xref: /linux/fs/nfsd/nfsproc.c (revision 3a39d672e7f48b8d6b91a09afa4b55352773b4b5)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Process version 2 NFS requests.
4  *
5  * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
6  */
7 
8 #include <linux/namei.h>
9 
10 #include "cache.h"
11 #include "xdr.h"
12 #include "vfs.h"
13 
14 #define NFSDDBG_FACILITY		NFSDDBG_PROC
15 
nfsd_map_status(__be32 status)16 static __be32 nfsd_map_status(__be32 status)
17 {
18 	switch (status) {
19 	case nfs_ok:
20 		break;
21 	case nfserr_nofilehandle:
22 	case nfserr_badhandle:
23 		status = nfserr_stale;
24 		break;
25 	case nfserr_wrongsec:
26 	case nfserr_xdev:
27 	case nfserr_file_open:
28 		status = nfserr_acces;
29 		break;
30 	case nfserr_symlink_not_dir:
31 		status = nfserr_notdir;
32 		break;
33 	case nfserr_symlink:
34 	case nfserr_wrong_type:
35 		status = nfserr_inval;
36 		break;
37 	}
38 	return status;
39 }
40 
41 static __be32
nfsd_proc_null(struct svc_rqst * rqstp)42 nfsd_proc_null(struct svc_rqst *rqstp)
43 {
44 	return rpc_success;
45 }
46 
47 /*
48  * Get a file's attributes
49  * N.B. After this call resp->fh needs an fh_put
50  */
51 static __be32
nfsd_proc_getattr(struct svc_rqst * rqstp)52 nfsd_proc_getattr(struct svc_rqst *rqstp)
53 {
54 	struct nfsd_fhandle *argp = rqstp->rq_argp;
55 	struct nfsd_attrstat *resp = rqstp->rq_resp;
56 
57 	dprintk("nfsd: GETATTR  %s\n", SVCFH_fmt(&argp->fh));
58 
59 	fh_copy(&resp->fh, &argp->fh);
60 	resp->status = fh_verify(rqstp, &resp->fh, 0,
61 				 NFSD_MAY_NOP | NFSD_MAY_BYPASS_GSS_ON_ROOT);
62 	if (resp->status != nfs_ok)
63 		goto out;
64 	resp->status = fh_getattr(&resp->fh, &resp->stat);
65 out:
66 	resp->status = nfsd_map_status(resp->status);
67 	return rpc_success;
68 }
69 
70 /*
71  * Set a file's attributes
72  * N.B. After this call resp->fh needs an fh_put
73  */
74 static __be32
nfsd_proc_setattr(struct svc_rqst * rqstp)75 nfsd_proc_setattr(struct svc_rqst *rqstp)
76 {
77 	struct nfsd_sattrargs *argp = rqstp->rq_argp;
78 	struct nfsd_attrstat *resp = rqstp->rq_resp;
79 	struct iattr *iap = &argp->attrs;
80 	struct nfsd_attrs attrs = {
81 		.na_iattr	= iap,
82 	};
83 	struct svc_fh *fhp;
84 
85 	dprintk("nfsd: SETATTR  %s, valid=%x, size=%ld\n",
86 		SVCFH_fmt(&argp->fh),
87 		argp->attrs.ia_valid, (long) argp->attrs.ia_size);
88 
89 	fhp = fh_copy(&resp->fh, &argp->fh);
90 
91 	/*
92 	 * NFSv2 does not differentiate between "set-[ac]time-to-now"
93 	 * which only requires access, and "set-[ac]time-to-X" which
94 	 * requires ownership.
95 	 * So if it looks like it might be "set both to the same time which
96 	 * is close to now", and if setattr_prepare fails, then we
97 	 * convert to "set to now" instead of "set to explicit time"
98 	 *
99 	 * We only call setattr_prepare as the last test as technically
100 	 * it is not an interface that we should be using.
101 	 */
102 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
103 #define	MAX_TOUCH_TIME_ERROR (30*60)
104 	if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET &&
105 	    iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) {
106 		/*
107 		 * Looks probable.
108 		 *
109 		 * Now just make sure time is in the right ballpark.
110 		 * Solaris, at least, doesn't seem to care what the time
111 		 * request is.  We require it be within 30 minutes of now.
112 		 */
113 		time64_t delta = iap->ia_atime.tv_sec - ktime_get_real_seconds();
114 
115 		resp->status = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
116 		if (resp->status != nfs_ok)
117 			goto out;
118 
119 		if (delta < 0)
120 			delta = -delta;
121 		if (delta < MAX_TOUCH_TIME_ERROR &&
122 		    setattr_prepare(&nop_mnt_idmap, fhp->fh_dentry, iap) != 0) {
123 			/*
124 			 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
125 			 * This will cause notify_change to set these times
126 			 * to "now"
127 			 */
128 			iap->ia_valid &= ~BOTH_TIME_SET;
129 		}
130 	}
131 
132 	resp->status = nfsd_setattr(rqstp, fhp, &attrs, NULL);
133 	if (resp->status != nfs_ok)
134 		goto out;
135 
136 	resp->status = fh_getattr(&resp->fh, &resp->stat);
137 out:
138 	resp->status = nfsd_map_status(resp->status);
139 	return rpc_success;
140 }
141 
142 /* Obsolete, replaced by MNTPROC_MNT. */
143 static __be32
nfsd_proc_root(struct svc_rqst * rqstp)144 nfsd_proc_root(struct svc_rqst *rqstp)
145 {
146 	return rpc_success;
147 }
148 
149 /*
150  * Look up a path name component
151  * Note: the dentry in the resp->fh may be negative if the file
152  * doesn't exist yet.
153  * N.B. After this call resp->fh needs an fh_put
154  */
155 static __be32
nfsd_proc_lookup(struct svc_rqst * rqstp)156 nfsd_proc_lookup(struct svc_rqst *rqstp)
157 {
158 	struct nfsd_diropargs *argp = rqstp->rq_argp;
159 	struct nfsd_diropres *resp = rqstp->rq_resp;
160 
161 	dprintk("nfsd: LOOKUP   %s %.*s\n",
162 		SVCFH_fmt(&argp->fh), argp->len, argp->name);
163 
164 	fh_init(&resp->fh, NFS_FHSIZE);
165 	resp->status = nfsd_lookup(rqstp, &argp->fh, argp->name, argp->len,
166 				   &resp->fh);
167 	fh_put(&argp->fh);
168 	if (resp->status != nfs_ok)
169 		goto out;
170 
171 	resp->status = fh_getattr(&resp->fh, &resp->stat);
172 out:
173 	resp->status = nfsd_map_status(resp->status);
174 	return rpc_success;
175 }
176 
177 /*
178  * Read a symlink.
179  */
180 static __be32
nfsd_proc_readlink(struct svc_rqst * rqstp)181 nfsd_proc_readlink(struct svc_rqst *rqstp)
182 {
183 	struct nfsd_fhandle *argp = rqstp->rq_argp;
184 	struct nfsd_readlinkres *resp = rqstp->rq_resp;
185 
186 	dprintk("nfsd: READLINK %s\n", SVCFH_fmt(&argp->fh));
187 
188 	/* Read the symlink. */
189 	resp->len = NFS_MAXPATHLEN;
190 	resp->page = *(rqstp->rq_next_page++);
191 	resp->status = nfsd_readlink(rqstp, &argp->fh,
192 				     page_address(resp->page), &resp->len);
193 
194 	fh_put(&argp->fh);
195 	resp->status = nfsd_map_status(resp->status);
196 	return rpc_success;
197 }
198 
199 /*
200  * Read a portion of a file.
201  * N.B. After this call resp->fh needs an fh_put
202  */
203 static __be32
nfsd_proc_read(struct svc_rqst * rqstp)204 nfsd_proc_read(struct svc_rqst *rqstp)
205 {
206 	struct nfsd_readargs *argp = rqstp->rq_argp;
207 	struct nfsd_readres *resp = rqstp->rq_resp;
208 	u32 eof;
209 
210 	dprintk("nfsd: READ    %s %d bytes at %d\n",
211 		SVCFH_fmt(&argp->fh),
212 		argp->count, argp->offset);
213 
214 	argp->count = min_t(u32, argp->count, NFSSVC_MAXBLKSIZE_V2);
215 	argp->count = min_t(u32, argp->count, rqstp->rq_res.buflen);
216 
217 	resp->pages = rqstp->rq_next_page;
218 
219 	/* Obtain buffer pointer for payload. 19 is 1 word for
220 	 * status, 17 words for fattr, and 1 word for the byte count.
221 	 */
222 	svc_reserve_auth(rqstp, (19<<2) + argp->count + 4);
223 
224 	resp->count = argp->count;
225 	fh_copy(&resp->fh, &argp->fh);
226 	resp->status = nfsd_read(rqstp, &resp->fh, argp->offset,
227 				 &resp->count, &eof);
228 	if (resp->status == nfs_ok)
229 		resp->status = fh_getattr(&resp->fh, &resp->stat);
230 	else if (resp->status == nfserr_jukebox)
231 		set_bit(RQ_DROPME, &rqstp->rq_flags);
232 	resp->status = nfsd_map_status(resp->status);
233 	return rpc_success;
234 }
235 
236 /* Reserved */
237 static __be32
nfsd_proc_writecache(struct svc_rqst * rqstp)238 nfsd_proc_writecache(struct svc_rqst *rqstp)
239 {
240 	return rpc_success;
241 }
242 
243 /*
244  * Write data to a file
245  * N.B. After this call resp->fh needs an fh_put
246  */
247 static __be32
nfsd_proc_write(struct svc_rqst * rqstp)248 nfsd_proc_write(struct svc_rqst *rqstp)
249 {
250 	struct nfsd_writeargs *argp = rqstp->rq_argp;
251 	struct nfsd_attrstat *resp = rqstp->rq_resp;
252 	unsigned long cnt = argp->len;
253 	unsigned int nvecs;
254 
255 	dprintk("nfsd: WRITE    %s %u bytes at %d\n",
256 		SVCFH_fmt(&argp->fh),
257 		argp->len, argp->offset);
258 
259 	nvecs = svc_fill_write_vector(rqstp, &argp->payload);
260 
261 	resp->status = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh),
262 				  argp->offset, rqstp->rq_vec, nvecs,
263 				  &cnt, NFS_DATA_SYNC, NULL);
264 	if (resp->status == nfs_ok)
265 		resp->status = fh_getattr(&resp->fh, &resp->stat);
266 	else if (resp->status == nfserr_jukebox)
267 		set_bit(RQ_DROPME, &rqstp->rq_flags);
268 	resp->status = nfsd_map_status(resp->status);
269 	return rpc_success;
270 }
271 
272 /*
273  * CREATE processing is complicated. The keyword here is `overloaded.'
274  * The parent directory is kept locked between the check for existence
275  * and the actual create() call in compliance with VFS protocols.
276  * N.B. After this call _both_ argp->fh and resp->fh need an fh_put
277  */
278 static __be32
nfsd_proc_create(struct svc_rqst * rqstp)279 nfsd_proc_create(struct svc_rqst *rqstp)
280 {
281 	struct nfsd_createargs *argp = rqstp->rq_argp;
282 	struct nfsd_diropres *resp = rqstp->rq_resp;
283 	svc_fh		*dirfhp = &argp->fh;
284 	svc_fh		*newfhp = &resp->fh;
285 	struct iattr	*attr = &argp->attrs;
286 	struct nfsd_attrs attrs = {
287 		.na_iattr	= attr,
288 	};
289 	struct inode	*inode;
290 	struct dentry	*dchild;
291 	int		type, mode;
292 	int		hosterr;
293 	dev_t		rdev = 0, wanted = new_decode_dev(attr->ia_size);
294 
295 	dprintk("nfsd: CREATE   %s %.*s\n",
296 		SVCFH_fmt(dirfhp), argp->len, argp->name);
297 
298 	/* First verify the parent file handle */
299 	resp->status = fh_verify(rqstp, dirfhp, S_IFDIR, NFSD_MAY_EXEC);
300 	if (resp->status != nfs_ok)
301 		goto done; /* must fh_put dirfhp even on error */
302 
303 	/* Check for NFSD_MAY_WRITE in nfsd_create if necessary */
304 
305 	resp->status = nfserr_exist;
306 	if (isdotent(argp->name, argp->len))
307 		goto done;
308 	hosterr = fh_want_write(dirfhp);
309 	if (hosterr) {
310 		resp->status = nfserrno(hosterr);
311 		goto done;
312 	}
313 
314 	inode_lock_nested(dirfhp->fh_dentry->d_inode, I_MUTEX_PARENT);
315 	dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len);
316 	if (IS_ERR(dchild)) {
317 		resp->status = nfserrno(PTR_ERR(dchild));
318 		goto out_unlock;
319 	}
320 	fh_init(newfhp, NFS_FHSIZE);
321 	resp->status = fh_compose(newfhp, dirfhp->fh_export, dchild, dirfhp);
322 	if (!resp->status && d_really_is_negative(dchild))
323 		resp->status = nfserr_noent;
324 	dput(dchild);
325 	if (resp->status) {
326 		if (resp->status != nfserr_noent)
327 			goto out_unlock;
328 		/*
329 		 * If the new file handle wasn't verified, we can't tell
330 		 * whether the file exists or not. Time to bail ...
331 		 */
332 		resp->status = nfserr_acces;
333 		if (!newfhp->fh_dentry) {
334 			printk(KERN_WARNING
335 				"nfsd_proc_create: file handle not verified\n");
336 			goto out_unlock;
337 		}
338 	}
339 
340 	inode = d_inode(newfhp->fh_dentry);
341 
342 	/* Unfudge the mode bits */
343 	if (attr->ia_valid & ATTR_MODE) {
344 		type = attr->ia_mode & S_IFMT;
345 		mode = attr->ia_mode & ~S_IFMT;
346 		if (!type) {
347 			/* no type, so if target exists, assume same as that,
348 			 * else assume a file */
349 			if (inode) {
350 				type = inode->i_mode & S_IFMT;
351 				switch(type) {
352 				case S_IFCHR:
353 				case S_IFBLK:
354 					/* reserve rdev for later checking */
355 					rdev = inode->i_rdev;
356 					attr->ia_valid |= ATTR_SIZE;
357 
358 					fallthrough;
359 				case S_IFIFO:
360 					/* this is probably a permission check..
361 					 * at least IRIX implements perm checking on
362 					 *   echo thing > device-special-file-or-pipe
363 					 * by doing a CREATE with type==0
364 					 */
365 					resp->status = nfsd_permission(
366 						&rqstp->rq_cred,
367 						newfhp->fh_export,
368 						newfhp->fh_dentry,
369 						NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS);
370 					if (resp->status && resp->status != nfserr_rofs)
371 						goto out_unlock;
372 				}
373 			} else
374 				type = S_IFREG;
375 		}
376 	} else if (inode) {
377 		type = inode->i_mode & S_IFMT;
378 		mode = inode->i_mode & ~S_IFMT;
379 	} else {
380 		type = S_IFREG;
381 		mode = 0;	/* ??? */
382 	}
383 
384 	attr->ia_valid |= ATTR_MODE;
385 	attr->ia_mode = mode;
386 
387 	/* Special treatment for non-regular files according to the
388 	 * gospel of sun micro
389 	 */
390 	if (type != S_IFREG) {
391 		if (type != S_IFBLK && type != S_IFCHR) {
392 			rdev = 0;
393 		} else if (type == S_IFCHR && !(attr->ia_valid & ATTR_SIZE)) {
394 			/* If you think you've seen the worst, grok this. */
395 			type = S_IFIFO;
396 		} else {
397 			/* Okay, char or block special */
398 			if (!rdev)
399 				rdev = wanted;
400 		}
401 
402 		/* we've used the SIZE information, so discard it */
403 		attr->ia_valid &= ~ATTR_SIZE;
404 
405 		/* Make sure the type and device matches */
406 		resp->status = nfserr_exist;
407 		if (inode && inode_wrong_type(inode, type))
408 			goto out_unlock;
409 	}
410 
411 	resp->status = nfs_ok;
412 	if (!inode) {
413 		/* File doesn't exist. Create it and set attrs */
414 		resp->status = nfsd_create_locked(rqstp, dirfhp, &attrs, type,
415 						  rdev, newfhp);
416 	} else if (type == S_IFREG) {
417 		dprintk("nfsd:   existing %s, valid=%x, size=%ld\n",
418 			argp->name, attr->ia_valid, (long) attr->ia_size);
419 		/* File already exists. We ignore all attributes except
420 		 * size, so that creat() behaves exactly like
421 		 * open(..., O_CREAT|O_TRUNC|O_WRONLY).
422 		 */
423 		attr->ia_valid &= ATTR_SIZE;
424 		if (attr->ia_valid)
425 			resp->status = nfsd_setattr(rqstp, newfhp, &attrs,
426 						    NULL);
427 	}
428 
429 out_unlock:
430 	inode_unlock(dirfhp->fh_dentry->d_inode);
431 	fh_drop_write(dirfhp);
432 done:
433 	fh_put(dirfhp);
434 	if (resp->status != nfs_ok)
435 		goto out;
436 	resp->status = fh_getattr(&resp->fh, &resp->stat);
437 out:
438 	resp->status = nfsd_map_status(resp->status);
439 	return rpc_success;
440 }
441 
442 static __be32
nfsd_proc_remove(struct svc_rqst * rqstp)443 nfsd_proc_remove(struct svc_rqst *rqstp)
444 {
445 	struct nfsd_diropargs *argp = rqstp->rq_argp;
446 	struct nfsd_stat *resp = rqstp->rq_resp;
447 
448 	dprintk("nfsd: REMOVE   %s %.*s\n", SVCFH_fmt(&argp->fh),
449 		argp->len, argp->name);
450 
451 	/* Unlink. -SIFDIR means file must not be a directory */
452 	resp->status = nfsd_unlink(rqstp, &argp->fh, -S_IFDIR,
453 				   argp->name, argp->len);
454 	fh_put(&argp->fh);
455 	resp->status = nfsd_map_status(resp->status);
456 	return rpc_success;
457 }
458 
459 static __be32
nfsd_proc_rename(struct svc_rqst * rqstp)460 nfsd_proc_rename(struct svc_rqst *rqstp)
461 {
462 	struct nfsd_renameargs *argp = rqstp->rq_argp;
463 	struct nfsd_stat *resp = rqstp->rq_resp;
464 
465 	dprintk("nfsd: RENAME   %s %.*s -> \n",
466 		SVCFH_fmt(&argp->ffh), argp->flen, argp->fname);
467 	dprintk("nfsd:        ->  %s %.*s\n",
468 		SVCFH_fmt(&argp->tfh), argp->tlen, argp->tname);
469 
470 	resp->status = nfsd_rename(rqstp, &argp->ffh, argp->fname, argp->flen,
471 				   &argp->tfh, argp->tname, argp->tlen);
472 	fh_put(&argp->ffh);
473 	fh_put(&argp->tfh);
474 	resp->status = nfsd_map_status(resp->status);
475 	return rpc_success;
476 }
477 
478 static __be32
nfsd_proc_link(struct svc_rqst * rqstp)479 nfsd_proc_link(struct svc_rqst *rqstp)
480 {
481 	struct nfsd_linkargs *argp = rqstp->rq_argp;
482 	struct nfsd_stat *resp = rqstp->rq_resp;
483 
484 	dprintk("nfsd: LINK     %s ->\n",
485 		SVCFH_fmt(&argp->ffh));
486 	dprintk("nfsd:    %s %.*s\n",
487 		SVCFH_fmt(&argp->tfh),
488 		argp->tlen,
489 		argp->tname);
490 
491 	resp->status = nfsd_link(rqstp, &argp->tfh, argp->tname, argp->tlen,
492 				 &argp->ffh);
493 	fh_put(&argp->ffh);
494 	fh_put(&argp->tfh);
495 	resp->status = nfsd_map_status(resp->status);
496 	return rpc_success;
497 }
498 
499 static __be32
nfsd_proc_symlink(struct svc_rqst * rqstp)500 nfsd_proc_symlink(struct svc_rqst *rqstp)
501 {
502 	struct nfsd_symlinkargs *argp = rqstp->rq_argp;
503 	struct nfsd_stat *resp = rqstp->rq_resp;
504 	struct nfsd_attrs attrs = {
505 		.na_iattr	= &argp->attrs,
506 	};
507 	struct svc_fh	newfh;
508 
509 	if (argp->tlen > NFS_MAXPATHLEN) {
510 		resp->status = nfserr_nametoolong;
511 		goto out;
512 	}
513 
514 	argp->tname = svc_fill_symlink_pathname(rqstp, &argp->first,
515 						page_address(rqstp->rq_arg.pages[0]),
516 						argp->tlen);
517 	if (IS_ERR(argp->tname)) {
518 		resp->status = nfserrno(PTR_ERR(argp->tname));
519 		goto out;
520 	}
521 
522 	dprintk("nfsd: SYMLINK  %s %.*s -> %.*s\n",
523 		SVCFH_fmt(&argp->ffh), argp->flen, argp->fname,
524 		argp->tlen, argp->tname);
525 
526 	fh_init(&newfh, NFS_FHSIZE);
527 	resp->status = nfsd_symlink(rqstp, &argp->ffh, argp->fname, argp->flen,
528 				    argp->tname, &attrs, &newfh);
529 
530 	kfree(argp->tname);
531 	fh_put(&argp->ffh);
532 	fh_put(&newfh);
533 out:
534 	resp->status = nfsd_map_status(resp->status);
535 	return rpc_success;
536 }
537 
538 /*
539  * Make directory. This operation is not idempotent.
540  * N.B. After this call resp->fh needs an fh_put
541  */
542 static __be32
nfsd_proc_mkdir(struct svc_rqst * rqstp)543 nfsd_proc_mkdir(struct svc_rqst *rqstp)
544 {
545 	struct nfsd_createargs *argp = rqstp->rq_argp;
546 	struct nfsd_diropres *resp = rqstp->rq_resp;
547 	struct nfsd_attrs attrs = {
548 		.na_iattr	= &argp->attrs,
549 	};
550 
551 	dprintk("nfsd: MKDIR    %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);
552 
553 	if (resp->fh.fh_dentry) {
554 		printk(KERN_WARNING
555 			"nfsd_proc_mkdir: response already verified??\n");
556 	}
557 
558 	argp->attrs.ia_valid &= ~ATTR_SIZE;
559 	fh_init(&resp->fh, NFS_FHSIZE);
560 	resp->status = nfsd_create(rqstp, &argp->fh, argp->name, argp->len,
561 				   &attrs, S_IFDIR, 0, &resp->fh);
562 	fh_put(&argp->fh);
563 	if (resp->status != nfs_ok)
564 		goto out;
565 
566 	resp->status = fh_getattr(&resp->fh, &resp->stat);
567 out:
568 	resp->status = nfsd_map_status(resp->status);
569 	return rpc_success;
570 }
571 
572 /*
573  * Remove a directory
574  */
575 static __be32
nfsd_proc_rmdir(struct svc_rqst * rqstp)576 nfsd_proc_rmdir(struct svc_rqst *rqstp)
577 {
578 	struct nfsd_diropargs *argp = rqstp->rq_argp;
579 	struct nfsd_stat *resp = rqstp->rq_resp;
580 
581 	dprintk("nfsd: RMDIR    %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);
582 
583 	resp->status = nfsd_unlink(rqstp, &argp->fh, S_IFDIR,
584 				   argp->name, argp->len);
585 	fh_put(&argp->fh);
586 	resp->status = nfsd_map_status(resp->status);
587 	return rpc_success;
588 }
589 
nfsd_init_dirlist_pages(struct svc_rqst * rqstp,struct nfsd_readdirres * resp,u32 count)590 static void nfsd_init_dirlist_pages(struct svc_rqst *rqstp,
591 				    struct nfsd_readdirres *resp,
592 				    u32 count)
593 {
594 	struct xdr_buf *buf = &resp->dirlist;
595 	struct xdr_stream *xdr = &resp->xdr;
596 
597 	memset(buf, 0, sizeof(*buf));
598 
599 	/* Reserve room for the NULL ptr & eof flag (-2 words) */
600 	buf->buflen = clamp(count, (u32)(XDR_UNIT * 2), (u32)PAGE_SIZE);
601 	buf->buflen -= XDR_UNIT * 2;
602 	buf->pages = rqstp->rq_next_page;
603 	rqstp->rq_next_page++;
604 
605 	xdr_init_encode_pages(xdr, buf, buf->pages,  NULL);
606 }
607 
608 /*
609  * Read a portion of a directory.
610  */
611 static __be32
nfsd_proc_readdir(struct svc_rqst * rqstp)612 nfsd_proc_readdir(struct svc_rqst *rqstp)
613 {
614 	struct nfsd_readdirargs *argp = rqstp->rq_argp;
615 	struct nfsd_readdirres *resp = rqstp->rq_resp;
616 	loff_t		offset;
617 
618 	dprintk("nfsd: READDIR  %s %d bytes at %d\n",
619 		SVCFH_fmt(&argp->fh),
620 		argp->count, argp->cookie);
621 
622 	nfsd_init_dirlist_pages(rqstp, resp, argp->count);
623 
624 	resp->common.err = nfs_ok;
625 	resp->cookie_offset = 0;
626 	offset = argp->cookie;
627 	resp->status = nfsd_readdir(rqstp, &argp->fh, &offset,
628 				    &resp->common, nfssvc_encode_entry);
629 	nfssvc_encode_nfscookie(resp, offset);
630 
631 	fh_put(&argp->fh);
632 	resp->status = nfsd_map_status(resp->status);
633 	return rpc_success;
634 }
635 
636 /*
637  * Get file system info
638  */
639 static __be32
nfsd_proc_statfs(struct svc_rqst * rqstp)640 nfsd_proc_statfs(struct svc_rqst *rqstp)
641 {
642 	struct nfsd_fhandle *argp = rqstp->rq_argp;
643 	struct nfsd_statfsres *resp = rqstp->rq_resp;
644 
645 	dprintk("nfsd: STATFS   %s\n", SVCFH_fmt(&argp->fh));
646 
647 	resp->status = nfsd_statfs(rqstp, &argp->fh, &resp->stats,
648 				   NFSD_MAY_BYPASS_GSS_ON_ROOT);
649 	fh_put(&argp->fh);
650 	resp->status = nfsd_map_status(resp->status);
651 	return rpc_success;
652 }
653 
654 /*
655  * NFSv2 Server procedures.
656  * Only the results of non-idempotent operations are cached.
657  */
658 
659 #define ST 1		/* status */
660 #define FH 8		/* filehandle */
661 #define	AT 18		/* attributes */
662 
663 static const struct svc_procedure nfsd_procedures2[18] = {
664 	[NFSPROC_NULL] = {
665 		.pc_func = nfsd_proc_null,
666 		.pc_decode = nfssvc_decode_voidarg,
667 		.pc_encode = nfssvc_encode_voidres,
668 		.pc_argsize = sizeof(struct nfsd_voidargs),
669 		.pc_argzero = sizeof(struct nfsd_voidargs),
670 		.pc_ressize = sizeof(struct nfsd_voidres),
671 		.pc_cachetype = RC_NOCACHE,
672 		.pc_xdrressize = 0,
673 		.pc_name = "NULL",
674 	},
675 	[NFSPROC_GETATTR] = {
676 		.pc_func = nfsd_proc_getattr,
677 		.pc_decode = nfssvc_decode_fhandleargs,
678 		.pc_encode = nfssvc_encode_attrstatres,
679 		.pc_release = nfssvc_release_attrstat,
680 		.pc_argsize = sizeof(struct nfsd_fhandle),
681 		.pc_argzero = sizeof(struct nfsd_fhandle),
682 		.pc_ressize = sizeof(struct nfsd_attrstat),
683 		.pc_cachetype = RC_NOCACHE,
684 		.pc_xdrressize = ST+AT,
685 		.pc_name = "GETATTR",
686 	},
687 	[NFSPROC_SETATTR] = {
688 		.pc_func = nfsd_proc_setattr,
689 		.pc_decode = nfssvc_decode_sattrargs,
690 		.pc_encode = nfssvc_encode_attrstatres,
691 		.pc_release = nfssvc_release_attrstat,
692 		.pc_argsize = sizeof(struct nfsd_sattrargs),
693 		.pc_argzero = sizeof(struct nfsd_sattrargs),
694 		.pc_ressize = sizeof(struct nfsd_attrstat),
695 		.pc_cachetype = RC_REPLBUFF,
696 		.pc_xdrressize = ST+AT,
697 		.pc_name = "SETATTR",
698 	},
699 	[NFSPROC_ROOT] = {
700 		.pc_func = nfsd_proc_root,
701 		.pc_decode = nfssvc_decode_voidarg,
702 		.pc_encode = nfssvc_encode_voidres,
703 		.pc_argsize = sizeof(struct nfsd_voidargs),
704 		.pc_argzero = sizeof(struct nfsd_voidargs),
705 		.pc_ressize = sizeof(struct nfsd_voidres),
706 		.pc_cachetype = RC_NOCACHE,
707 		.pc_xdrressize = 0,
708 		.pc_name = "ROOT",
709 	},
710 	[NFSPROC_LOOKUP] = {
711 		.pc_func = nfsd_proc_lookup,
712 		.pc_decode = nfssvc_decode_diropargs,
713 		.pc_encode = nfssvc_encode_diropres,
714 		.pc_release = nfssvc_release_diropres,
715 		.pc_argsize = sizeof(struct nfsd_diropargs),
716 		.pc_argzero = sizeof(struct nfsd_diropargs),
717 		.pc_ressize = sizeof(struct nfsd_diropres),
718 		.pc_cachetype = RC_NOCACHE,
719 		.pc_xdrressize = ST+FH+AT,
720 		.pc_name = "LOOKUP",
721 	},
722 	[NFSPROC_READLINK] = {
723 		.pc_func = nfsd_proc_readlink,
724 		.pc_decode = nfssvc_decode_fhandleargs,
725 		.pc_encode = nfssvc_encode_readlinkres,
726 		.pc_argsize = sizeof(struct nfsd_fhandle),
727 		.pc_argzero = sizeof(struct nfsd_fhandle),
728 		.pc_ressize = sizeof(struct nfsd_readlinkres),
729 		.pc_cachetype = RC_NOCACHE,
730 		.pc_xdrressize = ST+1+NFS_MAXPATHLEN/4,
731 		.pc_name = "READLINK",
732 	},
733 	[NFSPROC_READ] = {
734 		.pc_func = nfsd_proc_read,
735 		.pc_decode = nfssvc_decode_readargs,
736 		.pc_encode = nfssvc_encode_readres,
737 		.pc_release = nfssvc_release_readres,
738 		.pc_argsize = sizeof(struct nfsd_readargs),
739 		.pc_argzero = sizeof(struct nfsd_readargs),
740 		.pc_ressize = sizeof(struct nfsd_readres),
741 		.pc_cachetype = RC_NOCACHE,
742 		.pc_xdrressize = ST+AT+1+NFSSVC_MAXBLKSIZE_V2/4,
743 		.pc_name = "READ",
744 	},
745 	[NFSPROC_WRITECACHE] = {
746 		.pc_func = nfsd_proc_writecache,
747 		.pc_decode = nfssvc_decode_voidarg,
748 		.pc_encode = nfssvc_encode_voidres,
749 		.pc_argsize = sizeof(struct nfsd_voidargs),
750 		.pc_argzero = sizeof(struct nfsd_voidargs),
751 		.pc_ressize = sizeof(struct nfsd_voidres),
752 		.pc_cachetype = RC_NOCACHE,
753 		.pc_xdrressize = 0,
754 		.pc_name = "WRITECACHE",
755 	},
756 	[NFSPROC_WRITE] = {
757 		.pc_func = nfsd_proc_write,
758 		.pc_decode = nfssvc_decode_writeargs,
759 		.pc_encode = nfssvc_encode_attrstatres,
760 		.pc_release = nfssvc_release_attrstat,
761 		.pc_argsize = sizeof(struct nfsd_writeargs),
762 		.pc_argzero = sizeof(struct nfsd_writeargs),
763 		.pc_ressize = sizeof(struct nfsd_attrstat),
764 		.pc_cachetype = RC_REPLBUFF,
765 		.pc_xdrressize = ST+AT,
766 		.pc_name = "WRITE",
767 	},
768 	[NFSPROC_CREATE] = {
769 		.pc_func = nfsd_proc_create,
770 		.pc_decode = nfssvc_decode_createargs,
771 		.pc_encode = nfssvc_encode_diropres,
772 		.pc_release = nfssvc_release_diropres,
773 		.pc_argsize = sizeof(struct nfsd_createargs),
774 		.pc_argzero = sizeof(struct nfsd_createargs),
775 		.pc_ressize = sizeof(struct nfsd_diropres),
776 		.pc_cachetype = RC_REPLBUFF,
777 		.pc_xdrressize = ST+FH+AT,
778 		.pc_name = "CREATE",
779 	},
780 	[NFSPROC_REMOVE] = {
781 		.pc_func = nfsd_proc_remove,
782 		.pc_decode = nfssvc_decode_diropargs,
783 		.pc_encode = nfssvc_encode_statres,
784 		.pc_argsize = sizeof(struct nfsd_diropargs),
785 		.pc_argzero = sizeof(struct nfsd_diropargs),
786 		.pc_ressize = sizeof(struct nfsd_stat),
787 		.pc_cachetype = RC_REPLSTAT,
788 		.pc_xdrressize = ST,
789 		.pc_name = "REMOVE",
790 	},
791 	[NFSPROC_RENAME] = {
792 		.pc_func = nfsd_proc_rename,
793 		.pc_decode = nfssvc_decode_renameargs,
794 		.pc_encode = nfssvc_encode_statres,
795 		.pc_argsize = sizeof(struct nfsd_renameargs),
796 		.pc_argzero = sizeof(struct nfsd_renameargs),
797 		.pc_ressize = sizeof(struct nfsd_stat),
798 		.pc_cachetype = RC_REPLSTAT,
799 		.pc_xdrressize = ST,
800 		.pc_name = "RENAME",
801 	},
802 	[NFSPROC_LINK] = {
803 		.pc_func = nfsd_proc_link,
804 		.pc_decode = nfssvc_decode_linkargs,
805 		.pc_encode = nfssvc_encode_statres,
806 		.pc_argsize = sizeof(struct nfsd_linkargs),
807 		.pc_argzero = sizeof(struct nfsd_linkargs),
808 		.pc_ressize = sizeof(struct nfsd_stat),
809 		.pc_cachetype = RC_REPLSTAT,
810 		.pc_xdrressize = ST,
811 		.pc_name = "LINK",
812 	},
813 	[NFSPROC_SYMLINK] = {
814 		.pc_func = nfsd_proc_symlink,
815 		.pc_decode = nfssvc_decode_symlinkargs,
816 		.pc_encode = nfssvc_encode_statres,
817 		.pc_argsize = sizeof(struct nfsd_symlinkargs),
818 		.pc_argzero = sizeof(struct nfsd_symlinkargs),
819 		.pc_ressize = sizeof(struct nfsd_stat),
820 		.pc_cachetype = RC_REPLSTAT,
821 		.pc_xdrressize = ST,
822 		.pc_name = "SYMLINK",
823 	},
824 	[NFSPROC_MKDIR] = {
825 		.pc_func = nfsd_proc_mkdir,
826 		.pc_decode = nfssvc_decode_createargs,
827 		.pc_encode = nfssvc_encode_diropres,
828 		.pc_release = nfssvc_release_diropres,
829 		.pc_argsize = sizeof(struct nfsd_createargs),
830 		.pc_argzero = sizeof(struct nfsd_createargs),
831 		.pc_ressize = sizeof(struct nfsd_diropres),
832 		.pc_cachetype = RC_REPLBUFF,
833 		.pc_xdrressize = ST+FH+AT,
834 		.pc_name = "MKDIR",
835 	},
836 	[NFSPROC_RMDIR] = {
837 		.pc_func = nfsd_proc_rmdir,
838 		.pc_decode = nfssvc_decode_diropargs,
839 		.pc_encode = nfssvc_encode_statres,
840 		.pc_argsize = sizeof(struct nfsd_diropargs),
841 		.pc_argzero = sizeof(struct nfsd_diropargs),
842 		.pc_ressize = sizeof(struct nfsd_stat),
843 		.pc_cachetype = RC_REPLSTAT,
844 		.pc_xdrressize = ST,
845 		.pc_name = "RMDIR",
846 	},
847 	[NFSPROC_READDIR] = {
848 		.pc_func = nfsd_proc_readdir,
849 		.pc_decode = nfssvc_decode_readdirargs,
850 		.pc_encode = nfssvc_encode_readdirres,
851 		.pc_argsize = sizeof(struct nfsd_readdirargs),
852 		.pc_argzero = sizeof(struct nfsd_readdirargs),
853 		.pc_ressize = sizeof(struct nfsd_readdirres),
854 		.pc_cachetype = RC_NOCACHE,
855 		.pc_name = "READDIR",
856 	},
857 	[NFSPROC_STATFS] = {
858 		.pc_func = nfsd_proc_statfs,
859 		.pc_decode = nfssvc_decode_fhandleargs,
860 		.pc_encode = nfssvc_encode_statfsres,
861 		.pc_argsize = sizeof(struct nfsd_fhandle),
862 		.pc_argzero = sizeof(struct nfsd_fhandle),
863 		.pc_ressize = sizeof(struct nfsd_statfsres),
864 		.pc_cachetype = RC_NOCACHE,
865 		.pc_xdrressize = ST+5,
866 		.pc_name = "STATFS",
867 	},
868 };
869 
870 static DEFINE_PER_CPU_ALIGNED(unsigned long,
871 			      nfsd_count2[ARRAY_SIZE(nfsd_procedures2)]);
872 const struct svc_version nfsd_version2 = {
873 	.vs_vers	= 2,
874 	.vs_nproc	= ARRAY_SIZE(nfsd_procedures2),
875 	.vs_proc	= nfsd_procedures2,
876 	.vs_count	= nfsd_count2,
877 	.vs_dispatch	= nfsd_dispatch,
878 	.vs_xdrsize	= NFS2_SVC_XDRSIZE,
879 };
880