1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * vfsv0 quota IO operations on file
4 */
5
6 #include <linux/errno.h>
7 #include <linux/fs.h>
8 #include <linux/mount.h>
9 #include <linux/dqblk_v2.h>
10 #include <linux/kernel.h>
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/quotaops.h>
15
16 #include <asm/byteorder.h>
17
18 #include "quota_tree.h"
19 #include "quotaio_v2.h"
20
21 MODULE_AUTHOR("Jan Kara");
22 MODULE_DESCRIPTION("Quota format v2 support");
23 MODULE_LICENSE("GPL");
24
25 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
26 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
27 static int v2r0_is_id(void *dp, struct dquot *dquot);
28 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
29 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
30 static int v2r1_is_id(void *dp, struct dquot *dquot);
31
32 static const struct qtree_fmt_operations v2r0_qtree_ops = {
33 .mem2disk_dqblk = v2r0_mem2diskdqb,
34 .disk2mem_dqblk = v2r0_disk2memdqb,
35 .is_id = v2r0_is_id,
36 };
37
38 static const struct qtree_fmt_operations v2r1_qtree_ops = {
39 .mem2disk_dqblk = v2r1_mem2diskdqb,
40 .disk2mem_dqblk = v2r1_disk2memdqb,
41 .is_id = v2r1_is_id,
42 };
43
44 #define QUOTABLOCK_BITS 10
45 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
46
v2_stoqb(qsize_t space)47 static inline qsize_t v2_stoqb(qsize_t space)
48 {
49 return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
50 }
51
v2_qbtos(qsize_t blocks)52 static inline qsize_t v2_qbtos(qsize_t blocks)
53 {
54 return blocks << QUOTABLOCK_BITS;
55 }
56
v2_read_header(struct super_block * sb,int type,struct v2_disk_dqheader * dqhead)57 static int v2_read_header(struct super_block *sb, int type,
58 struct v2_disk_dqheader *dqhead)
59 {
60 ssize_t size;
61
62 size = sb->s_op->quota_read(sb, type, (char *)dqhead,
63 sizeof(struct v2_disk_dqheader), 0);
64 if (size != sizeof(struct v2_disk_dqheader)) {
65 quota_error(sb, "Failed header read: expected=%zd got=%zd",
66 sizeof(struct v2_disk_dqheader), size);
67 if (size < 0)
68 return size;
69 return -EIO;
70 }
71 return 0;
72 }
73
74 /* Check whether given file is really vfsv0 quotafile */
v2_check_quota_file(struct super_block * sb,int type)75 static int v2_check_quota_file(struct super_block *sb, int type)
76 {
77 struct v2_disk_dqheader dqhead;
78 static const uint quota_magics[] = V2_INITQMAGICS;
79 static const uint quota_versions[] = V2_INITQVERSIONS;
80
81 if (v2_read_header(sb, type, &dqhead))
82 return 0;
83 if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
84 le32_to_cpu(dqhead.dqh_version) > quota_versions[type])
85 return 0;
86 return 1;
87 }
88
89 /* Read information header from quota file */
v2_read_file_info(struct super_block * sb,int type)90 static int v2_read_file_info(struct super_block *sb, int type)
91 {
92 struct v2_disk_dqinfo dinfo;
93 struct v2_disk_dqheader dqhead;
94 struct quota_info *dqopt = sb_dqopt(sb);
95 struct mem_dqinfo *info = &dqopt->info[type];
96 struct qtree_mem_dqinfo *qinfo;
97 ssize_t size;
98 unsigned int version;
99 int ret;
100
101 down_read(&dqopt->dqio_sem);
102 ret = v2_read_header(sb, type, &dqhead);
103 if (ret < 0)
104 goto out;
105 version = le32_to_cpu(dqhead.dqh_version);
106 if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
107 (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) {
108 ret = -EINVAL;
109 goto out;
110 }
111
112 size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
113 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
114 if (size != sizeof(struct v2_disk_dqinfo)) {
115 quota_error(sb, "Can't read info structure");
116 if (size < 0)
117 ret = size;
118 else
119 ret = -EIO;
120 goto out;
121 }
122 info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
123 if (!info->dqi_priv) {
124 ret = -ENOMEM;
125 goto out;
126 }
127 qinfo = info->dqi_priv;
128 if (version == 0) {
129 /* limits are stored as unsigned 32-bit data */
130 info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
131 info->dqi_max_ino_limit = 0xffffffff;
132 } else {
133 /*
134 * Used space is stored as unsigned 64-bit value in bytes but
135 * quota core supports only signed 64-bit values so use that
136 * as a limit
137 */
138 info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
139 info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
140 }
141 info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
142 info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
143 /* No flags currently supported */
144 info->dqi_flags = 0;
145 qinfo->dqi_sb = sb;
146 qinfo->dqi_type = type;
147 qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
148 qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
149 qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
150 qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
151 qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
152 qinfo->dqi_qtree_depth = qtree_depth(qinfo);
153 if (version == 0) {
154 qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
155 qinfo->dqi_ops = &v2r0_qtree_ops;
156 } else {
157 qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
158 qinfo->dqi_ops = &v2r1_qtree_ops;
159 }
160 ret = 0;
161 out:
162 up_read(&dqopt->dqio_sem);
163 return ret;
164 }
165
166 /* Write information header to quota file */
v2_write_file_info(struct super_block * sb,int type)167 static int v2_write_file_info(struct super_block *sb, int type)
168 {
169 struct v2_disk_dqinfo dinfo;
170 struct quota_info *dqopt = sb_dqopt(sb);
171 struct mem_dqinfo *info = &dqopt->info[type];
172 struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
173 ssize_t size;
174
175 down_write(&dqopt->dqio_sem);
176 spin_lock(&dq_data_lock);
177 info->dqi_flags &= ~DQF_INFO_DIRTY;
178 dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
179 dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
180 /* No flags currently supported */
181 dinfo.dqi_flags = cpu_to_le32(0);
182 spin_unlock(&dq_data_lock);
183 dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
184 dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
185 dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
186 size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
187 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
188 up_write(&dqopt->dqio_sem);
189 if (size != sizeof(struct v2_disk_dqinfo)) {
190 quota_error(sb, "Can't write info structure");
191 return -1;
192 }
193 return 0;
194 }
195
v2r0_disk2memdqb(struct dquot * dquot,void * dp)196 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
197 {
198 struct v2r0_disk_dqblk *d = dp, empty;
199 struct mem_dqblk *m = &dquot->dq_dqb;
200
201 m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
202 m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
203 m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
204 m->dqb_itime = le64_to_cpu(d->dqb_itime);
205 m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
206 m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
207 m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
208 m->dqb_btime = le64_to_cpu(d->dqb_btime);
209 /* We need to escape back all-zero structure */
210 memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
211 empty.dqb_itime = cpu_to_le64(1);
212 if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
213 m->dqb_itime = 0;
214 }
215
v2r0_mem2diskdqb(void * dp,struct dquot * dquot)216 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
217 {
218 struct v2r0_disk_dqblk *d = dp;
219 struct mem_dqblk *m = &dquot->dq_dqb;
220 struct qtree_mem_dqinfo *info =
221 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
222
223 d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
224 d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
225 d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
226 d->dqb_itime = cpu_to_le64(m->dqb_itime);
227 d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
228 d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
229 d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
230 d->dqb_btime = cpu_to_le64(m->dqb_btime);
231 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
232 if (qtree_entry_unused(info, dp))
233 d->dqb_itime = cpu_to_le64(1);
234 }
235
v2r0_is_id(void * dp,struct dquot * dquot)236 static int v2r0_is_id(void *dp, struct dquot *dquot)
237 {
238 struct v2r0_disk_dqblk *d = dp;
239 struct qtree_mem_dqinfo *info =
240 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
241
242 if (qtree_entry_unused(info, dp))
243 return 0;
244 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
245 le32_to_cpu(d->dqb_id)),
246 dquot->dq_id);
247 }
248
v2r1_disk2memdqb(struct dquot * dquot,void * dp)249 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
250 {
251 struct v2r1_disk_dqblk *d = dp, empty;
252 struct mem_dqblk *m = &dquot->dq_dqb;
253
254 m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
255 m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
256 m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
257 m->dqb_itime = le64_to_cpu(d->dqb_itime);
258 m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
259 m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
260 m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
261 m->dqb_btime = le64_to_cpu(d->dqb_btime);
262 /* We need to escape back all-zero structure */
263 memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
264 empty.dqb_itime = cpu_to_le64(1);
265 if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
266 m->dqb_itime = 0;
267 }
268
v2r1_mem2diskdqb(void * dp,struct dquot * dquot)269 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
270 {
271 struct v2r1_disk_dqblk *d = dp;
272 struct mem_dqblk *m = &dquot->dq_dqb;
273 struct qtree_mem_dqinfo *info =
274 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
275
276 d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
277 d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
278 d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
279 d->dqb_itime = cpu_to_le64(m->dqb_itime);
280 d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
281 d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
282 d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
283 d->dqb_btime = cpu_to_le64(m->dqb_btime);
284 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
285 d->dqb_pad = 0;
286 if (qtree_entry_unused(info, dp))
287 d->dqb_itime = cpu_to_le64(1);
288 }
289
v2r1_is_id(void * dp,struct dquot * dquot)290 static int v2r1_is_id(void *dp, struct dquot *dquot)
291 {
292 struct v2r1_disk_dqblk *d = dp;
293 struct qtree_mem_dqinfo *info =
294 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
295
296 if (qtree_entry_unused(info, dp))
297 return 0;
298 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
299 le32_to_cpu(d->dqb_id)),
300 dquot->dq_id);
301 }
302
v2_read_dquot(struct dquot * dquot)303 static int v2_read_dquot(struct dquot *dquot)
304 {
305 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
306 int ret;
307
308 down_read(&dqopt->dqio_sem);
309 ret = qtree_read_dquot(
310 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
311 dquot);
312 up_read(&dqopt->dqio_sem);
313 return ret;
314 }
315
v2_write_dquot(struct dquot * dquot)316 static int v2_write_dquot(struct dquot *dquot)
317 {
318 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
319 int ret;
320 bool alloc = false;
321
322 /*
323 * If space for dquot is already allocated, we don't need any
324 * protection as we'll only overwrite the place of dquot. We are
325 * still protected by concurrent writes of the same dquot by
326 * dquot->dq_lock.
327 */
328 if (!dquot->dq_off) {
329 alloc = true;
330 down_write(&dqopt->dqio_sem);
331 } else {
332 down_read(&dqopt->dqio_sem);
333 }
334 ret = qtree_write_dquot(
335 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
336 dquot);
337 if (alloc)
338 up_write(&dqopt->dqio_sem);
339 else
340 up_read(&dqopt->dqio_sem);
341 return ret;
342 }
343
v2_release_dquot(struct dquot * dquot)344 static int v2_release_dquot(struct dquot *dquot)
345 {
346 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
347 int ret;
348
349 down_write(&dqopt->dqio_sem);
350 ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
351 up_write(&dqopt->dqio_sem);
352
353 return ret;
354 }
355
v2_free_file_info(struct super_block * sb,int type)356 static int v2_free_file_info(struct super_block *sb, int type)
357 {
358 kfree(sb_dqinfo(sb, type)->dqi_priv);
359 return 0;
360 }
361
v2_get_next_id(struct super_block * sb,struct kqid * qid)362 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
363 {
364 struct quota_info *dqopt = sb_dqopt(sb);
365 int ret;
366
367 down_read(&dqopt->dqio_sem);
368 ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
369 up_read(&dqopt->dqio_sem);
370 return ret;
371 }
372
373 static const struct quota_format_ops v2_format_ops = {
374 .check_quota_file = v2_check_quota_file,
375 .read_file_info = v2_read_file_info,
376 .write_file_info = v2_write_file_info,
377 .free_file_info = v2_free_file_info,
378 .read_dqblk = v2_read_dquot,
379 .commit_dqblk = v2_write_dquot,
380 .release_dqblk = v2_release_dquot,
381 .get_next_id = v2_get_next_id,
382 };
383
384 static struct quota_format_type v2r0_quota_format = {
385 .qf_fmt_id = QFMT_VFS_V0,
386 .qf_ops = &v2_format_ops,
387 .qf_owner = THIS_MODULE
388 };
389
390 static struct quota_format_type v2r1_quota_format = {
391 .qf_fmt_id = QFMT_VFS_V1,
392 .qf_ops = &v2_format_ops,
393 .qf_owner = THIS_MODULE
394 };
395
init_v2_quota_format(void)396 static int __init init_v2_quota_format(void)
397 {
398 int ret;
399
400 ret = register_quota_format(&v2r0_quota_format);
401 if (ret)
402 return ret;
403 return register_quota_format(&v2r1_quota_format);
404 }
405
exit_v2_quota_format(void)406 static void __exit exit_v2_quota_format(void)
407 {
408 unregister_quota_format(&v2r0_quota_format);
409 unregister_quota_format(&v2r1_quota_format);
410 }
411
412 module_init(init_v2_quota_format);
413 module_exit(exit_v2_quota_format);
414