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;