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   1 /*
   2  * linux/fs/nfsd/nfsfh.c
   3  *
   4  * NFS server file handle treatment.
   5  *
   6  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7  * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
   8  * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
   9  * ... and again Southern-Winter 2001 to support export_operations
  10  */
  11
  12 #include <linux/slab.h>
  13 #include <linux/fs.h>
  14 #include <linux/unistd.h>
  15 #include <linux/string.h>
  16 #include <linux/stat.h>
  17 #include <linux/dcache.h>
  18 #include <linux/exportfs.h>
  19 #include <linux/mount.h>
  20
  21 #include <linux/sunrpc/clnt.h>
  22 #include <linux/sunrpc/svc.h>
  23 #include <linux/sunrpc/svcauth_gss.h>
  24 #include <linux/nfsd/nfsd.h>
  25 #include "auth.h"
  26
  27 #define NFSDDBG_FACILITY                NFSDDBG_FH
  28
  29
  30 /*
  31  * our acceptability function.
  32  * if NOSUBTREECHECK, accept anything
  33  * if not, require that we can walk up to exp->ex_dentry
  34  * doing some checks on the 'x' bits
  35  */
  36 static int nfsd_acceptable(void *expv, struct dentry *dentry)
  37 {
  38         struct svc_export *exp = expv;
  39         int rv;
  40         struct dentry *tdentry;
  41         struct dentry *parent;
  42
  43         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
  44                 return 1;
  45
  46         tdentry = dget(dentry);
  47         while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
  48                 /* make sure parents give x permission to user */
  49                 int err;
  50                 parent = dget_parent(tdentry);
  51                 err = inode_permission(parent->d_inode, MAY_EXEC);
  52                 if (err < 0) {
  53                         dput(parent);
  54                         break;
  55                 }
  56                 dput(tdentry);
  57                 tdentry = parent;
  58         }
  59         if (tdentry != exp->ex_path.dentry)
  60                 dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
  61         rv = (tdentry == exp->ex_path.dentry);
  62         dput(tdentry);
  63         return rv;
  64 }
  65
  66 /* Type check. The correct error return for type mismatches does not seem to be
  67  * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
  68  * comment in the NFSv3 spec says this is incorrect (implementation notes for
  69  * the write call).
  70  */
  71 static inline __be32
  72 nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
  73 {
  74         /* Type can be negative when creating hardlinks - not to a dir */
  75         if (type > 0 && (mode & S_IFMT) != type) {
  76                 if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
  77                         return nfserr_symlink;
  78                 else if (type == S_IFDIR)
  79                         return nfserr_notdir;
  80                 else if ((mode & S_IFMT) == S_IFDIR)
  81                         return nfserr_isdir;
  82                 else
  83                         return nfserr_inval;
  84         }
  85         if (type < 0 && (mode & S_IFMT) == -type) {
  86                 if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
  87                         return nfserr_symlink;
  88                 else if (type == -S_IFDIR)
  89                         return nfserr_isdir;
  90                 else
  91                         return nfserr_notdir;
  92         }
  93         return 0;
  94 }
  95
  96 static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
  97                                           struct svc_export *exp)
  98 {
  99         /* Check if the request originated from a secure port. */
 100         if (!rqstp->rq_secure && EX_SECURE(exp)) {
 101                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 102                 dprintk(KERN_WARNING
 103                        "nfsd: request from insecure port %s!\n",
 104                        svc_print_addr(rqstp, buf, sizeof(buf)));
 105                 return nfserr_perm;
 106         }
 107
 108         /* Set user creds for this exportpoint */
 109         return nfserrno(nfsd_setuser(rqstp, exp));
 110 }
 111
 112 /*
 113  * Use the given filehandle to look up the corresponding export and
 114  * dentry.  On success, the results are used to set fh_export and
 115  * fh_dentry.
 116  */
 117 static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
 118 {
 119         struct knfsd_fh *fh = &fhp->fh_handle;
 120         struct fid *fid = NULL, sfid;
 121         struct svc_export *exp;
 122         struct dentry *dentry;
 123         int fileid_type;
 124         int data_left = fh->fh_size/4;
 125         __be32 error;
 126
 127         error = nfserr_stale;
 128         if (rqstp->rq_vers > 2)
 129                 error = nfserr_badhandle;
 130         if (rqstp->rq_vers == 4 && fh->fh_size == 0)
 131                 return nfserr_nofilehandle;
 132
 133         if (fh->fh_version == 1) {
 134                 int len;
 135
 136                 if (--data_left < 0)
 137                         return error;
 138                 if (fh->fh_auth_type != 0)
 139                         return error;
 140                 len = key_len(fh->fh_fsid_type) / 4;
 141                 if (len == 0)
 142                         return error;
 143                 if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
 144                         /* deprecated, convert to type 3 */
 145                         len = key_len(FSID_ENCODE_DEV)/4;
 146                         fh->fh_fsid_type = FSID_ENCODE_DEV;
 147                         fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
 148                         fh->fh_fsid[1] = fh->fh_fsid[2];
 149                 }
 150                 data_left -= len;
 151                 if (data_left < 0)
 152                         return error;
 153                 exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_auth);
 154                 fid = (struct fid *)(fh->fh_auth + len);
 155         } else {
 156                 __u32 tfh[2];
 157                 dev_t xdev;
 158                 ino_t xino;
 159
 160                 if (fh->fh_size != NFS_FHSIZE)
 161                         return error;
 162                 /* assume old filehandle format */
 163                 xdev = old_decode_dev(fh->ofh_xdev);
 164                 xino = u32_to_ino_t(fh->ofh_xino);
 165                 mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
 166                 exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
 167         }
 168
 169         error = nfserr_stale;
 170         if (PTR_ERR(exp) == -ENOENT)
 171                 return error;
 172
 173         if (IS_ERR(exp))
 174                 return nfserrno(PTR_ERR(exp));
 175
 176         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
 177                 /* Elevate privileges so that the lack of 'r' or 'x'
 178                  * permission on some parent directory will
 179                  * not stop exportfs_decode_fh from being able
 180                  * to reconnect a directory into the dentry cache.
 181                  * The same problem can affect "SUBTREECHECK" exports,
 182                  * but as nfsd_acceptable depends on correct
 183                  * access control settings being in effect, we cannot
 184                  * fix that case easily.
 185                  */
 186                 struct cred *new = prepare_creds();
 187                 if (!new)
 188                         return nfserrno(-ENOMEM);
 189                 new->cap_effective =
 190                         cap_raise_nfsd_set(new->cap_effective,
 191                                            new->cap_permitted);
 192                 put_cred(override_creds(new));
 193                 put_cred(new);
 194         } else {
 195                 error = nfsd_setuser_and_check_port(rqstp, exp);
 196                 if (error)
 197                         goto out;
 198         }
 199
 200         /*
 201          * Look up the dentry using the NFS file handle.
 202          */
 203         error = nfserr_stale;
 204         if (rqstp->rq_vers > 2)
 205                 error = nfserr_badhandle;
 206
 207         if (fh->fh_version != 1) {
 208                 sfid.i32.ino = fh->ofh_ino;
 209                 sfid.i32.gen = fh->ofh_generation;
 210                 sfid.i32.parent_ino = fh->ofh_dirino;
 211                 fid = &sfid;
 212                 data_left = 3;
 213                 if (fh->ofh_dirino == 0)
 214                         fileid_type = FILEID_INO32_GEN;
 215                 else
 216                         fileid_type = FILEID_INO32_GEN_PARENT;
 217         } else
 218                 fileid_type = fh->fh_fileid_type;
 219
 220         if (fileid_type == FILEID_ROOT)
 221                 dentry = dget(exp->ex_path.dentry);
 222         else {
 223                 dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
 224                                 data_left, fileid_type,
 225                                 nfsd_acceptable, exp);
 226         }
 227         if (dentry == NULL)
 228                 goto out;
 229         if (IS_ERR(dentry)) {
 230                 if (PTR_ERR(dentry) != -EINVAL)
 231                         error = nfserrno(PTR_ERR(dentry));
 232                 goto out;
 233         }
 234
 235         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
 236                 error = nfsd_setuser_and_check_port(rqstp, exp);
 237                 if (error) {
 238                         dput(dentry);
 239                         goto out;
 240                 }
 241         }
 242
 243         if (S_ISDIR(dentry->d_inode->i_mode) &&
 244                         (dentry->d_flags & DCACHE_DISCONNECTED)) {
 245                 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
 246                                 dentry->d_parent->d_name.name, dentry->d_name.name);
 247         }
 248
 249         fhp->fh_dentry = dentry;
 250         fhp->fh_export = exp;
 251         return 0;
 252 out:
 253         exp_put(exp);
 254         return error;
 255 }
 256
 257 /**
 258  * fh_verify - filehandle lookup and access checking
 259  * @rqstp: pointer to current rpc request
 260  * @fhp: filehandle to be verified
 261  * @type: expected type of object pointed to by filehandle
 262  * @access: type of access needed to object
 263  *
 264  * Look up a dentry from the on-the-wire filehandle, check the client's
 265  * access to the export, and set the current task's credentials.
 266  *
 267  * Regardless of success or failure of fh_verify(), fh_put() should be
 268  * called on @fhp when the caller is finished with the filehandle.
 269  *
 270  * fh_verify() may be called multiple times on a given filehandle, for
 271  * example, when processing an NFSv4 compound.  The first call will look
 272  * up a dentry using the on-the-wire filehandle.  Subsequent calls will
 273  * skip the lookup and just perform the other checks and possibly change
 274  * the current task's credentials.
 275  *
 276  * @type specifies the type of object expected using one of the S_IF*
 277  * constants defined in include/linux/stat.h.  The caller may use zero
 278  * to indicate that it doesn't care, or a negative integer to indicate
 279  * that it expects something not of the given type.
 280  *
 281  * @access is formed from the NFSD_MAY_* constants defined in
 282  * include/linux/nfsd/nfsd.h.
 283  */
 284 __be32
 285 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
 286 {
 287         struct svc_export *exp;
 288         struct dentry   *dentry;
 289         __be32          error;
 290
 291         dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
 292
 293         if (!fhp->fh_dentry) {
 294                 error = nfsd_set_fh_dentry(rqstp, fhp);
 295                 if (error)
 296                         goto out;
 297                 dentry = fhp->fh_dentry;
 298                 exp = fhp->fh_export;
 299         } else {
 300                 /*
 301                  * just rechecking permissions
 302                  * (e.g. nfsproc_create calls fh_verify, then nfsd_create
 303                  * does as well)
 304                  */
 305                 dprintk("nfsd: fh_verify - just checking\n");
 306                 dentry = fhp->fh_dentry;
 307                 exp = fhp->fh_export;
 308                 /*
 309                  * Set user creds for this exportpoint; necessary even
 310                  * in the "just checking" case because this may be a
 311                  * filehandle that was created by fh_compose, and that
 312                  * is about to be used in another nfsv4 compound
 313                  * operation.
 314                  */
 315                 error = nfsd_setuser_and_check_port(rqstp, exp);
 316                 if (error)
 317                         goto out;
 318         }
 319
 320         error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
 321         if (error)
 322                 goto out;
 323
 324         /*
 325          * pseudoflavor restrictions are not enforced on NLM,
 326          * which clients virtually always use auth_sys for,
 327          * even while using RPCSEC_GSS for NFS.
 328          */
 329         if (access & NFSD_MAY_LOCK)
 330                 goto skip_pseudoflavor_check;
 331         /*
 332          * Clients may expect to be able to use auth_sys during mount,
 333          * even if they use gss for everything else; see section 2.3.2
 334          * of rfc 2623.
 335          */
 336         if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
 337                         && exp->ex_path.dentry == dentry)
 338                 goto skip_pseudoflavor_check;
 339
 340         error = check_nfsd_access(exp, rqstp);
 341         if (error)
 342                 goto out;
 343
 344 skip_pseudoflavor_check:
 345         /* Finally, check access permissions. */
 346         error = nfsd_permission(rqstp, exp, dentry, access);
 347
 348         if (error) {
 349                 dprintk("fh_verify: %s/%s permission failure, "
 350                         "acc=%x, error=%d\n",
 351                         dentry->d_parent->d_name.name,
 352                         dentry->d_name.name,
 353                         access, ntohl(error));
 354         }
 355 out:
 356         if (error == nfserr_stale)
 357                 nfsdstats.fh_stale++;
 358         return error;
 359 }
 360
 361
 362 /*
 363  * Compose a file handle for an NFS reply.
 364  *
 365  * Note that when first composed, the dentry may not yet have
 366  * an inode.  In this case a call to fh_update should be made
 367  * before the fh goes out on the wire ...
 368  */
 369 static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
 370                 struct dentry *dentry)
 371 {
 372         if (dentry != exp->ex_path.dentry) {
 373                 struct fid *fid = (struct fid *)
 374                         (fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
 375                 int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
 376                 int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
 377
 378                 fhp->fh_handle.fh_fileid_type =
 379                         exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
 380                 fhp->fh_handle.fh_size += maxsize * 4;
 381         } else {
 382                 fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
 383         }
 384 }
 385
 386 /*
 387  * for composing old style file handles
 388  */
 389 static inline void _fh_update_old(struct dentry *dentry,
 390                                   struct svc_export *exp,
 391                                   struct knfsd_fh *fh)
 392 {
 393         fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
 394         fh->ofh_generation = dentry->d_inode->i_generation;
 395         if (S_ISDIR(dentry->d_inode->i_mode) ||
 396             (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
 397                 fh->ofh_dirino = 0;
 398 }
 399
 400 __be32
 401 fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
 402            struct svc_fh *ref_fh)
 403 {
 404         /* ref_fh is a reference file handle.
 405          * if it is non-null and for the same filesystem, then we should compose
 406          * a filehandle which is of the same version, where possible.
 407          * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
 408          * Then create a 32byte filehandle using nfs_fhbase_old
 409          *
 410          */
 411
 412         u8 version;
 413         u8 fsid_type = 0;
 414         struct inode * inode = dentry->d_inode;
 415         struct dentry *parent = dentry->d_parent;
 416         __u32 *datap;
 417         dev_t ex_dev = exp->ex_path.dentry->d_inode->i_sb->s_dev;
 418         int root_export = (exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root);
 419
 420         dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
 421                 MAJOR(ex_dev), MINOR(ex_dev),
 422                 (long) exp->ex_path.dentry->d_inode->i_ino,
 423                 parent->d_name.name, dentry->d_name.name,
 424                 (inode ? inode->i_ino : 0));
 425
 426         /* Choose filehandle version and fsid type based on
 427          * the reference filehandle (if it is in the same export)
 428          * or the export options.
 429          */
 430  retry:
 431         version = 1;
 432         if (ref_fh && ref_fh->fh_export == exp) {
 433                 version = ref_fh->fh_handle.fh_version;
 434                 fsid_type = ref_fh->fh_handle.fh_fsid_type;
 435
 436                 if (ref_fh == fhp)
 437                         fh_put(ref_fh);
 438                 ref_fh = NULL;
 439
 440                 switch (version) {
 441                 case 0xca:
 442                         fsid_type = FSID_DEV;
 443                         break;
 444                 case 1:
 445                         break;
 446                 default:
 447                         goto retry;
 448                 }
 449
 450                 /* Need to check that this type works for this
 451                  * export point.  As the fsid -> filesystem mapping
 452                  * was guided by user-space, there is no guarantee
 453                  * that the filesystem actually supports that fsid
 454                  * type. If it doesn't we loop around again without
 455                  * ref_fh set.
 456                  */
 457                 switch(fsid_type) {
 458                 case FSID_DEV:
 459                         if (!old_valid_dev(ex_dev))
 460                                 goto retry;
 461                         /* FALL THROUGH */
 462                 case FSID_MAJOR_MINOR:
 463                 case FSID_ENCODE_DEV:
 464                         if (!(exp->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
 465                               & FS_REQUIRES_DEV))
 466                                 goto retry;
 467                         break;
 468                 case FSID_NUM:
 469                         if (! (exp->ex_flags & NFSEXP_FSID))
 470                                 goto retry;
 471                         break;
 472                 case FSID_UUID8:
 473                 case FSID_UUID16:
 474                         if (!root_export)
 475                                 goto retry;
 476                         /* fall through */
 477                 case FSID_UUID4_INUM:
 478                 case FSID_UUID16_INUM:
 479                         if (exp->ex_uuid == NULL)
 480                                 goto retry;
 481                         break;
 482                 }
 483         } else if (exp->ex_flags & NFSEXP_FSID) {
 484                 fsid_type = FSID_NUM;
 485         } else if (exp->ex_uuid) {
 486                 if (fhp->fh_maxsize >= 64) {
 487                         if (root_export)
 488                                 fsid_type = FSID_UUID16;
 489                         else
 490                                 fsid_type = FSID_UUID16_INUM;
 491                 } else {
 492                         if (root_export)
 493                                 fsid_type = FSID_UUID8;
 494                         else
 495                                 fsid_type = FSID_UUID4_INUM;
 496                 }
 497         } else if (!old_valid_dev(ex_dev))
 498                 /* for newer device numbers, we must use a newer fsid format */
 499                 fsid_type = FSID_ENCODE_DEV;
 500         else
 501                 fsid_type = FSID_DEV;
 502
 503         if (ref_fh == fhp)
 504                 fh_put(ref_fh);
 505
 506         if (fhp->fh_locked || fhp->fh_dentry) {
 507                 printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
 508                        parent->d_name.name, dentry->d_name.name);
 509         }
 510         if (fhp->fh_maxsize < NFS_FHSIZE)
 511                 printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
 512                        fhp->fh_maxsize,
 513                        parent->d_name.name, dentry->d_name.name);
 514
 515         fhp->fh_dentry = dget(dentry); /* our internal copy */
 516         fhp->fh_export = exp;
 517         cache_get(&exp->h);
 518
 519         if (version == 0xca) {
 520                 /* old style filehandle please */
 521                 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
 522                 fhp->fh_handle.fh_size = NFS_FHSIZE;
 523                 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
 524                 fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
 525                 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
 526                 fhp->fh_handle.ofh_xino =
 527                         ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
 528                 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
 529                 if (inode)
 530                         _fh_update_old(dentry, exp, &fhp->fh_handle);
 531         } else {
 532                 int len;
 533                 fhp->fh_handle.fh_version = 1;
 534                 fhp->fh_handle.fh_auth_type = 0;
 535                 datap = fhp->fh_handle.fh_auth+0;
 536                 fhp->fh_handle.fh_fsid_type = fsid_type;
 537                 mk_fsid(fsid_type, datap, ex_dev,
 538                         exp->ex_path.dentry->d_inode->i_ino,
 539                         exp->ex_fsid, exp->ex_uuid);
 540
 541                 len = key_len(fsid_type);
 542                 datap += len/4;
 543                 fhp->fh_handle.fh_size = 4 + len;
 544
 545                 if (inode)
 546                         _fh_update(fhp, exp, dentry);
 547                 if (fhp->fh_handle.fh_fileid_type == 255)
 548                         return nfserr_opnotsupp;
 549         }
 550
 551         return 0;
 552 }
 553
 554 /*
 555  * Update file handle information after changing a dentry.
 556  * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
 557  */
 558 __be32
 559 fh_update(struct svc_fh *fhp)
 560 {
 561         struct dentry *dentry;
 562
 563         if (!fhp->fh_dentry)
 564                 goto out_bad;
 565
 566         dentry = fhp->fh_dentry;
 567         if (!dentry->d_inode)
 568                 goto out_negative;
 569         if (fhp->fh_handle.fh_version != 1) {
 570                 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
 571         } else {
 572                 if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
 573                         goto out;
 574
 575                 _fh_update(fhp, fhp->fh_export, dentry);
 576                 if (fhp->fh_handle.fh_fileid_type == 255)
 577                         return nfserr_opnotsupp;
 578         }
 579 out:
 580         return 0;
 581
 582 out_bad:
 583         printk(KERN_ERR "fh_update: fh not verified!\n");
 584         goto out;
 585 out_negative:
 586         printk(KERN_ERR "fh_update: %s/%s still negative!\n",
 587                 dentry->d_parent->d_name.name, dentry->d_name.name);
 588         goto out;
 589 }
 590
 591 /*
 592  * Release a file handle.
 593  */
 594 void
 595 fh_put(struct svc_fh *fhp)
 596 {
 597         struct dentry * dentry = fhp->fh_dentry;
 598         struct svc_export * exp = fhp->fh_export;
 599         if (dentry) {
 600                 fh_unlock(fhp);
 601                 fhp->fh_dentry = NULL;
 602                 dput(dentry);
 603 #ifdef CONFIG_NFSD_V3
 604                 fhp->fh_pre_saved = 0;
 605                 fhp->fh_post_saved = 0;
 606 #endif
 607         }
 608         if (exp) {
 609                 cache_put(&exp->h, &svc_export_cache);
 610                 fhp->fh_export = NULL;
 611         }
 612         return;
 613 }
 614
 615 /*
 616  * Shorthand for dprintk()'s
 617  */
 618 char * SVCFH_fmt(struct svc_fh *fhp)
 619 {
 620         struct knfsd_fh *fh = &fhp->fh_handle;
 621
 622         static char buf[80];
 623         sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
 624                 fh->fh_size,
 625                 fh->fh_base.fh_pad[0],
 626                 fh->fh_base.fh_pad[1],
 627                 fh->fh_base.fh_pad[2],
 628                 fh->fh_base.fh_pad[3],
 629                 fh->fh_base.fh_pad[4],
 630                 fh->fh_base.fh_pad[5]);
 631         return buf;
 632 }
 633
 634 enum fsid_source fsid_source(struct svc_fh *fhp)
 635 {
 636         if (fhp->fh_handle.fh_version != 1)
 637                 return FSIDSOURCE_DEV;
 638         switch(fhp->fh_handle.fh_fsid_type) {
 639         case FSID_DEV:
 640         case FSID_ENCODE_DEV:
 641         case FSID_MAJOR_MINOR:
 642                 if (fhp->fh_export->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
 643                     & FS_REQUIRES_DEV)
 644                         return FSIDSOURCE_DEV;
 645                 break;
 646         case FSID_NUM:
 647                 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
 648                         return FSIDSOURCE_FSID;
 649                 break;
 650         default:
 651                 break;
 652         }
 653         /* either a UUID type filehandle, or the filehandle doesn't
 654          * match the export.
 655          */
 656         if (fhp->fh_export->ex_flags & NFSEXP_FSID)
 657                 return FSIDSOURCE_FSID;
 658         if (fhp->fh_export->ex_uuid)
 659                 return FSIDSOURCE_UUID;
 660         return FSIDSOURCE_DEV;
 661 }