quota: Coding style fixes
[linux-2.6.git] / fs / quota / quota_v1.c
1 #include <linux/errno.h>
2 #include <linux/fs.h>
3 #include <linux/quota.h>
4 #include <linux/quotaops.h>
5 #include <linux/dqblk_v1.h>
6 #include <linux/kernel.h>
7 #include <linux/init.h>
8 #include <linux/module.h>
9
10 #include <asm/byteorder.h>
11
12 #include "quotaio_v1.h"
13
14 MODULE_AUTHOR("Jan Kara");
15 MODULE_DESCRIPTION("Old quota format support");
16 MODULE_LICENSE("GPL");
17
18 #define QUOTABLOCK_BITS 10
19 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
20
21 static inline qsize_t v1_stoqb(qsize_t space)
22 {
23         return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
24 }
25
26 static inline qsize_t v1_qbtos(qsize_t blocks)
27 {
28         return blocks << QUOTABLOCK_BITS;
29 }
30
31 static void v1_disk2mem_dqblk(struct mem_dqblk *m, struct v1_disk_dqblk *d)
32 {
33         m->dqb_ihardlimit = d->dqb_ihardlimit;
34         m->dqb_isoftlimit = d->dqb_isoftlimit;
35         m->dqb_curinodes = d->dqb_curinodes;
36         m->dqb_bhardlimit = v1_qbtos(d->dqb_bhardlimit);
37         m->dqb_bsoftlimit = v1_qbtos(d->dqb_bsoftlimit);
38         m->dqb_curspace = v1_qbtos(d->dqb_curblocks);
39         m->dqb_itime = d->dqb_itime;
40         m->dqb_btime = d->dqb_btime;
41 }
42
43 static void v1_mem2disk_dqblk(struct v1_disk_dqblk *d, struct mem_dqblk *m)
44 {
45         d->dqb_ihardlimit = m->dqb_ihardlimit;
46         d->dqb_isoftlimit = m->dqb_isoftlimit;
47         d->dqb_curinodes = m->dqb_curinodes;
48         d->dqb_bhardlimit = v1_stoqb(m->dqb_bhardlimit);
49         d->dqb_bsoftlimit = v1_stoqb(m->dqb_bsoftlimit);
50         d->dqb_curblocks = v1_stoqb(m->dqb_curspace);
51         d->dqb_itime = m->dqb_itime;
52         d->dqb_btime = m->dqb_btime;
53 }
54
55 static int v1_read_dqblk(struct dquot *dquot)
56 {
57         int type = dquot->dq_type;
58         struct v1_disk_dqblk dqblk;
59
60         if (!sb_dqopt(dquot->dq_sb)->files[type])
61                 return -EINVAL;
62
63         /* Set structure to 0s in case read fails/is after end of file */
64         memset(&dqblk, 0, sizeof(struct v1_disk_dqblk));
65         dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk,
66                         sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id));
67
68         v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
69         if (dquot->dq_dqb.dqb_bhardlimit == 0 &&
70             dquot->dq_dqb.dqb_bsoftlimit == 0 &&
71             dquot->dq_dqb.dqb_ihardlimit == 0 &&
72             dquot->dq_dqb.dqb_isoftlimit == 0)
73                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
74         dqstats.reads++;
75
76         return 0;
77 }
78
79 static int v1_commit_dqblk(struct dquot *dquot)
80 {
81         short type = dquot->dq_type;
82         ssize_t ret;
83         struct v1_disk_dqblk dqblk;
84
85         v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
86         if (dquot->dq_id == 0) {
87                 dqblk.dqb_btime =
88                         sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
89                 dqblk.dqb_itime =
90                         sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
91         }
92         ret = 0;
93         if (sb_dqopt(dquot->dq_sb)->files[type])
94                 ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type,
95                         (char *)&dqblk, sizeof(struct v1_disk_dqblk),
96                         v1_dqoff(dquot->dq_id));
97         if (ret != sizeof(struct v1_disk_dqblk)) {
98                 printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
99                         dquot->dq_sb->s_id);
100                 if (ret >= 0)
101                         ret = -EIO;
102                 goto out;
103         }
104         ret = 0;
105
106 out:
107         dqstats.writes++;
108
109         return ret;
110 }
111
112 /* Magics of new quota format */
113 #define V2_INITQMAGICS {\
114         0xd9c01f11,     /* USRQUOTA */\
115         0xd9c01927      /* GRPQUOTA */\
116 }
117
118 /* Header of new quota format */
119 struct v2_disk_dqheader {
120         __le32 dqh_magic;        /* Magic number identifying file */
121         __le32 dqh_version;      /* File version */
122 };
123
124 static int v1_check_quota_file(struct super_block *sb, int type)
125 {
126         struct inode *inode = sb_dqopt(sb)->files[type];
127         ulong blocks;
128         size_t off; 
129         struct v2_disk_dqheader dqhead;
130         ssize_t size;
131         loff_t isize;
132         static const uint quota_magics[] = V2_INITQMAGICS;
133
134         isize = i_size_read(inode);
135         if (!isize)
136                 return 0;
137         blocks = isize >> BLOCK_SIZE_BITS;
138         off = isize & (BLOCK_SIZE - 1);
139         if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) %
140             sizeof(struct v1_disk_dqblk))
141                 return 0;
142         /* Doublecheck whether we didn't get file with new format - with old
143          * quotactl() this could happen */
144         size = sb->s_op->quota_read(sb, type, (char *)&dqhead,
145                                     sizeof(struct v2_disk_dqheader), 0);
146         if (size != sizeof(struct v2_disk_dqheader))
147                 return 1;       /* Probably not new format */
148         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
149                 return 1;       /* Definitely not new format */
150         printk(KERN_INFO
151                "VFS: %s: Refusing to turn on old quota format on given file."
152                " It probably contains newer quota format.\n", sb->s_id);
153         return 0;               /* Seems like a new format file -> refuse it */
154 }
155
156 static int v1_read_file_info(struct super_block *sb, int type)
157 {
158         struct quota_info *dqopt = sb_dqopt(sb);
159         struct v1_disk_dqblk dqblk;
160         int ret;
161
162         ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
163                                 sizeof(struct v1_disk_dqblk), v1_dqoff(0));
164         if (ret != sizeof(struct v1_disk_dqblk)) {
165                 if (ret >= 0)
166                         ret = -EIO;
167                 goto out;
168         }
169         ret = 0;
170         /* limits are stored as unsigned 32-bit data */
171         dqopt->info[type].dqi_maxblimit = 0xffffffff;
172         dqopt->info[type].dqi_maxilimit = 0xffffffff;
173         dqopt->info[type].dqi_igrace =
174                         dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
175         dqopt->info[type].dqi_bgrace =
176                         dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
177 out:
178         return ret;
179 }
180
181 static int v1_write_file_info(struct super_block *sb, int type)
182 {
183         struct quota_info *dqopt = sb_dqopt(sb);
184         struct v1_disk_dqblk dqblk;
185         int ret;
186
187         dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
188         ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
189                                 sizeof(struct v1_disk_dqblk), v1_dqoff(0));
190         if (ret != sizeof(struct v1_disk_dqblk)) {
191                 if (ret >= 0)
192                         ret = -EIO;
193                 goto out;
194         }
195         dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
196         dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
197         ret = sb->s_op->quota_write(sb, type, (char *)&dqblk,
198               sizeof(struct v1_disk_dqblk), v1_dqoff(0));
199         if (ret == sizeof(struct v1_disk_dqblk))
200                 ret = 0;
201         else if (ret > 0)
202                 ret = -EIO;
203 out:
204         return ret;
205 }
206
207 static struct quota_format_ops v1_format_ops = {
208         .check_quota_file       = v1_check_quota_file,
209         .read_file_info         = v1_read_file_info,
210         .write_file_info        = v1_write_file_info,
211         .free_file_info         = NULL,
212         .read_dqblk             = v1_read_dqblk,
213         .commit_dqblk           = v1_commit_dqblk,
214 };
215
216 static struct quota_format_type v1_quota_format = {
217         .qf_fmt_id      = QFMT_VFS_OLD,
218         .qf_ops         = &v1_format_ops,
219         .qf_owner       = THIS_MODULE
220 };
221
222 static int __init init_v1_quota_format(void)
223 {
224         return register_quota_format(&v1_quota_format);
225 }
226
227 static void __exit exit_v1_quota_format(void)
228 {
229         unregister_quota_format(&v1_quota_format);
230 }
231
232 module_init(init_v1_quota_format);
233 module_exit(exit_v1_quota_format);
234