xref: /openbmc/linux/fs/quota/quota_v2.c (revision a06c488d)
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 v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
27 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
28 static int v2r0_is_id(void *dp, struct dquot *dquot);
29 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
30 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
31 static int v2r1_is_id(void *dp, struct dquot *dquot);
32 
33 static const struct qtree_fmt_operations v2r0_qtree_ops = {
34 	.mem2disk_dqblk = v2r0_mem2diskdqb,
35 	.disk2mem_dqblk = v2r0_disk2memdqb,
36 	.is_id = v2r0_is_id,
37 };
38 
39 static const struct qtree_fmt_operations v2r1_qtree_ops = {
40 	.mem2disk_dqblk = v2r1_mem2diskdqb,
41 	.disk2mem_dqblk = v2r1_disk2memdqb,
42 	.is_id = v2r1_is_id,
43 };
44 
45 #define QUOTABLOCK_BITS 10
46 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
47 
48 static inline qsize_t v2_stoqb(qsize_t space)
49 {
50 	return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
51 }
52 
53 static inline qsize_t v2_qbtos(qsize_t blocks)
54 {
55 	return blocks << QUOTABLOCK_BITS;
56 }
57 
58 static int v2_read_header(struct super_block *sb, int type,
59 			  struct v2_disk_dqheader *dqhead)
60 {
61 	ssize_t size;
62 
63 	size = sb->s_op->quota_read(sb, type, (char *)dqhead,
64 				    sizeof(struct v2_disk_dqheader), 0);
65 	if (size != sizeof(struct v2_disk_dqheader)) {
66 		quota_error(sb, "Failed header read: expected=%zd got=%zd",
67 			    sizeof(struct v2_disk_dqheader), size);
68 		return 0;
69 	}
70 	return 1;
71 }
72 
73 /* Check whether given file is really vfsv0 quotafile */
74 static int v2_check_quota_file(struct super_block *sb, int type)
75 {
76 	struct v2_disk_dqheader dqhead;
77 	static const uint quota_magics[] = V2_INITQMAGICS;
78 	static const uint quota_versions[] = V2_INITQVERSIONS;
79 
80 	if (!v2_read_header(sb, type, &dqhead))
81 		return 0;
82 	if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
83 	    le32_to_cpu(dqhead.dqh_version) > quota_versions[type])
84 		return 0;
85 	return 1;
86 }
87 
88 /* Read information header from quota file */
89 static int v2_read_file_info(struct super_block *sb, int type)
90 {
91 	struct v2_disk_dqinfo dinfo;
92 	struct v2_disk_dqheader dqhead;
93 	struct mem_dqinfo *info = sb_dqinfo(sb, type);
94 	struct qtree_mem_dqinfo *qinfo;
95 	ssize_t size;
96 	unsigned int version;
97 
98 	if (!v2_read_header(sb, type, &dqhead))
99 		return -1;
100 	version = le32_to_cpu(dqhead.dqh_version);
101 	if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
102 	    (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1))
103 		return -1;
104 
105 	size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
106 	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
107 	if (size != sizeof(struct v2_disk_dqinfo)) {
108 		quota_error(sb, "Can't read info structure");
109 		return -1;
110 	}
111 	info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
112 	if (!info->dqi_priv) {
113 		printk(KERN_WARNING
114 		       "Not enough memory for quota information structure.\n");
115 		return -ENOMEM;
116 	}
117 	qinfo = info->dqi_priv;
118 	if (version == 0) {
119 		/* limits are stored as unsigned 32-bit data */
120 		info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
121 		info->dqi_max_ino_limit = 0xffffffff;
122 	} else {
123 		/*
124 		 * Used space is stored as unsigned 64-bit value in bytes but
125 		 * quota core supports only signed 64-bit values so use that
126 		 * as a limit
127 		 */
128 		info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
129 		info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
130 	}
131 	info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
132 	info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
133 	/* No flags currently supported */
134 	info->dqi_flags = 0;
135 	qinfo->dqi_sb = sb;
136 	qinfo->dqi_type = type;
137 	qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
138 	qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
139 	qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
140 	qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
141 	qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
142 	qinfo->dqi_qtree_depth = qtree_depth(qinfo);
143 	if (version == 0) {
144 		qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
145 		qinfo->dqi_ops = &v2r0_qtree_ops;
146 	} else {
147 		qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
148 		qinfo->dqi_ops = &v2r1_qtree_ops;
149 	}
150 	return 0;
151 }
152 
153 /* Write information header to quota file */
154 static int v2_write_file_info(struct super_block *sb, int type)
155 {
156 	struct v2_disk_dqinfo dinfo;
157 	struct mem_dqinfo *info = sb_dqinfo(sb, type);
158 	struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
159 	ssize_t size;
160 
161 	spin_lock(&dq_data_lock);
162 	info->dqi_flags &= ~DQF_INFO_DIRTY;
163 	dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
164 	dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
165 	/* No flags currently supported */
166 	dinfo.dqi_flags = cpu_to_le32(0);
167 	spin_unlock(&dq_data_lock);
168 	dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
169 	dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
170 	dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
171 	size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
172 	       sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
173 	if (size != sizeof(struct v2_disk_dqinfo)) {
174 		quota_error(sb, "Can't write info structure");
175 		return -1;
176 	}
177 	return 0;
178 }
179 
180 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
181 {
182 	struct v2r0_disk_dqblk *d = dp, empty;
183 	struct mem_dqblk *m = &dquot->dq_dqb;
184 
185 	m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
186 	m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
187 	m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
188 	m->dqb_itime = le64_to_cpu(d->dqb_itime);
189 	m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
190 	m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
191 	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
192 	m->dqb_btime = le64_to_cpu(d->dqb_btime);
193 	/* We need to escape back all-zero structure */
194 	memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
195 	empty.dqb_itime = cpu_to_le64(1);
196 	if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
197 		m->dqb_itime = 0;
198 }
199 
200 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
201 {
202 	struct v2r0_disk_dqblk *d = dp;
203 	struct mem_dqblk *m = &dquot->dq_dqb;
204 	struct qtree_mem_dqinfo *info =
205 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
206 
207 	d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
208 	d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
209 	d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
210 	d->dqb_itime = cpu_to_le64(m->dqb_itime);
211 	d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
212 	d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
213 	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
214 	d->dqb_btime = cpu_to_le64(m->dqb_btime);
215 	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
216 	if (qtree_entry_unused(info, dp))
217 		d->dqb_itime = cpu_to_le64(1);
218 }
219 
220 static int v2r0_is_id(void *dp, struct dquot *dquot)
221 {
222 	struct v2r0_disk_dqblk *d = dp;
223 	struct qtree_mem_dqinfo *info =
224 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
225 
226 	if (qtree_entry_unused(info, dp))
227 		return 0;
228 	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
229 				le32_to_cpu(d->dqb_id)),
230 		      dquot->dq_id);
231 }
232 
233 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
234 {
235 	struct v2r1_disk_dqblk *d = dp, empty;
236 	struct mem_dqblk *m = &dquot->dq_dqb;
237 
238 	m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
239 	m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
240 	m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
241 	m->dqb_itime = le64_to_cpu(d->dqb_itime);
242 	m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
243 	m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
244 	m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
245 	m->dqb_btime = le64_to_cpu(d->dqb_btime);
246 	/* We need to escape back all-zero structure */
247 	memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
248 	empty.dqb_itime = cpu_to_le64(1);
249 	if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
250 		m->dqb_itime = 0;
251 }
252 
253 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
254 {
255 	struct v2r1_disk_dqblk *d = dp;
256 	struct mem_dqblk *m = &dquot->dq_dqb;
257 	struct qtree_mem_dqinfo *info =
258 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
259 
260 	d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
261 	d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
262 	d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
263 	d->dqb_itime = cpu_to_le64(m->dqb_itime);
264 	d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
265 	d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
266 	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
267 	d->dqb_btime = cpu_to_le64(m->dqb_btime);
268 	d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
269 	if (qtree_entry_unused(info, dp))
270 		d->dqb_itime = cpu_to_le64(1);
271 }
272 
273 static int v2r1_is_id(void *dp, struct dquot *dquot)
274 {
275 	struct v2r1_disk_dqblk *d = dp;
276 	struct qtree_mem_dqinfo *info =
277 			sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
278 
279 	if (qtree_entry_unused(info, dp))
280 		return 0;
281 	return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
282 				le32_to_cpu(d->dqb_id)),
283 		      dquot->dq_id);
284 }
285 
286 static int v2_read_dquot(struct dquot *dquot)
287 {
288 	return qtree_read_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
289 }
290 
291 static int v2_write_dquot(struct dquot *dquot)
292 {
293 	return qtree_write_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
294 }
295 
296 static int v2_release_dquot(struct dquot *dquot)
297 {
298 	return qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
299 }
300 
301 static int v2_free_file_info(struct super_block *sb, int type)
302 {
303 	kfree(sb_dqinfo(sb, type)->dqi_priv);
304 	return 0;
305 }
306 
307 static const struct quota_format_ops v2_format_ops = {
308 	.check_quota_file	= v2_check_quota_file,
309 	.read_file_info		= v2_read_file_info,
310 	.write_file_info	= v2_write_file_info,
311 	.free_file_info		= v2_free_file_info,
312 	.read_dqblk		= v2_read_dquot,
313 	.commit_dqblk		= v2_write_dquot,
314 	.release_dqblk		= v2_release_dquot,
315 };
316 
317 static struct quota_format_type v2r0_quota_format = {
318 	.qf_fmt_id	= QFMT_VFS_V0,
319 	.qf_ops		= &v2_format_ops,
320 	.qf_owner	= THIS_MODULE
321 };
322 
323 static struct quota_format_type v2r1_quota_format = {
324 	.qf_fmt_id	= QFMT_VFS_V1,
325 	.qf_ops		= &v2_format_ops,
326 	.qf_owner	= THIS_MODULE
327 };
328 
329 static int __init init_v2_quota_format(void)
330 {
331 	int ret;
332 
333 	ret = register_quota_format(&v2r0_quota_format);
334 	if (ret)
335 		return ret;
336 	return register_quota_format(&v2r1_quota_format);
337 }
338 
339 static void __exit exit_v2_quota_format(void)
340 {
341 	unregister_quota_format(&v2r0_quota_format);
342 	unregister_quota_format(&v2r1_quota_format);
343 }
344 
345 module_init(init_v2_quota_format);
346 module_exit(exit_v2_quota_format);
347