Merge remote-tracking branch 'asoc/topic/dmaengine' into asoc-next
[linux-2.6-microblaze.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 <ooo@electrozaur.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 <linux/module.h>
27 #include <asm/div64.h>
28 #include <linux/lcm.h>
29
30 #include "ore_raid.h"
31
32 MODULE_AUTHOR("Boaz Harrosh <ooo@electrozaur.com>");
33 MODULE_DESCRIPTION("Objects Raid Engine ore.ko");
34 MODULE_LICENSE("GPL");
35
36 /* ore_verify_layout does a couple of things:
37  * 1. Given a minimum number of needed parameters fixes up the rest of the
38  *    members to be operatonals for the ore. The needed parameters are those
39  *    that are defined by the pnfs-objects layout STD.
40  * 2. Check to see if the current ore code actually supports these parameters
41  *    for example stripe_unit must be a multple of the system PAGE_SIZE,
42  *    and etc...
43  * 3. Cache some havily used calculations that will be needed by users.
44  */
45
46 enum { BIO_MAX_PAGES_KMALLOC =
47                 (PAGE_SIZE - sizeof(struct bio)) / sizeof(struct bio_vec),};
48
49 int ore_verify_layout(unsigned total_comps, struct ore_layout *layout)
50 {
51         u64 stripe_length;
52
53         switch (layout->raid_algorithm) {
54         case PNFS_OSD_RAID_0:
55                 layout->parity = 0;
56                 break;
57         case PNFS_OSD_RAID_5:
58                 layout->parity = 1;
59                 break;
60         case PNFS_OSD_RAID_PQ:
61                 layout->parity = 2;
62                 break;
63         case PNFS_OSD_RAID_4:
64         default:
65                 ORE_ERR("Only RAID_0/5/6 for now received-enum=%d\n",
66                         layout->raid_algorithm);
67                 return -EINVAL;
68         }
69         if (0 != (layout->stripe_unit & ~PAGE_MASK)) {
70                 ORE_ERR("Stripe Unit(0x%llx)"
71                           " must be Multples of PAGE_SIZE(0x%lx)\n",
72                           _LLU(layout->stripe_unit), PAGE_SIZE);
73                 return -EINVAL;
74         }
75         if (layout->group_width) {
76                 if (!layout->group_depth) {
77                         ORE_ERR("group_depth == 0 && group_width != 0\n");
78                         return -EINVAL;
79                 }
80                 if (total_comps < (layout->group_width * layout->mirrors_p1)) {
81                         ORE_ERR("Data Map wrong, "
82                                 "numdevs=%d < group_width=%d * mirrors=%d\n",
83                                 total_comps, layout->group_width,
84                                 layout->mirrors_p1);
85                         return -EINVAL;
86                 }
87                 layout->group_count = total_comps / layout->mirrors_p1 /
88                                                 layout->group_width;
89         } else {
90                 if (layout->group_depth) {
91                         printk(KERN_NOTICE "Warning: group_depth ignored "
92                                 "group_width == 0 && group_depth == %lld\n",
93                                 _LLU(layout->group_depth));
94                 }
95                 layout->group_width = total_comps / layout->mirrors_p1;
96                 layout->group_depth = -1;
97                 layout->group_count = 1;
98         }
99
100         stripe_length = (u64)layout->group_width * layout->stripe_unit;
101         if (stripe_length >= (1ULL << 32)) {
102                 ORE_ERR("Stripe_length(0x%llx) >= 32bit is not supported\n",
103                         _LLU(stripe_length));
104                 return -EINVAL;
105         }
106
107         layout->max_io_length =
108                 (BIO_MAX_PAGES_KMALLOC * PAGE_SIZE - layout->stripe_unit) *
109                                         (layout->group_width - layout->parity);
110         if (layout->parity) {
111                 unsigned stripe_length =
112                                 (layout->group_width - layout->parity) *
113                                 layout->stripe_unit;
114
115                 layout->max_io_length /= stripe_length;
116                 layout->max_io_length *= stripe_length;
117         }
118         ORE_DBGMSG("max_io_length=0x%lx\n", layout->max_io_length);
119
120         return 0;
121 }
122 EXPORT_SYMBOL(ore_verify_layout);
123
124 static u8 *_ios_cred(struct ore_io_state *ios, unsigned index)
125 {
126         return ios->oc->comps[index & ios->oc->single_comp].cred;
127 }
128
129 static struct osd_obj_id *_ios_obj(struct ore_io_state *ios, unsigned index)
130 {
131         return &ios->oc->comps[index & ios->oc->single_comp].obj;
132 }
133
134 static struct osd_dev *_ios_od(struct ore_io_state *ios, unsigned index)
135 {
136         ORE_DBGMSG2("oc->first_dev=%d oc->numdevs=%d i=%d oc->ods=%p\n",
137                     ios->oc->first_dev, ios->oc->numdevs, index,
138                     ios->oc->ods);
139
140         return ore_comp_dev(ios->oc, index);
141 }
142
143 int  _ore_get_io_state(struct ore_layout *layout,
144                         struct ore_components *oc, unsigned numdevs,
145                         unsigned sgs_per_dev, unsigned num_par_pages,
146                         struct ore_io_state **pios)
147 {
148         struct ore_io_state *ios;
149         struct page **pages;
150         struct osd_sg_entry *sgilist;
151         struct __alloc_all_io_state {
152                 struct ore_io_state ios;
153                 struct ore_per_dev_state per_dev[numdevs];
154                 union {
155                         struct osd_sg_entry sglist[sgs_per_dev * numdevs];
156                         struct page *pages[num_par_pages];
157                 };
158         } *_aios;
159
160         if (likely(sizeof(*_aios) <= PAGE_SIZE)) {
161                 _aios = kzalloc(sizeof(*_aios), GFP_KERNEL);
162                 if (unlikely(!_aios)) {
163                         ORE_DBGMSG("Failed kzalloc bytes=%zd\n",
164                                    sizeof(*_aios));
165                         *pios = NULL;
166                         return -ENOMEM;
167                 }
168                 pages = num_par_pages ? _aios->pages : NULL;
169                 sgilist = sgs_per_dev ? _aios->sglist : NULL;
170                 ios = &_aios->ios;
171         } else {
172                 struct __alloc_small_io_state {
173                         struct ore_io_state ios;
174                         struct ore_per_dev_state per_dev[numdevs];
175                 } *_aio_small;
176                 union __extra_part {
177                         struct osd_sg_entry sglist[sgs_per_dev * numdevs];
178                         struct page *pages[num_par_pages];
179                 } *extra_part;
180
181                 _aio_small = kzalloc(sizeof(*_aio_small), GFP_KERNEL);
182                 if (unlikely(!_aio_small)) {
183                         ORE_DBGMSG("Failed alloc first part bytes=%zd\n",
184                                    sizeof(*_aio_small));
185                         *pios = NULL;
186                         return -ENOMEM;
187                 }
188                 extra_part = kzalloc(sizeof(*extra_part), GFP_KERNEL);
189                 if (unlikely(!extra_part)) {
190                         ORE_DBGMSG("Failed alloc second part bytes=%zd\n",
191                                    sizeof(*extra_part));
192                         kfree(_aio_small);
193                         *pios = NULL;
194                         return -ENOMEM;
195                 }
196
197                 pages = num_par_pages ? extra_part->pages : NULL;
198                 sgilist = sgs_per_dev ? extra_part->sglist : NULL;
199                 /* In this case the per_dev[0].sgilist holds the pointer to
200                  * be freed
201                  */
202                 ios = &_aio_small->ios;
203                 ios->extra_part_alloc = true;
204         }
205
206         if (pages) {
207                 ios->parity_pages = pages;
208                 ios->max_par_pages = num_par_pages;
209         }
210         if (sgilist) {
211                 unsigned d;
212
213                 for (d = 0; d < numdevs; ++d) {
214                         ios->per_dev[d].sglist = sgilist;
215                         sgilist += sgs_per_dev;
216                 }
217                 ios->sgs_per_dev = sgs_per_dev;
218         }
219
220         ios->layout = layout;
221         ios->oc = oc;
222         *pios = ios;
223         return 0;
224 }
225
226 /* Allocate an io_state for only a single group of devices
227  *
228  * If a user needs to call ore_read/write() this version must be used becase it
229  * allocates extra stuff for striping and raid.
230  * The ore might decide to only IO less then @length bytes do to alignmets
231  * and constrains as follows:
232  * - The IO cannot cross group boundary.
233  * - In raid5/6 The end of the IO must align at end of a stripe eg.
234  *   (@offset + @length) % strip_size == 0. Or the complete range is within a
235  *   single stripe.
236  * - Memory condition only permitted a shorter IO. (A user can use @length=~0
237  *   And check the returned ios->length for max_io_size.)
238  *
239  * The caller must check returned ios->length (and/or ios->nr_pages) and
240  * re-issue these pages that fall outside of ios->length
241  */
242 int  ore_get_rw_state(struct ore_layout *layout, struct ore_components *oc,
243                       bool is_reading, u64 offset, u64 length,
244                       struct ore_io_state **pios)
245 {
246         struct ore_io_state *ios;
247         unsigned numdevs = layout->group_width * layout->mirrors_p1;
248         unsigned sgs_per_dev = 0, max_par_pages = 0;
249         int ret;
250
251         if (layout->parity && length) {
252                 unsigned data_devs = layout->group_width - layout->parity;
253                 unsigned stripe_size = layout->stripe_unit * data_devs;
254                 unsigned pages_in_unit = layout->stripe_unit / PAGE_SIZE;
255                 u32 remainder;
256                 u64 num_stripes;
257                 u64 num_raid_units;
258
259                 num_stripes = div_u64_rem(length, stripe_size, &remainder);
260                 if (remainder)
261                         ++num_stripes;
262
263                 num_raid_units =  num_stripes * layout->parity;
264
265                 if (is_reading) {
266                         /* For reads add per_dev sglist array */
267                         /* TODO: Raid 6 we need twice more. Actually:
268                         *         num_stripes / LCMdP(W,P);
269                         *         if (W%P != 0) num_stripes *= parity;
270                         */
271
272                         /* first/last seg is split */
273                         num_raid_units += layout->group_width;
274                         sgs_per_dev = div_u64(num_raid_units, data_devs) + 2;
275                 } else {
276                         /* For Writes add parity pages array. */
277                         max_par_pages = num_raid_units * pages_in_unit *
278                                                 sizeof(struct page *);
279                 }
280         }
281
282         ret = _ore_get_io_state(layout, oc, numdevs, sgs_per_dev, max_par_pages,
283                                 pios);
284         if (unlikely(ret))
285                 return ret;
286
287         ios = *pios;
288         ios->reading = is_reading;
289         ios->offset = offset;
290
291         if (length) {
292                 ore_calc_stripe_info(layout, offset, length, &ios->si);
293                 ios->length = ios->si.length;
294                 ios->nr_pages = ((ios->offset & (PAGE_SIZE - 1)) +
295                                  ios->length + PAGE_SIZE - 1) / PAGE_SIZE;
296                 if (layout->parity)
297                         _ore_post_alloc_raid_stuff(ios);
298         }
299
300         return 0;
301 }
302 EXPORT_SYMBOL(ore_get_rw_state);
303
304 /* Allocate an io_state for all the devices in the comps array
305  *
306  * This version of io_state allocation is used mostly by create/remove
307  * and trunc where we currently need all the devices. The only wastful
308  * bit is the read/write_attributes with no IO. Those sites should
309  * be converted to use ore_get_rw_state() with length=0
310  */
311 int  ore_get_io_state(struct ore_layout *layout, struct ore_components *oc,
312                       struct ore_io_state **pios)
313 {
314         return _ore_get_io_state(layout, oc, oc->numdevs, 0, 0, pios);
315 }
316 EXPORT_SYMBOL(ore_get_io_state);
317
318 void ore_put_io_state(struct ore_io_state *ios)
319 {
320         if (ios) {
321                 unsigned i;
322
323                 for (i = 0; i < ios->numdevs; i++) {
324                         struct ore_per_dev_state *per_dev = &ios->per_dev[i];
325
326                         if (per_dev->or)
327                                 osd_end_request(per_dev->or);
328                         if (per_dev->bio)
329                                 bio_put(per_dev->bio);
330                 }
331
332                 _ore_free_raid_stuff(ios);
333                 kfree(ios);
334         }
335 }
336 EXPORT_SYMBOL(ore_put_io_state);
337
338 static void _sync_done(struct ore_io_state *ios, void *p)
339 {
340         struct completion *waiting = p;
341
342         complete(waiting);
343 }
344
345 static void _last_io(struct kref *kref)
346 {
347         struct ore_io_state *ios = container_of(
348                                         kref, struct ore_io_state, kref);
349
350         ios->done(ios, ios->private);
351 }
352
353 static void _done_io(struct osd_request *or, void *p)
354 {
355         struct ore_io_state *ios = p;
356
357         kref_put(&ios->kref, _last_io);
358 }
359
360 int ore_io_execute(struct ore_io_state *ios)
361 {
362         DECLARE_COMPLETION_ONSTACK(wait);
363         bool sync = (ios->done == NULL);
364         int i, ret;
365
366         if (sync) {
367                 ios->done = _sync_done;
368                 ios->private = &wait;
369         }
370
371         for (i = 0; i < ios->numdevs; i++) {
372                 struct osd_request *or = ios->per_dev[i].or;
373                 if (unlikely(!or))
374                         continue;
375
376                 ret = osd_finalize_request(or, 0, _ios_cred(ios, i), NULL);
377                 if (unlikely(ret)) {
378                         ORE_DBGMSG("Failed to osd_finalize_request() => %d\n",
379                                      ret);
380                         return ret;
381                 }
382         }
383
384         kref_init(&ios->kref);
385
386         for (i = 0; i < ios->numdevs; i++) {
387                 struct osd_request *or = ios->per_dev[i].or;
388                 if (unlikely(!or))
389                         continue;
390
391                 kref_get(&ios->kref);
392                 osd_execute_request_async(or, _done_io, ios);
393         }
394
395         kref_put(&ios->kref, _last_io);
396         ret = 0;
397
398         if (sync) {
399                 wait_for_completion(&wait);
400                 ret = ore_check_io(ios, NULL);
401         }
402         return ret;
403 }
404
405 static void _clear_bio(struct bio *bio)
406 {
407         struct bio_vec *bv;
408         unsigned i;
409
410         bio_for_each_segment_all(bv, bio, i) {
411                 unsigned this_count = bv->bv_len;
412
413                 if (likely(PAGE_SIZE == this_count))
414                         clear_highpage(bv->bv_page);
415                 else
416                         zero_user(bv->bv_page, bv->bv_offset, this_count);
417         }
418 }
419
420 int ore_check_io(struct ore_io_state *ios, ore_on_dev_error on_dev_error)
421 {
422         enum osd_err_priority acumulated_osd_err = 0;
423         int acumulated_lin_err = 0;
424         int i;
425
426         for (i = 0; i < ios->numdevs; i++) {
427                 struct osd_sense_info osi;
428                 struct ore_per_dev_state *per_dev = &ios->per_dev[i];
429                 struct osd_request *or = per_dev->or;
430                 int ret;
431
432                 if (unlikely(!or))
433                         continue;
434
435                 ret = osd_req_decode_sense(or, &osi);
436                 if (likely(!ret))
437                         continue;
438
439                 if ((OSD_ERR_PRI_CLEAR_PAGES == osi.osd_err_pri) &&
440                     per_dev->bio) {
441                         /* start read offset passed endof file.
442                          * Note: if we do not have bio it means read-attributes
443                          * In this case we should return error to caller.
444                          */
445                         _clear_bio(per_dev->bio);
446                         ORE_DBGMSG("start read offset passed end of file "
447                                 "offset=0x%llx, length=0x%llx\n",
448                                 _LLU(per_dev->offset),
449                                 _LLU(per_dev->length));
450
451                         continue; /* we recovered */
452                 }
453
454                 if (on_dev_error) {
455                         u64 residual = ios->reading ?
456                                         or->in.residual : or->out.residual;
457                         u64 offset = (ios->offset + ios->length) - residual;
458                         unsigned dev = per_dev->dev - ios->oc->first_dev;
459                         struct ore_dev *od = ios->oc->ods[dev];
460
461                         on_dev_error(ios, od, dev, osi.osd_err_pri,
462                                      offset, residual);
463                 }
464                 if (osi.osd_err_pri >= acumulated_osd_err) {
465                         acumulated_osd_err = osi.osd_err_pri;
466                         acumulated_lin_err = ret;
467                 }
468         }
469
470         return acumulated_lin_err;
471 }
472 EXPORT_SYMBOL(ore_check_io);
473
474 /*
475  * L - logical offset into the file
476  *
477  * D - number of Data devices
478  *      D = group_width - parity
479  *
480  * U - The number of bytes in a stripe within a group
481  *      U =  stripe_unit * D
482  *
483  * T - The number of bytes striped within a group of component objects
484  *     (before advancing to the next group)
485  *      T = U * group_depth
486  *
487  * S - The number of bytes striped across all component objects
488  *     before the pattern repeats
489  *      S = T * group_count
490  *
491  * M - The "major" (i.e., across all components) cycle number
492  *      M = L / S
493  *
494  * G - Counts the groups from the beginning of the major cycle
495  *      G = (L - (M * S)) / T   [or (L % S) / T]
496  *
497  * H - The byte offset within the group
498  *      H = (L - (M * S)) % T   [or (L % S) % T]
499  *
500  * N - The "minor" (i.e., across the group) stripe number
501  *      N = H / U
502  *
503  * C - The component index coresponding to L
504  *
505  *      C = (H - (N * U)) / stripe_unit + G * D
506  *      [or (L % U) / stripe_unit + G * D]
507  *
508  * O - The component offset coresponding to L
509  *      O = L % stripe_unit + N * stripe_unit + M * group_depth * stripe_unit
510  *
511  * LCMdP â€“ Parity cycle: Lowest Common Multiple of group_width, parity
512  *          divide by parity
513  *      LCMdP = lcm(group_width, parity) / parity
514  *
515  * R - The parity Rotation stripe
516  *     (Note parity cycle always starts at a group's boundary)
517  *      R = N % LCMdP
518  *
519  * I = the first parity device index
520  *      I = (group_width + group_width - R*parity - parity) % group_width
521  *
522  * Craid - The component index Rotated
523  *      Craid = (group_width + C - R*parity) % group_width
524  *      (We add the group_width to avoid negative numbers modulo math)
525  */
526 void ore_calc_stripe_info(struct ore_layout *layout, u64 file_offset,
527                           u64 length, struct ore_striping_info *si)
528 {
529         u32     stripe_unit = layout->stripe_unit;
530         u32     group_width = layout->group_width;
531         u64     group_depth = layout->group_depth;
532         u32     parity      = layout->parity;
533
534         u32     D = group_width - parity;
535         u32     U = D * stripe_unit;
536         u64     T = U * group_depth;
537         u64     S = T * layout->group_count;
538         u64     M = div64_u64(file_offset, S);
539
540         /*
541         G = (L - (M * S)) / T
542         H = (L - (M * S)) % T
543         */
544         u64     LmodS = file_offset - M * S;
545         u32     G = div64_u64(LmodS, T);
546         u64     H = LmodS - G * T;
547
548         u32     N = div_u64(H, U);
549         u32     Nlast;
550
551         /* "H - (N * U)" is just "H % U" so it's bound to u32 */
552         u32     C = (u32)(H - (N * U)) / stripe_unit + G * group_width;
553         u32 first_dev = C - C % group_width;
554
555         div_u64_rem(file_offset, stripe_unit, &si->unit_off);
556
557         si->obj_offset = si->unit_off + (N * stripe_unit) +
558                                   (M * group_depth * stripe_unit);
559         si->cur_comp = C - first_dev;
560         si->cur_pg = si->unit_off / PAGE_SIZE;
561
562         if (parity) {
563                 u32 LCMdP = lcm(group_width, parity) / parity;
564                 /* R     = N % LCMdP; */
565                 u32 RxP   = (N % LCMdP) * parity;
566
567                 si->par_dev = (group_width + group_width - parity - RxP) %
568                               group_width + first_dev;
569                 si->dev = (group_width + group_width + C - RxP) %
570                           group_width + first_dev;
571                 si->bytes_in_stripe = U;
572                 si->first_stripe_start = M * S + G * T + N * U;
573         } else {
574                 /* Make the math correct see _prepare_one_group */
575                 si->par_dev = group_width;
576                 si->dev = C;
577         }
578
579         si->dev *= layout->mirrors_p1;
580         si->par_dev *= layout->mirrors_p1;
581         si->offset = file_offset;
582         si->length = T - H;
583         if (si->length > length)
584                 si->length = length;
585
586         Nlast = div_u64(H + si->length + U - 1, U);
587         si->maxdevUnits = Nlast - N;
588
589         si->M = M;
590 }
591 EXPORT_SYMBOL(ore_calc_stripe_info);
592
593 int _ore_add_stripe_unit(struct ore_io_state *ios,  unsigned *cur_pg,
594                          unsigned pgbase, struct page **pages,
595                          struct ore_per_dev_state *per_dev, int cur_len)
596 {
597         unsigned pg = *cur_pg;
598         struct request_queue *q =
599                         osd_request_queue(_ios_od(ios, per_dev->dev));
600         unsigned len = cur_len;
601         int ret;
602
603         if (per_dev->bio == NULL) {
604                 unsigned bio_size;
605
606                 if (!ios->reading) {
607                         bio_size = ios->si.maxdevUnits;
608                 } else {
609                         bio_size = (ios->si.maxdevUnits + 1) *
610                              (ios->layout->group_width - ios->layout->parity) /
611                              ios->layout->group_width;
612                 }
613                 bio_size *= (ios->layout->stripe_unit / PAGE_SIZE);
614
615                 per_dev->bio = bio_kmalloc(GFP_KERNEL, bio_size);
616                 if (unlikely(!per_dev->bio)) {
617                         ORE_DBGMSG("Failed to allocate BIO size=%u\n",
618                                      bio_size);
619                         ret = -ENOMEM;
620                         goto out;
621                 }
622         }
623
624         while (cur_len > 0) {
625                 unsigned pglen = min_t(unsigned, PAGE_SIZE - pgbase, cur_len);
626                 unsigned added_len;
627
628                 cur_len -= pglen;
629
630                 added_len = bio_add_pc_page(q, per_dev->bio, pages[pg],
631                                             pglen, pgbase);
632                 if (unlikely(pglen != added_len)) {
633                         /* If bi_vcnt == bi_max then this is a SW BUG */
634                         ORE_DBGMSG("Failed bio_add_pc_page bi_vcnt=0x%x "
635                                    "bi_max=0x%x BIO_MAX=0x%x cur_len=0x%x\n",
636                                    per_dev->bio->bi_vcnt,
637                                    per_dev->bio->bi_max_vecs,
638                                    BIO_MAX_PAGES_KMALLOC, cur_len);
639                         ret = -ENOMEM;
640                         goto out;
641                 }
642                 _add_stripe_page(ios->sp2d, &ios->si, pages[pg]);
643
644                 pgbase = 0;
645                 ++pg;
646         }
647         BUG_ON(cur_len);
648
649         per_dev->length += len;
650         *cur_pg = pg;
651         ret = 0;
652 out:    /* we fail the complete unit on an error eg don't advance
653          * per_dev->length and cur_pg. This means that we might have a bigger
654          * bio than the CDB requested length (per_dev->length). That's fine
655          * only the oposite is fatal.
656          */
657         return ret;
658 }
659
660 static int _add_parity_units(struct ore_io_state *ios,
661                              struct ore_striping_info *si,
662                              unsigned dev, unsigned first_dev,
663                              unsigned mirrors_p1, unsigned devs_in_group,
664                              unsigned cur_len)
665 {
666         unsigned do_parity;
667         int ret = 0;
668
669         for (do_parity = ios->layout->parity; do_parity; --do_parity) {
670                 struct ore_per_dev_state *per_dev;
671
672                 per_dev = &ios->per_dev[dev - first_dev];
673                 if (!per_dev->length && !per_dev->offset) {
674                         /* Only/always the parity unit of the first
675                          * stripe will be empty. So this is a chance to
676                          * initialize the per_dev info.
677                          */
678                         per_dev->dev = dev;
679                         per_dev->offset = si->obj_offset - si->unit_off;
680                 }
681
682                 ret = _ore_add_parity_unit(ios, si, per_dev, cur_len,
683                                            do_parity == 1);
684                 if (unlikely(ret))
685                                 break;
686
687                 if (do_parity != 1) {
688                         dev = ((dev + mirrors_p1) % devs_in_group) + first_dev;
689                         si->cur_comp = (si->cur_comp + 1) %
690                                                        ios->layout->group_width;
691                 }
692         }
693
694         return ret;
695 }
696
697 static int _prepare_for_striping(struct ore_io_state *ios)
698 {
699         struct ore_striping_info *si = &ios->si;
700         unsigned stripe_unit = ios->layout->stripe_unit;
701         unsigned mirrors_p1 = ios->layout->mirrors_p1;
702         unsigned group_width = ios->layout->group_width;
703         unsigned devs_in_group = group_width * mirrors_p1;
704         unsigned dev = si->dev;
705         unsigned first_dev = dev - (dev % devs_in_group);
706         unsigned cur_pg = ios->pages_consumed;
707         u64 length = ios->length;
708         int ret = 0;
709
710         if (!ios->pages) {
711                 ios->numdevs = ios->layout->mirrors_p1;
712                 return 0;
713         }
714
715         BUG_ON(length > si->length);
716
717         while (length) {
718                 struct ore_per_dev_state *per_dev =
719                                                 &ios->per_dev[dev - first_dev];
720                 unsigned cur_len, page_off = 0;
721
722                 if (!per_dev->length && !per_dev->offset) {
723                         /* First time initialize the per_dev info. */
724                         per_dev->dev = dev;
725                         if (dev == si->dev) {
726                                 WARN_ON(dev == si->par_dev);
727                                 per_dev->offset = si->obj_offset;
728                                 cur_len = stripe_unit - si->unit_off;
729                                 page_off = si->unit_off & ~PAGE_MASK;
730                                 BUG_ON(page_off && (page_off != ios->pgbase));
731                         } else {
732                                 per_dev->offset = si->obj_offset - si->unit_off;
733                                 cur_len = stripe_unit;
734                         }
735                 } else {
736                         cur_len = stripe_unit;
737                 }
738                 if (cur_len >= length)
739                         cur_len = length;
740
741                 ret = _ore_add_stripe_unit(ios, &cur_pg, page_off, ios->pages,
742                                            per_dev, cur_len);
743                 if (unlikely(ret))
744                         goto out;
745
746                 length -= cur_len;
747
748                 dev = ((dev + mirrors_p1) % devs_in_group) + first_dev;
749                 si->cur_comp = (si->cur_comp + 1) % group_width;
750                 if (unlikely((dev == si->par_dev) || (!length && ios->sp2d))) {
751                         if (!length && ios->sp2d) {
752                                 /* If we are writing and this is the very last
753                                  * stripe. then operate on parity dev.
754                                  */
755                                 dev = si->par_dev;
756                                 /* If last stripe operate on parity comp */
757                                 si->cur_comp = group_width - ios->layout->parity;
758                         }
759
760                         /* In writes cur_len just means if it's the
761                          * last one. See _ore_add_parity_unit.
762                          */
763                         ret = _add_parity_units(ios, si, dev, first_dev,
764                                                 mirrors_p1, devs_in_group,
765                                                 ios->sp2d ? length : cur_len);
766                         if (unlikely(ret))
767                                         goto out;
768
769                         /* Rotate next par_dev backwards with wraping */
770                         si->par_dev = (devs_in_group + si->par_dev -
771                                        ios->layout->parity * mirrors_p1) %
772                                       devs_in_group + first_dev;
773                         /* Next stripe, start fresh */
774                         si->cur_comp = 0;
775                         si->cur_pg = 0;
776                         si->obj_offset += cur_len;
777                         si->unit_off = 0;
778                 }
779         }
780 out:
781         ios->numdevs = devs_in_group;
782         ios->pages_consumed = cur_pg;
783         return ret;
784 }
785
786 int ore_create(struct ore_io_state *ios)
787 {
788         int i, ret;
789
790         for (i = 0; i < ios->oc->numdevs; i++) {
791                 struct osd_request *or;
792
793                 or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
794                 if (unlikely(!or)) {
795                         ORE_ERR("%s: osd_start_request failed\n", __func__);
796                         ret = -ENOMEM;
797                         goto out;
798                 }
799                 ios->per_dev[i].or = or;
800                 ios->numdevs++;
801
802                 osd_req_create_object(or, _ios_obj(ios, i));
803         }
804         ret = ore_io_execute(ios);
805
806 out:
807         return ret;
808 }
809 EXPORT_SYMBOL(ore_create);
810
811 int ore_remove(struct ore_io_state *ios)
812 {
813         int i, ret;
814
815         for (i = 0; i < ios->oc->numdevs; i++) {
816                 struct osd_request *or;
817
818                 or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
819                 if (unlikely(!or)) {
820                         ORE_ERR("%s: osd_start_request failed\n", __func__);
821                         ret = -ENOMEM;
822                         goto out;
823                 }
824                 ios->per_dev[i].or = or;
825                 ios->numdevs++;
826
827                 osd_req_remove_object(or, _ios_obj(ios, i));
828         }
829         ret = ore_io_execute(ios);
830
831 out:
832         return ret;
833 }
834 EXPORT_SYMBOL(ore_remove);
835
836 static int _write_mirror(struct ore_io_state *ios, int cur_comp)
837 {
838         struct ore_per_dev_state *master_dev = &ios->per_dev[cur_comp];
839         unsigned dev = ios->per_dev[cur_comp].dev;
840         unsigned last_comp = cur_comp + ios->layout->mirrors_p1;
841         int ret = 0;
842
843         if (ios->pages && !master_dev->length)
844                 return 0; /* Just an empty slot */
845
846         for (; cur_comp < last_comp; ++cur_comp, ++dev) {
847                 struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
848                 struct osd_request *or;
849
850                 or = osd_start_request(_ios_od(ios, dev), GFP_KERNEL);
851                 if (unlikely(!or)) {
852                         ORE_ERR("%s: osd_start_request failed\n", __func__);
853                         ret = -ENOMEM;
854                         goto out;
855                 }
856                 per_dev->or = or;
857
858                 if (ios->pages) {
859                         struct bio *bio;
860
861                         if (per_dev != master_dev) {
862                                 bio = bio_clone_kmalloc(master_dev->bio,
863                                                         GFP_KERNEL);
864                                 if (unlikely(!bio)) {
865                                         ORE_DBGMSG(
866                                               "Failed to allocate BIO size=%u\n",
867                                               master_dev->bio->bi_max_vecs);
868                                         ret = -ENOMEM;
869                                         goto out;
870                                 }
871
872                                 bio->bi_bdev = NULL;
873                                 bio->bi_next = NULL;
874                                 per_dev->offset = master_dev->offset;
875                                 per_dev->length = master_dev->length;
876                                 per_dev->bio =  bio;
877                                 per_dev->dev = dev;
878                         } else {
879                                 bio = master_dev->bio;
880                                 /* FIXME: bio_set_dir() */
881                                 bio_set_op_attrs(bio, REQ_OP_WRITE, 0);
882                         }
883
884                         osd_req_write(or, _ios_obj(ios, cur_comp),
885                                       per_dev->offset, bio, per_dev->length);
886                         ORE_DBGMSG("write(0x%llx) offset=0x%llx "
887                                       "length=0x%llx dev=%d\n",
888                                      _LLU(_ios_obj(ios, cur_comp)->id),
889                                      _LLU(per_dev->offset),
890                                      _LLU(per_dev->length), dev);
891                 } else if (ios->kern_buff) {
892                         per_dev->offset = ios->si.obj_offset;
893                         per_dev->dev = ios->si.dev + dev;
894
895                         /* no cross device without page array */
896                         BUG_ON((ios->layout->group_width > 1) &&
897                                (ios->si.unit_off + ios->length >
898                                 ios->layout->stripe_unit));
899
900                         ret = osd_req_write_kern(or, _ios_obj(ios, cur_comp),
901                                                  per_dev->offset,
902                                                  ios->kern_buff, ios->length);
903                         if (unlikely(ret))
904                                 goto out;
905                         ORE_DBGMSG2("write_kern(0x%llx) offset=0x%llx "
906                                       "length=0x%llx dev=%d\n",
907                                      _LLU(_ios_obj(ios, cur_comp)->id),
908                                      _LLU(per_dev->offset),
909                                      _LLU(ios->length), per_dev->dev);
910                 } else {
911                         osd_req_set_attributes(or, _ios_obj(ios, cur_comp));
912                         ORE_DBGMSG2("obj(0x%llx) set_attributes=%d dev=%d\n",
913                                      _LLU(_ios_obj(ios, cur_comp)->id),
914                                      ios->out_attr_len, dev);
915                 }
916
917                 if (ios->out_attr)
918                         osd_req_add_set_attr_list(or, ios->out_attr,
919                                                   ios->out_attr_len);
920
921                 if (ios->in_attr)
922                         osd_req_add_get_attr_list(or, ios->in_attr,
923                                                   ios->in_attr_len);
924         }
925
926 out:
927         return ret;
928 }
929
930 int ore_write(struct ore_io_state *ios)
931 {
932         int i;
933         int ret;
934
935         if (unlikely(ios->sp2d && !ios->r4w)) {
936                 /* A library is attempting a RAID-write without providing
937                  * a pages lock interface.
938                  */
939                 WARN_ON_ONCE(1);
940                 return -ENOTSUPP;
941         }
942
943         ret = _prepare_for_striping(ios);
944         if (unlikely(ret))
945                 return ret;
946
947         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
948                 ret = _write_mirror(ios, i);
949                 if (unlikely(ret))
950                         return ret;
951         }
952
953         ret = ore_io_execute(ios);
954         return ret;
955 }
956 EXPORT_SYMBOL(ore_write);
957
958 int _ore_read_mirror(struct ore_io_state *ios, unsigned cur_comp)
959 {
960         struct osd_request *or;
961         struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
962         struct osd_obj_id *obj = _ios_obj(ios, cur_comp);
963         unsigned first_dev = (unsigned)obj->id;
964
965         if (ios->pages && !per_dev->length)
966                 return 0; /* Just an empty slot */
967
968         first_dev = per_dev->dev + first_dev % ios->layout->mirrors_p1;
969         or = osd_start_request(_ios_od(ios, first_dev), GFP_KERNEL);
970         if (unlikely(!or)) {
971                 ORE_ERR("%s: osd_start_request failed\n", __func__);
972                 return -ENOMEM;
973         }
974         per_dev->or = or;
975
976         if (ios->pages) {
977                 if (per_dev->cur_sg) {
978                         /* finalize the last sg_entry */
979                         _ore_add_sg_seg(per_dev, 0, false);
980                         if (unlikely(!per_dev->cur_sg))
981                                 return 0; /* Skip parity only device */
982
983                         osd_req_read_sg(or, obj, per_dev->bio,
984                                         per_dev->sglist, per_dev->cur_sg);
985                 } else {
986                         /* The no raid case */
987                         osd_req_read(or, obj, per_dev->offset,
988                                      per_dev->bio, per_dev->length);
989                 }
990
991                 ORE_DBGMSG("read(0x%llx) offset=0x%llx length=0x%llx"
992                              " dev=%d sg_len=%d\n", _LLU(obj->id),
993                              _LLU(per_dev->offset), _LLU(per_dev->length),
994                              first_dev, per_dev->cur_sg);
995         } else {
996                 BUG_ON(ios->kern_buff);
997
998                 osd_req_get_attributes(or, obj);
999                 ORE_DBGMSG2("obj(0x%llx) get_attributes=%d dev=%d\n",
1000                               _LLU(obj->id),
1001                               ios->in_attr_len, first_dev);
1002         }
1003         if (ios->out_attr)
1004                 osd_req_add_set_attr_list(or, ios->out_attr, ios->out_attr_len);
1005
1006         if (ios->in_attr)
1007                 osd_req_add_get_attr_list(or, ios->in_attr, ios->in_attr_len);
1008
1009         return 0;
1010 }
1011
1012 int ore_read(struct ore_io_state *ios)
1013 {
1014         int i;
1015         int ret;
1016
1017         ret = _prepare_for_striping(ios);
1018         if (unlikely(ret))
1019                 return ret;
1020
1021         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
1022                 ret = _ore_read_mirror(ios, i);
1023                 if (unlikely(ret))
1024                         return ret;
1025         }
1026
1027         ret = ore_io_execute(ios);
1028         return ret;
1029 }
1030 EXPORT_SYMBOL(ore_read);
1031
1032 int extract_attr_from_ios(struct ore_io_state *ios, struct osd_attr *attr)
1033 {
1034         struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
1035         void *iter = NULL;
1036         int nelem;
1037
1038         do {
1039                 nelem = 1;
1040                 osd_req_decode_get_attr_list(ios->per_dev[0].or,
1041                                              &cur_attr, &nelem, &iter);
1042                 if ((cur_attr.attr_page == attr->attr_page) &&
1043                     (cur_attr.attr_id == attr->attr_id)) {
1044                         attr->len = cur_attr.len;
1045                         attr->val_ptr = cur_attr.val_ptr;
1046                         return 0;
1047                 }
1048         } while (iter);
1049
1050         return -EIO;
1051 }
1052 EXPORT_SYMBOL(extract_attr_from_ios);
1053
1054 static int _truncate_mirrors(struct ore_io_state *ios, unsigned cur_comp,
1055                              struct osd_attr *attr)
1056 {
1057         int last_comp = cur_comp + ios->layout->mirrors_p1;
1058
1059         for (; cur_comp < last_comp; ++cur_comp) {
1060                 struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
1061                 struct osd_request *or;
1062
1063                 or = osd_start_request(_ios_od(ios, cur_comp), GFP_KERNEL);
1064                 if (unlikely(!or)) {
1065                         ORE_ERR("%s: osd_start_request failed\n", __func__);
1066                         return -ENOMEM;
1067                 }
1068                 per_dev->or = or;
1069
1070                 osd_req_set_attributes(or, _ios_obj(ios, cur_comp));
1071                 osd_req_add_set_attr_list(or, attr, 1);
1072         }
1073
1074         return 0;
1075 }
1076
1077 struct _trunc_info {
1078         struct ore_striping_info si;
1079         u64 prev_group_obj_off;
1080         u64 next_group_obj_off;
1081
1082         unsigned first_group_dev;
1083         unsigned nex_group_dev;
1084 };
1085
1086 static void _calc_trunk_info(struct ore_layout *layout, u64 file_offset,
1087                              struct _trunc_info *ti)
1088 {
1089         unsigned stripe_unit = layout->stripe_unit;
1090
1091         ore_calc_stripe_info(layout, file_offset, 0, &ti->si);
1092
1093         ti->prev_group_obj_off = ti->si.M * stripe_unit;
1094         ti->next_group_obj_off = ti->si.M ? (ti->si.M - 1) * stripe_unit : 0;
1095
1096         ti->first_group_dev = ti->si.dev - (ti->si.dev % layout->group_width);
1097         ti->nex_group_dev = ti->first_group_dev + layout->group_width;
1098 }
1099
1100 int ore_truncate(struct ore_layout *layout, struct ore_components *oc,
1101                    u64 size)
1102 {
1103         struct ore_io_state *ios;
1104         struct exofs_trunc_attr {
1105                 struct osd_attr attr;
1106                 __be64 newsize;
1107         } *size_attrs;
1108         struct _trunc_info ti;
1109         int i, ret;
1110
1111         ret = ore_get_io_state(layout, oc, &ios);
1112         if (unlikely(ret))
1113                 return ret;
1114
1115         _calc_trunk_info(ios->layout, size, &ti);
1116
1117         size_attrs = kcalloc(ios->oc->numdevs, sizeof(*size_attrs),
1118                              GFP_KERNEL);
1119         if (unlikely(!size_attrs)) {
1120                 ret = -ENOMEM;
1121                 goto out;
1122         }
1123
1124         ios->numdevs = ios->oc->numdevs;
1125
1126         for (i = 0; i < ios->numdevs; ++i) {
1127                 struct exofs_trunc_attr *size_attr = &size_attrs[i];
1128                 u64 obj_size;
1129
1130                 if (i < ti.first_group_dev)
1131                         obj_size = ti.prev_group_obj_off;
1132                 else if (i >= ti.nex_group_dev)
1133                         obj_size = ti.next_group_obj_off;
1134                 else if (i < ti.si.dev) /* dev within this group */
1135                         obj_size = ti.si.obj_offset +
1136                                       ios->layout->stripe_unit - ti.si.unit_off;
1137                 else if (i == ti.si.dev)
1138                         obj_size = ti.si.obj_offset;
1139                 else /* i > ti.dev */
1140                         obj_size = ti.si.obj_offset - ti.si.unit_off;
1141
1142                 size_attr->newsize = cpu_to_be64(obj_size);
1143                 size_attr->attr = g_attr_logical_length;
1144                 size_attr->attr.val_ptr = &size_attr->newsize;
1145
1146                 ORE_DBGMSG2("trunc(0x%llx) obj_offset=0x%llx dev=%d\n",
1147                              _LLU(oc->comps->obj.id), _LLU(obj_size), i);
1148                 ret = _truncate_mirrors(ios, i * ios->layout->mirrors_p1,
1149                                         &size_attr->attr);
1150                 if (unlikely(ret))
1151                         goto out;
1152         }
1153         ret = ore_io_execute(ios);
1154
1155 out:
1156         kfree(size_attrs);
1157         ore_put_io_state(ios);
1158         return ret;
1159 }
1160 EXPORT_SYMBOL(ore_truncate);
1161
1162 const struct osd_attr g_attr_logical_length = ATTR_DEF(
1163         OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
1164 EXPORT_SYMBOL(g_attr_logical_length);