2 * linux/fs/nfsd/nfsfh.c
4 * NFS server file handle treatment.
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
12 #include <linux/slab.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>
21 #include <linux/sunrpc/clnt.h>
22 #include <linux/sunrpc/svc.h>
23 #include <linux/nfsd/nfsd.h>
25 #define NFSDDBG_FACILITY NFSDDBG_FH
28 static int nfsd_nr_verified
;
29 static int nfsd_nr_put
;
32 * our acceptability function.
33 * if NOSUBTREECHECK, accept anything
34 * if not, require that we can walk up to exp->ex_dentry
35 * doing some checks on the 'x' bits
37 static int nfsd_acceptable(void *expv
, struct dentry
*dentry
)
39 struct svc_export
*exp
= expv
;
41 struct dentry
*tdentry
;
42 struct dentry
*parent
;
44 if (exp
->ex_flags
& NFSEXP_NOSUBTREECHECK
)
47 tdentry
= dget(dentry
);
48 while (tdentry
!= exp
->ex_dentry
&& ! IS_ROOT(tdentry
)) {
49 /* make sure parents give x permission to user */
51 parent
= dget_parent(tdentry
);
52 err
= permission(parent
->d_inode
, MAY_EXEC
, NULL
);
60 if (tdentry
!= exp
->ex_dentry
)
61 dprintk("nfsd_acceptable failed at %p %s\n", tdentry
, tdentry
->d_name
.name
);
62 rv
= (tdentry
== exp
->ex_dentry
);
67 /* Type check. The correct error return for type mismatches does not seem to be
68 * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a
69 * comment in the NFSv3 spec says this is incorrect (implementation notes for
73 nfsd_mode_check(struct svc_rqst
*rqstp
, umode_t mode
, int type
)
75 /* Type can be negative when creating hardlinks - not to a dir */
76 if (type
> 0 && (mode
& S_IFMT
) != type
) {
77 if (rqstp
->rq_vers
== 4 && (mode
& S_IFMT
) == S_IFLNK
)
78 return nfserr_symlink
;
79 else if (type
== S_IFDIR
)
81 else if ((mode
& S_IFMT
) == S_IFDIR
)
86 if (type
< 0 && (mode
& S_IFMT
) == -type
) {
87 if (rqstp
->rq_vers
== 4 && (mode
& S_IFMT
) == S_IFLNK
)
88 return nfserr_symlink
;
89 else if (type
== -S_IFDIR
)
98 * Perform sanity checks on the dentry in a client's file handle.
100 * Note that the file handle dentry may need to be freed even after
103 * This is only called at the start of an nfsproc call, so fhp points to
104 * a svc_fh which is all 0 except for the over-the-wire file handle.
107 fh_verify(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, int type
, int access
)
109 struct knfsd_fh
*fh
= &fhp
->fh_handle
;
110 struct svc_export
*exp
= NULL
;
111 struct dentry
*dentry
;
114 dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp
));
116 if (!fhp
->fh_dentry
) {
118 __u32 tfh
[3]; /* filehandle fragment for oldstyle filehandles */
120 int data_left
= fh
->fh_size
/4;
122 error
= nfserr_stale
;
123 if (rqstp
->rq_vers
> 2)
124 error
= nfserr_badhandle
;
125 if (rqstp
->rq_vers
== 4 && fh
->fh_size
== 0)
126 return nfserr_nofilehandle
;
128 if (fh
->fh_version
== 1) {
131 if (--data_left
<0) goto out
;
132 switch (fh
->fh_auth_type
) {
136 len
= key_len(fh
->fh_fsid_type
) / 4;
137 if (len
== 0) goto out
;
138 if (fh
->fh_fsid_type
== FSID_MAJOR_MINOR
) {
139 /* deprecated, convert to type 3 */
140 len
= key_len(FSID_ENCODE_DEV
)/4;
141 fh
->fh_fsid_type
= FSID_ENCODE_DEV
;
142 fh
->fh_fsid
[0] = new_encode_dev(MKDEV(ntohl(fh
->fh_fsid
[0]), ntohl(fh
->fh_fsid
[1])));
143 fh
->fh_fsid
[1] = fh
->fh_fsid
[2];
145 if ((data_left
-= len
)<0) goto out
;
146 exp
= rqst_exp_find(rqstp
, fh
->fh_fsid_type
, datap
);
151 if (fh
->fh_size
!= NFS_FHSIZE
)
153 /* assume old filehandle format */
154 xdev
= old_decode_dev(fh
->ofh_xdev
);
155 xino
= u32_to_ino_t(fh
->ofh_xino
);
156 mk_fsid(FSID_DEV
, tfh
, xdev
, xino
, 0, NULL
);
157 exp
= rqst_exp_find(rqstp
, FSID_DEV
, tfh
);
160 error
= nfserr_stale
;
161 if (PTR_ERR(exp
) == -ENOENT
)
165 error
= nfserrno(PTR_ERR(exp
));
169 /* Check if the request originated from a secure port. */
171 if (!rqstp
->rq_secure
&& EX_SECURE(exp
)) {
172 char buf
[RPC_MAX_ADDRBUFLEN
];
174 "nfsd: request from insecure port %s!\n",
175 svc_print_addr(rqstp
, buf
, sizeof(buf
)));
179 /* Set user creds for this exportpoint */
180 error
= nfserrno(nfsd_setuser(rqstp
, exp
));
185 * Look up the dentry using the NFS file handle.
187 error
= nfserr_stale
;
188 if (rqstp
->rq_vers
> 2)
189 error
= nfserr_badhandle
;
191 if (fh
->fh_version
!= 1) {
192 tfh
[0] = fh
->ofh_ino
;
193 tfh
[1] = fh
->ofh_generation
;
194 tfh
[2] = fh
->ofh_dirino
;
197 if (fh
->ofh_dirino
== 0)
202 fileid_type
= fh
->fh_fileid_type
;
204 if (fileid_type
== 0)
205 dentry
= dget(exp
->ex_dentry
);
207 dentry
= exportfs_decode_fh(exp
->ex_mnt
, datap
,
208 data_left
, fileid_type
,
209 nfsd_acceptable
, exp
);
213 if (IS_ERR(dentry
)) {
214 if (PTR_ERR(dentry
) != -EINVAL
)
215 error
= nfserrno(PTR_ERR(dentry
));
219 if (S_ISDIR(dentry
->d_inode
->i_mode
) &&
220 (dentry
->d_flags
& DCACHE_DISCONNECTED
)) {
221 printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n",
222 dentry
->d_parent
->d_name
.name
, dentry
->d_name
.name
);
225 fhp
->fh_dentry
= dentry
;
226 fhp
->fh_export
= exp
;
229 /* just rechecking permissions
230 * (e.g. nfsproc_create calls fh_verify, then nfsd_create does as well)
232 dprintk("nfsd: fh_verify - just checking\n");
233 dentry
= fhp
->fh_dentry
;
234 exp
= fhp
->fh_export
;
235 /* Set user creds for this exportpoint; necessary even
236 * in the "just checking" case because this may be a
237 * filehandle that was created by fh_compose, and that
238 * is about to be used in another nfsv4 compound
240 error
= nfserrno(nfsd_setuser(rqstp
, exp
));
247 error
= nfsd_mode_check(rqstp
, dentry
->d_inode
->i_mode
, type
);
251 /* Finally, check access permissions. */
252 error
= nfsd_permission(exp
, dentry
, access
);
255 dprintk("fh_verify: %s/%s permission failure, "
256 "acc=%x, error=%d\n",
257 dentry
->d_parent
->d_name
.name
,
259 access
, ntohl(error
));
262 if (exp
&& !IS_ERR(exp
))
264 if (error
== nfserr_stale
)
265 nfsdstats
.fh_stale
++;
271 * Compose a file handle for an NFS reply.
273 * Note that when first composed, the dentry may not yet have
274 * an inode. In this case a call to fh_update should be made
275 * before the fh goes out on the wire ...
277 static inline int _fh_update(struct dentry
*dentry
, struct svc_export
*exp
,
278 __u32
*datap
, int *maxsize
)
280 if (dentry
== exp
->ex_dentry
) {
285 return exportfs_encode_fh(dentry
, datap
, maxsize
,
286 !(exp
->ex_flags
& NFSEXP_NOSUBTREECHECK
));
290 * for composing old style file handles
292 static inline void _fh_update_old(struct dentry
*dentry
,
293 struct svc_export
*exp
,
296 fh
->ofh_ino
= ino_t_to_u32(dentry
->d_inode
->i_ino
);
297 fh
->ofh_generation
= dentry
->d_inode
->i_generation
;
298 if (S_ISDIR(dentry
->d_inode
->i_mode
) ||
299 (exp
->ex_flags
& NFSEXP_NOSUBTREECHECK
))
304 fh_compose(struct svc_fh
*fhp
, struct svc_export
*exp
, struct dentry
*dentry
,
305 struct svc_fh
*ref_fh
)
307 /* ref_fh is a reference file handle.
308 * if it is non-null and for the same filesystem, then we should compose
309 * a filehandle which is of the same version, where possible.
310 * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca
311 * Then create a 32byte filehandle using nfs_fhbase_old
317 struct inode
* inode
= dentry
->d_inode
;
318 struct dentry
*parent
= dentry
->d_parent
;
320 dev_t ex_dev
= exp
->ex_dentry
->d_inode
->i_sb
->s_dev
;
321 int root_export
= (exp
->ex_dentry
== exp
->ex_dentry
->d_sb
->s_root
);
323 dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
324 MAJOR(ex_dev
), MINOR(ex_dev
),
325 (long) exp
->ex_dentry
->d_inode
->i_ino
,
326 parent
->d_name
.name
, dentry
->d_name
.name
,
327 (inode
? inode
->i_ino
: 0));
329 /* Choose filehandle version and fsid type based on
330 * the reference filehandle (if it is in the same export)
331 * or the export options.
335 if (ref_fh
&& ref_fh
->fh_export
== exp
) {
336 version
= ref_fh
->fh_handle
.fh_version
;
337 fsid_type
= ref_fh
->fh_handle
.fh_fsid_type
;
345 fsid_type
= FSID_DEV
;
353 /* Need to check that this type works for this
354 * export point. As the fsid -> filesystem mapping
355 * was guided by user-space, there is no guarantee
356 * that the filesystem actually supports that fsid
357 * type. If it doesn't we loop around again without
362 if (!old_valid_dev(ex_dev
))
365 case FSID_MAJOR_MINOR
:
366 case FSID_ENCODE_DEV
:
367 if (!(exp
->ex_dentry
->d_inode
->i_sb
->s_type
->fs_flags
372 if (! (exp
->ex_flags
& NFSEXP_FSID
))
380 case FSID_UUID4_INUM
:
381 case FSID_UUID16_INUM
:
382 if (exp
->ex_uuid
== NULL
)
386 } else if (exp
->ex_uuid
) {
387 if (fhp
->fh_maxsize
>= 64) {
389 fsid_type
= FSID_UUID16
;
391 fsid_type
= FSID_UUID16_INUM
;
394 fsid_type
= FSID_UUID8
;
396 fsid_type
= FSID_UUID4_INUM
;
398 } else if (exp
->ex_flags
& NFSEXP_FSID
)
399 fsid_type
= FSID_NUM
;
400 else if (!old_valid_dev(ex_dev
))
401 /* for newer device numbers, we must use a newer fsid format */
402 fsid_type
= FSID_ENCODE_DEV
;
404 fsid_type
= FSID_DEV
;
409 if (fhp
->fh_locked
|| fhp
->fh_dentry
) {
410 printk(KERN_ERR
"fh_compose: fh %s/%s not initialized!\n",
411 parent
->d_name
.name
, dentry
->d_name
.name
);
413 if (fhp
->fh_maxsize
< NFS_FHSIZE
)
414 printk(KERN_ERR
"fh_compose: called with maxsize %d! %s/%s\n",
416 parent
->d_name
.name
, dentry
->d_name
.name
);
418 fhp
->fh_dentry
= dget(dentry
); /* our internal copy */
419 fhp
->fh_export
= exp
;
422 if (version
== 0xca) {
423 /* old style filehandle please */
424 memset(&fhp
->fh_handle
.fh_base
, 0, NFS_FHSIZE
);
425 fhp
->fh_handle
.fh_size
= NFS_FHSIZE
;
426 fhp
->fh_handle
.ofh_dcookie
= 0xfeebbaca;
427 fhp
->fh_handle
.ofh_dev
= old_encode_dev(ex_dev
);
428 fhp
->fh_handle
.ofh_xdev
= fhp
->fh_handle
.ofh_dev
;
429 fhp
->fh_handle
.ofh_xino
=
430 ino_t_to_u32(exp
->ex_dentry
->d_inode
->i_ino
);
431 fhp
->fh_handle
.ofh_dirino
= ino_t_to_u32(parent_ino(dentry
));
433 _fh_update_old(dentry
, exp
, &fhp
->fh_handle
);
436 fhp
->fh_handle
.fh_version
= 1;
437 fhp
->fh_handle
.fh_auth_type
= 0;
438 datap
= fhp
->fh_handle
.fh_auth
+0;
439 fhp
->fh_handle
.fh_fsid_type
= fsid_type
;
440 mk_fsid(fsid_type
, datap
, ex_dev
,
441 exp
->ex_dentry
->d_inode
->i_ino
,
442 exp
->ex_fsid
, exp
->ex_uuid
);
444 len
= key_len(fsid_type
);
446 fhp
->fh_handle
.fh_size
= 4 + len
;
449 int size
= (fhp
->fh_maxsize
-len
-4)/4;
450 fhp
->fh_handle
.fh_fileid_type
=
451 _fh_update(dentry
, exp
, datap
, &size
);
452 fhp
->fh_handle
.fh_size
+= size
*4;
454 if (fhp
->fh_handle
.fh_fileid_type
== 255)
455 return nfserr_opnotsupp
;
463 * Update file handle information after changing a dentry.
464 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
467 fh_update(struct svc_fh
*fhp
)
469 struct dentry
*dentry
;
475 dentry
= fhp
->fh_dentry
;
476 if (!dentry
->d_inode
)
478 if (fhp
->fh_handle
.fh_version
!= 1) {
479 _fh_update_old(dentry
, fhp
->fh_export
, &fhp
->fh_handle
);
482 if (fhp
->fh_handle
.fh_fileid_type
!= 0)
484 datap
= fhp
->fh_handle
.fh_auth
+
485 fhp
->fh_handle
.fh_size
/4 -1;
486 size
= (fhp
->fh_maxsize
- fhp
->fh_handle
.fh_size
)/4;
487 fhp
->fh_handle
.fh_fileid_type
=
488 _fh_update(dentry
, fhp
->fh_export
, datap
, &size
);
489 fhp
->fh_handle
.fh_size
+= size
*4;
490 if (fhp
->fh_handle
.fh_fileid_type
== 255)
491 return nfserr_opnotsupp
;
497 printk(KERN_ERR
"fh_update: fh not verified!\n");
500 printk(KERN_ERR
"fh_update: %s/%s still negative!\n",
501 dentry
->d_parent
->d_name
.name
, dentry
->d_name
.name
);
506 * Release a file handle.
509 fh_put(struct svc_fh
*fhp
)
511 struct dentry
* dentry
= fhp
->fh_dentry
;
512 struct svc_export
* exp
= fhp
->fh_export
;
515 fhp
->fh_dentry
= NULL
;
517 #ifdef CONFIG_NFSD_V3
518 fhp
->fh_pre_saved
= 0;
519 fhp
->fh_post_saved
= 0;
524 cache_put(&exp
->h
, &svc_export_cache
);
525 fhp
->fh_export
= NULL
;
531 * Shorthand for dprintk()'s
533 char * SVCFH_fmt(struct svc_fh
*fhp
)
535 struct knfsd_fh
*fh
= &fhp
->fh_handle
;
538 sprintf(buf
, "%d: %08x %08x %08x %08x %08x %08x",
540 fh
->fh_base
.fh_pad
[0],
541 fh
->fh_base
.fh_pad
[1],
542 fh
->fh_base
.fh_pad
[2],
543 fh
->fh_base
.fh_pad
[3],
544 fh
->fh_base
.fh_pad
[4],
545 fh
->fh_base
.fh_pad
[5]);
549 enum fsid_source
fsid_source(struct svc_fh
*fhp
)
551 if (fhp
->fh_handle
.fh_version
!= 1)
552 return FSIDSOURCE_DEV
;
553 switch(fhp
->fh_handle
.fh_fsid_type
) {
555 case FSID_ENCODE_DEV
:
556 case FSID_MAJOR_MINOR
:
557 return FSIDSOURCE_DEV
;
559 return FSIDSOURCE_FSID
;
561 if (fhp
->fh_export
->ex_flags
& NFSEXP_FSID
)
562 return FSIDSOURCE_FSID
;
564 return FSIDSOURCE_UUID
;