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   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);