Root/fs/quota/quota_v2.c

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_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

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