fs/nfs/proc.c

   1 /*
   2  *  linux/fs/nfs/proc.c
   3  *
   4  *  Copyright (C) 1992, 1993, 1994  Rick Sladkey
   5  *
   6  *  OS-independent nfs remote procedure call functions
   7  *
   8  *  Tuned by Alan Cox <A.Cox@swansea.ac.uk> for >3K buffers
   9  *  so at last we can have decent(ish) throughput off a
  10  *  Sun server.
  11  *
  12  *  Coding optimized and cleaned up by Florian La Roche.
  13  *  Note: Error returns are optimized for NFS_OK, which isn't translated via
  14  *  nfs_stat_to_errno(), but happens to be already the right return code.
  15  *
  16  *  Also, the code currently doesn't check the size of the packet, when
  17  *  it decodes the packet.
  18  *
  19  *  Feel free to fix it and mail me the diffs if it worries you.
  20  *
  21  *  Completely rewritten to support the new RPC call interface;
  22  *  rewrote and moved the entire XDR stuff to xdr.c
  23  *  --Olaf Kirch June 1996
  24  *
  25  *  The code below initializes all auto variables explicitly, otherwise
  26  *  it will fail to work as a module (gcc generates a memset call for an
  27  *  incomplete struct).
  28  */
  29
  30 #include <linux/types.h>
  31 #include <linux/param.h>
  32 #include <linux/time.h>
  33 #include <linux/mm.h>
  34 #include <linux/errno.h>
  35 #include <linux/string.h>
  36 #include <linux/in.h>
  37 #include <linux/pagemap.h>
  38 #include <linux/sunrpc/clnt.h>
  39 #include <linux/nfs.h>
  40 #include <linux/nfs2.h>
  41 #include <linux/nfs_fs.h>
  42 #include <linux/nfs_page.h>
  43 #include <linux/lockd/bind.h>
  44 #include <linux/freezer.h>
  45 #include "internal.h"
  46
  47 #define NFSDBG_FACILITY         NFSDBG_PROC
  48
  49 /*
  50  * wrapper to handle the -EKEYEXPIRED error message. This should generally
  51  * only happen if using krb5 auth and a user's TGT expires. NFSv2 doesn't
  52  * support the NFSERR_JUKEBOX error code, but we handle this situation in the
  53  * same way that we handle that error with NFSv3.
  54  */
  55 static int
  56 nfs_rpc_wrapper(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
  57 {
  58         int res;
  59         do {
  60                 res = rpc_call_sync(clnt, msg, flags);
  61                 if (res != -EKEYEXPIRED)
  62                         break;
  63                 freezable_schedule_timeout_killable(NFS_JUKEBOX_RETRY_TIME);
  64                 res = -ERESTARTSYS;
  65         } while (!fatal_signal_pending(current));
  66         return res;
  67 }
  68
  69 #define rpc_call_sync(clnt, msg, flags) nfs_rpc_wrapper(clnt, msg, flags)
  70
  71 static int
  72 nfs_async_handle_expired_key(struct rpc_task *task)
  73 {
  74         if (task->tk_status != -EKEYEXPIRED)
  75                 return 0;
  76         task->tk_status = 0;
  77         rpc_restart_call(task);
  78         rpc_delay(task, NFS_JUKEBOX_RETRY_TIME);
  79         return 1;
  80 }
  81
  82 /*
  83  * Bare-bones access to getattr: this is for nfs_read_super.
  84  */
  85 static int
  86 nfs_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
  87                   struct nfs_fsinfo *info)
  88 {
  89         struct nfs_fattr *fattr = info->fattr;
  90         struct nfs2_fsstat fsinfo;
  91         struct rpc_message msg = {
  92                 .rpc_proc       = &nfs_procedures[NFSPROC_GETATTR],
  93                 .rpc_argp       = fhandle,
  94                 .rpc_resp       = fattr,
  95         };
  96         int status;
  97
  98         dprintk("%s: call getattr\n", __func__);
  99         nfs_fattr_init(fattr);
 100         status = rpc_call_sync(server->client, &msg, 0);
 101         /* Retry with default authentication if different */
 102         if (status && server->nfs_client->cl_rpcclient != server->client)
 103                 status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
 104         dprintk("%s: reply getattr: %d\n", __func__, status);
 105         if (status)
 106                 return status;
 107         dprintk("%s: call statfs\n", __func__);
 108         msg.rpc_proc = &nfs_procedures[NFSPROC_STATFS];
 109         msg.rpc_resp = &fsinfo;
 110         status = rpc_call_sync(server->client, &msg, 0);
 111         /* Retry with default authentication if different */
 112         if (status && server->nfs_client->cl_rpcclient != server->client)
 113                 status = rpc_call_sync(server->nfs_client->cl_rpcclient, &msg, 0);
 114         dprintk("%s: reply statfs: %d\n", __func__, status);
 115         if (status)
 116                 return status;
 117         info->rtmax  = NFS_MAXDATA;
 118         info->rtpref = fsinfo.tsize;
 119         info->rtmult = fsinfo.bsize;
 120         info->wtmax  = NFS_MAXDATA;
 121         info->wtpref = fsinfo.tsize;
 122         info->wtmult = fsinfo.bsize;
 123         info->dtpref = fsinfo.tsize;
 124         info->maxfilesize = 0x7FFFFFFF;
 125         info->lease_time = 0;
 126         return 0;
 127 }
 128
 129 /*
 130  * One function for each procedure in the NFS protocol.
 131  */
 132 static int
 133 nfs_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
 134                 struct nfs_fattr *fattr)
 135 {
 136         struct rpc_message msg = {
 137                 .rpc_proc       = &nfs_procedures[NFSPROC_GETATTR],
 138                 .rpc_argp       = fhandle,
 139                 .rpc_resp       = fattr,
 140         };
 141         int     status;
 142
 143         dprintk("NFS call  getattr\n");
 144         nfs_fattr_init(fattr);
 145         status = rpc_call_sync(server->client, &msg, 0);
 146         dprintk("NFS reply getattr: %d\n", status);
 147         return status;
 148 }
 149
 150 static int
 151 nfs_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
 152                  struct iattr *sattr)
 153 {
 154         struct inode *inode = dentry->d_inode;
 155         struct nfs_sattrargs    arg = {
 156                 .fh     = NFS_FH(inode),
 157                 .sattr  = sattr
 158         };
 159         struct rpc_message msg = {
 160                 .rpc_proc       = &nfs_procedures[NFSPROC_SETATTR],
 161                 .rpc_argp       = &arg,
 162                 .rpc_resp       = fattr,
 163         };
 164         int     status;
 165
 166         /* Mask out the non-modebit related stuff from attr->ia_mode */
 167         sattr->ia_mode &= S_IALLUGO;
 168
 169         dprintk("NFS call  setattr\n");
 170         if (sattr->ia_valid & ATTR_FILE)
 171                 msg.rpc_cred = nfs_file_cred(sattr->ia_file);
 172         nfs_fattr_init(fattr);
 173         status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
 174         if (status == 0)
 175                 nfs_setattr_update_inode(inode, sattr);
 176         dprintk("NFS reply setattr: %d\n", status);
 177         return status;
 178 }
 179
 180 static int
 181 nfs_proc_lookup(struct rpc_clnt *clnt, struct inode *dir, struct qstr *name,
 182                 struct nfs_fh *fhandle, struct nfs_fattr *fattr)
 183 {
 184         struct nfs_diropargs    arg = {
 185                 .fh             = NFS_FH(dir),
 186                 .name           = name->name,
 187                 .len            = name->len
 188         };
 189         struct nfs_diropok      res = {
 190                 .fh             = fhandle,
 191                 .fattr          = fattr
 192         };
 193         struct rpc_message msg = {
 194                 .rpc_proc       = &nfs_procedures[NFSPROC_LOOKUP],
 195                 .rpc_argp       = &arg,
 196                 .rpc_resp       = &res,
 197         };
 198         int                     status;
 199
 200         dprintk("NFS call  lookup %s\n", name->name);
 201         nfs_fattr_init(fattr);
 202         status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 203         dprintk("NFS reply lookup: %d\n", status);
 204         return status;
 205 }
 206
 207 static int nfs_proc_readlink(struct inode *inode, struct page *page,
 208                 unsigned int pgbase, unsigned int pglen)
 209 {
 210         struct nfs_readlinkargs args = {
 211                 .fh             = NFS_FH(inode),
 212                 .pgbase         = pgbase,
 213                 .pglen          = pglen,
 214                 .pages          = &page
 215         };
 216         struct rpc_message msg = {
 217                 .rpc_proc       = &nfs_procedures[NFSPROC_READLINK],
 218                 .rpc_argp       = &args,
 219         };
 220         int                     status;
 221
 222         dprintk("NFS call  readlink\n");
 223         status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
 224         dprintk("NFS reply readlink: %d\n", status);
 225         return status;
 226 }
 227
 228 struct nfs_createdata {
 229         struct nfs_createargs arg;
 230         struct nfs_diropok res;
 231         struct nfs_fh fhandle;
 232         struct nfs_fattr fattr;
 233 };
 234
 235 static struct nfs_createdata *nfs_alloc_createdata(struct inode *dir,
 236                 struct dentry *dentry, struct iattr *sattr)
 237 {
 238         struct nfs_createdata *data;
 239
 240         data = kmalloc(sizeof(*data), GFP_KERNEL);
 241
 242         if (data != NULL) {
 243                 data->arg.fh = NFS_FH(dir);
 244                 data->arg.name = dentry->d_name.name;
 245                 data->arg.len = dentry->d_name.len;
 246                 data->arg.sattr = sattr;
 247                 nfs_fattr_init(&data->fattr);
 248                 data->fhandle.size = 0;
 249                 data->res.fh = &data->fhandle;
 250                 data->res.fattr = &data->fattr;
 251         }
 252         return data;
 253 };
 254
 255 static void nfs_free_createdata(const struct nfs_createdata *data)
 256 {
 257         kfree(data);
 258 }
 259
 260 static int
 261 nfs_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
 262                 int flags, struct nfs_open_context *ctx)
 263 {
 264         struct nfs_createdata *data;
 265         struct rpc_message msg = {
 266                 .rpc_proc       = &nfs_procedures[NFSPROC_CREATE],
 267         };
 268         int status = -ENOMEM;
 269
 270         dprintk("NFS call  create %s\n", dentry->d_name.name);
 271         data = nfs_alloc_createdata(dir, dentry, sattr);
 272         if (data == NULL)
 273                 goto out;
 274         msg.rpc_argp = &data->arg;
 275         msg.rpc_resp = &data->res;
 276         status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 277         nfs_mark_for_revalidate(dir);
 278         if (status == 0)
 279                 status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
 280         nfs_free_createdata(data);
 281 out:
 282         dprintk("NFS reply create: %d\n", status);
 283         return status;
 284 }
 285
 286 /*
 287  * In NFSv2, mknod is grafted onto the create call.
 288  */
 289 static int
 290 nfs_proc_mknod(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
 291                dev_t rdev)
 292 {
 293         struct nfs_createdata *data;
 294         struct rpc_message msg = {
 295                 .rpc_proc       = &nfs_procedures[NFSPROC_CREATE],
 296         };
 297         umode_t mode;
 298         int status = -ENOMEM;
 299
 300         dprintk("NFS call  mknod %s\n", dentry->d_name.name);
 301
 302         mode = sattr->ia_mode;
 303         if (S_ISFIFO(mode)) {
 304                 sattr->ia_mode = (mode & ~S_IFMT) | S_IFCHR;
 305                 sattr->ia_valid &= ~ATTR_SIZE;
 306         } else if (S_ISCHR(mode) || S_ISBLK(mode)) {
 307                 sattr->ia_valid |= ATTR_SIZE;
 308                 sattr->ia_size = new_encode_dev(rdev);/* get out your barf bag */
 309         }
 310
 311         data = nfs_alloc_createdata(dir, dentry, sattr);
 312         if (data == NULL)
 313                 goto out;
 314         msg.rpc_argp = &data->arg;
 315         msg.rpc_resp = &data->res;
 316
 317         status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 318         nfs_mark_for_revalidate(dir);
 319
 320         if (status == -EINVAL && S_ISFIFO(mode)) {
 321                 sattr->ia_mode = mode;
 322                 nfs_fattr_init(data->res.fattr);
 323                 status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 324         }
 325         if (status == 0)
 326                 status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
 327         nfs_free_createdata(data);
 328 out:
 329         dprintk("NFS reply mknod: %d\n", status);
 330         return status;
 331 }
 332
 333 static int
 334 nfs_proc_remove(struct inode *dir, struct qstr *name)
 335 {
 336         struct nfs_removeargs arg = {
 337                 .fh = NFS_FH(dir),
 338                 .name.len = name->len,
 339                 .name.name = name->name,
 340         };
 341         struct rpc_message msg = {
 342                 .rpc_proc = &nfs_procedures[NFSPROC_REMOVE],
 343                 .rpc_argp = &arg,
 344         };
 345         int                     status;
 346
 347         dprintk("NFS call  remove %s\n", name->name);
 348         status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 349         nfs_mark_for_revalidate(dir);
 350
 351         dprintk("NFS reply remove: %d\n", status);
 352         return status;
 353 }
 354
 355 static void
 356 nfs_proc_unlink_setup(struct rpc_message *msg, struct inode *dir)
 357 {
 358         msg->rpc_proc = &nfs_procedures[NFSPROC_REMOVE];
 359 }
 360
 361 static int nfs_proc_unlink_done(struct rpc_task *task, struct inode *dir)
 362 {
 363         if (nfs_async_handle_expired_key(task))
 364                 return 0;
 365         nfs_mark_for_revalidate(dir);
 366         return 1;
 367 }
 368
 369 static void
 370 nfs_proc_rename_setup(struct rpc_message *msg, struct inode *dir)
 371 {
 372         msg->rpc_proc = &nfs_procedures[NFSPROC_RENAME];
 373 }
 374
 375 static int
 376 nfs_proc_rename_done(struct rpc_task *task, struct inode *old_dir,
 377                      struct inode *new_dir)
 378 {
 379         if (nfs_async_handle_expired_key(task))
 380                 return 0;
 381         nfs_mark_for_revalidate(old_dir);
 382         nfs_mark_for_revalidate(new_dir);
 383         return 1;
 384 }
 385
 386 static int
 387 nfs_proc_rename(struct inode *old_dir, struct qstr *old_name,
 388                 struct inode *new_dir, struct qstr *new_name)
 389 {
 390         struct nfs_renameargs   arg = {
 391                 .old_dir        = NFS_FH(old_dir),
 392                 .old_name       = old_name,
 393                 .new_dir        = NFS_FH(new_dir),
 394                 .new_name       = new_name,
 395         };
 396         struct rpc_message msg = {
 397                 .rpc_proc       = &nfs_procedures[NFSPROC_RENAME],
 398                 .rpc_argp       = &arg,
 399         };
 400         int                     status;
 401
 402         dprintk("NFS call  rename %s -> %s\n", old_name->name, new_name->name);
 403         status = rpc_call_sync(NFS_CLIENT(old_dir), &msg, 0);
 404         nfs_mark_for_revalidate(old_dir);
 405         nfs_mark_for_revalidate(new_dir);
 406         dprintk("NFS reply rename: %d\n", status);
 407         return status;
 408 }
 409
 410 static int
 411 nfs_proc_link(struct inode *inode, struct inode *dir, struct qstr *name)
 412 {
 413         struct nfs_linkargs     arg = {
 414                 .fromfh         = NFS_FH(inode),
 415                 .tofh           = NFS_FH(dir),
 416                 .toname         = name->name,
 417                 .tolen          = name->len
 418         };
 419         struct rpc_message msg = {
 420                 .rpc_proc       = &nfs_procedures[NFSPROC_LINK],
 421                 .rpc_argp       = &arg,
 422         };
 423         int                     status;
 424
 425         dprintk("NFS call  link %s\n", name->name);
 426         status = rpc_call_sync(NFS_CLIENT(inode), &msg, 0);
 427         nfs_mark_for_revalidate(inode);
 428         nfs_mark_for_revalidate(dir);
 429         dprintk("NFS reply link: %d\n", status);
 430         return status;
 431 }
 432
 433 static int
 434 nfs_proc_symlink(struct inode *dir, struct dentry *dentry, struct page *page,
 435                  unsigned int len, struct iattr *sattr)
 436 {
 437         struct nfs_fh *fh;
 438         struct nfs_fattr *fattr;
 439         struct nfs_symlinkargs  arg = {
 440                 .fromfh         = NFS_FH(dir),
 441                 .fromname       = dentry->d_name.name,
 442                 .fromlen        = dentry->d_name.len,
 443                 .pages          = &page,
 444                 .pathlen        = len,
 445                 .sattr          = sattr
 446         };
 447         struct rpc_message msg = {
 448                 .rpc_proc       = &nfs_procedures[NFSPROC_SYMLINK],
 449                 .rpc_argp       = &arg,
 450         };
 451         int status = -ENAMETOOLONG;
 452
 453         dprintk("NFS call  symlink %s\n", dentry->d_name.name);
 454
 455         if (len > NFS2_MAXPATHLEN)
 456                 goto out;
 457
 458         fh = nfs_alloc_fhandle();
 459         fattr = nfs_alloc_fattr();
 460         status = -ENOMEM;
 461         if (fh == NULL || fattr == NULL)
 462                 goto out_free;
 463
 464         status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 465         nfs_mark_for_revalidate(dir);
 466
 467         /*
 468          * V2 SYMLINK requests don't return any attributes.  Setting the
 469          * filehandle size to zero indicates to nfs_instantiate that it
 470          * should fill in the data with a LOOKUP call on the wire.
 471          */
 472         if (status == 0)
 473                 status = nfs_instantiate(dentry, fh, fattr);
 474
 475 out_free:
 476         nfs_free_fattr(fattr);
 477         nfs_free_fhandle(fh);
 478 out:
 479         dprintk("NFS reply symlink: %d\n", status);
 480         return status;
 481 }
 482
 483 static int
 484 nfs_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
 485 {
 486         struct nfs_createdata *data;
 487         struct rpc_message msg = {
 488                 .rpc_proc       = &nfs_procedures[NFSPROC_MKDIR],
 489         };
 490         int status = -ENOMEM;
 491
 492         dprintk("NFS call  mkdir %s\n", dentry->d_name.name);
 493         data = nfs_alloc_createdata(dir, dentry, sattr);
 494         if (data == NULL)
 495                 goto out;
 496         msg.rpc_argp = &data->arg;
 497         msg.rpc_resp = &data->res;
 498
 499         status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 500         nfs_mark_for_revalidate(dir);
 501         if (status == 0)
 502                 status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
 503         nfs_free_createdata(data);
 504 out:
 505         dprintk("NFS reply mkdir: %d\n", status);
 506         return status;
 507 }
 508
 509 static int
 510 nfs_proc_rmdir(struct inode *dir, struct qstr *name)
 511 {
 512         struct nfs_diropargs    arg = {
 513                 .fh             = NFS_FH(dir),
 514                 .name           = name->name,
 515                 .len            = name->len
 516         };
 517         struct rpc_message msg = {
 518                 .rpc_proc       = &nfs_procedures[NFSPROC_RMDIR],
 519                 .rpc_argp       = &arg,
 520         };
 521         int                     status;
 522
 523         dprintk("NFS call  rmdir %s\n", name->name);
 524         status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 525         nfs_mark_for_revalidate(dir);
 526         dprintk("NFS reply rmdir: %d\n", status);
 527         return status;
 528 }
 529
 530 /*
 531  * The READDIR implementation is somewhat hackish - we pass a temporary
 532  * buffer to the encode function, which installs it in the receive
 533  * the receive iovec. The decode function just parses the reply to make
 534  * sure it is syntactically correct; the entries itself are decoded
 535  * from nfs_readdir by calling the decode_entry function directly.
 536  */
 537 static int
 538 nfs_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
 539                  u64 cookie, struct page **pages, unsigned int count, int plus)
 540 {
 541         struct inode            *dir = dentry->d_inode;
 542         struct nfs_readdirargs  arg = {
 543                 .fh             = NFS_FH(dir),
 544                 .cookie         = cookie,
 545                 .count          = count,
 546                 .pages          = pages,
 547         };
 548         struct rpc_message      msg = {
 549                 .rpc_proc       = &nfs_procedures[NFSPROC_READDIR],
 550                 .rpc_argp       = &arg,
 551                 .rpc_cred       = cred,
 552         };
 553         int                     status;
 554
 555         dprintk("NFS call  readdir %d\n", (unsigned int)cookie);
 556         status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 557
 558         nfs_invalidate_atime(dir);
 559
 560         dprintk("NFS reply readdir: %d\n", status);
 561         return status;
 562 }
 563
 564 static int
 565 nfs_proc_statfs(struct nfs_server *server, struct nfs_fh *fhandle,
 566                         struct nfs_fsstat *stat)
 567 {
 568         struct nfs2_fsstat fsinfo;
 569         struct rpc_message msg = {
 570                 .rpc_proc       = &nfs_procedures[NFSPROC_STATFS],
 571                 .rpc_argp       = fhandle,
 572                 .rpc_resp       = &fsinfo,
 573         };
 574         int     status;
 575
 576         dprintk("NFS call  statfs\n");
 577         nfs_fattr_init(stat->fattr);
 578         status = rpc_call_sync(server->client, &msg, 0);
 579         dprintk("NFS reply statfs: %d\n", status);
 580         if (status)
 581                 goto out;
 582         stat->tbytes = (u64)fsinfo.blocks * fsinfo.bsize;
 583         stat->fbytes = (u64)fsinfo.bfree  * fsinfo.bsize;
 584         stat->abytes = (u64)fsinfo.bavail * fsinfo.bsize;
 585         stat->tfiles = 0;
 586         stat->ffiles = 0;
 587         stat->afiles = 0;
 588 out:
 589         return status;
 590 }
 591
 592 static int
 593 nfs_proc_fsinfo(struct nfs_server *server, struct nfs_fh *fhandle,
 594                         struct nfs_fsinfo *info)
 595 {
 596         struct nfs2_fsstat fsinfo;
 597         struct rpc_message msg = {
 598                 .rpc_proc       = &nfs_procedures[NFSPROC_STATFS],
 599                 .rpc_argp       = fhandle,
 600                 .rpc_resp       = &fsinfo,
 601         };
 602         int     status;
 603
 604         dprintk("NFS call  fsinfo\n");
 605         nfs_fattr_init(info->fattr);
 606         status = rpc_call_sync(server->client, &msg, 0);
 607         dprintk("NFS reply fsinfo: %d\n", status);
 608         if (status)
 609                 goto out;
 610         info->rtmax  = NFS_MAXDATA;
 611         info->rtpref = fsinfo.tsize;
 612         info->rtmult = fsinfo.bsize;
 613         info->wtmax  = NFS_MAXDATA;
 614         info->wtpref = fsinfo.tsize;
 615         info->wtmult = fsinfo.bsize;
 616         info->dtpref = fsinfo.tsize;
 617         info->maxfilesize = 0x7FFFFFFF;
 618         info->lease_time = 0;
 619 out:
 620         return status;
 621 }
 622
 623 static int
 624 nfs_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
 625                   struct nfs_pathconf *info)
 626 {
 627         info->max_link = 0;
 628         info->max_namelen = NFS2_MAXNAMLEN;
 629         return 0;
 630 }
 631
 632 static int nfs_read_done(struct rpc_task *task, struct nfs_read_data *data)
 633 {
 634         if (nfs_async_handle_expired_key(task))
 635                 return -EAGAIN;
 636
 637         nfs_invalidate_atime(data->inode);
 638         if (task->tk_status >= 0) {
 639                 nfs_refresh_inode(data->inode, data->res.fattr);
 640                 /* Emulate the eof flag, which isn't normally needed in NFSv2
 641                  * as it is guaranteed to always return the file attributes
 642                  */
 643                 if (data->args.offset + data->args.count >= data->res.fattr->size)
 644                         data->res.eof = 1;
 645         }
 646         return 0;
 647 }
 648
 649 static void nfs_proc_read_setup(struct nfs_read_data *data, struct rpc_message *msg)
 650 {
 651         msg->rpc_proc = &nfs_procedures[NFSPROC_READ];
 652 }
 653
 654 static int nfs_write_done(struct rpc_task *task, struct nfs_write_data *data)
 655 {
 656         if (nfs_async_handle_expired_key(task))
 657                 return -EAGAIN;
 658
 659         if (task->tk_status >= 0)
 660                 nfs_post_op_update_inode_force_wcc(data->inode, data->res.fattr);
 661         return 0;
 662 }
 663
 664 static void nfs_proc_write_setup(struct nfs_write_data *data, struct rpc_message *msg)
 665 {
 666         /* Note: NFSv2 ignores @stable and always uses NFS_FILE_SYNC */
 667         data->args.stable = NFS_FILE_SYNC;
 668         msg->rpc_proc = &nfs_procedures[NFSPROC_WRITE];
 669 }
 670
 671 static void
 672 nfs_proc_commit_setup(struct nfs_write_data *data, struct rpc_message *msg)
 673 {
 674         BUG();
 675 }
 676
 677 static int
 678 nfs_proc_lock(struct file *filp, int cmd, struct file_lock *fl)
 679 {
 680         struct inode *inode = filp->f_path.dentry->d_inode;
 681
 682         return nlmclnt_proc(NFS_SERVER(inode)->nlm_host, cmd, fl);
 683 }
 684
 685 /* Helper functions for NFS lock bounds checking */
 686 #define NFS_LOCK32_OFFSET_MAX ((__s32)0x7fffffffUL)
 687 static int nfs_lock_check_bounds(const struct file_lock *fl)
 688 {
 689         __s32 start, end;
 690
 691         start = (__s32)fl->fl_start;
 692         if ((loff_t)start != fl->fl_start)
 693                 goto out_einval;
 694
 695         if (fl->fl_end != OFFSET_MAX) {
 696                 end = (__s32)fl->fl_end;
 697                 if ((loff_t)end != fl->fl_end)
 698                         goto out_einval;
 699         } else
 700                 end = NFS_LOCK32_OFFSET_MAX;
 701
 702         if (start < 0 || start > end)
 703                 goto out_einval;
 704         return 0;
 705 out_einval:
 706         return -EINVAL;
 707 }
 708
 709 const struct nfs_rpc_ops nfs_v2_clientops = {
 710         .version        = 2,                   /* protocol version */
 711         .dentry_ops     = &nfs_dentry_operations,
 712         .dir_inode_ops  = &nfs_dir_inode_operations,
 713         .file_inode_ops = &nfs_file_inode_operations,
 714         .file_ops       = &nfs_file_operations,
 715         .getroot        = nfs_proc_get_root,
 716         .getattr        = nfs_proc_getattr,
 717         .setattr        = nfs_proc_setattr,
 718         .lookup         = nfs_proc_lookup,
 719         .access         = NULL,                /* access */
 720         .readlink       = nfs_proc_readlink,
 721         .create         = nfs_proc_create,
 722         .remove         = nfs_proc_remove,
 723         .unlink_setup   = nfs_proc_unlink_setup,
 724         .unlink_done    = nfs_proc_unlink_done,
 725         .rename         = nfs_proc_rename,
 726         .rename_setup   = nfs_proc_rename_setup,
 727         .rename_done    = nfs_proc_rename_done,
 728         .link           = nfs_proc_link,
 729         .symlink        = nfs_proc_symlink,
 730         .mkdir          = nfs_proc_mkdir,
 731         .rmdir          = nfs_proc_rmdir,
 732         .readdir        = nfs_proc_readdir,
 733         .mknod          = nfs_proc_mknod,
 734         .statfs         = nfs_proc_statfs,
 735         .fsinfo         = nfs_proc_fsinfo,
 736         .pathconf       = nfs_proc_pathconf,
 737         .decode_dirent  = nfs2_decode_dirent,
 738         .read_setup     = nfs_proc_read_setup,
 739         .read_done      = nfs_read_done,
 740         .write_setup    = nfs_proc_write_setup,
 741         .write_done     = nfs_write_done,
 742         .commit_setup   = nfs_proc_commit_setup,
 743         .lock           = nfs_proc_lock,
 744         .lock_check_bounds = nfs_lock_check_bounds,
 745         .close_context  = nfs_close_context,
 746         .init_client    = nfs_init_client,
 747 };