1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Module for pnfs flexfile layout driver.
4  *
5  * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
6  *
7  * Tao Peng <bergwolf@primarydata.com>
8  */
9 
10 #include <linux/nfs_fs.h>
11 #include <linux/nfs_mount.h>
12 #include <linux/nfs_page.h>
13 #include <linux/module.h>
14 #include <linux/sched/mm.h>
15 
16 #include <linux/sunrpc/metrics.h>
17 
18 #include "flexfilelayout.h"
19 #include "../nfs4session.h"
20 #include "../nfs4idmap.h"
21 #include "../internal.h"
22 #include "../delegation.h"
23 #include "../nfs4trace.h"
24 #include "../iostat.h"
25 #include "../nfs.h"
26 #include "../nfs42.h"
27 
28 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
29 
30 #define FF_LAYOUT_POLL_RETRY_MAX     (15*HZ)
31 #define FF_LAYOUTRETURN_MAXERR 20
32 
33 enum nfs4_ff_op_type {
34 	NFS4_FF_OP_LAYOUTSTATS,
35 	NFS4_FF_OP_LAYOUTRETURN,
36 };
37 
38 static unsigned short io_maxretrans;
39 
40 static const struct pnfs_commit_ops ff_layout_commit_ops;
41 static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
42 		struct nfs_pgio_header *hdr);
43 static int
44 ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
45 			       struct nfs42_layoutstat_devinfo *devinfo,
46 			       int dev_limit, enum nfs4_ff_op_type type);
47 static void ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
48 			      const struct nfs42_layoutstat_devinfo *devinfo,
49 			      struct nfs4_ff_layout_mirror *mirror);
50 
51 static struct pnfs_layout_hdr *
52 ff_layout_alloc_layout_hdr(struct inode *inode, gfp_t gfp_flags)
53 {
54 	struct nfs4_flexfile_layout *ffl;
55 
56 	ffl = kzalloc(sizeof(*ffl), gfp_flags);
57 	if (ffl) {
58 		pnfs_init_ds_commit_info(&ffl->commit_info);
59 		INIT_LIST_HEAD(&ffl->error_list);
60 		INIT_LIST_HEAD(&ffl->mirrors);
61 		ffl->last_report_time = ktime_get();
62 		ffl->commit_info.ops = &ff_layout_commit_ops;
63 		return &ffl->generic_hdr;
64 	} else
65 		return NULL;
66 }
67 
68 static void
69 ff_layout_free_layout_hdr(struct pnfs_layout_hdr *lo)
70 {
71 	struct nfs4_flexfile_layout *ffl = FF_LAYOUT_FROM_HDR(lo);
72 	struct nfs4_ff_layout_ds_err *err, *n;
73 
74 	list_for_each_entry_safe(err, n, &ffl->error_list, list) {
75 		list_del(&err->list);
76 		kfree(err);
77 	}
78 	kfree_rcu(ffl, generic_hdr.plh_rcu);
79 }
80 
81 static int decode_pnfs_stateid(struct xdr_stream *xdr, nfs4_stateid *stateid)
82 {
83 	__be32 *p;
84 
85 	p = xdr_inline_decode(xdr, NFS4_STATEID_SIZE);
86 	if (unlikely(p == NULL))
87 		return -ENOBUFS;
88 	stateid->type = NFS4_PNFS_DS_STATEID_TYPE;
89 	memcpy(stateid->data, p, NFS4_STATEID_SIZE);
90 	dprintk("%s: stateid id= [%x%x%x%x]\n", __func__,
91 		p[0], p[1], p[2], p[3]);
92 	return 0;
93 }
94 
95 static int decode_deviceid(struct xdr_stream *xdr, struct nfs4_deviceid *devid)
96 {
97 	__be32 *p;
98 
99 	p = xdr_inline_decode(xdr, NFS4_DEVICEID4_SIZE);
100 	if (unlikely(!p))
101 		return -ENOBUFS;
102 	memcpy(devid, p, NFS4_DEVICEID4_SIZE);
103 	nfs4_print_deviceid(devid);
104 	return 0;
105 }
106 
107 static int decode_nfs_fh(struct xdr_stream *xdr, struct nfs_fh *fh)
108 {
109 	__be32 *p;
110 
111 	p = xdr_inline_decode(xdr, 4);
112 	if (unlikely(!p))
113 		return -ENOBUFS;
114 	fh->size = be32_to_cpup(p++);
115 	if (fh->size > NFS_MAXFHSIZE) {
116 		printk(KERN_ERR "NFS flexfiles: Too big fh received %d\n",
117 		       fh->size);
118 		return -EOVERFLOW;
119 	}
120 	/* fh.data */
121 	p = xdr_inline_decode(xdr, fh->size);
122 	if (unlikely(!p))
123 		return -ENOBUFS;
124 	memcpy(&fh->data, p, fh->size);
125 	dprintk("%s: fh len %d\n", __func__, fh->size);
126 
127 	return 0;
128 }
129 
130 /*
131  * Currently only stringified uids and gids are accepted.
132  * I.e., kerberos is not supported to the DSes, so no pricipals.
133  *
134  * That means that one common function will suffice, but when
135  * principals are added, this should be split to accomodate
136  * calls to both nfs_map_name_to_uid() and nfs_map_group_to_gid().
137  */
138 static int
139 decode_name(struct xdr_stream *xdr, u32 *id)
140 {
141 	__be32 *p;
142 	int len;
143 
144 	/* opaque_length(4)*/
145 	p = xdr_inline_decode(xdr, 4);
146 	if (unlikely(!p))
147 		return -ENOBUFS;
148 	len = be32_to_cpup(p++);
149 	if (len < 0)
150 		return -EINVAL;
151 
152 	dprintk("%s: len %u\n", __func__, len);
153 
154 	/* opaque body */
155 	p = xdr_inline_decode(xdr, len);
156 	if (unlikely(!p))
157 		return -ENOBUFS;
158 
159 	if (!nfs_map_string_to_numeric((char *)p, len, id))
160 		return -EINVAL;
161 
162 	return 0;
163 }
164 
165 static bool ff_mirror_match_fh(const struct nfs4_ff_layout_mirror *m1,
166 		const struct nfs4_ff_layout_mirror *m2)
167 {
168 	int i, j;
169 
170 	if (m1->fh_versions_cnt != m2->fh_versions_cnt)
171 		return false;
172 	for (i = 0; i < m1->fh_versions_cnt; i++) {
173 		bool found_fh = false;
174 		for (j = 0; j < m2->fh_versions_cnt; j++) {
175 			if (nfs_compare_fh(&m1->fh_versions[i],
176 					&m2->fh_versions[j]) == 0) {
177 				found_fh = true;
178 				break;
179 			}
180 		}
181 		if (!found_fh)
182 			return false;
183 	}
184 	return true;
185 }
186 
187 static struct nfs4_ff_layout_mirror *
188 ff_layout_add_mirror(struct pnfs_layout_hdr *lo,
189 		struct nfs4_ff_layout_mirror *mirror)
190 {
191 	struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
192 	struct nfs4_ff_layout_mirror *pos;
193 	struct inode *inode = lo->plh_inode;
194 
195 	spin_lock(&inode->i_lock);
196 	list_for_each_entry(pos, &ff_layout->mirrors, mirrors) {
197 		if (memcmp(&mirror->devid, &pos->devid, sizeof(pos->devid)) != 0)
198 			continue;
199 		if (!ff_mirror_match_fh(mirror, pos))
200 			continue;
201 		if (refcount_inc_not_zero(&pos->ref)) {
202 			spin_unlock(&inode->i_lock);
203 			return pos;
204 		}
205 	}
206 	list_add(&mirror->mirrors, &ff_layout->mirrors);
207 	mirror->layout = lo;
208 	spin_unlock(&inode->i_lock);
209 	return mirror;
210 }
211 
212 static void
213 ff_layout_remove_mirror(struct nfs4_ff_layout_mirror *mirror)
214 {
215 	struct inode *inode;
216 	if (mirror->layout == NULL)
217 		return;
218 	inode = mirror->layout->plh_inode;
219 	spin_lock(&inode->i_lock);
220 	list_del(&mirror->mirrors);
221 	spin_unlock(&inode->i_lock);
222 	mirror->layout = NULL;
223 }
224 
225 static struct nfs4_ff_layout_mirror *ff_layout_alloc_mirror(gfp_t gfp_flags)
226 {
227 	struct nfs4_ff_layout_mirror *mirror;
228 
229 	mirror = kzalloc(sizeof(*mirror), gfp_flags);
230 	if (mirror != NULL) {
231 		spin_lock_init(&mirror->lock);
232 		refcount_set(&mirror->ref, 1);
233 		INIT_LIST_HEAD(&mirror->mirrors);
234 	}
235 	return mirror;
236 }
237 
238 static void ff_layout_free_mirror(struct nfs4_ff_layout_mirror *mirror)
239 {
240 	const struct cred	*cred;
241 
242 	ff_layout_remove_mirror(mirror);
243 	kfree(mirror->fh_versions);
244 	cred = rcu_access_pointer(mirror->ro_cred);
245 	put_cred(cred);
246 	cred = rcu_access_pointer(mirror->rw_cred);
247 	put_cred(cred);
248 	nfs4_ff_layout_put_deviceid(mirror->mirror_ds);
249 	kfree(mirror);
250 }
251 
252 static void ff_layout_put_mirror(struct nfs4_ff_layout_mirror *mirror)
253 {
254 	if (mirror != NULL && refcount_dec_and_test(&mirror->ref))
255 		ff_layout_free_mirror(mirror);
256 }
257 
258 static void ff_layout_free_mirror_array(struct nfs4_ff_layout_segment *fls)
259 {
260 	u32 i;
261 
262 	for (i = 0; i < fls->mirror_array_cnt; i++)
263 		ff_layout_put_mirror(fls->mirror_array[i]);
264 }
265 
266 static void _ff_layout_free_lseg(struct nfs4_ff_layout_segment *fls)
267 {
268 	if (fls) {
269 		ff_layout_free_mirror_array(fls);
270 		kfree(fls);
271 	}
272 }
273 
274 static bool
275 ff_lseg_match_mirrors(struct pnfs_layout_segment *l1,
276 		struct pnfs_layout_segment *l2)
277 {
278 	const struct nfs4_ff_layout_segment *fl1 = FF_LAYOUT_LSEG(l1);
279 	const struct nfs4_ff_layout_segment *fl2 = FF_LAYOUT_LSEG(l1);
280 	u32 i;
281 
282 	if (fl1->mirror_array_cnt != fl2->mirror_array_cnt)
283 		return false;
284 	for (i = 0; i < fl1->mirror_array_cnt; i++) {
285 		if (fl1->mirror_array[i] != fl2->mirror_array[i])
286 			return false;
287 	}
288 	return true;
289 }
290 
291 static bool
292 ff_lseg_range_is_after(const struct pnfs_layout_range *l1,
293 		const struct pnfs_layout_range *l2)
294 {
295 	u64 end1, end2;
296 
297 	if (l1->iomode != l2->iomode)
298 		return l1->iomode != IOMODE_READ;
299 	end1 = pnfs_calc_offset_end(l1->offset, l1->length);
300 	end2 = pnfs_calc_offset_end(l2->offset, l2->length);
301 	if (end1 < l2->offset)
302 		return false;
303 	if (end2 < l1->offset)
304 		return true;
305 	return l2->offset <= l1->offset;
306 }
307 
308 static bool
309 ff_lseg_merge(struct pnfs_layout_segment *new,
310 		struct pnfs_layout_segment *old)
311 {
312 	u64 new_end, old_end;
313 
314 	if (test_bit(NFS_LSEG_LAYOUTRETURN, &old->pls_flags))
315 		return false;
316 	if (new->pls_range.iomode != old->pls_range.iomode)
317 		return false;
318 	old_end = pnfs_calc_offset_end(old->pls_range.offset,
319 			old->pls_range.length);
320 	if (old_end < new->pls_range.offset)
321 		return false;
322 	new_end = pnfs_calc_offset_end(new->pls_range.offset,
323 			new->pls_range.length);
324 	if (new_end < old->pls_range.offset)
325 		return false;
326 	if (!ff_lseg_match_mirrors(new, old))
327 		return false;
328 
329 	/* Mergeable: copy info from 'old' to 'new' */
330 	if (new_end < old_end)
331 		new_end = old_end;
332 	if (new->pls_range.offset < old->pls_range.offset)
333 		new->pls_range.offset = old->pls_range.offset;
334 	new->pls_range.length = pnfs_calc_offset_length(new->pls_range.offset,
335 			new_end);
336 	if (test_bit(NFS_LSEG_ROC, &old->pls_flags))
337 		set_bit(NFS_LSEG_ROC, &new->pls_flags);
338 	return true;
339 }
340 
341 static void
342 ff_layout_add_lseg(struct pnfs_layout_hdr *lo,
343 		struct pnfs_layout_segment *lseg,
344 		struct list_head *free_me)
345 {
346 	pnfs_generic_layout_insert_lseg(lo, lseg,
347 			ff_lseg_range_is_after,
348 			ff_lseg_merge,
349 			free_me);
350 }
351 
352 static void ff_layout_sort_mirrors(struct nfs4_ff_layout_segment *fls)
353 {
354 	int i, j;
355 
356 	for (i = 0; i < fls->mirror_array_cnt - 1; i++) {
357 		for (j = i + 1; j < fls->mirror_array_cnt; j++)
358 			if (fls->mirror_array[i]->efficiency <
359 			    fls->mirror_array[j]->efficiency)
360 				swap(fls->mirror_array[i],
361 				     fls->mirror_array[j]);
362 	}
363 }
364 
365 static struct pnfs_layout_segment *
366 ff_layout_alloc_lseg(struct pnfs_layout_hdr *lh,
367 		     struct nfs4_layoutget_res *lgr,
368 		     gfp_t gfp_flags)
369 {
370 	struct pnfs_layout_segment *ret;
371 	struct nfs4_ff_layout_segment *fls = NULL;
372 	struct xdr_stream stream;
373 	struct xdr_buf buf;
374 	struct page *scratch;
375 	u64 stripe_unit;
376 	u32 mirror_array_cnt;
377 	__be32 *p;
378 	int i, rc;
379 
380 	dprintk("--> %s\n", __func__);
381 	scratch = alloc_page(gfp_flags);
382 	if (!scratch)
383 		return ERR_PTR(-ENOMEM);
384 
385 	xdr_init_decode_pages(&stream, &buf, lgr->layoutp->pages,
386 			      lgr->layoutp->len);
387 	xdr_set_scratch_page(&stream, scratch);
388 
389 	/* stripe unit and mirror_array_cnt */
390 	rc = -EIO;
391 	p = xdr_inline_decode(&stream, 8 + 4);
392 	if (!p)
393 		goto out_err_free;
394 
395 	p = xdr_decode_hyper(p, &stripe_unit);
396 	mirror_array_cnt = be32_to_cpup(p++);
397 	dprintk("%s: stripe_unit=%llu mirror_array_cnt=%u\n", __func__,
398 		stripe_unit, mirror_array_cnt);
399 
400 	if (mirror_array_cnt > NFS4_FLEXFILE_LAYOUT_MAX_MIRROR_CNT ||
401 	    mirror_array_cnt == 0)
402 		goto out_err_free;
403 
404 	rc = -ENOMEM;
405 	fls = kzalloc(struct_size(fls, mirror_array, mirror_array_cnt),
406 			gfp_flags);
407 	if (!fls)
408 		goto out_err_free;
409 
410 	fls->mirror_array_cnt = mirror_array_cnt;
411 	fls->stripe_unit = stripe_unit;
412 
413 	for (i = 0; i < fls->mirror_array_cnt; i++) {
414 		struct nfs4_ff_layout_mirror *mirror;
415 		struct cred *kcred;
416 		const struct cred __rcu *cred;
417 		kuid_t uid;
418 		kgid_t gid;
419 		u32 ds_count, fh_count, id;
420 		int j;
421 
422 		rc = -EIO;
423 		p = xdr_inline_decode(&stream, 4);
424 		if (!p)
425 			goto out_err_free;
426 		ds_count = be32_to_cpup(p);
427 
428 		/* FIXME: allow for striping? */
429 		if (ds_count != 1)
430 			goto out_err_free;
431 
432 		fls->mirror_array[i] = ff_layout_alloc_mirror(gfp_flags);
433 		if (fls->mirror_array[i] == NULL) {
434 			rc = -ENOMEM;
435 			goto out_err_free;
436 		}
437 
438 		fls->mirror_array[i]->ds_count = ds_count;
439 
440 		/* deviceid */
441 		rc = decode_deviceid(&stream, &fls->mirror_array[i]->devid);
442 		if (rc)
443 			goto out_err_free;
444 
445 		/* efficiency */
446 		rc = -EIO;
447 		p = xdr_inline_decode(&stream, 4);
448 		if (!p)
449 			goto out_err_free;
450 		fls->mirror_array[i]->efficiency = be32_to_cpup(p);
451 
452 		/* stateid */
453 		rc = decode_pnfs_stateid(&stream, &fls->mirror_array[i]->stateid);
454 		if (rc)
455 			goto out_err_free;
456 
457 		/* fh */
458 		rc = -EIO;
459 		p = xdr_inline_decode(&stream, 4);
460 		if (!p)
461 			goto out_err_free;
462 		fh_count = be32_to_cpup(p);
463 
464 		fls->mirror_array[i]->fh_versions =
465 			kcalloc(fh_count, sizeof(struct nfs_fh),
466 				gfp_flags);
467 		if (fls->mirror_array[i]->fh_versions == NULL) {
468 			rc = -ENOMEM;
469 			goto out_err_free;
470 		}
471 
472 		for (j = 0; j < fh_count; j++) {
473 			rc = decode_nfs_fh(&stream,
474 					   &fls->mirror_array[i]->fh_versions[j]);
475 			if (rc)
476 				goto out_err_free;
477 		}
478 
479 		fls->mirror_array[i]->fh_versions_cnt = fh_count;
480 
481 		/* user */
482 		rc = decode_name(&stream, &id);
483 		if (rc)
484 			goto out_err_free;
485 
486 		uid = make_kuid(&init_user_ns, id);
487 
488 		/* group */
489 		rc = decode_name(&stream, &id);
490 		if (rc)
491 			goto out_err_free;
492 
493 		gid = make_kgid(&init_user_ns, id);
494 
495 		if (gfp_flags & __GFP_FS)
496 			kcred = prepare_kernel_cred(&init_task);
497 		else {
498 			unsigned int nofs_flags = memalloc_nofs_save();
499 			kcred = prepare_kernel_cred(&init_task);
500 			memalloc_nofs_restore(nofs_flags);
501 		}
502 		rc = -ENOMEM;
503 		if (!kcred)
504 			goto out_err_free;
505 		kcred->fsuid = uid;
506 		kcred->fsgid = gid;
507 		cred = RCU_INITIALIZER(kcred);
508 
509 		if (lgr->range.iomode == IOMODE_READ)
510 			rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
511 		else
512 			rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
513 
514 		mirror = ff_layout_add_mirror(lh, fls->mirror_array[i]);
515 		if (mirror != fls->mirror_array[i]) {
516 			/* swap cred ptrs so free_mirror will clean up old */
517 			if (lgr->range.iomode == IOMODE_READ) {
518 				cred = xchg(&mirror->ro_cred, cred);
519 				rcu_assign_pointer(fls->mirror_array[i]->ro_cred, cred);
520 			} else {
521 				cred = xchg(&mirror->rw_cred, cred);
522 				rcu_assign_pointer(fls->mirror_array[i]->rw_cred, cred);
523 			}
524 			ff_layout_free_mirror(fls->mirror_array[i]);
525 			fls->mirror_array[i] = mirror;
526 		}
527 
528 		dprintk("%s: iomode %s uid %u gid %u\n", __func__,
529 			lgr->range.iomode == IOMODE_READ ? "READ" : "RW",
530 			from_kuid(&init_user_ns, uid),
531 			from_kgid(&init_user_ns, gid));
532 	}
533 
534 	p = xdr_inline_decode(&stream, 4);
535 	if (!p)
536 		goto out_sort_mirrors;
537 	fls->flags = be32_to_cpup(p);
538 
539 	p = xdr_inline_decode(&stream, 4);
540 	if (!p)
541 		goto out_sort_mirrors;
542 	for (i=0; i < fls->mirror_array_cnt; i++)
543 		fls->mirror_array[i]->report_interval = be32_to_cpup(p);
544 
545 out_sort_mirrors:
546 	ff_layout_sort_mirrors(fls);
547 	ret = &fls->generic_hdr;
548 	dprintk("<-- %s (success)\n", __func__);
549 out_free_page:
550 	__free_page(scratch);
551 	return ret;
552 out_err_free:
553 	_ff_layout_free_lseg(fls);
554 	ret = ERR_PTR(rc);
555 	dprintk("<-- %s (%d)\n", __func__, rc);
556 	goto out_free_page;
557 }
558 
559 static void
560 ff_layout_free_lseg(struct pnfs_layout_segment *lseg)
561 {
562 	struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
563 
564 	dprintk("--> %s\n", __func__);
565 
566 	if (lseg->pls_range.iomode == IOMODE_RW) {
567 		struct nfs4_flexfile_layout *ffl;
568 		struct inode *inode;
569 
570 		ffl = FF_LAYOUT_FROM_HDR(lseg->pls_layout);
571 		inode = ffl->generic_hdr.plh_inode;
572 		spin_lock(&inode->i_lock);
573 		pnfs_generic_ds_cinfo_release_lseg(&ffl->commit_info, lseg);
574 		spin_unlock(&inode->i_lock);
575 	}
576 	_ff_layout_free_lseg(fls);
577 }
578 
579 static void
580 nfs4_ff_start_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
581 {
582 	/* first IO request? */
583 	if (atomic_inc_return(&timer->n_ops) == 1) {
584 		timer->start_time = now;
585 	}
586 }
587 
588 static ktime_t
589 nfs4_ff_end_busy_timer(struct nfs4_ff_busy_timer *timer, ktime_t now)
590 {
591 	ktime_t start;
592 
593 	if (atomic_dec_return(&timer->n_ops) < 0)
594 		WARN_ON_ONCE(1);
595 
596 	start = timer->start_time;
597 	timer->start_time = now;
598 	return ktime_sub(now, start);
599 }
600 
601 static bool
602 nfs4_ff_layoutstat_start_io(struct nfs4_ff_layout_mirror *mirror,
603 			    struct nfs4_ff_layoutstat *layoutstat,
604 			    ktime_t now)
605 {
606 	s64 report_interval = FF_LAYOUTSTATS_REPORT_INTERVAL;
607 	struct nfs4_flexfile_layout *ffl = FF_LAYOUT_FROM_HDR(mirror->layout);
608 
609 	nfs4_ff_start_busy_timer(&layoutstat->busy_timer, now);
610 	if (!mirror->start_time)
611 		mirror->start_time = now;
612 	if (mirror->report_interval != 0)
613 		report_interval = (s64)mirror->report_interval * 1000LL;
614 	else if (layoutstats_timer != 0)
615 		report_interval = (s64)layoutstats_timer * 1000LL;
616 	if (ktime_to_ms(ktime_sub(now, ffl->last_report_time)) >=
617 			report_interval) {
618 		ffl->last_report_time = now;
619 		return true;
620 	}
621 
622 	return false;
623 }
624 
625 static void
626 nfs4_ff_layout_stat_io_update_requested(struct nfs4_ff_layoutstat *layoutstat,
627 		__u64 requested)
628 {
629 	struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
630 
631 	iostat->ops_requested++;
632 	iostat->bytes_requested += requested;
633 }
634 
635 static void
636 nfs4_ff_layout_stat_io_update_completed(struct nfs4_ff_layoutstat *layoutstat,
637 		__u64 requested,
638 		__u64 completed,
639 		ktime_t time_completed,
640 		ktime_t time_started)
641 {
642 	struct nfs4_ff_io_stat *iostat = &layoutstat->io_stat;
643 	ktime_t completion_time = ktime_sub(time_completed, time_started);
644 	ktime_t timer;
645 
646 	iostat->ops_completed++;
647 	iostat->bytes_completed += completed;
648 	iostat->bytes_not_delivered += requested - completed;
649 
650 	timer = nfs4_ff_end_busy_timer(&layoutstat->busy_timer, time_completed);
651 	iostat->total_busy_time =
652 			ktime_add(iostat->total_busy_time, timer);
653 	iostat->aggregate_completion_time =
654 			ktime_add(iostat->aggregate_completion_time,
655 					completion_time);
656 }
657 
658 static void
659 nfs4_ff_layout_stat_io_start_read(struct inode *inode,
660 		struct nfs4_ff_layout_mirror *mirror,
661 		__u64 requested, ktime_t now)
662 {
663 	bool report;
664 
665 	spin_lock(&mirror->lock);
666 	report = nfs4_ff_layoutstat_start_io(mirror, &mirror->read_stat, now);
667 	nfs4_ff_layout_stat_io_update_requested(&mirror->read_stat, requested);
668 	set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
669 	spin_unlock(&mirror->lock);
670 
671 	if (report)
672 		pnfs_report_layoutstat(inode, nfs_io_gfp_mask());
673 }
674 
675 static void
676 nfs4_ff_layout_stat_io_end_read(struct rpc_task *task,
677 		struct nfs4_ff_layout_mirror *mirror,
678 		__u64 requested,
679 		__u64 completed)
680 {
681 	spin_lock(&mirror->lock);
682 	nfs4_ff_layout_stat_io_update_completed(&mirror->read_stat,
683 			requested, completed,
684 			ktime_get(), task->tk_start);
685 	set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
686 	spin_unlock(&mirror->lock);
687 }
688 
689 static void
690 nfs4_ff_layout_stat_io_start_write(struct inode *inode,
691 		struct nfs4_ff_layout_mirror *mirror,
692 		__u64 requested, ktime_t now)
693 {
694 	bool report;
695 
696 	spin_lock(&mirror->lock);
697 	report = nfs4_ff_layoutstat_start_io(mirror , &mirror->write_stat, now);
698 	nfs4_ff_layout_stat_io_update_requested(&mirror->write_stat, requested);
699 	set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
700 	spin_unlock(&mirror->lock);
701 
702 	if (report)
703 		pnfs_report_layoutstat(inode, nfs_io_gfp_mask());
704 }
705 
706 static void
707 nfs4_ff_layout_stat_io_end_write(struct rpc_task *task,
708 		struct nfs4_ff_layout_mirror *mirror,
709 		__u64 requested,
710 		__u64 completed,
711 		enum nfs3_stable_how committed)
712 {
713 	if (committed == NFS_UNSTABLE)
714 		requested = completed = 0;
715 
716 	spin_lock(&mirror->lock);
717 	nfs4_ff_layout_stat_io_update_completed(&mirror->write_stat,
718 			requested, completed, ktime_get(), task->tk_start);
719 	set_bit(NFS4_FF_MIRROR_STAT_AVAIL, &mirror->flags);
720 	spin_unlock(&mirror->lock);
721 }
722 
723 static void
724 ff_layout_mark_ds_unreachable(struct pnfs_layout_segment *lseg, u32 idx)
725 {
726 	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
727 
728 	if (devid)
729 		nfs4_mark_deviceid_unavailable(devid);
730 }
731 
732 static void
733 ff_layout_mark_ds_reachable(struct pnfs_layout_segment *lseg, u32 idx)
734 {
735 	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
736 
737 	if (devid)
738 		nfs4_mark_deviceid_available(devid);
739 }
740 
741 static struct nfs4_pnfs_ds *
742 ff_layout_choose_ds_for_read(struct pnfs_layout_segment *lseg,
743 			     u32 start_idx, u32 *best_idx,
744 			     bool check_device)
745 {
746 	struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg);
747 	struct nfs4_ff_layout_mirror *mirror;
748 	struct nfs4_pnfs_ds *ds;
749 	u32 idx;
750 
751 	/* mirrors are initially sorted by efficiency */
752 	for (idx = start_idx; idx < fls->mirror_array_cnt; idx++) {
753 		mirror = FF_LAYOUT_COMP(lseg, idx);
754 		ds = nfs4_ff_layout_prepare_ds(lseg, mirror, false);
755 		if (!ds)
756 			continue;
757 
758 		if (check_device &&
759 		    nfs4_test_deviceid_unavailable(&mirror->mirror_ds->id_node))
760 			continue;
761 
762 		*best_idx = idx;
763 		return ds;
764 	}
765 
766 	return NULL;
767 }
768 
769 static struct nfs4_pnfs_ds *
770 ff_layout_choose_any_ds_for_read(struct pnfs_layout_segment *lseg,
771 				 u32 start_idx, u32 *best_idx)
772 {
773 	return ff_layout_choose_ds_for_read(lseg, start_idx, best_idx, false);
774 }
775 
776 static struct nfs4_pnfs_ds *
777 ff_layout_choose_valid_ds_for_read(struct pnfs_layout_segment *lseg,
778 				   u32 start_idx, u32 *best_idx)
779 {
780 	return ff_layout_choose_ds_for_read(lseg, start_idx, best_idx, true);
781 }
782 
783 static struct nfs4_pnfs_ds *
784 ff_layout_choose_best_ds_for_read(struct pnfs_layout_segment *lseg,
785 				  u32 start_idx, u32 *best_idx)
786 {
787 	struct nfs4_pnfs_ds *ds;
788 
789 	ds = ff_layout_choose_valid_ds_for_read(lseg, start_idx, best_idx);
790 	if (ds)
791 		return ds;
792 	return ff_layout_choose_any_ds_for_read(lseg, start_idx, best_idx);
793 }
794 
795 static struct nfs4_pnfs_ds *
796 ff_layout_get_ds_for_read(struct nfs_pageio_descriptor *pgio,
797 			  u32 *best_idx)
798 {
799 	struct pnfs_layout_segment *lseg = pgio->pg_lseg;
800 	struct nfs4_pnfs_ds *ds;
801 
802 	ds = ff_layout_choose_best_ds_for_read(lseg, pgio->pg_mirror_idx,
803 					       best_idx);
804 	if (ds || !pgio->pg_mirror_idx)
805 		return ds;
806 	return ff_layout_choose_best_ds_for_read(lseg, 0, best_idx);
807 }
808 
809 static void
810 ff_layout_pg_get_read(struct nfs_pageio_descriptor *pgio,
811 		      struct nfs_page *req,
812 		      bool strict_iomode)
813 {
814 	pnfs_put_lseg(pgio->pg_lseg);
815 	pgio->pg_lseg =
816 		pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
817 				   req_offset(req), req->wb_bytes, IOMODE_READ,
818 				   strict_iomode, nfs_io_gfp_mask());
819 	if (IS_ERR(pgio->pg_lseg)) {
820 		pgio->pg_error = PTR_ERR(pgio->pg_lseg);
821 		pgio->pg_lseg = NULL;
822 	}
823 }
824 
825 static void
826 ff_layout_pg_check_layout(struct nfs_pageio_descriptor *pgio,
827 			  struct nfs_page *req)
828 {
829 	pnfs_generic_pg_check_layout(pgio);
830 	pnfs_generic_pg_check_range(pgio, req);
831 }
832 
833 static void
834 ff_layout_pg_init_read(struct nfs_pageio_descriptor *pgio,
835 			struct nfs_page *req)
836 {
837 	struct nfs_pgio_mirror *pgm;
838 	struct nfs4_ff_layout_mirror *mirror;
839 	struct nfs4_pnfs_ds *ds;
840 	u32 ds_idx;
841 
842 retry:
843 	ff_layout_pg_check_layout(pgio, req);
844 	/* Use full layout for now */
845 	if (!pgio->pg_lseg) {
846 		ff_layout_pg_get_read(pgio, req, false);
847 		if (!pgio->pg_lseg)
848 			goto out_nolseg;
849 	}
850 	if (ff_layout_avoid_read_on_rw(pgio->pg_lseg)) {
851 		ff_layout_pg_get_read(pgio, req, true);
852 		if (!pgio->pg_lseg)
853 			goto out_nolseg;
854 	}
855 
856 	ds = ff_layout_get_ds_for_read(pgio, &ds_idx);
857 	if (!ds) {
858 		if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
859 			goto out_mds;
860 		pnfs_generic_pg_cleanup(pgio);
861 		/* Sleep for 1 second before retrying */
862 		ssleep(1);
863 		goto retry;
864 	}
865 
866 	mirror = FF_LAYOUT_COMP(pgio->pg_lseg, ds_idx);
867 	pgm = &pgio->pg_mirrors[0];
868 	pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].rsize;
869 
870 	pgio->pg_mirror_idx = ds_idx;
871 
872 	if (NFS_SERVER(pgio->pg_inode)->flags &
873 			(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR))
874 		pgio->pg_maxretrans = io_maxretrans;
875 	return;
876 out_nolseg:
877 	if (pgio->pg_error < 0)
878 		return;
879 out_mds:
880 	trace_pnfs_mds_fallback_pg_init_read(pgio->pg_inode,
881 			0, NFS4_MAX_UINT64, IOMODE_READ,
882 			NFS_I(pgio->pg_inode)->layout,
883 			pgio->pg_lseg);
884 	pgio->pg_maxretrans = 0;
885 	nfs_pageio_reset_read_mds(pgio);
886 }
887 
888 static void
889 ff_layout_pg_init_write(struct nfs_pageio_descriptor *pgio,
890 			struct nfs_page *req)
891 {
892 	struct nfs4_ff_layout_mirror *mirror;
893 	struct nfs_pgio_mirror *pgm;
894 	struct nfs4_pnfs_ds *ds;
895 	u32 i;
896 
897 retry:
898 	ff_layout_pg_check_layout(pgio, req);
899 	if (!pgio->pg_lseg) {
900 		pgio->pg_lseg =
901 			pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
902 					   req_offset(req), req->wb_bytes,
903 					   IOMODE_RW, false, nfs_io_gfp_mask());
904 		if (IS_ERR(pgio->pg_lseg)) {
905 			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
906 			pgio->pg_lseg = NULL;
907 			return;
908 		}
909 	}
910 	/* If no lseg, fall back to write through mds */
911 	if (pgio->pg_lseg == NULL)
912 		goto out_mds;
913 
914 	/* Use a direct mapping of ds_idx to pgio mirror_idx */
915 	if (pgio->pg_mirror_count != FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg))
916 		goto out_eagain;
917 
918 	for (i = 0; i < pgio->pg_mirror_count; i++) {
919 		mirror = FF_LAYOUT_COMP(pgio->pg_lseg, i);
920 		ds = nfs4_ff_layout_prepare_ds(pgio->pg_lseg, mirror, true);
921 		if (!ds) {
922 			if (!ff_layout_no_fallback_to_mds(pgio->pg_lseg))
923 				goto out_mds;
924 			pnfs_generic_pg_cleanup(pgio);
925 			/* Sleep for 1 second before retrying */
926 			ssleep(1);
927 			goto retry;
928 		}
929 		pgm = &pgio->pg_mirrors[i];
930 		pgm->pg_bsize = mirror->mirror_ds->ds_versions[0].wsize;
931 	}
932 
933 	if (NFS_SERVER(pgio->pg_inode)->flags &
934 			(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR))
935 		pgio->pg_maxretrans = io_maxretrans;
936 	return;
937 out_eagain:
938 	pnfs_generic_pg_cleanup(pgio);
939 	pgio->pg_error = -EAGAIN;
940 	return;
941 out_mds:
942 	trace_pnfs_mds_fallback_pg_init_write(pgio->pg_inode,
943 			0, NFS4_MAX_UINT64, IOMODE_RW,
944 			NFS_I(pgio->pg_inode)->layout,
945 			pgio->pg_lseg);
946 	pgio->pg_maxretrans = 0;
947 	nfs_pageio_reset_write_mds(pgio);
948 	pgio->pg_error = -EAGAIN;
949 }
950 
951 static unsigned int
952 ff_layout_pg_get_mirror_count_write(struct nfs_pageio_descriptor *pgio,
953 				    struct nfs_page *req)
954 {
955 	if (!pgio->pg_lseg) {
956 		pgio->pg_lseg =
957 			pnfs_update_layout(pgio->pg_inode, nfs_req_openctx(req),
958 					   req_offset(req), req->wb_bytes,
959 					   IOMODE_RW, false, nfs_io_gfp_mask());
960 		if (IS_ERR(pgio->pg_lseg)) {
961 			pgio->pg_error = PTR_ERR(pgio->pg_lseg);
962 			pgio->pg_lseg = NULL;
963 			goto out;
964 		}
965 	}
966 	if (pgio->pg_lseg)
967 		return FF_LAYOUT_MIRROR_COUNT(pgio->pg_lseg);
968 
969 	trace_pnfs_mds_fallback_pg_get_mirror_count(pgio->pg_inode,
970 			0, NFS4_MAX_UINT64, IOMODE_RW,
971 			NFS_I(pgio->pg_inode)->layout,
972 			pgio->pg_lseg);
973 	/* no lseg means that pnfs is not in use, so no mirroring here */
974 	nfs_pageio_reset_write_mds(pgio);
975 out:
976 	return 1;
977 }
978 
979 static u32
980 ff_layout_pg_set_mirror_write(struct nfs_pageio_descriptor *desc, u32 idx)
981 {
982 	u32 old = desc->pg_mirror_idx;
983 
984 	desc->pg_mirror_idx = idx;
985 	return old;
986 }
987 
988 static struct nfs_pgio_mirror *
989 ff_layout_pg_get_mirror_write(struct nfs_pageio_descriptor *desc, u32 idx)
990 {
991 	return &desc->pg_mirrors[idx];
992 }
993 
994 static const struct nfs_pageio_ops ff_layout_pg_read_ops = {
995 	.pg_init = ff_layout_pg_init_read,
996 	.pg_test = pnfs_generic_pg_test,
997 	.pg_doio = pnfs_generic_pg_readpages,
998 	.pg_cleanup = pnfs_generic_pg_cleanup,
999 };
1000 
1001 static const struct nfs_pageio_ops ff_layout_pg_write_ops = {
1002 	.pg_init = ff_layout_pg_init_write,
1003 	.pg_test = pnfs_generic_pg_test,
1004 	.pg_doio = pnfs_generic_pg_writepages,
1005 	.pg_get_mirror_count = ff_layout_pg_get_mirror_count_write,
1006 	.pg_cleanup = pnfs_generic_pg_cleanup,
1007 	.pg_get_mirror = ff_layout_pg_get_mirror_write,
1008 	.pg_set_mirror = ff_layout_pg_set_mirror_write,
1009 };
1010 
1011 static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
1012 {
1013 	struct rpc_task *task = &hdr->task;
1014 
1015 	pnfs_layoutcommit_inode(hdr->inode, false);
1016 
1017 	if (retry_pnfs) {
1018 		dprintk("%s Reset task %5u for i/o through pNFS "
1019 			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1020 			hdr->task.tk_pid,
1021 			hdr->inode->i_sb->s_id,
1022 			(unsigned long long)NFS_FILEID(hdr->inode),
1023 			hdr->args.count,
1024 			(unsigned long long)hdr->args.offset);
1025 
1026 		hdr->completion_ops->reschedule_io(hdr);
1027 		return;
1028 	}
1029 
1030 	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1031 		dprintk("%s Reset task %5u for i/o through MDS "
1032 			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1033 			hdr->task.tk_pid,
1034 			hdr->inode->i_sb->s_id,
1035 			(unsigned long long)NFS_FILEID(hdr->inode),
1036 			hdr->args.count,
1037 			(unsigned long long)hdr->args.offset);
1038 
1039 		trace_pnfs_mds_fallback_write_done(hdr->inode,
1040 				hdr->args.offset, hdr->args.count,
1041 				IOMODE_RW, NFS_I(hdr->inode)->layout,
1042 				hdr->lseg);
1043 		task->tk_status = pnfs_write_done_resend_to_mds(hdr);
1044 	}
1045 }
1046 
1047 static void ff_layout_resend_pnfs_read(struct nfs_pgio_header *hdr)
1048 {
1049 	u32 idx = hdr->pgio_mirror_idx + 1;
1050 	u32 new_idx = 0;
1051 
1052 	if (ff_layout_choose_any_ds_for_read(hdr->lseg, idx, &new_idx))
1053 		ff_layout_send_layouterror(hdr->lseg);
1054 	else
1055 		pnfs_error_mark_layout_for_return(hdr->inode, hdr->lseg);
1056 	pnfs_read_resend_pnfs(hdr, new_idx);
1057 }
1058 
1059 static void ff_layout_reset_read(struct nfs_pgio_header *hdr)
1060 {
1061 	struct rpc_task *task = &hdr->task;
1062 
1063 	pnfs_layoutcommit_inode(hdr->inode, false);
1064 	pnfs_error_mark_layout_for_return(hdr->inode, hdr->lseg);
1065 
1066 	if (!test_and_set_bit(NFS_IOHDR_REDO, &hdr->flags)) {
1067 		dprintk("%s Reset task %5u for i/o through MDS "
1068 			"(req %s/%llu, %u bytes @ offset %llu)\n", __func__,
1069 			hdr->task.tk_pid,
1070 			hdr->inode->i_sb->s_id,
1071 			(unsigned long long)NFS_FILEID(hdr->inode),
1072 			hdr->args.count,
1073 			(unsigned long long)hdr->args.offset);
1074 
1075 		trace_pnfs_mds_fallback_read_done(hdr->inode,
1076 				hdr->args.offset, hdr->args.count,
1077 				IOMODE_READ, NFS_I(hdr->inode)->layout,
1078 				hdr->lseg);
1079 		task->tk_status = pnfs_read_done_resend_to_mds(hdr);
1080 	}
1081 }
1082 
1083 static int ff_layout_async_handle_error_v4(struct rpc_task *task,
1084 					   struct nfs4_state *state,
1085 					   struct nfs_client *clp,
1086 					   struct pnfs_layout_segment *lseg,
1087 					   u32 idx)
1088 {
1089 	struct pnfs_layout_hdr *lo = lseg->pls_layout;
1090 	struct inode *inode = lo->plh_inode;
1091 	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1092 	struct nfs4_slot_table *tbl = &clp->cl_session->fc_slot_table;
1093 
1094 	switch (task->tk_status) {
1095 	case -NFS4ERR_BADSESSION:
1096 	case -NFS4ERR_BADSLOT:
1097 	case -NFS4ERR_BAD_HIGH_SLOT:
1098 	case -NFS4ERR_DEADSESSION:
1099 	case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1100 	case -NFS4ERR_SEQ_FALSE_RETRY:
1101 	case -NFS4ERR_SEQ_MISORDERED:
1102 		dprintk("%s ERROR %d, Reset session. Exchangeid "
1103 			"flags 0x%x\n", __func__, task->tk_status,
1104 			clp->cl_exchange_flags);
1105 		nfs4_schedule_session_recovery(clp->cl_session, task->tk_status);
1106 		break;
1107 	case -NFS4ERR_DELAY:
1108 	case -NFS4ERR_GRACE:
1109 		rpc_delay(task, FF_LAYOUT_POLL_RETRY_MAX);
1110 		break;
1111 	case -NFS4ERR_RETRY_UNCACHED_REP:
1112 		break;
1113 	/* Invalidate Layout errors */
1114 	case -NFS4ERR_PNFS_NO_LAYOUT:
1115 	case -ESTALE:           /* mapped NFS4ERR_STALE */
1116 	case -EBADHANDLE:       /* mapped NFS4ERR_BADHANDLE */
1117 	case -EISDIR:           /* mapped NFS4ERR_ISDIR */
1118 	case -NFS4ERR_FHEXPIRED:
1119 	case -NFS4ERR_WRONG_TYPE:
1120 		dprintk("%s Invalid layout error %d\n", __func__,
1121 			task->tk_status);
1122 		/*
1123 		 * Destroy layout so new i/o will get a new layout.
1124 		 * Layout will not be destroyed until all current lseg
1125 		 * references are put. Mark layout as invalid to resend failed
1126 		 * i/o and all i/o waiting on the slot table to the MDS until
1127 		 * layout is destroyed and a new valid layout is obtained.
1128 		 */
1129 		pnfs_destroy_layout(NFS_I(inode));
1130 		rpc_wake_up(&tbl->slot_tbl_waitq);
1131 		goto reset;
1132 	/* RPC connection errors */
1133 	case -ECONNREFUSED:
1134 	case -EHOSTDOWN:
1135 	case -EHOSTUNREACH:
1136 	case -ENETUNREACH:
1137 	case -EIO:
1138 	case -ETIMEDOUT:
1139 	case -EPIPE:
1140 	case -EPROTO:
1141 	case -ENODEV:
1142 		dprintk("%s DS connection error %d\n", __func__,
1143 			task->tk_status);
1144 		nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1145 				&devid->deviceid);
1146 		rpc_wake_up(&tbl->slot_tbl_waitq);
1147 		fallthrough;
1148 	default:
1149 		if (ff_layout_avoid_mds_available_ds(lseg))
1150 			return -NFS4ERR_RESET_TO_PNFS;
1151 reset:
1152 		dprintk("%s Retry through MDS. Error %d\n", __func__,
1153 			task->tk_status);
1154 		return -NFS4ERR_RESET_TO_MDS;
1155 	}
1156 	task->tk_status = 0;
1157 	return -EAGAIN;
1158 }
1159 
1160 /* Retry all errors through either pNFS or MDS except for -EJUKEBOX */
1161 static int ff_layout_async_handle_error_v3(struct rpc_task *task,
1162 					   struct pnfs_layout_segment *lseg,
1163 					   u32 idx)
1164 {
1165 	struct nfs4_deviceid_node *devid = FF_LAYOUT_DEVID_NODE(lseg, idx);
1166 
1167 	switch (task->tk_status) {
1168 	/* File access problems. Don't mark the device as unavailable */
1169 	case -EACCES:
1170 	case -ESTALE:
1171 	case -EISDIR:
1172 	case -EBADHANDLE:
1173 	case -ELOOP:
1174 	case -ENOSPC:
1175 		break;
1176 	case -EJUKEBOX:
1177 		nfs_inc_stats(lseg->pls_layout->plh_inode, NFSIOS_DELAY);
1178 		goto out_retry;
1179 	default:
1180 		dprintk("%s DS connection error %d\n", __func__,
1181 			task->tk_status);
1182 		nfs4_delete_deviceid(devid->ld, devid->nfs_client,
1183 				&devid->deviceid);
1184 	}
1185 	/* FIXME: Need to prevent infinite looping here. */
1186 	return -NFS4ERR_RESET_TO_PNFS;
1187 out_retry:
1188 	task->tk_status = 0;
1189 	rpc_restart_call_prepare(task);
1190 	rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
1191 	return -EAGAIN;
1192 }
1193 
1194 static int ff_layout_async_handle_error(struct rpc_task *task,
1195 					struct nfs4_state *state,
1196 					struct nfs_client *clp,
1197 					struct pnfs_layout_segment *lseg,
1198 					u32 idx)
1199 {
1200 	int vers = clp->cl_nfs_mod->rpc_vers->number;
1201 
1202 	if (task->tk_status >= 0) {
1203 		ff_layout_mark_ds_reachable(lseg, idx);
1204 		return 0;
1205 	}
1206 
1207 	/* Handle the case of an invalid layout segment */
1208 	if (!pnfs_is_valid_lseg(lseg))
1209 		return -NFS4ERR_RESET_TO_PNFS;
1210 
1211 	switch (vers) {
1212 	case 3:
1213 		return ff_layout_async_handle_error_v3(task, lseg, idx);
1214 	case 4:
1215 		return ff_layout_async_handle_error_v4(task, state, clp,
1216 						       lseg, idx);
1217 	default:
1218 		/* should never happen */
1219 		WARN_ON_ONCE(1);
1220 		return 0;
1221 	}
1222 }
1223 
1224 static void ff_layout_io_track_ds_error(struct pnfs_layout_segment *lseg,
1225 					u32 idx, u64 offset, u64 length,
1226 					u32 *op_status, int opnum, int error)
1227 {
1228 	struct nfs4_ff_layout_mirror *mirror;
1229 	u32 status = *op_status;
1230 	int err;
1231 
1232 	if (status == 0) {
1233 		switch (error) {
1234 		case -ETIMEDOUT:
1235 		case -EPFNOSUPPORT:
1236 		case -EPROTONOSUPPORT:
1237 		case -EOPNOTSUPP:
1238 		case -EINVAL:
1239 		case -ECONNREFUSED:
1240 		case -ECONNRESET:
1241 		case -EHOSTDOWN:
1242 		case -EHOSTUNREACH:
1243 		case -ENETUNREACH:
1244 		case -EADDRINUSE:
1245 		case -ENOBUFS:
1246 		case -EPIPE:
1247 		case -EPERM:
1248 		case -EPROTO:
1249 		case -ENODEV:
1250 			*op_status = status = NFS4ERR_NXIO;
1251 			break;
1252 		case -EACCES:
1253 			*op_status = status = NFS4ERR_ACCESS;
1254 			break;
1255 		default:
1256 			return;
1257 		}
1258 	}
1259 
1260 	mirror = FF_LAYOUT_COMP(lseg, idx);
1261 	err = ff_layout_track_ds_error(FF_LAYOUT_FROM_HDR(lseg->pls_layout),
1262 				       mirror, offset, length, status, opnum,
1263 				       nfs_io_gfp_mask());
1264 
1265 	switch (status) {
1266 	case NFS4ERR_DELAY:
1267 	case NFS4ERR_GRACE:
1268 		break;
1269 	case NFS4ERR_NXIO:
1270 		ff_layout_mark_ds_unreachable(lseg, idx);
1271 		/*
1272 		 * Don't return the layout if this is a read and we still
1273 		 * have layouts to try
1274 		 */
1275 		if (opnum == OP_READ)
1276 			break;
1277 		fallthrough;
1278 	default:
1279 		pnfs_error_mark_layout_for_return(lseg->pls_layout->plh_inode,
1280 						  lseg);
1281 	}
1282 
1283 	dprintk("%s: err %d op %d status %u\n", __func__, err, opnum, status);
1284 }
1285 
1286 /* NFS_PROTO call done callback routines */
1287 static int ff_layout_read_done_cb(struct rpc_task *task,
1288 				struct nfs_pgio_header *hdr)
1289 {
1290 	int err;
1291 
1292 	if (task->tk_status < 0) {
1293 		ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1294 					    hdr->args.offset, hdr->args.count,
1295 					    &hdr->res.op_status, OP_READ,
1296 					    task->tk_status);
1297 		trace_ff_layout_read_error(hdr);
1298 	}
1299 
1300 	err = ff_layout_async_handle_error(task, hdr->args.context->state,
1301 					   hdr->ds_clp, hdr->lseg,
1302 					   hdr->pgio_mirror_idx);
1303 
1304 	trace_nfs4_pnfs_read(hdr, err);
1305 	clear_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1306 	clear_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1307 	switch (err) {
1308 	case -NFS4ERR_RESET_TO_PNFS:
1309 		set_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1310 		return task->tk_status;
1311 	case -NFS4ERR_RESET_TO_MDS:
1312 		set_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1313 		return task->tk_status;
1314 	case -EAGAIN:
1315 		goto out_eagain;
1316 	}
1317 
1318 	return 0;
1319 out_eagain:
1320 	rpc_restart_call_prepare(task);
1321 	return -EAGAIN;
1322 }
1323 
1324 static bool
1325 ff_layout_need_layoutcommit(struct pnfs_layout_segment *lseg)
1326 {
1327 	return !(FF_LAYOUT_LSEG(lseg)->flags & FF_FLAGS_NO_LAYOUTCOMMIT);
1328 }
1329 
1330 /*
1331  * We reference the rpc_cred of the first WRITE that triggers the need for
1332  * a LAYOUTCOMMIT, and use it to send the layoutcommit compound.
1333  * rfc5661 is not clear about which credential should be used.
1334  *
1335  * Flexlayout client should treat DS replied FILE_SYNC as DATA_SYNC, so
1336  * to follow http://www.rfc-editor.org/errata_search.php?rfc=5661&eid=2751
1337  * we always send layoutcommit after DS writes.
1338  */
1339 static void
1340 ff_layout_set_layoutcommit(struct inode *inode,
1341 		struct pnfs_layout_segment *lseg,
1342 		loff_t end_offset)
1343 {
1344 	if (!ff_layout_need_layoutcommit(lseg))
1345 		return;
1346 
1347 	pnfs_set_layoutcommit(inode, lseg, end_offset);
1348 	dprintk("%s inode %lu pls_end_pos %llu\n", __func__, inode->i_ino,
1349 		(unsigned long long) NFS_I(inode)->layout->plh_lwb);
1350 }
1351 
1352 static void ff_layout_read_record_layoutstats_start(struct rpc_task *task,
1353 		struct nfs_pgio_header *hdr)
1354 {
1355 	if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1356 		return;
1357 	nfs4_ff_layout_stat_io_start_read(hdr->inode,
1358 			FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1359 			hdr->args.count,
1360 			task->tk_start);
1361 }
1362 
1363 static void ff_layout_read_record_layoutstats_done(struct rpc_task *task,
1364 		struct nfs_pgio_header *hdr)
1365 {
1366 	if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1367 		return;
1368 	nfs4_ff_layout_stat_io_end_read(task,
1369 			FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1370 			hdr->args.count,
1371 			hdr->res.count);
1372 	set_bit(NFS_LSEG_LAYOUTRETURN, &hdr->lseg->pls_flags);
1373 }
1374 
1375 static int ff_layout_read_prepare_common(struct rpc_task *task,
1376 					 struct nfs_pgio_header *hdr)
1377 {
1378 	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1379 		rpc_exit(task, -EIO);
1380 		return -EIO;
1381 	}
1382 
1383 	if (!pnfs_is_valid_lseg(hdr->lseg)) {
1384 		rpc_exit(task, -EAGAIN);
1385 		return -EAGAIN;
1386 	}
1387 
1388 	ff_layout_read_record_layoutstats_start(task, hdr);
1389 	return 0;
1390 }
1391 
1392 /*
1393  * Call ops for the async read/write cases
1394  * In the case of dense layouts, the offset needs to be reset to its
1395  * original value.
1396  */
1397 static void ff_layout_read_prepare_v3(struct rpc_task *task, void *data)
1398 {
1399 	struct nfs_pgio_header *hdr = data;
1400 
1401 	if (ff_layout_read_prepare_common(task, hdr))
1402 		return;
1403 
1404 	rpc_call_start(task);
1405 }
1406 
1407 static void ff_layout_read_prepare_v4(struct rpc_task *task, void *data)
1408 {
1409 	struct nfs_pgio_header *hdr = data;
1410 
1411 	if (nfs4_setup_sequence(hdr->ds_clp,
1412 				&hdr->args.seq_args,
1413 				&hdr->res.seq_res,
1414 				task))
1415 		return;
1416 
1417 	ff_layout_read_prepare_common(task, hdr);
1418 }
1419 
1420 static void ff_layout_read_call_done(struct rpc_task *task, void *data)
1421 {
1422 	struct nfs_pgio_header *hdr = data;
1423 
1424 	if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1425 	    task->tk_status == 0) {
1426 		nfs4_sequence_done(task, &hdr->res.seq_res);
1427 		return;
1428 	}
1429 
1430 	/* Note this may cause RPC to be resent */
1431 	hdr->mds_ops->rpc_call_done(task, hdr);
1432 }
1433 
1434 static void ff_layout_read_count_stats(struct rpc_task *task, void *data)
1435 {
1436 	struct nfs_pgio_header *hdr = data;
1437 
1438 	ff_layout_read_record_layoutstats_done(task, hdr);
1439 	rpc_count_iostats_metrics(task,
1440 	    &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_READ]);
1441 }
1442 
1443 static void ff_layout_read_release(void *data)
1444 {
1445 	struct nfs_pgio_header *hdr = data;
1446 
1447 	ff_layout_read_record_layoutstats_done(&hdr->task, hdr);
1448 	if (test_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags))
1449 		ff_layout_resend_pnfs_read(hdr);
1450 	else if (test_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags))
1451 		ff_layout_reset_read(hdr);
1452 	pnfs_generic_rw_release(data);
1453 }
1454 
1455 
1456 static int ff_layout_write_done_cb(struct rpc_task *task,
1457 				struct nfs_pgio_header *hdr)
1458 {
1459 	loff_t end_offs = 0;
1460 	int err;
1461 
1462 	if (task->tk_status < 0) {
1463 		ff_layout_io_track_ds_error(hdr->lseg, hdr->pgio_mirror_idx,
1464 					    hdr->args.offset, hdr->args.count,
1465 					    &hdr->res.op_status, OP_WRITE,
1466 					    task->tk_status);
1467 		trace_ff_layout_write_error(hdr);
1468 	}
1469 
1470 	err = ff_layout_async_handle_error(task, hdr->args.context->state,
1471 					   hdr->ds_clp, hdr->lseg,
1472 					   hdr->pgio_mirror_idx);
1473 
1474 	trace_nfs4_pnfs_write(hdr, err);
1475 	clear_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1476 	clear_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1477 	switch (err) {
1478 	case -NFS4ERR_RESET_TO_PNFS:
1479 		set_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags);
1480 		return task->tk_status;
1481 	case -NFS4ERR_RESET_TO_MDS:
1482 		set_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags);
1483 		return task->tk_status;
1484 	case -EAGAIN:
1485 		return -EAGAIN;
1486 	}
1487 
1488 	if (hdr->res.verf->committed == NFS_FILE_SYNC ||
1489 	    hdr->res.verf->committed == NFS_DATA_SYNC)
1490 		end_offs = hdr->mds_offset + (loff_t)hdr->res.count;
1491 
1492 	/* Note: if the write is unstable, don't set end_offs until commit */
1493 	ff_layout_set_layoutcommit(hdr->inode, hdr->lseg, end_offs);
1494 
1495 	/* zero out fattr since we don't care DS attr at all */
1496 	hdr->fattr.valid = 0;
1497 	if (task->tk_status >= 0)
1498 		nfs_writeback_update_inode(hdr);
1499 
1500 	return 0;
1501 }
1502 
1503 static int ff_layout_commit_done_cb(struct rpc_task *task,
1504 				     struct nfs_commit_data *data)
1505 {
1506 	int err;
1507 
1508 	if (task->tk_status < 0) {
1509 		ff_layout_io_track_ds_error(data->lseg, data->ds_commit_index,
1510 					    data->args.offset, data->args.count,
1511 					    &data->res.op_status, OP_COMMIT,
1512 					    task->tk_status);
1513 		trace_ff_layout_commit_error(data);
1514 	}
1515 
1516 	err = ff_layout_async_handle_error(task, NULL, data->ds_clp,
1517 					   data->lseg, data->ds_commit_index);
1518 
1519 	trace_nfs4_pnfs_commit_ds(data, err);
1520 	switch (err) {
1521 	case -NFS4ERR_RESET_TO_PNFS:
1522 		pnfs_generic_prepare_to_resend_writes(data);
1523 		return -EAGAIN;
1524 	case -NFS4ERR_RESET_TO_MDS:
1525 		pnfs_generic_prepare_to_resend_writes(data);
1526 		return -EAGAIN;
1527 	case -EAGAIN:
1528 		rpc_restart_call_prepare(task);
1529 		return -EAGAIN;
1530 	}
1531 
1532 	ff_layout_set_layoutcommit(data->inode, data->lseg, data->lwb);
1533 
1534 	return 0;
1535 }
1536 
1537 static void ff_layout_write_record_layoutstats_start(struct rpc_task *task,
1538 		struct nfs_pgio_header *hdr)
1539 {
1540 	if (test_and_set_bit(NFS_IOHDR_STAT, &hdr->flags))
1541 		return;
1542 	nfs4_ff_layout_stat_io_start_write(hdr->inode,
1543 			FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1544 			hdr->args.count,
1545 			task->tk_start);
1546 }
1547 
1548 static void ff_layout_write_record_layoutstats_done(struct rpc_task *task,
1549 		struct nfs_pgio_header *hdr)
1550 {
1551 	if (!test_and_clear_bit(NFS_IOHDR_STAT, &hdr->flags))
1552 		return;
1553 	nfs4_ff_layout_stat_io_end_write(task,
1554 			FF_LAYOUT_COMP(hdr->lseg, hdr->pgio_mirror_idx),
1555 			hdr->args.count, hdr->res.count,
1556 			hdr->res.verf->committed);
1557 	set_bit(NFS_LSEG_LAYOUTRETURN, &hdr->lseg->pls_flags);
1558 }
1559 
1560 static int ff_layout_write_prepare_common(struct rpc_task *task,
1561 					  struct nfs_pgio_header *hdr)
1562 {
1563 	if (unlikely(test_bit(NFS_CONTEXT_BAD, &hdr->args.context->flags))) {
1564 		rpc_exit(task, -EIO);
1565 		return -EIO;
1566 	}
1567 
1568 	if (!pnfs_is_valid_lseg(hdr->lseg)) {
1569 		rpc_exit(task, -EAGAIN);
1570 		return -EAGAIN;
1571 	}
1572 
1573 	ff_layout_write_record_layoutstats_start(task, hdr);
1574 	return 0;
1575 }
1576 
1577 static void ff_layout_write_prepare_v3(struct rpc_task *task, void *data)
1578 {
1579 	struct nfs_pgio_header *hdr = data;
1580 
1581 	if (ff_layout_write_prepare_common(task, hdr))
1582 		return;
1583 
1584 	rpc_call_start(task);
1585 }
1586 
1587 static void ff_layout_write_prepare_v4(struct rpc_task *task, void *data)
1588 {
1589 	struct nfs_pgio_header *hdr = data;
1590 
1591 	if (nfs4_setup_sequence(hdr->ds_clp,
1592 				&hdr->args.seq_args,
1593 				&hdr->res.seq_res,
1594 				task))
1595 		return;
1596 
1597 	ff_layout_write_prepare_common(task, hdr);
1598 }
1599 
1600 static void ff_layout_write_call_done(struct rpc_task *task, void *data)
1601 {
1602 	struct nfs_pgio_header *hdr = data;
1603 
1604 	if (test_bit(NFS_IOHDR_REDO, &hdr->flags) &&
1605 	    task->tk_status == 0) {
1606 		nfs4_sequence_done(task, &hdr->res.seq_res);
1607 		return;
1608 	}
1609 
1610 	/* Note this may cause RPC to be resent */
1611 	hdr->mds_ops->rpc_call_done(task, hdr);
1612 }
1613 
1614 static void ff_layout_write_count_stats(struct rpc_task *task, void *data)
1615 {
1616 	struct nfs_pgio_header *hdr = data;
1617 
1618 	ff_layout_write_record_layoutstats_done(task, hdr);
1619 	rpc_count_iostats_metrics(task,
1620 	    &NFS_CLIENT(hdr->inode)->cl_metrics[NFSPROC4_CLNT_WRITE]);
1621 }
1622 
1623 static void ff_layout_write_release(void *data)
1624 {
1625 	struct nfs_pgio_header *hdr = data;
1626 
1627 	ff_layout_write_record_layoutstats_done(&hdr->task, hdr);
1628 	if (test_bit(NFS_IOHDR_RESEND_PNFS, &hdr->flags)) {
1629 		ff_layout_send_layouterror(hdr->lseg);
1630 		ff_layout_reset_write(hdr, true);
1631 	} else if (test_bit(NFS_IOHDR_RESEND_MDS, &hdr->flags))
1632 		ff_layout_reset_write(hdr, false);
1633 	pnfs_generic_rw_release(data);
1634 }
1635 
1636 static void ff_layout_commit_record_layoutstats_start(struct rpc_task *task,
1637 		struct nfs_commit_data *cdata)
1638 {
1639 	if (test_and_set_bit(NFS_IOHDR_STAT, &cdata->flags))
1640 		return;
1641 	nfs4_ff_layout_stat_io_start_write(cdata->inode,
1642 			FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1643 			0, task->tk_start);
1644 }
1645 
1646 static void ff_layout_commit_record_layoutstats_done(struct rpc_task *task,
1647 		struct nfs_commit_data *cdata)
1648 {
1649 	struct nfs_page *req;
1650 	__u64 count = 0;
1651 
1652 	if (!test_and_clear_bit(NFS_IOHDR_STAT, &cdata->flags))
1653 		return;
1654 
1655 	if (task->tk_status == 0) {
1656 		list_for_each_entry(req, &cdata->pages, wb_list)
1657 			count += req->wb_bytes;
1658 	}
1659 	nfs4_ff_layout_stat_io_end_write(task,
1660 			FF_LAYOUT_COMP(cdata->lseg, cdata->ds_commit_index),
1661 			count, count, NFS_FILE_SYNC);
1662 	set_bit(NFS_LSEG_LAYOUTRETURN, &cdata->lseg->pls_flags);
1663 }
1664 
1665 static int ff_layout_commit_prepare_common(struct rpc_task *task,
1666 					   struct nfs_commit_data *cdata)
1667 {
1668 	if (!pnfs_is_valid_lseg(cdata->lseg)) {
1669 		rpc_exit(task, -EAGAIN);
1670 		return -EAGAIN;
1671 	}
1672 
1673 	ff_layout_commit_record_layoutstats_start(task, cdata);
1674 	return 0;
1675 }
1676 
1677 static void ff_layout_commit_prepare_v3(struct rpc_task *task, void *data)
1678 {
1679 	if (ff_layout_commit_prepare_common(task, data))
1680 		return;
1681 
1682 	rpc_call_start(task);
1683 }
1684 
1685 static void ff_layout_commit_prepare_v4(struct rpc_task *task, void *data)
1686 {
1687 	struct nfs_commit_data *wdata = data;
1688 
1689 	if (nfs4_setup_sequence(wdata->ds_clp,
1690 				&wdata->args.seq_args,
1691 				&wdata->res.seq_res,
1692 				task))
1693 		return;
1694 	ff_layout_commit_prepare_common(task, data);
1695 }
1696 
1697 static void ff_layout_commit_done(struct rpc_task *task, void *data)
1698 {
1699 	pnfs_generic_write_commit_done(task, data);
1700 }
1701 
1702 static void ff_layout_commit_count_stats(struct rpc_task *task, void *data)
1703 {
1704 	struct nfs_commit_data *cdata = data;
1705 
1706 	ff_layout_commit_record_layoutstats_done(task, cdata);
1707 	rpc_count_iostats_metrics(task,
1708 	    &NFS_CLIENT(cdata->inode)->cl_metrics[NFSPROC4_CLNT_COMMIT]);
1709 }
1710 
1711 static void ff_layout_commit_release(void *data)
1712 {
1713 	struct nfs_commit_data *cdata = data;
1714 
1715 	ff_layout_commit_record_layoutstats_done(&cdata->task, cdata);
1716 	pnfs_generic_commit_release(data);
1717 }
1718 
1719 static const struct rpc_call_ops ff_layout_read_call_ops_v3 = {
1720 	.rpc_call_prepare = ff_layout_read_prepare_v3,
1721 	.rpc_call_done = ff_layout_read_call_done,
1722 	.rpc_count_stats = ff_layout_read_count_stats,
1723 	.rpc_release = ff_layout_read_release,
1724 };
1725 
1726 static const struct rpc_call_ops ff_layout_read_call_ops_v4 = {
1727 	.rpc_call_prepare = ff_layout_read_prepare_v4,
1728 	.rpc_call_done = ff_layout_read_call_done,
1729 	.rpc_count_stats = ff_layout_read_count_stats,
1730 	.rpc_release = ff_layout_read_release,
1731 };
1732 
1733 static const struct rpc_call_ops ff_layout_write_call_ops_v3 = {
1734 	.rpc_call_prepare = ff_layout_write_prepare_v3,
1735 	.rpc_call_done = ff_layout_write_call_done,
1736 	.rpc_count_stats = ff_layout_write_count_stats,
1737 	.rpc_release = ff_layout_write_release,
1738 };
1739 
1740 static const struct rpc_call_ops ff_layout_write_call_ops_v4 = {
1741 	.rpc_call_prepare = ff_layout_write_prepare_v4,
1742 	.rpc_call_done = ff_layout_write_call_done,
1743 	.rpc_count_stats = ff_layout_write_count_stats,
1744 	.rpc_release = ff_layout_write_release,
1745 };
1746 
1747 static const struct rpc_call_ops ff_layout_commit_call_ops_v3 = {
1748 	.rpc_call_prepare = ff_layout_commit_prepare_v3,
1749 	.rpc_call_done = ff_layout_commit_done,
1750 	.rpc_count_stats = ff_layout_commit_count_stats,
1751 	.rpc_release = ff_layout_commit_release,
1752 };
1753 
1754 static const struct rpc_call_ops ff_layout_commit_call_ops_v4 = {
1755 	.rpc_call_prepare = ff_layout_commit_prepare_v4,
1756 	.rpc_call_done = ff_layout_commit_done,
1757 	.rpc_count_stats = ff_layout_commit_count_stats,
1758 	.rpc_release = ff_layout_commit_release,
1759 };
1760 
1761 static enum pnfs_try_status
1762 ff_layout_read_pagelist(struct nfs_pgio_header *hdr)
1763 {
1764 	struct pnfs_layout_segment *lseg = hdr->lseg;
1765 	struct nfs4_pnfs_ds *ds;
1766 	struct rpc_clnt *ds_clnt;
1767 	struct nfs4_ff_layout_mirror *mirror;
1768 	const struct cred *ds_cred;
1769 	loff_t offset = hdr->args.offset;
1770 	u32 idx = hdr->pgio_mirror_idx;
1771 	int vers;
1772 	struct nfs_fh *fh;
1773 
1774 	dprintk("--> %s ino %lu pgbase %u req %zu@%llu\n",
1775 		__func__, hdr->inode->i_ino,
1776 		hdr->args.pgbase, (size_t)hdr->args.count, offset);
1777 
1778 	mirror = FF_LAYOUT_COMP(lseg, idx);
1779 	ds = nfs4_ff_layout_prepare_ds(lseg, mirror, false);
1780 	if (!ds)
1781 		goto out_failed;
1782 
1783 	ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
1784 						   hdr->inode);
1785 	if (IS_ERR(ds_clnt))
1786 		goto out_failed;
1787 
1788 	ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, hdr->cred);
1789 	if (!ds_cred)
1790 		goto out_failed;
1791 
1792 	vers = nfs4_ff_layout_ds_version(mirror);
1793 
1794 	dprintk("%s USE DS: %s cl_count %d vers %d\n", __func__,
1795 		ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count), vers);
1796 
1797 	hdr->pgio_done_cb = ff_layout_read_done_cb;
1798 	refcount_inc(&ds->ds_clp->cl_count);
1799 	hdr->ds_clp = ds->ds_clp;
1800 	fh = nfs4_ff_layout_select_ds_fh(mirror);
1801 	if (fh)
1802 		hdr->args.fh = fh;
1803 
1804 	nfs4_ff_layout_select_ds_stateid(mirror, &hdr->args.stateid);
1805 
1806 	/*
1807 	 * Note that if we ever decide to split across DSes,
1808 	 * then we may need to handle dense-like offsets.
1809 	 */
1810 	hdr->args.offset = offset;
1811 	hdr->mds_offset = offset;
1812 
1813 	/* Perform an asynchronous read to ds */
1814 	nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1815 			  vers == 3 ? &ff_layout_read_call_ops_v3 :
1816 				      &ff_layout_read_call_ops_v4,
1817 			  0, RPC_TASK_SOFTCONN);
1818 	put_cred(ds_cred);
1819 	return PNFS_ATTEMPTED;
1820 
1821 out_failed:
1822 	if (ff_layout_avoid_mds_available_ds(lseg))
1823 		return PNFS_TRY_AGAIN;
1824 	trace_pnfs_mds_fallback_read_pagelist(hdr->inode,
1825 			hdr->args.offset, hdr->args.count,
1826 			IOMODE_READ, NFS_I(hdr->inode)->layout, lseg);
1827 	return PNFS_NOT_ATTEMPTED;
1828 }
1829 
1830 /* Perform async writes. */
1831 static enum pnfs_try_status
1832 ff_layout_write_pagelist(struct nfs_pgio_header *hdr, int sync)
1833 {
1834 	struct pnfs_layout_segment *lseg = hdr->lseg;
1835 	struct nfs4_pnfs_ds *ds;
1836 	struct rpc_clnt *ds_clnt;
1837 	struct nfs4_ff_layout_mirror *mirror;
1838 	const struct cred *ds_cred;
1839 	loff_t offset = hdr->args.offset;
1840 	int vers;
1841 	struct nfs_fh *fh;
1842 	u32 idx = hdr->pgio_mirror_idx;
1843 
1844 	mirror = FF_LAYOUT_COMP(lseg, idx);
1845 	ds = nfs4_ff_layout_prepare_ds(lseg, mirror, true);
1846 	if (!ds)
1847 		goto out_failed;
1848 
1849 	ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
1850 						   hdr->inode);
1851 	if (IS_ERR(ds_clnt))
1852 		goto out_failed;
1853 
1854 	ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, hdr->cred);
1855 	if (!ds_cred)
1856 		goto out_failed;
1857 
1858 	vers = nfs4_ff_layout_ds_version(mirror);
1859 
1860 	dprintk("%s ino %lu sync %d req %zu@%llu DS: %s cl_count %d vers %d\n",
1861 		__func__, hdr->inode->i_ino, sync, (size_t) hdr->args.count,
1862 		offset, ds->ds_remotestr, refcount_read(&ds->ds_clp->cl_count),
1863 		vers);
1864 
1865 	hdr->pgio_done_cb = ff_layout_write_done_cb;
1866 	refcount_inc(&ds->ds_clp->cl_count);
1867 	hdr->ds_clp = ds->ds_clp;
1868 	hdr->ds_commit_idx = idx;
1869 	fh = nfs4_ff_layout_select_ds_fh(mirror);
1870 	if (fh)
1871 		hdr->args.fh = fh;
1872 
1873 	nfs4_ff_layout_select_ds_stateid(mirror, &hdr->args.stateid);
1874 
1875 	/*
1876 	 * Note that if we ever decide to split across DSes,
1877 	 * then we may need to handle dense-like offsets.
1878 	 */
1879 	hdr->args.offset = offset;
1880 
1881 	/* Perform an asynchronous write */
1882 	nfs_initiate_pgio(ds_clnt, hdr, ds_cred, ds->ds_clp->rpc_ops,
1883 			  vers == 3 ? &ff_layout_write_call_ops_v3 :
1884 				      &ff_layout_write_call_ops_v4,
1885 			  sync, RPC_TASK_SOFTCONN);
1886 	put_cred(ds_cred);
1887 	return PNFS_ATTEMPTED;
1888 
1889 out_failed:
1890 	if (ff_layout_avoid_mds_available_ds(lseg))
1891 		return PNFS_TRY_AGAIN;
1892 	trace_pnfs_mds_fallback_write_pagelist(hdr->inode,
1893 			hdr->args.offset, hdr->args.count,
1894 			IOMODE_RW, NFS_I(hdr->inode)->layout, lseg);
1895 	return PNFS_NOT_ATTEMPTED;
1896 }
1897 
1898 static u32 calc_ds_index_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1899 {
1900 	return i;
1901 }
1902 
1903 static struct nfs_fh *
1904 select_ds_fh_from_commit(struct pnfs_layout_segment *lseg, u32 i)
1905 {
1906 	struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
1907 
1908 	/* FIXME: Assume that there is only one NFS version available
1909 	 * for the DS.
1910 	 */
1911 	return &flseg->mirror_array[i]->fh_versions[0];
1912 }
1913 
1914 static int ff_layout_initiate_commit(struct nfs_commit_data *data, int how)
1915 {
1916 	struct pnfs_layout_segment *lseg = data->lseg;
1917 	struct nfs4_pnfs_ds *ds;
1918 	struct rpc_clnt *ds_clnt;
1919 	struct nfs4_ff_layout_mirror *mirror;
1920 	const struct cred *ds_cred;
1921 	u32 idx;
1922 	int vers, ret;
1923 	struct nfs_fh *fh;
1924 
1925 	if (!lseg || !(pnfs_is_valid_lseg(lseg) ||
1926 	    test_bit(NFS_LSEG_LAYOUTRETURN, &lseg->pls_flags)))
1927 		goto out_err;
1928 
1929 	idx = calc_ds_index_from_commit(lseg, data->ds_commit_index);
1930 	mirror = FF_LAYOUT_COMP(lseg, idx);
1931 	ds = nfs4_ff_layout_prepare_ds(lseg, mirror, true);
1932 	if (!ds)
1933 		goto out_err;
1934 
1935 	ds_clnt = nfs4_ff_find_or_create_ds_client(mirror, ds->ds_clp,
1936 						   data->inode);
1937 	if (IS_ERR(ds_clnt))
1938 		goto out_err;
1939 
1940 	ds_cred = ff_layout_get_ds_cred(mirror, &lseg->pls_range, data->cred);
1941 	if (!ds_cred)
1942 		goto out_err;
1943 
1944 	vers = nfs4_ff_layout_ds_version(mirror);
1945 
1946 	dprintk("%s ino %lu, how %d cl_count %d vers %d\n", __func__,
1947 		data->inode->i_ino, how, refcount_read(&ds->ds_clp->cl_count),
1948 		vers);
1949 	data->commit_done_cb = ff_layout_commit_done_cb;
1950 	data->cred = ds_cred;
1951 	refcount_inc(&ds->ds_clp->cl_count);
1952 	data->ds_clp = ds->ds_clp;
1953 	fh = select_ds_fh_from_commit(lseg, data->ds_commit_index);
1954 	if (fh)
1955 		data->args.fh = fh;
1956 
1957 	ret = nfs_initiate_commit(ds_clnt, data, ds->ds_clp->rpc_ops,
1958 				   vers == 3 ? &ff_layout_commit_call_ops_v3 :
1959 					       &ff_layout_commit_call_ops_v4,
1960 				   how, RPC_TASK_SOFTCONN);
1961 	put_cred(ds_cred);
1962 	return ret;
1963 out_err:
1964 	pnfs_generic_prepare_to_resend_writes(data);
1965 	pnfs_generic_commit_release(data);
1966 	return -EAGAIN;
1967 }
1968 
1969 static int
1970 ff_layout_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
1971 			   int how, struct nfs_commit_info *cinfo)
1972 {
1973 	return pnfs_generic_commit_pagelist(inode, mds_pages, how, cinfo,
1974 					    ff_layout_initiate_commit);
1975 }
1976 
1977 static bool ff_layout_match_rw(const struct rpc_task *task,
1978 			       const struct nfs_pgio_header *hdr,
1979 			       const struct pnfs_layout_segment *lseg)
1980 {
1981 	return hdr->lseg == lseg;
1982 }
1983 
1984 static bool ff_layout_match_commit(const struct rpc_task *task,
1985 				   const struct nfs_commit_data *cdata,
1986 				   const struct pnfs_layout_segment *lseg)
1987 {
1988 	return cdata->lseg == lseg;
1989 }
1990 
1991 static bool ff_layout_match_io(const struct rpc_task *task, const void *data)
1992 {
1993 	const struct rpc_call_ops *ops = task->tk_ops;
1994 
1995 	if (ops == &ff_layout_read_call_ops_v3 ||
1996 	    ops == &ff_layout_read_call_ops_v4 ||
1997 	    ops == &ff_layout_write_call_ops_v3 ||
1998 	    ops == &ff_layout_write_call_ops_v4)
1999 		return ff_layout_match_rw(task, task->tk_calldata, data);
2000 	if (ops == &ff_layout_commit_call_ops_v3 ||
2001 	    ops == &ff_layout_commit_call_ops_v4)
2002 		return ff_layout_match_commit(task, task->tk_calldata, data);
2003 	return false;
2004 }
2005 
2006 static void ff_layout_cancel_io(struct pnfs_layout_segment *lseg)
2007 {
2008 	struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
2009 	struct nfs4_ff_layout_mirror *mirror;
2010 	struct nfs4_ff_layout_ds *mirror_ds;
2011 	struct nfs4_pnfs_ds *ds;
2012 	struct nfs_client *ds_clp;
2013 	struct rpc_clnt *clnt;
2014 	u32 idx;
2015 
2016 	for (idx = 0; idx < flseg->mirror_array_cnt; idx++) {
2017 		mirror = flseg->mirror_array[idx];
2018 		mirror_ds = mirror->mirror_ds;
2019 		if (IS_ERR_OR_NULL(mirror_ds))
2020 			continue;
2021 		ds = mirror->mirror_ds->ds;
2022 		if (!ds)
2023 			continue;
2024 		ds_clp = ds->ds_clp;
2025 		if (!ds_clp)
2026 			continue;
2027 		clnt = ds_clp->cl_rpcclient;
2028 		if (!clnt)
2029 			continue;
2030 		if (!rpc_cancel_tasks(clnt, -EAGAIN, ff_layout_match_io, lseg))
2031 			continue;
2032 		rpc_clnt_disconnect(clnt);
2033 	}
2034 }
2035 
2036 static struct pnfs_ds_commit_info *
2037 ff_layout_get_ds_info(struct inode *inode)
2038 {
2039 	struct pnfs_layout_hdr *layout = NFS_I(inode)->layout;
2040 
2041 	if (layout == NULL)
2042 		return NULL;
2043 
2044 	return &FF_LAYOUT_FROM_HDR(layout)->commit_info;
2045 }
2046 
2047 static void
2048 ff_layout_setup_ds_info(struct pnfs_ds_commit_info *fl_cinfo,
2049 		struct pnfs_layout_segment *lseg)
2050 {
2051 	struct nfs4_ff_layout_segment *flseg = FF_LAYOUT_LSEG(lseg);
2052 	struct inode *inode = lseg->pls_layout->plh_inode;
2053 	struct pnfs_commit_array *array, *new;
2054 
2055 	new = pnfs_alloc_commit_array(flseg->mirror_array_cnt,
2056 				      nfs_io_gfp_mask());
2057 	if (new) {
2058 		spin_lock(&inode->i_lock);
2059 		array = pnfs_add_commit_array(fl_cinfo, new, lseg);
2060 		spin_unlock(&inode->i_lock);
2061 		if (array != new)
2062 			pnfs_free_commit_array(new);
2063 	}
2064 }
2065 
2066 static void
2067 ff_layout_release_ds_info(struct pnfs_ds_commit_info *fl_cinfo,
2068 		struct inode *inode)
2069 {
2070 	spin_lock(&inode->i_lock);
2071 	pnfs_generic_ds_cinfo_destroy(fl_cinfo);
2072 	spin_unlock(&inode->i_lock);
2073 }
2074 
2075 static void
2076 ff_layout_free_deviceid_node(struct nfs4_deviceid_node *d)
2077 {
2078 	nfs4_ff_layout_free_deviceid(container_of(d, struct nfs4_ff_layout_ds,
2079 						  id_node));
2080 }
2081 
2082 static int ff_layout_encode_ioerr(struct xdr_stream *xdr,
2083 				  const struct nfs4_layoutreturn_args *args,
2084 				  const struct nfs4_flexfile_layoutreturn_args *ff_args)
2085 {
2086 	__be32 *start;
2087 
2088 	start = xdr_reserve_space(xdr, 4);
2089 	if (unlikely(!start))
2090 		return -E2BIG;
2091 
2092 	*start = cpu_to_be32(ff_args->num_errors);
2093 	/* This assume we always return _ALL_ layouts */
2094 	return ff_layout_encode_ds_ioerr(xdr, &ff_args->errors);
2095 }
2096 
2097 static void
2098 encode_opaque_fixed(struct xdr_stream *xdr, const void *buf, size_t len)
2099 {
2100 	WARN_ON_ONCE(xdr_stream_encode_opaque_fixed(xdr, buf, len) < 0);
2101 }
2102 
2103 static void
2104 ff_layout_encode_ff_iostat_head(struct xdr_stream *xdr,
2105 			    const nfs4_stateid *stateid,
2106 			    const struct nfs42_layoutstat_devinfo *devinfo)
2107 {
2108 	__be32 *p;
2109 
2110 	p = xdr_reserve_space(xdr, 8 + 8);
2111 	p = xdr_encode_hyper(p, devinfo->offset);
2112 	p = xdr_encode_hyper(p, devinfo->length);
2113 	encode_opaque_fixed(xdr, stateid->data, NFS4_STATEID_SIZE);
2114 	p = xdr_reserve_space(xdr, 4*8);
2115 	p = xdr_encode_hyper(p, devinfo->read_count);
2116 	p = xdr_encode_hyper(p, devinfo->read_bytes);
2117 	p = xdr_encode_hyper(p, devinfo->write_count);
2118 	p = xdr_encode_hyper(p, devinfo->write_bytes);
2119 	encode_opaque_fixed(xdr, devinfo->dev_id.data, NFS4_DEVICEID4_SIZE);
2120 }
2121 
2122 static void
2123 ff_layout_encode_ff_iostat(struct xdr_stream *xdr,
2124 			    const nfs4_stateid *stateid,
2125 			    const struct nfs42_layoutstat_devinfo *devinfo)
2126 {
2127 	ff_layout_encode_ff_iostat_head(xdr, stateid, devinfo);
2128 	ff_layout_encode_ff_layoutupdate(xdr, devinfo,
2129 			devinfo->ld_private.data);
2130 }
2131 
2132 /* report nothing for now */
2133 static void ff_layout_encode_iostats_array(struct xdr_stream *xdr,
2134 		const struct nfs4_layoutreturn_args *args,
2135 		struct nfs4_flexfile_layoutreturn_args *ff_args)
2136 {
2137 	__be32 *p;
2138 	int i;
2139 
2140 	p = xdr_reserve_space(xdr, 4);
2141 	*p = cpu_to_be32(ff_args->num_dev);
2142 	for (i = 0; i < ff_args->num_dev; i++)
2143 		ff_layout_encode_ff_iostat(xdr,
2144 				&args->layout->plh_stateid,
2145 				&ff_args->devinfo[i]);
2146 }
2147 
2148 static void
2149 ff_layout_free_iostats_array(struct nfs42_layoutstat_devinfo *devinfo,
2150 		unsigned int num_entries)
2151 {
2152 	unsigned int i;
2153 
2154 	for (i = 0; i < num_entries; i++) {
2155 		if (!devinfo[i].ld_private.ops)
2156 			continue;
2157 		if (!devinfo[i].ld_private.ops->free)
2158 			continue;
2159 		devinfo[i].ld_private.ops->free(&devinfo[i].ld_private);
2160 	}
2161 }
2162 
2163 static struct nfs4_deviceid_node *
2164 ff_layout_alloc_deviceid_node(struct nfs_server *server,
2165 			      struct pnfs_device *pdev, gfp_t gfp_flags)
2166 {
2167 	struct nfs4_ff_layout_ds *dsaddr;
2168 
2169 	dsaddr = nfs4_ff_alloc_deviceid_node(server, pdev, gfp_flags);
2170 	if (!dsaddr)
2171 		return NULL;
2172 	return &dsaddr->id_node;
2173 }
2174 
2175 static void
2176 ff_layout_encode_layoutreturn(struct xdr_stream *xdr,
2177 		const void *voidargs,
2178 		const struct nfs4_xdr_opaque_data *ff_opaque)
2179 {
2180 	const struct nfs4_layoutreturn_args *args = voidargs;
2181 	struct nfs4_flexfile_layoutreturn_args *ff_args = ff_opaque->data;
2182 	struct xdr_buf tmp_buf = {
2183 		.head = {
2184 			[0] = {
2185 				.iov_base = page_address(ff_args->pages[0]),
2186 			},
2187 		},
2188 		.buflen = PAGE_SIZE,
2189 	};
2190 	struct xdr_stream tmp_xdr;
2191 	__be32 *start;
2192 
2193 	dprintk("%s: Begin\n", __func__);
2194 
2195 	xdr_init_encode(&tmp_xdr, &tmp_buf, NULL, NULL);
2196 
2197 	ff_layout_encode_ioerr(&tmp_xdr, args, ff_args);
2198 	ff_layout_encode_iostats_array(&tmp_xdr, args, ff_args);
2199 
2200 	start = xdr_reserve_space(xdr, 4);
2201 	*start = cpu_to_be32(tmp_buf.len);
2202 	xdr_write_pages(xdr, ff_args->pages, 0, tmp_buf.len);
2203 
2204 	dprintk("%s: Return\n", __func__);
2205 }
2206 
2207 static void
2208 ff_layout_free_layoutreturn(struct nfs4_xdr_opaque_data *args)
2209 {
2210 	struct nfs4_flexfile_layoutreturn_args *ff_args;
2211 
2212 	if (!args->data)
2213 		return;
2214 	ff_args = args->data;
2215 	args->data = NULL;
2216 
2217 	ff_layout_free_ds_ioerr(&ff_args->errors);
2218 	ff_layout_free_iostats_array(ff_args->devinfo, ff_args->num_dev);
2219 
2220 	put_page(ff_args->pages[0]);
2221 	kfree(ff_args);
2222 }
2223 
2224 static const struct nfs4_xdr_opaque_ops layoutreturn_ops = {
2225 	.encode = ff_layout_encode_layoutreturn,
2226 	.free = ff_layout_free_layoutreturn,
2227 };
2228 
2229 static int
2230 ff_layout_prepare_layoutreturn(struct nfs4_layoutreturn_args *args)
2231 {
2232 	struct nfs4_flexfile_layoutreturn_args *ff_args;
2233 	struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(args->layout);
2234 
2235 	ff_args = kmalloc(sizeof(*ff_args), nfs_io_gfp_mask());
2236 	if (!ff_args)
2237 		goto out_nomem;
2238 	ff_args->pages[0] = alloc_page(nfs_io_gfp_mask());
2239 	if (!ff_args->pages[0])
2240 		goto out_nomem_free;
2241 
2242 	INIT_LIST_HEAD(&ff_args->errors);
2243 	ff_args->num_errors = ff_layout_fetch_ds_ioerr(args->layout,
2244 			&args->range, &ff_args->errors,
2245 			FF_LAYOUTRETURN_MAXERR);
2246 
2247 	spin_lock(&args->inode->i_lock);
2248 	ff_args->num_dev = ff_layout_mirror_prepare_stats(
2249 		&ff_layout->generic_hdr, &ff_args->devinfo[0],
2250 		ARRAY_SIZE(ff_args->devinfo), NFS4_FF_OP_LAYOUTRETURN);
2251 	spin_unlock(&args->inode->i_lock);
2252 
2253 	args->ld_private->ops = &layoutreturn_ops;
2254 	args->ld_private->data = ff_args;
2255 	return 0;
2256 out_nomem_free:
2257 	kfree(ff_args);
2258 out_nomem:
2259 	return -ENOMEM;
2260 }
2261 
2262 #ifdef CONFIG_NFS_V4_2
2263 void
2264 ff_layout_send_layouterror(struct pnfs_layout_segment *lseg)
2265 {
2266 	struct pnfs_layout_hdr *lo = lseg->pls_layout;
2267 	struct nfs42_layout_error *errors;
2268 	LIST_HEAD(head);
2269 
2270 	if (!nfs_server_capable(lo->plh_inode, NFS_CAP_LAYOUTERROR))
2271 		return;
2272 	ff_layout_fetch_ds_ioerr(lo, &lseg->pls_range, &head, -1);
2273 	if (list_empty(&head))
2274 		return;
2275 
2276 	errors = kmalloc_array(NFS42_LAYOUTERROR_MAX, sizeof(*errors),
2277 			       nfs_io_gfp_mask());
2278 	if (errors != NULL) {
2279 		const struct nfs4_ff_layout_ds_err *pos;
2280 		size_t n = 0;
2281 
2282 		list_for_each_entry(pos, &head, list) {
2283 			errors[n].offset = pos->offset;
2284 			errors[n].length = pos->length;
2285 			nfs4_stateid_copy(&errors[n].stateid, &pos->stateid);
2286 			errors[n].errors[0].dev_id = pos->deviceid;
2287 			errors[n].errors[0].status = pos->status;
2288 			errors[n].errors[0].opnum = pos->opnum;
2289 			n++;
2290 			if (!list_is_last(&pos->list, &head) &&
2291 			    n < NFS42_LAYOUTERROR_MAX)
2292 				continue;
2293 			if (nfs42_proc_layouterror(lseg, errors, n) < 0)
2294 				break;
2295 			n = 0;
2296 		}
2297 		kfree(errors);
2298 	}
2299 	ff_layout_free_ds_ioerr(&head);
2300 }
2301 #else
2302 void
2303 ff_layout_send_layouterror(struct pnfs_layout_segment *lseg)
2304 {
2305 }
2306 #endif
2307 
2308 static int
2309 ff_layout_ntop4(const struct sockaddr *sap, char *buf, const size_t buflen)
2310 {
2311 	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
2312 
2313 	return snprintf(buf, buflen, "%pI4", &sin->sin_addr);
2314 }
2315 
2316 static size_t
2317 ff_layout_ntop6_noscopeid(const struct sockaddr *sap, char *buf,
2318 			  const int buflen)
2319 {
2320 	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
2321 	const struct in6_addr *addr = &sin6->sin6_addr;
2322 
2323 	/*
2324 	 * RFC 4291, Section 2.2.2
2325 	 *
2326 	 * Shorthanded ANY address
2327 	 */
2328 	if (ipv6_addr_any(addr))
2329 		return snprintf(buf, buflen, "::");
2330 
2331 	/*
2332 	 * RFC 4291, Section 2.2.2
2333 	 *
2334 	 * Shorthanded loopback address
2335 	 */
2336 	if (ipv6_addr_loopback(addr))
2337 		return snprintf(buf, buflen, "::1");
2338 
2339 	/*
2340 	 * RFC 4291, Section 2.2.3
2341 	 *
2342 	 * Special presentation address format for mapped v4
2343 	 * addresses.
2344 	 */
2345 	if (ipv6_addr_v4mapped(addr))
2346 		return snprintf(buf, buflen, "::ffff:%pI4",
2347 					&addr->s6_addr32[3]);
2348 
2349 	/*
2350 	 * RFC 4291, Section 2.2.1
2351 	 */
2352 	return snprintf(buf, buflen, "%pI6c", addr);
2353 }
2354 
2355 /* Derived from rpc_sockaddr2uaddr */
2356 static void
2357 ff_layout_encode_netaddr(struct xdr_stream *xdr, struct nfs4_pnfs_ds_addr *da)
2358 {
2359 	struct sockaddr *sap = (struct sockaddr *)&da->da_addr;
2360 	char portbuf[RPCBIND_MAXUADDRPLEN];
2361 	char addrbuf[RPCBIND_MAXUADDRLEN];
2362 	unsigned short port;
2363 	int len, netid_len;
2364 	__be32 *p;
2365 
2366 	switch (sap->sa_family) {
2367 	case AF_INET:
2368 		if (ff_layout_ntop4(sap, addrbuf, sizeof(addrbuf)) == 0)
2369 			return;
2370 		port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2371 		break;
2372 	case AF_INET6:
2373 		if (ff_layout_ntop6_noscopeid(sap, addrbuf, sizeof(addrbuf)) == 0)
2374 			return;
2375 		port = ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
2376 		break;
2377 	default:
2378 		WARN_ON_ONCE(1);
2379 		return;
2380 	}
2381 
2382 	snprintf(portbuf, sizeof(portbuf), ".%u.%u", port >> 8, port & 0xff);
2383 	len = strlcat(addrbuf, portbuf, sizeof(addrbuf));
2384 
2385 	netid_len = strlen(da->da_netid);
2386 	p = xdr_reserve_space(xdr, 4 + netid_len);
2387 	xdr_encode_opaque(p, da->da_netid, netid_len);
2388 
2389 	p = xdr_reserve_space(xdr, 4 + len);
2390 	xdr_encode_opaque(p, addrbuf, len);
2391 }
2392 
2393 static void
2394 ff_layout_encode_nfstime(struct xdr_stream *xdr,
2395 			 ktime_t t)
2396 {
2397 	struct timespec64 ts;
2398 	__be32 *p;
2399 
2400 	p = xdr_reserve_space(xdr, 12);
2401 	ts = ktime_to_timespec64(t);
2402 	p = xdr_encode_hyper(p, ts.tv_sec);
2403 	*p++ = cpu_to_be32(ts.tv_nsec);
2404 }
2405 
2406 static void
2407 ff_layout_encode_io_latency(struct xdr_stream *xdr,
2408 			    struct nfs4_ff_io_stat *stat)
2409 {
2410 	__be32 *p;
2411 
2412 	p = xdr_reserve_space(xdr, 5 * 8);
2413 	p = xdr_encode_hyper(p, stat->ops_requested);
2414 	p = xdr_encode_hyper(p, stat->bytes_requested);
2415 	p = xdr_encode_hyper(p, stat->ops_completed);
2416 	p = xdr_encode_hyper(p, stat->bytes_completed);
2417 	p = xdr_encode_hyper(p, stat->bytes_not_delivered);
2418 	ff_layout_encode_nfstime(xdr, stat->total_busy_time);
2419 	ff_layout_encode_nfstime(xdr, stat->aggregate_completion_time);
2420 }
2421 
2422 static void
2423 ff_layout_encode_ff_layoutupdate(struct xdr_stream *xdr,
2424 			      const struct nfs42_layoutstat_devinfo *devinfo,
2425 			      struct nfs4_ff_layout_mirror *mirror)
2426 {
2427 	struct nfs4_pnfs_ds_addr *da;
2428 	struct nfs4_pnfs_ds *ds = mirror->mirror_ds->ds;
2429 	struct nfs_fh *fh = &mirror->fh_versions[0];
2430 	__be32 *p;
2431 
2432 	da = list_first_entry(&ds->ds_addrs, struct nfs4_pnfs_ds_addr, da_node);
2433 	dprintk("%s: DS %s: encoding address %s\n",
2434 		__func__, ds->ds_remotestr, da->da_remotestr);
2435 	/* netaddr4 */
2436 	ff_layout_encode_netaddr(xdr, da);
2437 	/* nfs_fh4 */
2438 	p = xdr_reserve_space(xdr, 4 + fh->size);
2439 	xdr_encode_opaque(p, fh->data, fh->size);
2440 	/* ff_io_latency4 read */
2441 	spin_lock(&mirror->lock);
2442 	ff_layout_encode_io_latency(xdr, &mirror->read_stat.io_stat);
2443 	/* ff_io_latency4 write */
2444 	ff_layout_encode_io_latency(xdr, &mirror->write_stat.io_stat);
2445 	spin_unlock(&mirror->lock);
2446 	/* nfstime4 */
2447 	ff_layout_encode_nfstime(xdr, ktime_sub(ktime_get(), mirror->start_time));
2448 	/* bool */
2449 	p = xdr_reserve_space(xdr, 4);
2450 	*p = cpu_to_be32(false);
2451 }
2452 
2453 static void
2454 ff_layout_encode_layoutstats(struct xdr_stream *xdr, const void *args,
2455 			     const struct nfs4_xdr_opaque_data *opaque)
2456 {
2457 	struct nfs42_layoutstat_devinfo *devinfo = container_of(opaque,
2458 			struct nfs42_layoutstat_devinfo, ld_private);
2459 	__be32 *start;
2460 
2461 	/* layoutupdate length */
2462 	start = xdr_reserve_space(xdr, 4);
2463 	ff_layout_encode_ff_layoutupdate(xdr, devinfo, opaque->data);
2464 
2465 	*start = cpu_to_be32((xdr->p - start - 1) * 4);
2466 }
2467 
2468 static void
2469 ff_layout_free_layoutstats(struct nfs4_xdr_opaque_data *opaque)
2470 {
2471 	struct nfs4_ff_layout_mirror *mirror = opaque->data;
2472 
2473 	ff_layout_put_mirror(mirror);
2474 }
2475 
2476 static const struct nfs4_xdr_opaque_ops layoutstat_ops = {
2477 	.encode = ff_layout_encode_layoutstats,
2478 	.free	= ff_layout_free_layoutstats,
2479 };
2480 
2481 static int
2482 ff_layout_mirror_prepare_stats(struct pnfs_layout_hdr *lo,
2483 			       struct nfs42_layoutstat_devinfo *devinfo,
2484 			       int dev_limit, enum nfs4_ff_op_type type)
2485 {
2486 	struct nfs4_flexfile_layout *ff_layout = FF_LAYOUT_FROM_HDR(lo);
2487 	struct nfs4_ff_layout_mirror *mirror;
2488 	struct nfs4_deviceid_node *dev;
2489 	int i = 0;
2490 
2491 	list_for_each_entry(mirror, &ff_layout->mirrors, mirrors) {
2492 		if (i >= dev_limit)
2493 			break;
2494 		if (IS_ERR_OR_NULL(mirror->mirror_ds))
2495 			continue;
2496 		if (!test_and_clear_bit(NFS4_FF_MIRROR_STAT_AVAIL,
2497 					&mirror->flags) &&
2498 		    type != NFS4_FF_OP_LAYOUTRETURN)
2499 			continue;
2500 		/* mirror refcount put in cleanup_layoutstats */
2501 		if (!refcount_inc_not_zero(&mirror->ref))
2502 			continue;
2503 		dev = &mirror->mirror_ds->id_node;
2504 		memcpy(&devinfo->dev_id, &dev->deviceid, NFS4_DEVICEID4_SIZE);
2505 		devinfo->offset = 0;
2506 		devinfo->length = NFS4_MAX_UINT64;
2507 		spin_lock(&mirror->lock);
2508 		devinfo->read_count = mirror->read_stat.io_stat.ops_completed;
2509 		devinfo->read_bytes = mirror->read_stat.io_stat.bytes_completed;
2510 		devinfo->write_count = mirror->write_stat.io_stat.ops_completed;
2511 		devinfo->write_bytes = mirror->write_stat.io_stat.bytes_completed;
2512 		spin_unlock(&mirror->lock);
2513 		devinfo->layout_type = LAYOUT_FLEX_FILES;
2514 		devinfo->ld_private.ops = &layoutstat_ops;
2515 		devinfo->ld_private.data = mirror;
2516 
2517 		devinfo++;
2518 		i++;
2519 	}
2520 	return i;
2521 }
2522 
2523 static int ff_layout_prepare_layoutstats(struct nfs42_layoutstat_args *args)
2524 {
2525 	struct pnfs_layout_hdr *lo;
2526 	struct nfs4_flexfile_layout *ff_layout;
2527 	const int dev_count = PNFS_LAYOUTSTATS_MAXDEV;
2528 
2529 	/* For now, send at most PNFS_LAYOUTSTATS_MAXDEV statistics */
2530 	args->devinfo = kmalloc_array(dev_count, sizeof(*args->devinfo),
2531 				      nfs_io_gfp_mask());
2532 	if (!args->devinfo)
2533 		return -ENOMEM;
2534 
2535 	spin_lock(&args->inode->i_lock);
2536 	lo = NFS_I(args->inode)->layout;
2537 	if (lo && pnfs_layout_is_valid(lo)) {
2538 		ff_layout = FF_LAYOUT_FROM_HDR(lo);
2539 		args->num_dev = ff_layout_mirror_prepare_stats(
2540 			&ff_layout->generic_hdr, &args->devinfo[0], dev_count,
2541 			NFS4_FF_OP_LAYOUTSTATS);
2542 	} else
2543 		args->num_dev = 0;
2544 	spin_unlock(&args->inode->i_lock);
2545 	if (!args->num_dev) {
2546 		kfree(args->devinfo);
2547 		args->devinfo = NULL;
2548 		return -ENOENT;
2549 	}
2550 
2551 	return 0;
2552 }
2553 
2554 static int
2555 ff_layout_set_layoutdriver(struct nfs_server *server,
2556 		const struct nfs_fh *dummy)
2557 {
2558 #if IS_ENABLED(CONFIG_NFS_V4_2)
2559 	server->caps |= NFS_CAP_LAYOUTSTATS;
2560 #endif
2561 	return 0;
2562 }
2563 
2564 static const struct pnfs_commit_ops ff_layout_commit_ops = {
2565 	.setup_ds_info		= ff_layout_setup_ds_info,
2566 	.release_ds_info	= ff_layout_release_ds_info,
2567 	.mark_request_commit	= pnfs_layout_mark_request_commit,
2568 	.clear_request_commit	= pnfs_generic_clear_request_commit,
2569 	.scan_commit_lists	= pnfs_generic_scan_commit_lists,
2570 	.recover_commit_reqs	= pnfs_generic_recover_commit_reqs,
2571 	.commit_pagelist	= ff_layout_commit_pagelist,
2572 };
2573 
2574 static struct pnfs_layoutdriver_type flexfilelayout_type = {
2575 	.id			= LAYOUT_FLEX_FILES,
2576 	.name			= "LAYOUT_FLEX_FILES",
2577 	.owner			= THIS_MODULE,
2578 	.flags			= PNFS_LAYOUTGET_ON_OPEN,
2579 	.max_layoutget_response	= 4096, /* 1 page or so... */
2580 	.set_layoutdriver	= ff_layout_set_layoutdriver,
2581 	.alloc_layout_hdr	= ff_layout_alloc_layout_hdr,
2582 	.free_layout_hdr	= ff_layout_free_layout_hdr,
2583 	.alloc_lseg		= ff_layout_alloc_lseg,
2584 	.free_lseg		= ff_layout_free_lseg,
2585 	.add_lseg		= ff_layout_add_lseg,
2586 	.pg_read_ops		= &ff_layout_pg_read_ops,
2587 	.pg_write_ops		= &ff_layout_pg_write_ops,
2588 	.get_ds_info		= ff_layout_get_ds_info,
2589 	.free_deviceid_node	= ff_layout_free_deviceid_node,
2590 	.read_pagelist		= ff_layout_read_pagelist,
2591 	.write_pagelist		= ff_layout_write_pagelist,
2592 	.alloc_deviceid_node    = ff_layout_alloc_deviceid_node,
2593 	.prepare_layoutreturn   = ff_layout_prepare_layoutreturn,
2594 	.sync			= pnfs_nfs_generic_sync,
2595 	.prepare_layoutstats	= ff_layout_prepare_layoutstats,
2596 	.cancel_io		= ff_layout_cancel_io,
2597 };
2598 
2599 static int __init nfs4flexfilelayout_init(void)
2600 {
2601 	printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Registering...\n",
2602 	       __func__);
2603 	return pnfs_register_layoutdriver(&flexfilelayout_type);
2604 }
2605 
2606 static void __exit nfs4flexfilelayout_exit(void)
2607 {
2608 	printk(KERN_INFO "%s: NFSv4 Flexfile Layout Driver Unregistering...\n",
2609 	       __func__);
2610 	pnfs_unregister_layoutdriver(&flexfilelayout_type);
2611 }
2612 
2613 MODULE_ALIAS("nfs-layouttype4-4");
2614 
2615 MODULE_LICENSE("GPL");
2616 MODULE_DESCRIPTION("The NFSv4 flexfile layout driver");
2617 
2618 module_init(nfs4flexfilelayout_init);
2619 module_exit(nfs4flexfilelayout_exit);
2620 
2621 module_param(io_maxretrans, ushort, 0644);
2622 MODULE_PARM_DESC(io_maxretrans, "The  number of times the NFSv4.1 client "
2623 			"retries an I/O request before returning an error. ");
2624