xref: /openbmc/linux/fs/nfsd/nfsproc.c (revision a1117495)
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 %d 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 	if (!nvecs) {
239 		resp->status = nfserr_io;
240 		goto out;
241 	}
242 
243 	resp->status = nfsd_write(rqstp, fh_copy(&resp->fh, &argp->fh),
244 				  argp->offset, rqstp->rq_vec, nvecs,
245 				  &cnt, NFS_DATA_SYNC, NULL);
246 	if (resp->status == nfs_ok)
247 		resp->status = fh_getattr(&resp->fh, &resp->stat);
248 	else if (resp->status == nfserr_jukebox)
249 		return rpc_drop_reply;
250 out:
251 	return rpc_success;
252 }
253 
254 /*
255  * CREATE processing is complicated. The keyword here is `overloaded.'
256  * The parent directory is kept locked between the check for existence
257  * and the actual create() call in compliance with VFS protocols.
258  * N.B. After this call _both_ argp->fh and resp->fh need an fh_put
259  */
260 static __be32
261 nfsd_proc_create(struct svc_rqst *rqstp)
262 {
263 	struct nfsd_createargs *argp = rqstp->rq_argp;
264 	struct nfsd_diropres *resp = rqstp->rq_resp;
265 	svc_fh		*dirfhp = &argp->fh;
266 	svc_fh		*newfhp = &resp->fh;
267 	struct iattr	*attr = &argp->attrs;
268 	struct inode	*inode;
269 	struct dentry	*dchild;
270 	int		type, mode;
271 	int		hosterr;
272 	dev_t		rdev = 0, wanted = new_decode_dev(attr->ia_size);
273 
274 	dprintk("nfsd: CREATE   %s %.*s\n",
275 		SVCFH_fmt(dirfhp), argp->len, argp->name);
276 
277 	/* First verify the parent file handle */
278 	resp->status = fh_verify(rqstp, dirfhp, S_IFDIR, NFSD_MAY_EXEC);
279 	if (resp->status != nfs_ok)
280 		goto done; /* must fh_put dirfhp even on error */
281 
282 	/* Check for NFSD_MAY_WRITE in nfsd_create if necessary */
283 
284 	resp->status = nfserr_exist;
285 	if (isdotent(argp->name, argp->len))
286 		goto done;
287 	hosterr = fh_want_write(dirfhp);
288 	if (hosterr) {
289 		resp->status = nfserrno(hosterr);
290 		goto done;
291 	}
292 
293 	fh_lock_nested(dirfhp, I_MUTEX_PARENT);
294 	dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len);
295 	if (IS_ERR(dchild)) {
296 		resp->status = nfserrno(PTR_ERR(dchild));
297 		goto out_unlock;
298 	}
299 	fh_init(newfhp, NFS_FHSIZE);
300 	resp->status = fh_compose(newfhp, dirfhp->fh_export, dchild, dirfhp);
301 	if (!resp->status && d_really_is_negative(dchild))
302 		resp->status = nfserr_noent;
303 	dput(dchild);
304 	if (resp->status) {
305 		if (resp->status != nfserr_noent)
306 			goto out_unlock;
307 		/*
308 		 * If the new file handle wasn't verified, we can't tell
309 		 * whether the file exists or not. Time to bail ...
310 		 */
311 		resp->status = nfserr_acces;
312 		if (!newfhp->fh_dentry) {
313 			printk(KERN_WARNING
314 				"nfsd_proc_create: file handle not verified\n");
315 			goto out_unlock;
316 		}
317 	}
318 
319 	inode = d_inode(newfhp->fh_dentry);
320 
321 	/* Unfudge the mode bits */
322 	if (attr->ia_valid & ATTR_MODE) {
323 		type = attr->ia_mode & S_IFMT;
324 		mode = attr->ia_mode & ~S_IFMT;
325 		if (!type) {
326 			/* no type, so if target exists, assume same as that,
327 			 * else assume a file */
328 			if (inode) {
329 				type = inode->i_mode & S_IFMT;
330 				switch(type) {
331 				case S_IFCHR:
332 				case S_IFBLK:
333 					/* reserve rdev for later checking */
334 					rdev = inode->i_rdev;
335 					attr->ia_valid |= ATTR_SIZE;
336 
337 					fallthrough;
338 				case S_IFIFO:
339 					/* this is probably a permission check..
340 					 * at least IRIX implements perm checking on
341 					 *   echo thing > device-special-file-or-pipe
342 					 * by doing a CREATE with type==0
343 					 */
344 					resp->status = nfsd_permission(rqstp,
345 								 newfhp->fh_export,
346 								 newfhp->fh_dentry,
347 								 NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS);
348 					if (resp->status && resp->status != nfserr_rofs)
349 						goto out_unlock;
350 				}
351 			} else
352 				type = S_IFREG;
353 		}
354 	} else if (inode) {
355 		type = inode->i_mode & S_IFMT;
356 		mode = inode->i_mode & ~S_IFMT;
357 	} else {
358 		type = S_IFREG;
359 		mode = 0;	/* ??? */
360 	}
361 
362 	attr->ia_valid |= ATTR_MODE;
363 	attr->ia_mode = mode;
364 
365 	/* Special treatment for non-regular files according to the
366 	 * gospel of sun micro
367 	 */
368 	if (type != S_IFREG) {
369 		if (type != S_IFBLK && type != S_IFCHR) {
370 			rdev = 0;
371 		} else if (type == S_IFCHR && !(attr->ia_valid & ATTR_SIZE)) {
372 			/* If you think you've seen the worst, grok this. */
373 			type = S_IFIFO;
374 		} else {
375 			/* Okay, char or block special */
376 			if (!rdev)
377 				rdev = wanted;
378 		}
379 
380 		/* we've used the SIZE information, so discard it */
381 		attr->ia_valid &= ~ATTR_SIZE;
382 
383 		/* Make sure the type and device matches */
384 		resp->status = nfserr_exist;
385 		if (inode && inode_wrong_type(inode, type))
386 			goto out_unlock;
387 	}
388 
389 	resp->status = nfs_ok;
390 	if (!inode) {
391 		/* File doesn't exist. Create it and set attrs */
392 		resp->status = nfsd_create_locked(rqstp, dirfhp, argp->name,
393 						  argp->len, attr, type, rdev,
394 						  newfhp);
395 	} else if (type == S_IFREG) {
396 		dprintk("nfsd:   existing %s, valid=%x, size=%ld\n",
397 			argp->name, attr->ia_valid, (long) attr->ia_size);
398 		/* File already exists. We ignore all attributes except
399 		 * size, so that creat() behaves exactly like
400 		 * open(..., O_CREAT|O_TRUNC|O_WRONLY).
401 		 */
402 		attr->ia_valid &= ATTR_SIZE;
403 		if (attr->ia_valid)
404 			resp->status = nfsd_setattr(rqstp, newfhp, attr, 0,
405 						    (time64_t)0);
406 	}
407 
408 out_unlock:
409 	/* We don't really need to unlock, as fh_put does it. */
410 	fh_unlock(dirfhp);
411 	fh_drop_write(dirfhp);
412 done:
413 	fh_put(dirfhp);
414 	if (resp->status != nfs_ok)
415 		goto out;
416 	resp->status = fh_getattr(&resp->fh, &resp->stat);
417 out:
418 	return rpc_success;
419 }
420 
421 static __be32
422 nfsd_proc_remove(struct svc_rqst *rqstp)
423 {
424 	struct nfsd_diropargs *argp = rqstp->rq_argp;
425 	struct nfsd_stat *resp = rqstp->rq_resp;
426 
427 	dprintk("nfsd: REMOVE   %s %.*s\n", SVCFH_fmt(&argp->fh),
428 		argp->len, argp->name);
429 
430 	/* Unlink. -SIFDIR means file must not be a directory */
431 	resp->status = nfsd_unlink(rqstp, &argp->fh, -S_IFDIR,
432 				   argp->name, argp->len);
433 	fh_put(&argp->fh);
434 	return rpc_success;
435 }
436 
437 static __be32
438 nfsd_proc_rename(struct svc_rqst *rqstp)
439 {
440 	struct nfsd_renameargs *argp = rqstp->rq_argp;
441 	struct nfsd_stat *resp = rqstp->rq_resp;
442 
443 	dprintk("nfsd: RENAME   %s %.*s -> \n",
444 		SVCFH_fmt(&argp->ffh), argp->flen, argp->fname);
445 	dprintk("nfsd:        ->  %s %.*s\n",
446 		SVCFH_fmt(&argp->tfh), argp->tlen, argp->tname);
447 
448 	resp->status = nfsd_rename(rqstp, &argp->ffh, argp->fname, argp->flen,
449 				   &argp->tfh, argp->tname, argp->tlen);
450 	fh_put(&argp->ffh);
451 	fh_put(&argp->tfh);
452 	return rpc_success;
453 }
454 
455 static __be32
456 nfsd_proc_link(struct svc_rqst *rqstp)
457 {
458 	struct nfsd_linkargs *argp = rqstp->rq_argp;
459 	struct nfsd_stat *resp = rqstp->rq_resp;
460 
461 	dprintk("nfsd: LINK     %s ->\n",
462 		SVCFH_fmt(&argp->ffh));
463 	dprintk("nfsd:    %s %.*s\n",
464 		SVCFH_fmt(&argp->tfh),
465 		argp->tlen,
466 		argp->tname);
467 
468 	resp->status = nfsd_link(rqstp, &argp->tfh, argp->tname, argp->tlen,
469 				 &argp->ffh);
470 	fh_put(&argp->ffh);
471 	fh_put(&argp->tfh);
472 	return rpc_success;
473 }
474 
475 static __be32
476 nfsd_proc_symlink(struct svc_rqst *rqstp)
477 {
478 	struct nfsd_symlinkargs *argp = rqstp->rq_argp;
479 	struct nfsd_stat *resp = rqstp->rq_resp;
480 	struct svc_fh	newfh;
481 
482 	if (argp->tlen > NFS_MAXPATHLEN) {
483 		resp->status = nfserr_nametoolong;
484 		goto out;
485 	}
486 
487 	argp->tname = svc_fill_symlink_pathname(rqstp, &argp->first,
488 						page_address(rqstp->rq_arg.pages[0]),
489 						argp->tlen);
490 	if (IS_ERR(argp->tname)) {
491 		resp->status = nfserrno(PTR_ERR(argp->tname));
492 		goto out;
493 	}
494 
495 	dprintk("nfsd: SYMLINK  %s %.*s -> %.*s\n",
496 		SVCFH_fmt(&argp->ffh), argp->flen, argp->fname,
497 		argp->tlen, argp->tname);
498 
499 	fh_init(&newfh, NFS_FHSIZE);
500 	resp->status = nfsd_symlink(rqstp, &argp->ffh, argp->fname, argp->flen,
501 				    argp->tname, &newfh);
502 
503 	kfree(argp->tname);
504 	fh_put(&argp->ffh);
505 	fh_put(&newfh);
506 out:
507 	return rpc_success;
508 }
509 
510 /*
511  * Make directory. This operation is not idempotent.
512  * N.B. After this call resp->fh needs an fh_put
513  */
514 static __be32
515 nfsd_proc_mkdir(struct svc_rqst *rqstp)
516 {
517 	struct nfsd_createargs *argp = rqstp->rq_argp;
518 	struct nfsd_diropres *resp = rqstp->rq_resp;
519 
520 	dprintk("nfsd: MKDIR    %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);
521 
522 	if (resp->fh.fh_dentry) {
523 		printk(KERN_WARNING
524 			"nfsd_proc_mkdir: response already verified??\n");
525 	}
526 
527 	argp->attrs.ia_valid &= ~ATTR_SIZE;
528 	fh_init(&resp->fh, NFS_FHSIZE);
529 	resp->status = nfsd_create(rqstp, &argp->fh, argp->name, argp->len,
530 				   &argp->attrs, S_IFDIR, 0, &resp->fh);
531 	fh_put(&argp->fh);
532 	if (resp->status != nfs_ok)
533 		goto out;
534 
535 	resp->status = fh_getattr(&resp->fh, &resp->stat);
536 out:
537 	return rpc_success;
538 }
539 
540 /*
541  * Remove a directory
542  */
543 static __be32
544 nfsd_proc_rmdir(struct svc_rqst *rqstp)
545 {
546 	struct nfsd_diropargs *argp = rqstp->rq_argp;
547 	struct nfsd_stat *resp = rqstp->rq_resp;
548 
549 	dprintk("nfsd: RMDIR    %s %.*s\n", SVCFH_fmt(&argp->fh), argp->len, argp->name);
550 
551 	resp->status = nfsd_unlink(rqstp, &argp->fh, S_IFDIR,
552 				   argp->name, argp->len);
553 	fh_put(&argp->fh);
554 	return rpc_success;
555 }
556 
557 static void nfsd_init_dirlist_pages(struct svc_rqst *rqstp,
558 				    struct nfsd_readdirres *resp,
559 				    int count)
560 {
561 	struct xdr_buf *buf = &resp->dirlist;
562 	struct xdr_stream *xdr = &resp->xdr;
563 
564 	count = min_t(u32, count, PAGE_SIZE);
565 
566 	memset(buf, 0, sizeof(*buf));
567 
568 	/* Reserve room for the NULL ptr & eof flag (-2 words) */
569 	buf->buflen = count - sizeof(__be32) * 2;
570 	buf->pages = rqstp->rq_next_page;
571 	rqstp->rq_next_page++;
572 
573 	/* This is xdr_init_encode(), but it assumes that
574 	 * the head kvec has already been consumed. */
575 	xdr_set_scratch_buffer(xdr, NULL, 0);
576 	xdr->buf = buf;
577 	xdr->page_ptr = buf->pages;
578 	xdr->iov = NULL;
579 	xdr->p = page_address(*buf->pages);
580 	xdr->end = xdr->p + (PAGE_SIZE >> 2);
581 	xdr->rqst = NULL;
582 }
583 
584 /*
585  * Read a portion of a directory.
586  */
587 static __be32
588 nfsd_proc_readdir(struct svc_rqst *rqstp)
589 {
590 	struct nfsd_readdirargs *argp = rqstp->rq_argp;
591 	struct nfsd_readdirres *resp = rqstp->rq_resp;
592 	loff_t		offset;
593 
594 	dprintk("nfsd: READDIR  %s %d bytes at %d\n",
595 		SVCFH_fmt(&argp->fh),
596 		argp->count, argp->cookie);
597 
598 	nfsd_init_dirlist_pages(rqstp, resp, argp->count);
599 
600 	resp->common.err = nfs_ok;
601 	resp->cookie_offset = 0;
602 	offset = argp->cookie;
603 	resp->status = nfsd_readdir(rqstp, &argp->fh, &offset,
604 				    &resp->common, nfssvc_encode_entry);
605 	nfssvc_encode_nfscookie(resp, offset);
606 
607 	fh_put(&argp->fh);
608 	return rpc_success;
609 }
610 
611 /*
612  * Get file system info
613  */
614 static __be32
615 nfsd_proc_statfs(struct svc_rqst *rqstp)
616 {
617 	struct nfsd_fhandle *argp = rqstp->rq_argp;
618 	struct nfsd_statfsres *resp = rqstp->rq_resp;
619 
620 	dprintk("nfsd: STATFS   %s\n", SVCFH_fmt(&argp->fh));
621 
622 	resp->status = nfsd_statfs(rqstp, &argp->fh, &resp->stats,
623 				   NFSD_MAY_BYPASS_GSS_ON_ROOT);
624 	fh_put(&argp->fh);
625 	return rpc_success;
626 }
627 
628 /*
629  * NFSv2 Server procedures.
630  * Only the results of non-idempotent operations are cached.
631  */
632 
633 #define ST 1		/* status */
634 #define FH 8		/* filehandle */
635 #define	AT 18		/* attributes */
636 
637 static const struct svc_procedure nfsd_procedures2[18] = {
638 	[NFSPROC_NULL] = {
639 		.pc_func = nfsd_proc_null,
640 		.pc_decode = nfssvc_decode_voidarg,
641 		.pc_encode = nfssvc_encode_voidres,
642 		.pc_argsize = sizeof(struct nfsd_voidargs),
643 		.pc_ressize = sizeof(struct nfsd_voidres),
644 		.pc_cachetype = RC_NOCACHE,
645 		.pc_xdrressize = 0,
646 		.pc_name = "NULL",
647 	},
648 	[NFSPROC_GETATTR] = {
649 		.pc_func = nfsd_proc_getattr,
650 		.pc_decode = nfssvc_decode_fhandleargs,
651 		.pc_encode = nfssvc_encode_attrstatres,
652 		.pc_release = nfssvc_release_attrstat,
653 		.pc_argsize = sizeof(struct nfsd_fhandle),
654 		.pc_ressize = sizeof(struct nfsd_attrstat),
655 		.pc_cachetype = RC_NOCACHE,
656 		.pc_xdrressize = ST+AT,
657 		.pc_name = "GETATTR",
658 	},
659 	[NFSPROC_SETATTR] = {
660 		.pc_func = nfsd_proc_setattr,
661 		.pc_decode = nfssvc_decode_sattrargs,
662 		.pc_encode = nfssvc_encode_attrstatres,
663 		.pc_release = nfssvc_release_attrstat,
664 		.pc_argsize = sizeof(struct nfsd_sattrargs),
665 		.pc_ressize = sizeof(struct nfsd_attrstat),
666 		.pc_cachetype = RC_REPLBUFF,
667 		.pc_xdrressize = ST+AT,
668 		.pc_name = "SETATTR",
669 	},
670 	[NFSPROC_ROOT] = {
671 		.pc_func = nfsd_proc_root,
672 		.pc_decode = nfssvc_decode_voidarg,
673 		.pc_encode = nfssvc_encode_voidres,
674 		.pc_argsize = sizeof(struct nfsd_voidargs),
675 		.pc_ressize = sizeof(struct nfsd_voidres),
676 		.pc_cachetype = RC_NOCACHE,
677 		.pc_xdrressize = 0,
678 		.pc_name = "ROOT",
679 	},
680 	[NFSPROC_LOOKUP] = {
681 		.pc_func = nfsd_proc_lookup,
682 		.pc_decode = nfssvc_decode_diropargs,
683 		.pc_encode = nfssvc_encode_diropres,
684 		.pc_release = nfssvc_release_diropres,
685 		.pc_argsize = sizeof(struct nfsd_diropargs),
686 		.pc_ressize = sizeof(struct nfsd_diropres),
687 		.pc_cachetype = RC_NOCACHE,
688 		.pc_xdrressize = ST+FH+AT,
689 		.pc_name = "LOOKUP",
690 	},
691 	[NFSPROC_READLINK] = {
692 		.pc_func = nfsd_proc_readlink,
693 		.pc_decode = nfssvc_decode_fhandleargs,
694 		.pc_encode = nfssvc_encode_readlinkres,
695 		.pc_argsize = sizeof(struct nfsd_fhandle),
696 		.pc_ressize = sizeof(struct nfsd_readlinkres),
697 		.pc_cachetype = RC_NOCACHE,
698 		.pc_xdrressize = ST+1+NFS_MAXPATHLEN/4,
699 		.pc_name = "READLINK",
700 	},
701 	[NFSPROC_READ] = {
702 		.pc_func = nfsd_proc_read,
703 		.pc_decode = nfssvc_decode_readargs,
704 		.pc_encode = nfssvc_encode_readres,
705 		.pc_release = nfssvc_release_readres,
706 		.pc_argsize = sizeof(struct nfsd_readargs),
707 		.pc_ressize = sizeof(struct nfsd_readres),
708 		.pc_cachetype = RC_NOCACHE,
709 		.pc_xdrressize = ST+AT+1+NFSSVC_MAXBLKSIZE_V2/4,
710 		.pc_name = "READ",
711 	},
712 	[NFSPROC_WRITECACHE] = {
713 		.pc_func = nfsd_proc_writecache,
714 		.pc_decode = nfssvc_decode_voidarg,
715 		.pc_encode = nfssvc_encode_voidres,
716 		.pc_argsize = sizeof(struct nfsd_voidargs),
717 		.pc_ressize = sizeof(struct nfsd_voidres),
718 		.pc_cachetype = RC_NOCACHE,
719 		.pc_xdrressize = 0,
720 		.pc_name = "WRITECACHE",
721 	},
722 	[NFSPROC_WRITE] = {
723 		.pc_func = nfsd_proc_write,
724 		.pc_decode = nfssvc_decode_writeargs,
725 		.pc_encode = nfssvc_encode_attrstatres,
726 		.pc_release = nfssvc_release_attrstat,
727 		.pc_argsize = sizeof(struct nfsd_writeargs),
728 		.pc_ressize = sizeof(struct nfsd_attrstat),
729 		.pc_cachetype = RC_REPLBUFF,
730 		.pc_xdrressize = ST+AT,
731 		.pc_name = "WRITE",
732 	},
733 	[NFSPROC_CREATE] = {
734 		.pc_func = nfsd_proc_create,
735 		.pc_decode = nfssvc_decode_createargs,
736 		.pc_encode = nfssvc_encode_diropres,
737 		.pc_release = nfssvc_release_diropres,
738 		.pc_argsize = sizeof(struct nfsd_createargs),
739 		.pc_ressize = sizeof(struct nfsd_diropres),
740 		.pc_cachetype = RC_REPLBUFF,
741 		.pc_xdrressize = ST+FH+AT,
742 		.pc_name = "CREATE",
743 	},
744 	[NFSPROC_REMOVE] = {
745 		.pc_func = nfsd_proc_remove,
746 		.pc_decode = nfssvc_decode_diropargs,
747 		.pc_encode = nfssvc_encode_statres,
748 		.pc_argsize = sizeof(struct nfsd_diropargs),
749 		.pc_ressize = sizeof(struct nfsd_stat),
750 		.pc_cachetype = RC_REPLSTAT,
751 		.pc_xdrressize = ST,
752 		.pc_name = "REMOVE",
753 	},
754 	[NFSPROC_RENAME] = {
755 		.pc_func = nfsd_proc_rename,
756 		.pc_decode = nfssvc_decode_renameargs,
757 		.pc_encode = nfssvc_encode_statres,
758 		.pc_argsize = sizeof(struct nfsd_renameargs),
759 		.pc_ressize = sizeof(struct nfsd_stat),
760 		.pc_cachetype = RC_REPLSTAT,
761 		.pc_xdrressize = ST,
762 		.pc_name = "RENAME",
763 	},
764 	[NFSPROC_LINK] = {
765 		.pc_func = nfsd_proc_link,
766 		.pc_decode = nfssvc_decode_linkargs,
767 		.pc_encode = nfssvc_encode_statres,
768 		.pc_argsize = sizeof(struct nfsd_linkargs),
769 		.pc_ressize = sizeof(struct nfsd_stat),
770 		.pc_cachetype = RC_REPLSTAT,
771 		.pc_xdrressize = ST,
772 		.pc_name = "LINK",
773 	},
774 	[NFSPROC_SYMLINK] = {
775 		.pc_func = nfsd_proc_symlink,
776 		.pc_decode = nfssvc_decode_symlinkargs,
777 		.pc_encode = nfssvc_encode_statres,
778 		.pc_argsize = sizeof(struct nfsd_symlinkargs),
779 		.pc_ressize = sizeof(struct nfsd_stat),
780 		.pc_cachetype = RC_REPLSTAT,
781 		.pc_xdrressize = ST,
782 		.pc_name = "SYMLINK",
783 	},
784 	[NFSPROC_MKDIR] = {
785 		.pc_func = nfsd_proc_mkdir,
786 		.pc_decode = nfssvc_decode_createargs,
787 		.pc_encode = nfssvc_encode_diropres,
788 		.pc_release = nfssvc_release_diropres,
789 		.pc_argsize = sizeof(struct nfsd_createargs),
790 		.pc_ressize = sizeof(struct nfsd_diropres),
791 		.pc_cachetype = RC_REPLBUFF,
792 		.pc_xdrressize = ST+FH+AT,
793 		.pc_name = "MKDIR",
794 	},
795 	[NFSPROC_RMDIR] = {
796 		.pc_func = nfsd_proc_rmdir,
797 		.pc_decode = nfssvc_decode_diropargs,
798 		.pc_encode = nfssvc_encode_statres,
799 		.pc_argsize = sizeof(struct nfsd_diropargs),
800 		.pc_ressize = sizeof(struct nfsd_stat),
801 		.pc_cachetype = RC_REPLSTAT,
802 		.pc_xdrressize = ST,
803 		.pc_name = "RMDIR",
804 	},
805 	[NFSPROC_READDIR] = {
806 		.pc_func = nfsd_proc_readdir,
807 		.pc_decode = nfssvc_decode_readdirargs,
808 		.pc_encode = nfssvc_encode_readdirres,
809 		.pc_argsize = sizeof(struct nfsd_readdirargs),
810 		.pc_ressize = sizeof(struct nfsd_readdirres),
811 		.pc_cachetype = RC_NOCACHE,
812 		.pc_name = "READDIR",
813 	},
814 	[NFSPROC_STATFS] = {
815 		.pc_func = nfsd_proc_statfs,
816 		.pc_decode = nfssvc_decode_fhandleargs,
817 		.pc_encode = nfssvc_encode_statfsres,
818 		.pc_argsize = sizeof(struct nfsd_fhandle),
819 		.pc_ressize = sizeof(struct nfsd_statfsres),
820 		.pc_cachetype = RC_NOCACHE,
821 		.pc_xdrressize = ST+5,
822 		.pc_name = "STATFS",
823 	},
824 };
825 
826 
827 static unsigned int nfsd_count2[ARRAY_SIZE(nfsd_procedures2)];
828 const struct svc_version nfsd_version2 = {
829 	.vs_vers	= 2,
830 	.vs_nproc	= 18,
831 	.vs_proc	= nfsd_procedures2,
832 	.vs_count	= nfsd_count2,
833 	.vs_dispatch	= nfsd_dispatch,
834 	.vs_xdrsize	= NFS2_SVC_XDRSIZE,
835 };
836 
837 /*
838  * Map errnos to NFS errnos.
839  */
840 __be32
841 nfserrno (int errno)
842 {
843 	static struct {
844 		__be32	nfserr;
845 		int	syserr;
846 	} nfs_errtbl[] = {
847 		{ nfs_ok, 0 },
848 		{ nfserr_perm, -EPERM },
849 		{ nfserr_noent, -ENOENT },
850 		{ nfserr_io, -EIO },
851 		{ nfserr_nxio, -ENXIO },
852 		{ nfserr_fbig, -E2BIG },
853 		{ nfserr_acces, -EACCES },
854 		{ nfserr_exist, -EEXIST },
855 		{ nfserr_xdev, -EXDEV },
856 		{ nfserr_mlink, -EMLINK },
857 		{ nfserr_nodev, -ENODEV },
858 		{ nfserr_notdir, -ENOTDIR },
859 		{ nfserr_isdir, -EISDIR },
860 		{ nfserr_inval, -EINVAL },
861 		{ nfserr_fbig, -EFBIG },
862 		{ nfserr_nospc, -ENOSPC },
863 		{ nfserr_rofs, -EROFS },
864 		{ nfserr_mlink, -EMLINK },
865 		{ nfserr_nametoolong, -ENAMETOOLONG },
866 		{ nfserr_notempty, -ENOTEMPTY },
867 #ifdef EDQUOT
868 		{ nfserr_dquot, -EDQUOT },
869 #endif
870 		{ nfserr_stale, -ESTALE },
871 		{ nfserr_jukebox, -ETIMEDOUT },
872 		{ nfserr_jukebox, -ERESTARTSYS },
873 		{ nfserr_jukebox, -EAGAIN },
874 		{ nfserr_jukebox, -EWOULDBLOCK },
875 		{ nfserr_jukebox, -ENOMEM },
876 		{ nfserr_io, -ETXTBSY },
877 		{ nfserr_notsupp, -EOPNOTSUPP },
878 		{ nfserr_toosmall, -ETOOSMALL },
879 		{ nfserr_serverfault, -ESERVERFAULT },
880 		{ nfserr_serverfault, -ENFILE },
881 		{ nfserr_io, -EUCLEAN },
882 		{ nfserr_perm, -ENOKEY },
883 		{ nfserr_no_grace, -ENOGRACE},
884 	};
885 	int	i;
886 
887 	for (i = 0; i < ARRAY_SIZE(nfs_errtbl); i++) {
888 		if (nfs_errtbl[i].syserr == errno)
889 			return nfs_errtbl[i].nfserr;
890 	}
891 	WARN_ONCE(1, "nfsd: non-standard errno: %d\n", errno);
892 	return nfserr_io;
893 }
894 
895