1/*
2 *	vfsv0 quota IO operations on file
3 */
4
5#include <linux/errno.h>
6#include <linux/fs.h>
7#include <linux/mount.h>
8#include <linux/dqblk_v2.h>
9#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/quotaops.h>
14
15#include <asm/byteorder.h>
16
17#include "quota_tree.h"
18#include "quotaio_v2.h"
19
20MODULE_AUTHOR("Jan Kara");
21MODULE_DESCRIPTION("Quota format v2 support");
22MODULE_LICENSE("GPL");
23
24#define __QUOTA_V2_PARANOIA
25
26static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
27static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
28static int v2r0_is_id(void *dp, struct dquot *dquot);
29static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
30static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
31static int v2r1_is_id(void *dp, struct dquot *dquot);
32
33static struct qtree_fmt_operations v2r0_qtree_ops = {
34	.mem2disk_dqblk = v2r0_mem2diskdqb,
35	.disk2mem_dqblk = v2r0_disk2memdqb,
36	.is_id = v2r0_is_id,
37};
38
39static struct qtree_fmt_operations v2r1_qtree_ops = {
40	.mem2disk_dqblk = v2r1_mem2diskdqb,
41	.disk2mem_dqblk = v2r1_disk2memdqb,
42	.is_id = v2r1_is_id,
43};
44
45#define QUOTABLOCK_BITS 10
46#define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
47
48static inline qsize_t v2_stoqb(qsize_t space)
49{
50	return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
51}
52
53static inline qsize_t v2_qbtos(qsize_t blocks)
54{
55	return blocks << QUOTABLOCK_BITS;
56}
57
58static int v2_read_header(struct super_block *sb, int type,
59			  struct v2_disk_dqheader *dqhead)
60{
61	ssize_t size;
62
63	size = sb->s_op->quota_read(sb, type, (char *)dqhead,
64				    sizeof(struct v2_disk_dqheader), 0);
65	if (size != sizeof(struct v2_disk_dqheader)) {
66		quota_error(sb, "Failed header read: expected=%zd got=%zd",
67			    sizeof(struct v2_disk_dqheader), size);
68		return 0;
69	}
70	return 1;
71}
72
73/* Check whether given file is really vfsv0 quotafile */
74static int v2_check_quota_file(struct super_block *sb, int type)
75{
76	struct v2_disk_dqheader dqhead;
77	static const uint quota_magics[] = V2_INITQMAGICS;
78	static const uint quota_versions[] = V2_INITQVERSIONS;
79
80	if (!v2_read_header(sb, type, &dqhead))
81		return 0;
82	if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
83	    le32_to_cpu(dqhead.dqh_version) > quota_versions[type])
84		return 0;
85	return 1;
86}
87
88/* Read information header from quota file */
89static int v2_read_file_info(struct super_block *sb, int type)
90{
91	struct v2_disk_dqinfo dinfo;
92	struct v2_disk_dqheader dqhead;
93	struct mem_dqinfo *info = sb_dqinfo(sb, type);
94	struct qtree_mem_dqinfo *qinfo;
95	ssize_t size;
96	unsigned int version;
97
98	if (!v2_read_header(sb, type, &dqhead))
99		return -1;
100	version = le32_to_cpu(dqhead.dqh_version);
101	if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
102	    (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1))
103		return -1;
104
105	size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
106	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
107	if (size != sizeof(struct v2_disk_dqinfo)) {
108		quota_error(sb, "Can't read info structure");
109		return -1;
110	}
111	info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
112	if (!info->dqi_priv) {
113		printk(KERN_WARNING
114		       "Not enough memory for quota information structure.\n");
115		return -ENOMEM;
116	}
117	qinfo = info->dqi_priv;
118	if (version == 0) {
119		/* limits are stored as unsigned 32-bit data */
120		info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
121		info->dqi_max_ino_limit = 0xffffffff;
122	} else {
123		/*
124		 * Used space is stored as unsigned 64-bit value in bytes but
125		 * quota core supports only signed 64-bit values so use that
126		 * as a limit
127		 */
128		info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
129		info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
130	}
131	info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
132	info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
133	/* No flags currently supported */
134	info->dqi_flags = 0;
135	qinfo->dqi_sb = sb;
136	qinfo->dqi_type = type;
137	qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
138	qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
139	qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
140	qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
141	qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
142	qinfo->dqi_qtree_depth = qtree_depth(qinfo);
143	if (version == 0) {
144		qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
145		qinfo->dqi_ops = &v2r0_qtree_ops;
146	} else {
147		qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
148		qinfo->dqi_ops = &v2r1_qtree_ops;
149	}
150	return 0;
151}
152
153/* Write information header to quota file */
154static int v2_write_file_info(struct super_block *sb, int type)
155{
156	struct v2_disk_dqinfo dinfo;
157	struct mem_dqinfo *info = sb_dqinfo(sb, type);
158	struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
159	ssize_t size;
160
161	spin_lock(&dq_data_lock);
162	info->dqi_flags &= ~DQF_INFO_DIRTY;
163	dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
164	dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
165	/* No flags currently supported */
166	dinfo.dqi_flags = cpu_to_le32(0);
167	spin_unlock(&dq_data_lock);
168	dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
169	dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
170	dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
171	size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
172	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
173	if (size != sizeof(struct v2_disk_dqinfo)) {
174		quota_error(sb, "Can't write info structure");
175		return -1;
176	}
177	return 0;
178}
179
180static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
181{
182	struct v2r0_disk_dqblk *d = dp, empty;
183	struct mem_dqblk *m = &dquot->dq_dqb;
184
185	m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
186	m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
187	m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
188	m->dqb_itime = le64_to_cpu(d->dqb_itime);
189	m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
190	m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
191	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
192	m->dqb_btime = le64_to_cpu(d->dqb_btime);
193	/* We need to escape back all-zero structure */
194	memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
195	empty.dqb_itime = cpu_to_le64(1);
196	if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
197		m->dqb_itime = 0;
198}
199
200static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
201{
202	struct v2r0_disk_dqblk *d = dp;
203	struct mem_dqblk *m = &dquot->dq_dqb;
204	struct qtree_mem_dqinfo *info =
205			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
206
207	d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
208	d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
209	d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
210	d->dqb_itime = cpu_to_le64(m->dqb_itime);
211	d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
212	d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
213	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
214	d->dqb_btime = cpu_to_le64(m->dqb_btime);
215	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
216	if (qtree_entry_unused(info, dp))
217		d->dqb_itime = cpu_to_le64(1);
218}
219
220static int v2r0_is_id(void *dp, struct dquot *dquot)
221{
222	struct v2r0_disk_dqblk *d = dp;
223	struct qtree_mem_dqinfo *info =
224			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
225
226	if (qtree_entry_unused(info, dp))
227		return 0;
228	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
229				le32_to_cpu(d->dqb_id)),
230		      dquot->dq_id);
231}
232
233static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
234{
235	struct v2r1_disk_dqblk *d = dp, empty;
236	struct mem_dqblk *m = &dquot->dq_dqb;
237
238	m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
239	m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
240	m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
241	m->dqb_itime = le64_to_cpu(d->dqb_itime);
242	m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
243	m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
244	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
245	m->dqb_btime = le64_to_cpu(d->dqb_btime);
246	/* We need to escape back all-zero structure */
247	memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
248	empty.dqb_itime = cpu_to_le64(1);
249	if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
250		m->dqb_itime = 0;
251}
252
253static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
254{
255	struct v2r1_disk_dqblk *d = dp;
256	struct mem_dqblk *m = &dquot->dq_dqb;
257	struct qtree_mem_dqinfo *info =
258			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
259
260	d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
261	d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
262	d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
263	d->dqb_itime = cpu_to_le64(m->dqb_itime);
264	d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
265	d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
266	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
267	d->dqb_btime = cpu_to_le64(m->dqb_btime);
268	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
269	if (qtree_entry_unused(info, dp))
270		d->dqb_itime = cpu_to_le64(1);
271}
272
273static int v2r1_is_id(void *dp, struct dquot *dquot)
274{
275	struct v2r1_disk_dqblk *d = dp;
276	struct qtree_mem_dqinfo *info =
277			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
278
279	if (qtree_entry_unused(info, dp))
280		return 0;
281	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
282				le32_to_cpu(d->dqb_id)),
283		      dquot->dq_id);
284}
285
286static int v2_read_dquot(struct dquot *dquot)
287{
288	return qtree_read_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
289}
290
291static int v2_write_dquot(struct dquot *dquot)
292{
293	return qtree_write_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
294}
295
296static int v2_release_dquot(struct dquot *dquot)
297{
298	return qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
299}
300
301static int v2_free_file_info(struct super_block *sb, int type)
302{
303	kfree(sb_dqinfo(sb, type)->dqi_priv);
304	return 0;
305}
306
307static const struct quota_format_ops v2_format_ops = {
308	.check_quota_file	= v2_check_quota_file,
309	.read_file_info		= v2_read_file_info,
310	.write_file_info	= v2_write_file_info,
311	.free_file_info		= v2_free_file_info,
312	.read_dqblk		= v2_read_dquot,
313	.commit_dqblk		= v2_write_dquot,
314	.release_dqblk		= v2_release_dquot,
315};
316
317static struct quota_format_type v2r0_quota_format = {
318	.qf_fmt_id	= QFMT_VFS_V0,
319	.qf_ops		= &v2_format_ops,
320	.qf_owner	= THIS_MODULE
321};
322
323static struct quota_format_type v2r1_quota_format = {
324	.qf_fmt_id	= QFMT_VFS_V1,
325	.qf_ops		= &v2_format_ops,
326	.qf_owner	= THIS_MODULE
327};
328
329static int __init init_v2_quota_format(void)
330{
331	int ret;
332
333	ret = register_quota_format(&v2r0_quota_format);
334	if (ret)
335		return ret;
336	return register_quota_format(&v2r1_quota_format);
337}
338
339static void __exit exit_v2_quota_format(void)
340{
341	unregister_quota_format(&v2r0_quota_format);
342	unregister_quota_format(&v2r1_quota_format);
343}
344
345module_init(init_v2_quota_format);
346module_exit(exit_v2_quota_format);
347