Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-2.6-microblaze.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(false);
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(true);
519                 data->ds_commit_index = -1;
520                 list_splice_init(mds_pages, &data->pages);
521                 list_add_tail(&data->list, &list);
522                 nreq++;
523         }
524
525         nreq += pnfs_alloc_ds_commits_list(&list, fl_cinfo, cinfo);
526         if (nreq == 0)
527                 goto out;
528
529         list_for_each_entry_safe(data, tmp, &list, list) {
530                 list_del(&data->list);
531                 if (data->ds_commit_index < 0) {
532                         nfs_init_commit(data, NULL, NULL, cinfo);
533                         nfs_initiate_commit(NFS_CLIENT(inode), data,
534                                             NFS_PROTO(data->inode),
535                                             data->mds_ops, how,
536                                             RPC_TASK_CRED_NOREF);
537                 } else {
538                         nfs_init_commit(data, NULL, data->lseg, cinfo);
539                         initiate_commit(data, how);
540                 }
541         }
542 out:
543         return PNFS_ATTEMPTED;
544 }
545 EXPORT_SYMBOL_GPL(pnfs_generic_commit_pagelist);
546
547 /*
548  * Data server cache
549  *
550  * Data servers can be mapped to different device ids.
551  * nfs4_pnfs_ds reference counting
552  *   - set to 1 on allocation
553  *   - incremented when a device id maps a data server already in the cache.
554  *   - decremented when deviceid is removed from the cache.
555  */
556 static DEFINE_SPINLOCK(nfs4_ds_cache_lock);
557 static LIST_HEAD(nfs4_data_server_cache);
558
559 /* Debug routines */
560 static void
561 print_ds(struct nfs4_pnfs_ds *ds)
562 {
563         if (ds == NULL) {
564                 printk(KERN_WARNING "%s NULL device\n", __func__);
565                 return;
566         }
567         printk(KERN_WARNING "        ds %s\n"
568                 "        ref count %d\n"
569                 "        client %p\n"
570                 "        cl_exchange_flags %x\n",
571                 ds->ds_remotestr,
572                 refcount_read(&ds->ds_count), ds->ds_clp,
573                 ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
574 }
575
576 static bool
577 same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
578 {
579         struct sockaddr_in *a, *b;
580         struct sockaddr_in6 *a6, *b6;
581
582         if (addr1->sa_family != addr2->sa_family)
583                 return false;
584
585         switch (addr1->sa_family) {
586         case AF_INET:
587                 a = (struct sockaddr_in *)addr1;
588                 b = (struct sockaddr_in *)addr2;
589
590                 if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
591                     a->sin_port == b->sin_port)
592                         return true;
593                 break;
594
595         case AF_INET6:
596                 a6 = (struct sockaddr_in6 *)addr1;
597                 b6 = (struct sockaddr_in6 *)addr2;
598
599                 /* LINKLOCAL addresses must have matching scope_id */
600                 if (ipv6_addr_src_scope(&a6->sin6_addr) ==
601                     IPV6_ADDR_SCOPE_LINKLOCAL &&
602                     a6->sin6_scope_id != b6->sin6_scope_id)
603                         return false;
604
605                 if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
606                     a6->sin6_port == b6->sin6_port)
607                         return true;
608                 break;
609
610         default:
611                 dprintk("%s: unhandled address family: %u\n",
612                         __func__, addr1->sa_family);
613                 return false;
614         }
615
616         return false;
617 }
618
619 /*
620  * Checks if 'dsaddrs1' contains a subset of 'dsaddrs2'. If it does,
621  * declare a match.
622  */
623 static bool
624 _same_data_server_addrs_locked(const struct list_head *dsaddrs1,
625                                const struct list_head *dsaddrs2)
626 {
627         struct nfs4_pnfs_ds_addr *da1, *da2;
628         struct sockaddr *sa1, *sa2;
629         bool match = false;
630
631         list_for_each_entry(da1, dsaddrs1, da_node) {
632                 sa1 = (struct sockaddr *)&da1->da_addr;
633                 match = false;
634                 list_for_each_entry(da2, dsaddrs2, da_node) {
635                         sa2 = (struct sockaddr *)&da2->da_addr;
636                         match = same_sockaddr(sa1, sa2);
637                         if (match)
638                                 break;
639                 }
640                 if (!match)
641                         break;
642         }
643         return match;
644 }
645
646 /*
647  * Lookup DS by addresses.  nfs4_ds_cache_lock is held
648  */
649 static struct nfs4_pnfs_ds *
650 _data_server_lookup_locked(const struct list_head *dsaddrs)
651 {
652         struct nfs4_pnfs_ds *ds;
653
654         list_for_each_entry(ds, &nfs4_data_server_cache, ds_node)
655                 if (_same_data_server_addrs_locked(&ds->ds_addrs, dsaddrs))
656                         return ds;
657         return NULL;
658 }
659
660 static struct nfs4_pnfs_ds_addr *nfs4_pnfs_ds_addr_alloc(gfp_t gfp_flags)
661 {
662         struct nfs4_pnfs_ds_addr *da = kzalloc(sizeof(*da), gfp_flags);
663         if (da)
664                 INIT_LIST_HEAD(&da->da_node);
665         return da;
666 }
667
668 static void nfs4_pnfs_ds_addr_free(struct nfs4_pnfs_ds_addr *da)
669 {
670         kfree(da->da_remotestr);
671         kfree(da->da_netid);
672         kfree(da);
673 }
674
675 static void destroy_ds(struct nfs4_pnfs_ds *ds)
676 {
677         struct nfs4_pnfs_ds_addr *da;
678
679         dprintk("--> %s\n", __func__);
680         ifdebug(FACILITY)
681                 print_ds(ds);
682
683         nfs_put_client(ds->ds_clp);
684
685         while (!list_empty(&ds->ds_addrs)) {
686                 da = list_first_entry(&ds->ds_addrs,
687                                       struct nfs4_pnfs_ds_addr,
688                                       da_node);
689                 list_del_init(&da->da_node);
690                 nfs4_pnfs_ds_addr_free(da);
691         }
692
693         kfree(ds->ds_remotestr);
694         kfree(ds);
695 }
696
697 void nfs4_pnfs_ds_put(struct nfs4_pnfs_ds *ds)
698 {
699         if (refcount_dec_and_lock(&ds->ds_count,
700                                 &nfs4_ds_cache_lock)) {
701                 list_del_init(&ds->ds_node);
702                 spin_unlock(&nfs4_ds_cache_lock);
703                 destroy_ds(ds);
704         }
705 }
706 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_put);
707
708 /*
709  * Create a string with a human readable address and port to avoid
710  * complicated setup around many dprinks.
711  */
712 static char *
713 nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags)
714 {
715         struct nfs4_pnfs_ds_addr *da;
716         char *remotestr;
717         size_t len;
718         char *p;
719
720         len = 3;        /* '{', '}' and eol */
721         list_for_each_entry(da, dsaddrs, da_node) {
722                 len += strlen(da->da_remotestr) + 1;    /* string plus comma */
723         }
724
725         remotestr = kzalloc(len, gfp_flags);
726         if (!remotestr)
727                 return NULL;
728
729         p = remotestr;
730         *(p++) = '{';
731         len--;
732         list_for_each_entry(da, dsaddrs, da_node) {
733                 size_t ll = strlen(da->da_remotestr);
734
735                 if (ll > len)
736                         goto out_err;
737
738                 memcpy(p, da->da_remotestr, ll);
739                 p += ll;
740                 len -= ll;
741
742                 if (len < 1)
743                         goto out_err;
744                 (*p++) = ',';
745                 len--;
746         }
747         if (len < 2)
748                 goto out_err;
749         *(p++) = '}';
750         *p = '\0';
751         return remotestr;
752 out_err:
753         kfree(remotestr);
754         return NULL;
755 }
756
757 /*
758  * Given a list of multipath struct nfs4_pnfs_ds_addr, add it to ds cache if
759  * uncached and return cached struct nfs4_pnfs_ds.
760  */
761 struct nfs4_pnfs_ds *
762 nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags)
763 {
764         struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
765         char *remotestr;
766
767         if (list_empty(dsaddrs)) {
768                 dprintk("%s: no addresses defined\n", __func__);
769                 goto out;
770         }
771
772         ds = kzalloc(sizeof(*ds), gfp_flags);
773         if (!ds)
774                 goto out;
775
776         /* this is only used for debugging, so it's ok if its NULL */
777         remotestr = nfs4_pnfs_remotestr(dsaddrs, gfp_flags);
778
779         spin_lock(&nfs4_ds_cache_lock);
780         tmp_ds = _data_server_lookup_locked(dsaddrs);
781         if (tmp_ds == NULL) {
782                 INIT_LIST_HEAD(&ds->ds_addrs);
783                 list_splice_init(dsaddrs, &ds->ds_addrs);
784                 ds->ds_remotestr = remotestr;
785                 refcount_set(&ds->ds_count, 1);
786                 INIT_LIST_HEAD(&ds->ds_node);
787                 ds->ds_clp = NULL;
788                 list_add(&ds->ds_node, &nfs4_data_server_cache);
789                 dprintk("%s add new data server %s\n", __func__,
790                         ds->ds_remotestr);
791         } else {
792                 kfree(remotestr);
793                 kfree(ds);
794                 refcount_inc(&tmp_ds->ds_count);
795                 dprintk("%s data server %s found, inc'ed ds_count to %d\n",
796                         __func__, tmp_ds->ds_remotestr,
797                         refcount_read(&tmp_ds->ds_count));
798                 ds = tmp_ds;
799         }
800         spin_unlock(&nfs4_ds_cache_lock);
801 out:
802         return ds;
803 }
804 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_add);
805
806 static int nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds)
807 {
808         might_sleep();
809         return wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING, TASK_KILLABLE);
810 }
811
812 static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
813 {
814         smp_mb__before_atomic();
815         clear_and_wake_up_bit(NFS4DS_CONNECTING, &ds->ds_state);
816 }
817
818 static struct nfs_client *(*get_v3_ds_connect)(
819                         struct nfs_server *mds_srv,
820                         const struct sockaddr *ds_addr,
821                         int ds_addrlen,
822                         int ds_proto,
823                         unsigned int ds_timeo,
824                         unsigned int ds_retrans);
825
826 static bool load_v3_ds_connect(void)
827 {
828         if (!get_v3_ds_connect) {
829                 get_v3_ds_connect = symbol_request(nfs3_set_ds_client);
830                 WARN_ON_ONCE(!get_v3_ds_connect);
831         }
832
833         return(get_v3_ds_connect != NULL);
834 }
835
836 void nfs4_pnfs_v3_ds_connect_unload(void)
837 {
838         if (get_v3_ds_connect) {
839                 symbol_put(nfs3_set_ds_client);
840                 get_v3_ds_connect = NULL;
841         }
842 }
843
844 static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
845                                  struct nfs4_pnfs_ds *ds,
846                                  unsigned int timeo,
847                                  unsigned int retrans)
848 {
849         struct nfs_client *clp = ERR_PTR(-EIO);
850         struct nfs4_pnfs_ds_addr *da;
851         int status = 0;
852
853         dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
854
855         if (!load_v3_ds_connect())
856                 return -EPROTONOSUPPORT;
857
858         list_for_each_entry(da, &ds->ds_addrs, da_node) {
859                 dprintk("%s: DS %s: trying address %s\n",
860                         __func__, ds->ds_remotestr, da->da_remotestr);
861
862                 if (!IS_ERR(clp)) {
863                         struct xprt_create xprt_args = {
864                                 .ident = da->da_transport,
865                                 .net = clp->cl_net,
866                                 .dstaddr = (struct sockaddr *)&da->da_addr,
867                                 .addrlen = da->da_addrlen,
868                                 .servername = clp->cl_hostname,
869                         };
870
871                         if (da->da_transport != clp->cl_proto)
872                                 continue;
873                         if (da->da_addr.ss_family != clp->cl_addr.ss_family)
874                                 continue;
875                         /* Add this address as an alias */
876                         rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
877                                         rpc_clnt_test_and_add_xprt, NULL);
878                         continue;
879                 }
880                 clp = get_v3_ds_connect(mds_srv,
881                                 (struct sockaddr *)&da->da_addr,
882                                 da->da_addrlen, da->da_transport,
883                                 timeo, retrans);
884                 if (IS_ERR(clp))
885                         continue;
886                 clp->cl_rpcclient->cl_softerr = 0;
887                 clp->cl_rpcclient->cl_softrtry = 0;
888         }
889
890         if (IS_ERR(clp)) {
891                 status = PTR_ERR(clp);
892                 goto out;
893         }
894
895         smp_wmb();
896         WRITE_ONCE(ds->ds_clp, clp);
897         dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
898 out:
899         return status;
900 }
901
902 static int _nfs4_pnfs_v4_ds_connect(struct nfs_server *mds_srv,
903                                  struct nfs4_pnfs_ds *ds,
904                                  unsigned int timeo,
905                                  unsigned int retrans,
906                                  u32 minor_version)
907 {
908         struct nfs_client *clp = ERR_PTR(-EIO);
909         struct nfs4_pnfs_ds_addr *da;
910         int status = 0;
911
912         dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
913
914         list_for_each_entry(da, &ds->ds_addrs, da_node) {
915                 dprintk("%s: DS %s: trying address %s\n",
916                         __func__, ds->ds_remotestr, da->da_remotestr);
917
918                 if (!IS_ERR(clp) && clp->cl_mvops->session_trunk) {
919                         struct xprt_create xprt_args = {
920                                 .ident = da->da_transport,
921                                 .net = clp->cl_net,
922                                 .dstaddr = (struct sockaddr *)&da->da_addr,
923                                 .addrlen = da->da_addrlen,
924                                 .servername = clp->cl_hostname,
925                         };
926                         struct nfs4_add_xprt_data xprtdata = {
927                                 .clp = clp,
928                         };
929                         struct rpc_add_xprt_test rpcdata = {
930                                 .add_xprt_test = clp->cl_mvops->session_trunk,
931                                 .data = &xprtdata,
932                         };
933
934                         if (da->da_transport != clp->cl_proto)
935                                 continue;
936                         if (da->da_addr.ss_family != clp->cl_addr.ss_family)
937                                 continue;
938                         /**
939                         * Test this address for session trunking and
940                         * add as an alias
941                         */
942                         xprtdata.cred = nfs4_get_clid_cred(clp),
943                         rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
944                                           rpc_clnt_setup_test_and_add_xprt,
945                                           &rpcdata);
946                         if (xprtdata.cred)
947                                 put_cred(xprtdata.cred);
948                 } else {
949                         clp = nfs4_set_ds_client(mds_srv,
950                                                 (struct sockaddr *)&da->da_addr,
951                                                 da->da_addrlen,
952                                                 da->da_transport, timeo,
953                                                 retrans, minor_version);
954                         if (IS_ERR(clp))
955                                 continue;
956
957                         status = nfs4_init_ds_session(clp,
958                                         mds_srv->nfs_client->cl_lease_time);
959                         if (status) {
960                                 nfs_put_client(clp);
961                                 clp = ERR_PTR(-EIO);
962                                 continue;
963                         }
964
965                 }
966         }
967
968         if (IS_ERR(clp)) {
969                 status = PTR_ERR(clp);
970                 goto out;
971         }
972
973         smp_wmb();
974         WRITE_ONCE(ds->ds_clp, clp);
975         dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
976 out:
977         return status;
978 }
979
980 /*
981  * Create an rpc connection to the nfs4_pnfs_ds data server.
982  * Currently only supports IPv4 and IPv6 addresses.
983  * If connection fails, make devid unavailable and return a -errno.
984  */
985 int nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
986                           struct nfs4_deviceid_node *devid, unsigned int timeo,
987                           unsigned int retrans, u32 version, u32 minor_version)
988 {
989         int err;
990
991         do {
992                 err = nfs4_wait_ds_connect(ds);
993                 if (err || ds->ds_clp)
994                         goto out;
995                 if (nfs4_test_deviceid_unavailable(devid))
996                         return -ENODEV;
997         } while (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) != 0);
998
999         if (ds->ds_clp)
1000                 goto connect_done;
1001
1002         switch (version) {
1003         case 3:
1004                 err = _nfs4_pnfs_v3_ds_connect(mds_srv, ds, timeo, retrans);
1005                 break;
1006         case 4:
1007                 err = _nfs4_pnfs_v4_ds_connect(mds_srv, ds, timeo, retrans,
1008                                                minor_version);
1009                 break;
1010         default:
1011                 dprintk("%s: unsupported DS version %d\n", __func__, version);
1012                 err = -EPROTONOSUPPORT;
1013         }
1014
1015 connect_done:
1016         nfs4_clear_ds_conn_bit(ds);
1017 out:
1018         /*
1019          * At this point the ds->ds_clp should be ready, but it might have
1020          * hit an error.
1021          */
1022         if (!err) {
1023                 if (!ds->ds_clp || !nfs_client_init_is_complete(ds->ds_clp)) {
1024                         WARN_ON_ONCE(ds->ds_clp ||
1025                                 !nfs4_test_deviceid_unavailable(devid));
1026                         return -EINVAL;
1027                 }
1028                 err = nfs_client_init_status(ds->ds_clp);
1029         }
1030
1031         return err;
1032 }
1033 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_connect);
1034
1035 /*
1036  * Currently only supports ipv4, ipv6 and one multi-path address.
1037  */
1038 struct nfs4_pnfs_ds_addr *
1039 nfs4_decode_mp_ds_addr(struct net *net, struct xdr_stream *xdr, gfp_t gfp_flags)
1040 {
1041         struct nfs4_pnfs_ds_addr *da = NULL;
1042         char *buf, *portstr;
1043         __be16 port;
1044         ssize_t nlen, rlen;
1045         int tmp[2];
1046         char *netid;
1047         size_t len;
1048         char *startsep = "";
1049         char *endsep = "";
1050
1051
1052         /* r_netid */
1053         nlen = xdr_stream_decode_string_dup(xdr, &netid, XDR_MAX_NETOBJ,
1054                                             gfp_flags);
1055         if (unlikely(nlen < 0))
1056                 goto out_err;
1057
1058         /* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */
1059         /* port is ".ABC.DEF", 8 chars max */
1060         rlen = xdr_stream_decode_string_dup(xdr, &buf, INET6_ADDRSTRLEN +
1061                                             IPV6_SCOPE_ID_LEN + 8, gfp_flags);
1062         if (unlikely(rlen < 0))
1063                 goto out_free_netid;
1064
1065         /* replace port '.' with '-' */
1066         portstr = strrchr(buf, '.');
1067         if (!portstr) {
1068                 dprintk("%s: Failed finding expected dot in port\n",
1069                         __func__);
1070                 goto out_free_buf;
1071         }
1072         *portstr = '-';
1073
1074         /* find '.' between address and port */
1075         portstr = strrchr(buf, '.');
1076         if (!portstr) {
1077                 dprintk("%s: Failed finding expected dot between address and "
1078                         "port\n", __func__);
1079                 goto out_free_buf;
1080         }
1081         *portstr = '\0';
1082
1083         da = nfs4_pnfs_ds_addr_alloc(gfp_flags);
1084         if (unlikely(!da))
1085                 goto out_free_buf;
1086
1087         if (!rpc_pton(net, buf, portstr-buf, (struct sockaddr *)&da->da_addr,
1088                       sizeof(da->da_addr))) {
1089                 dprintk("%s: error parsing address %s\n", __func__, buf);
1090                 goto out_free_da;
1091         }
1092
1093         portstr++;
1094         sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]);
1095         port = htons((tmp[0] << 8) | (tmp[1]));
1096
1097         switch (da->da_addr.ss_family) {
1098         case AF_INET:
1099                 ((struct sockaddr_in *)&da->da_addr)->sin_port = port;
1100                 da->da_addrlen = sizeof(struct sockaddr_in);
1101                 break;
1102
1103         case AF_INET6:
1104                 ((struct sockaddr_in6 *)&da->da_addr)->sin6_port = port;
1105                 da->da_addrlen = sizeof(struct sockaddr_in6);
1106                 startsep = "[";
1107                 endsep = "]";
1108                 break;
1109
1110         default:
1111                 dprintk("%s: unsupported address family: %u\n",
1112                         __func__, da->da_addr.ss_family);
1113                 goto out_free_da;
1114         }
1115
1116         da->da_transport = xprt_find_transport_ident(netid);
1117         if (da->da_transport < 0) {
1118                 dprintk("%s: ERROR: unknown r_netid \"%s\"\n",
1119                         __func__, netid);
1120                 goto out_free_da;
1121         }
1122
1123         da->da_netid = netid;
1124
1125         /* save human readable address */
1126         len = strlen(startsep) + strlen(buf) + strlen(endsep) + 7;
1127         da->da_remotestr = kzalloc(len, gfp_flags);
1128
1129         /* NULL is ok, only used for dprintk */
1130         if (da->da_remotestr)
1131                 snprintf(da->da_remotestr, len, "%s%s%s:%u", startsep,
1132                          buf, endsep, ntohs(port));
1133
1134         dprintk("%s: Parsed DS addr %s\n", __func__, da->da_remotestr);
1135         kfree(buf);
1136         return da;
1137
1138 out_free_da:
1139         kfree(da);
1140 out_free_buf:
1141         dprintk("%s: Error parsing DS addr: %s\n", __func__, buf);
1142         kfree(buf);
1143 out_free_netid:
1144         kfree(netid);
1145 out_err:
1146         return NULL;
1147 }
1148 EXPORT_SYMBOL_GPL(nfs4_decode_mp_ds_addr);
1149
1150 void
1151 pnfs_layout_mark_request_commit(struct nfs_page *req,
1152                                 struct pnfs_layout_segment *lseg,
1153                                 struct nfs_commit_info *cinfo,
1154                                 u32 ds_commit_idx)
1155 {
1156         struct list_head *list;
1157         struct pnfs_commit_array *array;
1158         struct pnfs_commit_bucket *bucket;
1159
1160         mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
1161         array = pnfs_lookup_commit_array(cinfo->ds, lseg);
1162         if (!array || !pnfs_is_valid_lseg(lseg))
1163                 goto out_resched;
1164         bucket = &array->buckets[ds_commit_idx];
1165         list = &bucket->written;
1166         /* Non-empty buckets hold a reference on the lseg.  That ref
1167          * is normally transferred to the COMMIT call and released
1168          * there.  It could also be released if the last req is pulled
1169          * off due to a rewrite, in which case it will be done in
1170          * pnfs_common_clear_request_commit
1171          */
1172         if (!bucket->lseg)
1173                 bucket->lseg = pnfs_get_lseg(lseg);
1174         set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1175         cinfo->ds->nwritten++;
1176
1177         nfs_request_add_commit_list_locked(req, list, cinfo);
1178         mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1179         nfs_mark_page_unstable(req->wb_page, cinfo);
1180         return;
1181 out_resched:
1182         mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1183         cinfo->completion_ops->resched_write(cinfo, req);
1184 }
1185 EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);
1186
1187 int
1188 pnfs_nfs_generic_sync(struct inode *inode, bool datasync)
1189 {
1190         int ret;
1191
1192         if (!pnfs_layoutcommit_outstanding(inode))
1193                 return 0;
1194         ret = nfs_commit_inode(inode, FLUSH_SYNC);
1195         if (ret < 0)
1196                 return ret;
1197         if (datasync)
1198                 return 0;
1199         return pnfs_layoutcommit_inode(inode, true);
1200 }
1201 EXPORT_SYMBOL_GPL(pnfs_nfs_generic_sync);
1202