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1/*
2 *  dir.c
3 *
4 *  Copyright (C) 1995, 1996 by Paal-Kr. Engstad and Volker Lendecke
5 *  Copyright (C) 1997 by Volker Lendecke
6 *
7 *  Please add a note about your changes to smbfs in the ChangeLog file.
8 */
9
10#include <linux/time.h>
11#include <linux/errno.h>
12#include <linux/kernel.h>
13#include <linux/smp_lock.h>
14#include <linux/ctype.h>
15#include <linux/net.h>
16#include <linux/sched.h>
17
18#include <linux/smb_fs.h>
19#include <linux/smb_mount.h>
20#include <linux/smbno.h>
21
22#include "smb_debug.h"
23#include "proto.h"
24
25static int smb_readdir(struct file *, void *, filldir_t);
26static int smb_dir_open(struct inode *, struct file *);
27
28static struct dentry *smb_lookup(struct inode *, struct dentry *, struct nameidata *);
29static int smb_create(struct inode *, struct dentry *, int, struct nameidata *);
30static int smb_mkdir(struct inode *, struct dentry *, int);
31static int smb_rmdir(struct inode *, struct dentry *);
32static int smb_unlink(struct inode *, struct dentry *);
33static int smb_rename(struct inode *, struct dentry *,
34		      struct inode *, struct dentry *);
35static int smb_make_node(struct inode *,struct dentry *,int,dev_t);
36static int smb_link(struct dentry *, struct inode *, struct dentry *);
37
38const struct file_operations smb_dir_operations =
39{
40	.llseek		= generic_file_llseek,
41	.read		= generic_read_dir,
42	.readdir	= smb_readdir,
43	.unlocked_ioctl	= smb_ioctl,
44	.open		= smb_dir_open,
45};
46
47const struct inode_operations smb_dir_inode_operations =
48{
49	.create		= smb_create,
50	.lookup		= smb_lookup,
51	.unlink		= smb_unlink,
52	.mkdir		= smb_mkdir,
53	.rmdir		= smb_rmdir,
54	.rename		= smb_rename,
55	.getattr	= smb_getattr,
56	.setattr	= smb_notify_change,
57};
58
59const struct inode_operations smb_dir_inode_operations_unix =
60{
61	.create		= smb_create,
62	.lookup		= smb_lookup,
63	.unlink		= smb_unlink,
64	.mkdir		= smb_mkdir,
65	.rmdir		= smb_rmdir,
66	.rename		= smb_rename,
67	.getattr	= smb_getattr,
68	.setattr	= smb_notify_change,
69	.symlink	= smb_symlink,
70	.mknod		= smb_make_node,
71	.link		= smb_link,
72};
73
74/*
75 * Read a directory, using filldir to fill the dirent memory.
76 * smb_proc_readdir does the actual reading from the smb server.
77 *
78 * The cache code is almost directly taken from ncpfs
79 */
80static int
81smb_readdir(struct file *filp, void *dirent, filldir_t filldir)
82{
83	struct dentry *dentry = filp->f_path.dentry;
84	struct inode *dir = dentry->d_inode;
85	struct smb_sb_info *server = server_from_dentry(dentry);
86	union  smb_dir_cache *cache = NULL;
87	struct smb_cache_control ctl;
88	struct page *page = NULL;
89	int result;
90
91	ctl.page  = NULL;
92	ctl.cache = NULL;
93
94	VERBOSE("reading %s/%s, f_pos=%d\n",
95		DENTRY_PATH(dentry),  (int) filp->f_pos);
96
97	result = 0;
98
99	lock_kernel();
100
101	switch ((unsigned int) filp->f_pos) {
102	case 0:
103		if (filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR) < 0)
104			goto out;
105		filp->f_pos = 1;
106		/* fallthrough */
107	case 1:
108		if (filldir(dirent, "..", 2, 1, parent_ino(dentry), DT_DIR) < 0)
109			goto out;
110		filp->f_pos = 2;
111	}
112
113	/*
114	 * Make sure our inode is up-to-date.
115	 */
116	result = smb_revalidate_inode(dentry);
117	if (result)
118		goto out;
119
120
121	page = grab_cache_page(&dir->i_data, 0);
122	if (!page)
123		goto read_really;
124
125	ctl.cache = cache = kmap(page);
126	ctl.head  = cache->head;
127
128	if (!PageUptodate(page) || !ctl.head.eof) {
129		VERBOSE("%s/%s, page uptodate=%d, eof=%d\n",
130			 DENTRY_PATH(dentry), PageUptodate(page),ctl.head.eof);
131		goto init_cache;
132	}
133
134	if (filp->f_pos == 2) {
135		if (jiffies - ctl.head.time >= SMB_MAX_AGE(server))
136			goto init_cache;
137
138		/*
139		 * N.B. ncpfs checks mtime of dentry too here, we don't.
140		 *   1. common smb servers do not update mtime on dir changes
141		 *   2. it requires an extra smb request
142		 *      (revalidate has the same timeout as ctl.head.time)
143		 *
144		 * Instead smbfs invalidates its own cache on local changes
145		 * and remote changes are not seen until timeout.
146		 */
147	}
148
149	if (filp->f_pos > ctl.head.end)
150		goto finished;
151
152	ctl.fpos = filp->f_pos + (SMB_DIRCACHE_START - 2);
153	ctl.ofs  = ctl.fpos / SMB_DIRCACHE_SIZE;
154	ctl.idx  = ctl.fpos % SMB_DIRCACHE_SIZE;
155
156	for (;;) {
157		if (ctl.ofs != 0) {
158			ctl.page = find_lock_page(&dir->i_data, ctl.ofs);
159			if (!ctl.page)
160				goto invalid_cache;
161			ctl.cache = kmap(ctl.page);
162			if (!PageUptodate(ctl.page))
163				goto invalid_cache;
164		}
165		while (ctl.idx < SMB_DIRCACHE_SIZE) {
166			struct dentry *dent;
167			int res;
168
169			dent = smb_dget_fpos(ctl.cache->dentry[ctl.idx],
170					     dentry, filp->f_pos);
171			if (!dent)
172				goto invalid_cache;
173
174			res = filldir(dirent, dent->d_name.name,
175				      dent->d_name.len, filp->f_pos,
176				      dent->d_inode->i_ino, DT_UNKNOWN);
177			dput(dent);
178			if (res)
179				goto finished;
180			filp->f_pos += 1;
181			ctl.idx += 1;
182			if (filp->f_pos > ctl.head.end)
183				goto finished;
184		}
185		if (ctl.page) {
186			kunmap(ctl.page);
187			SetPageUptodate(ctl.page);
188			unlock_page(ctl.page);
189			page_cache_release(ctl.page);
190			ctl.page = NULL;
191		}
192		ctl.idx  = 0;
193		ctl.ofs += 1;
194	}
195invalid_cache:
196	if (ctl.page) {
197		kunmap(ctl.page);
198		unlock_page(ctl.page);
199		page_cache_release(ctl.page);
200		ctl.page = NULL;
201	}
202	ctl.cache = cache;
203init_cache:
204	smb_invalidate_dircache_entries(dentry);
205	ctl.head.time = jiffies;
206	ctl.head.eof = 0;
207	ctl.fpos = 2;
208	ctl.ofs = 0;
209	ctl.idx = SMB_DIRCACHE_START;
210	ctl.filled = 0;
211	ctl.valid  = 1;
212read_really:
213	result = server->ops->readdir(filp, dirent, filldir, &ctl);
214	if (result == -ERESTARTSYS && page)
215		ClearPageUptodate(page);
216	if (ctl.idx == -1)
217		goto invalid_cache;	/* retry */
218	ctl.head.end = ctl.fpos - 1;
219	ctl.head.eof = ctl.valid;
220finished:
221	if (page) {
222		cache->head = ctl.head;
223		kunmap(page);
224		if (result != -ERESTARTSYS)
225			SetPageUptodate(page);
226		unlock_page(page);
227		page_cache_release(page);
228	}
229	if (ctl.page) {
230		kunmap(ctl.page);
231		SetPageUptodate(ctl.page);
232		unlock_page(ctl.page);
233		page_cache_release(ctl.page);
234	}
235out:
236	unlock_kernel();
237	return result;
238}
239
240static int
241smb_dir_open(struct inode *dir, struct file *file)
242{
243	struct dentry *dentry = file->f_path.dentry;
244	struct smb_sb_info *server;
245	int error = 0;
246
247	VERBOSE("(%s/%s)\n", dentry->d_parent->d_name.name,
248		file->f_path.dentry->d_name.name);
249
250	/*
251	 * Directory timestamps in the core protocol aren't updated
252	 * when a file is added, so we give them a very short TTL.
253	 */
254	lock_kernel();
255	server = server_from_dentry(dentry);
256	if (server->opt.protocol < SMB_PROTOCOL_LANMAN2) {
257		unsigned long age = jiffies - SMB_I(dir)->oldmtime;
258		if (age > 2*HZ)
259			smb_invalid_dir_cache(dir);
260	}
261
262	/*
263	 * Note: in order to allow the smbmount process to open the
264	 * mount point, we only revalidate if the connection is valid or
265	 * if the process is trying to access something other than the root.
266	 */
267	if (server->state == CONN_VALID || !IS_ROOT(dentry))
268		error = smb_revalidate_inode(dentry);
269	unlock_kernel();
270	return error;
271}
272
273/*
274 * Dentry operations routines
275 */
276static int smb_lookup_validate(struct dentry *, struct nameidata *);
277static int smb_hash_dentry(struct dentry *, struct qstr *);
278static int smb_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
279static int smb_delete_dentry(struct dentry *);
280
281static const struct dentry_operations smbfs_dentry_operations =
282{
283	.d_revalidate	= smb_lookup_validate,
284	.d_hash		= smb_hash_dentry,
285	.d_compare	= smb_compare_dentry,
286	.d_delete	= smb_delete_dentry,
287};
288
289static const struct dentry_operations smbfs_dentry_operations_case =
290{
291	.d_revalidate	= smb_lookup_validate,
292	.d_delete	= smb_delete_dentry,
293};
294
295
296/*
297 * This is the callback when the dcache has a lookup hit.
298 */
299static int
300smb_lookup_validate(struct dentry * dentry, struct nameidata *nd)
301{
302	struct smb_sb_info *server = server_from_dentry(dentry);
303	struct inode * inode = dentry->d_inode;
304	unsigned long age = jiffies - dentry->d_time;
305	int valid;
306
307	/*
308	 * The default validation is based on dentry age:
309	 * we believe in dentries for a few seconds.  (But each
310	 * successful server lookup renews the timestamp.)
311	 */
312	valid = (age <= SMB_MAX_AGE(server));
313#ifdef SMBFS_DEBUG_VERBOSE
314	if (!valid)
315		VERBOSE("%s/%s not valid, age=%lu\n",
316			DENTRY_PATH(dentry), age);
317#endif
318
319	if (inode) {
320		lock_kernel();
321		if (is_bad_inode(inode)) {
322			PARANOIA("%s/%s has dud inode\n", DENTRY_PATH(dentry));
323			valid = 0;
324		} else if (!valid)
325			valid = (smb_revalidate_inode(dentry) == 0);
326		unlock_kernel();
327	} else {
328		/*
329		 * What should we do for negative dentries?
330		 */
331	}
332	return valid;
333}
334
335static int
336smb_hash_dentry(struct dentry *dir, struct qstr *this)
337{
338	unsigned long hash;
339	int i;
340
341	hash = init_name_hash();
342	for (i=0; i < this->len ; i++)
343		hash = partial_name_hash(tolower(this->name[i]), hash);
344	this->hash = end_name_hash(hash);
345
346	return 0;
347}
348
349static int
350smb_compare_dentry(struct dentry *dir, struct qstr *a, struct qstr *b)
351{
352	int i, result = 1;
353
354	if (a->len != b->len)
355		goto out;
356	for (i=0; i < a->len; i++) {
357		if (tolower(a->name[i]) != tolower(b->name[i]))
358			goto out;
359	}
360	result = 0;
361out:
362	return result;
363}
364
365/*
366 * This is the callback from dput() when d_count is going to 0.
367 * We use this to unhash dentries with bad inodes.
368 */
369static int
370smb_delete_dentry(struct dentry * dentry)
371{
372	if (dentry->d_inode) {
373		if (is_bad_inode(dentry->d_inode)) {
374			PARANOIA("bad inode, unhashing %s/%s\n",
375				 DENTRY_PATH(dentry));
376			return 1;
377		}
378	} else {
379		/* N.B. Unhash negative dentries? */
380	}
381	return 0;
382}
383
384/*
385 * Initialize a new dentry
386 */
387void
388smb_new_dentry(struct dentry *dentry)
389{
390	struct smb_sb_info *server = server_from_dentry(dentry);
391
392	if (server->mnt->flags & SMB_MOUNT_CASE)
393		dentry->d_op = &smbfs_dentry_operations_case;
394	else
395		dentry->d_op = &smbfs_dentry_operations;
396	dentry->d_time = jiffies;
397}
398
399
400/*
401 * Whenever a lookup succeeds, we know the parent directories
402 * are all valid, so we want to update the dentry timestamps.
403 * N.B. Move this to dcache?
404 */
405void
406smb_renew_times(struct dentry * dentry)
407{
408	dget(dentry);
409	spin_lock(&dentry->d_lock);
410	for (;;) {
411		struct dentry *parent;
412
413		dentry->d_time = jiffies;
414		if (IS_ROOT(dentry))
415			break;
416		parent = dentry->d_parent;
417		dget(parent);
418		spin_unlock(&dentry->d_lock);
419		dput(dentry);
420		dentry = parent;
421		spin_lock(&dentry->d_lock);
422	}
423	spin_unlock(&dentry->d_lock);
424	dput(dentry);
425}
426
427static struct dentry *
428smb_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
429{
430	struct smb_fattr finfo;
431	struct inode *inode;
432	int error;
433	struct smb_sb_info *server;
434
435	error = -ENAMETOOLONG;
436	if (dentry->d_name.len > SMB_MAXNAMELEN)
437		goto out;
438
439	/* Do not allow lookup of names with backslashes in */
440	error = -EINVAL;
441	if (memchr(dentry->d_name.name, '\\', dentry->d_name.len))
442		goto out;
443
444	lock_kernel();
445	error = smb_proc_getattr(dentry, &finfo);
446#ifdef SMBFS_PARANOIA
447	if (error && error != -ENOENT)
448		PARANOIA("find %s/%s failed, error=%d\n",
449			 DENTRY_PATH(dentry), error);
450#endif
451
452	inode = NULL;
453	if (error == -ENOENT)
454		goto add_entry;
455	if (!error) {
456		error = -EACCES;
457		finfo.f_ino = iunique(dentry->d_sb, 2);
458		inode = smb_iget(dir->i_sb, &finfo);
459		if (inode) {
460	add_entry:
461			server = server_from_dentry(dentry);
462			if (server->mnt->flags & SMB_MOUNT_CASE)
463				dentry->d_op = &smbfs_dentry_operations_case;
464			else
465				dentry->d_op = &smbfs_dentry_operations;
466
467			d_add(dentry, inode);
468			smb_renew_times(dentry);
469			error = 0;
470		}
471	}
472	unlock_kernel();
473out:
474	return ERR_PTR(error);
475}
476
477/*
478 * This code is common to all routines creating a new inode.
479 */
480static int
481smb_instantiate(struct dentry *dentry, __u16 fileid, int have_id)
482{
483	struct smb_sb_info *server = server_from_dentry(dentry);
484	struct inode *inode;
485	int error;
486	struct smb_fattr fattr;
487
488	VERBOSE("file %s/%s, fileid=%u\n", DENTRY_PATH(dentry), fileid);
489
490	error = smb_proc_getattr(dentry, &fattr);
491	if (error)
492		goto out_close;
493
494	smb_renew_times(dentry);
495	fattr.f_ino = iunique(dentry->d_sb, 2);
496	inode = smb_iget(dentry->d_sb, &fattr);
497	if (!inode)
498		goto out_no_inode;
499
500	if (have_id) {
501		struct smb_inode_info *ei = SMB_I(inode);
502		ei->fileid = fileid;
503		ei->access = SMB_O_RDWR;
504		ei->open = server->generation;
505	}
506	d_instantiate(dentry, inode);
507out:
508	return error;
509
510out_no_inode:
511	error = -EACCES;
512out_close:
513	if (have_id) {
514		PARANOIA("%s/%s failed, error=%d, closing %u\n",
515			 DENTRY_PATH(dentry), error, fileid);
516		smb_close_fileid(dentry, fileid);
517	}
518	goto out;
519}
520
521/* N.B. How should the mode argument be used? */
522static int
523smb_create(struct inode *dir, struct dentry *dentry, int mode,
524		struct nameidata *nd)
525{
526	struct smb_sb_info *server = server_from_dentry(dentry);
527	__u16 fileid;
528	int error;
529	struct iattr attr;
530
531	VERBOSE("creating %s/%s, mode=%d\n", DENTRY_PATH(dentry), mode);
532
533	lock_kernel();
534	smb_invalid_dir_cache(dir);
535	error = smb_proc_create(dentry, 0, get_seconds(), &fileid);
536	if (!error) {
537		if (server->opt.capabilities & SMB_CAP_UNIX) {
538			/* Set attributes for new file */
539			attr.ia_valid = ATTR_MODE;
540			attr.ia_mode = mode;
541			error = smb_proc_setattr_unix(dentry, &attr, 0, 0);
542		}
543		error = smb_instantiate(dentry, fileid, 1);
544	} else {
545		PARANOIA("%s/%s failed, error=%d\n",
546			 DENTRY_PATH(dentry), error);
547	}
548	unlock_kernel();
549	return error;
550}
551
552/* N.B. How should the mode argument be used? */
553static int
554smb_mkdir(struct inode *dir, struct dentry *dentry, int mode)
555{
556	struct smb_sb_info *server = server_from_dentry(dentry);
557	int error;
558	struct iattr attr;
559
560	lock_kernel();
561	smb_invalid_dir_cache(dir);
562	error = smb_proc_mkdir(dentry);
563	if (!error) {
564		if (server->opt.capabilities & SMB_CAP_UNIX) {
565			/* Set attributes for new directory */
566			attr.ia_valid = ATTR_MODE;
567			attr.ia_mode = mode;
568			error = smb_proc_setattr_unix(dentry, &attr, 0, 0);
569		}
570		error = smb_instantiate(dentry, 0, 0);
571	}
572	unlock_kernel();
573	return error;
574}
575
576static int
577smb_rmdir(struct inode *dir, struct dentry *dentry)
578{
579	struct inode *inode = dentry->d_inode;
580	int error;
581
582	/*
583	 * Close the directory if it's open.
584	 */
585	lock_kernel();
586	smb_close(inode);
587
588	/*
589	 * Check that nobody else is using the directory..
590	 */
591	error = -EBUSY;
592	if (!d_unhashed(dentry))
593		goto out;
594
595	smb_invalid_dir_cache(dir);
596	error = smb_proc_rmdir(dentry);
597
598out:
599	unlock_kernel();
600	return error;
601}
602
603static int
604smb_unlink(struct inode *dir, struct dentry *dentry)
605{
606	int error;
607
608	/*
609	 * Close the file if it's open.
610	 */
611	lock_kernel();
612	smb_close(dentry->d_inode);
613
614	smb_invalid_dir_cache(dir);
615	error = smb_proc_unlink(dentry);
616	if (!error)
617		smb_renew_times(dentry);
618	unlock_kernel();
619	return error;
620}
621
622static int
623smb_rename(struct inode *old_dir, struct dentry *old_dentry,
624	   struct inode *new_dir, struct dentry *new_dentry)
625{
626	int error;
627
628	/*
629	 * Close any open files, and check whether to delete the
630	 * target before attempting the rename.
631	 */
632	lock_kernel();
633	if (old_dentry->d_inode)
634		smb_close(old_dentry->d_inode);
635	if (new_dentry->d_inode) {
636		smb_close(new_dentry->d_inode);
637		error = smb_proc_unlink(new_dentry);
638		if (error) {
639			VERBOSE("unlink %s/%s, error=%d\n",
640				DENTRY_PATH(new_dentry), error);
641			goto out;
642		}
643		d_delete(new_dentry);
644	}
645
646	smb_invalid_dir_cache(old_dir);
647	smb_invalid_dir_cache(new_dir);
648	error = smb_proc_mv(old_dentry, new_dentry);
649	if (!error) {
650		smb_renew_times(old_dentry);
651		smb_renew_times(new_dentry);
652	}
653out:
654	unlock_kernel();
655	return error;
656}
657
658static int
659smb_make_node(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
660{
661	int error;
662	struct iattr attr;
663
664	attr.ia_valid = ATTR_MODE | ATTR_UID | ATTR_GID;
665	attr.ia_mode = mode;
666	current_euid_egid(&attr.ia_uid, &attr.ia_gid);
667
668	if (!new_valid_dev(dev))
669		return -EINVAL;
670
671	smb_invalid_dir_cache(dir);
672	error = smb_proc_setattr_unix(dentry, &attr, MAJOR(dev), MINOR(dev));
673	if (!error) {
674		error = smb_instantiate(dentry, 0, 0);
675	}
676	return error;
677}
678
679/*
680 * dentry = existing file
681 * new_dentry = new file
682 */
683static int
684smb_link(struct dentry *dentry, struct inode *dir, struct dentry *new_dentry)
685{
686	int error;
687
688	DEBUG1("smb_link old=%s/%s new=%s/%s\n",
689	       DENTRY_PATH(dentry), DENTRY_PATH(new_dentry));
690	smb_invalid_dir_cache(dir);
691	error = smb_proc_link(server_from_dentry(dentry), dentry, new_dentry);
692	if (!error) {
693		smb_renew_times(dentry);
694		error = smb_instantiate(new_dentry, 0, 0);
695	}
696	return error;
697}
698