xref: /openbmc/linux/fs/nfsd/vfs.c (revision 643d1f7f)
1 #define MSNFS	/* HACK HACK */
2 /*
3  * linux/fs/nfsd/vfs.c
4  *
5  * File operations used by nfsd. Some of these have been ripped from
6  * other parts of the kernel because they weren't exported, others
7  * are partial duplicates with added or changed functionality.
8  *
9  * Note that several functions dget() the dentry upon which they want
10  * to act, most notably those that create directory entries. Response
11  * dentry's are dput()'d if necessary in the release callback.
12  * So if you notice code paths that apparently fail to dput() the
13  * dentry, don't worry--they have been taken care of.
14  *
15  * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
16  * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
17  */
18 
19 #include <linux/string.h>
20 #include <linux/time.h>
21 #include <linux/errno.h>
22 #include <linux/fs.h>
23 #include <linux/file.h>
24 #include <linux/mount.h>
25 #include <linux/major.h>
26 #include <linux/splice.h>
27 #include <linux/proc_fs.h>
28 #include <linux/stat.h>
29 #include <linux/fcntl.h>
30 #include <linux/net.h>
31 #include <linux/unistd.h>
32 #include <linux/slab.h>
33 #include <linux/pagemap.h>
34 #include <linux/in.h>
35 #include <linux/module.h>
36 #include <linux/namei.h>
37 #include <linux/vfs.h>
38 #include <linux/delay.h>
39 #include <linux/sunrpc/svc.h>
40 #include <linux/nfsd/nfsd.h>
41 #ifdef CONFIG_NFSD_V3
42 #include <linux/nfs3.h>
43 #include <linux/nfsd/xdr3.h>
44 #endif /* CONFIG_NFSD_V3 */
45 #include <linux/nfsd/nfsfh.h>
46 #include <linux/quotaops.h>
47 #include <linux/fsnotify.h>
48 #include <linux/posix_acl.h>
49 #include <linux/posix_acl_xattr.h>
50 #include <linux/xattr.h>
51 #ifdef CONFIG_NFSD_V4
52 #include <linux/nfs4.h>
53 #include <linux/nfs4_acl.h>
54 #include <linux/nfsd_idmap.h>
55 #include <linux/security.h>
56 #endif /* CONFIG_NFSD_V4 */
57 #include <linux/jhash.h>
58 
59 #include <asm/uaccess.h>
60 
61 #define NFSDDBG_FACILITY		NFSDDBG_FILEOP
62 
63 
64 /*
65  * This is a cache of readahead params that help us choose the proper
66  * readahead strategy. Initially, we set all readahead parameters to 0
67  * and let the VFS handle things.
68  * If you increase the number of cached files very much, you'll need to
69  * add a hash table here.
70  */
71 struct raparms {
72 	struct raparms		*p_next;
73 	unsigned int		p_count;
74 	ino_t			p_ino;
75 	dev_t			p_dev;
76 	int			p_set;
77 	struct file_ra_state	p_ra;
78 	unsigned int		p_hindex;
79 };
80 
81 struct raparm_hbucket {
82 	struct raparms		*pb_head;
83 	spinlock_t		pb_lock;
84 } ____cacheline_aligned_in_smp;
85 
86 static struct raparms *		raparml;
87 #define RAPARM_HASH_BITS	4
88 #define RAPARM_HASH_SIZE	(1<<RAPARM_HASH_BITS)
89 #define RAPARM_HASH_MASK	(RAPARM_HASH_SIZE-1)
90 static struct raparm_hbucket	raparm_hash[RAPARM_HASH_SIZE];
91 
92 /*
93  * Called from nfsd_lookup and encode_dirent. Check if we have crossed
94  * a mount point.
95  * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
96  *  or nfs_ok having possibly changed *dpp and *expp
97  */
98 int
99 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
100 		        struct svc_export **expp)
101 {
102 	struct svc_export *exp = *expp, *exp2 = NULL;
103 	struct dentry *dentry = *dpp;
104 	struct vfsmount *mnt = mntget(exp->ex_mnt);
105 	struct dentry *mounts = dget(dentry);
106 	int err = 0;
107 
108 	while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts));
109 
110 	exp2 = rqst_exp_get_by_name(rqstp, mnt, mounts);
111 	if (IS_ERR(exp2)) {
112 		if (PTR_ERR(exp2) != -ENOENT)
113 			err = PTR_ERR(exp2);
114 		dput(mounts);
115 		mntput(mnt);
116 		goto out;
117 	}
118 	if ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
119 		/* successfully crossed mount point */
120 		exp_put(exp);
121 		*expp = exp2;
122 		dput(dentry);
123 		*dpp = mounts;
124 	} else {
125 		exp_put(exp2);
126 		dput(mounts);
127 	}
128 	mntput(mnt);
129 out:
130 	return err;
131 }
132 
133 __be32
134 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
135 		   const char *name, unsigned int len,
136 		   struct svc_export **exp_ret, struct dentry **dentry_ret)
137 {
138 	struct svc_export	*exp;
139 	struct dentry		*dparent;
140 	struct dentry		*dentry;
141 	__be32			err;
142 	int			host_err;
143 
144 	dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
145 
146 	/* Obtain dentry and export. */
147 	err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC);
148 	if (err)
149 		return err;
150 
151 	dparent = fhp->fh_dentry;
152 	exp  = fhp->fh_export;
153 	exp_get(exp);
154 
155 	/* Lookup the name, but don't follow links */
156 	if (isdotent(name, len)) {
157 		if (len==1)
158 			dentry = dget(dparent);
159 		else if (dparent != exp->ex_dentry) {
160 			dentry = dget_parent(dparent);
161 		} else  if (!EX_NOHIDE(exp))
162 			dentry = dget(dparent); /* .. == . just like at / */
163 		else {
164 			/* checking mountpoint crossing is very different when stepping up */
165 			struct svc_export *exp2 = NULL;
166 			struct dentry *dp;
167 			struct vfsmount *mnt = mntget(exp->ex_mnt);
168 			dentry = dget(dparent);
169 			while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry))
170 				;
171 			dp = dget_parent(dentry);
172 			dput(dentry);
173 			dentry = dp;
174 
175 			exp2 = rqst_exp_parent(rqstp, mnt, dentry);
176 			if (PTR_ERR(exp2) == -ENOENT) {
177 				dput(dentry);
178 				dentry = dget(dparent);
179 			} else if (IS_ERR(exp2)) {
180 				host_err = PTR_ERR(exp2);
181 				dput(dentry);
182 				mntput(mnt);
183 				goto out_nfserr;
184 			} else {
185 				exp_put(exp);
186 				exp = exp2;
187 			}
188 			mntput(mnt);
189 		}
190 	} else {
191 		fh_lock(fhp);
192 		dentry = lookup_one_len(name, dparent, len);
193 		host_err = PTR_ERR(dentry);
194 		if (IS_ERR(dentry))
195 			goto out_nfserr;
196 		/*
197 		 * check if we have crossed a mount point ...
198 		 */
199 		if (d_mountpoint(dentry)) {
200 			if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
201 				dput(dentry);
202 				goto out_nfserr;
203 			}
204 		}
205 	}
206 	*dentry_ret = dentry;
207 	*exp_ret = exp;
208 	return 0;
209 
210 out_nfserr:
211 	exp_put(exp);
212 	return nfserrno(host_err);
213 }
214 
215 /*
216  * Look up one component of a pathname.
217  * N.B. After this call _both_ fhp and resfh need an fh_put
218  *
219  * If the lookup would cross a mountpoint, and the mounted filesystem
220  * is exported to the client with NFSEXP_NOHIDE, then the lookup is
221  * accepted as it stands and the mounted directory is
222  * returned. Otherwise the covered directory is returned.
223  * NOTE: this mountpoint crossing is not supported properly by all
224  *   clients and is explicitly disallowed for NFSv3
225  *      NeilBrown <neilb@cse.unsw.edu.au>
226  */
227 __be32
228 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
229 				unsigned int len, struct svc_fh *resfh)
230 {
231 	struct svc_export	*exp;
232 	struct dentry		*dentry;
233 	__be32 err;
234 
235 	err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
236 	if (err)
237 		return err;
238 	err = check_nfsd_access(exp, rqstp);
239 	if (err)
240 		goto out;
241 	/*
242 	 * Note: we compose the file handle now, but as the
243 	 * dentry may be negative, it may need to be updated.
244 	 */
245 	err = fh_compose(resfh, exp, dentry, fhp);
246 	if (!err && !dentry->d_inode)
247 		err = nfserr_noent;
248 out:
249 	dput(dentry);
250 	exp_put(exp);
251 	return err;
252 }
253 
254 
255 /*
256  * Set various file attributes.
257  * N.B. After this call fhp needs an fh_put
258  */
259 __be32
260 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
261 	     int check_guard, time_t guardtime)
262 {
263 	struct dentry	*dentry;
264 	struct inode	*inode;
265 	int		accmode = MAY_SATTR;
266 	int		ftype = 0;
267 	int		imode;
268 	__be32		err;
269 	int		host_err;
270 	int		size_change = 0;
271 
272 	if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
273 		accmode |= MAY_WRITE|MAY_OWNER_OVERRIDE;
274 	if (iap->ia_valid & ATTR_SIZE)
275 		ftype = S_IFREG;
276 
277 	/* Get inode */
278 	err = fh_verify(rqstp, fhp, ftype, accmode);
279 	if (err)
280 		goto out;
281 
282 	dentry = fhp->fh_dentry;
283 	inode = dentry->d_inode;
284 
285 	/* Ignore any mode updates on symlinks */
286 	if (S_ISLNK(inode->i_mode))
287 		iap->ia_valid &= ~ATTR_MODE;
288 
289 	if (!iap->ia_valid)
290 		goto out;
291 
292 	/*
293 	 * NFSv2 does not differentiate between "set-[ac]time-to-now"
294 	 * which only requires access, and "set-[ac]time-to-X" which
295 	 * requires ownership.
296 	 * So if it looks like it might be "set both to the same time which
297 	 * is close to now", and if inode_change_ok fails, then we
298 	 * convert to "set to now" instead of "set to explicit time"
299 	 *
300 	 * We only call inode_change_ok as the last test as technically
301 	 * it is not an interface that we should be using.  It is only
302 	 * valid if the filesystem does not define it's own i_op->setattr.
303 	 */
304 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
305 #define	MAX_TOUCH_TIME_ERROR (30*60)
306 	if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET &&
307 	    iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) {
308 		/*
309 		 * Looks probable.
310 		 *
311 		 * Now just make sure time is in the right ballpark.
312 		 * Solaris, at least, doesn't seem to care what the time
313 		 * request is.  We require it be within 30 minutes of now.
314 		 */
315 		time_t delta = iap->ia_atime.tv_sec - get_seconds();
316 		if (delta < 0)
317 			delta = -delta;
318 		if (delta < MAX_TOUCH_TIME_ERROR &&
319 		    inode_change_ok(inode, iap) != 0) {
320 			/*
321 			 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
322 			 * This will cause notify_change to set these times
323 			 * to "now"
324 			 */
325 			iap->ia_valid &= ~BOTH_TIME_SET;
326 		}
327 	}
328 
329 	/*
330 	 * The size case is special.
331 	 * It changes the file as well as the attributes.
332 	 */
333 	if (iap->ia_valid & ATTR_SIZE) {
334 		if (iap->ia_size < inode->i_size) {
335 			err = nfsd_permission(rqstp, fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE);
336 			if (err)
337 				goto out;
338 		}
339 
340 		/*
341 		 * If we are changing the size of the file, then
342 		 * we need to break all leases.
343 		 */
344 		host_err = break_lease(inode, FMODE_WRITE | O_NONBLOCK);
345 		if (host_err == -EWOULDBLOCK)
346 			host_err = -ETIMEDOUT;
347 		if (host_err) /* ENOMEM or EWOULDBLOCK */
348 			goto out_nfserr;
349 
350 		host_err = get_write_access(inode);
351 		if (host_err)
352 			goto out_nfserr;
353 
354 		size_change = 1;
355 		host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
356 		if (host_err) {
357 			put_write_access(inode);
358 			goto out_nfserr;
359 		}
360 		DQUOT_INIT(inode);
361 	}
362 
363 	imode = inode->i_mode;
364 	if (iap->ia_valid & ATTR_MODE) {
365 		iap->ia_mode &= S_IALLUGO;
366 		imode = iap->ia_mode |= (imode & ~S_IALLUGO);
367 		/* if changing uid/gid revoke setuid/setgid in mode */
368 		if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) {
369 			iap->ia_valid |= ATTR_KILL_PRIV;
370 			iap->ia_mode &= ~S_ISUID;
371 		}
372 		if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
373 			iap->ia_mode &= ~S_ISGID;
374 	} else {
375 		/*
376 		 * Revoke setuid/setgid bit on chown/chgrp
377 		 */
378 		if ((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid)
379 			iap->ia_valid |= ATTR_KILL_SUID | ATTR_KILL_PRIV;
380 		if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid)
381 			iap->ia_valid |= ATTR_KILL_SGID;
382 	}
383 
384 	/* Change the attributes. */
385 
386 	iap->ia_valid |= ATTR_CTIME;
387 
388 	err = nfserr_notsync;
389 	if (!check_guard || guardtime == inode->i_ctime.tv_sec) {
390 		fh_lock(fhp);
391 		host_err = notify_change(dentry, iap);
392 		err = nfserrno(host_err);
393 		fh_unlock(fhp);
394 	}
395 	if (size_change)
396 		put_write_access(inode);
397 	if (!err)
398 		if (EX_ISSYNC(fhp->fh_export))
399 			write_inode_now(inode, 1);
400 out:
401 	return err;
402 
403 out_nfserr:
404 	err = nfserrno(host_err);
405 	goto out;
406 }
407 
408 #if defined(CONFIG_NFSD_V2_ACL) || \
409     defined(CONFIG_NFSD_V3_ACL) || \
410     defined(CONFIG_NFSD_V4)
411 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf)
412 {
413 	ssize_t buflen;
414 
415 	buflen = vfs_getxattr(dentry, key, NULL, 0);
416 	if (buflen <= 0)
417 		return buflen;
418 
419 	*buf = kmalloc(buflen, GFP_KERNEL);
420 	if (!*buf)
421 		return -ENOMEM;
422 
423 	return vfs_getxattr(dentry, key, *buf, buflen);
424 }
425 #endif
426 
427 #if defined(CONFIG_NFSD_V4)
428 static int
429 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key)
430 {
431 	int len;
432 	size_t buflen;
433 	char *buf = NULL;
434 	int error = 0;
435 
436 	buflen = posix_acl_xattr_size(pacl->a_count);
437 	buf = kmalloc(buflen, GFP_KERNEL);
438 	error = -ENOMEM;
439 	if (buf == NULL)
440 		goto out;
441 
442 	len = posix_acl_to_xattr(pacl, buf, buflen);
443 	if (len < 0) {
444 		error = len;
445 		goto out;
446 	}
447 
448 	error = vfs_setxattr(dentry, key, buf, len, 0);
449 out:
450 	kfree(buf);
451 	return error;
452 }
453 
454 __be32
455 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
456     struct nfs4_acl *acl)
457 {
458 	__be32 error;
459 	int host_error;
460 	struct dentry *dentry;
461 	struct inode *inode;
462 	struct posix_acl *pacl = NULL, *dpacl = NULL;
463 	unsigned int flags = 0;
464 
465 	/* Get inode */
466 	error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, MAY_SATTR);
467 	if (error)
468 		return error;
469 
470 	dentry = fhp->fh_dentry;
471 	inode = dentry->d_inode;
472 	if (S_ISDIR(inode->i_mode))
473 		flags = NFS4_ACL_DIR;
474 
475 	host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags);
476 	if (host_error == -EINVAL) {
477 		return nfserr_attrnotsupp;
478 	} else if (host_error < 0)
479 		goto out_nfserr;
480 
481 	host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS);
482 	if (host_error < 0)
483 		goto out_release;
484 
485 	if (S_ISDIR(inode->i_mode))
486 		host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT);
487 
488 out_release:
489 	posix_acl_release(pacl);
490 	posix_acl_release(dpacl);
491 out_nfserr:
492 	if (host_error == -EOPNOTSUPP)
493 		return nfserr_attrnotsupp;
494 	else
495 		return nfserrno(host_error);
496 }
497 
498 static struct posix_acl *
499 _get_posix_acl(struct dentry *dentry, char *key)
500 {
501 	void *buf = NULL;
502 	struct posix_acl *pacl = NULL;
503 	int buflen;
504 
505 	buflen = nfsd_getxattr(dentry, key, &buf);
506 	if (!buflen)
507 		buflen = -ENODATA;
508 	if (buflen <= 0)
509 		return ERR_PTR(buflen);
510 
511 	pacl = posix_acl_from_xattr(buf, buflen);
512 	kfree(buf);
513 	return pacl;
514 }
515 
516 int
517 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl)
518 {
519 	struct inode *inode = dentry->d_inode;
520 	int error = 0;
521 	struct posix_acl *pacl = NULL, *dpacl = NULL;
522 	unsigned int flags = 0;
523 
524 	pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS);
525 	if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA)
526 		pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
527 	if (IS_ERR(pacl)) {
528 		error = PTR_ERR(pacl);
529 		pacl = NULL;
530 		goto out;
531 	}
532 
533 	if (S_ISDIR(inode->i_mode)) {
534 		dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT);
535 		if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA)
536 			dpacl = NULL;
537 		else if (IS_ERR(dpacl)) {
538 			error = PTR_ERR(dpacl);
539 			dpacl = NULL;
540 			goto out;
541 		}
542 		flags = NFS4_ACL_DIR;
543 	}
544 
545 	*acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags);
546 	if (IS_ERR(*acl)) {
547 		error = PTR_ERR(*acl);
548 		*acl = NULL;
549 	}
550  out:
551 	posix_acl_release(pacl);
552 	posix_acl_release(dpacl);
553 	return error;
554 }
555 
556 #endif /* defined(CONFIG_NFS_V4) */
557 
558 #ifdef CONFIG_NFSD_V3
559 /*
560  * Check server access rights to a file system object
561  */
562 struct accessmap {
563 	u32		access;
564 	int		how;
565 };
566 static struct accessmap	nfs3_regaccess[] = {
567     {	NFS3_ACCESS_READ,	MAY_READ			},
568     {	NFS3_ACCESS_EXECUTE,	MAY_EXEC			},
569     {	NFS3_ACCESS_MODIFY,	MAY_WRITE|MAY_TRUNC		},
570     {	NFS3_ACCESS_EXTEND,	MAY_WRITE			},
571 
572     {	0,			0				}
573 };
574 
575 static struct accessmap	nfs3_diraccess[] = {
576     {	NFS3_ACCESS_READ,	MAY_READ			},
577     {	NFS3_ACCESS_LOOKUP,	MAY_EXEC			},
578     {	NFS3_ACCESS_MODIFY,	MAY_EXEC|MAY_WRITE|MAY_TRUNC	},
579     {	NFS3_ACCESS_EXTEND,	MAY_EXEC|MAY_WRITE		},
580     {	NFS3_ACCESS_DELETE,	MAY_REMOVE			},
581 
582     {	0,			0				}
583 };
584 
585 static struct accessmap	nfs3_anyaccess[] = {
586 	/* Some clients - Solaris 2.6 at least, make an access call
587 	 * to the server to check for access for things like /dev/null
588 	 * (which really, the server doesn't care about).  So
589 	 * We provide simple access checking for them, looking
590 	 * mainly at mode bits, and we make sure to ignore read-only
591 	 * filesystem checks
592 	 */
593     {	NFS3_ACCESS_READ,	MAY_READ			},
594     {	NFS3_ACCESS_EXECUTE,	MAY_EXEC			},
595     {	NFS3_ACCESS_MODIFY,	MAY_WRITE|MAY_LOCAL_ACCESS	},
596     {	NFS3_ACCESS_EXTEND,	MAY_WRITE|MAY_LOCAL_ACCESS	},
597 
598     {	0,			0				}
599 };
600 
601 __be32
602 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
603 {
604 	struct accessmap	*map;
605 	struct svc_export	*export;
606 	struct dentry		*dentry;
607 	u32			query, result = 0, sresult = 0;
608 	__be32			error;
609 
610 	error = fh_verify(rqstp, fhp, 0, MAY_NOP);
611 	if (error)
612 		goto out;
613 
614 	export = fhp->fh_export;
615 	dentry = fhp->fh_dentry;
616 
617 	if (S_ISREG(dentry->d_inode->i_mode))
618 		map = nfs3_regaccess;
619 	else if (S_ISDIR(dentry->d_inode->i_mode))
620 		map = nfs3_diraccess;
621 	else
622 		map = nfs3_anyaccess;
623 
624 
625 	query = *access;
626 	for  (; map->access; map++) {
627 		if (map->access & query) {
628 			__be32 err2;
629 
630 			sresult |= map->access;
631 
632 			err2 = nfsd_permission(rqstp, export, dentry, map->how);
633 			switch (err2) {
634 			case nfs_ok:
635 				result |= map->access;
636 				break;
637 
638 			/* the following error codes just mean the access was not allowed,
639 			 * rather than an error occurred */
640 			case nfserr_rofs:
641 			case nfserr_acces:
642 			case nfserr_perm:
643 				/* simply don't "or" in the access bit. */
644 				break;
645 			default:
646 				error = err2;
647 				goto out;
648 			}
649 		}
650 	}
651 	*access = result;
652 	if (supported)
653 		*supported = sresult;
654 
655  out:
656 	return error;
657 }
658 #endif /* CONFIG_NFSD_V3 */
659 
660 
661 
662 /*
663  * Open an existing file or directory.
664  * The access argument indicates the type of open (read/write/lock)
665  * N.B. After this call fhp needs an fh_put
666  */
667 __be32
668 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
669 			int access, struct file **filp)
670 {
671 	struct dentry	*dentry;
672 	struct inode	*inode;
673 	int		flags = O_RDONLY|O_LARGEFILE;
674 	__be32		err;
675 	int		host_err;
676 
677 	/*
678 	 * If we get here, then the client has already done an "open",
679 	 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
680 	 * in case a chmod has now revoked permission.
681 	 */
682 	err = fh_verify(rqstp, fhp, type, access | MAY_OWNER_OVERRIDE);
683 	if (err)
684 		goto out;
685 
686 	dentry = fhp->fh_dentry;
687 	inode = dentry->d_inode;
688 
689 	/* Disallow write access to files with the append-only bit set
690 	 * or any access when mandatory locking enabled
691 	 */
692 	err = nfserr_perm;
693 	if (IS_APPEND(inode) && (access & MAY_WRITE))
694 		goto out;
695 	/*
696 	 * We must ignore files (but only files) which might have mandatory
697 	 * locks on them because there is no way to know if the accesser has
698 	 * the lock.
699 	 */
700 	if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
701 		goto out;
702 
703 	if (!inode->i_fop)
704 		goto out;
705 
706 	/*
707 	 * Check to see if there are any leases on this file.
708 	 * This may block while leases are broken.
709 	 */
710 	host_err = break_lease(inode, O_NONBLOCK | ((access & MAY_WRITE) ? FMODE_WRITE : 0));
711 	if (host_err == -EWOULDBLOCK)
712 		host_err = -ETIMEDOUT;
713 	if (host_err) /* NOMEM or WOULDBLOCK */
714 		goto out_nfserr;
715 
716 	if (access & MAY_WRITE) {
717 		if (access & MAY_READ)
718 			flags = O_RDWR|O_LARGEFILE;
719 		else
720 			flags = O_WRONLY|O_LARGEFILE;
721 
722 		DQUOT_INIT(inode);
723 	}
724 	*filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_mnt), flags);
725 	if (IS_ERR(*filp))
726 		host_err = PTR_ERR(*filp);
727 out_nfserr:
728 	err = nfserrno(host_err);
729 out:
730 	return err;
731 }
732 
733 /*
734  * Close a file.
735  */
736 void
737 nfsd_close(struct file *filp)
738 {
739 	fput(filp);
740 }
741 
742 /*
743  * Sync a file
744  * As this calls fsync (not fdatasync) there is no need for a write_inode
745  * after it.
746  */
747 static inline int nfsd_dosync(struct file *filp, struct dentry *dp,
748 			      const struct file_operations *fop)
749 {
750 	struct inode *inode = dp->d_inode;
751 	int (*fsync) (struct file *, struct dentry *, int);
752 	int err;
753 
754 	err = filemap_fdatawrite(inode->i_mapping);
755 	if (err == 0 && fop && (fsync = fop->fsync))
756 		err = fsync(filp, dp, 0);
757 	if (err == 0)
758 		err = filemap_fdatawait(inode->i_mapping);
759 
760 	return err;
761 }
762 
763 
764 static int
765 nfsd_sync(struct file *filp)
766 {
767         int err;
768 	struct inode *inode = filp->f_path.dentry->d_inode;
769 	dprintk("nfsd: sync file %s\n", filp->f_path.dentry->d_name.name);
770 	mutex_lock(&inode->i_mutex);
771 	err=nfsd_dosync(filp, filp->f_path.dentry, filp->f_op);
772 	mutex_unlock(&inode->i_mutex);
773 
774 	return err;
775 }
776 
777 int
778 nfsd_sync_dir(struct dentry *dp)
779 {
780 	return nfsd_dosync(NULL, dp, dp->d_inode->i_fop);
781 }
782 
783 /*
784  * Obtain the readahead parameters for the file
785  * specified by (dev, ino).
786  */
787 
788 static inline struct raparms *
789 nfsd_get_raparms(dev_t dev, ino_t ino)
790 {
791 	struct raparms	*ra, **rap, **frap = NULL;
792 	int depth = 0;
793 	unsigned int hash;
794 	struct raparm_hbucket *rab;
795 
796 	hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
797 	rab = &raparm_hash[hash];
798 
799 	spin_lock(&rab->pb_lock);
800 	for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
801 		if (ra->p_ino == ino && ra->p_dev == dev)
802 			goto found;
803 		depth++;
804 		if (ra->p_count == 0)
805 			frap = rap;
806 	}
807 	depth = nfsdstats.ra_size*11/10;
808 	if (!frap) {
809 		spin_unlock(&rab->pb_lock);
810 		return NULL;
811 	}
812 	rap = frap;
813 	ra = *frap;
814 	ra->p_dev = dev;
815 	ra->p_ino = ino;
816 	ra->p_set = 0;
817 	ra->p_hindex = hash;
818 found:
819 	if (rap != &rab->pb_head) {
820 		*rap = ra->p_next;
821 		ra->p_next   = rab->pb_head;
822 		rab->pb_head = ra;
823 	}
824 	ra->p_count++;
825 	nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
826 	spin_unlock(&rab->pb_lock);
827 	return ra;
828 }
829 
830 /*
831  * Grab and keep cached pages associated with a file in the svc_rqst
832  * so that they can be passed to the network sendmsg/sendpage routines
833  * directly. They will be released after the sending has completed.
834  */
835 static int
836 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
837 		  struct splice_desc *sd)
838 {
839 	struct svc_rqst *rqstp = sd->u.data;
840 	struct page **pp = rqstp->rq_respages + rqstp->rq_resused;
841 	struct page *page = buf->page;
842 	size_t size;
843 	int ret;
844 
845 	ret = buf->ops->confirm(pipe, buf);
846 	if (unlikely(ret))
847 		return ret;
848 
849 	size = sd->len;
850 
851 	if (rqstp->rq_res.page_len == 0) {
852 		get_page(page);
853 		put_page(*pp);
854 		*pp = page;
855 		rqstp->rq_resused++;
856 		rqstp->rq_res.page_base = buf->offset;
857 		rqstp->rq_res.page_len = size;
858 	} else if (page != pp[-1]) {
859 		get_page(page);
860 		if (*pp)
861 			put_page(*pp);
862 		*pp = page;
863 		rqstp->rq_resused++;
864 		rqstp->rq_res.page_len += size;
865 	} else
866 		rqstp->rq_res.page_len += size;
867 
868 	return size;
869 }
870 
871 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
872 				    struct splice_desc *sd)
873 {
874 	return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
875 }
876 
877 static inline int svc_msnfs(struct svc_fh *ffhp)
878 {
879 #ifdef MSNFS
880 	return (ffhp->fh_export->ex_flags & NFSEXP_MSNFS);
881 #else
882 	return 0;
883 #endif
884 }
885 
886 static __be32
887 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
888               loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
889 {
890 	struct inode *inode;
891 	struct raparms	*ra;
892 	mm_segment_t	oldfs;
893 	__be32		err;
894 	int		host_err;
895 
896 	err = nfserr_perm;
897 	inode = file->f_path.dentry->d_inode;
898 
899 	if (svc_msnfs(fhp) && !lock_may_read(inode, offset, *count))
900 		goto out;
901 
902 	/* Get readahead parameters */
903 	ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);
904 
905 	if (ra && ra->p_set)
906 		file->f_ra = ra->p_ra;
907 
908 	if (file->f_op->splice_read && rqstp->rq_splice_ok) {
909 		struct splice_desc sd = {
910 			.len		= 0,
911 			.total_len	= *count,
912 			.pos		= offset,
913 			.u.data		= rqstp,
914 		};
915 
916 		rqstp->rq_resused = 1;
917 		host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
918 	} else {
919 		oldfs = get_fs();
920 		set_fs(KERNEL_DS);
921 		host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
922 		set_fs(oldfs);
923 	}
924 
925 	/* Write back readahead params */
926 	if (ra) {
927 		struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
928 		spin_lock(&rab->pb_lock);
929 		ra->p_ra = file->f_ra;
930 		ra->p_set = 1;
931 		ra->p_count--;
932 		spin_unlock(&rab->pb_lock);
933 	}
934 
935 	if (host_err >= 0) {
936 		nfsdstats.io_read += host_err;
937 		*count = host_err;
938 		err = 0;
939 		fsnotify_access(file->f_path.dentry);
940 	} else
941 		err = nfserrno(host_err);
942 out:
943 	return err;
944 }
945 
946 static void kill_suid(struct dentry *dentry)
947 {
948 	struct iattr	ia;
949 	ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
950 
951 	mutex_lock(&dentry->d_inode->i_mutex);
952 	notify_change(dentry, &ia);
953 	mutex_unlock(&dentry->d_inode->i_mutex);
954 }
955 
956 static __be32
957 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
958 				loff_t offset, struct kvec *vec, int vlen,
959 	   			unsigned long cnt, int *stablep)
960 {
961 	struct svc_export	*exp;
962 	struct dentry		*dentry;
963 	struct inode		*inode;
964 	mm_segment_t		oldfs;
965 	__be32			err = 0;
966 	int			host_err;
967 	int			stable = *stablep;
968 
969 #ifdef MSNFS
970 	err = nfserr_perm;
971 
972 	if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
973 		(!lock_may_write(file->f_path.dentry->d_inode, offset, cnt)))
974 		goto out;
975 #endif
976 
977 	dentry = file->f_path.dentry;
978 	inode = dentry->d_inode;
979 	exp   = fhp->fh_export;
980 
981 	/*
982 	 * Request sync writes if
983 	 *  -	the sync export option has been set, or
984 	 *  -	the client requested O_SYNC behavior (NFSv3 feature).
985 	 *  -   The file system doesn't support fsync().
986 	 * When gathered writes have been configured for this volume,
987 	 * flushing the data to disk is handled separately below.
988 	 */
989 
990 	if (file->f_op->fsync == 0) {/* COMMIT3 cannot work */
991 	       stable = 2;
992 	       *stablep = 2; /* FILE_SYNC */
993 	}
994 
995 	if (!EX_ISSYNC(exp))
996 		stable = 0;
997 	if (stable && !EX_WGATHER(exp))
998 		file->f_flags |= O_SYNC;
999 
1000 	/* Write the data. */
1001 	oldfs = get_fs(); set_fs(KERNEL_DS);
1002 	host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
1003 	set_fs(oldfs);
1004 	if (host_err >= 0) {
1005 		nfsdstats.io_write += cnt;
1006 		fsnotify_modify(file->f_path.dentry);
1007 	}
1008 
1009 	/* clear setuid/setgid flag after write */
1010 	if (host_err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID)))
1011 		kill_suid(dentry);
1012 
1013 	if (host_err >= 0 && stable) {
1014 		static ino_t	last_ino;
1015 		static dev_t	last_dev;
1016 
1017 		/*
1018 		 * Gathered writes: If another process is currently
1019 		 * writing to the file, there's a high chance
1020 		 * this is another nfsd (triggered by a bulk write
1021 		 * from a client's biod). Rather than syncing the
1022 		 * file with each write request, we sleep for 10 msec.
1023 		 *
1024 		 * I don't know if this roughly approximates
1025 		 * C. Juszak's idea of gathered writes, but it's a
1026 		 * nice and simple solution (IMHO), and it seems to
1027 		 * work:-)
1028 		 */
1029 		if (EX_WGATHER(exp)) {
1030 			if (atomic_read(&inode->i_writecount) > 1
1031 			    || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
1032 				dprintk("nfsd: write defer %d\n", task_pid_nr(current));
1033 				msleep(10);
1034 				dprintk("nfsd: write resume %d\n", task_pid_nr(current));
1035 			}
1036 
1037 			if (inode->i_state & I_DIRTY) {
1038 				dprintk("nfsd: write sync %d\n", task_pid_nr(current));
1039 				host_err=nfsd_sync(file);
1040 			}
1041 #if 0
1042 			wake_up(&inode->i_wait);
1043 #endif
1044 		}
1045 		last_ino = inode->i_ino;
1046 		last_dev = inode->i_sb->s_dev;
1047 	}
1048 
1049 	dprintk("nfsd: write complete host_err=%d\n", host_err);
1050 	if (host_err >= 0)
1051 		err = 0;
1052 	else
1053 		err = nfserrno(host_err);
1054 out:
1055 	return err;
1056 }
1057 
1058 /*
1059  * Read data from a file. count must contain the requested read count
1060  * on entry. On return, *count contains the number of bytes actually read.
1061  * N.B. After this call fhp needs an fh_put
1062  */
1063 __be32
1064 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1065 		loff_t offset, struct kvec *vec, int vlen,
1066 		unsigned long *count)
1067 {
1068 	__be32		err;
1069 
1070 	if (file) {
1071 		err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1072 				MAY_READ|MAY_OWNER_OVERRIDE);
1073 		if (err)
1074 			goto out;
1075 		err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
1076 	} else {
1077 		err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file);
1078 		if (err)
1079 			goto out;
1080 		err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
1081 		nfsd_close(file);
1082 	}
1083 out:
1084 	return err;
1085 }
1086 
1087 /*
1088  * Write data to a file.
1089  * The stable flag requests synchronous writes.
1090  * N.B. After this call fhp needs an fh_put
1091  */
1092 __be32
1093 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1094 		loff_t offset, struct kvec *vec, int vlen, unsigned long cnt,
1095 		int *stablep)
1096 {
1097 	__be32			err = 0;
1098 
1099 	if (file) {
1100 		err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1101 				MAY_WRITE|MAY_OWNER_OVERRIDE);
1102 		if (err)
1103 			goto out;
1104 		err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt,
1105 				stablep);
1106 	} else {
1107 		err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file);
1108 		if (err)
1109 			goto out;
1110 
1111 		if (cnt)
1112 			err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen,
1113 					     cnt, stablep);
1114 		nfsd_close(file);
1115 	}
1116 out:
1117 	return err;
1118 }
1119 
1120 #ifdef CONFIG_NFSD_V3
1121 /*
1122  * Commit all pending writes to stable storage.
1123  * Strictly speaking, we could sync just the indicated file region here,
1124  * but there's currently no way we can ask the VFS to do so.
1125  *
1126  * Unfortunately we cannot lock the file to make sure we return full WCC
1127  * data to the client, as locking happens lower down in the filesystem.
1128  */
1129 __be32
1130 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1131                loff_t offset, unsigned long count)
1132 {
1133 	struct file	*file;
1134 	__be32		err;
1135 
1136 	if ((u64)count > ~(u64)offset)
1137 		return nfserr_inval;
1138 
1139 	if ((err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file)) != 0)
1140 		return err;
1141 	if (EX_ISSYNC(fhp->fh_export)) {
1142 		if (file->f_op && file->f_op->fsync) {
1143 			err = nfserrno(nfsd_sync(file));
1144 		} else {
1145 			err = nfserr_notsupp;
1146 		}
1147 	}
1148 
1149 	nfsd_close(file);
1150 	return err;
1151 }
1152 #endif /* CONFIG_NFSD_V3 */
1153 
1154 __be32
1155 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1156 			struct iattr *iap)
1157 {
1158 	/*
1159 	 * Mode has already been set earlier in create:
1160 	 */
1161 	iap->ia_valid &= ~ATTR_MODE;
1162 	/*
1163 	 * Setting uid/gid works only for root.  Irix appears to
1164 	 * send along the gid on create when it tries to implement
1165 	 * setgid directories via NFS:
1166 	 */
1167 	if (current->fsuid != 0)
1168 		iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1169 	if (iap->ia_valid)
1170 		return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1171 	return 0;
1172 }
1173 
1174 /*
1175  * Create a file (regular, directory, device, fifo); UNIX sockets
1176  * not yet implemented.
1177  * If the response fh has been verified, the parent directory should
1178  * already be locked. Note that the parent directory is left locked.
1179  *
1180  * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1181  */
1182 __be32
1183 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1184 		char *fname, int flen, struct iattr *iap,
1185 		int type, dev_t rdev, struct svc_fh *resfhp)
1186 {
1187 	struct dentry	*dentry, *dchild = NULL;
1188 	struct inode	*dirp;
1189 	__be32		err;
1190 	__be32		err2;
1191 	int		host_err;
1192 
1193 	err = nfserr_perm;
1194 	if (!flen)
1195 		goto out;
1196 	err = nfserr_exist;
1197 	if (isdotent(fname, flen))
1198 		goto out;
1199 
1200 	err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
1201 	if (err)
1202 		goto out;
1203 
1204 	dentry = fhp->fh_dentry;
1205 	dirp = dentry->d_inode;
1206 
1207 	err = nfserr_notdir;
1208 	if(!dirp->i_op || !dirp->i_op->lookup)
1209 		goto out;
1210 	/*
1211 	 * Check whether the response file handle has been verified yet.
1212 	 * If it has, the parent directory should already be locked.
1213 	 */
1214 	if (!resfhp->fh_dentry) {
1215 		/* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
1216 		fh_lock_nested(fhp, I_MUTEX_PARENT);
1217 		dchild = lookup_one_len(fname, dentry, flen);
1218 		host_err = PTR_ERR(dchild);
1219 		if (IS_ERR(dchild))
1220 			goto out_nfserr;
1221 		err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1222 		if (err)
1223 			goto out;
1224 	} else {
1225 		/* called from nfsd_proc_create */
1226 		dchild = dget(resfhp->fh_dentry);
1227 		if (!fhp->fh_locked) {
1228 			/* not actually possible */
1229 			printk(KERN_ERR
1230 				"nfsd_create: parent %s/%s not locked!\n",
1231 				dentry->d_parent->d_name.name,
1232 				dentry->d_name.name);
1233 			err = nfserr_io;
1234 			goto out;
1235 		}
1236 	}
1237 	/*
1238 	 * Make sure the child dentry is still negative ...
1239 	 */
1240 	err = nfserr_exist;
1241 	if (dchild->d_inode) {
1242 		dprintk("nfsd_create: dentry %s/%s not negative!\n",
1243 			dentry->d_name.name, dchild->d_name.name);
1244 		goto out;
1245 	}
1246 
1247 	if (!(iap->ia_valid & ATTR_MODE))
1248 		iap->ia_mode = 0;
1249 	iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1250 
1251 	/*
1252 	 * Get the dir op function pointer.
1253 	 */
1254 	err = 0;
1255 	switch (type) {
1256 	case S_IFREG:
1257 		host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1258 		break;
1259 	case S_IFDIR:
1260 		host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
1261 		break;
1262 	case S_IFCHR:
1263 	case S_IFBLK:
1264 	case S_IFIFO:
1265 	case S_IFSOCK:
1266 		host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
1267 		break;
1268 	default:
1269 	        printk("nfsd: bad file type %o in nfsd_create\n", type);
1270 		host_err = -EINVAL;
1271 	}
1272 	if (host_err < 0)
1273 		goto out_nfserr;
1274 
1275 	if (EX_ISSYNC(fhp->fh_export)) {
1276 		err = nfserrno(nfsd_sync_dir(dentry));
1277 		write_inode_now(dchild->d_inode, 1);
1278 	}
1279 
1280 
1281 	err2 = nfsd_create_setattr(rqstp, resfhp, iap);
1282 	if (err2)
1283 		err = err2;
1284 	/*
1285 	 * Update the file handle to get the new inode info.
1286 	 */
1287 	if (!err)
1288 		err = fh_update(resfhp);
1289 out:
1290 	if (dchild && !IS_ERR(dchild))
1291 		dput(dchild);
1292 	return err;
1293 
1294 out_nfserr:
1295 	err = nfserrno(host_err);
1296 	goto out;
1297 }
1298 
1299 #ifdef CONFIG_NFSD_V3
1300 /*
1301  * NFSv3 version of nfsd_create
1302  */
1303 __be32
1304 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp,
1305 		char *fname, int flen, struct iattr *iap,
1306 		struct svc_fh *resfhp, int createmode, u32 *verifier,
1307 	        int *truncp, int *created)
1308 {
1309 	struct dentry	*dentry, *dchild = NULL;
1310 	struct inode	*dirp;
1311 	__be32		err;
1312 	__be32		err2;
1313 	int		host_err;
1314 	__u32		v_mtime=0, v_atime=0;
1315 
1316 	err = nfserr_perm;
1317 	if (!flen)
1318 		goto out;
1319 	err = nfserr_exist;
1320 	if (isdotent(fname, flen))
1321 		goto out;
1322 	if (!(iap->ia_valid & ATTR_MODE))
1323 		iap->ia_mode = 0;
1324 	err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
1325 	if (err)
1326 		goto out;
1327 
1328 	dentry = fhp->fh_dentry;
1329 	dirp = dentry->d_inode;
1330 
1331 	/* Get all the sanity checks out of the way before
1332 	 * we lock the parent. */
1333 	err = nfserr_notdir;
1334 	if(!dirp->i_op || !dirp->i_op->lookup)
1335 		goto out;
1336 	fh_lock_nested(fhp, I_MUTEX_PARENT);
1337 
1338 	/*
1339 	 * Compose the response file handle.
1340 	 */
1341 	dchild = lookup_one_len(fname, dentry, flen);
1342 	host_err = PTR_ERR(dchild);
1343 	if (IS_ERR(dchild))
1344 		goto out_nfserr;
1345 
1346 	err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1347 	if (err)
1348 		goto out;
1349 
1350 	if (createmode == NFS3_CREATE_EXCLUSIVE) {
1351 		/* solaris7 gets confused (bugid 4218508) if these have
1352 		 * the high bit set, so just clear the high bits. If this is
1353 		 * ever changed to use different attrs for storing the
1354 		 * verifier, then do_open_lookup() will also need to be fixed
1355 		 * accordingly.
1356 		 */
1357 		v_mtime = verifier[0]&0x7fffffff;
1358 		v_atime = verifier[1]&0x7fffffff;
1359 	}
1360 
1361 	if (dchild->d_inode) {
1362 		err = 0;
1363 
1364 		switch (createmode) {
1365 		case NFS3_CREATE_UNCHECKED:
1366 			if (! S_ISREG(dchild->d_inode->i_mode))
1367 				err = nfserr_exist;
1368 			else if (truncp) {
1369 				/* in nfsv4, we need to treat this case a little
1370 				 * differently.  we don't want to truncate the
1371 				 * file now; this would be wrong if the OPEN
1372 				 * fails for some other reason.  furthermore,
1373 				 * if the size is nonzero, we should ignore it
1374 				 * according to spec!
1375 				 */
1376 				*truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1377 			}
1378 			else {
1379 				iap->ia_valid &= ATTR_SIZE;
1380 				goto set_attr;
1381 			}
1382 			break;
1383 		case NFS3_CREATE_EXCLUSIVE:
1384 			if (   dchild->d_inode->i_mtime.tv_sec == v_mtime
1385 			    && dchild->d_inode->i_atime.tv_sec == v_atime
1386 			    && dchild->d_inode->i_size  == 0 )
1387 				break;
1388 			 /* fallthru */
1389 		case NFS3_CREATE_GUARDED:
1390 			err = nfserr_exist;
1391 		}
1392 		goto out;
1393 	}
1394 
1395 	host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL);
1396 	if (host_err < 0)
1397 		goto out_nfserr;
1398 	if (created)
1399 		*created = 1;
1400 
1401 	if (EX_ISSYNC(fhp->fh_export)) {
1402 		err = nfserrno(nfsd_sync_dir(dentry));
1403 		/* setattr will sync the child (or not) */
1404 	}
1405 
1406 	if (createmode == NFS3_CREATE_EXCLUSIVE) {
1407 		/* Cram the verifier into atime/mtime */
1408 		iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1409 			| ATTR_MTIME_SET|ATTR_ATIME_SET;
1410 		/* XXX someone who knows this better please fix it for nsec */
1411 		iap->ia_mtime.tv_sec = v_mtime;
1412 		iap->ia_atime.tv_sec = v_atime;
1413 		iap->ia_mtime.tv_nsec = 0;
1414 		iap->ia_atime.tv_nsec = 0;
1415 	}
1416 
1417  set_attr:
1418 	err2 = nfsd_create_setattr(rqstp, resfhp, iap);
1419 	if (err2)
1420 		err = err2;
1421 
1422 	/*
1423 	 * Update the filehandle to get the new inode info.
1424 	 */
1425 	if (!err)
1426 		err = fh_update(resfhp);
1427 
1428  out:
1429 	fh_unlock(fhp);
1430 	if (dchild && !IS_ERR(dchild))
1431 		dput(dchild);
1432  	return err;
1433 
1434  out_nfserr:
1435 	err = nfserrno(host_err);
1436 	goto out;
1437 }
1438 #endif /* CONFIG_NFSD_V3 */
1439 
1440 /*
1441  * Read a symlink. On entry, *lenp must contain the maximum path length that
1442  * fits into the buffer. On return, it contains the true length.
1443  * N.B. After this call fhp needs an fh_put
1444  */
1445 __be32
1446 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1447 {
1448 	struct dentry	*dentry;
1449 	struct inode	*inode;
1450 	mm_segment_t	oldfs;
1451 	__be32		err;
1452 	int		host_err;
1453 
1454 	err = fh_verify(rqstp, fhp, S_IFLNK, MAY_NOP);
1455 	if (err)
1456 		goto out;
1457 
1458 	dentry = fhp->fh_dentry;
1459 	inode = dentry->d_inode;
1460 
1461 	err = nfserr_inval;
1462 	if (!inode->i_op || !inode->i_op->readlink)
1463 		goto out;
1464 
1465 	touch_atime(fhp->fh_export->ex_mnt, dentry);
1466 	/* N.B. Why does this call need a get_fs()??
1467 	 * Remove the set_fs and watch the fireworks:-) --okir
1468 	 */
1469 
1470 	oldfs = get_fs(); set_fs(KERNEL_DS);
1471 	host_err = inode->i_op->readlink(dentry, buf, *lenp);
1472 	set_fs(oldfs);
1473 
1474 	if (host_err < 0)
1475 		goto out_nfserr;
1476 	*lenp = host_err;
1477 	err = 0;
1478 out:
1479 	return err;
1480 
1481 out_nfserr:
1482 	err = nfserrno(host_err);
1483 	goto out;
1484 }
1485 
1486 /*
1487  * Create a symlink and look up its inode
1488  * N.B. After this call _both_ fhp and resfhp need an fh_put
1489  */
1490 __be32
1491 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1492 				char *fname, int flen,
1493 				char *path,  int plen,
1494 				struct svc_fh *resfhp,
1495 				struct iattr *iap)
1496 {
1497 	struct dentry	*dentry, *dnew;
1498 	__be32		err, cerr;
1499 	int		host_err;
1500 	umode_t		mode;
1501 
1502 	err = nfserr_noent;
1503 	if (!flen || !plen)
1504 		goto out;
1505 	err = nfserr_exist;
1506 	if (isdotent(fname, flen))
1507 		goto out;
1508 
1509 	err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE);
1510 	if (err)
1511 		goto out;
1512 	fh_lock(fhp);
1513 	dentry = fhp->fh_dentry;
1514 	dnew = lookup_one_len(fname, dentry, flen);
1515 	host_err = PTR_ERR(dnew);
1516 	if (IS_ERR(dnew))
1517 		goto out_nfserr;
1518 
1519 	mode = S_IALLUGO;
1520 	/* Only the MODE ATTRibute is even vaguely meaningful */
1521 	if (iap && (iap->ia_valid & ATTR_MODE))
1522 		mode = iap->ia_mode & S_IALLUGO;
1523 
1524 	if (unlikely(path[plen] != 0)) {
1525 		char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
1526 		if (path_alloced == NULL)
1527 			host_err = -ENOMEM;
1528 		else {
1529 			strncpy(path_alloced, path, plen);
1530 			path_alloced[plen] = 0;
1531 			host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced, mode);
1532 			kfree(path_alloced);
1533 		}
1534 	} else
1535 		host_err = vfs_symlink(dentry->d_inode, dnew, path, mode);
1536 
1537 	if (!host_err) {
1538 		if (EX_ISSYNC(fhp->fh_export))
1539 			host_err = nfsd_sync_dir(dentry);
1540 	}
1541 	err = nfserrno(host_err);
1542 	fh_unlock(fhp);
1543 
1544 	cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1545 	dput(dnew);
1546 	if (err==0) err = cerr;
1547 out:
1548 	return err;
1549 
1550 out_nfserr:
1551 	err = nfserrno(host_err);
1552 	goto out;
1553 }
1554 
1555 /*
1556  * Create a hardlink
1557  * N.B. After this call _both_ ffhp and tfhp need an fh_put
1558  */
1559 __be32
1560 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1561 				char *name, int len, struct svc_fh *tfhp)
1562 {
1563 	struct dentry	*ddir, *dnew, *dold;
1564 	struct inode	*dirp, *dest;
1565 	__be32		err;
1566 	int		host_err;
1567 
1568 	err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_CREATE);
1569 	if (err)
1570 		goto out;
1571 	err = fh_verify(rqstp, tfhp, -S_IFDIR, MAY_NOP);
1572 	if (err)
1573 		goto out;
1574 
1575 	err = nfserr_perm;
1576 	if (!len)
1577 		goto out;
1578 	err = nfserr_exist;
1579 	if (isdotent(name, len))
1580 		goto out;
1581 
1582 	fh_lock_nested(ffhp, I_MUTEX_PARENT);
1583 	ddir = ffhp->fh_dentry;
1584 	dirp = ddir->d_inode;
1585 
1586 	dnew = lookup_one_len(name, ddir, len);
1587 	host_err = PTR_ERR(dnew);
1588 	if (IS_ERR(dnew))
1589 		goto out_nfserr;
1590 
1591 	dold = tfhp->fh_dentry;
1592 	dest = dold->d_inode;
1593 
1594 	host_err = vfs_link(dold, dirp, dnew);
1595 	if (!host_err) {
1596 		if (EX_ISSYNC(ffhp->fh_export)) {
1597 			err = nfserrno(nfsd_sync_dir(ddir));
1598 			write_inode_now(dest, 1);
1599 		}
1600 		err = 0;
1601 	} else {
1602 		if (host_err == -EXDEV && rqstp->rq_vers == 2)
1603 			err = nfserr_acces;
1604 		else
1605 			err = nfserrno(host_err);
1606 	}
1607 
1608 	dput(dnew);
1609 out_unlock:
1610 	fh_unlock(ffhp);
1611 out:
1612 	return err;
1613 
1614 out_nfserr:
1615 	err = nfserrno(host_err);
1616 	goto out_unlock;
1617 }
1618 
1619 /*
1620  * Rename a file
1621  * N.B. After this call _both_ ffhp and tfhp need an fh_put
1622  */
1623 __be32
1624 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1625 			    struct svc_fh *tfhp, char *tname, int tlen)
1626 {
1627 	struct dentry	*fdentry, *tdentry, *odentry, *ndentry, *trap;
1628 	struct inode	*fdir, *tdir;
1629 	__be32		err;
1630 	int		host_err;
1631 
1632 	err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_REMOVE);
1633 	if (err)
1634 		goto out;
1635 	err = fh_verify(rqstp, tfhp, S_IFDIR, MAY_CREATE);
1636 	if (err)
1637 		goto out;
1638 
1639 	fdentry = ffhp->fh_dentry;
1640 	fdir = fdentry->d_inode;
1641 
1642 	tdentry = tfhp->fh_dentry;
1643 	tdir = tdentry->d_inode;
1644 
1645 	err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
1646 	if (ffhp->fh_export != tfhp->fh_export)
1647 		goto out;
1648 
1649 	err = nfserr_perm;
1650 	if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1651 		goto out;
1652 
1653 	/* cannot use fh_lock as we need deadlock protective ordering
1654 	 * so do it by hand */
1655 	trap = lock_rename(tdentry, fdentry);
1656 	ffhp->fh_locked = tfhp->fh_locked = 1;
1657 	fill_pre_wcc(ffhp);
1658 	fill_pre_wcc(tfhp);
1659 
1660 	odentry = lookup_one_len(fname, fdentry, flen);
1661 	host_err = PTR_ERR(odentry);
1662 	if (IS_ERR(odentry))
1663 		goto out_nfserr;
1664 
1665 	host_err = -ENOENT;
1666 	if (!odentry->d_inode)
1667 		goto out_dput_old;
1668 	host_err = -EINVAL;
1669 	if (odentry == trap)
1670 		goto out_dput_old;
1671 
1672 	ndentry = lookup_one_len(tname, tdentry, tlen);
1673 	host_err = PTR_ERR(ndentry);
1674 	if (IS_ERR(ndentry))
1675 		goto out_dput_old;
1676 	host_err = -ENOTEMPTY;
1677 	if (ndentry == trap)
1678 		goto out_dput_new;
1679 
1680 #ifdef MSNFS
1681 	if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
1682 		((atomic_read(&odentry->d_count) > 1)
1683 		 || (atomic_read(&ndentry->d_count) > 1))) {
1684 			host_err = -EPERM;
1685 	} else
1686 #endif
1687 	host_err = vfs_rename(fdir, odentry, tdir, ndentry);
1688 	if (!host_err && EX_ISSYNC(tfhp->fh_export)) {
1689 		host_err = nfsd_sync_dir(tdentry);
1690 		if (!host_err)
1691 			host_err = nfsd_sync_dir(fdentry);
1692 	}
1693 
1694  out_dput_new:
1695 	dput(ndentry);
1696  out_dput_old:
1697 	dput(odentry);
1698  out_nfserr:
1699 	err = nfserrno(host_err);
1700 
1701 	/* we cannot reply on fh_unlock on the two filehandles,
1702 	 * as that would do the wrong thing if the two directories
1703 	 * were the same, so again we do it by hand
1704 	 */
1705 	fill_post_wcc(ffhp);
1706 	fill_post_wcc(tfhp);
1707 	unlock_rename(tdentry, fdentry);
1708 	ffhp->fh_locked = tfhp->fh_locked = 0;
1709 
1710 out:
1711 	return err;
1712 }
1713 
1714 /*
1715  * Unlink a file or directory
1716  * N.B. After this call fhp needs an fh_put
1717  */
1718 __be32
1719 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1720 				char *fname, int flen)
1721 {
1722 	struct dentry	*dentry, *rdentry;
1723 	struct inode	*dirp;
1724 	__be32		err;
1725 	int		host_err;
1726 
1727 	err = nfserr_acces;
1728 	if (!flen || isdotent(fname, flen))
1729 		goto out;
1730 	err = fh_verify(rqstp, fhp, S_IFDIR, MAY_REMOVE);
1731 	if (err)
1732 		goto out;
1733 
1734 	fh_lock_nested(fhp, I_MUTEX_PARENT);
1735 	dentry = fhp->fh_dentry;
1736 	dirp = dentry->d_inode;
1737 
1738 	rdentry = lookup_one_len(fname, dentry, flen);
1739 	host_err = PTR_ERR(rdentry);
1740 	if (IS_ERR(rdentry))
1741 		goto out_nfserr;
1742 
1743 	if (!rdentry->d_inode) {
1744 		dput(rdentry);
1745 		err = nfserr_noent;
1746 		goto out;
1747 	}
1748 
1749 	if (!type)
1750 		type = rdentry->d_inode->i_mode & S_IFMT;
1751 
1752 	if (type != S_IFDIR) { /* It's UNLINK */
1753 #ifdef MSNFS
1754 		if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) &&
1755 			(atomic_read(&rdentry->d_count) > 1)) {
1756 			host_err = -EPERM;
1757 		} else
1758 #endif
1759 		host_err = vfs_unlink(dirp, rdentry);
1760 	} else { /* It's RMDIR */
1761 		host_err = vfs_rmdir(dirp, rdentry);
1762 	}
1763 
1764 	dput(rdentry);
1765 
1766 	if (host_err)
1767 		goto out_nfserr;
1768 	if (EX_ISSYNC(fhp->fh_export))
1769 		host_err = nfsd_sync_dir(dentry);
1770 
1771 out_nfserr:
1772 	err = nfserrno(host_err);
1773 out:
1774 	return err;
1775 }
1776 
1777 /*
1778  * Read entries from a directory.
1779  * The  NFSv3/4 verifier we ignore for now.
1780  */
1781 __be32
1782 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
1783 	     struct readdir_cd *cdp, filldir_t func)
1784 {
1785 	__be32		err;
1786 	int 		host_err;
1787 	struct file	*file;
1788 	loff_t		offset = *offsetp;
1789 
1790 	err = nfsd_open(rqstp, fhp, S_IFDIR, MAY_READ, &file);
1791 	if (err)
1792 		goto out;
1793 
1794 	offset = vfs_llseek(file, offset, 0);
1795 	if (offset < 0) {
1796 		err = nfserrno((int)offset);
1797 		goto out_close;
1798 	}
1799 
1800 	/*
1801 	 * Read the directory entries. This silly loop is necessary because
1802 	 * readdir() is not guaranteed to fill up the entire buffer, but
1803 	 * may choose to do less.
1804 	 */
1805 
1806 	do {
1807 		cdp->err = nfserr_eof; /* will be cleared on successful read */
1808 		host_err = vfs_readdir(file, func, cdp);
1809 	} while (host_err >=0 && cdp->err == nfs_ok);
1810 	if (host_err)
1811 		err = nfserrno(host_err);
1812 	else
1813 		err = cdp->err;
1814 	*offsetp = vfs_llseek(file, 0, 1);
1815 
1816 	if (err == nfserr_eof || err == nfserr_toosmall)
1817 		err = nfs_ok; /* can still be found in ->err */
1818 out_close:
1819 	nfsd_close(file);
1820 out:
1821 	return err;
1822 }
1823 
1824 /*
1825  * Get file system stats
1826  * N.B. After this call fhp needs an fh_put
1827  */
1828 __be32
1829 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat)
1830 {
1831 	__be32 err = fh_verify(rqstp, fhp, 0, MAY_NOP);
1832 	if (!err && vfs_statfs(fhp->fh_dentry,stat))
1833 		err = nfserr_io;
1834 	return err;
1835 }
1836 
1837 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
1838 {
1839 	return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
1840 }
1841 
1842 /*
1843  * Check for a user's access permissions to this inode.
1844  */
1845 __be32
1846 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
1847 					struct dentry *dentry, int acc)
1848 {
1849 	struct inode	*inode = dentry->d_inode;
1850 	int		err;
1851 
1852 	if (acc == MAY_NOP)
1853 		return 0;
1854 #if 0
1855 	dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
1856 		acc,
1857 		(acc & MAY_READ)?	" read"  : "",
1858 		(acc & MAY_WRITE)?	" write" : "",
1859 		(acc & MAY_EXEC)?	" exec"  : "",
1860 		(acc & MAY_SATTR)?	" sattr" : "",
1861 		(acc & MAY_TRUNC)?	" trunc" : "",
1862 		(acc & MAY_LOCK)?	" lock"  : "",
1863 		(acc & MAY_OWNER_OVERRIDE)? " owneroverride" : "",
1864 		inode->i_mode,
1865 		IS_IMMUTABLE(inode)?	" immut" : "",
1866 		IS_APPEND(inode)?	" append" : "",
1867 		IS_RDONLY(inode)?	" ro" : "");
1868 	dprintk("      owner %d/%d user %d/%d\n",
1869 		inode->i_uid, inode->i_gid, current->fsuid, current->fsgid);
1870 #endif
1871 
1872 	/* Normally we reject any write/sattr etc access on a read-only file
1873 	 * system.  But if it is IRIX doing check on write-access for a
1874 	 * device special file, we ignore rofs.
1875 	 */
1876 	if (!(acc & MAY_LOCAL_ACCESS))
1877 		if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) {
1878 			if (exp_rdonly(rqstp, exp) || IS_RDONLY(inode))
1879 				return nfserr_rofs;
1880 			if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode))
1881 				return nfserr_perm;
1882 		}
1883 	if ((acc & MAY_TRUNC) && IS_APPEND(inode))
1884 		return nfserr_perm;
1885 
1886 	if (acc & MAY_LOCK) {
1887 		/* If we cannot rely on authentication in NLM requests,
1888 		 * just allow locks, otherwise require read permission, or
1889 		 * ownership
1890 		 */
1891 		if (exp->ex_flags & NFSEXP_NOAUTHNLM)
1892 			return 0;
1893 		else
1894 			acc = MAY_READ | MAY_OWNER_OVERRIDE;
1895 	}
1896 	/*
1897 	 * The file owner always gets access permission for accesses that
1898 	 * would normally be checked at open time. This is to make
1899 	 * file access work even when the client has done a fchmod(fd, 0).
1900 	 *
1901 	 * However, `cp foo bar' should fail nevertheless when bar is
1902 	 * readonly. A sensible way to do this might be to reject all
1903 	 * attempts to truncate a read-only file, because a creat() call
1904 	 * always implies file truncation.
1905 	 * ... but this isn't really fair.  A process may reasonably call
1906 	 * ftruncate on an open file descriptor on a file with perm 000.
1907 	 * We must trust the client to do permission checking - using "ACCESS"
1908 	 * with NFSv3.
1909 	 */
1910 	if ((acc & MAY_OWNER_OVERRIDE) &&
1911 	    inode->i_uid == current->fsuid)
1912 		return 0;
1913 
1914 	err = permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC), NULL);
1915 
1916 	/* Allow read access to binaries even when mode 111 */
1917 	if (err == -EACCES && S_ISREG(inode->i_mode) &&
1918 	    acc == (MAY_READ | MAY_OWNER_OVERRIDE))
1919 		err = permission(inode, MAY_EXEC, NULL);
1920 
1921 	return err? nfserrno(err) : 0;
1922 }
1923 
1924 void
1925 nfsd_racache_shutdown(void)
1926 {
1927 	if (!raparml)
1928 		return;
1929 	dprintk("nfsd: freeing readahead buffers.\n");
1930 	kfree(raparml);
1931 	raparml = NULL;
1932 }
1933 /*
1934  * Initialize readahead param cache
1935  */
1936 int
1937 nfsd_racache_init(int cache_size)
1938 {
1939 	int	i;
1940 	int	j = 0;
1941 	int	nperbucket;
1942 
1943 
1944 	if (raparml)
1945 		return 0;
1946 	if (cache_size < 2*RAPARM_HASH_SIZE)
1947 		cache_size = 2*RAPARM_HASH_SIZE;
1948 	raparml = kcalloc(cache_size, sizeof(struct raparms), GFP_KERNEL);
1949 
1950 	if (!raparml) {
1951 		printk(KERN_WARNING
1952 			"nfsd: Could not allocate memory read-ahead cache.\n");
1953 		return -ENOMEM;
1954 	}
1955 
1956 	dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
1957 	for (i = 0 ; i < RAPARM_HASH_SIZE ; i++) {
1958 		raparm_hash[i].pb_head = NULL;
1959 		spin_lock_init(&raparm_hash[i].pb_lock);
1960 	}
1961 	nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
1962 	for (i = 0; i < cache_size - 1; i++) {
1963 		if (i % nperbucket == 0)
1964 			raparm_hash[j++].pb_head = raparml + i;
1965 		if (i % nperbucket < nperbucket-1)
1966 			raparml[i].p_next = raparml + i + 1;
1967 	}
1968 
1969 	nfsdstats.ra_size = cache_size;
1970 	return 0;
1971 }
1972 
1973 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
1974 struct posix_acl *
1975 nfsd_get_posix_acl(struct svc_fh *fhp, int type)
1976 {
1977 	struct inode *inode = fhp->fh_dentry->d_inode;
1978 	char *name;
1979 	void *value = NULL;
1980 	ssize_t size;
1981 	struct posix_acl *acl;
1982 
1983 	if (!IS_POSIXACL(inode))
1984 		return ERR_PTR(-EOPNOTSUPP);
1985 
1986 	switch (type) {
1987 	case ACL_TYPE_ACCESS:
1988 		name = POSIX_ACL_XATTR_ACCESS;
1989 		break;
1990 	case ACL_TYPE_DEFAULT:
1991 		name = POSIX_ACL_XATTR_DEFAULT;
1992 		break;
1993 	default:
1994 		return ERR_PTR(-EOPNOTSUPP);
1995 	}
1996 
1997 	size = nfsd_getxattr(fhp->fh_dentry, name, &value);
1998 	if (size < 0)
1999 		return ERR_PTR(size);
2000 
2001 	acl = posix_acl_from_xattr(value, size);
2002 	kfree(value);
2003 	return acl;
2004 }
2005 
2006 int
2007 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl)
2008 {
2009 	struct inode *inode = fhp->fh_dentry->d_inode;
2010 	char *name;
2011 	void *value = NULL;
2012 	size_t size;
2013 	int error;
2014 
2015 	if (!IS_POSIXACL(inode) || !inode->i_op ||
2016 	    !inode->i_op->setxattr || !inode->i_op->removexattr)
2017 		return -EOPNOTSUPP;
2018 	switch(type) {
2019 		case ACL_TYPE_ACCESS:
2020 			name = POSIX_ACL_XATTR_ACCESS;
2021 			break;
2022 		case ACL_TYPE_DEFAULT:
2023 			name = POSIX_ACL_XATTR_DEFAULT;
2024 			break;
2025 		default:
2026 			return -EOPNOTSUPP;
2027 	}
2028 
2029 	if (acl && acl->a_count) {
2030 		size = posix_acl_xattr_size(acl->a_count);
2031 		value = kmalloc(size, GFP_KERNEL);
2032 		if (!value)
2033 			return -ENOMEM;
2034 		error = posix_acl_to_xattr(acl, value, size);
2035 		if (error < 0)
2036 			goto getout;
2037 		size = error;
2038 	} else
2039 		size = 0;
2040 
2041 	if (size)
2042 		error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0);
2043 	else {
2044 		if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT)
2045 			error = 0;
2046 		else {
2047 			error = vfs_removexattr(fhp->fh_dentry, name);
2048 			if (error == -ENODATA)
2049 				error = 0;
2050 		}
2051 	}
2052 
2053 getout:
2054 	kfree(value);
2055 	return error;
2056 }
2057 #endif  /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
2058