summaryrefslogtreecommitdiffstats
path: root/fs/quota/quota_v2.c
blob: e69a2bfdd81c050c1ff2653528f803bd402fb399 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 *	vfsv0 quota IO operations on file
 */

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/dqblk_v2.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/quotaops.h>

#include <asm/byteorder.h>

#include "quota_tree.h"
#include "quotaio_v2.h"

MODULE_AUTHOR("Jan Kara");
MODULE_DESCRIPTION("Quota format v2 support");
MODULE_LICENSE("GPL");

static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
static int v2r0_is_id(void *dp, struct dquot *dquot);
static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
static int v2r1_is_id(void *dp, struct dquot *dquot);

static const struct qtree_fmt_operations v2r0_qtree_ops = {
	.mem2disk_dqblk = v2r0_mem2diskdqb,
	.disk2mem_dqblk = v2r0_disk2memdqb,
	.is_id = v2r0_is_id,
};

static const struct qtree_fmt_operations v2r1_qtree_ops = {
	.mem2disk_dqblk = v2r1_mem2diskdqb,
	.disk2mem_dqblk = v2r1_disk2memdqb,
	.is_id = v2r1_is_id,
};

#define QUOTABLOCK_BITS 10
#define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)

static inline qsize_t v2_stoqb(qsize_t space)
{
	return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
}

static inline qsize_t v2_qbtos(qsize_t blocks)
{
	return blocks << QUOTABLOCK_BITS;
}

static int v2_read_header(struct super_block *sb, int type,
			  struct v2_disk_dqheader *dqhead)
{
	ssize_t size;

	size = sb->s_op->quota_read(sb, type, (char *)dqhead,
				    sizeof(struct v2_disk_dqheader), 0);
	if (size != sizeof(struct v2_disk_dqheader)) {
		quota_error(sb, "Failed header read: expected=%zd got=%zd",
			    sizeof(struct v2_disk_dqheader), size);
		if (size < 0)
			return size;
		return -EIO;
	}
	return 0;
}

/* Check whether given file is really vfsv0 quotafile */
static int v2_check_quota_file(struct super_block *sb, int type)
{
	struct v2_disk_dqheader dqhead;
	static const uint quota_magics[] = V2_INITQMAGICS;
	static const uint quota_versions[] = V2_INITQVERSIONS;

	if (v2_read_header(sb, type, &dqhead))
		return 0;
	if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
	    le32_to_cpu(dqhead.dqh_version) > quota_versions[type])
		return 0;
	return 1;
}

/* Read information header from quota file */
static int v2_read_file_info(struct super_block *sb, int type)
{
	struct v2_disk_dqinfo dinfo;
	struct v2_disk_dqheader dqhead;
	struct quota_info *dqopt = sb_dqopt(sb);
	struct mem_dqinfo *info = &dqopt->info[type];
	struct qtree_mem_dqinfo *qinfo;
	ssize_t size;
	unsigned int version;
	int ret;

	down_read(&dqopt->dqio_sem);
	ret = v2_read_header(sb, type, &dqhead);
	if (ret < 0)
		goto out;
	version = le32_to_cpu(dqhead.dqh_version);
	if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
	    (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) {
		ret = -EINVAL;
		goto out;
	}

	size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
	if (size != sizeof(struct v2_disk_dqinfo)) {
		quota_error(sb, "Can't read info structure");
		if (size < 0)
			ret = size;
		else
			ret = -EIO;
		goto out;
	}
	info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
	if (!info->dqi_priv) {
		ret = -ENOMEM;
		goto out;
	}
	qinfo = info->dqi_priv;
	if (version == 0) {
		/* limits are stored as unsigned 32-bit data */
		info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
		info->dqi_max_ino_limit = 0xffffffff;
	} else {
		/*
		 * Used space is stored as unsigned 64-bit value in bytes but
		 * quota core supports only signed 64-bit values so use that
		 * as a limit
		 */
		info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
		info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
	}
	info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
	info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
	/* No flags currently supported */
	info->dqi_flags = 0;
	qinfo->dqi_sb = sb;
	qinfo->dqi_type = type;
	qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
	qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
	qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
	qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
	qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
	qinfo->dqi_qtree_depth = qtree_depth(qinfo);
	if (version == 0) {
		qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
		qinfo->dqi_ops = &v2r0_qtree_ops;
	} else {
		qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
		qinfo->dqi_ops = &v2r1_qtree_ops;
	}
	ret = 0;
out:
	up_read(&dqopt->dqio_sem);
	return ret;
}

/* Write information header to quota file */
static int v2_write_file_info(struct super_block *sb, int type)
{
	struct v2_disk_dqinfo dinfo;
	struct quota_info *dqopt = sb_dqopt(sb);
	struct mem_dqinfo *info = &dqopt->info[type];
	struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
	ssize_t size;

	down_write(&dqopt->dqio_sem);
	spin_lock(&dq_data_lock);
	info->dqi_flags &= ~DQF_INFO_DIRTY;
	dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
	dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
	/* No flags currently supported */
	dinfo.dqi_flags = cpu_to_le32(0);
	spin_unlock(&dq_data_lock);
	dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
	dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
	dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
	size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
	up_write(&dqopt->dqio_sem);
	if (size != sizeof(struct v2_disk_dqinfo)) {
		quota_error(sb, "Can't write info structure");
		return -1;
	}
	return 0;
}

static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
{
	struct v2r0_disk_dqblk *d = dp, empty;
	struct mem_dqblk *m = &dquot->dq_dqb;

	m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
	m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
	m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
	m->dqb_itime = le64_to_cpu(d->dqb_itime);
	m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
	m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
	m->dqb_btime = le64_to_cpu(d->dqb_btime);
	/* We need to escape back all-zero structure */
	memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
	empty.dqb_itime = cpu_to_le64(1);
	if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
		m->dqb_itime = 0;
}

static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
{
	struct v2r0_disk_dqblk *d = dp;
	struct mem_dqblk *m = &dquot->dq_dqb;
	struct qtree_mem_dqinfo *info =
			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;

	d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
	d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
	d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
	d->dqb_itime = cpu_to_le64(m->dqb_itime);
	d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
	d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
	d->dqb_btime = cpu_to_le64(m->dqb_btime);
	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
	if (qtree_entry_unused(info, dp))
		d->dqb_itime = cpu_to_le64(1);
}

static int v2r0_is_id(void *dp, struct dquot *dquot)
{
	struct v2r0_disk_dqblk *d = dp;
	struct qtree_mem_dqinfo *info =
			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;

	if (qtree_entry_unused(info, dp))
		return 0;
	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
				le32_to_cpu(d->dqb_id)),
		      dquot->dq_id);
}

static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
{
	struct v2r1_disk_dqblk *d = dp, empty;
	struct mem_dqblk *m = &dquot->dq_dqb;

	m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
	m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
	m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
	m->dqb_itime = le64_to_cpu(d->dqb_itime);
	m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
	m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
	m->dqb_btime = le64_to_cpu(d->dqb_btime);
	/* We need to escape back all-zero structure */
	memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
	empty.dqb_itime = cpu_to_le64(1);
	if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
		m->dqb_itime = 0;
}

static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
{
	struct v2r1_disk_dqblk *d = dp;
	struct mem_dqblk *m = &dquot->dq_dqb;
	struct qtree_mem_dqinfo *info =
			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;

	d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
	d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
	d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
	d->dqb_itime = cpu_to_le64(m->dqb_itime);
	d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
	d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
	d->dqb_btime = cpu_to_le64(m->dqb_btime);
	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
	d->dqb_pad = 0;
	if (qtree_entry_unused(info, dp))
		d->dqb_itime = cpu_to_le64(1);
}

static int v2r1_is_id(void *dp, struct dquot *dquot)
{
	struct v2r1_disk_dqblk *d = dp;
	struct qtree_mem_dqinfo *info =
			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;

	if (qtree_entry_unused(info, dp))
		return 0;
	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
				le32_to_cpu(d->dqb_id)),
		      dquot->dq_id);
}

static int v2_read_dquot(struct dquot *dquot)
{
	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
	int ret;

	down_read(&dqopt->dqio_sem);
	ret = qtree_read_dquot(
			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
			dquot);
	up_read(&dqopt->dqio_sem);
	return ret;
}

static int v2_write_dquot(struct dquot *dquot)
{
	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
	int ret;
	bool alloc = false;

	/*
	 * If space for dquot is already allocated, we don't need any
	 * protection as we'll only overwrite the place of dquot. We are
	 * still protected by concurrent writes of the same dquot by
	 * dquot->dq_lock.
	 */
	if (!dquot->dq_off) {
		alloc = true;
		down_write(&dqopt->dqio_sem);
	} else {
		down_read(&dqopt->dqio_sem);
	}
	ret = qtree_write_dquot(
			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
			dquot);
	if (alloc)
		up_write(&dqopt->dqio_sem);
	else
		up_read(&dqopt->dqio_sem);
	return ret;
}

static int v2_release_dquot(struct dquot *dquot)
{
	struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
	int ret;

	down_write(&dqopt->dqio_sem);
	ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
	up_write(&dqopt->dqio_sem);

	return ret;
}

static int v2_free_file_info(struct super_block *sb, int type)
{
	kfree(sb_dqinfo(sb, type)->dqi_priv);
	return 0;
}

static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
{
	struct quota_info *dqopt = sb_dqopt(sb);
	int ret;

	down_read(&dqopt->dqio_sem);
	ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
	up_read(&dqopt->dqio_sem);
	return ret;
}

static const struct quota_format_ops v2_format_ops = {
	.check_quota_file	= v2_check_quota_file,
	.read_file_info		= v2_read_file_info,
	.write_file_info	= v2_write_file_info,
	.free_file_info		= v2_free_file_info,
	.read_dqblk		= v2_read_dquot,
	.commit_dqblk		= v2_write_dquot,
	.release_dqblk		= v2_release_dquot,
	.get_next_id		= v2_get_next_id,
};

static struct quota_format_type v2r0_quota_format = {
	.qf_fmt_id	= QFMT_VFS_V0,
	.qf_ops		= &v2_format_ops,
	.qf_owner	= THIS_MODULE
};

static struct quota_format_type v2r1_quota_format = {
	.qf_fmt_id	= QFMT_VFS_V1,
	.qf_ops		= &v2_format_ops,
	.qf_owner	= THIS_MODULE
};

static int __init init_v2_quota_format(void)
{
	int ret;

	ret = register_quota_format(&v2r0_quota_format);
	if (ret)
		return ret;
	return register_quota_format(&v2r1_quota_format);
}

static void __exit exit_v2_quota_format(void)
{
	unregister_quota_format(&v2r0_quota_format);
	unregister_quota_format(&v2r1_quota_format);
}

module_init(init_v2_quota_format);
module_exit(exit_v2_quota_format);