1 #define MSNFS /* HACK HACK */
2 /*
3 * linux/fs/nfsd/vfs.c
4 *
5 * File operations used by nfsd. Some of these have been ripped from
6 * other parts of the kernel because they weren't exported, others
7 * are partial duplicates with added or changed functionality.
8 *
9 * Note that several functions dget() the dentry upon which they want
10 * to act, most notably those that create directory entries. Response
11 * dentry's are dput()'d if necessary in the release callback.
12 * So if you notice code paths that apparently fail to dput() the
13 * dentry, don't worry--they have been taken care of.
14 *
15 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
16 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
17 */
18
19 #include <linux/config.h>
20 #include <linux/string.h>
21 #include <linux/time.h>
22 #include <linux/errno.h>
23 #include <linux/fs.h>
24 #include <linux/file.h>
25 #include <linux/mount.h>
26 #include <linux/major.h>
27 #include <linux/ext2_fs.h>
28 #include <linux/proc_fs.h>
29 #include <linux/stat.h>
30 #include <linux/fcntl.h>
31 #include <linux/net.h>
32 #include <linux/unistd.h>
33 #include <linux/slab.h>
34 #include <linux/pagemap.h>
35 #include <linux/in.h>
36 #include <linux/module.h>
37 #include <linux/namei.h>
38 #include <linux/vfs.h>
39 #include <linux/sunrpc/svc.h>
40 #include <linux/nfsd/nfsd.h>
41 #ifdef CONFIG_NFSD_V3
42 #include <linux/nfs3.h>
43 #include <linux/nfsd/xdr3.h>
44 #endif /* CONFIG_NFSD_V3 */
45 #include <linux/nfsd/nfsfh.h>
46 #include <linux/quotaops.h>
47 #include <linux/dnotify.h>
48 #ifdef CONFIG_NFSD_V4
49 #include <linux/posix_acl.h>
50 #include <linux/posix_acl_xattr.h>
51 #include <linux/xattr_acl.h>
52 #include <linux/xattr.h>
53 #include <linux/nfs4.h>
54 #include <linux/nfs4_acl.h>
55 #include <linux/nfsd_idmap.h>
56 #include <linux/security.h>
57 #endif /* CONFIG_NFSD_V4 */
58
59 #include <asm/uaccess.h>
60
61 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
62 #define NFSD_PARANOIA
63
64
65 /* We must ignore files (but only files) which might have mandatory
66 * locks on them because there is no way to know if the accesser has
67 * the lock.
68 */
69 #define IS_ISMNDLK(i) (S_ISREG((i)->i_mode) && MANDATORY_LOCK(i))
70
71 /*
72 * This is a cache of readahead params that help us choose the proper
73 * readahead strategy. Initially, we set all readahead parameters to 0
74 * and let the VFS handle things.
75 * If you increase the number of cached files very much, you'll need to
76 * add a hash table here.
77 */
78 struct raparms {
79 struct raparms *p_next;
80 unsigned int p_count;
81 ino_t p_ino;
82 dev_t p_dev;
83 int p_set;
84 struct file_ra_state p_ra;
85 };
86
87 static struct raparms * raparml;
88 static struct raparms * raparm_cache;
89
90 /*
91 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
92 * a mount point.
93 * Returns -EAGAIN leaving *dpp and *expp unchanged,
94 * or nfs_ok having possibly changed *dpp and *expp
95 */
96 int
97 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
98 struct svc_export **expp)
99 {
100 struct svc_export *exp = *expp, *exp2 = NULL;
101 struct dentry *dentry = *dpp;
102 struct vfsmount *mnt = mntget(exp->ex_mnt);
103 struct dentry *mounts = dget(dentry);
104 int err = nfs_ok;
105
106 while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts));
107
108 exp2 = exp_get_by_name(exp->ex_client, mnt, mounts, &rqstp->rq_chandle);
109 if (IS_ERR(exp2)) {
110 err = PTR_ERR(exp2);
111 dput(mounts);
112 mntput(mnt);
113 goto out;
114 }
115 if (exp2 && ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2))) {
116 /* successfully crossed mount point */
117 exp_put(exp);
118 *expp = exp2;
119 dput(dentry);
120 *dpp = mounts;
121 } else {
122 if (exp2) exp_put(exp2);
123 dput(mounts);
124 }
125 mntput(mnt);
126 out:
127 return err;
128 }
129
130 /*
131 * Look up one component of a pathname.
132 * N.B. After this call _both_ fhp and resfh need an fh_put
133 *
134 * If the lookup would cross a mountpoint, and the mounted filesystem
135 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
136 * accepted as it stands and the mounted directory is
137 * returned. Otherwise the covered directory is returned.
138 * NOTE: this mountpoint crossing is not supported properly by all
139 * clients and is explicitly disallowed for NFSv3
140 * NeilBrown <neilb@cse.unsw.edu.au>
141 */
142 int
143 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
144 int len, struct svc_fh *resfh)
145 {
146 struct svc_export *exp;
147 struct dentry *dparent;
148 struct dentry *dentry;
149 int err;
150
151 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
152
153 /* Obtain dentry and export. */
154 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC);
155 if (err)
156 return err;
157
158 dparent = fhp->fh_dentry;
159 exp = fhp->fh_export;
160 exp_get(exp);
161
162 err = nfserr_acces;
163
164 /* Lookup the name, but don't follow links */
165 if (isdotent(name, len)) {
166 if (len==1)
167 dentry = dget(dparent);
168 else if (dparent != exp->ex_dentry) {
169 dentry = dget_parent(dparent);
170 } else if (!EX_NOHIDE(exp))
171 dentry = dget(dparent); /* .. == . just like at / */
172 else {
173 /* checking mountpoint crossing is very different when stepping up */
174 struct svc_export *exp2 = NULL;
175 struct dentry *dp;
176 struct vfsmount *mnt = mntget(exp->ex_mnt);
177 dentry = dget(dparent);
178 while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry))
179 ;
180 dp = dget_parent(dentry);
181 dput(dentry);
182 dentry = dp;
183
184 exp2 = exp_parent(exp->ex_client, mnt, dentry,
185 &rqstp->rq_chandle);
186 if (IS_ERR(exp2)) {
187 err = PTR_ERR(exp2);
188 dput(dentry);
189 mntput(mnt);
190 goto out_nfserr;
191 }
192 if (!exp2) {
193 dput(dentry);
194 dentry = dget(dparent);
195 } else {
196 exp_put(exp);
197 exp = exp2;
198 }
199 mntput(mnt);
200 }
201 } else {
202 fh_lock(fhp);
203 dentry = lookup_one_len(name, dparent, len);
204 err = PTR_ERR(dentry);
205 if (IS_ERR(dentry))
206 goto out_nfserr;
207 /*
208 * check if we have crossed a mount point ...
209 */
210 if (d_mountpoint(dentry)) {
211 if ((err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
212 dput(dentry);
213 goto out_nfserr;
214 }
215 }
216 }
217 /*
218 * Note: we compose the file handle now, but as the
219 * dentry may be negative, it may need to be updated.
220 */
221 err = fh_compose(resfh, exp, dentry, fhp);
222 if (!err && !dentry->d_inode)
223 err = nfserr_noent;
224 dput(dentry);
225 out:
226 exp_put(exp);
227 return err;
228
229 out_nfserr:
230 err = nfserrno(err);
231 goto out;
232 }
233
234 /*
235 * Set various file attributes.
236 * N.B. After this call fhp needs an fh_put
237 */
238 int
239 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
240 int check_guard, time_t guardtime)
241 {
242 struct dentry *dentry;
243 struct inode *inode;
244 int accmode = MAY_SATTR;
245 int ftype = 0;
246 int imode;
247 int err;
248 int size_change = 0;
249
250 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
251 accmode |= MAY_WRITE|MAY_OWNER_OVERRIDE;
252 if (iap->ia_valid & ATTR_SIZE)
253 ftype = S_IFREG;
254
255 /* Get inode */
256 err = fh_verify(rqstp, fhp, ftype, accmode);
257 if (err || !iap->ia_valid)
258 goto out;
259
260 dentry = fhp->fh_dentry;
261 inode = dentry->d_inode;
262
263 /* NFSv2 does not differentiate between "set-[ac]time-to-now"
264 * which only requires access, and "set-[ac]time-to-X" which
265 * requires ownership.
266 * So if it looks like it might be "set both to the same time which
267 * is close to now", and if inode_change_ok fails, then we
268 * convert to "set to now" instead of "set to explicit time"
269 *
270 * We only call inode_change_ok as the last test as technically
271 * it is not an interface that we should be using. It is only
272 * valid if the filesystem does not define it's own i_op->setattr.
273 */
274 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
275 #define MAX_TOUCH_TIME_ERROR (30*60)
276 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET
277 && iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec
278 ) {
279 /* Looks probable. Now just make sure time is in the right ballpark.
280 * Solaris, at least, doesn't seem to care what the time request is.
281 * We require it be within 30 minutes of now.
282 */
283 time_t delta = iap->ia_atime.tv_sec - get_seconds();
284 if (delta<0) delta = -delta;
285 if (delta < MAX_TOUCH_TIME_ERROR &&
286 inode_change_ok(inode, iap) != 0) {
287 /* turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME
288 * this will cause notify_change to set these times to "now"
289 */
290 iap->ia_valid &= ~BOTH_TIME_SET;
291 }
292 }
293
294 /* The size case is special. It changes the file as well as the attributes. */
295 if (iap->ia_valid & ATTR_SIZE) {
296 if (iap->ia_size < inode->i_size) {
297 err = nfsd_permission(fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE);
298 if (err)
299 goto out;
300 }
301
302 /*
303 * If we are changing the size of the file, then
304 * we need to break all leases.
305 */
306 err = break_lease(inode, FMODE_WRITE | O_NONBLOCK);
307 if (err == -EWOULDBLOCK)
308 err = -ETIMEDOUT;
309 if (err) /* ENOMEM or EWOULDBLOCK */
310 goto out_nfserr;
311
312 err = get_write_access(inode);
313 if (err)
314 goto out_nfserr;
315
316 size_change = 1;
317 err = locks_verify_truncate(inode, NULL, iap->ia_size);
318 if (err) {
319 put_write_access(inode);
320 goto out_nfserr;
321 }
322 DQUOT_INIT(inode);
323 }
324
325 imode = inode->i_mode;
326 if (iap->ia_valid & ATTR_MODE) {
327 iap->ia_mode &= S_IALLUGO;
328 imode = iap->ia_mode |= (imode & ~S_IALLUGO);
329 }
330
331 /* Revoke setuid/setgid bit on chown/chgrp */
332 if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid)
333 iap->ia_valid |= ATTR_KILL_SUID;
334 if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
335 iap->ia_valid |= ATTR_KILL_SGID;
336
337 /* Change the attributes. */
338
339 iap->ia_valid |= ATTR_CTIME;
340
341 err = nfserr_notsync;
342 if (!check_guard || guardtime == inode->i_ctime.tv_sec) {
343 fh_lock(fhp);
344 err = notify_change(dentry, iap);
345 err = nfserrno(err);
346 fh_unlock(fhp);
347 }
348 if (size_change)
349 put_write_access(inode);
350 if (!err)
351 if (EX_ISSYNC(fhp->fh_export))
352 write_inode_now(inode, 1);
353 out:
354 return err;
355
356 out_nfserr:
357 err = nfserrno(err);
358 goto out;
359 }
360
361 #if defined(CONFIG_NFSD_V4)
362
363 static int
364 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key)
365 {
366 int len;
367 size_t buflen;
368 char *buf = NULL;
369 int error = 0;
370 struct inode *inode = dentry->d_inode;
371
372 buflen = posix_acl_xattr_size(pacl->a_count);
373 buf = kmalloc(buflen, GFP_KERNEL);
374 error = -ENOMEM;
375 if (buf == NULL)
376 goto out;
377
378 len = posix_acl_to_xattr(pacl, buf, buflen);
379 if (len < 0) {
380 error = len;
381 goto out;
382 }
383
384 error = -EOPNOTSUPP;
385 if (inode->i_op && inode->i_op->setxattr) {
386 down(&inode->i_sem);
387 security_inode_setxattr(dentry, key, buf, len, 0);
388 error = inode->i_op->setxattr(dentry, key, buf, len, 0);
389 if (!error)
390 security_inode_post_setxattr(dentry, key, buf, len, 0);
391 up(&inode->i_sem);
392 }
393 out:
394 kfree(buf);
395 return (error);
396 }
397
398 int
399 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
400 struct nfs4_acl *acl)
401 {
402 int error;
403 struct dentry *dentry;
404 struct inode *inode;
405 struct posix_acl *pacl = NULL, *dpacl = NULL;
406 unsigned int flags = 0;
407
408 /* Get inode */
409 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, MAY_SATTR);
410 if (error)
411 goto out;
412
413 dentry = fhp->fh_dentry;
414 inode = dentry->d_inode;
415 if (S_ISDIR(inode->i_mode))
416 flags = NFS4_ACL_DIR;
417
418 error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
419 if (error < 0)
420 goto out_nfserr;
421
422 if (pacl) {
423 error = set_nfsv4_acl_one(dentry, pacl, XATTR_NAME_ACL_ACCESS);
424 if (error < 0)
425 goto out_nfserr;
426 }
427
428 if (dpacl) {
429 error = set_nfsv4_acl_one(dentry, dpacl, XATTR_NAME_ACL_DEFAULT);
430 if (error < 0)
431 goto out_nfserr;
432 }
433
434 error = nfs_ok;
435
436 out:
437 posix_acl_release(pacl);
438 posix_acl_release(dpacl);
439 return (error);
440 out_nfserr:
441 error = nfserrno(error);
442 goto out;
443 }
444
445 static struct posix_acl *
446 _get_posix_acl(struct dentry *dentry, char *key)
447 {
448 struct inode *inode = dentry->d_inode;
449 char *buf = NULL;
450 int buflen, error = 0;
451 struct posix_acl *pacl = NULL;
452
453 error = -EOPNOTSUPP;
454 if (inode->i_op == NULL)
455 goto out_err;
456 if (inode->i_op->getxattr == NULL)
457 goto out_err;
458
459 error = security_inode_getxattr(dentry, key);
460 if (error)
461 goto out_err;
462
463 buflen = inode->i_op->getxattr(dentry, key, NULL, 0);
464 if (buflen <= 0) {
465 error = buflen < 0 ? buflen : -ENODATA;
466 goto out_err;
467 }
468
469 buf = kmalloc(buflen, GFP_KERNEL);
470 if (buf == NULL) {
471 error = -ENOMEM;
472 goto out_err;
473 }
474
475 error = inode->i_op->getxattr(dentry, key, buf, buflen);
476 if (error < 0)
477 goto out_err;
478
479 pacl = posix_acl_from_xattr(buf, buflen);
480 out:
481 kfree(buf);
482 return pacl;
483 out_err:
484 pacl = ERR_PTR(error);
485 goto out;
486 }
487
488 int
489 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl)
490 {
491 struct inode *inode = dentry->d_inode;
492 int error = 0;
493 struct posix_acl *pacl = NULL, *dpacl = NULL;
494 unsigned int flags = 0;
495
496 pacl = _get_posix_acl(dentry, XATTR_NAME_ACL_ACCESS);
497 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA)
498 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
499 if (IS_ERR(pacl)) {
500 error = PTR_ERR(pacl);
501 pacl = NULL;
502 goto out;
503 }
504
505 if (S_ISDIR(inode->i_mode)) {
506 dpacl = _get_posix_acl(dentry, XATTR_NAME_ACL_DEFAULT);
507 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA)
508 dpacl = NULL;
509 else if (IS_ERR(dpacl)) {
510 error = PTR_ERR(dpacl);
511 dpacl = NULL;
512 goto out;
513 }
514 flags = NFS4_ACL_DIR;
515 }
516
517 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags);
518 if (IS_ERR(*acl)) {
519 error = PTR_ERR(*acl);
520 *acl = NULL;
521 }
522 out:
523 posix_acl_release(pacl);
524 posix_acl_release(dpacl);
525 return error;
526 }
527
528 #endif /* defined(CONFIG_NFS_V4) */
529
530 #ifdef CONFIG_NFSD_V3
531 /*
532 * Check server access rights to a file system object
533 */
534 struct accessmap {
535 u32 access;
536 int how;
537 };
538 static struct accessmap nfs3_regaccess[] = {
539 { NFS3_ACCESS_READ, MAY_READ },
540 { NFS3_ACCESS_EXECUTE, MAY_EXEC },
541 { NFS3_ACCESS_MODIFY, MAY_WRITE|MAY_TRUNC },
542 { NFS3_ACCESS_EXTEND, MAY_WRITE },
543
544 { 0, 0 }
545 };
546
547 static struct accessmap nfs3_diraccess[] = {
548 { NFS3_ACCESS_READ, MAY_READ },
549 { NFS3_ACCESS_LOOKUP, MAY_EXEC },
550 { NFS3_ACCESS_MODIFY, MAY_EXEC|MAY_WRITE|MAY_TRUNC },
551 { NFS3_ACCESS_EXTEND, MAY_EXEC|MAY_WRITE },
552 { NFS3_ACCESS_DELETE, MAY_REMOVE },
553
554 { 0, 0 }
555 };
556
557 static struct accessmap nfs3_anyaccess[] = {
558 /* Some clients - Solaris 2.6 at least, make an access call
559 * to the server to check for access for things like /dev/null
560 * (which really, the server doesn't care about). So
561 * We provide simple access checking for them, looking
562 * mainly at mode bits, and we make sure to ignore read-only
563 * filesystem checks
564 */
565 { NFS3_ACCESS_READ, MAY_READ },
566 { NFS3_ACCESS_EXECUTE, MAY_EXEC },
567 { NFS3_ACCESS_MODIFY, MAY_WRITE|MAY_LOCAL_ACCESS },
568 { NFS3_ACCESS_EXTEND, MAY_WRITE|MAY_LOCAL_ACCESS },
569
570 { 0, 0 }
571 };
572
573 int
574 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
575 {
576 struct accessmap *map;
577 struct svc_export *export;
578 struct dentry *dentry;
579 u32 query, result = 0, sresult = 0;
580 unsigned int error;
581
582 error = fh_verify(rqstp, fhp, 0, MAY_NOP);
583 if (error)
584 goto out;
585
586 export = fhp->fh_export;
587 dentry = fhp->fh_dentry;
588
589 if (S_ISREG(dentry->d_inode->i_mode))
590 map = nfs3_regaccess;
591 else if (S_ISDIR(dentry->d_inode->i_mode))
592 map = nfs3_diraccess;
593 else
594 map = nfs3_anyaccess;
595
596
597 query = *access;
598 for (; map->access; map++) {
599 if (map->access & query) {
600 unsigned int err2;
601
602 sresult |= map->access;
603
604 err2 = nfsd_permission(export, dentry, map->how);
605 switch (err2) {
606 case nfs_ok:
607 result |= map->access;
608 break;
609
610 /* the following error codes just mean the access was not allowed,
611 * rather than an error occurred */
612 case nfserr_rofs:
613 case nfserr_acces:
614 case nfserr_perm:
615 /* simply don't "or" in the access bit. */
616 break;
617 default:
618 error = err2;
619 goto out;
620 }
621 }
622 }
623 *access = result;
624 if (supported)
625 *supported = sresult;
626
627 out:
628 return error;
629 }
630 #endif /* CONFIG_NFSD_V3 */
631
632
633
634 /*
635 * Open an existing file or directory.
636 * The access argument indicates the type of open (read/write/lock)
637 * N.B. After this call fhp needs an fh_put
638 */
639 int
640 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
641 int access, struct file **filp)
642 {
643 struct dentry *dentry;
644 struct inode *inode;
645 int flags = O_RDONLY|O_LARGEFILE, err;
646
647 /*
648 * If we get here, then the client has already done an "open",
649 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
650 * in case a chmod has now revoked permission.
651 */
652 err = fh_verify(rqstp, fhp, type, access | MAY_OWNER_OVERRIDE);
653 if (err)
654 goto out;
655
656 dentry = fhp->fh_dentry;
657 inode = dentry->d_inode;
658
659 /* Disallow write access to files with the append-only bit set
660 * or any access when mandatory locking enabled
661 */
662 err = nfserr_perm;
663 if (IS_APPEND(inode) && (access & MAY_WRITE))
664 goto out;
665 if (IS_ISMNDLK(inode))
666 goto out;
667
668 if (!inode->i_fop)
669 goto out;
670
671 /*
672 * Check to see if there are any leases on this file.
673 * This may block while leases are broken.
674 */
675 err = break_lease(inode, O_NONBLOCK | ((access & MAY_WRITE) ? FMODE_WRITE : 0));
676 if (err == -EWOULDBLOCK)
677 err = -ETIMEDOUT;
678 if (err) /* NOMEM or WOULDBLOCK */
679 goto out_nfserr;
680
681 if (access & MAY_WRITE) {
682 flags = O_WRONLY|O_LARGEFILE;
683
684 DQUOT_INIT(inode);
685 }
686 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_mnt), flags);
687 if (IS_ERR(*filp))
688 err = PTR_ERR(*filp);
689 out_nfserr:
690 if (err)
691 err = nfserrno(err);
692 out:
693 return err;
694 }
695
696 /*
697 * Close a file.
698 */
699 void
700 nfsd_close(struct file *filp)
701 {
702 fput(filp);
703 }
704
705 /*
706 * Sync a file
707 * As this calls fsync (not fdatasync) there is no need for a write_inode
708 * after it.
709 */
710 inline void nfsd_dosync(struct file *filp, struct dentry *dp,
711 struct file_operations *fop)
712 {
713 struct inode *inode = dp->d_inode;
714 int (*fsync) (struct file *, struct dentry *, int);
715
716 filemap_fdatawrite(inode->i_mapping);
717 if (fop && (fsync = fop->fsync))
718 fsync(filp, dp, 0);
719 filemap_fdatawait(inode->i_mapping);
720 }
721
722
723 void
724 nfsd_sync(struct file *filp)
725 {
726 struct inode *inode = filp->f_dentry->d_inode;
727 dprintk("nfsd: sync file %s\n", filp->f_dentry->d_name.name);
728 down(&inode->i_sem);
729 nfsd_dosync(filp, filp->f_dentry, filp->f_op);
730 up(&inode->i_sem);
731 }
732
733 void
734 nfsd_sync_dir(struct dentry *dp)
735 {
736 nfsd_dosync(NULL, dp, dp->d_inode->i_fop);
737 }
738
739 /*
740 * Obtain the readahead parameters for the file
741 * specified by (dev, ino).
742 */
743 static DEFINE_SPINLOCK(ra_lock);
744
745 static inline struct raparms *
746 nfsd_get_raparms(dev_t dev, ino_t ino)
747 {
748 struct raparms *ra, **rap, **frap = NULL;
749 int depth = 0;
750
751 spin_lock(&ra_lock);
752 for (rap = &raparm_cache; (ra = *rap); rap = &ra->p_next) {
753 if (ra->p_ino == ino && ra->p_dev == dev)
754 goto found;
755 depth++;
756 if (ra->p_count == 0)
757 frap = rap;
758 }
759 depth = nfsdstats.ra_size*11/10;
760 if (!frap) {
761 spin_unlock(&ra_lock);
762 return NULL;
763 }
764 rap = frap;
765 ra = *frap;
766 ra->p_dev = dev;
767 ra->p_ino = ino;
768 ra->p_set = 0;
769 found:
770 if (rap != &raparm_cache) {
771 *rap = ra->p_next;
772 ra->p_next = raparm_cache;
773 raparm_cache = ra;
774 }
775 ra->p_count++;
776 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
777 spin_unlock(&ra_lock);
778 return ra;
779 }
780
781 /*
782 * Grab and keep cached pages assosiated with a file in the svc_rqst
783 * so that they can be passed to the netowork sendmsg/sendpage routines
784 * directrly. They will be released after the sending has completed.
785 */
786 static int
787 nfsd_read_actor(read_descriptor_t *desc, struct page *page, unsigned long offset , unsigned long size)
788 {
789 unsigned long count = desc->count;
790 struct svc_rqst *rqstp = desc->arg.data;
791
792 if (size > count)
793 size = count;
794
795 if (rqstp->rq_res.page_len == 0) {
796 get_page(page);
797 rqstp->rq_respages[rqstp->rq_resused++] = page;
798 rqstp->rq_res.page_base = offset;
799 rqstp->rq_res.page_len = size;
800 } else if (page != rqstp->rq_respages[rqstp->rq_resused-1]) {
801 get_page(page);
802 rqstp->rq_respages[rqstp->rq_resused++] = page;
803 rqstp->rq_res.page_len += size;
804 } else {
805 rqstp->rq_res.page_len += size;
806 }
807
808 desc->count = count - size;
809 desc->written += size;
810 return size;
811 }
812
813 /*
814 * Read data from a file. count must contain the requested read count
815 * on entry. On return, *count contains the number of bytes actually read.
816 * N.B. After this call fhp needs an fh_put
817 */
818 int
819 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
820 struct kvec *vec, int vlen, unsigned long *count)
821 {
822 struct raparms *ra;
823 mm_segment_t oldfs;
824 int err;
825 struct file *file;
826 struct inode *inode;
827
828 err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file);
829 if (err)
830 goto out;
831 err = nfserr_perm;
832 inode = file->f_dentry->d_inode;
833 #ifdef MSNFS
834 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
835 (!lock_may_read(inode, offset, *count)))
836 goto out_close;
837 #endif
838
839 /* Get readahead parameters */
840 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);
841
842 if (ra && ra->p_set)
843 file->f_ra = ra->p_ra;
844
845 if (file->f_op->sendfile) {
846 svc_pushback_unused_pages(rqstp);
847 err = file->f_op->sendfile(file, &offset, *count,
848 nfsd_read_actor, rqstp);
849 } else {
850 oldfs = get_fs();
851 set_fs(KERNEL_DS);
852 err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
853 set_fs(oldfs);
854 }
855
856 /* Write back readahead params */
857 if (ra) {
858 spin_lock(&ra_lock);
859 ra->p_ra = file->f_ra;
860 ra->p_set = 1;
861 ra->p_count--;
862 spin_unlock(&ra_lock);
863 }
864
865 if (err >= 0) {
866 nfsdstats.io_read += err;
867 *count = err;
868 err = 0;
869 dnotify_parent(file->f_dentry, DN_ACCESS);
870 } else
871 err = nfserrno(err);
872 out_close:
873 nfsd_close(file);
874 out:
875 return err;
876 }
877
878 /*
879 * Write data to a file.
880 * The stable flag requests synchronous writes.
881 * N.B. After this call fhp needs an fh_put
882 */
883 int
884 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
885 struct kvec *vec, int vlen,
886 unsigned long cnt, int *stablep)
887 {
888 struct svc_export *exp;
889 struct file *file;
890 struct dentry *dentry;
891 struct inode *inode;
892 mm_segment_t oldfs;
893 int err = 0;
894 int stable = *stablep;
895
896 err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file);
897 if (err)
898 goto out;
899 if (!cnt)
900 goto out_close;
901 err = nfserr_perm;
902
903 #ifdef MSNFS
904 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
905 (!lock_may_write(file->f_dentry->d_inode, offset, cnt)))
906 goto out_close;
907 #endif
908
909 dentry = file->f_dentry;
910 inode = dentry->d_inode;
911 exp = fhp->fh_export;
912
913 /*
914 * Request sync writes if
915 * - the sync export option has been set, or
916 * - the client requested O_SYNC behavior (NFSv3 feature).
917 * - The file system doesn't support fsync().
918 * When gathered writes have been configured for this volume,
919 * flushing the data to disk is handled separately below.
920 */
921
922 if (file->f_op->fsync == 0) {/* COMMIT3 cannot work */
923 stable = 2;
924 *stablep = 2; /* FILE_SYNC */
925 }
926
927 if (!EX_ISSYNC(exp))
928 stable = 0;
929 if (stable && !EX_WGATHER(exp))
930 file->f_flags |= O_SYNC;
931
932 /* Write the data. */
933 oldfs = get_fs(); set_fs(KERNEL_DS);
934 err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
935 set_fs(oldfs);
936 if (err >= 0) {
937 nfsdstats.io_write += cnt;
938 dnotify_parent(file->f_dentry, DN_MODIFY);
939 }
940
941 /* clear setuid/setgid flag after write */
942 if (err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID))) {
943 struct iattr ia;
944 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID;
945
946 down(&inode->i_sem);
947 notify_change(dentry, &ia);
948 up(&inode->i_sem);
949 }
950
951 if (err >= 0 && stable) {
952 static ino_t last_ino;
953 static dev_t last_dev;
954
955 /*
956 * Gathered writes: If another process is currently
957 * writing to the file, there's a high chance
958 * this is another nfsd (triggered by a bulk write
959 * from a client's biod). Rather than syncing the
960 * file with each write request, we sleep for 10 msec.
961 *
962 * I don't know if this roughly approximates
963 * C. Juszak's idea of gathered writes, but it's a
964 * nice and simple solution (IMHO), and it seems to
965 * work:-)
966 */
967 if (EX_WGATHER(exp)) {
968 if (atomic_read(&inode->i_writecount) > 1
969 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
970 dprintk("nfsd: write defer %d\n", current->pid);
971 set_current_state(TASK_UNINTERRUPTIBLE);
972 schedule_timeout((HZ+99)/100);
973 dprintk("nfsd: write resume %d\n", current->pid);
974 }
975
976 if (inode->i_state & I_DIRTY) {
977 dprintk("nfsd: write sync %d\n", current->pid);
978 nfsd_sync(file);
979 }
980 #if 0
981 wake_up(&inode->i_wait);
982 #endif
983 }
984 last_ino = inode->i_ino;
985 last_dev = inode->i_sb->s_dev;
986 }
987
988 dprintk("nfsd: write complete err=%d\n", err);
989 if (err >= 0)
990 err = 0;
991 else
992 err = nfserrno(err);
993 out_close:
994 nfsd_close(file);
995 out:
996 return err;
997 }
998
999
1000 #ifdef CONFIG_NFSD_V3
1001 /*
1002 * Commit all pending writes to stable storage.
1003 * Strictly speaking, we could sync just the indicated file region here,
1004 * but there's currently no way we can ask the VFS to do so.
1005 *
1006 * Unfortunately we cannot lock the file to make sure we return full WCC
1007 * data to the client, as locking happens lower down in the filesystem.
1008 */
1009 int
1010 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1011 loff_t offset, unsigned long count)
1012 {
1013 struct file *file;
1014 int err;
1015
1016 if ((u64)count > ~(u64)offset)
1017 return nfserr_inval;
1018
1019 if ((err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file)) != 0)
1020 return err;
1021 if (EX_ISSYNC(fhp->fh_export)) {
1022 if (file->f_op && file->f_op->fsync) {
1023 nfsd_sync(file);
1024 } else {
1025 err = nfserr_notsupp;
1026 }
1027 }
1028
1029 nfsd_close(file);
1030 return err;
1031 }
1032 #endif /* CONFIG_NFSD_V3 */
1033
1034 /*
1035 * Create a file (regular, directory, device, fifo); UNIX sockets
1036 * not yet implemented.
1037 * If the response fh has been verified, the parent directory should
1038 * already be locked. Note that the parent directory is left locked.
1039 *
1040 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1041 */
1042 int
1043 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1044 char *fname, int flen, struct iattr *iap,
1045 int type, dev_t rdev, struct svc_fh *resfhp)
1046 {
1047 struct dentry *dentry, *dchild = NULL;
1048 struct inode *dirp;
1049 int err;
1050
1051 err = nfserr_perm;
1052 if (!flen)
1053 goto out;
1054 err = nfserr_exist;
1055 if (isdotent(fname, flen))
1056 goto out;
1057
1058 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
1059 if (err)
1060 goto out;
1061
1062 dentry = fhp->fh_dentry;
1063 dirp = dentry->d_inode;
1064
1065 err = nfserr_notdir;
1066 if(!dirp->i_op || !dirp->i_op->lookup)
1067 goto out;
1068 /*
1069 * Check whether the response file handle has been verified yet.
1070 * If it has, the parent directory should already be locked.
1071 */
1072 if (!resfhp->fh_dentry) {
1073 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
1074 fh_lock(fhp);
1075 dchild = lookup_one_len(fname, dentry, flen);
1076 err = PTR_ERR(dchild);
1077 if (IS_ERR(dchild))
1078 goto out_nfserr;
1079 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1080 if (err)
1081 goto out;
1082 } else {
1083 /* called from nfsd_proc_create */
1084 dchild = dget(resfhp->fh_dentry);
1085 if (!fhp->fh_locked) {
1086 /* not actually possible */
1087 printk(KERN_ERR
1088 "nfsd_create: parent %s/%s not locked!\n",
1089 dentry->d_parent->d_name.name,
1090 dentry->d_name.name);
1091 err = -EIO;
1092 goto out;
1093 }
1094 }
1095 /*
1096 * Make sure the child dentry is still negative ...
1097 */
1098 err = nfserr_exist;
1099 if (dchild->d_inode) {
1100 dprintk("nfsd_create: dentry %s/%s not negative!\n",
1101 dentry->d_name.name, dchild->d_name.name);
1102 goto out;
1103 }
1104
1105 if (!(iap->ia_valid & ATTR_MODE))
1106 iap->ia_mode = 0;
1107 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1108
1109 /*
1110 * Get the dir op function pointer.
1111 */
1112 err = nfserr_perm;
1113 switch (type) {
1114 case S_IFREG:
1115 err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1116 break;
1117 case S_IFDIR:
1118 err = vfs_mkdir(dirp, dchild, iap->ia_mode);
1119 break;
1120 case S_IFCHR:
1121 case S_IFBLK:
1122 case S_IFIFO:
1123 case S_IFSOCK:
1124 err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
1125 break;
1126 default:
1127 printk("nfsd: bad file type %o in nfsd_create\n", type);
1128 err = -EINVAL;
1129 }
1130 if (err < 0)
1131 goto out_nfserr;
1132
1133 if (EX_ISSYNC(fhp->fh_export)) {
1134 nfsd_sync_dir(dentry);
1135 write_inode_now(dchild->d_inode, 1);
1136 }
1137
1138
1139 /* Set file attributes. Mode has already been set and
1140 * setting uid/gid works only for root. Irix appears to
1141 * send along the gid when it tries to implement setgid
1142 * directories via NFS.
1143 */
1144 err = 0;
1145 if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0)
1146 err = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1147 /*
1148 * Update the file handle to get the new inode info.
1149 */
1150 if (!err)
1151 err = fh_update(resfhp);
1152 out:
1153 if (dchild && !IS_ERR(dchild))
1154 dput(dchild);
1155 return err;
1156
1157 out_nfserr:
1158 err = nfserrno(err);
1159 goto out;
1160 }
1161
1162 #ifdef CONFIG_NFSD_V3
1163 /*
1164 * NFSv3 version of nfsd_create
1165 */
1166 int
1167 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
1168 char *fname, int flen, struct iattr *iap,
1169 struct svc_fh *resfhp, int createmode, u32 *verifier,
1170 int *truncp)
1171 {
1172 struct dentry *dentry, *dchild = NULL;
1173 struct inode *dirp;
1174 int err;
1175 __u32 v_mtime=0, v_atime=0;
1176 int v_mode=0;
1177
1178 err = nfserr_perm;
1179 if (!flen)
1180 goto out;
1181 err = nfserr_exist;
1182 if (isdotent(fname, flen))
1183 goto out;
1184 if (!(iap->ia_valid & ATTR_MODE))
1185 iap->ia_mode = 0;
1186 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
1187 if (err)
1188 goto out;
1189
1190 dentry = fhp->fh_dentry;
1191 dirp = dentry->d_inode;
1192
1193 /* Get all the sanity checks out of the way before
1194 * we lock the parent. */
1195 err = nfserr_notdir;
1196 if(!dirp->i_op || !dirp->i_op->lookup)
1197 goto out;
1198 fh_lock(fhp);
1199
1200 /*
1201 * Compose the response file handle.
1202 */
1203 dchild = lookup_one_len(fname, dentry, flen);
1204 err = PTR_ERR(dchild);
1205 if (IS_ERR(dchild))
1206 goto out_nfserr;
1207
1208 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1209 if (err)
1210 goto out;
1211
1212 if (createmode == NFS3_CREATE_EXCLUSIVE) {
1213 /* while the verifier would fit in mtime+atime,
1214 * solaris7 gets confused (bugid 4218508) if these have
1215 * the high bit set, so we use the mode as well
1216 */
1217 v_mtime = verifier[0]&0x7fffffff;
1218 v_atime = verifier[1]&0x7fffffff;
1219 v_mode = S_IFREG
1220 | ((verifier[0]&0x80000000) >> (32-7)) /* u+x */
1221 | ((verifier[1]&0x80000000) >> (32-9)) /* u+r */
1222 ;
1223 }
1224
1225 if (dchild->d_inode) {
1226 err = 0;
1227
1228 switch (createmode) {
1229 case NFS3_CREATE_UNCHECKED:
1230 if (! S_ISREG(dchild->d_inode->i_mode))
1231 err = nfserr_exist;
1232 else if (truncp) {
1233 /* in nfsv4, we need to treat this case a little
1234 * differently. we don't want to truncate the
1235 * file now; this would be wrong if the OPEN
1236 * fails for some other reason. furthermore,
1237 * if the size is nonzero, we should ignore it
1238 * according to spec!
1239 */
1240 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1241 }
1242 else {
1243 iap->ia_valid &= ATTR_SIZE;
1244 goto set_attr;
1245 }
1246 break;
1247 case NFS3_CREATE_EXCLUSIVE:
1248 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1249 && dchild->d_inode->i_atime.tv_sec == v_atime
1250 && dchild->d_inode->i_mode == v_mode
1251 && dchild->d_inode->i_size == 0 )
1252 break;
1253 /* fallthru */
1254 case NFS3_CREATE_GUARDED:
1255 err = nfserr_exist;
1256 }
1257 goto out;
1258 }
1259
1260 err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1261 if (err < 0)
1262 goto out_nfserr;
1263
1264 if (EX_ISSYNC(fhp->fh_export)) {
1265 nfsd_sync_dir(dentry);
1266 /* setattr will sync the child (or not) */
1267 }
1268
1269 /*
1270 * Update the filehandle to get the new inode info.
1271 */
1272 err = fh_update(resfhp);
1273 if (err)
1274 goto out;
1275
1276 if (createmode == NFS3_CREATE_EXCLUSIVE) {
1277 /* Cram the verifier into atime/mtime/mode */
1278 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1279 | ATTR_MTIME_SET|ATTR_ATIME_SET
1280 | ATTR_MODE;
1281 /* XXX someone who knows this better please fix it for nsec */
1282 iap->ia_mtime.tv_sec = v_mtime;
1283 iap->ia_atime.tv_sec = v_atime;
1284 iap->ia_mtime.tv_nsec = 0;
1285 iap->ia_atime.tv_nsec = 0;
1286 iap->ia_mode = v_mode;
1287 }
1288
1289 /* Set file attributes.
1290 * Mode has already been set but we might need to reset it
1291 * for CREATE_EXCLUSIVE
1292 * Irix appears to send along the gid when it tries to
1293 * implement setgid directories via NFS. Clear out all that cruft.
1294 */
1295 set_attr:
1296 if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID)) != 0)
1297 err = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1298
1299 out:
1300 fh_unlock(fhp);
1301 if (dchild && !IS_ERR(dchild))
1302 dput(dchild);
1303 return err;
1304
1305 out_nfserr:
1306 err = nfserrno(err);
1307 goto out;
1308 }
1309 #endif /* CONFIG_NFSD_V3 */
1310
1311 /*
1312 * Read a symlink. On entry, *lenp must contain the maximum path length that
1313 * fits into the buffer. On return, it contains the true length.
1314 * N.B. After this call fhp needs an fh_put
1315 */
1316 int
1317 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1318 {
1319 struct dentry *dentry;
1320 struct inode *inode;
1321 mm_segment_t oldfs;
1322 int err;
1323
1324 err = fh_verify(rqstp, fhp, S_IFLNK, MAY_NOP);
1325 if (err)
1326 goto out;
1327
1328 dentry = fhp->fh_dentry;
1329 inode = dentry->d_inode;
1330
1331 err = nfserr_inval;
1332 if (!inode->i_op || !inode->i_op->readlink)
1333 goto out;
1334
1335 touch_atime(fhp->fh_export->ex_mnt, dentry);
1336 /* N.B. Why does this call need a get_fs()??
1337 * Remove the set_fs and watch the fireworks:-) --okir
1338 */
1339
1340 oldfs = get_fs(); set_fs(KERNEL_DS);
1341 err = inode->i_op->readlink(dentry, buf, *lenp);
1342 set_fs(oldfs);
1343
1344 if (err < 0)
1345 goto out_nfserr;
1346 *lenp = err;
1347 err = 0;
1348 out:
1349 return err;
1350
1351 out_nfserr:
1352 err = nfserrno(err);
1353 goto out;
1354 }
1355
1356 /*
1357 * Create a symlink and look up its inode
1358 * N.B. After this call _both_ fhp and resfhp need an fh_put
1359 */
1360 int
1361 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1362 char *fname, int flen,
1363 char *path, int plen,
1364 struct svc_fh *resfhp,
1365 struct iattr *iap)
1366 {
1367 struct dentry *dentry, *dnew;
1368 int err, cerr;
1369 umode_t mode;
1370
1371 err = nfserr_noent;
1372 if (!flen || !plen)
1373 goto out;
1374 err = nfserr_exist;
1375 if (isdotent(fname, flen))
1376 goto out;
1377
1378 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
1379 if (err)
1380 goto out;
1381 fh_lock(fhp);
1382 dentry = fhp->fh_dentry;
1383 dnew = lookup_one_len(fname, dentry, flen);
1384 err = PTR_ERR(dnew);
1385 if (IS_ERR(dnew))
1386 goto out_nfserr;
1387
1388 mode = S_IALLUGO;
1389 /* Only the MODE ATTRibute is even vaguely meaningful */
1390 if (iap && (iap->ia_valid & ATTR_MODE))
1391 mode = iap->ia_mode & S_IALLUGO;
1392
1393 if (unlikely(path[plen] != 0)) {
1394 char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
1395 if (path_alloced == NULL)
1396 err = -ENOMEM;
1397 else {
1398 strncpy(path_alloced, path, plen);
1399 path_alloced[plen] = 0;
1400 err = vfs_symlink(dentry->d_inode, dnew, path_alloced, mode);
1401 kfree(path_alloced);
1402 }
1403 } else
1404 err = vfs_symlink(dentry->d_inode, dnew, path, mode);
1405
1406 if (!err) {
1407 if (EX_ISSYNC(fhp->fh_export))
1408 nfsd_sync_dir(dentry);
1409 } else
1410 err = nfserrno(err);
1411 fh_unlock(fhp);
1412
1413 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1414 dput(dnew);
1415 if (err==0) err = cerr;
1416 out:
1417 return err;
1418
1419 out_nfserr:
1420 err = nfserrno(err);
1421 goto out;
1422 }
1423
1424 /*
1425 * Create a hardlink
1426 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1427 */
1428 int
1429 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1430 char *name, int len, struct svc_fh *tfhp)
1431 {
1432 struct dentry *ddir, *dnew, *dold;
1433 struct inode *dirp, *dest;
1434 int err;
1435
1436 err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_CREATE);
1437 if (err)
1438 goto out;
1439 err = fh_verify(rqstp, tfhp, -S_IFDIR, MAY_NOP);
1440 if (err)
1441 goto out;
1442
1443 err = nfserr_perm;
1444 if (!len)
1445 goto out;
1446 err = nfserr_exist;
1447 if (isdotent(name, len))
1448 goto out;
1449
1450 fh_lock(ffhp);
1451 ddir = ffhp->fh_dentry;
1452 dirp = ddir->d_inode;
1453
1454 dnew = lookup_one_len(name, ddir, len);
1455 err = PTR_ERR(dnew);
1456 if (IS_ERR(dnew))
1457 goto out_nfserr;
1458
1459 dold = tfhp->fh_dentry;
1460 dest = dold->d_inode;
1461
1462 err = vfs_link(dold, dirp, dnew);
1463 if (!err) {
1464 if (EX_ISSYNC(ffhp->fh_export)) {
1465 nfsd_sync_dir(ddir);
1466 write_inode_now(dest, 1);
1467 }
1468 } else {
1469 if (err == -EXDEV && rqstp->rq_vers == 2)
1470 err = nfserr_acces;
1471 else
1472 err = nfserrno(err);
1473 }
1474
1475 fh_unlock(ffhp);
1476 dput(dnew);
1477 out:
1478 return err;
1479
1480 out_nfserr:
1481 err = nfserrno(err);
1482 goto out;
1483 }
1484
1485 /*
1486 * Rename a file
1487 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1488 */
1489 int
1490 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1491 struct svc_fh *tfhp, char *tname, int tlen)
1492 {
1493 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1494 struct inode *fdir, *tdir;
1495 int err;
1496
1497 err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_REMOVE);
1498 if (err)
1499 goto out;
1500 err = fh_verify(rqstp, tfhp, S_IFDIR, MAY_CREATE);
1501 if (err)
1502 goto out;
1503
1504 fdentry = ffhp->fh_dentry;
1505 fdir = fdentry->d_inode;
1506
1507 tdentry = tfhp->fh_dentry;
1508 tdir = tdentry->d_inode;
1509
1510 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
1511 if (fdir->i_sb != tdir->i_sb)
1512 goto out;
1513
1514 err = nfserr_perm;
1515 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1516 goto out;
1517
1518 /* cannot use fh_lock as we need deadlock protective ordering
1519 * so do it by hand */
1520 trap = lock_rename(tdentry, fdentry);
1521 ffhp->fh_locked = tfhp->fh_locked = 1;
1522 fill_pre_wcc(ffhp);
1523 fill_pre_wcc(tfhp);
1524
1525 odentry = lookup_one_len(fname, fdentry, flen);
1526 err = PTR_ERR(odentry);
1527 if (IS_ERR(odentry))
1528 goto out_nfserr;
1529
1530 err = -ENOENT;
1531 if (!odentry->d_inode)
1532 goto out_dput_old;
1533 err = -EINVAL;
1534 if (odentry == trap)
1535 goto out_dput_old;
1536
1537 ndentry = lookup_one_len(tname, tdentry, tlen);
1538 err = PTR_ERR(ndentry);
1539 if (IS_ERR(ndentry))
1540 goto out_dput_old;
1541 err = -ENOTEMPTY;
1542 if (ndentry == trap)
1543 goto out_dput_new;
1544
1545 #ifdef MSNFS
1546 if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
1547 ((atomic_read(&odentry->d_count) > 1)
1548 || (atomic_read(&ndentry->d_count) > 1))) {
1549 err = nfserr_perm;
1550 } else
1551 #endif
1552 err = vfs_rename(fdir, odentry, tdir, ndentry);
1553 if (!err && EX_ISSYNC(tfhp->fh_export)) {
1554 nfsd_sync_dir(tdentry);
1555 nfsd_sync_dir(fdentry);
1556 }
1557
1558 out_dput_new:
1559 dput(ndentry);
1560 out_dput_old:
1561 dput(odentry);
1562 out_nfserr:
1563 if (err)
1564 err = nfserrno(err);
1565
1566 /* we cannot reply on fh_unlock on the two filehandles,
1567 * as that would do the wrong thing if the two directories
1568 * were the same, so again we do it by hand
1569 */
1570 fill_post_wcc(ffhp);
1571 fill_post_wcc(tfhp);
1572 unlock_rename(tdentry, fdentry);
1573 ffhp->fh_locked = tfhp->fh_locked = 0;
1574
1575 out:
1576 return err;
1577 }
1578
1579 /*
1580 * Unlink a file or directory
1581 * N.B. After this call fhp needs an fh_put
1582 */
1583 int
1584 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1585 char *fname, int flen)
1586 {
1587 struct dentry *dentry, *rdentry;
1588 struct inode *dirp;
1589 int err;
1590
1591 err = nfserr_acces;
1592 if (!flen || isdotent(fname, flen))
1593 goto out;
1594 err = fh_verify(rqstp, fhp, S_IFDIR, MAY_REMOVE);
1595 if (err)
1596 goto out;
1597
1598 fh_lock(fhp);
1599 dentry = fhp->fh_dentry;
1600 dirp = dentry->d_inode;
1601
1602 rdentry = lookup_one_len(fname, dentry, flen);
1603 err = PTR_ERR(rdentry);
1604 if (IS_ERR(rdentry))
1605 goto out_nfserr;
1606
1607 if (!rdentry->d_inode) {
1608 dput(rdentry);
1609 err = nfserr_noent;
1610 goto out;
1611 }
1612
1613 if (!type)
1614 type = rdentry->d_inode->i_mode & S_IFMT;
1615
1616 if (type != S_IFDIR) { /* It's UNLINK */
1617 #ifdef MSNFS
1618 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
1619 (atomic_read(&rdentry->d_count) > 1)) {
1620 err = nfserr_perm;
1621 } else
1622 #endif
1623 err = vfs_unlink(dirp, rdentry);
1624 } else { /* It's RMDIR */
1625 err = vfs_rmdir(dirp, rdentry);
1626 }
1627
1628 dput(rdentry);
1629
1630 if (err)
1631 goto out_nfserr;
1632 if (EX_ISSYNC(fhp->fh_export))
1633 nfsd_sync_dir(dentry);
1634
1635 out:
1636 return err;
1637
1638 out_nfserr:
1639 err = nfserrno(err);
1640 goto out;
1641 }
1642
1643 /*
1644 * Read entries from a directory.
1645 * The NFSv3/4 verifier we ignore for now.
1646 */
1647 int
1648 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
1649 struct readdir_cd *cdp, encode_dent_fn func)
1650 {
1651 int err;
1652 struct file *file;
1653 loff_t offset = *offsetp;
1654
1655 err = nfsd_open(rqstp, fhp, S_IFDIR, MAY_READ, &file);
1656 if (err)
1657 goto out;
1658
1659 offset = vfs_llseek(file, offset, 0);
1660 if (offset < 0) {
1661 err = nfserrno((int)offset);
1662 goto out_close;
1663 }
1664
1665 /*
1666 * Read the directory entries. This silly loop is necessary because
1667 * readdir() is not guaranteed to fill up the entire buffer, but
1668 * may choose to do less.
1669 */
1670
1671 do {
1672 cdp->err = nfserr_eof; /* will be cleared on successful read */
1673 err = vfs_readdir(file, (filldir_t) func, cdp);
1674 } while (err >=0 && cdp->err == nfs_ok);
1675 if (err)
1676 err = nfserrno(err);
1677 else
1678 err = cdp->err;
1679 *offsetp = vfs_llseek(file, 0, 1);
1680
1681 if (err == nfserr_eof || err == nfserr_toosmall)
1682 err = nfs_ok; /* can still be found in ->err */
1683 out_close:
1684 nfsd_close(file);
1685 out:
1686 return err;
1687 }
1688
1689 /*
1690 * Get file system stats
1691 * N.B. After this call fhp needs an fh_put
1692 */
1693 int
1694 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat)
1695 {
1696 int err = fh_verify(rqstp, fhp, 0, MAY_NOP);
1697 if (!err && vfs_statfs(fhp->fh_dentry->d_inode->i_sb,stat))
1698 err = nfserr_io;
1699 return err;
1700 }
1701
1702 /*
1703 * Check for a user's access permissions to this inode.
1704 */
1705 int
1706 nfsd_permission(struct svc_export *exp, struct dentry *dentry, int acc)
1707 {
1708 struct inode *inode = dentry->d_inode;
1709 int err;
1710
1711 if (acc == MAY_NOP)
1712 return 0;
1713 #if 0
1714 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
1715 acc,
1716 (acc & MAY_READ)? " read" : "",
1717 (acc & MAY_WRITE)? " write" : "",
1718 (acc & MAY_EXEC)? " exec" : "",
1719 (acc & MAY_SATTR)? " sattr" : "",
1720 (acc & MAY_TRUNC)? " trunc" : "",
1721 (acc & MAY_LOCK)? " lock" : "",
1722 (acc & MAY_OWNER_OVERRIDE)? " owneroverride" : "",
1723 inode->i_mode,
1724 IS_IMMUTABLE(inode)? " immut" : "",
1725 IS_APPEND(inode)? " append" : "",
1726 IS_RDONLY(inode)? " ro" : "");
1727 dprintk(" owner %d/%d user %d/%d\n",
1728 inode->i_uid, inode->i_gid, current->fsuid, current->fsgid);
1729 #endif
1730
1731 /* Normally we reject any write/sattr etc access on a read-only file
1732 * system. But if it is IRIX doing check on write-access for a
1733 * device special file, we ignore rofs.
1734 */
1735 if (!(acc & MAY_LOCAL_ACCESS))
1736 if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) {
1737 if (EX_RDONLY(exp) || IS_RDONLY(inode))
1738 return nfserr_rofs;
1739 if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode))
1740 return nfserr_perm;
1741 }
1742 if ((acc & MAY_TRUNC) && IS_APPEND(inode))
1743 return nfserr_perm;
1744
1745 if (acc & MAY_LOCK) {
1746 /* If we cannot rely on authentication in NLM requests,
1747 * just allow locks, otherwise require read permission, or
1748 * ownership
1749 */
1750 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
1751 return 0;
1752 else
1753 acc = MAY_READ | MAY_OWNER_OVERRIDE;
1754 }
1755 /*
1756 * The file owner always gets access permission for accesses that
1757 * would normally be checked at open time. This is to make
1758 * file access work even when the client has done a fchmod(fd, 0).
1759 *
1760 * However, `cp foo bar' should fail nevertheless when bar is
1761 * readonly. A sensible way to do this might be to reject all
1762 * attempts to truncate a read-only file, because a creat() call
1763 * always implies file truncation.
1764 * ... but this isn't really fair. A process may reasonably call
1765 * ftruncate on an open file descriptor on a file with perm 000.
1766 * We must trust the client to do permission checking - using "ACCESS"
1767 * with NFSv3.
1768 */
1769 if ((acc & MAY_OWNER_OVERRIDE) &&
1770 inode->i_uid == current->fsuid)
1771 return 0;
1772
1773 err = permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC), NULL);
1774
1775 /* Allow read access to binaries even when mode 111 */
1776 if (err == -EACCES && S_ISREG(inode->i_mode) &&
1777 acc == (MAY_READ | MAY_OWNER_OVERRIDE))
1778 err = permission(inode, MAY_EXEC, NULL);
1779
1780 return err? nfserrno(err) : 0;
1781 }
1782
1783 void
1784 nfsd_racache_shutdown(void)
1785 {
1786 if (!raparm_cache)
1787 return;
1788 dprintk("nfsd: freeing readahead buffers.\n");
1789 kfree(raparml);
1790 raparm_cache = raparml = NULL;
1791 }
1792 /*
1793 * Initialize readahead param cache
1794 */
1795 int
1796 nfsd_racache_init(int cache_size)
1797 {
1798 int i;
1799
1800 if (raparm_cache)
1801 return 0;
1802 raparml = kmalloc(sizeof(struct raparms) * cache_size, GFP_KERNEL);
1803
1804 if (raparml != NULL) {
1805 dprintk("nfsd: allocating %d readahead buffers.\n",
1806 cache_size);
1807 memset(raparml, 0, sizeof(struct raparms) * cache_size);
1808 for (i = 0; i < cache_size - 1; i++) {
1809 raparml[i].p_next = raparml + i + 1;
1810 }
1811 raparm_cache = raparml;
1812 } else {
1813 printk(KERN_WARNING
1814 "nfsd: Could not allocate memory read-ahead cache.\n");
1815 return -ENOMEM;
1816 }
1817 nfsdstats.ra_size = cache_size;
1818 return 0;
1819 }
1820
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