xref: /linux/fs/nfsd/nfsproc.c (revision 722ecdbce68a87de2d9296f91308f44ea900a039)
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 
16 static __be32
17 nfsd_proc_null(struct svc_rqst *rqstp)
18 {
19 	return rpc_success;
20 }
21 
22 /*
23  * Get a file's attributes
24  * N.B. After this call resp->fh needs an fh_put
25  */
26 static __be32
27 nfsd_proc_getattr(struct svc_rqst *rqstp)
28 {
29 	struct nfsd_fhandle *argp = rqstp->rq_argp;
30 	struct nfsd_attrstat *resp = rqstp->rq_resp;
31 
32 	dprintk("nfsd: GETATTR  %s\n", SVCFH_fmt(&argp->fh));
33 
34 	fh_copy(&resp->fh, &argp->fh);
35 	resp->status = fh_verify(rqstp, &resp->fh, 0,
36 				 NFSD_MAY_NOP | NFSD_MAY_BYPASS_GSS_ON_ROOT);
37 	if (resp->status != nfs_ok)
38 		goto out;
39 	resp->status = fh_getattr(&resp->fh, &resp->stat);
40 out:
41 	return rpc_success;
42 }
43 
44 /*
45  * Set a file's attributes
46  * N.B. After this call resp->fh needs an fh_put
47  */
48 static __be32
49 nfsd_proc_setattr(struct svc_rqst *rqstp)
50 {
51 	struct nfsd_sattrargs *argp = rqstp->rq_argp;
52 	struct nfsd_attrstat *resp = rqstp->rq_resp;
53 	struct iattr *iap = &argp->attrs;
54 	struct svc_fh *fhp;
55 
56 	dprintk("nfsd: SETATTR  %s, valid=%x, size=%ld\n",
57 		SVCFH_fmt(&argp->fh),
58 		argp->attrs.ia_valid, (long) argp->attrs.ia_size);
59 
60 	fhp = fh_copy(&resp->fh, &argp->fh);
61 
62 	/*
63 	 * NFSv2 does not differentiate between "set-[ac]time-to-now"
64 	 * which only requires access, and "set-[ac]time-to-X" which
65 	 * requires ownership.
66 	 * So if it looks like it might be "set both to the same time which
67 	 * is close to now", and if setattr_prepare fails, then we
68 	 * convert to "set to now" instead of "set to explicit time"
69 	 *
70 	 * We only call setattr_prepare as the last test as technically
71 	 * it is not an interface that we should be using.
72 	 */
73 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
74 #define	MAX_TOUCH_TIME_ERROR (30*60)
75 	if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET &&
76 	    iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) {
77 		/*
78 		 * Looks probable.
79 		 *
80 		 * Now just make sure time is in the right ballpark.
81 		 * Solaris, at least, doesn't seem to care what the time
82 		 * request is.  We require it be within 30 minutes of now.
83 		 */
84 		time64_t delta = iap->ia_atime.tv_sec - ktime_get_real_seconds();
85 
86 		resp->status = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
87 		if (resp->status != nfs_ok)
88 			goto out;
89 
90 		if (delta < 0)
91 			delta = -delta;
92 		if (delta < MAX_TOUCH_TIME_ERROR &&
93 		    setattr_prepare(&init_user_ns, fhp->fh_dentry, iap) != 0) {
94 			/*
95 			 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
96 			 * This will cause notify_change to set these times
97 			 * to "now"
98 			 */
99 			iap->ia_valid &= ~BOTH_TIME_SET;
100 		}
101 	}
102 
103 	resp->status = nfsd_setattr(rqstp, fhp, iap, 0, (time64_t)0);
104 	if (resp->status != nfs_ok)
105 		goto out;
106 
107 	resp->status = fh_getattr(&resp->fh, &resp->stat);
108 out:
109 	return rpc_success;
110 }
111 
112 /* Obsolete, replaced by MNTPROC_MNT. */
113 static __be32
114 nfsd_proc_root(struct svc_rqst *rqstp)
115 {
116 	return rpc_success;
117 }
118 
119 /*
120  * Look up a path name component
121  * Note: the dentry in the resp->fh may be negative if the file
122  * doesn't exist yet.
123  * N.B. After this call resp->fh needs an fh_put
124  */
125 static __be32
126 nfsd_proc_lookup(struct svc_rqst *rqstp)
127 {
128 	struct nfsd_diropargs *argp = rqstp->rq_argp;
129 	struct nfsd_diropres *resp = rqstp->rq_resp;
130 
131 	dprintk("nfsd: LOOKUP   %s %.*s\n",
132 		SVCFH_fmt(&argp->fh), argp->len, argp->name);
133 
134 	fh_init(&resp->fh, NFS_FHSIZE);
135 	resp->status = nfsd_lookup(rqstp, &argp->fh, argp->name, argp->len,
136 				   &resp->fh);
137 	fh_put(&argp->fh);
138 	if (resp->status != nfs_ok)
139 		goto out;
140 
141 	resp->status = fh_getattr(&resp->fh, &resp->stat);
142 out:
143 	return rpc_success;
144 }
145 
146 /*
147  * Read a symlink.
148  */
149 static __be32
150 nfsd_proc_readlink(struct svc_rqst *rqstp)
151 {
152 	struct nfsd_fhandle *argp = rqstp->rq_argp;
153 	struct nfsd_readlinkres *resp = rqstp->rq_resp;
154 
155 	dprintk("nfsd: READLINK %s\n", SVCFH_fmt(&argp->fh));
156 
157 	/* Read the symlink. */
158 	resp->len = NFS_MAXPATHLEN;
159 	resp->page = *(rqstp->rq_next_page++);
160 	resp->status = nfsd_readlink(rqstp, &argp->fh,
161 				     page_address(resp->page), &resp->len);
162 
163 	fh_put(&argp->fh);
164 	return rpc_success;
165 }
166 
167 /*
168  * Read a portion of a file.
169  * N.B. After this call resp->fh needs an fh_put
170  */
171 static __be32
172 nfsd_proc_read(struct svc_rqst *rqstp)
173 {
174 	struct nfsd_readargs *argp = rqstp->rq_argp;
175 	struct nfsd_readres *resp = rqstp->rq_resp;
176 	unsigned int len;
177 	u32 eof;
178 	int v;
179 
180 	dprintk("nfsd: READ    %s %d bytes at %d\n",
181 		SVCFH_fmt(&argp->fh),
182 		argp->count, argp->offset);
183 
184 	argp->count = min_t(u32, argp->count, NFSSVC_MAXBLKSIZE_V2);
185 
186 	v = 0;
187 	len = argp->count;
188 	resp->pages = rqstp->rq_next_page;
189 	while (len > 0) {
190 		struct page *page = *(rqstp->rq_next_page++);
191 
192 		rqstp->rq_vec[v].iov_base = page_address(page);
193 		rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
194 		len -= rqstp->rq_vec[v].iov_len;
195 		v++;
196 	}
197 
198 	/* Obtain buffer pointer for payload. 19 is 1 word for
199 	 * status, 17 words for fattr, and 1 word for the byte count.
200 	 */
201 	svc_reserve_auth(rqstp, (19<<2) + argp->count + 4);
202 
203 	resp->count = argp->count;
204 	fh_copy(&resp->fh, &argp->fh);
205 	resp->status = nfsd_read(rqstp, &resp->fh, argp->offset,
206 				 rqstp->rq_vec, v, &resp->count, &eof);
207 	if (resp->status == nfs_ok)
208 		resp->status = fh_getattr(&resp->fh, &resp->stat);
209 	else if (resp->status == nfserr_jukebox)
210 		return rpc_drop_reply;
211 	return rpc_success;
212 }
213 
214 /* Reserved */
215 static __be32
216 nfsd_proc_writecache(struct svc_rqst *rqstp)
217 {
218 	return rpc_success;
219 }
220 
221 /*
222  * Write data to a file
223  * N.B. After this call resp->fh needs an fh_put
224  */
225 static __be32
226 nfsd_proc_write(struct svc_rqst *rqstp)
227 {
228 	struct nfsd_writeargs *argp = rqstp->rq_argp;
229 	struct nfsd_attrstat *resp = rqstp->rq_resp;
230 	unsigned long cnt = argp->len;
231 	unsigned int nvecs;
232 
233 	dprintk("nfsd: WRITE    %s %u bytes at %d\n",
234 		SVCFH_fmt(&argp->fh),
235 		argp->len, argp->offset);
236 
237 	nvecs = svc_fill_write_vector(rqstp, &argp->payload);
238 
239 	resp->status = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh),
240 				  argp->offset, rqstp->rq_vec, nvecs,
241 				  &cnt, NFS_DATA_SYNC, NULL);
242 	if (resp->status == nfs_ok)
243 		resp->status = fh_getattr(&resp->fh, &resp->stat);
244 	else if (resp->status == nfserr_jukebox)
245 		return rpc_drop_reply;
246 	return rpc_success;
247 }
248 
249 /*
250  * CREATE processing is complicated. The keyword here is `overloaded.'
251  * The parent directory is kept locked between the check for existence
252  * and the actual create() call in compliance with VFS protocols.
253  * N.B. After this call _both_ argp->fh and resp->fh need an fh_put
254  */
255 static __be32
256 nfsd_proc_create(struct svc_rqst *rqstp)
257 {
258 	struct nfsd_createargs *argp = rqstp->rq_argp;
259 	struct nfsd_diropres *resp = rqstp->rq_resp;
260 	svc_fh		*dirfhp = &argp->fh;
261 	svc_fh		*newfhp = &resp->fh;
262 	struct iattr	*attr = &argp->attrs;
263 	struct inode	*inode;
264 	struct dentry	*dchild;
265 	int		type, mode;
266 	int		hosterr;
267 	dev_t		rdev = 0, wanted = new_decode_dev(attr->ia_size);
268 
269 	dprintk("nfsd: CREATE   %s %.*s\n",
270 		SVCFH_fmt(dirfhp), argp->len, argp->name);
271 
272 	/* First verify the parent file handle */
273 	resp->status = fh_verify(rqstp, dirfhp, S_IFDIR, NFSD_MAY_EXEC);
274 	if (resp->status != nfs_ok)
275 		goto done; /* must fh_put dirfhp even on error */
276 
277 	/* Check for NFSD_MAY_WRITE in nfsd_create if necessary */
278 
279 	resp->status = nfserr_exist;
280 	if (isdotent(argp->name, argp->len))
281 		goto done;
282 	hosterr = fh_want_write(dirfhp);
283 	if (hosterr) {
284 		resp->status = nfserrno(hosterr);
285 		goto done;
286 	}
287 
288 	fh_lock_nested(dirfhp, I_MUTEX_PARENT);
289 	dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len);
290 	if (IS_ERR(dchild)) {
291 		resp->status = nfserrno(PTR_ERR(dchild));
292 		goto out_unlock;
293 	}
294 	fh_init(newfhp, NFS_FHSIZE);
295 	resp->status = fh_compose(newfhp, dirfhp->fh_export, dchild, dirfhp);
296 	if (!resp->status && d_really_is_negative(dchild))
297 		resp->status = nfserr_noent;
298 	dput(dchild);
299 	if (resp->status) {
300 		if (resp->status != nfserr_noent)
301 			goto out_unlock;
302 		/*
303 		 * If the new file handle wasn't verified, we can't tell
304 		 * whether the file exists or not. Time to bail ...
305 		 */
306 		resp->status = nfserr_acces;
307 		if (!newfhp->fh_dentry) {
308 			printk(KERN_WARNING
309 				"nfsd_proc_create: file handle not verified\n");
310 			goto out_unlock;
311 		}
312 	}
313 
314 	inode = d_inode(newfhp->fh_dentry);
315 
316 	/* Unfudge the mode bits */
317 	if (attr->ia_valid & ATTR_MODE) {
318 		type = attr->ia_mode & S_IFMT;
319 		mode = attr->ia_mode & ~S_IFMT;
320 		if (!type) {
321 			/* no type, so if target exists, assume same as that,
322 			 * else assume a file */
323 			if (inode) {
324 				type = inode->i_mode & S_IFMT;
325 				switch(type) {
326 				case S_IFCHR:
327 				case S_IFBLK:
328 					/* reserve rdev for later checking */
329 					rdev = inode->i_rdev;
330 					attr->ia_valid |= ATTR_SIZE;
331 
332 					fallthrough;
333 				case S_IFIFO:
334 					/* this is probably a permission check..
335 					 * at least IRIX implements perm checking on
336 					 *   echo thing > device-special-file-or-pipe
337 					 * by doing a CREATE with type==0
338 					 */
339 					resp->status = nfsd_permission(rqstp,
340 								 newfhp->fh_export,
341 								 newfhp->fh_dentry,
342 								 NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS);
343 					if (resp->status && resp->status != nfserr_rofs)
344 						goto out_unlock;
345 				}
346 			} else
347 				type = S_IFREG;
348 		}
349 	} else if (inode) {
350 		type = inode->i_mode & S_IFMT;
351 		mode = inode->i_mode & ~S_IFMT;
352 	} else {
353 		type = S_IFREG;
354 		mode = 0;	/* ??? */
355 	}
356 
357 	attr->ia_valid |= ATTR_MODE;
358 	attr->ia_mode = mode;
359 
360 	/* Special treatment for non-regular files according to the
361 	 * gospel of sun micro
362 	 */
363 	if (type != S_IFREG) {
364 		if (type != S_IFBLK && type != S_IFCHR) {
365 			rdev = 0;
366 		} else if (type == S_IFCHR && !(attr->ia_valid & ATTR_SIZE)) {
367 			/* If you think you've seen the worst, grok this. */
368 			type = S_IFIFO;
369 		} else {
370 			/* Okay, char or block special */
371 			if (!rdev)
372 				rdev = wanted;
373 		}
374 
375 		/* we've used the SIZE information, so discard it */
376 		attr->ia_valid &= ~ATTR_SIZE;
377 
378 		/* Make sure the type and device matches */
379 		resp->status = nfserr_exist;
380 		if (inode && inode_wrong_type(inode, type))
381 			goto out_unlock;
382 	}
383 
384 	resp->status = nfs_ok;
385 	if (!inode) {
386 		/* File doesn't exist. Create it and set attrs */
387 		resp->status = nfsd_create_locked(rqstp, dirfhp, argp->name,
388 						  argp->len, attr, type, rdev,
389 						  newfhp);
390 	} else if (type == S_IFREG) {
391 		dprintk("nfsd:   existing %s, valid=%x, size=%ld\n",
392 			argp->name, attr->ia_valid, (long) attr->ia_size);
393 		/* File already exists. We ignore all attributes except
394 		 * size, so that creat() behaves exactly like
395 		 * open(..., O_CREAT|O_TRUNC|O_WRONLY).
396 		 */
397 		attr->ia_valid &= ATTR_SIZE;
398 		if (attr->ia_valid)
399 			resp->status = nfsd_setattr(rqstp, newfhp, attr, 0,
400 						    (time64_t)0);
401 	}
402 
403 out_unlock:
404 	/* We don't really need to unlock, as fh_put does it. */
405 	fh_unlock(dirfhp);
406 	fh_drop_write(dirfhp);
407 done:
408 	fh_put(dirfhp);
409 	if (resp->status != nfs_ok)
410 		goto out;
411 	resp->status = fh_getattr(&resp->fh, &resp->stat);
412 out:
413 	return rpc_success;
414 }
415 
416 static __be32
417 nfsd_proc_remove(struct svc_rqst *rqstp)
418 {
419 	struct nfsd_diropargs *argp = rqstp->rq_argp;
420 	struct nfsd_stat *resp = rqstp->rq_resp;
421 
422 	dprintk("nfsd: REMOVE   %s %.*s\n", SVCFH_fmt(&argp->fh),
423 		argp->len, argp->name);
424 
425 	/* Unlink. -SIFDIR means file must not be a directory */
426 	resp->status = nfsd_unlink(rqstp, &argp->fh, -S_IFDIR,
427 				   argp->name, argp->len);
428 	fh_put(&argp->fh);
429 	return rpc_success;
430 }
431 
432 static __be32
433 nfsd_proc_rename(struct svc_rqst *rqstp)
434 {
435 	struct nfsd_renameargs *argp = rqstp->rq_argp;
436 	struct nfsd_stat *resp = rqstp->rq_resp;
437 
438 	dprintk("nfsd: RENAME   %s %.*s -> \n",
439 		SVCFH_fmt(&argp->ffh), argp->flen, argp->fname);
440 	dprintk("nfsd:        ->  %s %.*s\n",
441 		SVCFH_fmt(&argp->tfh), argp->tlen, argp->tname);
442 
443 	resp->status = nfsd_rename(rqstp, &argp->ffh, argp->fname, argp->flen,
444 				   &argp->tfh, argp->tname, argp->tlen);
445 	fh_put(&argp->ffh);
446 	fh_put(&argp->tfh);
447 	return rpc_success;
448 }
449 
450 static __be32
451 nfsd_proc_link(struct svc_rqst *rqstp)
452 {
453 	struct nfsd_linkargs *argp = rqstp->rq_argp;
454 	struct nfsd_stat *resp = rqstp->rq_resp;
455 
456 	dprintk("nfsd: LINK     %s ->\n",
457 		SVCFH_fmt(&argp->ffh));
458 	dprintk("nfsd:    %s %.*s\n",
459 		SVCFH_fmt(&argp->tfh),
460 		argp->tlen,
461 		argp->tname);
462 
463 	resp->status = nfsd_link(rqstp, &argp->tfh, argp->tname, argp->tlen,
464 				 &argp->ffh);
465 	fh_put(&argp->ffh);
466 	fh_put(&argp->tfh);
467 	return rpc_success;
468 }
469 
470 static __be32
471 nfsd_proc_symlink(struct svc_rqst *rqstp)
472 {
473 	struct nfsd_symlinkargs *argp = rqstp->rq_argp;
474 	struct nfsd_stat *resp = rqstp->rq_resp;
475 	struct svc_fh	newfh;
476 
477 	if (argp->tlen > NFS_MAXPATHLEN) {
478 		resp->status = nfserr_nametoolong;
479 		goto out;
480 	}
481 
482 	argp->tname = svc_fill_symlink_pathname(rqstp, &argp->first,
483 						page_address(rqstp->rq_arg.pages[0]),
484 						argp->tlen);
485 	if (IS_ERR(argp->tname)) {
486 		resp->status = nfserrno(PTR_ERR(argp->tname));
487 		goto out;
488 	}
489 
490 	dprintk("nfsd: SYMLINK  %s %.*s -> %.*s\n",
491 		SVCFH_fmt(&argp->ffh), argp->flen, argp->fname,
492 		argp->tlen, argp->tname);
493 
494 	fh_init(&newfh, NFS_FHSIZE);
495 	resp->status = nfsd_symlink(rqstp, &argp->ffh, argp->fname, argp->flen,
496 				    argp->tname, &newfh);
497 
498 	kfree(argp->tname);
499 	fh_put(&argp->ffh);
500 	fh_put(&newfh);
501 out:
502 	return rpc_success;
503 }
504 
505 /*
506  * Make directory. This operation is not idempotent.
507  * N.B. After this call resp->fh needs an fh_put
508  */
509 static __be32
510 nfsd_proc_mkdir(struct svc_rqst *rqstp)
511 {
512 	struct nfsd_createargs *argp = rqstp->rq_argp;
513 	struct nfsd_diropres *resp = rqstp->rq_resp;
514 
515 	dprintk("nfsd: MKDIR    %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);
516 
517 	if (resp->fh.fh_dentry) {
518 		printk(KERN_WARNING
519 			"nfsd_proc_mkdir: response already verified??\n");
520 	}
521 
522 	argp->attrs.ia_valid &= ~ATTR_SIZE;
523 	fh_init(&resp->fh, NFS_FHSIZE);
524 	resp->status = nfsd_create(rqstp, &argp->fh, argp->name, argp->len,
525 				   &argp->attrs, S_IFDIR, 0, &resp->fh);
526 	fh_put(&argp->fh);
527 	if (resp->status != nfs_ok)
528 		goto out;
529 
530 	resp->status = fh_getattr(&resp->fh, &resp->stat);
531 out:
532 	return rpc_success;
533 }
534 
535 /*
536  * Remove a directory
537  */
538 static __be32
539 nfsd_proc_rmdir(struct svc_rqst *rqstp)
540 {
541 	struct nfsd_diropargs *argp = rqstp->rq_argp;
542 	struct nfsd_stat *resp = rqstp->rq_resp;
543 
544 	dprintk("nfsd: RMDIR    %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);
545 
546 	resp->status = nfsd_unlink(rqstp, &argp->fh, S_IFDIR,
547 				   argp->name, argp->len);
548 	fh_put(&argp->fh);
549 	return rpc_success;
550 }
551 
552 static void nfsd_init_dirlist_pages(struct svc_rqst *rqstp,
553 				    struct nfsd_readdirres *resp,
554 				    u32 count)
555 {
556 	struct xdr_buf *buf = &resp->dirlist;
557 	struct xdr_stream *xdr = &resp->xdr;
558 
559 	count = clamp(count, (u32)(XDR_UNIT * 2), svc_max_payload(rqstp));
560 
561 	memset(buf, 0, sizeof(*buf));
562 
563 	/* Reserve room for the NULL ptr & eof flag (-2 words) */
564 	buf->buflen = count - XDR_UNIT * 2;
565 	buf->pages = rqstp->rq_next_page;
566 	rqstp->rq_next_page++;
567 
568 	/* This is xdr_init_encode(), but it assumes that
569 	 * the head kvec has already been consumed. */
570 	xdr_set_scratch_buffer(xdr, NULL, 0);
571 	xdr->buf = buf;
572 	xdr->page_ptr = buf->pages;
573 	xdr->iov = NULL;
574 	xdr->p = page_address(*buf->pages);
575 	xdr->end = (void *)xdr->p + min_t(u32, buf->buflen, PAGE_SIZE);
576 	xdr->rqst = NULL;
577 }
578 
579 /*
580  * Read a portion of a directory.
581  */
582 static __be32
583 nfsd_proc_readdir(struct svc_rqst *rqstp)
584 {
585 	struct nfsd_readdirargs *argp = rqstp->rq_argp;
586 	struct nfsd_readdirres *resp = rqstp->rq_resp;
587 	loff_t		offset;
588 
589 	dprintk("nfsd: READDIR  %s %d bytes at %d\n",
590 		SVCFH_fmt(&argp->fh),
591 		argp->count, argp->cookie);
592 
593 	nfsd_init_dirlist_pages(rqstp, resp, argp->count);
594 
595 	resp->common.err = nfs_ok;
596 	resp->cookie_offset = 0;
597 	offset = argp->cookie;
598 	resp->status = nfsd_readdir(rqstp, &argp->fh, &offset,
599 				    &resp->common, nfssvc_encode_entry);
600 	nfssvc_encode_nfscookie(resp, offset);
601 
602 	fh_put(&argp->fh);
603 	return rpc_success;
604 }
605 
606 /*
607  * Get file system info
608  */
609 static __be32
610 nfsd_proc_statfs(struct svc_rqst *rqstp)
611 {
612 	struct nfsd_fhandle *argp = rqstp->rq_argp;
613 	struct nfsd_statfsres *resp = rqstp->rq_resp;
614 
615 	dprintk("nfsd: STATFS   %s\n", SVCFH_fmt(&argp->fh));
616 
617 	resp->status = nfsd_statfs(rqstp, &argp->fh, &resp->stats,
618 				   NFSD_MAY_BYPASS_GSS_ON_ROOT);
619 	fh_put(&argp->fh);
620 	return rpc_success;
621 }
622 
623 /*
624  * NFSv2 Server procedures.
625  * Only the results of non-idempotent operations are cached.
626  */
627 
628 #define ST 1		/* status */
629 #define FH 8		/* filehandle */
630 #define	AT 18		/* attributes */
631 
632 static const struct svc_procedure nfsd_procedures2[18] = {
633 	[NFSPROC_NULL] = {
634 		.pc_func = nfsd_proc_null,
635 		.pc_decode = nfssvc_decode_voidarg,
636 		.pc_encode = nfssvc_encode_voidres,
637 		.pc_argsize = sizeof(struct nfsd_voidargs),
638 		.pc_ressize = sizeof(struct nfsd_voidres),
639 		.pc_cachetype = RC_NOCACHE,
640 		.pc_xdrressize = 0,
641 		.pc_name = "NULL",
642 	},
643 	[NFSPROC_GETATTR] = {
644 		.pc_func = nfsd_proc_getattr,
645 		.pc_decode = nfssvc_decode_fhandleargs,
646 		.pc_encode = nfssvc_encode_attrstatres,
647 		.pc_release = nfssvc_release_attrstat,
648 		.pc_argsize = sizeof(struct nfsd_fhandle),
649 		.pc_ressize = sizeof(struct nfsd_attrstat),
650 		.pc_cachetype = RC_NOCACHE,
651 		.pc_xdrressize = ST+AT,
652 		.pc_name = "GETATTR",
653 	},
654 	[NFSPROC_SETATTR] = {
655 		.pc_func = nfsd_proc_setattr,
656 		.pc_decode = nfssvc_decode_sattrargs,
657 		.pc_encode = nfssvc_encode_attrstatres,
658 		.pc_release = nfssvc_release_attrstat,
659 		.pc_argsize = sizeof(struct nfsd_sattrargs),
660 		.pc_ressize = sizeof(struct nfsd_attrstat),
661 		.pc_cachetype = RC_REPLBUFF,
662 		.pc_xdrressize = ST+AT,
663 		.pc_name = "SETATTR",
664 	},
665 	[NFSPROC_ROOT] = {
666 		.pc_func = nfsd_proc_root,
667 		.pc_decode = nfssvc_decode_voidarg,
668 		.pc_encode = nfssvc_encode_voidres,
669 		.pc_argsize = sizeof(struct nfsd_voidargs),
670 		.pc_ressize = sizeof(struct nfsd_voidres),
671 		.pc_cachetype = RC_NOCACHE,
672 		.pc_xdrressize = 0,
673 		.pc_name = "ROOT",
674 	},
675 	[NFSPROC_LOOKUP] = {
676 		.pc_func = nfsd_proc_lookup,
677 		.pc_decode = nfssvc_decode_diropargs,
678 		.pc_encode = nfssvc_encode_diropres,
679 		.pc_release = nfssvc_release_diropres,
680 		.pc_argsize = sizeof(struct nfsd_diropargs),
681 		.pc_ressize = sizeof(struct nfsd_diropres),
682 		.pc_cachetype = RC_NOCACHE,
683 		.pc_xdrressize = ST+FH+AT,
684 		.pc_name = "LOOKUP",
685 	},
686 	[NFSPROC_READLINK] = {
687 		.pc_func = nfsd_proc_readlink,
688 		.pc_decode = nfssvc_decode_fhandleargs,
689 		.pc_encode = nfssvc_encode_readlinkres,
690 		.pc_argsize = sizeof(struct nfsd_fhandle),
691 		.pc_ressize = sizeof(struct nfsd_readlinkres),
692 		.pc_cachetype = RC_NOCACHE,
693 		.pc_xdrressize = ST+1+NFS_MAXPATHLEN/4,
694 		.pc_name = "READLINK",
695 	},
696 	[NFSPROC_READ] = {
697 		.pc_func = nfsd_proc_read,
698 		.pc_decode = nfssvc_decode_readargs,
699 		.pc_encode = nfssvc_encode_readres,
700 		.pc_release = nfssvc_release_readres,
701 		.pc_argsize = sizeof(struct nfsd_readargs),
702 		.pc_ressize = sizeof(struct nfsd_readres),
703 		.pc_cachetype = RC_NOCACHE,
704 		.pc_xdrressize = ST+AT+1+NFSSVC_MAXBLKSIZE_V2/4,
705 		.pc_name = "READ",
706 	},
707 	[NFSPROC_WRITECACHE] = {
708 		.pc_func = nfsd_proc_writecache,
709 		.pc_decode = nfssvc_decode_voidarg,
710 		.pc_encode = nfssvc_encode_voidres,
711 		.pc_argsize = sizeof(struct nfsd_voidargs),
712 		.pc_ressize = sizeof(struct nfsd_voidres),
713 		.pc_cachetype = RC_NOCACHE,
714 		.pc_xdrressize = 0,
715 		.pc_name = "WRITECACHE",
716 	},
717 	[NFSPROC_WRITE] = {
718 		.pc_func = nfsd_proc_write,
719 		.pc_decode = nfssvc_decode_writeargs,
720 		.pc_encode = nfssvc_encode_attrstatres,
721 		.pc_release = nfssvc_release_attrstat,
722 		.pc_argsize = sizeof(struct nfsd_writeargs),
723 		.pc_ressize = sizeof(struct nfsd_attrstat),
724 		.pc_cachetype = RC_REPLBUFF,
725 		.pc_xdrressize = ST+AT,
726 		.pc_name = "WRITE",
727 	},
728 	[NFSPROC_CREATE] = {
729 		.pc_func = nfsd_proc_create,
730 		.pc_decode = nfssvc_decode_createargs,
731 		.pc_encode = nfssvc_encode_diropres,
732 		.pc_release = nfssvc_release_diropres,
733 		.pc_argsize = sizeof(struct nfsd_createargs),
734 		.pc_ressize = sizeof(struct nfsd_diropres),
735 		.pc_cachetype = RC_REPLBUFF,
736 		.pc_xdrressize = ST+FH+AT,
737 		.pc_name = "CREATE",
738 	},
739 	[NFSPROC_REMOVE] = {
740 		.pc_func = nfsd_proc_remove,
741 		.pc_decode = nfssvc_decode_diropargs,
742 		.pc_encode = nfssvc_encode_statres,
743 		.pc_argsize = sizeof(struct nfsd_diropargs),
744 		.pc_ressize = sizeof(struct nfsd_stat),
745 		.pc_cachetype = RC_REPLSTAT,
746 		.pc_xdrressize = ST,
747 		.pc_name = "REMOVE",
748 	},
749 	[NFSPROC_RENAME] = {
750 		.pc_func = nfsd_proc_rename,
751 		.pc_decode = nfssvc_decode_renameargs,
752 		.pc_encode = nfssvc_encode_statres,
753 		.pc_argsize = sizeof(struct nfsd_renameargs),
754 		.pc_ressize = sizeof(struct nfsd_stat),
755 		.pc_cachetype = RC_REPLSTAT,
756 		.pc_xdrressize = ST,
757 		.pc_name = "RENAME",
758 	},
759 	[NFSPROC_LINK] = {
760 		.pc_func = nfsd_proc_link,
761 		.pc_decode = nfssvc_decode_linkargs,
762 		.pc_encode = nfssvc_encode_statres,
763 		.pc_argsize = sizeof(struct nfsd_linkargs),
764 		.pc_ressize = sizeof(struct nfsd_stat),
765 		.pc_cachetype = RC_REPLSTAT,
766 		.pc_xdrressize = ST,
767 		.pc_name = "LINK",
768 	},
769 	[NFSPROC_SYMLINK] = {
770 		.pc_func = nfsd_proc_symlink,
771 		.pc_decode = nfssvc_decode_symlinkargs,
772 		.pc_encode = nfssvc_encode_statres,
773 		.pc_argsize = sizeof(struct nfsd_symlinkargs),
774 		.pc_ressize = sizeof(struct nfsd_stat),
775 		.pc_cachetype = RC_REPLSTAT,
776 		.pc_xdrressize = ST,
777 		.pc_name = "SYMLINK",
778 	},
779 	[NFSPROC_MKDIR] = {
780 		.pc_func = nfsd_proc_mkdir,
781 		.pc_decode = nfssvc_decode_createargs,
782 		.pc_encode = nfssvc_encode_diropres,
783 		.pc_release = nfssvc_release_diropres,
784 		.pc_argsize = sizeof(struct nfsd_createargs),
785 		.pc_ressize = sizeof(struct nfsd_diropres),
786 		.pc_cachetype = RC_REPLBUFF,
787 		.pc_xdrressize = ST+FH+AT,
788 		.pc_name = "MKDIR",
789 	},
790 	[NFSPROC_RMDIR] = {
791 		.pc_func = nfsd_proc_rmdir,
792 		.pc_decode = nfssvc_decode_diropargs,
793 		.pc_encode = nfssvc_encode_statres,
794 		.pc_argsize = sizeof(struct nfsd_diropargs),
795 		.pc_ressize = sizeof(struct nfsd_stat),
796 		.pc_cachetype = RC_REPLSTAT,
797 		.pc_xdrressize = ST,
798 		.pc_name = "RMDIR",
799 	},
800 	[NFSPROC_READDIR] = {
801 		.pc_func = nfsd_proc_readdir,
802 		.pc_decode = nfssvc_decode_readdirargs,
803 		.pc_encode = nfssvc_encode_readdirres,
804 		.pc_argsize = sizeof(struct nfsd_readdirargs),
805 		.pc_ressize = sizeof(struct nfsd_readdirres),
806 		.pc_cachetype = RC_NOCACHE,
807 		.pc_name = "READDIR",
808 	},
809 	[NFSPROC_STATFS] = {
810 		.pc_func = nfsd_proc_statfs,
811 		.pc_decode = nfssvc_decode_fhandleargs,
812 		.pc_encode = nfssvc_encode_statfsres,
813 		.pc_argsize = sizeof(struct nfsd_fhandle),
814 		.pc_ressize = sizeof(struct nfsd_statfsres),
815 		.pc_cachetype = RC_NOCACHE,
816 		.pc_xdrressize = ST+5,
817 		.pc_name = "STATFS",
818 	},
819 };
820 
821 
822 static unsigned int nfsd_count2[ARRAY_SIZE(nfsd_procedures2)];
823 const struct svc_version nfsd_version2 = {
824 	.vs_vers	= 2,
825 	.vs_nproc	= 18,
826 	.vs_proc	= nfsd_procedures2,
827 	.vs_count	= nfsd_count2,
828 	.vs_dispatch	= nfsd_dispatch,
829 	.vs_xdrsize	= NFS2_SVC_XDRSIZE,
830 };
831 
832 /*
833  * Map errnos to NFS errnos.
834  */
835 __be32
836 nfserrno (int errno)
837 {
838 	static struct {
839 		__be32	nfserr;
840 		int	syserr;
841 	} nfs_errtbl[] = {
842 		{ nfs_ok, 0 },
843 		{ nfserr_perm, -EPERM },
844 		{ nfserr_noent, -ENOENT },
845 		{ nfserr_io, -EIO },
846 		{ nfserr_nxio, -ENXIO },
847 		{ nfserr_fbig, -E2BIG },
848 		{ nfserr_stale, -EBADF },
849 		{ nfserr_acces, -EACCES },
850 		{ nfserr_exist, -EEXIST },
851 		{ nfserr_xdev, -EXDEV },
852 		{ nfserr_mlink, -EMLINK },
853 		{ nfserr_nodev, -ENODEV },
854 		{ nfserr_notdir, -ENOTDIR },
855 		{ nfserr_isdir, -EISDIR },
856 		{ nfserr_inval, -EINVAL },
857 		{ nfserr_fbig, -EFBIG },
858 		{ nfserr_nospc, -ENOSPC },
859 		{ nfserr_rofs, -EROFS },
860 		{ nfserr_mlink, -EMLINK },
861 		{ nfserr_nametoolong, -ENAMETOOLONG },
862 		{ nfserr_notempty, -ENOTEMPTY },
863 #ifdef EDQUOT
864 		{ nfserr_dquot, -EDQUOT },
865 #endif
866 		{ nfserr_stale, -ESTALE },
867 		{ nfserr_jukebox, -ETIMEDOUT },
868 		{ nfserr_jukebox, -ERESTARTSYS },
869 		{ nfserr_jukebox, -EAGAIN },
870 		{ nfserr_jukebox, -EWOULDBLOCK },
871 		{ nfserr_jukebox, -ENOMEM },
872 		{ nfserr_io, -ETXTBSY },
873 		{ nfserr_notsupp, -EOPNOTSUPP },
874 		{ nfserr_toosmall, -ETOOSMALL },
875 		{ nfserr_serverfault, -ESERVERFAULT },
876 		{ nfserr_serverfault, -ENFILE },
877 		{ nfserr_io, -EREMOTEIO },
878 		{ nfserr_stale, -EOPENSTALE },
879 		{ nfserr_io, -EUCLEAN },
880 		{ nfserr_perm, -ENOKEY },
881 		{ nfserr_no_grace, -ENOGRACE},
882 	};
883 	int	i;
884 
885 	for (i = 0; i < ARRAY_SIZE(nfs_errtbl); i++) {
886 		if (nfs_errtbl[i].syserr == errno)
887 			return nfs_errtbl[i].nfserr;
888 	}
889 	WARN_ONCE(1, "nfsd: non-standard errno: %d\n", errno);
890 	return nfserr_io;
891 }
892 
893