fs/nfs/pnfs_nfs.c

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