xref: /linux/fs/9p/vfs_inode.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 		if (fcall && fcall->id == RWALK)
274 			goto clunk_fid;
275 		else
276 			goto put_fid;
277 	}
278 	kfree(fcall);
279 
280 	err = v9fs_t_create(v9ses, fid, name, perm, mode, extension, &fcall);
281 	if (err < 0) {
282 		PRINT_FCALL_ERROR("create fails", fcall);
283 		goto clunk_fid;
284 	}
285 
286 	if (iounit)
287 		*iounit = fcall->params.rcreate.iounit;
288 
289 	if (qid)
290 		*qid = fcall->params.rcreate.qid;
291 
292 	if (fidp)
293 		*fidp = fid;
294 
295 	kfree(fcall);
296 	return 0;
297 
298 clunk_fid:
299 	v9fs_t_clunk(v9ses, fid);
300 	fid = V9FS_NOFID;
301 
302 put_fid:
303 	if (fid >= 0)
304 		v9fs_put_idpool(fid, &v9ses->fidpool);
305 
306 	kfree(fcall);
307 	return err;
308 }
309 
310 static struct v9fs_fid*
311 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
312 {
313 	int err;
314 	u32 nfid;
315 	struct v9fs_fid *ret;
316 	struct v9fs_fcall *fcall;
317 
318 	nfid = v9fs_get_idpool(&v9ses->fidpool);
319 	if (nfid < 0) {
320 		eprintk(KERN_WARNING, "no free fids available\n");
321 		return ERR_PTR(-ENOSPC);
322 	}
323 
324 	err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
325 		&fcall);
326 
327 	if (err < 0) {
328 		if (fcall && fcall->id == RWALK)
329 			goto clunk_fid;
330 
331 		PRINT_FCALL_ERROR("walk error", fcall);
332 		v9fs_put_idpool(nfid, &v9ses->fidpool);
333 		goto error;
334 	}
335 
336 	kfree(fcall);
337 	fcall = NULL;
338 	ret = v9fs_fid_create(v9ses, nfid);
339 	if (!ret) {
340 		err = -ENOMEM;
341 		goto clunk_fid;
342 	}
343 
344 	err = v9fs_fid_insert(ret, dentry);
345 	if (err < 0) {
346 		v9fs_fid_destroy(ret);
347 		goto clunk_fid;
348 	}
349 
350 	return ret;
351 
352 clunk_fid:
353 	v9fs_t_clunk(v9ses, nfid);
354 
355 error:
356 	kfree(fcall);
357 	return ERR_PTR(err);
358 }
359 
360 static struct inode *
361 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, u32 fid,
362 	struct super_block *sb)
363 {
364 	int err, umode;
365 	struct inode *ret;
366 	struct v9fs_fcall *fcall;
367 
368 	ret = NULL;
369 	err = v9fs_t_stat(v9ses, fid, &fcall);
370 	if (err) {
371 		PRINT_FCALL_ERROR("stat error", fcall);
372 		goto error;
373 	}
374 
375 	umode = p9mode2unixmode(v9ses, fcall->params.rstat.stat.mode);
376 	ret = v9fs_get_inode(sb, umode);
377 	if (IS_ERR(ret)) {
378 		err = PTR_ERR(ret);
379 		ret = NULL;
380 		goto error;
381 	}
382 
383 	v9fs_stat2inode(&fcall->params.rstat.stat, ret, sb);
384 	kfree(fcall);
385 	return ret;
386 
387 error:
388 	kfree(fcall);
389 	if (ret)
390 		iput(ret);
391 
392 	return ERR_PTR(err);
393 }
394 
395 /**
396  * v9fs_remove - helper function to remove files and directories
397  * @dir: directory inode that is being deleted
398  * @file:  dentry that is being deleted
399  * @rmdir: removing a directory
400  *
401  */
402 
403 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
404 {
405 	struct v9fs_fcall *fcall = NULL;
406 	struct super_block *sb = NULL;
407 	struct v9fs_session_info *v9ses = NULL;
408 	struct v9fs_fid *v9fid = NULL;
409 	struct inode *file_inode = NULL;
410 	int fid = -1;
411 	int result = 0;
412 
413 	dprintk(DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
414 		rmdir);
415 
416 	file_inode = file->d_inode;
417 	sb = file_inode->i_sb;
418 	v9ses = v9fs_inode2v9ses(file_inode);
419 	v9fid = v9fs_fid_lookup(file);
420 
421 	if (!v9fid) {
422 		dprintk(DEBUG_ERROR,
423 			"no v9fs_fid\n");
424 		return -EBADF;
425 	}
426 
427 	fid = v9fid->fid;
428 	if (fid < 0) {
429 		dprintk(DEBUG_ERROR, "inode #%lu, no fid!\n",
430 			file_inode->i_ino);
431 		return -EBADF;
432 	}
433 
434 	result = v9fs_t_remove(v9ses, fid, &fcall);
435 	if (result < 0) {
436 		PRINT_FCALL_ERROR("remove fails", fcall);
437 	} else {
438 		v9fs_put_idpool(fid, &v9ses->fidpool);
439 		v9fs_fid_destroy(v9fid);
440 	}
441 
442 	kfree(fcall);
443 	return result;
444 }
445 
446 static int
447 v9fs_open_created(struct inode *inode, struct file *file)
448 {
449 	return 0;
450 }
451 
452 /**
453  * v9fs_vfs_create - VFS hook to create files
454  * @inode: directory inode that is being deleted
455  * @dentry:  dentry that is being deleted
456  * @mode: create permissions
457  * @nd: path information
458  *
459  */
460 
461 static int
462 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
463 		struct nameidata *nd)
464 {
465 	int err;
466 	u32 fid, perm, iounit;
467 	int flags;
468 	struct v9fs_session_info *v9ses;
469 	struct v9fs_fid *dfid, *vfid, *ffid;
470 	struct inode *inode;
471 	struct v9fs_qid qid;
472 	struct file *filp;
473 
474 	inode = NULL;
475 	vfid = NULL;
476 	v9ses = v9fs_inode2v9ses(dir);
477 	dfid = v9fs_fid_lookup(dentry->d_parent);
478 	perm = unixmode2p9mode(v9ses, mode);
479 
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 error;
490 
491 	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
492 	if (IS_ERR(vfid)) {
493 		err = PTR_ERR(vfid);
494 		vfid = NULL;
495 		goto error;
496 	}
497 
498 	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
499 	if (IS_ERR(inode)) {
500 		err = PTR_ERR(inode);
501 		inode = NULL;
502 		goto error;
503 	}
504 
505 	dentry->d_op = &v9fs_dentry_operations;
506 	d_instantiate(dentry, inode);
507 
508 	if (nd && nd->flags & LOOKUP_OPEN) {
509 		ffid = v9fs_fid_create(v9ses, fid);
510 		if (!ffid)
511 			return -ENOMEM;
512 
513 		filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
514 		if (IS_ERR(filp)) {
515 			v9fs_fid_destroy(ffid);
516 			return PTR_ERR(filp);
517 		}
518 
519 		ffid->rdir_pos = 0;
520 		ffid->rdir_fcall = NULL;
521 		ffid->fidopen = 1;
522 		ffid->iounit = iounit;
523 		ffid->filp = filp;
524 		filp->private_data = ffid;
525 	}
526 
527 	return 0;
528 
529 error:
530 	if (vfid)
531 		v9fs_fid_destroy(vfid);
532 
533 	if (inode)
534 		iput(inode);
535 
536 	return err;
537 }
538 
539 /**
540  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
541  * @inode:  inode that is being unlinked
542  * @dentry: dentry that is being unlinked
543  * @mode: mode for new directory
544  *
545  */
546 
547 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
548 {
549 	int err;
550 	u32 fid, perm;
551 	struct v9fs_session_info *v9ses;
552 	struct v9fs_fid *dfid, *vfid;
553 	struct inode *inode;
554 
555 	inode = NULL;
556 	vfid = NULL;
557 	v9ses = v9fs_inode2v9ses(dir);
558 	dfid = v9fs_fid_lookup(dentry->d_parent);
559 	perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
560 
561 	err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
562 		perm, V9FS_OREAD, NULL, &fid, NULL, NULL);
563 
564 	if (err) {
565 		dprintk(DEBUG_ERROR, "create error %d\n", err);
566 		goto error;
567 	}
568 
569 	err = v9fs_t_clunk(v9ses, fid);
570 	if (err) {
571 		dprintk(DEBUG_ERROR, "clunk error %d\n", err);
572 		goto error;
573 	}
574 
575 	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
576 	if (IS_ERR(vfid)) {
577 		err = PTR_ERR(vfid);
578 		vfid = NULL;
579 		goto error;
580 	}
581 
582 	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
583 	if (IS_ERR(inode)) {
584 		err = PTR_ERR(inode);
585 		inode = NULL;
586 		goto error;
587 	}
588 
589 	dentry->d_op = &v9fs_dentry_operations;
590 	d_instantiate(dentry, inode);
591 	return 0;
592 
593 error:
594 	if (vfid)
595 		v9fs_fid_destroy(vfid);
596 
597 	return err;
598 }
599 
600 /**
601  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
602  * @dir:  inode that is being walked from
603  * @dentry: dentry that is being walked to?
604  * @nameidata: path data
605  *
606  */
607 
608 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
609 				      struct nameidata *nameidata)
610 {
611 	struct super_block *sb;
612 	struct v9fs_session_info *v9ses;
613 	struct v9fs_fid *dirfid;
614 	struct v9fs_fid *fid;
615 	struct inode *inode;
616 	struct v9fs_fcall *fcall = NULL;
617 	int dirfidnum = -1;
618 	int newfid = -1;
619 	int result = 0;
620 
621 	dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
622 		dir, dentry->d_name.name, dentry, nameidata);
623 
624 	sb = dir->i_sb;
625 	v9ses = v9fs_inode2v9ses(dir);
626 	dentry->d_op = &v9fs_dentry_operations;
627 	dirfid = v9fs_fid_lookup(dentry->d_parent);
628 
629 	if (!dirfid) {
630 		dprintk(DEBUG_ERROR, "no dirfid\n");
631 		return ERR_PTR(-EINVAL);
632 	}
633 
634 	dirfidnum = dirfid->fid;
635 
636 	if (dirfidnum < 0) {
637 		dprintk(DEBUG_ERROR, "no dirfid for inode %p, #%lu\n",
638 			dir, dir->i_ino);
639 		return ERR_PTR(-EBADF);
640 	}
641 
642 	newfid = v9fs_get_idpool(&v9ses->fidpool);
643 	if (newfid < 0) {
644 		eprintk(KERN_WARNING, "newfid fails!\n");
645 		return ERR_PTR(-ENOSPC);
646 	}
647 
648 	result = v9fs_t_walk(v9ses, dirfidnum, newfid,
649 		(char *)dentry->d_name.name, &fcall);
650 
651 	if (result < 0) {
652 		if (fcall && fcall->id == RWALK)
653 			v9fs_t_clunk(v9ses, newfid);
654 		else
655 			v9fs_put_idpool(newfid, &v9ses->fidpool);
656 
657 		if (result == -ENOENT) {
658 			d_add(dentry, NULL);
659 			dprintk(DEBUG_VFS,
660 				"Return negative dentry %p count %d\n",
661 				dentry, atomic_read(&dentry->d_count));
662 			kfree(fcall);
663 			return NULL;
664 		}
665 		dprintk(DEBUG_ERROR, "walk error:%d\n", result);
666 		goto FreeFcall;
667 	}
668 	kfree(fcall);
669 
670 	result = v9fs_t_stat(v9ses, newfid, &fcall);
671 	if (result < 0) {
672 		dprintk(DEBUG_ERROR, "stat error\n");
673 		goto FreeFcall;
674 	}
675 
676 	inode = v9fs_get_inode(sb, p9mode2unixmode(v9ses,
677 		fcall->params.rstat.stat.mode));
678 
679 	if (IS_ERR(inode) && (PTR_ERR(inode) == -ENOSPC)) {
680 		eprintk(KERN_WARNING, "inode alloc failes, returns %ld\n",
681 			PTR_ERR(inode));
682 
683 		result = -ENOSPC;
684 		goto FreeFcall;
685 	}
686 
687 	inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid);
688 
689 	fid = v9fs_fid_create(v9ses, newfid);
690 	if (fid == NULL) {
691 		dprintk(DEBUG_ERROR, "couldn't insert\n");
692 		result = -ENOMEM;
693 		goto FreeFcall;
694 	}
695 
696 	result = v9fs_fid_insert(fid, dentry);
697 	if (result < 0)
698 		goto FreeFcall;
699 
700 	fid->qid = fcall->params.rstat.stat.qid;
701 	v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
702 
703 	d_add(dentry, inode);
704 	kfree(fcall);
705 
706 	return NULL;
707 
708       FreeFcall:
709 	kfree(fcall);
710 	return ERR_PTR(result);
711 }
712 
713 /**
714  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
715  * @i:  inode that is being unlinked
716  * @d: dentry that is being unlinked
717  *
718  */
719 
720 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
721 {
722 	return v9fs_remove(i, d, 0);
723 }
724 
725 /**
726  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
727  * @i:  inode that is being unlinked
728  * @d: dentry that is being unlinked
729  *
730  */
731 
732 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
733 {
734 	return v9fs_remove(i, d, 1);
735 }
736 
737 /**
738  * v9fs_vfs_rename - VFS hook to rename an inode
739  * @old_dir:  old dir inode
740  * @old_dentry: old dentry
741  * @new_dir: new dir inode
742  * @new_dentry: new dentry
743  *
744  */
745 
746 static int
747 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
748 		struct inode *new_dir, struct dentry *new_dentry)
749 {
750 	struct inode *old_inode = old_dentry->d_inode;
751 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(old_inode);
752 	struct v9fs_fid *oldfid = v9fs_fid_lookup(old_dentry);
753 	struct v9fs_fid *olddirfid =
754 	    v9fs_fid_lookup(old_dentry->d_parent);
755 	struct v9fs_fid *newdirfid =
756 	    v9fs_fid_lookup(new_dentry->d_parent);
757 	struct v9fs_wstat wstat;
758 	struct v9fs_fcall *fcall = NULL;
759 	int fid = -1;
760 	int olddirfidnum = -1;
761 	int newdirfidnum = -1;
762 	int retval = 0;
763 
764 	dprintk(DEBUG_VFS, "\n");
765 
766 	if ((!oldfid) || (!olddirfid) || (!newdirfid)) {
767 		dprintk(DEBUG_ERROR, "problem with arguments\n");
768 		return -EBADF;
769 	}
770 
771 	/* 9P can only handle file rename in the same directory */
772 	if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
773 		dprintk(DEBUG_ERROR, "old dir and new dir are different\n");
774 		retval = -EPERM;
775 		goto FreeFcallnBail;
776 	}
777 
778 	fid = oldfid->fid;
779 	olddirfidnum = olddirfid->fid;
780 	newdirfidnum = newdirfid->fid;
781 
782 	if (fid < 0) {
783 		dprintk(DEBUG_ERROR, "no fid for old file #%lu\n",
784 			old_inode->i_ino);
785 		retval = -EBADF;
786 		goto FreeFcallnBail;
787 	}
788 
789 	v9fs_blank_wstat(&wstat);
790 	wstat.muid = v9ses->name;
791 	wstat.name = (char *) new_dentry->d_name.name;
792 
793 	retval = v9fs_t_wstat(v9ses, fid, &wstat, &fcall);
794 
795       FreeFcallnBail:
796 	if (retval < 0)
797 		PRINT_FCALL_ERROR("wstat error", fcall);
798 
799 	kfree(fcall);
800 	return retval;
801 }
802 
803 /**
804  * v9fs_vfs_getattr - retrieve file metadata
805  * @mnt - mount information
806  * @dentry - file to get attributes on
807  * @stat - metadata structure to populate
808  *
809  */
810 
811 static int
812 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
813 		 struct kstat *stat)
814 {
815 	struct v9fs_fcall *fcall = NULL;
816 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
817 	struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
818 	int err = -EPERM;
819 
820 	dprintk(DEBUG_VFS, "dentry: %p\n", dentry);
821 	if (!fid) {
822 		dprintk(DEBUG_ERROR,
823 			"couldn't find fid associated with dentry\n");
824 		return -EBADF;
825 	}
826 
827 	err = v9fs_t_stat(v9ses, fid->fid, &fcall);
828 
829 	if (err < 0)
830 		dprintk(DEBUG_ERROR, "stat error\n");
831 	else {
832 		v9fs_stat2inode(&fcall->params.rstat.stat, dentry->d_inode,
833 				  dentry->d_inode->i_sb);
834 		generic_fillattr(dentry->d_inode, stat);
835 	}
836 
837 	kfree(fcall);
838 	return err;
839 }
840 
841 /**
842  * v9fs_vfs_setattr - set file metadata
843  * @dentry: file whose metadata to set
844  * @iattr: metadata assignment structure
845  *
846  */
847 
848 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
849 {
850 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
851 	struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
852 	struct v9fs_fcall *fcall = NULL;
853 	struct v9fs_wstat wstat;
854 	int res = -EPERM;
855 
856 	dprintk(DEBUG_VFS, "\n");
857 
858 	if (!fid) {
859 		dprintk(DEBUG_ERROR,
860 			"Couldn't find fid associated with dentry\n");
861 		return -EBADF;
862 	}
863 
864 	v9fs_blank_wstat(&wstat);
865 	if (iattr->ia_valid & ATTR_MODE)
866 		wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
867 
868 	if (iattr->ia_valid & ATTR_MTIME)
869 		wstat.mtime = iattr->ia_mtime.tv_sec;
870 
871 	if (iattr->ia_valid & ATTR_ATIME)
872 		wstat.atime = iattr->ia_atime.tv_sec;
873 
874 	if (iattr->ia_valid & ATTR_SIZE)
875 		wstat.length = iattr->ia_size;
876 
877 	if (v9ses->extended) {
878 		if (iattr->ia_valid & ATTR_UID)
879 			wstat.n_uid = iattr->ia_uid;
880 
881 		if (iattr->ia_valid & ATTR_GID)
882 			wstat.n_gid = iattr->ia_gid;
883 	}
884 
885 	res = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall);
886 
887 	if (res < 0)
888 		PRINT_FCALL_ERROR("wstat error", fcall);
889 
890 	kfree(fcall);
891 	if (res >= 0)
892 		res = inode_setattr(dentry->d_inode, iattr);
893 
894 	return res;
895 }
896 
897 /**
898  * v9fs_stat2inode - populate an inode structure with mistat info
899  * @stat: Plan 9 metadata (mistat) structure
900  * @inode: inode to populate
901  * @sb: superblock of filesystem
902  *
903  */
904 
905 void
906 v9fs_stat2inode(struct v9fs_stat *stat, struct inode *inode,
907 	struct super_block *sb)
908 {
909 	int n;
910 	char ext[32];
911 	struct v9fs_session_info *v9ses = sb->s_fs_info;
912 
913 	inode->i_nlink = 1;
914 
915 	inode->i_atime.tv_sec = stat->atime;
916 	inode->i_mtime.tv_sec = stat->mtime;
917 	inode->i_ctime.tv_sec = stat->mtime;
918 
919 	inode->i_uid = v9ses->uid;
920 	inode->i_gid = v9ses->gid;
921 
922 	if (v9ses->extended) {
923 		inode->i_uid = stat->n_uid;
924 		inode->i_gid = stat->n_gid;
925 	}
926 
927 	inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
928 	if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
929 		char type = 0;
930 		int major = -1;
931 		int minor = -1;
932 
933 		n = stat->extension.len;
934 		if (n > sizeof(ext)-1)
935 			n = sizeof(ext)-1;
936 		memmove(ext, stat->extension.str, n);
937 		ext[n] = 0;
938 		sscanf(ext, "%c %u %u", &type, &major, &minor);
939 		switch (type) {
940 		case 'c':
941 			inode->i_mode &= ~S_IFBLK;
942 			inode->i_mode |= S_IFCHR;
943 			break;
944 		case 'b':
945 			break;
946 		default:
947 			dprintk(DEBUG_ERROR, "Unknown special type %c (%.*s)\n",
948 				type, stat->extension.len, stat->extension.str);
949 		};
950 		inode->i_rdev = MKDEV(major, minor);
951 	} else
952 		inode->i_rdev = 0;
953 
954 	inode->i_size = stat->length;
955 
956 	inode->i_blksize = sb->s_blocksize;
957 	inode->i_blocks =
958 	    (inode->i_size + inode->i_blksize - 1) >> sb->s_blocksize_bits;
959 }
960 
961 /**
962  * v9fs_qid2ino - convert qid into inode number
963  * @qid: qid to hash
964  *
965  * BUG: potential for inode number collisions?
966  */
967 
968 ino_t v9fs_qid2ino(struct v9fs_qid *qid)
969 {
970 	u64 path = qid->path + 2;
971 	ino_t i = 0;
972 
973 	if (sizeof(ino_t) == sizeof(path))
974 		memcpy(&i, &path, sizeof(ino_t));
975 	else
976 		i = (ino_t) (path ^ (path >> 32));
977 
978 	return i;
979 }
980 
981 /**
982  * v9fs_readlink - read a symlink's location (internal version)
983  * @dentry: dentry for symlink
984  * @buffer: buffer to load symlink location into
985  * @buflen: length of buffer
986  *
987  */
988 
989 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
990 {
991 	int retval = -EPERM;
992 
993 	struct v9fs_fcall *fcall = NULL;
994 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
995 	struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
996 
997 	if (!fid) {
998 		dprintk(DEBUG_ERROR, "could not resolve fid from dentry\n");
999 		retval = -EBADF;
1000 		goto FreeFcall;
1001 	}
1002 
1003 	if (!v9ses->extended) {
1004 		retval = -EBADF;
1005 		dprintk(DEBUG_ERROR, "not extended\n");
1006 		goto FreeFcall;
1007 	}
1008 
1009 	dprintk(DEBUG_VFS, " %s\n", dentry->d_name.name);
1010 	retval = v9fs_t_stat(v9ses, fid->fid, &fcall);
1011 
1012 	if (retval < 0) {
1013 		dprintk(DEBUG_ERROR, "stat error\n");
1014 		goto FreeFcall;
1015 	}
1016 
1017 	if (!fcall)
1018 		return -EIO;
1019 
1020 	if (!(fcall->params.rstat.stat.mode & V9FS_DMSYMLINK)) {
1021 		retval = -EINVAL;
1022 		goto FreeFcall;
1023 	}
1024 
1025 	/* copy extension buffer into buffer */
1026 	if (fcall->params.rstat.stat.extension.len < buflen)
1027 		buflen = fcall->params.rstat.stat.extension.len + 1;
1028 
1029 	memmove(buffer, fcall->params.rstat.stat.extension.str, buflen - 1);
1030 	buffer[buflen-1] = 0;
1031 
1032 	dprintk(DEBUG_ERROR, "%s -> %.*s (%s)\n", dentry->d_name.name, fcall->params.rstat.stat.extension.len,
1033 		fcall->params.rstat.stat.extension.str, buffer);
1034 	retval = buflen;
1035 
1036       FreeFcall:
1037 	kfree(fcall);
1038 
1039 	return retval;
1040 }
1041 
1042 /**
1043  * v9fs_vfs_readlink - read a symlink's location
1044  * @dentry: dentry for symlink
1045  * @buf: buffer to load symlink location into
1046  * @buflen: length of buffer
1047  *
1048  */
1049 
1050 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
1051 			     int buflen)
1052 {
1053 	int retval;
1054 	int ret;
1055 	char *link = __getname();
1056 
1057 	if (buflen > PATH_MAX)
1058 		buflen = PATH_MAX;
1059 
1060 	dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
1061 
1062 	retval = v9fs_readlink(dentry, link, buflen);
1063 
1064 	if (retval > 0) {
1065 		if ((ret = copy_to_user(buffer, link, retval)) != 0) {
1066 			dprintk(DEBUG_ERROR, "problem copying to user: %d\n",
1067 				ret);
1068 			retval = ret;
1069 		}
1070 	}
1071 
1072 	__putname(link);
1073 	return retval;
1074 }
1075 
1076 /**
1077  * v9fs_vfs_follow_link - follow a symlink path
1078  * @dentry: dentry for symlink
1079  * @nd: nameidata
1080  *
1081  */
1082 
1083 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1084 {
1085 	int len = 0;
1086 	char *link = __getname();
1087 
1088 	dprintk(DEBUG_VFS, "%s n", dentry->d_name.name);
1089 
1090 	if (!link)
1091 		link = ERR_PTR(-ENOMEM);
1092 	else {
1093 		len = v9fs_readlink(dentry, link, PATH_MAX);
1094 
1095 		if (len < 0) {
1096 			__putname(link);
1097 			link = ERR_PTR(len);
1098 		} else
1099 			link[len] = 0;
1100 	}
1101 	nd_set_link(nd, link);
1102 
1103 	return NULL;
1104 }
1105 
1106 /**
1107  * v9fs_vfs_put_link - release a symlink path
1108  * @dentry: dentry for symlink
1109  * @nd: nameidata
1110  *
1111  */
1112 
1113 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1114 {
1115 	char *s = nd_get_link(nd);
1116 
1117 	dprintk(DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1118 	if (!IS_ERR(s))
1119 		__putname(s);
1120 }
1121 
1122 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1123 	int mode, const char *extension)
1124 {
1125 	int err;
1126 	u32 fid, perm;
1127 	struct v9fs_session_info *v9ses;
1128 	struct v9fs_fid *dfid, *vfid;
1129 	struct inode *inode;
1130 
1131 	inode = NULL;
1132 	vfid = NULL;
1133 	v9ses = v9fs_inode2v9ses(dir);
1134 	dfid = v9fs_fid_lookup(dentry->d_parent);
1135 	perm = unixmode2p9mode(v9ses, mode);
1136 
1137 	if (!v9ses->extended) {
1138 		dprintk(DEBUG_ERROR, "not extended\n");
1139 		return -EPERM;
1140 	}
1141 
1142 	err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
1143 		perm, V9FS_OREAD, (char *) extension, &fid, NULL, NULL);
1144 
1145 	if (err)
1146 		goto error;
1147 
1148 	err = v9fs_t_clunk(v9ses, fid);
1149 	if (err)
1150 		goto error;
1151 
1152 	vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
1153 	if (IS_ERR(vfid)) {
1154 		err = PTR_ERR(vfid);
1155 		vfid = NULL;
1156 		goto error;
1157 	}
1158 
1159 	inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
1160 	if (IS_ERR(inode)) {
1161 		err = PTR_ERR(inode);
1162 		inode = NULL;
1163 		goto error;
1164 	}
1165 
1166 	dentry->d_op = &v9fs_dentry_operations;
1167 	d_instantiate(dentry, inode);
1168 	return 0;
1169 
1170 error:
1171 	if (vfid)
1172 		v9fs_fid_destroy(vfid);
1173 
1174 	if (inode)
1175 		iput(inode);
1176 
1177 	return err;
1178 
1179 }
1180 
1181 /**
1182  * v9fs_vfs_symlink - helper function to create symlinks
1183  * @dir: directory inode containing symlink
1184  * @dentry: dentry for symlink
1185  * @symname: symlink data
1186  *
1187  * See 9P2000.u RFC for more information
1188  *
1189  */
1190 
1191 static int
1192 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1193 {
1194 	dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1195 		symname);
1196 
1197 	return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1198 }
1199 
1200 /**
1201  * v9fs_vfs_link - create a hardlink
1202  * @old_dentry: dentry for file to link to
1203  * @dir: inode destination for new link
1204  * @dentry: dentry for link
1205  *
1206  */
1207 
1208 /* XXX - lots of code dup'd from symlink and creates,
1209  * figure out a better reuse strategy
1210  */
1211 
1212 static int
1213 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1214 	      struct dentry *dentry)
1215 {
1216 	int retval;
1217 	struct v9fs_fid *oldfid;
1218 	char *name;
1219 
1220 	dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1221 		old_dentry->d_name.name);
1222 
1223 	oldfid = v9fs_fid_lookup(old_dentry);
1224 	if (!oldfid) {
1225 		dprintk(DEBUG_ERROR, "can't find oldfid\n");
1226 		return -EPERM;
1227 	}
1228 
1229 	name = __getname();
1230 	sprintf(name, "%d\n", oldfid->fid);
1231 	retval = v9fs_vfs_mkspecial(dir, dentry, V9FS_DMLINK, name);
1232 	__putname(name);
1233 
1234 	return retval;
1235 }
1236 
1237 /**
1238  * v9fs_vfs_mknod - create a special file
1239  * @dir: inode destination for new link
1240  * @dentry: dentry for file
1241  * @mode: mode for creation
1242  * @dev_t: device associated with special file
1243  *
1244  */
1245 
1246 static int
1247 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1248 {
1249 	int retval;
1250 	char *name;
1251 
1252 	dprintk(DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1253 		dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1254 
1255 	if (!new_valid_dev(rdev))
1256 		return -EINVAL;
1257 
1258 	name = __getname();
1259 	if (!name)
1260 		return -ENOMEM;
1261 	/* build extension */
1262 	if (S_ISBLK(mode))
1263 		sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1264 	else if (S_ISCHR(mode))
1265 		sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1266 	else if (S_ISFIFO(mode))
1267 		*name = 0;
1268 	else {
1269 		__putname(name);
1270 		return -EINVAL;
1271 	}
1272 
1273 	retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1274 	__putname(name);
1275 
1276 	return retval;
1277 }
1278 
1279 static struct inode_operations v9fs_dir_inode_operations_ext = {
1280 	.create = v9fs_vfs_create,
1281 	.lookup = v9fs_vfs_lookup,
1282 	.symlink = v9fs_vfs_symlink,
1283 	.link = v9fs_vfs_link,
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 	.readlink = v9fs_vfs_readlink,
1290 	.getattr = v9fs_vfs_getattr,
1291 	.setattr = v9fs_vfs_setattr,
1292 };
1293 
1294 static struct inode_operations v9fs_dir_inode_operations = {
1295 	.create = v9fs_vfs_create,
1296 	.lookup = v9fs_vfs_lookup,
1297 	.unlink = v9fs_vfs_unlink,
1298 	.mkdir = v9fs_vfs_mkdir,
1299 	.rmdir = v9fs_vfs_rmdir,
1300 	.mknod = v9fs_vfs_mknod,
1301 	.rename = v9fs_vfs_rename,
1302 	.getattr = v9fs_vfs_getattr,
1303 	.setattr = v9fs_vfs_setattr,
1304 };
1305 
1306 static struct inode_operations v9fs_file_inode_operations = {
1307 	.getattr = v9fs_vfs_getattr,
1308 	.setattr = v9fs_vfs_setattr,
1309 };
1310 
1311 static struct inode_operations v9fs_symlink_inode_operations = {
1312 	.readlink = v9fs_vfs_readlink,
1313 	.follow_link = v9fs_vfs_follow_link,
1314 	.put_link = v9fs_vfs_put_link,
1315 	.getattr = v9fs_vfs_getattr,
1316 	.setattr = v9fs_vfs_setattr,
1317 };
1318