summaryrefslogtreecommitdiff
path: root/fs/nilfs2/namei.c
blob: 38d67f3e25bc838468a56ba4b8488d3c4bb47bda (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
/*
 * namei.c - NILFS pathname lookup operations.
 *
 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Modified for NILFS by Amagai Yoshiji <amagai@osrg.net>,
 *                       Ryusuke Konishi <ryusuke@osrg.net>
 */
/*
 *  linux/fs/ext2/namei.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/fs/minix/namei.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  Big-endian to little-endian byte-swapping/bitmaps by
 *        David S. Miller (davem@caip.rutgers.edu), 1995
 */

#include <linux/pagemap.h>
#include "nilfs.h"
#include "export.h"

#define NILFS_FID_SIZE_NON_CONNECTABLE \
	(offsetof(struct nilfs_fid, parent_gen) / 4)
#define NILFS_FID_SIZE_CONNECTABLE	(sizeof(struct nilfs_fid) / 4)

static inline int nilfs_add_nondir(struct dentry *dentry, struct inode *inode)
{
	int err = nilfs_add_link(dentry, inode);
	if (!err) {
		d_instantiate(dentry, inode);
		unlock_new_inode(inode);
		return 0;
	}
	inode_dec_link_count(inode);
	unlock_new_inode(inode);
	iput(inode);
	return err;
}

/*
 * Methods themselves.
 */

static struct dentry *
nilfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
	struct inode *inode;
	ino_t ino;

	if (dentry->d_name.len > NILFS_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);

	ino = nilfs_inode_by_name(dir, &dentry->d_name);
	inode = ino ? nilfs_iget(dir->i_sb, NILFS_I(dir)->i_root, ino) : NULL;
	return d_splice_alias(inode, dentry);
}

/*
 * By the time this is called, we already have created
 * the directory cache entry for the new file, but it
 * is so far negative - it has no inode.
 *
 * If the create succeeds, we fill in the inode information
 * with d_instantiate().
 */
static int nilfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
			bool excl)
{
	struct inode *inode;
	struct nilfs_transaction_info ti;
	int err;

	err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
	if (err)
		return err;
	inode = nilfs_new_inode(dir, mode);
	err = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		inode->i_op = &nilfs_file_inode_operations;
		inode->i_fop = &nilfs_file_operations;
		inode->i_mapping->a_ops = &nilfs_aops;
		nilfs_mark_inode_dirty(inode);
		err = nilfs_add_nondir(dentry, inode);
	}
	if (!err)
		err = nilfs_transaction_commit(dir->i_sb);
	else
		nilfs_transaction_abort(dir->i_sb);

	return err;
}

static int
nilfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
{
	struct inode *inode;
	struct nilfs_transaction_info ti;
	int err;

	err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
	if (err)
		return err;
	inode = nilfs_new_inode(dir, mode);
	err = PTR_ERR(inode);
	if (!IS_ERR(inode)) {
		init_special_inode(inode, inode->i_mode, rdev);
		nilfs_mark_inode_dirty(inode);
		err = nilfs_add_nondir(dentry, inode);
	}
	if (!err)
		err = nilfs_transaction_commit(dir->i_sb);
	else
		nilfs_transaction_abort(dir->i_sb);

	return err;
}

static int nilfs_symlink(struct inode *dir, struct dentry *dentry,
			 const char *symname)
{
	struct nilfs_transaction_info ti;
	struct super_block *sb = dir->i_sb;
	unsigned l = strlen(symname)+1;
	struct inode *inode;
	int err;

	if (l > sb->s_blocksize)
		return -ENAMETOOLONG;

	err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
	if (err)
		return err;

	inode = nilfs_new_inode(dir, S_IFLNK | S_IRWXUGO);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out;

	/* slow symlink */
	inode->i_op = &nilfs_symlink_inode_operations;
	inode_nohighmem(inode);
	inode->i_mapping->a_ops = &nilfs_aops;
	err = page_symlink(inode, symname, l);
	if (err)
		goto out_fail;

	/* mark_inode_dirty(inode); */
	/* page_symlink() do this */

	err = nilfs_add_nondir(dentry, inode);
out:
	if (!err)
		err = nilfs_transaction_commit(dir->i_sb);
	else
		nilfs_transaction_abort(dir->i_sb);

	return err;

out_fail:
	drop_nlink(inode);
	nilfs_mark_inode_dirty(inode);
	unlock_new_inode(inode);
	iput(inode);
	goto out;
}

static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
		      struct dentry *dentry)
{
	struct inode *inode = d_inode(old_dentry);
	struct nilfs_transaction_info ti;
	int err;

	err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
	if (err)
		return err;

	inode->i_ctime = CURRENT_TIME;
	inode_inc_link_count(inode);
	ihold(inode);

	err = nilfs_add_link(dentry, inode);
	if (!err) {
		d_instantiate(dentry, inode);
		err = nilfs_transaction_commit(dir->i_sb);
	} else {
		inode_dec_link_count(inode);
		iput(inode);
		nilfs_transaction_abort(dir->i_sb);
	}

	return err;
}

static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
	struct inode *inode;
	struct nilfs_transaction_info ti;
	int err;

	err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
	if (err)
		return err;

	inc_nlink(dir);

	inode = nilfs_new_inode(dir, S_IFDIR | mode);
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_dir;

	inode->i_op = &nilfs_dir_inode_operations;
	inode->i_fop = &nilfs_dir_operations;
	inode->i_mapping->a_ops = &nilfs_aops;

	inc_nlink(inode);

	err = nilfs_make_empty(inode, dir);
	if (err)
		goto out_fail;

	err = nilfs_add_link(dentry, inode);
	if (err)
		goto out_fail;

	nilfs_mark_inode_dirty(inode);
	d_instantiate(dentry, inode);
	unlock_new_inode(inode);
out:
	if (!err)
		err = nilfs_transaction_commit(dir->i_sb);
	else
		nilfs_transaction_abort(dir->i_sb);

	return err;

out_fail:
	drop_nlink(inode);
	drop_nlink(inode);
	nilfs_mark_inode_dirty(inode);
	unlock_new_inode(inode);
	iput(inode);
out_dir:
	drop_nlink(dir);
	nilfs_mark_inode_dirty(dir);
	goto out;
}

static int nilfs_do_unlink(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode;
	struct nilfs_dir_entry *de;
	struct page *page;
	int err;

	err = -ENOENT;
	de = nilfs_find_entry(dir, &dentry->d_name, &page);
	if (!de)
		goto out;

	inode = d_inode(dentry);
	err = -EIO;
	if (le64_to_cpu(de->inode) != inode->i_ino)
		goto out;

	if (!inode->i_nlink) {
		nilfs_warning(inode->i_sb, __func__,
			      "deleting nonexistent file (%lu), %d\n",
			      inode->i_ino, inode->i_nlink);
		set_nlink(inode, 1);
	}
	err = nilfs_delete_entry(de, page);
	if (err)
		goto out;

	inode->i_ctime = dir->i_ctime;
	drop_nlink(inode);
	err = 0;
out:
	return err;
}

static int nilfs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct nilfs_transaction_info ti;
	int err;

	err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
	if (err)
		return err;

	err = nilfs_do_unlink(dir, dentry);

	if (!err) {
		nilfs_mark_inode_dirty(dir);
		nilfs_mark_inode_dirty(d_inode(dentry));
		err = nilfs_transaction_commit(dir->i_sb);
	} else
		nilfs_transaction_abort(dir->i_sb);

	return err;
}

static int nilfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = d_inode(dentry);
	struct nilfs_transaction_info ti;
	int err;

	err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
	if (err)
		return err;

	err = -ENOTEMPTY;
	if (nilfs_empty_dir(inode)) {
		err = nilfs_do_unlink(dir, dentry);
		if (!err) {
			inode->i_size = 0;
			drop_nlink(inode);
			nilfs_mark_inode_dirty(inode);
			drop_nlink(dir);
			nilfs_mark_inode_dirty(dir);
		}
	}
	if (!err)
		err = nilfs_transaction_commit(dir->i_sb);
	else
		nilfs_transaction_abort(dir->i_sb);

	return err;
}

static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
			struct inode *new_dir,	struct dentry *new_dentry)
{
	struct inode *old_inode = d_inode(old_dentry);
	struct inode *new_inode = d_inode(new_dentry);
	struct page *dir_page = NULL;
	struct nilfs_dir_entry *dir_de = NULL;
	struct page *old_page;
	struct nilfs_dir_entry *old_de;
	struct nilfs_transaction_info ti;
	int err;

	err = nilfs_transaction_begin(old_dir->i_sb, &ti, 1);
	if (unlikely(err))
		return err;

	err = -ENOENT;
	old_de = nilfs_find_entry(old_dir, &old_dentry->d_name, &old_page);
	if (!old_de)
		goto out;

	if (S_ISDIR(old_inode->i_mode)) {
		err = -EIO;
		dir_de = nilfs_dotdot(old_inode, &dir_page);
		if (!dir_de)
			goto out_old;
	}

	if (new_inode) {
		struct page *new_page;
		struct nilfs_dir_entry *new_de;

		err = -ENOTEMPTY;
		if (dir_de && !nilfs_empty_dir(new_inode))
			goto out_dir;

		err = -ENOENT;
		new_de = nilfs_find_entry(new_dir, &new_dentry->d_name, &new_page);
		if (!new_de)
			goto out_dir;
		nilfs_set_link(new_dir, new_de, new_page, old_inode);
		nilfs_mark_inode_dirty(new_dir);
		new_inode->i_ctime = CURRENT_TIME;
		if (dir_de)
			drop_nlink(new_inode);
		drop_nlink(new_inode);
		nilfs_mark_inode_dirty(new_inode);
	} else {
		err = nilfs_add_link(new_dentry, old_inode);
		if (err)
			goto out_dir;
		if (dir_de) {
			inc_nlink(new_dir);
			nilfs_mark_inode_dirty(new_dir);
		}
	}

	/*
	 * Like most other Unix systems, set the ctime for inodes on a
	 * rename.
	 */
	old_inode->i_ctime = CURRENT_TIME;

	nilfs_delete_entry(old_de, old_page);

	if (dir_de) {
		nilfs_set_link(old_inode, dir_de, dir_page, new_dir);
		drop_nlink(old_dir);
	}
	nilfs_mark_inode_dirty(old_dir);
	nilfs_mark_inode_dirty(old_inode);

	err = nilfs_transaction_commit(old_dir->i_sb);
	return err;

out_dir:
	if (dir_de) {
		kunmap(dir_page);
		page_cache_release(dir_page);
	}
out_old:
	kunmap(old_page);
	page_cache_release(old_page);
out:
	nilfs_transaction_abort(old_dir->i_sb);
	return err;
}

/*
 * Export operations
 */
static struct dentry *nilfs_get_parent(struct dentry *child)
{
	unsigned long ino;
	struct inode *inode;
	struct qstr dotdot = QSTR_INIT("..", 2);
	struct nilfs_root *root;

	ino = nilfs_inode_by_name(d_inode(child), &dotdot);
	if (!ino)
		return ERR_PTR(-ENOENT);

	root = NILFS_I(d_inode(child))->i_root;

	inode = nilfs_iget(child->d_sb, root, ino);
	if (IS_ERR(inode))
		return ERR_CAST(inode);

	return d_obtain_alias(inode);
}

static struct dentry *nilfs_get_dentry(struct super_block *sb, u64 cno,
				       u64 ino, u32 gen)
{
	struct nilfs_root *root;
	struct inode *inode;

	if (ino < NILFS_FIRST_INO(sb) && ino != NILFS_ROOT_INO)
		return ERR_PTR(-ESTALE);

	root = nilfs_lookup_root(sb->s_fs_info, cno);
	if (!root)
		return ERR_PTR(-ESTALE);

	inode = nilfs_iget(sb, root, ino);
	nilfs_put_root(root);

	if (IS_ERR(inode))
		return ERR_CAST(inode);
	if (gen && inode->i_generation != gen) {
		iput(inode);
		return ERR_PTR(-ESTALE);
	}
	return d_obtain_alias(inode);
}

static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
					 int fh_len, int fh_type)
{
	struct nilfs_fid *fid = (struct nilfs_fid *)fh;

	if (fh_len < NILFS_FID_SIZE_NON_CONNECTABLE ||
	    (fh_type != FILEID_NILFS_WITH_PARENT &&
	     fh_type != FILEID_NILFS_WITHOUT_PARENT))
		return NULL;

	return nilfs_get_dentry(sb, fid->cno, fid->ino, fid->gen);
}

static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh,
					 int fh_len, int fh_type)
{
	struct nilfs_fid *fid = (struct nilfs_fid *)fh;

	if (fh_len < NILFS_FID_SIZE_CONNECTABLE ||
	    fh_type != FILEID_NILFS_WITH_PARENT)
		return NULL;

	return nilfs_get_dentry(sb, fid->cno, fid->parent_ino, fid->parent_gen);
}

static int nilfs_encode_fh(struct inode *inode, __u32 *fh, int *lenp,
			   struct inode *parent)
{
	struct nilfs_fid *fid = (struct nilfs_fid *)fh;
	struct nilfs_root *root = NILFS_I(inode)->i_root;
	int type;

	if (parent && *lenp < NILFS_FID_SIZE_CONNECTABLE) {
		*lenp = NILFS_FID_SIZE_CONNECTABLE;
		return FILEID_INVALID;
	}
	if (*lenp < NILFS_FID_SIZE_NON_CONNECTABLE) {
		*lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
		return FILEID_INVALID;
	}

	fid->cno = root->cno;
	fid->ino = inode->i_ino;
	fid->gen = inode->i_generation;

	if (parent) {
		fid->parent_ino = parent->i_ino;
		fid->parent_gen = parent->i_generation;
		type = FILEID_NILFS_WITH_PARENT;
		*lenp = NILFS_FID_SIZE_CONNECTABLE;
	} else {
		type = FILEID_NILFS_WITHOUT_PARENT;
		*lenp = NILFS_FID_SIZE_NON_CONNECTABLE;
	}

	return type;
}

const struct inode_operations nilfs_dir_inode_operations = {
	.create		= nilfs_create,
	.lookup		= nilfs_lookup,
	.link		= nilfs_link,
	.unlink		= nilfs_unlink,
	.symlink	= nilfs_symlink,
	.mkdir		= nilfs_mkdir,
	.rmdir		= nilfs_rmdir,
	.mknod		= nilfs_mknod,
	.rename		= nilfs_rename,
	.setattr	= nilfs_setattr,
	.permission	= nilfs_permission,
	.fiemap		= nilfs_fiemap,
};

const struct inode_operations nilfs_special_inode_operations = {
	.setattr	= nilfs_setattr,
	.permission	= nilfs_permission,
};

const struct inode_operations nilfs_symlink_inode_operations = {
	.readlink	= generic_readlink,
	.get_link	= page_get_link,
	.permission     = nilfs_permission,
};

const struct export_operations nilfs_export_ops = {
	.encode_fh = nilfs_encode_fh,
	.fh_to_dentry = nilfs_fh_to_dentry,
	.fh_to_parent = nilfs_fh_to_parent,
	.get_parent = nilfs_get_parent,
};