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[fs/lustre-release.git] / lustre / lov / lov_pack.c
1 /*
2  * GPL HEADER START
3  *
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 only,
8  * as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * General Public License version 2 for more details (a copy is included
14  * in the LICENSE file that accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License
17  * version 2 along with this program; If not, see
18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19  *
20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21  * CA 95054 USA or visit www.sun.com if you need additional information or
22  * have any questions.
23  *
24  * GPL HEADER END
25  */
26 /*
27  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
28  * Use is subject to license terms.
29  *
30  * Copyright (c) 2011, 2013, Intel Corporation.
31  */
32 /*
33  * This file is part of Lustre, http://www.lustre.org/
34  * Lustre is a trademark of Sun Microsystems, Inc.
35  *
36  * lustre/lov/lov_pack.c
37  *
38  * (Un)packing of OST/MDS requests
39  *
40  * Author: Andreas Dilger <adilger@clusterfs.com>
41  */
42
43 #define DEBUG_SUBSYSTEM S_LOV
44 #ifndef __KERNEL__
45 #include <liblustre.h>
46 #endif
47
48 #include <lustre_net.h>
49 #include <obd.h>
50 #include <obd_lov.h>
51 #include <obd_class.h>
52 #include <obd_support.h>
53 #include <lustre/lustre_user.h>
54
55 #include "lov_internal.h"
56
57 void lov_dump_lmm_common(int level, void *lmmp)
58 {
59         struct lov_mds_md *lmm = lmmp;
60         struct ost_id   oi;
61
62         lmm_oi_le_to_cpu(&oi, &lmm->lmm_oi);
63         CDEBUG(level, "objid "DOSTID", magic 0x%08x, pattern %#x\n",
64                POSTID(&oi), le32_to_cpu(lmm->lmm_magic),
65                le32_to_cpu(lmm->lmm_pattern));
66         CDEBUG(level, "stripe_size %u, stripe_count %u, layout_gen %u\n",
67                le32_to_cpu(lmm->lmm_stripe_size),
68                le16_to_cpu(lmm->lmm_stripe_count),
69                le16_to_cpu(lmm->lmm_layout_gen));
70 }
71
72 static void lov_dump_lmm_objects(int level, struct lov_ost_data *lod,
73                                  int stripe_count)
74 {
75         int i;
76
77         if (stripe_count > LOV_V1_INSANE_STRIPE_COUNT) {
78                 CDEBUG(level, "bad stripe_count %u > max_stripe_count %u\n",
79                        stripe_count, LOV_V1_INSANE_STRIPE_COUNT);
80                 return;
81         }
82
83         for (i = 0; i < stripe_count; ++i, ++lod) {
84                 struct ost_id   oi;
85
86                 ostid_le_to_cpu(&lod->l_ost_oi, &oi);
87                 CDEBUG(level, "stripe %u idx %u subobj "DOSTID"\n", i,
88                        le32_to_cpu(lod->l_ost_idx), POSTID(&oi));
89         }
90 }
91
92 void lov_dump_lmm_v1(int level, struct lov_mds_md_v1 *lmm)
93 {
94         lov_dump_lmm_common(level, lmm);
95         lov_dump_lmm_objects(level, lmm->lmm_objects,
96                              le16_to_cpu(lmm->lmm_stripe_count));
97 }
98
99 void lov_dump_lmm_v3(int level, struct lov_mds_md_v3 *lmm)
100 {
101         lov_dump_lmm_common(level, lmm);
102         CDEBUG(level,"pool_name "LOV_POOLNAMEF"\n", lmm->lmm_pool_name);
103         lov_dump_lmm_objects(level, lmm->lmm_objects,
104                              le16_to_cpu(lmm->lmm_stripe_count));
105 }
106
107 void lov_dump_lmm(int level, void *lmm)
108 {
109         int magic;
110
111         magic = le32_to_cpu(((struct lov_mds_md *)lmm)->lmm_magic);
112         switch (magic) {
113         case LOV_MAGIC_V1:
114                 lov_dump_lmm_v1(level, (struct lov_mds_md_v1 *)lmm);
115                 break;
116         case LOV_MAGIC_V3:
117                 lov_dump_lmm_v3(level, (struct lov_mds_md_v3 *)lmm);
118                 break;
119         default:
120                 CDEBUG(level, "unrecognized lmm_magic %x, assuming %x\n",
121                        magic, LOV_MAGIC_V1);
122                 lov_dump_lmm_common(level, lmm);
123                 break;
124         }
125 }
126
127 /* Pack LOV object metadata for disk storage.  It is packed in LE byte
128  * order and is opaque to the networking layer.
129  *
130  * XXX In the future, this will be enhanced to get the EA size from the
131  *     underlying OSC device(s) to get their EA sizes so we can stack
132  *     LOVs properly.  For now lov_mds_md_size() just assumes one obd_id
133  *     per stripe.
134  */
135 int lov_packmd(struct obd_export *exp, struct lov_mds_md **lmmp,
136                struct lov_stripe_md *lsm)
137 {
138         struct obd_device *obd = class_exp2obd(exp);
139         struct lov_obd *lov = &obd->u.lov;
140         struct lov_mds_md_v1 *lmmv1;
141         struct lov_mds_md_v3 *lmmv3;
142         __u16 stripe_count;
143         struct lov_ost_data_v1 *lmm_objects;
144         int lmm_size, lmm_magic;
145         int i;
146         int cplen = 0;
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 if (!lsm_is_released(lsm)) {
175                         stripe_count = lsm->lsm_stripe_count;
176                 } else {
177                         stripe_count = 0;
178                 }
179         } else {
180                 /* No need to allocate more than maximum supported stripes.
181                  * Anyway, this is pretty inaccurate since ld_tgt_count now
182                  * represents max index and we should rely on the actual number
183                  * of OSTs instead */
184                 stripe_count = lov_mds_md_stripecnt(lov->lov_ocd.ocd_max_easize,
185                                                     lmm_magic);
186                 if (stripe_count > lov->desc.ld_tgt_count)
187                         stripe_count = lov->desc.ld_tgt_count;
188         }
189
190         /* XXX LOV STACKING call into osc for sizes */
191         lmm_size = lov_mds_md_size(stripe_count, lmm_magic);
192
193         if (!lmmp)
194                 RETURN(lmm_size);
195
196         if (*lmmp && !lsm) {
197                 stripe_count = le16_to_cpu((*lmmp)->lmm_stripe_count);
198                 lmm_size = lov_mds_md_size(stripe_count, lmm_magic);
199                 OBD_FREE_LARGE(*lmmp, lmm_size);
200                 *lmmp = NULL;
201                 RETURN(0);
202         }
203
204         if (!*lmmp) {
205                 OBD_ALLOC_LARGE(*lmmp, lmm_size);
206                 if (!*lmmp)
207                         RETURN(-ENOMEM);
208         }
209
210         CDEBUG(D_INFO, "lov_packmd: LOV_MAGIC 0x%08X, lmm_size = %d \n",
211                lmm_magic, lmm_size);
212
213         lmmv1 = *lmmp;
214         lmmv3 = (struct lov_mds_md_v3 *)*lmmp;
215         if (lmm_magic == LOV_MAGIC_V3)
216                 lmmv3->lmm_magic = cpu_to_le32(LOV_MAGIC_V3);
217         else
218                 lmmv1->lmm_magic = cpu_to_le32(LOV_MAGIC_V1);
219
220         if (!lsm)
221                 RETURN(lmm_size);
222
223         /* lmmv1 and lmmv3 point to the same struct and have the
224          * same first fields
225          */
226         lmm_oi_cpu_to_le(&lmmv1->lmm_oi, &lsm->lsm_oi);
227         lmmv1->lmm_stripe_size = cpu_to_le32(lsm->lsm_stripe_size);
228         lmmv1->lmm_stripe_count = cpu_to_le16(stripe_count);
229         lmmv1->lmm_pattern = cpu_to_le32(lsm->lsm_pattern);
230         lmmv1->lmm_layout_gen = cpu_to_le16(lsm->lsm_layout_gen);
231         if (lsm->lsm_magic == LOV_MAGIC_V3) {
232                 cplen = strlcpy(lmmv3->lmm_pool_name, lsm->lsm_pool_name,
233                                 sizeof(lmmv3->lmm_pool_name));
234                 if (cplen >= sizeof(lmmv3->lmm_pool_name))
235                         RETURN(-E2BIG);
236                 lmm_objects = lmmv3->lmm_objects;
237         } else {
238                 lmm_objects = lmmv1->lmm_objects;
239         }
240
241         for (i = 0; i < stripe_count; i++) {
242                 struct lov_oinfo *loi = lsm->lsm_oinfo[i];
243                 /* XXX LOV STACKING call down to osc_packmd() to do packing */
244                 LASSERTF(ostid_id(&loi->loi_oi) != 0, "lmm_oi "DOSTID
245                          " stripe %u/%u idx %u\n", POSTID(&lmmv1->lmm_oi),
246                          i, stripe_count, loi->loi_ost_idx);
247                 ostid_cpu_to_le(&loi->loi_oi, &lmm_objects[i].l_ost_oi);
248                 lmm_objects[i].l_ost_gen = cpu_to_le32(loi->loi_ost_gen);
249                 lmm_objects[i].l_ost_idx = cpu_to_le32(loi->loi_ost_idx);
250         }
251
252         RETURN(lmm_size);
253 }
254
255 /* Find the max stripecount we should use */
256 __u16 lov_get_stripecnt(struct lov_obd *lov, __u32 magic, __u16 stripe_count)
257 {
258         __u32 max_stripes = LOV_MAX_STRIPE_COUNT_OLD;
259
260         if (!stripe_count)
261                 stripe_count = lov->desc.ld_default_stripe_count;
262         if (stripe_count > lov->desc.ld_active_tgt_count)
263                 stripe_count = lov->desc.ld_active_tgt_count;
264         if (!stripe_count)
265                 stripe_count = 1;
266
267         /* stripe count is based on whether ldiskfs can handle
268          * larger EA sizes */
269         if (lov->lov_ocd.ocd_connect_flags & OBD_CONNECT_MAX_EASIZE &&
270             lov->lov_ocd.ocd_max_easize)
271                 max_stripes = lov_mds_md_stripecnt(lov->lov_ocd.ocd_max_easize,
272                                                    magic);
273
274         if (stripe_count > max_stripes)
275                 stripe_count = max_stripes;
276
277         return stripe_count;
278 }
279
280
281 static int lov_verify_lmm(void *lmm, int lmm_bytes, __u16 *stripe_count)
282 {
283         int rc;
284
285         if (lsm_op_find(le32_to_cpu(*(__u32 *)lmm)) == NULL) {
286                 char *buffer;
287                 int sz;
288
289                 CERROR("bad disk LOV MAGIC: 0x%08X; dumping LMM (size=%d):\n",
290                        le32_to_cpu(*(__u32 *)lmm), lmm_bytes);
291                 sz = lmm_bytes * 2 + 1;
292                 OBD_ALLOC_LARGE(buffer, sz);
293                 if (buffer != NULL) {
294                         int i;
295
296                         for (i = 0; i < lmm_bytes; i++)
297                                 sprintf(buffer+2*i, "%.2X", ((char *)lmm)[i]);
298                         buffer[sz - 1] = '\0';
299                         CERROR("%s\n", buffer);
300                         OBD_FREE_LARGE(buffer, sz);
301                 }
302                 return -EINVAL;
303         }
304         rc = lsm_op_find(le32_to_cpu(*(__u32 *)lmm))->lsm_lmm_verify(lmm,
305                                      lmm_bytes, stripe_count);
306         return rc;
307 }
308
309 int lov_alloc_memmd(struct lov_stripe_md **lsmp, __u16 stripe_count,
310                     int pattern, int magic)
311 {
312         int i, lsm_size;
313         ENTRY;
314
315         CDEBUG(D_INFO, "alloc lsm, stripe_count %d\n", stripe_count);
316
317         *lsmp = lsm_alloc_plain(stripe_count, &lsm_size);
318         if (!*lsmp) {
319                 CERROR("can't allocate lsmp stripe_count %d\n", stripe_count);
320                 RETURN(-ENOMEM);
321         }
322
323         cfs_atomic_set(&(*lsmp)->lsm_refc, 1);
324         spin_lock_init(&(*lsmp)->lsm_lock);
325         (*lsmp)->lsm_magic = magic;
326         (*lsmp)->lsm_stripe_count = stripe_count;
327         (*lsmp)->lsm_maxbytes = LUSTRE_STRIPE_MAXBYTES * stripe_count;
328         (*lsmp)->lsm_pattern = pattern;
329         (*lsmp)->lsm_pool_name[0] = '\0';
330         (*lsmp)->lsm_layout_gen = 0;
331         if (stripe_count > 0)
332                 (*lsmp)->lsm_oinfo[0]->loi_ost_idx = ~0;
333
334         for (i = 0; i < stripe_count; i++)
335                 loi_init((*lsmp)->lsm_oinfo[i]);
336
337         RETURN(lsm_size);
338 }
339
340 int lov_free_memmd(struct lov_stripe_md **lsmp)
341 {
342         struct lov_stripe_md *lsm = *lsmp;
343         int refc;
344
345         *lsmp = NULL;
346         LASSERT(cfs_atomic_read(&lsm->lsm_refc) > 0);
347         if ((refc = cfs_atomic_dec_return(&lsm->lsm_refc)) == 0) {
348                 LASSERT(lsm_op_find(lsm->lsm_magic) != NULL);
349                 lsm_op_find(lsm->lsm_magic)->lsm_free(lsm);
350         }
351         return refc;
352 }
353
354
355 /* Unpack LOV object metadata from disk storage.  It is packed in LE byte
356  * order and is opaque to the networking layer.
357  */
358 int lov_unpackmd(struct obd_export *exp,  struct lov_stripe_md **lsmp,
359                  struct lov_mds_md *lmm, int lmm_bytes)
360 {
361         struct obd_device *obd = class_exp2obd(exp);
362         struct lov_obd *lov = &obd->u.lov;
363         int rc = 0, lsm_size;
364         __u16 stripe_count;
365         __u32 magic;
366         __u32 pattern;
367         ENTRY;
368
369         /* If passed an MDS struct use values from there, otherwise defaults */
370         if (lmm) {
371                 rc = lov_verify_lmm(lmm, lmm_bytes, &stripe_count);
372                 if (rc)
373                         RETURN(rc);
374                 magic = le32_to_cpu(lmm->lmm_magic);
375         } else {
376                 magic = LOV_MAGIC;
377                 stripe_count = lov_get_stripecnt(lov, magic, 0);
378         }
379
380         /* If we aren't passed an lsmp struct, we just want the size */
381         if (!lsmp) {
382                 /* XXX LOV STACKING call into osc for sizes */
383                 LBUG();
384                 RETURN(lov_stripe_md_size(stripe_count));
385         }
386         /* If we are passed an allocated struct but nothing to unpack, free */
387         if (*lsmp && !lmm) {
388                 lov_free_memmd(lsmp);
389                 RETURN(0);
390         }
391
392         pattern = le32_to_cpu(lmm->lmm_pattern);
393         lsm_size = lov_alloc_memmd(lsmp, stripe_count, pattern, magic);
394         if (lsm_size < 0)
395                 RETURN(lsm_size);
396
397         /* If we are passed a pointer but nothing to unpack, we only alloc */
398         if (!lmm)
399                 RETURN(lsm_size);
400
401         LASSERT(lsm_op_find(magic) != NULL);
402         rc = lsm_op_find(magic)->lsm_unpackmd(lov, *lsmp, lmm);
403         if (rc) {
404                 lov_free_memmd(lsmp);
405                 RETURN(rc);
406         }
407
408         RETURN(lsm_size);
409 }
410
411 static int __lov_setstripe(struct obd_export *exp, int max_lmm_size,
412                            struct lov_stripe_md **lsmp,
413                            struct lov_user_md *lump)
414 {
415         struct obd_device *obd = class_exp2obd(exp);
416         struct lov_obd *lov = &obd->u.lov;
417         char buffer[sizeof(struct lov_user_md_v3)];
418         struct lov_user_md_v3 *lumv3 = (struct lov_user_md_v3 *)&buffer[0];
419         struct lov_user_md_v1 *lumv1 = (struct lov_user_md_v1 *)&buffer[0];
420         int lmm_magic;
421         __u16 stripe_count;
422         int rc;
423         int cplen = 0;
424         ENTRY;
425
426         rc = lov_lum_swab_if_needed(lumv3, &lmm_magic, lump);
427         if (rc)
428                 RETURN(rc);
429
430         /* in the rest of the tests, as *lumv1 and lumv3 have the same
431          * fields, we use lumv1 to avoid code duplication */
432
433         if (lumv1->lmm_pattern == 0) {
434                 lumv1->lmm_pattern = lov->desc.ld_pattern ?
435                         lov->desc.ld_pattern : LOV_PATTERN_RAID0;
436         }
437
438         if (lov_pattern(lumv1->lmm_pattern) != LOV_PATTERN_RAID0) {
439                 CDEBUG(D_IOCTL, "bad userland stripe pattern: %#x\n",
440                        lumv1->lmm_pattern);
441                 RETURN(-EINVAL);
442         }
443
444         /* 64kB is the largest common page size we see (ia64), and matches the
445          * check in lfs */
446         if (lumv1->lmm_stripe_size & (LOV_MIN_STRIPE_SIZE - 1)) {
447                 CDEBUG(D_IOCTL, "stripe size %u not multiple of %u, fixing\n",
448                        lumv1->lmm_stripe_size, LOV_MIN_STRIPE_SIZE);
449                 lumv1->lmm_stripe_size = LOV_MIN_STRIPE_SIZE;
450         }
451
452         if ((lumv1->lmm_stripe_offset >= lov->desc.ld_tgt_count) &&
453             (lumv1->lmm_stripe_offset !=
454              (typeof(lumv1->lmm_stripe_offset))(-1))) {
455                 CDEBUG(D_IOCTL, "stripe offset %u > number of OSTs %u\n",
456                        lumv1->lmm_stripe_offset, lov->desc.ld_tgt_count);
457                 RETURN(-EINVAL);
458         }
459         stripe_count = lov_get_stripecnt(lov, lmm_magic,
460                                          lumv1->lmm_stripe_count);
461
462         if (max_lmm_size) {
463                 int max_stripes = (max_lmm_size -
464                                    lov_mds_md_size(0, lmm_magic)) /
465                                    sizeof(struct lov_ost_data_v1);
466                 if (unlikely(max_stripes < stripe_count)) {
467                         CDEBUG(D_IOCTL, "stripe count reset from %d to %d\n",
468                                stripe_count, max_stripes);
469                         stripe_count = max_stripes;
470                 }
471         }
472
473         if (lmm_magic == LOV_USER_MAGIC_V3) {
474                 struct pool_desc *pool;
475
476                 /* In the function below, .hs_keycmp resolves to
477                  * pool_hashkey_keycmp() */
478                 /* coverity[overrun-buffer-val] */
479                 pool = lov_find_pool(lov, lumv3->lmm_pool_name);
480                 if (pool != NULL) {
481                         if (lumv3->lmm_stripe_offset !=
482                             (typeof(lumv3->lmm_stripe_offset))(-1)) {
483                                 rc = lov_check_index_in_pool(
484                                         lumv3->lmm_stripe_offset, pool);
485                                 if (rc < 0) {
486                                         lov_pool_putref(pool);
487                                         RETURN(-EINVAL);
488                                 }
489                         }
490
491                         if (stripe_count > pool_tgt_count(pool))
492                                 stripe_count = pool_tgt_count(pool);
493
494                         lov_pool_putref(pool);
495                 }
496         }
497
498         if (lumv1->lmm_pattern & LOV_PATTERN_F_RELEASED)
499                 stripe_count = 0;
500
501         rc = lov_alloc_memmd(lsmp, stripe_count, lumv1->lmm_pattern, lmm_magic);
502
503         if (rc >= 0) {
504                 (*lsmp)->lsm_oinfo[0]->loi_ost_idx = lumv1->lmm_stripe_offset;
505                 (*lsmp)->lsm_stripe_size = lumv1->lmm_stripe_size;
506                 if (lmm_magic == LOV_USER_MAGIC_V3) {
507                         cplen = strlcpy((*lsmp)->lsm_pool_name,
508                                         lumv3->lmm_pool_name,
509                                         sizeof((*lsmp)->lsm_pool_name));
510                         if (cplen >= sizeof((*lsmp)->lsm_pool_name))
511                                 rc = -E2BIG;
512                 }
513                 rc = 0;
514         }
515
516         RETURN(rc);
517 }
518
519 /* Configure object striping information on a new file.
520  *
521  * @lmmu is a pointer to a user struct with one or more of the fields set to
522  * indicate the application preference: lmm_stripe_count, lmm_stripe_size,
523  * lmm_stripe_offset, and lmm_stripe_pattern.  lmm_magic must be LOV_MAGIC.
524  * @lsmp is a pointer to an in-core stripe MD that needs to be filled in.
525  */
526 int lov_setstripe(struct obd_export *exp, int max_lmm_size,
527                   struct lov_stripe_md **lsmp, struct lov_user_md *lump)
528 {
529         int rc;
530         mm_segment_t seg;
531
532         seg = get_fs();
533         set_fs(KERNEL_DS);
534
535         rc = __lov_setstripe(exp, max_lmm_size, lsmp, lump);
536         set_fs(seg);
537         RETURN(rc);
538 }
539
540 int lov_setea(struct obd_export *exp, struct lov_stripe_md **lsmp,
541               struct lov_user_md *lump)
542 {
543         int i;
544         int rc;
545         struct obd_export *oexp;
546         struct lov_obd *lov = &exp->exp_obd->u.lov;
547         obd_id last_id = 0;
548         struct lov_user_ost_data_v1 *lmm_objects;
549
550         ENTRY;
551
552         if (lump->lmm_magic == LOV_USER_MAGIC_V3)
553                 lmm_objects = ((struct lov_user_md_v3 *)lump)->lmm_objects;
554         else
555                 lmm_objects = lump->lmm_objects;
556
557         for (i = 0; i < lump->lmm_stripe_count; i++) {
558                 __u32 len = sizeof(last_id);
559                 oexp = lov->lov_tgts[lmm_objects[i].l_ost_idx]->ltd_exp;
560                 rc = obd_get_info(NULL, oexp, sizeof(KEY_LAST_ID), KEY_LAST_ID,
561                                   &len, &last_id, NULL);
562                 if (rc)
563                         RETURN(rc);
564                 if (ostid_id(&lmm_objects[i].l_ost_oi) > last_id) {
565                         CERROR("Setting EA for object > than last id on"
566                                " ost idx %d "DOSTID" > "LPD64" \n",
567                                lmm_objects[i].l_ost_idx,
568                                POSTID(&lmm_objects[i].l_ost_oi), last_id);
569                         RETURN(-EINVAL);
570                 }
571         }
572
573         rc = lov_setstripe(exp, 0, lsmp, lump);
574         if (rc)
575                 RETURN(rc);
576
577         for (i = 0; i < lump->lmm_stripe_count; i++) {
578                 (*lsmp)->lsm_oinfo[i]->loi_ost_idx =
579                         lmm_objects[i].l_ost_idx;
580                 (*lsmp)->lsm_oinfo[i]->loi_oi = lmm_objects[i].l_ost_oi;
581         }
582         RETURN(0);
583 }
584
585
586 /* Retrieve object striping information.
587  *
588  * @lump is a pointer to an in-core struct with lmm_ost_count indicating
589  * the maximum number of OST indices which will fit in the user buffer.
590  * lmm_magic must be LOV_USER_MAGIC.
591  */
592 int lov_getstripe(struct obd_export *exp, struct lov_stripe_md *lsm,
593                   struct lov_user_md *lump)
594 {
595         /*
596          * XXX huge struct allocated on stack.
597          */
598         /* we use lov_user_md_v3 because it is larger than lov_user_md_v1 */
599         struct lov_user_md_v3 lum;
600         struct lov_mds_md *lmmk = NULL;
601         int rc, lmm_size;
602         int lum_size;
603         ENTRY;
604
605         if (!lsm)
606                 RETURN(-ENODATA);
607
608         /* we only need the header part from user space to get lmm_magic and
609          * lmm_stripe_count, (the header part is common to v1 and v3) */
610         lum_size = sizeof(struct lov_user_md_v1);
611         if (copy_from_user(&lum, lump, lum_size))
612                 GOTO(out_set, rc = -EFAULT);
613         else if ((lum.lmm_magic != LOV_USER_MAGIC) &&
614                  (lum.lmm_magic != LOV_USER_MAGIC_V3))
615                 GOTO(out_set, rc = -EINVAL);
616
617         if (lum.lmm_stripe_count &&
618             (lum.lmm_stripe_count < lsm->lsm_stripe_count)) {
619                 /* Return right size of stripe to user */
620                 lum.lmm_stripe_count = lsm->lsm_stripe_count;
621                 rc = copy_to_user(lump, &lum, lum_size);
622                 GOTO(out_set, rc = -EOVERFLOW);
623         }
624         rc = lov_packmd(exp, &lmmk, lsm);
625         if (rc < 0)
626                 GOTO(out_set, rc);
627         lmm_size = rc;
628         rc = 0;
629
630         /* FIXME: Bug 1185 - copy fields properly when structs change */
631         /* struct lov_user_md_v3 and struct lov_mds_md_v3 must be the same */
632         CLASSERT(sizeof(lum) == sizeof(struct lov_mds_md_v3));
633         CLASSERT(sizeof lum.lmm_objects[0] == sizeof lmmk->lmm_objects[0]);
634
635         if ((cpu_to_le32(LOV_MAGIC) != LOV_MAGIC) &&
636             ((lmmk->lmm_magic == cpu_to_le32(LOV_MAGIC_V1)) ||
637             (lmmk->lmm_magic == cpu_to_le32(LOV_MAGIC_V3)))) {
638                 lustre_swab_lov_mds_md(lmmk);
639                 lustre_swab_lov_user_md_objects(
640                                 (struct lov_user_ost_data*)lmmk->lmm_objects,
641                                 lmmk->lmm_stripe_count);
642         }
643         if (lum.lmm_magic == LOV_USER_MAGIC) {
644                 /* User request for v1, we need skip lmm_pool_name */
645                 if (lmmk->lmm_magic == LOV_MAGIC_V3) {
646                         memmove(((struct lov_mds_md_v1 *)lmmk)->lmm_objects,
647                                 ((struct lov_mds_md_v3 *)lmmk)->lmm_objects,
648                                 lmmk->lmm_stripe_count *
649                                 sizeof(struct lov_ost_data_v1));
650                         lmm_size -= LOV_MAXPOOLNAME;
651                 }
652         } else {
653                 /* if v3 we just have to update the lum_size */
654                 lum_size = sizeof(struct lov_user_md_v3);
655         }
656
657         /* User wasn't expecting this many OST entries */
658         if (lum.lmm_stripe_count == 0)
659                 lmm_size = lum_size;
660         else if (lum.lmm_stripe_count < lmmk->lmm_stripe_count)
661                 GOTO(out_set, rc = -EOVERFLOW);
662         /*
663          * Have a difference between lov_mds_md & lov_user_md.
664          * So we have to re-order the data before copy to user.
665          */
666         lum.lmm_stripe_count = lmmk->lmm_stripe_count;
667         lum.lmm_layout_gen = lmmk->lmm_layout_gen;
668         ((struct lov_user_md *)lmmk)->lmm_layout_gen = lum.lmm_layout_gen;
669         ((struct lov_user_md *)lmmk)->lmm_stripe_count = lum.lmm_stripe_count;
670         if (copy_to_user(lump, lmmk, lmm_size))
671                 rc = -EFAULT;
672
673         obd_free_diskmd(exp, &lmmk);
674 out_set:
675         RETURN(rc);
676 }