xref: /openbmc/linux/fs/9p/vfs_inode.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 
37 #include "debug.h"
38 #include "v9fs.h"
39 #include "9p.h"
40 #include "v9fs_vfs.h"
41 #include "fid.h"
42 
43 static const struct inode_operations v9fs_dir_inode_operations;
44 static const struct inode_operations v9fs_dir_inode_operations_ext;
45 static const struct inode_operations v9fs_file_inode_operations;
46 static const struct inode_operations v9fs_symlink_inode_operations;
47 
48 /**
49  * unixmode2p9mode - convert unix mode bits to plan 9
50  * @v9ses: v9fs session information
51  * @mode: mode to convert
52  *
53  */
54 
55 static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
56 {
57 	int res;
58 	res = mode & 0777;
59 	if (S_ISDIR(mode))
60 		res |= V9FS_DMDIR;
61 	if (v9ses->extended) {
62 		if (S_ISLNK(mode))
63 			res |= V9FS_DMSYMLINK;
64 		if (v9ses->nodev == 0) {
65 			if (S_ISSOCK(mode))
66 				res |= V9FS_DMSOCKET;
67 			if (S_ISFIFO(mode))
68 				res |= V9FS_DMNAMEDPIPE;
69 			if (S_ISBLK(mode))
70 				res |= V9FS_DMDEVICE;
71 			if (S_ISCHR(mode))
72 				res |= V9FS_DMDEVICE;
73 		}
74 
75 		if ((mode & S_ISUID) == S_ISUID)
76 			res |= V9FS_DMSETUID;
77 		if ((mode & S_ISGID) == S_ISGID)
78 			res |= V9FS_DMSETGID;
79 		if ((mode & V9FS_DMLINK))
80 			res |= V9FS_DMLINK;
81 	}
82 
83 	return res;
84 }
85 
86 /**
87  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
88  * @v9ses: v9fs session information
89  * @mode: mode to convert
90  *
91  */
92 
93 static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
94 {
95 	int res;
96 
97 	res = mode & 0777;
98 
99 	if ((mode & V9FS_DMDIR) == V9FS_DMDIR)
100 		res |= S_IFDIR;
101 	else if ((mode & V9FS_DMSYMLINK) && (v9ses->extended))
102 		res |= S_IFLNK;
103 	else if ((mode & V9FS_DMSOCKET) && (v9ses->extended)
104 		 && (v9ses->nodev == 0))
105 		res |= S_IFSOCK;
106 	else if ((mode & V9FS_DMNAMEDPIPE) && (v9ses->extended)
107 		 && (v9ses->nodev == 0))
108 		res |= S_IFIFO;
109 	else if ((mode & V9FS_DMDEVICE) && (v9ses->extended)
110 		 && (v9ses->nodev == 0))
111 		res |= S_IFBLK;
112 	else
113 		res |= S_IFREG;
114 
115 	if (v9ses->extended) {
116 		if ((mode & V9FS_DMSETUID) == V9FS_DMSETUID)
117 			res |= S_ISUID;
118 
119 		if ((mode & V9FS_DMSETGID) == V9FS_DMSETGID)
120 			res |= S_ISGID;
121 	}
122 
123 	return res;
124 }
125 
126 int v9fs_uflags2omode(int uflags)
127 {
128 	int ret;
129 
130 	ret = 0;
131 	switch (uflags&3) {
132 	default:
133 	case O_RDONLY:
134 		ret = V9FS_OREAD;
135 		break;
136 
137 	case O_WRONLY:
138 		ret = V9FS_OWRITE;
139 		break;
140 
141 	case O_RDWR:
142 		ret = V9FS_ORDWR;
143 		break;
144 	}
145 
146 	if (uflags & O_EXCL)
147 		ret |= V9FS_OEXCL;
148 
149 	if (uflags & O_TRUNC)
150 		ret |= V9FS_OTRUNC;
151 
152 	if (uflags & O_APPEND)
153 		ret |= V9FS_OAPPEND;
154 
155 	return ret;
156 }
157 
158 /**
159  * v9fs_blank_wstat - helper function to setup a 9P stat structure
160  * @v9ses: 9P session info (for determining extended mode)
161  * @wstat: structure to initialize
162  *
163  */
164 
165 static void
166 v9fs_blank_wstat(struct v9fs_wstat *wstat)
167 {
168 	wstat->type = ~0;
169 	wstat->dev = ~0;
170 	wstat->qid.type = ~0;
171 	wstat->qid.version = ~0;
172 	*((long long *)&wstat->qid.path) = ~0;
173 	wstat->mode = ~0;
174 	wstat->atime = ~0;
175 	wstat->mtime = ~0;
176 	wstat->length = ~0;
177 	wstat->name = NULL;
178 	wstat->uid = NULL;
179 	wstat->gid = NULL;
180 	wstat->muid = NULL;
181 	wstat->n_uid = ~0;
182 	wstat->n_gid = ~0;
183 	wstat->n_muid = ~0;
184 	wstat->extension = NULL;
185 }
186 
187 /**
188  * v9fs_get_inode - helper function to setup an inode
189  * @sb: superblock
190  * @mode: mode to setup inode with
191  *
192  */
193 
194 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
195 {
196 	struct inode *inode;
197 	struct v9fs_session_info *v9ses = sb->s_fs_info;
198 
199 	dprintk(DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
200 
201 	inode = new_inode(sb);
202 	if (inode) {
203 		inode->i_mode = mode;
204 		inode->i_uid = current->fsuid;
205 		inode->i_gid = current->fsgid;
206 		inode->i_blocks = 0;
207 		inode->i_rdev = 0;
208 		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
209 		inode->i_mapping->a_ops = &v9fs_addr_operations;
210 
211 		switch (mode & S_IFMT) {
212 		case S_IFIFO:
213 		case S_IFBLK:
214 		case S_IFCHR:
215 		case S_IFSOCK:
216 			if(!v9ses->extended) {
217 				dprintk(DEBUG_ERROR, "special files without extended mode\n");
218 				return ERR_PTR(-EINVAL);
219 			}
220 			init_special_inode(inode, inode->i_mode,
221 					   inode->i_rdev);
222 			break;
223 		case S_IFREG:
224 			inode->i_op = &v9fs_file_inode_operations;
225 			inode->i_fop = &v9fs_file_operations;
226 			break;
227 		case S_IFLNK:
228 			if(!v9ses->extended) {
229 				dprintk(DEBUG_ERROR, "extended modes used w/o 9P2000.u\n");
230 				return ERR_PTR(-EINVAL);
231 			}
232 			inode->i_op = &v9fs_symlink_inode_operations;
233 			break;
234 		case S_IFDIR:
235 			inc_nlink(inode);
236 			if(v9ses->extended)
237 				inode->i_op = &v9fs_dir_inode_operations_ext;
238 			else
239 				inode->i_op = &v9fs_dir_inode_operations;
240 			inode->i_fop = &v9fs_dir_operations;
241 			break;
242 		default:
243 			dprintk(DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
244 				mode, mode & S_IFMT);
245 			return ERR_PTR(-EINVAL);
246 		}
247 	} else {
248 		eprintk(KERN_WARNING, "Problem allocating inode\n");
249 		return ERR_PTR(-ENOMEM);
250 	}
251 	return inode;
252 }
253 
254 static int
255 v9fs_create(struct v9fs_session_info *v9ses, u32 pfid, char *name, u32 perm,
256 	u8 mode, char *extension, u32 *fidp, struct v9fs_qid *qid, u32 *iounit)
257 {
258 	int fid;
259 	int err;
260 	struct v9fs_fcall *fcall;
261 
262 	fid = v9fs_get_idpool(&v9ses->fidpool);
263 	if (fid < 0) {
264 		eprintk(KERN_WARNING, "no free fids available\n");
265 		return -ENOSPC;
266 	}
267 
268 	err = v9fs_t_walk(v9ses, pfid, fid, NULL, &fcall);
269 	if (err < 0) {
270 		PRINT_FCALL_ERROR("clone error", fcall);
271 		if (fcall && fcall->id == RWALK)
272 			goto clunk_fid;
273 		else
274 			goto put_fid;
275 	}
276 	kfree(fcall);
277 
278 	err = v9fs_t_create(v9ses, fid, name, perm, mode, extension, &fcall);
279 	if (err < 0) {
280 		PRINT_FCALL_ERROR("create fails", fcall);
281 		goto clunk_fid;
282 	}
283 
284 	if (iounit)
285 		*iounit = fcall->params.rcreate.iounit;
286 
287 	if (qid)
288 		*qid = fcall->params.rcreate.qid;
289 
290 	if (fidp)
291 		*fidp = fid;
292 
293 	kfree(fcall);
294 	return 0;
295 
296 clunk_fid:
297 	v9fs_t_clunk(v9ses, fid);
298 	fid = V9FS_NOFID;
299 
300 put_fid:
301 	if (fid != V9FS_NOFID)
302 		v9fs_put_idpool(fid, &v9ses->fidpool);
303 
304 	kfree(fcall);
305 	return err;
306 }
307 
308 static struct v9fs_fid*
309 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
310 {
311 	int err;
312 	int nfid;
313 	struct v9fs_fid *ret;
314 	struct v9fs_fcall *fcall;
315 
316 	nfid = v9fs_get_idpool(&v9ses->fidpool);
317 	if (nfid < 0) {
318 		eprintk(KERN_WARNING, "no free fids available\n");
319 		return ERR_PTR(-ENOSPC);
320 	}
321 
322 	err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
323 		&fcall);
324 
325 	if (err < 0) {
326 		if (fcall && fcall->id == RWALK)
327 			goto clunk_fid;
328 
329 		PRINT_FCALL_ERROR("walk error", fcall);
330 		v9fs_put_idpool(nfid, &v9ses->fidpool);
331 		goto error;
332 	}
333 
334 	kfree(fcall);
335 	fcall = NULL;
336 	ret = v9fs_fid_create(v9ses, nfid);
337 	if (!ret) {
338 		err = -ENOMEM;
339 		goto clunk_fid;
340 	}
341 
342 	err = v9fs_fid_insert(ret, dentry);
343 	if (err < 0) {
344 		v9fs_fid_destroy(ret);
345 		goto clunk_fid;
346 	}
347 
348 	return ret;
349 
350 clunk_fid:
351 	v9fs_t_clunk(v9ses, nfid);
352 
353 error:
354 	kfree(fcall);
355 	return ERR_PTR(err);
356 }
357 
358 static struct inode *
359 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, u32 fid,
360 	struct super_block *sb)
361 {
362 	int err, umode;
363 	struct inode *ret;
364 	struct v9fs_fcall *fcall;
365 
366 	ret = NULL;
367 	err = v9fs_t_stat(v9ses, fid, &fcall);
368 	if (err) {
369 		PRINT_FCALL_ERROR("stat error", fcall);
370 		goto error;
371 	}
372 
373 	umode = p9mode2unixmode(v9ses, fcall->params.rstat.stat.mode);
374 	ret = v9fs_get_inode(sb, umode);
375 	if (IS_ERR(ret)) {
376 		err = PTR_ERR(ret);
377 		ret = NULL;
378 		goto error;
379 	}
380 
381 	v9fs_stat2inode(&fcall->params.rstat.stat, ret, sb);
382 	kfree(fcall);
383 	return ret;
384 
385 error:
386 	kfree(fcall);
387 	if (ret)
388 		iput(ret);
389 
390 	return ERR_PTR(err);
391 }
392 
393 /**
394  * v9fs_remove - helper function to remove files and directories
395  * @dir: directory inode that is being deleted
396  * @file:  dentry that is being deleted
397  * @rmdir: removing a directory
398  *
399  */
400 
401 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
402 {
403 	struct v9fs_fcall *fcall = NULL;
404 	struct super_block *sb = NULL;
405 	struct v9fs_session_info *v9ses = NULL;
406 	struct v9fs_fid *v9fid = NULL;
407 	struct inode *file_inode = NULL;
408 	int fid = -1;
409 	int result = 0;
410 
411 	dprintk(DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
412 		rmdir);
413 
414 	file_inode = file->d_inode;
415 	sb = file_inode->i_sb;
416 	v9ses = v9fs_inode2v9ses(file_inode);
417 	v9fid = v9fs_fid_clone(file);
418 	if(IS_ERR(v9fid))
419 		return PTR_ERR(v9fid);
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 		goto Error;
432 	}
433 
434 	v9fs_put_idpool(fid, &v9ses->fidpool);
435 	v9fs_fid_destroy(v9fid);
436 
437 Error:
438 	kfree(fcall);
439 	return result;
440 }
441 
442 static int
443 v9fs_open_created(struct inode *inode, struct file *file)
444 {
445 	return 0;
446 }
447 
448 /**
449  * v9fs_vfs_create - VFS hook to create files
450  * @inode: directory inode that is being deleted
451  * @dentry:  dentry that is being deleted
452  * @mode: create permissions
453  * @nd: path information
454  *
455  */
456 
457 static int
458 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
459 		struct nameidata *nd)
460 {
461 	int err;
462 	u32 fid, perm, iounit;
463 	int flags;
464 	struct v9fs_session_info *v9ses;
465 	struct v9fs_fid *dfid, *vfid, *ffid;
466 	struct inode *inode;
467 	struct v9fs_qid qid;
468 	struct file *filp;
469 
470 	inode = NULL;
471 	vfid = NULL;
472 	v9ses = v9fs_inode2v9ses(dir);
473 	dfid = v9fs_fid_clone(dentry->d_parent);
474 	if(IS_ERR(dfid)) {
475 		err = PTR_ERR(dfid);
476 		goto error;
477 	}
478 
479 	perm = unixmode2p9mode(v9ses, mode);
480 	if (nd && nd->flags & LOOKUP_OPEN)
481 		flags = nd->intent.open.flags - 1;
482 	else
483 		flags = O_RDWR;
484 
485 	err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
486 		perm, v9fs_uflags2omode(flags), NULL, &fid, &qid, &iounit);
487 
488 	if (err)
489 		goto clunk_dfid;
490 
491 	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
492 	v9fs_fid_clunk(v9ses, dfid);
493 	if (IS_ERR(vfid)) {
494 		err = PTR_ERR(vfid);
495 		vfid = NULL;
496 		goto error;
497 	}
498 
499 	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
500 	if (IS_ERR(inode)) {
501 		err = PTR_ERR(inode);
502 		inode = NULL;
503 		goto error;
504 	}
505 
506 	if(v9ses->cache)
507 		dentry->d_op = &v9fs_cached_dentry_operations;
508 	else
509 		dentry->d_op = &v9fs_dentry_operations;
510 	d_instantiate(dentry, inode);
511 
512 	if (nd && nd->flags & LOOKUP_OPEN) {
513 		ffid = v9fs_fid_create(v9ses, fid);
514 		if (!ffid)
515 			return -ENOMEM;
516 
517 		filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
518 		if (IS_ERR(filp)) {
519 			v9fs_fid_destroy(ffid);
520 			return PTR_ERR(filp);
521 		}
522 
523 		ffid->rdir_pos = 0;
524 		ffid->rdir_fcall = NULL;
525 		ffid->fidopen = 1;
526 		ffid->iounit = iounit;
527 		ffid->filp = filp;
528 		filp->private_data = ffid;
529 	}
530 
531 	return 0;
532 
533 clunk_dfid:
534 	v9fs_fid_clunk(v9ses, dfid);
535 
536 error:
537 	if (vfid)
538 		v9fs_fid_destroy(vfid);
539 
540 	return err;
541 }
542 
543 /**
544  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
545  * @inode:  inode that is being unlinked
546  * @dentry: dentry that is being unlinked
547  * @mode: mode for new directory
548  *
549  */
550 
551 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
552 {
553 	int err;
554 	u32 fid, perm;
555 	struct v9fs_session_info *v9ses;
556 	struct v9fs_fid *dfid, *vfid;
557 	struct inode *inode;
558 
559 	inode = NULL;
560 	vfid = NULL;
561 	v9ses = v9fs_inode2v9ses(dir);
562 	dfid = v9fs_fid_clone(dentry->d_parent);
563 	if(IS_ERR(dfid)) {
564 		err = PTR_ERR(dfid);
565 		goto error;
566 	}
567 
568 	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
569 
570 	err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
571 		perm, V9FS_OREAD, NULL, &fid, NULL, NULL);
572 
573 	if (err) {
574 		dprintk(DEBUG_ERROR, "create error %d\n", err);
575 		goto clean_up_dfid;
576 	}
577 
578 	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
579 	if (IS_ERR(vfid)) {
580 		err = PTR_ERR(vfid);
581 		vfid = NULL;
582 		goto clean_up_dfid;
583 	}
584 
585 	v9fs_fid_clunk(v9ses, dfid);
586 	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
587 	if (IS_ERR(inode)) {
588 		err = PTR_ERR(inode);
589 		inode = NULL;
590 		v9fs_fid_destroy(vfid);
591 		goto error;
592 	}
593 
594 	if(v9ses->cache)
595 		dentry->d_op = &v9fs_cached_dentry_operations;
596 	else
597 		dentry->d_op = &v9fs_dentry_operations;
598 	d_instantiate(dentry, inode);
599 	return 0;
600 
601 clean_up_dfid:
602 	v9fs_fid_clunk(v9ses, dfid);
603 
604 error:
605 	return err;
606 }
607 
608 /**
609  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
610  * @dir:  inode that is being walked from
611  * @dentry: dentry that is being walked to?
612  * @nameidata: path data
613  *
614  */
615 
616 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
617 				      struct nameidata *nameidata)
618 {
619 	struct super_block *sb;
620 	struct v9fs_session_info *v9ses;
621 	struct v9fs_fid *dirfid;
622 	struct v9fs_fid *fid;
623 	struct inode *inode;
624 	struct v9fs_fcall *fcall = NULL;
625 	int dirfidnum = -1;
626 	int newfid = -1;
627 	int result = 0;
628 
629 	dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
630 		dir, dentry->d_name.name, dentry, nameidata);
631 
632 	sb = dir->i_sb;
633 	v9ses = v9fs_inode2v9ses(dir);
634 	dirfid = v9fs_fid_lookup(dentry->d_parent);
635 
636 	if(IS_ERR(dirfid))
637 		return ERR_PTR(PTR_ERR(dirfid));
638 
639 	dirfidnum = dirfid->fid;
640 
641 	newfid = v9fs_get_idpool(&v9ses->fidpool);
642 	if (newfid < 0) {
643 		eprintk(KERN_WARNING, "newfid fails!\n");
644 		result = -ENOSPC;
645 		goto Release_Dirfid;
646 	}
647 
648 	result = v9fs_t_walk(v9ses, dirfidnum, newfid,
649 		(char *)dentry->d_name.name, &fcall);
650 
651 	up(&dirfid->lock);
652 
653 	if (result < 0) {
654 		if (fcall && fcall->id == RWALK)
655 			v9fs_t_clunk(v9ses, newfid);
656 		else
657 			v9fs_put_idpool(newfid, &v9ses->fidpool);
658 
659 		if (result == -ENOENT) {
660 			d_add(dentry, NULL);
661 			dprintk(DEBUG_VFS,
662 				"Return negative dentry %p count %d\n",
663 				dentry, atomic_read(&dentry->d_count));
664 			kfree(fcall);
665 			return NULL;
666 		}
667 		dprintk(DEBUG_ERROR, "walk error:%d\n", result);
668 		goto FreeFcall;
669 	}
670 	kfree(fcall);
671 
672 	result = v9fs_t_stat(v9ses, newfid, &fcall);
673 	if (result < 0) {
674 		dprintk(DEBUG_ERROR, "stat error\n");
675 		goto FreeFcall;
676 	}
677 
678 	inode = v9fs_get_inode(sb, p9mode2unixmode(v9ses,
679 		fcall->params.rstat.stat.mode));
680 
681 	if (IS_ERR(inode) && (PTR_ERR(inode) == -ENOSPC)) {
682 		eprintk(KERN_WARNING, "inode alloc failes, returns %ld\n",
683 			PTR_ERR(inode));
684 
685 		result = -ENOSPC;
686 		goto FreeFcall;
687 	}
688 
689 	inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid);
690 
691 	fid = v9fs_fid_create(v9ses, newfid);
692 	if (fid == NULL) {
693 		dprintk(DEBUG_ERROR, "couldn't insert\n");
694 		result = -ENOMEM;
695 		goto FreeFcall;
696 	}
697 
698 	result = v9fs_fid_insert(fid, dentry);
699 	if (result < 0)
700 		goto FreeFcall;
701 
702 	fid->qid = fcall->params.rstat.stat.qid;
703 	v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
704 	if((fid->qid.version)&&(v9ses->cache))
705 		dentry->d_op = &v9fs_cached_dentry_operations;
706 	else
707 		dentry->d_op = &v9fs_dentry_operations;
708 
709 	d_add(dentry, inode);
710 	kfree(fcall);
711 
712 	return NULL;
713 
714 Release_Dirfid:
715 	up(&dirfid->lock);
716 
717 FreeFcall:
718 	kfree(fcall);
719 
720 	return ERR_PTR(result);
721 }
722 
723 /**
724  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
725  * @i:  inode that is being unlinked
726  * @d: dentry that is being unlinked
727  *
728  */
729 
730 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
731 {
732 	return v9fs_remove(i, d, 0);
733 }
734 
735 /**
736  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
737  * @i:  inode that is being unlinked
738  * @d: dentry that is being unlinked
739  *
740  */
741 
742 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
743 {
744 	return v9fs_remove(i, d, 1);
745 }
746 
747 /**
748  * v9fs_vfs_rename - VFS hook to rename an inode
749  * @old_dir:  old dir inode
750  * @old_dentry: old dentry
751  * @new_dir: new dir inode
752  * @new_dentry: new dentry
753  *
754  */
755 
756 static int
757 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
758 		struct inode *new_dir, struct dentry *new_dentry)
759 {
760 	struct inode *old_inode = old_dentry->d_inode;
761 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(old_inode);
762 	struct v9fs_fid *oldfid = v9fs_fid_lookup(old_dentry);
763 	struct v9fs_fid *olddirfid;
764 	struct v9fs_fid *newdirfid;
765 	struct v9fs_wstat wstat;
766 	struct v9fs_fcall *fcall = NULL;
767 	int fid = -1;
768 	int olddirfidnum = -1;
769 	int newdirfidnum = -1;
770 	int retval = 0;
771 
772 	dprintk(DEBUG_VFS, "\n");
773 
774 	if(IS_ERR(oldfid))
775 		return PTR_ERR(oldfid);
776 
777 	olddirfid = v9fs_fid_clone(old_dentry->d_parent);
778 	if(IS_ERR(olddirfid)) {
779 		retval = PTR_ERR(olddirfid);
780 		goto Release_lock;
781 	}
782 
783 	newdirfid = v9fs_fid_clone(new_dentry->d_parent);
784 	if(IS_ERR(newdirfid)) {
785 		retval = PTR_ERR(newdirfid);
786 		goto Clunk_olddir;
787 	}
788 
789 	/* 9P can only handle file rename in the same directory */
790 	if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
791 		dprintk(DEBUG_ERROR, "old dir and new dir are different\n");
792 		retval = -EXDEV;
793 		goto Clunk_newdir;
794 	}
795 
796 	fid = oldfid->fid;
797 	olddirfidnum = olddirfid->fid;
798 	newdirfidnum = newdirfid->fid;
799 
800 	if (fid < 0) {
801 		dprintk(DEBUG_ERROR, "no fid for old file #%lu\n",
802 			old_inode->i_ino);
803 		retval = -EBADF;
804 		goto Clunk_newdir;
805 	}
806 
807 	v9fs_blank_wstat(&wstat);
808 	wstat.muid = v9ses->name;
809 	wstat.name = (char *) new_dentry->d_name.name;
810 
811 	retval = v9fs_t_wstat(v9ses, fid, &wstat, &fcall);
812 
813 	if (retval < 0)
814 		PRINT_FCALL_ERROR("wstat error", fcall);
815 
816 	kfree(fcall);
817 
818 Clunk_newdir:
819 	v9fs_fid_clunk(v9ses, newdirfid);
820 
821 Clunk_olddir:
822 	v9fs_fid_clunk(v9ses, olddirfid);
823 
824 Release_lock:
825 	up(&oldfid->lock);
826 
827 	return retval;
828 }
829 
830 /**
831  * v9fs_vfs_getattr - retrieve file metadata
832  * @mnt - mount information
833  * @dentry - file to get attributes on
834  * @stat - metadata structure to populate
835  *
836  */
837 
838 static int
839 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
840 		 struct kstat *stat)
841 {
842 	struct v9fs_fcall *fcall = NULL;
843 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
844 	struct v9fs_fid *fid = v9fs_fid_clone(dentry);
845 	int err = -EPERM;
846 
847 	dprintk(DEBUG_VFS, "dentry: %p\n", dentry);
848 	if(IS_ERR(fid))
849 		return PTR_ERR(fid);
850 
851 	err = v9fs_t_stat(v9ses, fid->fid, &fcall);
852 
853 	if (err < 0)
854 		dprintk(DEBUG_ERROR, "stat error\n");
855 	else {
856 		v9fs_stat2inode(&fcall->params.rstat.stat, dentry->d_inode,
857 				  dentry->d_inode->i_sb);
858 		generic_fillattr(dentry->d_inode, stat);
859 	}
860 
861 	kfree(fcall);
862 	v9fs_fid_clunk(v9ses, fid);
863 	return err;
864 }
865 
866 /**
867  * v9fs_vfs_setattr - set file metadata
868  * @dentry: file whose metadata to set
869  * @iattr: metadata assignment structure
870  *
871  */
872 
873 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
874 {
875 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
876 	struct v9fs_fid *fid = v9fs_fid_clone(dentry);
877 	struct v9fs_fcall *fcall = NULL;
878 	struct v9fs_wstat wstat;
879 	int res = -EPERM;
880 
881 	dprintk(DEBUG_VFS, "\n");
882 	if(IS_ERR(fid))
883 		return PTR_ERR(fid);
884 
885 	v9fs_blank_wstat(&wstat);
886 	if (iattr->ia_valid & ATTR_MODE)
887 		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
888 
889 	if (iattr->ia_valid & ATTR_MTIME)
890 		wstat.mtime = iattr->ia_mtime.tv_sec;
891 
892 	if (iattr->ia_valid & ATTR_ATIME)
893 		wstat.atime = iattr->ia_atime.tv_sec;
894 
895 	if (iattr->ia_valid & ATTR_SIZE)
896 		wstat.length = iattr->ia_size;
897 
898 	if (v9ses->extended) {
899 		if (iattr->ia_valid & ATTR_UID)
900 			wstat.n_uid = iattr->ia_uid;
901 
902 		if (iattr->ia_valid & ATTR_GID)
903 			wstat.n_gid = iattr->ia_gid;
904 	}
905 
906 	res = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall);
907 
908 	if (res < 0)
909 		PRINT_FCALL_ERROR("wstat error", fcall);
910 
911 	kfree(fcall);
912 	if (res >= 0)
913 		res = inode_setattr(dentry->d_inode, iattr);
914 
915 	v9fs_fid_clunk(v9ses, fid);
916 	return res;
917 }
918 
919 /**
920  * v9fs_stat2inode - populate an inode structure with mistat info
921  * @stat: Plan 9 metadata (mistat) structure
922  * @inode: inode to populate
923  * @sb: superblock of filesystem
924  *
925  */
926 
927 void
928 v9fs_stat2inode(struct v9fs_stat *stat, struct inode *inode,
929 	struct super_block *sb)
930 {
931 	int n;
932 	char ext[32];
933 	struct v9fs_session_info *v9ses = sb->s_fs_info;
934 
935 	inode->i_nlink = 1;
936 
937 	inode->i_atime.tv_sec = stat->atime;
938 	inode->i_mtime.tv_sec = stat->mtime;
939 	inode->i_ctime.tv_sec = stat->mtime;
940 
941 	inode->i_uid = v9ses->uid;
942 	inode->i_gid = v9ses->gid;
943 
944 	if (v9ses->extended) {
945 		inode->i_uid = stat->n_uid;
946 		inode->i_gid = stat->n_gid;
947 	}
948 
949 	inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
950 	if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
951 		char type = 0;
952 		int major = -1;
953 		int minor = -1;
954 
955 		n = stat->extension.len;
956 		if (n > sizeof(ext)-1)
957 			n = sizeof(ext)-1;
958 		memmove(ext, stat->extension.str, n);
959 		ext[n] = 0;
960 		sscanf(ext, "%c %u %u", &type, &major, &minor);
961 		switch (type) {
962 		case 'c':
963 			inode->i_mode &= ~S_IFBLK;
964 			inode->i_mode |= S_IFCHR;
965 			break;
966 		case 'b':
967 			break;
968 		default:
969 			dprintk(DEBUG_ERROR, "Unknown special type %c (%.*s)\n",
970 				type, stat->extension.len, stat->extension.str);
971 		};
972 		inode->i_rdev = MKDEV(major, minor);
973 	} else
974 		inode->i_rdev = 0;
975 
976 	inode->i_size = stat->length;
977 
978 	inode->i_blocks =
979 	    (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
980 }
981 
982 /**
983  * v9fs_qid2ino - convert qid into inode number
984  * @qid: qid to hash
985  *
986  * BUG: potential for inode number collisions?
987  */
988 
989 ino_t v9fs_qid2ino(struct v9fs_qid *qid)
990 {
991 	u64 path = qid->path + 2;
992 	ino_t i = 0;
993 
994 	if (sizeof(ino_t) == sizeof(path))
995 		memcpy(&i, &path, sizeof(ino_t));
996 	else
997 		i = (ino_t) (path ^ (path >> 32));
998 
999 	return i;
1000 }
1001 
1002 /**
1003  * v9fs_readlink - read a symlink's location (internal version)
1004  * @dentry: dentry for symlink
1005  * @buffer: buffer to load symlink location into
1006  * @buflen: length of buffer
1007  *
1008  */
1009 
1010 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1011 {
1012 	int retval = -EPERM;
1013 
1014 	struct v9fs_fcall *fcall = NULL;
1015 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
1016 	struct v9fs_fid *fid = v9fs_fid_clone(dentry);
1017 
1018 	if(IS_ERR(fid))
1019 		return PTR_ERR(fid);
1020 
1021 	if (!v9ses->extended) {
1022 		retval = -EBADF;
1023 		dprintk(DEBUG_ERROR, "not extended\n");
1024 		goto ClunkFid;
1025 	}
1026 
1027 	dprintk(DEBUG_VFS, " %s\n", dentry->d_name.name);
1028 	retval = v9fs_t_stat(v9ses, fid->fid, &fcall);
1029 
1030 	if (retval < 0) {
1031 		dprintk(DEBUG_ERROR, "stat error\n");
1032 		goto FreeFcall;
1033 	}
1034 
1035 	if (!fcall) {
1036 		retval = -EIO;
1037 		goto ClunkFid;
1038 	}
1039 
1040 	if (!(fcall->params.rstat.stat.mode & V9FS_DMSYMLINK)) {
1041 		retval = -EINVAL;
1042 		goto FreeFcall;
1043 	}
1044 
1045 	/* copy extension buffer into buffer */
1046 	if (fcall->params.rstat.stat.extension.len < buflen)
1047 		buflen = fcall->params.rstat.stat.extension.len + 1;
1048 
1049 	memmove(buffer, fcall->params.rstat.stat.extension.str, buflen - 1);
1050 	buffer[buflen-1] = 0;
1051 
1052 	dprintk(DEBUG_ERROR, "%s -> %.*s (%s)\n", dentry->d_name.name, fcall->params.rstat.stat.extension.len,
1053 		fcall->params.rstat.stat.extension.str, buffer);
1054 	retval = buflen;
1055 
1056 FreeFcall:
1057 	kfree(fcall);
1058 
1059 ClunkFid:
1060 	v9fs_fid_clunk(v9ses, fid);
1061 
1062 	return retval;
1063 }
1064 
1065 /**
1066  * v9fs_vfs_readlink - read a symlink's location
1067  * @dentry: dentry for symlink
1068  * @buf: buffer to load symlink location into
1069  * @buflen: length of buffer
1070  *
1071  */
1072 
1073 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
1074 			     int buflen)
1075 {
1076 	int retval;
1077 	int ret;
1078 	char *link = __getname();
1079 
1080 	if (unlikely(!link))
1081 		return -ENOMEM;
1082 
1083 	if (buflen > PATH_MAX)
1084 		buflen = PATH_MAX;
1085 
1086 	dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
1087 
1088 	retval = v9fs_readlink(dentry, link, buflen);
1089 
1090 	if (retval > 0) {
1091 		if ((ret = copy_to_user(buffer, link, retval)) != 0) {
1092 			dprintk(DEBUG_ERROR, "problem copying to user: %d\n",
1093 				ret);
1094 			retval = ret;
1095 		}
1096 	}
1097 
1098 	__putname(link);
1099 	return retval;
1100 }
1101 
1102 /**
1103  * v9fs_vfs_follow_link - follow a symlink path
1104  * @dentry: dentry for symlink
1105  * @nd: nameidata
1106  *
1107  */
1108 
1109 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1110 {
1111 	int len = 0;
1112 	char *link = __getname();
1113 
1114 	dprintk(DEBUG_VFS, "%s n", dentry->d_name.name);
1115 
1116 	if (!link)
1117 		link = ERR_PTR(-ENOMEM);
1118 	else {
1119 		len = v9fs_readlink(dentry, link, PATH_MAX);
1120 
1121 		if (len < 0) {
1122 			__putname(link);
1123 			link = ERR_PTR(len);
1124 		} else
1125 			link[len] = 0;
1126 	}
1127 	nd_set_link(nd, link);
1128 
1129 	return NULL;
1130 }
1131 
1132 /**
1133  * v9fs_vfs_put_link - release a symlink path
1134  * @dentry: dentry for symlink
1135  * @nd: nameidata
1136  *
1137  */
1138 
1139 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1140 {
1141 	char *s = nd_get_link(nd);
1142 
1143 	dprintk(DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1144 	if (!IS_ERR(s))
1145 		__putname(s);
1146 }
1147 
1148 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1149 	int mode, const char *extension)
1150 {
1151 	int err;
1152 	u32 fid, perm;
1153 	struct v9fs_session_info *v9ses;
1154 	struct v9fs_fid *dfid, *vfid = NULL;
1155 	struct inode *inode = NULL;
1156 
1157 	v9ses = v9fs_inode2v9ses(dir);
1158 	if (!v9ses->extended) {
1159 		dprintk(DEBUG_ERROR, "not extended\n");
1160 		return -EPERM;
1161 	}
1162 
1163 	dfid = v9fs_fid_clone(dentry->d_parent);
1164 	if(IS_ERR(dfid)) {
1165 		err = PTR_ERR(dfid);
1166 		goto error;
1167 	}
1168 
1169 	perm = unixmode2p9mode(v9ses, mode);
1170 
1171 	err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
1172 		perm, V9FS_OREAD, (char *) extension, &fid, NULL, NULL);
1173 
1174 	if (err)
1175 		goto clunk_dfid;
1176 
1177 	err = v9fs_t_clunk(v9ses, fid);
1178 	if (err)
1179 		goto clunk_dfid;
1180 
1181 	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
1182 	if (IS_ERR(vfid)) {
1183 		err = PTR_ERR(vfid);
1184 		vfid = NULL;
1185 		goto clunk_dfid;
1186 	}
1187 
1188 	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
1189 	if (IS_ERR(inode)) {
1190 		err = PTR_ERR(inode);
1191 		inode = NULL;
1192 		goto free_vfid;
1193 	}
1194 
1195 	if(v9ses->cache)
1196 		dentry->d_op = &v9fs_cached_dentry_operations;
1197 	else
1198 		dentry->d_op = &v9fs_dentry_operations;
1199 	d_instantiate(dentry, inode);
1200 	return 0;
1201 
1202 free_vfid:
1203 	v9fs_fid_destroy(vfid);
1204 
1205 clunk_dfid:
1206 	v9fs_fid_clunk(v9ses, dfid);
1207 
1208 error:
1209 	return err;
1210 
1211 }
1212 
1213 /**
1214  * v9fs_vfs_symlink - helper function to create symlinks
1215  * @dir: directory inode containing symlink
1216  * @dentry: dentry for symlink
1217  * @symname: symlink data
1218  *
1219  * See 9P2000.u RFC for more information
1220  *
1221  */
1222 
1223 static int
1224 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1225 {
1226 	dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1227 		symname);
1228 
1229 	return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1230 }
1231 
1232 /**
1233  * v9fs_vfs_link - create a hardlink
1234  * @old_dentry: dentry for file to link to
1235  * @dir: inode destination for new link
1236  * @dentry: dentry for link
1237  *
1238  */
1239 
1240 /* XXX - lots of code dup'd from symlink and creates,
1241  * figure out a better reuse strategy
1242  */
1243 
1244 static int
1245 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1246 	      struct dentry *dentry)
1247 {
1248 	int retval;
1249 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1250 	struct v9fs_fid *oldfid;
1251 	char *name;
1252 
1253 	dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1254 		old_dentry->d_name.name);
1255 
1256 	oldfid = v9fs_fid_clone(old_dentry);
1257 	if(IS_ERR(oldfid))
1258 		return PTR_ERR(oldfid);
1259 
1260 	name = __getname();
1261 	if (unlikely(!name)) {
1262 		retval = -ENOMEM;
1263 		goto clunk_fid;
1264 	}
1265 
1266 	sprintf(name, "%d\n", oldfid->fid);
1267 	retval = v9fs_vfs_mkspecial(dir, dentry, V9FS_DMLINK, name);
1268 	__putname(name);
1269 
1270 clunk_fid:
1271 	v9fs_fid_clunk(v9ses, oldfid);
1272 	return retval;
1273 }
1274 
1275 /**
1276  * v9fs_vfs_mknod - create a special file
1277  * @dir: inode destination for new link
1278  * @dentry: dentry for file
1279  * @mode: mode for creation
1280  * @dev_t: device associated with special file
1281  *
1282  */
1283 
1284 static int
1285 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1286 {
1287 	int retval;
1288 	char *name;
1289 
1290 	dprintk(DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1291 		dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1292 
1293 	if (!new_valid_dev(rdev))
1294 		return -EINVAL;
1295 
1296 	name = __getname();
1297 	if (!name)
1298 		return -ENOMEM;
1299 	/* build extension */
1300 	if (S_ISBLK(mode))
1301 		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1302 	else if (S_ISCHR(mode))
1303 		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1304 	else if (S_ISFIFO(mode))
1305 		*name = 0;
1306 	else {
1307 		__putname(name);
1308 		return -EINVAL;
1309 	}
1310 
1311 	retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1312 	__putname(name);
1313 
1314 	return retval;
1315 }
1316 
1317 static const struct inode_operations v9fs_dir_inode_operations_ext = {
1318 	.create = v9fs_vfs_create,
1319 	.lookup = v9fs_vfs_lookup,
1320 	.symlink = v9fs_vfs_symlink,
1321 	.link = v9fs_vfs_link,
1322 	.unlink = v9fs_vfs_unlink,
1323 	.mkdir = v9fs_vfs_mkdir,
1324 	.rmdir = v9fs_vfs_rmdir,
1325 	.mknod = v9fs_vfs_mknod,
1326 	.rename = v9fs_vfs_rename,
1327 	.readlink = v9fs_vfs_readlink,
1328 	.getattr = v9fs_vfs_getattr,
1329 	.setattr = v9fs_vfs_setattr,
1330 };
1331 
1332 static const struct inode_operations v9fs_dir_inode_operations = {
1333 	.create = v9fs_vfs_create,
1334 	.lookup = v9fs_vfs_lookup,
1335 	.unlink = v9fs_vfs_unlink,
1336 	.mkdir = v9fs_vfs_mkdir,
1337 	.rmdir = v9fs_vfs_rmdir,
1338 	.mknod = v9fs_vfs_mknod,
1339 	.rename = v9fs_vfs_rename,
1340 	.getattr = v9fs_vfs_getattr,
1341 	.setattr = v9fs_vfs_setattr,
1342 };
1343 
1344 static const struct inode_operations v9fs_file_inode_operations = {
1345 	.getattr = v9fs_vfs_getattr,
1346 	.setattr = v9fs_vfs_setattr,
1347 };
1348 
1349 static const struct inode_operations v9fs_symlink_inode_operations = {
1350 	.readlink = v9fs_vfs_readlink,
1351 	.follow_link = v9fs_vfs_follow_link,
1352 	.put_link = v9fs_vfs_put_link,
1353 	.getattr = v9fs_vfs_getattr,
1354 	.setattr = v9fs_vfs_setattr,
1355 };
1356