo[i]->loi_seq = lmm_objects[i].l_object_seq;
 577         }
 578         RETURN(0);
 579 }
 580
 581
 582 /* Retrieve object striping information.
 583  *
 584  * @lump is a pointer to an in-core struct with lmm_ost_count indicating
 585  * the maximum number of OST indices which will fit in the user buffer.
 586  * lmm_magic must be LOV_USER_MAGIC.
 587  */
 588 int lov_getstripe(struct obd_export *exp, struct lov_stripe_md *lsm,
 589                   struct lov_user_md *lump)
 590 {
 591         /*
 592          * XXX huge struct allocated on stack.
 593          */
 594         /* we use lov_user_md_v3 because it is larger than lov_user_md_v1 */
 595         struct lov_user_md_v3 lum;
 596         struct lov_mds_md *lmmk = NULL;
 597         int rc, lmm_size;
 598         int lum_size;
 599         mm_segment_t seg;
 600         ENTRY;
 601
 602         if (!lsm)
 603                 RETURN(-ENODATA);
 604
 605         /*
 606          * "Switch to kernel segment" to allow copying from kernel space by
 607          * copy_{to,from}_user().
 608          */
 609         seg = get_fs();
 610         set_fs(KERNEL_DS);
 611
 612         /* we only need the header part from user space to get lmm_magic and
 613          * lmm_stripe_count, (the header part is common to v1 and v3) */
 614         lum_size = sizeof(struct lov_user_md_v1);
 615         if (cfs_copy_from_user(&lum, lump, lum_size))
 616                 GOTO(out_set, rc = -EFAULT);
 617         else if ((lum.lmm_magic != LOV_USER_MAGIC) &&
 618                  (lum.lmm_magic != LOV_USER_MAGIC_V3))
 619                 GOTO(out_set, rc = -EINVAL);
 620
 621         if (lum.lmm_stripe_count &&
 622             (lum.lmm_stripe_count < lsm->lsm_stripe_count)) {
 623                 /* Return right size of stripe to user */
 624                 lum.lmm_stripe_count = lsm->lsm_stripe_count;
 625                 rc = cfs_copy_to_user(lump, &lum, lum_size);
 626                 GOTO(out_set, rc = -EOVERFLOW);
 627         }
 628         rc = lov_packmd(exp, &lmmk, lsm);
 629         if (rc < 0)
 630                 GOTO(out_set, rc);
 631         lmm_size = rc;
 632         rc = 0;
 633
 634         /* FIXME: Bug 1185 - copy fields properly when structs change */
 635         /* struct lov_user_md_v3 and struct lov_mds_md_v3 must be the same */
 636         CLASSERT(sizeof(lum) == sizeof(struct lov_mds_md_v3));
 637         CLASSERT(sizeof lum.lmm_objects[0] == sizeof lmmk->lmm_objects[0]);
 638
 639         if ((cpu_to_le32(LOV_MAGIC) != LOV_MAGIC) &&
 640             ((lmmk->lmm_magic == cpu_to_le32(LOV_MAGIC_V1)) ||
 641             (lmmk->lmm_magic == cpu_to_le32(LOV_MAGIC_V3)))) {
 642                 lustre_swab_lov_mds_md(lmmk);
 643                 lustre_swab_lov_user_md_objects(
 644                                 (struct lov_user_ost_data*)lmmk->lmm_objects,
 645                                 lmmk->lmm_stripe_count);
 646         }
 647         if (lum.lmm_magic == LOV_USER_MAGIC) {
 648                 /* User request for v1, we need skip lmm_pool_name */
 649                 if (lmmk->lmm_magic == LOV_MAGIC_V3) {
 650                         memmove((char*)(&lmmk->lmm_stripe_count) +
 651                                 sizeof(lmmk->lmm_stripe_count),
 652                                 ((struct lov_mds_md_v3*)lmmk)->lmm_objects,
 653                                 lmmk->lmm_stripe_count *
 654                                 sizeof(struct lov_ost_data_v1));
 655                         lmm_size -= LOV_MAXPOOLNAME;
 656                 }
 657         } else {
 658                 /* if v3 we just have to update the lum_size */
 659                 lum_size = sizeof(struct lov_user_md_v3);
 660         }
 661
 662         /* User wasn't expecting this many OST entries */
 663         if (lum.lmm_stripe_count == 0)
 664                 lmm_size = lum_size;
 665         else if (lum.lmm_stripe_count < lmmk->lmm_stripe_count)
 666                 GOTO(out_set, rc = -EOVERFLOW);
 667         /*
 668          * Have a difference between lov_mds_md & lov_user_md.
 669          * So we have to re-order the data before copy to user.
 670          */
 671         lum.lmm_stripe_count = lmmk->lmm_stripe_count;
 672         ((struct lov_user_md*)lmmk)->lmm_stripe_offset = 0;
 673         ((struct lov_user_md*)lmmk)->lmm_stripe_count = lum.lmm_stripe_count;
 674         if (cfs_copy_to_user(lump, lmmk, lmm_size))
 675                 rc = -EFAULT;
 676
 677         obd_free_diskmd(exp, &lmmk);
 678 out_set:
 679         set_fs(seg);
 680         RETURN(rc);
 681 }