xref: /openbmc/linux/fs/nfs/pnfs_nfs.c (revision c8dbaa22)
1 /*
2  * Common NFS I/O  operations for the pnfs file based
3  * layout drivers.
4  *
5  * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
6  *
7  * Tom Haynes <loghyr@primarydata.com>
8  */
9 
10 #include <linux/nfs_fs.h>
11 #include <linux/nfs_page.h>
12 #include <linux/sunrpc/addr.h>
13 #include <linux/module.h>
14 
15 #include "nfs4session.h"
16 #include "internal.h"
17 #include "pnfs.h"
18 
19 #define NFSDBG_FACILITY		NFSDBG_PNFS
20 
21 void pnfs_generic_rw_release(void *data)
22 {
23 	struct nfs_pgio_header *hdr = data;
24 
25 	nfs_put_client(hdr->ds_clp);
26 	hdr->mds_ops->rpc_release(data);
27 }
28 EXPORT_SYMBOL_GPL(pnfs_generic_rw_release);
29 
30 /* Fake up some data that will cause nfs_commit_release to retry the writes. */
31 void pnfs_generic_prepare_to_resend_writes(struct nfs_commit_data *data)
32 {
33 	struct nfs_page *first = nfs_list_entry(data->pages.next);
34 
35 	data->task.tk_status = 0;
36 	memcpy(&data->verf.verifier, &first->wb_verf,
37 	       sizeof(data->verf.verifier));
38 	data->verf.verifier.data[0]++; /* ensure verifier mismatch */
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 /* The generic layer is about to remove the req from the commit list.
63  * If this will make the bucket empty, it will need to put the lseg reference.
64  * Note this must be called holding i_lock
65  */
66 void
67 pnfs_generic_clear_request_commit(struct nfs_page *req,
68 				  struct nfs_commit_info *cinfo)
69 {
70 	struct pnfs_layout_segment *freeme = NULL;
71 
72 	if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
73 		goto out;
74 	cinfo->ds->nwritten--;
75 	if (list_is_singular(&req->wb_list)) {
76 		struct pnfs_commit_bucket *bucket;
77 
78 		bucket = list_first_entry(&req->wb_list,
79 					  struct pnfs_commit_bucket,
80 					  written);
81 		freeme = bucket->wlseg;
82 		bucket->wlseg = NULL;
83 	}
84 out:
85 	nfs_request_remove_commit_list(req, cinfo);
86 	pnfs_put_lseg_locked(freeme);
87 }
88 EXPORT_SYMBOL_GPL(pnfs_generic_clear_request_commit);
89 
90 static int
91 pnfs_generic_transfer_commit_list(struct list_head *src, struct list_head *dst,
92 				  struct nfs_commit_info *cinfo, int max)
93 {
94 	struct nfs_page *req, *tmp;
95 	int ret = 0;
96 
97 	list_for_each_entry_safe(req, tmp, src, wb_list) {
98 		if (!nfs_lock_request(req))
99 			continue;
100 		kref_get(&req->wb_kref);
101 		if (cond_resched_lock(&cinfo->inode->i_lock))
102 			list_safe_reset_next(req, tmp, wb_list);
103 		nfs_request_remove_commit_list(req, cinfo);
104 		clear_bit(PG_COMMIT_TO_DS, &req->wb_flags);
105 		nfs_list_add_request(req, dst);
106 		ret++;
107 		if ((ret == max) && !cinfo->dreq)
108 			break;
109 	}
110 	return ret;
111 }
112 
113 static int
114 pnfs_generic_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
115 				 struct nfs_commit_info *cinfo,
116 				 int max)
117 {
118 	struct list_head *src = &bucket->written;
119 	struct list_head *dst = &bucket->committing;
120 	int ret;
121 
122 	lockdep_assert_held(&cinfo->inode->i_lock);
123 	ret = pnfs_generic_transfer_commit_list(src, dst, cinfo, max);
124 	if (ret) {
125 		cinfo->ds->nwritten -= ret;
126 		cinfo->ds->ncommitting += ret;
127 		if (bucket->clseg == NULL)
128 			bucket->clseg = pnfs_get_lseg(bucket->wlseg);
129 		if (list_empty(src)) {
130 			pnfs_put_lseg_locked(bucket->wlseg);
131 			bucket->wlseg = NULL;
132 		}
133 	}
134 	return ret;
135 }
136 
137 /* Move reqs from written to committing lists, returning count
138  * of number moved.
139  */
140 int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo,
141 				   int max)
142 {
143 	int i, rv = 0, cnt;
144 
145 	lockdep_assert_held(&cinfo->inode->i_lock);
146 	for (i = 0; i < cinfo->ds->nbuckets && max != 0; i++) {
147 		cnt = pnfs_generic_scan_ds_commit_list(&cinfo->ds->buckets[i],
148 						       cinfo, max);
149 		max -= cnt;
150 		rv += cnt;
151 	}
152 	return rv;
153 }
154 EXPORT_SYMBOL_GPL(pnfs_generic_scan_commit_lists);
155 
156 /* Pull everything off the committing lists and dump into @dst.  */
157 void pnfs_generic_recover_commit_reqs(struct list_head *dst,
158 				      struct nfs_commit_info *cinfo)
159 {
160 	struct pnfs_commit_bucket *b;
161 	struct pnfs_layout_segment *freeme;
162 	int nwritten;
163 	int i;
164 
165 	lockdep_assert_held(&cinfo->inode->i_lock);
166 restart:
167 	for (i = 0, b = cinfo->ds->buckets; i < cinfo->ds->nbuckets; i++, b++) {
168 		nwritten = pnfs_generic_transfer_commit_list(&b->written,
169 				dst, cinfo, 0);
170 		if (!nwritten)
171 			continue;
172 		cinfo->ds->nwritten -= nwritten;
173 		if (list_empty(&b->written)) {
174 			freeme = b->wlseg;
175 			b->wlseg = NULL;
176 			spin_unlock(&cinfo->inode->i_lock);
177 			pnfs_put_lseg(freeme);
178 			spin_lock(&cinfo->inode->i_lock);
179 			goto restart;
180 		}
181 	}
182 }
183 EXPORT_SYMBOL_GPL(pnfs_generic_recover_commit_reqs);
184 
185 static void pnfs_generic_retry_commit(struct nfs_commit_info *cinfo, int idx)
186 {
187 	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
188 	struct pnfs_commit_bucket *bucket;
189 	struct pnfs_layout_segment *freeme;
190 	struct list_head *pos;
191 	LIST_HEAD(pages);
192 	int i;
193 
194 	spin_lock(&cinfo->inode->i_lock);
195 	for (i = idx; i < fl_cinfo->nbuckets; i++) {
196 		bucket = &fl_cinfo->buckets[i];
197 		if (list_empty(&bucket->committing))
198 			continue;
199 		freeme = bucket->clseg;
200 		bucket->clseg = NULL;
201 		list_for_each(pos, &bucket->committing)
202 			cinfo->ds->ncommitting--;
203 		list_splice_init(&bucket->committing, &pages);
204 		spin_unlock(&cinfo->inode->i_lock);
205 		nfs_retry_commit(&pages, freeme, cinfo, i);
206 		pnfs_put_lseg(freeme);
207 		spin_lock(&cinfo->inode->i_lock);
208 	}
209 	spin_unlock(&cinfo->inode->i_lock);
210 }
211 
212 static unsigned int
213 pnfs_generic_alloc_ds_commits(struct nfs_commit_info *cinfo,
214 			      struct list_head *list)
215 {
216 	struct pnfs_ds_commit_info *fl_cinfo;
217 	struct pnfs_commit_bucket *bucket;
218 	struct nfs_commit_data *data;
219 	int i;
220 	unsigned int nreq = 0;
221 
222 	fl_cinfo = cinfo->ds;
223 	bucket = fl_cinfo->buckets;
224 	for (i = 0; i < fl_cinfo->nbuckets; i++, bucket++) {
225 		if (list_empty(&bucket->committing))
226 			continue;
227 		data = nfs_commitdata_alloc(false);
228 		if (!data)
229 			break;
230 		data->ds_commit_index = i;
231 		list_add(&data->pages, list);
232 		nreq++;
233 	}
234 
235 	/* Clean up on error */
236 	pnfs_generic_retry_commit(cinfo, i);
237 	return nreq;
238 }
239 
240 static inline
241 void pnfs_fetch_commit_bucket_list(struct list_head *pages,
242 		struct nfs_commit_data *data,
243 		struct nfs_commit_info *cinfo)
244 {
245 	struct pnfs_commit_bucket *bucket;
246 	struct list_head *pos;
247 
248 	bucket = &cinfo->ds->buckets[data->ds_commit_index];
249 	spin_lock(&cinfo->inode->i_lock);
250 	list_for_each(pos, &bucket->committing)
251 		cinfo->ds->ncommitting--;
252 	list_splice_init(&bucket->committing, pages);
253 	data->lseg = bucket->clseg;
254 	bucket->clseg = NULL;
255 	spin_unlock(&cinfo->inode->i_lock);
256 
257 }
258 
259 /* Helper function for pnfs_generic_commit_pagelist to catch an empty
260  * page list. This can happen when two commits race.
261  *
262  * This must be called instead of nfs_init_commit - call one or the other, but
263  * not both!
264  */
265 static bool
266 pnfs_generic_commit_cancel_empty_pagelist(struct list_head *pages,
267 					  struct nfs_commit_data *data,
268 					  struct nfs_commit_info *cinfo)
269 {
270 	if (list_empty(pages)) {
271 		if (atomic_dec_and_test(&cinfo->mds->rpcs_out))
272 			wake_up_atomic_t(&cinfo->mds->rpcs_out);
273 		/* don't call nfs_commitdata_release - it tries to put
274 		 * the open_context which is not acquired until nfs_init_commit
275 		 * which has not been called on @data */
276 		WARN_ON_ONCE(data->context);
277 		nfs_commit_free(data);
278 		return true;
279 	}
280 
281 	return false;
282 }
283 
284 /* This follows nfs_commit_list pretty closely */
285 int
286 pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
287 			     int how, struct nfs_commit_info *cinfo,
288 			     int (*initiate_commit)(struct nfs_commit_data *data,
289 						    int how))
290 {
291 	struct nfs_commit_data *data, *tmp;
292 	LIST_HEAD(list);
293 	unsigned int nreq = 0;
294 
295 	if (!list_empty(mds_pages)) {
296 		data = nfs_commitdata_alloc(true);
297 		data->ds_commit_index = -1;
298 		list_add(&data->pages, &list);
299 		nreq++;
300 	}
301 
302 	nreq += pnfs_generic_alloc_ds_commits(cinfo, &list);
303 
304 	if (nreq == 0)
305 		goto out;
306 
307 	atomic_add(nreq, &cinfo->mds->rpcs_out);
308 
309 	list_for_each_entry_safe(data, tmp, &list, pages) {
310 		list_del_init(&data->pages);
311 		if (data->ds_commit_index < 0) {
312 			/* another commit raced with us */
313 			if (pnfs_generic_commit_cancel_empty_pagelist(mds_pages,
314 				data, cinfo))
315 				continue;
316 
317 			nfs_init_commit(data, mds_pages, NULL, cinfo);
318 			nfs_initiate_commit(NFS_CLIENT(inode), data,
319 					    NFS_PROTO(data->inode),
320 					    data->mds_ops, how, 0);
321 		} else {
322 			LIST_HEAD(pages);
323 
324 			pnfs_fetch_commit_bucket_list(&pages, data, cinfo);
325 
326 			/* another commit raced with us */
327 			if (pnfs_generic_commit_cancel_empty_pagelist(&pages,
328 				data, cinfo))
329 				continue;
330 
331 			nfs_init_commit(data, &pages, data->lseg, cinfo);
332 			initiate_commit(data, how);
333 		}
334 	}
335 out:
336 	return PNFS_ATTEMPTED;
337 }
338 EXPORT_SYMBOL_GPL(pnfs_generic_commit_pagelist);
339 
340 /*
341  * Data server cache
342  *
343  * Data servers can be mapped to different device ids.
344  * nfs4_pnfs_ds reference counting
345  *   - set to 1 on allocation
346  *   - incremented when a device id maps a data server already in the cache.
347  *   - decremented when deviceid is removed from the cache.
348  */
349 static DEFINE_SPINLOCK(nfs4_ds_cache_lock);
350 static LIST_HEAD(nfs4_data_server_cache);
351 
352 /* Debug routines */
353 static void
354 print_ds(struct nfs4_pnfs_ds *ds)
355 {
356 	if (ds == NULL) {
357 		printk(KERN_WARNING "%s NULL device\n", __func__);
358 		return;
359 	}
360 	printk(KERN_WARNING "        ds %s\n"
361 		"        ref count %d\n"
362 		"        client %p\n"
363 		"        cl_exchange_flags %x\n",
364 		ds->ds_remotestr,
365 		atomic_read(&ds->ds_count), ds->ds_clp,
366 		ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
367 }
368 
369 static bool
370 same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
371 {
372 	struct sockaddr_in *a, *b;
373 	struct sockaddr_in6 *a6, *b6;
374 
375 	if (addr1->sa_family != addr2->sa_family)
376 		return false;
377 
378 	switch (addr1->sa_family) {
379 	case AF_INET:
380 		a = (struct sockaddr_in *)addr1;
381 		b = (struct sockaddr_in *)addr2;
382 
383 		if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
384 		    a->sin_port == b->sin_port)
385 			return true;
386 		break;
387 
388 	case AF_INET6:
389 		a6 = (struct sockaddr_in6 *)addr1;
390 		b6 = (struct sockaddr_in6 *)addr2;
391 
392 		/* LINKLOCAL addresses must have matching scope_id */
393 		if (ipv6_addr_src_scope(&a6->sin6_addr) ==
394 		    IPV6_ADDR_SCOPE_LINKLOCAL &&
395 		    a6->sin6_scope_id != b6->sin6_scope_id)
396 			return false;
397 
398 		if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
399 		    a6->sin6_port == b6->sin6_port)
400 			return true;
401 		break;
402 
403 	default:
404 		dprintk("%s: unhandled address family: %u\n",
405 			__func__, addr1->sa_family);
406 		return false;
407 	}
408 
409 	return false;
410 }
411 
412 /*
413  * Checks if 'dsaddrs1' contains a subset of 'dsaddrs2'. If it does,
414  * declare a match.
415  */
416 static bool
417 _same_data_server_addrs_locked(const struct list_head *dsaddrs1,
418 			       const struct list_head *dsaddrs2)
419 {
420 	struct nfs4_pnfs_ds_addr *da1, *da2;
421 	struct sockaddr *sa1, *sa2;
422 	bool match = false;
423 
424 	list_for_each_entry(da1, dsaddrs1, da_node) {
425 		sa1 = (struct sockaddr *)&da1->da_addr;
426 		match = false;
427 		list_for_each_entry(da2, dsaddrs2, da_node) {
428 			sa2 = (struct sockaddr *)&da2->da_addr;
429 			match = same_sockaddr(sa1, sa2);
430 			if (match)
431 				break;
432 		}
433 		if (!match)
434 			break;
435 	}
436 	return match;
437 }
438 
439 /*
440  * Lookup DS by addresses.  nfs4_ds_cache_lock is held
441  */
442 static struct nfs4_pnfs_ds *
443 _data_server_lookup_locked(const struct list_head *dsaddrs)
444 {
445 	struct nfs4_pnfs_ds *ds;
446 
447 	list_for_each_entry(ds, &nfs4_data_server_cache, ds_node)
448 		if (_same_data_server_addrs_locked(&ds->ds_addrs, dsaddrs))
449 			return ds;
450 	return NULL;
451 }
452 
453 static void destroy_ds(struct nfs4_pnfs_ds *ds)
454 {
455 	struct nfs4_pnfs_ds_addr *da;
456 
457 	dprintk("--> %s\n", __func__);
458 	ifdebug(FACILITY)
459 		print_ds(ds);
460 
461 	nfs_put_client(ds->ds_clp);
462 
463 	while (!list_empty(&ds->ds_addrs)) {
464 		da = list_first_entry(&ds->ds_addrs,
465 				      struct nfs4_pnfs_ds_addr,
466 				      da_node);
467 		list_del_init(&da->da_node);
468 		kfree(da->da_remotestr);
469 		kfree(da);
470 	}
471 
472 	kfree(ds->ds_remotestr);
473 	kfree(ds);
474 }
475 
476 void nfs4_pnfs_ds_put(struct nfs4_pnfs_ds *ds)
477 {
478 	if (atomic_dec_and_lock(&ds->ds_count,
479 				&nfs4_ds_cache_lock)) {
480 		list_del_init(&ds->ds_node);
481 		spin_unlock(&nfs4_ds_cache_lock);
482 		destroy_ds(ds);
483 	}
484 }
485 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_put);
486 
487 /*
488  * Create a string with a human readable address and port to avoid
489  * complicated setup around many dprinks.
490  */
491 static char *
492 nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags)
493 {
494 	struct nfs4_pnfs_ds_addr *da;
495 	char *remotestr;
496 	size_t len;
497 	char *p;
498 
499 	len = 3;        /* '{', '}' and eol */
500 	list_for_each_entry(da, dsaddrs, da_node) {
501 		len += strlen(da->da_remotestr) + 1;    /* string plus comma */
502 	}
503 
504 	remotestr = kzalloc(len, gfp_flags);
505 	if (!remotestr)
506 		return NULL;
507 
508 	p = remotestr;
509 	*(p++) = '{';
510 	len--;
511 	list_for_each_entry(da, dsaddrs, da_node) {
512 		size_t ll = strlen(da->da_remotestr);
513 
514 		if (ll > len)
515 			goto out_err;
516 
517 		memcpy(p, da->da_remotestr, ll);
518 		p += ll;
519 		len -= ll;
520 
521 		if (len < 1)
522 			goto out_err;
523 		(*p++) = ',';
524 		len--;
525 	}
526 	if (len < 2)
527 		goto out_err;
528 	*(p++) = '}';
529 	*p = '\0';
530 	return remotestr;
531 out_err:
532 	kfree(remotestr);
533 	return NULL;
534 }
535 
536 /*
537  * Given a list of multipath struct nfs4_pnfs_ds_addr, add it to ds cache if
538  * uncached and return cached struct nfs4_pnfs_ds.
539  */
540 struct nfs4_pnfs_ds *
541 nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags)
542 {
543 	struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
544 	char *remotestr;
545 
546 	if (list_empty(dsaddrs)) {
547 		dprintk("%s: no addresses defined\n", __func__);
548 		goto out;
549 	}
550 
551 	ds = kzalloc(sizeof(*ds), gfp_flags);
552 	if (!ds)
553 		goto out;
554 
555 	/* this is only used for debugging, so it's ok if its NULL */
556 	remotestr = nfs4_pnfs_remotestr(dsaddrs, gfp_flags);
557 
558 	spin_lock(&nfs4_ds_cache_lock);
559 	tmp_ds = _data_server_lookup_locked(dsaddrs);
560 	if (tmp_ds == NULL) {
561 		INIT_LIST_HEAD(&ds->ds_addrs);
562 		list_splice_init(dsaddrs, &ds->ds_addrs);
563 		ds->ds_remotestr = remotestr;
564 		atomic_set(&ds->ds_count, 1);
565 		INIT_LIST_HEAD(&ds->ds_node);
566 		ds->ds_clp = NULL;
567 		list_add(&ds->ds_node, &nfs4_data_server_cache);
568 		dprintk("%s add new data server %s\n", __func__,
569 			ds->ds_remotestr);
570 	} else {
571 		kfree(remotestr);
572 		kfree(ds);
573 		atomic_inc(&tmp_ds->ds_count);
574 		dprintk("%s data server %s found, inc'ed ds_count to %d\n",
575 			__func__, tmp_ds->ds_remotestr,
576 			atomic_read(&tmp_ds->ds_count));
577 		ds = tmp_ds;
578 	}
579 	spin_unlock(&nfs4_ds_cache_lock);
580 out:
581 	return ds;
582 }
583 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_add);
584 
585 static void nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds)
586 {
587 	might_sleep();
588 	wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING,
589 			TASK_KILLABLE);
590 }
591 
592 static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
593 {
594 	smp_mb__before_atomic();
595 	clear_bit(NFS4DS_CONNECTING, &ds->ds_state);
596 	smp_mb__after_atomic();
597 	wake_up_bit(&ds->ds_state, NFS4DS_CONNECTING);
598 }
599 
600 static struct nfs_client *(*get_v3_ds_connect)(
601 			struct nfs_server *mds_srv,
602 			const struct sockaddr *ds_addr,
603 			int ds_addrlen,
604 			int ds_proto,
605 			unsigned int ds_timeo,
606 			unsigned int ds_retrans);
607 
608 static bool load_v3_ds_connect(void)
609 {
610 	if (!get_v3_ds_connect) {
611 		get_v3_ds_connect = symbol_request(nfs3_set_ds_client);
612 		WARN_ON_ONCE(!get_v3_ds_connect);
613 	}
614 
615 	return(get_v3_ds_connect != NULL);
616 }
617 
618 void nfs4_pnfs_v3_ds_connect_unload(void)
619 {
620 	if (get_v3_ds_connect) {
621 		symbol_put(nfs3_set_ds_client);
622 		get_v3_ds_connect = NULL;
623 	}
624 }
625 
626 static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
627 				 struct nfs4_pnfs_ds *ds,
628 				 unsigned int timeo,
629 				 unsigned int retrans)
630 {
631 	struct nfs_client *clp = ERR_PTR(-EIO);
632 	struct nfs4_pnfs_ds_addr *da;
633 	int status = 0;
634 
635 	dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
636 
637 	if (!load_v3_ds_connect())
638 		goto out;
639 
640 	list_for_each_entry(da, &ds->ds_addrs, da_node) {
641 		dprintk("%s: DS %s: trying address %s\n",
642 			__func__, ds->ds_remotestr, da->da_remotestr);
643 
644 		if (!IS_ERR(clp)) {
645 			struct xprt_create xprt_args = {
646 				.ident = XPRT_TRANSPORT_TCP,
647 				.net = clp->cl_net,
648 				.dstaddr = (struct sockaddr *)&da->da_addr,
649 				.addrlen = da->da_addrlen,
650 				.servername = clp->cl_hostname,
651 			};
652 			/* Add this address as an alias */
653 			rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
654 					rpc_clnt_test_and_add_xprt, NULL);
655 		} else
656 			clp = get_v3_ds_connect(mds_srv,
657 					(struct sockaddr *)&da->da_addr,
658 					da->da_addrlen, IPPROTO_TCP,
659 					timeo, retrans);
660 	}
661 
662 	if (IS_ERR(clp)) {
663 		status = PTR_ERR(clp);
664 		goto out;
665 	}
666 
667 	smp_wmb();
668 	ds->ds_clp = clp;
669 	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
670 out:
671 	return status;
672 }
673 
674 static int _nfs4_pnfs_v4_ds_connect(struct nfs_server *mds_srv,
675 				 struct nfs4_pnfs_ds *ds,
676 				 unsigned int timeo,
677 				 unsigned int retrans,
678 				 u32 minor_version)
679 {
680 	struct nfs_client *clp = ERR_PTR(-EIO);
681 	struct nfs4_pnfs_ds_addr *da;
682 	int status = 0;
683 
684 	dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
685 
686 	list_for_each_entry(da, &ds->ds_addrs, da_node) {
687 		dprintk("%s: DS %s: trying address %s\n",
688 			__func__, ds->ds_remotestr, da->da_remotestr);
689 
690 		if (!IS_ERR(clp) && clp->cl_mvops->session_trunk) {
691 			struct xprt_create xprt_args = {
692 				.ident = XPRT_TRANSPORT_TCP,
693 				.net = clp->cl_net,
694 				.dstaddr = (struct sockaddr *)&da->da_addr,
695 				.addrlen = da->da_addrlen,
696 				.servername = clp->cl_hostname,
697 			};
698 			struct nfs4_add_xprt_data xprtdata = {
699 				.clp = clp,
700 				.cred = nfs4_get_clid_cred(clp),
701 			};
702 			struct rpc_add_xprt_test rpcdata = {
703 				.add_xprt_test = clp->cl_mvops->session_trunk,
704 				.data = &xprtdata,
705 			};
706 
707 			/**
708 			* Test this address for session trunking and
709 			* add as an alias
710 			*/
711 			rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
712 					  rpc_clnt_setup_test_and_add_xprt,
713 					  &rpcdata);
714 			if (xprtdata.cred)
715 				put_rpccred(xprtdata.cred);
716 		} else {
717 			clp = nfs4_set_ds_client(mds_srv,
718 						(struct sockaddr *)&da->da_addr,
719 						da->da_addrlen, IPPROTO_TCP,
720 						timeo, retrans, minor_version);
721 			if (IS_ERR(clp))
722 				continue;
723 
724 			status = nfs4_init_ds_session(clp,
725 					mds_srv->nfs_client->cl_lease_time);
726 			if (status) {
727 				nfs_put_client(clp);
728 				clp = ERR_PTR(-EIO);
729 				continue;
730 			}
731 
732 		}
733 	}
734 
735 	if (IS_ERR(clp)) {
736 		status = PTR_ERR(clp);
737 		goto out;
738 	}
739 
740 	smp_wmb();
741 	ds->ds_clp = clp;
742 	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
743 out:
744 	return status;
745 }
746 
747 /*
748  * Create an rpc connection to the nfs4_pnfs_ds data server.
749  * Currently only supports IPv4 and IPv6 addresses.
750  * If connection fails, make devid unavailable and return a -errno.
751  */
752 int nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
753 			  struct nfs4_deviceid_node *devid, unsigned int timeo,
754 			  unsigned int retrans, u32 version, u32 minor_version)
755 {
756 	int err;
757 
758 again:
759 	err = 0;
760 	if (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) == 0) {
761 		if (version == 3) {
762 			err = _nfs4_pnfs_v3_ds_connect(mds_srv, ds, timeo,
763 						       retrans);
764 		} else if (version == 4) {
765 			err = _nfs4_pnfs_v4_ds_connect(mds_srv, ds, timeo,
766 						       retrans, minor_version);
767 		} else {
768 			dprintk("%s: unsupported DS version %d\n", __func__,
769 				version);
770 			err = -EPROTONOSUPPORT;
771 		}
772 
773 		nfs4_clear_ds_conn_bit(ds);
774 	} else {
775 		nfs4_wait_ds_connect(ds);
776 
777 		/* what was waited on didn't connect AND didn't mark unavail */
778 		if (!ds->ds_clp && !nfs4_test_deviceid_unavailable(devid))
779 			goto again;
780 	}
781 
782 	/*
783 	 * At this point the ds->ds_clp should be ready, but it might have
784 	 * hit an error.
785 	 */
786 	if (!err) {
787 		if (!ds->ds_clp || !nfs_client_init_is_complete(ds->ds_clp)) {
788 			WARN_ON_ONCE(ds->ds_clp ||
789 				!nfs4_test_deviceid_unavailable(devid));
790 			return -EINVAL;
791 		}
792 		err = nfs_client_init_status(ds->ds_clp);
793 	}
794 
795 	return err;
796 }
797 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_connect);
798 
799 /*
800  * Currently only supports ipv4, ipv6 and one multi-path address.
801  */
802 struct nfs4_pnfs_ds_addr *
803 nfs4_decode_mp_ds_addr(struct net *net, struct xdr_stream *xdr, gfp_t gfp_flags)
804 {
805 	struct nfs4_pnfs_ds_addr *da = NULL;
806 	char *buf, *portstr;
807 	__be16 port;
808 	int nlen, rlen;
809 	int tmp[2];
810 	__be32 *p;
811 	char *netid, *match_netid;
812 	size_t len, match_netid_len;
813 	char *startsep = "";
814 	char *endsep = "";
815 
816 
817 	/* r_netid */
818 	p = xdr_inline_decode(xdr, 4);
819 	if (unlikely(!p))
820 		goto out_err;
821 	nlen = be32_to_cpup(p++);
822 
823 	p = xdr_inline_decode(xdr, nlen);
824 	if (unlikely(!p))
825 		goto out_err;
826 
827 	netid = kmalloc(nlen+1, gfp_flags);
828 	if (unlikely(!netid))
829 		goto out_err;
830 
831 	netid[nlen] = '\0';
832 	memcpy(netid, p, nlen);
833 
834 	/* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */
835 	p = xdr_inline_decode(xdr, 4);
836 	if (unlikely(!p))
837 		goto out_free_netid;
838 	rlen = be32_to_cpup(p);
839 
840 	p = xdr_inline_decode(xdr, rlen);
841 	if (unlikely(!p))
842 		goto out_free_netid;
843 
844 	/* port is ".ABC.DEF", 8 chars max */
845 	if (rlen > INET6_ADDRSTRLEN + IPV6_SCOPE_ID_LEN + 8) {
846 		dprintk("%s: Invalid address, length %d\n", __func__,
847 			rlen);
848 		goto out_free_netid;
849 	}
850 	buf = kmalloc(rlen + 1, gfp_flags);
851 	if (!buf) {
852 		dprintk("%s: Not enough memory\n", __func__);
853 		goto out_free_netid;
854 	}
855 	buf[rlen] = '\0';
856 	memcpy(buf, p, rlen);
857 
858 	/* replace port '.' with '-' */
859 	portstr = strrchr(buf, '.');
860 	if (!portstr) {
861 		dprintk("%s: Failed finding expected dot in port\n",
862 			__func__);
863 		goto out_free_buf;
864 	}
865 	*portstr = '-';
866 
867 	/* find '.' between address and port */
868 	portstr = strrchr(buf, '.');
869 	if (!portstr) {
870 		dprintk("%s: Failed finding expected dot between address and "
871 			"port\n", __func__);
872 		goto out_free_buf;
873 	}
874 	*portstr = '\0';
875 
876 	da = kzalloc(sizeof(*da), gfp_flags);
877 	if (unlikely(!da))
878 		goto out_free_buf;
879 
880 	INIT_LIST_HEAD(&da->da_node);
881 
882 	if (!rpc_pton(net, buf, portstr-buf, (struct sockaddr *)&da->da_addr,
883 		      sizeof(da->da_addr))) {
884 		dprintk("%s: error parsing address %s\n", __func__, buf);
885 		goto out_free_da;
886 	}
887 
888 	portstr++;
889 	sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]);
890 	port = htons((tmp[0] << 8) | (tmp[1]));
891 
892 	switch (da->da_addr.ss_family) {
893 	case AF_INET:
894 		((struct sockaddr_in *)&da->da_addr)->sin_port = port;
895 		da->da_addrlen = sizeof(struct sockaddr_in);
896 		match_netid = "tcp";
897 		match_netid_len = 3;
898 		break;
899 
900 	case AF_INET6:
901 		((struct sockaddr_in6 *)&da->da_addr)->sin6_port = port;
902 		da->da_addrlen = sizeof(struct sockaddr_in6);
903 		match_netid = "tcp6";
904 		match_netid_len = 4;
905 		startsep = "[";
906 		endsep = "]";
907 		break;
908 
909 	default:
910 		dprintk("%s: unsupported address family: %u\n",
911 			__func__, da->da_addr.ss_family);
912 		goto out_free_da;
913 	}
914 
915 	if (nlen != match_netid_len || strncmp(netid, match_netid, nlen)) {
916 		dprintk("%s: ERROR: r_netid \"%s\" != \"%s\"\n",
917 			__func__, netid, match_netid);
918 		goto out_free_da;
919 	}
920 
921 	/* save human readable address */
922 	len = strlen(startsep) + strlen(buf) + strlen(endsep) + 7;
923 	da->da_remotestr = kzalloc(len, gfp_flags);
924 
925 	/* NULL is ok, only used for dprintk */
926 	if (da->da_remotestr)
927 		snprintf(da->da_remotestr, len, "%s%s%s:%u", startsep,
928 			 buf, endsep, ntohs(port));
929 
930 	dprintk("%s: Parsed DS addr %s\n", __func__, da->da_remotestr);
931 	kfree(buf);
932 	kfree(netid);
933 	return da;
934 
935 out_free_da:
936 	kfree(da);
937 out_free_buf:
938 	dprintk("%s: Error parsing DS addr: %s\n", __func__, buf);
939 	kfree(buf);
940 out_free_netid:
941 	kfree(netid);
942 out_err:
943 	return NULL;
944 }
945 EXPORT_SYMBOL_GPL(nfs4_decode_mp_ds_addr);
946 
947 void
948 pnfs_layout_mark_request_commit(struct nfs_page *req,
949 				struct pnfs_layout_segment *lseg,
950 				struct nfs_commit_info *cinfo,
951 				u32 ds_commit_idx)
952 {
953 	struct list_head *list;
954 	struct pnfs_commit_bucket *buckets;
955 
956 	spin_lock(&cinfo->inode->i_lock);
957 	buckets = cinfo->ds->buckets;
958 	list = &buckets[ds_commit_idx].written;
959 	if (list_empty(list)) {
960 		if (!pnfs_is_valid_lseg(lseg)) {
961 			spin_unlock(&cinfo->inode->i_lock);
962 			cinfo->completion_ops->resched_write(cinfo, req);
963 			return;
964 		}
965 		/* Non-empty buckets hold a reference on the lseg.  That ref
966 		 * is normally transferred to the COMMIT call and released
967 		 * there.  It could also be released if the last req is pulled
968 		 * off due to a rewrite, in which case it will be done in
969 		 * pnfs_common_clear_request_commit
970 		 */
971 		WARN_ON_ONCE(buckets[ds_commit_idx].wlseg != NULL);
972 		buckets[ds_commit_idx].wlseg = pnfs_get_lseg(lseg);
973 	}
974 	set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
975 	cinfo->ds->nwritten++;
976 
977 	nfs_request_add_commit_list_locked(req, list, cinfo);
978 	spin_unlock(&cinfo->inode->i_lock);
979 	nfs_mark_page_unstable(req->wb_page, cinfo);
980 }
981 EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);
982 
983 int
984 pnfs_nfs_generic_sync(struct inode *inode, bool datasync)
985 {
986 	int ret;
987 
988 	if (!pnfs_layoutcommit_outstanding(inode))
989 		return 0;
990 	ret = nfs_commit_inode(inode, FLUSH_SYNC);
991 	if (ret < 0)
992 		return ret;
993 	if (datasync)
994 		return 0;
995 	return pnfs_layoutcommit_inode(inode, true);
996 }
997 EXPORT_SYMBOL_GPL(pnfs_nfs_generic_sync);
998 
999