GNU Linux-libre 5.10.153-gnu1
[releases.git] / fs / nfs / pnfs_nfs.c
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_commit_bucket *bucket = 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                 bucket = list_first_entry(&req->wb_list,
88                                           struct pnfs_commit_bucket, written);
89 out:
90         nfs_request_remove_commit_list(req, cinfo);
91         if (bucket)
92                 pnfs_put_lseg(pnfs_free_bucket_lseg(bucket));
93 }
94 EXPORT_SYMBOL_GPL(pnfs_generic_clear_request_commit);
95
96 struct pnfs_commit_array *
97 pnfs_alloc_commit_array(size_t n, gfp_t gfp_flags)
98 {
99         struct pnfs_commit_array *p;
100         struct pnfs_commit_bucket *b;
101
102         p = kmalloc(struct_size(p, buckets, n), gfp_flags);
103         if (!p)
104                 return NULL;
105         p->nbuckets = n;
106         INIT_LIST_HEAD(&p->cinfo_list);
107         INIT_LIST_HEAD(&p->lseg_list);
108         p->lseg = NULL;
109         for (b = &p->buckets[0]; n != 0; b++, n--) {
110                 INIT_LIST_HEAD(&b->written);
111                 INIT_LIST_HEAD(&b->committing);
112                 b->lseg = NULL;
113                 b->direct_verf.committed = NFS_INVALID_STABLE_HOW;
114         }
115         return p;
116 }
117 EXPORT_SYMBOL_GPL(pnfs_alloc_commit_array);
118
119 void
120 pnfs_free_commit_array(struct pnfs_commit_array *p)
121 {
122         kfree_rcu(p, rcu);
123 }
124 EXPORT_SYMBOL_GPL(pnfs_free_commit_array);
125
126 static struct pnfs_commit_array *
127 pnfs_find_commit_array_by_lseg(struct pnfs_ds_commit_info *fl_cinfo,
128                 struct pnfs_layout_segment *lseg)
129 {
130         struct pnfs_commit_array *array;
131
132         list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
133                 if (array->lseg == lseg)
134                         return array;
135         }
136         return NULL;
137 }
138
139 struct pnfs_commit_array *
140 pnfs_add_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
141                 struct pnfs_commit_array *new,
142                 struct pnfs_layout_segment *lseg)
143 {
144         struct pnfs_commit_array *array;
145
146         array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
147         if (array)
148                 return array;
149         new->lseg = lseg;
150         refcount_set(&new->refcount, 1);
151         list_add_rcu(&new->cinfo_list, &fl_cinfo->commits);
152         list_add(&new->lseg_list, &lseg->pls_commits);
153         return new;
154 }
155 EXPORT_SYMBOL_GPL(pnfs_add_commit_array);
156
157 static struct pnfs_commit_array *
158 pnfs_lookup_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
159                 struct pnfs_layout_segment *lseg)
160 {
161         struct pnfs_commit_array *array;
162
163         rcu_read_lock();
164         array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
165         if (!array) {
166                 rcu_read_unlock();
167                 fl_cinfo->ops->setup_ds_info(fl_cinfo, lseg);
168                 rcu_read_lock();
169                 array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
170         }
171         rcu_read_unlock();
172         return array;
173 }
174
175 static void
176 pnfs_release_commit_array_locked(struct pnfs_commit_array *array)
177 {
178         list_del_rcu(&array->cinfo_list);
179         list_del(&array->lseg_list);
180         pnfs_free_commit_array(array);
181 }
182
183 static void
184 pnfs_put_commit_array_locked(struct pnfs_commit_array *array)
185 {
186         if (refcount_dec_and_test(&array->refcount))
187                 pnfs_release_commit_array_locked(array);
188 }
189
190 static void
191 pnfs_put_commit_array(struct pnfs_commit_array *array, struct inode *inode)
192 {
193         if (refcount_dec_and_lock(&array->refcount, &inode->i_lock)) {
194                 pnfs_release_commit_array_locked(array);
195                 spin_unlock(&inode->i_lock);
196         }
197 }
198
199 static struct pnfs_commit_array *
200 pnfs_get_commit_array(struct pnfs_commit_array *array)
201 {
202         if (refcount_inc_not_zero(&array->refcount))
203                 return array;
204         return NULL;
205 }
206
207 static void
208 pnfs_remove_and_free_commit_array(struct pnfs_commit_array *array)
209 {
210         array->lseg = NULL;
211         list_del_init(&array->lseg_list);
212         pnfs_put_commit_array_locked(array);
213 }
214
215 void
216 pnfs_generic_ds_cinfo_release_lseg(struct pnfs_ds_commit_info *fl_cinfo,
217                 struct pnfs_layout_segment *lseg)
218 {
219         struct pnfs_commit_array *array, *tmp;
220
221         list_for_each_entry_safe(array, tmp, &lseg->pls_commits, lseg_list)
222                 pnfs_remove_and_free_commit_array(array);
223 }
224 EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_release_lseg);
225
226 void
227 pnfs_generic_ds_cinfo_destroy(struct pnfs_ds_commit_info *fl_cinfo)
228 {
229         struct pnfs_commit_array *array, *tmp;
230
231         list_for_each_entry_safe(array, tmp, &fl_cinfo->commits, cinfo_list)
232                 pnfs_remove_and_free_commit_array(array);
233 }
234 EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_destroy);
235
236 /*
237  * Locks the nfs_page requests for commit and moves them to
238  * @bucket->committing.
239  */
240 static int
241 pnfs_bucket_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
242                                 struct nfs_commit_info *cinfo,
243                                 int max)
244 {
245         struct list_head *src = &bucket->written;
246         struct list_head *dst = &bucket->committing;
247         int ret;
248
249         lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
250         ret = nfs_scan_commit_list(src, dst, cinfo, max);
251         if (ret) {
252                 cinfo->ds->nwritten -= ret;
253                 cinfo->ds->ncommitting += ret;
254         }
255         return ret;
256 }
257
258 static int pnfs_bucket_scan_array(struct nfs_commit_info *cinfo,
259                                   struct pnfs_commit_bucket *buckets,
260                                   unsigned int nbuckets,
261                                   int max)
262 {
263         unsigned int i;
264         int rv = 0, cnt;
265
266         for (i = 0; i < nbuckets && max != 0; i++) {
267                 cnt = pnfs_bucket_scan_ds_commit_list(&buckets[i], cinfo, max);
268                 rv += cnt;
269                 max -= cnt;
270         }
271         return rv;
272 }
273
274 /* Move reqs from written to committing lists, returning count
275  * of number moved.
276  */
277 int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo, int max)
278 {
279         struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
280         struct pnfs_commit_array *array;
281         int rv = 0, cnt;
282
283         rcu_read_lock();
284         list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
285                 if (!array->lseg || !pnfs_get_commit_array(array))
286                         continue;
287                 rcu_read_unlock();
288                 cnt = pnfs_bucket_scan_array(cinfo, array->buckets,
289                                 array->nbuckets, max);
290                 rcu_read_lock();
291                 pnfs_put_commit_array(array, cinfo->inode);
292                 rv += cnt;
293                 max -= cnt;
294                 if (!max)
295                         break;
296         }
297         rcu_read_unlock();
298         return rv;
299 }
300 EXPORT_SYMBOL_GPL(pnfs_generic_scan_commit_lists);
301
302 static unsigned int
303 pnfs_bucket_recover_commit_reqs(struct list_head *dst,
304                                 struct pnfs_commit_bucket *buckets,
305                                 unsigned int nbuckets,
306                                 struct nfs_commit_info *cinfo)
307 {
308         struct pnfs_commit_bucket *b;
309         struct pnfs_layout_segment *freeme;
310         unsigned int nwritten, ret = 0;
311         unsigned int i;
312
313 restart:
314         for (i = 0, b = buckets; i < nbuckets; i++, b++) {
315                 nwritten = nfs_scan_commit_list(&b->written, dst, cinfo, 0);
316                 if (!nwritten)
317                         continue;
318                 ret += nwritten;
319                 freeme = pnfs_free_bucket_lseg(b);
320                 if (freeme) {
321                         pnfs_put_lseg(freeme);
322                         goto restart;
323                 }
324         }
325         return ret;
326 }
327
328 /* Pull everything off the committing lists and dump into @dst.  */
329 void pnfs_generic_recover_commit_reqs(struct list_head *dst,
330                                       struct nfs_commit_info *cinfo)
331 {
332         struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
333         struct pnfs_commit_array *array;
334         unsigned int nwritten;
335
336         lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
337         rcu_read_lock();
338         list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
339                 if (!array->lseg || !pnfs_get_commit_array(array))
340                         continue;
341                 rcu_read_unlock();
342                 nwritten = pnfs_bucket_recover_commit_reqs(dst,
343                                                            array->buckets,
344                                                            array->nbuckets,
345                                                            cinfo);
346                 rcu_read_lock();
347                 pnfs_put_commit_array(array, cinfo->inode);
348                 fl_cinfo->nwritten -= nwritten;
349         }
350         rcu_read_unlock();
351 }
352 EXPORT_SYMBOL_GPL(pnfs_generic_recover_commit_reqs);
353
354 static struct nfs_page *
355 pnfs_bucket_search_commit_reqs(struct pnfs_commit_bucket *buckets,
356                 unsigned int nbuckets, struct page *page)
357 {
358         struct nfs_page *req;
359         struct pnfs_commit_bucket *b;
360         unsigned int i;
361
362         /* Linearly search the commit lists for each bucket until a matching
363          * request is found */
364         for (i = 0, b = buckets; i < nbuckets; i++, b++) {
365                 list_for_each_entry(req, &b->written, wb_list) {
366                         if (req->wb_page == page)
367                                 return req->wb_head;
368                 }
369                 list_for_each_entry(req, &b->committing, wb_list) {
370                         if (req->wb_page == page)
371                                 return req->wb_head;
372                 }
373         }
374         return NULL;
375 }
376
377 /* pnfs_generic_search_commit_reqs - Search lists in @cinfo for the head reqest
378  *                                 for @page
379  * @cinfo - commit info for current inode
380  * @page - page to search for matching head request
381  *
382  * Returns a the head request if one is found, otherwise returns NULL.
383  */
384 struct nfs_page *
385 pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo, struct page *page)
386 {
387         struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
388         struct pnfs_commit_array *array;
389         struct nfs_page *req;
390
391         list_for_each_entry(array, &fl_cinfo->commits, cinfo_list) {
392                 req = pnfs_bucket_search_commit_reqs(array->buckets,
393                                 array->nbuckets, page);
394                 if (req)
395                         return req;
396         }
397         return NULL;
398 }
399 EXPORT_SYMBOL_GPL(pnfs_generic_search_commit_reqs);
400
401 static struct pnfs_layout_segment *
402 pnfs_bucket_get_committing(struct list_head *head,
403                            struct pnfs_commit_bucket *bucket,
404                            struct nfs_commit_info *cinfo)
405 {
406         struct pnfs_layout_segment *lseg;
407         struct list_head *pos;
408
409         list_for_each(pos, &bucket->committing)
410                 cinfo->ds->ncommitting--;
411         list_splice_init(&bucket->committing, head);
412         lseg = pnfs_free_bucket_lseg(bucket);
413         if (!lseg)
414                 lseg = pnfs_get_lseg(bucket->lseg);
415         return lseg;
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();
423
424         if (!data)
425                 return NULL;
426         data->lseg = pnfs_bucket_get_committing(&data->pages, bucket, cinfo);
427         return data;
428 }
429
430 static void pnfs_generic_retry_commit(struct pnfs_commit_bucket *buckets,
431                                       unsigned int nbuckets,
432                                       struct nfs_commit_info *cinfo,
433                                       unsigned int idx)
434 {
435         struct pnfs_commit_bucket *bucket;
436         struct pnfs_layout_segment *freeme;
437         LIST_HEAD(pages);
438
439         for (bucket = buckets; idx < nbuckets; bucket++, idx++) {
440                 if (list_empty(&bucket->committing))
441                         continue;
442                 mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
443                 freeme = pnfs_bucket_get_committing(&pages, bucket, cinfo);
444                 mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
445                 nfs_retry_commit(&pages, freeme, cinfo, idx);
446                 pnfs_put_lseg(freeme);
447         }
448 }
449
450 static unsigned int
451 pnfs_bucket_alloc_ds_commits(struct list_head *list,
452                              struct pnfs_commit_bucket *buckets,
453                              unsigned int nbuckets,
454                              struct nfs_commit_info *cinfo)
455 {
456         struct pnfs_commit_bucket *bucket;
457         struct nfs_commit_data *data;
458         unsigned int i;
459         unsigned int nreq = 0;
460
461         for (i = 0, bucket = buckets; i < nbuckets; i++, bucket++) {
462                 if (list_empty(&bucket->committing))
463                         continue;
464                 mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
465                 if (!list_empty(&bucket->committing)) {
466                         data = pnfs_bucket_fetch_commitdata(bucket, cinfo);
467                         if (!data)
468                                 goto out_error;
469                         data->ds_commit_index = i;
470                         list_add_tail(&data->list, list);
471                         nreq++;
472                 }
473                 mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
474         }
475         return nreq;
476 out_error:
477         mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
478         /* Clean up on error */
479         pnfs_generic_retry_commit(buckets, nbuckets, cinfo, i);
480         return nreq;
481 }
482
483 static unsigned int
484 pnfs_alloc_ds_commits_list(struct list_head *list,
485                            struct pnfs_ds_commit_info *fl_cinfo,
486                            struct nfs_commit_info *cinfo)
487 {
488         struct pnfs_commit_array *array;
489         unsigned int ret = 0;
490
491         rcu_read_lock();
492         list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
493                 if (!array->lseg || !pnfs_get_commit_array(array))
494                         continue;
495                 rcu_read_unlock();
496                 ret += pnfs_bucket_alloc_ds_commits(list, array->buckets,
497                                 array->nbuckets, cinfo);
498                 rcu_read_lock();
499                 pnfs_put_commit_array(array, cinfo->inode);
500         }
501         rcu_read_unlock();
502         return ret;
503 }
504
505 /* This follows nfs_commit_list pretty closely */
506 int
507 pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
508                              int how, struct nfs_commit_info *cinfo,
509                              int (*initiate_commit)(struct nfs_commit_data *data,
510                                                     int how))
511 {
512         struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
513         struct nfs_commit_data *data, *tmp;
514         LIST_HEAD(list);
515         unsigned int nreq = 0;
516
517         if (!list_empty(mds_pages)) {
518                 data = nfs_commitdata_alloc();
519                 if (!data) {
520                         nfs_retry_commit(mds_pages, NULL, cinfo, -1);
521                         return -ENOMEM;
522                 }
523                 data->ds_commit_index = -1;
524                 list_splice_init(mds_pages, &data->pages);
525                 list_add_tail(&data->list, &list);
526                 nreq++;
527         }
528
529         nreq += pnfs_alloc_ds_commits_list(&list, fl_cinfo, cinfo);
530         if (nreq == 0)
531                 goto out;
532
533         list_for_each_entry_safe(data, tmp, &list, list) {
534                 list_del(&data->list);
535                 if (data->ds_commit_index < 0) {
536                         nfs_init_commit(data, NULL, NULL, cinfo);
537                         nfs_initiate_commit(NFS_CLIENT(inode), data,
538                                             NFS_PROTO(data->inode),
539                                             data->mds_ops, how,
540                                             RPC_TASK_CRED_NOREF);
541                 } else {
542                         nfs_init_commit(data, NULL, data->lseg, cinfo);
543                         initiate_commit(data, how);
544                 }
545         }
546 out:
547         return PNFS_ATTEMPTED;
548 }
549 EXPORT_SYMBOL_GPL(pnfs_generic_commit_pagelist);
550
551 /*
552  * Data server cache
553  *
554  * Data servers can be mapped to different device ids.
555  * nfs4_pnfs_ds reference counting
556  *   - set to 1 on allocation
557  *   - incremented when a device id maps a data server already in the cache.
558  *   - decremented when deviceid is removed from the cache.
559  */
560 static DEFINE_SPINLOCK(nfs4_ds_cache_lock);
561 static LIST_HEAD(nfs4_data_server_cache);
562
563 /* Debug routines */
564 static void
565 print_ds(struct nfs4_pnfs_ds *ds)
566 {
567         if (ds == NULL) {
568                 printk(KERN_WARNING "%s NULL device\n", __func__);
569                 return;
570         }
571         printk(KERN_WARNING "        ds %s\n"
572                 "        ref count %d\n"
573                 "        client %p\n"
574                 "        cl_exchange_flags %x\n",
575                 ds->ds_remotestr,
576                 refcount_read(&ds->ds_count), ds->ds_clp,
577                 ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
578 }
579
580 static bool
581 same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
582 {
583         struct sockaddr_in *a, *b;
584         struct sockaddr_in6 *a6, *b6;
585
586         if (addr1->sa_family != addr2->sa_family)
587                 return false;
588
589         switch (addr1->sa_family) {
590         case AF_INET:
591                 a = (struct sockaddr_in *)addr1;
592                 b = (struct sockaddr_in *)addr2;
593
594                 if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
595                     a->sin_port == b->sin_port)
596                         return true;
597                 break;
598
599         case AF_INET6:
600                 a6 = (struct sockaddr_in6 *)addr1;
601                 b6 = (struct sockaddr_in6 *)addr2;
602
603                 /* LINKLOCAL addresses must have matching scope_id */
604                 if (ipv6_addr_src_scope(&a6->sin6_addr) ==
605                     IPV6_ADDR_SCOPE_LINKLOCAL &&
606                     a6->sin6_scope_id != b6->sin6_scope_id)
607                         return false;
608
609                 if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
610                     a6->sin6_port == b6->sin6_port)
611                         return true;
612                 break;
613
614         default:
615                 dprintk("%s: unhandled address family: %u\n",
616                         __func__, addr1->sa_family);
617                 return false;
618         }
619
620         return false;
621 }
622
623 /*
624  * Checks if 'dsaddrs1' contains a subset of 'dsaddrs2'. If it does,
625  * declare a match.
626  */
627 static bool
628 _same_data_server_addrs_locked(const struct list_head *dsaddrs1,
629                                const struct list_head *dsaddrs2)
630 {
631         struct nfs4_pnfs_ds_addr *da1, *da2;
632         struct sockaddr *sa1, *sa2;
633         bool match = false;
634
635         list_for_each_entry(da1, dsaddrs1, da_node) {
636                 sa1 = (struct sockaddr *)&da1->da_addr;
637                 match = false;
638                 list_for_each_entry(da2, dsaddrs2, da_node) {
639                         sa2 = (struct sockaddr *)&da2->da_addr;
640                         match = same_sockaddr(sa1, sa2);
641                         if (match)
642                                 break;
643                 }
644                 if (!match)
645                         break;
646         }
647         return match;
648 }
649
650 /*
651  * Lookup DS by addresses.  nfs4_ds_cache_lock is held
652  */
653 static struct nfs4_pnfs_ds *
654 _data_server_lookup_locked(const struct list_head *dsaddrs)
655 {
656         struct nfs4_pnfs_ds *ds;
657
658         list_for_each_entry(ds, &nfs4_data_server_cache, ds_node)
659                 if (_same_data_server_addrs_locked(&ds->ds_addrs, dsaddrs))
660                         return ds;
661         return NULL;
662 }
663
664 static void destroy_ds(struct nfs4_pnfs_ds *ds)
665 {
666         struct nfs4_pnfs_ds_addr *da;
667
668         dprintk("--> %s\n", __func__);
669         ifdebug(FACILITY)
670                 print_ds(ds);
671
672         nfs_put_client(ds->ds_clp);
673
674         while (!list_empty(&ds->ds_addrs)) {
675                 da = list_first_entry(&ds->ds_addrs,
676                                       struct nfs4_pnfs_ds_addr,
677                                       da_node);
678                 list_del_init(&da->da_node);
679                 kfree(da->da_remotestr);
680                 kfree(da);
681         }
682
683         kfree(ds->ds_remotestr);
684         kfree(ds);
685 }
686
687 void nfs4_pnfs_ds_put(struct nfs4_pnfs_ds *ds)
688 {
689         if (refcount_dec_and_lock(&ds->ds_count,
690                                 &nfs4_ds_cache_lock)) {
691                 list_del_init(&ds->ds_node);
692                 spin_unlock(&nfs4_ds_cache_lock);
693                 destroy_ds(ds);
694         }
695 }
696 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_put);
697
698 /*
699  * Create a string with a human readable address and port to avoid
700  * complicated setup around many dprinks.
701  */
702 static char *
703 nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags)
704 {
705         struct nfs4_pnfs_ds_addr *da;
706         char *remotestr;
707         size_t len;
708         char *p;
709
710         len = 3;        /* '{', '}' and eol */
711         list_for_each_entry(da, dsaddrs, da_node) {
712                 len += strlen(da->da_remotestr) + 1;    /* string plus comma */
713         }
714
715         remotestr = kzalloc(len, gfp_flags);
716         if (!remotestr)
717                 return NULL;
718
719         p = remotestr;
720         *(p++) = '{';
721         len--;
722         list_for_each_entry(da, dsaddrs, da_node) {
723                 size_t ll = strlen(da->da_remotestr);
724
725                 if (ll > len)
726                         goto out_err;
727
728                 memcpy(p, da->da_remotestr, ll);
729                 p += ll;
730                 len -= ll;
731
732                 if (len < 1)
733                         goto out_err;
734                 (*p++) = ',';
735                 len--;
736         }
737         if (len < 2)
738                 goto out_err;
739         *(p++) = '}';
740         *p = '\0';
741         return remotestr;
742 out_err:
743         kfree(remotestr);
744         return NULL;
745 }
746
747 /*
748  * Given a list of multipath struct nfs4_pnfs_ds_addr, add it to ds cache if
749  * uncached and return cached struct nfs4_pnfs_ds.
750  */
751 struct nfs4_pnfs_ds *
752 nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags)
753 {
754         struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
755         char *remotestr;
756
757         if (list_empty(dsaddrs)) {
758                 dprintk("%s: no addresses defined\n", __func__);
759                 goto out;
760         }
761
762         ds = kzalloc(sizeof(*ds), gfp_flags);
763         if (!ds)
764                 goto out;
765
766         /* this is only used for debugging, so it's ok if its NULL */
767         remotestr = nfs4_pnfs_remotestr(dsaddrs, gfp_flags);
768
769         spin_lock(&nfs4_ds_cache_lock);
770         tmp_ds = _data_server_lookup_locked(dsaddrs);
771         if (tmp_ds == NULL) {
772                 INIT_LIST_HEAD(&ds->ds_addrs);
773                 list_splice_init(dsaddrs, &ds->ds_addrs);
774                 ds->ds_remotestr = remotestr;
775                 refcount_set(&ds->ds_count, 1);
776                 INIT_LIST_HEAD(&ds->ds_node);
777                 ds->ds_clp = NULL;
778                 list_add(&ds->ds_node, &nfs4_data_server_cache);
779                 dprintk("%s add new data server %s\n", __func__,
780                         ds->ds_remotestr);
781         } else {
782                 kfree(remotestr);
783                 kfree(ds);
784                 refcount_inc(&tmp_ds->ds_count);
785                 dprintk("%s data server %s found, inc'ed ds_count to %d\n",
786                         __func__, tmp_ds->ds_remotestr,
787                         refcount_read(&tmp_ds->ds_count));
788                 ds = tmp_ds;
789         }
790         spin_unlock(&nfs4_ds_cache_lock);
791 out:
792         return ds;
793 }
794 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_add);
795
796 static int nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds)
797 {
798         might_sleep();
799         return wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING, TASK_KILLABLE);
800 }
801
802 static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
803 {
804         smp_mb__before_atomic();
805         clear_and_wake_up_bit(NFS4DS_CONNECTING, &ds->ds_state);
806 }
807
808 static struct nfs_client *(*get_v3_ds_connect)(
809                         struct nfs_server *mds_srv,
810                         const struct sockaddr *ds_addr,
811                         int ds_addrlen,
812                         int ds_proto,
813                         unsigned int ds_timeo,
814                         unsigned int ds_retrans);
815
816 static bool load_v3_ds_connect(void)
817 {
818         if (!get_v3_ds_connect) {
819                 get_v3_ds_connect = symbol_request(nfs3_set_ds_client);
820                 WARN_ON_ONCE(!get_v3_ds_connect);
821         }
822
823         return(get_v3_ds_connect != NULL);
824 }
825
826 void nfs4_pnfs_v3_ds_connect_unload(void)
827 {
828         if (get_v3_ds_connect) {
829                 symbol_put(nfs3_set_ds_client);
830                 get_v3_ds_connect = NULL;
831         }
832 }
833
834 static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
835                                  struct nfs4_pnfs_ds *ds,
836                                  unsigned int timeo,
837                                  unsigned int retrans)
838 {
839         struct nfs_client *clp = ERR_PTR(-EIO);
840         struct nfs4_pnfs_ds_addr *da;
841         int status = 0;
842
843         dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
844
845         if (!load_v3_ds_connect())
846                 goto out;
847
848         list_for_each_entry(da, &ds->ds_addrs, da_node) {
849                 dprintk("%s: DS %s: trying address %s\n",
850                         __func__, ds->ds_remotestr, da->da_remotestr);
851
852                 if (!IS_ERR(clp)) {
853                         struct xprt_create xprt_args = {
854                                 .ident = XPRT_TRANSPORT_TCP,
855                                 .net = clp->cl_net,
856                                 .dstaddr = (struct sockaddr *)&da->da_addr,
857                                 .addrlen = da->da_addrlen,
858                                 .servername = clp->cl_hostname,
859                         };
860                         /* Add this address as an alias */
861                         rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
862                                         rpc_clnt_test_and_add_xprt, NULL);
863                         continue;
864                 }
865                 clp = get_v3_ds_connect(mds_srv,
866                                 (struct sockaddr *)&da->da_addr,
867                                 da->da_addrlen, IPPROTO_TCP,
868                                 timeo, retrans);
869                 if (IS_ERR(clp))
870                         continue;
871                 clp->cl_rpcclient->cl_softerr = 0;
872                 clp->cl_rpcclient->cl_softrtry = 0;
873         }
874
875         if (IS_ERR(clp)) {
876                 status = PTR_ERR(clp);
877                 goto out;
878         }
879
880         smp_wmb();
881         WRITE_ONCE(ds->ds_clp, clp);
882         dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
883 out:
884         return status;
885 }
886
887 static int _nfs4_pnfs_v4_ds_connect(struct nfs_server *mds_srv,
888                                  struct nfs4_pnfs_ds *ds,
889                                  unsigned int timeo,
890                                  unsigned int retrans,
891                                  u32 minor_version)
892 {
893         struct nfs_client *clp = ERR_PTR(-EIO);
894         struct nfs4_pnfs_ds_addr *da;
895         int status = 0;
896
897         dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
898
899         list_for_each_entry(da, &ds->ds_addrs, da_node) {
900                 dprintk("%s: DS %s: trying address %s\n",
901                         __func__, ds->ds_remotestr, da->da_remotestr);
902
903                 if (!IS_ERR(clp) && clp->cl_mvops->session_trunk) {
904                         struct xprt_create xprt_args = {
905                                 .ident = XPRT_TRANSPORT_TCP,
906                                 .net = clp->cl_net,
907                                 .dstaddr = (struct sockaddr *)&da->da_addr,
908                                 .addrlen = da->da_addrlen,
909                                 .servername = clp->cl_hostname,
910                         };
911                         struct nfs4_add_xprt_data xprtdata = {
912                                 .clp = clp,
913                                 .cred = nfs4_get_clid_cred(clp),
914                         };
915                         struct rpc_add_xprt_test rpcdata = {
916                                 .add_xprt_test = clp->cl_mvops->session_trunk,
917                                 .data = &xprtdata,
918                         };
919
920                         /**
921                         * Test this address for session trunking and
922                         * add as an alias
923                         */
924                         rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
925                                           rpc_clnt_setup_test_and_add_xprt,
926                                           &rpcdata);
927                         if (xprtdata.cred)
928                                 put_cred(xprtdata.cred);
929                 } else {
930                         clp = nfs4_set_ds_client(mds_srv,
931                                                 (struct sockaddr *)&da->da_addr,
932                                                 da->da_addrlen, IPPROTO_TCP,
933                                                 timeo, retrans, minor_version);
934                         if (IS_ERR(clp))
935                                 continue;
936
937                         status = nfs4_init_ds_session(clp,
938                                         mds_srv->nfs_client->cl_lease_time);
939                         if (status) {
940                                 nfs_put_client(clp);
941                                 clp = ERR_PTR(-EIO);
942                                 continue;
943                         }
944
945                 }
946         }
947
948         if (IS_ERR(clp)) {
949                 status = PTR_ERR(clp);
950                 goto out;
951         }
952
953         smp_wmb();
954         WRITE_ONCE(ds->ds_clp, clp);
955         dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
956 out:
957         return status;
958 }
959
960 /*
961  * Create an rpc connection to the nfs4_pnfs_ds data server.
962  * Currently only supports IPv4 and IPv6 addresses.
963  * If connection fails, make devid unavailable and return a -errno.
964  */
965 int nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
966                           struct nfs4_deviceid_node *devid, unsigned int timeo,
967                           unsigned int retrans, u32 version, u32 minor_version)
968 {
969         int err;
970
971         do {
972                 err = nfs4_wait_ds_connect(ds);
973                 if (err || ds->ds_clp)
974                         goto out;
975                 if (nfs4_test_deviceid_unavailable(devid))
976                         return -ENODEV;
977         } while (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) != 0);
978
979         if (ds->ds_clp)
980                 goto connect_done;
981
982         switch (version) {
983         case 3:
984                 err = _nfs4_pnfs_v3_ds_connect(mds_srv, ds, timeo, retrans);
985                 break;
986         case 4:
987                 err = _nfs4_pnfs_v4_ds_connect(mds_srv, ds, timeo, retrans,
988                                                minor_version);
989                 break;
990         default:
991                 dprintk("%s: unsupported DS version %d\n", __func__, version);
992                 err = -EPROTONOSUPPORT;
993         }
994
995 connect_done:
996         nfs4_clear_ds_conn_bit(ds);
997 out:
998         /*
999          * At this point the ds->ds_clp should be ready, but it might have
1000          * hit an error.
1001          */
1002         if (!err) {
1003                 if (!ds->ds_clp || !nfs_client_init_is_complete(ds->ds_clp)) {
1004                         WARN_ON_ONCE(ds->ds_clp ||
1005                                 !nfs4_test_deviceid_unavailable(devid));
1006                         return -EINVAL;
1007                 }
1008                 err = nfs_client_init_status(ds->ds_clp);
1009         }
1010
1011         return err;
1012 }
1013 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_connect);
1014
1015 /*
1016  * Currently only supports ipv4, ipv6 and one multi-path address.
1017  */
1018 struct nfs4_pnfs_ds_addr *
1019 nfs4_decode_mp_ds_addr(struct net *net, struct xdr_stream *xdr, gfp_t gfp_flags)
1020 {
1021         struct nfs4_pnfs_ds_addr *da = NULL;
1022         char *buf, *portstr;
1023         __be16 port;
1024         int nlen, rlen;
1025         int tmp[2];
1026         __be32 *p;
1027         char *netid, *match_netid;
1028         size_t len, match_netid_len;
1029         char *startsep = "";
1030         char *endsep = "";
1031
1032
1033         /* r_netid */
1034         p = xdr_inline_decode(xdr, 4);
1035         if (unlikely(!p))
1036                 goto out_err;
1037         nlen = be32_to_cpup(p++);
1038
1039         p = xdr_inline_decode(xdr, nlen);
1040         if (unlikely(!p))
1041                 goto out_err;
1042
1043         netid = kmalloc(nlen+1, gfp_flags);
1044         if (unlikely(!netid))
1045                 goto out_err;
1046
1047         netid[nlen] = '\0';
1048         memcpy(netid, p, nlen);
1049
1050         /* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */
1051         p = xdr_inline_decode(xdr, 4);
1052         if (unlikely(!p))
1053                 goto out_free_netid;
1054         rlen = be32_to_cpup(p);
1055
1056         p = xdr_inline_decode(xdr, rlen);
1057         if (unlikely(!p))
1058                 goto out_free_netid;
1059
1060         /* port is ".ABC.DEF", 8 chars max */
1061         if (rlen > INET6_ADDRSTRLEN + IPV6_SCOPE_ID_LEN + 8) {
1062                 dprintk("%s: Invalid address, length %d\n", __func__,
1063                         rlen);
1064                 goto out_free_netid;
1065         }
1066         buf = kmalloc(rlen + 1, gfp_flags);
1067         if (!buf) {
1068                 dprintk("%s: Not enough memory\n", __func__);
1069                 goto out_free_netid;
1070         }
1071         buf[rlen] = '\0';
1072         memcpy(buf, p, rlen);
1073
1074         /* replace port '.' with '-' */
1075         portstr = strrchr(buf, '.');
1076         if (!portstr) {
1077                 dprintk("%s: Failed finding expected dot in port\n",
1078                         __func__);
1079                 goto out_free_buf;
1080         }
1081         *portstr = '-';
1082
1083         /* find '.' between address and port */
1084         portstr = strrchr(buf, '.');
1085         if (!portstr) {
1086                 dprintk("%s: Failed finding expected dot between address and "
1087                         "port\n", __func__);
1088                 goto out_free_buf;
1089         }
1090         *portstr = '\0';
1091
1092         da = kzalloc(sizeof(*da), gfp_flags);
1093         if (unlikely(!da))
1094                 goto out_free_buf;
1095
1096         INIT_LIST_HEAD(&da->da_node);
1097
1098         if (!rpc_pton(net, buf, portstr-buf, (struct sockaddr *)&da->da_addr,
1099                       sizeof(da->da_addr))) {
1100                 dprintk("%s: error parsing address %s\n", __func__, buf);
1101                 goto out_free_da;
1102         }
1103
1104         portstr++;
1105         sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]);
1106         port = htons((tmp[0] << 8) | (tmp[1]));
1107
1108         switch (da->da_addr.ss_family) {
1109         case AF_INET:
1110                 ((struct sockaddr_in *)&da->da_addr)->sin_port = port;
1111                 da->da_addrlen = sizeof(struct sockaddr_in);
1112                 match_netid = "tcp";
1113                 match_netid_len = 3;
1114                 break;
1115
1116         case AF_INET6:
1117                 ((struct sockaddr_in6 *)&da->da_addr)->sin6_port = port;
1118                 da->da_addrlen = sizeof(struct sockaddr_in6);
1119                 match_netid = "tcp6";
1120                 match_netid_len = 4;
1121                 startsep = "[";
1122                 endsep = "]";
1123                 break;
1124
1125         default:
1126                 dprintk("%s: unsupported address family: %u\n",
1127                         __func__, da->da_addr.ss_family);
1128                 goto out_free_da;
1129         }
1130
1131         if (nlen != match_netid_len || strncmp(netid, match_netid, nlen)) {
1132                 dprintk("%s: ERROR: r_netid \"%s\" != \"%s\"\n",
1133                         __func__, netid, match_netid);
1134                 goto out_free_da;
1135         }
1136
1137         /* save human readable address */
1138         len = strlen(startsep) + strlen(buf) + strlen(endsep) + 7;
1139         da->da_remotestr = kzalloc(len, gfp_flags);
1140
1141         /* NULL is ok, only used for dprintk */
1142         if (da->da_remotestr)
1143                 snprintf(da->da_remotestr, len, "%s%s%s:%u", startsep,
1144                          buf, endsep, ntohs(port));
1145
1146         dprintk("%s: Parsed DS addr %s\n", __func__, da->da_remotestr);
1147         kfree(buf);
1148         kfree(netid);
1149         return da;
1150
1151 out_free_da:
1152         kfree(da);
1153 out_free_buf:
1154         dprintk("%s: Error parsing DS addr: %s\n", __func__, buf);
1155         kfree(buf);
1156 out_free_netid:
1157         kfree(netid);
1158 out_err:
1159         return NULL;
1160 }
1161 EXPORT_SYMBOL_GPL(nfs4_decode_mp_ds_addr);
1162
1163 void
1164 pnfs_layout_mark_request_commit(struct nfs_page *req,
1165                                 struct pnfs_layout_segment *lseg,
1166                                 struct nfs_commit_info *cinfo,
1167                                 u32 ds_commit_idx)
1168 {
1169         struct list_head *list;
1170         struct pnfs_commit_array *array;
1171         struct pnfs_commit_bucket *bucket;
1172
1173         mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
1174         array = pnfs_lookup_commit_array(cinfo->ds, lseg);
1175         if (!array || !pnfs_is_valid_lseg(lseg))
1176                 goto out_resched;
1177         bucket = &array->buckets[ds_commit_idx];
1178         list = &bucket->written;
1179         /* Non-empty buckets hold a reference on the lseg.  That ref
1180          * is normally transferred to the COMMIT call and released
1181          * there.  It could also be released if the last req is pulled
1182          * off due to a rewrite, in which case it will be done in
1183          * pnfs_common_clear_request_commit
1184          */
1185         if (!bucket->lseg)
1186                 bucket->lseg = pnfs_get_lseg(lseg);
1187         set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1188         cinfo->ds->nwritten++;
1189
1190         nfs_request_add_commit_list_locked(req, list, cinfo);
1191         mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1192         nfs_mark_page_unstable(req->wb_page, cinfo);
1193         return;
1194 out_resched:
1195         mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1196         cinfo->completion_ops->resched_write(cinfo, req);
1197 }
1198 EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);
1199
1200 int
1201 pnfs_nfs_generic_sync(struct inode *inode, bool datasync)
1202 {
1203         int ret;
1204
1205         if (!pnfs_layoutcommit_outstanding(inode))
1206                 return 0;
1207         ret = nfs_commit_inode(inode, FLUSH_SYNC);
1208         if (ret < 0)
1209                 return ret;
1210         if (datasync)
1211                 return 0;
1212         return pnfs_layoutcommit_inode(inode, true);
1213 }
1214 EXPORT_SYMBOL_GPL(pnfs_nfs_generic_sync);
1215