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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[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 if (EX_ISSYNC(fhp->fh_export))
447 write_inode_now(inode, 1);
448 out:
449 return err;
450
451 out_nfserr:
452 err = nfserrno(host_err);
453 goto out;
454 }
455
456 #if defined(CONFIG_NFSD_V2_ACL) || \
457 defined(CONFIG_NFSD_V3_ACL) || \
458 defined(CONFIG_NFSD_V4)
459 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
460 {
461 ssize_t buflen;
462 ssize_t ret;
463
464 buflen = vfs_getxattr(dentry, key, NULL, 0);
465 if (buflen <= 0)
466 return buflen;
467
468 *buf = kmalloc(buflen, GFP_KERNEL);
469 if (!*buf)
470 return -ENOMEM;
471
472 ret = vfs_getxattr(dentry, key, *buf, buflen);
473 if (ret < 0)
474 kfree(*buf);
475 return ret;
476 }
477 #endif
478
479 #if defined(CONFIG_NFSD_V4)
480 static int
481 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key)
482 {
483 int len;
484 size_t buflen;
485 char *buf = NULL;
486 int error = 0;
487
488 buflen = posix_acl_xattr_size(pacl->a_count);
489 buf = kmalloc(buflen, GFP_KERNEL);
490 error = -ENOMEM;
491 if (buf == NULL)
492 goto out;
493
494 len = posix_acl_to_xattr(pacl, buf, buflen);
495 if (len < 0) {
496 error = len;
497 goto out;
498 }
499
500 error = vfs_setxattr(dentry, key, buf, len, 0);
501 out:
502 kfree(buf);
503 return error;
504 }
505
506 __be32
507 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
508 struct nfs4_acl *acl)
509 {
510 __be32 error;
511 int host_error;
512 struct dentry *dentry;
513 struct inode *inode;
514 struct posix_acl *pacl = NULL, *dpacl = NULL;
515 unsigned int flags = 0;
516
517 /* Get inode */
518 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
519 if (error)
520 return error;
521
522 dentry = fhp->fh_dentry;
523 inode = dentry->d_inode;
524 if (S_ISDIR(inode->i_mode))
525 flags = NFS4_ACL_DIR;
526
527 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
528 if (host_error == -EINVAL) {
529 return nfserr_attrnotsupp;
530 } else if (host_error < 0)
531 goto out_nfserr;
532
533 host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS);
534 if (host_error < 0)
535 goto out_release;
536
537 if (S_ISDIR(inode->i_mode))
538 host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT);
539
540 out_release:
541 posix_acl_release(pacl);
542 posix_acl_release(dpacl);
543 out_nfserr:
544 if (host_error == -EOPNOTSUPP)
545 return nfserr_attrnotsupp;
546 else
547 return nfserrno(host_error);
548 }
549
550 static struct posix_acl *
551 _get_posix_acl(struct dentry *dentry, char *key)
552 {
553 void *buf = NULL;
554 struct posix_acl *pacl = NULL;
555 int buflen;
556
557 buflen = nfsd_getxattr(dentry, key, &buf);
558 if (!buflen)
559 buflen = -ENODATA;
560 if (buflen <= 0)
561 return ERR_PTR(buflen);
562
563 pacl = posix_acl_from_xattr(buf, buflen);
564 kfree(buf);
565 return pacl;
566 }
567
568 int
569 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl)
570 {
571 struct inode *inode = dentry->d_inode;
572 int error = 0;
573 struct posix_acl *pacl = NULL, *dpacl = NULL;
574 unsigned int flags = 0;
575
576 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS);
577 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA)
578 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
579 if (IS_ERR(pacl)) {
580 error = PTR_ERR(pacl);
581 pacl = NULL;
582 goto out;
583 }
584
585 if (S_ISDIR(inode->i_mode)) {
586 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT);
587 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA)
588 dpacl = NULL;
589 else if (IS_ERR(dpacl)) {
590 error = PTR_ERR(dpacl);
591 dpacl = NULL;
592 goto out;
593 }
594 flags = NFS4_ACL_DIR;
595 }
596
597 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags);
598 if (IS_ERR(*acl)) {
599 error = PTR_ERR(*acl);
600 *acl = NULL;
601 }
602 out:
603 posix_acl_release(pacl);
604 posix_acl_release(dpacl);
605 return error;
606 }
607
608 #endif /* defined(CONFIG_NFS_V4) */
609
610 #ifdef CONFIG_NFSD_V3
611 /*
612 * Check server access rights to a file system object
613 */
614 struct accessmap {
615 u32 access;
616 int how;
617 };
618 static struct accessmap nfs3_regaccess[] = {
619 { NFS3_ACCESS_READ, NFSD_MAY_READ },
620 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
621 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
622 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
623
624 { 0, 0 }
625 };
626
627 static struct accessmap nfs3_diraccess[] = {
628 { NFS3_ACCESS_READ, NFSD_MAY_READ },
629 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
630 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
631 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
632 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
633
634 { 0, 0 }
635 };
636
637 static struct accessmap nfs3_anyaccess[] = {
638 /* Some clients - Solaris 2.6 at least, make an access call
639 * to the server to check for access for things like /dev/null
640 * (which really, the server doesn't care about). So
641 * We provide simple access checking for them, looking
642 * mainly at mode bits, and we make sure to ignore read-only
643 * filesystem checks
644 */
645 { NFS3_ACCESS_READ, NFSD_MAY_READ },
646 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
647 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
648 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
649
650 { 0, 0 }
651 };
652
653 __be32
654 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
655 {
656 struct accessmap *map;
657 struct svc_export *export;
658 struct dentry *dentry;
659 u32 query, result = 0, sresult = 0;
660 __be32 error;
661
662 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
663 if (error)
664 goto out;
665
666 export = fhp->fh_export;
667 dentry = fhp->fh_dentry;
668
669 if (S_ISREG(dentry->d_inode->i_mode))
670 map = nfs3_regaccess;
671 else if (S_ISDIR(dentry->d_inode->i_mode))
672 map = nfs3_diraccess;
673 else
674 map = nfs3_anyaccess;
675
676
677 query = *access;
678 for (; map->access; map++) {
679 if (map->access & query) {
680 __be32 err2;
681
682 sresult |= map->access;
683
684 err2 = nfsd_permission(rqstp, export, dentry, map->how);
685 switch (err2) {
686 case nfs_ok:
687 result |= map->access;
688 break;
689
690 /* the following error codes just mean the access was not allowed,
691 * rather than an error occurred */
692 case nfserr_rofs:
693 case nfserr_acces:
694 case nfserr_perm:
695 /* simply don't "or" in the access bit. */
696 break;
697 default:
698 error = err2;
699 goto out;
700 }
701 }
702 }
703 *access = result;
704 if (supported)
705 *supported = sresult;
706
707 out:
708 return error;
709 }
710 #endif /* CONFIG_NFSD_V3 */
711
712
713
714 /*
715 * Open an existing file or directory.
716 * The access argument indicates the type of open (read/write/lock)
717 * N.B. After this call fhp needs an fh_put
718 */
719 __be32
720 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
721 int access, struct file **filp)
722 {
723 struct dentry *dentry;
724 struct inode *inode;
725 int flags = O_RDONLY|O_LARGEFILE;
726 __be32 err;
727 int host_err;
728
729 validate_process_creds();
730
731 /*
732 * If we get here, then the client has already done an "open",
733 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
734 * in case a chmod has now revoked permission.
735 */
736 err = fh_verify(rqstp, fhp, type, access | NFSD_MAY_OWNER_OVERRIDE);
737 if (err)
738 goto out;
739
740 dentry = fhp->fh_dentry;
741 inode = dentry->d_inode;
742
743 /* Disallow write access to files with the append-only bit set
744 * or any access when mandatory locking enabled
745 */
746 err = nfserr_perm;
747 if (IS_APPEND(inode) && (access & NFSD_MAY_WRITE))
748 goto out;
749 /*
750 * We must ignore files (but only files) which might have mandatory
751 * locks on them because there is no way to know if the accesser has
752 * the lock.
753 */
754 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
755 goto out;
756
757 if (!inode->i_fop)
758 goto out;
759
760 /*
761 * Check to see if there are any leases on this file.
762 * This may block while leases are broken.
763 */
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 struct raparms *ra;
907 mm_segment_t oldfs;
908 __be32 err;
909 int host_err;
910
911 err = nfserr_perm;
912 inode = file->f_path.dentry->d_inode;
913
914 if (svc_msnfs(fhp) && !lock_may_read(inode, offset, *count))
915 goto out;
916
917 /* Get readahead parameters */
918 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);
919
920 if (ra && ra->p_set)
921 file->f_ra = ra->p_ra;
922
923 if (file->f_op->splice_read && rqstp->rq_splice_ok) {
924 struct splice_desc sd = {
925 .len = 0,
926 .total_len = *count,
927 .pos = offset,
928 .u.data = rqstp,
929 };
930
931 rqstp->rq_resused = 1;
932 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
933 } else {
934 oldfs = get_fs();
935 set_fs(KERNEL_DS);
936 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
937 set_fs(oldfs);
938 }
939
940 /* Write back readahead params */
941 if (ra) {
942 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
943 spin_lock(&rab->pb_lock);
944 ra->p_ra = file->f_ra;
945 ra->p_set = 1;
946 ra->p_count--;
947 spin_unlock(&rab->pb_lock);
948 }
949
950 if (host_err >= 0) {
951 nfsdstats.io_read += host_err;
952 *count = host_err;
953 err = 0;
954 fsnotify_access(file->f_path.dentry);
955 } else
956 err = nfserrno(host_err);
957 out:
958 return err;
959 }
960
961 static void kill_suid(struct dentry *dentry)
962 {
963 struct iattr ia;
964 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
965
966 mutex_lock(&dentry->d_inode->i_mutex);
967 notify_change(dentry, &ia);
968 mutex_unlock(&dentry->d_inode->i_mutex);
969 }
970
971 /*
972 * Gathered writes: If another process is currently writing to the file,
973 * there's a high chance this is another nfsd (triggered by a bulk write
974 * from a client's biod). Rather than syncing the file with each write
975 * request, we sleep for 10 msec.
976 *
977 * I don't know if this roughly approximates C. Juszak's idea of
978 * gathered writes, but it's a nice and simple solution (IMHO), and it
979 * seems to work:-)
980 *
981 * Note: we do this only in the NFSv2 case, since v3 and higher have a
982 * better tool (separate unstable writes and commits) for solving this
983 * problem.
984 */
985 static int wait_for_concurrent_writes(struct file *file)
986 {
987 struct inode *inode = file->f_path.dentry->d_inode;
988 static ino_t last_ino;
989 static dev_t last_dev;
990 int err = 0;
991
992 if (atomic_read(&inode->i_writecount) > 1
993 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
994 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
995 msleep(10);
996 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
997 }
998
999 if (inode->i_state & I_DIRTY) {
1000 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
1001 err = vfs_fsync(file, file->f_path.dentry, 0);
1002 }
1003 last_ino = inode->i_ino;
1004 last_dev = inode->i_sb->s_dev;
1005 return err;
1006 }
1007
1008 static __be32
1009 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1010 loff_t offset, struct kvec *vec, int vlen,
1011 unsigned long *cnt, int *stablep)
1012 {
1013 struct svc_export *exp;
1014 struct dentry *dentry;
1015 struct inode *inode;
1016 mm_segment_t oldfs;
1017 __be32 err = 0;
1018 int host_err;
1019 int stable = *stablep;
1020 int use_wgather;
1021
1022 #ifdef MSNFS
1023 err = nfserr_perm;
1024
1025 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
1026 (!lock_may_write(file->f_path.dentry->d_inode, offset, *cnt)))
1027 goto out;
1028 #endif
1029
1030 dentry = file->f_path.dentry;
1031 inode = dentry->d_inode;
1032 exp = fhp->fh_export;
1033
1034 /*
1035 * Request sync writes if
1036 * - the sync export option has been set, or
1037 * - the client requested O_SYNC behavior (NFSv3 feature).
1038 * - The file system doesn't support fsync().
1039 * When NFSv2 gathered writes have been configured for this volume,
1040 * flushing the data to disk is handled separately below.
1041 */
1042 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
1043
1044 if (!file->f_op->fsync) {/* COMMIT3 cannot work */
1045 stable = 2;
1046 *stablep = 2; /* FILE_SYNC */
1047 }
1048
1049 if (!EX_ISSYNC(exp))
1050 stable = 0;
1051 if (stable && !use_wgather) {
1052 spin_lock(&file->f_lock);
1053 file->f_flags |= O_SYNC;
1054 spin_unlock(&file->f_lock);
1055 }
1056
1057 /* Write the data. */
1058 oldfs = get_fs(); set_fs(KERNEL_DS);
1059 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
1060 set_fs(oldfs);
1061 if (host_err < 0)
1062 goto out_nfserr;
1063 *cnt = host_err;
1064 nfsdstats.io_write += host_err;
1065 fsnotify_modify(file->f_path.dentry);
1066
1067 /* clear setuid/setgid flag after write */
1068 if (inode->i_mode & (S_ISUID | S_ISGID))
1069 kill_suid(dentry);
1070
1071 if (stable && use_wgather)
1072 host_err = wait_for_concurrent_writes(file);
1073
1074 out_nfserr:
1075 dprintk("nfsd: write complete host_err=%d\n", host_err);
1076 if (host_err >= 0)
1077 err = 0;
1078 else
1079 err = nfserrno(host_err);
1080 out:
1081 return err;
1082 }
1083
1084 /*
1085 * Read data from a file. count must contain the requested read count
1086 * on entry. On return, *count contains the number of bytes actually read.
1087 * N.B. After this call fhp needs an fh_put
1088 */
1089 __be32
1090 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1091 loff_t offset, struct kvec *vec, int vlen,
1092 unsigned long *count)
1093 {
1094 __be32 err;
1095
1096 if (file) {
1097 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1098 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE);
1099 if (err)
1100 goto out;
1101 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
1102 } else {
1103 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
1104 if (err)
1105 goto out;
1106 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
1107 nfsd_close(file);
1108 }
1109 out:
1110 return err;
1111 }
1112
1113 /*
1114 * Write data to a file.
1115 * The stable flag requests synchronous writes.
1116 * N.B. After this call fhp needs an fh_put
1117 */
1118 __be32
1119 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1120 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt,
1121 int *stablep)
1122 {
1123 __be32 err = 0;
1124
1125 if (file) {
1126 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1127 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE);
1128 if (err)
1129 goto out;
1130 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt,
1131 stablep);
1132 } else {
1133 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
1134 if (err)
1135 goto out;
1136
1137 if (cnt)
1138 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen,
1139 cnt, stablep);
1140 nfsd_close(file);
1141 }
1142 out:
1143 return err;
1144 }
1145
1146 #ifdef CONFIG_NFSD_V3
1147 /*
1148 * Commit all pending writes to stable storage.
1149 *
1150 * Note: we only guarantee that data that lies within the range specified
1151 * by the 'offset' and 'count' parameters will be synced.
1152 *
1153 * Unfortunately we cannot lock the file to make sure we return full WCC
1154 * data to the client, as locking happens lower down in the filesystem.
1155 */
1156 __be32
1157 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1158 loff_t offset, unsigned long count)
1159 {
1160 struct file *file;
1161 loff_t end = LLONG_MAX;
1162 __be32 err = nfserr_inval;
1163
1164 if (offset < 0)
1165 goto out;
1166 if (count != 0) {
1167 end = offset + (loff_t)count - 1;
1168 if (end < offset)
1169 goto out;
1170 }
1171
1172 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
1173 if (err)
1174 goto out;
1175 if (EX_ISSYNC(fhp->fh_export)) {
1176 int err2 = vfs_fsync_range(file, file->f_path.dentry,
1177 offset, end, 0);
1178
1179 if (err2 != -EINVAL)
1180 err = nfserrno(err2);
1181 else
1182 err = nfserr_notsupp;
1183 }
1184
1185 nfsd_close(file);
1186 out:
1187 return err;
1188 }
1189 #endif /* CONFIG_NFSD_V3 */
1190
1191 static __be32
1192 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1193 struct iattr *iap)
1194 {
1195 /*
1196 * Mode has already been set earlier in create:
1197 */
1198 iap->ia_valid &= ~ATTR_MODE;
1199 /*
1200 * Setting uid/gid works only for root. Irix appears to
1201 * send along the gid on create when it tries to implement
1202 * setgid directories via NFS:
1203 */
1204 if (current_fsuid() != 0)
1205 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1206 if (iap->ia_valid)
1207 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1208 return 0;
1209 }
1210
1211 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1212 * setting size to 0 may fail for some specific file systems by the permission
1213 * checking which requires WRITE permission but the mode is 000.
1214 * we ignore the resizing(to 0) on the just new created file, since the size is
1215 * 0 after file created.
1216 *
1217 * call this only after vfs_create() is called.
1218 * */
1219 static void
1220 nfsd_check_ignore_resizing(struct iattr *iap)
1221 {
1222 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1223 iap->ia_valid &= ~ATTR_SIZE;
1224 }
1225
1226 /*
1227 * Create a file (regular, directory, device, fifo); UNIX sockets
1228 * not yet implemented.
1229 * If the response fh has been verified, the parent directory should
1230 * already be locked. Note that the parent directory is left locked.
1231 *
1232 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1233 */
1234 __be32
1235 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1236 char *fname, int flen, struct iattr *iap,
1237 int type, dev_t rdev, struct svc_fh *resfhp)
1238 {
1239 struct dentry *dentry, *dchild = NULL;
1240 struct inode *dirp;
1241 __be32 err;
1242 __be32 err2;
1243 int host_err;
1244
1245 err = nfserr_perm;
1246 if (!flen)
1247 goto out;
1248 err = nfserr_exist;
1249 if (isdotent(fname, flen))
1250 goto out;
1251
1252 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1253 if (err)
1254 goto out;
1255
1256 dentry = fhp->fh_dentry;
1257 dirp = dentry->d_inode;
1258
1259 err = nfserr_notdir;
1260 if (!dirp->i_op->lookup)
1261 goto out;
1262 /*
1263 * Check whether the response file handle has been verified yet.
1264 * If it has, the parent directory should already be locked.
1265 */
1266 if (!resfhp->fh_dentry) {
1267 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
1268 fh_lock_nested(fhp, I_MUTEX_PARENT);
1269 dchild = lookup_one_len(fname, dentry, flen);
1270 host_err = PTR_ERR(dchild);
1271 if (IS_ERR(dchild))
1272 goto out_nfserr;
1273 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1274 if (err)
1275 goto out;
1276 } else {
1277 /* called from nfsd_proc_create */
1278 dchild = dget(resfhp->fh_dentry);
1279 if (!fhp->fh_locked) {
1280 /* not actually possible */
1281 printk(KERN_ERR
1282 "nfsd_create: parent %s/%s not locked!\n",
1283 dentry->d_parent->d_name.name,
1284 dentry->d_name.name);
1285 err = nfserr_io;
1286 goto out;
1287 }
1288 }
1289 /*
1290 * Make sure the child dentry is still negative ...
1291 */
1292 err = nfserr_exist;
1293 if (dchild->d_inode) {
1294 dprintk("nfsd_create: dentry %s/%s not negative!\n",
1295 dentry->d_name.name, dchild->d_name.name);
1296 goto out;
1297 }
1298
1299 if (!(iap->ia_valid & ATTR_MODE))
1300 iap->ia_mode = 0;
1301 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1302
1303 err = nfserr_inval;
1304 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) {
1305 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1306 type);
1307 goto out;
1308 }
1309
1310 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1311 if (host_err)
1312 goto out_nfserr;
1313
1314 /*
1315 * Get the dir op function pointer.
1316 */
1317 err = 0;
1318 switch (type) {
1319 case S_IFREG:
1320 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1321 if (!host_err)
1322 nfsd_check_ignore_resizing(iap);
1323 break;
1324 case S_IFDIR:
1325 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
1326 break;
1327 case S_IFCHR:
1328 case S_IFBLK:
1329 case S_IFIFO:
1330 case S_IFSOCK:
1331 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
1332 break;
1333 }
1334 if (host_err < 0) {
1335 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1336 goto out_nfserr;
1337 }
1338
1339 err = nfsd_create_setattr(rqstp, resfhp, iap);
1340
1341 /*
1342 * nfsd_setattr already committed the child. Transactional filesystems
1343 * had a chance to commit changes for both parent and child
1344 * simultaneously making the following commit_metadata a noop.
1345 */
1346 err2 = nfserrno(commit_metadata(fhp));
1347 if (err2)
1348 err = err2;
1349 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1350 /*
1351 * Update the file handle to get the new inode info.
1352 */
1353 if (!err)
1354 err = fh_update(resfhp);
1355 out:
1356 if (dchild && !IS_ERR(dchild))
1357 dput(dchild);
1358 return err;
1359
1360 out_nfserr:
1361 err = nfserrno(host_err);
1362 goto out;
1363 }
1364
1365 #ifdef CONFIG_NFSD_V3
1366 /*
1367 * NFSv3 version of nfsd_create
1368 */
1369 __be32
1370 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
1371 char *fname, int flen, struct iattr *iap,
1372 struct svc_fh *resfhp, int createmode, u32 *verifier,
1373 int *truncp, int *created)
1374 {
1375 struct dentry *dentry, *dchild = NULL;
1376 struct inode *dirp;
1377 __be32 err;
1378 int host_err;
1379 __u32 v_mtime=0, v_atime=0;
1380
1381 err = nfserr_perm;
1382 if (!flen)
1383 goto out;
1384 err = nfserr_exist;
1385 if (isdotent(fname, flen))
1386 goto out;
1387 if (!(iap->ia_valid & ATTR_MODE))
1388 iap->ia_mode = 0;
1389 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1390 if (err)
1391 goto out;
1392
1393 dentry = fhp->fh_dentry;
1394 dirp = dentry->d_inode;
1395
1396 /* Get all the sanity checks out of the way before
1397 * we lock the parent. */
1398 err = nfserr_notdir;
1399 if (!dirp->i_op->lookup)
1400 goto out;
1401 fh_lock_nested(fhp, I_MUTEX_PARENT);
1402
1403 /*
1404 * Compose the response file handle.
1405 */
1406 dchild = lookup_one_len(fname, dentry, flen);
1407 host_err = PTR_ERR(dchild);
1408 if (IS_ERR(dchild))
1409 goto out_nfserr;
1410
1411 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1412 if (err)
1413 goto out;
1414
1415 if (createmode == NFS3_CREATE_EXCLUSIVE) {
1416 /* solaris7 gets confused (bugid 4218508) if these have
1417 * the high bit set, so just clear the high bits. If this is
1418 * ever changed to use different attrs for storing the
1419 * verifier, then do_open_lookup() will also need to be fixed
1420 * accordingly.
1421 */
1422 v_mtime = verifier[0]&0x7fffffff;
1423 v_atime = verifier[1]&0x7fffffff;
1424 }
1425
1426 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1427 if (host_err)
1428 goto out_nfserr;
1429 if (dchild->d_inode) {
1430 err = 0;
1431
1432 switch (createmode) {
1433 case NFS3_CREATE_UNCHECKED:
1434 if (! S_ISREG(dchild->d_inode->i_mode))
1435 err = nfserr_exist;
1436 else if (truncp) {
1437 /* in nfsv4, we need to treat this case a little
1438 * differently. we don't want to truncate the
1439 * file now; this would be wrong if the OPEN
1440 * fails for some other reason. furthermore,
1441 * if the size is nonzero, we should ignore it
1442 * according to spec!
1443 */
1444 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1445 }
1446 else {
1447 iap->ia_valid &= ATTR_SIZE;
1448 goto set_attr;
1449 }
1450 break;
1451 case NFS3_CREATE_EXCLUSIVE:
1452 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1453 && dchild->d_inode->i_atime.tv_sec == v_atime
1454 && dchild->d_inode->i_size == 0 )
1455 break;
1456 /* fallthru */
1457 case NFS3_CREATE_GUARDED:
1458 err = nfserr_exist;
1459 }
1460 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1461 goto out;
1462 }
1463
1464 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1465 if (host_err < 0) {
1466 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1467 goto out_nfserr;
1468 }
1469 if (created)
1470 *created = 1;
1471
1472 nfsd_check_ignore_resizing(iap);
1473
1474 if (createmode == NFS3_CREATE_EXCLUSIVE) {
1475 /* Cram the verifier into atime/mtime */
1476 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1477 | ATTR_MTIME_SET|ATTR_ATIME_SET;
1478 /* XXX someone who knows this better please fix it for nsec */
1479 iap->ia_mtime.tv_sec = v_mtime;
1480 iap->ia_atime.tv_sec = v_atime;
1481 iap->ia_mtime.tv_nsec = 0;
1482 iap->ia_atime.tv_nsec = 0;
1483 }
1484
1485 set_attr:
1486 err = nfsd_create_setattr(rqstp, resfhp, iap);
1487
1488 /*
1489 * nfsd_setattr already committed the child (and possibly also the parent).
1490 */
1491 if (!err)
1492 err = nfserrno(commit_metadata(fhp));
1493
1494 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1495 /*
1496 * Update the filehandle to get the new inode info.
1497 */
1498 if (!err)
1499 err = fh_update(resfhp);
1500
1501 out:
1502 fh_unlock(fhp);
1503 if (dchild && !IS_ERR(dchild))
1504 dput(dchild);
1505 return err;
1506
1507 out_nfserr:
1508 err = nfserrno(host_err);
1509 goto out;
1510 }
1511 #endif /* CONFIG_NFSD_V3 */
1512
1513 /*
1514 * Read a symlink. On entry, *lenp must contain the maximum path length that
1515 * fits into the buffer. On return, it contains the true length.
1516 * N.B. After this call fhp needs an fh_put
1517 */
1518 __be32
1519 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1520 {
1521 struct dentry *dentry;
1522 struct inode *inode;
1523 mm_segment_t oldfs;
1524 __be32 err;
1525 int host_err;
1526
1527 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1528 if (err)
1529 goto out;
1530
1531 dentry = fhp->fh_dentry;
1532 inode = dentry->d_inode;
1533
1534 err = nfserr_inval;
1535 if (!inode->i_op->readlink)
1536 goto out;
1537
1538 touch_atime(fhp->fh_export->ex_path.mnt, dentry);
1539 /* N.B. Why does this call need a get_fs()??
1540 * Remove the set_fs and watch the fireworks:-) --okir
1541 */
1542
1543 oldfs = get_fs(); set_fs(KERNEL_DS);
1544 host_err = inode->i_op->readlink(dentry, buf, *lenp);
1545 set_fs(oldfs);
1546
1547 if (host_err < 0)
1548 goto out_nfserr;
1549 *lenp = host_err;
1550 err = 0;
1551 out:
1552 return err;
1553
1554 out_nfserr:
1555 err = nfserrno(host_err);
1556 goto out;
1557 }
1558
1559 /*
1560 * Create a symlink and look up its inode
1561 * N.B. After this call _both_ fhp and resfhp need an fh_put
1562 */
1563 __be32
1564 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1565 char *fname, int flen,
1566 char *path, int plen,
1567 struct svc_fh *resfhp,
1568 struct iattr *iap)
1569 {
1570 struct dentry *dentry, *dnew;
1571 __be32 err, cerr;
1572 int host_err;
1573
1574 err = nfserr_noent;
1575 if (!flen || !plen)
1576 goto out;
1577 err = nfserr_exist;
1578 if (isdotent(fname, flen))
1579 goto out;
1580
1581 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1582 if (err)
1583 goto out;
1584 fh_lock(fhp);
1585 dentry = fhp->fh_dentry;
1586 dnew = lookup_one_len(fname, dentry, flen);
1587 host_err = PTR_ERR(dnew);
1588 if (IS_ERR(dnew))
1589 goto out_nfserr;
1590
1591 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1592 if (host_err)
1593 goto out_nfserr;
1594
1595 if (unlikely(path[plen] != 0)) {
1596 char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
1597 if (path_alloced == NULL)
1598 host_err = -ENOMEM;
1599 else {
1600 strncpy(path_alloced, path, plen);
1601 path_alloced[plen] = 0;
1602 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced);
1603 kfree(path_alloced);
1604 }
1605 } else
1606 host_err = vfs_symlink(dentry->d_inode, dnew, path);
1607 err = nfserrno(host_err);
1608 if (!err)
1609 err = nfserrno(commit_metadata(fhp));
1610 fh_unlock(fhp);
1611
1612 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1613
1614 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1615 dput(dnew);
1616 if (err==0) err = cerr;
1617 out:
1618 return err;
1619
1620 out_nfserr:
1621 err = nfserrno(host_err);
1622 goto out;
1623 }
1624
1625 /*
1626 * Create a hardlink
1627 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1628 */
1629 __be32
1630 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1631 char *name, int len, struct svc_fh *tfhp)
1632 {
1633 struct dentry *ddir, *dnew, *dold;
1634 struct inode *dirp, *dest;
1635 __be32 err;
1636 int host_err;
1637
1638 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1639 if (err)
1640 goto out;
1641 err = fh_verify(rqstp, tfhp, -S_IFDIR, NFSD_MAY_NOP);
1642 if (err)
1643 goto out;
1644
1645 err = nfserr_perm;
1646 if (!len)
1647 goto out;
1648 err = nfserr_exist;
1649 if (isdotent(name, len))
1650 goto out;
1651
1652 fh_lock_nested(ffhp, I_MUTEX_PARENT);
1653 ddir = ffhp->fh_dentry;
1654 dirp = ddir->d_inode;
1655
1656 dnew = lookup_one_len(name, ddir, len);
1657 host_err = PTR_ERR(dnew);
1658 if (IS_ERR(dnew))
1659 goto out_nfserr;
1660
1661 dold = tfhp->fh_dentry;
1662 dest = dold->d_inode;
1663
1664 host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt);
1665 if (host_err) {
1666 err = nfserrno(host_err);
1667 goto out_dput;
1668 }
1669 host_err = vfs_link(dold, dirp, dnew);
1670 if (!host_err) {
1671 err = nfserrno(commit_metadata(ffhp));
1672 if (!err)
1673 err = nfserrno(commit_metadata(tfhp));
1674 } else {
1675 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1676 err = nfserr_acces;
1677 else
1678 err = nfserrno(host_err);
1679 }
1680 mnt_drop_write(tfhp->fh_export->ex_path.mnt);
1681 out_dput:
1682 dput(dnew);
1683 out_unlock:
1684 fh_unlock(ffhp);
1685 out:
1686 return err;
1687
1688 out_nfserr:
1689 err = nfserrno(host_err);
1690 goto out_unlock;
1691 }
1692
1693 /*
1694 * Rename a file
1695 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1696 */
1697 __be32
1698 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1699 struct svc_fh *tfhp, char *tname, int tlen)
1700 {
1701 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1702 struct inode *fdir, *tdir;
1703 __be32 err;
1704 int host_err;
1705
1706 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1707 if (err)
1708 goto out;
1709 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1710 if (err)
1711 goto out;
1712
1713 fdentry = ffhp->fh_dentry;
1714 fdir = fdentry->d_inode;
1715
1716 tdentry = tfhp->fh_dentry;
1717 tdir = tdentry->d_inode;
1718
1719 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
1720 if (ffhp->fh_export != tfhp->fh_export)
1721 goto out;
1722
1723 err = nfserr_perm;
1724 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1725 goto out;
1726
1727 /* cannot use fh_lock as we need deadlock protective ordering
1728 * so do it by hand */
1729 trap = lock_rename(tdentry, fdentry);
1730 ffhp->fh_locked = tfhp->fh_locked = 1;
1731 fill_pre_wcc(ffhp);
1732 fill_pre_wcc(tfhp);
1733
1734 odentry = lookup_one_len(fname, fdentry, flen);
1735 host_err = PTR_ERR(odentry);
1736 if (IS_ERR(odentry))
1737 goto out_nfserr;
1738
1739 host_err = -ENOENT;
1740 if (!odentry->d_inode)
1741 goto out_dput_old;
1742 host_err = -EINVAL;
1743 if (odentry == trap)
1744 goto out_dput_old;
1745
1746 ndentry = lookup_one_len(tname, tdentry, tlen);
1747 host_err = PTR_ERR(ndentry);
1748 if (IS_ERR(ndentry))
1749 goto out_dput_old;
1750 host_err = -ENOTEMPTY;
1751 if (ndentry == trap)
1752 goto out_dput_new;
1753
1754 if (svc_msnfs(ffhp) &&
1755 ((atomic_read(&odentry->d_count) > 1)
1756 || (atomic_read(&ndentry->d_count) > 1))) {
1757 host_err = -EPERM;
1758 goto out_dput_new;
1759 }
1760
1761 host_err = -EXDEV;
1762 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1763 goto out_dput_new;
1764 host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt);
1765 if (host_err)
1766 goto out_dput_new;
1767
1768 host_err = vfs_rename(fdir, odentry, tdir, ndentry);
1769 if (!host_err) {
1770 host_err = commit_metadata(tfhp);
1771 if (!host_err)
1772 host_err = commit_metadata(ffhp);
1773 }
1774
1775 mnt_drop_write(ffhp->fh_export->ex_path.mnt);
1776
1777 out_dput_new:
1778 dput(ndentry);
1779 out_dput_old:
1780 dput(odentry);
1781 out_nfserr:
1782 err = nfserrno(host_err);
1783
1784 /* we cannot reply on fh_unlock on the two filehandles,
1785 * as that would do the wrong thing if the two directories
1786 * were the same, so again we do it by hand
1787 */
1788 fill_post_wcc(ffhp);
1789 fill_post_wcc(tfhp);
1790 unlock_rename(tdentry, fdentry);
1791 ffhp->fh_locked = tfhp->fh_locked = 0;
1792
1793 out:
1794 return err;
1795 }
1796
1797 /*
1798 * Unlink a file or directory
1799 * N.B. After this call fhp needs an fh_put
1800 */
1801 __be32
1802 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1803 char *fname, int flen)
1804 {
1805 struct dentry *dentry, *rdentry;
1806 struct inode *dirp;
1807 __be32 err;
1808 int host_err;
1809
1810 err = nfserr_acces;
1811 if (!flen || isdotent(fname, flen))
1812 goto out;
1813 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1814 if (err)
1815 goto out;
1816
1817 fh_lock_nested(fhp, I_MUTEX_PARENT);
1818 dentry = fhp->fh_dentry;
1819 dirp = dentry->d_inode;
1820
1821 rdentry = lookup_one_len(fname, dentry, flen);
1822 host_err = PTR_ERR(rdentry);
1823 if (IS_ERR(rdentry))
1824 goto out_nfserr;
1825
1826 if (!rdentry->d_inode) {
1827 dput(rdentry);
1828 err = nfserr_noent;
1829 goto out;
1830 }
1831
1832 if (!type)
1833 type = rdentry->d_inode->i_mode & S_IFMT;
1834
1835 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1836 if (host_err)
1837 goto out_nfserr;
1838
1839 if (type != S_IFDIR) { /* It's UNLINK */
1840 #ifdef MSNFS
1841 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
1842 (atomic_read(&rdentry->d_count) > 1)) {
1843 host_err = -EPERM;
1844 } else
1845 #endif
1846 host_err = vfs_unlink(dirp, rdentry);
1847 } else { /* It's RMDIR */
1848 host_err = vfs_rmdir(dirp, rdentry);
1849 }
1850
1851 dput(rdentry);
1852
1853 if (!host_err)
1854 host_err = commit_metadata(fhp);
1855
1856 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1857 out_nfserr:
1858 err = nfserrno(host_err);
1859 out:
1860 return err;
1861 }
1862
1863 /*
1864 * We do this buffering because we must not call back into the file
1865 * system's ->lookup() method from the filldir callback. That may well
1866 * deadlock a number of file systems.
1867 *
1868 * This is based heavily on the implementation of same in XFS.
1869 */
1870 struct buffered_dirent {
1871 u64 ino;
1872 loff_t offset;
1873 int namlen;
1874 unsigned int d_type;
1875 char name[];
1876 };
1877
1878 struct readdir_data {
1879 char *dirent;
1880 size_t used;
1881 int full;
1882 };
1883
1884 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen,
1885 loff_t offset, u64 ino, unsigned int d_type)
1886 {
1887 struct readdir_data *buf = __buf;
1888 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1889 unsigned int reclen;
1890
1891 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1892 if (buf->used + reclen > PAGE_SIZE) {
1893 buf->full = 1;
1894 return -EINVAL;
1895 }
1896
1897 de->namlen = namlen;
1898 de->offset = offset;
1899 de->ino = ino;
1900 de->d_type = d_type;
1901 memcpy(de->name, name, namlen);
1902 buf->used += reclen;
1903
1904 return 0;
1905 }
1906
1907 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func,
1908 struct readdir_cd *cdp, loff_t *offsetp)
1909 {
1910 struct readdir_data buf;
1911 struct buffered_dirent *de;
1912 int host_err;
1913 int size;
1914 loff_t offset;
1915
1916 buf.dirent = (void *)__get_free_page(GFP_KERNEL);
1917 if (!buf.dirent)
1918 return nfserrno(-ENOMEM);
1919
1920 offset = *offsetp;
1921
1922 while (1) {
1923 struct inode *dir_inode = file->f_path.dentry->d_inode;
1924 unsigned int reclen;
1925
1926 cdp->err = nfserr_eof; /* will be cleared on successful read */
1927 buf.used = 0;
1928 buf.full = 0;
1929
1930 host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf);
1931 if (buf.full)
1932 host_err = 0;
1933
1934 if (host_err < 0)
1935 break;
1936
1937 size = buf.used;
1938
1939 if (!size)
1940 break;
1941
1942 /*
1943 * Various filldir functions may end up calling back into
1944 * lookup_one_len() and the file system's ->lookup() method.
1945 * These expect i_mutex to be held, as it would within readdir.
1946 */
1947 host_err = mutex_lock_killable(&dir_inode->i_mutex);
1948 if (host_err)
1949 break;
1950
1951 de = (struct buffered_dirent *)buf.dirent;
1952 while (size > 0) {
1953 offset = de->offset;
1954
1955 if (func(cdp, de->name, de->namlen, de->offset,
1956 de->ino, de->d_type))
1957 break;
1958
1959 if (cdp->err != nfs_ok)
1960 break;
1961
1962 reclen = ALIGN(sizeof(*de) + de->namlen,
1963 sizeof(u64));
1964 size -= reclen;
1965 de = (struct buffered_dirent *)((char *)de + reclen);
1966 }
1967 mutex_unlock(&dir_inode->i_mutex);
1968 if (size > 0) /* We bailed out early */
1969 break;
1970
1971 offset = vfs_llseek(file, 0, SEEK_CUR);
1972 }
1973
1974 free_page((unsigned long)(buf.dirent));
1975
1976 if (host_err)
1977 return nfserrno(host_err);
1978
1979 *offsetp = offset;
1980 return cdp->err;
1981 }
1982
1983 /*
1984 * Read entries from a directory.
1985 * The NFSv3/4 verifier we ignore for now.
1986 */
1987 __be32
1988 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
1989 struct readdir_cd *cdp, filldir_t func)
1990 {
1991 __be32 err;
1992 struct file *file;
1993 loff_t offset = *offsetp;
1994
1995 err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file);
1996 if (err)
1997 goto out;
1998
1999 offset = vfs_llseek(file, offset, 0);
2000 if (offset < 0) {
2001 err = nfserrno((int)offset);
2002 goto out_close;
2003 }
2004
2005 err = nfsd_buffered_readdir(file, func, cdp, offsetp);
2006
2007 if (err == nfserr_eof || err == nfserr_toosmall)
2008 err = nfs_ok; /* can still be found in ->err */
2009 out_close:
2010 nfsd_close(file);
2011 out:
2012 return err;
2013 }
2014
2015 /*
2016 * Get file system stats
2017 * N.B. After this call fhp needs an fh_put
2018 */
2019 __be32
2020 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
2021 {
2022 __be32 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
2023 if (!err && vfs_statfs(fhp->fh_dentry,stat))
2024 err = nfserr_io;
2025 return err;
2026 }
2027
2028 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
2029 {
2030 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
2031 }
2032
2033 /*
2034 * Check for a user's access permissions to this inode.
2035 */
2036 __be32
2037 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
2038 struct dentry *dentry, int acc)
2039 {
2040 struct inode *inode = dentry->d_inode;
2041 struct path path;
2042 int err;
2043
2044 if (acc == NFSD_MAY_NOP)
2045 return 0;
2046 #if 0
2047 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2048 acc,
2049 (acc & NFSD_MAY_READ)? " read" : "",
2050 (acc & NFSD_MAY_WRITE)? " write" : "",
2051 (acc & NFSD_MAY_EXEC)? " exec" : "",
2052 (acc & NFSD_MAY_SATTR)? " sattr" : "",
2053 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
2054 (acc & NFSD_MAY_LOCK)? " lock" : "",
2055 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
2056 inode->i_mode,
2057 IS_IMMUTABLE(inode)? " immut" : "",
2058 IS_APPEND(inode)? " append" : "",
2059 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
2060 dprintk(" owner %d/%d user %d/%d\n",
2061 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2062 #endif
2063
2064 /* Normally we reject any write/sattr etc access on a read-only file
2065 * system. But if it is IRIX doing check on write-access for a
2066 * device special file, we ignore rofs.
2067 */
2068 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2069 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2070 if (exp_rdonly(rqstp, exp) ||
2071 __mnt_is_readonly(exp->ex_path.mnt))
2072 return nfserr_rofs;
2073 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2074 return nfserr_perm;
2075 }
2076 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2077 return nfserr_perm;
2078
2079 if (acc & NFSD_MAY_LOCK) {
2080 /* If we cannot rely on authentication in NLM requests,
2081 * just allow locks, otherwise require read permission, or
2082 * ownership
2083 */
2084 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2085 return 0;
2086 else
2087 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2088 }
2089 /*
2090 * The file owner always gets access permission for accesses that
2091 * would normally be checked at open time. This is to make
2092 * file access work even when the client has done a fchmod(fd, 0).
2093 *
2094 * However, `cp foo bar' should fail nevertheless when bar is
2095 * readonly. A sensible way to do this might be to reject all
2096 * attempts to truncate a read-only file, because a creat() call
2097 * always implies file truncation.
2098 * ... but this isn't really fair. A process may reasonably call
2099 * ftruncate on an open file descriptor on a file with perm 000.
2100 * We must trust the client to do permission checking - using "ACCESS"
2101 * with NFSv3.
2102 */
2103 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2104 inode->i_uid == current_fsuid())
2105 return 0;
2106
2107 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2108 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC));
2109
2110 /* Allow read access to binaries even when mode 111 */
2111 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2112 acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE))
2113 err = inode_permission(inode, MAY_EXEC);
2114 if (err)
2115 goto nfsd_out;
2116
2117 /* Do integrity (permission) checking now, but defer incrementing
2118 * IMA counts to the actual file open.
2119 */
2120 path.mnt = exp->ex_path.mnt;
2121 path.dentry = dentry;
2122 nfsd_out:
2123 return err? nfserrno(err) : 0;
2124 }
2125
2126 void
2127 nfsd_racache_shutdown(void)
2128 {
2129 struct raparms *raparm, *last_raparm;
2130 unsigned int i;
2131
2132 dprintk("nfsd: freeing readahead buffers.\n");
2133
2134 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2135 raparm = raparm_hash[i].pb_head;
2136 while(raparm) {
2137 last_raparm = raparm;
2138 raparm = raparm->p_next;
2139 kfree(last_raparm);
2140 }
2141 raparm_hash[i].pb_head = NULL;
2142 }
2143 }
2144 /*
2145 * Initialize readahead param cache
2146 */
2147 int
2148 nfsd_racache_init(int cache_size)
2149 {
2150 int i;
2151 int j = 0;
2152 int nperbucket;
2153 struct raparms **raparm = NULL;
2154
2155
2156 if (raparm_hash[0].pb_head)
2157 return 0;
2158 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
2159 if (nperbucket < 2)
2160 nperbucket = 2;
2161 cache_size = nperbucket * RAPARM_HASH_SIZE;
2162
2163 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
2164
2165 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2166 spin_lock_init(&raparm_hash[i].pb_lock);
2167
2168 raparm = &raparm_hash[i].pb_head;
2169 for (j = 0; j < nperbucket; j++) {
2170 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
2171 if (!*raparm)
2172 goto out_nomem;
2173 raparm = &(*raparm)->p_next;
2174 }
2175 *raparm = NULL;
2176 }
2177
2178 nfsdstats.ra_size = cache_size;
2179 return 0;
2180
2181 out_nomem:
2182 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
2183 nfsd_racache_shutdown();
2184 return -ENOMEM;
2185 }
2186
2187 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
2188 struct posix_acl *
2189 nfsd_get_posix_acl(struct svc_fh *fhp, int type)
2190 {
2191 struct inode *inode = fhp->fh_dentry->d_inode;
2192 char *name;
2193 void *value = NULL;
2194 ssize_t size;
2195 struct posix_acl *acl;
2196
2197 if (!IS_POSIXACL(inode))
2198 return ERR_PTR(-EOPNOTSUPP);
2199
2200 switch (type) {
2201 case ACL_TYPE_ACCESS:
2202 name = POSIX_ACL_XATTR_ACCESS;
2203 break;
2204 case ACL_TYPE_DEFAULT:
2205 name = POSIX_ACL_XATTR_DEFAULT;
2206 break;
2207 default:
2208 return ERR_PTR(-EOPNOTSUPP);
2209 }
2210
2211 size = nfsd_getxattr(fhp->fh_dentry, name, &value);
2212 if (size < 0)
2213 return ERR_PTR(size);
2214
2215 acl = posix_acl_from_xattr(value, size);
2216 kfree(value);
2217 return acl;
2218 }
2219
2220 int
2221 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl)
2222 {
2223 struct inode *inode = fhp->fh_dentry->d_inode;
2224 char *name;
2225 void *value = NULL;
2226 size_t size;
2227 int error;
2228
2229 if (!IS_POSIXACL(inode) ||
2230 !inode->i_op->setxattr || !inode->i_op->removexattr)
2231 return -EOPNOTSUPP;
2232 switch(type) {
2233 case ACL_TYPE_ACCESS:
2234 name = POSIX_ACL_XATTR_ACCESS;
2235 break;
2236 case ACL_TYPE_DEFAULT:
2237 name = POSIX_ACL_XATTR_DEFAULT;
2238 break;
2239 default:
2240 return -EOPNOTSUPP;
2241 }
2242
2243 if (acl && acl->a_count) {
2244 size = posix_acl_xattr_size(acl->a_count);
2245 value = kmalloc(size, GFP_KERNEL);
2246 if (!value)
2247 return -ENOMEM;
2248 error = posix_acl_to_xattr(acl, value, size);
2249 if (error < 0)
2250 goto getout;
2251 size = error;
2252 } else
2253 size = 0;
2254
2255 error = mnt_want_write(fhp->fh_export->ex_path.mnt);
2256 if (error)
2257 goto getout;
2258 if (size)
2259 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0);
2260 else {
2261 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT)
2262 error = 0;
2263 else {
2264 error = vfs_removexattr(fhp->fh_dentry, name);
2265 if (error == -ENODATA)
2266 error = 0;
2267 }
2268 }
2269 mnt_drop_write(fhp->fh_export->ex_path.mnt);
2270
2271 getout:
2272 kfree(value);
2273 return error;
2274 }
2275 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
kernel source for telekom puls (alcatel/mediatek)