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dquot: cleanup dquot drop routine
[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/quotaops.h>
24 #include <linux/fsnotify.h>
25 #include <linux/posix_acl_xattr.h>
26 #include <linux/xattr.h>
27 #include <linux/jhash.h>
28 #include <linux/ima.h>
29 #include <asm/uaccess.h>
30
31 #ifdef CONFIG_NFSD_V3
32 #include "xdr3.h"
33 #endif /* CONFIG_NFSD_V3 */
34
35 #ifdef CONFIG_NFSD_V4
36 #include <linux/nfs4_acl.h>
37 #include <linux/nfsd_idmap.h>
38 #endif /* CONFIG_NFSD_V4 */
39
40 #include "nfsd.h"
41 #include "vfs.h"
42
43 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
44
45
46 /*
47 * This is a cache of readahead params that help us choose the proper
48 * readahead strategy. Initially, we set all readahead parameters to 0
49 * and let the VFS handle things.
50 * If you increase the number of cached files very much, you'll need to
51 * add a hash table here.
52 */
53 struct raparms {
54 struct raparms *p_next;
55 unsigned int p_count;
56 ino_t p_ino;
57 dev_t p_dev;
58 int p_set;
59 struct file_ra_state p_ra;
60 unsigned int p_hindex;
61 };
62
63 struct raparm_hbucket {
64 struct raparms *pb_head;
65 spinlock_t pb_lock;
66 } ____cacheline_aligned_in_smp;
67
68 #define RAPARM_HASH_BITS 4
69 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS)
70 #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1)
71 static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE];
72
73 /*
74 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
75 * a mount point.
76 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
77 * or nfs_ok having possibly changed *dpp and *expp
78 */
79 int
80 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
81 struct svc_export **expp)
82 {
83 struct svc_export *exp = *expp, *exp2 = NULL;
84 struct dentry *dentry = *dpp;
85 struct path path = {.mnt = mntget(exp->ex_path.mnt),
86 .dentry = dget(dentry)};
87 int err = 0;
88
89 while (d_mountpoint(path.dentry) && follow_down(&path))
90 ;
91
92 exp2 = rqst_exp_get_by_name(rqstp, &path);
93 if (IS_ERR(exp2)) {
94 err = PTR_ERR(exp2);
95 /*
96 * We normally allow NFS clients to continue
97 * "underneath" a mountpoint that is not exported.
98 * The exception is V4ROOT, where no traversal is ever
99 * allowed without an explicit export of the new
100 * directory.
101 */
102 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
103 err = 0;
104 path_put(&path);
105 goto out;
106 }
107 if (nfsd_v4client(rqstp) ||
108 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
109 /* successfully crossed mount point */
110 /*
111 * This is subtle: path.dentry is *not* on path.mnt
112 * at this point. The only reason we are safe is that
113 * original mnt is pinned down by exp, so we should
114 * put path *before* putting exp
115 */
116 *dpp = path.dentry;
117 path.dentry = dentry;
118 *expp = exp2;
119 exp2 = exp;
120 }
121 path_put(&path);
122 exp_put(exp2);
123 out:
124 return err;
125 }
126
127 static void follow_to_parent(struct path *path)
128 {
129 struct dentry *dp;
130
131 while (path->dentry == path->mnt->mnt_root && follow_up(path))
132 ;
133 dp = dget_parent(path->dentry);
134 dput(path->dentry);
135 path->dentry = dp;
136 }
137
138 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
139 {
140 struct svc_export *exp2;
141 struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
142 .dentry = dget(dparent)};
143
144 follow_to_parent(&path);
145
146 exp2 = rqst_exp_parent(rqstp, &path);
147 if (PTR_ERR(exp2) == -ENOENT) {
148 *dentryp = dget(dparent);
149 } else if (IS_ERR(exp2)) {
150 path_put(&path);
151 return PTR_ERR(exp2);
152 } else {
153 *dentryp = dget(path.dentry);
154 exp_put(*exp);
155 *exp = exp2;
156 }
157 path_put(&path);
158 return 0;
159 }
160
161 /*
162 * For nfsd purposes, we treat V4ROOT exports as though there was an
163 * export at *every* directory.
164 */
165 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
166 {
167 if (d_mountpoint(dentry))
168 return 1;
169 if (!(exp->ex_flags & NFSEXP_V4ROOT))
170 return 0;
171 return dentry->d_inode != NULL;
172 }
173
174 __be32
175 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
176 const char *name, unsigned int len,
177 struct svc_export **exp_ret, struct dentry **dentry_ret)
178 {
179 struct svc_export *exp;
180 struct dentry *dparent;
181 struct dentry *dentry;
182 __be32 err;
183 int host_err;
184
185 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
186
187 /* Obtain dentry and export. */
188 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
189 if (err)
190 return err;
191
192 dparent = fhp->fh_dentry;
193 exp = fhp->fh_export;
194 exp_get(exp);
195
196 /* Lookup the name, but don't follow links */
197 if (isdotent(name, len)) {
198 if (len==1)
199 dentry = dget(dparent);
200 else if (dparent != exp->ex_path.dentry)
201 dentry = dget_parent(dparent);
202 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
203 dentry = dget(dparent); /* .. == . just like at / */
204 else {
205 /* checking mountpoint crossing is very different when stepping up */
206 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
207 if (host_err)
208 goto out_nfserr;
209 }
210 } else {
211 fh_lock(fhp);
212 dentry = lookup_one_len(name, dparent, len);
213 host_err = PTR_ERR(dentry);
214 if (IS_ERR(dentry))
215 goto out_nfserr;
216 /*
217 * check if we have crossed a mount point ...
218 */
219 if (nfsd_mountpoint(dentry, exp)) {
220 if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
221 dput(dentry);
222 goto out_nfserr;
223 }
224 }
225 }
226 *dentry_ret = dentry;
227 *exp_ret = exp;
228 return 0;
229
230 out_nfserr:
231 exp_put(exp);
232 return nfserrno(host_err);
233 }
234
235 /*
236 * Look up one component of a pathname.
237 * N.B. After this call _both_ fhp and resfh need an fh_put
238 *
239 * If the lookup would cross a mountpoint, and the mounted filesystem
240 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
241 * accepted as it stands and the mounted directory is
242 * returned. Otherwise the covered directory is returned.
243 * NOTE: this mountpoint crossing is not supported properly by all
244 * clients and is explicitly disallowed for NFSv3
245 * NeilBrown <neilb@cse.unsw.edu.au>
246 */
247 __be32
248 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
249 unsigned int len, struct svc_fh *resfh)
250 {
251 struct svc_export *exp;
252 struct dentry *dentry;
253 __be32 err;
254
255 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
256 if (err)
257 return err;
258 err = check_nfsd_access(exp, rqstp);
259 if (err)
260 goto out;
261 /*
262 * Note: we compose the file handle now, but as the
263 * dentry may be negative, it may need to be updated.
264 */
265 err = fh_compose(resfh, exp, dentry, fhp);
266 if (!err && !dentry->d_inode)
267 err = nfserr_noent;
268 out:
269 dput(dentry);
270 exp_put(exp);
271 return err;
272 }
273
274
275 /*
276 * Set various file attributes.
277 * N.B. After this call fhp needs an fh_put
278 */
279 __be32
280 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
281 int check_guard, time_t guardtime)
282 {
283 struct dentry *dentry;
284 struct inode *inode;
285 int accmode = NFSD_MAY_SATTR;
286 int ftype = 0;
287 __be32 err;
288 int host_err;
289 int size_change = 0;
290
291 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
292 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
293 if (iap->ia_valid & ATTR_SIZE)
294 ftype = S_IFREG;
295
296 /* Get inode */
297 err = fh_verify(rqstp, fhp, ftype, accmode);
298 if (err)
299 goto out;
300
301 dentry = fhp->fh_dentry;
302 inode = dentry->d_inode;
303
304 /* Ignore any mode updates on symlinks */
305 if (S_ISLNK(inode->i_mode))
306 iap->ia_valid &= ~ATTR_MODE;
307
308 if (!iap->ia_valid)
309 goto out;
310
311 /*
312 * NFSv2 does not differentiate between "set-[ac]time-to-now"
313 * which only requires access, and "set-[ac]time-to-X" which
314 * requires ownership.
315 * So if it looks like it might be "set both to the same time which
316 * is close to now", and if inode_change_ok fails, then we
317 * convert to "set to now" instead of "set to explicit time"
318 *
319 * We only call inode_change_ok as the last test as technically
320 * it is not an interface that we should be using. It is only
321 * valid if the filesystem does not define it's own i_op->setattr.
322 */
323 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
324 #define MAX_TOUCH_TIME_ERROR (30*60)
325 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET &&
326 iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) {
327 /*
328 * Looks probable.
329 *
330 * Now just make sure time is in the right ballpark.
331 * Solaris, at least, doesn't seem to care what the time
332 * request is. We require it be within 30 minutes of now.
333 */
334 time_t delta = iap->ia_atime.tv_sec - get_seconds();
335 if (delta < 0)
336 delta = -delta;
337 if (delta < MAX_TOUCH_TIME_ERROR &&
338 inode_change_ok(inode, iap) != 0) {
339 /*
340 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
341 * This will cause notify_change to set these times
342 * to "now"
343 */
344 iap->ia_valid &= ~BOTH_TIME_SET;
345 }
346 }
347
348 /*
349 * The size case is special.
350 * It changes the file as well as the attributes.
351 */
352 if (iap->ia_valid & ATTR_SIZE) {
353 if (iap->ia_size < inode->i_size) {
354 err = nfsd_permission(rqstp, fhp->fh_export, dentry,
355 NFSD_MAY_TRUNC|NFSD_MAY_OWNER_OVERRIDE);
356 if (err)
357 goto out;
358 }
359
360 /*
361 * If we are changing the size of the file, then
362 * we need to break all leases.
363 */
364 host_err = break_lease(inode, FMODE_WRITE | O_NONBLOCK);
365 if (host_err == -EWOULDBLOCK)
366 host_err = -ETIMEDOUT;
367 if (host_err) /* ENOMEM or EWOULDBLOCK */
368 goto out_nfserr;
369
370 host_err = get_write_access(inode);
371 if (host_err)
372 goto out_nfserr;
373
374 size_change = 1;
375 host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
376 if (host_err) {
377 put_write_access(inode);
378 goto out_nfserr;
379 }
380 vfs_dq_init(inode);
381 }
382
383 /* sanitize the mode change */
384 if (iap->ia_valid & ATTR_MODE) {
385 iap->ia_mode &= S_IALLUGO;
386 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
387 }
388
389 /* Revoke setuid/setgid on chown */
390 if (!S_ISDIR(inode->i_mode) &&
391 (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) ||
392 ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid))) {
393 iap->ia_valid |= ATTR_KILL_PRIV;
394 if (iap->ia_valid & ATTR_MODE) {
395 /* we're setting mode too, just clear the s*id bits */
396 iap->ia_mode &= ~S_ISUID;
397 if (iap->ia_mode & S_IXGRP)
398 iap->ia_mode &= ~S_ISGID;
399 } else {
400 /* set ATTR_KILL_* bits and let VFS handle it */
401 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
402 }
403 }
404
405 /* Change the attributes. */
406
407 iap->ia_valid |= ATTR_CTIME;
408
409 err = nfserr_notsync;
410 if (!check_guard || guardtime == inode->i_ctime.tv_sec) {
411 fh_lock(fhp);
412 host_err = notify_change(dentry, iap);
413 err = nfserrno(host_err);
414 fh_unlock(fhp);
415 }
416 if (size_change)
417 put_write_access(inode);
418 if (!err)
419 if (EX_ISSYNC(fhp->fh_export))
420 write_inode_now(inode, 1);
421 out:
422 return err;
423
424 out_nfserr:
425 err = nfserrno(host_err);
426 goto out;
427 }
428
429 #if defined(CONFIG_NFSD_V2_ACL) || \
430 defined(CONFIG_NFSD_V3_ACL) || \
431 defined(CONFIG_NFSD_V4)
432 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
433 {
434 ssize_t buflen;
435 ssize_t ret;
436
437 buflen = vfs_getxattr(dentry, key, NULL, 0);
438 if (buflen <= 0)
439 return buflen;
440
441 *buf = kmalloc(buflen, GFP_KERNEL);
442 if (!*buf)
443 return -ENOMEM;
444
445 ret = vfs_getxattr(dentry, key, *buf, buflen);
446 if (ret < 0)
447 kfree(*buf);
448 return ret;
449 }
450 #endif
451
452 #if defined(CONFIG_NFSD_V4)
453 static int
454 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key)
455 {
456 int len;
457 size_t buflen;
458 char *buf = NULL;
459 int error = 0;
460
461 buflen = posix_acl_xattr_size(pacl->a_count);
462 buf = kmalloc(buflen, GFP_KERNEL);
463 error = -ENOMEM;
464 if (buf == NULL)
465 goto out;
466
467 len = posix_acl_to_xattr(pacl, buf, buflen);
468 if (len < 0) {
469 error = len;
470 goto out;
471 }
472
473 error = vfs_setxattr(dentry, key, buf, len, 0);
474 out:
475 kfree(buf);
476 return error;
477 }
478
479 __be32
480 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
481 struct nfs4_acl *acl)
482 {
483 __be32 error;
484 int host_error;
485 struct dentry *dentry;
486 struct inode *inode;
487 struct posix_acl *pacl = NULL, *dpacl = NULL;
488 unsigned int flags = 0;
489
490 /* Get inode */
491 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
492 if (error)
493 return error;
494
495 dentry = fhp->fh_dentry;
496 inode = dentry->d_inode;
497 if (S_ISDIR(inode->i_mode))
498 flags = NFS4_ACL_DIR;
499
500 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
501 if (host_error == -EINVAL) {
502 return nfserr_attrnotsupp;
503 } else if (host_error < 0)
504 goto out_nfserr;
505
506 host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS);
507 if (host_error < 0)
508 goto out_release;
509
510 if (S_ISDIR(inode->i_mode))
511 host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT);
512
513 out_release:
514 posix_acl_release(pacl);
515 posix_acl_release(dpacl);
516 out_nfserr:
517 if (host_error == -EOPNOTSUPP)
518 return nfserr_attrnotsupp;
519 else
520 return nfserrno(host_error);
521 }
522
523 static struct posix_acl *
524 _get_posix_acl(struct dentry *dentry, char *key)
525 {
526 void *buf = NULL;
527 struct posix_acl *pacl = NULL;
528 int buflen;
529
530 buflen = nfsd_getxattr(dentry, key, &buf);
531 if (!buflen)
532 buflen = -ENODATA;
533 if (buflen <= 0)
534 return ERR_PTR(buflen);
535
536 pacl = posix_acl_from_xattr(buf, buflen);
537 kfree(buf);
538 return pacl;
539 }
540
541 int
542 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl)
543 {
544 struct inode *inode = dentry->d_inode;
545 int error = 0;
546 struct posix_acl *pacl = NULL, *dpacl = NULL;
547 unsigned int flags = 0;
548
549 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS);
550 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA)
551 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
552 if (IS_ERR(pacl)) {
553 error = PTR_ERR(pacl);
554 pacl = NULL;
555 goto out;
556 }
557
558 if (S_ISDIR(inode->i_mode)) {
559 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT);
560 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA)
561 dpacl = NULL;
562 else if (IS_ERR(dpacl)) {
563 error = PTR_ERR(dpacl);
564 dpacl = NULL;
565 goto out;
566 }
567 flags = NFS4_ACL_DIR;
568 }
569
570 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags);
571 if (IS_ERR(*acl)) {
572 error = PTR_ERR(*acl);
573 *acl = NULL;
574 }
575 out:
576 posix_acl_release(pacl);
577 posix_acl_release(dpacl);
578 return error;
579 }
580
581 #endif /* defined(CONFIG_NFS_V4) */
582
583 #ifdef CONFIG_NFSD_V3
584 /*
585 * Check server access rights to a file system object
586 */
587 struct accessmap {
588 u32 access;
589 int how;
590 };
591 static struct accessmap nfs3_regaccess[] = {
592 { NFS3_ACCESS_READ, NFSD_MAY_READ },
593 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
594 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
595 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
596
597 { 0, 0 }
598 };
599
600 static struct accessmap nfs3_diraccess[] = {
601 { NFS3_ACCESS_READ, NFSD_MAY_READ },
602 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
603 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
604 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
605 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
606
607 { 0, 0 }
608 };
609
610 static struct accessmap nfs3_anyaccess[] = {
611 /* Some clients - Solaris 2.6 at least, make an access call
612 * to the server to check for access for things like /dev/null
613 * (which really, the server doesn't care about). So
614 * We provide simple access checking for them, looking
615 * mainly at mode bits, and we make sure to ignore read-only
616 * filesystem checks
617 */
618 { NFS3_ACCESS_READ, NFSD_MAY_READ },
619 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
620 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
621 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
622
623 { 0, 0 }
624 };
625
626 __be32
627 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
628 {
629 struct accessmap *map;
630 struct svc_export *export;
631 struct dentry *dentry;
632 u32 query, result = 0, sresult = 0;
633 __be32 error;
634
635 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
636 if (error)
637 goto out;
638
639 export = fhp->fh_export;
640 dentry = fhp->fh_dentry;
641
642 if (S_ISREG(dentry->d_inode->i_mode))
643 map = nfs3_regaccess;
644 else if (S_ISDIR(dentry->d_inode->i_mode))
645 map = nfs3_diraccess;
646 else
647 map = nfs3_anyaccess;
648
649
650 query = *access;
651 for (; map->access; map++) {
652 if (map->access & query) {
653 __be32 err2;
654
655 sresult |= map->access;
656
657 err2 = nfsd_permission(rqstp, export, dentry, map->how);
658 switch (err2) {
659 case nfs_ok:
660 result |= map->access;
661 break;
662
663 /* the following error codes just mean the access was not allowed,
664 * rather than an error occurred */
665 case nfserr_rofs:
666 case nfserr_acces:
667 case nfserr_perm:
668 /* simply don't "or" in the access bit. */
669 break;
670 default:
671 error = err2;
672 goto out;
673 }
674 }
675 }
676 *access = result;
677 if (supported)
678 *supported = sresult;
679
680 out:
681 return error;
682 }
683 #endif /* CONFIG_NFSD_V3 */
684
685
686
687 /*
688 * Open an existing file or directory.
689 * The access argument indicates the type of open (read/write/lock)
690 * N.B. After this call fhp needs an fh_put
691 */
692 __be32
693 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
694 int access, struct file **filp)
695 {
696 struct dentry *dentry;
697 struct inode *inode;
698 int flags = O_RDONLY|O_LARGEFILE;
699 __be32 err;
700 int host_err;
701
702 validate_process_creds();
703
704 /*
705 * If we get here, then the client has already done an "open",
706 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
707 * in case a chmod has now revoked permission.
708 */
709 err = fh_verify(rqstp, fhp, type, access | NFSD_MAY_OWNER_OVERRIDE);
710 if (err)
711 goto out;
712
713 dentry = fhp->fh_dentry;
714 inode = dentry->d_inode;
715
716 /* Disallow write access to files with the append-only bit set
717 * or any access when mandatory locking enabled
718 */
719 err = nfserr_perm;
720 if (IS_APPEND(inode) && (access & NFSD_MAY_WRITE))
721 goto out;
722 /*
723 * We must ignore files (but only files) which might have mandatory
724 * locks on them because there is no way to know if the accesser has
725 * the lock.
726 */
727 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
728 goto out;
729
730 if (!inode->i_fop)
731 goto out;
732
733 /*
734 * Check to see if there are any leases on this file.
735 * This may block while leases are broken.
736 */
737 host_err = break_lease(inode, O_NONBLOCK | ((access & NFSD_MAY_WRITE) ? FMODE_WRITE : 0));
738 if (host_err == -EWOULDBLOCK)
739 host_err = -ETIMEDOUT;
740 if (host_err) /* NOMEM or WOULDBLOCK */
741 goto out_nfserr;
742
743 if (access & NFSD_MAY_WRITE) {
744 if (access & NFSD_MAY_READ)
745 flags = O_RDWR|O_LARGEFILE;
746 else
747 flags = O_WRONLY|O_LARGEFILE;
748
749 vfs_dq_init(inode);
750 }
751 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt),
752 flags, current_cred());
753 if (IS_ERR(*filp))
754 host_err = PTR_ERR(*filp);
755 else
756 host_err = ima_file_check(*filp, access);
757 out_nfserr:
758 err = nfserrno(host_err);
759 out:
760 validate_process_creds();
761 return err;
762 }
763
764 /*
765 * Close a file.
766 */
767 void
768 nfsd_close(struct file *filp)
769 {
770 fput(filp);
771 }
772
773 /*
774 * Sync a file
775 * As this calls fsync (not fdatasync) there is no need for a write_inode
776 * after it.
777 */
778 static inline int nfsd_dosync(struct file *filp, struct dentry *dp,
779 const struct file_operations *fop)
780 {
781 struct inode *inode = dp->d_inode;
782 int (*fsync) (struct file *, struct dentry *, int);
783 int err;
784
785 err = filemap_write_and_wait(inode->i_mapping);
786 if (err == 0 && fop && (fsync = fop->fsync))
787 err = fsync(filp, dp, 0);
788 return err;
789 }
790
791 static int
792 nfsd_sync(struct file *filp)
793 {
794 int err;
795 struct inode *inode = filp->f_path.dentry->d_inode;
796 dprintk("nfsd: sync file %s\n", filp->f_path.dentry->d_name.name);
797 mutex_lock(&inode->i_mutex);
798 err=nfsd_dosync(filp, filp->f_path.dentry, filp->f_op);
799 mutex_unlock(&inode->i_mutex);
800
801 return err;
802 }
803
804 int
805 nfsd_sync_dir(struct dentry *dp)
806 {
807 return nfsd_dosync(NULL, dp, dp->d_inode->i_fop);
808 }
809
810 /*
811 * Obtain the readahead parameters for the file
812 * specified by (dev, ino).
813 */
814
815 static inline struct raparms *
816 nfsd_get_raparms(dev_t dev, ino_t ino)
817 {
818 struct raparms *ra, **rap, **frap = NULL;
819 int depth = 0;
820 unsigned int hash;
821 struct raparm_hbucket *rab;
822
823 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
824 rab = &raparm_hash[hash];
825
826 spin_lock(&rab->pb_lock);
827 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
828 if (ra->p_ino == ino && ra->p_dev == dev)
829 goto found;
830 depth++;
831 if (ra->p_count == 0)
832 frap = rap;
833 }
834 depth = nfsdstats.ra_size*11/10;
835 if (!frap) {
836 spin_unlock(&rab->pb_lock);
837 return NULL;
838 }
839 rap = frap;
840 ra = *frap;
841 ra->p_dev = dev;
842 ra->p_ino = ino;
843 ra->p_set = 0;
844 ra->p_hindex = hash;
845 found:
846 if (rap != &rab->pb_head) {
847 *rap = ra->p_next;
848 ra->p_next = rab->pb_head;
849 rab->pb_head = ra;
850 }
851 ra->p_count++;
852 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
853 spin_unlock(&rab->pb_lock);
854 return ra;
855 }
856
857 /*
858 * Grab and keep cached pages associated with a file in the svc_rqst
859 * so that they can be passed to the network sendmsg/sendpage routines
860 * directly. They will be released after the sending has completed.
861 */
862 static int
863 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
864 struct splice_desc *sd)
865 {
866 struct svc_rqst *rqstp = sd->u.data;
867 struct page **pp = rqstp->rq_respages + rqstp->rq_resused;
868 struct page *page = buf->page;
869 size_t size;
870 int ret;
871
872 ret = buf->ops->confirm(pipe, buf);
873 if (unlikely(ret))
874 return ret;
875
876 size = sd->len;
877
878 if (rqstp->rq_res.page_len == 0) {
879 get_page(page);
880 put_page(*pp);
881 *pp = page;
882 rqstp->rq_resused++;
883 rqstp->rq_res.page_base = buf->offset;
884 rqstp->rq_res.page_len = size;
885 } else if (page != pp[-1]) {
886 get_page(page);
887 if (*pp)
888 put_page(*pp);
889 *pp = page;
890 rqstp->rq_resused++;
891 rqstp->rq_res.page_len += size;
892 } else
893 rqstp->rq_res.page_len += size;
894
895 return size;
896 }
897
898 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
899 struct splice_desc *sd)
900 {
901 return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
902 }
903
904 static inline int svc_msnfs(struct svc_fh *ffhp)
905 {
906 #ifdef MSNFS
907 return (ffhp->fh_export->ex_flags & NFSEXP_MSNFS);
908 #else
909 return 0;
910 #endif
911 }
912
913 static __be32
914 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
915 loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
916 {
917 struct inode *inode;
918 struct raparms *ra;
919 mm_segment_t oldfs;
920 __be32 err;
921 int host_err;
922
923 err = nfserr_perm;
924 inode = file->f_path.dentry->d_inode;
925
926 if (svc_msnfs(fhp) && !lock_may_read(inode, offset, *count))
927 goto out;
928
929 /* Get readahead parameters */
930 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);
931
932 if (ra && ra->p_set)
933 file->f_ra = ra->p_ra;
934
935 if (file->f_op->splice_read && rqstp->rq_splice_ok) {
936 struct splice_desc sd = {
937 .len = 0,
938 .total_len = *count,
939 .pos = offset,
940 .u.data = rqstp,
941 };
942
943 rqstp->rq_resused = 1;
944 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
945 } else {
946 oldfs = get_fs();
947 set_fs(KERNEL_DS);
948 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
949 set_fs(oldfs);
950 }
951
952 /* Write back readahead params */
953 if (ra) {
954 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
955 spin_lock(&rab->pb_lock);
956 ra->p_ra = file->f_ra;
957 ra->p_set = 1;
958 ra->p_count--;
959 spin_unlock(&rab->pb_lock);
960 }
961
962 if (host_err >= 0) {
963 nfsdstats.io_read += host_err;
964 *count = host_err;
965 err = 0;
966 fsnotify_access(file->f_path.dentry);
967 } else
968 err = nfserrno(host_err);
969 out:
970 return err;
971 }
972
973 static void kill_suid(struct dentry *dentry)
974 {
975 struct iattr ia;
976 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
977
978 mutex_lock(&dentry->d_inode->i_mutex);
979 notify_change(dentry, &ia);
980 mutex_unlock(&dentry->d_inode->i_mutex);
981 }
982
983 /*
984 * Gathered writes: If another process is currently writing to the file,
985 * there's a high chance this is another nfsd (triggered by a bulk write
986 * from a client's biod). Rather than syncing the file with each write
987 * request, we sleep for 10 msec.
988 *
989 * I don't know if this roughly approximates C. Juszak's idea of
990 * gathered writes, but it's a nice and simple solution (IMHO), and it
991 * seems to work:-)
992 *
993 * Note: we do this only in the NFSv2 case, since v3 and higher have a
994 * better tool (separate unstable writes and commits) for solving this
995 * problem.
996 */
997 static int wait_for_concurrent_writes(struct file *file)
998 {
999 struct inode *inode = file->f_path.dentry->d_inode;
1000 static ino_t last_ino;
1001 static dev_t last_dev;
1002 int err = 0;
1003
1004 if (atomic_read(&inode->i_writecount) > 1
1005 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
1006 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
1007 msleep(10);
1008 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
1009 }
1010
1011 if (inode->i_state & I_DIRTY) {
1012 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
1013 err = nfsd_sync(file);
1014 }
1015 last_ino = inode->i_ino;
1016 last_dev = inode->i_sb->s_dev;
1017 return err;
1018 }
1019
1020 static __be32
1021 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1022 loff_t offset, struct kvec *vec, int vlen,
1023 unsigned long *cnt, int *stablep)
1024 {
1025 struct svc_export *exp;
1026 struct dentry *dentry;
1027 struct inode *inode;
1028 mm_segment_t oldfs;
1029 __be32 err = 0;
1030 int host_err;
1031 int stable = *stablep;
1032 int use_wgather;
1033
1034 #ifdef MSNFS
1035 err = nfserr_perm;
1036
1037 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
1038 (!lock_may_write(file->f_path.dentry->d_inode, offset, *cnt)))
1039 goto out;
1040 #endif
1041
1042 dentry = file->f_path.dentry;
1043 inode = dentry->d_inode;
1044 exp = fhp->fh_export;
1045
1046 /*
1047 * Request sync writes if
1048 * - the sync export option has been set, or
1049 * - the client requested O_SYNC behavior (NFSv3 feature).
1050 * - The file system doesn't support fsync().
1051 * When NFSv2 gathered writes have been configured for this volume,
1052 * flushing the data to disk is handled separately below.
1053 */
1054 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
1055
1056 if (!file->f_op->fsync) {/* COMMIT3 cannot work */
1057 stable = 2;
1058 *stablep = 2; /* FILE_SYNC */
1059 }
1060
1061 if (!EX_ISSYNC(exp))
1062 stable = 0;
1063 if (stable && !use_wgather) {
1064 spin_lock(&file->f_lock);
1065 file->f_flags |= O_SYNC;
1066 spin_unlock(&file->f_lock);
1067 }
1068
1069 /* Write the data. */
1070 oldfs = get_fs(); set_fs(KERNEL_DS);
1071 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
1072 set_fs(oldfs);
1073 if (host_err < 0)
1074 goto out_nfserr;
1075 *cnt = host_err;
1076 nfsdstats.io_write += host_err;
1077 fsnotify_modify(file->f_path.dentry);
1078
1079 /* clear setuid/setgid flag after write */
1080 if (inode->i_mode & (S_ISUID | S_ISGID))
1081 kill_suid(dentry);
1082
1083 if (stable && use_wgather)
1084 host_err = wait_for_concurrent_writes(file);
1085
1086 out_nfserr:
1087 dprintk("nfsd: write complete host_err=%d\n", host_err);
1088 if (host_err >= 0)
1089 err = 0;
1090 else
1091 err = nfserrno(host_err);
1092 out:
1093 return err;
1094 }
1095
1096 /*
1097 * Read data from a file. count must contain the requested read count
1098 * on entry. On return, *count contains the number of bytes actually read.
1099 * N.B. After this call fhp needs an fh_put
1100 */
1101 __be32
1102 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1103 loff_t offset, struct kvec *vec, int vlen,
1104 unsigned long *count)
1105 {
1106 __be32 err;
1107
1108 if (file) {
1109 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1110 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE);
1111 if (err)
1112 goto out;
1113 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
1114 } else {
1115 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
1116 if (err)
1117 goto out;
1118 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
1119 nfsd_close(file);
1120 }
1121 out:
1122 return err;
1123 }
1124
1125 /*
1126 * Write data to a file.
1127 * The stable flag requests synchronous writes.
1128 * N.B. After this call fhp needs an fh_put
1129 */
1130 __be32
1131 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1132 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt,
1133 int *stablep)
1134 {
1135 __be32 err = 0;
1136
1137 if (file) {
1138 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1139 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE);
1140 if (err)
1141 goto out;
1142 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt,
1143 stablep);
1144 } else {
1145 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
1146 if (err)
1147 goto out;
1148
1149 if (cnt)
1150 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen,
1151 cnt, stablep);
1152 nfsd_close(file);
1153 }
1154 out:
1155 return err;
1156 }
1157
1158 #ifdef CONFIG_NFSD_V3
1159 /*
1160 * Commit all pending writes to stable storage.
1161 * Strictly speaking, we could sync just the indicated file region here,
1162 * but there's currently no way we can ask the VFS to do so.
1163 *
1164 * Unfortunately we cannot lock the file to make sure we return full WCC
1165 * data to the client, as locking happens lower down in the filesystem.
1166 */
1167 __be32
1168 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1169 loff_t offset, unsigned long count)
1170 {
1171 struct file *file;
1172 __be32 err;
1173
1174 if ((u64)count > ~(u64)offset)
1175 return nfserr_inval;
1176
1177 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
1178 if (err)
1179 return err;
1180 if (EX_ISSYNC(fhp->fh_export)) {
1181 if (file->f_op && file->f_op->fsync) {
1182 err = nfserrno(nfsd_sync(file));
1183 } else {
1184 err = nfserr_notsupp;
1185 }
1186 }
1187
1188 nfsd_close(file);
1189 return err;
1190 }
1191 #endif /* CONFIG_NFSD_V3 */
1192
1193 static __be32
1194 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1195 struct iattr *iap)
1196 {
1197 /*
1198 * Mode has already been set earlier in create:
1199 */
1200 iap->ia_valid &= ~ATTR_MODE;
1201 /*
1202 * Setting uid/gid works only for root. Irix appears to
1203 * send along the gid on create when it tries to implement
1204 * setgid directories via NFS:
1205 */
1206 if (current_fsuid() != 0)
1207 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1208 if (iap->ia_valid)
1209 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1210 return 0;
1211 }
1212
1213 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1214 * setting size to 0 may fail for some specific file systems by the permission
1215 * checking which requires WRITE permission but the mode is 000.
1216 * we ignore the resizing(to 0) on the just new created file, since the size is
1217 * 0 after file created.
1218 *
1219 * call this only after vfs_create() is called.
1220 * */
1221 static void
1222 nfsd_check_ignore_resizing(struct iattr *iap)
1223 {
1224 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1225 iap->ia_valid &= ~ATTR_SIZE;
1226 }
1227
1228 /*
1229 * Create a file (regular, directory, device, fifo); UNIX sockets
1230 * not yet implemented.
1231 * If the response fh has been verified, the parent directory should
1232 * already be locked. Note that the parent directory is left locked.
1233 *
1234 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1235 */
1236 __be32
1237 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1238 char *fname, int flen, struct iattr *iap,
1239 int type, dev_t rdev, struct svc_fh *resfhp)
1240 {
1241 struct dentry *dentry, *dchild = NULL;
1242 struct inode *dirp;
1243 __be32 err;
1244 __be32 err2;
1245 int host_err;
1246
1247 err = nfserr_perm;
1248 if (!flen)
1249 goto out;
1250 err = nfserr_exist;
1251 if (isdotent(fname, flen))
1252 goto out;
1253
1254 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1255 if (err)
1256 goto out;
1257
1258 dentry = fhp->fh_dentry;
1259 dirp = dentry->d_inode;
1260
1261 err = nfserr_notdir;
1262 if (!dirp->i_op->lookup)
1263 goto out;
1264 /*
1265 * Check whether the response file handle has been verified yet.
1266 * If it has, the parent directory should already be locked.
1267 */
1268 if (!resfhp->fh_dentry) {
1269 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
1270 fh_lock_nested(fhp, I_MUTEX_PARENT);
1271 dchild = lookup_one_len(fname, dentry, flen);
1272 host_err = PTR_ERR(dchild);
1273 if (IS_ERR(dchild))
1274 goto out_nfserr;
1275 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1276 if (err)
1277 goto out;
1278 } else {
1279 /* called from nfsd_proc_create */
1280 dchild = dget(resfhp->fh_dentry);
1281 if (!fhp->fh_locked) {
1282 /* not actually possible */
1283 printk(KERN_ERR
1284 "nfsd_create: parent %s/%s not locked!\n",
1285 dentry->d_parent->d_name.name,
1286 dentry->d_name.name);
1287 err = nfserr_io;
1288 goto out;
1289 }
1290 }
1291 /*
1292 * Make sure the child dentry is still negative ...
1293 */
1294 err = nfserr_exist;
1295 if (dchild->d_inode) {
1296 dprintk("nfsd_create: dentry %s/%s not negative!\n",
1297 dentry->d_name.name, dchild->d_name.name);
1298 goto out;
1299 }
1300
1301 if (!(iap->ia_valid & ATTR_MODE))
1302 iap->ia_mode = 0;
1303 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1304
1305 err = nfserr_inval;
1306 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) {
1307 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1308 type);
1309 goto out;
1310 }
1311
1312 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1313 if (host_err)
1314 goto out_nfserr;
1315
1316 /*
1317 * Get the dir op function pointer.
1318 */
1319 err = 0;
1320 switch (type) {
1321 case S_IFREG:
1322 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1323 if (!host_err)
1324 nfsd_check_ignore_resizing(iap);
1325 break;
1326 case S_IFDIR:
1327 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
1328 break;
1329 case S_IFCHR:
1330 case S_IFBLK:
1331 case S_IFIFO:
1332 case S_IFSOCK:
1333 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
1334 break;
1335 }
1336 if (host_err < 0) {
1337 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1338 goto out_nfserr;
1339 }
1340
1341 if (EX_ISSYNC(fhp->fh_export)) {
1342 err = nfserrno(nfsd_sync_dir(dentry));
1343 write_inode_now(dchild->d_inode, 1);
1344 }
1345
1346 err2 = nfsd_create_setattr(rqstp, resfhp, iap);
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 __be32 err2;
1379 int host_err;
1380 __u32 v_mtime=0, v_atime=0;
1381
1382 err = nfserr_perm;
1383 if (!flen)
1384 goto out;
1385 err = nfserr_exist;
1386 if (isdotent(fname, flen))
1387 goto out;
1388 if (!(iap->ia_valid & ATTR_MODE))
1389 iap->ia_mode = 0;
1390 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1391 if (err)
1392 goto out;
1393
1394 dentry = fhp->fh_dentry;
1395 dirp = dentry->d_inode;
1396
1397 /* Get all the sanity checks out of the way before
1398 * we lock the parent. */
1399 err = nfserr_notdir;
1400 if (!dirp->i_op->lookup)
1401 goto out;
1402 fh_lock_nested(fhp, I_MUTEX_PARENT);
1403
1404 /*
1405 * Compose the response file handle.
1406 */
1407 dchild = lookup_one_len(fname, dentry, flen);
1408 host_err = PTR_ERR(dchild);
1409 if (IS_ERR(dchild))
1410 goto out_nfserr;
1411
1412 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1413 if (err)
1414 goto out;
1415
1416 if (createmode == NFS3_CREATE_EXCLUSIVE) {
1417 /* solaris7 gets confused (bugid 4218508) if these have
1418 * the high bit set, so just clear the high bits. If this is
1419 * ever changed to use different attrs for storing the
1420 * verifier, then do_open_lookup() will also need to be fixed
1421 * accordingly.
1422 */
1423 v_mtime = verifier[0]&0x7fffffff;
1424 v_atime = verifier[1]&0x7fffffff;
1425 }
1426
1427 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1428 if (host_err)
1429 goto out_nfserr;
1430 if (dchild->d_inode) {
1431 err = 0;
1432
1433 switch (createmode) {
1434 case NFS3_CREATE_UNCHECKED:
1435 if (! S_ISREG(dchild->d_inode->i_mode))
1436 err = nfserr_exist;
1437 else if (truncp) {
1438 /* in nfsv4, we need to treat this case a little
1439 * differently. we don't want to truncate the
1440 * file now; this would be wrong if the OPEN
1441 * fails for some other reason. furthermore,
1442 * if the size is nonzero, we should ignore it
1443 * according to spec!
1444 */
1445 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1446 }
1447 else {
1448 iap->ia_valid &= ATTR_SIZE;
1449 goto set_attr;
1450 }
1451 break;
1452 case NFS3_CREATE_EXCLUSIVE:
1453 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1454 && dchild->d_inode->i_atime.tv_sec == v_atime
1455 && dchild->d_inode->i_size == 0 )
1456 break;
1457 /* fallthru */
1458 case NFS3_CREATE_GUARDED:
1459 err = nfserr_exist;
1460 }
1461 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1462 goto out;
1463 }
1464
1465 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1466 if (host_err < 0) {
1467 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1468 goto out_nfserr;
1469 }
1470 if (created)
1471 *created = 1;
1472
1473 if (EX_ISSYNC(fhp->fh_export)) {
1474 err = nfserrno(nfsd_sync_dir(dentry));
1475 /* setattr will sync the child (or not) */
1476 }
1477
1478 nfsd_check_ignore_resizing(iap);
1479
1480 if (createmode == NFS3_CREATE_EXCLUSIVE) {
1481 /* Cram the verifier into atime/mtime */
1482 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1483 | ATTR_MTIME_SET|ATTR_ATIME_SET;
1484 /* XXX someone who knows this better please fix it for nsec */
1485 iap->ia_mtime.tv_sec = v_mtime;
1486 iap->ia_atime.tv_sec = v_atime;
1487 iap->ia_mtime.tv_nsec = 0;
1488 iap->ia_atime.tv_nsec = 0;
1489 }
1490
1491 set_attr:
1492 err2 = nfsd_create_setattr(rqstp, resfhp, iap);
1493 if (err2)
1494 err = err2;
1495
1496 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1497 /*
1498 * Update the filehandle to get the new inode info.
1499 */
1500 if (!err)
1501 err = fh_update(resfhp);
1502
1503 out:
1504 fh_unlock(fhp);
1505 if (dchild && !IS_ERR(dchild))
1506 dput(dchild);
1507 return err;
1508
1509 out_nfserr:
1510 err = nfserrno(host_err);
1511 goto out;
1512 }
1513 #endif /* CONFIG_NFSD_V3 */
1514
1515 /*
1516 * Read a symlink. On entry, *lenp must contain the maximum path length that
1517 * fits into the buffer. On return, it contains the true length.
1518 * N.B. After this call fhp needs an fh_put
1519 */
1520 __be32
1521 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1522 {
1523 struct dentry *dentry;
1524 struct inode *inode;
1525 mm_segment_t oldfs;
1526 __be32 err;
1527 int host_err;
1528
1529 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1530 if (err)
1531 goto out;
1532
1533 dentry = fhp->fh_dentry;
1534 inode = dentry->d_inode;
1535
1536 err = nfserr_inval;
1537 if (!inode->i_op->readlink)
1538 goto out;
1539
1540 touch_atime(fhp->fh_export->ex_path.mnt, dentry);
1541 /* N.B. Why does this call need a get_fs()??
1542 * Remove the set_fs and watch the fireworks:-) --okir
1543 */
1544
1545 oldfs = get_fs(); set_fs(KERNEL_DS);
1546 host_err = inode->i_op->readlink(dentry, buf, *lenp);
1547 set_fs(oldfs);
1548
1549 if (host_err < 0)
1550 goto out_nfserr;
1551 *lenp = host_err;
1552 err = 0;
1553 out:
1554 return err;
1555
1556 out_nfserr:
1557 err = nfserrno(host_err);
1558 goto out;
1559 }
1560
1561 /*
1562 * Create a symlink and look up its inode
1563 * N.B. After this call _both_ fhp and resfhp need an fh_put
1564 */
1565 __be32
1566 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1567 char *fname, int flen,
1568 char *path, int plen,
1569 struct svc_fh *resfhp,
1570 struct iattr *iap)
1571 {
1572 struct dentry *dentry, *dnew;
1573 __be32 err, cerr;
1574 int host_err;
1575
1576 err = nfserr_noent;
1577 if (!flen || !plen)
1578 goto out;
1579 err = nfserr_exist;
1580 if (isdotent(fname, flen))
1581 goto out;
1582
1583 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1584 if (err)
1585 goto out;
1586 fh_lock(fhp);
1587 dentry = fhp->fh_dentry;
1588 dnew = lookup_one_len(fname, dentry, flen);
1589 host_err = PTR_ERR(dnew);
1590 if (IS_ERR(dnew))
1591 goto out_nfserr;
1592
1593 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1594 if (host_err)
1595 goto out_nfserr;
1596
1597 if (unlikely(path[plen] != 0)) {
1598 char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
1599 if (path_alloced == NULL)
1600 host_err = -ENOMEM;
1601 else {
1602 strncpy(path_alloced, path, plen);
1603 path_alloced[plen] = 0;
1604 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced);
1605 kfree(path_alloced);
1606 }
1607 } else
1608 host_err = vfs_symlink(dentry->d_inode, dnew, path);
1609
1610 if (!host_err) {
1611 if (EX_ISSYNC(fhp->fh_export))
1612 host_err = nfsd_sync_dir(dentry);
1613 }
1614 err = nfserrno(host_err);
1615 fh_unlock(fhp);
1616
1617 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1618
1619 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1620 dput(dnew);
1621 if (err==0) err = cerr;
1622 out:
1623 return err;
1624
1625 out_nfserr:
1626 err = nfserrno(host_err);
1627 goto out;
1628 }
1629
1630 /*
1631 * Create a hardlink
1632 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1633 */
1634 __be32
1635 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1636 char *name, int len, struct svc_fh *tfhp)
1637 {
1638 struct dentry *ddir, *dnew, *dold;
1639 struct inode *dirp, *dest;
1640 __be32 err;
1641 int host_err;
1642
1643 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1644 if (err)
1645 goto out;
1646 err = fh_verify(rqstp, tfhp, -S_IFDIR, NFSD_MAY_NOP);
1647 if (err)
1648 goto out;
1649
1650 err = nfserr_perm;
1651 if (!len)
1652 goto out;
1653 err = nfserr_exist;
1654 if (isdotent(name, len))
1655 goto out;
1656
1657 fh_lock_nested(ffhp, I_MUTEX_PARENT);
1658 ddir = ffhp->fh_dentry;
1659 dirp = ddir->d_inode;
1660
1661 dnew = lookup_one_len(name, ddir, len);
1662 host_err = PTR_ERR(dnew);
1663 if (IS_ERR(dnew))
1664 goto out_nfserr;
1665
1666 dold = tfhp->fh_dentry;
1667 dest = dold->d_inode;
1668
1669 host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt);
1670 if (host_err) {
1671 err = nfserrno(host_err);
1672 goto out_dput;
1673 }
1674 host_err = vfs_link(dold, dirp, dnew);
1675 if (!host_err) {
1676 if (EX_ISSYNC(ffhp->fh_export)) {
1677 err = nfserrno(nfsd_sync_dir(ddir));
1678 write_inode_now(dest, 1);
1679 }
1680 err = 0;
1681 } else {
1682 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1683 err = nfserr_acces;
1684 else
1685 err = nfserrno(host_err);
1686 }
1687 mnt_drop_write(tfhp->fh_export->ex_path.mnt);
1688 out_dput:
1689 dput(dnew);
1690 out_unlock:
1691 fh_unlock(ffhp);
1692 out:
1693 return err;
1694
1695 out_nfserr:
1696 err = nfserrno(host_err);
1697 goto out_unlock;
1698 }
1699
1700 /*
1701 * Rename a file
1702 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1703 */
1704 __be32
1705 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1706 struct svc_fh *tfhp, char *tname, int tlen)
1707 {
1708 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1709 struct inode *fdir, *tdir;
1710 __be32 err;
1711 int host_err;
1712
1713 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1714 if (err)
1715 goto out;
1716 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1717 if (err)
1718 goto out;
1719
1720 fdentry = ffhp->fh_dentry;
1721 fdir = fdentry->d_inode;
1722
1723 tdentry = tfhp->fh_dentry;
1724 tdir = tdentry->d_inode;
1725
1726 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
1727 if (ffhp->fh_export != tfhp->fh_export)
1728 goto out;
1729
1730 err = nfserr_perm;
1731 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1732 goto out;
1733
1734 /* cannot use fh_lock as we need deadlock protective ordering
1735 * so do it by hand */
1736 trap = lock_rename(tdentry, fdentry);
1737 ffhp->fh_locked = tfhp->fh_locked = 1;
1738 fill_pre_wcc(ffhp);
1739 fill_pre_wcc(tfhp);
1740
1741 odentry = lookup_one_len(fname, fdentry, flen);
1742 host_err = PTR_ERR(odentry);
1743 if (IS_ERR(odentry))
1744 goto out_nfserr;
1745
1746 host_err = -ENOENT;
1747 if (!odentry->d_inode)
1748 goto out_dput_old;
1749 host_err = -EINVAL;
1750 if (odentry == trap)
1751 goto out_dput_old;
1752
1753 ndentry = lookup_one_len(tname, tdentry, tlen);
1754 host_err = PTR_ERR(ndentry);
1755 if (IS_ERR(ndentry))
1756 goto out_dput_old;
1757 host_err = -ENOTEMPTY;
1758 if (ndentry == trap)
1759 goto out_dput_new;
1760
1761 if (svc_msnfs(ffhp) &&
1762 ((atomic_read(&odentry->d_count) > 1)
1763 || (atomic_read(&ndentry->d_count) > 1))) {
1764 host_err = -EPERM;
1765 goto out_dput_new;
1766 }
1767
1768 host_err = -EXDEV;
1769 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1770 goto out_dput_new;
1771 host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt);
1772 if (host_err)
1773 goto out_dput_new;
1774
1775 host_err = vfs_rename(fdir, odentry, tdir, ndentry);
1776 if (!host_err && EX_ISSYNC(tfhp->fh_export)) {
1777 host_err = nfsd_sync_dir(tdentry);
1778 if (!host_err)
1779 host_err = nfsd_sync_dir(fdentry);
1780 }
1781
1782 mnt_drop_write(ffhp->fh_export->ex_path.mnt);
1783
1784 out_dput_new:
1785 dput(ndentry);
1786 out_dput_old:
1787 dput(odentry);
1788 out_nfserr:
1789 err = nfserrno(host_err);
1790
1791 /* we cannot reply on fh_unlock on the two filehandles,
1792 * as that would do the wrong thing if the two directories
1793 * were the same, so again we do it by hand
1794 */
1795 fill_post_wcc(ffhp);
1796 fill_post_wcc(tfhp);
1797 unlock_rename(tdentry, fdentry);
1798 ffhp->fh_locked = tfhp->fh_locked = 0;
1799
1800 out:
1801 return err;
1802 }
1803
1804 /*
1805 * Unlink a file or directory
1806 * N.B. After this call fhp needs an fh_put
1807 */
1808 __be32
1809 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1810 char *fname, int flen)
1811 {
1812 struct dentry *dentry, *rdentry;
1813 struct inode *dirp;
1814 __be32 err;
1815 int host_err;
1816
1817 err = nfserr_acces;
1818 if (!flen || isdotent(fname, flen))
1819 goto out;
1820 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1821 if (err)
1822 goto out;
1823
1824 fh_lock_nested(fhp, I_MUTEX_PARENT);
1825 dentry = fhp->fh_dentry;
1826 dirp = dentry->d_inode;
1827
1828 rdentry = lookup_one_len(fname, dentry, flen);
1829 host_err = PTR_ERR(rdentry);
1830 if (IS_ERR(rdentry))
1831 goto out_nfserr;
1832
1833 if (!rdentry->d_inode) {
1834 dput(rdentry);
1835 err = nfserr_noent;
1836 goto out;
1837 }
1838
1839 if (!type)
1840 type = rdentry->d_inode->i_mode & S_IFMT;
1841
1842 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1843 if (host_err)
1844 goto out_nfserr;
1845
1846 if (type != S_IFDIR) { /* It's UNLINK */
1847 #ifdef MSNFS
1848 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
1849 (atomic_read(&rdentry->d_count) > 1)) {
1850 host_err = -EPERM;
1851 } else
1852 #endif
1853 host_err = vfs_unlink(dirp, rdentry);
1854 } else { /* It's RMDIR */
1855 host_err = vfs_rmdir(dirp, rdentry);
1856 }
1857
1858 dput(rdentry);
1859
1860 if (host_err)
1861 goto out_drop;
1862 if (EX_ISSYNC(fhp->fh_export))
1863 host_err = nfsd_sync_dir(dentry);
1864
1865 out_drop:
1866 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1867 out_nfserr:
1868 err = nfserrno(host_err);
1869 out:
1870 return err;
1871 }
1872
1873 /*
1874 * We do this buffering because we must not call back into the file
1875 * system's ->lookup() method from the filldir callback. That may well
1876 * deadlock a number of file systems.
1877 *
1878 * This is based heavily on the implementation of same in XFS.
1879 */
1880 struct buffered_dirent {
1881 u64 ino;
1882 loff_t offset;
1883 int namlen;
1884 unsigned int d_type;
1885 char name[];
1886 };
1887
1888 struct readdir_data {
1889 char *dirent;
1890 size_t used;
1891 int full;
1892 };
1893
1894 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen,
1895 loff_t offset, u64 ino, unsigned int d_type)
1896 {
1897 struct readdir_data *buf = __buf;
1898 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1899 unsigned int reclen;
1900
1901 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1902 if (buf->used + reclen > PAGE_SIZE) {
1903 buf->full = 1;
1904 return -EINVAL;
1905 }
1906
1907 de->namlen = namlen;
1908 de->offset = offset;
1909 de->ino = ino;
1910 de->d_type = d_type;
1911 memcpy(de->name, name, namlen);
1912 buf->used += reclen;
1913
1914 return 0;
1915 }
1916
1917 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func,
1918 struct readdir_cd *cdp, loff_t *offsetp)
1919 {
1920 struct readdir_data buf;
1921 struct buffered_dirent *de;
1922 int host_err;
1923 int size;
1924 loff_t offset;
1925
1926 buf.dirent = (void *)__get_free_page(GFP_KERNEL);
1927 if (!buf.dirent)
1928 return nfserrno(-ENOMEM);
1929
1930 offset = *offsetp;
1931
1932 while (1) {
1933 struct inode *dir_inode = file->f_path.dentry->d_inode;
1934 unsigned int reclen;
1935
1936 cdp->err = nfserr_eof; /* will be cleared on successful read */
1937 buf.used = 0;
1938 buf.full = 0;
1939
1940 host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf);
1941 if (buf.full)
1942 host_err = 0;
1943
1944 if (host_err < 0)
1945 break;
1946
1947 size = buf.used;
1948
1949 if (!size)
1950 break;
1951
1952 /*
1953 * Various filldir functions may end up calling back into
1954 * lookup_one_len() and the file system's ->lookup() method.
1955 * These expect i_mutex to be held, as it would within readdir.
1956 */
1957 host_err = mutex_lock_killable(&dir_inode->i_mutex);
1958 if (host_err)
1959 break;
1960
1961 de = (struct buffered_dirent *)buf.dirent;
1962 while (size > 0) {
1963 offset = de->offset;
1964
1965 if (func(cdp, de->name, de->namlen, de->offset,
1966 de->ino, de->d_type))
1967 break;
1968
1969 if (cdp->err != nfs_ok)
1970 break;
1971
1972 reclen = ALIGN(sizeof(*de) + de->namlen,
1973 sizeof(u64));
1974 size -= reclen;
1975 de = (struct buffered_dirent *)((char *)de + reclen);
1976 }
1977 mutex_unlock(&dir_inode->i_mutex);
1978 if (size > 0) /* We bailed out early */
1979 break;
1980
1981 offset = vfs_llseek(file, 0, SEEK_CUR);
1982 }
1983
1984 free_page((unsigned long)(buf.dirent));
1985
1986 if (host_err)
1987 return nfserrno(host_err);
1988
1989 *offsetp = offset;
1990 return cdp->err;
1991 }
1992
1993 /*
1994 * Read entries from a directory.
1995 * The NFSv3/4 verifier we ignore for now.
1996 */
1997 __be32
1998 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
1999 struct readdir_cd *cdp, filldir_t func)
2000 {
2001 __be32 err;
2002 struct file *file;
2003 loff_t offset = *offsetp;
2004
2005 err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file);
2006 if (err)
2007 goto out;
2008
2009 offset = vfs_llseek(file, offset, 0);
2010 if (offset < 0) {
2011 err = nfserrno((int)offset);
2012 goto out_close;
2013 }
2014
2015 err = nfsd_buffered_readdir(file, func, cdp, offsetp);
2016
2017 if (err == nfserr_eof || err == nfserr_toosmall)
2018 err = nfs_ok; /* can still be found in ->err */
2019 out_close:
2020 nfsd_close(file);
2021 out:
2022 return err;
2023 }
2024
2025 /*
2026 * Get file system stats
2027 * N.B. After this call fhp needs an fh_put
2028 */
2029 __be32
2030 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
2031 {
2032 __be32 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
2033 if (!err && vfs_statfs(fhp->fh_dentry,stat))
2034 err = nfserr_io;
2035 return err;
2036 }
2037
2038 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
2039 {
2040 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
2041 }
2042
2043 /*
2044 * Check for a user's access permissions to this inode.
2045 */
2046 __be32
2047 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
2048 struct dentry *dentry, int acc)
2049 {
2050 struct inode *inode = dentry->d_inode;
2051 struct path path;
2052 int err;
2053
2054 if (acc == NFSD_MAY_NOP)
2055 return 0;
2056 #if 0
2057 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2058 acc,
2059 (acc & NFSD_MAY_READ)? " read" : "",
2060 (acc & NFSD_MAY_WRITE)? " write" : "",
2061 (acc & NFSD_MAY_EXEC)? " exec" : "",
2062 (acc & NFSD_MAY_SATTR)? " sattr" : "",
2063 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
2064 (acc & NFSD_MAY_LOCK)? " lock" : "",
2065 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
2066 inode->i_mode,
2067 IS_IMMUTABLE(inode)? " immut" : "",
2068 IS_APPEND(inode)? " append" : "",
2069 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
2070 dprintk(" owner %d/%d user %d/%d\n",
2071 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2072 #endif
2073
2074 /* Normally we reject any write/sattr etc access on a read-only file
2075 * system. But if it is IRIX doing check on write-access for a
2076 * device special file, we ignore rofs.
2077 */
2078 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2079 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2080 if (exp_rdonly(rqstp, exp) ||
2081 __mnt_is_readonly(exp->ex_path.mnt))
2082 return nfserr_rofs;
2083 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2084 return nfserr_perm;
2085 }
2086 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2087 return nfserr_perm;
2088
2089 if (acc & NFSD_MAY_LOCK) {
2090 /* If we cannot rely on authentication in NLM requests,
2091 * just allow locks, otherwise require read permission, or
2092 * ownership
2093 */
2094 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2095 return 0;
2096 else
2097 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2098 }
2099 /*
2100 * The file owner always gets access permission for accesses that
2101 * would normally be checked at open time. This is to make
2102 * file access work even when the client has done a fchmod(fd, 0).
2103 *
2104 * However, `cp foo bar' should fail nevertheless when bar is
2105 * readonly. A sensible way to do this might be to reject all
2106 * attempts to truncate a read-only file, because a creat() call
2107 * always implies file truncation.
2108 * ... but this isn't really fair. A process may reasonably call
2109 * ftruncate on an open file descriptor on a file with perm 000.
2110 * We must trust the client to do permission checking - using "ACCESS"
2111 * with NFSv3.
2112 */
2113 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2114 inode->i_uid == current_fsuid())
2115 return 0;
2116
2117 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2118 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC));
2119
2120 /* Allow read access to binaries even when mode 111 */
2121 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2122 acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE))
2123 err = inode_permission(inode, MAY_EXEC);
2124 if (err)
2125 goto nfsd_out;
2126
2127 /* Do integrity (permission) checking now, but defer incrementing
2128 * IMA counts to the actual file open.
2129 */
2130 path.mnt = exp->ex_path.mnt;
2131 path.dentry = dentry;
2132 nfsd_out:
2133 return err? nfserrno(err) : 0;
2134 }
2135
2136 void
2137 nfsd_racache_shutdown(void)
2138 {
2139 struct raparms *raparm, *last_raparm;
2140 unsigned int i;
2141
2142 dprintk("nfsd: freeing readahead buffers.\n");
2143
2144 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2145 raparm = raparm_hash[i].pb_head;
2146 while(raparm) {
2147 last_raparm = raparm;
2148 raparm = raparm->p_next;
2149 kfree(last_raparm);
2150 }
2151 raparm_hash[i].pb_head = NULL;
2152 }
2153 }
2154 /*
2155 * Initialize readahead param cache
2156 */
2157 int
2158 nfsd_racache_init(int cache_size)
2159 {
2160 int i;
2161 int j = 0;
2162 int nperbucket;
2163 struct raparms **raparm = NULL;
2164
2165
2166 if (raparm_hash[0].pb_head)
2167 return 0;
2168 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
2169 if (nperbucket < 2)
2170 nperbucket = 2;
2171 cache_size = nperbucket * RAPARM_HASH_SIZE;
2172
2173 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
2174
2175 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2176 spin_lock_init(&raparm_hash[i].pb_lock);
2177
2178 raparm = &raparm_hash[i].pb_head;
2179 for (j = 0; j < nperbucket; j++) {
2180 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
2181 if (!*raparm)
2182 goto out_nomem;
2183 raparm = &(*raparm)->p_next;
2184 }
2185 *raparm = NULL;
2186 }
2187
2188 nfsdstats.ra_size = cache_size;
2189 return 0;
2190
2191 out_nomem:
2192 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
2193 nfsd_racache_shutdown();
2194 return -ENOMEM;
2195 }
2196
2197 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
2198 struct posix_acl *
2199 nfsd_get_posix_acl(struct svc_fh *fhp, int type)
2200 {
2201 struct inode *inode = fhp->fh_dentry->d_inode;
2202 char *name;
2203 void *value = NULL;
2204 ssize_t size;
2205 struct posix_acl *acl;
2206
2207 if (!IS_POSIXACL(inode))
2208 return ERR_PTR(-EOPNOTSUPP);
2209
2210 switch (type) {
2211 case ACL_TYPE_ACCESS:
2212 name = POSIX_ACL_XATTR_ACCESS;
2213 break;
2214 case ACL_TYPE_DEFAULT:
2215 name = POSIX_ACL_XATTR_DEFAULT;
2216 break;
2217 default:
2218 return ERR_PTR(-EOPNOTSUPP);
2219 }
2220
2221 size = nfsd_getxattr(fhp->fh_dentry, name, &value);
2222 if (size < 0)
2223 return ERR_PTR(size);
2224
2225 acl = posix_acl_from_xattr(value, size);
2226 kfree(value);
2227 return acl;
2228 }
2229
2230 int
2231 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl)
2232 {
2233 struct inode *inode = fhp->fh_dentry->d_inode;
2234 char *name;
2235 void *value = NULL;
2236 size_t size;
2237 int error;
2238
2239 if (!IS_POSIXACL(inode) ||
2240 !inode->i_op->setxattr || !inode->i_op->removexattr)
2241 return -EOPNOTSUPP;
2242 switch(type) {
2243 case ACL_TYPE_ACCESS:
2244 name = POSIX_ACL_XATTR_ACCESS;
2245 break;
2246 case ACL_TYPE_DEFAULT:
2247 name = POSIX_ACL_XATTR_DEFAULT;
2248 break;
2249 default:
2250 return -EOPNOTSUPP;
2251 }
2252
2253 if (acl && acl->a_count) {
2254 size = posix_acl_xattr_size(acl->a_count);
2255 value = kmalloc(size, GFP_KERNEL);
2256 if (!value)
2257 return -ENOMEM;
2258 error = posix_acl_to_xattr(acl, value, size);
2259 if (error < 0)
2260 goto getout;
2261 size = error;
2262 } else
2263 size = 0;
2264
2265 error = mnt_want_write(fhp->fh_export->ex_path.mnt);
2266 if (error)
2267 goto getout;
2268 if (size)
2269 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0);
2270 else {
2271 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT)
2272 error = 0;
2273 else {
2274 error = vfs_removexattr(fhp->fh_dentry, name);
2275 if (error == -ENODATA)
2276 error = 0;
2277 }
2278 }
2279 mnt_drop_write(fhp->fh_export->ex_path.mnt);
2280
2281 getout:
2282 kfree(value);
2283 return error;
2284 }
2285 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
kernel source for telekom puls (alcatel/mediatek)