1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | #include <linux/errno.h> |
3 | #include <linux/fs.h> |
4 | #include <linux/quota.h> |
5 | #include <linux/quotaops.h> |
6 | #include <linux/dqblk_v1.h> |
7 | #include <linux/kernel.h> |
8 | #include <linux/init.h> |
9 | #include <linux/module.h> |
10 | |
11 | #include <asm/byteorder.h> |
12 | |
13 | #include "quotaio_v1.h" |
14 | |
15 | MODULE_AUTHOR("Jan Kara" ); |
16 | MODULE_DESCRIPTION("Old quota format support" ); |
17 | MODULE_LICENSE("GPL" ); |
18 | |
19 | #define QUOTABLOCK_BITS 10 |
20 | #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS) |
21 | |
22 | static inline qsize_t v1_stoqb(qsize_t space) |
23 | { |
24 | return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS; |
25 | } |
26 | |
27 | static inline qsize_t v1_qbtos(qsize_t blocks) |
28 | { |
29 | return blocks << QUOTABLOCK_BITS; |
30 | } |
31 | |
32 | static void v1_disk2mem_dqblk(struct mem_dqblk *m, struct v1_disk_dqblk *d) |
33 | { |
34 | m->dqb_ihardlimit = d->dqb_ihardlimit; |
35 | m->dqb_isoftlimit = d->dqb_isoftlimit; |
36 | m->dqb_curinodes = d->dqb_curinodes; |
37 | m->dqb_bhardlimit = v1_qbtos(blocks: d->dqb_bhardlimit); |
38 | m->dqb_bsoftlimit = v1_qbtos(blocks: d->dqb_bsoftlimit); |
39 | m->dqb_curspace = v1_qbtos(blocks: d->dqb_curblocks); |
40 | m->dqb_itime = d->dqb_itime; |
41 | m->dqb_btime = d->dqb_btime; |
42 | } |
43 | |
44 | static void v1_mem2disk_dqblk(struct v1_disk_dqblk *d, struct mem_dqblk *m) |
45 | { |
46 | d->dqb_ihardlimit = m->dqb_ihardlimit; |
47 | d->dqb_isoftlimit = m->dqb_isoftlimit; |
48 | d->dqb_curinodes = m->dqb_curinodes; |
49 | d->dqb_bhardlimit = v1_stoqb(space: m->dqb_bhardlimit); |
50 | d->dqb_bsoftlimit = v1_stoqb(space: m->dqb_bsoftlimit); |
51 | d->dqb_curblocks = v1_stoqb(space: m->dqb_curspace); |
52 | d->dqb_itime = m->dqb_itime; |
53 | d->dqb_btime = m->dqb_btime; |
54 | } |
55 | |
56 | static int v1_read_dqblk(struct dquot *dquot) |
57 | { |
58 | int type = dquot->dq_id.type; |
59 | struct v1_disk_dqblk dqblk; |
60 | struct quota_info *dqopt = sb_dqopt(sb: dquot->dq_sb); |
61 | |
62 | if (!dqopt->files[type]) |
63 | return -EINVAL; |
64 | |
65 | /* Set structure to 0s in case read fails/is after end of file */ |
66 | memset(&dqblk, 0, sizeof(struct v1_disk_dqblk)); |
67 | dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk, |
68 | sizeof(struct v1_disk_dqblk), |
69 | v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id))); |
70 | |
71 | v1_disk2mem_dqblk(m: &dquot->dq_dqb, d: &dqblk); |
72 | if (dquot->dq_dqb.dqb_bhardlimit == 0 && |
73 | dquot->dq_dqb.dqb_bsoftlimit == 0 && |
74 | dquot->dq_dqb.dqb_ihardlimit == 0 && |
75 | dquot->dq_dqb.dqb_isoftlimit == 0) |
76 | set_bit(DQ_FAKE_B, addr: &dquot->dq_flags); |
77 | dqstats_inc(type: DQST_READS); |
78 | |
79 | return 0; |
80 | } |
81 | |
82 | static int v1_commit_dqblk(struct dquot *dquot) |
83 | { |
84 | short type = dquot->dq_id.type; |
85 | ssize_t ret; |
86 | struct v1_disk_dqblk dqblk; |
87 | |
88 | v1_mem2disk_dqblk(d: &dqblk, m: &dquot->dq_dqb); |
89 | if (((type == USRQUOTA) && uid_eq(left: dquot->dq_id.uid, GLOBAL_ROOT_UID)) || |
90 | ((type == GRPQUOTA) && gid_eq(dquot->dq_id.gid, GLOBAL_ROOT_GID))) { |
91 | dqblk.dqb_btime = |
92 | sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace; |
93 | dqblk.dqb_itime = |
94 | sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace; |
95 | } |
96 | ret = 0; |
97 | if (sb_dqopt(dquot->dq_sb)->files[type]) |
98 | ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type, |
99 | (char *)&dqblk, sizeof(struct v1_disk_dqblk), |
100 | v1_dqoff(from_kqid(&init_user_ns, dquot->dq_id))); |
101 | if (ret != sizeof(struct v1_disk_dqblk)) { |
102 | quota_error(dquot->dq_sb, "dquota write failed" ); |
103 | if (ret >= 0) |
104 | ret = -EIO; |
105 | goto out; |
106 | } |
107 | ret = 0; |
108 | |
109 | out: |
110 | dqstats_inc(DQST_WRITES); |
111 | |
112 | return ret; |
113 | } |
114 | |
115 | /* Magics of new quota format */ |
116 | #define V2_INITQMAGICS {\ |
117 | 0xd9c01f11, /* USRQUOTA */\ |
118 | 0xd9c01927 /* GRPQUOTA */\ |
119 | } |
120 | |
121 | /* Header of new quota format */ |
122 | struct { |
123 | __le32 ; /* Magic number identifying file */ |
124 | __le32 ; /* File version */ |
125 | }; |
126 | |
127 | static int v1_check_quota_file(struct super_block *sb, int type) |
128 | { |
129 | struct inode *inode = sb_dqopt(sb)->files[type]; |
130 | ulong blocks; |
131 | size_t off; |
132 | struct v2_disk_dqheader dqhead; |
133 | ssize_t size; |
134 | loff_t isize; |
135 | static const uint quota_magics[] = V2_INITQMAGICS; |
136 | |
137 | isize = i_size_read(inode); |
138 | if (!isize) |
139 | return 0; |
140 | blocks = isize >> BLOCK_SIZE_BITS; |
141 | off = isize & (BLOCK_SIZE - 1); |
142 | if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % |
143 | sizeof(struct v1_disk_dqblk)) |
144 | return 0; |
145 | /* Doublecheck whether we didn't get file with new format - with old |
146 | * quotactl() this could happen */ |
147 | size = sb->s_op->quota_read(sb, type, (char *)&dqhead, |
148 | sizeof(struct v2_disk_dqheader), 0); |
149 | if (size != sizeof(struct v2_disk_dqheader)) |
150 | return 1; /* Probably not new format */ |
151 | if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type]) |
152 | return 1; /* Definitely not new format */ |
153 | printk(KERN_INFO |
154 | "VFS: %s: Refusing to turn on old quota format on given file." |
155 | " It probably contains newer quota format.\n" , sb->s_id); |
156 | return 0; /* Seems like a new format file -> refuse it */ |
157 | } |
158 | |
159 | static int v1_read_file_info(struct super_block *sb, int type) |
160 | { |
161 | struct quota_info *dqopt = sb_dqopt(sb); |
162 | struct v1_disk_dqblk dqblk; |
163 | int ret; |
164 | |
165 | down_read(sem: &dqopt->dqio_sem); |
166 | ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, |
167 | sizeof(struct v1_disk_dqblk), v1_dqoff(0)); |
168 | if (ret != sizeof(struct v1_disk_dqblk)) { |
169 | if (ret >= 0) |
170 | ret = -EIO; |
171 | goto out; |
172 | } |
173 | ret = 0; |
174 | /* limits are stored as unsigned 32-bit data */ |
175 | dqopt->info[type].dqi_max_spc_limit = 0xffffffffULL << QUOTABLOCK_BITS; |
176 | dqopt->info[type].dqi_max_ino_limit = 0xffffffff; |
177 | dqopt->info[type].dqi_igrace = |
178 | dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME; |
179 | dqopt->info[type].dqi_bgrace = |
180 | dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME; |
181 | out: |
182 | up_read(sem: &dqopt->dqio_sem); |
183 | return ret; |
184 | } |
185 | |
186 | static int v1_write_file_info(struct super_block *sb, int type) |
187 | { |
188 | struct quota_info *dqopt = sb_dqopt(sb); |
189 | struct v1_disk_dqblk dqblk; |
190 | int ret; |
191 | |
192 | down_write(sem: &dqopt->dqio_sem); |
193 | ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, |
194 | sizeof(struct v1_disk_dqblk), v1_dqoff(0)); |
195 | if (ret != sizeof(struct v1_disk_dqblk)) { |
196 | if (ret >= 0) |
197 | ret = -EIO; |
198 | goto out; |
199 | } |
200 | spin_lock(lock: &dq_data_lock); |
201 | dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY; |
202 | dqblk.dqb_itime = dqopt->info[type].dqi_igrace; |
203 | dqblk.dqb_btime = dqopt->info[type].dqi_bgrace; |
204 | spin_unlock(lock: &dq_data_lock); |
205 | ret = sb->s_op->quota_write(sb, type, (char *)&dqblk, |
206 | sizeof(struct v1_disk_dqblk), v1_dqoff(0)); |
207 | if (ret == sizeof(struct v1_disk_dqblk)) |
208 | ret = 0; |
209 | else if (ret >= 0) |
210 | ret = -EIO; |
211 | out: |
212 | up_write(sem: &dqopt->dqio_sem); |
213 | return ret; |
214 | } |
215 | |
216 | static const struct quota_format_ops v1_format_ops = { |
217 | .check_quota_file = v1_check_quota_file, |
218 | .read_file_info = v1_read_file_info, |
219 | .write_file_info = v1_write_file_info, |
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 | |
230 | static int __init init_v1_quota_format(void) |
231 | { |
232 | return register_quota_format(fmt: &v1_quota_format); |
233 | } |
234 | |
235 | static void __exit exit_v1_quota_format(void) |
236 | { |
237 | unregister_quota_format(fmt: &v1_quota_format); |
238 | } |
239 | |
240 | module_init(init_v1_quota_format); |
241 | module_exit(exit_v1_quota_format); |
242 | |
243 | |