xref: /openbmc/linux/fs/9p/vfs_inode.c (revision 643d1f7f)
1 /*
2  *  linux/fs/9p/vfs_inode.c
3  *
4  * This file contains vfs inode ops for the 9P2000 protocol.
5  *
6  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
7  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License version 2
11  *  as published by the Free Software Foundation.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to:
20  *  Free Software Foundation
21  *  51 Franklin Street, Fifth Floor
22  *  Boston, MA  02111-1301  USA
23  *
24  */
25 
26 #include <linux/module.h>
27 #include <linux/errno.h>
28 #include <linux/fs.h>
29 #include <linux/file.h>
30 #include <linux/pagemap.h>
31 #include <linux/stat.h>
32 #include <linux/string.h>
33 #include <linux/inet.h>
34 #include <linux/namei.h>
35 #include <linux/idr.h>
36 #include <linux/sched.h>
37 #include <net/9p/9p.h>
38 #include <net/9p/client.h>
39 
40 #include "v9fs.h"
41 #include "v9fs_vfs.h"
42 #include "fid.h"
43 
44 static const struct inode_operations v9fs_dir_inode_operations;
45 static const struct inode_operations v9fs_dir_inode_operations_ext;
46 static const struct inode_operations v9fs_file_inode_operations;
47 static const struct inode_operations v9fs_symlink_inode_operations;
48 
49 /**
50  * unixmode2p9mode - convert unix mode bits to plan 9
51  * @v9ses: v9fs session information
52  * @mode: mode to convert
53  *
54  */
55 
56 static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
57 {
58 	int res;
59 	res = mode & 0777;
60 	if (S_ISDIR(mode))
61 		res |= P9_DMDIR;
62 	if (v9fs_extended(v9ses)) {
63 		if (S_ISLNK(mode))
64 			res |= P9_DMSYMLINK;
65 		if (v9ses->nodev == 0) {
66 			if (S_ISSOCK(mode))
67 				res |= P9_DMSOCKET;
68 			if (S_ISFIFO(mode))
69 				res |= P9_DMNAMEDPIPE;
70 			if (S_ISBLK(mode))
71 				res |= P9_DMDEVICE;
72 			if (S_ISCHR(mode))
73 				res |= P9_DMDEVICE;
74 		}
75 
76 		if ((mode & S_ISUID) == S_ISUID)
77 			res |= P9_DMSETUID;
78 		if ((mode & S_ISGID) == S_ISGID)
79 			res |= P9_DMSETGID;
80 		if ((mode & P9_DMLINK))
81 			res |= P9_DMLINK;
82 	}
83 
84 	return res;
85 }
86 
87 /**
88  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
89  * @v9ses: v9fs session information
90  * @mode: mode to convert
91  *
92  */
93 
94 static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
95 {
96 	int res;
97 
98 	res = mode & 0777;
99 
100 	if ((mode & P9_DMDIR) == P9_DMDIR)
101 		res |= S_IFDIR;
102 	else if ((mode & P9_DMSYMLINK) && (v9fs_extended(v9ses)))
103 		res |= S_IFLNK;
104 	else if ((mode & P9_DMSOCKET) && (v9fs_extended(v9ses))
105 		 && (v9ses->nodev == 0))
106 		res |= S_IFSOCK;
107 	else if ((mode & P9_DMNAMEDPIPE) && (v9fs_extended(v9ses))
108 		 && (v9ses->nodev == 0))
109 		res |= S_IFIFO;
110 	else if ((mode & P9_DMDEVICE) && (v9fs_extended(v9ses))
111 		 && (v9ses->nodev == 0))
112 		res |= S_IFBLK;
113 	else
114 		res |= S_IFREG;
115 
116 	if (v9fs_extended(v9ses)) {
117 		if ((mode & P9_DMSETUID) == P9_DMSETUID)
118 			res |= S_ISUID;
119 
120 		if ((mode & P9_DMSETGID) == P9_DMSETGID)
121 			res |= S_ISGID;
122 	}
123 
124 	return res;
125 }
126 
127 int v9fs_uflags2omode(int uflags)
128 {
129 	int ret;
130 
131 	ret = 0;
132 	switch (uflags&3) {
133 	default:
134 	case O_RDONLY:
135 		ret = P9_OREAD;
136 		break;
137 
138 	case O_WRONLY:
139 		ret = P9_OWRITE;
140 		break;
141 
142 	case O_RDWR:
143 		ret = P9_ORDWR;
144 		break;
145 	}
146 
147 	if (uflags & O_EXCL)
148 		ret |= P9_OEXCL;
149 
150 	if (uflags & O_TRUNC)
151 		ret |= P9_OTRUNC;
152 
153 	if (uflags & O_APPEND)
154 		ret |= P9_OAPPEND;
155 
156 	return ret;
157 }
158 
159 /**
160  * v9fs_blank_wstat - helper function to setup a 9P stat structure
161  * @v9ses: 9P session info (for determining extended mode)
162  * @wstat: structure to initialize
163  *
164  */
165 
166 static void
167 v9fs_blank_wstat(struct p9_wstat *wstat)
168 {
169 	wstat->type = ~0;
170 	wstat->dev = ~0;
171 	wstat->qid.type = ~0;
172 	wstat->qid.version = ~0;
173 	*((long long *)&wstat->qid.path) = ~0;
174 	wstat->mode = ~0;
175 	wstat->atime = ~0;
176 	wstat->mtime = ~0;
177 	wstat->length = ~0;
178 	wstat->name = NULL;
179 	wstat->uid = NULL;
180 	wstat->gid = NULL;
181 	wstat->muid = NULL;
182 	wstat->n_uid = ~0;
183 	wstat->n_gid = ~0;
184 	wstat->n_muid = ~0;
185 	wstat->extension = NULL;
186 }
187 
188 /**
189  * v9fs_get_inode - helper function to setup an inode
190  * @sb: superblock
191  * @mode: mode to setup inode with
192  *
193  */
194 
195 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
196 {
197 	struct inode *inode;
198 	struct v9fs_session_info *v9ses = sb->s_fs_info;
199 
200 	P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
201 
202 	inode = new_inode(sb);
203 	if (inode) {
204 		inode->i_mode = mode;
205 		inode->i_uid = current->fsuid;
206 		inode->i_gid = current->fsgid;
207 		inode->i_blocks = 0;
208 		inode->i_rdev = 0;
209 		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
210 		inode->i_mapping->a_ops = &v9fs_addr_operations;
211 
212 		switch (mode & S_IFMT) {
213 		case S_IFIFO:
214 		case S_IFBLK:
215 		case S_IFCHR:
216 		case S_IFSOCK:
217 			if (!v9fs_extended(v9ses)) {
218 				P9_DPRINTK(P9_DEBUG_ERROR,
219 				      "special files without extended mode\n");
220 				return ERR_PTR(-EINVAL);
221 			}
222 			init_special_inode(inode, inode->i_mode,
223 					   inode->i_rdev);
224 			break;
225 		case S_IFREG:
226 			inode->i_op = &v9fs_file_inode_operations;
227 			inode->i_fop = &v9fs_file_operations;
228 			break;
229 		case S_IFLNK:
230 			if (!v9fs_extended(v9ses)) {
231 				P9_DPRINTK(P9_DEBUG_ERROR,
232 					"extended modes used w/o 9P2000.u\n");
233 				return ERR_PTR(-EINVAL);
234 			}
235 			inode->i_op = &v9fs_symlink_inode_operations;
236 			break;
237 		case S_IFDIR:
238 			inc_nlink(inode);
239 			if (v9fs_extended(v9ses))
240 				inode->i_op = &v9fs_dir_inode_operations_ext;
241 			else
242 				inode->i_op = &v9fs_dir_inode_operations;
243 			inode->i_fop = &v9fs_dir_operations;
244 			break;
245 		default:
246 			P9_DPRINTK(P9_DEBUG_ERROR,
247 				"BAD mode 0x%x S_IFMT 0x%x\n",
248 				mode, mode & S_IFMT);
249 			return ERR_PTR(-EINVAL);
250 		}
251 	} else {
252 		P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
253 		return ERR_PTR(-ENOMEM);
254 	}
255 	return inode;
256 }
257 
258 /*
259 static struct v9fs_fid*
260 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
261 {
262 	int err;
263 	int nfid;
264 	struct v9fs_fid *ret;
265 	struct v9fs_fcall *fcall;
266 
267 	nfid = v9fs_get_idpool(&v9ses->fidpool);
268 	if (nfid < 0) {
269 		eprintk(KERN_WARNING, "no free fids available\n");
270 		return ERR_PTR(-ENOSPC);
271 	}
272 
273 	err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
274 		&fcall);
275 
276 	if (err < 0) {
277 		if (fcall && fcall->id == RWALK)
278 			goto clunk_fid;
279 
280 		PRINT_FCALL_ERROR("walk error", fcall);
281 		v9fs_put_idpool(nfid, &v9ses->fidpool);
282 		goto error;
283 	}
284 
285 	kfree(fcall);
286 	fcall = NULL;
287 	ret = v9fs_fid_create(v9ses, nfid);
288 	if (!ret) {
289 		err = -ENOMEM;
290 		goto clunk_fid;
291 	}
292 
293 	err = v9fs_fid_insert(ret, dentry);
294 	if (err < 0) {
295 		v9fs_fid_destroy(ret);
296 		goto clunk_fid;
297 	}
298 
299 	return ret;
300 
301 clunk_fid:
302 	v9fs_t_clunk(v9ses, nfid);
303 
304 error:
305 	kfree(fcall);
306 	return ERR_PTR(err);
307 }
308 */
309 
310 static struct inode *
311 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
312 	struct super_block *sb)
313 {
314 	int err, umode;
315 	struct inode *ret;
316 	struct p9_stat *st;
317 
318 	ret = NULL;
319 	st = p9_client_stat(fid);
320 	if (IS_ERR(st)) {
321 		err = PTR_ERR(st);
322 		st = NULL;
323 		goto error;
324 	}
325 
326 	umode = p9mode2unixmode(v9ses, st->mode);
327 	ret = v9fs_get_inode(sb, umode);
328 	if (IS_ERR(ret)) {
329 		err = PTR_ERR(ret);
330 		ret = NULL;
331 		goto error;
332 	}
333 
334 	v9fs_stat2inode(st, ret, sb);
335 	ret->i_ino = v9fs_qid2ino(&st->qid);
336 	kfree(st);
337 	return ret;
338 
339 error:
340 	kfree(st);
341 	if (ret)
342 		iput(ret);
343 
344 	return ERR_PTR(err);
345 }
346 
347 /**
348  * v9fs_remove - helper function to remove files and directories
349  * @dir: directory inode that is being deleted
350  * @file:  dentry that is being deleted
351  * @rmdir: removing a directory
352  *
353  */
354 
355 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
356 {
357 	struct inode *file_inode;
358 	struct v9fs_session_info *v9ses;
359 	struct p9_fid *v9fid;
360 
361 	P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
362 		rmdir);
363 
364 	file_inode = file->d_inode;
365 	v9ses = v9fs_inode2v9ses(file_inode);
366 	v9fid = v9fs_fid_clone(file);
367 	if (IS_ERR(v9fid))
368 		return PTR_ERR(v9fid);
369 
370 	return p9_client_remove(v9fid);
371 }
372 
373 static int
374 v9fs_open_created(struct inode *inode, struct file *file)
375 {
376 	return 0;
377 }
378 
379 
380 /**
381  * v9fs_create - Create a file
382  * @dentry:  dentry that is being created
383  * @perm: create permissions
384  * @mode: open mode
385  *
386  */
387 static struct p9_fid *
388 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
389 		struct dentry *dentry, char *extension, u32 perm, u8 mode)
390 {
391 	int err;
392 	char *name;
393 	struct p9_fid *dfid, *ofid, *fid;
394 	struct inode *inode;
395 
396 	err = 0;
397 	ofid = NULL;
398 	fid = NULL;
399 	name = (char *) dentry->d_name.name;
400 	dfid = v9fs_fid_clone(dentry->d_parent);
401 	if (IS_ERR(dfid)) {
402 		err = PTR_ERR(dfid);
403 		dfid = NULL;
404 		goto error;
405 	}
406 
407 	/* clone a fid to use for creation */
408 	ofid = p9_client_walk(dfid, 0, NULL, 1);
409 	if (IS_ERR(ofid)) {
410 		err = PTR_ERR(ofid);
411 		ofid = NULL;
412 		goto error;
413 	}
414 
415 	err = p9_client_fcreate(ofid, name, perm, mode, extension);
416 	if (err < 0)
417 		goto error;
418 
419 	/* now walk from the parent so we can get unopened fid */
420 	fid = p9_client_walk(dfid, 1, &name, 0);
421 	if (IS_ERR(fid)) {
422 		err = PTR_ERR(fid);
423 		fid = NULL;
424 		goto error;
425 	} else
426 		dfid = NULL;
427 
428 	/* instantiate inode and assign the unopened fid to the dentry */
429 	inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
430 	if (IS_ERR(inode)) {
431 		err = PTR_ERR(inode);
432 		goto error;
433 	}
434 
435 	if (v9ses->cache)
436 		dentry->d_op = &v9fs_cached_dentry_operations;
437 	else
438 		dentry->d_op = &v9fs_dentry_operations;
439 
440 	d_instantiate(dentry, inode);
441 	v9fs_fid_add(dentry, fid);
442 	return ofid;
443 
444 error:
445 	if (dfid)
446 		p9_client_clunk(dfid);
447 
448 	if (ofid)
449 		p9_client_clunk(ofid);
450 
451 	if (fid)
452 		p9_client_clunk(fid);
453 
454 	return ERR_PTR(err);
455 }
456 
457 /**
458  * v9fs_vfs_create - VFS hook to create files
459  * @inode: directory inode that is being created
460  * @dentry:  dentry that is being deleted
461  * @mode: create permissions
462  * @nd: path information
463  *
464  */
465 
466 static int
467 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
468 		struct nameidata *nd)
469 {
470 	int err;
471 	u32 perm;
472 	int flags;
473 	struct v9fs_session_info *v9ses;
474 	struct p9_fid *fid;
475 	struct file *filp;
476 
477 	err = 0;
478 	fid = NULL;
479 	v9ses = v9fs_inode2v9ses(dir);
480 	perm = unixmode2p9mode(v9ses, mode);
481 	if (nd && nd->flags & LOOKUP_OPEN)
482 		flags = nd->intent.open.flags - 1;
483 	else
484 		flags = O_RDWR;
485 
486 	fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
487 						v9fs_uflags2omode(flags));
488 	if (IS_ERR(fid)) {
489 		err = PTR_ERR(fid);
490 		fid = NULL;
491 		goto error;
492 	}
493 
494 	/* if we are opening a file, assign the open fid to the file */
495 	if (nd && nd->flags & LOOKUP_OPEN) {
496 		filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
497 		if (IS_ERR(filp)) {
498 			err = PTR_ERR(filp);
499 			goto error;
500 		}
501 
502 		filp->private_data = fid;
503 	} else
504 		p9_client_clunk(fid);
505 
506 	return 0;
507 
508 error:
509 	if (fid)
510 		p9_client_clunk(fid);
511 
512 	return err;
513 }
514 
515 /**
516  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
517  * @inode:  inode that is being unlinked
518  * @dentry: dentry that is being unlinked
519  * @mode: mode for new directory
520  *
521  */
522 
523 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
524 {
525 	int err;
526 	u32 perm;
527 	struct v9fs_session_info *v9ses;
528 	struct p9_fid *fid;
529 
530 	P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
531 	err = 0;
532 	v9ses = v9fs_inode2v9ses(dir);
533 	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
534 	fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
535 	if (IS_ERR(fid)) {
536 		err = PTR_ERR(fid);
537 		fid = NULL;
538 	}
539 
540 	if (fid)
541 		p9_client_clunk(fid);
542 
543 	return err;
544 }
545 
546 /**
547  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
548  * @dir:  inode that is being walked from
549  * @dentry: dentry that is being walked to?
550  * @nameidata: path data
551  *
552  */
553 
554 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
555 				      struct nameidata *nameidata)
556 {
557 	struct super_block *sb;
558 	struct v9fs_session_info *v9ses;
559 	struct p9_fid *dfid, *fid;
560 	struct inode *inode;
561 	char *name;
562 	int result = 0;
563 
564 	P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
565 		dir, dentry->d_name.name, dentry, nameidata);
566 
567 	sb = dir->i_sb;
568 	v9ses = v9fs_inode2v9ses(dir);
569 	dfid = v9fs_fid_lookup(dentry->d_parent);
570 	if (IS_ERR(dfid))
571 		return ERR_PTR(PTR_ERR(dfid));
572 
573 	name = (char *) dentry->d_name.name;
574 	fid = p9_client_walk(dfid, 1, &name, 1);
575 	if (IS_ERR(fid)) {
576 		result = PTR_ERR(fid);
577 		if (result == -ENOENT) {
578 			d_add(dentry, NULL);
579 			return NULL;
580 		}
581 
582 		return ERR_PTR(result);
583 	}
584 
585 	inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
586 	if (IS_ERR(inode)) {
587 		result = PTR_ERR(inode);
588 		inode = NULL;
589 		goto error;
590 	}
591 
592 	result = v9fs_fid_add(dentry, fid);
593 	if (result < 0)
594 		goto error;
595 
596 	if ((fid->qid.version) && (v9ses->cache))
597 		dentry->d_op = &v9fs_cached_dentry_operations;
598 	else
599 		dentry->d_op = &v9fs_dentry_operations;
600 
601 	d_add(dentry, inode);
602 	return NULL;
603 
604 error:
605 	if (fid)
606 		p9_client_clunk(fid);
607 
608 	return ERR_PTR(result);
609 }
610 
611 /**
612  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
613  * @i:  inode that is being unlinked
614  * @d: dentry that is being unlinked
615  *
616  */
617 
618 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
619 {
620 	return v9fs_remove(i, d, 0);
621 }
622 
623 /**
624  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
625  * @i:  inode that is being unlinked
626  * @d: dentry that is being unlinked
627  *
628  */
629 
630 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
631 {
632 	return v9fs_remove(i, d, 1);
633 }
634 
635 /**
636  * v9fs_vfs_rename - VFS hook to rename an inode
637  * @old_dir:  old dir inode
638  * @old_dentry: old dentry
639  * @new_dir: new dir inode
640  * @new_dentry: new dentry
641  *
642  */
643 
644 static int
645 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
646 		struct inode *new_dir, struct dentry *new_dentry)
647 {
648 	struct inode *old_inode;
649 	struct v9fs_session_info *v9ses;
650 	struct p9_fid *oldfid;
651 	struct p9_fid *olddirfid;
652 	struct p9_fid *newdirfid;
653 	struct p9_wstat wstat;
654 	int retval;
655 
656 	P9_DPRINTK(P9_DEBUG_VFS, "\n");
657 	retval = 0;
658 	old_inode = old_dentry->d_inode;
659 	v9ses = v9fs_inode2v9ses(old_inode);
660 	oldfid = v9fs_fid_lookup(old_dentry);
661 	if (IS_ERR(oldfid))
662 		return PTR_ERR(oldfid);
663 
664 	olddirfid = v9fs_fid_clone(old_dentry->d_parent);
665 	if (IS_ERR(olddirfid)) {
666 		retval = PTR_ERR(olddirfid);
667 		goto done;
668 	}
669 
670 	newdirfid = v9fs_fid_clone(new_dentry->d_parent);
671 	if (IS_ERR(newdirfid)) {
672 		retval = PTR_ERR(newdirfid);
673 		goto clunk_olddir;
674 	}
675 
676 	/* 9P can only handle file rename in the same directory */
677 	if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
678 		P9_DPRINTK(P9_DEBUG_ERROR,
679 				"old dir and new dir are different\n");
680 		retval = -EXDEV;
681 		goto clunk_newdir;
682 	}
683 
684 	v9fs_blank_wstat(&wstat);
685 	wstat.muid = v9ses->uname;
686 	wstat.name = (char *) new_dentry->d_name.name;
687 	retval = p9_client_wstat(oldfid, &wstat);
688 
689 clunk_newdir:
690 	p9_client_clunk(newdirfid);
691 
692 clunk_olddir:
693 	p9_client_clunk(olddirfid);
694 
695 done:
696 	return retval;
697 }
698 
699 /**
700  * v9fs_vfs_getattr - retrieve file metadata
701  * @mnt - mount information
702  * @dentry - file to get attributes on
703  * @stat - metadata structure to populate
704  *
705  */
706 
707 static int
708 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
709 		 struct kstat *stat)
710 {
711 	int err;
712 	struct v9fs_session_info *v9ses;
713 	struct p9_fid *fid;
714 	struct p9_stat *st;
715 
716 	P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
717 	err = -EPERM;
718 	v9ses = v9fs_inode2v9ses(dentry->d_inode);
719 	if (v9ses->cache == CACHE_LOOSE)
720 		return simple_getattr(mnt, dentry, stat);
721 
722 	fid = v9fs_fid_lookup(dentry);
723 	if (IS_ERR(fid))
724 		return PTR_ERR(fid);
725 
726 	st = p9_client_stat(fid);
727 	if (IS_ERR(st))
728 		return PTR_ERR(st);
729 
730 	v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
731 		generic_fillattr(dentry->d_inode, stat);
732 
733 	kfree(st);
734 	return 0;
735 }
736 
737 /**
738  * v9fs_vfs_setattr - set file metadata
739  * @dentry: file whose metadata to set
740  * @iattr: metadata assignment structure
741  *
742  */
743 
744 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
745 {
746 	int retval;
747 	struct v9fs_session_info *v9ses;
748 	struct p9_fid *fid;
749 	struct p9_wstat wstat;
750 
751 	P9_DPRINTK(P9_DEBUG_VFS, "\n");
752 	retval = -EPERM;
753 	v9ses = v9fs_inode2v9ses(dentry->d_inode);
754 	fid = v9fs_fid_lookup(dentry);
755 	if(IS_ERR(fid))
756 		return PTR_ERR(fid);
757 
758 	v9fs_blank_wstat(&wstat);
759 	if (iattr->ia_valid & ATTR_MODE)
760 		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
761 
762 	if (iattr->ia_valid & ATTR_MTIME)
763 		wstat.mtime = iattr->ia_mtime.tv_sec;
764 
765 	if (iattr->ia_valid & ATTR_ATIME)
766 		wstat.atime = iattr->ia_atime.tv_sec;
767 
768 	if (iattr->ia_valid & ATTR_SIZE)
769 		wstat.length = iattr->ia_size;
770 
771 	if (v9fs_extended(v9ses)) {
772 		if (iattr->ia_valid & ATTR_UID)
773 			wstat.n_uid = iattr->ia_uid;
774 
775 		if (iattr->ia_valid & ATTR_GID)
776 			wstat.n_gid = iattr->ia_gid;
777 	}
778 
779 	retval = p9_client_wstat(fid, &wstat);
780 	if (retval >= 0)
781 		retval = inode_setattr(dentry->d_inode, iattr);
782 
783 	return retval;
784 }
785 
786 /**
787  * v9fs_stat2inode - populate an inode structure with mistat info
788  * @stat: Plan 9 metadata (mistat) structure
789  * @inode: inode to populate
790  * @sb: superblock of filesystem
791  *
792  */
793 
794 void
795 v9fs_stat2inode(struct p9_stat *stat, struct inode *inode,
796 	struct super_block *sb)
797 {
798 	int n;
799 	char ext[32];
800 	struct v9fs_session_info *v9ses = sb->s_fs_info;
801 
802 	inode->i_nlink = 1;
803 
804 	inode->i_atime.tv_sec = stat->atime;
805 	inode->i_mtime.tv_sec = stat->mtime;
806 	inode->i_ctime.tv_sec = stat->mtime;
807 
808 	inode->i_uid = v9ses->dfltuid;
809 	inode->i_gid = v9ses->dfltgid;
810 
811 	if (v9fs_extended(v9ses)) {
812 		inode->i_uid = stat->n_uid;
813 		inode->i_gid = stat->n_gid;
814 	}
815 
816 	inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
817 	if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
818 		char type = 0;
819 		int major = -1;
820 		int minor = -1;
821 
822 		n = stat->extension.len;
823 		if (n > sizeof(ext)-1)
824 			n = sizeof(ext)-1;
825 		memmove(ext, stat->extension.str, n);
826 		ext[n] = 0;
827 		sscanf(ext, "%c %u %u", &type, &major, &minor);
828 		switch (type) {
829 		case 'c':
830 			inode->i_mode &= ~S_IFBLK;
831 			inode->i_mode |= S_IFCHR;
832 			break;
833 		case 'b':
834 			break;
835 		default:
836 			P9_DPRINTK(P9_DEBUG_ERROR,
837 				"Unknown special type %c (%.*s)\n", type,
838 				stat->extension.len, stat->extension.str);
839 		};
840 		inode->i_rdev = MKDEV(major, minor);
841 	} else
842 		inode->i_rdev = 0;
843 
844 	inode->i_size = stat->length;
845 
846 	/* not real number of blocks, but 512 byte ones ... */
847 	inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
848 }
849 
850 /**
851  * v9fs_qid2ino - convert qid into inode number
852  * @qid: qid to hash
853  *
854  * BUG: potential for inode number collisions?
855  */
856 
857 ino_t v9fs_qid2ino(struct p9_qid *qid)
858 {
859 	u64 path = qid->path + 2;
860 	ino_t i = 0;
861 
862 	if (sizeof(ino_t) == sizeof(path))
863 		memcpy(&i, &path, sizeof(ino_t));
864 	else
865 		i = (ino_t) (path ^ (path >> 32));
866 
867 	return i;
868 }
869 
870 /**
871  * v9fs_readlink - read a symlink's location (internal version)
872  * @dentry: dentry for symlink
873  * @buffer: buffer to load symlink location into
874  * @buflen: length of buffer
875  *
876  */
877 
878 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
879 {
880 	int retval;
881 
882 	struct v9fs_session_info *v9ses;
883 	struct p9_fid *fid;
884 	struct p9_stat *st;
885 
886 	P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
887 	retval = -EPERM;
888 	v9ses = v9fs_inode2v9ses(dentry->d_inode);
889 	fid = v9fs_fid_lookup(dentry);
890 	if (IS_ERR(fid))
891 		return PTR_ERR(fid);
892 
893 	if (!v9fs_extended(v9ses))
894 		return -EBADF;
895 
896 	st = p9_client_stat(fid);
897 	if (IS_ERR(st))
898 		return PTR_ERR(st);
899 
900 	if (!(st->mode & P9_DMSYMLINK)) {
901 		retval = -EINVAL;
902 		goto done;
903 	}
904 
905 	/* copy extension buffer into buffer */
906 	if (st->extension.len < buflen)
907 		buflen = st->extension.len + 1;
908 
909 	memmove(buffer, st->extension.str, buflen - 1);
910 	buffer[buflen-1] = 0;
911 
912 	P9_DPRINTK(P9_DEBUG_VFS,
913 		"%s -> %.*s (%s)\n", dentry->d_name.name, st->extension.len,
914 		st->extension.str, buffer);
915 
916 	retval = buflen;
917 
918 done:
919 	kfree(st);
920 	return retval;
921 }
922 
923 /**
924  * v9fs_vfs_readlink - read a symlink's location
925  * @dentry: dentry for symlink
926  * @buf: buffer to load symlink location into
927  * @buflen: length of buffer
928  *
929  */
930 
931 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
932 			     int buflen)
933 {
934 	int retval;
935 	int ret;
936 	char *link = __getname();
937 
938 	if (unlikely(!link))
939 		return -ENOMEM;
940 
941 	if (buflen > PATH_MAX)
942 		buflen = PATH_MAX;
943 
944 	P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
945 
946 	retval = v9fs_readlink(dentry, link, buflen);
947 
948 	if (retval > 0) {
949 		if ((ret = copy_to_user(buffer, link, retval)) != 0) {
950 			P9_DPRINTK(P9_DEBUG_ERROR,
951 					"problem copying to user: %d\n", ret);
952 			retval = ret;
953 		}
954 	}
955 
956 	__putname(link);
957 	return retval;
958 }
959 
960 /**
961  * v9fs_vfs_follow_link - follow a symlink path
962  * @dentry: dentry for symlink
963  * @nd: nameidata
964  *
965  */
966 
967 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
968 {
969 	int len = 0;
970 	char *link = __getname();
971 
972 	P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
973 
974 	if (!link)
975 		link = ERR_PTR(-ENOMEM);
976 	else {
977 		len = v9fs_readlink(dentry, link, PATH_MAX);
978 
979 		if (len < 0) {
980 			__putname(link);
981 			link = ERR_PTR(len);
982 		} else
983 			link[len] = 0;
984 	}
985 	nd_set_link(nd, link);
986 
987 	return NULL;
988 }
989 
990 /**
991  * v9fs_vfs_put_link - release a symlink path
992  * @dentry: dentry for symlink
993  * @nd: nameidata
994  *
995  */
996 
997 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
998 {
999 	char *s = nd_get_link(nd);
1000 
1001 	P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1002 	if (!IS_ERR(s))
1003 		__putname(s);
1004 }
1005 
1006 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1007 	int mode, const char *extension)
1008 {
1009 	u32 perm;
1010 	struct v9fs_session_info *v9ses;
1011 	struct p9_fid *fid;
1012 
1013 	v9ses = v9fs_inode2v9ses(dir);
1014 	if (!v9fs_extended(v9ses)) {
1015 		P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1016 		return -EPERM;
1017 	}
1018 
1019 	perm = unixmode2p9mode(v9ses, mode);
1020 	fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1021 								P9_OREAD);
1022 	if (IS_ERR(fid))
1023 		return PTR_ERR(fid);
1024 
1025 	p9_client_clunk(fid);
1026 	return 0;
1027 }
1028 
1029 /**
1030  * v9fs_vfs_symlink - helper function to create symlinks
1031  * @dir: directory inode containing symlink
1032  * @dentry: dentry for symlink
1033  * @symname: symlink data
1034  *
1035  * See 9P2000.u RFC for more information
1036  *
1037  */
1038 
1039 static int
1040 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1041 {
1042 	P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1043 					dentry->d_name.name, symname);
1044 
1045 	return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1046 }
1047 
1048 /**
1049  * v9fs_vfs_link - create a hardlink
1050  * @old_dentry: dentry for file to link to
1051  * @dir: inode destination for new link
1052  * @dentry: dentry for link
1053  *
1054  */
1055 
1056 /* XXX - lots of code dup'd from symlink and creates,
1057  * figure out a better reuse strategy
1058  */
1059 
1060 static int
1061 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1062 	      struct dentry *dentry)
1063 {
1064 	int retval;
1065 	struct p9_fid *oldfid;
1066 	char *name;
1067 
1068 	P9_DPRINTK(P9_DEBUG_VFS,
1069 		" %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1070 		old_dentry->d_name.name);
1071 
1072 	oldfid = v9fs_fid_clone(old_dentry);
1073 	if (IS_ERR(oldfid))
1074 		return PTR_ERR(oldfid);
1075 
1076 	name = __getname();
1077 	if (unlikely(!name)) {
1078 		retval = -ENOMEM;
1079 		goto clunk_fid;
1080 	}
1081 
1082 	sprintf(name, "%d\n", oldfid->fid);
1083 	retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1084 	__putname(name);
1085 
1086 clunk_fid:
1087 	p9_client_clunk(oldfid);
1088 	return retval;
1089 }
1090 
1091 /**
1092  * v9fs_vfs_mknod - create a special file
1093  * @dir: inode destination for new link
1094  * @dentry: dentry for file
1095  * @mode: mode for creation
1096  * @dev_t: device associated with special file
1097  *
1098  */
1099 
1100 static int
1101 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1102 {
1103 	int retval;
1104 	char *name;
1105 
1106 	P9_DPRINTK(P9_DEBUG_VFS,
1107 		" %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1108 		dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1109 
1110 	if (!new_valid_dev(rdev))
1111 		return -EINVAL;
1112 
1113 	name = __getname();
1114 	if (!name)
1115 		return -ENOMEM;
1116 	/* build extension */
1117 	if (S_ISBLK(mode))
1118 		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1119 	else if (S_ISCHR(mode))
1120 		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1121 	else if (S_ISFIFO(mode))
1122 		*name = 0;
1123 	else {
1124 		__putname(name);
1125 		return -EINVAL;
1126 	}
1127 
1128 	retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1129 	__putname(name);
1130 
1131 	return retval;
1132 }
1133 
1134 static const struct inode_operations v9fs_dir_inode_operations_ext = {
1135 	.create = v9fs_vfs_create,
1136 	.lookup = v9fs_vfs_lookup,
1137 	.symlink = v9fs_vfs_symlink,
1138 	.link = v9fs_vfs_link,
1139 	.unlink = v9fs_vfs_unlink,
1140 	.mkdir = v9fs_vfs_mkdir,
1141 	.rmdir = v9fs_vfs_rmdir,
1142 	.mknod = v9fs_vfs_mknod,
1143 	.rename = v9fs_vfs_rename,
1144 	.readlink = v9fs_vfs_readlink,
1145 	.getattr = v9fs_vfs_getattr,
1146 	.setattr = v9fs_vfs_setattr,
1147 };
1148 
1149 static const struct inode_operations v9fs_dir_inode_operations = {
1150 	.create = v9fs_vfs_create,
1151 	.lookup = v9fs_vfs_lookup,
1152 	.unlink = v9fs_vfs_unlink,
1153 	.mkdir = v9fs_vfs_mkdir,
1154 	.rmdir = v9fs_vfs_rmdir,
1155 	.mknod = v9fs_vfs_mknod,
1156 	.rename = v9fs_vfs_rename,
1157 	.getattr = v9fs_vfs_getattr,
1158 	.setattr = v9fs_vfs_setattr,
1159 };
1160 
1161 static const struct inode_operations v9fs_file_inode_operations = {
1162 	.getattr = v9fs_vfs_getattr,
1163 	.setattr = v9fs_vfs_setattr,
1164 };
1165 
1166 static const struct inode_operations v9fs_symlink_inode_operations = {
1167 	.readlink = v9fs_vfs_readlink,
1168 	.follow_link = v9fs_vfs_follow_link,
1169 	.put_link = v9fs_vfs_put_link,
1170 	.getattr = v9fs_vfs_getattr,
1171 	.setattr = v9fs_vfs_setattr,
1172 };
1173