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Linux/fs/nfsd/nfsfh.c

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  1 /*
  2  * NFS server file handle treatment.
  3  *
  4  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
  5  * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org>
  6  * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999
  7  * ... and again Southern-Winter 2001 to support export_operations
  8  */
  9 
 10 #include <linux/exportfs.h>
 11 
 12 #include <linux/sunrpc/svcauth_gss.h>
 13 #include "nfsd.h"
 14 #include "vfs.h"
 15 #include "auth.h"
 16 
 17 #define NFSDDBG_FACILITY                NFSDDBG_FH
 18 
 19 
 20 /*
 21  * our acceptability function.
 22  * if NOSUBTREECHECK, accept anything
 23  * if not, require that we can walk up to exp->ex_dentry
 24  * doing some checks on the 'x' bits
 25  */
 26 static int nfsd_acceptable(void *expv, struct dentry *dentry)
 27 {
 28         struct svc_export *exp = expv;
 29         int rv;
 30         struct dentry *tdentry;
 31         struct dentry *parent;
 32 
 33         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
 34                 return 1;
 35 
 36         tdentry = dget(dentry);
 37         while (tdentry != exp->ex_path.dentry && !IS_ROOT(tdentry)) {
 38                 /* make sure parents give x permission to user */
 39                 int err;
 40                 parent = dget_parent(tdentry);
 41                 err = inode_permission(parent->d_inode, MAY_EXEC);
 42                 if (err < 0) {
 43                         dput(parent);
 44                         break;
 45                 }
 46                 dput(tdentry);
 47                 tdentry = parent;
 48         }
 49         if (tdentry != exp->ex_path.dentry)
 50                 dprintk("nfsd_acceptable failed at %p %pd\n", tdentry, tdentry);
 51         rv = (tdentry == exp->ex_path.dentry);
 52         dput(tdentry);
 53         return rv;
 54 }
 55 
 56 /* Type check. The correct error return for type mismatches does not seem to be
 57  * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
 58  * comment in the NFSv3 spec says this is incorrect (implementation notes for
 59  * the write call).
 60  */
 61 static inline __be32
 62 nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, umode_t requested)
 63 {
 64         mode &= S_IFMT;
 65 
 66         if (requested == 0) /* the caller doesn't care */
 67                 return nfs_ok;
 68         if (mode == requested)
 69                 return nfs_ok;
 70         /*
 71          * v4 has an error more specific than err_notdir which we should
 72          * return in preference to err_notdir:
 73          */
 74         if (rqstp->rq_vers == 4 && mode == S_IFLNK)
 75                 return nfserr_symlink;
 76         if (requested == S_IFDIR)
 77                 return nfserr_notdir;
 78         if (mode == S_IFDIR)
 79                 return nfserr_isdir;
 80         return nfserr_inval;
 81 }
 82 
 83 static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
 84                                           struct svc_export *exp)
 85 {
 86         int flags = nfsexp_flags(rqstp, exp);
 87 
 88         /* Check if the request originated from a secure port. */
 89         if (!rqstp->rq_secure && !(flags & NFSEXP_INSECURE_PORT)) {
 90                 RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
 91                 dprintk("nfsd: request from insecure port %s!\n",
 92                         svc_print_addr(rqstp, buf, sizeof(buf)));
 93                 return nfserr_perm;
 94         }
 95 
 96         /* Set user creds for this exportpoint */
 97         return nfserrno(nfsd_setuser(rqstp, exp));
 98 }
 99 
100 static inline __be32 check_pseudo_root(struct svc_rqst *rqstp,
101         struct dentry *dentry, struct svc_export *exp)
102 {
103         if (!(exp->ex_flags & NFSEXP_V4ROOT))
104                 return nfs_ok;
105         /*
106          * v2/v3 clients have no need for the V4ROOT export--they use
107          * the mount protocl instead; also, further V4ROOT checks may be
108          * in v4-specific code, in which case v2/v3 clients could bypass
109          * them.
110          */
111         if (!nfsd_v4client(rqstp))
112                 return nfserr_stale;
113         /*
114          * We're exposing only the directories and symlinks that have to be
115          * traversed on the way to real exports:
116          */
117         if (unlikely(!S_ISDIR(dentry->d_inode->i_mode) &&
118                      !S_ISLNK(dentry->d_inode->i_mode)))
119                 return nfserr_stale;
120         /*
121          * A pseudoroot export gives permission to access only one
122          * single directory; the kernel has to make another upcall
123          * before granting access to anything else under it:
124          */
125         if (unlikely(dentry != exp->ex_path.dentry))
126                 return nfserr_stale;
127         return nfs_ok;
128 }
129 
130 /*
131  * Use the given filehandle to look up the corresponding export and
132  * dentry.  On success, the results are used to set fh_export and
133  * fh_dentry.
134  */
135 static __be32 nfsd_set_fh_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp)
136 {
137         struct knfsd_fh *fh = &fhp->fh_handle;
138         struct fid *fid = NULL, sfid;
139         struct svc_export *exp;
140         struct dentry *dentry;
141         int fileid_type;
142         int data_left = fh->fh_size/4;
143         __be32 error;
144 
145         error = nfserr_stale;
146         if (rqstp->rq_vers > 2)
147                 error = nfserr_badhandle;
148         if (rqstp->rq_vers == 4 && fh->fh_size == 0)
149                 return nfserr_nofilehandle;
150 
151         if (fh->fh_version == 1) {
152                 int len;
153 
154                 if (--data_left < 0)
155                         return error;
156                 if (fh->fh_auth_type != 0)
157                         return error;
158                 len = key_len(fh->fh_fsid_type) / 4;
159                 if (len == 0)
160                         return error;
161                 if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
162                         /* deprecated, convert to type 3 */
163                         len = key_len(FSID_ENCODE_DEV)/4;
164                         fh->fh_fsid_type = FSID_ENCODE_DEV;
165                         /*
166                          * struct knfsd_fh uses host-endian fields, which are
167                          * sometimes used to hold net-endian values. This
168                          * confuses sparse, so we must use __force here to
169                          * keep it from complaining.
170                          */
171                         fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl((__force __be32)fh->fh_fsid[0]),
172                                                         ntohl((__force __be32)fh->fh_fsid[1])));
173                         fh->fh_fsid[1] = fh->fh_fsid[2];
174                 }
175                 data_left -= len;
176                 if (data_left < 0)
177                         return error;
178                 exp = rqst_exp_find(rqstp, fh->fh_fsid_type, fh->fh_fsid);
179                 fid = (struct fid *)(fh->fh_fsid + len);
180         } else {
181                 __u32 tfh[2];
182                 dev_t xdev;
183                 ino_t xino;
184 
185                 if (fh->fh_size != NFS_FHSIZE)
186                         return error;
187                 /* assume old filehandle format */
188                 xdev = old_decode_dev(fh->ofh_xdev);
189                 xino = u32_to_ino_t(fh->ofh_xino);
190                 mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
191                 exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
192         }
193 
194         error = nfserr_stale;
195         if (PTR_ERR(exp) == -ENOENT)
196                 return error;
197 
198         if (IS_ERR(exp))
199                 return nfserrno(PTR_ERR(exp));
200 
201         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
202                 /* Elevate privileges so that the lack of 'r' or 'x'
203                  * permission on some parent directory will
204                  * not stop exportfs_decode_fh from being able
205                  * to reconnect a directory into the dentry cache.
206                  * The same problem can affect "SUBTREECHECK" exports,
207                  * but as nfsd_acceptable depends on correct
208                  * access control settings being in effect, we cannot
209                  * fix that case easily.
210                  */
211                 struct cred *new = prepare_creds();
212                 if (!new) {
213                         error =  nfserrno(-ENOMEM);
214                         goto out;
215                 }
216                 new->cap_effective =
217                         cap_raise_nfsd_set(new->cap_effective,
218                                            new->cap_permitted);
219                 put_cred(override_creds(new));
220                 put_cred(new);
221         } else {
222                 error = nfsd_setuser_and_check_port(rqstp, exp);
223                 if (error)
224                         goto out;
225         }
226 
227         /*
228          * Look up the dentry using the NFS file handle.
229          */
230         error = nfserr_stale;
231         if (rqstp->rq_vers > 2)
232                 error = nfserr_badhandle;
233 
234         if (fh->fh_version != 1) {
235                 sfid.i32.ino = fh->ofh_ino;
236                 sfid.i32.gen = fh->ofh_generation;
237                 sfid.i32.parent_ino = fh->ofh_dirino;
238                 fid = &sfid;
239                 data_left = 3;
240                 if (fh->ofh_dirino == 0)
241                         fileid_type = FILEID_INO32_GEN;
242                 else
243                         fileid_type = FILEID_INO32_GEN_PARENT;
244         } else
245                 fileid_type = fh->fh_fileid_type;
246 
247         if (fileid_type == FILEID_ROOT)
248                 dentry = dget(exp->ex_path.dentry);
249         else {
250                 dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
251                                 data_left, fileid_type,
252                                 nfsd_acceptable, exp);
253         }
254         if (dentry == NULL)
255                 goto out;
256         if (IS_ERR(dentry)) {
257                 if (PTR_ERR(dentry) != -EINVAL)
258                         error = nfserrno(PTR_ERR(dentry));
259                 goto out;
260         }
261 
262         if (S_ISDIR(dentry->d_inode->i_mode) &&
263                         (dentry->d_flags & DCACHE_DISCONNECTED)) {
264                 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %pd2\n",
265                                 dentry);
266         }
267 
268         fhp->fh_dentry = dentry;
269         fhp->fh_export = exp;
270         return 0;
271 out:
272         exp_put(exp);
273         return error;
274 }
275 
276 /**
277  * fh_verify - filehandle lookup and access checking
278  * @rqstp: pointer to current rpc request
279  * @fhp: filehandle to be verified
280  * @type: expected type of object pointed to by filehandle
281  * @access: type of access needed to object
282  *
283  * Look up a dentry from the on-the-wire filehandle, check the client's
284  * access to the export, and set the current task's credentials.
285  *
286  * Regardless of success or failure of fh_verify(), fh_put() should be
287  * called on @fhp when the caller is finished with the filehandle.
288  *
289  * fh_verify() may be called multiple times on a given filehandle, for
290  * example, when processing an NFSv4 compound.  The first call will look
291  * up a dentry using the on-the-wire filehandle.  Subsequent calls will
292  * skip the lookup and just perform the other checks and possibly change
293  * the current task's credentials.
294  *
295  * @type specifies the type of object expected using one of the S_IF*
296  * constants defined in include/linux/stat.h.  The caller may use zero
297  * to indicate that it doesn't care, or a negative integer to indicate
298  * that it expects something not of the given type.
299  *
300  * @access is formed from the NFSD_MAY_* constants defined in
301  * include/linux/nfsd/nfsd.h.
302  */
303 __be32
304 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int access)
305 {
306         struct svc_export *exp;
307         struct dentry   *dentry;
308         __be32          error;
309 
310         dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
311 
312         if (!fhp->fh_dentry) {
313                 error = nfsd_set_fh_dentry(rqstp, fhp);
314                 if (error)
315                         goto out;
316         }
317         dentry = fhp->fh_dentry;
318         exp = fhp->fh_export;
319         /*
320          * We still have to do all these permission checks, even when
321          * fh_dentry is already set:
322          *      - fh_verify may be called multiple times with different
323          *        "access" arguments (e.g. nfsd_proc_create calls
324          *        fh_verify(...,NFSD_MAY_EXEC) first, then later (in
325          *        nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
326          *      - in the NFSv4 case, the filehandle may have been filled
327          *        in by fh_compose, and given a dentry, but further
328          *        compound operations performed with that filehandle
329          *        still need permissions checks.  In the worst case, a
330          *        mountpoint crossing may have changed the export
331          *        options, and we may now need to use a different uid
332          *        (for example, if different id-squashing options are in
333          *        effect on the new filesystem).
334          */
335         error = check_pseudo_root(rqstp, dentry, exp);
336         if (error)
337                 goto out;
338 
339         error = nfsd_setuser_and_check_port(rqstp, exp);
340         if (error)
341                 goto out;
342 
343         error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
344         if (error)
345                 goto out;
346 
347         /*
348          * pseudoflavor restrictions are not enforced on NLM,
349          * which clients virtually always use auth_sys for,
350          * even while using RPCSEC_GSS for NFS.
351          */
352         if (access & NFSD_MAY_LOCK || access & NFSD_MAY_BYPASS_GSS)
353                 goto skip_pseudoflavor_check;
354         /*
355          * Clients may expect to be able to use auth_sys during mount,
356          * even if they use gss for everything else; see section 2.3.2
357          * of rfc 2623.
358          */
359         if (access & NFSD_MAY_BYPASS_GSS_ON_ROOT
360                         && exp->ex_path.dentry == dentry)
361                 goto skip_pseudoflavor_check;
362 
363         error = check_nfsd_access(exp, rqstp);
364         if (error)
365                 goto out;
366 
367 skip_pseudoflavor_check:
368         /* Finally, check access permissions. */
369         error = nfsd_permission(rqstp, exp, dentry, access);
370 
371         if (error) {
372                 dprintk("fh_verify: %pd2 permission failure, "
373                         "acc=%x, error=%d\n",
374                         dentry,
375                         access, ntohl(error));
376         }
377 out:
378         if (error == nfserr_stale)
379                 nfsdstats.fh_stale++;
380         return error;
381 }
382 
383 
384 /*
385  * Compose a file handle for an NFS reply.
386  *
387  * Note that when first composed, the dentry may not yet have
388  * an inode.  In this case a call to fh_update should be made
389  * before the fh goes out on the wire ...
390  */
391 static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
392                 struct dentry *dentry)
393 {
394         if (dentry != exp->ex_path.dentry) {
395                 struct fid *fid = (struct fid *)
396                         (fhp->fh_handle.fh_fsid + fhp->fh_handle.fh_size/4 - 1);
397                 int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
398                 int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
399 
400                 fhp->fh_handle.fh_fileid_type =
401                         exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
402                 fhp->fh_handle.fh_size += maxsize * 4;
403         } else {
404                 fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
405         }
406 }
407 
408 /*
409  * for composing old style file handles
410  */
411 static inline void _fh_update_old(struct dentry *dentry,
412                                   struct svc_export *exp,
413                                   struct knfsd_fh *fh)
414 {
415         fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
416         fh->ofh_generation = dentry->d_inode->i_generation;
417         if (S_ISDIR(dentry->d_inode->i_mode) ||
418             (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
419                 fh->ofh_dirino = 0;
420 }
421 
422 static bool is_root_export(struct svc_export *exp)
423 {
424         return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
425 }
426 
427 static struct super_block *exp_sb(struct svc_export *exp)
428 {
429         return exp->ex_path.dentry->d_inode->i_sb;
430 }
431 
432 static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
433 {
434         switch (fsid_type) {
435         case FSID_DEV:
436                 if (!old_valid_dev(exp_sb(exp)->s_dev))
437                         return 0;
438                 /* FALL THROUGH */
439         case FSID_MAJOR_MINOR:
440         case FSID_ENCODE_DEV:
441                 return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
442         case FSID_NUM:
443                 return exp->ex_flags & NFSEXP_FSID;
444         case FSID_UUID8:
445         case FSID_UUID16:
446                 if (!is_root_export(exp))
447                         return 0;
448                 /* fall through */
449         case FSID_UUID4_INUM:
450         case FSID_UUID16_INUM:
451                 return exp->ex_uuid != NULL;
452         }
453         return 1;
454 }
455 
456 
457 static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
458 {
459         u8 version;
460         u8 fsid_type;
461 retry:
462         version = 1;
463         if (ref_fh && ref_fh->fh_export == exp) {
464                 version = ref_fh->fh_handle.fh_version;
465                 fsid_type = ref_fh->fh_handle.fh_fsid_type;
466 
467                 ref_fh = NULL;
468 
469                 switch (version) {
470                 case 0xca:
471                         fsid_type = FSID_DEV;
472                         break;
473                 case 1:
474                         break;
475                 default:
476                         goto retry;
477                 }
478 
479                 /*
480                  * As the fsid -> filesystem mapping was guided by
481                  * user-space, there is no guarantee that the filesystem
482                  * actually supports that fsid type. If it doesn't we
483                  * loop around again without ref_fh set.
484                  */
485                 if (!fsid_type_ok_for_exp(fsid_type, exp))
486                         goto retry;
487         } else if (exp->ex_flags & NFSEXP_FSID) {
488                 fsid_type = FSID_NUM;
489         } else if (exp->ex_uuid) {
490                 if (fhp->fh_maxsize >= 64) {
491                         if (is_root_export(exp))
492                                 fsid_type = FSID_UUID16;
493                         else
494                                 fsid_type = FSID_UUID16_INUM;
495                 } else {
496                         if (is_root_export(exp))
497                                 fsid_type = FSID_UUID8;
498                         else
499                                 fsid_type = FSID_UUID4_INUM;
500                 }
501         } else if (!old_valid_dev(exp_sb(exp)->s_dev))
502                 /* for newer device numbers, we must use a newer fsid format */
503                 fsid_type = FSID_ENCODE_DEV;
504         else
505                 fsid_type = FSID_DEV;
506         fhp->fh_handle.fh_version = version;
507         if (version)
508                 fhp->fh_handle.fh_fsid_type = fsid_type;
509 }
510 
511 __be32
512 fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
513            struct svc_fh *ref_fh)
514 {
515         /* ref_fh is a reference file handle.
516          * if it is non-null and for the same filesystem, then we should compose
517          * a filehandle which is of the same version, where possible.
518          * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
519          * Then create a 32byte filehandle using nfs_fhbase_old
520          *
521          */
522 
523         struct inode * inode = dentry->d_inode;
524         dev_t ex_dev = exp_sb(exp)->s_dev;
525 
526         dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %pd2, ino=%ld)\n",
527                 MAJOR(ex_dev), MINOR(ex_dev),
528                 (long) exp->ex_path.dentry->d_inode->i_ino,
529                 dentry,
530                 (inode ? inode->i_ino : 0));
531 
532         /* Choose filehandle version and fsid type based on
533          * the reference filehandle (if it is in the same export)
534          * or the export options.
535          */
536          set_version_and_fsid_type(fhp, exp, ref_fh);
537 
538         if (ref_fh == fhp)
539                 fh_put(ref_fh);
540 
541         if (fhp->fh_locked || fhp->fh_dentry) {
542                 printk(KERN_ERR "fh_compose: fh %pd2 not initialized!\n",
543                        dentry);
544         }
545         if (fhp->fh_maxsize < NFS_FHSIZE)
546                 printk(KERN_ERR "fh_compose: called with maxsize %d! %pd2\n",
547                        fhp->fh_maxsize,
548                        dentry);
549 
550         fhp->fh_dentry = dget(dentry); /* our internal copy */
551         fhp->fh_export = exp_get(exp);
552 
553         if (fhp->fh_handle.fh_version == 0xca) {
554                 /* old style filehandle please */
555                 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
556                 fhp->fh_handle.fh_size = NFS_FHSIZE;
557                 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
558                 fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
559                 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
560                 fhp->fh_handle.ofh_xino =
561                         ino_t_to_u32(exp->ex_path.dentry->d_inode->i_ino);
562                 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
563                 if (inode)
564                         _fh_update_old(dentry, exp, &fhp->fh_handle);
565         } else {
566                 fhp->fh_handle.fh_size =
567                         key_len(fhp->fh_handle.fh_fsid_type) + 4;
568                 fhp->fh_handle.fh_auth_type = 0;
569 
570                 mk_fsid(fhp->fh_handle.fh_fsid_type,
571                         fhp->fh_handle.fh_fsid,
572                         ex_dev,
573                         exp->ex_path.dentry->d_inode->i_ino,
574                         exp->ex_fsid, exp->ex_uuid);
575 
576                 if (inode)
577                         _fh_update(fhp, exp, dentry);
578                 if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID) {
579                         fh_put(fhp);
580                         return nfserr_opnotsupp;
581                 }
582         }
583 
584         return 0;
585 }
586 
587 /*
588  * Update file handle information after changing a dentry.
589  * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
590  */
591 __be32
592 fh_update(struct svc_fh *fhp)
593 {
594         struct dentry *dentry;
595 
596         if (!fhp->fh_dentry)
597                 goto out_bad;
598 
599         dentry = fhp->fh_dentry;
600         if (!dentry->d_inode)
601                 goto out_negative;
602         if (fhp->fh_handle.fh_version != 1) {
603                 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
604         } else {
605                 if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
606                         return 0;
607 
608                 _fh_update(fhp, fhp->fh_export, dentry);
609                 if (fhp->fh_handle.fh_fileid_type == FILEID_INVALID)
610                         return nfserr_opnotsupp;
611         }
612         return 0;
613 out_bad:
614         printk(KERN_ERR "fh_update: fh not verified!\n");
615         return nfserr_serverfault;
616 out_negative:
617         printk(KERN_ERR "fh_update: %pd2 still negative!\n",
618                 dentry);
619         return nfserr_serverfault;
620 }
621 
622 /*
623  * Release a file handle.
624  */
625 void
626 fh_put(struct svc_fh *fhp)
627 {
628         struct dentry * dentry = fhp->fh_dentry;
629         struct svc_export * exp = fhp->fh_export;
630         if (dentry) {
631                 fh_unlock(fhp);
632                 fhp->fh_dentry = NULL;
633                 dput(dentry);
634 #ifdef CONFIG_NFSD_V3
635                 fhp->fh_pre_saved = 0;
636                 fhp->fh_post_saved = 0;
637 #endif
638         }
639         fh_drop_write(fhp);
640         if (exp) {
641                 exp_put(exp);
642                 fhp->fh_export = NULL;
643         }
644         return;
645 }
646 
647 /*
648  * Shorthand for dprintk()'s
649  */
650 char * SVCFH_fmt(struct svc_fh *fhp)
651 {
652         struct knfsd_fh *fh = &fhp->fh_handle;
653 
654         static char buf[80];
655         sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
656                 fh->fh_size,
657                 fh->fh_base.fh_pad[0],
658                 fh->fh_base.fh_pad[1],
659                 fh->fh_base.fh_pad[2],
660                 fh->fh_base.fh_pad[3],
661                 fh->fh_base.fh_pad[4],
662                 fh->fh_base.fh_pad[5]);
663         return buf;
664 }
665 
666 enum fsid_source fsid_source(struct svc_fh *fhp)
667 {
668         if (fhp->fh_handle.fh_version != 1)
669                 return FSIDSOURCE_DEV;
670         switch(fhp->fh_handle.fh_fsid_type) {
671         case FSID_DEV:
672         case FSID_ENCODE_DEV:
673         case FSID_MAJOR_MINOR:
674                 if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
675                         return FSIDSOURCE_DEV;
676                 break;
677         case FSID_NUM:
678                 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
679                         return FSIDSOURCE_FSID;
680                 break;
681         default:
682                 break;
683         }
684         /* either a UUID type filehandle, or the filehandle doesn't
685          * match the export.
686          */
687         if (fhp->fh_export->ex_flags & NFSEXP_FSID)
688                 return FSIDSOURCE_FSID;
689         if (fhp->fh_export->ex_uuid)
690                 return FSIDSOURCE_UUID;
691         return FSIDSOURCE_DEV;
692 }
693 

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