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
v1_stoqb(qsize_t space)21 static inline qsize_t v1_stoqb(qsize_t space)
22 {
23 return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
24 }
25
v1_qbtos(qsize_t blocks)26 static inline qsize_t v1_qbtos(qsize_t blocks)
27 {
28 return blocks << QUOTABLOCK_BITS;
29 }
30
v1_disk2mem_dqblk(struct mem_dqblk * m,struct v1_disk_dqblk * d)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
v1_mem2disk_dqblk(struct v1_disk_dqblk * d,struct mem_dqblk * m)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
v1_read_dqblk(struct dquot * dquot)55 static int v1_read_dqblk(struct dquot *dquot)
56 {
57 int type = dquot->dq_id.type;
58 struct v1_disk_dqblk dqblk;
59 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
60
61 if (!dqopt->files[type])
62 return -EINVAL;
63
64 /* Set structure to 0s in case read fails/is after end of file */
65 memset(&dqblk, 0, sizeof(struct v1_disk_dqblk));
66 dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk,
67 sizeof(struct v1_disk_dqblk),
68 v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id)));
69
70 v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
71 if (dquot->dq_dqb.dqb_bhardlimit == 0 &&
72 dquot->dq_dqb.dqb_bsoftlimit == 0 &&
73 dquot->dq_dqb.dqb_ihardlimit == 0 &&
74 dquot->dq_dqb.dqb_isoftlimit == 0)
75 set_bit(DQ_FAKE_B, &dquot->dq_flags);
76 dqstats_inc(DQST_READS);
77
78 return 0;
79 }
80
v1_commit_dqblk(struct dquot * dquot)81 static int v1_commit_dqblk(struct dquot *dquot)
82 {
83 short type = dquot->dq_id.type;
84 ssize_t ret;
85 struct v1_disk_dqblk dqblk;
86
87 v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
88 if (((type == USRQUOTA) && uid_eq(dquot->dq_id.uid, GLOBAL_ROOT_UID)) ||
89 ((type == GRPQUOTA) && gid_eq(dquot->dq_id.gid, GLOBAL_ROOT_GID))) {
90 dqblk.dqb_btime =
91 sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
92 dqblk.dqb_itime =
93 sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
94 }
95 ret = 0;
96 if (sb_dqopt(dquot->dq_sb)->files[type])
97 ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type,
98 (char *)&dqblk, sizeof(struct v1_disk_dqblk),
99 v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id)));
100 if (ret != sizeof(struct v1_disk_dqblk)) {
101 quota_error(dquot->dq_sb, "dquota write failed");
102 if (ret >= 0)
103 ret = -EIO;
104 goto out;
105 }
106 ret = 0;
107
108 out:
109 dqstats_inc(DQST_WRITES);
110
111 return ret;
112 }
113
114 /* Magics of new quota format */
115 #define V2_INITQMAGICS {\
116 0xd9c01f11, /* USRQUOTA */\
117 0xd9c01927 /* GRPQUOTA */\
118 }
119
120 /* Header of new quota format */
121 struct v2_disk_dqheader {
122 __le32 dqh_magic; /* Magic number identifying file */
123 __le32 dqh_version; /* File version */
124 };
125
v1_check_quota_file(struct super_block * sb,int type)126 static int v1_check_quota_file(struct super_block *sb, int type)
127 {
128 struct inode *inode = sb_dqopt(sb)->files[type];
129 ulong blocks;
130 size_t off;
131 struct v2_disk_dqheader dqhead;
132 ssize_t size;
133 loff_t isize;
134 static const uint quota_magics[] = V2_INITQMAGICS;
135
136 isize = i_size_read(inode);
137 if (!isize)
138 return 0;
139 blocks = isize >> BLOCK_SIZE_BITS;
140 off = isize & (BLOCK_SIZE - 1);
141 if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) %
142 sizeof(struct v1_disk_dqblk))
143 return 0;
144 /* Doublecheck whether we didn't get file with new format - with old
145 * quotactl() this could happen */
146 size = sb->s_op->quota_read(sb, type, (char *)&dqhead,
147 sizeof(struct v2_disk_dqheader), 0);
148 if (size != sizeof(struct v2_disk_dqheader))
149 return 1; /* Probably not new format */
150 if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
151 return 1; /* Definitely not new format */
152 printk(KERN_INFO
153 "VFS: %s: Refusing to turn on old quota format on given file."
154 " It probably contains newer quota format.\n", sb->s_id);
155 return 0; /* Seems like a new format file -> refuse it */
156 }
157
v1_read_file_info(struct super_block * sb,int type)158 static int v1_read_file_info(struct super_block *sb, int type)
159 {
160 struct quota_info *dqopt = sb_dqopt(sb);
161 struct v1_disk_dqblk dqblk;
162 int ret;
163
164 down_read(&dqopt->dqio_sem);
165 ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
166 sizeof(struct v1_disk_dqblk), v1_dqoff(0));
167 if (ret != sizeof(struct v1_disk_dqblk)) {
168 if (ret >= 0)
169 ret = -EIO;
170 goto out;
171 }
172 ret = 0;
173 /* limits are stored as unsigned 32-bit data */
174 dqopt->info[type].dqi_max_spc_limit = 0xffffffffULL << QUOTABLOCK_BITS;
175 dqopt->info[type].dqi_max_ino_limit = 0xffffffff;
176 dqopt->info[type].dqi_igrace =
177 dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
178 dqopt->info[type].dqi_bgrace =
179 dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
180 out:
181 up_read(&dqopt->dqio_sem);
182 return ret;
183 }
184
v1_write_file_info(struct super_block * sb,int type)185 static int v1_write_file_info(struct super_block *sb, int type)
186 {
187 struct quota_info *dqopt = sb_dqopt(sb);
188 struct v1_disk_dqblk dqblk;
189 int ret;
190
191 down_write(&dqopt->dqio_sem);
192 ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
193 sizeof(struct v1_disk_dqblk), v1_dqoff(0));
194 if (ret != sizeof(struct v1_disk_dqblk)) {
195 if (ret >= 0)
196 ret = -EIO;
197 goto out;
198 }
199 spin_lock(&dq_data_lock);
200 dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
201 dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
202 dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
203 spin_unlock(&dq_data_lock);
204 ret = sb->s_op->quota_write(sb, type, (char *)&dqblk,
205 sizeof(struct v1_disk_dqblk), v1_dqoff(0));
206 if (ret == sizeof(struct v1_disk_dqblk))
207 ret = 0;
208 else if (ret > 0)
209 ret = -EIO;
210 out:
211 up_write(&dqopt->dqio_sem);
212 return ret;
213 }
214
215 static const struct quota_format_ops v1_format_ops = {
216 .check_quota_file = v1_check_quota_file,
217 .read_file_info = v1_read_file_info,
218 .write_file_info = v1_write_file_info,
219 .free_file_info = NULL,
220 .read_dqblk = v1_read_dqblk,
221 .commit_dqblk = v1_commit_dqblk,
222 };
223
224 static struct quota_format_type v1_quota_format = {
225 .qf_fmt_id = QFMT_VFS_OLD,
226 .qf_ops = &v1_format_ops,
227 .qf_owner = THIS_MODULE
228 };
229
init_v1_quota_format(void)230 static int __init init_v1_quota_format(void)
231 {
232 return register_quota_format(&v1_quota_format);
233 }
234
exit_v1_quota_format(void)235 static void __exit exit_v1_quota_format(void)
236 {
237 unregister_quota_format(&v1_quota_format);
238 }
239
240 module_init(init_v1_quota_format);
241 module_exit(exit_v1_quota_format);
242
243
