summaryrefslogtreecommitdiff
path: root/drivers/staging/smbfs/dir.c
blob: dd612f50749f606b9dec9f04788f94bfb97b45d6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
/*
 *  dir.c
 *
 *  Copyright (C) 1995, 1996 by Paal-Kr. Engstad and Volker Lendecke
 *  Copyright (C) 1997 by Volker Lendecke
 *
 *  Please add a note about your changes to smbfs in the ChangeLog file.
 */

#include <linux/time.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/smp_lock.h>
#include <linux/ctype.h>
#include <linux/net.h>
#include <linux/sched.h>
#include <linux/namei.h>

#include "smb_fs.h"
#include "smb_mount.h"
#include "smbno.h"

#include "smb_debug.h"
#include "proto.h"

static int smb_readdir(struct file *, void *, filldir_t);
static int smb_dir_open(struct inode *, struct file *);

static struct dentry *smb_lookup(struct inode *, struct dentry *, struct nameidata *);
static int smb_create(struct inode *, struct dentry *, int, struct nameidata *);
static int smb_mkdir(struct inode *, struct dentry *, int);
static int smb_rmdir(struct inode *, struct dentry *);
static int smb_unlink(struct inode *, struct dentry *);
static int smb_rename(struct inode *, struct dentry *,
		      struct inode *, struct dentry *);
static int smb_make_node(struct inode *,struct dentry *,int,dev_t);
static int smb_link(struct dentry *, struct inode *, struct dentry *);

const struct file_operations smb_dir_operations =
{
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.readdir	= smb_readdir,
	.unlocked_ioctl	= smb_ioctl,
	.open		= smb_dir_open,
};

const struct inode_operations smb_dir_inode_operations =
{
	.create		= smb_create,
	.lookup		= smb_lookup,
	.unlink		= smb_unlink,
	.mkdir		= smb_mkdir,
	.rmdir		= smb_rmdir,
	.rename		= smb_rename,
	.getattr	= smb_getattr,
	.setattr	= smb_notify_change,
};

const struct inode_operations smb_dir_inode_operations_unix =
{
	.create		= smb_create,
	.lookup		= smb_lookup,
	.unlink		= smb_unlink,
	.mkdir		= smb_mkdir,
	.rmdir		= smb_rmdir,
	.rename		= smb_rename,
	.getattr	= smb_getattr,
	.setattr	= smb_notify_change,
	.symlink	= smb_symlink,
	.mknod		= smb_make_node,
	.link		= smb_link,
};

/*
 * Read a directory, using filldir to fill the dirent memory.
 * smb_proc_readdir does the actual reading from the smb server.
 *
 * The cache code is almost directly taken from ncpfs
 */
static int 
smb_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
	struct dentry *dentry = filp->f_path.dentry;
	struct inode *dir = dentry->d_inode;
	struct smb_sb_info *server = server_from_dentry(dentry);
	union  smb_dir_cache *cache = NULL;
	struct smb_cache_control ctl;
	struct page *page = NULL;
	int result;

	ctl.page  = NULL;
	ctl.cache = NULL;

	VERBOSE("reading %s/%s, f_pos=%d\n",
		DENTRY_PATH(dentry),  (int) filp->f_pos);

	result = 0;

	lock_kernel();

	switch ((unsigned int) filp->f_pos) {
	case 0:
		if (filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR) < 0)
			goto out;
		filp->f_pos = 1;
		/* fallthrough */
	case 1:
		if (filldir(dirent, "..", 2, 1, parent_ino(dentry), DT_DIR) < 0)
			goto out;
		filp->f_pos = 2;
	}

	/*
	 * Make sure our inode is up-to-date.
	 */
	result = smb_revalidate_inode(dentry);
	if (result)
		goto out;


	page = grab_cache_page(&dir->i_data, 0);
	if (!page)
		goto read_really;

	ctl.cache = cache = kmap(page);
	ctl.head  = cache->head;

	if (!PageUptodate(page) || !ctl.head.eof) {
		VERBOSE("%s/%s, page uptodate=%d, eof=%d\n",
			 DENTRY_PATH(dentry), PageUptodate(page),ctl.head.eof);
		goto init_cache;
	}

	if (filp->f_pos == 2) {
		if (jiffies - ctl.head.time >= SMB_MAX_AGE(server))
			goto init_cache;

		/*
		 * N.B. ncpfs checks mtime of dentry too here, we don't.
		 *   1. common smb servers do not update mtime on dir changes
		 *   2. it requires an extra smb request
		 *      (revalidate has the same timeout as ctl.head.time)
		 *
		 * Instead smbfs invalidates its own cache on local changes
		 * and remote changes are not seen until timeout.
		 */
	}

	if (filp->f_pos > ctl.head.end)
		goto finished;

	ctl.fpos = filp->f_pos + (SMB_DIRCACHE_START - 2);
	ctl.ofs  = ctl.fpos / SMB_DIRCACHE_SIZE;
	ctl.idx  = ctl.fpos % SMB_DIRCACHE_SIZE;

	for (;;) {
		if (ctl.ofs != 0) {
			ctl.page = find_lock_page(&dir->i_data, ctl.ofs);
			if (!ctl.page)
				goto invalid_cache;
			ctl.cache = kmap(ctl.page);
			if (!PageUptodate(ctl.page))
				goto invalid_cache;
		}
		while (ctl.idx < SMB_DIRCACHE_SIZE) {
			struct dentry *dent;
			int res;

			dent = smb_dget_fpos(ctl.cache->dentry[ctl.idx],
					     dentry, filp->f_pos);
			if (!dent)
				goto invalid_cache;

			res = filldir(dirent, dent->d_name.name,
				      dent->d_name.len, filp->f_pos,
				      dent->d_inode->i_ino, DT_UNKNOWN);
			dput(dent);
			if (res)
				goto finished;
			filp->f_pos += 1;
			ctl.idx += 1;
			if (filp->f_pos > ctl.head.end)
				goto finished;
		}
		if (ctl.page) {
			kunmap(ctl.page);
			SetPageUptodate(ctl.page);
			unlock_page(ctl.page);
			page_cache_release(ctl.page);
			ctl.page = NULL;
		}
		ctl.idx  = 0;
		ctl.ofs += 1;
	}
invalid_cache:
	if (ctl.page) {
		kunmap(ctl.page);
		unlock_page(ctl.page);
		page_cache_release(ctl.page);
		ctl.page = NULL;
	}
	ctl.cache = cache;
init_cache:
	smb_invalidate_dircache_entries(dentry);
	ctl.head.time = jiffies;
	ctl.head.eof = 0;
	ctl.fpos = 2;
	ctl.ofs = 0;
	ctl.idx = SMB_DIRCACHE_START;
	ctl.filled = 0;
	ctl.valid  = 1;
read_really:
	result = server->ops->readdir(filp, dirent, filldir, &ctl);
	if (result == -ERESTARTSYS && page)
		ClearPageUptodate(page);
	if (ctl.idx == -1)
		goto invalid_cache;	/* retry */
	ctl.head.end = ctl.fpos - 1;
	ctl.head.eof = ctl.valid;
finished:
	if (page) {
		cache->head = ctl.head;
		kunmap(page);
		if (result != -ERESTARTSYS)
			SetPageUptodate(page);
		unlock_page(page);
		page_cache_release(page);
	}
	if (ctl.page) {
		kunmap(ctl.page);
		SetPageUptodate(ctl.page);
		unlock_page(ctl.page);
		page_cache_release(ctl.page);
	}
out:
	unlock_kernel();
	return result;
}

static int
smb_dir_open(struct inode *dir, struct file *file)
{
	struct dentry *dentry = file->f_path.dentry;
	struct smb_sb_info *server;
	int error = 0;

	VERBOSE("(%s/%s)\n", dentry->d_parent->d_name.name,
		file->f_path.dentry->d_name.name);

	/*
	 * Directory timestamps in the core protocol aren't updated
	 * when a file is added, so we give them a very short TTL.
	 */
	lock_kernel();
	server = server_from_dentry(dentry);
	if (server->opt.protocol < SMB_PROTOCOL_LANMAN2) {
		unsigned long age = jiffies - SMB_I(dir)->oldmtime;
		if (age > 2*HZ)
			smb_invalid_dir_cache(dir);
	}

	/*
	 * Note: in order to allow the smbmount process to open the
	 * mount point, we only revalidate if the connection is valid or
	 * if the process is trying to access something other than the root.
	 */
	if (server->state == CONN_VALID || !IS_ROOT(dentry))
		error = smb_revalidate_inode(dentry);
	unlock_kernel();
	return error;
}

/*
 * Dentry operations routines
 */
static int smb_lookup_validate(struct dentry *, struct nameidata *);
static int smb_hash_dentry(const struct dentry *, const struct inode *,
		struct qstr *);
static int smb_compare_dentry(const struct dentry *,
		const struct inode *,
		const struct dentry *, const struct inode *,
		unsigned int, const char *, const struct qstr *);
static int smb_delete_dentry(const struct dentry *);

static const struct dentry_operations smbfs_dentry_operations =
{
	.d_revalidate	= smb_lookup_validate,
	.d_hash		= smb_hash_dentry,
	.d_compare	= smb_compare_dentry,
	.d_delete	= smb_delete_dentry,
};

static const struct dentry_operations smbfs_dentry_operations_case =
{
	.d_revalidate	= smb_lookup_validate,
	.d_delete	= smb_delete_dentry,
};


/*
 * This is the callback when the dcache has a lookup hit.
 */
static int
smb_lookup_validate(struct dentry *dentry, struct nameidata *nd)
{
	struct smb_sb_info *server;
	struct inode *inode;
	unsigned long age;
	int valid;

	if (nd->flags & LOOKUP_RCU)
		return -ECHILD;

	server = server_from_dentry(dentry);
	inode = dentry->d_inode;
	age = jiffies - dentry->d_time;

	/*
	 * The default validation is based on dentry age:
	 * we believe in dentries for a few seconds.  (But each
	 * successful server lookup renews the timestamp.)
	 */
	valid = (age <= SMB_MAX_AGE(server));
#ifdef SMBFS_DEBUG_VERBOSE
	if (!valid)
		VERBOSE("%s/%s not valid, age=%lu\n", 
			DENTRY_PATH(dentry), age);
#endif

	if (inode) {
		lock_kernel();
		if (is_bad_inode(inode)) {
			PARANOIA("%s/%s has dud inode\n", DENTRY_PATH(dentry));
			valid = 0;
		} else if (!valid)
			valid = (smb_revalidate_inode(dentry) == 0);
		unlock_kernel();
	} else {
		/*
		 * What should we do for negative dentries?
		 */
	}
	return valid;
}

static int 
smb_hash_dentry(const struct dentry *dir, const struct inode *inode,
		struct qstr *this)
{
	unsigned long hash;
	int i;

	hash = init_name_hash();
	for (i=0; i < this->len ; i++)
		hash = partial_name_hash(tolower(this->name[i]), hash);
	this->hash = end_name_hash(hash);
  
	return 0;
}

static int
smb_compare_dentry(const struct dentry *parent,
		const struct inode *pinode,
		const struct dentry *dentry, const struct inode *inode,
		unsigned int len, const char *str, const struct qstr *name)
{
	int i, result = 1;

	if (len != name->len)
		goto out;
	for (i=0; i < len; i++) {
		if (tolower(str[i]) != tolower(name->name[i]))
			goto out;
	}
	result = 0;
out:
	return result;
}

/*
 * This is the callback from dput() when d_count is going to 0.
 * We use this to unhash dentries with bad inodes.
 */
static int
smb_delete_dentry(const struct dentry *dentry)
{
	if (dentry->d_inode) {
		if (is_bad_inode(dentry->d_inode)) {
			PARANOIA("bad inode, unhashing %s/%s\n",
				 DENTRY_PATH(dentry));
			return 1;
		}
	} else {
		/* N.B. Unhash negative dentries? */
	}
	return 0;
}

/*
 * Initialize a new dentry
 */
void
smb_new_dentry(struct dentry *dentry)
{
	struct smb_sb_info *server = server_from_dentry(dentry);

	if (server->mnt->flags & SMB_MOUNT_CASE)
		d_set_d_op(dentry, &smbfs_dentry_operations_case);
	else
		d_set_d_op(dentry, &smbfs_dentry_operations);
	dentry->d_time = jiffies;
}


/*
 * Whenever a lookup succeeds, we know the parent directories
 * are all valid, so we want to update the dentry timestamps.
 * N.B. Move this to dcache?
 */
void
smb_renew_times(struct dentry * dentry)
{
	dget(dentry);
	dentry->d_time = jiffies;

	while (!IS_ROOT(dentry)) {
		struct dentry *parent = dget_parent(dentry);
		dput(dentry);
		dentry = parent;

		dentry->d_time = jiffies;
	}
	dput(dentry);
}

static struct dentry *
smb_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
	struct smb_fattr finfo;
	struct inode *inode;
	int error;
	struct smb_sb_info *server;

	error = -ENAMETOOLONG;
	if (dentry->d_name.len > SMB_MAXNAMELEN)
		goto out;

	/* Do not allow lookup of names with backslashes in */
	error = -EINVAL;
	if (memchr(dentry->d_name.name, '\\', dentry->d_name.len))
		goto out;

	lock_kernel();
	error = smb_proc_getattr(dentry, &finfo);
#ifdef SMBFS_PARANOIA
	if (error && error != -ENOENT)
		PARANOIA("find %s/%s failed, error=%d\n",
			 DENTRY_PATH(dentry), error);
#endif

	inode = NULL;
	if (error == -ENOENT)
		goto add_entry;
	if (!error) {
		error = -EACCES;
		finfo.f_ino = iunique(dentry->d_sb, 2);
		inode = smb_iget(dir->i_sb, &finfo);
		if (inode) {
	add_entry:
			server = server_from_dentry(dentry);
			if (server->mnt->flags & SMB_MOUNT_CASE)
				d_set_d_op(dentry, &smbfs_dentry_operations_case);
			else
				d_set_d_op(dentry, &smbfs_dentry_operations);

			d_add(dentry, inode);
			smb_renew_times(dentry);
			error = 0;
		}
	}
	unlock_kernel();
out:
	return ERR_PTR(error);
}

/*
 * This code is common to all routines creating a new inode.
 */
static int
smb_instantiate(struct dentry *dentry, __u16 fileid, int have_id)
{
	struct smb_sb_info *server = server_from_dentry(dentry);
	struct inode *inode;
	int error;
	struct smb_fattr fattr;

	VERBOSE("file %s/%s, fileid=%u\n", DENTRY_PATH(dentry), fileid);

	error = smb_proc_getattr(dentry, &fattr);
	if (error)
		goto out_close;

	smb_renew_times(dentry);
	fattr.f_ino = iunique(dentry->d_sb, 2);
	inode = smb_iget(dentry->d_sb, &fattr);
	if (!inode)
		goto out_no_inode;

	if (have_id) {
		struct smb_inode_info *ei = SMB_I(inode);
		ei->fileid = fileid;
		ei->access = SMB_O_RDWR;
		ei->open = server->generation;
	}
	d_instantiate(dentry, inode);
out:
	return error;

out_no_inode:
	error = -EACCES;
out_close:
	if (have_id) {
		PARANOIA("%s/%s failed, error=%d, closing %u\n",
			 DENTRY_PATH(dentry), error, fileid);
		smb_close_fileid(dentry, fileid);
	}
	goto out;
}

/* N.B. How should the mode argument be used? */
static int
smb_create(struct inode *dir, struct dentry *dentry, int mode,
		struct nameidata *nd)
{
	struct smb_sb_info *server = server_from_dentry(dentry);
	__u16 fileid;
	int error;
	struct iattr attr;

	VERBOSE("creating %s/%s, mode=%d\n", DENTRY_PATH(dentry), mode);

	lock_kernel();
	smb_invalid_dir_cache(dir);
	error = smb_proc_create(dentry, 0, get_seconds(), &fileid);
	if (!error) {
		if (server->opt.capabilities & SMB_CAP_UNIX) {
			/* Set attributes for new file */
			attr.ia_valid = ATTR_MODE;
			attr.ia_mode = mode;
			error = smb_proc_setattr_unix(dentry, &attr, 0, 0);
		}
		error = smb_instantiate(dentry, fileid, 1);
	} else {
		PARANOIA("%s/%s failed, error=%d\n",
			 DENTRY_PATH(dentry), error);
	}
	unlock_kernel();
	return error;
}

/* N.B. How should the mode argument be used? */
static int
smb_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
	struct smb_sb_info *server = server_from_dentry(dentry);
	int error;
	struct iattr attr;

	lock_kernel();
	smb_invalid_dir_cache(dir);
	error = smb_proc_mkdir(dentry);
	if (!error) {
		if (server->opt.capabilities & SMB_CAP_UNIX) {
			/* Set attributes for new directory */
			attr.ia_valid = ATTR_MODE;
			attr.ia_mode = mode;
			error = smb_proc_setattr_unix(dentry, &attr, 0, 0);
		}
		error = smb_instantiate(dentry, 0, 0);
	}
	unlock_kernel();
	return error;
}

static int
smb_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
	int error;

	/*
	 * Close the directory if it's open.
	 */
	lock_kernel();
	smb_close(inode);

	/*
	 * Check that nobody else is using the directory..
	 */
	error = -EBUSY;
	if (!d_unhashed(dentry))
		goto out;

	smb_invalid_dir_cache(dir);
	error = smb_proc_rmdir(dentry);

out:
	unlock_kernel();
	return error;
}

static int
smb_unlink(struct inode *dir, struct dentry *dentry)
{
	int error;

	/*
	 * Close the file if it's open.
	 */
	lock_kernel();
	smb_close(dentry->d_inode);

	smb_invalid_dir_cache(dir);
	error = smb_proc_unlink(dentry);
	if (!error)
		smb_renew_times(dentry);
	unlock_kernel();
	return error;
}

static int
smb_rename(struct inode *old_dir, struct dentry *old_dentry,
	   struct inode *new_dir, struct dentry *new_dentry)
{
	int error;

	/*
	 * Close any open files, and check whether to delete the
	 * target before attempting the rename.
	 */
	lock_kernel();
	if (old_dentry->d_inode)
		smb_close(old_dentry->d_inode);
	if (new_dentry->d_inode) {
		smb_close(new_dentry->d_inode);
		error = smb_proc_unlink(new_dentry);
		if (error) {
			VERBOSE("unlink %s/%s, error=%d\n",
				DENTRY_PATH(new_dentry), error);
			goto out;
		}
		/* FIXME */
		d_delete(new_dentry);
	}

	smb_invalid_dir_cache(old_dir);
	smb_invalid_dir_cache(new_dir);
	error = smb_proc_mv(old_dentry, new_dentry);
	if (!error) {
		smb_renew_times(old_dentry);
		smb_renew_times(new_dentry);
	}
out:
	unlock_kernel();
	return error;
}

/*
 * FIXME: samba servers won't let you create device nodes unless uid/gid
 * matches the connection credentials (and we don't know which those are ...)
 */
static int
smb_make_node(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
{
	int error;
	struct iattr attr;

	attr.ia_valid = ATTR_MODE | ATTR_UID | ATTR_GID;
	attr.ia_mode = mode;
	current_euid_egid(&attr.ia_uid, &attr.ia_gid);

	if (!new_valid_dev(dev))
		return -EINVAL;

	smb_invalid_dir_cache(dir);
	error = smb_proc_setattr_unix(dentry, &attr, MAJOR(dev), MINOR(dev));
	if (!error) {
		error = smb_instantiate(dentry, 0, 0);
	}
	return error;
}

/*
 * dentry = existing file
 * new_dentry = new file
 */
static int
smb_link(struct dentry *dentry, struct inode *dir, struct dentry *new_dentry)
{
	int error;

	DEBUG1("smb_link old=%s/%s new=%s/%s\n",
	       DENTRY_PATH(dentry), DENTRY_PATH(new_dentry));
	smb_invalid_dir_cache(dir);
	error = smb_proc_link(server_from_dentry(dentry), dentry, new_dentry);
	if (!error) {
		smb_renew_times(dentry);
		error = smb_instantiate(new_dentry, 0, 0);
	}
	return error;
}