revert-mm-fix-blkdev-size-calculation-in-generic_write_checks
[linux-2.6/linux-trees-mm.git] / fs / nfsd / nfsfh.c
blob03766b1047fda791ad4d79bb81fa48b340c68118
1 /*
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>
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>
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>
26 #define NFSDDBG_FACILITY NFSDDBG_FH
29 static int nfsd_nr_verified;
30 static int nfsd_nr_put;
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
38 static int nfsd_acceptable(void *expv, struct dentry *dentry)
40 struct svc_export *exp = expv;
41 int rv;
42 struct dentry *tdentry;
43 struct dentry *parent;
45 if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
46 return 1;
48 tdentry = dget(dentry);
49 while (tdentry != exp->ex_path.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;
58 dput(tdentry);
59 tdentry = parent;
61 if (tdentry != exp->ex_path.dentry)
62 dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name);
63 rv = (tdentry == exp->ex_path.dentry);
64 dput(tdentry);
65 return rv;
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).
73 static inline __be32
74 nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
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;
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;
95 return 0;
98 static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
99 struct svc_export *exp)
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;
110 /* Set user creds for this exportpoint */
111 return nfserrno(nfsd_setuser(rqstp, exp));
115 * Perform sanity checks on the dentry in a client's file handle.
117 * Note that the file handle dentry may need to be freed even after
118 * an error return.
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.
123 __be32
124 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
126 struct knfsd_fh *fh = &fhp->fh_handle;
127 struct svc_export *exp = NULL;
128 struct dentry *dentry;
129 __be32 error = 0;
131 dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp));
133 if (!fhp->fh_dentry) {
134 struct fid *fid = NULL, sfid;
135 int fileid_type;
136 int data_left = fh->fh_size/4;
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;
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;
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];
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);
177 error = nfserr_stale;
178 if (PTR_ERR(exp) == -ENOENT)
179 goto out;
181 if (IS_ERR(exp)) {
182 error = nfserrno(PTR_ERR(exp));
183 goto out;
186 error = nfsd_setuser_and_check_port(rqstp, exp);
187 if (error)
188 goto out;
191 * Look up the dentry using the NFS file handle.
193 error = nfserr_stale;
194 if (rqstp->rq_vers > 2)
195 error = nfserr_badhandle;
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;
210 if (fileid_type == FILEID_ROOT)
211 dentry = dget(exp->ex_path.dentry);
212 else {
213 dentry = exportfs_decode_fh(exp->ex_path.mnt, fid,
214 data_left, fileid_type,
215 nfsd_acceptable, exp);
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;
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);
231 fhp->fh_dentry = dentry;
232 fhp->fh_export = exp;
233 nfsd_nr_verified++;
234 } else {
236 * just rechecking permissions
237 * (e.g. nfsproc_create calls fh_verify, then nfsd_create
238 * does as well)
240 dprintk("nfsd: fh_verify - just checking\n");
241 dentry = fhp->fh_dentry;
242 exp = fhp->fh_export;
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.
250 error = nfsd_setuser_and_check_port(rqstp, exp);
251 if (error)
252 goto out;
254 cache_get(&exp->h);
257 error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
258 if (error)
259 goto out;
261 if (!(access & MAY_LOCK)) {
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.
267 error = check_nfsd_access(exp, rqstp);
268 if (error)
269 goto out;
272 /* Finally, check access permissions. */
273 error = nfsd_permission(rqstp, exp, dentry, access);
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));
282 out:
283 if (exp && !IS_ERR(exp))
284 exp_put(exp);
285 if (error == nfserr_stale)
286 nfsdstats.fh_stale++;
287 return error;
292 * Compose a file handle for an NFS reply.
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 ...
298 static void _fh_update(struct svc_fh *fhp, struct svc_export *exp,
299 struct dentry *dentry)
301 if (dentry != exp->ex_path.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);
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;
316 * for composing old style file handles
318 static inline void _fh_update_old(struct dentry *dentry,
319 struct svc_export *exp,
320 struct knfsd_fh *fh)
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;
329 __be32
330 fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
331 struct svc_fh *ref_fh)
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
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_path.dentry->d_inode->i_sb->s_dev;
347 int root_export = (exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root);
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_path.dentry->d_inode->i_ino,
352 parent->d_name.name, dentry->d_name.name,
353 (inode ? inode->i_ino : 0));
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.
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;
365 if (ref_fh == fhp)
366 fh_put(ref_fh);
367 ref_fh = NULL;
369 switch (version) {
370 case 0xca:
371 fsid_type = FSID_DEV;
372 break;
373 case 1:
374 break;
375 default:
376 goto retry;
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.
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_path.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;
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;
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;
432 if (ref_fh == fhp)
433 fh_put(ref_fh);
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);
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);
444 fhp->fh_dentry = dget(dentry); /* our internal copy */
445 fhp->fh_export = exp;
446 cache_get(&exp->h);
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_path.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_path.dentry->d_inode->i_ino,
468 exp->ex_fsid, exp->ex_uuid);
470 len = key_len(fsid_type);
471 datap += len/4;
472 fhp->fh_handle.fh_size = 4 + len;
474 if (inode)
475 _fh_update(fhp, exp, dentry);
476 if (fhp->fh_handle.fh_fileid_type == 255)
477 return nfserr_opnotsupp;
480 nfsd_nr_verified++;
481 return 0;
485 * Update file handle information after changing a dentry.
486 * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create
488 __be32
489 fh_update(struct svc_fh *fhp)
491 struct dentry *dentry;
493 if (!fhp->fh_dentry)
494 goto out_bad;
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;
505 _fh_update(fhp, fhp->fh_export, dentry);
506 if (fhp->fh_handle.fh_fileid_type == 255)
507 return nfserr_opnotsupp;
509 out:
510 return 0;
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;
522 * Release a file handle.
524 void
525 fh_put(struct svc_fh *fhp)
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++;
539 if (exp) {
540 cache_put(&exp->h, &svc_export_cache);
541 fhp->fh_export = NULL;
543 return;
547 * Shorthand for dprintk()'s
549 char * SVCFH_fmt(struct svc_fh *fhp)
551 struct knfsd_fh *fh = &fhp->fh_handle;
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;
565 enum fsid_source fsid_source(struct svc_fh *fhp)
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_path.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;
584 /* either a UUID type filehandle, or the filehandle doesn't
585 * match the export.
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;