summaryrefslogtreecommitdiffstats
path: root/fs/nfs/objlayout/objio_osd.c
blob: 88f9611a945cad359dfca1d0196f3d87b294e1c8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
/*
 *  pNFS Objects layout implementation over open-osd initiator library
 *
 *  Copyright (C) 2009 Panasas Inc. [year of first publication]
 *  All rights reserved.
 *
 *  Benny Halevy <bhalevy@panasas.com>
 *  Boaz Harrosh <bharrosh@panasas.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  See the file COPYING included with this distribution for more details.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the Panasas company nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <linux/module.h>
#include <scsi/osd_ore.h>

#include "objlayout.h"
#include "../internal.h"

#define NFSDBG_FACILITY         NFSDBG_PNFS_LD

struct objio_dev_ent {
	struct nfs4_deviceid_node id_node;
	struct ore_dev od;
};

static void
objio_free_deviceid_node(struct nfs4_deviceid_node *d)
{
	struct objio_dev_ent *de = container_of(d, struct objio_dev_ent, id_node);

	dprintk("%s: free od=%p\n", __func__, de->od.od);
	osduld_put_device(de->od.od);
	kfree(de);
}

static struct objio_dev_ent *_dev_list_find(const struct nfs_server *nfss,
	const struct nfs4_deviceid *d_id)
{
	struct nfs4_deviceid_node *d;
	struct objio_dev_ent *de;

	d = nfs4_find_get_deviceid(nfss->pnfs_curr_ld, nfss->nfs_client, d_id);
	if (!d)
		return NULL;

	de = container_of(d, struct objio_dev_ent, id_node);
	return de;
}

static struct objio_dev_ent *
_dev_list_add(const struct nfs_server *nfss,
	const struct nfs4_deviceid *d_id, struct osd_dev *od,
	gfp_t gfp_flags)
{
	struct nfs4_deviceid_node *d;
	struct objio_dev_ent *de = kzalloc(sizeof(*de), gfp_flags);
	struct objio_dev_ent *n;

	if (!de) {
		dprintk("%s: -ENOMEM od=%p\n", __func__, od);
		return NULL;
	}

	dprintk("%s: Adding od=%p\n", __func__, od);
	nfs4_init_deviceid_node(&de->id_node,
				nfss->pnfs_curr_ld,
				nfss->nfs_client,
				d_id);
	de->od.od = od;

	d = nfs4_insert_deviceid_node(&de->id_node);
	n = container_of(d, struct objio_dev_ent, id_node);
	if (n != de) {
		dprintk("%s: Race with other n->od=%p\n", __func__, n->od.od);
		objio_free_deviceid_node(&de->id_node);
		de = n;
	}

	return de;
}

struct objio_segment {
	struct pnfs_layout_segment lseg;

	struct ore_layout layout;
	struct ore_components oc;
};

static inline struct objio_segment *
OBJIO_LSEG(struct pnfs_layout_segment *lseg)
{
	return container_of(lseg, struct objio_segment, lseg);
}

struct objio_state {
	/* Generic layer */
	struct objlayout_io_res oir;

	bool sync;
	/*FIXME: Support for extra_bytes at ore_get_rw_state() */
	struct ore_io_state *ios;
};

/* Send and wait for a get_device_info of devices in the layout,
   then look them up with the osd_initiator library */
static int objio_devices_lookup(struct pnfs_layout_hdr *pnfslay,
	struct objio_segment *objio_seg, unsigned c, struct nfs4_deviceid *d_id,
	gfp_t gfp_flags)
{
	struct pnfs_osd_deviceaddr *deviceaddr;
	struct objio_dev_ent *ode;
	struct osd_dev *od;
	struct osd_dev_info odi;
	bool retry_flag = true;
	int err;

	ode = _dev_list_find(NFS_SERVER(pnfslay->plh_inode), d_id);
	if (ode) {
		objio_seg->oc.ods[c] = &ode->od; /* must use container_of */
		return 0;
	}

	err = objlayout_get_deviceinfo(pnfslay, d_id, &deviceaddr, gfp_flags);
	if (unlikely(err)) {
		dprintk("%s: objlayout_get_deviceinfo dev(%llx:%llx) =>%d\n",
			__func__, _DEVID_LO(d_id), _DEVID_HI(d_id), err);
		return err;
	}

	odi.systemid_len = deviceaddr->oda_systemid.len;
	if (odi.systemid_len > sizeof(odi.systemid)) {
		dprintk("%s: odi.systemid_len > sizeof(systemid=%zd)\n",
			__func__, sizeof(odi.systemid));
		err = -EINVAL;
		goto out;
	} else if (odi.systemid_len)
		memcpy(odi.systemid, deviceaddr->oda_systemid.data,
		       odi.systemid_len);
	odi.osdname_len	 = deviceaddr->oda_osdname.len;
	odi.osdname	 = (u8 *)deviceaddr->oda_osdname.data;

	if (!odi.osdname_len && !odi.systemid_len) {
		dprintk("%s: !odi.osdname_len && !odi.systemid_len\n",
			__func__);
		err = -ENODEV;
		goto out;
	}

retry_lookup:
	od = osduld_info_lookup(&odi);
	if (unlikely(IS_ERR(od))) {
		err = PTR_ERR(od);
		dprintk("%s: osduld_info_lookup => %d\n", __func__, err);
		if (err == -ENODEV && retry_flag) {
			err = objlayout_autologin(deviceaddr);
			if (likely(!err)) {
				retry_flag = false;
				goto retry_lookup;
			}
		}
		goto out;
	}

	ode = _dev_list_add(NFS_SERVER(pnfslay->plh_inode), d_id, od,
			    gfp_flags);
	objio_seg->oc.ods[c] = &ode->od; /* must use container_of */
	dprintk("Adding new dev_id(%llx:%llx)\n",
		_DEVID_LO(d_id), _DEVID_HI(d_id));
out:
	objlayout_put_deviceinfo(deviceaddr);
	return err;
}

static void copy_single_comp(struct ore_components *oc, unsigned c,
			     struct pnfs_osd_object_cred *src_comp)
{
	struct ore_comp *ocomp = &oc->comps[c];

	WARN_ON(src_comp->oc_cap_key.cred_len > 0); /* libosd is NO_SEC only */
	WARN_ON(src_comp->oc_cap.cred_len > sizeof(ocomp->cred));

	ocomp->obj.partition = src_comp->oc_object_id.oid_partition_id;
	ocomp->obj.id = src_comp->oc_object_id.oid_object_id;

	memcpy(ocomp->cred, src_comp->oc_cap.cred, sizeof(ocomp->cred));
}

static int __alloc_objio_seg(unsigned numdevs, gfp_t gfp_flags,
		       struct objio_segment **pseg)
{
/*	This is the in memory structure of the objio_segment
 *
 *	struct __alloc_objio_segment {
 *		struct objio_segment olseg;
 *		struct ore_dev *ods[numdevs];
 *		struct ore_comp	comps[numdevs];
 *	} *aolseg;
 *	NOTE: The code as above compiles and runs perfectly. It is elegant,
 *	type safe and compact. At some Past time Linus has decided he does not
 *	like variable length arrays, For the sake of this principal we uglify
 *	the code as below.
 */
	struct objio_segment *lseg;
	size_t lseg_size = sizeof(*lseg) +
			numdevs * sizeof(lseg->oc.ods[0]) +
			numdevs * sizeof(*lseg->oc.comps);

	lseg = kzalloc(lseg_size, gfp_flags);
	if (unlikely(!lseg)) {
		dprintk("%s: Faild allocation numdevs=%d size=%zd\n", __func__,
			numdevs, lseg_size);
		return -ENOMEM;
	}

	lseg->oc.numdevs = numdevs;
	lseg->oc.single_comp = EC_MULTPLE_COMPS;
	lseg->oc.ods = (void *)(lseg + 1);
	lseg->oc.comps = (void *)(lseg->oc.ods + numdevs);

	*pseg = lseg;
	return 0;
}

int objio_alloc_lseg(struct pnfs_layout_segment **outp,
	struct pnfs_layout_hdr *pnfslay,
	struct pnfs_layout_range *range,
	struct xdr_stream *xdr,
	gfp_t gfp_flags)
{
	struct objio_segment *objio_seg;
	struct pnfs_osd_xdr_decode_layout_iter iter;
	struct pnfs_osd_layout layout;
	struct pnfs_osd_object_cred src_comp;
	unsigned cur_comp;
	int err;

	err = pnfs_osd_xdr_decode_layout_map(&layout, &iter, xdr);
	if (unlikely(err))
		return err;

	err = __alloc_objio_seg(layout.olo_num_comps, gfp_flags, &objio_seg);
	if (unlikely(err))
		return err;

	objio_seg->layout.stripe_unit = layout.olo_map.odm_stripe_unit;
	objio_seg->layout.group_width = layout.olo_map.odm_group_width;
	objio_seg->layout.group_depth = layout.olo_map.odm_group_depth;
	objio_seg->layout.mirrors_p1 = layout.olo_map.odm_mirror_cnt + 1;
	objio_seg->layout.raid_algorithm = layout.olo_map.odm_raid_algorithm;

	err = ore_verify_layout(layout.olo_map.odm_num_comps,
					  &objio_seg->layout);
	if (unlikely(err))
		goto err;

	objio_seg->oc.first_dev = layout.olo_comps_index;
	cur_comp = 0;
	while (pnfs_osd_xdr_decode_layout_comp(&src_comp, &iter, xdr, &err)) {
		copy_single_comp(&objio_seg->oc, cur_comp, &src_comp);
		err = objio_devices_lookup(pnfslay, objio_seg, cur_comp,
					   &src_comp.oc_object_id.oid_device_id,
					   gfp_flags);
		if (err)
			goto err;
		++cur_comp;
	}
	/* pnfs_osd_xdr_decode_layout_comp returns false on error */
	if (unlikely(err))
		goto err;

	*outp = &objio_seg->lseg;
	return 0;

err:
	kfree(objio_seg);
	dprintk("%s: Error: return %d\n", __func__, err);
	*outp = NULL;
	return err;
}

void objio_free_lseg(struct pnfs_layout_segment *lseg)
{
	int i;
	struct objio_segment *objio_seg = OBJIO_LSEG(lseg);

	for (i = 0; i < objio_seg->oc.numdevs; i++) {
		struct ore_dev *od = objio_seg->oc.ods[i];
		struct objio_dev_ent *ode;

		if (!od)
			break;
		ode = container_of(od, typeof(*ode), od);
		nfs4_put_deviceid_node(&ode->id_node);
	}
	kfree(objio_seg);
}

static int
objio_alloc_io_state(struct pnfs_layout_hdr *pnfs_layout_type, bool is_reading,
	struct pnfs_layout_segment *lseg, struct page **pages, unsigned pgbase,
	loff_t offset, size_t count, void *rpcdata, gfp_t gfp_flags,
	struct objio_state **outp)
{
	struct objio_segment *objio_seg = OBJIO_LSEG(lseg);
	struct ore_io_state *ios;
	int ret;
	struct __alloc_objio_state {
		struct objio_state objios;
		struct pnfs_osd_ioerr ioerrs[objio_seg->oc.numdevs];
	} *aos;

	aos = kzalloc(sizeof(*aos), gfp_flags);
	if (unlikely(!aos))
		return -ENOMEM;

	objlayout_init_ioerrs(&aos->objios.oir, objio_seg->oc.numdevs,
			aos->ioerrs, rpcdata, pnfs_layout_type);

	ret = ore_get_rw_state(&objio_seg->layout, &objio_seg->oc, is_reading,
			       offset, count, &ios);
	if (unlikely(ret)) {
		kfree(aos);
		return ret;
	}

	ios->pages = pages;
	ios->pgbase = pgbase;
	ios->private = aos;
	BUG_ON(ios->nr_pages > (pgbase + count + PAGE_SIZE - 1) >> PAGE_SHIFT);

	aos->objios.sync = 0;
	aos->objios.ios = ios;
	*outp = &aos->objios;
	return 0;
}

void objio_free_result(struct objlayout_io_res *oir)
{
	struct objio_state *objios = container_of(oir, struct objio_state, oir);

	ore_put_io_state(objios->ios);
	kfree(objios);
}

static enum pnfs_osd_errno osd_pri_2_pnfs_err(enum osd_err_priority oep)
{
	switch (oep) {
	case OSD_ERR_PRI_NO_ERROR:
		return (enum pnfs_osd_errno)0;

	case OSD_ERR_PRI_CLEAR_PAGES:
		BUG_ON(1);
		return 0;

	case OSD_ERR_PRI_RESOURCE:
		return PNFS_OSD_ERR_RESOURCE;
	case OSD_ERR_PRI_BAD_CRED:
		return PNFS_OSD_ERR_BAD_CRED;
	case OSD_ERR_PRI_NO_ACCESS:
		return PNFS_OSD_ERR_NO_ACCESS;
	case OSD_ERR_PRI_UNREACHABLE:
		return PNFS_OSD_ERR_UNREACHABLE;
	case OSD_ERR_PRI_NOT_FOUND:
		return PNFS_OSD_ERR_NOT_FOUND;
	case OSD_ERR_PRI_NO_SPACE:
		return PNFS_OSD_ERR_NO_SPACE;
	default:
		WARN_ON(1);
		/* fallthrough */
	case OSD_ERR_PRI_EIO:
		return PNFS_OSD_ERR_EIO;
	}
}

static void __on_dev_error(struct ore_io_state *ios,
	struct ore_dev *od, unsigned dev_index, enum osd_err_priority oep,
	u64 dev_offset, u64  dev_len)
{
	struct objio_state *objios = ios->private;
	struct pnfs_osd_objid pooid;
	struct objio_dev_ent *ode = container_of(od, typeof(*ode), od);
	/* FIXME: what to do with more-then-one-group layouts. We need to
	 * translate from ore_io_state index to oc->comps index
	 */
	unsigned comp = dev_index;

	pooid.oid_device_id = ode->id_node.deviceid;
	pooid.oid_partition_id = ios->oc->comps[comp].obj.partition;
	pooid.oid_object_id = ios->oc->comps[comp].obj.id;

	objlayout_io_set_result(&objios->oir, comp,
				&pooid, osd_pri_2_pnfs_err(oep),
				dev_offset, dev_len, !ios->reading);
}

/*
 * read
 */
static void _read_done(struct ore_io_state *ios, void *private)
{
	struct objio_state *objios = private;
	ssize_t status;
	int ret = ore_check_io(ios, &__on_dev_error);

	/* FIXME: _io_free(ios) can we dealocate the libosd resources; */

	if (likely(!ret))
		status = ios->length;
	else
		status = ret;

	objlayout_read_done(&objios->oir, status, objios->sync);
}

int objio_read_pagelist(struct nfs_read_data *rdata)
{
	struct nfs_pgio_header *hdr = rdata->header;
	struct objio_state *objios;
	int ret;

	ret = objio_alloc_io_state(NFS_I(hdr->inode)->layout, true,
			hdr->lseg, rdata->args.pages, rdata->args.pgbase,
			rdata->args.offset, rdata->args.count, rdata,
			GFP_KERNEL, &objios);
	if (unlikely(ret))
		return ret;

	objios->ios->done = _read_done;
	dprintk("%s: offset=0x%llx length=0x%x\n", __func__,
		rdata->args.offset, rdata->args.count);
	ret = ore_read(objios->ios);
	if (unlikely(ret))
		objio_free_result(&objios->oir);
	return ret;
}

/*
 * write
 */
static void _write_done(struct ore_io_state *ios, void *private)
{
	struct objio_state *objios = private;
	ssize_t status;
	int ret = ore_check_io(ios, &__on_dev_error);

	/* FIXME: _io_free(ios) can we dealocate the libosd resources; */

	if (likely(!ret)) {
		/* FIXME: should be based on the OSD's persistence model
		 * See OSD2r05 Section 4.13 Data persistence model */
		objios->oir.committed = NFS_FILE_SYNC;
		status = ios->length;
	} else {
		status = ret;
	}

	objlayout_write_done(&objios->oir, status, objios->sync);
}

static struct page *__r4w_get_page(void *priv, u64 offset, bool *uptodate)
{
	struct objio_state *objios = priv;
	struct nfs_write_data *wdata = objios->oir.rpcdata;
	struct address_space *mapping = wdata->header->inode->i_mapping;
	pgoff_t index = offset / PAGE_SIZE;
	struct page *page;
	loff_t i_size = i_size_read(wdata->header->inode);

	if (offset >= i_size) {
		*uptodate = true;
		dprintk("%s: g_zero_page index=0x%lx\n", __func__, index);
		return ZERO_PAGE(0);
	}

	page = find_get_page(mapping, index);
	if (!page) {
		page = find_or_create_page(mapping, index, GFP_NOFS);
		if (unlikely(!page)) {
			dprintk("%s: grab_cache_page Failed index=0x%lx\n",
				__func__, index);
			return NULL;
		}
		unlock_page(page);
	}
	if (PageDirty(page) || PageWriteback(page))
		*uptodate = true;
	else
		*uptodate = PageUptodate(page);
	dprintk("%s: index=0x%lx uptodate=%d\n", __func__, index, *uptodate);
	return page;
}

static void __r4w_put_page(void *priv, struct page *page)
{
	dprintk("%s: index=0x%lx\n", __func__,
		(page == ZERO_PAGE(0)) ? -1UL : page->index);
	if (ZERO_PAGE(0) != page)
		page_cache_release(page);
	return;
}

static const struct _ore_r4w_op _r4w_op = {
	.get_page = &__r4w_get_page,
	.put_page = &__r4w_put_page,
};

int objio_write_pagelist(struct nfs_write_data *wdata, int how)
{
	struct nfs_pgio_header *hdr = wdata->header;
	struct objio_state *objios;
	int ret;

	ret = objio_alloc_io_state(NFS_I(hdr->inode)->layout, false,
			hdr->lseg, wdata->args.pages, wdata->args.pgbase,
			wdata->args.offset, wdata->args.count, wdata, GFP_NOFS,
			&objios);
	if (unlikely(ret))
		return ret;

	objios->sync = 0 != (how & FLUSH_SYNC);
	objios->ios->r4w = &_r4w_op;

	if (!objios->sync)
		objios->ios->done = _write_done;

	dprintk("%s: offset=0x%llx length=0x%x\n", __func__,
		wdata->args.offset, wdata->args.count);
	ret = ore_write(objios->ios);
	if (unlikely(ret)) {
		objio_free_result(&objios->oir);
		return ret;
	}

	if (objios->sync)
		_write_done(objios->ios, objios);

	return 0;
}

static bool objio_pg_test(struct nfs_pageio_descriptor *pgio,
			  struct nfs_page *prev, struct nfs_page *req)
{
	if (!pnfs_generic_pg_test(pgio, prev, req))
		return false;

	return pgio->pg_count + req->wb_bytes <=
			(unsigned long)pgio->pg_layout_private;
}

static void objio_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
{
	pnfs_generic_pg_init_read(pgio, req);
	if (unlikely(pgio->pg_lseg == NULL))
		return; /* Not pNFS */

	pgio->pg_layout_private = (void *)
				OBJIO_LSEG(pgio->pg_lseg)->layout.max_io_length;
}

static bool aligned_on_raid_stripe(u64 offset, struct ore_layout *layout,
				   unsigned long *stripe_end)
{
	u32 stripe_off;
	unsigned stripe_size;

	if (layout->raid_algorithm == PNFS_OSD_RAID_0)
		return true;

	stripe_size = layout->stripe_unit *
				(layout->group_width - layout->parity);

	div_u64_rem(offset, stripe_size, &stripe_off);
	if (!stripe_off)
		return true;

	*stripe_end = stripe_size - stripe_off;
	return false;
}

static void objio_init_write(struct nfs_pageio_descriptor *pgio, struct nfs_page *req)
{
	unsigned long stripe_end = 0;
	u64 wb_size;

	if (pgio->pg_dreq == NULL)
		wb_size = i_size_read(pgio->pg_inode) - req_offset(req);
	else
		wb_size = nfs_dreq_bytes_left(pgio->pg_dreq);

	pnfs_generic_pg_init_write(pgio, req, wb_size);
	if (unlikely(pgio->pg_lseg == NULL))
		return; /* Not pNFS */

	if (req->wb_offset ||
	    !aligned_on_raid_stripe(req->wb_index * PAGE_SIZE,
			       &OBJIO_LSEG(pgio->pg_lseg)->layout,
			       &stripe_end)) {
		pgio->pg_layout_private = (void *)stripe_end;
	} else {
		pgio->pg_layout_private = (void *)
				OBJIO_LSEG(pgio->pg_lseg)->layout.max_io_length;
	}
}

static const struct nfs_pageio_ops objio_pg_read_ops = {
	.pg_init = objio_init_read,
	.pg_test = objio_pg_test,
	.pg_doio = pnfs_generic_pg_readpages,
};

static const struct nfs_pageio_ops objio_pg_write_ops = {
	.pg_init = objio_init_write,
	.pg_test = objio_pg_test,
	.pg_doio = pnfs_generic_pg_writepages,
};

static struct pnfs_layoutdriver_type objlayout_type = {
	.id = LAYOUT_OSD2_OBJECTS,
	.name = "LAYOUT_OSD2_OBJECTS",
	.flags                   = PNFS_LAYOUTRET_ON_SETATTR |
				   PNFS_LAYOUTRET_ON_ERROR,

	.owner		       	 = THIS_MODULE,
	.alloc_layout_hdr        = objlayout_alloc_layout_hdr,
	.free_layout_hdr         = objlayout_free_layout_hdr,

	.alloc_lseg              = objlayout_alloc_lseg,
	.free_lseg               = objlayout_free_lseg,

	.read_pagelist           = objlayout_read_pagelist,
	.write_pagelist          = objlayout_write_pagelist,
	.pg_read_ops             = &objio_pg_read_ops,
	.pg_write_ops            = &objio_pg_write_ops,

	.free_deviceid_node	 = objio_free_deviceid_node,

	.encode_layoutcommit	 = objlayout_encode_layoutcommit,
	.encode_layoutreturn     = objlayout_encode_layoutreturn,
};

MODULE_DESCRIPTION("pNFS Layout Driver for OSD2 objects");
MODULE_AUTHOR("Benny Halevy <bhalevy@panasas.com>");
MODULE_LICENSE("GPL");

static int __init
objlayout_init(void)
{
	int ret = pnfs_register_layoutdriver(&objlayout_type);

	if (ret)
		printk(KERN_INFO
			"NFS: %s: Registering OSD pNFS Layout Driver failed: error=%d\n",
			__func__, ret);
	else
		printk(KERN_INFO "NFS: %s: Registered OSD pNFS Layout Driver\n",
			__func__);
	return ret;
}

static void __exit
objlayout_exit(void)
{
	pnfs_unregister_layoutdriver(&objlayout_type);
	printk(KERN_INFO "NFS: %s: Unregistered OSD pNFS Layout Driver\n",
	       __func__);
}

MODULE_ALIAS("nfs-layouttype4-2");

module_init(objlayout_init);
module_exit(objlayout_exit);