01f25eae684d858d43254fb33e049af30f134fd7
[linux-2.6.git] / 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
20 MODULE_AUTHOR("Jan Kara");
21 MODULE_DESCRIPTION("Quota format v2 support");
22 MODULE_LICENSE("GPL");
23
24 #define __QUOTA_V2_PARANOIA
25
26 static void v2_mem2diskdqb(void *dp, struct dquot *dquot);
27 static void v2_disk2memdqb(struct dquot *dquot, void *dp);
28 static int v2_is_id(void *dp, struct dquot *dquot);
29
30 static struct qtree_fmt_operations v2_qtree_ops = {
31         .mem2disk_dqblk = v2_mem2diskdqb,
32         .disk2mem_dqblk = v2_disk2memdqb,
33         .is_id = v2_is_id,
34 };
35
36 #define QUOTABLOCK_BITS 10
37 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
38
39 static inline qsize_t v2_stoqb(qsize_t space)
40 {
41         return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
42 }
43
44 static inline qsize_t v2_qbtos(qsize_t blocks)
45 {
46         return blocks << QUOTABLOCK_BITS;
47 }
48
49 /* Check whether given file is really vfsv0 quotafile */
50 static int v2_check_quota_file(struct super_block *sb, int type)
51 {
52         struct v2_disk_dqheader dqhead;
53         ssize_t size;
54         static const uint quota_magics[] = V2_INITQMAGICS;
55         static const uint quota_versions[] = V2_INITQVERSIONS;
56  
57         size = sb->s_op->quota_read(sb, type, (char *)&dqhead,
58                                     sizeof(struct v2_disk_dqheader), 0);
59         if (size != sizeof(struct v2_disk_dqheader)) {
60                 printk("quota_v2: failed read expected=%zd got=%zd\n",
61                         sizeof(struct v2_disk_dqheader), size);
62                 return 0;
63         }
64         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
65             le32_to_cpu(dqhead.dqh_version) != quota_versions[type])
66                 return 0;
67         return 1;
68 }
69
70 /* Read information header from quota file */
71 static int v2_read_file_info(struct super_block *sb, int type)
72 {
73         struct v2_disk_dqinfo dinfo;
74         struct mem_dqinfo *info = sb_dqinfo(sb, type);
75         struct qtree_mem_dqinfo *qinfo;
76         ssize_t size;
77
78         size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
79                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
80         if (size != sizeof(struct v2_disk_dqinfo)) {
81                 printk(KERN_WARNING "Can't read info structure on device %s.\n",
82                         sb->s_id);
83                 return -1;
84         }
85         info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
86         if (!info->dqi_priv) {
87                 printk(KERN_WARNING
88                        "Not enough memory for quota information structure.\n");
89                 return -1;
90         }
91         qinfo = info->dqi_priv;
92         /* limits are stored as unsigned 32-bit data */
93         info->dqi_maxblimit = 0xffffffff;
94         info->dqi_maxilimit = 0xffffffff;
95         info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
96         info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
97         info->dqi_flags = le32_to_cpu(dinfo.dqi_flags);
98         qinfo->dqi_sb = sb;
99         qinfo->dqi_type = type;
100         qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
101         qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
102         qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
103         qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
104         qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
105         qinfo->dqi_qtree_depth = qtree_depth(qinfo);
106         qinfo->dqi_entry_size = sizeof(struct v2_disk_dqblk);
107         qinfo->dqi_ops = &v2_qtree_ops;
108         return 0;
109 }
110
111 /* Write information header to quota file */
112 static int v2_write_file_info(struct super_block *sb, int type)
113 {
114         struct v2_disk_dqinfo dinfo;
115         struct mem_dqinfo *info = sb_dqinfo(sb, type);
116         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
117         ssize_t size;
118
119         spin_lock(&dq_data_lock);
120         info->dqi_flags &= ~DQF_INFO_DIRTY;
121         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
122         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
123         dinfo.dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
124         spin_unlock(&dq_data_lock);
125         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
126         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
127         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
128         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
129                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
130         if (size != sizeof(struct v2_disk_dqinfo)) {
131                 printk(KERN_WARNING "Can't write info structure on device %s.\n",
132                         sb->s_id);
133                 return -1;
134         }
135         return 0;
136 }
137
138 static void v2_disk2memdqb(struct dquot *dquot, void *dp)
139 {
140         struct v2_disk_dqblk *d = dp, empty;
141         struct mem_dqblk *m = &dquot->dq_dqb;
142
143         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
144         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
145         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
146         m->dqb_itime = le64_to_cpu(d->dqb_itime);
147         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
148         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
149         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
150         m->dqb_btime = le64_to_cpu(d->dqb_btime);
151         /* We need to escape back all-zero structure */
152         memset(&empty, 0, sizeof(struct v2_disk_dqblk));
153         empty.dqb_itime = cpu_to_le64(1);
154         if (!memcmp(&empty, dp, sizeof(struct v2_disk_dqblk)))
155                 m->dqb_itime = 0;
156 }
157
158 static void v2_mem2diskdqb(void *dp, struct dquot *dquot)
159 {
160         struct v2_disk_dqblk *d = dp;
161         struct mem_dqblk *m = &dquot->dq_dqb;
162         struct qtree_mem_dqinfo *info =
163                         sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
164
165         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
166         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
167         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
168         d->dqb_itime = cpu_to_le64(m->dqb_itime);
169         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
170         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
171         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
172         d->dqb_btime = cpu_to_le64(m->dqb_btime);
173         d->dqb_id = cpu_to_le32(dquot->dq_id);
174         if (qtree_entry_unused(info, dp))
175                 d->dqb_itime = cpu_to_le64(1);
176 }
177
178 static int v2_is_id(void *dp, struct dquot *dquot)
179 {
180         struct v2_disk_dqblk *d = dp;
181         struct qtree_mem_dqinfo *info =
182                         sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
183
184         if (qtree_entry_unused(info, dp))
185                 return 0;
186         return le32_to_cpu(d->dqb_id) == dquot->dq_id;
187 }
188
189 static int v2_read_dquot(struct dquot *dquot)
190 {
191         return qtree_read_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
192 }
193
194 static int v2_write_dquot(struct dquot *dquot)
195 {
196         return qtree_write_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
197 }
198
199 static int v2_release_dquot(struct dquot *dquot)
200 {
201         return qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
202 }
203
204 static int v2_free_file_info(struct super_block *sb, int type)
205 {
206         kfree(sb_dqinfo(sb, type)->dqi_priv);
207         return 0;
208 }
209
210 static const struct quota_format_ops v2_format_ops = {
211         .check_quota_file       = v2_check_quota_file,
212         .read_file_info         = v2_read_file_info,
213         .write_file_info        = v2_write_file_info,
214         .free_file_info         = v2_free_file_info,
215         .read_dqblk             = v2_read_dquot,
216         .commit_dqblk           = v2_write_dquot,
217         .release_dqblk          = v2_release_dquot,
218 };
219
220 static struct quota_format_type v2_quota_format = {
221         .qf_fmt_id      = QFMT_VFS_V0,
222         .qf_ops         = &v2_format_ops,
223         .qf_owner       = THIS_MODULE
224 };
225
226 static int __init init_v2_quota_format(void)
227 {
228         return register_quota_format(&v2_quota_format);
229 }
230
231 static void __exit exit_v2_quota_format(void)
232 {
233         unregister_quota_format(&v2_quota_format);
234 }
235
236 module_init(init_v2_quota_format);
237 module_exit(exit_v2_quota_format);