exofs/ore.c: local functions should be static
[linux-3.10.git] / fs / exofs / ore.c
1 /*
2  * Copyright (C) 2005, 2006
3  * Avishay Traeger (avishay@gmail.com)
4  * Copyright (C) 2008, 2009
5  * Boaz Harrosh <bharrosh@panasas.com>
6  *
7  * This file is part of exofs.
8  *
9  * exofs is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation.  Since it is based on ext2, and the only
12  * valid version of GPL for the Linux kernel is version 2, the only valid
13  * version of GPL for exofs is version 2.
14  *
15  * exofs is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with exofs; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
23  */
24
25 #include <linux/slab.h>
26 #include <asm/div64.h>
27
28 #include <scsi/osd_ore.h>
29
30 #define ORE_ERR(fmt, a...) printk(KERN_ERR "ore: " fmt, ##a)
31
32 #ifdef CONFIG_EXOFS_DEBUG
33 #define ORE_DBGMSG(fmt, a...) \
34         printk(KERN_NOTICE "ore @%s:%d: " fmt, __func__, __LINE__, ##a)
35 #else
36 #define ORE_DBGMSG(fmt, a...) \
37         do { if (0) printk(fmt, ##a); } while (0)
38 #endif
39
40 /* u64 has problems with printk this will cast it to unsigned long long */
41 #define _LLU(x) (unsigned long long)(x)
42
43 #define ORE_DBGMSG2(M...) do {} while (0)
44 /* #define ORE_DBGMSG2 ORE_DBGMSG */
45
46 MODULE_AUTHOR("Boaz Harrosh <bharrosh@panasas.com>");
47 MODULE_DESCRIPTION("Objects Raid Engine ore.ko");
48 MODULE_LICENSE("GPL");
49
50 static u8 *_ios_cred(struct ore_io_state *ios, unsigned index)
51 {
52         return ios->comps->comps[index & ios->comps->single_comp].cred;
53 }
54
55 static struct osd_obj_id *_ios_obj(struct ore_io_state *ios, unsigned index)
56 {
57         return &ios->comps->comps[index & ios->comps->single_comp].obj;
58 }
59
60 static struct osd_dev *_ios_od(struct ore_io_state *ios, unsigned index)
61 {
62         return ios->comps->ods[index];
63 }
64
65 int  ore_get_rw_state(struct ore_layout *layout, struct ore_components *comps,
66                       bool is_reading, u64 offset, u64 length,
67                       struct ore_io_state **pios)
68 {
69         struct ore_io_state *ios;
70
71         /*TODO: Maybe use kmem_cach per sbi of size
72          * exofs_io_state_size(layout->s_numdevs)
73          */
74         ios = kzalloc(ore_io_state_size(comps->numdevs), GFP_KERNEL);
75         if (unlikely(!ios)) {
76                 ORE_DBGMSG("Failed kzalloc bytes=%d\n",
77                              ore_io_state_size(comps->numdevs));
78                 *pios = NULL;
79                 return -ENOMEM;
80         }
81
82         ios->layout = layout;
83         ios->comps = comps;
84         ios->offset = offset;
85         ios->length = length;
86         ios->reading = is_reading;
87
88         *pios = ios;
89         return 0;
90 }
91 EXPORT_SYMBOL(ore_get_rw_state);
92
93 int  ore_get_io_state(struct ore_layout *layout, struct ore_components *comps,
94                       struct ore_io_state **ios)
95 {
96         return ore_get_rw_state(layout, comps, true, 0, 0, ios);
97 }
98 EXPORT_SYMBOL(ore_get_io_state);
99
100 void ore_put_io_state(struct ore_io_state *ios)
101 {
102         if (ios) {
103                 unsigned i;
104
105                 for (i = 0; i < ios->numdevs; i++) {
106                         struct ore_per_dev_state *per_dev = &ios->per_dev[i];
107
108                         if (per_dev->or)
109                                 osd_end_request(per_dev->or);
110                         if (per_dev->bio)
111                                 bio_put(per_dev->bio);
112                 }
113
114                 kfree(ios);
115         }
116 }
117 EXPORT_SYMBOL(ore_put_io_state);
118
119 static void _sync_done(struct ore_io_state *ios, void *p)
120 {
121         struct completion *waiting = p;
122
123         complete(waiting);
124 }
125
126 static void _last_io(struct kref *kref)
127 {
128         struct ore_io_state *ios = container_of(
129                                         kref, struct ore_io_state, kref);
130
131         ios->done(ios, ios->private);
132 }
133
134 static void _done_io(struct osd_request *or, void *p)
135 {
136         struct ore_io_state *ios = p;
137
138         kref_put(&ios->kref, _last_io);
139 }
140
141 static int ore_io_execute(struct ore_io_state *ios)
142 {
143         DECLARE_COMPLETION_ONSTACK(wait);
144         bool sync = (ios->done == NULL);
145         int i, ret;
146
147         if (sync) {
148                 ios->done = _sync_done;
149                 ios->private = &wait;
150         }
151
152         for (i = 0; i < ios->numdevs; i++) {
153                 struct osd_request *or = ios->per_dev[i].or;
154                 if (unlikely(!or))
155                         continue;
156
157                 ret = osd_finalize_request(or, 0, _ios_cred(ios, i), NULL);
158                 if (unlikely(ret)) {
159                         ORE_DBGMSG("Failed to osd_finalize_request() => %d\n",
160                                      ret);
161                         return ret;
162                 }
163         }
164
165         kref_init(&ios->kref);
166
167         for (i = 0; i < ios->numdevs; i++) {
168                 struct osd_request *or = ios->per_dev[i].or;
169                 if (unlikely(!or))
170                         continue;
171
172                 kref_get(&ios->kref);
173                 osd_execute_request_async(or, _done_io, ios);
174         }
175
176         kref_put(&ios->kref, _last_io);
177         ret = 0;
178
179         if (sync) {
180                 wait_for_completion(&wait);
181                 ret = ore_check_io(ios, NULL);
182         }
183         return ret;
184 }
185
186 static void _clear_bio(struct bio *bio)
187 {
188         struct bio_vec *bv;
189         unsigned i;
190
191         __bio_for_each_segment(bv, bio, i, 0) {
192                 unsigned this_count = bv->bv_len;
193
194                 if (likely(PAGE_SIZE == this_count))
195                         clear_highpage(bv->bv_page);
196                 else
197                         zero_user(bv->bv_page, bv->bv_offset, this_count);
198         }
199 }
200
201 int ore_check_io(struct ore_io_state *ios, u64 *resid)
202 {
203         enum osd_err_priority acumulated_osd_err = 0;
204         int acumulated_lin_err = 0;
205         int i;
206
207         for (i = 0; i < ios->numdevs; i++) {
208                 struct osd_sense_info osi;
209                 struct osd_request *or = ios->per_dev[i].or;
210                 int ret;
211
212                 if (unlikely(!or))
213                         continue;
214
215                 ret = osd_req_decode_sense(or, &osi);
216                 if (likely(!ret))
217                         continue;
218
219                 if (OSD_ERR_PRI_CLEAR_PAGES == osi.osd_err_pri) {
220                         /* start read offset passed endof file */
221                         _clear_bio(ios->per_dev[i].bio);
222                         ORE_DBGMSG("start read offset passed end of file "
223                                 "offset=0x%llx, length=0x%llx\n",
224                                 _LLU(ios->per_dev[i].offset),
225                                 _LLU(ios->per_dev[i].length));
226
227                         continue; /* we recovered */
228                 }
229
230                 if (osi.osd_err_pri >= acumulated_osd_err) {
231                         acumulated_osd_err = osi.osd_err_pri;
232                         acumulated_lin_err = ret;
233                 }
234         }
235
236         /* TODO: raid specific residual calculations */
237         if (resid) {
238                 if (likely(!acumulated_lin_err))
239                         *resid = 0;
240                 else
241                         *resid = ios->length;
242         }
243
244         return acumulated_lin_err;
245 }
246 EXPORT_SYMBOL(ore_check_io);
247
248 /*
249  * L - logical offset into the file
250  *
251  * U - The number of bytes in a stripe within a group
252  *
253  *      U = stripe_unit * group_width
254  *
255  * T - The number of bytes striped within a group of component objects
256  *     (before advancing to the next group)
257  *
258  *      T = stripe_unit * group_width * group_depth
259  *
260  * S - The number of bytes striped across all component objects
261  *     before the pattern repeats
262  *
263  *      S = stripe_unit * group_width * group_depth * group_count
264  *
265  * M - The "major" (i.e., across all components) stripe number
266  *
267  *      M = L / S
268  *
269  * G - Counts the groups from the beginning of the major stripe
270  *
271  *      G = (L - (M * S)) / T   [or (L % S) / T]
272  *
273  * H - The byte offset within the group
274  *
275  *      H = (L - (M * S)) % T   [or (L % S) % T]
276  *
277  * N - The "minor" (i.e., across the group) stripe number
278  *
279  *      N = H / U
280  *
281  * C - The component index coresponding to L
282  *
283  *      C = (H - (N * U)) / stripe_unit + G * group_width
284  *      [or (L % U) / stripe_unit + G * group_width]
285  *
286  * O - The component offset coresponding to L
287  *
288  *      O = L % stripe_unit + N * stripe_unit + M * group_depth * stripe_unit
289  */
290 struct _striping_info {
291         u64 obj_offset;
292         u64 group_length;
293         u64 M; /* for truncate */
294         unsigned dev;
295         unsigned unit_off;
296 };
297
298 static void _calc_stripe_info(struct ore_layout *layout, u64 file_offset,
299                               struct _striping_info *si)
300 {
301         u32     stripe_unit = layout->stripe_unit;
302         u32     group_width = layout->group_width;
303         u64     group_depth = layout->group_depth;
304
305         u32     U = stripe_unit * group_width;
306         u64     T = U * group_depth;
307         u64     S = T * layout->group_count;
308         u64     M = div64_u64(file_offset, S);
309
310         /*
311         G = (L - (M * S)) / T
312         H = (L - (M * S)) % T
313         */
314         u64     LmodS = file_offset - M * S;
315         u32     G = div64_u64(LmodS, T);
316         u64     H = LmodS - G * T;
317
318         u32     N = div_u64(H, U);
319
320         /* "H - (N * U)" is just "H % U" so it's bound to u32 */
321         si->dev = (u32)(H - (N * U)) / stripe_unit + G * group_width;
322         si->dev *= layout->mirrors_p1;
323
324         div_u64_rem(file_offset, stripe_unit, &si->unit_off);
325
326         si->obj_offset = si->unit_off + (N * stripe_unit) +
327                                   (M * group_depth * stripe_unit);
328
329         si->group_length = T - H;
330         si->M = M;
331 }
332
333 static int _add_stripe_unit(struct ore_io_state *ios,  unsigned *cur_pg,
334                 unsigned pgbase, struct ore_per_dev_state *per_dev,
335                 int cur_len)
336 {
337         unsigned pg = *cur_pg;
338         struct request_queue *q =
339                         osd_request_queue(_ios_od(ios, per_dev->dev));
340
341         per_dev->length += cur_len;
342
343         if (per_dev->bio == NULL) {
344                 unsigned pages_in_stripe = ios->layout->group_width *
345                                         (ios->layout->stripe_unit / PAGE_SIZE);
346                 unsigned bio_size = (ios->nr_pages + pages_in_stripe) /
347                                                 ios->layout->group_width;
348
349                 per_dev->bio = bio_kmalloc(GFP_KERNEL, bio_size);
350                 if (unlikely(!per_dev->bio)) {
351                         ORE_DBGMSG("Failed to allocate BIO size=%u\n",
352                                      bio_size);
353                         return -ENOMEM;
354                 }
355         }
356
357         while (cur_len > 0) {
358                 unsigned pglen = min_t(unsigned, PAGE_SIZE - pgbase, cur_len);
359                 unsigned added_len;
360
361                 BUG_ON(ios->nr_pages <= pg);
362                 cur_len -= pglen;
363
364                 added_len = bio_add_pc_page(q, per_dev->bio, ios->pages[pg],
365                                             pglen, pgbase);
366                 if (unlikely(pglen != added_len))
367                         return -ENOMEM;
368                 pgbase = 0;
369                 ++pg;
370         }
371         BUG_ON(cur_len);
372
373         *cur_pg = pg;
374         return 0;
375 }
376
377 static int _prepare_one_group(struct ore_io_state *ios, u64 length,
378                               struct _striping_info *si)
379 {
380         unsigned stripe_unit = ios->layout->stripe_unit;
381         unsigned mirrors_p1 = ios->layout->mirrors_p1;
382         unsigned devs_in_group = ios->layout->group_width * mirrors_p1;
383         unsigned dev = si->dev;
384         unsigned first_dev = dev - (dev % devs_in_group);
385         unsigned max_comp = ios->numdevs ? ios->numdevs - mirrors_p1 : 0;
386         unsigned cur_pg = ios->pages_consumed;
387         int ret = 0;
388
389         while (length) {
390                 struct ore_per_dev_state *per_dev = &ios->per_dev[dev];
391                 unsigned cur_len, page_off = 0;
392
393                 if (!per_dev->length) {
394                         per_dev->dev = dev;
395                         if (dev < si->dev) {
396                                 per_dev->offset = si->obj_offset + stripe_unit -
397                                                                    si->unit_off;
398                                 cur_len = stripe_unit;
399                         } else if (dev == si->dev) {
400                                 per_dev->offset = si->obj_offset;
401                                 cur_len = stripe_unit - si->unit_off;
402                                 page_off = si->unit_off & ~PAGE_MASK;
403                                 BUG_ON(page_off && (page_off != ios->pgbase));
404                         } else { /* dev > si->dev */
405                                 per_dev->offset = si->obj_offset - si->unit_off;
406                                 cur_len = stripe_unit;
407                         }
408
409                         if (max_comp < dev)
410                                 max_comp = dev;
411                 } else {
412                         cur_len = stripe_unit;
413                 }
414                 if (cur_len >= length)
415                         cur_len = length;
416
417                 ret = _add_stripe_unit(ios, &cur_pg, page_off , per_dev,
418                                        cur_len);
419                 if (unlikely(ret))
420                         goto out;
421
422                 dev += mirrors_p1;
423                 dev = (dev % devs_in_group) + first_dev;
424
425                 length -= cur_len;
426         }
427 out:
428         ios->numdevs = max_comp + mirrors_p1;
429         ios->pages_consumed = cur_pg;
430         return ret;
431 }
432
433 static int _prepare_for_striping(struct ore_io_state *ios)
434 {
435         u64 length = ios->length;
436         u64 offset = ios->offset;
437         struct _striping_info si;
438         int ret = 0;
439
440         if (!ios->pages) {
441                 if (ios->kern_buff) {
442                         struct ore_per_dev_state *per_dev = &ios->per_dev[0];
443
444                         _calc_stripe_info(ios->layout, ios->offset, &si);
445                         per_dev->offset = si.obj_offset;
446                         per_dev->dev = si.dev;
447
448                         /* no cross device without page array */
449                         BUG_ON((ios->layout->group_width > 1) &&
450                                (si.unit_off + ios->length >
451                                 ios->layout->stripe_unit));
452                 }
453                 ios->numdevs = ios->layout->mirrors_p1;
454                 return 0;
455         }
456
457         while (length) {
458                 _calc_stripe_info(ios->layout, offset, &si);
459
460                 if (length < si.group_length)
461                         si.group_length = length;
462
463                 ret = _prepare_one_group(ios, si.group_length, &si);
464                 if (unlikely(ret))
465                         goto out;
466
467                 offset += si.group_length;
468                 length -= si.group_length;
469         }
470
471 out:
472         return ret;
473 }
474
475 int ore_create(struct ore_io_state *ios)
476 {
477         int i, ret;
478
479         for (i = 0; i < ios->comps->numdevs; i++) {
480                 struct osd_request *or;
481
482                 or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
483                 if (unlikely(!or)) {
484                         ORE_ERR("%s: osd_start_request failed\n", __func__);
485                         ret = -ENOMEM;
486                         goto out;
487                 }
488                 ios->per_dev[i].or = or;
489                 ios->numdevs++;
490
491                 osd_req_create_object(or, _ios_obj(ios, i));
492         }
493         ret = ore_io_execute(ios);
494
495 out:
496         return ret;
497 }
498 EXPORT_SYMBOL(ore_create);
499
500 int ore_remove(struct ore_io_state *ios)
501 {
502         int i, ret;
503
504         for (i = 0; i < ios->comps->numdevs; i++) {
505                 struct osd_request *or;
506
507                 or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
508                 if (unlikely(!or)) {
509                         ORE_ERR("%s: osd_start_request failed\n", __func__);
510                         ret = -ENOMEM;
511                         goto out;
512                 }
513                 ios->per_dev[i].or = or;
514                 ios->numdevs++;
515
516                 osd_req_remove_object(or, _ios_obj(ios, i));
517         }
518         ret = ore_io_execute(ios);
519
520 out:
521         return ret;
522 }
523 EXPORT_SYMBOL(ore_remove);
524
525 static int _write_mirror(struct ore_io_state *ios, int cur_comp)
526 {
527         struct ore_per_dev_state *master_dev = &ios->per_dev[cur_comp];
528         unsigned dev = ios->per_dev[cur_comp].dev;
529         unsigned last_comp = cur_comp + ios->layout->mirrors_p1;
530         int ret = 0;
531
532         if (ios->pages && !master_dev->length)
533                 return 0; /* Just an empty slot */
534
535         for (; cur_comp < last_comp; ++cur_comp, ++dev) {
536                 struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
537                 struct osd_request *or;
538
539                 or = osd_start_request(_ios_od(ios, dev), GFP_KERNEL);
540                 if (unlikely(!or)) {
541                         ORE_ERR("%s: osd_start_request failed\n", __func__);
542                         ret = -ENOMEM;
543                         goto out;
544                 }
545                 per_dev->or = or;
546                 per_dev->offset = master_dev->offset;
547
548                 if (ios->pages) {
549                         struct bio *bio;
550
551                         if (per_dev != master_dev) {
552                                 bio = bio_kmalloc(GFP_KERNEL,
553                                                   master_dev->bio->bi_max_vecs);
554                                 if (unlikely(!bio)) {
555                                         ORE_DBGMSG(
556                                               "Failed to allocate BIO size=%u\n",
557                                               master_dev->bio->bi_max_vecs);
558                                         ret = -ENOMEM;
559                                         goto out;
560                                 }
561
562                                 __bio_clone(bio, master_dev->bio);
563                                 bio->bi_bdev = NULL;
564                                 bio->bi_next = NULL;
565                                 per_dev->length = master_dev->length;
566                                 per_dev->bio =  bio;
567                                 per_dev->dev = dev;
568                         } else {
569                                 bio = master_dev->bio;
570                                 /* FIXME: bio_set_dir() */
571                                 bio->bi_rw |= REQ_WRITE;
572                         }
573
574                         osd_req_write(or, _ios_obj(ios, dev), per_dev->offset,
575                                       bio, per_dev->length);
576                         ORE_DBGMSG("write(0x%llx) offset=0x%llx "
577                                       "length=0x%llx dev=%d\n",
578                                      _LLU(_ios_obj(ios, dev)->id),
579                                      _LLU(per_dev->offset),
580                                      _LLU(per_dev->length), dev);
581                 } else if (ios->kern_buff) {
582                         ret = osd_req_write_kern(or, _ios_obj(ios, dev),
583                                                  per_dev->offset,
584                                                  ios->kern_buff, ios->length);
585                         if (unlikely(ret))
586                                 goto out;
587                         ORE_DBGMSG2("write_kern(0x%llx) offset=0x%llx "
588                                       "length=0x%llx dev=%d\n",
589                                      _LLU(_ios_obj(ios, dev)->id),
590                                      _LLU(per_dev->offset),
591                                      _LLU(ios->length), dev);
592                 } else {
593                         osd_req_set_attributes(or, _ios_obj(ios, dev));
594                         ORE_DBGMSG2("obj(0x%llx) set_attributes=%d dev=%d\n",
595                                      _LLU(_ios_obj(ios, dev)->id),
596                                      ios->out_attr_len, dev);
597                 }
598
599                 if (ios->out_attr)
600                         osd_req_add_set_attr_list(or, ios->out_attr,
601                                                   ios->out_attr_len);
602
603                 if (ios->in_attr)
604                         osd_req_add_get_attr_list(or, ios->in_attr,
605                                                   ios->in_attr_len);
606         }
607
608 out:
609         return ret;
610 }
611
612 int ore_write(struct ore_io_state *ios)
613 {
614         int i;
615         int ret;
616
617         ret = _prepare_for_striping(ios);
618         if (unlikely(ret))
619                 return ret;
620
621         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
622                 ret = _write_mirror(ios, i);
623                 if (unlikely(ret))
624                         return ret;
625         }
626
627         ret = ore_io_execute(ios);
628         return ret;
629 }
630 EXPORT_SYMBOL(ore_write);
631
632 static int _read_mirror(struct ore_io_state *ios, unsigned cur_comp)
633 {
634         struct osd_request *or;
635         struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
636         struct osd_obj_id *obj = _ios_obj(ios, cur_comp);
637         unsigned first_dev = (unsigned)obj->id;
638
639         if (ios->pages && !per_dev->length)
640                 return 0; /* Just an empty slot */
641
642         first_dev = per_dev->dev + first_dev % ios->layout->mirrors_p1;
643         or = osd_start_request(_ios_od(ios, first_dev), GFP_KERNEL);
644         if (unlikely(!or)) {
645                 ORE_ERR("%s: osd_start_request failed\n", __func__);
646                 return -ENOMEM;
647         }
648         per_dev->or = or;
649
650         if (ios->pages) {
651                 osd_req_read(or, obj, per_dev->offset,
652                                 per_dev->bio, per_dev->length);
653                 ORE_DBGMSG("read(0x%llx) offset=0x%llx length=0x%llx"
654                              " dev=%d\n", _LLU(obj->id),
655                              _LLU(per_dev->offset), _LLU(per_dev->length),
656                              first_dev);
657         } else if (ios->kern_buff) {
658                 int ret = osd_req_read_kern(or, obj, per_dev->offset,
659                                             ios->kern_buff, ios->length);
660                 ORE_DBGMSG2("read_kern(0x%llx) offset=0x%llx "
661                               "length=0x%llx dev=%d ret=>%d\n",
662                               _LLU(obj->id), _LLU(per_dev->offset),
663                               _LLU(ios->length), first_dev, ret);
664                 if (unlikely(ret))
665                         return ret;
666         } else {
667                 osd_req_get_attributes(or, obj);
668                 ORE_DBGMSG2("obj(0x%llx) get_attributes=%d dev=%d\n",
669                               _LLU(obj->id),
670                               ios->in_attr_len, first_dev);
671         }
672         if (ios->out_attr)
673                 osd_req_add_set_attr_list(or, ios->out_attr, ios->out_attr_len);
674
675         if (ios->in_attr)
676                 osd_req_add_get_attr_list(or, ios->in_attr, ios->in_attr_len);
677
678         return 0;
679 }
680
681 int ore_read(struct ore_io_state *ios)
682 {
683         int i;
684         int ret;
685
686         ret = _prepare_for_striping(ios);
687         if (unlikely(ret))
688                 return ret;
689
690         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
691                 ret = _read_mirror(ios, i);
692                 if (unlikely(ret))
693                         return ret;
694         }
695
696         ret = ore_io_execute(ios);
697         return ret;
698 }
699 EXPORT_SYMBOL(ore_read);
700
701 int extract_attr_from_ios(struct ore_io_state *ios, struct osd_attr *attr)
702 {
703         struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
704         void *iter = NULL;
705         int nelem;
706
707         do {
708                 nelem = 1;
709                 osd_req_decode_get_attr_list(ios->per_dev[0].or,
710                                              &cur_attr, &nelem, &iter);
711                 if ((cur_attr.attr_page == attr->attr_page) &&
712                     (cur_attr.attr_id == attr->attr_id)) {
713                         attr->len = cur_attr.len;
714                         attr->val_ptr = cur_attr.val_ptr;
715                         return 0;
716                 }
717         } while (iter);
718
719         return -EIO;
720 }
721 EXPORT_SYMBOL(extract_attr_from_ios);
722
723 static int _truncate_mirrors(struct ore_io_state *ios, unsigned cur_comp,
724                              struct osd_attr *attr)
725 {
726         int last_comp = cur_comp + ios->layout->mirrors_p1;
727
728         for (; cur_comp < last_comp; ++cur_comp) {
729                 struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
730                 struct osd_request *or;
731
732                 or = osd_start_request(_ios_od(ios, cur_comp), GFP_KERNEL);
733                 if (unlikely(!or)) {
734                         ORE_ERR("%s: osd_start_request failed\n", __func__);
735                         return -ENOMEM;
736                 }
737                 per_dev->or = or;
738
739                 osd_req_set_attributes(or, _ios_obj(ios, cur_comp));
740                 osd_req_add_set_attr_list(or, attr, 1);
741         }
742
743         return 0;
744 }
745
746 struct _trunc_info {
747         struct _striping_info si;
748         u64 prev_group_obj_off;
749         u64 next_group_obj_off;
750
751         unsigned first_group_dev;
752         unsigned nex_group_dev;
753         unsigned max_devs;
754 };
755
756 static void _calc_trunk_info(struct ore_layout *layout, u64 file_offset,
757                              struct _trunc_info *ti)
758 {
759         unsigned stripe_unit = layout->stripe_unit;
760
761         _calc_stripe_info(layout, file_offset, &ti->si);
762
763         ti->prev_group_obj_off = ti->si.M * stripe_unit;
764         ti->next_group_obj_off = ti->si.M ? (ti->si.M - 1) * stripe_unit : 0;
765
766         ti->first_group_dev = ti->si.dev - (ti->si.dev % layout->group_width);
767         ti->nex_group_dev = ti->first_group_dev + layout->group_width;
768         ti->max_devs = layout->group_width * layout->group_count;
769 }
770
771 int ore_truncate(struct ore_layout *layout, struct ore_components *comps,
772                    u64 size)
773 {
774         struct ore_io_state *ios;
775         struct exofs_trunc_attr {
776                 struct osd_attr attr;
777                 __be64 newsize;
778         } *size_attrs;
779         struct _trunc_info ti;
780         int i, ret;
781
782         ret = ore_get_io_state(layout, comps, &ios);
783         if (unlikely(ret))
784                 return ret;
785
786         _calc_trunk_info(ios->layout, size, &ti);
787
788         size_attrs = kcalloc(ti.max_devs, sizeof(*size_attrs),
789                              GFP_KERNEL);
790         if (unlikely(!size_attrs)) {
791                 ret = -ENOMEM;
792                 goto out;
793         }
794
795         ios->numdevs = ios->comps->numdevs;
796
797         for (i = 0; i < ti.max_devs; ++i) {
798                 struct exofs_trunc_attr *size_attr = &size_attrs[i];
799                 u64 obj_size;
800
801                 if (i < ti.first_group_dev)
802                         obj_size = ti.prev_group_obj_off;
803                 else if (i >= ti.nex_group_dev)
804                         obj_size = ti.next_group_obj_off;
805                 else if (i < ti.si.dev) /* dev within this group */
806                         obj_size = ti.si.obj_offset +
807                                       ios->layout->stripe_unit - ti.si.unit_off;
808                 else if (i == ti.si.dev)
809                         obj_size = ti.si.obj_offset;
810                 else /* i > ti.dev */
811                         obj_size = ti.si.obj_offset - ti.si.unit_off;
812
813                 size_attr->newsize = cpu_to_be64(obj_size);
814                 size_attr->attr = g_attr_logical_length;
815                 size_attr->attr.val_ptr = &size_attr->newsize;
816
817                 ORE_DBGMSG("trunc(0x%llx) obj_offset=0x%llx dev=%d\n",
818                              _LLU(comps->comps->obj.id), _LLU(obj_size), i);
819                 ret = _truncate_mirrors(ios, i * ios->layout->mirrors_p1,
820                                         &size_attr->attr);
821                 if (unlikely(ret))
822                         goto out;
823         }
824         ret = ore_io_execute(ios);
825
826 out:
827         kfree(size_attrs);
828         ore_put_io_state(ios);
829         return ret;
830 }
831 EXPORT_SYMBOL(ore_truncate);
832
833 const struct osd_attr g_attr_logical_length = ATTR_DEF(
834         OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
835 EXPORT_SYMBOL(g_attr_logical_length);