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  1/*
  2 * Copyright (C) 2005, 2006
  3 * Avishay Traeger (avishay@gmail.com)
  4 * Copyright (C) 2008, 2009
  5 * Boaz Harrosh <bharrosh@panasas.com>
  6 *
  7 * This file is part of exofs.
  8 *
  9 * exofs is free software; you can redistribute it and/or modify
 10 * it under the terms of the GNU General Public License as published by
 11 * the Free Software Foundation.  Since it is based on ext2, and the only
 12 * valid version of GPL for the Linux kernel is version 2, the only valid
 13 * version of GPL for exofs is version 2.
 14 *
 15 * exofs is distributed in the hope that it will be useful,
 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 18 * GNU General Public License for more details.
 19 *
 20 * You should have received a copy of the GNU General Public License
 21 * along with exofs; if not, write to the Free Software
 22 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 23 */
 24
 25#include <linux/slab.h>
 26#include <asm/div64.h>
 27
 28#include <scsi/osd_ore.h>
 29
 30#define ORE_ERR(fmt, a...) printk(KERN_ERR "ore: " fmt, ##a)
 31
 32#ifdef CONFIG_EXOFS_DEBUG
 33#define ORE_DBGMSG(fmt, a...) \
 34	printk(KERN_NOTICE "ore @%s:%d: " fmt, __func__, __LINE__, ##a)
 35#else
 36#define ORE_DBGMSG(fmt, a...) \
 37	do { if (0) printk(fmt, ##a); } while (0)
 38#endif
 39
 40/* u64 has problems with printk this will cast it to unsigned long long */
 41#define _LLU(x) (unsigned long long)(x)
 42
 43#define ORE_DBGMSG2(M...) do {} while (0)
 44/* #define ORE_DBGMSG2 ORE_DBGMSG */
 45
 46MODULE_AUTHOR("Boaz Harrosh <bharrosh@panasas.com>");
 47MODULE_DESCRIPTION("Objects Raid Engine ore.ko");
 48MODULE_LICENSE("GPL");
 49
 50static u8 *_ios_cred(struct ore_io_state *ios, unsigned index)
 51{
 52	return ios->comps->comps[index & ios->comps->single_comp].cred;
 53}
 54
 55static struct osd_obj_id *_ios_obj(struct ore_io_state *ios, unsigned index)
 56{
 57	return &ios->comps->comps[index & ios->comps->single_comp].obj;
 58}
 59
 60static struct osd_dev *_ios_od(struct ore_io_state *ios, unsigned index)
 61{
 62	return ios->comps->ods[index];
 63}
 64
 65int  ore_get_rw_state(struct ore_layout *layout, struct ore_components *comps,
 66		      bool is_reading, u64 offset, u64 length,
 67		      struct ore_io_state **pios)
 68{
 69	struct ore_io_state *ios;
 70
 71	/*TODO: Maybe use kmem_cach per sbi of size
 72	 * exofs_io_state_size(layout->s_numdevs)
 73	 */
 74	ios = kzalloc(ore_io_state_size(comps->numdevs), GFP_KERNEL);
 75	if (unlikely(!ios)) {
 76		ORE_DBGMSG("Failed kzalloc bytes=%d\n",
 77			     ore_io_state_size(comps->numdevs));
 78		*pios = NULL;
 79		return -ENOMEM;
 80	}
 81
 82	ios->layout = layout;
 83	ios->comps = comps;
 84	ios->offset = offset;
 85	ios->length = length;
 86	ios->reading = is_reading;
 87
 88	*pios = ios;
 89	return 0;
 90}
 91EXPORT_SYMBOL(ore_get_rw_state);
 92
 93int  ore_get_io_state(struct ore_layout *layout, struct ore_components *comps,
 94		      struct ore_io_state **ios)
 95{
 96	return ore_get_rw_state(layout, comps, true, 0, 0, ios);
 97}
 98EXPORT_SYMBOL(ore_get_io_state);
 99
100void ore_put_io_state(struct ore_io_state *ios)
101{
102	if (ios) {
103		unsigned i;
104
105		for (i = 0; i < ios->numdevs; i++) {
106			struct ore_per_dev_state *per_dev = &ios->per_dev[i];
107
108			if (per_dev->or)
109				osd_end_request(per_dev->or);
110			if (per_dev->bio)
111				bio_put(per_dev->bio);
112		}
113
114		kfree(ios);
115	}
116}
117EXPORT_SYMBOL(ore_put_io_state);
118
119static void _sync_done(struct ore_io_state *ios, void *p)
120{
121	struct completion *waiting = p;
122
123	complete(waiting);
124}
125
126static void _last_io(struct kref *kref)
127{
128	struct ore_io_state *ios = container_of(
129					kref, struct ore_io_state, kref);
130
131	ios->done(ios, ios->private);
132}
133
134static void _done_io(struct osd_request *or, void *p)
135{
136	struct ore_io_state *ios = p;
137
138	kref_put(&ios->kref, _last_io);
139}
140
141static int ore_io_execute(struct ore_io_state *ios)
142{
143	DECLARE_COMPLETION_ONSTACK(wait);
144	bool sync = (ios->done == NULL);
145	int i, ret;
146
147	if (sync) {
148		ios->done = _sync_done;
149		ios->private = &wait;
150	}
151
152	for (i = 0; i < ios->numdevs; i++) {
153		struct osd_request *or = ios->per_dev[i].or;
154		if (unlikely(!or))
155			continue;
156
157		ret = osd_finalize_request(or, 0, _ios_cred(ios, i), NULL);
158		if (unlikely(ret)) {
159			ORE_DBGMSG("Failed to osd_finalize_request() => %d\n",
160				     ret);
161			return ret;
162		}
163	}
164
165	kref_init(&ios->kref);
166
167	for (i = 0; i < ios->numdevs; i++) {
168		struct osd_request *or = ios->per_dev[i].or;
169		if (unlikely(!or))
170			continue;
171
172		kref_get(&ios->kref);
173		osd_execute_request_async(or, _done_io, ios);
174	}
175
176	kref_put(&ios->kref, _last_io);
177	ret = 0;
178
179	if (sync) {
180		wait_for_completion(&wait);
181		ret = ore_check_io(ios, NULL);
182	}
183	return ret;
184}
185
186static void _clear_bio(struct bio *bio)
187{
188	struct bio_vec *bv;
189	unsigned i;
190
191	__bio_for_each_segment(bv, bio, i, 0) {
192		unsigned this_count = bv->bv_len;
193
194		if (likely(PAGE_SIZE == this_count))
195			clear_highpage(bv->bv_page);
196		else
197			zero_user(bv->bv_page, bv->bv_offset, this_count);
198	}
199}
200
201int ore_check_io(struct ore_io_state *ios, u64 *resid)
202{
203	enum osd_err_priority acumulated_osd_err = 0;
204	int acumulated_lin_err = 0;
205	int i;
206
207	for (i = 0; i < ios->numdevs; i++) {
208		struct osd_sense_info osi;
209		struct osd_request *or = ios->per_dev[i].or;
210		int ret;
211
212		if (unlikely(!or))
213			continue;
214
215		ret = osd_req_decode_sense(or, &osi);
216		if (likely(!ret))
217			continue;
218
219		if (OSD_ERR_PRI_CLEAR_PAGES == osi.osd_err_pri) {
220			/* start read offset passed endof file */
221			_clear_bio(ios->per_dev[i].bio);
222			ORE_DBGMSG("start read offset passed end of file "
223				"offset=0x%llx, length=0x%llx\n",
224				_LLU(ios->per_dev[i].offset),
225				_LLU(ios->per_dev[i].length));
226
227			continue; /* we recovered */
228		}
229
230		if (osi.osd_err_pri >= acumulated_osd_err) {
231			acumulated_osd_err = osi.osd_err_pri;
232			acumulated_lin_err = ret;
233		}
234	}
235
236	/* TODO: raid specific residual calculations */
237	if (resid) {
238		if (likely(!acumulated_lin_err))
239			*resid = 0;
240		else
241			*resid = ios->length;
242	}
243
244	return acumulated_lin_err;
245}
246EXPORT_SYMBOL(ore_check_io);
247
248/*
249 * L - logical offset into the file
250 *
251 * U - The number of bytes in a stripe within a group
252 *
253 *	U = stripe_unit * group_width
254 *
255 * T - The number of bytes striped within a group of component objects
256 *     (before advancing to the next group)
257 *
258 *	T = stripe_unit * group_width * group_depth
259 *
260 * S - The number of bytes striped across all component objects
261 *     before the pattern repeats
262 *
263 *	S = stripe_unit * group_width * group_depth * group_count
264 *
265 * M - The "major" (i.e., across all components) stripe number
266 *
267 *	M = L / S
268 *
269 * G - Counts the groups from the beginning of the major stripe
270 *
271 *	G = (L - (M * S)) / T	[or (L % S) / T]
272 *
273 * H - The byte offset within the group
274 *
275 *	H = (L - (M * S)) % T	[or (L % S) % T]
276 *
277 * N - The "minor" (i.e., across the group) stripe number
278 *
279 *	N = H / U
280 *
281 * C - The component index coresponding to L
282 *
283 *	C = (H - (N * U)) / stripe_unit + G * group_width
284 *	[or (L % U) / stripe_unit + G * group_width]
285 *
286 * O - The component offset coresponding to L
287 *
288 *	O = L % stripe_unit + N * stripe_unit + M * group_depth * stripe_unit
289 */
290struct _striping_info {
291	u64 obj_offset;
292	u64 group_length;
293	u64 M; /* for truncate */
294	unsigned dev;
295	unsigned unit_off;
296};
297
298static void _calc_stripe_info(struct ore_layout *layout, u64 file_offset,
299			      struct _striping_info *si)
300{
301	u32	stripe_unit = layout->stripe_unit;
302	u32	group_width = layout->group_width;
303	u64	group_depth = layout->group_depth;
304
305	u32	U = stripe_unit * group_width;
306	u64	T = U * group_depth;
307	u64	S = T * layout->group_count;
308	u64	M = div64_u64(file_offset, S);
309
310	/*
311	G = (L - (M * S)) / T
312	H = (L - (M * S)) % T
313	*/
314	u64	LmodS = file_offset - M * S;
315	u32	G = div64_u64(LmodS, T);
316	u64	H = LmodS - G * T;
317
318	u32	N = div_u64(H, U);
319
320	/* "H - (N * U)" is just "H % U" so it's bound to u32 */
321	si->dev = (u32)(H - (N * U)) / stripe_unit + G * group_width;
322	si->dev *= layout->mirrors_p1;
323
324	div_u64_rem(file_offset, stripe_unit, &si->unit_off);
325
326	si->obj_offset = si->unit_off + (N * stripe_unit) +
327				  (M * group_depth * stripe_unit);
328
329	si->group_length = T - H;
330	si->M = M;
331}
332
333static int _add_stripe_unit(struct ore_io_state *ios,  unsigned *cur_pg,
334		unsigned pgbase, struct ore_per_dev_state *per_dev,
335		int cur_len)
336{
337	unsigned pg = *cur_pg;
338	struct request_queue *q =
339			osd_request_queue(_ios_od(ios, per_dev->dev));
340
341	per_dev->length += cur_len;
342
343	if (per_dev->bio == NULL) {
344		unsigned pages_in_stripe = ios->layout->group_width *
345					(ios->layout->stripe_unit / PAGE_SIZE);
346		unsigned bio_size = (ios->nr_pages + pages_in_stripe) /
347						ios->layout->group_width;
348
349		per_dev->bio = bio_kmalloc(GFP_KERNEL, bio_size);
350		if (unlikely(!per_dev->bio)) {
351			ORE_DBGMSG("Failed to allocate BIO size=%u\n",
352				     bio_size);
353			return -ENOMEM;
354		}
355	}
356
357	while (cur_len > 0) {
358		unsigned pglen = min_t(unsigned, PAGE_SIZE - pgbase, cur_len);
359		unsigned added_len;
360
361		BUG_ON(ios->nr_pages <= pg);
362		cur_len -= pglen;
363
364		added_len = bio_add_pc_page(q, per_dev->bio, ios->pages[pg],
365					    pglen, pgbase);
366		if (unlikely(pglen != added_len))
367			return -ENOMEM;
368		pgbase = 0;
369		++pg;
370	}
371	BUG_ON(cur_len);
372
373	*cur_pg = pg;
374	return 0;
375}
376
377static int _prepare_one_group(struct ore_io_state *ios, u64 length,
378			      struct _striping_info *si)
379{
380	unsigned stripe_unit = ios->layout->stripe_unit;
381	unsigned mirrors_p1 = ios->layout->mirrors_p1;
382	unsigned devs_in_group = ios->layout->group_width * mirrors_p1;
383	unsigned dev = si->dev;
384	unsigned first_dev = dev - (dev % devs_in_group);
385	unsigned max_comp = ios->numdevs ? ios->numdevs - mirrors_p1 : 0;
386	unsigned cur_pg = ios->pages_consumed;
387	int ret = 0;
388
389	while (length) {
390		struct ore_per_dev_state *per_dev = &ios->per_dev[dev];
391		unsigned cur_len, page_off = 0;
392
393		if (!per_dev->length) {
394			per_dev->dev = dev;
395			if (dev < si->dev) {
396				per_dev->offset = si->obj_offset + stripe_unit -
397								   si->unit_off;
398				cur_len = stripe_unit;
399			} else if (dev == si->dev) {
400				per_dev->offset = si->obj_offset;
401				cur_len = stripe_unit - si->unit_off;
402				page_off = si->unit_off & ~PAGE_MASK;
403				BUG_ON(page_off && (page_off != ios->pgbase));
404			} else { /* dev > si->dev */
405				per_dev->offset = si->obj_offset - si->unit_off;
406				cur_len = stripe_unit;
407			}
408
409			if (max_comp < dev)
410				max_comp = dev;
411		} else {
412			cur_len = stripe_unit;
413		}
414		if (cur_len >= length)
415			cur_len = length;
416
417		ret = _add_stripe_unit(ios, &cur_pg, page_off , per_dev,
418				       cur_len);
419		if (unlikely(ret))
420			goto out;
421
422		dev += mirrors_p1;
423		dev = (dev % devs_in_group) + first_dev;
424
425		length -= cur_len;
426	}
427out:
428	ios->numdevs = max_comp + mirrors_p1;
429	ios->pages_consumed = cur_pg;
430	return ret;
431}
432
433static int _prepare_for_striping(struct ore_io_state *ios)
434{
435	u64 length = ios->length;
436	u64 offset = ios->offset;
437	struct _striping_info si;
438	int ret = 0;
439
440	if (!ios->pages) {
441		if (ios->kern_buff) {
442			struct ore_per_dev_state *per_dev = &ios->per_dev[0];
443
444			_calc_stripe_info(ios->layout, ios->offset, &si);
445			per_dev->offset = si.obj_offset;
446			per_dev->dev = si.dev;
447
448			/* no cross device without page array */
449			BUG_ON((ios->layout->group_width > 1) &&
450			       (si.unit_off + ios->length >
451				ios->layout->stripe_unit));
452		}
453		ios->numdevs = ios->layout->mirrors_p1;
454		return 0;
455	}
456
457	while (length) {
458		_calc_stripe_info(ios->layout, offset, &si);
459
460		if (length < si.group_length)
461			si.group_length = length;
462
463		ret = _prepare_one_group(ios, si.group_length, &si);
464		if (unlikely(ret))
465			goto out;
466
467		offset += si.group_length;
468		length -= si.group_length;
469	}
470
471out:
472	return ret;
473}
474
475int ore_create(struct ore_io_state *ios)
476{
477	int i, ret;
478
479	for (i = 0; i < ios->comps->numdevs; i++) {
480		struct osd_request *or;
481
482		or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
483		if (unlikely(!or)) {
484			ORE_ERR("%s: osd_start_request failed\n", __func__);
485			ret = -ENOMEM;
486			goto out;
487		}
488		ios->per_dev[i].or = or;
489		ios->numdevs++;
490
491		osd_req_create_object(or, _ios_obj(ios, i));
492	}
493	ret = ore_io_execute(ios);
494
495out:
496	return ret;
497}
498EXPORT_SYMBOL(ore_create);
499
500int ore_remove(struct ore_io_state *ios)
501{
502	int i, ret;
503
504	for (i = 0; i < ios->comps->numdevs; i++) {
505		struct osd_request *or;
506
507		or = osd_start_request(_ios_od(ios, i), GFP_KERNEL);
508		if (unlikely(!or)) {
509			ORE_ERR("%s: osd_start_request failed\n", __func__);
510			ret = -ENOMEM;
511			goto out;
512		}
513		ios->per_dev[i].or = or;
514		ios->numdevs++;
515
516		osd_req_remove_object(or, _ios_obj(ios, i));
517	}
518	ret = ore_io_execute(ios);
519
520out:
521	return ret;
522}
523EXPORT_SYMBOL(ore_remove);
524
525static int _write_mirror(struct ore_io_state *ios, int cur_comp)
526{
527	struct ore_per_dev_state *master_dev = &ios->per_dev[cur_comp];
528	unsigned dev = ios->per_dev[cur_comp].dev;
529	unsigned last_comp = cur_comp + ios->layout->mirrors_p1;
530	int ret = 0;
531
532	if (ios->pages && !master_dev->length)
533		return 0; /* Just an empty slot */
534
535	for (; cur_comp < last_comp; ++cur_comp, ++dev) {
536		struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
537		struct osd_request *or;
538
539		or = osd_start_request(_ios_od(ios, dev), GFP_KERNEL);
540		if (unlikely(!or)) {
541			ORE_ERR("%s: osd_start_request failed\n", __func__);
542			ret = -ENOMEM;
543			goto out;
544		}
545		per_dev->or = or;
546		per_dev->offset = master_dev->offset;
547
548		if (ios->pages) {
549			struct bio *bio;
550
551			if (per_dev != master_dev) {
552				bio = bio_kmalloc(GFP_KERNEL,
553						  master_dev->bio->bi_max_vecs);
554				if (unlikely(!bio)) {
555					ORE_DBGMSG(
556					      "Failed to allocate BIO size=%u\n",
557					      master_dev->bio->bi_max_vecs);
558					ret = -ENOMEM;
559					goto out;
560				}
561
562				__bio_clone(bio, master_dev->bio);
563				bio->bi_bdev = NULL;
564				bio->bi_next = NULL;
565				per_dev->length = master_dev->length;
566				per_dev->bio =  bio;
567				per_dev->dev = dev;
568			} else {
569				bio = master_dev->bio;
570				/* FIXME: bio_set_dir() */
571				bio->bi_rw |= REQ_WRITE;
572			}
573
574			osd_req_write(or, _ios_obj(ios, dev), per_dev->offset,
575				      bio, per_dev->length);
576			ORE_DBGMSG("write(0x%llx) offset=0x%llx "
577				      "length=0x%llx dev=%d\n",
578				     _LLU(_ios_obj(ios, dev)->id),
579				     _LLU(per_dev->offset),
580				     _LLU(per_dev->length), dev);
581		} else if (ios->kern_buff) {
582			ret = osd_req_write_kern(or, _ios_obj(ios, dev),
583						 per_dev->offset,
584						 ios->kern_buff, ios->length);
585			if (unlikely(ret))
586				goto out;
587			ORE_DBGMSG2("write_kern(0x%llx) offset=0x%llx "
588				      "length=0x%llx dev=%d\n",
589				     _LLU(_ios_obj(ios, dev)->id),
590				     _LLU(per_dev->offset),
591				     _LLU(ios->length), dev);
592		} else {
593			osd_req_set_attributes(or, _ios_obj(ios, dev));
594			ORE_DBGMSG2("obj(0x%llx) set_attributes=%d dev=%d\n",
595				     _LLU(_ios_obj(ios, dev)->id),
596				     ios->out_attr_len, dev);
597		}
598
599		if (ios->out_attr)
600			osd_req_add_set_attr_list(or, ios->out_attr,
601						  ios->out_attr_len);
602
603		if (ios->in_attr)
604			osd_req_add_get_attr_list(or, ios->in_attr,
605						  ios->in_attr_len);
606	}
607
608out:
609	return ret;
610}
611
612int ore_write(struct ore_io_state *ios)
613{
614	int i;
615	int ret;
616
617	ret = _prepare_for_striping(ios);
618	if (unlikely(ret))
619		return ret;
620
621	for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
622		ret = _write_mirror(ios, i);
623		if (unlikely(ret))
624			return ret;
625	}
626
627	ret = ore_io_execute(ios);
628	return ret;
629}
630EXPORT_SYMBOL(ore_write);
631
632static int _read_mirror(struct ore_io_state *ios, unsigned cur_comp)
633{
634	struct osd_request *or;
635	struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
636	struct osd_obj_id *obj = _ios_obj(ios, cur_comp);
637	unsigned first_dev = (unsigned)obj->id;
638
639	if (ios->pages && !per_dev->length)
640		return 0; /* Just an empty slot */
641
642	first_dev = per_dev->dev + first_dev % ios->layout->mirrors_p1;
643	or = osd_start_request(_ios_od(ios, first_dev), GFP_KERNEL);
644	if (unlikely(!or)) {
645		ORE_ERR("%s: osd_start_request failed\n", __func__);
646		return -ENOMEM;
647	}
648	per_dev->or = or;
649
650	if (ios->pages) {
651		osd_req_read(or, obj, per_dev->offset,
652				per_dev->bio, per_dev->length);
653		ORE_DBGMSG("read(0x%llx) offset=0x%llx length=0x%llx"
654			     " dev=%d\n", _LLU(obj->id),
655			     _LLU(per_dev->offset), _LLU(per_dev->length),
656			     first_dev);
657	} else if (ios->kern_buff) {
658		int ret = osd_req_read_kern(or, obj, per_dev->offset,
659					    ios->kern_buff, ios->length);
660		ORE_DBGMSG2("read_kern(0x%llx) offset=0x%llx "
661			      "length=0x%llx dev=%d ret=>%d\n",
662			      _LLU(obj->id), _LLU(per_dev->offset),
663			      _LLU(ios->length), first_dev, ret);
664		if (unlikely(ret))
665			return ret;
666	} else {
667		osd_req_get_attributes(or, obj);
668		ORE_DBGMSG2("obj(0x%llx) get_attributes=%d dev=%d\n",
669			      _LLU(obj->id),
670			      ios->in_attr_len, first_dev);
671	}
672	if (ios->out_attr)
673		osd_req_add_set_attr_list(or, ios->out_attr, ios->out_attr_len);
674
675	if (ios->in_attr)
676		osd_req_add_get_attr_list(or, ios->in_attr, ios->in_attr_len);
677
678	return 0;
679}
680
681int ore_read(struct ore_io_state *ios)
682{
683	int i;
684	int ret;
685
686	ret = _prepare_for_striping(ios);
687	if (unlikely(ret))
688		return ret;
689
690	for (i = 0; i < ios->numdevs; i += ios->layout->mirrors_p1) {
691		ret = _read_mirror(ios, i);
692		if (unlikely(ret))
693			return ret;
694	}
695
696	ret = ore_io_execute(ios);
697	return ret;
698}
699EXPORT_SYMBOL(ore_read);
700
701int extract_attr_from_ios(struct ore_io_state *ios, struct osd_attr *attr)
702{
703	struct osd_attr cur_attr = {.attr_page = 0}; /* start with zeros */
704	void *iter = NULL;
705	int nelem;
706
707	do {
708		nelem = 1;
709		osd_req_decode_get_attr_list(ios->per_dev[0].or,
710					     &cur_attr, &nelem, &iter);
711		if ((cur_attr.attr_page == attr->attr_page) &&
712		    (cur_attr.attr_id == attr->attr_id)) {
713			attr->len = cur_attr.len;
714			attr->val_ptr = cur_attr.val_ptr;
715			return 0;
716		}
717	} while (iter);
718
719	return -EIO;
720}
721EXPORT_SYMBOL(extract_attr_from_ios);
722
723static int _truncate_mirrors(struct ore_io_state *ios, unsigned cur_comp,
724			     struct osd_attr *attr)
725{
726	int last_comp = cur_comp + ios->layout->mirrors_p1;
727
728	for (; cur_comp < last_comp; ++cur_comp) {
729		struct ore_per_dev_state *per_dev = &ios->per_dev[cur_comp];
730		struct osd_request *or;
731
732		or = osd_start_request(_ios_od(ios, cur_comp), GFP_KERNEL);
733		if (unlikely(!or)) {
734			ORE_ERR("%s: osd_start_request failed\n", __func__);
735			return -ENOMEM;
736		}
737		per_dev->or = or;
738
739		osd_req_set_attributes(or, _ios_obj(ios, cur_comp));
740		osd_req_add_set_attr_list(or, attr, 1);
741	}
742
743	return 0;
744}
745
746struct _trunc_info {
747	struct _striping_info si;
748	u64 prev_group_obj_off;
749	u64 next_group_obj_off;
750
751	unsigned first_group_dev;
752	unsigned nex_group_dev;
753	unsigned max_devs;
754};
755
756void _calc_trunk_info(struct ore_layout *layout, u64 file_offset,
757		       struct _trunc_info *ti)
758{
759	unsigned stripe_unit = layout->stripe_unit;
760
761	_calc_stripe_info(layout, file_offset, &ti->si);
762
763	ti->prev_group_obj_off = ti->si.M * stripe_unit;
764	ti->next_group_obj_off = ti->si.M ? (ti->si.M - 1) * stripe_unit : 0;
765
766	ti->first_group_dev = ti->si.dev - (ti->si.dev % layout->group_width);
767	ti->nex_group_dev = ti->first_group_dev + layout->group_width;
768	ti->max_devs = layout->group_width * layout->group_count;
769}
770
771int ore_truncate(struct ore_layout *layout, struct ore_components *comps,
772		   u64 size)
773{
774	struct ore_io_state *ios;
775	struct exofs_trunc_attr {
776		struct osd_attr attr;
777		__be64 newsize;
778	} *size_attrs;
779	struct _trunc_info ti;
780	int i, ret;
781
782	ret = ore_get_io_state(layout, comps, &ios);
783	if (unlikely(ret))
784		return ret;
785
786	_calc_trunk_info(ios->layout, size, &ti);
787
788	size_attrs = kcalloc(ti.max_devs, sizeof(*size_attrs),
789			     GFP_KERNEL);
790	if (unlikely(!size_attrs)) {
791		ret = -ENOMEM;
792		goto out;
793	}
794
795	ios->numdevs = ios->comps->numdevs;
796
797	for (i = 0; i < ti.max_devs; ++i) {
798		struct exofs_trunc_attr *size_attr = &size_attrs[i];
799		u64 obj_size;
800
801		if (i < ti.first_group_dev)
802			obj_size = ti.prev_group_obj_off;
803		else if (i >= ti.nex_group_dev)
804			obj_size = ti.next_group_obj_off;
805		else if (i < ti.si.dev) /* dev within this group */
806			obj_size = ti.si.obj_offset +
807				      ios->layout->stripe_unit - ti.si.unit_off;
808		else if (i == ti.si.dev)
809			obj_size = ti.si.obj_offset;
810		else /* i > ti.dev */
811			obj_size = ti.si.obj_offset - ti.si.unit_off;
812
813		size_attr->newsize = cpu_to_be64(obj_size);
814		size_attr->attr = g_attr_logical_length;
815		size_attr->attr.val_ptr = &size_attr->newsize;
816
817		ORE_DBGMSG("trunc(0x%llx) obj_offset=0x%llx dev=%d\n",
818			     _LLU(comps->comps->obj.id), _LLU(obj_size), i);
819		ret = _truncate_mirrors(ios, i * ios->layout->mirrors_p1,
820					&size_attr->attr);
821		if (unlikely(ret))
822			goto out;
823	}
824	ret = ore_io_execute(ios);
825
826out:
827	kfree(size_attrs);
828	ore_put_io_state(ios);
829	return ret;
830}
831EXPORT_SYMBOL(ore_truncate);
832
833const struct osd_attr g_attr_logical_length = ATTR_DEF(
834	OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
835EXPORT_SYMBOL(g_attr_logical_length);