x86, ptrace: use jiffies for BTS timestamps
[linux-2.6] / fs / nfsd / nfsfh.c
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
26 #define NFSDDBG_FACILITY                NFSDDBG_FH
27
28
29 static int nfsd_nr_verified;
30 static int nfsd_nr_put;
31
32 /*
33  * our acceptability function.
34  * if NOSUBTREECHECK, accept anything
35  * if not, require that we can walk up to exp->ex_dentry
36  * doing some checks on the 'x' bits
37  */
38 static int nfsd_acceptable(void *expv, struct dentry *dentry)
39 {
40         struct svc_export *exp = expv;
41         int rv;
42         struct dentry *tdentry;
43         struct dentry *parent;
44
45         if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
46                 return 1;
47
48         tdentry = dget(dentry);
49         while (tdentry != exp->ex_dentry && ! IS_ROOT(tdentry)) {
50                 /* make sure parents give x permission to user */
51                 int err;
52                 parent = dget_parent(tdentry);
53                 err = permission(parent->d_inode, MAY_EXEC, NULL);
54                 if (err < 0) {
55                         dput(parent);
56                         break;
57                 }
58                 dput(tdentry);
59                 tdentry = parent;
60         }
61         if (tdentry != exp->ex_dentry)
62                 dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
63         rv = (tdentry == exp->ex_dentry);
64         dput(tdentry);
65         return rv;
66 }
67
68 /* Type check. The correct error return for type mismatches does not seem to be
69  * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
70  * comment in the NFSv3 spec says this is incorrect (implementation notes for
71  * the write call).
72  */
73 static inline __be32
74 nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
75 {
76         /* Type can be negative when creating hardlinks - not to a dir */
77         if (type > 0 && (mode & S_IFMT) != type) {
78                 if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
79                         return nfserr_symlink;
80                 else if (type == S_IFDIR)
81                         return nfserr_notdir;
82                 else if ((mode & S_IFMT) == S_IFDIR)
83                         return nfserr_isdir;
84                 else
85                         return nfserr_inval;
86         }
87         if (type < 0 && (mode & S_IFMT) == -type) {
88                 if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
89                         return nfserr_symlink;
90                 else if (type == -S_IFDIR)
91                         return nfserr_isdir;
92                 else
93                         return nfserr_notdir;
94         }
95         return 0;
96 }
97
98 static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
99                                           struct svc_export *exp)
100 {
101         /* Check if the request originated from a secure port. */
102         if (!rqstp->rq_secure && EX_SECURE(exp)) {
103                 char buf[RPC_MAX_ADDRBUFLEN];
104                 dprintk(KERN_WARNING
105                        "nfsd: request from insecure port %s!\n",
106                        svc_print_addr(rqstp, buf, sizeof(buf)));
107                 return nfserr_perm;
108         }
109
110         /* Set user creds for this exportpoint */
111         return nfserrno(nfsd_setuser(rqstp, exp));
112 }
113
114 /*
115  * Perform sanity checks on the dentry in a client's file handle.
116  *
117  * Note that the file handle dentry may need to be freed even after
118  * an error return.
119  *
120  * This is only called at the start of an nfsproc call, so fhp points to
121  * a svc_fh which is all 0 except for the over-the-wire file handle.
122  */
123 __be32
124 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
125 {
126         struct knfsd_fh *fh = &fhp->fh_handle;
127         struct svc_export *exp = NULL;
128         struct dentry   *dentry;
129         __be32          error = 0;
130
131         dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
132
133         if (!fhp->fh_dentry) {
134                 struct fid *fid = NULL, sfid;
135                 int fileid_type;
136                 int data_left = fh->fh_size/4;
137
138                 error = nfserr_stale;
139                 if (rqstp->rq_vers > 2)
140                         error = nfserr_badhandle;
141                 if (rqstp->rq_vers == 4 && fh->fh_size == 0)
142                         return nfserr_nofilehandle;
143
144                 if (fh->fh_version == 1) {
145                         int len;
146                         if (--data_left<0) goto out;
147                         switch (fh->fh_auth_type) {
148                         case 0: break;
149                         default: goto out;
150                         }
151                         len = key_len(fh->fh_fsid_type) / 4;
152                         if (len == 0) goto out;
153                         if  (fh->fh_fsid_type == FSID_MAJOR_MINOR) {
154                                 /* deprecated, convert to type 3 */
155                                 len = key_len(FSID_ENCODE_DEV)/4;
156                                 fh->fh_fsid_type = FSID_ENCODE_DEV;
157                                 fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1])));
158                                 fh->fh_fsid[1] = fh->fh_fsid[2];
159                         }
160                         if ((data_left -= len)<0) goto out;
161                         exp = rqst_exp_find(rqstp, fh->fh_fsid_type,
162                                             fh->fh_auth);
163                         fid = (struct fid *)(fh->fh_auth + len);
164                 } else {
165                         __u32 tfh[2];
166                         dev_t xdev;
167                         ino_t xino;
168                         if (fh->fh_size != NFS_FHSIZE)
169                                 goto out;
170                         /* assume old filehandle format */
171                         xdev = old_decode_dev(fh->ofh_xdev);
172                         xino = u32_to_ino_t(fh->ofh_xino);
173                         mk_fsid(FSID_DEV, tfh, xdev, xino, 0, NULL);
174                         exp = rqst_exp_find(rqstp, FSID_DEV, tfh);
175                 }
176
177                 error = nfserr_stale;
178                 if (PTR_ERR(exp) == -ENOENT)
179                         goto out;
180
181                 if (IS_ERR(exp)) {
182                         error = nfserrno(PTR_ERR(exp));
183                         goto out;
184                 }
185
186                 error = nfsd_setuser_and_check_port(rqstp, exp);
187                 if (error)
188                         goto out;
189
190                 /*
191                  * Look up the dentry using the NFS file handle.
192                  */
193                 error = nfserr_stale;
194                 if (rqstp->rq_vers > 2)
195                         error = nfserr_badhandle;
196
197                 if (fh->fh_version != 1) {
198                         sfid.i32.ino = fh->ofh_ino;
199                         sfid.i32.gen = fh->ofh_generation;
200                         sfid.i32.parent_ino = fh->ofh_dirino;
201                         fid = &sfid;
202                         data_left = 3;
203                         if (fh->ofh_dirino == 0)
204                                 fileid_type = FILEID_INO32_GEN;
205                         else
206                                 fileid_type = FILEID_INO32_GEN_PARENT;
207                 } else
208                         fileid_type = fh->fh_fileid_type;
209
210                 if (fileid_type == FILEID_ROOT)
211                         dentry = dget(exp->ex_dentry);
212                 else {
213                         dentry = exportfs_decode_fh(exp->ex_mnt, fid,
214                                         data_left, fileid_type,
215                                         nfsd_acceptable, exp);
216                 }
217                 if (dentry == NULL)
218                         goto out;
219                 if (IS_ERR(dentry)) {
220                         if (PTR_ERR(dentry) != -EINVAL)
221                                 error = nfserrno(PTR_ERR(dentry));
222                         goto out;
223                 }
224
225                 if (S_ISDIR(dentry->d_inode->i_mode) &&
226                     (dentry->d_flags & DCACHE_DISCONNECTED)) {
227                         printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
228                                dentry->d_parent->d_name.name, dentry->d_name.name);
229                 }
230
231                 fhp->fh_dentry = dentry;
232                 fhp->fh_export = exp;
233                 nfsd_nr_verified++;
234         } else {
235                 /*
236                  * just rechecking permissions
237                  * (e.g. nfsproc_create calls fh_verify, then nfsd_create
238                  * does as well)
239                  */
240                 dprintk("nfsd: fh_verify - just checking\n");
241                 dentry = fhp->fh_dentry;
242                 exp = fhp->fh_export;
243                 /*
244                  * Set user creds for this exportpoint; necessary even
245                  * in the "just checking" case because this may be a
246                  * filehandle that was created by fh_compose, and that
247                  * is about to be used in another nfsv4 compound
248                  * operation.
249                  */
250                 error = nfsd_setuser_and_check_port(rqstp, exp);
251                 if (error)
252                         goto out;
253         }
254         cache_get(&exp->h);
255
256
257         error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
258         if (error)
259                 goto out;
260
261         if (!(access & MAY_LOCK)) {
262                 /*
263                  * pseudoflavor restrictions are not enforced on NLM,
264                  * which clients virtually always use auth_sys for,
265                  * even while using RPCSEC_GSS for NFS.
266                  */
267                 error = check_nfsd_access(exp, rqstp);
268                 if (error)
269                         goto out;
270         }
271
272         /* Finally, check access permissions. */
273         error = nfsd_permission(rqstp, exp, dentry, access);
274
275         if (error) {
276                 dprintk("fh_verify: %s/%s permission failure, "
277                         "acc=%x, error=%d\n",
278                         dentry->d_parent->d_name.name,
279                         dentry->d_name.name,
280                         access, ntohl(error));
281         }
282 out:
283         if (exp && !IS_ERR(exp))
284                 exp_put(exp);
285         if (error == nfserr_stale)
286                 nfsdstats.fh_stale++;
287         return error;
288 }
289
290
291 /*
292  * Compose a file handle for an NFS reply.
293  *
294  * Note that when first composed, the dentry may not yet have
295  * an inode.  In this case a call to fh_update should be made
296  * before the fh goes out on the wire ...
297  */
298 static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
299                 struct dentry *dentry)
300 {
301         if (dentry != exp->ex_dentry) {
302                 struct fid *fid = (struct fid *)
303                         (fhp->fh_handle.fh_auth + fhp->fh_handle.fh_size/4 - 1);
304                 int maxsize = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4;
305                 int subtreecheck = !(exp->ex_flags & NFSEXP_NOSUBTREECHECK);
306
307                 fhp->fh_handle.fh_fileid_type =
308                         exportfs_encode_fh(dentry, fid, &maxsize, subtreecheck);
309                 fhp->fh_handle.fh_size += maxsize * 4;
310         } else {
311                 fhp->fh_handle.fh_fileid_type = FILEID_ROOT;
312         }
313 }
314
315 /*
316  * for composing old style file handles
317  */
318 static inline void _fh_update_old(struct dentry *dentry,
319                                   struct svc_export *exp,
320                                   struct knfsd_fh *fh)
321 {
322         fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino);
323         fh->ofh_generation = dentry->d_inode->i_generation;
324         if (S_ISDIR(dentry->d_inode->i_mode) ||
325             (exp->ex_flags & NFSEXP_NOSUBTREECHECK))
326                 fh->ofh_dirino = 0;
327 }
328
329 __be32
330 fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
331            struct svc_fh *ref_fh)
332 {
333         /* ref_fh is a reference file handle.
334          * if it is non-null and for the same filesystem, then we should compose
335          * a filehandle which is of the same version, where possible.
336          * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
337          * Then create a 32byte filehandle using nfs_fhbase_old
338          *
339          */
340
341         u8 version;
342         u8 fsid_type = 0;
343         struct inode * inode = dentry->d_inode;
344         struct dentry *parent = dentry->d_parent;
345         __u32 *datap;
346         dev_t ex_dev = exp->ex_dentry->d_inode->i_sb->s_dev;
347         int root_export = (exp->ex_dentry == exp->ex_dentry->d_sb->s_root);
348
349         dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
350                 MAJOR(ex_dev), MINOR(ex_dev),
351                 (long) exp->ex_dentry->d_inode->i_ino,
352                 parent->d_name.name, dentry->d_name.name,
353                 (inode ? inode->i_ino : 0));
354
355         /* Choose filehandle version and fsid type based on
356          * the reference filehandle (if it is in the same export)
357          * or the export options.
358          */
359  retry:
360         version = 1;
361         if (ref_fh && ref_fh->fh_export == exp) {
362                 version = ref_fh->fh_handle.fh_version;
363                 fsid_type = ref_fh->fh_handle.fh_fsid_type;
364
365                 if (ref_fh == fhp)
366                         fh_put(ref_fh);
367                 ref_fh = NULL;
368
369                 switch (version) {
370                 case 0xca:
371                         fsid_type = FSID_DEV;
372                         break;
373                 case 1:
374                         break;
375                 default:
376                         goto retry;
377                 }
378
379                 /* Need to check that this type works for this
380                  * export point.  As the fsid -> filesystem mapping
381                  * was guided by user-space, there is no guarantee
382                  * that the filesystem actually supports that fsid
383                  * type. If it doesn't we loop around again without
384                  * ref_fh set.
385                  */
386                 switch(fsid_type) {
387                 case FSID_DEV:
388                         if (!old_valid_dev(ex_dev))
389                                 goto retry;
390                         /* FALL THROUGH */
391                 case FSID_MAJOR_MINOR:
392                 case FSID_ENCODE_DEV:
393                         if (!(exp->ex_dentry->d_inode->i_sb->s_type->fs_flags
394                               & FS_REQUIRES_DEV))
395                                 goto retry;
396                         break;
397                 case FSID_NUM:
398                         if (! (exp->ex_flags & NFSEXP_FSID))
399                                 goto retry;
400                         break;
401                 case FSID_UUID8:
402                 case FSID_UUID16:
403                         if (!root_export)
404                                 goto retry;
405                         /* fall through */
406                 case FSID_UUID4_INUM:
407                 case FSID_UUID16_INUM:
408                         if (exp->ex_uuid == NULL)
409                                 goto retry;
410                         break;
411                 }
412         } else if (exp->ex_uuid) {
413                 if (fhp->fh_maxsize >= 64) {
414                         if (root_export)
415                                 fsid_type = FSID_UUID16;
416                         else
417                                 fsid_type = FSID_UUID16_INUM;
418                 } else {
419                         if (root_export)
420                                 fsid_type = FSID_UUID8;
421                         else
422                                 fsid_type = FSID_UUID4_INUM;
423                 }
424         } else if (exp->ex_flags & NFSEXP_FSID)
425                 fsid_type = FSID_NUM;
426         else if (!old_valid_dev(ex_dev))
427                 /* for newer device numbers, we must use a newer fsid format */
428                 fsid_type = FSID_ENCODE_DEV;
429         else
430                 fsid_type = FSID_DEV;
431
432         if (ref_fh == fhp)
433                 fh_put(ref_fh);
434
435         if (fhp->fh_locked || fhp->fh_dentry) {
436                 printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n",
437                        parent->d_name.name, dentry->d_name.name);
438         }
439         if (fhp->fh_maxsize < NFS_FHSIZE)
440                 printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n",
441                        fhp->fh_maxsize,
442                        parent->d_name.name, dentry->d_name.name);
443
444         fhp->fh_dentry = dget(dentry); /* our internal copy */
445         fhp->fh_export = exp;
446         cache_get(&exp->h);
447
448         if (version == 0xca) {
449                 /* old style filehandle please */
450                 memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
451                 fhp->fh_handle.fh_size = NFS_FHSIZE;
452                 fhp->fh_handle.ofh_dcookie = 0xfeebbaca;
453                 fhp->fh_handle.ofh_dev =  old_encode_dev(ex_dev);
454                 fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev;
455                 fhp->fh_handle.ofh_xino =
456                         ino_t_to_u32(exp->ex_dentry->d_inode->i_ino);
457                 fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry));
458                 if (inode)
459                         _fh_update_old(dentry, exp, &fhp->fh_handle);
460         } else {
461                 int len;
462                 fhp->fh_handle.fh_version = 1;
463                 fhp->fh_handle.fh_auth_type = 0;
464                 datap = fhp->fh_handle.fh_auth+0;
465                 fhp->fh_handle.fh_fsid_type = fsid_type;
466                 mk_fsid(fsid_type, datap, ex_dev,
467                         exp->ex_dentry->d_inode->i_ino,
468                         exp->ex_fsid, exp->ex_uuid);
469
470                 len = key_len(fsid_type);
471                 datap += len/4;
472                 fhp->fh_handle.fh_size = 4 + len;
473
474                 if (inode)
475                         _fh_update(fhp, exp, dentry);
476                 if (fhp->fh_handle.fh_fileid_type == 255)
477                         return nfserr_opnotsupp;
478         }
479
480         nfsd_nr_verified++;
481         return 0;
482 }
483
484 /*
485  * Update file handle information after changing a dentry.
486  * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
487  */
488 __be32
489 fh_update(struct svc_fh *fhp)
490 {
491         struct dentry *dentry;
492
493         if (!fhp->fh_dentry)
494                 goto out_bad;
495
496         dentry = fhp->fh_dentry;
497         if (!dentry->d_inode)
498                 goto out_negative;
499         if (fhp->fh_handle.fh_version != 1) {
500                 _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle);
501         } else {
502                 if (fhp->fh_handle.fh_fileid_type != FILEID_ROOT)
503                         goto out;
504
505                 _fh_update(fhp, fhp->fh_export, dentry);
506                 if (fhp->fh_handle.fh_fileid_type == 255)
507                         return nfserr_opnotsupp;
508         }
509 out:
510         return 0;
511
512 out_bad:
513         printk(KERN_ERR "fh_update: fh not verified!\n");
514         goto out;
515 out_negative:
516         printk(KERN_ERR "fh_update: %s/%s still negative!\n",
517                 dentry->d_parent->d_name.name, dentry->d_name.name);
518         goto out;
519 }
520
521 /*
522  * Release a file handle.
523  */
524 void
525 fh_put(struct svc_fh *fhp)
526 {
527         struct dentry * dentry = fhp->fh_dentry;
528         struct svc_export * exp = fhp->fh_export;
529         if (dentry) {
530                 fh_unlock(fhp);
531                 fhp->fh_dentry = NULL;
532                 dput(dentry);
533 #ifdef CONFIG_NFSD_V3
534                 fhp->fh_pre_saved = 0;
535                 fhp->fh_post_saved = 0;
536 #endif
537                 nfsd_nr_put++;
538         }
539         if (exp) {
540                 cache_put(&exp->h, &svc_export_cache);
541                 fhp->fh_export = NULL;
542         }
543         return;
544 }
545
546 /*
547  * Shorthand for dprintk()'s
548  */
549 char * SVCFH_fmt(struct svc_fh *fhp)
550 {
551         struct knfsd_fh *fh = &fhp->fh_handle;
552
553         static char buf[80];
554         sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x",
555                 fh->fh_size,
556                 fh->fh_base.fh_pad[0],
557                 fh->fh_base.fh_pad[1],
558                 fh->fh_base.fh_pad[2],
559                 fh->fh_base.fh_pad[3],
560                 fh->fh_base.fh_pad[4],
561                 fh->fh_base.fh_pad[5]);
562         return buf;
563 }
564
565 enum fsid_source fsid_source(struct svc_fh *fhp)
566 {
567         if (fhp->fh_handle.fh_version != 1)
568                 return FSIDSOURCE_DEV;
569         switch(fhp->fh_handle.fh_fsid_type) {
570         case FSID_DEV:
571         case FSID_ENCODE_DEV:
572         case FSID_MAJOR_MINOR:
573                 if (fhp->fh_export->ex_dentry->d_inode->i_sb->s_type->fs_flags
574                     & FS_REQUIRES_DEV)
575                         return FSIDSOURCE_DEV;
576                 break;
577         case FSID_NUM:
578                 if (fhp->fh_export->ex_flags & NFSEXP_FSID)
579                         return FSIDSOURCE_FSID;
580                 break;
581         default:
582                 break;
583         }
584         /* either a UUID type filehandle, or the filehandle doesn't
585          * match the export.
586          */
587         if (fhp->fh_export->ex_flags & NFSEXP_FSID)
588                 return FSIDSOURCE_FSID;
589         if (fhp->fh_export->ex_uuid)
590                 return FSIDSOURCE_UUID;
591         return FSIDSOURCE_DEV;
592 }