xref: /linux/fs/9p/vfs_inode.c (revision de2fe5e07d58424bc286fff3fd3c1b0bf933cd58)
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/smp_lock.h>
34 #include <linux/inet.h>
35 #include <linux/namei.h>
36 #include <linux/idr.h>
37 
38 #include "debug.h"
39 #include "v9fs.h"
40 #include "9p.h"
41 #include "v9fs_vfs.h"
42 #include "fid.h"
43 
44 static struct inode_operations v9fs_dir_inode_operations;
45 static struct inode_operations v9fs_dir_inode_operations_ext;
46 static struct inode_operations v9fs_file_inode_operations;
47 static 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 |= V9FS_DMDIR;
62 	if (v9ses->extended) {
63 		if (S_ISLNK(mode))
64 			res |= V9FS_DMSYMLINK;
65 		if (v9ses->nodev == 0) {
66 			if (S_ISSOCK(mode))
67 				res |= V9FS_DMSOCKET;
68 			if (S_ISFIFO(mode))
69 				res |= V9FS_DMNAMEDPIPE;
70 			if (S_ISBLK(mode))
71 				res |= V9FS_DMDEVICE;
72 			if (S_ISCHR(mode))
73 				res |= V9FS_DMDEVICE;
74 		}
75 
76 		if ((mode & S_ISUID) == S_ISUID)
77 			res |= V9FS_DMSETUID;
78 		if ((mode & S_ISGID) == S_ISGID)
79 			res |= V9FS_DMSETGID;
80 		if ((mode & V9FS_DMLINK))
81 			res |= V9FS_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 & V9FS_DMDIR) == V9FS_DMDIR)
101 		res |= S_IFDIR;
102 	else if ((mode & V9FS_DMSYMLINK) && (v9ses->extended))
103 		res |= S_IFLNK;
104 	else if ((mode & V9FS_DMSOCKET) && (v9ses->extended)
105 		 && (v9ses->nodev == 0))
106 		res |= S_IFSOCK;
107 	else if ((mode & V9FS_DMNAMEDPIPE) && (v9ses->extended)
108 		 && (v9ses->nodev == 0))
109 		res |= S_IFIFO;
110 	else if ((mode & V9FS_DMDEVICE) && (v9ses->extended)
111 		 && (v9ses->nodev == 0))
112 		res |= S_IFBLK;
113 	else
114 		res |= S_IFREG;
115 
116 	if (v9ses->extended) {
117 		if ((mode & V9FS_DMSETUID) == V9FS_DMSETUID)
118 			res |= S_ISUID;
119 
120 		if ((mode & V9FS_DMSETGID) == V9FS_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 = V9FS_OREAD;
136 		break;
137 
138 	case O_WRONLY:
139 		ret = V9FS_OWRITE;
140 		break;
141 
142 	case O_RDWR:
143 		ret = V9FS_ORDWR;
144 		break;
145 	}
146 
147 	if (uflags & O_EXCL)
148 		ret |= V9FS_OEXCL;
149 
150 	if (uflags & O_TRUNC)
151 		ret |= V9FS_OTRUNC;
152 
153 	if (uflags & O_APPEND)
154 		ret |= V9FS_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 v9fs_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 	dprintk(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_blksize = sb->s_blocksize;
208 		inode->i_blocks = 0;
209 		inode->i_rdev = 0;
210 		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
211 		inode->i_mapping->a_ops = &v9fs_addr_operations;
212 
213 		switch (mode & S_IFMT) {
214 		case S_IFIFO:
215 		case S_IFBLK:
216 		case S_IFCHR:
217 		case S_IFSOCK:
218 			if(!v9ses->extended) {
219 				dprintk(DEBUG_ERROR, "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(!v9ses->extended) {
231 				dprintk(DEBUG_ERROR, "extended modes used w/o 9P2000.u\n");
232 				return ERR_PTR(-EINVAL);
233 			}
234 			inode->i_op = &v9fs_symlink_inode_operations;
235 			break;
236 		case S_IFDIR:
237 			inode->i_nlink++;
238 			if(v9ses->extended)
239 				inode->i_op = &v9fs_dir_inode_operations_ext;
240 			else
241 				inode->i_op = &v9fs_dir_inode_operations;
242 			inode->i_fop = &v9fs_dir_operations;
243 			break;
244 		default:
245 			dprintk(DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
246 				mode, mode & S_IFMT);
247 			return ERR_PTR(-EINVAL);
248 		}
249 	} else {
250 		eprintk(KERN_WARNING, "Problem allocating inode\n");
251 		return ERR_PTR(-ENOMEM);
252 	}
253 	return inode;
254 }
255 
256 static int
257 v9fs_create(struct v9fs_session_info *v9ses, u32 pfid, char *name, u32 perm,
258 	u8 mode, char *extension, u32 *fidp, struct v9fs_qid *qid, u32 *iounit)
259 {
260 	u32 fid;
261 	int err;
262 	struct v9fs_fcall *fcall;
263 
264 	fid = v9fs_get_idpool(&v9ses->fidpool);
265 	if (fid < 0) {
266 		eprintk(KERN_WARNING, "no free fids available\n");
267 		return -ENOSPC;
268 	}
269 
270 	err = v9fs_t_walk(v9ses, pfid, fid, NULL, &fcall);
271 	if (err < 0) {
272 		PRINT_FCALL_ERROR("clone error", fcall);
273 		goto put_fid;
274 	}
275 	kfree(fcall);
276 
277 	err = v9fs_t_create(v9ses, fid, name, perm, mode, extension, &fcall);
278 	if (err < 0) {
279 		PRINT_FCALL_ERROR("create fails", fcall);
280 		goto clunk_fid;
281 	}
282 
283 	if (iounit)
284 		*iounit = fcall->params.rcreate.iounit;
285 
286 	if (qid)
287 		*qid = fcall->params.rcreate.qid;
288 
289 	if (fidp)
290 		*fidp = fid;
291 
292 	kfree(fcall);
293 	return 0;
294 
295 clunk_fid:
296 	v9fs_t_clunk(v9ses, fid);
297 	fid = V9FS_NOFID;
298 
299 put_fid:
300 	if (fid >= 0)
301 		v9fs_put_idpool(fid, &v9ses->fidpool);
302 
303 	kfree(fcall);
304 	return err;
305 }
306 
307 static struct v9fs_fid*
308 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
309 {
310 	int err;
311 	u32 nfid;
312 	struct v9fs_fid *ret;
313 	struct v9fs_fcall *fcall;
314 
315 	nfid = v9fs_get_idpool(&v9ses->fidpool);
316 	if (nfid < 0) {
317 		eprintk(KERN_WARNING, "no free fids available\n");
318 		return ERR_PTR(-ENOSPC);
319 	}
320 
321 	err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
322 		&fcall);
323 
324 	if (err < 0) {
325 		PRINT_FCALL_ERROR("walk error", fcall);
326 		v9fs_put_idpool(nfid, &v9ses->fidpool);
327 		goto error;
328 	}
329 
330 	kfree(fcall);
331 	fcall = NULL;
332 	ret = v9fs_fid_create(v9ses, nfid);
333 	if (!ret) {
334 		err = -ENOMEM;
335 		goto clunk_fid;
336 	}
337 
338 	err = v9fs_fid_insert(ret, dentry);
339 	if (err < 0) {
340 		v9fs_fid_destroy(ret);
341 		goto clunk_fid;
342 	}
343 
344 	return ret;
345 
346 clunk_fid:
347 	v9fs_t_clunk(v9ses, nfid);
348 
349 error:
350 	kfree(fcall);
351 	return ERR_PTR(err);
352 }
353 
354 static struct inode *
355 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, u32 fid,
356 	struct super_block *sb)
357 {
358 	int err, umode;
359 	struct inode *ret;
360 	struct v9fs_fcall *fcall;
361 
362 	ret = NULL;
363 	err = v9fs_t_stat(v9ses, fid, &fcall);
364 	if (err) {
365 		PRINT_FCALL_ERROR("stat error", fcall);
366 		goto error;
367 	}
368 
369 	umode = p9mode2unixmode(v9ses, fcall->params.rstat.stat.mode);
370 	ret = v9fs_get_inode(sb, umode);
371 	if (IS_ERR(ret)) {
372 		err = PTR_ERR(ret);
373 		ret = NULL;
374 		goto error;
375 	}
376 
377 	v9fs_stat2inode(&fcall->params.rstat.stat, ret, sb);
378 	kfree(fcall);
379 	return ret;
380 
381 error:
382 	kfree(fcall);
383 	if (ret)
384 		iput(ret);
385 
386 	return ERR_PTR(err);
387 }
388 
389 /**
390  * v9fs_remove - helper function to remove files and directories
391  * @dir: directory inode that is being deleted
392  * @file:  dentry that is being deleted
393  * @rmdir: removing a directory
394  *
395  */
396 
397 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
398 {
399 	struct v9fs_fcall *fcall = NULL;
400 	struct super_block *sb = NULL;
401 	struct v9fs_session_info *v9ses = NULL;
402 	struct v9fs_fid *v9fid = NULL;
403 	struct inode *file_inode = NULL;
404 	int fid = -1;
405 	int result = 0;
406 
407 	dprintk(DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
408 		rmdir);
409 
410 	file_inode = file->d_inode;
411 	sb = file_inode->i_sb;
412 	v9ses = v9fs_inode2v9ses(file_inode);
413 	v9fid = v9fs_fid_lookup(file);
414 
415 	if (!v9fid) {
416 		dprintk(DEBUG_ERROR,
417 			"no v9fs_fid\n");
418 		return -EBADF;
419 	}
420 
421 	fid = v9fid->fid;
422 	if (fid < 0) {
423 		dprintk(DEBUG_ERROR, "inode #%lu, no fid!\n",
424 			file_inode->i_ino);
425 		return -EBADF;
426 	}
427 
428 	result = v9fs_t_remove(v9ses, fid, &fcall);
429 	if (result < 0) {
430 		PRINT_FCALL_ERROR("remove fails", fcall);
431 	} else {
432 		v9fs_put_idpool(fid, &v9ses->fidpool);
433 		v9fs_fid_destroy(v9fid);
434 	}
435 
436 	kfree(fcall);
437 	return result;
438 }
439 
440 static int
441 v9fs_open_created(struct inode *inode, struct file *file)
442 {
443 	return 0;
444 }
445 
446 /**
447  * v9fs_vfs_create - VFS hook to create files
448  * @inode: directory inode that is being deleted
449  * @dentry:  dentry that is being deleted
450  * @mode: create permissions
451  * @nd: path information
452  *
453  */
454 
455 static int
456 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
457 		struct nameidata *nd)
458 {
459 	int err;
460 	u32 fid, perm, iounit;
461 	int flags;
462 	struct v9fs_session_info *v9ses;
463 	struct v9fs_fid *dfid, *vfid, *ffid;
464 	struct inode *inode;
465 	struct v9fs_qid qid;
466 	struct file *filp;
467 
468 	inode = NULL;
469 	vfid = NULL;
470 	v9ses = v9fs_inode2v9ses(dir);
471 	dfid = v9fs_fid_lookup(dentry->d_parent);
472 	perm = unixmode2p9mode(v9ses, mode);
473 
474 	if (nd && nd->flags & LOOKUP_OPEN)
475 		flags = nd->intent.open.flags - 1;
476 	else
477 		flags = O_RDWR;
478 
479 	err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
480 		perm, v9fs_uflags2omode(flags), NULL, &fid, &qid, &iounit);
481 
482 	if (err)
483 		goto error;
484 
485 	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
486 	if (IS_ERR(vfid)) {
487 		err = PTR_ERR(vfid);
488 		vfid = NULL;
489 		goto error;
490 	}
491 
492 	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
493 	if (IS_ERR(inode)) {
494 		err = PTR_ERR(inode);
495 		inode = NULL;
496 		goto error;
497 	}
498 
499 	dentry->d_op = &v9fs_dentry_operations;
500 	d_instantiate(dentry, inode);
501 
502 	if (nd && nd->flags & LOOKUP_OPEN) {
503 		ffid = v9fs_fid_create(v9ses, fid);
504 		if (!ffid)
505 			return -ENOMEM;
506 
507 		filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
508 		if (IS_ERR(filp)) {
509 			v9fs_fid_destroy(ffid);
510 			return PTR_ERR(filp);
511 		}
512 
513 		ffid->rdir_pos = 0;
514 		ffid->rdir_fcall = NULL;
515 		ffid->fidopen = 1;
516 		ffid->iounit = iounit;
517 		ffid->filp = filp;
518 		filp->private_data = ffid;
519 	}
520 
521 	return 0;
522 
523 error:
524 	if (vfid)
525 		v9fs_fid_destroy(vfid);
526 
527 	if (inode)
528 		iput(inode);
529 
530 	return err;
531 }
532 
533 /**
534  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
535  * @inode:  inode that is being unlinked
536  * @dentry: dentry that is being unlinked
537  * @mode: mode for new directory
538  *
539  */
540 
541 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
542 {
543 	int err;
544 	u32 fid, perm;
545 	struct v9fs_session_info *v9ses;
546 	struct v9fs_fid *dfid, *vfid;
547 	struct inode *inode;
548 
549 	inode = NULL;
550 	vfid = NULL;
551 	v9ses = v9fs_inode2v9ses(dir);
552 	dfid = v9fs_fid_lookup(dentry->d_parent);
553 	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
554 
555 	err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
556 		perm, V9FS_OREAD, NULL, &fid, NULL, NULL);
557 
558 	if (err) {
559 		dprintk(DEBUG_ERROR, "create error %d\n", err);
560 		goto error;
561 	}
562 
563 	err = v9fs_t_clunk(v9ses, fid);
564 	if (err) {
565 		dprintk(DEBUG_ERROR, "clunk error %d\n", err);
566 		goto error;
567 	}
568 
569 	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
570 	if (IS_ERR(vfid)) {
571 		err = PTR_ERR(vfid);
572 		vfid = NULL;
573 		goto error;
574 	}
575 
576 	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
577 	if (IS_ERR(inode)) {
578 		err = PTR_ERR(inode);
579 		inode = NULL;
580 		goto error;
581 	}
582 
583 	dentry->d_op = &v9fs_dentry_operations;
584 	d_instantiate(dentry, inode);
585 	return 0;
586 
587 error:
588 	if (vfid)
589 		v9fs_fid_destroy(vfid);
590 
591 	return err;
592 }
593 
594 /**
595  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
596  * @dir:  inode that is being walked from
597  * @dentry: dentry that is being walked to?
598  * @nameidata: path data
599  *
600  */
601 
602 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
603 				      struct nameidata *nameidata)
604 {
605 	struct super_block *sb;
606 	struct v9fs_session_info *v9ses;
607 	struct v9fs_fid *dirfid;
608 	struct v9fs_fid *fid;
609 	struct inode *inode;
610 	struct v9fs_fcall *fcall = NULL;
611 	int dirfidnum = -1;
612 	int newfid = -1;
613 	int result = 0;
614 
615 	dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
616 		dir, dentry->d_name.name, dentry, nameidata);
617 
618 	sb = dir->i_sb;
619 	v9ses = v9fs_inode2v9ses(dir);
620 	dentry->d_op = &v9fs_dentry_operations;
621 	dirfid = v9fs_fid_lookup(dentry->d_parent);
622 
623 	if (!dirfid) {
624 		dprintk(DEBUG_ERROR, "no dirfid\n");
625 		return ERR_PTR(-EINVAL);
626 	}
627 
628 	dirfidnum = dirfid->fid;
629 
630 	if (dirfidnum < 0) {
631 		dprintk(DEBUG_ERROR, "no dirfid for inode %p, #%lu\n",
632 			dir, dir->i_ino);
633 		return ERR_PTR(-EBADF);
634 	}
635 
636 	newfid = v9fs_get_idpool(&v9ses->fidpool);
637 	if (newfid < 0) {
638 		eprintk(KERN_WARNING, "newfid fails!\n");
639 		return ERR_PTR(-ENOSPC);
640 	}
641 
642 	result = v9fs_t_walk(v9ses, dirfidnum, newfid,
643 		(char *)dentry->d_name.name, NULL);
644 	if (result < 0) {
645 		v9fs_put_idpool(newfid, &v9ses->fidpool);
646 		if (result == -ENOENT) {
647 			d_add(dentry, NULL);
648 			dprintk(DEBUG_VFS,
649 				"Return negative dentry %p count %d\n",
650 				dentry, atomic_read(&dentry->d_count));
651 			return NULL;
652 		}
653 		dprintk(DEBUG_ERROR, "walk error:%d\n", result);
654 		goto FreeFcall;
655 	}
656 
657 	result = v9fs_t_stat(v9ses, newfid, &fcall);
658 	if (result < 0) {
659 		dprintk(DEBUG_ERROR, "stat error\n");
660 		goto FreeFcall;
661 	}
662 
663 	inode = v9fs_get_inode(sb, p9mode2unixmode(v9ses,
664 		fcall->params.rstat.stat.mode));
665 
666 	if (IS_ERR(inode) && (PTR_ERR(inode) == -ENOSPC)) {
667 		eprintk(KERN_WARNING, "inode alloc failes, returns %ld\n",
668 			PTR_ERR(inode));
669 
670 		result = -ENOSPC;
671 		goto FreeFcall;
672 	}
673 
674 	inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid);
675 
676 	fid = v9fs_fid_create(v9ses, newfid);
677 	if (fid == NULL) {
678 		dprintk(DEBUG_ERROR, "couldn't insert\n");
679 		result = -ENOMEM;
680 		goto FreeFcall;
681 	}
682 
683 	result = v9fs_fid_insert(fid, dentry);
684 	if (result < 0)
685 		goto FreeFcall;
686 
687 	fid->qid = fcall->params.rstat.stat.qid;
688 	v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
689 
690 	d_add(dentry, inode);
691 	kfree(fcall);
692 
693 	return NULL;
694 
695       FreeFcall:
696 	kfree(fcall);
697 	return ERR_PTR(result);
698 }
699 
700 /**
701  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
702  * @i:  inode that is being unlinked
703  * @d: dentry that is being unlinked
704  *
705  */
706 
707 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
708 {
709 	return v9fs_remove(i, d, 0);
710 }
711 
712 /**
713  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
714  * @i:  inode that is being unlinked
715  * @d: dentry that is being unlinked
716  *
717  */
718 
719 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
720 {
721 	return v9fs_remove(i, d, 1);
722 }
723 
724 /**
725  * v9fs_vfs_rename - VFS hook to rename an inode
726  * @old_dir:  old dir inode
727  * @old_dentry: old dentry
728  * @new_dir: new dir inode
729  * @new_dentry: new dentry
730  *
731  */
732 
733 static int
734 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
735 		struct inode *new_dir, struct dentry *new_dentry)
736 {
737 	struct inode *old_inode = old_dentry->d_inode;
738 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(old_inode);
739 	struct v9fs_fid *oldfid = v9fs_fid_lookup(old_dentry);
740 	struct v9fs_fid *olddirfid =
741 	    v9fs_fid_lookup(old_dentry->d_parent);
742 	struct v9fs_fid *newdirfid =
743 	    v9fs_fid_lookup(new_dentry->d_parent);
744 	struct v9fs_wstat wstat;
745 	struct v9fs_fcall *fcall = NULL;
746 	int fid = -1;
747 	int olddirfidnum = -1;
748 	int newdirfidnum = -1;
749 	int retval = 0;
750 
751 	dprintk(DEBUG_VFS, "\n");
752 
753 	if ((!oldfid) || (!olddirfid) || (!newdirfid)) {
754 		dprintk(DEBUG_ERROR, "problem with arguments\n");
755 		return -EBADF;
756 	}
757 
758 	/* 9P can only handle file rename in the same directory */
759 	if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
760 		dprintk(DEBUG_ERROR, "old dir and new dir are different\n");
761 		retval = -EPERM;
762 		goto FreeFcallnBail;
763 	}
764 
765 	fid = oldfid->fid;
766 	olddirfidnum = olddirfid->fid;
767 	newdirfidnum = newdirfid->fid;
768 
769 	if (fid < 0) {
770 		dprintk(DEBUG_ERROR, "no fid for old file #%lu\n",
771 			old_inode->i_ino);
772 		retval = -EBADF;
773 		goto FreeFcallnBail;
774 	}
775 
776 	v9fs_blank_wstat(&wstat);
777 	wstat.muid = v9ses->name;
778 	wstat.name = (char *) new_dentry->d_name.name;
779 
780 	retval = v9fs_t_wstat(v9ses, fid, &wstat, &fcall);
781 
782       FreeFcallnBail:
783 	if (retval < 0)
784 		PRINT_FCALL_ERROR("wstat error", fcall);
785 
786 	kfree(fcall);
787 	return retval;
788 }
789 
790 /**
791  * v9fs_vfs_getattr - retrieve file metadata
792  * @mnt - mount information
793  * @dentry - file to get attributes on
794  * @stat - metadata structure to populate
795  *
796  */
797 
798 static int
799 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
800 		 struct kstat *stat)
801 {
802 	struct v9fs_fcall *fcall = NULL;
803 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
804 	struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
805 	int err = -EPERM;
806 
807 	dprintk(DEBUG_VFS, "dentry: %p\n", dentry);
808 	if (!fid) {
809 		dprintk(DEBUG_ERROR,
810 			"couldn't find fid associated with dentry\n");
811 		return -EBADF;
812 	}
813 
814 	err = v9fs_t_stat(v9ses, fid->fid, &fcall);
815 
816 	if (err < 0)
817 		dprintk(DEBUG_ERROR, "stat error\n");
818 	else {
819 		v9fs_stat2inode(&fcall->params.rstat.stat, dentry->d_inode,
820 				  dentry->d_inode->i_sb);
821 		generic_fillattr(dentry->d_inode, stat);
822 	}
823 
824 	kfree(fcall);
825 	return err;
826 }
827 
828 /**
829  * v9fs_vfs_setattr - set file metadata
830  * @dentry: file whose metadata to set
831  * @iattr: metadata assignment structure
832  *
833  */
834 
835 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
836 {
837 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
838 	struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
839 	struct v9fs_fcall *fcall = NULL;
840 	struct v9fs_wstat wstat;
841 	int res = -EPERM;
842 
843 	dprintk(DEBUG_VFS, "\n");
844 
845 	if (!fid) {
846 		dprintk(DEBUG_ERROR,
847 			"Couldn't find fid associated with dentry\n");
848 		return -EBADF;
849 	}
850 
851 	v9fs_blank_wstat(&wstat);
852 	if (iattr->ia_valid & ATTR_MODE)
853 		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
854 
855 	if (iattr->ia_valid & ATTR_MTIME)
856 		wstat.mtime = iattr->ia_mtime.tv_sec;
857 
858 	if (iattr->ia_valid & ATTR_ATIME)
859 		wstat.atime = iattr->ia_atime.tv_sec;
860 
861 	if (iattr->ia_valid & ATTR_SIZE)
862 		wstat.length = iattr->ia_size;
863 
864 	if (v9ses->extended) {
865 		if (iattr->ia_valid & ATTR_UID)
866 			wstat.n_uid = iattr->ia_uid;
867 
868 		if (iattr->ia_valid & ATTR_GID)
869 			wstat.n_gid = iattr->ia_gid;
870 	}
871 
872 	res = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall);
873 
874 	if (res < 0)
875 		PRINT_FCALL_ERROR("wstat error", fcall);
876 
877 	kfree(fcall);
878 	if (res >= 0)
879 		res = inode_setattr(dentry->d_inode, iattr);
880 
881 	return res;
882 }
883 
884 /**
885  * v9fs_stat2inode - populate an inode structure with mistat info
886  * @stat: Plan 9 metadata (mistat) structure
887  * @inode: inode to populate
888  * @sb: superblock of filesystem
889  *
890  */
891 
892 void
893 v9fs_stat2inode(struct v9fs_stat *stat, struct inode *inode,
894 	struct super_block *sb)
895 {
896 	int n;
897 	char ext[32];
898 	struct v9fs_session_info *v9ses = sb->s_fs_info;
899 
900 	inode->i_nlink = 1;
901 
902 	inode->i_atime.tv_sec = stat->atime;
903 	inode->i_mtime.tv_sec = stat->mtime;
904 	inode->i_ctime.tv_sec = stat->mtime;
905 
906 	inode->i_uid = v9ses->uid;
907 	inode->i_gid = v9ses->gid;
908 
909 	if (v9ses->extended) {
910 		inode->i_uid = stat->n_uid;
911 		inode->i_gid = stat->n_gid;
912 	}
913 
914 	inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
915 	if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
916 		char type = 0;
917 		int major = -1;
918 		int minor = -1;
919 
920 		n = stat->extension.len;
921 		if (n > sizeof(ext)-1)
922 			n = sizeof(ext)-1;
923 		memmove(ext, stat->extension.str, n);
924 		ext[n] = 0;
925 		sscanf(ext, "%c %u %u", &type, &major, &minor);
926 		switch (type) {
927 		case 'c':
928 			inode->i_mode &= ~S_IFBLK;
929 			inode->i_mode |= S_IFCHR;
930 			break;
931 		case 'b':
932 			break;
933 		default:
934 			dprintk(DEBUG_ERROR, "Unknown special type %c (%.*s)\n",
935 				type, stat->extension.len, stat->extension.str);
936 		};
937 		inode->i_rdev = MKDEV(major, minor);
938 	} else
939 		inode->i_rdev = 0;
940 
941 	inode->i_size = stat->length;
942 
943 	inode->i_blksize = sb->s_blocksize;
944 	inode->i_blocks =
945 	    (inode->i_size + inode->i_blksize - 1) >> sb->s_blocksize_bits;
946 }
947 
948 /**
949  * v9fs_qid2ino - convert qid into inode number
950  * @qid: qid to hash
951  *
952  * BUG: potential for inode number collisions?
953  */
954 
955 ino_t v9fs_qid2ino(struct v9fs_qid *qid)
956 {
957 	u64 path = qid->path + 2;
958 	ino_t i = 0;
959 
960 	if (sizeof(ino_t) == sizeof(path))
961 		memcpy(&i, &path, sizeof(ino_t));
962 	else
963 		i = (ino_t) (path ^ (path >> 32));
964 
965 	return i;
966 }
967 
968 /**
969  * v9fs_readlink - read a symlink's location (internal version)
970  * @dentry: dentry for symlink
971  * @buffer: buffer to load symlink location into
972  * @buflen: length of buffer
973  *
974  */
975 
976 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
977 {
978 	int retval = -EPERM;
979 
980 	struct v9fs_fcall *fcall = NULL;
981 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
982 	struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
983 
984 	if (!fid) {
985 		dprintk(DEBUG_ERROR, "could not resolve fid from dentry\n");
986 		retval = -EBADF;
987 		goto FreeFcall;
988 	}
989 
990 	if (!v9ses->extended) {
991 		retval = -EBADF;
992 		dprintk(DEBUG_ERROR, "not extended\n");
993 		goto FreeFcall;
994 	}
995 
996 	dprintk(DEBUG_VFS, " %s\n", dentry->d_name.name);
997 	retval = v9fs_t_stat(v9ses, fid->fid, &fcall);
998 
999 	if (retval < 0) {
1000 		dprintk(DEBUG_ERROR, "stat error\n");
1001 		goto FreeFcall;
1002 	}
1003 
1004 	if (!fcall)
1005 		return -EIO;
1006 
1007 	if (!(fcall->params.rstat.stat.mode & V9FS_DMSYMLINK)) {
1008 		retval = -EINVAL;
1009 		goto FreeFcall;
1010 	}
1011 
1012 	/* copy extension buffer into buffer */
1013 	if (fcall->params.rstat.stat.extension.len < buflen)
1014 		buflen = fcall->params.rstat.stat.extension.len + 1;
1015 
1016 	memmove(buffer, fcall->params.rstat.stat.extension.str, buflen - 1);
1017 	buffer[buflen-1] = 0;
1018 
1019 	dprintk(DEBUG_ERROR, "%s -> %.*s (%s)\n", dentry->d_name.name, fcall->params.rstat.stat.extension.len,
1020 		fcall->params.rstat.stat.extension.str, buffer);
1021 	retval = buflen;
1022 
1023       FreeFcall:
1024 	kfree(fcall);
1025 
1026 	return retval;
1027 }
1028 
1029 /**
1030  * v9fs_vfs_readlink - read a symlink's location
1031  * @dentry: dentry for symlink
1032  * @buf: buffer to load symlink location into
1033  * @buflen: length of buffer
1034  *
1035  */
1036 
1037 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
1038 			     int buflen)
1039 {
1040 	int retval;
1041 	int ret;
1042 	char *link = __getname();
1043 
1044 	if (buflen > PATH_MAX)
1045 		buflen = PATH_MAX;
1046 
1047 	dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
1048 
1049 	retval = v9fs_readlink(dentry, link, buflen);
1050 
1051 	if (retval > 0) {
1052 		if ((ret = copy_to_user(buffer, link, retval)) != 0) {
1053 			dprintk(DEBUG_ERROR, "problem copying to user: %d\n",
1054 				ret);
1055 			retval = ret;
1056 		}
1057 	}
1058 
1059 	__putname(link);
1060 	return retval;
1061 }
1062 
1063 /**
1064  * v9fs_vfs_follow_link - follow a symlink path
1065  * @dentry: dentry for symlink
1066  * @nd: nameidata
1067  *
1068  */
1069 
1070 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1071 {
1072 	int len = 0;
1073 	char *link = __getname();
1074 
1075 	dprintk(DEBUG_VFS, "%s n", dentry->d_name.name);
1076 
1077 	if (!link)
1078 		link = ERR_PTR(-ENOMEM);
1079 	else {
1080 		len = v9fs_readlink(dentry, link, PATH_MAX);
1081 
1082 		if (len < 0) {
1083 			__putname(link);
1084 			link = ERR_PTR(len);
1085 		} else
1086 			link[len] = 0;
1087 	}
1088 	nd_set_link(nd, link);
1089 
1090 	return NULL;
1091 }
1092 
1093 /**
1094  * v9fs_vfs_put_link - release a symlink path
1095  * @dentry: dentry for symlink
1096  * @nd: nameidata
1097  *
1098  */
1099 
1100 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1101 {
1102 	char *s = nd_get_link(nd);
1103 
1104 	dprintk(DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1105 	if (!IS_ERR(s))
1106 		__putname(s);
1107 }
1108 
1109 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1110 	int mode, const char *extension)
1111 {
1112 	int err;
1113 	u32 fid, perm;
1114 	struct v9fs_session_info *v9ses;
1115 	struct v9fs_fid *dfid, *vfid;
1116 	struct inode *inode;
1117 
1118 	inode = NULL;
1119 	vfid = NULL;
1120 	v9ses = v9fs_inode2v9ses(dir);
1121 	dfid = v9fs_fid_lookup(dentry->d_parent);
1122 	perm = unixmode2p9mode(v9ses, mode);
1123 
1124 	if (!v9ses->extended) {
1125 		dprintk(DEBUG_ERROR, "not extended\n");
1126 		return -EPERM;
1127 	}
1128 
1129 	err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
1130 		perm, V9FS_OREAD, (char *) extension, &fid, NULL, NULL);
1131 
1132 	if (err)
1133 		goto error;
1134 
1135 	err = v9fs_t_clunk(v9ses, fid);
1136 	if (err)
1137 		goto error;
1138 
1139 	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
1140 	if (IS_ERR(vfid)) {
1141 		err = PTR_ERR(vfid);
1142 		vfid = NULL;
1143 		goto error;
1144 	}
1145 
1146 	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
1147 	if (IS_ERR(inode)) {
1148 		err = PTR_ERR(inode);
1149 		inode = NULL;
1150 		goto error;
1151 	}
1152 
1153 	dentry->d_op = &v9fs_dentry_operations;
1154 	d_instantiate(dentry, inode);
1155 	return 0;
1156 
1157 error:
1158 	if (vfid)
1159 		v9fs_fid_destroy(vfid);
1160 
1161 	if (inode)
1162 		iput(inode);
1163 
1164 	return err;
1165 
1166 }
1167 
1168 /**
1169  * v9fs_vfs_symlink - helper function to create symlinks
1170  * @dir: directory inode containing symlink
1171  * @dentry: dentry for symlink
1172  * @symname: symlink data
1173  *
1174  * See 9P2000.u RFC for more information
1175  *
1176  */
1177 
1178 static int
1179 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1180 {
1181 	dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1182 		symname);
1183 
1184 	return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1185 }
1186 
1187 /**
1188  * v9fs_vfs_link - create a hardlink
1189  * @old_dentry: dentry for file to link to
1190  * @dir: inode destination for new link
1191  * @dentry: dentry for link
1192  *
1193  */
1194 
1195 /* XXX - lots of code dup'd from symlink and creates,
1196  * figure out a better reuse strategy
1197  */
1198 
1199 static int
1200 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1201 	      struct dentry *dentry)
1202 {
1203 	int retval;
1204 	struct v9fs_fid *oldfid;
1205 	char *name;
1206 
1207 	dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1208 		old_dentry->d_name.name);
1209 
1210 	oldfid = v9fs_fid_lookup(old_dentry);
1211 	if (!oldfid) {
1212 		dprintk(DEBUG_ERROR, "can't find oldfid\n");
1213 		return -EPERM;
1214 	}
1215 
1216 	name = __getname();
1217 	sprintf(name, "%d\n", oldfid->fid);
1218 	retval = v9fs_vfs_mkspecial(dir, dentry, V9FS_DMLINK, name);
1219 	__putname(name);
1220 
1221 	return retval;
1222 }
1223 
1224 /**
1225  * v9fs_vfs_mknod - create a special file
1226  * @dir: inode destination for new link
1227  * @dentry: dentry for file
1228  * @mode: mode for creation
1229  * @dev_t: device associated with special file
1230  *
1231  */
1232 
1233 static int
1234 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1235 {
1236 	int retval;
1237 	char *name;
1238 
1239 	dprintk(DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1240 		dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1241 
1242 	if (!new_valid_dev(rdev))
1243 		return -EINVAL;
1244 
1245 	name = __getname();
1246 	if (!name)
1247 		return -ENOMEM;
1248 	/* build extension */
1249 	if (S_ISBLK(mode))
1250 		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1251 	else if (S_ISCHR(mode))
1252 		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1253 	else if (S_ISFIFO(mode))
1254 		*name = 0;
1255 	else {
1256 		__putname(name);
1257 		return -EINVAL;
1258 	}
1259 
1260 	retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1261 	__putname(name);
1262 
1263 	return retval;
1264 }
1265 
1266 static struct inode_operations v9fs_dir_inode_operations_ext = {
1267 	.create = v9fs_vfs_create,
1268 	.lookup = v9fs_vfs_lookup,
1269 	.symlink = v9fs_vfs_symlink,
1270 	.link = v9fs_vfs_link,
1271 	.unlink = v9fs_vfs_unlink,
1272 	.mkdir = v9fs_vfs_mkdir,
1273 	.rmdir = v9fs_vfs_rmdir,
1274 	.mknod = v9fs_vfs_mknod,
1275 	.rename = v9fs_vfs_rename,
1276 	.readlink = v9fs_vfs_readlink,
1277 	.getattr = v9fs_vfs_getattr,
1278 	.setattr = v9fs_vfs_setattr,
1279 };
1280 
1281 static struct inode_operations v9fs_dir_inode_operations = {
1282 	.create = v9fs_vfs_create,
1283 	.lookup = v9fs_vfs_lookup,
1284 	.unlink = v9fs_vfs_unlink,
1285 	.mkdir = v9fs_vfs_mkdir,
1286 	.rmdir = v9fs_vfs_rmdir,
1287 	.mknod = v9fs_vfs_mknod,
1288 	.rename = v9fs_vfs_rename,
1289 	.getattr = v9fs_vfs_getattr,
1290 	.setattr = v9fs_vfs_setattr,
1291 };
1292 
1293 static struct inode_operations v9fs_file_inode_operations = {
1294 	.getattr = v9fs_vfs_getattr,
1295 	.setattr = v9fs_vfs_setattr,
1296 };
1297 
1298 static struct inode_operations v9fs_symlink_inode_operations = {
1299 	.readlink = v9fs_vfs_readlink,
1300 	.follow_link = v9fs_vfs_follow_link,
1301 	.put_link = v9fs_vfs_put_link,
1302 	.getattr = v9fs_vfs_getattr,
1303 	.setattr = v9fs_vfs_setattr,
1304 };
1305