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Merge branch 'devel' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/edac
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / nfsd / vfs.c
1 #define MSNFS /* HACK HACK */
2 /*
3 * File operations used by nfsd. Some of these have been ripped from
4 * other parts of the kernel because they weren't exported, others
5 * are partial duplicates with added or changed functionality.
6 *
7 * Note that several functions dget() the dentry upon which they want
8 * to act, most notably those that create directory entries. Response
9 * dentry's are dput()'d if necessary in the release callback.
10 * So if you notice code paths that apparently fail to dput() the
11 * dentry, don't worry--they have been taken care of.
12 *
13 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
14 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
15 */
16
17 #include <linux/fs.h>
18 #include <linux/file.h>
19 #include <linux/splice.h>
20 #include <linux/fcntl.h>
21 #include <linux/namei.h>
22 #include <linux/delay.h>
23 #include <linux/fsnotify.h>
24 #include <linux/posix_acl_xattr.h>
25 #include <linux/xattr.h>
26 #include <linux/jhash.h>
27 #include <linux/ima.h>
28 #include <linux/slab.h>
29 #include <asm/uaccess.h>
30 #include <linux/exportfs.h>
31 #include <linux/writeback.h>
32
33 #ifdef CONFIG_NFSD_V3
34 #include "xdr3.h"
35 #endif /* CONFIG_NFSD_V3 */
36
37 #ifdef CONFIG_NFSD_V4
38 #include <linux/nfs4_acl.h>
39 #include <linux/nfsd_idmap.h>
40 #endif /* CONFIG_NFSD_V4 */
41
42 #include "nfsd.h"
43 #include "vfs.h"
44
45 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
46
47
48 /*
49 * This is a cache of readahead params that help us choose the proper
50 * readahead strategy. Initially, we set all readahead parameters to 0
51 * and let the VFS handle things.
52 * If you increase the number of cached files very much, you'll need to
53 * add a hash table here.
54 */
55 struct raparms {
56 struct raparms *p_next;
57 unsigned int p_count;
58 ino_t p_ino;
59 dev_t p_dev;
60 int p_set;
61 struct file_ra_state p_ra;
62 unsigned int p_hindex;
63 };
64
65 struct raparm_hbucket {
66 struct raparms *pb_head;
67 spinlock_t pb_lock;
68 } ____cacheline_aligned_in_smp;
69
70 #define RAPARM_HASH_BITS 4
71 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS)
72 #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1)
73 static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE];
74
75 /*
76 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
77 * a mount point.
78 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
79 * or nfs_ok having possibly changed *dpp and *expp
80 */
81 int
82 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
83 struct svc_export **expp)
84 {
85 struct svc_export *exp = *expp, *exp2 = NULL;
86 struct dentry *dentry = *dpp;
87 struct path path = {.mnt = mntget(exp->ex_path.mnt),
88 .dentry = dget(dentry)};
89 int err = 0;
90
91 while (d_mountpoint(path.dentry) && follow_down(&path))
92 ;
93
94 exp2 = rqst_exp_get_by_name(rqstp, &path);
95 if (IS_ERR(exp2)) {
96 err = PTR_ERR(exp2);
97 /*
98 * We normally allow NFS clients to continue
99 * "underneath" a mountpoint that is not exported.
100 * The exception is V4ROOT, where no traversal is ever
101 * allowed without an explicit export of the new
102 * directory.
103 */
104 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
105 err = 0;
106 path_put(&path);
107 goto out;
108 }
109 if (nfsd_v4client(rqstp) ||
110 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
111 /* successfully crossed mount point */
112 /*
113 * This is subtle: path.dentry is *not* on path.mnt
114 * at this point. The only reason we are safe is that
115 * original mnt is pinned down by exp, so we should
116 * put path *before* putting exp
117 */
118 *dpp = path.dentry;
119 path.dentry = dentry;
120 *expp = exp2;
121 exp2 = exp;
122 }
123 path_put(&path);
124 exp_put(exp2);
125 out:
126 return err;
127 }
128
129 static void follow_to_parent(struct path *path)
130 {
131 struct dentry *dp;
132
133 while (path->dentry == path->mnt->mnt_root && follow_up(path))
134 ;
135 dp = dget_parent(path->dentry);
136 dput(path->dentry);
137 path->dentry = dp;
138 }
139
140 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
141 {
142 struct svc_export *exp2;
143 struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
144 .dentry = dget(dparent)};
145
146 follow_to_parent(&path);
147
148 exp2 = rqst_exp_parent(rqstp, &path);
149 if (PTR_ERR(exp2) == -ENOENT) {
150 *dentryp = dget(dparent);
151 } else if (IS_ERR(exp2)) {
152 path_put(&path);
153 return PTR_ERR(exp2);
154 } else {
155 *dentryp = dget(path.dentry);
156 exp_put(*exp);
157 *exp = exp2;
158 }
159 path_put(&path);
160 return 0;
161 }
162
163 /*
164 * For nfsd purposes, we treat V4ROOT exports as though there was an
165 * export at *every* directory.
166 */
167 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
168 {
169 if (d_mountpoint(dentry))
170 return 1;
171 if (!(exp->ex_flags & NFSEXP_V4ROOT))
172 return 0;
173 return dentry->d_inode != NULL;
174 }
175
176 __be32
177 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
178 const char *name, unsigned int len,
179 struct svc_export **exp_ret, struct dentry **dentry_ret)
180 {
181 struct svc_export *exp;
182 struct dentry *dparent;
183 struct dentry *dentry;
184 __be32 err;
185 int host_err;
186
187 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
188
189 /* Obtain dentry and export. */
190 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
191 if (err)
192 return err;
193
194 dparent = fhp->fh_dentry;
195 exp = fhp->fh_export;
196 exp_get(exp);
197
198 /* Lookup the name, but don't follow links */
199 if (isdotent(name, len)) {
200 if (len==1)
201 dentry = dget(dparent);
202 else if (dparent != exp->ex_path.dentry)
203 dentry = dget_parent(dparent);
204 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
205 dentry = dget(dparent); /* .. == . just like at / */
206 else {
207 /* checking mountpoint crossing is very different when stepping up */
208 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
209 if (host_err)
210 goto out_nfserr;
211 }
212 } else {
213 fh_lock(fhp);
214 dentry = lookup_one_len(name, dparent, len);
215 host_err = PTR_ERR(dentry);
216 if (IS_ERR(dentry))
217 goto out_nfserr;
218 /*
219 * check if we have crossed a mount point ...
220 */
221 if (nfsd_mountpoint(dentry, exp)) {
222 if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
223 dput(dentry);
224 goto out_nfserr;
225 }
226 }
227 }
228 *dentry_ret = dentry;
229 *exp_ret = exp;
230 return 0;
231
232 out_nfserr:
233 exp_put(exp);
234 return nfserrno(host_err);
235 }
236
237 /*
238 * Look up one component of a pathname.
239 * N.B. After this call _both_ fhp and resfh need an fh_put
240 *
241 * If the lookup would cross a mountpoint, and the mounted filesystem
242 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
243 * accepted as it stands and the mounted directory is
244 * returned. Otherwise the covered directory is returned.
245 * NOTE: this mountpoint crossing is not supported properly by all
246 * clients and is explicitly disallowed for NFSv3
247 * NeilBrown <neilb@cse.unsw.edu.au>
248 */
249 __be32
250 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
251 unsigned int len, struct svc_fh *resfh)
252 {
253 struct svc_export *exp;
254 struct dentry *dentry;
255 __be32 err;
256
257 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
258 if (err)
259 return err;
260 err = check_nfsd_access(exp, rqstp);
261 if (err)
262 goto out;
263 /*
264 * Note: we compose the file handle now, but as the
265 * dentry may be negative, it may need to be updated.
266 */
267 err = fh_compose(resfh, exp, dentry, fhp);
268 if (!err && !dentry->d_inode)
269 err = nfserr_noent;
270 out:
271 dput(dentry);
272 exp_put(exp);
273 return err;
274 }
275
276 /*
277 * Commit metadata changes to stable storage.
278 */
279 static int
280 commit_metadata(struct svc_fh *fhp)
281 {
282 struct inode *inode = fhp->fh_dentry->d_inode;
283 const struct export_operations *export_ops = inode->i_sb->s_export_op;
284 int error = 0;
285
286 if (!EX_ISSYNC(fhp->fh_export))
287 return 0;
288
289 if (export_ops->commit_metadata) {
290 error = export_ops->commit_metadata(inode);
291 } else {
292 struct writeback_control wbc = {
293 .sync_mode = WB_SYNC_ALL,
294 .nr_to_write = 0, /* metadata only */
295 };
296
297 error = sync_inode(inode, &wbc);
298 }
299
300 return error;
301 }
302
303 /*
304 * Set various file attributes.
305 * N.B. After this call fhp needs an fh_put
306 */
307 __be32
308 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
309 int check_guard, time_t guardtime)
310 {
311 struct dentry *dentry;
312 struct inode *inode;
313 int accmode = NFSD_MAY_SATTR;
314 int ftype = 0;
315 __be32 err;
316 int host_err;
317 int size_change = 0;
318
319 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
320 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
321 if (iap->ia_valid & ATTR_SIZE)
322 ftype = S_IFREG;
323
324 /* Get inode */
325 err = fh_verify(rqstp, fhp, ftype, accmode);
326 if (err)
327 goto out;
328
329 dentry = fhp->fh_dentry;
330 inode = dentry->d_inode;
331
332 /* Ignore any mode updates on symlinks */
333 if (S_ISLNK(inode->i_mode))
334 iap->ia_valid &= ~ATTR_MODE;
335
336 if (!iap->ia_valid)
337 goto out;
338
339 /*
340 * NFSv2 does not differentiate between "set-[ac]time-to-now"
341 * which only requires access, and "set-[ac]time-to-X" which
342 * requires ownership.
343 * So if it looks like it might be "set both to the same time which
344 * is close to now", and if inode_change_ok fails, then we
345 * convert to "set to now" instead of "set to explicit time"
346 *
347 * We only call inode_change_ok as the last test as technically
348 * it is not an interface that we should be using. It is only
349 * valid if the filesystem does not define it's own i_op->setattr.
350 */
351 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
352 #define MAX_TOUCH_TIME_ERROR (30*60)
353 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET &&
354 iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) {
355 /*
356 * Looks probable.
357 *
358 * Now just make sure time is in the right ballpark.
359 * Solaris, at least, doesn't seem to care what the time
360 * request is. We require it be within 30 minutes of now.
361 */
362 time_t delta = iap->ia_atime.tv_sec - get_seconds();
363 if (delta < 0)
364 delta = -delta;
365 if (delta < MAX_TOUCH_TIME_ERROR &&
366 inode_change_ok(inode, iap) != 0) {
367 /*
368 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
369 * This will cause notify_change to set these times
370 * to "now"
371 */
372 iap->ia_valid &= ~BOTH_TIME_SET;
373 }
374 }
375
376 /*
377 * The size case is special.
378 * It changes the file as well as the attributes.
379 */
380 if (iap->ia_valid & ATTR_SIZE) {
381 if (iap->ia_size < inode->i_size) {
382 err = nfsd_permission(rqstp, fhp->fh_export, dentry,
383 NFSD_MAY_TRUNC|NFSD_MAY_OWNER_OVERRIDE);
384 if (err)
385 goto out;
386 }
387
388 /*
389 * If we are changing the size of the file, then
390 * we need to break all leases.
391 */
392 host_err = break_lease(inode, O_WRONLY | O_NONBLOCK);
393 if (host_err == -EWOULDBLOCK)
394 host_err = -ETIMEDOUT;
395 if (host_err) /* ENOMEM or EWOULDBLOCK */
396 goto out_nfserr;
397
398 host_err = get_write_access(inode);
399 if (host_err)
400 goto out_nfserr;
401
402 size_change = 1;
403 host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
404 if (host_err) {
405 put_write_access(inode);
406 goto out_nfserr;
407 }
408 }
409
410 /* sanitize the mode change */
411 if (iap->ia_valid & ATTR_MODE) {
412 iap->ia_mode &= S_IALLUGO;
413 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
414 }
415
416 /* Revoke setuid/setgid on chown */
417 if (!S_ISDIR(inode->i_mode) &&
418 (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) ||
419 ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid))) {
420 iap->ia_valid |= ATTR_KILL_PRIV;
421 if (iap->ia_valid & ATTR_MODE) {
422 /* we're setting mode too, just clear the s*id bits */
423 iap->ia_mode &= ~S_ISUID;
424 if (iap->ia_mode & S_IXGRP)
425 iap->ia_mode &= ~S_ISGID;
426 } else {
427 /* set ATTR_KILL_* bits and let VFS handle it */
428 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
429 }
430 }
431
432 /* Change the attributes. */
433
434 iap->ia_valid |= ATTR_CTIME;
435
436 err = nfserr_notsync;
437 if (!check_guard || guardtime == inode->i_ctime.tv_sec) {
438 fh_lock(fhp);
439 host_err = notify_change(dentry, iap);
440 err = nfserrno(host_err);
441 fh_unlock(fhp);
442 }
443 if (size_change)
444 put_write_access(inode);
445 if (!err)
446 commit_metadata(fhp);
447 out:
448 return err;
449
450 out_nfserr:
451 err = nfserrno(host_err);
452 goto out;
453 }
454
455 #if defined(CONFIG_NFSD_V2_ACL) || \
456 defined(CONFIG_NFSD_V3_ACL) || \
457 defined(CONFIG_NFSD_V4)
458 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
459 {
460 ssize_t buflen;
461 ssize_t ret;
462
463 buflen = vfs_getxattr(dentry, key, NULL, 0);
464 if (buflen <= 0)
465 return buflen;
466
467 *buf = kmalloc(buflen, GFP_KERNEL);
468 if (!*buf)
469 return -ENOMEM;
470
471 ret = vfs_getxattr(dentry, key, *buf, buflen);
472 if (ret < 0)
473 kfree(*buf);
474 return ret;
475 }
476 #endif
477
478 #if defined(CONFIG_NFSD_V4)
479 static int
480 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key)
481 {
482 int len;
483 size_t buflen;
484 char *buf = NULL;
485 int error = 0;
486
487 buflen = posix_acl_xattr_size(pacl->a_count);
488 buf = kmalloc(buflen, GFP_KERNEL);
489 error = -ENOMEM;
490 if (buf == NULL)
491 goto out;
492
493 len = posix_acl_to_xattr(pacl, buf, buflen);
494 if (len < 0) {
495 error = len;
496 goto out;
497 }
498
499 error = vfs_setxattr(dentry, key, buf, len, 0);
500 out:
501 kfree(buf);
502 return error;
503 }
504
505 __be32
506 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
507 struct nfs4_acl *acl)
508 {
509 __be32 error;
510 int host_error;
511 struct dentry *dentry;
512 struct inode *inode;
513 struct posix_acl *pacl = NULL, *dpacl = NULL;
514 unsigned int flags = 0;
515
516 /* Get inode */
517 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
518 if (error)
519 return error;
520
521 dentry = fhp->fh_dentry;
522 inode = dentry->d_inode;
523 if (S_ISDIR(inode->i_mode))
524 flags = NFS4_ACL_DIR;
525
526 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
527 if (host_error == -EINVAL) {
528 return nfserr_attrnotsupp;
529 } else if (host_error < 0)
530 goto out_nfserr;
531
532 host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS);
533 if (host_error < 0)
534 goto out_release;
535
536 if (S_ISDIR(inode->i_mode))
537 host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT);
538
539 out_release:
540 posix_acl_release(pacl);
541 posix_acl_release(dpacl);
542 out_nfserr:
543 if (host_error == -EOPNOTSUPP)
544 return nfserr_attrnotsupp;
545 else
546 return nfserrno(host_error);
547 }
548
549 static struct posix_acl *
550 _get_posix_acl(struct dentry *dentry, char *key)
551 {
552 void *buf = NULL;
553 struct posix_acl *pacl = NULL;
554 int buflen;
555
556 buflen = nfsd_getxattr(dentry, key, &buf);
557 if (!buflen)
558 buflen = -ENODATA;
559 if (buflen <= 0)
560 return ERR_PTR(buflen);
561
562 pacl = posix_acl_from_xattr(buf, buflen);
563 kfree(buf);
564 return pacl;
565 }
566
567 int
568 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl)
569 {
570 struct inode *inode = dentry->d_inode;
571 int error = 0;
572 struct posix_acl *pacl = NULL, *dpacl = NULL;
573 unsigned int flags = 0;
574
575 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS);
576 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA)
577 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
578 if (IS_ERR(pacl)) {
579 error = PTR_ERR(pacl);
580 pacl = NULL;
581 goto out;
582 }
583
584 if (S_ISDIR(inode->i_mode)) {
585 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT);
586 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA)
587 dpacl = NULL;
588 else if (IS_ERR(dpacl)) {
589 error = PTR_ERR(dpacl);
590 dpacl = NULL;
591 goto out;
592 }
593 flags = NFS4_ACL_DIR;
594 }
595
596 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags);
597 if (IS_ERR(*acl)) {
598 error = PTR_ERR(*acl);
599 *acl = NULL;
600 }
601 out:
602 posix_acl_release(pacl);
603 posix_acl_release(dpacl);
604 return error;
605 }
606
607 #endif /* defined(CONFIG_NFSD_V4) */
608
609 #ifdef CONFIG_NFSD_V3
610 /*
611 * Check server access rights to a file system object
612 */
613 struct accessmap {
614 u32 access;
615 int how;
616 };
617 static struct accessmap nfs3_regaccess[] = {
618 { NFS3_ACCESS_READ, NFSD_MAY_READ },
619 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
620 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
621 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
622
623 { 0, 0 }
624 };
625
626 static struct accessmap nfs3_diraccess[] = {
627 { NFS3_ACCESS_READ, NFSD_MAY_READ },
628 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
629 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
630 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
631 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
632
633 { 0, 0 }
634 };
635
636 static struct accessmap nfs3_anyaccess[] = {
637 /* Some clients - Solaris 2.6 at least, make an access call
638 * to the server to check for access for things like /dev/null
639 * (which really, the server doesn't care about). So
640 * We provide simple access checking for them, looking
641 * mainly at mode bits, and we make sure to ignore read-only
642 * filesystem checks
643 */
644 { NFS3_ACCESS_READ, NFSD_MAY_READ },
645 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
646 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
647 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
648
649 { 0, 0 }
650 };
651
652 __be32
653 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
654 {
655 struct accessmap *map;
656 struct svc_export *export;
657 struct dentry *dentry;
658 u32 query, result = 0, sresult = 0;
659 __be32 error;
660
661 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
662 if (error)
663 goto out;
664
665 export = fhp->fh_export;
666 dentry = fhp->fh_dentry;
667
668 if (S_ISREG(dentry->d_inode->i_mode))
669 map = nfs3_regaccess;
670 else if (S_ISDIR(dentry->d_inode->i_mode))
671 map = nfs3_diraccess;
672 else
673 map = nfs3_anyaccess;
674
675
676 query = *access;
677 for (; map->access; map++) {
678 if (map->access & query) {
679 __be32 err2;
680
681 sresult |= map->access;
682
683 err2 = nfsd_permission(rqstp, export, dentry, map->how);
684 switch (err2) {
685 case nfs_ok:
686 result |= map->access;
687 break;
688
689 /* the following error codes just mean the access was not allowed,
690 * rather than an error occurred */
691 case nfserr_rofs:
692 case nfserr_acces:
693 case nfserr_perm:
694 /* simply don't "or" in the access bit. */
695 break;
696 default:
697 error = err2;
698 goto out;
699 }
700 }
701 }
702 *access = result;
703 if (supported)
704 *supported = sresult;
705
706 out:
707 return error;
708 }
709 #endif /* CONFIG_NFSD_V3 */
710
711
712
713 /*
714 * Open an existing file or directory.
715 * The access argument indicates the type of open (read/write/lock)
716 * N.B. After this call fhp needs an fh_put
717 */
718 __be32
719 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
720 int access, struct file **filp)
721 {
722 struct dentry *dentry;
723 struct inode *inode;
724 int flags = O_RDONLY|O_LARGEFILE;
725 __be32 err;
726 int host_err = 0;
727
728 validate_process_creds();
729
730 /*
731 * If we get here, then the client has already done an "open",
732 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
733 * in case a chmod has now revoked permission.
734 */
735 err = fh_verify(rqstp, fhp, type, access | NFSD_MAY_OWNER_OVERRIDE);
736 if (err)
737 goto out;
738
739 dentry = fhp->fh_dentry;
740 inode = dentry->d_inode;
741
742 /* Disallow write access to files with the append-only bit set
743 * or any access when mandatory locking enabled
744 */
745 err = nfserr_perm;
746 if (IS_APPEND(inode) && (access & NFSD_MAY_WRITE))
747 goto out;
748 /*
749 * We must ignore files (but only files) which might have mandatory
750 * locks on them because there is no way to know if the accesser has
751 * the lock.
752 */
753 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
754 goto out;
755
756 if (!inode->i_fop)
757 goto out;
758
759 /*
760 * Check to see if there are any leases on this file.
761 * This may block while leases are broken.
762 */
763 if (!(access & NFSD_MAY_NOT_BREAK_LEASE))
764 host_err = break_lease(inode, O_NONBLOCK | ((access & NFSD_MAY_WRITE) ? O_WRONLY : 0));
765 if (host_err == -EWOULDBLOCK)
766 host_err = -ETIMEDOUT;
767 if (host_err) /* NOMEM or WOULDBLOCK */
768 goto out_nfserr;
769
770 if (access & NFSD_MAY_WRITE) {
771 if (access & NFSD_MAY_READ)
772 flags = O_RDWR|O_LARGEFILE;
773 else
774 flags = O_WRONLY|O_LARGEFILE;
775 }
776 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt),
777 flags, current_cred());
778 if (IS_ERR(*filp))
779 host_err = PTR_ERR(*filp);
780 else
781 host_err = ima_file_check(*filp, access);
782 out_nfserr:
783 err = nfserrno(host_err);
784 out:
785 validate_process_creds();
786 return err;
787 }
788
789 /*
790 * Close a file.
791 */
792 void
793 nfsd_close(struct file *filp)
794 {
795 fput(filp);
796 }
797
798 /*
799 * Obtain the readahead parameters for the file
800 * specified by (dev, ino).
801 */
802
803 static inline struct raparms *
804 nfsd_get_raparms(dev_t dev, ino_t ino)
805 {
806 struct raparms *ra, **rap, **frap = NULL;
807 int depth = 0;
808 unsigned int hash;
809 struct raparm_hbucket *rab;
810
811 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
812 rab = &raparm_hash[hash];
813
814 spin_lock(&rab->pb_lock);
815 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
816 if (ra->p_ino == ino && ra->p_dev == dev)
817 goto found;
818 depth++;
819 if (ra->p_count == 0)
820 frap = rap;
821 }
822 depth = nfsdstats.ra_size*11/10;
823 if (!frap) {
824 spin_unlock(&rab->pb_lock);
825 return NULL;
826 }
827 rap = frap;
828 ra = *frap;
829 ra->p_dev = dev;
830 ra->p_ino = ino;
831 ra->p_set = 0;
832 ra->p_hindex = hash;
833 found:
834 if (rap != &rab->pb_head) {
835 *rap = ra->p_next;
836 ra->p_next = rab->pb_head;
837 rab->pb_head = ra;
838 }
839 ra->p_count++;
840 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
841 spin_unlock(&rab->pb_lock);
842 return ra;
843 }
844
845 /*
846 * Grab and keep cached pages associated with a file in the svc_rqst
847 * so that they can be passed to the network sendmsg/sendpage routines
848 * directly. They will be released after the sending has completed.
849 */
850 static int
851 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
852 struct splice_desc *sd)
853 {
854 struct svc_rqst *rqstp = sd->u.data;
855 struct page **pp = rqstp->rq_respages + rqstp->rq_resused;
856 struct page *page = buf->page;
857 size_t size;
858 int ret;
859
860 ret = buf->ops->confirm(pipe, buf);
861 if (unlikely(ret))
862 return ret;
863
864 size = sd->len;
865
866 if (rqstp->rq_res.page_len == 0) {
867 get_page(page);
868 put_page(*pp);
869 *pp = page;
870 rqstp->rq_resused++;
871 rqstp->rq_res.page_base = buf->offset;
872 rqstp->rq_res.page_len = size;
873 } else if (page != pp[-1]) {
874 get_page(page);
875 if (*pp)
876 put_page(*pp);
877 *pp = page;
878 rqstp->rq_resused++;
879 rqstp->rq_res.page_len += size;
880 } else
881 rqstp->rq_res.page_len += size;
882
883 return size;
884 }
885
886 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
887 struct splice_desc *sd)
888 {
889 return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
890 }
891
892 static inline int svc_msnfs(struct svc_fh *ffhp)
893 {
894 #ifdef MSNFS
895 return (ffhp->fh_export->ex_flags & NFSEXP_MSNFS);
896 #else
897 return 0;
898 #endif
899 }
900
901 static __be32
902 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
903 loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
904 {
905 struct inode *inode;
906 mm_segment_t oldfs;
907 __be32 err;
908 int host_err;
909
910 err = nfserr_perm;
911 inode = file->f_path.dentry->d_inode;
912
913 if (svc_msnfs(fhp) && !lock_may_read(inode, offset, *count))
914 goto out;
915
916 if (file->f_op->splice_read && rqstp->rq_splice_ok) {
917 struct splice_desc sd = {
918 .len = 0,
919 .total_len = *count,
920 .pos = offset,
921 .u.data = rqstp,
922 };
923
924 rqstp->rq_resused = 1;
925 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
926 } else {
927 oldfs = get_fs();
928 set_fs(KERNEL_DS);
929 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
930 set_fs(oldfs);
931 }
932
933 if (host_err >= 0) {
934 nfsdstats.io_read += host_err;
935 *count = host_err;
936 err = 0;
937 fsnotify_access(file);
938 } else
939 err = nfserrno(host_err);
940 out:
941 return err;
942 }
943
944 static void kill_suid(struct dentry *dentry)
945 {
946 struct iattr ia;
947 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
948
949 mutex_lock(&dentry->d_inode->i_mutex);
950 notify_change(dentry, &ia);
951 mutex_unlock(&dentry->d_inode->i_mutex);
952 }
953
954 /*
955 * Gathered writes: If another process is currently writing to the file,
956 * there's a high chance this is another nfsd (triggered by a bulk write
957 * from a client's biod). Rather than syncing the file with each write
958 * request, we sleep for 10 msec.
959 *
960 * I don't know if this roughly approximates C. Juszak's idea of
961 * gathered writes, but it's a nice and simple solution (IMHO), and it
962 * seems to work:-)
963 *
964 * Note: we do this only in the NFSv2 case, since v3 and higher have a
965 * better tool (separate unstable writes and commits) for solving this
966 * problem.
967 */
968 static int wait_for_concurrent_writes(struct file *file)
969 {
970 struct inode *inode = file->f_path.dentry->d_inode;
971 static ino_t last_ino;
972 static dev_t last_dev;
973 int err = 0;
974
975 if (atomic_read(&inode->i_writecount) > 1
976 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
977 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
978 msleep(10);
979 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
980 }
981
982 if (inode->i_state & I_DIRTY) {
983 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
984 err = vfs_fsync(file, 0);
985 }
986 last_ino = inode->i_ino;
987 last_dev = inode->i_sb->s_dev;
988 return err;
989 }
990
991 static __be32
992 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
993 loff_t offset, struct kvec *vec, int vlen,
994 unsigned long *cnt, int *stablep)
995 {
996 struct svc_export *exp;
997 struct dentry *dentry;
998 struct inode *inode;
999 mm_segment_t oldfs;
1000 __be32 err = 0;
1001 int host_err;
1002 int stable = *stablep;
1003 int use_wgather;
1004
1005 #ifdef MSNFS
1006 err = nfserr_perm;
1007
1008 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
1009 (!lock_may_write(file->f_path.dentry->d_inode, offset, *cnt)))
1010 goto out;
1011 #endif
1012
1013 dentry = file->f_path.dentry;
1014 inode = dentry->d_inode;
1015 exp = fhp->fh_export;
1016
1017 /*
1018 * Request sync writes if
1019 * - the sync export option has been set, or
1020 * - the client requested O_SYNC behavior (NFSv3 feature).
1021 * - The file system doesn't support fsync().
1022 * When NFSv2 gathered writes have been configured for this volume,
1023 * flushing the data to disk is handled separately below.
1024 */
1025 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
1026
1027 if (!file->f_op->fsync) {/* COMMIT3 cannot work */
1028 stable = 2;
1029 *stablep = 2; /* FILE_SYNC */
1030 }
1031
1032 if (!EX_ISSYNC(exp))
1033 stable = 0;
1034 if (stable && !use_wgather) {
1035 spin_lock(&file->f_lock);
1036 file->f_flags |= O_SYNC;
1037 spin_unlock(&file->f_lock);
1038 }
1039
1040 /* Write the data. */
1041 oldfs = get_fs(); set_fs(KERNEL_DS);
1042 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
1043 set_fs(oldfs);
1044 if (host_err < 0)
1045 goto out_nfserr;
1046 *cnt = host_err;
1047 nfsdstats.io_write += host_err;
1048 fsnotify_modify(file);
1049
1050 /* clear setuid/setgid flag after write */
1051 if (inode->i_mode & (S_ISUID | S_ISGID))
1052 kill_suid(dentry);
1053
1054 if (stable && use_wgather)
1055 host_err = wait_for_concurrent_writes(file);
1056
1057 out_nfserr:
1058 dprintk("nfsd: write complete host_err=%d\n", host_err);
1059 if (host_err >= 0)
1060 err = 0;
1061 else
1062 err = nfserrno(host_err);
1063 out:
1064 return err;
1065 }
1066
1067 /*
1068 * Read data from a file. count must contain the requested read count
1069 * on entry. On return, *count contains the number of bytes actually read.
1070 * N.B. After this call fhp needs an fh_put
1071 */
1072 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1073 loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
1074 {
1075 struct file *file;
1076 struct inode *inode;
1077 struct raparms *ra;
1078 __be32 err;
1079
1080 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
1081 if (err)
1082 return err;
1083
1084 inode = file->f_path.dentry->d_inode;
1085
1086 /* Get readahead parameters */
1087 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);
1088
1089 if (ra && ra->p_set)
1090 file->f_ra = ra->p_ra;
1091
1092 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
1093
1094 /* Write back readahead params */
1095 if (ra) {
1096 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
1097 spin_lock(&rab->pb_lock);
1098 ra->p_ra = file->f_ra;
1099 ra->p_set = 1;
1100 ra->p_count--;
1101 spin_unlock(&rab->pb_lock);
1102 }
1103
1104 nfsd_close(file);
1105 return err;
1106 }
1107
1108 /* As above, but use the provided file descriptor. */
1109 __be32
1110 nfsd_read_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1111 loff_t offset, struct kvec *vec, int vlen,
1112 unsigned long *count)
1113 {
1114 __be32 err;
1115
1116 if (file) {
1117 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1118 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE);
1119 if (err)
1120 goto out;
1121 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
1122 } else /* Note file may still be NULL in NFSv4 special stateid case: */
1123 err = nfsd_read(rqstp, fhp, offset, vec, vlen, count);
1124 out:
1125 return err;
1126 }
1127
1128 /*
1129 * Write data to a file.
1130 * The stable flag requests synchronous writes.
1131 * N.B. After this call fhp needs an fh_put
1132 */
1133 __be32
1134 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1135 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt,
1136 int *stablep)
1137 {
1138 __be32 err = 0;
1139
1140 if (file) {
1141 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1142 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE);
1143 if (err)
1144 goto out;
1145 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt,
1146 stablep);
1147 } else {
1148 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
1149 if (err)
1150 goto out;
1151
1152 if (cnt)
1153 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen,
1154 cnt, stablep);
1155 nfsd_close(file);
1156 }
1157 out:
1158 return err;
1159 }
1160
1161 #ifdef CONFIG_NFSD_V3
1162 /*
1163 * Commit all pending writes to stable storage.
1164 *
1165 * Note: we only guarantee that data that lies within the range specified
1166 * by the 'offset' and 'count' parameters will be synced.
1167 *
1168 * Unfortunately we cannot lock the file to make sure we return full WCC
1169 * data to the client, as locking happens lower down in the filesystem.
1170 */
1171 __be32
1172 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1173 loff_t offset, unsigned long count)
1174 {
1175 struct file *file;
1176 loff_t end = LLONG_MAX;
1177 __be32 err = nfserr_inval;
1178
1179 if (offset < 0)
1180 goto out;
1181 if (count != 0) {
1182 end = offset + (loff_t)count - 1;
1183 if (end < offset)
1184 goto out;
1185 }
1186
1187 err = nfsd_open(rqstp, fhp, S_IFREG,
1188 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file);
1189 if (err)
1190 goto out;
1191 if (EX_ISSYNC(fhp->fh_export)) {
1192 int err2 = vfs_fsync_range(file, offset, end, 0);
1193
1194 if (err2 != -EINVAL)
1195 err = nfserrno(err2);
1196 else
1197 err = nfserr_notsupp;
1198 }
1199
1200 nfsd_close(file);
1201 out:
1202 return err;
1203 }
1204 #endif /* CONFIG_NFSD_V3 */
1205
1206 static __be32
1207 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1208 struct iattr *iap)
1209 {
1210 /*
1211 * Mode has already been set earlier in create:
1212 */
1213 iap->ia_valid &= ~ATTR_MODE;
1214 /*
1215 * Setting uid/gid works only for root. Irix appears to
1216 * send along the gid on create when it tries to implement
1217 * setgid directories via NFS:
1218 */
1219 if (current_fsuid() != 0)
1220 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1221 if (iap->ia_valid)
1222 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1223 return 0;
1224 }
1225
1226 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1227 * setting size to 0 may fail for some specific file systems by the permission
1228 * checking which requires WRITE permission but the mode is 000.
1229 * we ignore the resizing(to 0) on the just new created file, since the size is
1230 * 0 after file created.
1231 *
1232 * call this only after vfs_create() is called.
1233 * */
1234 static void
1235 nfsd_check_ignore_resizing(struct iattr *iap)
1236 {
1237 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1238 iap->ia_valid &= ~ATTR_SIZE;
1239 }
1240
1241 /*
1242 * Create a file (regular, directory, device, fifo); UNIX sockets
1243 * not yet implemented.
1244 * If the response fh has been verified, the parent directory should
1245 * already be locked. Note that the parent directory is left locked.
1246 *
1247 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1248 */
1249 __be32
1250 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1251 char *fname, int flen, struct iattr *iap,
1252 int type, dev_t rdev, struct svc_fh *resfhp)
1253 {
1254 struct dentry *dentry, *dchild = NULL;
1255 struct inode *dirp;
1256 __be32 err;
1257 __be32 err2;
1258 int host_err;
1259
1260 err = nfserr_perm;
1261 if (!flen)
1262 goto out;
1263 err = nfserr_exist;
1264 if (isdotent(fname, flen))
1265 goto out;
1266
1267 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1268 if (err)
1269 goto out;
1270
1271 dentry = fhp->fh_dentry;
1272 dirp = dentry->d_inode;
1273
1274 err = nfserr_notdir;
1275 if (!dirp->i_op->lookup)
1276 goto out;
1277 /*
1278 * Check whether the response file handle has been verified yet.
1279 * If it has, the parent directory should already be locked.
1280 */
1281 if (!resfhp->fh_dentry) {
1282 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
1283 fh_lock_nested(fhp, I_MUTEX_PARENT);
1284 dchild = lookup_one_len(fname, dentry, flen);
1285 host_err = PTR_ERR(dchild);
1286 if (IS_ERR(dchild))
1287 goto out_nfserr;
1288 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1289 if (err)
1290 goto out;
1291 } else {
1292 /* called from nfsd_proc_create */
1293 dchild = dget(resfhp->fh_dentry);
1294 if (!fhp->fh_locked) {
1295 /* not actually possible */
1296 printk(KERN_ERR
1297 "nfsd_create: parent %s/%s not locked!\n",
1298 dentry->d_parent->d_name.name,
1299 dentry->d_name.name);
1300 err = nfserr_io;
1301 goto out;
1302 }
1303 }
1304 /*
1305 * Make sure the child dentry is still negative ...
1306 */
1307 err = nfserr_exist;
1308 if (dchild->d_inode) {
1309 dprintk("nfsd_create: dentry %s/%s not negative!\n",
1310 dentry->d_name.name, dchild->d_name.name);
1311 goto out;
1312 }
1313
1314 if (!(iap->ia_valid & ATTR_MODE))
1315 iap->ia_mode = 0;
1316 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1317
1318 err = nfserr_inval;
1319 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) {
1320 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1321 type);
1322 goto out;
1323 }
1324
1325 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1326 if (host_err)
1327 goto out_nfserr;
1328
1329 /*
1330 * Get the dir op function pointer.
1331 */
1332 err = 0;
1333 switch (type) {
1334 case S_IFREG:
1335 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1336 if (!host_err)
1337 nfsd_check_ignore_resizing(iap);
1338 break;
1339 case S_IFDIR:
1340 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
1341 break;
1342 case S_IFCHR:
1343 case S_IFBLK:
1344 case S_IFIFO:
1345 case S_IFSOCK:
1346 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
1347 break;
1348 }
1349 if (host_err < 0) {
1350 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1351 goto out_nfserr;
1352 }
1353
1354 err = nfsd_create_setattr(rqstp, resfhp, iap);
1355
1356 /*
1357 * nfsd_setattr already committed the child. Transactional filesystems
1358 * had a chance to commit changes for both parent and child
1359 * simultaneously making the following commit_metadata a noop.
1360 */
1361 err2 = nfserrno(commit_metadata(fhp));
1362 if (err2)
1363 err = err2;
1364 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1365 /*
1366 * Update the file handle to get the new inode info.
1367 */
1368 if (!err)
1369 err = fh_update(resfhp);
1370 out:
1371 if (dchild && !IS_ERR(dchild))
1372 dput(dchild);
1373 return err;
1374
1375 out_nfserr:
1376 err = nfserrno(host_err);
1377 goto out;
1378 }
1379
1380 #ifdef CONFIG_NFSD_V3
1381 /*
1382 * NFSv3 version of nfsd_create
1383 */
1384 __be32
1385 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
1386 char *fname, int flen, struct iattr *iap,
1387 struct svc_fh *resfhp, int createmode, u32 *verifier,
1388 int *truncp, int *created)
1389 {
1390 struct dentry *dentry, *dchild = NULL;
1391 struct inode *dirp;
1392 __be32 err;
1393 int host_err;
1394 __u32 v_mtime=0, v_atime=0;
1395
1396 err = nfserr_perm;
1397 if (!flen)
1398 goto out;
1399 err = nfserr_exist;
1400 if (isdotent(fname, flen))
1401 goto out;
1402 if (!(iap->ia_valid & ATTR_MODE))
1403 iap->ia_mode = 0;
1404 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1405 if (err)
1406 goto out;
1407
1408 dentry = fhp->fh_dentry;
1409 dirp = dentry->d_inode;
1410
1411 /* Get all the sanity checks out of the way before
1412 * we lock the parent. */
1413 err = nfserr_notdir;
1414 if (!dirp->i_op->lookup)
1415 goto out;
1416 fh_lock_nested(fhp, I_MUTEX_PARENT);
1417
1418 /*
1419 * Compose the response file handle.
1420 */
1421 dchild = lookup_one_len(fname, dentry, flen);
1422 host_err = PTR_ERR(dchild);
1423 if (IS_ERR(dchild))
1424 goto out_nfserr;
1425
1426 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1427 if (err)
1428 goto out;
1429
1430 if (createmode == NFS3_CREATE_EXCLUSIVE) {
1431 /* solaris7 gets confused (bugid 4218508) if these have
1432 * the high bit set, so just clear the high bits. If this is
1433 * ever changed to use different attrs for storing the
1434 * verifier, then do_open_lookup() will also need to be fixed
1435 * accordingly.
1436 */
1437 v_mtime = verifier[0]&0x7fffffff;
1438 v_atime = verifier[1]&0x7fffffff;
1439 }
1440
1441 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1442 if (host_err)
1443 goto out_nfserr;
1444 if (dchild->d_inode) {
1445 err = 0;
1446
1447 switch (createmode) {
1448 case NFS3_CREATE_UNCHECKED:
1449 if (! S_ISREG(dchild->d_inode->i_mode))
1450 err = nfserr_exist;
1451 else if (truncp) {
1452 /* in nfsv4, we need to treat this case a little
1453 * differently. we don't want to truncate the
1454 * file now; this would be wrong if the OPEN
1455 * fails for some other reason. furthermore,
1456 * if the size is nonzero, we should ignore it
1457 * according to spec!
1458 */
1459 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1460 }
1461 else {
1462 iap->ia_valid &= ATTR_SIZE;
1463 goto set_attr;
1464 }
1465 break;
1466 case NFS3_CREATE_EXCLUSIVE:
1467 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1468 && dchild->d_inode->i_atime.tv_sec == v_atime
1469 && dchild->d_inode->i_size == 0 )
1470 break;
1471 /* fallthru */
1472 case NFS3_CREATE_GUARDED:
1473 err = nfserr_exist;
1474 }
1475 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1476 goto out;
1477 }
1478
1479 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1480 if (host_err < 0) {
1481 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1482 goto out_nfserr;
1483 }
1484 if (created)
1485 *created = 1;
1486
1487 nfsd_check_ignore_resizing(iap);
1488
1489 if (createmode == NFS3_CREATE_EXCLUSIVE) {
1490 /* Cram the verifier into atime/mtime */
1491 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1492 | ATTR_MTIME_SET|ATTR_ATIME_SET;
1493 /* XXX someone who knows this better please fix it for nsec */
1494 iap->ia_mtime.tv_sec = v_mtime;
1495 iap->ia_atime.tv_sec = v_atime;
1496 iap->ia_mtime.tv_nsec = 0;
1497 iap->ia_atime.tv_nsec = 0;
1498 }
1499
1500 set_attr:
1501 err = nfsd_create_setattr(rqstp, resfhp, iap);
1502
1503 /*
1504 * nfsd_setattr already committed the child (and possibly also the parent).
1505 */
1506 if (!err)
1507 err = nfserrno(commit_metadata(fhp));
1508
1509 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1510 /*
1511 * Update the filehandle to get the new inode info.
1512 */
1513 if (!err)
1514 err = fh_update(resfhp);
1515
1516 out:
1517 fh_unlock(fhp);
1518 if (dchild && !IS_ERR(dchild))
1519 dput(dchild);
1520 return err;
1521
1522 out_nfserr:
1523 err = nfserrno(host_err);
1524 goto out;
1525 }
1526 #endif /* CONFIG_NFSD_V3 */
1527
1528 /*
1529 * Read a symlink. On entry, *lenp must contain the maximum path length that
1530 * fits into the buffer. On return, it contains the true length.
1531 * N.B. After this call fhp needs an fh_put
1532 */
1533 __be32
1534 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1535 {
1536 struct dentry *dentry;
1537 struct inode *inode;
1538 mm_segment_t oldfs;
1539 __be32 err;
1540 int host_err;
1541
1542 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1543 if (err)
1544 goto out;
1545
1546 dentry = fhp->fh_dentry;
1547 inode = dentry->d_inode;
1548
1549 err = nfserr_inval;
1550 if (!inode->i_op->readlink)
1551 goto out;
1552
1553 touch_atime(fhp->fh_export->ex_path.mnt, dentry);
1554 /* N.B. Why does this call need a get_fs()??
1555 * Remove the set_fs and watch the fireworks:-) --okir
1556 */
1557
1558 oldfs = get_fs(); set_fs(KERNEL_DS);
1559 host_err = inode->i_op->readlink(dentry, buf, *lenp);
1560 set_fs(oldfs);
1561
1562 if (host_err < 0)
1563 goto out_nfserr;
1564 *lenp = host_err;
1565 err = 0;
1566 out:
1567 return err;
1568
1569 out_nfserr:
1570 err = nfserrno(host_err);
1571 goto out;
1572 }
1573
1574 /*
1575 * Create a symlink and look up its inode
1576 * N.B. After this call _both_ fhp and resfhp need an fh_put
1577 */
1578 __be32
1579 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1580 char *fname, int flen,
1581 char *path, int plen,
1582 struct svc_fh *resfhp,
1583 struct iattr *iap)
1584 {
1585 struct dentry *dentry, *dnew;
1586 __be32 err, cerr;
1587 int host_err;
1588
1589 err = nfserr_noent;
1590 if (!flen || !plen)
1591 goto out;
1592 err = nfserr_exist;
1593 if (isdotent(fname, flen))
1594 goto out;
1595
1596 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1597 if (err)
1598 goto out;
1599 fh_lock(fhp);
1600 dentry = fhp->fh_dentry;
1601 dnew = lookup_one_len(fname, dentry, flen);
1602 host_err = PTR_ERR(dnew);
1603 if (IS_ERR(dnew))
1604 goto out_nfserr;
1605
1606 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1607 if (host_err)
1608 goto out_nfserr;
1609
1610 if (unlikely(path[plen] != 0)) {
1611 char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
1612 if (path_alloced == NULL)
1613 host_err = -ENOMEM;
1614 else {
1615 strncpy(path_alloced, path, plen);
1616 path_alloced[plen] = 0;
1617 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced);
1618 kfree(path_alloced);
1619 }
1620 } else
1621 host_err = vfs_symlink(dentry->d_inode, dnew, path);
1622 err = nfserrno(host_err);
1623 if (!err)
1624 err = nfserrno(commit_metadata(fhp));
1625 fh_unlock(fhp);
1626
1627 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1628
1629 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1630 dput(dnew);
1631 if (err==0) err = cerr;
1632 out:
1633 return err;
1634
1635 out_nfserr:
1636 err = nfserrno(host_err);
1637 goto out;
1638 }
1639
1640 /*
1641 * Create a hardlink
1642 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1643 */
1644 __be32
1645 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1646 char *name, int len, struct svc_fh *tfhp)
1647 {
1648 struct dentry *ddir, *dnew, *dold;
1649 struct inode *dirp;
1650 __be32 err;
1651 int host_err;
1652
1653 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1654 if (err)
1655 goto out;
1656 err = fh_verify(rqstp, tfhp, -S_IFDIR, NFSD_MAY_NOP);
1657 if (err)
1658 goto out;
1659
1660 err = nfserr_perm;
1661 if (!len)
1662 goto out;
1663 err = nfserr_exist;
1664 if (isdotent(name, len))
1665 goto out;
1666
1667 fh_lock_nested(ffhp, I_MUTEX_PARENT);
1668 ddir = ffhp->fh_dentry;
1669 dirp = ddir->d_inode;
1670
1671 dnew = lookup_one_len(name, ddir, len);
1672 host_err = PTR_ERR(dnew);
1673 if (IS_ERR(dnew))
1674 goto out_nfserr;
1675
1676 dold = tfhp->fh_dentry;
1677
1678 host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt);
1679 if (host_err) {
1680 err = nfserrno(host_err);
1681 goto out_dput;
1682 }
1683 host_err = vfs_link(dold, dirp, dnew);
1684 if (!host_err) {
1685 err = nfserrno(commit_metadata(ffhp));
1686 if (!err)
1687 err = nfserrno(commit_metadata(tfhp));
1688 } else {
1689 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1690 err = nfserr_acces;
1691 else
1692 err = nfserrno(host_err);
1693 }
1694 mnt_drop_write(tfhp->fh_export->ex_path.mnt);
1695 out_dput:
1696 dput(dnew);
1697 out_unlock:
1698 fh_unlock(ffhp);
1699 out:
1700 return err;
1701
1702 out_nfserr:
1703 err = nfserrno(host_err);
1704 goto out_unlock;
1705 }
1706
1707 /*
1708 * Rename a file
1709 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1710 */
1711 __be32
1712 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1713 struct svc_fh *tfhp, char *tname, int tlen)
1714 {
1715 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1716 struct inode *fdir, *tdir;
1717 __be32 err;
1718 int host_err;
1719
1720 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1721 if (err)
1722 goto out;
1723 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1724 if (err)
1725 goto out;
1726
1727 fdentry = ffhp->fh_dentry;
1728 fdir = fdentry->d_inode;
1729
1730 tdentry = tfhp->fh_dentry;
1731 tdir = tdentry->d_inode;
1732
1733 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
1734 if (ffhp->fh_export != tfhp->fh_export)
1735 goto out;
1736
1737 err = nfserr_perm;
1738 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1739 goto out;
1740
1741 /* cannot use fh_lock as we need deadlock protective ordering
1742 * so do it by hand */
1743 trap = lock_rename(tdentry, fdentry);
1744 ffhp->fh_locked = tfhp->fh_locked = 1;
1745 fill_pre_wcc(ffhp);
1746 fill_pre_wcc(tfhp);
1747
1748 odentry = lookup_one_len(fname, fdentry, flen);
1749 host_err = PTR_ERR(odentry);
1750 if (IS_ERR(odentry))
1751 goto out_nfserr;
1752
1753 host_err = -ENOENT;
1754 if (!odentry->d_inode)
1755 goto out_dput_old;
1756 host_err = -EINVAL;
1757 if (odentry == trap)
1758 goto out_dput_old;
1759
1760 ndentry = lookup_one_len(tname, tdentry, tlen);
1761 host_err = PTR_ERR(ndentry);
1762 if (IS_ERR(ndentry))
1763 goto out_dput_old;
1764 host_err = -ENOTEMPTY;
1765 if (ndentry == trap)
1766 goto out_dput_new;
1767
1768 if (svc_msnfs(ffhp) &&
1769 ((atomic_read(&odentry->d_count) > 1)
1770 || (atomic_read(&ndentry->d_count) > 1))) {
1771 host_err = -EPERM;
1772 goto out_dput_new;
1773 }
1774
1775 host_err = -EXDEV;
1776 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1777 goto out_dput_new;
1778 host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt);
1779 if (host_err)
1780 goto out_dput_new;
1781
1782 host_err = vfs_rename(fdir, odentry, tdir, ndentry);
1783 if (!host_err) {
1784 host_err = commit_metadata(tfhp);
1785 if (!host_err)
1786 host_err = commit_metadata(ffhp);
1787 }
1788
1789 mnt_drop_write(ffhp->fh_export->ex_path.mnt);
1790
1791 out_dput_new:
1792 dput(ndentry);
1793 out_dput_old:
1794 dput(odentry);
1795 out_nfserr:
1796 err = nfserrno(host_err);
1797
1798 /* we cannot reply on fh_unlock on the two filehandles,
1799 * as that would do the wrong thing if the two directories
1800 * were the same, so again we do it by hand
1801 */
1802 fill_post_wcc(ffhp);
1803 fill_post_wcc(tfhp);
1804 unlock_rename(tdentry, fdentry);
1805 ffhp->fh_locked = tfhp->fh_locked = 0;
1806
1807 out:
1808 return err;
1809 }
1810
1811 /*
1812 * Unlink a file or directory
1813 * N.B. After this call fhp needs an fh_put
1814 */
1815 __be32
1816 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1817 char *fname, int flen)
1818 {
1819 struct dentry *dentry, *rdentry;
1820 struct inode *dirp;
1821 __be32 err;
1822 int host_err;
1823
1824 err = nfserr_acces;
1825 if (!flen || isdotent(fname, flen))
1826 goto out;
1827 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1828 if (err)
1829 goto out;
1830
1831 fh_lock_nested(fhp, I_MUTEX_PARENT);
1832 dentry = fhp->fh_dentry;
1833 dirp = dentry->d_inode;
1834
1835 rdentry = lookup_one_len(fname, dentry, flen);
1836 host_err = PTR_ERR(rdentry);
1837 if (IS_ERR(rdentry))
1838 goto out_nfserr;
1839
1840 if (!rdentry->d_inode) {
1841 dput(rdentry);
1842 err = nfserr_noent;
1843 goto out;
1844 }
1845
1846 if (!type)
1847 type = rdentry->d_inode->i_mode & S_IFMT;
1848
1849 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1850 if (host_err)
1851 goto out_nfserr;
1852
1853 if (type != S_IFDIR) { /* It's UNLINK */
1854 #ifdef MSNFS
1855 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
1856 (atomic_read(&rdentry->d_count) > 1)) {
1857 host_err = -EPERM;
1858 } else
1859 #endif
1860 host_err = vfs_unlink(dirp, rdentry);
1861 } else { /* It's RMDIR */
1862 host_err = vfs_rmdir(dirp, rdentry);
1863 }
1864
1865 dput(rdentry);
1866
1867 if (!host_err)
1868 host_err = commit_metadata(fhp);
1869
1870 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1871 out_nfserr:
1872 err = nfserrno(host_err);
1873 out:
1874 return err;
1875 }
1876
1877 /*
1878 * We do this buffering because we must not call back into the file
1879 * system's ->lookup() method from the filldir callback. That may well
1880 * deadlock a number of file systems.
1881 *
1882 * This is based heavily on the implementation of same in XFS.
1883 */
1884 struct buffered_dirent {
1885 u64 ino;
1886 loff_t offset;
1887 int namlen;
1888 unsigned int d_type;
1889 char name[];
1890 };
1891
1892 struct readdir_data {
1893 char *dirent;
1894 size_t used;
1895 int full;
1896 };
1897
1898 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen,
1899 loff_t offset, u64 ino, unsigned int d_type)
1900 {
1901 struct readdir_data *buf = __buf;
1902 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1903 unsigned int reclen;
1904
1905 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1906 if (buf->used + reclen > PAGE_SIZE) {
1907 buf->full = 1;
1908 return -EINVAL;
1909 }
1910
1911 de->namlen = namlen;
1912 de->offset = offset;
1913 de->ino = ino;
1914 de->d_type = d_type;
1915 memcpy(de->name, name, namlen);
1916 buf->used += reclen;
1917
1918 return 0;
1919 }
1920
1921 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func,
1922 struct readdir_cd *cdp, loff_t *offsetp)
1923 {
1924 struct readdir_data buf;
1925 struct buffered_dirent *de;
1926 int host_err;
1927 int size;
1928 loff_t offset;
1929
1930 buf.dirent = (void *)__get_free_page(GFP_KERNEL);
1931 if (!buf.dirent)
1932 return nfserrno(-ENOMEM);
1933
1934 offset = *offsetp;
1935
1936 while (1) {
1937 struct inode *dir_inode = file->f_path.dentry->d_inode;
1938 unsigned int reclen;
1939
1940 cdp->err = nfserr_eof; /* will be cleared on successful read */
1941 buf.used = 0;
1942 buf.full = 0;
1943
1944 host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf);
1945 if (buf.full)
1946 host_err = 0;
1947
1948 if (host_err < 0)
1949 break;
1950
1951 size = buf.used;
1952
1953 if (!size)
1954 break;
1955
1956 /*
1957 * Various filldir functions may end up calling back into
1958 * lookup_one_len() and the file system's ->lookup() method.
1959 * These expect i_mutex to be held, as it would within readdir.
1960 */
1961 host_err = mutex_lock_killable(&dir_inode->i_mutex);
1962 if (host_err)
1963 break;
1964
1965 de = (struct buffered_dirent *)buf.dirent;
1966 while (size > 0) {
1967 offset = de->offset;
1968
1969 if (func(cdp, de->name, de->namlen, de->offset,
1970 de->ino, de->d_type))
1971 break;
1972
1973 if (cdp->err != nfs_ok)
1974 break;
1975
1976 reclen = ALIGN(sizeof(*de) + de->namlen,
1977 sizeof(u64));
1978 size -= reclen;
1979 de = (struct buffered_dirent *)((char *)de + reclen);
1980 }
1981 mutex_unlock(&dir_inode->i_mutex);
1982 if (size > 0) /* We bailed out early */
1983 break;
1984
1985 offset = vfs_llseek(file, 0, SEEK_CUR);
1986 }
1987
1988 free_page((unsigned long)(buf.dirent));
1989
1990 if (host_err)
1991 return nfserrno(host_err);
1992
1993 *offsetp = offset;
1994 return cdp->err;
1995 }
1996
1997 /*
1998 * Read entries from a directory.
1999 * The NFSv3/4 verifier we ignore for now.
2000 */
2001 __be32
2002 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
2003 struct readdir_cd *cdp, filldir_t func)
2004 {
2005 __be32 err;
2006 struct file *file;
2007 loff_t offset = *offsetp;
2008
2009 err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file);
2010 if (err)
2011 goto out;
2012
2013 offset = vfs_llseek(file, offset, 0);
2014 if (offset < 0) {
2015 err = nfserrno((int)offset);
2016 goto out_close;
2017 }
2018
2019 err = nfsd_buffered_readdir(file, func, cdp, offsetp);
2020
2021 if (err == nfserr_eof || err == nfserr_toosmall)
2022 err = nfs_ok; /* can still be found in ->err */
2023 out_close:
2024 nfsd_close(file);
2025 out:
2026 return err;
2027 }
2028
2029 /*
2030 * Get file system stats
2031 * N.B. After this call fhp needs an fh_put
2032 */
2033 __be32
2034 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
2035 {
2036 __be32 err;
2037
2038 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
2039 if (!err) {
2040 struct path path = {
2041 .mnt = fhp->fh_export->ex_path.mnt,
2042 .dentry = fhp->fh_dentry,
2043 };
2044 if (vfs_statfs(&path, stat))
2045 err = nfserr_io;
2046 }
2047 return err;
2048 }
2049
2050 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
2051 {
2052 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
2053 }
2054
2055 /*
2056 * Check for a user's access permissions to this inode.
2057 */
2058 __be32
2059 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
2060 struct dentry *dentry, int acc)
2061 {
2062 struct inode *inode = dentry->d_inode;
2063 int err;
2064
2065 if (acc == NFSD_MAY_NOP)
2066 return 0;
2067 #if 0
2068 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2069 acc,
2070 (acc & NFSD_MAY_READ)? " read" : "",
2071 (acc & NFSD_MAY_WRITE)? " write" : "",
2072 (acc & NFSD_MAY_EXEC)? " exec" : "",
2073 (acc & NFSD_MAY_SATTR)? " sattr" : "",
2074 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
2075 (acc & NFSD_MAY_LOCK)? " lock" : "",
2076 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
2077 inode->i_mode,
2078 IS_IMMUTABLE(inode)? " immut" : "",
2079 IS_APPEND(inode)? " append" : "",
2080 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
2081 dprintk(" owner %d/%d user %d/%d\n",
2082 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2083 #endif
2084
2085 /* Normally we reject any write/sattr etc access on a read-only file
2086 * system. But if it is IRIX doing check on write-access for a
2087 * device special file, we ignore rofs.
2088 */
2089 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2090 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2091 if (exp_rdonly(rqstp, exp) ||
2092 __mnt_is_readonly(exp->ex_path.mnt))
2093 return nfserr_rofs;
2094 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2095 return nfserr_perm;
2096 }
2097 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2098 return nfserr_perm;
2099
2100 if (acc & NFSD_MAY_LOCK) {
2101 /* If we cannot rely on authentication in NLM requests,
2102 * just allow locks, otherwise require read permission, or
2103 * ownership
2104 */
2105 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2106 return 0;
2107 else
2108 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2109 }
2110 /*
2111 * The file owner always gets access permission for accesses that
2112 * would normally be checked at open time. This is to make
2113 * file access work even when the client has done a fchmod(fd, 0).
2114 *
2115 * However, `cp foo bar' should fail nevertheless when bar is
2116 * readonly. A sensible way to do this might be to reject all
2117 * attempts to truncate a read-only file, because a creat() call
2118 * always implies file truncation.
2119 * ... but this isn't really fair. A process may reasonably call
2120 * ftruncate on an open file descriptor on a file with perm 000.
2121 * We must trust the client to do permission checking - using "ACCESS"
2122 * with NFSv3.
2123 */
2124 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2125 inode->i_uid == current_fsuid())
2126 return 0;
2127
2128 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2129 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC));
2130
2131 /* Allow read access to binaries even when mode 111 */
2132 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2133 acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE))
2134 err = inode_permission(inode, MAY_EXEC);
2135
2136 return err? nfserrno(err) : 0;
2137 }
2138
2139 void
2140 nfsd_racache_shutdown(void)
2141 {
2142 struct raparms *raparm, *last_raparm;
2143 unsigned int i;
2144
2145 dprintk("nfsd: freeing readahead buffers.\n");
2146
2147 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2148 raparm = raparm_hash[i].pb_head;
2149 while(raparm) {
2150 last_raparm = raparm;
2151 raparm = raparm->p_next;
2152 kfree(last_raparm);
2153 }
2154 raparm_hash[i].pb_head = NULL;
2155 }
2156 }
2157 /*
2158 * Initialize readahead param cache
2159 */
2160 int
2161 nfsd_racache_init(int cache_size)
2162 {
2163 int i;
2164 int j = 0;
2165 int nperbucket;
2166 struct raparms **raparm = NULL;
2167
2168
2169 if (raparm_hash[0].pb_head)
2170 return 0;
2171 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
2172 if (nperbucket < 2)
2173 nperbucket = 2;
2174 cache_size = nperbucket * RAPARM_HASH_SIZE;
2175
2176 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
2177
2178 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2179 spin_lock_init(&raparm_hash[i].pb_lock);
2180
2181 raparm = &raparm_hash[i].pb_head;
2182 for (j = 0; j < nperbucket; j++) {
2183 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
2184 if (!*raparm)
2185 goto out_nomem;
2186 raparm = &(*raparm)->p_next;
2187 }
2188 *raparm = NULL;
2189 }
2190
2191 nfsdstats.ra_size = cache_size;
2192 return 0;
2193
2194 out_nomem:
2195 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
2196 nfsd_racache_shutdown();
2197 return -ENOMEM;
2198 }
2199
2200 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
2201 struct posix_acl *
2202 nfsd_get_posix_acl(struct svc_fh *fhp, int type)
2203 {
2204 struct inode *inode = fhp->fh_dentry->d_inode;
2205 char *name;
2206 void *value = NULL;
2207 ssize_t size;
2208 struct posix_acl *acl;
2209
2210 if (!IS_POSIXACL(inode))
2211 return ERR_PTR(-EOPNOTSUPP);
2212
2213 switch (type) {
2214 case ACL_TYPE_ACCESS:
2215 name = POSIX_ACL_XATTR_ACCESS;
2216 break;
2217 case ACL_TYPE_DEFAULT:
2218 name = POSIX_ACL_XATTR_DEFAULT;
2219 break;
2220 default:
2221 return ERR_PTR(-EOPNOTSUPP);
2222 }
2223
2224 size = nfsd_getxattr(fhp->fh_dentry, name, &value);
2225 if (size < 0)
2226 return ERR_PTR(size);
2227
2228 acl = posix_acl_from_xattr(value, size);
2229 kfree(value);
2230 return acl;
2231 }
2232
2233 int
2234 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl)
2235 {
2236 struct inode *inode = fhp->fh_dentry->d_inode;
2237 char *name;
2238 void *value = NULL;
2239 size_t size;
2240 int error;
2241
2242 if (!IS_POSIXACL(inode) ||
2243 !inode->i_op->setxattr || !inode->i_op->removexattr)
2244 return -EOPNOTSUPP;
2245 switch(type) {
2246 case ACL_TYPE_ACCESS:
2247 name = POSIX_ACL_XATTR_ACCESS;
2248 break;
2249 case ACL_TYPE_DEFAULT:
2250 name = POSIX_ACL_XATTR_DEFAULT;
2251 break;
2252 default:
2253 return -EOPNOTSUPP;
2254 }
2255
2256 if (acl && acl->a_count) {
2257 size = posix_acl_xattr_size(acl->a_count);
2258 value = kmalloc(size, GFP_KERNEL);
2259 if (!value)
2260 return -ENOMEM;
2261 error = posix_acl_to_xattr(acl, value, size);
2262 if (error < 0)
2263 goto getout;
2264 size = error;
2265 } else
2266 size = 0;
2267
2268 error = mnt_want_write(fhp->fh_export->ex_path.mnt);
2269 if (error)
2270 goto getout;
2271 if (size)
2272 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0);
2273 else {
2274 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT)
2275 error = 0;
2276 else {
2277 error = vfs_removexattr(fhp->fh_dentry, name);
2278 if (error == -ENODATA)
2279 error = 0;
2280 }
2281 }
2282 mnt_drop_write(fhp->fh_export->ex_path.mnt);
2283
2284 getout:
2285 kfree(value);
2286 return error;
2287 }
2288 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
kernel source for telekom puls (alcatel/mediatek)