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
32MODULE_AUTHOR("Boaz Harrosh <ooo@electrozaur.com>");
33MODULE_DESCRIPTION("Objects Raid Engine ore.ko");
34MODULE_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
46enum { BIO_MAX_PAGES_KMALLOC =
47		(PAGE_SIZE - sizeof(struct bio)) / sizeof(struct bio_vec),};
48
49int 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}
122EXPORT_SYMBOL(ore_verify_layout);
123
124static u8 *_ios_cred(struct ore_io_state *ios, unsigned index)
125{
126	return ios->oc->comps[index & ios->oc->single_comp].cred;
127}
128
129static 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
134static 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
143int  _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 */
242int  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}
302EXPORT_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 */
311int  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}
316EXPORT_SYMBOL(ore_get_io_state);
317
318void 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}
336EXPORT_SYMBOL(ore_put_io_state);
337
338static void _sync_done(struct ore_io_state *ios, void *p)
339{
340	struct completion *waiting = p;
341
342	complete(waiting);
343}
344
345static 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
353static 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
360int 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
405static 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
420int 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}
472EXPORT_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 – 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 */
526void 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}
591EXPORT_SYMBOL(ore_calc_stripe_info);
592
593int _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;
652out:	/* 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
660static 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
697static 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	}
780out:
781	ios->numdevs = devs_in_group;
782	ios->pages_consumed = cur_pg;
783	return ret;
784}
785
786int 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
806out:
807	return ret;
808}
809EXPORT_SYMBOL(ore_create);
810
811int 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
831out:
832	return ret;
833}
834EXPORT_SYMBOL(ore_remove);
835
836static 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->bi_rw |= REQ_WRITE;
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
926out:
927	return ret;
928}
929
930int 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}
956EXPORT_SYMBOL(ore_write);
957
958int _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
1012int 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}
1030EXPORT_SYMBOL(ore_read);
1031
1032int 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}
1052EXPORT_SYMBOL(extract_attr_from_ios);
1053
1054static 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
1077struct _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
1086static 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
1100int 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
1155out:
1156	kfree(size_attrs);
1157	ore_put_io_state(ios);
1158	return ret;
1159}
1160EXPORT_SYMBOL(ore_truncate);
1161
1162const struct osd_attr g_attr_logical_length = ATTR_DEF(
1163	OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
1164EXPORT_SYMBOL(g_attr_logical_length);
1165