xref: /linux/fs/nfs/pnfs_nfs.c (revision 06bd48b6cd97ef3889b68c8e09014d81dbc463f1)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Common NFS I/O  operations for the pnfs file based
4  * layout drivers.
5  *
6  * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
7  *
8  * Tom Haynes <loghyr@primarydata.com>
9  */
10 
11 #include <linux/nfs_fs.h>
12 #include <linux/nfs_page.h>
13 #include <linux/sunrpc/addr.h>
14 #include <linux/module.h>
15 
16 #include "nfs4session.h"
17 #include "internal.h"
18 #include "pnfs.h"
19 
20 #define NFSDBG_FACILITY		NFSDBG_PNFS
21 
22 void pnfs_generic_rw_release(void *data)
23 {
24 	struct nfs_pgio_header *hdr = data;
25 
26 	nfs_put_client(hdr->ds_clp);
27 	hdr->mds_ops->rpc_release(data);
28 }
29 EXPORT_SYMBOL_GPL(pnfs_generic_rw_release);
30 
31 /* Fake up some data that will cause nfs_commit_release to retry the writes. */
32 void pnfs_generic_prepare_to_resend_writes(struct nfs_commit_data *data)
33 {
34 	struct nfs_writeverf *verf = data->res.verf;
35 
36 	data->task.tk_status = 0;
37 	memset(&verf->verifier, 0, sizeof(verf->verifier));
38 	verf->committed = NFS_UNSTABLE;
39 }
40 EXPORT_SYMBOL_GPL(pnfs_generic_prepare_to_resend_writes);
41 
42 void pnfs_generic_write_commit_done(struct rpc_task *task, void *data)
43 {
44 	struct nfs_commit_data *wdata = data;
45 
46 	/* Note this may cause RPC to be resent */
47 	wdata->mds_ops->rpc_call_done(task, data);
48 }
49 EXPORT_SYMBOL_GPL(pnfs_generic_write_commit_done);
50 
51 void pnfs_generic_commit_release(void *calldata)
52 {
53 	struct nfs_commit_data *data = calldata;
54 
55 	data->completion_ops->completion(data);
56 	pnfs_put_lseg(data->lseg);
57 	nfs_put_client(data->ds_clp);
58 	nfs_commitdata_release(data);
59 }
60 EXPORT_SYMBOL_GPL(pnfs_generic_commit_release);
61 
62 static struct pnfs_layout_segment *
63 pnfs_free_bucket_lseg(struct pnfs_commit_bucket *bucket)
64 {
65 	if (list_empty(&bucket->committing) && list_empty(&bucket->written)) {
66 		struct pnfs_layout_segment *freeme = bucket->lseg;
67 		bucket->lseg = NULL;
68 		return freeme;
69 	}
70 	return NULL;
71 }
72 
73 /* The generic layer is about to remove the req from the commit list.
74  * If this will make the bucket empty, it will need to put the lseg reference.
75  * Note this must be called holding nfsi->commit_mutex
76  */
77 void
78 pnfs_generic_clear_request_commit(struct nfs_page *req,
79 				  struct nfs_commit_info *cinfo)
80 {
81 	struct pnfs_layout_segment *freeme = NULL;
82 
83 	if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
84 		goto out;
85 	cinfo->ds->nwritten--;
86 	if (list_is_singular(&req->wb_list)) {
87 		struct pnfs_commit_bucket *bucket;
88 
89 		bucket = list_first_entry(&req->wb_list,
90 					  struct pnfs_commit_bucket,
91 					  written);
92 		freeme = pnfs_free_bucket_lseg(bucket);
93 	}
94 out:
95 	nfs_request_remove_commit_list(req, cinfo);
96 	pnfs_put_lseg(freeme);
97 }
98 EXPORT_SYMBOL_GPL(pnfs_generic_clear_request_commit);
99 
100 struct pnfs_commit_array *
101 pnfs_alloc_commit_array(size_t n, gfp_t gfp_flags)
102 {
103 	struct pnfs_commit_array *p;
104 	struct pnfs_commit_bucket *b;
105 
106 	p = kmalloc(struct_size(p, buckets, n), gfp_flags);
107 	if (!p)
108 		return NULL;
109 	p->nbuckets = n;
110 	INIT_LIST_HEAD(&p->cinfo_list);
111 	INIT_LIST_HEAD(&p->lseg_list);
112 	p->lseg = NULL;
113 	for (b = &p->buckets[0]; n != 0; b++, n--) {
114 		INIT_LIST_HEAD(&b->written);
115 		INIT_LIST_HEAD(&b->committing);
116 		b->lseg = NULL;
117 		b->direct_verf.committed = NFS_INVALID_STABLE_HOW;
118 	}
119 	return p;
120 }
121 EXPORT_SYMBOL_GPL(pnfs_alloc_commit_array);
122 
123 void
124 pnfs_free_commit_array(struct pnfs_commit_array *p)
125 {
126 	kfree_rcu(p, rcu);
127 }
128 EXPORT_SYMBOL_GPL(pnfs_free_commit_array);
129 
130 static struct pnfs_commit_array *
131 pnfs_find_commit_array_by_lseg(struct pnfs_ds_commit_info *fl_cinfo,
132 		struct pnfs_layout_segment *lseg)
133 {
134 	struct pnfs_commit_array *array;
135 
136 	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
137 		if (array->lseg == lseg)
138 			return array;
139 	}
140 	return NULL;
141 }
142 
143 struct pnfs_commit_array *
144 pnfs_add_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
145 		struct pnfs_commit_array *new,
146 		struct pnfs_layout_segment *lseg)
147 {
148 	struct pnfs_commit_array *array;
149 
150 	array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
151 	if (array)
152 		return array;
153 	new->lseg = lseg;
154 	refcount_set(&new->refcount, 1);
155 	list_add_rcu(&new->cinfo_list, &fl_cinfo->commits);
156 	list_add(&new->lseg_list, &lseg->pls_commits);
157 	return new;
158 }
159 EXPORT_SYMBOL_GPL(pnfs_add_commit_array);
160 
161 static struct pnfs_commit_array *
162 pnfs_lookup_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
163 		struct pnfs_layout_segment *lseg)
164 {
165 	struct pnfs_commit_array *array;
166 
167 	rcu_read_lock();
168 	array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
169 	if (!array) {
170 		rcu_read_unlock();
171 		fl_cinfo->ops->setup_ds_info(fl_cinfo, lseg);
172 		rcu_read_lock();
173 		array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
174 	}
175 	rcu_read_unlock();
176 	return array;
177 }
178 
179 static void
180 pnfs_release_commit_array_locked(struct pnfs_commit_array *array)
181 {
182 	list_del_rcu(&array->cinfo_list);
183 	list_del(&array->lseg_list);
184 	pnfs_free_commit_array(array);
185 }
186 
187 static void
188 pnfs_put_commit_array_locked(struct pnfs_commit_array *array)
189 {
190 	if (refcount_dec_and_test(&array->refcount))
191 		pnfs_release_commit_array_locked(array);
192 }
193 
194 static void
195 pnfs_put_commit_array(struct pnfs_commit_array *array, struct inode *inode)
196 {
197 	if (refcount_dec_and_lock(&array->refcount, &inode->i_lock)) {
198 		pnfs_release_commit_array_locked(array);
199 		spin_unlock(&inode->i_lock);
200 	}
201 }
202 
203 static struct pnfs_commit_array *
204 pnfs_get_commit_array(struct pnfs_commit_array *array)
205 {
206 	if (refcount_inc_not_zero(&array->refcount))
207 		return array;
208 	return NULL;
209 }
210 
211 static void
212 pnfs_remove_and_free_commit_array(struct pnfs_commit_array *array)
213 {
214 	array->lseg = NULL;
215 	list_del_init(&array->lseg_list);
216 	pnfs_put_commit_array_locked(array);
217 }
218 
219 void
220 pnfs_generic_ds_cinfo_release_lseg(struct pnfs_ds_commit_info *fl_cinfo,
221 		struct pnfs_layout_segment *lseg)
222 {
223 	struct pnfs_commit_array *array, *tmp;
224 
225 	list_for_each_entry_safe(array, tmp, &lseg->pls_commits, lseg_list)
226 		pnfs_remove_and_free_commit_array(array);
227 }
228 EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_release_lseg);
229 
230 void
231 pnfs_generic_ds_cinfo_destroy(struct pnfs_ds_commit_info *fl_cinfo)
232 {
233 	struct pnfs_commit_array *array, *tmp;
234 
235 	list_for_each_entry_safe(array, tmp, &fl_cinfo->commits, cinfo_list)
236 		pnfs_remove_and_free_commit_array(array);
237 }
238 EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_destroy);
239 
240 /*
241  * Locks the nfs_page requests for commit and moves them to
242  * @bucket->committing.
243  */
244 static int
245 pnfs_bucket_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
246 				struct nfs_commit_info *cinfo,
247 				int max)
248 {
249 	struct list_head *src = &bucket->written;
250 	struct list_head *dst = &bucket->committing;
251 	int ret;
252 
253 	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
254 	ret = nfs_scan_commit_list(src, dst, cinfo, max);
255 	if (ret) {
256 		cinfo->ds->nwritten -= ret;
257 		cinfo->ds->ncommitting += ret;
258 	}
259 	return ret;
260 }
261 
262 static int pnfs_bucket_scan_array(struct nfs_commit_info *cinfo,
263 				  struct pnfs_commit_bucket *buckets,
264 				  unsigned int nbuckets,
265 				  int max)
266 {
267 	unsigned int i;
268 	int rv = 0, cnt;
269 
270 	for (i = 0; i < nbuckets && max != 0; i++) {
271 		cnt = pnfs_bucket_scan_ds_commit_list(&buckets[i], cinfo, max);
272 		rv += cnt;
273 		max -= cnt;
274 	}
275 	return rv;
276 }
277 
278 /* Move reqs from written to committing lists, returning count
279  * of number moved.
280  */
281 int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo, int max)
282 {
283 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
284 	struct pnfs_commit_array *array;
285 	int rv = 0, cnt;
286 
287 	rcu_read_lock();
288 	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
289 		if (!array->lseg || !pnfs_get_commit_array(array))
290 			continue;
291 		rcu_read_unlock();
292 		cnt = pnfs_bucket_scan_array(cinfo, array->buckets,
293 				array->nbuckets, max);
294 		rcu_read_lock();
295 		pnfs_put_commit_array(array, cinfo->inode);
296 		rv += cnt;
297 		max -= cnt;
298 		if (!max)
299 			break;
300 	}
301 	rcu_read_unlock();
302 	return rv;
303 }
304 EXPORT_SYMBOL_GPL(pnfs_generic_scan_commit_lists);
305 
306 static unsigned int
307 pnfs_bucket_recover_commit_reqs(struct list_head *dst,
308 			        struct pnfs_commit_bucket *buckets,
309 				unsigned int nbuckets,
310 				struct nfs_commit_info *cinfo)
311 {
312 	struct pnfs_commit_bucket *b;
313 	struct pnfs_layout_segment *freeme;
314 	unsigned int nwritten, ret = 0;
315 	unsigned int i;
316 
317 restart:
318 	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
319 		nwritten = nfs_scan_commit_list(&b->written, dst, cinfo, 0);
320 		if (!nwritten)
321 			continue;
322 		ret += nwritten;
323 		freeme = pnfs_free_bucket_lseg(b);
324 		if (freeme) {
325 			pnfs_put_lseg(freeme);
326 			goto restart;
327 		}
328 	}
329 	return ret;
330 }
331 
332 /* Pull everything off the committing lists and dump into @dst.  */
333 void pnfs_generic_recover_commit_reqs(struct list_head *dst,
334 				      struct nfs_commit_info *cinfo)
335 {
336 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
337 	struct pnfs_commit_array *array;
338 	unsigned int nwritten;
339 
340 	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
341 	rcu_read_lock();
342 	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
343 		if (!array->lseg || !pnfs_get_commit_array(array))
344 			continue;
345 		rcu_read_unlock();
346 		nwritten = pnfs_bucket_recover_commit_reqs(dst,
347 							   array->buckets,
348 							   array->nbuckets,
349 							   cinfo);
350 		rcu_read_lock();
351 		pnfs_put_commit_array(array, cinfo->inode);
352 		fl_cinfo->nwritten -= nwritten;
353 	}
354 	rcu_read_unlock();
355 }
356 EXPORT_SYMBOL_GPL(pnfs_generic_recover_commit_reqs);
357 
358 static struct nfs_page *
359 pnfs_bucket_search_commit_reqs(struct pnfs_commit_bucket *buckets,
360 		unsigned int nbuckets, struct page *page)
361 {
362 	struct nfs_page *req;
363 	struct pnfs_commit_bucket *b;
364 	unsigned int i;
365 
366 	/* Linearly search the commit lists for each bucket until a matching
367 	 * request is found */
368 	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
369 		list_for_each_entry(req, &b->written, wb_list) {
370 			if (req->wb_page == page)
371 				return req->wb_head;
372 		}
373 		list_for_each_entry(req, &b->committing, wb_list) {
374 			if (req->wb_page == page)
375 				return req->wb_head;
376 		}
377 	}
378 	return NULL;
379 }
380 
381 /* pnfs_generic_search_commit_reqs - Search lists in @cinfo for the head reqest
382  *				   for @page
383  * @cinfo - commit info for current inode
384  * @page - page to search for matching head request
385  *
386  * Returns a the head request if one is found, otherwise returns NULL.
387  */
388 struct nfs_page *
389 pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
390 {
391 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
392 	struct pnfs_commit_array *array;
393 	struct nfs_page *req;
394 
395 	list_for_each_entry(array, &fl_cinfo->commits, cinfo_list) {
396 		req = pnfs_bucket_search_commit_reqs(array->buckets,
397 				array->nbuckets, page);
398 		if (req)
399 			return req;
400 	}
401 	return NULL;
402 }
403 EXPORT_SYMBOL_GPL(pnfs_generic_search_commit_reqs);
404 
405 static struct pnfs_layout_segment *
406 pnfs_bucket_get_committing(struct list_head *head,
407 			   struct pnfs_commit_bucket *bucket,
408 			   struct nfs_commit_info *cinfo)
409 {
410 	struct list_head *pos;
411 
412 	list_for_each(pos, &bucket->committing)
413 		cinfo->ds->ncommitting--;
414 	list_splice_init(&bucket->committing, head);
415 	return pnfs_free_bucket_lseg(bucket);
416 }
417 
418 static struct nfs_commit_data *
419 pnfs_bucket_fetch_commitdata(struct pnfs_commit_bucket *bucket,
420 			     struct nfs_commit_info *cinfo)
421 {
422 	struct nfs_commit_data *data = nfs_commitdata_alloc(false);
423 
424 	if (!data)
425 		return NULL;
426 	data->lseg = pnfs_bucket_get_committing(&data->pages, bucket, cinfo);
427 	if (!data->lseg)
428 		data->lseg = pnfs_get_lseg(bucket->lseg);
429 	return data;
430 }
431 
432 static void pnfs_generic_retry_commit(struct pnfs_commit_bucket *buckets,
433 				      unsigned int nbuckets,
434 				      struct nfs_commit_info *cinfo,
435 				      unsigned int idx)
436 {
437 	struct pnfs_commit_bucket *bucket;
438 	struct pnfs_layout_segment *freeme;
439 	LIST_HEAD(pages);
440 
441 	for (bucket = buckets; idx < nbuckets; bucket++, idx++) {
442 		if (list_empty(&bucket->committing))
443 			continue;
444 		mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
445 		freeme = pnfs_bucket_get_committing(&pages, bucket, cinfo);
446 		mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
447 		nfs_retry_commit(&pages, freeme, cinfo, idx);
448 		pnfs_put_lseg(freeme);
449 	}
450 }
451 
452 static unsigned int
453 pnfs_bucket_alloc_ds_commits(struct list_head *list,
454 			     struct pnfs_commit_bucket *buckets,
455 			     unsigned int nbuckets,
456 			     struct nfs_commit_info *cinfo)
457 {
458 	struct pnfs_commit_bucket *bucket;
459 	struct nfs_commit_data *data;
460 	unsigned int i;
461 	unsigned int nreq = 0;
462 
463 	for (i = 0, bucket = buckets; i < nbuckets; i++, bucket++) {
464 		if (list_empty(&bucket->committing))
465 			continue;
466 		mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
467 		if (!list_empty(&bucket->committing)) {
468 			data = pnfs_bucket_fetch_commitdata(bucket, cinfo);
469 			if (!data)
470 				goto out_error;
471 			data->ds_commit_index = i;
472 			list_add_tail(&data->list, list);
473 			atomic_inc(&cinfo->mds->rpcs_out);
474 			nreq++;
475 		}
476 		mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
477 	}
478 	return nreq;
479 out_error:
480 	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
481 	/* Clean up on error */
482 	pnfs_generic_retry_commit(buckets, nbuckets, cinfo, i);
483 	return nreq;
484 }
485 
486 static unsigned int
487 pnfs_alloc_ds_commits_list(struct list_head *list,
488 			   struct pnfs_ds_commit_info *fl_cinfo,
489 			   struct nfs_commit_info *cinfo)
490 {
491 	struct pnfs_commit_array *array;
492 	unsigned int ret = 0;
493 
494 	rcu_read_lock();
495 	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
496 		if (!array->lseg || !pnfs_get_commit_array(array))
497 			continue;
498 		rcu_read_unlock();
499 		ret += pnfs_bucket_alloc_ds_commits(list, array->buckets,
500 				array->nbuckets, cinfo);
501 		rcu_read_lock();
502 		pnfs_put_commit_array(array, cinfo->inode);
503 	}
504 	return ret;
505 }
506 
507 /* This follows nfs_commit_list pretty closely */
508 int
509 pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
510 			     int how, struct nfs_commit_info *cinfo,
511 			     int (*initiate_commit)(struct nfs_commit_data *data,
512 						    int how))
513 {
514 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
515 	struct nfs_commit_data *data, *tmp;
516 	LIST_HEAD(list);
517 	unsigned int nreq = 0;
518 
519 	if (!list_empty(mds_pages)) {
520 		data = nfs_commitdata_alloc(true);
521 		data->ds_commit_index = -1;
522 		list_splice_init(mds_pages, &data->pages);
523 		list_add_tail(&data->list, &list);
524 		atomic_inc(&cinfo->mds->rpcs_out);
525 		nreq++;
526 	}
527 
528 	nreq += pnfs_alloc_ds_commits_list(&list, fl_cinfo, cinfo);
529 	if (nreq == 0)
530 		goto out;
531 
532 	list_for_each_entry_safe(data, tmp, &list, list) {
533 		list_del(&data->list);
534 		if (data->ds_commit_index < 0) {
535 			nfs_init_commit(data, NULL, NULL, cinfo);
536 			nfs_initiate_commit(NFS_CLIENT(inode), data,
537 					    NFS_PROTO(data->inode),
538 					    data->mds_ops, how, 0);
539 		} else {
540 			nfs_init_commit(data, NULL, data->lseg, cinfo);
541 			initiate_commit(data, how);
542 		}
543 	}
544 out:
545 	return PNFS_ATTEMPTED;
546 }
547 EXPORT_SYMBOL_GPL(pnfs_generic_commit_pagelist);
548 
549 /*
550  * Data server cache
551  *
552  * Data servers can be mapped to different device ids.
553  * nfs4_pnfs_ds reference counting
554  *   - set to 1 on allocation
555  *   - incremented when a device id maps a data server already in the cache.
556  *   - decremented when deviceid is removed from the cache.
557  */
558 static DEFINE_SPINLOCK(nfs4_ds_cache_lock);
559 static LIST_HEAD(nfs4_data_server_cache);
560 
561 /* Debug routines */
562 static void
563 print_ds(struct nfs4_pnfs_ds *ds)
564 {
565 	if (ds == NULL) {
566 		printk(KERN_WARNING "%s NULL device\n", __func__);
567 		return;
568 	}
569 	printk(KERN_WARNING "        ds %s\n"
570 		"        ref count %d\n"
571 		"        client %p\n"
572 		"        cl_exchange_flags %x\n",
573 		ds->ds_remotestr,
574 		refcount_read(&ds->ds_count), ds->ds_clp,
575 		ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
576 }
577 
578 static bool
579 same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
580 {
581 	struct sockaddr_in *a, *b;
582 	struct sockaddr_in6 *a6, *b6;
583 
584 	if (addr1->sa_family != addr2->sa_family)
585 		return false;
586 
587 	switch (addr1->sa_family) {
588 	case AF_INET:
589 		a = (struct sockaddr_in *)addr1;
590 		b = (struct sockaddr_in *)addr2;
591 
592 		if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
593 		    a->sin_port == b->sin_port)
594 			return true;
595 		break;
596 
597 	case AF_INET6:
598 		a6 = (struct sockaddr_in6 *)addr1;
599 		b6 = (struct sockaddr_in6 *)addr2;
600 
601 		/* LINKLOCAL addresses must have matching scope_id */
602 		if (ipv6_addr_src_scope(&a6->sin6_addr) ==
603 		    IPV6_ADDR_SCOPE_LINKLOCAL &&
604 		    a6->sin6_scope_id != b6->sin6_scope_id)
605 			return false;
606 
607 		if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
608 		    a6->sin6_port == b6->sin6_port)
609 			return true;
610 		break;
611 
612 	default:
613 		dprintk("%s: unhandled address family: %u\n",
614 			__func__, addr1->sa_family);
615 		return false;
616 	}
617 
618 	return false;
619 }
620 
621 /*
622  * Checks if 'dsaddrs1' contains a subset of 'dsaddrs2'. If it does,
623  * declare a match.
624  */
625 static bool
626 _same_data_server_addrs_locked(const struct list_head *dsaddrs1,
627 			       const struct list_head *dsaddrs2)
628 {
629 	struct nfs4_pnfs_ds_addr *da1, *da2;
630 	struct sockaddr *sa1, *sa2;
631 	bool match = false;
632 
633 	list_for_each_entry(da1, dsaddrs1, da_node) {
634 		sa1 = (struct sockaddr *)&da1->da_addr;
635 		match = false;
636 		list_for_each_entry(da2, dsaddrs2, da_node) {
637 			sa2 = (struct sockaddr *)&da2->da_addr;
638 			match = same_sockaddr(sa1, sa2);
639 			if (match)
640 				break;
641 		}
642 		if (!match)
643 			break;
644 	}
645 	return match;
646 }
647 
648 /*
649  * Lookup DS by addresses.  nfs4_ds_cache_lock is held
650  */
651 static struct nfs4_pnfs_ds *
652 _data_server_lookup_locked(const struct list_head *dsaddrs)
653 {
654 	struct nfs4_pnfs_ds *ds;
655 
656 	list_for_each_entry(ds, &nfs4_data_server_cache, ds_node)
657 		if (_same_data_server_addrs_locked(&ds->ds_addrs, dsaddrs))
658 			return ds;
659 	return NULL;
660 }
661 
662 static void destroy_ds(struct nfs4_pnfs_ds *ds)
663 {
664 	struct nfs4_pnfs_ds_addr *da;
665 
666 	dprintk("--> %s\n", __func__);
667 	ifdebug(FACILITY)
668 		print_ds(ds);
669 
670 	nfs_put_client(ds->ds_clp);
671 
672 	while (!list_empty(&ds->ds_addrs)) {
673 		da = list_first_entry(&ds->ds_addrs,
674 				      struct nfs4_pnfs_ds_addr,
675 				      da_node);
676 		list_del_init(&da->da_node);
677 		kfree(da->da_remotestr);
678 		kfree(da);
679 	}
680 
681 	kfree(ds->ds_remotestr);
682 	kfree(ds);
683 }
684 
685 void nfs4_pnfs_ds_put(struct nfs4_pnfs_ds *ds)
686 {
687 	if (refcount_dec_and_lock(&ds->ds_count,
688 				&nfs4_ds_cache_lock)) {
689 		list_del_init(&ds->ds_node);
690 		spin_unlock(&nfs4_ds_cache_lock);
691 		destroy_ds(ds);
692 	}
693 }
694 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_put);
695 
696 /*
697  * Create a string with a human readable address and port to avoid
698  * complicated setup around many dprinks.
699  */
700 static char *
701 nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags)
702 {
703 	struct nfs4_pnfs_ds_addr *da;
704 	char *remotestr;
705 	size_t len;
706 	char *p;
707 
708 	len = 3;        /* '{', '}' and eol */
709 	list_for_each_entry(da, dsaddrs, da_node) {
710 		len += strlen(da->da_remotestr) + 1;    /* string plus comma */
711 	}
712 
713 	remotestr = kzalloc(len, gfp_flags);
714 	if (!remotestr)
715 		return NULL;
716 
717 	p = remotestr;
718 	*(p++) = '{';
719 	len--;
720 	list_for_each_entry(da, dsaddrs, da_node) {
721 		size_t ll = strlen(da->da_remotestr);
722 
723 		if (ll > len)
724 			goto out_err;
725 
726 		memcpy(p, da->da_remotestr, ll);
727 		p += ll;
728 		len -= ll;
729 
730 		if (len < 1)
731 			goto out_err;
732 		(*p++) = ',';
733 		len--;
734 	}
735 	if (len < 2)
736 		goto out_err;
737 	*(p++) = '}';
738 	*p = '\0';
739 	return remotestr;
740 out_err:
741 	kfree(remotestr);
742 	return NULL;
743 }
744 
745 /*
746  * Given a list of multipath struct nfs4_pnfs_ds_addr, add it to ds cache if
747  * uncached and return cached struct nfs4_pnfs_ds.
748  */
749 struct nfs4_pnfs_ds *
750 nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags)
751 {
752 	struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
753 	char *remotestr;
754 
755 	if (list_empty(dsaddrs)) {
756 		dprintk("%s: no addresses defined\n", __func__);
757 		goto out;
758 	}
759 
760 	ds = kzalloc(sizeof(*ds), gfp_flags);
761 	if (!ds)
762 		goto out;
763 
764 	/* this is only used for debugging, so it's ok if its NULL */
765 	remotestr = nfs4_pnfs_remotestr(dsaddrs, gfp_flags);
766 
767 	spin_lock(&nfs4_ds_cache_lock);
768 	tmp_ds = _data_server_lookup_locked(dsaddrs);
769 	if (tmp_ds == NULL) {
770 		INIT_LIST_HEAD(&ds->ds_addrs);
771 		list_splice_init(dsaddrs, &ds->ds_addrs);
772 		ds->ds_remotestr = remotestr;
773 		refcount_set(&ds->ds_count, 1);
774 		INIT_LIST_HEAD(&ds->ds_node);
775 		ds->ds_clp = NULL;
776 		list_add(&ds->ds_node, &nfs4_data_server_cache);
777 		dprintk("%s add new data server %s\n", __func__,
778 			ds->ds_remotestr);
779 	} else {
780 		kfree(remotestr);
781 		kfree(ds);
782 		refcount_inc(&tmp_ds->ds_count);
783 		dprintk("%s data server %s found, inc'ed ds_count to %d\n",
784 			__func__, tmp_ds->ds_remotestr,
785 			refcount_read(&tmp_ds->ds_count));
786 		ds = tmp_ds;
787 	}
788 	spin_unlock(&nfs4_ds_cache_lock);
789 out:
790 	return ds;
791 }
792 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_add);
793 
794 static void nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds)
795 {
796 	might_sleep();
797 	wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING,
798 			TASK_KILLABLE);
799 }
800 
801 static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
802 {
803 	smp_mb__before_atomic();
804 	clear_bit(NFS4DS_CONNECTING, &ds->ds_state);
805 	smp_mb__after_atomic();
806 	wake_up_bit(&ds->ds_state, NFS4DS_CONNECTING);
807 }
808 
809 static struct nfs_client *(*get_v3_ds_connect)(
810 			struct nfs_server *mds_srv,
811 			const struct sockaddr *ds_addr,
812 			int ds_addrlen,
813 			int ds_proto,
814 			unsigned int ds_timeo,
815 			unsigned int ds_retrans);
816 
817 static bool load_v3_ds_connect(void)
818 {
819 	if (!get_v3_ds_connect) {
820 		get_v3_ds_connect = symbol_request(nfs3_set_ds_client);
821 		WARN_ON_ONCE(!get_v3_ds_connect);
822 	}
823 
824 	return(get_v3_ds_connect != NULL);
825 }
826 
827 void nfs4_pnfs_v3_ds_connect_unload(void)
828 {
829 	if (get_v3_ds_connect) {
830 		symbol_put(nfs3_set_ds_client);
831 		get_v3_ds_connect = NULL;
832 	}
833 }
834 
835 static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
836 				 struct nfs4_pnfs_ds *ds,
837 				 unsigned int timeo,
838 				 unsigned int retrans)
839 {
840 	struct nfs_client *clp = ERR_PTR(-EIO);
841 	struct nfs4_pnfs_ds_addr *da;
842 	int status = 0;
843 
844 	dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
845 
846 	if (!load_v3_ds_connect())
847 		goto out;
848 
849 	list_for_each_entry(da, &ds->ds_addrs, da_node) {
850 		dprintk("%s: DS %s: trying address %s\n",
851 			__func__, ds->ds_remotestr, da->da_remotestr);
852 
853 		if (!IS_ERR(clp)) {
854 			struct xprt_create xprt_args = {
855 				.ident = XPRT_TRANSPORT_TCP,
856 				.net = clp->cl_net,
857 				.dstaddr = (struct sockaddr *)&da->da_addr,
858 				.addrlen = da->da_addrlen,
859 				.servername = clp->cl_hostname,
860 			};
861 			/* Add this address as an alias */
862 			rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
863 					rpc_clnt_test_and_add_xprt, NULL);
864 			continue;
865 		}
866 		clp = get_v3_ds_connect(mds_srv,
867 				(struct sockaddr *)&da->da_addr,
868 				da->da_addrlen, IPPROTO_TCP,
869 				timeo, retrans);
870 		if (IS_ERR(clp))
871 			continue;
872 		clp->cl_rpcclient->cl_softerr = 0;
873 		clp->cl_rpcclient->cl_softrtry = 0;
874 	}
875 
876 	if (IS_ERR(clp)) {
877 		status = PTR_ERR(clp);
878 		goto out;
879 	}
880 
881 	smp_wmb();
882 	ds->ds_clp = clp;
883 	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
884 out:
885 	return status;
886 }
887 
888 static int _nfs4_pnfs_v4_ds_connect(struct nfs_server *mds_srv,
889 				 struct nfs4_pnfs_ds *ds,
890 				 unsigned int timeo,
891 				 unsigned int retrans,
892 				 u32 minor_version)
893 {
894 	struct nfs_client *clp = ERR_PTR(-EIO);
895 	struct nfs4_pnfs_ds_addr *da;
896 	int status = 0;
897 
898 	dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
899 
900 	list_for_each_entry(da, &ds->ds_addrs, da_node) {
901 		dprintk("%s: DS %s: trying address %s\n",
902 			__func__, ds->ds_remotestr, da->da_remotestr);
903 
904 		if (!IS_ERR(clp) && clp->cl_mvops->session_trunk) {
905 			struct xprt_create xprt_args = {
906 				.ident = XPRT_TRANSPORT_TCP,
907 				.net = clp->cl_net,
908 				.dstaddr = (struct sockaddr *)&da->da_addr,
909 				.addrlen = da->da_addrlen,
910 				.servername = clp->cl_hostname,
911 			};
912 			struct nfs4_add_xprt_data xprtdata = {
913 				.clp = clp,
914 				.cred = nfs4_get_clid_cred(clp),
915 			};
916 			struct rpc_add_xprt_test rpcdata = {
917 				.add_xprt_test = clp->cl_mvops->session_trunk,
918 				.data = &xprtdata,
919 			};
920 
921 			/**
922 			* Test this address for session trunking and
923 			* add as an alias
924 			*/
925 			rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
926 					  rpc_clnt_setup_test_and_add_xprt,
927 					  &rpcdata);
928 			if (xprtdata.cred)
929 				put_cred(xprtdata.cred);
930 		} else {
931 			clp = nfs4_set_ds_client(mds_srv,
932 						(struct sockaddr *)&da->da_addr,
933 						da->da_addrlen, IPPROTO_TCP,
934 						timeo, retrans, minor_version);
935 			if (IS_ERR(clp))
936 				continue;
937 
938 			status = nfs4_init_ds_session(clp,
939 					mds_srv->nfs_client->cl_lease_time);
940 			if (status) {
941 				nfs_put_client(clp);
942 				clp = ERR_PTR(-EIO);
943 				continue;
944 			}
945 
946 		}
947 	}
948 
949 	if (IS_ERR(clp)) {
950 		status = PTR_ERR(clp);
951 		goto out;
952 	}
953 
954 	smp_wmb();
955 	ds->ds_clp = clp;
956 	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
957 out:
958 	return status;
959 }
960 
961 /*
962  * Create an rpc connection to the nfs4_pnfs_ds data server.
963  * Currently only supports IPv4 and IPv6 addresses.
964  * If connection fails, make devid unavailable and return a -errno.
965  */
966 int nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
967 			  struct nfs4_deviceid_node *devid, unsigned int timeo,
968 			  unsigned int retrans, u32 version, u32 minor_version)
969 {
970 	int err;
971 
972 again:
973 	err = 0;
974 	if (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) == 0) {
975 		if (version == 3) {
976 			err = _nfs4_pnfs_v3_ds_connect(mds_srv, ds, timeo,
977 						       retrans);
978 		} else if (version == 4) {
979 			err = _nfs4_pnfs_v4_ds_connect(mds_srv, ds, timeo,
980 						       retrans, minor_version);
981 		} else {
982 			dprintk("%s: unsupported DS version %d\n", __func__,
983 				version);
984 			err = -EPROTONOSUPPORT;
985 		}
986 
987 		nfs4_clear_ds_conn_bit(ds);
988 	} else {
989 		nfs4_wait_ds_connect(ds);
990 
991 		/* what was waited on didn't connect AND didn't mark unavail */
992 		if (!ds->ds_clp && !nfs4_test_deviceid_unavailable(devid))
993 			goto again;
994 	}
995 
996 	/*
997 	 * At this point the ds->ds_clp should be ready, but it might have
998 	 * hit an error.
999 	 */
1000 	if (!err) {
1001 		if (!ds->ds_clp || !nfs_client_init_is_complete(ds->ds_clp)) {
1002 			WARN_ON_ONCE(ds->ds_clp ||
1003 				!nfs4_test_deviceid_unavailable(devid));
1004 			return -EINVAL;
1005 		}
1006 		err = nfs_client_init_status(ds->ds_clp);
1007 	}
1008 
1009 	return err;
1010 }
1011 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_connect);
1012 
1013 /*
1014  * Currently only supports ipv4, ipv6 and one multi-path address.
1015  */
1016 struct nfs4_pnfs_ds_addr *
1017 nfs4_decode_mp_ds_addr(struct net *net, struct xdr_stream *xdr, gfp_t gfp_flags)
1018 {
1019 	struct nfs4_pnfs_ds_addr *da = NULL;
1020 	char *buf, *portstr;
1021 	__be16 port;
1022 	int nlen, rlen;
1023 	int tmp[2];
1024 	__be32 *p;
1025 	char *netid, *match_netid;
1026 	size_t len, match_netid_len;
1027 	char *startsep = "";
1028 	char *endsep = "";
1029 
1030 
1031 	/* r_netid */
1032 	p = xdr_inline_decode(xdr, 4);
1033 	if (unlikely(!p))
1034 		goto out_err;
1035 	nlen = be32_to_cpup(p++);
1036 
1037 	p = xdr_inline_decode(xdr, nlen);
1038 	if (unlikely(!p))
1039 		goto out_err;
1040 
1041 	netid = kmalloc(nlen+1, gfp_flags);
1042 	if (unlikely(!netid))
1043 		goto out_err;
1044 
1045 	netid[nlen] = '\0';
1046 	memcpy(netid, p, nlen);
1047 
1048 	/* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */
1049 	p = xdr_inline_decode(xdr, 4);
1050 	if (unlikely(!p))
1051 		goto out_free_netid;
1052 	rlen = be32_to_cpup(p);
1053 
1054 	p = xdr_inline_decode(xdr, rlen);
1055 	if (unlikely(!p))
1056 		goto out_free_netid;
1057 
1058 	/* port is ".ABC.DEF", 8 chars max */
1059 	if (rlen > INET6_ADDRSTRLEN + IPV6_SCOPE_ID_LEN + 8) {
1060 		dprintk("%s: Invalid address, length %d\n", __func__,
1061 			rlen);
1062 		goto out_free_netid;
1063 	}
1064 	buf = kmalloc(rlen + 1, gfp_flags);
1065 	if (!buf) {
1066 		dprintk("%s: Not enough memory\n", __func__);
1067 		goto out_free_netid;
1068 	}
1069 	buf[rlen] = '\0';
1070 	memcpy(buf, p, rlen);
1071 
1072 	/* replace port '.' with '-' */
1073 	portstr = strrchr(buf, '.');
1074 	if (!portstr) {
1075 		dprintk("%s: Failed finding expected dot in port\n",
1076 			__func__);
1077 		goto out_free_buf;
1078 	}
1079 	*portstr = '-';
1080 
1081 	/* find '.' between address and port */
1082 	portstr = strrchr(buf, '.');
1083 	if (!portstr) {
1084 		dprintk("%s: Failed finding expected dot between address and "
1085 			"port\n", __func__);
1086 		goto out_free_buf;
1087 	}
1088 	*portstr = '\0';
1089 
1090 	da = kzalloc(sizeof(*da), gfp_flags);
1091 	if (unlikely(!da))
1092 		goto out_free_buf;
1093 
1094 	INIT_LIST_HEAD(&da->da_node);
1095 
1096 	if (!rpc_pton(net, buf, portstr-buf, (struct sockaddr *)&da->da_addr,
1097 		      sizeof(da->da_addr))) {
1098 		dprintk("%s: error parsing address %s\n", __func__, buf);
1099 		goto out_free_da;
1100 	}
1101 
1102 	portstr++;
1103 	sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]);
1104 	port = htons((tmp[0] << 8) | (tmp[1]));
1105 
1106 	switch (da->da_addr.ss_family) {
1107 	case AF_INET:
1108 		((struct sockaddr_in *)&da->da_addr)->sin_port = port;
1109 		da->da_addrlen = sizeof(struct sockaddr_in);
1110 		match_netid = "tcp";
1111 		match_netid_len = 3;
1112 		break;
1113 
1114 	case AF_INET6:
1115 		((struct sockaddr_in6 *)&da->da_addr)->sin6_port = port;
1116 		da->da_addrlen = sizeof(struct sockaddr_in6);
1117 		match_netid = "tcp6";
1118 		match_netid_len = 4;
1119 		startsep = "[";
1120 		endsep = "]";
1121 		break;
1122 
1123 	default:
1124 		dprintk("%s: unsupported address family: %u\n",
1125 			__func__, da->da_addr.ss_family);
1126 		goto out_free_da;
1127 	}
1128 
1129 	if (nlen != match_netid_len || strncmp(netid, match_netid, nlen)) {
1130 		dprintk("%s: ERROR: r_netid \"%s\" != \"%s\"\n",
1131 			__func__, netid, match_netid);
1132 		goto out_free_da;
1133 	}
1134 
1135 	/* save human readable address */
1136 	len = strlen(startsep) + strlen(buf) + strlen(endsep) + 7;
1137 	da->da_remotestr = kzalloc(len, gfp_flags);
1138 
1139 	/* NULL is ok, only used for dprintk */
1140 	if (da->da_remotestr)
1141 		snprintf(da->da_remotestr, len, "%s%s%s:%u", startsep,
1142 			 buf, endsep, ntohs(port));
1143 
1144 	dprintk("%s: Parsed DS addr %s\n", __func__, da->da_remotestr);
1145 	kfree(buf);
1146 	kfree(netid);
1147 	return da;
1148 
1149 out_free_da:
1150 	kfree(da);
1151 out_free_buf:
1152 	dprintk("%s: Error parsing DS addr: %s\n", __func__, buf);
1153 	kfree(buf);
1154 out_free_netid:
1155 	kfree(netid);
1156 out_err:
1157 	return NULL;
1158 }
1159 EXPORT_SYMBOL_GPL(nfs4_decode_mp_ds_addr);
1160 
1161 void
1162 pnfs_layout_mark_request_commit(struct nfs_page *req,
1163 				struct pnfs_layout_segment *lseg,
1164 				struct nfs_commit_info *cinfo,
1165 				u32 ds_commit_idx)
1166 {
1167 	struct list_head *list;
1168 	struct pnfs_commit_array *array;
1169 	struct pnfs_commit_bucket *bucket;
1170 
1171 	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
1172 	array = pnfs_lookup_commit_array(cinfo->ds, lseg);
1173 	if (!array || !pnfs_is_valid_lseg(lseg))
1174 		goto out_resched;
1175 	bucket = &array->buckets[ds_commit_idx];
1176 	list = &bucket->written;
1177 	/* Non-empty buckets hold a reference on the lseg.  That ref
1178 	 * is normally transferred to the COMMIT call and released
1179 	 * there.  It could also be released if the last req is pulled
1180 	 * off due to a rewrite, in which case it will be done in
1181 	 * pnfs_common_clear_request_commit
1182 	 */
1183 	if (!bucket->lseg)
1184 		bucket->lseg = pnfs_get_lseg(lseg);
1185 	set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1186 	cinfo->ds->nwritten++;
1187 
1188 	nfs_request_add_commit_list_locked(req, list, cinfo);
1189 	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1190 	nfs_mark_page_unstable(req->wb_page, cinfo);
1191 	return;
1192 out_resched:
1193 	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1194 	cinfo->completion_ops->resched_write(cinfo, req);
1195 }
1196 EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);
1197 
1198 int
1199 pnfs_nfs_generic_sync(struct inode *inode, bool datasync)
1200 {
1201 	int ret;
1202 
1203 	if (!pnfs_layoutcommit_outstanding(inode))
1204 		return 0;
1205 	ret = nfs_commit_inode(inode, FLUSH_SYNC);
1206 	if (ret < 0)
1207 		return ret;
1208 	if (datasync)
1209 		return 0;
1210 	return pnfs_layoutcommit_inode(inode, true);
1211 }
1212 EXPORT_SYMBOL_GPL(pnfs_nfs_generic_sync);
1213 
1214