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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/fs/quota/
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 -1;
116	}
117	qinfo = info->dqi_priv;
118	if (version == 0) {
119		/* limits are stored as unsigned 32-bit data */
120		info->dqi_maxblimit = 0xffffffff;
121		info->dqi_maxilimit = 0xffffffff;
122	} else {
123		/* used space is stored as unsigned 64-bit value */
124		info->dqi_maxblimit = 0xffffffffffffffffULL;	/* 2^64-1 */
125		info->dqi_maxilimit = 0xffffffffffffffffULL;
126	}
127	info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
128	info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
129	info->dqi_flags = le32_to_cpu(dinfo.dqi_flags);
130	qinfo->dqi_sb = sb;
131	qinfo->dqi_type = type;
132	qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
133	qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
134	qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
135	qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
136	qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
137	qinfo->dqi_qtree_depth = qtree_depth(qinfo);
138	if (version == 0) {
139		qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
140		qinfo->dqi_ops = &v2r0_qtree_ops;
141	} else {
142		qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
143		qinfo->dqi_ops = &v2r1_qtree_ops;
144	}
145	return 0;
146}
147
148/* Write information header to quota file */
149static int v2_write_file_info(struct super_block *sb, int type)
150{
151	struct v2_disk_dqinfo dinfo;
152	struct mem_dqinfo *info = sb_dqinfo(sb, type);
153	struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
154	ssize_t size;
155
156	spin_lock(&dq_data_lock);
157	info->dqi_flags &= ~DQF_INFO_DIRTY;
158	dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
159	dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
160	dinfo.dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
161	spin_unlock(&dq_data_lock);
162	dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
163	dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
164	dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
165	size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
166	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
167	if (size != sizeof(struct v2_disk_dqinfo)) {
168		quota_error(sb, "Can't write info structure");
169		return -1;
170	}
171	return 0;
172}
173
174static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
175{
176	struct v2r0_disk_dqblk *d = dp, empty;
177	struct mem_dqblk *m = &dquot->dq_dqb;
178
179	m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
180	m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
181	m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
182	m->dqb_itime = le64_to_cpu(d->dqb_itime);
183	m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
184	m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
185	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
186	m->dqb_btime = le64_to_cpu(d->dqb_btime);
187	/* We need to escape back all-zero structure */
188	memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
189	empty.dqb_itime = cpu_to_le64(1);
190	if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
191		m->dqb_itime = 0;
192}
193
194static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
195{
196	struct v2r0_disk_dqblk *d = dp;
197	struct mem_dqblk *m = &dquot->dq_dqb;
198	struct qtree_mem_dqinfo *info =
199			sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
200
201	d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
202	d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
203	d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
204	d->dqb_itime = cpu_to_le64(m->dqb_itime);
205	d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
206	d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
207	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
208	d->dqb_btime = cpu_to_le64(m->dqb_btime);
209	d->dqb_id = cpu_to_le32(dquot->dq_id);
210	if (qtree_entry_unused(info, dp))
211		d->dqb_itime = cpu_to_le64(1);
212}
213
214static int v2r0_is_id(void *dp, struct dquot *dquot)
215{
216	struct v2r0_disk_dqblk *d = dp;
217	struct qtree_mem_dqinfo *info =
218			sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
219
220	if (qtree_entry_unused(info, dp))
221		return 0;
222	return le32_to_cpu(d->dqb_id) == dquot->dq_id;
223}
224
225static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
226{
227	struct v2r1_disk_dqblk *d = dp, empty;
228	struct mem_dqblk *m = &dquot->dq_dqb;
229
230	m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
231	m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
232	m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
233	m->dqb_itime = le64_to_cpu(d->dqb_itime);
234	m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
235	m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
236	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
237	m->dqb_btime = le64_to_cpu(d->dqb_btime);
238	/* We need to escape back all-zero structure */
239	memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
240	empty.dqb_itime = cpu_to_le64(1);
241	if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
242		m->dqb_itime = 0;
243}
244
245static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
246{
247	struct v2r1_disk_dqblk *d = dp;
248	struct mem_dqblk *m = &dquot->dq_dqb;
249	struct qtree_mem_dqinfo *info =
250			sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
251
252	d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
253	d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
254	d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
255	d->dqb_itime = cpu_to_le64(m->dqb_itime);
256	d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
257	d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
258	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
259	d->dqb_btime = cpu_to_le64(m->dqb_btime);
260	d->dqb_id = cpu_to_le32(dquot->dq_id);
261	if (qtree_entry_unused(info, dp))
262		d->dqb_itime = cpu_to_le64(1);
263}
264
265static int v2r1_is_id(void *dp, struct dquot *dquot)
266{
267	struct v2r1_disk_dqblk *d = dp;
268	struct qtree_mem_dqinfo *info =
269			sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
270
271	if (qtree_entry_unused(info, dp))
272		return 0;
273	return le32_to_cpu(d->dqb_id) == dquot->dq_id;
274}
275
276static int v2_read_dquot(struct dquot *dquot)
277{
278	return qtree_read_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
279}
280
281static int v2_write_dquot(struct dquot *dquot)
282{
283	return qtree_write_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
284}
285
286static int v2_release_dquot(struct dquot *dquot)
287{
288	return qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
289}
290
291static int v2_free_file_info(struct super_block *sb, int type)
292{
293	kfree(sb_dqinfo(sb, type)->dqi_priv);
294	return 0;
295}
296
297static const struct quota_format_ops v2_format_ops = {
298	.check_quota_file	= v2_check_quota_file,
299	.read_file_info		= v2_read_file_info,
300	.write_file_info	= v2_write_file_info,
301	.free_file_info		= v2_free_file_info,
302	.read_dqblk		= v2_read_dquot,
303	.commit_dqblk		= v2_write_dquot,
304	.release_dqblk		= v2_release_dquot,
305};
306
307static struct quota_format_type v2r0_quota_format = {
308	.qf_fmt_id	= QFMT_VFS_V0,
309	.qf_ops		= &v2_format_ops,
310	.qf_owner	= THIS_MODULE
311};
312
313static struct quota_format_type v2r1_quota_format = {
314	.qf_fmt_id	= QFMT_VFS_V1,
315	.qf_ops		= &v2_format_ops,
316	.qf_owner	= THIS_MODULE
317};
318
319static int __init init_v2_quota_format(void)
320{
321	int ret;
322
323	ret = register_quota_format(&v2r0_quota_format);
324	if (ret)
325		return ret;
326	return register_quota_format(&v2r1_quota_format);
327}
328
329static void __exit exit_v2_quota_format(void)
330{
331	unregister_quota_format(&v2r0_quota_format);
332	unregister_quota_format(&v2r1_quota_format);
333}
334
335module_init(init_v2_quota_format);
336module_exit(exit_v2_quota_format);
337