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 = -EUCLEAN;
161 /* Some sanity checks of the read headers... */
162 if ((loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits >
163 i_size_read(sb_dqopt(sb)->files[type])) {
164 quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).",
165 (loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits,
166 i_size_read(sb_dqopt(sb)->files[type]));
167 goto out_free;
168 }
169 if (qinfo->dqi_free_blk && (qinfo->dqi_free_blk <= QT_TREEOFF ||
170 qinfo->dqi_free_blk >= qinfo->dqi_blocks)) {
171 quota_error(sb, "Free block number %u out of range (%u, %u).",
172 qinfo->dqi_free_blk, QT_TREEOFF, qinfo->dqi_blocks);
173 goto out_free;
174 }
175 if (qinfo->dqi_free_entry && (qinfo->dqi_free_entry <= QT_TREEOFF ||
176 qinfo->dqi_free_entry >= qinfo->dqi_blocks)) {
177 quota_error(sb, "Block with free entry %u out of range (%u, %u).",
178 qinfo->dqi_free_entry, QT_TREEOFF,
179 qinfo->dqi_blocks);
180 goto out_free;
181 }
182 ret = 0;
183 out_free:
184 if (ret) {
185 kfree(info->dqi_priv);
186 info->dqi_priv = NULL;
187 }
188 out:
189 up_read(&dqopt->dqio_sem);
190 return ret;
191 }
192
193 /* Write information header to quota file */
v2_write_file_info(struct super_block * sb,int type)194 static int v2_write_file_info(struct super_block *sb, int type)
195 {
196 struct v2_disk_dqinfo dinfo;
197 struct quota_info *dqopt = sb_dqopt(sb);
198 struct mem_dqinfo *info = &dqopt->info[type];
199 struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
200 ssize_t size;
201
202 down_write(&dqopt->dqio_sem);
203 spin_lock(&dq_data_lock);
204 info->dqi_flags &= ~DQF_INFO_DIRTY;
205 dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
206 dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
207 /* No flags currently supported */
208 dinfo.dqi_flags = cpu_to_le32(0);
209 spin_unlock(&dq_data_lock);
210 dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
211 dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
212 dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
213 size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
214 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
215 up_write(&dqopt->dqio_sem);
216 if (size != sizeof(struct v2_disk_dqinfo)) {
217 quota_error(sb, "Can't write info structure");
218 return size < 0 ? size : -EIO;
219 }
220 return 0;
221 }
222
v2r0_disk2memdqb(struct dquot * dquot,void * dp)223 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
224 {
225 struct v2r0_disk_dqblk *d = dp, empty;
226 struct mem_dqblk *m = &dquot->dq_dqb;
227
228 m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
229 m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
230 m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
231 m->dqb_itime = le64_to_cpu(d->dqb_itime);
232 m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
233 m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
234 m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
235 m->dqb_btime = le64_to_cpu(d->dqb_btime);
236 /* We need to escape back all-zero structure */
237 memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
238 empty.dqb_itime = cpu_to_le64(1);
239 if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
240 m->dqb_itime = 0;
241 }
242
v2r0_mem2diskdqb(void * dp,struct dquot * dquot)243 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
244 {
245 struct v2r0_disk_dqblk *d = dp;
246 struct mem_dqblk *m = &dquot->dq_dqb;
247 struct qtree_mem_dqinfo *info =
248 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
249
250 d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
251 d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
252 d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
253 d->dqb_itime = cpu_to_le64(m->dqb_itime);
254 d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
255 d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
256 d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
257 d->dqb_btime = cpu_to_le64(m->dqb_btime);
258 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
259 if (qtree_entry_unused(info, dp))
260 d->dqb_itime = cpu_to_le64(1);
261 }
262
v2r0_is_id(void * dp,struct dquot * dquot)263 static int v2r0_is_id(void *dp, struct dquot *dquot)
264 {
265 struct v2r0_disk_dqblk *d = dp;
266 struct qtree_mem_dqinfo *info =
267 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
268
269 if (qtree_entry_unused(info, dp))
270 return 0;
271 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
272 le32_to_cpu(d->dqb_id)),
273 dquot->dq_id);
274 }
275
v2r1_disk2memdqb(struct dquot * dquot,void * dp)276 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
277 {
278 struct v2r1_disk_dqblk *d = dp, empty;
279 struct mem_dqblk *m = &dquot->dq_dqb;
280
281 m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
282 m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
283 m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
284 m->dqb_itime = le64_to_cpu(d->dqb_itime);
285 m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
286 m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
287 m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
288 m->dqb_btime = le64_to_cpu(d->dqb_btime);
289 /* We need to escape back all-zero structure */
290 memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
291 empty.dqb_itime = cpu_to_le64(1);
292 if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
293 m->dqb_itime = 0;
294 }
295
v2r1_mem2diskdqb(void * dp,struct dquot * dquot)296 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
297 {
298 struct v2r1_disk_dqblk *d = dp;
299 struct mem_dqblk *m = &dquot->dq_dqb;
300 struct qtree_mem_dqinfo *info =
301 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
302
303 d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
304 d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
305 d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
306 d->dqb_itime = cpu_to_le64(m->dqb_itime);
307 d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
308 d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
309 d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
310 d->dqb_btime = cpu_to_le64(m->dqb_btime);
311 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
312 d->dqb_pad = 0;
313 if (qtree_entry_unused(info, dp))
314 d->dqb_itime = cpu_to_le64(1);
315 }
316
v2r1_is_id(void * dp,struct dquot * dquot)317 static int v2r1_is_id(void *dp, struct dquot *dquot)
318 {
319 struct v2r1_disk_dqblk *d = dp;
320 struct qtree_mem_dqinfo *info =
321 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
322
323 if (qtree_entry_unused(info, dp))
324 return 0;
325 return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
326 le32_to_cpu(d->dqb_id)),
327 dquot->dq_id);
328 }
329
v2_read_dquot(struct dquot * dquot)330 static int v2_read_dquot(struct dquot *dquot)
331 {
332 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
333 int ret;
334
335 down_read(&dqopt->dqio_sem);
336 ret = qtree_read_dquot(
337 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
338 dquot);
339 up_read(&dqopt->dqio_sem);
340 return ret;
341 }
342
v2_write_dquot(struct dquot * dquot)343 static int v2_write_dquot(struct dquot *dquot)
344 {
345 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
346 int ret;
347 bool alloc = false;
348
349 /*
350 * If space for dquot is already allocated, we don't need any
351 * protection as we'll only overwrite the place of dquot. We are
352 * still protected by concurrent writes of the same dquot by
353 * dquot->dq_lock.
354 */
355 if (!dquot->dq_off) {
356 alloc = true;
357 down_write(&dqopt->dqio_sem);
358 } else {
359 down_read(&dqopt->dqio_sem);
360 }
361 ret = qtree_write_dquot(
362 sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
363 dquot);
364 if (alloc)
365 up_write(&dqopt->dqio_sem);
366 else
367 up_read(&dqopt->dqio_sem);
368 return ret;
369 }
370
v2_release_dquot(struct dquot * dquot)371 static int v2_release_dquot(struct dquot *dquot)
372 {
373 struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
374 int ret;
375
376 down_write(&dqopt->dqio_sem);
377 ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
378 up_write(&dqopt->dqio_sem);
379
380 return ret;
381 }
382
v2_free_file_info(struct super_block * sb,int type)383 static int v2_free_file_info(struct super_block *sb, int type)
384 {
385 kfree(sb_dqinfo(sb, type)->dqi_priv);
386 return 0;
387 }
388
v2_get_next_id(struct super_block * sb,struct kqid * qid)389 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
390 {
391 struct quota_info *dqopt = sb_dqopt(sb);
392 int ret;
393
394 down_read(&dqopt->dqio_sem);
395 ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
396 up_read(&dqopt->dqio_sem);
397 return ret;
398 }
399
400 static const struct quota_format_ops v2_format_ops = {
401 .check_quota_file = v2_check_quota_file,
402 .read_file_info = v2_read_file_info,
403 .write_file_info = v2_write_file_info,
404 .free_file_info = v2_free_file_info,
405 .read_dqblk = v2_read_dquot,
406 .commit_dqblk = v2_write_dquot,
407 .release_dqblk = v2_release_dquot,
408 .get_next_id = v2_get_next_id,
409 };
410
411 static struct quota_format_type v2r0_quota_format = {
412 .qf_fmt_id = QFMT_VFS_V0,
413 .qf_ops = &v2_format_ops,
414 .qf_owner = THIS_MODULE
415 };
416
417 static struct quota_format_type v2r1_quota_format = {
418 .qf_fmt_id = QFMT_VFS_V1,
419 .qf_ops = &v2_format_ops,
420 .qf_owner = THIS_MODULE
421 };
422
init_v2_quota_format(void)423 static int __init init_v2_quota_format(void)
424 {
425 int ret;
426
427 ret = register_quota_format(&v2r0_quota_format);
428 if (ret)
429 return ret;
430 return register_quota_format(&v2r1_quota_format);
431 }
432
exit_v2_quota_format(void)433 static void __exit exit_v2_quota_format(void)
434 {
435 unregister_quota_format(&v2r0_quota_format);
436 unregister_quota_format(&v2r1_quota_format);
437 }
438
439 module_init(init_v2_quota_format);
440 module_exit(exit_v2_quota_format);
441