Merge commit 'v3.4.9' into android-t114-3.4
[linux-2.6.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 <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 <bharrosh@panasas.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         case PNFS_OSD_RAID_4:
62         default:
63                 ORE_ERR("Only RAID_0/5 for now\n");
64                 return -EINVAL;
65         }
66         if (0 != (layout->stripe_unit & ~PAGE_MASK)) {
67                 ORE_ERR("Stripe Unit(0x%llx)"
68                           " must be Multples of PAGE_SIZE(0x%lx)\n",
69                           _LLU(layout->stripe_unit), PAGE_SIZE);
70                 return -EINVAL;
71         }
72         if (layout->group_width) {
73                 if (!layout->group_depth) {
74                         ORE_ERR("group_depth == 0 && group_width != 0\n");
75                         return -EINVAL;
76                 }
77                 if (total_comps < (layout->group_width * layout->mirrors_p1)) {
78                         ORE_ERR("Data Map wrong, "
79                                 "numdevs=%d < group_width=%d * mirrors=%d\n",
80                                 total_comps, layout->group_width,
81                                 layout->mirrors_p1);
82                         return -EINVAL;
83                 }
84                 layout->group_count = total_comps / layout->mirrors_p1 /
85                                                 layout->group_width;
86         } else {
87                 if (layout->group_depth) {
88                         printk(KERN_NOTICE "Warning: group_depth ignored "
89                                 "group_width == 0 && group_depth == %lld\n",
90                                 _LLU(layout->group_depth));
91                 }
92                 layout->group_width = total_comps / layout->mirrors_p1;
93                 layout->group_depth = -1;
94                 layout->group_count = 1;
95         }
96
97         stripe_length = (u64)layout->group_width * layout->stripe_unit;
98         if (stripe_length >= (1ULL << 32)) {
99                 ORE_ERR("Stripe_length(0x%llx) >= 32bit is not supported\n",
100                         _LLU(stripe_length));
101                 return -EINVAL;
102         }
103
104         layout->max_io_length =
105                 (BIO_MAX_PAGES_KMALLOC * PAGE_SIZE - layout->stripe_unit) *
106                                                         layout->group_width;
107         if (layout->parity) {
108                 unsigned stripe_length =
109                                 (layout->group_width - layout->parity) *
110                                 layout->stripe_unit;
111
112                 layout->max_io_length /= stripe_length;
113                 layout->max_io_length *= stripe_length;
114         }
115         return 0;
116 }
117 EXPORT_SYMBOL(ore_verify_layout);
118
119 static u8 *_ios_cred(struct ore_io_state *ios, unsigned index)
120 {
121         return ios->oc->comps[index & ios->oc->single_comp].cred;
122 }
123
124 static struct osd_obj_id *_ios_obj(struct ore_io_state *ios, unsigned index)
125 {
126         return &ios->oc->comps[index & ios->oc->single_comp].obj;
127 }
128
129 static struct osd_dev *_ios_od(struct ore_io_state *ios, unsigned index)
130 {
131         ORE_DBGMSG2("oc->first_dev=%d oc->numdevs=%d i=%d oc->ods=%p\n",
132                     ios->oc->first_dev, ios->oc->numdevs, index,
133                     ios->oc->ods);
134
135         return ore_comp_dev(ios->oc, index);
136 }
137
138 int  _ore_get_io_state(struct ore_layout *layout,
139                         struct ore_components *oc, unsigned numdevs,
140                         unsigned sgs_per_dev, unsigned num_par_pages,
141                         struct ore_io_state **pios)
142 {
143         struct ore_io_state *ios;
144         struct page **pages;
145         struct osd_sg_entry *sgilist;
146         struct __alloc_all_io_state {
147                 struct ore_io_state ios;
148                 struct ore_per_dev_state per_dev[numdevs];
149                 union {
150                         struct osd_sg_entry sglist[sgs_per_dev * numdevs];
151                         struct page *pages[num_par_pages];
152                 };
153         } *_aios;
154
155         if (likely(sizeof(*_aios) <= PAGE_SIZE)) {
156                 _aios = kzalloc(sizeof(*_aios), GFP_KERNEL);
157                 if (unlikely(!_aios)) {
158                         ORE_DBGMSG("Failed kzalloc bytes=%zd\n",
159                                    sizeof(*_aios));
160                         *pios = NULL;
161                         return -ENOMEM;
162                 }
163                 pages = num_par_pages ? _aios->pages : NULL;
164                 sgilist = sgs_per_dev ? _aios->sglist : NULL;
165                 ios = &_aios->ios;
166         } else {
167                 struct __alloc_small_io_state {
168                         struct ore_io_state ios;
169                         struct ore_per_dev_state per_dev[numdevs];
170                 } *_aio_small;
171                 union __extra_part {
172                         struct osd_sg_entry sglist[sgs_per_dev * numdevs];
173                         struct page *pages[num_par_pages];
174                 } *extra_part;
175
176                 _aio_small = kzalloc(sizeof(*_aio_small), GFP_KERNEL);
177                 if (unlikely(!_aio_small)) {
178                         ORE_DBGMSG("Failed alloc first part bytes=%zd\n",
179                                    sizeof(*_aio_small));
180                         *pios = NULL;
181                         return -ENOMEM;
182                 }
183                 extra_part = kzalloc(sizeof(*extra_part), GFP_KERNEL);
184                 if (unlikely(!extra_part)) {
185                         ORE_DBGMSG("Failed alloc second part bytes=%zd\n",
186                                    sizeof(*extra_part));
187                         kfree(_aio_small);
188                         *pios = NULL;
189                         return -ENOMEM;
190                 }
191
192                 pages = num_par_pages ? extra_part->pages : NULL;
193                 sgilist = sgs_per_dev ? extra_part->sglist : NULL;
194                 /* In this case the per_dev[0].sgilist holds the pointer to
195                  * be freed
196                  */
197                 ios = &_aio_small->ios;
198                 ios->extra_part_alloc = true;
199         }
200
201         if (pages) {
202                 ios->parity_pages = pages;
203                 ios->max_par_pages = num_par_pages;
204         }
205         if (sgilist) {
206                 unsigned d;
207
208                 for (d = 0; d < numdevs; ++d) {
209                         ios->per_dev[d].sglist = sgilist;
210                         sgilist += sgs_per_dev;
211                 }
212                 ios->sgs_per_dev = sgs_per_dev;
213         }
214
215         ios->layout = layout;
216         ios->oc = oc;
217         *pios = ios;
218         return 0;
219 }
220
221 /* Allocate an io_state for only a single group of devices
222  *
223  * If a user needs to call ore_read/write() this version must be used becase it
224  * allocates extra stuff for striping and raid.
225  * The ore might decide to only IO less then @length bytes do to alignmets
226  * and constrains as follows:
227  * - The IO cannot cross group boundary.
228  * - In raid5/6 The end of the IO must align at end of a stripe eg.
229  *   (@offset + @length) % strip_size == 0. Or the complete range is within a
230  *   single stripe.
231  * - Memory condition only permitted a shorter IO. (A user can use @length=~0
232  *   And check the returned ios->length for max_io_size.)
233  *
234  * The caller must check returned ios->length (and/or ios->nr_pages) and
235  * re-issue these pages that fall outside of ios->length
236  */
237 int  ore_get_rw_state(struct ore_layout *layout, struct ore_components *oc,
238                       bool is_reading, u64 offset, u64 length,
239                       struct ore_io_state **pios)
240 {
241         struct ore_io_state *ios;
242         unsigned numdevs = layout->group_width * layout->mirrors_p1;
243         unsigned sgs_per_dev = 0, max_par_pages = 0;
244         int ret;
245
246         if (layout->parity && length) {
247                 unsigned data_devs = layout->group_width - layout->parity;
248                 unsigned stripe_size = layout->stripe_unit * data_devs;
249                 unsigned pages_in_unit = layout->stripe_unit / PAGE_SIZE;
250                 u32 remainder;
251                 u64 num_stripes;
252                 u64 num_raid_units;
253
254                 num_stripes = div_u64_rem(length, stripe_size, &remainder);
255                 if (remainder)
256                         ++num_stripes;
257
258                 num_raid_units =  num_stripes * layout->parity;
259
260                 if (is_reading) {
261                         /* For reads add per_dev sglist array */
262                         /* TODO: Raid 6 we need twice more. Actually:
263                         *         num_stripes / LCMdP(W,P);
264                         *         if (W%P != 0) num_stripes *= parity;
265                         */
266
267                         /* first/last seg is split */
268                         num_raid_units += layout->group_width;
269                         sgs_per_dev = div_u64(num_raid_units, data_devs) + 2;
270                 } else {
271                         /* For Writes add parity pages array. */
272                         max_par_pages = num_raid_units * pages_in_unit *
273                                                 sizeof(struct page *);
274                 }
275         }
276
277         ret = _ore_get_io_state(layout, oc, numdevs, sgs_per_dev, max_par_pages,
278                                 pios);
279         if (unlikely(ret))
280                 return ret;
281
282         ios = *pios;
283         ios->reading = is_reading;
284         ios->offset = offset;
285
286         if (length) {
287                 ore_calc_stripe_info(layout, offset, length, &ios->si);
288                 ios->length = ios->si.length;
289                 ios->nr_pages = (ios->length + PAGE_SIZE - 1) / PAGE_SIZE;
290                 if (layout->parity)
291                         _ore_post_alloc_raid_stuff(ios);
292         }
293
294         return 0;
295 }
296 EXPORT_SYMBOL(ore_get_rw_state);
297
298 /* Allocate an io_state for all the devices in the comps array
299  *
300  * This version of io_state allocation is used mostly by create/remove
301  * and trunc where we currently need all the devices. The only wastful
302  * bit is the read/write_attributes with no IO. Those sites should
303  * be converted to use ore_get_rw_state() with length=0
304  */
305 int  ore_get_io_state(struct ore_layout *layout, struct ore_components *oc,
306                       struct ore_io_state **pios)
307 {
308         return _ore_get_io_state(layout, oc, oc->numdevs, 0, 0, pios);
309 }
310 EXPORT_SYMBOL(ore_get_io_state);
311
312 void ore_put_io_state(struct ore_io_state *ios)
313 {
314         if (ios) {
315                 unsigned i;
316
317                 for (i = 0; i < ios->numdevs; i++) {
318                         struct ore_per_dev_state *per_dev = &ios->per_dev[i];
319
320                         if (per_dev->or)
321                                 osd_end_request(per_dev->or);
322                         if (per_dev->bio)
323                                 bio_put(per_dev->bio);
324                 }
325
326                 _ore_free_raid_stuff(ios);
327                 kfree(ios);
328         }
329 }
330 EXPORT_SYMBOL(ore_put_io_state);
331
332 static void _sync_done(struct ore_io_state *ios, void *p)
333 {
334         struct completion *waiting = p;
335
336         complete(waiting);
337 }
338
339 static void _last_io(struct kref *kref)
340 {
341         struct ore_io_state *ios = container_of(
342                                         kref, struct ore_io_state, kref);
343
344         ios->done(ios, ios->private);
345 }
346
347 static void _done_io(struct osd_request *or, void *p)
348 {
349         struct ore_io_state *ios = p;
350
351         kref_put(&ios->kref, _last_io);
352 }
353
354 int ore_io_execute(struct ore_io_state *ios)
355 {
356         DECLARE_COMPLETION_ONSTACK(wait);
357         bool sync = (ios->done == NULL);
358         int i, ret;
359
360         if (sync) {
361                 ios->done = _sync_done;
362                 ios->private = &wait;
363         }
364
365         for (i = 0; i < ios->numdevs; i++) {
366                 struct osd_request *or = ios->per_dev[i].or;
367                 if (unlikely(!or))
368                         continue;
369
370                 ret = osd_finalize_request(or, 0, _ios_cred(ios, i), NULL);
371                 if (unlikely(ret)) {
372                         ORE_DBGMSG("Failed to osd_finalize_request() => %d\n",
373                                      ret);
374                         return ret;
375                 }
376         }
377
378         kref_init(&ios->kref);
379
380         for (i = 0; i < ios->numdevs; i++) {
381                 struct osd_request *or = ios->per_dev[i].or;
382                 if (unlikely(!or))
383                         continue;
384
385                 kref_get(&ios->kref);
386                 osd_execute_request_async(or, _done_io, ios);
387         }
388
389         kref_put(&ios->kref, _last_io);
390         ret = 0;
391
392         if (sync) {
393                 wait_for_completion(&wait);
394                 ret = ore_check_io(ios, NULL);
395         }
396         return ret;
397 }
398
399 static void _clear_bio(struct bio *bio)
400 {
401         struct bio_vec *bv;
402         unsigned i;
403
404         __bio_for_each_segment(bv, bio, i, 0) {
405                 unsigned this_count = bv->bv_len;
406
407                 if (likely(PAGE_SIZE == this_count))
408                         clear_highpage(bv->bv_page);
409                 else
410                         zero_user(bv->bv_page, bv->bv_offset, this_count);
411         }
412 }
413
414 int ore_check_io(struct ore_io_state *ios, ore_on_dev_error on_dev_error)
415 {
416         enum osd_err_priority acumulated_osd_err = 0;
417         int acumulated_lin_err = 0;
418         int i;
419
420         for (i = 0; i < ios->numdevs; i++) {
421                 struct osd_sense_info osi;
422                 struct ore_per_dev_state *per_dev = &ios->per_dev[i];
423                 struct osd_request *or = per_dev->or;
424                 int ret;
425
426                 if (unlikely(!or))
427                         continue;
428
429                 ret = osd_req_decode_sense(or, &osi);
430                 if (likely(!ret))
431                         continue;
432
433                 if (OSD_ERR_PRI_CLEAR_PAGES == osi.osd_err_pri) {
434                         /* start read offset passed endof file */
435                         _clear_bio(per_dev->bio);
436                         ORE_DBGMSG("start read offset passed end of file "
437                                 "offset=0x%llx, length=0x%llx\n",
438                                 _LLU(per_dev->offset),
439                                 _LLU(per_dev->length));
440
441                         continue; /* we recovered */
442                 }
443
444                 if (on_dev_error) {
445                         u64 residual = ios->reading ?
446                                         or->in.residual : or->out.residual;
447                         u64 offset = (ios->offset + ios->length) - residual;
448                         unsigned dev = per_dev->dev - ios->oc->first_dev;
449                         struct ore_dev *od = ios->oc->ods[dev];
450
451                         on_dev_error(ios, od, dev, osi.osd_err_pri,
452                                      offset, residual);
453                 }
454                 if (osi.osd_err_pri >= acumulated_osd_err) {
455                         acumulated_osd_err = osi.osd_err_pri;
456                         acumulated_lin_err = ret;
457                 }
458         }
459
460         return acumulated_lin_err;
461 }
462 EXPORT_SYMBOL(ore_check_io);
463
464 /*
465  * L - logical offset into the file
466  *
467  * D - number of Data devices
468  *      D = group_width - parity
469  *
470  * U - The number of bytes in a stripe within a group
471  *      U =  stripe_unit * D
472  *
473  * T - The number of bytes striped within a group of component objects
474  *     (before advancing to the next group)
475  *      T = U * group_depth
476  *
477  * S - The number of bytes striped across all component objects
478  *     before the pattern repeats
479  *      S = T * group_count
480  *
481  * M - The "major" (i.e., across all components) cycle number
482  *      M = L / S
483  *
484  * G - Counts the groups from the beginning of the major cycle
485  *      G = (L - (M * S)) / T   [or (L % S) / T]
486  *
487  * H - The byte offset within the group
488  *      H = (L - (M * S)) % T   [or (L % S) % T]
489  *
490  * N - The "minor" (i.e., across the group) stripe number
491  *      N = H / U
492  *
493  * C - The component index coresponding to L
494  *
495  *      C = (H - (N * U)) / stripe_unit + G * D
496  *      [or (L % U) / stripe_unit + G * D]
497  *
498  * O - The component offset coresponding to L
499  *      O = L % stripe_unit + N * stripe_unit + M * group_depth * stripe_unit
500  *
501  * LCMdP – Parity cycle: Lowest Common Multiple of group_width, parity
502  *          divide by parity
503  *      LCMdP = lcm(group_width, parity) / parity
504  *
505  * R - The parity Rotation stripe
506  *     (Note parity cycle always starts at a group's boundary)
507  *      R = N % LCMdP
508  *
509  * I = the first parity device index
510  *      I = (group_width + group_width - R*parity - parity) % group_width
511  *
512  * Craid - The component index Rotated
513  *      Craid = (group_width + C - R*parity) % group_width
514  *      (We add the group_width to avoid negative numbers modulo math)
515  */
516 void ore_calc_stripe_info(struct ore_layout *layout, u64 file_offset,
517                           u64 length, struct ore_striping_info *si)
518 {
519         u32     stripe_unit = layout->stripe_unit;
520         u32     group_width = layout->group_width;
521         u64     group_depth = layout->group_depth;
522         u32     parity      = layout->parity;
523
524         u32     D = group_width - parity;
525         u32     U = D * stripe_unit;
526         u64     T = U * group_depth;
527         u64     S = T * layout->group_count;
528         u64     M = div64_u64(file_offset, S);
529
530         /*
531         G = (L - (M * S)) / T
532         H = (L - (M * S)) % T
533         */
534         u64     LmodS = file_offset - M * S;
535         u32     G = div64_u64(LmodS, T);
536         u64     H = LmodS - G * T;
537
538         u32     N = div_u64(H, U);
539
540         /* "H - (N * U)" is just "H % U" so it's bound to u32 */
541         u32     C = (u32)(H - (N * U)) / stripe_unit + G * group_width;
542
543         div_u64_rem(file_offset, stripe_unit, &si->unit_off);
544
545         si->obj_offset = si->unit_off + (N * stripe_unit) +
546                                   (M * group_depth * stripe_unit);
547
548         if (parity) {
549                 u32 LCMdP = lcm(group_width, parity) / parity;
550                 /* R     = N % LCMdP; */
551                 u32 RxP   = (N % LCMdP) * parity;
552                 u32 first_dev = C - C % group_width;
553
554                 si->par_dev = (group_width + group_width - parity - RxP) %
555                               group_width + first_dev;
556                 si->dev = (group_width + C - RxP) % group_width + first_dev;
557                 si->bytes_in_stripe = U;
558                 si->first_stripe_start = M * S + G * T + N * U;
559         } else {
560                 /* Make the math correct see _prepare_one_group */
561                 si->par_dev = group_width;
562                 si->dev = C;
563         }
564
565         si->dev *= layout->mirrors_p1;
566         si->par_dev *= layout->mirrors_p1;
567         si->offset = file_offset;
568         si->length = T - H;
569         if (si->length > length)
570                 si->length = length;
571         si->M = M;
572 }
573 EXPORT_SYMBOL(ore_calc_stripe_info);
574
575 int _ore_add_stripe_unit(struct ore_io_state *ios,  unsigned *cur_pg,
576                          unsigned pgbase, struct page **pages,
577                          struct ore_per_dev_state *per_dev, int cur_len)
578 {
579         unsigned pg = *cur_pg;
580         struct request_queue *q =
581                         osd_request_queue(_ios_od(ios, per_dev->dev));
582         unsigned len = cur_len;
583         int ret;
584
585         if (per_dev->bio == NULL) {
586                 unsigned pages_in_stripe = ios->layout->group_width *
587                                         (ios->layout->stripe_unit / PAGE_SIZE);
588                 unsigned nr_pages = ios->nr_pages * ios->layout->group_width /
589                                         (ios->layout->group_width -
590                                          ios->layout->parity);
591                 unsigned bio_size = (nr_pages + pages_in_stripe) /
592                                         ios->layout->group_width;
593
594                 per_dev->bio = bio_kmalloc(GFP_KERNEL, bio_size);
595                 if (unlikely(!per_dev->bio)) {
596                         ORE_DBGMSG("Failed to allocate BIO size=%u\n",
597                                      bio_size);
598                         ret = -ENOMEM;
599                         goto out;
600                 }
601         }
602
603         while (cur_len > 0) {
604                 unsigned pglen = min_t(unsigned, PAGE_SIZE - pgbase, cur_len);
605                 unsigned added_len;
606
607                 cur_len -= pglen;
608
609                 added_len = bio_add_pc_page(q, per_dev->bio, pages[pg],
610                                             pglen, pgbase);
611                 if (unlikely(pglen != added_len)) {
612                         ORE_DBGMSG("Failed bio_add_pc_page bi_vcnt=%u\n",
613                                    per_dev->bio->bi_vcnt);
614                         ret = -ENOMEM;
615                         goto out;
616                 }
617                 _add_stripe_page(ios->sp2d, &ios->si, pages[pg]);
618
619                 pgbase = 0;
620                 ++pg;
621         }
622         BUG_ON(cur_len);
623
624         per_dev->length += len;
625         *cur_pg = pg;
626         ret = 0;
627 out:    /* we fail the complete unit on an error eg don't advance
628          * per_dev->length and cur_pg. This means that we might have a bigger
629          * bio than the CDB requested length (per_dev->length). That's fine
630          * only the oposite is fatal.
631          */
632         return ret;
633 }
634
635 static int _prepare_for_striping(struct ore_io_state *ios)
636 {
637         struct ore_striping_info *si = &ios->si;
638         unsigned stripe_unit = ios->layout->stripe_unit;
639         unsigned mirrors_p1 = ios->layout->mirrors_p1;
640         unsigned group_width = ios->layout->group_width;
641         unsigned devs_in_group = group_width * mirrors_p1;
642         unsigned dev = si->dev;
643         unsigned first_dev = dev - (dev % devs_in_group);
644         unsigned dev_order;
645         unsigned cur_pg = ios->pages_consumed;
646         u64 length = ios->length;
647         int ret = 0;
648
649         if (!ios->pages) {
650                 ios->numdevs = ios->layout->mirrors_p1;
651                 return 0;
652         }
653
654         BUG_ON(length > si->length);
655
656         dev_order = _dev_order(devs_in_group, mirrors_p1, si->par_dev, dev);
657         si->cur_comp = dev_order;
658         si->cur_pg = si->unit_off / PAGE_SIZE;
659
660         while (length) {
661                 unsigned comp = dev - first_dev;
662                 struct ore_per_dev_state *per_dev = &ios->per_dev[comp];
663                 unsigned cur_len, page_off = 0;
664
665                 if (!per_dev->length) {
666                         per_dev->dev = dev;
667                         if (dev == si->dev) {
668                                 WARN_ON(dev == si->par_dev);
669                                 per_dev->offset = si->obj_offset;
670                                 cur_len = stripe_unit - si->unit_off;
671                                 page_off = si->unit_off & ~PAGE_MASK;
672                                 BUG_ON(page_off && (page_off != ios->pgbase));
673                         } else {
674                                 if (si->cur_comp > dev_order)
675                                         per_dev->offset =
676                                                 si->obj_offset - si->unit_off;
677                                 else /* si->cur_comp < dev_order */
678                                         per_dev->offset =
679                                                 si->obj_offset + stripe_unit -
680                                                                    si->unit_off;
681                                 cur_len = stripe_unit;
682                         }
683                 } else {
684                         cur_len = stripe_unit;
685                 }
686                 if (cur_len >= length)
687                         cur_len = length;
688
689                 ret = _ore_add_stripe_unit(ios, &cur_pg, page_off, ios->pages,
690                                            per_dev, cur_len);
691                 if (unlikely(ret))
692                         goto out;
693
694                 dev += mirrors_p1;
695                 dev = (dev % devs_in_group) + first_dev;
696
697                 length -= cur_len;
698
699                 si->cur_comp = (si->cur_comp + 1) % group_width;
700                 if (unlikely((dev == si->par_dev) || (!length && ios->sp2d))) {
701                         if (!length && ios->sp2d) {
702                                 /* If we are writing and this is the very last
703                                  * stripe. then operate on parity dev.
704                                  */
705                                 dev = si->par_dev;
706                         }
707                         if (ios->sp2d)
708                                 /* In writes cur_len just means if it's the
709                                  * last one. See _ore_add_parity_unit.
710                                  */
711                                 cur_len = length;
712                         per_dev = &ios->per_dev[dev - first_dev];
713                         if (!per_dev->length) {
714                                 /* Only/always the parity unit of the first
715                                  * stripe will be empty. So this is a chance to
716                                  * initialize the per_dev info.
717                                  */
718                                 per_dev->dev = dev;
719                                 per_dev->offset = si->obj_offset - si->unit_off;
720                         }
721
722                         ret = _ore_add_parity_unit(ios, si, per_dev, cur_len);
723                         if (unlikely(ret))
724                                         goto out;
725
726                         /* Rotate next par_dev backwards with wraping */
727                         si->par_dev = (devs_in_group + si->par_dev -
728                                        ios->layout->parity * mirrors_p1) %
729                                       devs_in_group + first_dev;
730                         /* Next stripe, start fresh */
731                         si->cur_comp = 0;
732                         si->cur_pg = 0;
733                 }
734         }
735 out:
736         ios->numdevs = devs_in_group;
737         ios->pages_consumed = cur_pg;
738         return ret;
739 }
740
741 int ore_create(struct ore_io_state *ios)
742 {
743         int i, ret;
744
745         for (i = 0; i < ios->oc->numdevs; i++) {
746                 struct osd_request *or;
747
748                 or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
749                 if (unlikely(!or)) {
750                         ORE_ERR("%s: osd_start_request failed\n", __func__);
751                         ret = -ENOMEM;
752                         goto out;
753                 }
754                 ios->per_dev[i].or = or;
755                 ios->numdevs++;
756
757                 osd_req_create_object(or, _ios_obj(ios, i));
758         }
759         ret = ore_io_execute(ios);
760
761 out:
762         return ret;
763 }
764 EXPORT_SYMBOL(ore_create);
765
766 int ore_remove(struct ore_io_state *ios)
767 {
768         int i, ret;
769
770         for (i = 0; i < ios->oc->numdevs; i++) {
771                 struct osd_request *or;
772
773                 or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
774                 if (unlikely(!or)) {
775                         ORE_ERR("%s: osd_start_request failed\n", __func__);
776                         ret = -ENOMEM;
777                         goto out;
778                 }
779                 ios->per_dev[i].or = or;
780                 ios->numdevs++;
781
782                 osd_req_remove_object(or, _ios_obj(ios, i));
783         }
784         ret = ore_io_execute(ios);
785
786 out:
787         return ret;
788 }
789 EXPORT_SYMBOL(ore_remove);
790
791 static int _write_mirror(struct ore_io_state *ios, int cur_comp)
792 {
793         struct ore_per_dev_state *master_dev = &ios->per_dev[cur_comp];
794         unsigned dev = ios->per_dev[cur_comp].dev;
795         unsigned last_comp = cur_comp + ios->layout->mirrors_p1;
796         int ret = 0;
797
798         if (ios->pages && !master_dev->length)
799                 return 0; /* Just an empty slot */
800
801         for (; cur_comp < last_comp; ++cur_comp, ++dev) {
802                 struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
803                 struct osd_request *or;
804
805                 or = osd_start_request(_ios_od(ios, dev), GFP_KERNEL);
806                 if (unlikely(!or)) {
807                         ORE_ERR("%s: osd_start_request failed\n", __func__);
808                         ret = -ENOMEM;
809                         goto out;
810                 }
811                 per_dev->or = or;
812
813                 if (ios->pages) {
814                         struct bio *bio;
815
816                         if (per_dev != master_dev) {
817                                 bio = bio_kmalloc(GFP_KERNEL,
818                                                   master_dev->bio->bi_max_vecs);
819                                 if (unlikely(!bio)) {
820                                         ORE_DBGMSG(
821                                               "Failed to allocate BIO size=%u\n",
822                                               master_dev->bio->bi_max_vecs);
823                                         ret = -ENOMEM;
824                                         goto out;
825                                 }
826
827                                 __bio_clone(bio, master_dev->bio);
828                                 bio->bi_bdev = NULL;
829                                 bio->bi_next = NULL;
830                                 per_dev->offset = master_dev->offset;
831                                 per_dev->length = master_dev->length;
832                                 per_dev->bio =  bio;
833                                 per_dev->dev = dev;
834                         } else {
835                                 bio = master_dev->bio;
836                                 /* FIXME: bio_set_dir() */
837                                 bio->bi_rw |= REQ_WRITE;
838                         }
839
840                         osd_req_write(or, _ios_obj(ios, cur_comp),
841                                       per_dev->offset, bio, per_dev->length);
842                         ORE_DBGMSG("write(0x%llx) offset=0x%llx "
843                                       "length=0x%llx dev=%d\n",
844                                      _LLU(_ios_obj(ios, cur_comp)->id),
845                                      _LLU(per_dev->offset),
846                                      _LLU(per_dev->length), dev);
847                 } else if (ios->kern_buff) {
848                         per_dev->offset = ios->si.obj_offset;
849                         per_dev->dev = ios->si.dev + dev;
850
851                         /* no cross device without page array */
852                         BUG_ON((ios->layout->group_width > 1) &&
853                                (ios->si.unit_off + ios->length >
854                                 ios->layout->stripe_unit));
855
856                         ret = osd_req_write_kern(or, _ios_obj(ios, cur_comp),
857                                                  per_dev->offset,
858                                                  ios->kern_buff, ios->length);
859                         if (unlikely(ret))
860                                 goto out;
861                         ORE_DBGMSG2("write_kern(0x%llx) offset=0x%llx "
862                                       "length=0x%llx dev=%d\n",
863                                      _LLU(_ios_obj(ios, cur_comp)->id),
864                                      _LLU(per_dev->offset),
865                                      _LLU(ios->length), per_dev->dev);
866                 } else {
867                         osd_req_set_attributes(or, _ios_obj(ios, cur_comp));
868                         ORE_DBGMSG2("obj(0x%llx) set_attributes=%d dev=%d\n",
869                                      _LLU(_ios_obj(ios, cur_comp)->id),
870                                      ios->out_attr_len, dev);
871                 }
872
873                 if (ios->out_attr)
874                         osd_req_add_set_attr_list(or, ios->out_attr,
875                                                   ios->out_attr_len);
876
877                 if (ios->in_attr)
878                         osd_req_add_get_attr_list(or, ios->in_attr,
879                                                   ios->in_attr_len);
880         }
881
882 out:
883         return ret;
884 }
885
886 int ore_write(struct ore_io_state *ios)
887 {
888         int i;
889         int ret;
890
891         if (unlikely(ios->sp2d && !ios->r4w)) {
892                 /* A library is attempting a RAID-write without providing
893                  * a pages lock interface.
894                  */
895                 WARN_ON_ONCE(1);
896                 return -ENOTSUPP;
897         }
898
899         ret = _prepare_for_striping(ios);
900         if (unlikely(ret))
901                 return ret;
902
903         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
904                 ret = _write_mirror(ios, i);
905                 if (unlikely(ret))
906                         return ret;
907         }
908
909         ret = ore_io_execute(ios);
910         return ret;
911 }
912 EXPORT_SYMBOL(ore_write);
913
914 int _ore_read_mirror(struct ore_io_state *ios, unsigned cur_comp)
915 {
916         struct osd_request *or;
917         struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
918         struct osd_obj_id *obj = _ios_obj(ios, cur_comp);
919         unsigned first_dev = (unsigned)obj->id;
920
921         if (ios->pages && !per_dev->length)
922                 return 0; /* Just an empty slot */
923
924         first_dev = per_dev->dev + first_dev % ios->layout->mirrors_p1;
925         or = osd_start_request(_ios_od(ios, first_dev), GFP_KERNEL);
926         if (unlikely(!or)) {
927                 ORE_ERR("%s: osd_start_request failed\n", __func__);
928                 return -ENOMEM;
929         }
930         per_dev->or = or;
931
932         if (ios->pages) {
933                 if (per_dev->cur_sg) {
934                         /* finalize the last sg_entry */
935                         _ore_add_sg_seg(per_dev, 0, false);
936                         if (unlikely(!per_dev->cur_sg))
937                                 return 0; /* Skip parity only device */
938
939                         osd_req_read_sg(or, obj, per_dev->bio,
940                                         per_dev->sglist, per_dev->cur_sg);
941                 } else {
942                         /* The no raid case */
943                         osd_req_read(or, obj, per_dev->offset,
944                                      per_dev->bio, per_dev->length);
945                 }
946
947                 ORE_DBGMSG("read(0x%llx) offset=0x%llx length=0x%llx"
948                              " dev=%d sg_len=%d\n", _LLU(obj->id),
949                              _LLU(per_dev->offset), _LLU(per_dev->length),
950                              first_dev, per_dev->cur_sg);
951         } else {
952                 BUG_ON(ios->kern_buff);
953
954                 osd_req_get_attributes(or, obj);
955                 ORE_DBGMSG2("obj(0x%llx) get_attributes=%d dev=%d\n",
956                               _LLU(obj->id),
957                               ios->in_attr_len, first_dev);
958         }
959         if (ios->out_attr)
960                 osd_req_add_set_attr_list(or, ios->out_attr, ios->out_attr_len);
961
962         if (ios->in_attr)
963                 osd_req_add_get_attr_list(or, ios->in_attr, ios->in_attr_len);
964
965         return 0;
966 }
967
968 int ore_read(struct ore_io_state *ios)
969 {
970         int i;
971         int ret;
972
973         ret = _prepare_for_striping(ios);
974         if (unlikely(ret))
975                 return ret;
976
977         for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
978                 ret = _ore_read_mirror(ios, i);
979                 if (unlikely(ret))
980                         return ret;
981         }
982
983         ret = ore_io_execute(ios);
984         return ret;
985 }
986 EXPORT_SYMBOL(ore_read);
987
988 int extract_attr_from_ios(struct ore_io_state *ios, struct osd_attr *attr)
989 {
990         struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
991         void *iter = NULL;
992         int nelem;
993
994         do {
995                 nelem = 1;
996                 osd_req_decode_get_attr_list(ios->per_dev[0].or,
997                                              &cur_attr, &nelem, &iter);
998                 if ((cur_attr.attr_page == attr->attr_page) &&
999                     (cur_attr.attr_id == attr->attr_id)) {
1000                         attr->len = cur_attr.len;
1001                         attr->val_ptr = cur_attr.val_ptr;
1002                         return 0;
1003                 }
1004         } while (iter);
1005
1006         return -EIO;
1007 }
1008 EXPORT_SYMBOL(extract_attr_from_ios);
1009
1010 static int _truncate_mirrors(struct ore_io_state *ios, unsigned cur_comp,
1011                              struct osd_attr *attr)
1012 {
1013         int last_comp = cur_comp + ios->layout->mirrors_p1;
1014
1015         for (; cur_comp < last_comp; ++cur_comp) {
1016                 struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
1017                 struct osd_request *or;
1018
1019                 or = osd_start_request(_ios_od(ios, cur_comp), GFP_KERNEL);
1020                 if (unlikely(!or)) {
1021                         ORE_ERR("%s: osd_start_request failed\n", __func__);
1022                         return -ENOMEM;
1023                 }
1024                 per_dev->or = or;
1025
1026                 osd_req_set_attributes(or, _ios_obj(ios, cur_comp));
1027                 osd_req_add_set_attr_list(or, attr, 1);
1028         }
1029
1030         return 0;
1031 }
1032
1033 struct _trunc_info {
1034         struct ore_striping_info si;
1035         u64 prev_group_obj_off;
1036         u64 next_group_obj_off;
1037
1038         unsigned first_group_dev;
1039         unsigned nex_group_dev;
1040 };
1041
1042 static void _calc_trunk_info(struct ore_layout *layout, u64 file_offset,
1043                              struct _trunc_info *ti)
1044 {
1045         unsigned stripe_unit = layout->stripe_unit;
1046
1047         ore_calc_stripe_info(layout, file_offset, 0, &ti->si);
1048
1049         ti->prev_group_obj_off = ti->si.M * stripe_unit;
1050         ti->next_group_obj_off = ti->si.M ? (ti->si.M - 1) * stripe_unit : 0;
1051
1052         ti->first_group_dev = ti->si.dev - (ti->si.dev % layout->group_width);
1053         ti->nex_group_dev = ti->first_group_dev + layout->group_width;
1054 }
1055
1056 int ore_truncate(struct ore_layout *layout, struct ore_components *oc,
1057                    u64 size)
1058 {
1059         struct ore_io_state *ios;
1060         struct exofs_trunc_attr {
1061                 struct osd_attr attr;
1062                 __be64 newsize;
1063         } *size_attrs;
1064         struct _trunc_info ti;
1065         int i, ret;
1066
1067         ret = ore_get_io_state(layout, oc, &ios);
1068         if (unlikely(ret))
1069                 return ret;
1070
1071         _calc_trunk_info(ios->layout, size, &ti);
1072
1073         size_attrs = kcalloc(ios->oc->numdevs, sizeof(*size_attrs),
1074                              GFP_KERNEL);
1075         if (unlikely(!size_attrs)) {
1076                 ret = -ENOMEM;
1077                 goto out;
1078         }
1079
1080         ios->numdevs = ios->oc->numdevs;
1081
1082         for (i = 0; i < ios->numdevs; ++i) {
1083                 struct exofs_trunc_attr *size_attr = &size_attrs[i];
1084                 u64 obj_size;
1085
1086                 if (i < ti.first_group_dev)
1087                         obj_size = ti.prev_group_obj_off;
1088                 else if (i >= ti.nex_group_dev)
1089                         obj_size = ti.next_group_obj_off;
1090                 else if (i < ti.si.dev) /* dev within this group */
1091                         obj_size = ti.si.obj_offset +
1092                                       ios->layout->stripe_unit - ti.si.unit_off;
1093                 else if (i == ti.si.dev)
1094                         obj_size = ti.si.obj_offset;
1095                 else /* i > ti.dev */
1096                         obj_size = ti.si.obj_offset - ti.si.unit_off;
1097
1098                 size_attr->newsize = cpu_to_be64(obj_size);
1099                 size_attr->attr = g_attr_logical_length;
1100                 size_attr->attr.val_ptr = &size_attr->newsize;
1101
1102                 ORE_DBGMSG("trunc(0x%llx) obj_offset=0x%llx dev=%d\n",
1103                              _LLU(oc->comps->obj.id), _LLU(obj_size), i);
1104                 ret = _truncate_mirrors(ios, i * ios->layout->mirrors_p1,
1105                                         &size_attr->attr);
1106                 if (unlikely(ret))
1107                         goto out;
1108         }
1109         ret = ore_io_execute(ios);
1110
1111 out:
1112         kfree(size_attrs);
1113         ore_put_io_state(ios);
1114         return ret;
1115 }
1116 EXPORT_SYMBOL(ore_truncate);
1117
1118 const struct osd_attr g_attr_logical_length = ATTR_DEF(
1119         OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
1120 EXPORT_SYMBOL(g_attr_logical_length);