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 #define __QUOTA_V2_PARANOIA
26
27 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
28 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
29 static int v2r0_is_id(void *dp, struct dquot *dquot);
30 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
31 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
32 static int v2r1_is_id(void *dp, struct dquot *dquot);
33
34 static const struct qtree_fmt_operations v2r0_qtree_ops = {
35 .mem2disk_dqblk = v2r0_mem2diskdqb,
36 .disk2mem_dqblk = v2r0_disk2memdqb,
37 .is_id = v2r0_is_id,
38 };
39
40 static const struct qtree_fmt_operations v2r1_qtree_ops = {
41 .mem2disk_dqblk = v2r1_mem2diskdqb,
42 .disk2mem_dqblk = v2r1_disk2memdqb,
43 .is_id = v2r1_is_id,
44 };
45
46 #define QUOTABLOCK_BITS 10
47 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
48
v2_stoqb(qsize_t space)49 static inline qsize_t v2_stoqb(qsize_t space)
50 {
51 return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
52 }
53
v2_qbtos(qsize_t blocks)54 static inline qsize_t v2_qbtos(qsize_t blocks)
55 {
56 return blocks << QUOTABLOCK_BITS;
57 }
58
v2_read_header(struct super_block * sb,int type,struct v2_disk_dqheader * dqhead)59 static int v2_read_header(struct super_block *sb, int type,
60 struct v2_disk_dqheader *dqhead)
61 {
62 ssize_t size;
63
64 size = sb->s_op->quota_read(sb, type, (char *)dqhead,
65 sizeof(struct v2_disk_dqheader), 0);
66 if (size != sizeof(struct v2_disk_dqheader)) {
67 quota_error(sb, "Failed header read: expected=%zd got=%zd",
68 sizeof(struct v2_disk_dqheader), size);
69 if (size < 0)
70 return size;
71 return -EIO;
72 }
73 return 0;
74 }
75
76 /* Check whether given file is really vfsv0 quotafile */
v2_check_quota_file(struct super_block * sb,int type)77 static int v2_check_quota_file(struct super_block *sb, int type)
78 {
79 struct v2_disk_dqheader dqhead;
80 static const uint quota_magics[] = V2_INITQMAGICS;
81 static const uint quota_versions[] = V2_INITQVERSIONS;
82
83 if (v2_read_header(sb, type, &dqhead))
84 return 0;
85 if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
86 le32_to_cpu(dqhead.dqh_version) > quota_versions[type])
87 return 0;
88 return 1;
89 }
90
91 /* Read information header from quota file */
v2_read_file_info(struct super_block * sb,int type)92 static int v2_read_file_info(struct super_block *sb, int type)
93 {
94 struct v2_disk_dqinfo dinfo;
95 struct v2_disk_dqheader dqhead;
96 struct quota_info *dqopt = sb_dqopt(sb);
97 struct mem_dqinfo *info = &dqopt->info[type];
98 struct qtree_mem_dqinfo *qinfo;
99 ssize_t size;
100 unsigned int version;
101 int ret;
102
103 down_read(&dqopt->dqio_sem);
104 ret = v2_read_header(sb, type, &dqhead);
105 if (ret < 0)
106 goto out;
107 version = le32_to_cpu(dqhead.dqh_version);
108 if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
109 (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) {
110 ret = -EINVAL;
111 goto out;
112 }
113
114 size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
115 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
116 if (size != sizeof(struct v2_disk_dqinfo)) {
117 quota_error(sb, "Can't read info structure");
118 if (size < 0)
119 ret = size;
120 else
121 ret = -EIO;
122 goto out;
123 }
124 info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
125 if (!info->dqi_priv) {
126 ret = -ENOMEM;
127 goto out;
128 }
129 qinfo = info->dqi_priv;
130 if (version == 0) {
131 /* limits are stored as unsigned 32-bit data */
132 info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
133 info->dqi_max_ino_limit = 0xffffffff;
134 } else {
135 /*
136 * Used space is stored as unsigned 64-bit value in bytes but
137 * quota core supports only signed 64-bit values so use that
138 * as a limit
139 */
140 info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
141 info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
142 }
143 info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
144 info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
145 /* No flags currently supported */
146 info->dqi_flags = 0;
147 qinfo->dqi_sb = sb;
148 qinfo->dqi_type = type;
149 qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
150 qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
151 qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
152 qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
153 qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
154 qinfo->dqi_qtree_depth = qtree_depth(qinfo);
155 if (version == 0) {
156 qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
157 qinfo->dqi_ops = &v2r0_qtree_ops;
158 } else {
159 qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
160 qinfo->dqi_ops = &v2r1_qtree_ops;
161 }
162 ret = 0;
163 out:
164 up_read(&dqopt->dqio_sem);
165 return ret;
166 }
167
168 /* Write information header to quota file */
v2_write_file_info(struct super_block * sb,int type)169 static int v2_write_file_info(struct super_block *sb, int type)
170 {
171 struct v2_disk_dqinfo dinfo;
172 struct quota_info *dqopt = sb_dqopt(sb);
173 struct mem_dqinfo *info = &dqopt->info[type];
174 struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
175 ssize_t size;
176
177 down_write(&dqopt->dqio_sem);
178 spin_lock(&dq_data_lock);
179 info->dqi_flags &= ~DQF_INFO_DIRTY;
180 dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
181 dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
182 /* No flags currently supported */
183 dinfo.dqi_flags = cpu_to_le32(0);
184 spin_unlock(&dq_data_lock);
185 dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
186 dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
187 dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
188 size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
189 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
190 up_write(&dqopt->dqio_sem);
191 if (size != sizeof(struct v2_disk_dqinfo)) {
192 quota_error(sb, "Can't write info structure");
193 return -1;
194 }
195 return 0;
196 }
197
v2r0_disk2memdqb(struct dquot * dquot,void * dp)198 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
199 {
200 struct v2r0_disk_dqblk *d = dp, empty;
201 struct mem_dqblk *m = &dquot->dq_dqb;
202
203 m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
204 m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
205 m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
206 m->dqb_itime = le64_to_cpu(d->dqb_itime);
207 m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
208 m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
209 m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
210 m->dqb_btime = le64_to_cpu(d->dqb_btime);
211 /* We need to escape back all-zero structure */
212 memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
213 empty.dqb_itime = cpu_to_le64(1);
214 if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
215 m->dqb_itime = 0;
216 }
217
v2r0_mem2diskdqb(void * dp,struct dquot * dquot)218 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
219 {
220 struct v2r0_disk_dqblk *d = dp;
221 struct mem_dqblk *m = &dquot->dq_dqb;
222 struct qtree_mem_dqinfo *info =
223 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
224
225 d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
226 d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
227 d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
228 d->dqb_itime = cpu_to_le64(m->dqb_itime);
229 d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
230 d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
231 d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
232 d->dqb_btime = cpu_to_le64(m->dqb_btime);
233 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
234 if (qtree_entry_unused(info, dp))
235 d->dqb_itime = cpu_to_le64(1);
236 }
237
v2r0_is_id(void * dp,struct dquot * dquot)238 static int v2r0_is_id(void *dp, struct dquot *dquot)
239 {
240 struct v2r0_disk_dqblk *d = dp;
241 struct qtree_mem_dqinfo *info =
242 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
243
244 if (qtree_entry_unused(info, dp))
245 return 0;
246 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
247 le32_to_cpu(d->dqb_id)),
248 dquot->dq_id);
249 }
250
v2r1_disk2memdqb(struct dquot * dquot,void * dp)251 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
252 {
253 struct v2r1_disk_dqblk *d = dp, empty;
254 struct mem_dqblk *m = &dquot->dq_dqb;
255
256 m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
257 m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
258 m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
259 m->dqb_itime = le64_to_cpu(d->dqb_itime);
260 m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
261 m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
262 m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
263 m->dqb_btime = le64_to_cpu(d->dqb_btime);
264 /* We need to escape back all-zero structure */
265 memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
266 empty.dqb_itime = cpu_to_le64(1);
267 if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
268 m->dqb_itime = 0;
269 }
270
v2r1_mem2diskdqb(void * dp,struct dquot * dquot)271 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
272 {
273 struct v2r1_disk_dqblk *d = dp;
274 struct mem_dqblk *m = &dquot->dq_dqb;
275 struct qtree_mem_dqinfo *info =
276 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
277
278 d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
279 d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
280 d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
281 d->dqb_itime = cpu_to_le64(m->dqb_itime);
282 d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
283 d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
284 d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
285 d->dqb_btime = cpu_to_le64(m->dqb_btime);
286 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
287 if (qtree_entry_unused(info, dp))
288 d->dqb_itime = cpu_to_le64(1);
289 }
290
v2r1_is_id(void * dp,struct dquot * dquot)291 static int v2r1_is_id(void *dp, struct dquot *dquot)
292 {
293 struct v2r1_disk_dqblk *d = dp;
294 struct qtree_mem_dqinfo *info =
295 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
296
297 if (qtree_entry_unused(info, dp))
298 return 0;
299 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
300 le32_to_cpu(d->dqb_id)),
301 dquot->dq_id);
302 }
303
v2_read_dquot(struct dquot * dquot)304 static int v2_read_dquot(struct dquot *dquot)
305 {
306 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
307 int ret;
308
309 down_read(&dqopt->dqio_sem);
310 ret = qtree_read_dquot(
311 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
312 dquot);
313 up_read(&dqopt->dqio_sem);
314 return ret;
315 }
316
v2_write_dquot(struct dquot * dquot)317 static int v2_write_dquot(struct dquot *dquot)
318 {
319 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
320 int ret;
321 bool alloc = false;
322
323 /*
324 * If space for dquot is already allocated, we don't need any
325 * protection as we'll only overwrite the place of dquot. We are
326 * still protected by concurrent writes of the same dquot by
327 * dquot->dq_lock.
328 */
329 if (!dquot->dq_off) {
330 alloc = true;
331 down_write(&dqopt->dqio_sem);
332 } else {
333 down_read(&dqopt->dqio_sem);
334 }
335 ret = qtree_write_dquot(
336 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
337 dquot);
338 if (alloc)
339 up_write(&dqopt->dqio_sem);
340 else
341 up_read(&dqopt->dqio_sem);
342 return ret;
343 }
344
v2_release_dquot(struct dquot * dquot)345 static int v2_release_dquot(struct dquot *dquot)
346 {
347 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
348 int ret;
349
350 down_write(&dqopt->dqio_sem);
351 ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
352 up_write(&dqopt->dqio_sem);
353
354 return ret;
355 }
356
v2_free_file_info(struct super_block * sb,int type)357 static int v2_free_file_info(struct super_block *sb, int type)
358 {
359 kfree(sb_dqinfo(sb, type)->dqi_priv);
360 return 0;
361 }
362
v2_get_next_id(struct super_block * sb,struct kqid * qid)363 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
364 {
365 struct quota_info *dqopt = sb_dqopt(sb);
366 int ret;
367
368 down_read(&dqopt->dqio_sem);
369 ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
370 up_read(&dqopt->dqio_sem);
371 return ret;
372 }
373
374 static const struct quota_format_ops v2_format_ops = {
375 .check_quota_file = v2_check_quota_file,
376 .read_file_info = v2_read_file_info,
377 .write_file_info = v2_write_file_info,
378 .free_file_info = v2_free_file_info,
379 .read_dqblk = v2_read_dquot,
380 .commit_dqblk = v2_write_dquot,
381 .release_dqblk = v2_release_dquot,
382 .get_next_id = v2_get_next_id,
383 };
384
385 static struct quota_format_type v2r0_quota_format = {
386 .qf_fmt_id = QFMT_VFS_V0,
387 .qf_ops = &v2_format_ops,
388 .qf_owner = THIS_MODULE
389 };
390
391 static struct quota_format_type v2r1_quota_format = {
392 .qf_fmt_id = QFMT_VFS_V1,
393 .qf_ops = &v2_format_ops,
394 .qf_owner = THIS_MODULE
395 };
396
init_v2_quota_format(void)397 static int __init init_v2_quota_format(void)
398 {
399 int ret;
400
401 ret = register_quota_format(&v2r0_quota_format);
402 if (ret)
403 return ret;
404 return register_quota_format(&v2r1_quota_format);
405 }
406
exit_v2_quota_format(void)407 static void __exit exit_v2_quota_format(void)
408 {
409 unregister_quota_format(&v2r0_quota_format);
410 unregister_quota_format(&v2r1_quota_format);
411 }
412
413 module_init(init_v2_quota_format);
414 module_exit(exit_v2_quota_format);
415