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