ore: Enable RAID5 mounts
[pandora-kernel.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 #include <linux/lcm.h>
28
29 #include "ore_raid.h"
30
31 MODULE_AUTHOR("Boaz Harrosh <bharrosh@panasas.com>");
32 MODULE_DESCRIPTION("Objects Raid Engine ore.ko");
33 MODULE_LICENSE("GPL");
34
35 /* ore_verify_layout does a couple of things:
36  * 1. Given a minimum number of needed parameters fixes up the rest of the
37  *    members to be operatonals for the ore. The needed parameters are those
38  *    that are defined by the pnfs-objects layout STD.
39  * 2. Check to see if the current ore code actually supports these parameters
40  *    for example stripe_unit must be a multple of the system PAGE_SIZE,
41  *    and etc...
42  * 3. Cache some havily used calculations that will be needed by users.
43  */
44
45 enum { BIO_MAX_PAGES_KMALLOC =
46                 (PAGE_SIZE - sizeof(struct bio)) / sizeof(struct bio_vec),};
47
48 int ore_verify_layout(unsigned total_comps, struct ore_layout *layout)
49 {
50         u64 stripe_length;
51
52         switch (layout->raid_algorithm) {
53         case PNFS_OSD_RAID_0:
54                 layout->parity = 0;
55                 break;
56         case PNFS_OSD_RAID_5:
57                 layout->parity = 1;
58                 break;
59         case PNFS_OSD_RAID_PQ:
60         case PNFS_OSD_RAID_4:
61         default:
62                 ORE_ERR("Only RAID_0/5 for now\n");
63                 return -EINVAL;
64         }
65         if (0 != (layout->stripe_unit & ~PAGE_MASK)) {
66                 ORE_ERR("Stripe Unit(0x%llx)"
67                           " must be Multples of PAGE_SIZE(0x%lx)\n",
68                           _LLU(layout->stripe_unit), PAGE_SIZE);
69                 return -EINVAL;
70         }
71         if (layout->group_width) {
72                 if (!layout->group_depth) {
73                         ORE_ERR("group_depth == 0 && group_width != 0\n");
74                         return -EINVAL;
75                 }
76                 if (total_comps < (layout->group_width * layout->mirrors_p1)) {
77                         ORE_ERR("Data Map wrong, "
78                                 "numdevs=%d < group_width=%d * mirrors=%d\n",
79                                 total_comps, layout->group_width,
80                                 layout->mirrors_p1);
81                         return -EINVAL;
82                 }
83                 layout->group_count = total_comps / layout->mirrors_p1 /
84                                                 layout->group_width;
85         } else {
86                 if (layout->group_depth) {
87                         printk(KERN_NOTICE "Warning: group_depth ignored "
88                                 "group_width == 0 && group_depth == %lld\n",
89                                 _LLU(layout->group_depth));
90                 }
91                 layout->group_width = total_comps / layout->mirrors_p1;
92                 layout->group_depth = -1;
93                 layout->group_count = 1;
94         }
95
96         stripe_length = (u64)layout->group_width * layout->stripe_unit;
97         if (stripe_length >= (1ULL << 32)) {
98                 ORE_ERR("Stripe_length(0x%llx) >= 32bit is not supported\n",
99                         _LLU(stripe_length));
100                 return -EINVAL;
101         }
102
103         layout->max_io_length =
104                 (BIO_MAX_PAGES_KMALLOC * PAGE_SIZE - layout->stripe_unit) *
105                                                         layout->group_width;
106         if (layout->parity) {
107                 unsigned stripe_length =
108                                 (layout->group_width - layout->parity) *
109                                 layout->stripe_unit;
110
111                 layout->max_io_length /= stripe_length;
112                 layout->max_io_length *= stripe_length;
113         }
114         return 0;
115 }
116 EXPORT_SYMBOL(ore_verify_layout);
117
118 static u8 *_ios_cred(struct ore_io_state *ios, unsigned index)
119 {
120         return ios->oc->comps[index & ios->oc->single_comp].cred;
121 }
122
123 static struct osd_obj_id *_ios_obj(struct ore_io_state *ios, unsigned index)
124 {
125         return &ios->oc->comps[index & ios->oc->single_comp].obj;
126 }
127
128 static struct osd_dev *_ios_od(struct ore_io_state *ios, unsigned index)
129 {
130         ORE_DBGMSG2("oc->first_dev=%d oc->numdevs=%d i=%d oc->ods=%p\n",
131                     ios->oc->first_dev, ios->oc->numdevs, index,
132                     ios->oc->ods);
133
134         return ore_comp_dev(ios->oc, index);
135 }
136
137 int  _ore_get_io_state(struct ore_layout *layout,
138                         struct ore_components *oc, unsigned numdevs,
139                         unsigned sgs_per_dev, unsigned num_par_pages,
140                         struct ore_io_state **pios)
141 {
142         struct ore_io_state *ios;
143         struct page **pages;
144         struct osd_sg_entry *sgilist;
145         struct __alloc_all_io_state {
146                 struct ore_io_state ios;
147                 struct ore_per_dev_state per_dev[numdevs];
148                 union {
149                         struct osd_sg_entry sglist[sgs_per_dev * numdevs];
150                         struct page *pages[num_par_pages];
151                 };
152         } *_aios;
153
154         if (likely(sizeof(*_aios) <= PAGE_SIZE)) {
155                 _aios = kzalloc(sizeof(*_aios), GFP_KERNEL);
156                 if (unlikely(!_aios)) {
157                         ORE_DBGMSG("Failed kzalloc bytes=%zd\n",
158                                    sizeof(*_aios));
159                         *pios = NULL;
160                         return -ENOMEM;
161                 }
162                 pages = num_par_pages ? _aios->pages : NULL;
163                 sgilist = sgs_per_dev ? _aios->sglist : NULL;
164                 ios = &_aios->ios;
165         } else {
166                 struct __alloc_small_io_state {
167                         struct ore_io_state ios;
168                         struct ore_per_dev_state per_dev[numdevs];
169                 } *_aio_small;
170                 union __extra_part {
171                         struct osd_sg_entry sglist[sgs_per_dev * numdevs];
172                         struct page *pages[num_par_pages];
173                 } *extra_part;
174
175                 _aio_small = kzalloc(sizeof(*_aio_small), GFP_KERNEL);
176                 if (unlikely(!_aio_small)) {
177                         ORE_DBGMSG("Failed alloc first part bytes=%zd\n",
178                                    sizeof(*_aio_small));
179                         *pios = NULL;
180                         return -ENOMEM;
181                 }
182                 extra_part = kzalloc(sizeof(*extra_part), GFP_KERNEL);
183                 if (unlikely(!extra_part)) {
184                         ORE_DBGMSG("Failed alloc second part bytes=%zd\n",
185                                    sizeof(*extra_part));
186                         kfree(_aio_small);
187                         *pios = NULL;
188                         return -ENOMEM;
189                 }
190
191                 pages = num_par_pages ? extra_part->pages : NULL;
192                 sgilist = sgs_per_dev ? extra_part->sglist : NULL;
193                 /* In this case the per_dev[0].sgilist holds the pointer to
194                  * be freed
195                  */
196                 ios = &_aio_small->ios;
197                 ios->extra_part_alloc = true;
198         }
199
200         if (pages) {
201                 ios->parity_pages = pages;
202                 ios->max_par_pages = num_par_pages;
203         }
204         if (sgilist) {
205                 unsigned d;
206
207                 for (d = 0; d < numdevs; ++d) {
208                         ios->per_dev[d].sglist = sgilist;
209                         sgilist += sgs_per_dev;
210                 }
211                 ios->sgs_per_dev = sgs_per_dev;
212         }
213
214         ios->layout = layout;
215         ios->oc = oc;
216         *pios = ios;
217         return 0;
218 }
219
220 /* Allocate an io_state for only a single group of devices
221  *
222  * If a user needs to call ore_read/write() this version must be used becase it
223  * allocates extra stuff for striping and raid.
224  * The ore might decide to only IO less then @length bytes do to alignmets
225  * and constrains as follows:
226  * - The IO cannot cross group boundary.
227  * - In raid5/6 The end of the IO must align at end of a stripe eg.
228  *   (@offset + @length) % strip_size == 0. Or the complete range is within a
229  *   single stripe.
230  * - Memory condition only permitted a shorter IO. (A user can use @length=~0
231  *   And check the returned ios->length for max_io_size.)
232  *
233  * The caller must check returned ios->length (and/or ios->nr_pages) and
234  * re-issue these pages that fall outside of ios->length
235  */
236 int  ore_get_rw_state(struct ore_layout *layout, struct ore_components *oc,
237                       bool is_reading, u64 offset, u64 length,
238                       struct ore_io_state **pios)
239 {
240         struct ore_io_state *ios;
241         unsigned numdevs = layout->group_width * layout->mirrors_p1;
242         unsigned sgs_per_dev = 0, max_par_pages = 0;
243         int ret;
244
245         if (layout->parity && length) {
246                 unsigned data_devs = layout->group_width - layout->parity;
247                 unsigned stripe_size = layout->stripe_unit * data_devs;
248                 unsigned pages_in_unit = layout->stripe_unit / PAGE_SIZE;
249                 u32 remainder;
250                 u64 num_stripes;
251                 u64 num_raid_units;
252
253                 num_stripes = div_u64_rem(length, stripe_size, &remainder);
254                 if (remainder)
255                         ++num_stripes;
256
257                 num_raid_units =  num_stripes * layout->parity;
258
259                 if (is_reading) {
260                         /* For reads add per_dev sglist array */
261                         /* TODO: Raid 6 we need twice more. Actually:
262                         *         num_stripes / LCMdP(W,P);
263                         *         if (W%P != 0) num_stripes *= parity;
264                         */
265
266                         /* first/last seg is split */
267                         num_raid_units += layout->group_width;
268                         sgs_per_dev = div_u64(num_raid_units, data_devs);
269                 } else {
270                         /* For Writes add parity pages array. */
271                         max_par_pages = num_raid_units * pages_in_unit *
272                                                 sizeof(struct page *);
273                 }
274         }
275
276         ret = _ore_get_io_state(layout, oc, numdevs, sgs_per_dev, max_par_pages,
277                                 pios);
278         if (unlikely(ret))
279                 return ret;
280
281         ios = *pios;
282         ios->reading = is_reading;
283         ios->offset = offset;
284
285         if (length) {
286                 ore_calc_stripe_info(layout, offset, length, &ios->si);
287                 ios->length = ios->si.length;
288                 ios->nr_pages = (ios->length + PAGE_SIZE - 1) / PAGE_SIZE;
289                 if (layout->parity)
290                         _ore_post_alloc_raid_stuff(ios);
291         }
292
293         return 0;
294 }
295 EXPORT_SYMBOL(ore_get_rw_state);
296
297 /* Allocate an io_state for all the devices in the comps array
298  *
299  * This version of io_state allocation is used mostly by create/remove
300  * and trunc where we currently need all the devices. The only wastful
301  * bit is the read/write_attributes with no IO. Those sites should
302  * be converted to use ore_get_rw_state() with length=0
303  */
304 int  ore_get_io_state(struct ore_layout *layout, struct ore_components *oc,
305                       struct ore_io_state **pios)
306 {
307         return _ore_get_io_state(layout, oc, oc->numdevs, 0, 0, pios);
308 }
309 EXPORT_SYMBOL(ore_get_io_state);
310
311 void ore_put_io_state(struct ore_io_state *ios)
312 {
313         if (ios) {
314                 unsigned i;
315
316                 for (i = 0; i < ios->numdevs; i++) {
317                         struct ore_per_dev_state *per_dev = &ios->per_dev[i];
318
319                         if (per_dev->or)
320                                 osd_end_request(per_dev->or);
321                         if (per_dev->bio)
322                                 bio_put(per_dev->bio);
323                 }
324
325                 _ore_free_raid_stuff(ios);
326                 kfree(ios);
327         }
328 }
329 EXPORT_SYMBOL(ore_put_io_state);
330
331 static void _sync_done(struct ore_io_state *ios, void *p)
332 {
333         struct completion *waiting = p;
334
335         complete(waiting);
336 }
337
338 static void _last_io(struct kref *kref)
339 {
340         struct ore_io_state *ios = container_of(
341                                         kref, struct ore_io_state, kref);
342
343         ios->done(ios, ios->private);
344 }
345
346 static void _done_io(struct osd_request *or, void *p)
347 {
348         struct ore_io_state *ios = p;
349
350         kref_put(&ios->kref, _last_io);
351 }
352
353 int ore_io_execute(struct ore_io_state *ios)
354 {
355         DECLARE_COMPLETION_ONSTACK(wait);
356         bool sync = (ios->done == NULL);
357         int i, ret;
358
359         if (sync) {
360                 ios->done = _sync_done;
361                 ios->private = &wait;
362         }
363
364         for (i = 0; i < ios->numdevs; i++) {
365                 struct osd_request *or = ios->per_dev[i].or;
366                 if (unlikely(!or))
367                         continue;
368
369                 ret = osd_finalize_request(or, 0, _ios_cred(ios, i), NULL);
370                 if (unlikely(ret)) {
371                         ORE_DBGMSG("Failed to osd_finalize_request() => %d\n",
372                                      ret);
373                         return ret;
374                 }
375         }
376
377         kref_init(&ios->kref);
378
379         for (i = 0; i < ios->numdevs; i++) {
380                 struct osd_request *or = ios->per_dev[i].or;
381                 if (unlikely(!or))
382                         continue;
383
384                 kref_get(&ios->kref);
385                 osd_execute_request_async(or, _done_io, ios);
386         }
387
388         kref_put(&ios->kref, _last_io);
389         ret = 0;
390
391         if (sync) {
392                 wait_for_completion(&wait);
393                 ret = ore_check_io(ios, NULL);
394         }
395         return ret;
396 }
397
398 static void _clear_bio(struct bio *bio)
399 {
400         struct bio_vec *bv;
401         unsigned i;
402
403         __bio_for_each_segment(bv, bio, i, 0) {
404                 unsigned this_count = bv->bv_len;
405
406                 if (likely(PAGE_SIZE == this_count))
407                         clear_highpage(bv->bv_page);
408                 else
409                         zero_user(bv->bv_page, bv->bv_offset, this_count);
410         }
411 }
412
413 int ore_check_io(struct ore_io_state *ios, ore_on_dev_error on_dev_error)
414 {
415         enum osd_err_priority acumulated_osd_err = 0;
416         int acumulated_lin_err = 0;
417         int i;
418
419         for (i = 0; i < ios->numdevs; i++) {
420                 struct osd_sense_info osi;
421                 struct ore_per_dev_state *per_dev = &ios->per_dev[i];
422                 struct osd_request *or = per_dev->or;
423                 int ret;
424
425                 if (unlikely(!or))
426                         continue;
427
428                 ret = osd_req_decode_sense(or, &osi);
429                 if (likely(!ret))
430                         continue;
431
432                 if (OSD_ERR_PRI_CLEAR_PAGES == osi.osd_err_pri) {
433                         /* start read offset passed endof file */
434                         _clear_bio(per_dev->bio);
435                         ORE_DBGMSG("start read offset passed end of file "
436                                 "offset=0x%llx, length=0x%llx\n",
437                                 _LLU(per_dev->offset),
438                                 _LLU(per_dev->length));
439
440                         continue; /* we recovered */
441                 }
442
443                 if (on_dev_error) {
444                         u64 residual = ios->reading ?
445                                         or->in.residual : or->out.residual;
446                         u64 offset = (ios->offset + ios->length) - residual;
447                         struct ore_dev *od = ios->oc->ods[
448                                         per_dev->dev - ios->oc->first_dev];
449
450                         on_dev_error(ios, od, per_dev->dev, osi.osd_err_pri,
451                                      offset, residual);
452                 }
453                 if (osi.osd_err_pri >= acumulated_osd_err) {
454                         acumulated_osd_err = osi.osd_err_pri;
455                         acumulated_lin_err = ret;
456                 }
457         }
458
459         return acumulated_lin_err;
460 }
461 EXPORT_SYMBOL(ore_check_io);
462
463 /*
464  * L - logical offset into the file
465  *
466  * D - number of Data devices
467  *      D = group_width - parity
468  *
469  * U - The number of bytes in a stripe within a group
470  *      U =  stripe_unit * D
471  *
472  * T - The number of bytes striped within a group of component objects
473  *     (before advancing to the next group)
474  *      T = U * group_depth
475  *
476  * S - The number of bytes striped across all component objects
477  *     before the pattern repeats
478  *      S = T * group_count
479  *
480  * M - The "major" (i.e., across all components) cycle number
481  *      M = L / S
482  *
483  * G - Counts the groups from the beginning of the major cycle
484  *      G = (L - (M * S)) / T   [or (L % S) / T]
485  *
486  * H - The byte offset within the group
487  *      H = (L - (M * S)) % T   [or (L % S) % T]
488  *
489  * N - The "minor" (i.e., across the group) stripe number
490  *      N = H / U
491  *
492  * C - The component index coresponding to L
493  *
494  *      C = (H - (N * U)) / stripe_unit + G * D
495  *      [or (L % U) / stripe_unit + G * D]
496  *
497  * O - The component offset coresponding to L
498  *      O = L % stripe_unit + N * stripe_unit + M * group_depth * stripe_unit
499  *
500  * LCMdP – Parity cycle: Lowest Common Multiple of group_width, parity
501  *          divide by parity
502  *      LCMdP = lcm(group_width, parity) / parity
503  *
504  * R - The parity Rotation stripe
505  *     (Note parity cycle always starts at a group's boundary)
506  *      R = N % LCMdP
507  *
508  * I = the first parity device index
509  *      I = (group_width + group_width - R*parity - parity) % group_width
510  *
511  * Craid - The component index Rotated
512  *      Craid = (group_width + C - R*parity) % group_width
513  *      (We add the group_width to avoid negative numbers modulo math)
514  */
515 void ore_calc_stripe_info(struct ore_layout *layout, u64 file_offset,
516                           u64 length, struct ore_striping_info *si)
517 {
518         u32     stripe_unit = layout->stripe_unit;
519         u32     group_width = layout->group_width;
520         u64     group_depth = layout->group_depth;
521         u32     parity      = layout->parity;
522
523         u32     D = group_width - parity;
524         u32     U = D * stripe_unit;
525         u64     T = U * group_depth;
526         u64     S = T * layout->group_count;
527         u64     M = div64_u64(file_offset, S);
528
529         /*
530         G = (L - (M * S)) / T
531         H = (L - (M * S)) % T
532         */
533         u64     LmodS = file_offset - M * S;
534         u32     G = div64_u64(LmodS, T);
535         u64     H = LmodS - G * T;
536
537         u32     N = div_u64(H, U);
538
539         /* "H - (N * U)" is just "H % U" so it's bound to u32 */
540         u32     C = (u32)(H - (N * U)) / stripe_unit + G * group_width;
541
542         div_u64_rem(file_offset, stripe_unit, &si->unit_off);
543
544         si->obj_offset = si->unit_off + (N * stripe_unit) +
545                                   (M * group_depth * stripe_unit);
546
547         if (parity) {
548                 u32 LCMdP = lcm(group_width, parity) / parity;
549                 /* R     = N % LCMdP; */
550                 u32 RxP   = (N % LCMdP) * parity;
551                 u32 first_dev = C - C % group_width;
552
553                 si->par_dev = (group_width + group_width - parity - RxP) %
554                               group_width + first_dev;
555                 si->dev = (group_width + C - RxP) % group_width + first_dev;
556                 si->bytes_in_stripe = U;
557                 si->first_stripe_start = M * S + G * T + N * U;
558         } else {
559                 /* Make the math correct see _prepare_one_group */
560                 si->par_dev = group_width;
561                 si->dev = C;
562         }
563
564         si->dev *= layout->mirrors_p1;
565         si->par_dev *= layout->mirrors_p1;
566         si->offset = file_offset;
567         si->length = T - H;
568         if (si->length > length)
569                 si->length = length;
570         si->M = M;
571 }
572 EXPORT_SYMBOL(ore_calc_stripe_info);
573
574 int _ore_add_stripe_unit(struct ore_io_state *ios,  unsigned *cur_pg,
575                          unsigned pgbase, struct page **pages,
576                          struct ore_per_dev_state *per_dev, int cur_len)
577 {
578         unsigned pg = *cur_pg;
579         struct request_queue *q =
580                         osd_request_queue(_ios_od(ios, per_dev->dev));
581         unsigned len = cur_len;
582         int ret;
583
584         if (per_dev->bio == NULL) {
585                 unsigned pages_in_stripe = ios->layout->group_width *
586                                         (ios->layout->stripe_unit / PAGE_SIZE);
587                 unsigned nr_pages = ios->nr_pages * ios->layout->group_width /
588                                         (ios->layout->group_width -
589                                          ios->layout->parity);
590                 unsigned bio_size = (nr_pages + pages_in_stripe) /
591                                         ios->layout->group_width;
592
593                 per_dev->bio = bio_kmalloc(GFP_KERNEL, bio_size);
594                 if (unlikely(!per_dev->bio)) {
595                         ORE_DBGMSG("Failed to allocate BIO size=%u\n",
596                                      bio_size);
597                         ret = -ENOMEM;
598                         goto out;
599                 }
600         }
601
602         while (cur_len > 0) {
603                 unsigned pglen = min_t(unsigned, PAGE_SIZE - pgbase, cur_len);
604                 unsigned added_len;
605
606                 cur_len -= pglen;
607
608                 added_len = bio_add_pc_page(q, per_dev->bio, pages[pg],
609                                             pglen, pgbase);
610                 if (unlikely(pglen != added_len)) {
611                         ORE_DBGMSG("Failed bio_add_pc_page bi_vcnt=%u\n",
612                                    per_dev->bio->bi_vcnt);
613                         ret = -ENOMEM;
614                         goto out;
615                 }
616                 _add_stripe_page(ios->sp2d, &ios->si, pages[pg]);
617
618                 pgbase = 0;
619                 ++pg;
620         }
621         BUG_ON(cur_len);
622
623         per_dev->length += len;
624         *cur_pg = pg;
625         ret = 0;
626 out:    /* we fail the complete unit on an error eg don't advance
627          * per_dev->length and cur_pg. This means that we might have a bigger
628          * bio than the CDB requested length (per_dev->length). That's fine
629          * only the oposite is fatal.
630          */
631         return ret;
632 }
633
634 static int _prepare_for_striping(struct ore_io_state *ios)
635 {
636         struct ore_striping_info *si = &ios->si;
637         unsigned stripe_unit = ios->layout->stripe_unit;
638         unsigned mirrors_p1 = ios->layout->mirrors_p1;
639         unsigned group_width = ios->layout->group_width;
640         unsigned devs_in_group = group_width * mirrors_p1;
641         unsigned dev = si->dev;
642         unsigned first_dev = dev - (dev % devs_in_group);
643         unsigned dev_order;
644         unsigned cur_pg = ios->pages_consumed;
645         u64 length = ios->length;
646         int ret = 0;
647
648         if (!ios->pages) {
649                 ios->numdevs = ios->layout->mirrors_p1;
650                 return 0;
651         }
652
653         BUG_ON(length > si->length);
654
655         dev_order = _dev_order(devs_in_group, mirrors_p1, si->par_dev, dev);
656         si->cur_comp = dev_order;
657         si->cur_pg = si->unit_off / PAGE_SIZE;
658
659         while (length) {
660                 unsigned comp = dev - first_dev;
661                 struct ore_per_dev_state *per_dev = &ios->per_dev[comp];
662                 unsigned cur_len, page_off = 0;
663
664                 if (!per_dev->length) {
665                         per_dev->dev = dev;
666                         if (dev == si->dev) {
667                                 WARN_ON(dev == si->par_dev);
668                                 per_dev->offset = si->obj_offset;
669                                 cur_len = stripe_unit - si->unit_off;
670                                 page_off = si->unit_off & ~PAGE_MASK;
671                                 BUG_ON(page_off && (page_off != ios->pgbase));
672                         } else {
673                                 if (si->cur_comp > dev_order)
674                                         per_dev->offset =
675                                                 si->obj_offset - si->unit_off;
676                                 else /* si->cur_comp < dev_order */
677                                         per_dev->offset =
678                                                 si->obj_offset + stripe_unit -
679                                                                    si->unit_off;
680                                 cur_len = stripe_unit;
681                         }
682                 } else {
683                         cur_len = stripe_unit;
684                 }
685                 if (cur_len >= length)
686                         cur_len = length;
687
688                 ret = _ore_add_stripe_unit(ios, &cur_pg, page_off, ios->pages,
689                                            per_dev, cur_len);
690                 if (unlikely(ret))
691                         goto out;
692
693                 dev += mirrors_p1;
694                 dev = (dev % devs_in_group) + first_dev;
695
696                 length -= cur_len;
697
698                 si->cur_comp = (si->cur_comp + 1) % group_width;
699                 if (unlikely((dev == si->par_dev) || (!length && ios->sp2d))) {
700                         if (!length && ios->sp2d) {
701                                 /* If we are writing and this is the very last
702                                  * stripe. then operate on parity dev.
703                                  */
704                                 dev = si->par_dev;
705                         }
706                         if (ios->sp2d)
707                                 /* In writes cur_len just means if it's the
708                                  * last one. See _ore_add_parity_unit.
709                                  */
710                                 cur_len = length;
711                         per_dev = &ios->per_dev[dev - first_dev];
712                         if (!per_dev->length) {
713                                 /* Only/always the parity unit of the first
714                                  * stripe will be empty. So this is a chance to
715                                  * initialize the per_dev info.
716                                  */
717                                 per_dev->dev = dev;
718                                 per_dev->offset = si->obj_offset - si->unit_off;
719                         }
720
721                         ret = _ore_add_parity_unit(ios, si, per_dev, cur_len);
722                         if (unlikely(ret))
723                                         goto out;
724
725                         /* Rotate next par_dev backwards with wraping */
726                         si->par_dev = (devs_in_group + si->par_dev -
727                                        ios->layout->parity * mirrors_p1) %
728                                       devs_in_group + first_dev;
729                         /* Next stripe, start fresh */
730                         si->cur_comp = 0;
731                         si->cur_pg = 0;
732                 }
733         }
734 out:
735         ios->numdevs = devs_in_group;
736         ios->pages_consumed = cur_pg;
737         if (unlikely(ret)) {
738                 if (length == ios->length)
739                         return ret;
740                 else
741                         ios->length -= length;
742         }
743         return 0;
744 }
745
746 int ore_create(struct ore_io_state *ios)
747 {
748         int i, ret;
749
750         for (i = 0; i < ios->oc->numdevs; i++) {
751                 struct osd_request *or;
752
753                 or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
754                 if (unlikely(!or)) {
755                         ORE_ERR("%s: osd_start_request failed\n", __func__);
756                         ret = -ENOMEM;
757                         goto out;
758                 }
759                 ios->per_dev[i].or = or;
760                 ios->numdevs++;
761
762                 osd_req_create_object(or, _ios_obj(ios, i));
763         }
764         ret = ore_io_execute(ios);
765
766 out:
767         return ret;
768 }
769 EXPORT_SYMBOL(ore_create);
770
771 int ore_remove(struct ore_io_state *ios)
772 {
773         int i, ret;
774
775         for (i = 0; i < ios->oc->numdevs; i++) {
776                 struct osd_request *or;
777
778                 or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
779                 if (unlikely(!or)) {
780                         ORE_ERR("%s: osd_start_request failed\n", __func__);
781                         ret = -ENOMEM;
782                         goto out;
783                 }
784                 ios->per_dev[i].or = or;
785                 ios->numdevs++;
786
787                 osd_req_remove_object(or, _ios_obj(ios, i));
788         }
789         ret = ore_io_execute(ios);
790
791 out:
792         return ret;
793 }
794 EXPORT_SYMBOL(ore_remove);
795
796 static int _write_mirror(struct ore_io_state *ios, int cur_comp)
797 {
798         struct ore_per_dev_state *master_dev = &ios->per_dev[cur_comp];
799         unsigned dev = ios->per_dev[cur_comp].dev;
800         unsigned last_comp = cur_comp + ios->layout->mirrors_p1;
801         int ret = 0;
802
803         if (ios->pages && !master_dev->length)
804                 return 0; /* Just an empty slot */
805
806         for (; cur_comp < last_comp; ++cur_comp, ++dev) {
807                 struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
808                 struct osd_request *or;
809
810                 or = osd_start_request(_ios_od(ios, dev), GFP_KERNEL);
811                 if (unlikely(!or)) {
812                         ORE_ERR("%s: osd_start_request failed\n", __func__);
813                         ret = -ENOMEM;
814                         goto out;
815                 }
816                 per_dev->or = or;
817
818                 if (ios->pages) {
819                         struct bio *bio;
820
821                         if (per_dev != master_dev) {
822                                 bio = bio_kmalloc(GFP_KERNEL,
823                                                   master_dev->bio->bi_max_vecs);
824                                 if (unlikely(!bio)) {
825                                         ORE_DBGMSG(
826                                               "Failed to allocate BIO size=%u\n",
827                                               master_dev->bio->bi_max_vecs);
828                                         ret = -ENOMEM;
829                                         goto out;
830                                 }
831
832                                 __bio_clone(bio, master_dev->bio);
833                                 bio->bi_bdev = NULL;
834                                 bio->bi_next = NULL;
835                                 per_dev->offset = master_dev->offset;
836                                 per_dev->length = master_dev->length;
837                                 per_dev->bio =  bio;
838                                 per_dev->dev = dev;
839                         } else {
840                                 bio = master_dev->bio;
841                                 /* FIXME: bio_set_dir() */
842                                 bio->bi_rw |= REQ_WRITE;
843                         }
844
845                         osd_req_write(or, _ios_obj(ios, dev), per_dev->offset,
846                                       bio, per_dev->length);
847                         ORE_DBGMSG("write(0x%llx) offset=0x%llx "
848                                       "length=0x%llx dev=%d\n",
849                                      _LLU(_ios_obj(ios, dev)->id),
850                                      _LLU(per_dev->offset),
851                                      _LLU(per_dev->length), dev);
852                 } else if (ios->kern_buff) {
853                         per_dev->offset = ios->si.obj_offset;
854                         per_dev->dev = ios->si.dev + dev;
855
856                         /* no cross device without page array */
857                         BUG_ON((ios->layout->group_width > 1) &&
858                                (ios->si.unit_off + ios->length >
859                                 ios->layout->stripe_unit));
860
861                         ret = osd_req_write_kern(or, _ios_obj(ios, per_dev->dev),
862                                                  per_dev->offset,
863                                                  ios->kern_buff, ios->length);
864                         if (unlikely(ret))
865                                 goto out;
866                         ORE_DBGMSG2("write_kern(0x%llx) offset=0x%llx "
867                                       "length=0x%llx dev=%d\n",
868                                      _LLU(_ios_obj(ios, dev)->id),
869                                      _LLU(per_dev->offset),
870                                      _LLU(ios->length), per_dev->dev);
871                 } else {
872                         osd_req_set_attributes(or, _ios_obj(ios, dev));
873                         ORE_DBGMSG2("obj(0x%llx) set_attributes=%d dev=%d\n",
874                                      _LLU(_ios_obj(ios, dev)->id),
875                                      ios->out_attr_len, dev);
876                 }
877
878                 if (ios->out_attr)
879                         osd_req_add_set_attr_list(or, ios->out_attr,
880                                                   ios->out_attr_len);
881
882                 if (ios->in_attr)
883                         osd_req_add_get_attr_list(or, ios->in_attr,
884                                                   ios->in_attr_len);
885         }
886
887 out:
888         return ret;
889 }
890
891 int ore_write(struct ore_io_state *ios)
892 {
893         int i;
894         int ret;
895
896         if (unlikely(ios->sp2d && !ios->r4w)) {
897                 /* A library is attempting a RAID-write without providing
898                  * a pages lock interface.
899                  */
900                 WARN_ON_ONCE(1);
901                 return -ENOTSUPP;
902         }
903
904         ret = _prepare_for_striping(ios);
905         if (unlikely(ret))
906                 return ret;
907
908         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
909                 ret = _write_mirror(ios, i);
910                 if (unlikely(ret))
911                         return ret;
912         }
913
914         ret = ore_io_execute(ios);
915         return ret;
916 }
917 EXPORT_SYMBOL(ore_write);
918
919 int _ore_read_mirror(struct ore_io_state *ios, unsigned cur_comp)
920 {
921         struct osd_request *or;
922         struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
923         struct osd_obj_id *obj = _ios_obj(ios, cur_comp);
924         unsigned first_dev = (unsigned)obj->id;
925
926         if (ios->pages && !per_dev->length)
927                 return 0; /* Just an empty slot */
928
929         first_dev = per_dev->dev + first_dev % ios->layout->mirrors_p1;
930         or = osd_start_request(_ios_od(ios, first_dev), GFP_KERNEL);
931         if (unlikely(!or)) {
932                 ORE_ERR("%s: osd_start_request failed\n", __func__);
933                 return -ENOMEM;
934         }
935         per_dev->or = or;
936
937         if (ios->pages) {
938                 if (per_dev->cur_sg) {
939                         /* finalize the last sg_entry */
940                         _ore_add_sg_seg(per_dev, 0, false);
941                         if (unlikely(!per_dev->cur_sg))
942                                 return 0; /* Skip parity only device */
943
944                         osd_req_read_sg(or, obj, per_dev->bio,
945                                         per_dev->sglist, per_dev->cur_sg);
946                 } else {
947                         /* The no raid case */
948                         osd_req_read(or, obj, per_dev->offset,
949                                      per_dev->bio, per_dev->length);
950                 }
951
952                 ORE_DBGMSG("read(0x%llx) offset=0x%llx length=0x%llx"
953                              " dev=%d sg_len=%d\n", _LLU(obj->id),
954                              _LLU(per_dev->offset), _LLU(per_dev->length),
955                              first_dev, per_dev->cur_sg);
956         } else {
957                 BUG_ON(ios->kern_buff);
958
959                 osd_req_get_attributes(or, obj);
960                 ORE_DBGMSG2("obj(0x%llx) get_attributes=%d dev=%d\n",
961                               _LLU(obj->id),
962                               ios->in_attr_len, first_dev);
963         }
964         if (ios->out_attr)
965                 osd_req_add_set_attr_list(or, ios->out_attr, ios->out_attr_len);
966
967         if (ios->in_attr)
968                 osd_req_add_get_attr_list(or, ios->in_attr, ios->in_attr_len);
969
970         return 0;
971 }
972
973 int ore_read(struct ore_io_state *ios)
974 {
975         int i;
976         int ret;
977
978         ret = _prepare_for_striping(ios);
979         if (unlikely(ret))
980                 return ret;
981
982         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
983                 ret = _ore_read_mirror(ios, i);
984                 if (unlikely(ret))
985                         return ret;
986         }
987
988         ret = ore_io_execute(ios);
989         return ret;
990 }
991 EXPORT_SYMBOL(ore_read);
992
993 int extract_attr_from_ios(struct ore_io_state *ios, struct osd_attr *attr)
994 {
995         struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
996         void *iter = NULL;
997         int nelem;
998
999         do {
1000                 nelem = 1;
1001                 osd_req_decode_get_attr_list(ios->per_dev[0].or,
1002                                              &cur_attr, &nelem, &iter);
1003                 if ((cur_attr.attr_page == attr->attr_page) &&
1004                     (cur_attr.attr_id == attr->attr_id)) {
1005                         attr->len = cur_attr.len;
1006                         attr->val_ptr = cur_attr.val_ptr;
1007                         return 0;
1008                 }
1009         } while (iter);
1010
1011         return -EIO;
1012 }
1013 EXPORT_SYMBOL(extract_attr_from_ios);
1014
1015 static int _truncate_mirrors(struct ore_io_state *ios, unsigned cur_comp,
1016                              struct osd_attr *attr)
1017 {
1018         int last_comp = cur_comp + ios->layout->mirrors_p1;
1019
1020         for (; cur_comp < last_comp; ++cur_comp) {
1021                 struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
1022                 struct osd_request *or;
1023
1024                 or = osd_start_request(_ios_od(ios, cur_comp), GFP_KERNEL);
1025                 if (unlikely(!or)) {
1026                         ORE_ERR("%s: osd_start_request failed\n", __func__);
1027                         return -ENOMEM;
1028                 }
1029                 per_dev->or = or;
1030
1031                 osd_req_set_attributes(or, _ios_obj(ios, cur_comp));
1032                 osd_req_add_set_attr_list(or, attr, 1);
1033         }
1034
1035         return 0;
1036 }
1037
1038 struct _trunc_info {
1039         struct ore_striping_info si;
1040         u64 prev_group_obj_off;
1041         u64 next_group_obj_off;
1042
1043         unsigned first_group_dev;
1044         unsigned nex_group_dev;
1045 };
1046
1047 static void _calc_trunk_info(struct ore_layout *layout, u64 file_offset,
1048                              struct _trunc_info *ti)
1049 {
1050         unsigned stripe_unit = layout->stripe_unit;
1051
1052         ore_calc_stripe_info(layout, file_offset, 0, &ti->si);
1053
1054         ti->prev_group_obj_off = ti->si.M * stripe_unit;
1055         ti->next_group_obj_off = ti->si.M ? (ti->si.M - 1) * stripe_unit : 0;
1056
1057         ti->first_group_dev = ti->si.dev - (ti->si.dev % layout->group_width);
1058         ti->nex_group_dev = ti->first_group_dev + layout->group_width;
1059 }
1060
1061 int ore_truncate(struct ore_layout *layout, struct ore_components *oc,
1062                    u64 size)
1063 {
1064         struct ore_io_state *ios;
1065         struct exofs_trunc_attr {
1066                 struct osd_attr attr;
1067                 __be64 newsize;
1068         } *size_attrs;
1069         struct _trunc_info ti;
1070         int i, ret;
1071
1072         ret = ore_get_io_state(layout, oc, &ios);
1073         if (unlikely(ret))
1074                 return ret;
1075
1076         _calc_trunk_info(ios->layout, size, &ti);
1077
1078         size_attrs = kcalloc(ios->oc->numdevs, sizeof(*size_attrs),
1079                              GFP_KERNEL);
1080         if (unlikely(!size_attrs)) {
1081                 ret = -ENOMEM;
1082                 goto out;
1083         }
1084
1085         ios->numdevs = ios->oc->numdevs;
1086
1087         for (i = 0; i < ios->numdevs; ++i) {
1088                 struct exofs_trunc_attr *size_attr = &size_attrs[i];
1089                 u64 obj_size;
1090
1091                 if (i < ti.first_group_dev)
1092                         obj_size = ti.prev_group_obj_off;
1093                 else if (i >= ti.nex_group_dev)
1094                         obj_size = ti.next_group_obj_off;
1095                 else if (i < ti.si.dev) /* dev within this group */
1096                         obj_size = ti.si.obj_offset +
1097                                       ios->layout->stripe_unit - ti.si.unit_off;
1098                 else if (i == ti.si.dev)
1099                         obj_size = ti.si.obj_offset;
1100                 else /* i > ti.dev */
1101                         obj_size = ti.si.obj_offset - ti.si.unit_off;
1102
1103                 size_attr->newsize = cpu_to_be64(obj_size);
1104                 size_attr->attr = g_attr_logical_length;
1105                 size_attr->attr.val_ptr = &size_attr->newsize;
1106
1107                 ORE_DBGMSG("trunc(0x%llx) obj_offset=0x%llx dev=%d\n",
1108                              _LLU(oc->comps->obj.id), _LLU(obj_size), i);
1109                 ret = _truncate_mirrors(ios, i * ios->layout->mirrors_p1,
1110                                         &size_attr->attr);
1111                 if (unlikely(ret))
1112                         goto out;
1113         }
1114         ret = ore_io_execute(ios);
1115
1116 out:
1117         kfree(size_attrs);
1118         ore_put_io_state(ios);
1119         return ret;
1120 }
1121 EXPORT_SYMBOL(ore_truncate);
1122
1123 const struct osd_attr g_attr_logical_length = ATTR_DEF(
1124         OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
1125 EXPORT_SYMBOL(g_attr_logical_length);