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[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / nfsd / vfs.c
1 /*
2 * File operations used by nfsd. Some of these have been ripped from
3 * other parts of the kernel because they weren't exported, others
4 * are partial duplicates with added or changed functionality.
5 *
6 * Note that several functions dget() the dentry upon which they want
7 * to act, most notably those that create directory entries. Response
8 * dentry's are dput()'d if necessary in the release callback.
9 * So if you notice code paths that apparently fail to dput() the
10 * dentry, don't worry--they have been taken care of.
11 *
12 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
13 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
14 */
15
16 #include <linux/fs.h>
17 #include <linux/file.h>
18 #include <linux/splice.h>
19 #include <linux/fcntl.h>
20 #include <linux/namei.h>
21 #include <linux/delay.h>
22 #include <linux/fsnotify.h>
23 #include <linux/posix_acl_xattr.h>
24 #include <linux/xattr.h>
25 #include <linux/jhash.h>
26 #include <linux/ima.h>
27 #include <linux/slab.h>
28 #include <asm/uaccess.h>
29 #include <linux/exportfs.h>
30 #include <linux/writeback.h>
31
32 #ifdef CONFIG_NFSD_V3
33 #include "xdr3.h"
34 #endif /* CONFIG_NFSD_V3 */
35
36 #ifdef CONFIG_NFSD_V4
37 #include "acl.h"
38 #include "idmap.h"
39 #endif /* CONFIG_NFSD_V4 */
40
41 #include "nfsd.h"
42 #include "vfs.h"
43
44 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
45
46
47 /*
48 * This is a cache of readahead params that help us choose the proper
49 * readahead strategy. Initially, we set all readahead parameters to 0
50 * and let the VFS handle things.
51 * If you increase the number of cached files very much, you'll need to
52 * add a hash table here.
53 */
54 struct raparms {
55 struct raparms *p_next;
56 unsigned int p_count;
57 ino_t p_ino;
58 dev_t p_dev;
59 int p_set;
60 struct file_ra_state p_ra;
61 unsigned int p_hindex;
62 };
63
64 struct raparm_hbucket {
65 struct raparms *pb_head;
66 spinlock_t pb_lock;
67 } ____cacheline_aligned_in_smp;
68
69 #define RAPARM_HASH_BITS 4
70 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS)
71 #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1)
72 static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE];
73
74 /*
75 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
76 * a mount point.
77 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
78 * or nfs_ok having possibly changed *dpp and *expp
79 */
80 int
81 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
82 struct svc_export **expp)
83 {
84 struct svc_export *exp = *expp, *exp2 = NULL;
85 struct dentry *dentry = *dpp;
86 struct path path = {.mnt = mntget(exp->ex_path.mnt),
87 .dentry = dget(dentry)};
88 int err = 0;
89
90 err = follow_down(&path);
91 if (err < 0)
92 goto out;
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 int host_err;
185
186 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
187
188 dparent = fhp->fh_dentry;
189 exp = fhp->fh_export;
190 exp_get(exp);
191
192 /* Lookup the name, but don't follow links */
193 if (isdotent(name, len)) {
194 if (len==1)
195 dentry = dget(dparent);
196 else if (dparent != exp->ex_path.dentry)
197 dentry = dget_parent(dparent);
198 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
199 dentry = dget(dparent); /* .. == . just like at / */
200 else {
201 /* checking mountpoint crossing is very different when stepping up */
202 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
203 if (host_err)
204 goto out_nfserr;
205 }
206 } else {
207 fh_lock(fhp);
208 dentry = lookup_one_len(name, dparent, len);
209 host_err = PTR_ERR(dentry);
210 if (IS_ERR(dentry))
211 goto out_nfserr;
212 /*
213 * check if we have crossed a mount point ...
214 */
215 if (nfsd_mountpoint(dentry, exp)) {
216 if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
217 dput(dentry);
218 goto out_nfserr;
219 }
220 }
221 }
222 *dentry_ret = dentry;
223 *exp_ret = exp;
224 return 0;
225
226 out_nfserr:
227 exp_put(exp);
228 return nfserrno(host_err);
229 }
230
231 /*
232 * Look up one component of a pathname.
233 * N.B. After this call _both_ fhp and resfh need an fh_put
234 *
235 * If the lookup would cross a mountpoint, and the mounted filesystem
236 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
237 * accepted as it stands and the mounted directory is
238 * returned. Otherwise the covered directory is returned.
239 * NOTE: this mountpoint crossing is not supported properly by all
240 * clients and is explicitly disallowed for NFSv3
241 * NeilBrown <neilb@cse.unsw.edu.au>
242 */
243 __be32
244 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
245 unsigned int len, struct svc_fh *resfh)
246 {
247 struct svc_export *exp;
248 struct dentry *dentry;
249 __be32 err;
250
251 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
252 if (err)
253 return err;
254 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
255 if (err)
256 return err;
257 err = check_nfsd_access(exp, rqstp);
258 if (err)
259 goto out;
260 /*
261 * Note: we compose the file handle now, but as the
262 * dentry may be negative, it may need to be updated.
263 */
264 err = fh_compose(resfh, exp, dentry, fhp);
265 if (!err && !dentry->d_inode)
266 err = nfserr_noent;
267 out:
268 dput(dentry);
269 exp_put(exp);
270 return err;
271 }
272
273 static int nfsd_break_lease(struct inode *inode)
274 {
275 if (!S_ISREG(inode->i_mode))
276 return 0;
277 return break_lease(inode, O_WRONLY | O_NONBLOCK);
278 }
279
280 /*
281 * Commit metadata changes to stable storage.
282 */
283 static int
284 commit_metadata(struct svc_fh *fhp)
285 {
286 struct inode *inode = fhp->fh_dentry->d_inode;
287 const struct export_operations *export_ops = inode->i_sb->s_export_op;
288
289 if (!EX_ISSYNC(fhp->fh_export))
290 return 0;
291
292 if (export_ops->commit_metadata)
293 return export_ops->commit_metadata(inode);
294 return sync_inode_metadata(inode, 1);
295 }
296
297 /*
298 * Set various file attributes.
299 * N.B. After this call fhp needs an fh_put
300 */
301 __be32
302 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
303 int check_guard, time_t guardtime)
304 {
305 struct dentry *dentry;
306 struct inode *inode;
307 int accmode = NFSD_MAY_SATTR;
308 int ftype = 0;
309 __be32 err;
310 int host_err;
311 int size_change = 0;
312
313 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
314 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
315 if (iap->ia_valid & ATTR_SIZE)
316 ftype = S_IFREG;
317
318 /* Get inode */
319 err = fh_verify(rqstp, fhp, ftype, accmode);
320 if (err)
321 goto out;
322
323 dentry = fhp->fh_dentry;
324 inode = dentry->d_inode;
325
326 /* Ignore any mode updates on symlinks */
327 if (S_ISLNK(inode->i_mode))
328 iap->ia_valid &= ~ATTR_MODE;
329
330 if (!iap->ia_valid)
331 goto out;
332
333 /*
334 * NFSv2 does not differentiate between "set-[ac]time-to-now"
335 * which only requires access, and "set-[ac]time-to-X" which
336 * requires ownership.
337 * So if it looks like it might be "set both to the same time which
338 * is close to now", and if inode_change_ok fails, then we
339 * convert to "set to now" instead of "set to explicit time"
340 *
341 * We only call inode_change_ok as the last test as technically
342 * it is not an interface that we should be using. It is only
343 * valid if the filesystem does not define it's own i_op->setattr.
344 */
345 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
346 #define MAX_TOUCH_TIME_ERROR (30*60)
347 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET &&
348 iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) {
349 /*
350 * Looks probable.
351 *
352 * Now just make sure time is in the right ballpark.
353 * Solaris, at least, doesn't seem to care what the time
354 * request is. We require it be within 30 minutes of now.
355 */
356 time_t delta = iap->ia_atime.tv_sec - get_seconds();
357 if (delta < 0)
358 delta = -delta;
359 if (delta < MAX_TOUCH_TIME_ERROR &&
360 inode_change_ok(inode, iap) != 0) {
361 /*
362 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
363 * This will cause notify_change to set these times
364 * to "now"
365 */
366 iap->ia_valid &= ~BOTH_TIME_SET;
367 }
368 }
369
370 /*
371 * The size case is special.
372 * It changes the file as well as the attributes.
373 */
374 if (iap->ia_valid & ATTR_SIZE) {
375 if (iap->ia_size < inode->i_size) {
376 err = nfsd_permission(rqstp, fhp->fh_export, dentry,
377 NFSD_MAY_TRUNC|NFSD_MAY_OWNER_OVERRIDE);
378 if (err)
379 goto out;
380 }
381
382 host_err = get_write_access(inode);
383 if (host_err)
384 goto out_nfserr;
385
386 size_change = 1;
387 host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
388 if (host_err) {
389 put_write_access(inode);
390 goto out_nfserr;
391 }
392 }
393
394 /* sanitize the mode change */
395 if (iap->ia_valid & ATTR_MODE) {
396 iap->ia_mode &= S_IALLUGO;
397 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
398 }
399
400 /* Revoke setuid/setgid on chown */
401 if (!S_ISDIR(inode->i_mode) &&
402 (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) ||
403 ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid))) {
404 iap->ia_valid |= ATTR_KILL_PRIV;
405 if (iap->ia_valid & ATTR_MODE) {
406 /* we're setting mode too, just clear the s*id bits */
407 iap->ia_mode &= ~S_ISUID;
408 if (iap->ia_mode & S_IXGRP)
409 iap->ia_mode &= ~S_ISGID;
410 } else {
411 /* set ATTR_KILL_* bits and let VFS handle it */
412 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
413 }
414 }
415
416 /* Change the attributes. */
417
418 iap->ia_valid |= ATTR_CTIME;
419
420 err = nfserr_notsync;
421 if (!check_guard || guardtime == inode->i_ctime.tv_sec) {
422 host_err = nfsd_break_lease(inode);
423 if (host_err)
424 goto out_nfserr;
425 fh_lock(fhp);
426
427 host_err = notify_change(dentry, iap);
428 err = nfserrno(host_err);
429 fh_unlock(fhp);
430 }
431 if (size_change)
432 put_write_access(inode);
433 if (!err)
434 commit_metadata(fhp);
435 out:
436 return err;
437
438 out_nfserr:
439 err = nfserrno(host_err);
440 goto out;
441 }
442
443 #if defined(CONFIG_NFSD_V2_ACL) || \
444 defined(CONFIG_NFSD_V3_ACL) || \
445 defined(CONFIG_NFSD_V4)
446 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
447 {
448 ssize_t buflen;
449 ssize_t ret;
450
451 buflen = vfs_getxattr(dentry, key, NULL, 0);
452 if (buflen <= 0)
453 return buflen;
454
455 *buf = kmalloc(buflen, GFP_KERNEL);
456 if (!*buf)
457 return -ENOMEM;
458
459 ret = vfs_getxattr(dentry, key, *buf, buflen);
460 if (ret < 0)
461 kfree(*buf);
462 return ret;
463 }
464 #endif
465
466 #if defined(CONFIG_NFSD_V4)
467 static int
468 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key)
469 {
470 int len;
471 size_t buflen;
472 char *buf = NULL;
473 int error = 0;
474
475 buflen = posix_acl_xattr_size(pacl->a_count);
476 buf = kmalloc(buflen, GFP_KERNEL);
477 error = -ENOMEM;
478 if (buf == NULL)
479 goto out;
480
481 len = posix_acl_to_xattr(pacl, buf, buflen);
482 if (len < 0) {
483 error = len;
484 goto out;
485 }
486
487 error = vfs_setxattr(dentry, key, buf, len, 0);
488 out:
489 kfree(buf);
490 return error;
491 }
492
493 __be32
494 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
495 struct nfs4_acl *acl)
496 {
497 __be32 error;
498 int host_error;
499 struct dentry *dentry;
500 struct inode *inode;
501 struct posix_acl *pacl = NULL, *dpacl = NULL;
502 unsigned int flags = 0;
503
504 /* Get inode */
505 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
506 if (error)
507 return error;
508
509 dentry = fhp->fh_dentry;
510 inode = dentry->d_inode;
511 if (S_ISDIR(inode->i_mode))
512 flags = NFS4_ACL_DIR;
513
514 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
515 if (host_error == -EINVAL) {
516 return nfserr_attrnotsupp;
517 } else if (host_error < 0)
518 goto out_nfserr;
519
520 host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS);
521 if (host_error < 0)
522 goto out_release;
523
524 if (S_ISDIR(inode->i_mode))
525 host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT);
526
527 out_release:
528 posix_acl_release(pacl);
529 posix_acl_release(dpacl);
530 out_nfserr:
531 if (host_error == -EOPNOTSUPP)
532 return nfserr_attrnotsupp;
533 else
534 return nfserrno(host_error);
535 }
536
537 static struct posix_acl *
538 _get_posix_acl(struct dentry *dentry, char *key)
539 {
540 void *buf = NULL;
541 struct posix_acl *pacl = NULL;
542 int buflen;
543
544 buflen = nfsd_getxattr(dentry, key, &buf);
545 if (!buflen)
546 buflen = -ENODATA;
547 if (buflen <= 0)
548 return ERR_PTR(buflen);
549
550 pacl = posix_acl_from_xattr(buf, buflen);
551 kfree(buf);
552 return pacl;
553 }
554
555 int
556 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl)
557 {
558 struct inode *inode = dentry->d_inode;
559 int error = 0;
560 struct posix_acl *pacl = NULL, *dpacl = NULL;
561 unsigned int flags = 0;
562
563 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS);
564 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA)
565 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
566 if (IS_ERR(pacl)) {
567 error = PTR_ERR(pacl);
568 pacl = NULL;
569 goto out;
570 }
571
572 if (S_ISDIR(inode->i_mode)) {
573 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT);
574 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA)
575 dpacl = NULL;
576 else if (IS_ERR(dpacl)) {
577 error = PTR_ERR(dpacl);
578 dpacl = NULL;
579 goto out;
580 }
581 flags = NFS4_ACL_DIR;
582 }
583
584 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags);
585 if (IS_ERR(*acl)) {
586 error = PTR_ERR(*acl);
587 *acl = NULL;
588 }
589 out:
590 posix_acl_release(pacl);
591 posix_acl_release(dpacl);
592 return error;
593 }
594
595 #endif /* defined(CONFIG_NFSD_V4) */
596
597 #ifdef CONFIG_NFSD_V3
598 /*
599 * Check server access rights to a file system object
600 */
601 struct accessmap {
602 u32 access;
603 int how;
604 };
605 static struct accessmap nfs3_regaccess[] = {
606 { NFS3_ACCESS_READ, NFSD_MAY_READ },
607 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
608 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
609 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
610
611 { 0, 0 }
612 };
613
614 static struct accessmap nfs3_diraccess[] = {
615 { NFS3_ACCESS_READ, NFSD_MAY_READ },
616 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
617 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
618 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
619 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
620
621 { 0, 0 }
622 };
623
624 static struct accessmap nfs3_anyaccess[] = {
625 /* Some clients - Solaris 2.6 at least, make an access call
626 * to the server to check for access for things like /dev/null
627 * (which really, the server doesn't care about). So
628 * We provide simple access checking for them, looking
629 * mainly at mode bits, and we make sure to ignore read-only
630 * filesystem checks
631 */
632 { NFS3_ACCESS_READ, NFSD_MAY_READ },
633 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
634 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
635 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
636
637 { 0, 0 }
638 };
639
640 __be32
641 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
642 {
643 struct accessmap *map;
644 struct svc_export *export;
645 struct dentry *dentry;
646 u32 query, result = 0, sresult = 0;
647 __be32 error;
648
649 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
650 if (error)
651 goto out;
652
653 export = fhp->fh_export;
654 dentry = fhp->fh_dentry;
655
656 if (S_ISREG(dentry->d_inode->i_mode))
657 map = nfs3_regaccess;
658 else if (S_ISDIR(dentry->d_inode->i_mode))
659 map = nfs3_diraccess;
660 else
661 map = nfs3_anyaccess;
662
663
664 query = *access;
665 for (; map->access; map++) {
666 if (map->access & query) {
667 __be32 err2;
668
669 sresult |= map->access;
670
671 err2 = nfsd_permission(rqstp, export, dentry, map->how);
672 switch (err2) {
673 case nfs_ok:
674 result |= map->access;
675 break;
676
677 /* the following error codes just mean the access was not allowed,
678 * rather than an error occurred */
679 case nfserr_rofs:
680 case nfserr_acces:
681 case nfserr_perm:
682 /* simply don't "or" in the access bit. */
683 break;
684 default:
685 error = err2;
686 goto out;
687 }
688 }
689 }
690 *access = result;
691 if (supported)
692 *supported = sresult;
693
694 out:
695 return error;
696 }
697 #endif /* CONFIG_NFSD_V3 */
698
699
700
701 /*
702 * Open an existing file or directory.
703 * The access argument indicates the type of open (read/write/lock)
704 * N.B. After this call fhp needs an fh_put
705 */
706 __be32
707 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
708 int access, struct file **filp)
709 {
710 struct dentry *dentry;
711 struct inode *inode;
712 int flags = O_RDONLY|O_LARGEFILE;
713 __be32 err;
714 int host_err = 0;
715
716 validate_process_creds();
717
718 /*
719 * If we get here, then the client has already done an "open",
720 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
721 * in case a chmod has now revoked permission.
722 */
723 err = fh_verify(rqstp, fhp, type, access | NFSD_MAY_OWNER_OVERRIDE);
724 if (err)
725 goto out;
726
727 dentry = fhp->fh_dentry;
728 inode = dentry->d_inode;
729
730 /* Disallow write access to files with the append-only bit set
731 * or any access when mandatory locking enabled
732 */
733 err = nfserr_perm;
734 if (IS_APPEND(inode) && (access & NFSD_MAY_WRITE))
735 goto out;
736 /*
737 * We must ignore files (but only files) which might have mandatory
738 * locks on them because there is no way to know if the accesser has
739 * the lock.
740 */
741 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
742 goto out;
743
744 if (!inode->i_fop)
745 goto out;
746
747 /*
748 * Check to see if there are any leases on this file.
749 * This may block while leases are broken.
750 */
751 if (!(access & NFSD_MAY_NOT_BREAK_LEASE))
752 host_err = break_lease(inode, O_NONBLOCK | ((access & NFSD_MAY_WRITE) ? O_WRONLY : 0));
753 if (host_err) /* NOMEM or WOULDBLOCK */
754 goto out_nfserr;
755
756 if (access & NFSD_MAY_WRITE) {
757 if (access & NFSD_MAY_READ)
758 flags = O_RDWR|O_LARGEFILE;
759 else
760 flags = O_WRONLY|O_LARGEFILE;
761 }
762 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt),
763 flags, current_cred());
764 if (IS_ERR(*filp))
765 host_err = PTR_ERR(*filp);
766 else
767 host_err = ima_file_check(*filp, access);
768 out_nfserr:
769 err = nfserrno(host_err);
770 out:
771 validate_process_creds();
772 return err;
773 }
774
775 /*
776 * Close a file.
777 */
778 void
779 nfsd_close(struct file *filp)
780 {
781 fput(filp);
782 }
783
784 /*
785 * Obtain the readahead parameters for the file
786 * specified by (dev, ino).
787 */
788
789 static inline struct raparms *
790 nfsd_get_raparms(dev_t dev, ino_t ino)
791 {
792 struct raparms *ra, **rap, **frap = NULL;
793 int depth = 0;
794 unsigned int hash;
795 struct raparm_hbucket *rab;
796
797 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
798 rab = &raparm_hash[hash];
799
800 spin_lock(&rab->pb_lock);
801 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
802 if (ra->p_ino == ino && ra->p_dev == dev)
803 goto found;
804 depth++;
805 if (ra->p_count == 0)
806 frap = rap;
807 }
808 depth = nfsdstats.ra_size;
809 if (!frap) {
810 spin_unlock(&rab->pb_lock);
811 return NULL;
812 }
813 rap = frap;
814 ra = *frap;
815 ra->p_dev = dev;
816 ra->p_ino = ino;
817 ra->p_set = 0;
818 ra->p_hindex = hash;
819 found:
820 if (rap != &rab->pb_head) {
821 *rap = ra->p_next;
822 ra->p_next = rab->pb_head;
823 rab->pb_head = ra;
824 }
825 ra->p_count++;
826 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
827 spin_unlock(&rab->pb_lock);
828 return ra;
829 }
830
831 /*
832 * Grab and keep cached pages associated with a file in the svc_rqst
833 * so that they can be passed to the network sendmsg/sendpage routines
834 * directly. They will be released after the sending has completed.
835 */
836 static int
837 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
838 struct splice_desc *sd)
839 {
840 struct svc_rqst *rqstp = sd->u.data;
841 struct page **pp = rqstp->rq_respages + rqstp->rq_resused;
842 struct page *page = buf->page;
843 size_t size;
844
845 size = sd->len;
846
847 if (rqstp->rq_res.page_len == 0) {
848 get_page(page);
849 put_page(*pp);
850 *pp = page;
851 rqstp->rq_resused++;
852 rqstp->rq_res.page_base = buf->offset;
853 rqstp->rq_res.page_len = size;
854 } else if (page != pp[-1]) {
855 get_page(page);
856 if (*pp)
857 put_page(*pp);
858 *pp = page;
859 rqstp->rq_resused++;
860 rqstp->rq_res.page_len += size;
861 } else
862 rqstp->rq_res.page_len += size;
863
864 return size;
865 }
866
867 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
868 struct splice_desc *sd)
869 {
870 return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
871 }
872
873 static __be32
874 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
875 loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
876 {
877 mm_segment_t oldfs;
878 __be32 err;
879 int host_err;
880
881 err = nfserr_perm;
882
883 if (file->f_op->splice_read && rqstp->rq_splice_ok) {
884 struct splice_desc sd = {
885 .len = 0,
886 .total_len = *count,
887 .pos = offset,
888 .u.data = rqstp,
889 };
890
891 rqstp->rq_resused = 1;
892 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
893 } else {
894 oldfs = get_fs();
895 set_fs(KERNEL_DS);
896 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
897 set_fs(oldfs);
898 }
899
900 if (host_err >= 0) {
901 nfsdstats.io_read += host_err;
902 *count = host_err;
903 err = 0;
904 fsnotify_access(file);
905 } else
906 err = nfserrno(host_err);
907 return err;
908 }
909
910 static void kill_suid(struct dentry *dentry)
911 {
912 struct iattr ia;
913 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
914
915 mutex_lock(&dentry->d_inode->i_mutex);
916 notify_change(dentry, &ia);
917 mutex_unlock(&dentry->d_inode->i_mutex);
918 }
919
920 /*
921 * Gathered writes: If another process is currently writing to the file,
922 * there's a high chance this is another nfsd (triggered by a bulk write
923 * from a client's biod). Rather than syncing the file with each write
924 * request, we sleep for 10 msec.
925 *
926 * I don't know if this roughly approximates C. Juszak's idea of
927 * gathered writes, but it's a nice and simple solution (IMHO), and it
928 * seems to work:-)
929 *
930 * Note: we do this only in the NFSv2 case, since v3 and higher have a
931 * better tool (separate unstable writes and commits) for solving this
932 * problem.
933 */
934 static int wait_for_concurrent_writes(struct file *file)
935 {
936 struct inode *inode = file->f_path.dentry->d_inode;
937 static ino_t last_ino;
938 static dev_t last_dev;
939 int err = 0;
940
941 if (atomic_read(&inode->i_writecount) > 1
942 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
943 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
944 msleep(10);
945 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
946 }
947
948 if (inode->i_state & I_DIRTY) {
949 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
950 err = vfs_fsync(file, 0);
951 }
952 last_ino = inode->i_ino;
953 last_dev = inode->i_sb->s_dev;
954 return err;
955 }
956
957 static __be32
958 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
959 loff_t offset, struct kvec *vec, int vlen,
960 unsigned long *cnt, int *stablep)
961 {
962 struct svc_export *exp;
963 struct dentry *dentry;
964 struct inode *inode;
965 mm_segment_t oldfs;
966 __be32 err = 0;
967 int host_err;
968 int stable = *stablep;
969 int use_wgather;
970
971 dentry = file->f_path.dentry;
972 inode = dentry->d_inode;
973 exp = fhp->fh_export;
974
975 /*
976 * Request sync writes if
977 * - the sync export option has been set, or
978 * - the client requested O_SYNC behavior (NFSv3 feature).
979 * - The file system doesn't support fsync().
980 * When NFSv2 gathered writes have been configured for this volume,
981 * flushing the data to disk is handled separately below.
982 */
983 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
984
985 if (!file->f_op->fsync) {/* COMMIT3 cannot work */
986 stable = 2;
987 *stablep = 2; /* FILE_SYNC */
988 }
989
990 if (!EX_ISSYNC(exp))
991 stable = 0;
992 if (stable && !use_wgather) {
993 spin_lock(&file->f_lock);
994 file->f_flags |= O_SYNC;
995 spin_unlock(&file->f_lock);
996 }
997
998 /* Write the data. */
999 oldfs = get_fs(); set_fs(KERNEL_DS);
1000 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
1001 set_fs(oldfs);
1002 if (host_err < 0)
1003 goto out_nfserr;
1004 *cnt = host_err;
1005 nfsdstats.io_write += host_err;
1006 fsnotify_modify(file);
1007
1008 /* clear setuid/setgid flag after write */
1009 if (inode->i_mode & (S_ISUID | S_ISGID))
1010 kill_suid(dentry);
1011
1012 if (stable && use_wgather)
1013 host_err = wait_for_concurrent_writes(file);
1014
1015 out_nfserr:
1016 dprintk("nfsd: write complete host_err=%d\n", host_err);
1017 if (host_err >= 0)
1018 err = 0;
1019 else
1020 err = nfserrno(host_err);
1021 return err;
1022 }
1023
1024 /*
1025 * Read data from a file. count must contain the requested read count
1026 * on entry. On return, *count contains the number of bytes actually read.
1027 * N.B. After this call fhp needs an fh_put
1028 */
1029 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1030 loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
1031 {
1032 struct file *file;
1033 struct inode *inode;
1034 struct raparms *ra;
1035 __be32 err;
1036
1037 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
1038 if (err)
1039 return err;
1040
1041 inode = file->f_path.dentry->d_inode;
1042
1043 /* Get readahead parameters */
1044 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);
1045
1046 if (ra && ra->p_set)
1047 file->f_ra = ra->p_ra;
1048
1049 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
1050
1051 /* Write back readahead params */
1052 if (ra) {
1053 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
1054 spin_lock(&rab->pb_lock);
1055 ra->p_ra = file->f_ra;
1056 ra->p_set = 1;
1057 ra->p_count--;
1058 spin_unlock(&rab->pb_lock);
1059 }
1060
1061 nfsd_close(file);
1062 return err;
1063 }
1064
1065 /* As above, but use the provided file descriptor. */
1066 __be32
1067 nfsd_read_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1068 loff_t offset, struct kvec *vec, int vlen,
1069 unsigned long *count)
1070 {
1071 __be32 err;
1072
1073 if (file) {
1074 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1075 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE);
1076 if (err)
1077 goto out;
1078 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
1079 } else /* Note file may still be NULL in NFSv4 special stateid case: */
1080 err = nfsd_read(rqstp, fhp, offset, vec, vlen, count);
1081 out:
1082 return err;
1083 }
1084
1085 /*
1086 * Write data to a file.
1087 * The stable flag requests synchronous writes.
1088 * N.B. After this call fhp needs an fh_put
1089 */
1090 __be32
1091 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1092 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt,
1093 int *stablep)
1094 {
1095 __be32 err = 0;
1096
1097 if (file) {
1098 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1099 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE);
1100 if (err)
1101 goto out;
1102 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt,
1103 stablep);
1104 } else {
1105 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
1106 if (err)
1107 goto out;
1108
1109 if (cnt)
1110 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen,
1111 cnt, stablep);
1112 nfsd_close(file);
1113 }
1114 out:
1115 return err;
1116 }
1117
1118 #ifdef CONFIG_NFSD_V3
1119 /*
1120 * Commit all pending writes to stable storage.
1121 *
1122 * Note: we only guarantee that data that lies within the range specified
1123 * by the 'offset' and 'count' parameters will be synced.
1124 *
1125 * Unfortunately we cannot lock the file to make sure we return full WCC
1126 * data to the client, as locking happens lower down in the filesystem.
1127 */
1128 __be32
1129 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1130 loff_t offset, unsigned long count)
1131 {
1132 struct file *file;
1133 loff_t end = LLONG_MAX;
1134 __be32 err = nfserr_inval;
1135
1136 if (offset < 0)
1137 goto out;
1138 if (count != 0) {
1139 end = offset + (loff_t)count - 1;
1140 if (end < offset)
1141 goto out;
1142 }
1143
1144 err = nfsd_open(rqstp, fhp, S_IFREG,
1145 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file);
1146 if (err)
1147 goto out;
1148 if (EX_ISSYNC(fhp->fh_export)) {
1149 int err2 = vfs_fsync_range(file, offset, end, 0);
1150
1151 if (err2 != -EINVAL)
1152 err = nfserrno(err2);
1153 else
1154 err = nfserr_notsupp;
1155 }
1156
1157 nfsd_close(file);
1158 out:
1159 return err;
1160 }
1161 #endif /* CONFIG_NFSD_V3 */
1162
1163 static __be32
1164 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1165 struct iattr *iap)
1166 {
1167 /*
1168 * Mode has already been set earlier in create:
1169 */
1170 iap->ia_valid &= ~ATTR_MODE;
1171 /*
1172 * Setting uid/gid works only for root. Irix appears to
1173 * send along the gid on create when it tries to implement
1174 * setgid directories via NFS:
1175 */
1176 if (current_fsuid() != 0)
1177 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1178 if (iap->ia_valid)
1179 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1180 return 0;
1181 }
1182
1183 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1184 * setting size to 0 may fail for some specific file systems by the permission
1185 * checking which requires WRITE permission but the mode is 000.
1186 * we ignore the resizing(to 0) on the just new created file, since the size is
1187 * 0 after file created.
1188 *
1189 * call this only after vfs_create() is called.
1190 * */
1191 static void
1192 nfsd_check_ignore_resizing(struct iattr *iap)
1193 {
1194 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1195 iap->ia_valid &= ~ATTR_SIZE;
1196 }
1197
1198 /*
1199 * Create a file (regular, directory, device, fifo); UNIX sockets
1200 * not yet implemented.
1201 * If the response fh has been verified, the parent directory should
1202 * already be locked. Note that the parent directory is left locked.
1203 *
1204 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1205 */
1206 __be32
1207 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1208 char *fname, int flen, struct iattr *iap,
1209 int type, dev_t rdev, struct svc_fh *resfhp)
1210 {
1211 struct dentry *dentry, *dchild = NULL;
1212 struct inode *dirp;
1213 __be32 err;
1214 __be32 err2;
1215 int host_err;
1216
1217 err = nfserr_perm;
1218 if (!flen)
1219 goto out;
1220 err = nfserr_exist;
1221 if (isdotent(fname, flen))
1222 goto out;
1223
1224 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1225 if (err)
1226 goto out;
1227
1228 dentry = fhp->fh_dentry;
1229 dirp = dentry->d_inode;
1230
1231 err = nfserr_notdir;
1232 if (!dirp->i_op->lookup)
1233 goto out;
1234 /*
1235 * Check whether the response file handle has been verified yet.
1236 * If it has, the parent directory should already be locked.
1237 */
1238 if (!resfhp->fh_dentry) {
1239 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
1240 fh_lock_nested(fhp, I_MUTEX_PARENT);
1241 dchild = lookup_one_len(fname, dentry, flen);
1242 host_err = PTR_ERR(dchild);
1243 if (IS_ERR(dchild))
1244 goto out_nfserr;
1245 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1246 if (err)
1247 goto out;
1248 } else {
1249 /* called from nfsd_proc_create */
1250 dchild = dget(resfhp->fh_dentry);
1251 if (!fhp->fh_locked) {
1252 /* not actually possible */
1253 printk(KERN_ERR
1254 "nfsd_create: parent %s/%s not locked!\n",
1255 dentry->d_parent->d_name.name,
1256 dentry->d_name.name);
1257 err = nfserr_io;
1258 goto out;
1259 }
1260 }
1261 /*
1262 * Make sure the child dentry is still negative ...
1263 */
1264 err = nfserr_exist;
1265 if (dchild->d_inode) {
1266 dprintk("nfsd_create: dentry %s/%s not negative!\n",
1267 dentry->d_name.name, dchild->d_name.name);
1268 goto out;
1269 }
1270
1271 if (!(iap->ia_valid & ATTR_MODE))
1272 iap->ia_mode = 0;
1273 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1274
1275 err = nfserr_inval;
1276 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) {
1277 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1278 type);
1279 goto out;
1280 }
1281
1282 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1283 if (host_err)
1284 goto out_nfserr;
1285
1286 /*
1287 * Get the dir op function pointer.
1288 */
1289 err = 0;
1290 switch (type) {
1291 case S_IFREG:
1292 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1293 if (!host_err)
1294 nfsd_check_ignore_resizing(iap);
1295 break;
1296 case S_IFDIR:
1297 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
1298 break;
1299 case S_IFCHR:
1300 case S_IFBLK:
1301 case S_IFIFO:
1302 case S_IFSOCK:
1303 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
1304 break;
1305 }
1306 if (host_err < 0) {
1307 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1308 goto out_nfserr;
1309 }
1310
1311 err = nfsd_create_setattr(rqstp, resfhp, iap);
1312
1313 /*
1314 * nfsd_setattr already committed the child. Transactional filesystems
1315 * had a chance to commit changes for both parent and child
1316 * simultaneously making the following commit_metadata a noop.
1317 */
1318 err2 = nfserrno(commit_metadata(fhp));
1319 if (err2)
1320 err = err2;
1321 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1322 /*
1323 * Update the file handle to get the new inode info.
1324 */
1325 if (!err)
1326 err = fh_update(resfhp);
1327 out:
1328 if (dchild && !IS_ERR(dchild))
1329 dput(dchild);
1330 return err;
1331
1332 out_nfserr:
1333 err = nfserrno(host_err);
1334 goto out;
1335 }
1336
1337 #ifdef CONFIG_NFSD_V3
1338
1339 static inline int nfsd_create_is_exclusive(int createmode)
1340 {
1341 return createmode == NFS3_CREATE_EXCLUSIVE
1342 || createmode == NFS4_CREATE_EXCLUSIVE4_1;
1343 }
1344
1345 /*
1346 * NFSv3 and NFSv4 version of nfsd_create
1347 */
1348 __be32
1349 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1350 char *fname, int flen, struct iattr *iap,
1351 struct svc_fh *resfhp, int createmode, u32 *verifier,
1352 int *truncp, int *created)
1353 {
1354 struct dentry *dentry, *dchild = NULL;
1355 struct inode *dirp;
1356 __be32 err;
1357 int host_err;
1358 __u32 v_mtime=0, v_atime=0;
1359
1360 err = nfserr_perm;
1361 if (!flen)
1362 goto out;
1363 err = nfserr_exist;
1364 if (isdotent(fname, flen))
1365 goto out;
1366 if (!(iap->ia_valid & ATTR_MODE))
1367 iap->ia_mode = 0;
1368 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
1369 if (err)
1370 goto out;
1371
1372 dentry = fhp->fh_dentry;
1373 dirp = dentry->d_inode;
1374
1375 /* Get all the sanity checks out of the way before
1376 * we lock the parent. */
1377 err = nfserr_notdir;
1378 if (!dirp->i_op->lookup)
1379 goto out;
1380 fh_lock_nested(fhp, I_MUTEX_PARENT);
1381
1382 /*
1383 * Compose the response file handle.
1384 */
1385 dchild = lookup_one_len(fname, dentry, flen);
1386 host_err = PTR_ERR(dchild);
1387 if (IS_ERR(dchild))
1388 goto out_nfserr;
1389
1390 /* If file doesn't exist, check for permissions to create one */
1391 if (!dchild->d_inode) {
1392 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1393 if (err)
1394 goto out;
1395 }
1396
1397 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1398 if (err)
1399 goto out;
1400
1401 if (nfsd_create_is_exclusive(createmode)) {
1402 /* solaris7 gets confused (bugid 4218508) if these have
1403 * the high bit set, so just clear the high bits. If this is
1404 * ever changed to use different attrs for storing the
1405 * verifier, then do_open_lookup() will also need to be fixed
1406 * accordingly.
1407 */
1408 v_mtime = verifier[0]&0x7fffffff;
1409 v_atime = verifier[1]&0x7fffffff;
1410 }
1411
1412 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1413 if (host_err)
1414 goto out_nfserr;
1415 if (dchild->d_inode) {
1416 err = 0;
1417
1418 switch (createmode) {
1419 case NFS3_CREATE_UNCHECKED:
1420 if (! S_ISREG(dchild->d_inode->i_mode))
1421 err = nfserr_exist;
1422 else if (truncp) {
1423 /* in nfsv4, we need to treat this case a little
1424 * differently. we don't want to truncate the
1425 * file now; this would be wrong if the OPEN
1426 * fails for some other reason. furthermore,
1427 * if the size is nonzero, we should ignore it
1428 * according to spec!
1429 */
1430 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1431 }
1432 else {
1433 iap->ia_valid &= ATTR_SIZE;
1434 goto set_attr;
1435 }
1436 break;
1437 case NFS3_CREATE_EXCLUSIVE:
1438 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1439 && dchild->d_inode->i_atime.tv_sec == v_atime
1440 && dchild->d_inode->i_size == 0 )
1441 break;
1442 case NFS4_CREATE_EXCLUSIVE4_1:
1443 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1444 && dchild->d_inode->i_atime.tv_sec == v_atime
1445 && dchild->d_inode->i_size == 0 )
1446 goto set_attr;
1447 /* fallthru */
1448 case NFS3_CREATE_GUARDED:
1449 err = nfserr_exist;
1450 }
1451 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1452 goto out;
1453 }
1454
1455 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1456 if (host_err < 0) {
1457 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1458 goto out_nfserr;
1459 }
1460 if (created)
1461 *created = 1;
1462
1463 nfsd_check_ignore_resizing(iap);
1464
1465 if (nfsd_create_is_exclusive(createmode)) {
1466 /* Cram the verifier into atime/mtime */
1467 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1468 | ATTR_MTIME_SET|ATTR_ATIME_SET;
1469 /* XXX someone who knows this better please fix it for nsec */
1470 iap->ia_mtime.tv_sec = v_mtime;
1471 iap->ia_atime.tv_sec = v_atime;
1472 iap->ia_mtime.tv_nsec = 0;
1473 iap->ia_atime.tv_nsec = 0;
1474 }
1475
1476 set_attr:
1477 err = nfsd_create_setattr(rqstp, resfhp, iap);
1478
1479 /*
1480 * nfsd_setattr already committed the child (and possibly also the parent).
1481 */
1482 if (!err)
1483 err = nfserrno(commit_metadata(fhp));
1484
1485 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1486 /*
1487 * Update the filehandle to get the new inode info.
1488 */
1489 if (!err)
1490 err = fh_update(resfhp);
1491
1492 out:
1493 fh_unlock(fhp);
1494 if (dchild && !IS_ERR(dchild))
1495 dput(dchild);
1496 return err;
1497
1498 out_nfserr:
1499 err = nfserrno(host_err);
1500 goto out;
1501 }
1502 #endif /* CONFIG_NFSD_V3 */
1503
1504 /*
1505 * Read a symlink. On entry, *lenp must contain the maximum path length that
1506 * fits into the buffer. On return, it contains the true length.
1507 * N.B. After this call fhp needs an fh_put
1508 */
1509 __be32
1510 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1511 {
1512 struct dentry *dentry;
1513 struct inode *inode;
1514 mm_segment_t oldfs;
1515 __be32 err;
1516 int host_err;
1517
1518 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1519 if (err)
1520 goto out;
1521
1522 dentry = fhp->fh_dentry;
1523 inode = dentry->d_inode;
1524
1525 err = nfserr_inval;
1526 if (!inode->i_op->readlink)
1527 goto out;
1528
1529 touch_atime(fhp->fh_export->ex_path.mnt, dentry);
1530 /* N.B. Why does this call need a get_fs()??
1531 * Remove the set_fs and watch the fireworks:-) --okir
1532 */
1533
1534 oldfs = get_fs(); set_fs(KERNEL_DS);
1535 host_err = inode->i_op->readlink(dentry, buf, *lenp);
1536 set_fs(oldfs);
1537
1538 if (host_err < 0)
1539 goto out_nfserr;
1540 *lenp = host_err;
1541 err = 0;
1542 out:
1543 return err;
1544
1545 out_nfserr:
1546 err = nfserrno(host_err);
1547 goto out;
1548 }
1549
1550 /*
1551 * Create a symlink and look up its inode
1552 * N.B. After this call _both_ fhp and resfhp need an fh_put
1553 */
1554 __be32
1555 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1556 char *fname, int flen,
1557 char *path, int plen,
1558 struct svc_fh *resfhp,
1559 struct iattr *iap)
1560 {
1561 struct dentry *dentry, *dnew;
1562 __be32 err, cerr;
1563 int host_err;
1564
1565 err = nfserr_noent;
1566 if (!flen || !plen)
1567 goto out;
1568 err = nfserr_exist;
1569 if (isdotent(fname, flen))
1570 goto out;
1571
1572 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1573 if (err)
1574 goto out;
1575 fh_lock(fhp);
1576 dentry = fhp->fh_dentry;
1577 dnew = lookup_one_len(fname, dentry, flen);
1578 host_err = PTR_ERR(dnew);
1579 if (IS_ERR(dnew))
1580 goto out_nfserr;
1581
1582 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1583 if (host_err)
1584 goto out_nfserr;
1585
1586 if (unlikely(path[plen] != 0)) {
1587 char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
1588 if (path_alloced == NULL)
1589 host_err = -ENOMEM;
1590 else {
1591 strncpy(path_alloced, path, plen);
1592 path_alloced[plen] = 0;
1593 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced);
1594 kfree(path_alloced);
1595 }
1596 } else
1597 host_err = vfs_symlink(dentry->d_inode, dnew, path);
1598 err = nfserrno(host_err);
1599 if (!err)
1600 err = nfserrno(commit_metadata(fhp));
1601 fh_unlock(fhp);
1602
1603 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1604
1605 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1606 dput(dnew);
1607 if (err==0) err = cerr;
1608 out:
1609 return err;
1610
1611 out_nfserr:
1612 err = nfserrno(host_err);
1613 goto out;
1614 }
1615
1616 /*
1617 * Create a hardlink
1618 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1619 */
1620 __be32
1621 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1622 char *name, int len, struct svc_fh *tfhp)
1623 {
1624 struct dentry *ddir, *dnew, *dold;
1625 struct inode *dirp;
1626 __be32 err;
1627 int host_err;
1628
1629 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1630 if (err)
1631 goto out;
1632 err = fh_verify(rqstp, tfhp, -S_IFDIR, NFSD_MAY_NOP);
1633 if (err)
1634 goto out;
1635
1636 err = nfserr_perm;
1637 if (!len)
1638 goto out;
1639 err = nfserr_exist;
1640 if (isdotent(name, len))
1641 goto out;
1642
1643 fh_lock_nested(ffhp, I_MUTEX_PARENT);
1644 ddir = ffhp->fh_dentry;
1645 dirp = ddir->d_inode;
1646
1647 dnew = lookup_one_len(name, ddir, len);
1648 host_err = PTR_ERR(dnew);
1649 if (IS_ERR(dnew))
1650 goto out_nfserr;
1651
1652 dold = tfhp->fh_dentry;
1653
1654 host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt);
1655 if (host_err) {
1656 err = nfserrno(host_err);
1657 goto out_dput;
1658 }
1659 err = nfserr_noent;
1660 if (!dold->d_inode)
1661 goto out_drop_write;
1662 host_err = nfsd_break_lease(dold->d_inode);
1663 if (host_err)
1664 goto out_drop_write;
1665 host_err = vfs_link(dold, dirp, dnew);
1666 if (!host_err) {
1667 err = nfserrno(commit_metadata(ffhp));
1668 if (!err)
1669 err = nfserrno(commit_metadata(tfhp));
1670 } else {
1671 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1672 err = nfserr_acces;
1673 else
1674 err = nfserrno(host_err);
1675 }
1676 out_drop_write:
1677 mnt_drop_write(tfhp->fh_export->ex_path.mnt);
1678 out_dput:
1679 dput(dnew);
1680 out_unlock:
1681 fh_unlock(ffhp);
1682 out:
1683 return err;
1684
1685 out_nfserr:
1686 err = nfserrno(host_err);
1687 goto out_unlock;
1688 }
1689
1690 /*
1691 * Rename a file
1692 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1693 */
1694 __be32
1695 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1696 struct svc_fh *tfhp, char *tname, int tlen)
1697 {
1698 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1699 struct inode *fdir, *tdir;
1700 __be32 err;
1701 int host_err;
1702
1703 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1704 if (err)
1705 goto out;
1706 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1707 if (err)
1708 goto out;
1709
1710 fdentry = ffhp->fh_dentry;
1711 fdir = fdentry->d_inode;
1712
1713 tdentry = tfhp->fh_dentry;
1714 tdir = tdentry->d_inode;
1715
1716 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
1717 if (ffhp->fh_export != tfhp->fh_export)
1718 goto out;
1719
1720 err = nfserr_perm;
1721 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1722 goto out;
1723
1724 /* cannot use fh_lock as we need deadlock protective ordering
1725 * so do it by hand */
1726 trap = lock_rename(tdentry, fdentry);
1727 ffhp->fh_locked = tfhp->fh_locked = 1;
1728 fill_pre_wcc(ffhp);
1729 fill_pre_wcc(tfhp);
1730
1731 odentry = lookup_one_len(fname, fdentry, flen);
1732 host_err = PTR_ERR(odentry);
1733 if (IS_ERR(odentry))
1734 goto out_nfserr;
1735
1736 host_err = -ENOENT;
1737 if (!odentry->d_inode)
1738 goto out_dput_old;
1739 host_err = -EINVAL;
1740 if (odentry == trap)
1741 goto out_dput_old;
1742
1743 ndentry = lookup_one_len(tname, tdentry, tlen);
1744 host_err = PTR_ERR(ndentry);
1745 if (IS_ERR(ndentry))
1746 goto out_dput_old;
1747 host_err = -ENOTEMPTY;
1748 if (ndentry == trap)
1749 goto out_dput_new;
1750
1751 host_err = -EXDEV;
1752 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1753 goto out_dput_new;
1754 host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt);
1755 if (host_err)
1756 goto out_dput_new;
1757
1758 host_err = nfsd_break_lease(odentry->d_inode);
1759 if (host_err)
1760 goto out_drop_write;
1761 if (ndentry->d_inode) {
1762 host_err = nfsd_break_lease(ndentry->d_inode);
1763 if (host_err)
1764 goto out_drop_write;
1765 }
1766 host_err = vfs_rename(fdir, odentry, tdir, ndentry);
1767 if (!host_err) {
1768 host_err = commit_metadata(tfhp);
1769 if (!host_err)
1770 host_err = commit_metadata(ffhp);
1771 }
1772 out_drop_write:
1773 mnt_drop_write(ffhp->fh_export->ex_path.mnt);
1774 out_dput_new:
1775 dput(ndentry);
1776 out_dput_old:
1777 dput(odentry);
1778 out_nfserr:
1779 err = nfserrno(host_err);
1780
1781 /* we cannot reply on fh_unlock on the two filehandles,
1782 * as that would do the wrong thing if the two directories
1783 * were the same, so again we do it by hand
1784 */
1785 fill_post_wcc(ffhp);
1786 fill_post_wcc(tfhp);
1787 unlock_rename(tdentry, fdentry);
1788 ffhp->fh_locked = tfhp->fh_locked = 0;
1789
1790 out:
1791 return err;
1792 }
1793
1794 /*
1795 * Unlink a file or directory
1796 * N.B. After this call fhp needs an fh_put
1797 */
1798 __be32
1799 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1800 char *fname, int flen)
1801 {
1802 struct dentry *dentry, *rdentry;
1803 struct inode *dirp;
1804 __be32 err;
1805 int host_err;
1806
1807 err = nfserr_acces;
1808 if (!flen || isdotent(fname, flen))
1809 goto out;
1810 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1811 if (err)
1812 goto out;
1813
1814 fh_lock_nested(fhp, I_MUTEX_PARENT);
1815 dentry = fhp->fh_dentry;
1816 dirp = dentry->d_inode;
1817
1818 rdentry = lookup_one_len(fname, dentry, flen);
1819 host_err = PTR_ERR(rdentry);
1820 if (IS_ERR(rdentry))
1821 goto out_nfserr;
1822
1823 if (!rdentry->d_inode) {
1824 dput(rdentry);
1825 err = nfserr_noent;
1826 goto out;
1827 }
1828
1829 if (!type)
1830 type = rdentry->d_inode->i_mode & S_IFMT;
1831
1832 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt);
1833 if (host_err)
1834 goto out_put;
1835
1836 host_err = nfsd_break_lease(rdentry->d_inode);
1837 if (host_err)
1838 goto out_drop_write;
1839 if (type != S_IFDIR)
1840 host_err = vfs_unlink(dirp, rdentry);
1841 else
1842 host_err = vfs_rmdir(dirp, rdentry);
1843 if (!host_err)
1844 host_err = commit_metadata(fhp);
1845 out_drop_write:
1846 mnt_drop_write(fhp->fh_export->ex_path.mnt);
1847 out_put:
1848 dput(rdentry);
1849
1850 out_nfserr:
1851 err = nfserrno(host_err);
1852 out:
1853 return err;
1854 }
1855
1856 /*
1857 * We do this buffering because we must not call back into the file
1858 * system's ->lookup() method from the filldir callback. That may well
1859 * deadlock a number of file systems.
1860 *
1861 * This is based heavily on the implementation of same in XFS.
1862 */
1863 struct buffered_dirent {
1864 u64 ino;
1865 loff_t offset;
1866 int namlen;
1867 unsigned int d_type;
1868 char name[];
1869 };
1870
1871 struct readdir_data {
1872 char *dirent;
1873 size_t used;
1874 int full;
1875 };
1876
1877 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen,
1878 loff_t offset, u64 ino, unsigned int d_type)
1879 {
1880 struct readdir_data *buf = __buf;
1881 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1882 unsigned int reclen;
1883
1884 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1885 if (buf->used + reclen > PAGE_SIZE) {
1886 buf->full = 1;
1887 return -EINVAL;
1888 }
1889
1890 de->namlen = namlen;
1891 de->offset = offset;
1892 de->ino = ino;
1893 de->d_type = d_type;
1894 memcpy(de->name, name, namlen);
1895 buf->used += reclen;
1896
1897 return 0;
1898 }
1899
1900 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func,
1901 struct readdir_cd *cdp, loff_t *offsetp)
1902 {
1903 struct readdir_data buf;
1904 struct buffered_dirent *de;
1905 int host_err;
1906 int size;
1907 loff_t offset;
1908
1909 buf.dirent = (void *)__get_free_page(GFP_KERNEL);
1910 if (!buf.dirent)
1911 return nfserrno(-ENOMEM);
1912
1913 offset = *offsetp;
1914
1915 while (1) {
1916 struct inode *dir_inode = file->f_path.dentry->d_inode;
1917 unsigned int reclen;
1918
1919 cdp->err = nfserr_eof; /* will be cleared on successful read */
1920 buf.used = 0;
1921 buf.full = 0;
1922
1923 host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf);
1924 if (buf.full)
1925 host_err = 0;
1926
1927 if (host_err < 0)
1928 break;
1929
1930 size = buf.used;
1931
1932 if (!size)
1933 break;
1934
1935 /*
1936 * Various filldir functions may end up calling back into
1937 * lookup_one_len() and the file system's ->lookup() method.
1938 * These expect i_mutex to be held, as it would within readdir.
1939 */
1940 host_err = mutex_lock_killable(&dir_inode->i_mutex);
1941 if (host_err)
1942 break;
1943
1944 de = (struct buffered_dirent *)buf.dirent;
1945 while (size > 0) {
1946 offset = de->offset;
1947
1948 if (func(cdp, de->name, de->namlen, de->offset,
1949 de->ino, de->d_type))
1950 break;
1951
1952 if (cdp->err != nfs_ok)
1953 break;
1954
1955 reclen = ALIGN(sizeof(*de) + de->namlen,
1956 sizeof(u64));
1957 size -= reclen;
1958 de = (struct buffered_dirent *)((char *)de + reclen);
1959 }
1960 mutex_unlock(&dir_inode->i_mutex);
1961 if (size > 0) /* We bailed out early */
1962 break;
1963
1964 offset = vfs_llseek(file, 0, SEEK_CUR);
1965 }
1966
1967 free_page((unsigned long)(buf.dirent));
1968
1969 if (host_err)
1970 return nfserrno(host_err);
1971
1972 *offsetp = offset;
1973 return cdp->err;
1974 }
1975
1976 /*
1977 * Read entries from a directory.
1978 * The NFSv3/4 verifier we ignore for now.
1979 */
1980 __be32
1981 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
1982 struct readdir_cd *cdp, filldir_t func)
1983 {
1984 __be32 err;
1985 struct file *file;
1986 loff_t offset = *offsetp;
1987
1988 err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file);
1989 if (err)
1990 goto out;
1991
1992 offset = vfs_llseek(file, offset, 0);
1993 if (offset < 0) {
1994 err = nfserrno((int)offset);
1995 goto out_close;
1996 }
1997
1998 err = nfsd_buffered_readdir(file, func, cdp, offsetp);
1999
2000 if (err == nfserr_eof || err == nfserr_toosmall)
2001 err = nfs_ok; /* can still be found in ->err */
2002 out_close:
2003 nfsd_close(file);
2004 out:
2005 return err;
2006 }
2007
2008 /*
2009 * Get file system stats
2010 * N.B. After this call fhp needs an fh_put
2011 */
2012 __be32
2013 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
2014 {
2015 __be32 err;
2016
2017 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
2018 if (!err) {
2019 struct path path = {
2020 .mnt = fhp->fh_export->ex_path.mnt,
2021 .dentry = fhp->fh_dentry,
2022 };
2023 if (vfs_statfs(&path, stat))
2024 err = nfserr_io;
2025 }
2026 return err;
2027 }
2028
2029 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
2030 {
2031 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
2032 }
2033
2034 /*
2035 * Check for a user's access permissions to this inode.
2036 */
2037 __be32
2038 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
2039 struct dentry *dentry, int acc)
2040 {
2041 struct inode *inode = dentry->d_inode;
2042 int err;
2043
2044 if ((acc & NFSD_MAY_MASK) == 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
2115 return err? nfserrno(err) : 0;
2116 }
2117
2118 void
2119 nfsd_racache_shutdown(void)
2120 {
2121 struct raparms *raparm, *last_raparm;
2122 unsigned int i;
2123
2124 dprintk("nfsd: freeing readahead buffers.\n");
2125
2126 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2127 raparm = raparm_hash[i].pb_head;
2128 while(raparm) {
2129 last_raparm = raparm;
2130 raparm = raparm->p_next;
2131 kfree(last_raparm);
2132 }
2133 raparm_hash[i].pb_head = NULL;
2134 }
2135 }
2136 /*
2137 * Initialize readahead param cache
2138 */
2139 int
2140 nfsd_racache_init(int cache_size)
2141 {
2142 int i;
2143 int j = 0;
2144 int nperbucket;
2145 struct raparms **raparm = NULL;
2146
2147
2148 if (raparm_hash[0].pb_head)
2149 return 0;
2150 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
2151 if (nperbucket < 2)
2152 nperbucket = 2;
2153 cache_size = nperbucket * RAPARM_HASH_SIZE;
2154
2155 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
2156
2157 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2158 spin_lock_init(&raparm_hash[i].pb_lock);
2159
2160 raparm = &raparm_hash[i].pb_head;
2161 for (j = 0; j < nperbucket; j++) {
2162 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
2163 if (!*raparm)
2164 goto out_nomem;
2165 raparm = &(*raparm)->p_next;
2166 }
2167 *raparm = NULL;
2168 }
2169
2170 nfsdstats.ra_size = cache_size;
2171 return 0;
2172
2173 out_nomem:
2174 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
2175 nfsd_racache_shutdown();
2176 return -ENOMEM;
2177 }
2178
2179 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
2180 struct posix_acl *
2181 nfsd_get_posix_acl(struct svc_fh *fhp, int type)
2182 {
2183 struct inode *inode = fhp->fh_dentry->d_inode;
2184 char *name;
2185 void *value = NULL;
2186 ssize_t size;
2187 struct posix_acl *acl;
2188
2189 if (!IS_POSIXACL(inode))
2190 return ERR_PTR(-EOPNOTSUPP);
2191
2192 switch (type) {
2193 case ACL_TYPE_ACCESS:
2194 name = POSIX_ACL_XATTR_ACCESS;
2195 break;
2196 case ACL_TYPE_DEFAULT:
2197 name = POSIX_ACL_XATTR_DEFAULT;
2198 break;
2199 default:
2200 return ERR_PTR(-EOPNOTSUPP);
2201 }
2202
2203 size = nfsd_getxattr(fhp->fh_dentry, name, &value);
2204 if (size < 0)
2205 return ERR_PTR(size);
2206
2207 acl = posix_acl_from_xattr(value, size);
2208 kfree(value);
2209 return acl;
2210 }
2211
2212 int
2213 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl)
2214 {
2215 struct inode *inode = fhp->fh_dentry->d_inode;
2216 char *name;
2217 void *value = NULL;
2218 size_t size;
2219 int error;
2220
2221 if (!IS_POSIXACL(inode) ||
2222 !inode->i_op->setxattr || !inode->i_op->removexattr)
2223 return -EOPNOTSUPP;
2224 switch(type) {
2225 case ACL_TYPE_ACCESS:
2226 name = POSIX_ACL_XATTR_ACCESS;
2227 break;
2228 case ACL_TYPE_DEFAULT:
2229 name = POSIX_ACL_XATTR_DEFAULT;
2230 break;
2231 default:
2232 return -EOPNOTSUPP;
2233 }
2234
2235 if (acl && acl->a_count) {
2236 size = posix_acl_xattr_size(acl->a_count);
2237 value = kmalloc(size, GFP_KERNEL);
2238 if (!value)
2239 return -ENOMEM;
2240 error = posix_acl_to_xattr(acl, value, size);
2241 if (error < 0)
2242 goto getout;
2243 size = error;
2244 } else
2245 size = 0;
2246
2247 error = mnt_want_write(fhp->fh_export->ex_path.mnt);
2248 if (error)
2249 goto getout;
2250 if (size)
2251 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0);
2252 else {
2253 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT)
2254 error = 0;
2255 else {
2256 error = vfs_removexattr(fhp->fh_dentry, name);
2257 if (error == -ENODATA)
2258 error = 0;
2259 }
2260 }
2261 mnt_drop_write(fhp->fh_export->ex_path.mnt);
2262
2263 getout:
2264 kfree(value);
2265 return error;
2266 }
2267 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
kernel source for telekom puls (alcatel/mediatek)