Merge branch 'work.namei' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[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                         atomic_inc(&cinfo->mds->rpcs_out);
472                         nreq++;
473                 }
474                 mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
475         }
476         return nreq;
477 out_error:
478         mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
479         /* Clean up on error */
480         pnfs_generic_retry_commit(buckets, nbuckets, cinfo, i);
481         return nreq;
482 }
483
484 static unsigned int
485 pnfs_alloc_ds_commits_list(struct list_head *list,
486                            struct pnfs_ds_commit_info *fl_cinfo,
487                            struct nfs_commit_info *cinfo)
488 {
489         struct pnfs_commit_array *array;
490         unsigned int ret = 0;
491
492         rcu_read_lock();
493         list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
494                 if (!array->lseg || !pnfs_get_commit_array(array))
495                         continue;
496                 rcu_read_unlock();
497                 ret += pnfs_bucket_alloc_ds_commits(list, array->buckets,
498                                 array->nbuckets, cinfo);
499                 rcu_read_lock();
500                 pnfs_put_commit_array(array, cinfo->inode);
501         }
502         rcu_read_unlock();
503         return ret;
504 }
505
506 /* This follows nfs_commit_list pretty closely */
507 int
508 pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
509                              int how, struct nfs_commit_info *cinfo,
510                              int (*initiate_commit)(struct nfs_commit_data *data,
511                                                     int how))
512 {
513         struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
514         struct nfs_commit_data *data, *tmp;
515         LIST_HEAD(list);
516         unsigned int nreq = 0;
517
518         if (!list_empty(mds_pages)) {
519                 data = nfs_commitdata_alloc(true);
520                 data->ds_commit_index = -1;
521                 list_splice_init(mds_pages, &data->pages);
522                 list_add_tail(&data->list, &list);
523                 atomic_inc(&cinfo->mds->rpcs_out);
524                 nreq++;
525         }
526
527         nreq += pnfs_alloc_ds_commits_list(&list, fl_cinfo, cinfo);
528         if (nreq == 0)
529                 goto out;
530
531         list_for_each_entry_safe(data, tmp, &list, list) {
532                 list_del(&data->list);
533                 if (data->ds_commit_index < 0) {
534                         nfs_init_commit(data, NULL, NULL, cinfo);
535                         nfs_initiate_commit(NFS_CLIENT(inode), data,
536                                             NFS_PROTO(data->inode),
537                                             data->mds_ops, how,
538                                             RPC_TASK_CRED_NOREF);
539                 } else {
540                         nfs_init_commit(data, NULL, data->lseg, cinfo);
541                         initiate_commit(data, how);
542                 }
543         }
544 out:
545         return PNFS_ATTEMPTED;
546 }
547 EXPORT_SYMBOL_GPL(pnfs_generic_commit_pagelist);
548
549 /*
550  * Data server cache
551  *
552  * Data servers can be mapped to different device ids.
553  * nfs4_pnfs_ds reference counting
554  *   - set to 1 on allocation
555  *   - incremented when a device id maps a data server already in the cache.
556  *   - decremented when deviceid is removed from the cache.
557  */
558 static DEFINE_SPINLOCK(nfs4_ds_cache_lock);
559 static LIST_HEAD(nfs4_data_server_cache);
560
561 /* Debug routines */
562 static void
563 print_ds(struct nfs4_pnfs_ds *ds)
564 {
565         if (ds == NULL) {
566                 printk(KERN_WARNING "%s NULL device\n", __func__);
567                 return;
568         }
569         printk(KERN_WARNING "        ds %s\n"
570                 "        ref count %d\n"
571                 "        client %p\n"
572                 "        cl_exchange_flags %x\n",
573                 ds->ds_remotestr,
574                 refcount_read(&ds->ds_count), ds->ds_clp,
575                 ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
576 }
577
578 static bool
579 same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
580 {
581         struct sockaddr_in *a, *b;
582         struct sockaddr_in6 *a6, *b6;
583
584         if (addr1->sa_family != addr2->sa_family)
585                 return false;
586
587         switch (addr1->sa_family) {
588         case AF_INET:
589                 a = (struct sockaddr_in *)addr1;
590                 b = (struct sockaddr_in *)addr2;
591
592                 if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
593                     a->sin_port == b->sin_port)
594                         return true;
595                 break;
596
597         case AF_INET6:
598                 a6 = (struct sockaddr_in6 *)addr1;
599                 b6 = (struct sockaddr_in6 *)addr2;
600
601                 /* LINKLOCAL addresses must have matching scope_id */
602                 if (ipv6_addr_src_scope(&a6->sin6_addr) ==
603                     IPV6_ADDR_SCOPE_LINKLOCAL &&
604                     a6->sin6_scope_id != b6->sin6_scope_id)
605                         return false;
606
607                 if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
608                     a6->sin6_port == b6->sin6_port)
609                         return true;
610                 break;
611
612         default:
613                 dprintk("%s: unhandled address family: %u\n",
614                         __func__, addr1->sa_family);
615                 return false;
616         }
617
618         return false;
619 }
620
621 /*
622  * Checks if 'dsaddrs1' contains a subset of 'dsaddrs2'. If it does,
623  * declare a match.
624  */
625 static bool
626 _same_data_server_addrs_locked(const struct list_head *dsaddrs1,
627                                const struct list_head *dsaddrs2)
628 {
629         struct nfs4_pnfs_ds_addr *da1, *da2;
630         struct sockaddr *sa1, *sa2;
631         bool match = false;
632
633         list_for_each_entry(da1, dsaddrs1, da_node) {
634                 sa1 = (struct sockaddr *)&da1->da_addr;
635                 match = false;
636                 list_for_each_entry(da2, dsaddrs2, da_node) {
637                         sa2 = (struct sockaddr *)&da2->da_addr;
638                         match = same_sockaddr(sa1, sa2);
639                         if (match)
640                                 break;
641                 }
642                 if (!match)
643                         break;
644         }
645         return match;
646 }
647
648 /*
649  * Lookup DS by addresses.  nfs4_ds_cache_lock is held
650  */
651 static struct nfs4_pnfs_ds *
652 _data_server_lookup_locked(const struct list_head *dsaddrs)
653 {
654         struct nfs4_pnfs_ds *ds;
655
656         list_for_each_entry(ds, &nfs4_data_server_cache, ds_node)
657                 if (_same_data_server_addrs_locked(&ds->ds_addrs, dsaddrs))
658                         return ds;
659         return NULL;
660 }
661
662 static struct nfs4_pnfs_ds_addr *nfs4_pnfs_ds_addr_alloc(gfp_t gfp_flags)
663 {
664         struct nfs4_pnfs_ds_addr *da = kzalloc(sizeof(*da), gfp_flags);
665         if (da)
666                 INIT_LIST_HEAD(&da->da_node);
667         return da;
668 }
669
670 static void nfs4_pnfs_ds_addr_free(struct nfs4_pnfs_ds_addr *da)
671 {
672         kfree(da->da_remotestr);
673         kfree(da->da_netid);
674         kfree(da);
675 }
676
677 static void destroy_ds(struct nfs4_pnfs_ds *ds)
678 {
679         struct nfs4_pnfs_ds_addr *da;
680
681         dprintk("--> %s\n", __func__);
682         ifdebug(FACILITY)
683                 print_ds(ds);
684
685         nfs_put_client(ds->ds_clp);
686
687         while (!list_empty(&ds->ds_addrs)) {
688                 da = list_first_entry(&ds->ds_addrs,
689                                       struct nfs4_pnfs_ds_addr,
690                                       da_node);
691                 list_del_init(&da->da_node);
692                 nfs4_pnfs_ds_addr_free(da);
693         }
694
695         kfree(ds->ds_remotestr);
696         kfree(ds);
697 }
698
699 void nfs4_pnfs_ds_put(struct nfs4_pnfs_ds *ds)
700 {
701         if (refcount_dec_and_lock(&ds->ds_count,
702                                 &nfs4_ds_cache_lock)) {
703                 list_del_init(&ds->ds_node);
704                 spin_unlock(&nfs4_ds_cache_lock);
705                 destroy_ds(ds);
706         }
707 }
708 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_put);
709
710 /*
711  * Create a string with a human readable address and port to avoid
712  * complicated setup around many dprinks.
713  */
714 static char *
715 nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags)
716 {
717         struct nfs4_pnfs_ds_addr *da;
718         char *remotestr;
719         size_t len;
720         char *p;
721
722         len = 3;        /* '{', '}' and eol */
723         list_for_each_entry(da, dsaddrs, da_node) {
724                 len += strlen(da->da_remotestr) + 1;    /* string plus comma */
725         }
726
727         remotestr = kzalloc(len, gfp_flags);
728         if (!remotestr)
729                 return NULL;
730
731         p = remotestr;
732         *(p++) = '{';
733         len--;
734         list_for_each_entry(da, dsaddrs, da_node) {
735                 size_t ll = strlen(da->da_remotestr);
736
737                 if (ll > len)
738                         goto out_err;
739
740                 memcpy(p, da->da_remotestr, ll);
741                 p += ll;
742                 len -= ll;
743
744                 if (len < 1)
745                         goto out_err;
746                 (*p++) = ',';
747                 len--;
748         }
749         if (len < 2)
750                 goto out_err;
751         *(p++) = '}';
752         *p = '\0';
753         return remotestr;
754 out_err:
755         kfree(remotestr);
756         return NULL;
757 }
758
759 /*
760  * Given a list of multipath struct nfs4_pnfs_ds_addr, add it to ds cache if
761  * uncached and return cached struct nfs4_pnfs_ds.
762  */
763 struct nfs4_pnfs_ds *
764 nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags)
765 {
766         struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
767         char *remotestr;
768
769         if (list_empty(dsaddrs)) {
770                 dprintk("%s: no addresses defined\n", __func__);
771                 goto out;
772         }
773
774         ds = kzalloc(sizeof(*ds), gfp_flags);
775         if (!ds)
776                 goto out;
777
778         /* this is only used for debugging, so it's ok if its NULL */
779         remotestr = nfs4_pnfs_remotestr(dsaddrs, gfp_flags);
780
781         spin_lock(&nfs4_ds_cache_lock);
782         tmp_ds = _data_server_lookup_locked(dsaddrs);
783         if (tmp_ds == NULL) {
784                 INIT_LIST_HEAD(&ds->ds_addrs);
785                 list_splice_init(dsaddrs, &ds->ds_addrs);
786                 ds->ds_remotestr = remotestr;
787                 refcount_set(&ds->ds_count, 1);
788                 INIT_LIST_HEAD(&ds->ds_node);
789                 ds->ds_clp = NULL;
790                 list_add(&ds->ds_node, &nfs4_data_server_cache);
791                 dprintk("%s add new data server %s\n", __func__,
792                         ds->ds_remotestr);
793         } else {
794                 kfree(remotestr);
795                 kfree(ds);
796                 refcount_inc(&tmp_ds->ds_count);
797                 dprintk("%s data server %s found, inc'ed ds_count to %d\n",
798                         __func__, tmp_ds->ds_remotestr,
799                         refcount_read(&tmp_ds->ds_count));
800                 ds = tmp_ds;
801         }
802         spin_unlock(&nfs4_ds_cache_lock);
803 out:
804         return ds;
805 }
806 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_add);
807
808 static void nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds)
809 {
810         might_sleep();
811         wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING,
812                         TASK_KILLABLE);
813 }
814
815 static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
816 {
817         smp_mb__before_atomic();
818         clear_bit(NFS4DS_CONNECTING, &ds->ds_state);
819         smp_mb__after_atomic();
820         wake_up_bit(&ds->ds_state, NFS4DS_CONNECTING);
821 }
822
823 static struct nfs_client *(*get_v3_ds_connect)(
824                         struct nfs_server *mds_srv,
825                         const struct sockaddr *ds_addr,
826                         int ds_addrlen,
827                         int ds_proto,
828                         unsigned int ds_timeo,
829                         unsigned int ds_retrans);
830
831 static bool load_v3_ds_connect(void)
832 {
833         if (!get_v3_ds_connect) {
834                 get_v3_ds_connect = symbol_request(nfs3_set_ds_client);
835                 WARN_ON_ONCE(!get_v3_ds_connect);
836         }
837
838         return(get_v3_ds_connect != NULL);
839 }
840
841 void nfs4_pnfs_v3_ds_connect_unload(void)
842 {
843         if (get_v3_ds_connect) {
844                 symbol_put(nfs3_set_ds_client);
845                 get_v3_ds_connect = NULL;
846         }
847 }
848
849 static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
850                                  struct nfs4_pnfs_ds *ds,
851                                  unsigned int timeo,
852                                  unsigned int retrans)
853 {
854         struct nfs_client *clp = ERR_PTR(-EIO);
855         struct nfs4_pnfs_ds_addr *da;
856         int status = 0;
857
858         dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
859
860         if (!load_v3_ds_connect())
861                 goto out;
862
863         list_for_each_entry(da, &ds->ds_addrs, da_node) {
864                 dprintk("%s: DS %s: trying address %s\n",
865                         __func__, ds->ds_remotestr, da->da_remotestr);
866
867                 if (!IS_ERR(clp)) {
868                         struct xprt_create xprt_args = {
869                                 .ident = da->da_transport,
870                                 .net = clp->cl_net,
871                                 .dstaddr = (struct sockaddr *)&da->da_addr,
872                                 .addrlen = da->da_addrlen,
873                                 .servername = clp->cl_hostname,
874                         };
875
876                         if (da->da_transport != clp->cl_proto)
877                                 continue;
878                         if (da->da_addr.ss_family != clp->cl_addr.ss_family)
879                                 continue;
880                         /* Add this address as an alias */
881                         rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
882                                         rpc_clnt_test_and_add_xprt, NULL);
883                         continue;
884                 }
885                 clp = get_v3_ds_connect(mds_srv,
886                                 (struct sockaddr *)&da->da_addr,
887                                 da->da_addrlen, da->da_transport,
888                                 timeo, retrans);
889                 if (IS_ERR(clp))
890                         continue;
891                 clp->cl_rpcclient->cl_softerr = 0;
892                 clp->cl_rpcclient->cl_softrtry = 0;
893         }
894
895         if (IS_ERR(clp)) {
896                 status = PTR_ERR(clp);
897                 goto out;
898         }
899
900         smp_wmb();
901         ds->ds_clp = clp;
902         dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
903 out:
904         return status;
905 }
906
907 static int _nfs4_pnfs_v4_ds_connect(struct nfs_server *mds_srv,
908                                  struct nfs4_pnfs_ds *ds,
909                                  unsigned int timeo,
910                                  unsigned int retrans,
911                                  u32 minor_version)
912 {
913         struct nfs_client *clp = ERR_PTR(-EIO);
914         struct nfs4_pnfs_ds_addr *da;
915         int status = 0;
916
917         dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);
918
919         list_for_each_entry(da, &ds->ds_addrs, da_node) {
920                 dprintk("%s: DS %s: trying address %s\n",
921                         __func__, ds->ds_remotestr, da->da_remotestr);
922
923                 if (!IS_ERR(clp) && clp->cl_mvops->session_trunk) {
924                         struct xprt_create xprt_args = {
925                                 .ident = da->da_transport,
926                                 .net = clp->cl_net,
927                                 .dstaddr = (struct sockaddr *)&da->da_addr,
928                                 .addrlen = da->da_addrlen,
929                                 .servername = clp->cl_hostname,
930                         };
931                         struct nfs4_add_xprt_data xprtdata = {
932                                 .clp = clp,
933                         };
934                         struct rpc_add_xprt_test rpcdata = {
935                                 .add_xprt_test = clp->cl_mvops->session_trunk,
936                                 .data = &xprtdata,
937                         };
938
939                         if (da->da_transport != clp->cl_proto)
940                                 continue;
941                         if (da->da_addr.ss_family != clp->cl_addr.ss_family)
942                                 continue;
943                         /**
944                         * Test this address for session trunking and
945                         * add as an alias
946                         */
947                         xprtdata.cred = nfs4_get_clid_cred(clp),
948                         rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
949                                           rpc_clnt_setup_test_and_add_xprt,
950                                           &rpcdata);
951                         if (xprtdata.cred)
952                                 put_cred(xprtdata.cred);
953                 } else {
954                         clp = nfs4_set_ds_client(mds_srv,
955                                                 (struct sockaddr *)&da->da_addr,
956                                                 da->da_addrlen,
957                                                 da->da_transport, timeo,
958                                                 retrans, minor_version);
959                         if (IS_ERR(clp))
960                                 continue;
961
962                         status = nfs4_init_ds_session(clp,
963                                         mds_srv->nfs_client->cl_lease_time);
964                         if (status) {
965                                 nfs_put_client(clp);
966                                 clp = ERR_PTR(-EIO);
967                                 continue;
968                         }
969
970                 }
971         }
972
973         if (IS_ERR(clp)) {
974                 status = PTR_ERR(clp);
975                 goto out;
976         }
977
978         smp_wmb();
979         ds->ds_clp = clp;
980         dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
981 out:
982         return status;
983 }
984
985 /*
986  * Create an rpc connection to the nfs4_pnfs_ds data server.
987  * Currently only supports IPv4 and IPv6 addresses.
988  * If connection fails, make devid unavailable and return a -errno.
989  */
990 int nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
991                           struct nfs4_deviceid_node *devid, unsigned int timeo,
992                           unsigned int retrans, u32 version, u32 minor_version)
993 {
994         int err;
995
996 again:
997         err = 0;
998         if (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) == 0) {
999                 if (version == 3) {
1000                         err = _nfs4_pnfs_v3_ds_connect(mds_srv, ds, timeo,
1001                                                        retrans);
1002                 } else if (version == 4) {
1003                         err = _nfs4_pnfs_v4_ds_connect(mds_srv, ds, timeo,
1004                                                        retrans, minor_version);
1005                 } else {
1006                         dprintk("%s: unsupported DS version %d\n", __func__,
1007                                 version);
1008                         err = -EPROTONOSUPPORT;
1009                 }
1010
1011                 nfs4_clear_ds_conn_bit(ds);
1012         } else {
1013                 nfs4_wait_ds_connect(ds);
1014
1015                 /* what was waited on didn't connect AND didn't mark unavail */
1016                 if (!ds->ds_clp && !nfs4_test_deviceid_unavailable(devid))
1017                         goto again;
1018         }
1019
1020         /*
1021          * At this point the ds->ds_clp should be ready, but it might have
1022          * hit an error.
1023          */
1024         if (!err) {
1025                 if (!ds->ds_clp || !nfs_client_init_is_complete(ds->ds_clp)) {
1026                         WARN_ON_ONCE(ds->ds_clp ||
1027                                 !nfs4_test_deviceid_unavailable(devid));
1028                         return -EINVAL;
1029                 }
1030                 err = nfs_client_init_status(ds->ds_clp);
1031         }
1032
1033         return err;
1034 }
1035 EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_connect);
1036
1037 /*
1038  * Currently only supports ipv4, ipv6 and one multi-path address.
1039  */
1040 struct nfs4_pnfs_ds_addr *
1041 nfs4_decode_mp_ds_addr(struct net *net, struct xdr_stream *xdr, gfp_t gfp_flags)
1042 {
1043         struct nfs4_pnfs_ds_addr *da = NULL;
1044         char *buf, *portstr;
1045         __be16 port;
1046         ssize_t nlen, rlen;
1047         int tmp[2];
1048         char *netid;
1049         size_t len;
1050         char *startsep = "";
1051         char *endsep = "";
1052
1053
1054         /* r_netid */
1055         nlen = xdr_stream_decode_string_dup(xdr, &netid, XDR_MAX_NETOBJ,
1056                                             gfp_flags);
1057         if (unlikely(nlen < 0))
1058                 goto out_err;
1059
1060         /* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */
1061         /* port is ".ABC.DEF", 8 chars max */
1062         rlen = xdr_stream_decode_string_dup(xdr, &buf, INET6_ADDRSTRLEN +
1063                                             IPV6_SCOPE_ID_LEN + 8, gfp_flags);
1064         if (unlikely(rlen < 0))
1065                 goto out_free_netid;
1066
1067         /* replace port '.' with '-' */
1068         portstr = strrchr(buf, '.');
1069         if (!portstr) {
1070                 dprintk("%s: Failed finding expected dot in port\n",
1071                         __func__);
1072                 goto out_free_buf;
1073         }
1074         *portstr = '-';
1075
1076         /* find '.' between address and port */
1077         portstr = strrchr(buf, '.');
1078         if (!portstr) {
1079                 dprintk("%s: Failed finding expected dot between address and "
1080                         "port\n", __func__);
1081                 goto out_free_buf;
1082         }
1083         *portstr = '\0';
1084
1085         da = nfs4_pnfs_ds_addr_alloc(gfp_flags);
1086         if (unlikely(!da))
1087                 goto out_free_buf;
1088
1089         if (!rpc_pton(net, buf, portstr-buf, (struct sockaddr *)&da->da_addr,
1090                       sizeof(da->da_addr))) {
1091                 dprintk("%s: error parsing address %s\n", __func__, buf);
1092                 goto out_free_da;
1093         }
1094
1095         portstr++;
1096         sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]);
1097         port = htons((tmp[0] << 8) | (tmp[1]));
1098
1099         switch (da->da_addr.ss_family) {
1100         case AF_INET:
1101                 ((struct sockaddr_in *)&da->da_addr)->sin_port = port;
1102                 da->da_addrlen = sizeof(struct sockaddr_in);
1103                 break;
1104
1105         case AF_INET6:
1106                 ((struct sockaddr_in6 *)&da->da_addr)->sin6_port = port;
1107                 da->da_addrlen = sizeof(struct sockaddr_in6);
1108                 startsep = "[";
1109                 endsep = "]";
1110                 break;
1111
1112         default:
1113                 dprintk("%s: unsupported address family: %u\n",
1114                         __func__, da->da_addr.ss_family);
1115                 goto out_free_da;
1116         }
1117
1118         da->da_transport = xprt_find_transport_ident(netid);
1119         if (da->da_transport < 0) {
1120                 dprintk("%s: ERROR: unknown r_netid \"%s\"\n",
1121                         __func__, netid);
1122                 goto out_free_da;
1123         }
1124
1125         da->da_netid = netid;
1126
1127         /* save human readable address */
1128         len = strlen(startsep) + strlen(buf) + strlen(endsep) + 7;
1129         da->da_remotestr = kzalloc(len, gfp_flags);
1130
1131         /* NULL is ok, only used for dprintk */
1132         if (da->da_remotestr)
1133                 snprintf(da->da_remotestr, len, "%s%s%s:%u", startsep,
1134                          buf, endsep, ntohs(port));
1135
1136         dprintk("%s: Parsed DS addr %s\n", __func__, da->da_remotestr);
1137         kfree(buf);
1138         return da;
1139
1140 out_free_da:
1141         kfree(da);
1142 out_free_buf:
1143         dprintk("%s: Error parsing DS addr: %s\n", __func__, buf);
1144         kfree(buf);
1145 out_free_netid:
1146         kfree(netid);
1147 out_err:
1148         return NULL;
1149 }
1150 EXPORT_SYMBOL_GPL(nfs4_decode_mp_ds_addr);
1151
1152 void
1153 pnfs_layout_mark_request_commit(struct nfs_page *req,
1154                                 struct pnfs_layout_segment *lseg,
1155                                 struct nfs_commit_info *cinfo,
1156                                 u32 ds_commit_idx)
1157 {
1158         struct list_head *list;
1159         struct pnfs_commit_array *array;
1160         struct pnfs_commit_bucket *bucket;
1161
1162         mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
1163         array = pnfs_lookup_commit_array(cinfo->ds, lseg);
1164         if (!array || !pnfs_is_valid_lseg(lseg))
1165                 goto out_resched;
1166         bucket = &array->buckets[ds_commit_idx];
1167         list = &bucket->written;
1168         /* Non-empty buckets hold a reference on the lseg.  That ref
1169          * is normally transferred to the COMMIT call and released
1170          * there.  It could also be released if the last req is pulled
1171          * off due to a rewrite, in which case it will be done in
1172          * pnfs_common_clear_request_commit
1173          */
1174         if (!bucket->lseg)
1175                 bucket->lseg = pnfs_get_lseg(lseg);
1176         set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
1177         cinfo->ds->nwritten++;
1178
1179         nfs_request_add_commit_list_locked(req, list, cinfo);
1180         mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1181         nfs_mark_page_unstable(req->wb_page, cinfo);
1182         return;
1183 out_resched:
1184         mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
1185         cinfo->completion_ops->resched_write(cinfo, req);
1186 }
1187 EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);
1188
1189 int
1190 pnfs_nfs_generic_sync(struct inode *inode, bool datasync)
1191 {
1192         int ret;
1193
1194         if (!pnfs_layoutcommit_outstanding(inode))
1195                 return 0;
1196         ret = nfs_commit_inode(inode, FLUSH_SYNC);
1197         if (ret < 0)
1198                 return ret;
1199         if (datasync)
1200                 return 0;
1201         return pnfs_layoutcommit_inode(inode, true);
1202 }
1203 EXPORT_SYMBOL_GPL(pnfs_nfs_generic_sync);
1204