fs/nfs/nfs4filelayoutdev.c

   1 /*
   2  *  Device operations for the pnfs nfs4 file layout driver.
   3  *
   4  *  Copyright (c) 2002
   5  *  The Regents of the University of Michigan
   6  *  All Rights Reserved
   7  *
   8  *  Dean Hildebrand <dhildebz@umich.edu>
   9  *  Garth Goodson   <Garth.Goodson@netapp.com>
  10  *
  11  *  Permission is granted to use, copy, create derivative works, and
  12  *  redistribute this software and such derivative works for any purpose,
  13  *  so long as the name of the University of Michigan is not used in
  14  *  any advertising or publicity pertaining to the use or distribution
  15  *  of this software without specific, written prior authorization. If
  16  *  the above copyright notice or any other identification of the
  17  *  University of Michigan is included in any copy of any portion of
  18  *  this software, then the disclaimer below must also be included.
  19  *
  20  *  This software is provided as is, without representation or warranty
  21  *  of any kind either express or implied, including without limitation
  22  *  the implied warranties of merchantability, fitness for a particular
  23  *  purpose, or noninfringement.  The Regents of the University of
  24  *  Michigan shall not be liable for any damages, including special,
  25  *  indirect, incidental, or consequential damages, with respect to any
  26  *  claim arising out of or in connection with the use of the software,
  27  *  even if it has been or is hereafter advised of the possibility of
  28  *  such damages.
  29  */
  30
  31 #include <linux/nfs_fs.h>
  32 #include <linux/vmalloc.h>
  33 #include <linux/module.h>
  34 #include <linux/sunrpc/addr.h>
  35
  36 #include "internal.h"
  37 #include "nfs4session.h"
  38 #include "nfs4filelayout.h"
  39
  40 #define NFSDBG_FACILITY         NFSDBG_PNFS_LD
  41
  42 static unsigned int dataserver_timeo = NFS4_DEF_DS_TIMEO;
  43 static unsigned int dataserver_retrans = NFS4_DEF_DS_RETRANS;
  44
  45 /*
  46  * Data server cache
  47  *
  48  * Data servers can be mapped to different device ids.
  49  * nfs4_pnfs_ds reference counting
  50  *   - set to 1 on allocation
  51  *   - incremented when a device id maps a data server already in the cache.
  52  *   - decremented when deviceid is removed from the cache.
  53  */
  54 static DEFINE_SPINLOCK(nfs4_ds_cache_lock);
  55 static LIST_HEAD(nfs4_data_server_cache);
  56
  57 /* Debug routines */
  58 void
  59 print_ds(struct nfs4_pnfs_ds *ds)
  60 {
  61         if (ds == NULL) {
  62                 printk("%s NULL device\n", __func__);
  63                 return;
  64         }
  65         printk("        ds %s\n"
  66                 "        ref count %d\n"
  67                 "        client %p\n"
  68                 "        cl_exchange_flags %x\n",
  69                 ds->ds_remotestr,
  70                 atomic_read(&ds->ds_count), ds->ds_clp,
  71                 ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
  72 }
  73
  74 static bool
  75 same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
  76 {
  77         struct sockaddr_in *a, *b;
  78         struct sockaddr_in6 *a6, *b6;
  79
  80         if (addr1->sa_family != addr2->sa_family)
  81                 return false;
  82
  83         switch (addr1->sa_family) {
  84         case AF_INET:
  85                 a = (struct sockaddr_in *)addr1;
  86                 b = (struct sockaddr_in *)addr2;
  87
  88                 if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
  89                     a->sin_port == b->sin_port)
  90                         return true;
  91                 break;
  92
  93         case AF_INET6:
  94                 a6 = (struct sockaddr_in6 *)addr1;
  95                 b6 = (struct sockaddr_in6 *)addr2;
  96
  97                 /* LINKLOCAL addresses must have matching scope_id */
  98                 if (ipv6_addr_scope(&a6->sin6_addr) ==
  99                     IPV6_ADDR_SCOPE_LINKLOCAL &&
 100                     a6->sin6_scope_id != b6->sin6_scope_id)
 101                         return false;
 102
 103                 if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
 104                     a6->sin6_port == b6->sin6_port)
 105                         return true;
 106                 break;
 107
 108         default:
 109                 dprintk("%s: unhandled address family: %u\n",
 110                         __func__, addr1->sa_family);
 111                 return false;
 112         }
 113
 114         return false;
 115 }
 116
 117 static bool
 118 _same_data_server_addrs_locked(const struct list_head *dsaddrs1,
 119                                const struct list_head *dsaddrs2)
 120 {
 121         struct nfs4_pnfs_ds_addr *da1, *da2;
 122
 123         /* step through both lists, comparing as we go */
 124         for (da1 = list_first_entry(dsaddrs1, typeof(*da1), da_node),
 125              da2 = list_first_entry(dsaddrs2, typeof(*da2), da_node);
 126              da1 != NULL && da2 != NULL;
 127              da1 = list_entry(da1->da_node.next, typeof(*da1), da_node),
 128              da2 = list_entry(da2->da_node.next, typeof(*da2), da_node)) {
 129                 if (!same_sockaddr((struct sockaddr *)&da1->da_addr,
 130                                    (struct sockaddr *)&da2->da_addr))
 131                         return false;
 132         }
 133         if (da1 == NULL && da2 == NULL)
 134                 return true;
 135
 136         return false;
 137 }
 138
 139 /*
 140  * Lookup DS by addresses.  nfs4_ds_cache_lock is held
 141  */
 142 static struct nfs4_pnfs_ds *
 143 _data_server_lookup_locked(const struct list_head *dsaddrs)
 144 {
 145         struct nfs4_pnfs_ds *ds;
 146
 147         list_for_each_entry(ds, &nfs4_data_server_cache, ds_node)
 148                 if (_same_data_server_addrs_locked(&ds->ds_addrs, dsaddrs))
 149                         return ds;
 150         return NULL;
 151 }
 152
 153 /*
 154  * Create an rpc connection to the nfs4_pnfs_ds data server
 155  * Currently only supports IPv4 and IPv6 addresses
 156  */
 157 static int
 158 nfs4_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds)
 159 {
 160         struct nfs_client *clp = ERR_PTR(-EIO);
 161         struct nfs4_pnfs_ds_addr *da;
 162         int status = 0;
 163
 164         dprintk("--> %s DS %s au_flavor %d\n", __func__, ds->ds_remotestr,
 165                 mds_srv->nfs_client->cl_rpcclient->cl_auth->au_flavor);
 166
 167         list_for_each_entry(da, &ds->ds_addrs, da_node) {
 168                 dprintk("%s: DS %s: trying address %s\n",
 169                         __func__, ds->ds_remotestr, da->da_remotestr);
 170
 171                 clp = nfs4_set_ds_client(mds_srv->nfs_client,
 172                                         (struct sockaddr *)&da->da_addr,
 173                                         da->da_addrlen, IPPROTO_TCP,
 174                                         dataserver_timeo, dataserver_retrans);
 175                 if (!IS_ERR(clp))
 176                         break;
 177         }
 178
 179         if (IS_ERR(clp)) {
 180                 status = PTR_ERR(clp);
 181                 goto out;
 182         }
 183
 184         status = nfs4_init_ds_session(clp, mds_srv->nfs_client->cl_lease_time);
 185         if (status)
 186                 goto out_put;
 187
 188         ds->ds_clp = clp;
 189         dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
 190 out:
 191         return status;
 192 out_put:
 193         nfs_put_client(clp);
 194         goto out;
 195 }
 196
 197 static void
 198 destroy_ds(struct nfs4_pnfs_ds *ds)
 199 {
 200         struct nfs4_pnfs_ds_addr *da;
 201
 202         dprintk("--> %s\n", __func__);
 203         ifdebug(FACILITY)
 204                 print_ds(ds);
 205
 206         if (ds->ds_clp)
 207                 nfs_put_client(ds->ds_clp);
 208
 209         while (!list_empty(&ds->ds_addrs)) {
 210                 da = list_first_entry(&ds->ds_addrs,
 211                                       struct nfs4_pnfs_ds_addr,
 212                                       da_node);
 213                 list_del_init(&da->da_node);
 214                 kfree(da->da_remotestr);
 215                 kfree(da);
 216         }
 217
 218         kfree(ds->ds_remotestr);
 219         kfree(ds);
 220 }
 221
 222 void
 223 nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
 224 {
 225         struct nfs4_pnfs_ds *ds;
 226         int i;
 227
 228         nfs4_print_deviceid(&dsaddr->id_node.deviceid);
 229
 230         for (i = 0; i < dsaddr->ds_num; i++) {
 231                 ds = dsaddr->ds_list[i];
 232                 if (ds != NULL) {
 233                         if (atomic_dec_and_lock(&ds->ds_count,
 234                                                 &nfs4_ds_cache_lock)) {
 235                                 list_del_init(&ds->ds_node);
 236                                 spin_unlock(&nfs4_ds_cache_lock);
 237                                 destroy_ds(ds);
 238                         }
 239                 }
 240         }
 241         kfree(dsaddr->stripe_indices);
 242         kfree(dsaddr);
 243 }
 244
 245 /*
 246  * Create a string with a human readable address and port to avoid
 247  * complicated setup around many dprinks.
 248  */
 249 static char *
 250 nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags)
 251 {
 252         struct nfs4_pnfs_ds_addr *da;
 253         char *remotestr;
 254         size_t len;
 255         char *p;
 256
 257         len = 3;        /* '{', '}' and eol */
 258         list_for_each_entry(da, dsaddrs, da_node) {
 259                 len += strlen(da->da_remotestr) + 1;    /* string plus comma */
 260         }
 261
 262         remotestr = kzalloc(len, gfp_flags);
 263         if (!remotestr)
 264                 return NULL;
 265
 266         p = remotestr;
 267         *(p++) = '{';
 268         len--;
 269         list_for_each_entry(da, dsaddrs, da_node) {
 270                 size_t ll = strlen(da->da_remotestr);
 271
 272                 if (ll > len)
 273                         goto out_err;
 274
 275                 memcpy(p, da->da_remotestr, ll);
 276                 p += ll;
 277                 len -= ll;
 278
 279                 if (len < 1)
 280                         goto out_err;
 281                 (*p++) = ',';
 282                 len--;
 283         }
 284         if (len < 2)
 285                 goto out_err;
 286         *(p++) = '}';
 287         *p = '\0';
 288         return remotestr;
 289 out_err:
 290         kfree(remotestr);
 291         return NULL;
 292 }
 293
 294 static struct nfs4_pnfs_ds *
 295 nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags)
 296 {
 297         struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
 298         char *remotestr;
 299
 300         if (list_empty(dsaddrs)) {
 301                 dprintk("%s: no addresses defined\n", __func__);
 302                 goto out;
 303         }
 304
 305         ds = kzalloc(sizeof(*ds), gfp_flags);
 306         if (!ds)
 307                 goto out;
 308
 309         /* this is only used for debugging, so it's ok if its NULL */
 310         remotestr = nfs4_pnfs_remotestr(dsaddrs, gfp_flags);
 311
 312         spin_lock(&nfs4_ds_cache_lock);
 313         tmp_ds = _data_server_lookup_locked(dsaddrs);
 314         if (tmp_ds == NULL) {
 315                 INIT_LIST_HEAD(&ds->ds_addrs);
 316                 list_splice_init(dsaddrs, &ds->ds_addrs);
 317                 ds->ds_remotestr = remotestr;
 318                 atomic_set(&ds->ds_count, 1);
 319                 INIT_LIST_HEAD(&ds->ds_node);
 320                 ds->ds_clp = NULL;
 321                 list_add(&ds->ds_node, &nfs4_data_server_cache);
 322                 dprintk("%s add new data server %s\n", __func__,
 323                         ds->ds_remotestr);
 324         } else {
 325                 kfree(remotestr);
 326                 kfree(ds);
 327                 atomic_inc(&tmp_ds->ds_count);
 328                 dprintk("%s data server %s found, inc'ed ds_count to %d\n",
 329                         __func__, tmp_ds->ds_remotestr,
 330                         atomic_read(&tmp_ds->ds_count));
 331                 ds = tmp_ds;
 332         }
 333         spin_unlock(&nfs4_ds_cache_lock);
 334 out:
 335         return ds;
 336 }
 337
 338 /*
 339  * Currently only supports ipv4, ipv6 and one multi-path address.
 340  */
 341 static struct nfs4_pnfs_ds_addr *
 342 decode_ds_addr(struct net *net, struct xdr_stream *streamp, gfp_t gfp_flags)
 343 {
 344         struct nfs4_pnfs_ds_addr *da = NULL;
 345         char *buf, *portstr;
 346         __be16 port;
 347         int nlen, rlen;
 348         int tmp[2];
 349         __be32 *p;
 350         char *netid, *match_netid;
 351         size_t len, match_netid_len;
 352         char *startsep = "";
 353         char *endsep = "";
 354
 355
 356         /* r_netid */
 357         p = xdr_inline_decode(streamp, 4);
 358         if (unlikely(!p))
 359                 goto out_err;
 360         nlen = be32_to_cpup(p++);
 361
 362         p = xdr_inline_decode(streamp, nlen);
 363         if (unlikely(!p))
 364                 goto out_err;
 365
 366         netid = kmalloc(nlen+1, gfp_flags);
 367         if (unlikely(!netid))
 368                 goto out_err;
 369
 370         netid[nlen] = '\0';
 371         memcpy(netid, p, nlen);
 372
 373         /* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */
 374         p = xdr_inline_decode(streamp, 4);
 375         if (unlikely(!p))
 376                 goto out_free_netid;
 377         rlen = be32_to_cpup(p);
 378
 379         p = xdr_inline_decode(streamp, rlen);
 380         if (unlikely(!p))
 381                 goto out_free_netid;
 382
 383         /* port is ".ABC.DEF", 8 chars max */
 384         if (rlen > INET6_ADDRSTRLEN + IPV6_SCOPE_ID_LEN + 8) {
 385                 dprintk("%s: Invalid address, length %d\n", __func__,
 386                         rlen);
 387                 goto out_free_netid;
 388         }
 389         buf = kmalloc(rlen + 1, gfp_flags);
 390         if (!buf) {
 391                 dprintk("%s: Not enough memory\n", __func__);
 392                 goto out_free_netid;
 393         }
 394         buf[rlen] = '\0';
 395         memcpy(buf, p, rlen);
 396
 397         /* replace port '.' with '-' */
 398         portstr = strrchr(buf, '.');
 399         if (!portstr) {
 400                 dprintk("%s: Failed finding expected dot in port\n",
 401                         __func__);
 402                 goto out_free_buf;
 403         }
 404         *portstr = '-';
 405
 406         /* find '.' between address and port */
 407         portstr = strrchr(buf, '.');
 408         if (!portstr) {
 409                 dprintk("%s: Failed finding expected dot between address and "
 410                         "port\n", __func__);
 411                 goto out_free_buf;
 412         }
 413         *portstr = '\0';
 414
 415         da = kzalloc(sizeof(*da), gfp_flags);
 416         if (unlikely(!da))
 417                 goto out_free_buf;
 418
 419         INIT_LIST_HEAD(&da->da_node);
 420
 421         if (!rpc_pton(net, buf, portstr-buf, (struct sockaddr *)&da->da_addr,
 422                       sizeof(da->da_addr))) {
 423                 dprintk("%s: error parsing address %s\n", __func__, buf);
 424                 goto out_free_da;
 425         }
 426
 427         portstr++;
 428         sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]);
 429         port = htons((tmp[0] << 8) | (tmp[1]));
 430
 431         switch (da->da_addr.ss_family) {
 432         case AF_INET:
 433                 ((struct sockaddr_in *)&da->da_addr)->sin_port = port;
 434                 da->da_addrlen = sizeof(struct sockaddr_in);
 435                 match_netid = "tcp";
 436                 match_netid_len = 3;
 437                 break;
 438
 439         case AF_INET6:
 440                 ((struct sockaddr_in6 *)&da->da_addr)->sin6_port = port;
 441                 da->da_addrlen = sizeof(struct sockaddr_in6);
 442                 match_netid = "tcp6";
 443                 match_netid_len = 4;
 444                 startsep = "[";
 445                 endsep = "]";
 446                 break;
 447
 448         default:
 449                 dprintk("%s: unsupported address family: %u\n",
 450                         __func__, da->da_addr.ss_family);
 451                 goto out_free_da;
 452         }
 453
 454         if (nlen != match_netid_len || strncmp(netid, match_netid, nlen)) {
 455                 dprintk("%s: ERROR: r_netid \"%s\" != \"%s\"\n",
 456                         __func__, netid, match_netid);
 457                 goto out_free_da;
 458         }
 459
 460         /* save human readable address */
 461         len = strlen(startsep) + strlen(buf) + strlen(endsep) + 7;
 462         da->da_remotestr = kzalloc(len, gfp_flags);
 463
 464         /* NULL is ok, only used for dprintk */
 465         if (da->da_remotestr)
 466                 snprintf(da->da_remotestr, len, "%s%s%s:%u", startsep,
 467                          buf, endsep, ntohs(port));
 468
 469         dprintk("%s: Parsed DS addr %s\n", __func__, da->da_remotestr);
 470         kfree(buf);
 471         kfree(netid);
 472         return da;
 473
 474 out_free_da:
 475         kfree(da);
 476 out_free_buf:
 477         dprintk("%s: Error parsing DS addr: %s\n", __func__, buf);
 478         kfree(buf);
 479 out_free_netid:
 480         kfree(netid);
 481 out_err:
 482         return NULL;
 483 }
 484
 485 /* Decode opaque device data and return the result */
 486 static struct nfs4_file_layout_dsaddr*
 487 decode_device(struct inode *ino, struct pnfs_device *pdev, gfp_t gfp_flags)
 488 {
 489         int i;
 490         u32 cnt, num;
 491         u8 *indexp;
 492         __be32 *p;
 493         u8 *stripe_indices;
 494         u8 max_stripe_index;
 495         struct nfs4_file_layout_dsaddr *dsaddr = NULL;
 496         struct xdr_stream stream;
 497         struct xdr_buf buf;
 498         struct page *scratch;
 499         struct list_head dsaddrs;
 500         struct nfs4_pnfs_ds_addr *da;
 501
 502         /* set up xdr stream */
 503         scratch = alloc_page(gfp_flags);
 504         if (!scratch)
 505                 goto out_err;
 506
 507         xdr_init_decode_pages(&stream, &buf, pdev->pages, pdev->pglen);
 508         xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
 509
 510         /* Get the stripe count (number of stripe index) */
 511         p = xdr_inline_decode(&stream, 4);
 512         if (unlikely(!p))
 513                 goto out_err_free_scratch;
 514
 515         cnt = be32_to_cpup(p);
 516         dprintk("%s stripe count  %d\n", __func__, cnt);
 517         if (cnt > NFS4_PNFS_MAX_STRIPE_CNT) {
 518                 printk(KERN_WARNING "NFS: %s: stripe count %d greater than "
 519                        "supported maximum %d\n", __func__,
 520                         cnt, NFS4_PNFS_MAX_STRIPE_CNT);
 521                 goto out_err_free_scratch;
 522         }
 523
 524         /* read stripe indices */
 525         stripe_indices = kcalloc(cnt, sizeof(u8), gfp_flags);
 526         if (!stripe_indices)
 527                 goto out_err_free_scratch;
 528
 529         p = xdr_inline_decode(&stream, cnt << 2);
 530         if (unlikely(!p))
 531                 goto out_err_free_stripe_indices;
 532
 533         indexp = &stripe_indices[0];
 534         max_stripe_index = 0;
 535         for (i = 0; i < cnt; i++) {
 536                 *indexp = be32_to_cpup(p++);
 537                 max_stripe_index = max(max_stripe_index, *indexp);
 538                 indexp++;
 539         }
 540
 541         /* Check the multipath list count */
 542         p = xdr_inline_decode(&stream, 4);
 543         if (unlikely(!p))
 544                 goto out_err_free_stripe_indices;
 545
 546         num = be32_to_cpup(p);
 547         dprintk("%s ds_num %u\n", __func__, num);
 548         if (num > NFS4_PNFS_MAX_MULTI_CNT) {
 549                 printk(KERN_WARNING "NFS: %s: multipath count %d greater than "
 550                         "supported maximum %d\n", __func__,
 551                         num, NFS4_PNFS_MAX_MULTI_CNT);
 552                 goto out_err_free_stripe_indices;
 553         }
 554
 555         /* validate stripe indices are all < num */
 556         if (max_stripe_index >= num) {
 557                 printk(KERN_WARNING "NFS: %s: stripe index %u >= num ds %u\n",
 558                         __func__, max_stripe_index, num);
 559                 goto out_err_free_stripe_indices;
 560         }
 561
 562         dsaddr = kzalloc(sizeof(*dsaddr) +
 563                         (sizeof(struct nfs4_pnfs_ds *) * (num - 1)),
 564                         gfp_flags);
 565         if (!dsaddr)
 566                 goto out_err_free_stripe_indices;
 567
 568         dsaddr->stripe_count = cnt;
 569         dsaddr->stripe_indices = stripe_indices;
 570         stripe_indices = NULL;
 571         dsaddr->ds_num = num;
 572         nfs4_init_deviceid_node(&dsaddr->id_node,
 573                                 NFS_SERVER(ino)->pnfs_curr_ld,
 574                                 NFS_SERVER(ino)->nfs_client,
 575                                 &pdev->dev_id);
 576
 577         INIT_LIST_HEAD(&dsaddrs);
 578
 579         for (i = 0; i < dsaddr->ds_num; i++) {
 580                 int j;
 581                 u32 mp_count;
 582
 583                 p = xdr_inline_decode(&stream, 4);
 584                 if (unlikely(!p))
 585                         goto out_err_free_deviceid;
 586
 587                 mp_count = be32_to_cpup(p); /* multipath count */
 588                 for (j = 0; j < mp_count; j++) {
 589                         da = decode_ds_addr(NFS_SERVER(ino)->nfs_client->cl_net,
 590                                             &stream, gfp_flags);
 591                         if (da)
 592                                 list_add_tail(&da->da_node, &dsaddrs);
 593                 }
 594                 if (list_empty(&dsaddrs)) {
 595                         dprintk("%s: no suitable DS addresses found\n",
 596                                 __func__);
 597                         goto out_err_free_deviceid;
 598                 }
 599
 600                 dsaddr->ds_list[i] = nfs4_pnfs_ds_add(&dsaddrs, gfp_flags);
 601                 if (!dsaddr->ds_list[i])
 602                         goto out_err_drain_dsaddrs;
 603
 604                 /* If DS was already in cache, free ds addrs */
 605                 while (!list_empty(&dsaddrs)) {
 606                         da = list_first_entry(&dsaddrs,
 607                                               struct nfs4_pnfs_ds_addr,
 608                                               da_node);
 609                         list_del_init(&da->da_node);
 610                         kfree(da->da_remotestr);
 611                         kfree(da);
 612                 }
 613         }
 614
 615         __free_page(scratch);
 616         return dsaddr;
 617
 618 out_err_drain_dsaddrs:
 619         while (!list_empty(&dsaddrs)) {
 620                 da = list_first_entry(&dsaddrs, struct nfs4_pnfs_ds_addr,
 621                                       da_node);
 622                 list_del_init(&da->da_node);
 623                 kfree(da->da_remotestr);
 624                 kfree(da);
 625         }
 626 out_err_free_deviceid:
 627         nfs4_fl_free_deviceid(dsaddr);
 628         /* stripe_indicies was part of dsaddr */
 629         goto out_err_free_scratch;
 630 out_err_free_stripe_indices:
 631         kfree(stripe_indices);
 632 out_err_free_scratch:
 633         __free_page(scratch);
 634 out_err:
 635         dprintk("%s ERROR: returning NULL\n", __func__);
 636         return NULL;
 637 }
 638
 639 /*
 640  * Decode the opaque device specified in 'dev' and add it to the cache of
 641  * available devices.
 642  */
 643 static struct nfs4_file_layout_dsaddr *
 644 decode_and_add_device(struct inode *inode, struct pnfs_device *dev, gfp_t gfp_flags)
 645 {
 646         struct nfs4_deviceid_node *d;
 647         struct nfs4_file_layout_dsaddr *n, *new;
 648
 649         new = decode_device(inode, dev, gfp_flags);
 650         if (!new) {
 651                 printk(KERN_WARNING "NFS: %s: Could not decode or add device\n",
 652                         __func__);
 653                 return NULL;
 654         }
 655
 656         d = nfs4_insert_deviceid_node(&new->id_node);
 657         n = container_of(d, struct nfs4_file_layout_dsaddr, id_node);
 658         if (n != new) {
 659                 nfs4_fl_free_deviceid(new);
 660                 return n;
 661         }
 662
 663         return new;
 664 }
 665
 666 /*
 667  * Retrieve the information for dev_id, add it to the list
 668  * of available devices, and return it.
 669  */
 670 struct nfs4_file_layout_dsaddr *
 671 filelayout_get_device_info(struct inode *inode, struct nfs4_deviceid *dev_id, gfp_t gfp_flags)
 672 {
 673         struct pnfs_device *pdev = NULL;
 674         u32 max_resp_sz;
 675         int max_pages;
 676         struct page **pages = NULL;
 677         struct nfs4_file_layout_dsaddr *dsaddr = NULL;
 678         int rc, i;
 679         struct nfs_server *server = NFS_SERVER(inode);
 680
 681         /*
 682          * Use the session max response size as the basis for setting
 683          * GETDEVICEINFO's maxcount
 684          */
 685         max_resp_sz = server->nfs_client->cl_session->fc_attrs.max_resp_sz;
 686         max_pages = nfs_page_array_len(0, max_resp_sz);
 687         dprintk("%s inode %p max_resp_sz %u max_pages %d\n",
 688                 __func__, inode, max_resp_sz, max_pages);
 689
 690         pdev = kzalloc(sizeof(struct pnfs_device), gfp_flags);
 691         if (pdev == NULL)
 692                 return NULL;
 693
 694         pages = kzalloc(max_pages * sizeof(struct page *), gfp_flags);
 695         if (pages == NULL) {
 696                 kfree(pdev);
 697                 return NULL;
 698         }
 699         for (i = 0; i < max_pages; i++) {
 700                 pages[i] = alloc_page(gfp_flags);
 701                 if (!pages[i])
 702                         goto out_free;
 703         }
 704
 705         memcpy(&pdev->dev_id, dev_id, sizeof(*dev_id));
 706         pdev->layout_type = LAYOUT_NFSV4_1_FILES;
 707         pdev->pages = pages;
 708         pdev->pgbase = 0;
 709         pdev->pglen = max_resp_sz;
 710         pdev->mincount = 0;
 711
 712         rc = nfs4_proc_getdeviceinfo(server, pdev);
 713         dprintk("%s getdevice info returns %d\n", __func__, rc);
 714         if (rc)
 715                 goto out_free;
 716
 717         /*
 718          * Found new device, need to decode it and then add it to the
 719          * list of known devices for this mountpoint.
 720          */
 721         dsaddr = decode_and_add_device(inode, pdev, gfp_flags);
 722 out_free:
 723         for (i = 0; i < max_pages; i++)
 724                 __free_page(pages[i]);
 725         kfree(pages);
 726         kfree(pdev);
 727         dprintk("<-- %s dsaddr %p\n", __func__, dsaddr);
 728         return dsaddr;
 729 }
 730
 731 void
 732 nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr)
 733 {
 734         nfs4_put_deviceid_node(&dsaddr->id_node);
 735 }
 736
 737 /*
 738  * Want res = (offset - layout->pattern_offset)/ layout->stripe_unit
 739  * Then: ((res + fsi) % dsaddr->stripe_count)
 740  */
 741 u32
 742 nfs4_fl_calc_j_index(struct pnfs_layout_segment *lseg, loff_t offset)
 743 {
 744         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
 745         u64 tmp;
 746
 747         tmp = offset - flseg->pattern_offset;
 748         do_div(tmp, flseg->stripe_unit);
 749         tmp += flseg->first_stripe_index;
 750         return do_div(tmp, flseg->dsaddr->stripe_count);
 751 }
 752
 753 u32
 754 nfs4_fl_calc_ds_index(struct pnfs_layout_segment *lseg, u32 j)
 755 {
 756         return FILELAYOUT_LSEG(lseg)->dsaddr->stripe_indices[j];
 757 }
 758
 759 struct nfs_fh *
 760 nfs4_fl_select_ds_fh(struct pnfs_layout_segment *lseg, u32 j)
 761 {
 762         struct nfs4_filelayout_segment *flseg = FILELAYOUT_LSEG(lseg);
 763         u32 i;
 764
 765         if (flseg->stripe_type == STRIPE_SPARSE) {
 766                 if (flseg->num_fh == 1)
 767                         i = 0;
 768                 else if (flseg->num_fh == 0)
 769                         /* Use the MDS OPEN fh set in nfs_read_rpcsetup */
 770                         return NULL;
 771                 else
 772                         i = nfs4_fl_calc_ds_index(lseg, j);
 773         } else
 774                 i = j;
 775         return flseg->fh_array[i];
 776 }
 777
 778 static void nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds)
 779 {
 780         might_sleep();
 781         wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING,
 782                         nfs_wait_bit_killable, TASK_KILLABLE);
 783 }
 784
 785 static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
 786 {
 787         smp_mb__before_clear_bit();
 788         clear_bit(NFS4DS_CONNECTING, &ds->ds_state);
 789         smp_mb__after_clear_bit();
 790         wake_up_bit(&ds->ds_state, NFS4DS_CONNECTING);
 791 }
 792
 793
 794 struct nfs4_pnfs_ds *
 795 nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx)
 796 {
 797         struct nfs4_file_layout_dsaddr *dsaddr = FILELAYOUT_LSEG(lseg)->dsaddr;
 798         struct nfs4_pnfs_ds *ds = dsaddr->ds_list[ds_idx];
 799         struct nfs4_deviceid_node *devid = FILELAYOUT_DEVID_NODE(lseg);
 800         struct nfs4_pnfs_ds *ret = ds;
 801
 802         if (ds == NULL) {
 803                 printk(KERN_ERR "NFS: %s: No data server for offset index %d\n",
 804                         __func__, ds_idx);
 805                 filelayout_mark_devid_invalid(devid);
 806                 goto out;
 807         }
 808         if (ds->ds_clp)
 809                 goto out_test_devid;
 810
 811         if (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) == 0) {
 812                 struct nfs_server *s = NFS_SERVER(lseg->pls_layout->plh_inode);
 813                 int err;
 814
 815                 err = nfs4_ds_connect(s, ds);
 816                 if (err)
 817                         nfs4_mark_deviceid_unavailable(devid);
 818                 nfs4_clear_ds_conn_bit(ds);
 819         } else {
 820                 /* Either ds is connected, or ds is NULL */
 821                 nfs4_wait_ds_connect(ds);
 822         }
 823 out_test_devid:
 824         if (filelayout_test_devid_unavailable(devid))
 825                 ret = NULL;
 826 out:
 827         return ret;
 828 }
 829
 830 module_param(dataserver_retrans, uint, 0644);
 831 MODULE_PARM_DESC(dataserver_retrans, "The  number of times the NFSv4.1 client "
 832                         "retries a request before it attempts further "
 833                         " recovery  action.");
 834 module_param(dataserver_timeo, uint, 0644);
 835 MODULE_PARM_DESC(dataserver_timeo, "The time (in tenths of a second) the "
 836                         "NFSv4.1  client  waits for a response from a "
 837                         " data server before it retries an NFS request.");