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
21MODULE_AUTHOR("Jan Kara");
22MODULE_DESCRIPTION("Quota format v2 support");
23MODULE_LICENSE("GPL");
24
25static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
26static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
27static int v2r0_is_id(void *dp, struct dquot *dquot);
28static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
29static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
30static int v2r1_is_id(void *dp, struct dquot *dquot);
31
32static 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
38static 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
47static inline qsize_t v2_stoqb(qsize_t space)
48{
49 return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
50}
51
52static inline qsize_t v2_qbtos(qsize_t blocks)
53{
54 return blocks << QUOTABLOCK_BITS;
55}
56
57static 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 */
75static 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: &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 */
90static 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(sem: &dqopt->dqio_sem);
102 ret = v2_read_header(sb, type, dqhead: &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(size: 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(info: 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(inode: 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_blocks) {
170 quota_error(sb, "Free block number too big (%u >= %u).",
171 qinfo->dqi_free_blk, qinfo->dqi_blocks);
172 goto out_free;
173 }
174 if (qinfo->dqi_free_entry >= qinfo->dqi_blocks) {
175 quota_error(sb, "Block with free entry too big (%u >= %u).",
176 qinfo->dqi_free_entry, qinfo->dqi_blocks);
177 goto out_free;
178 }
179 ret = 0;
180out_free:
181 if (ret) {
182 kfree(objp: info->dqi_priv);
183 info->dqi_priv = NULL;
184 }
185out:
186 up_read(sem: &dqopt->dqio_sem);
187 return ret;
188}
189
190/* Write information header to quota file */
191static int v2_write_file_info(struct super_block *sb, int type)
192{
193 struct v2_disk_dqinfo dinfo;
194 struct quota_info *dqopt = sb_dqopt(sb);
195 struct mem_dqinfo *info = &dqopt->info[type];
196 struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
197 ssize_t size;
198
199 down_write(sem: &dqopt->dqio_sem);
200 spin_lock(lock: &dq_data_lock);
201 info->dqi_flags &= ~DQF_INFO_DIRTY;
202 dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
203 dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
204 /* No flags currently supported */
205 dinfo.dqi_flags = cpu_to_le32(0);
206 spin_unlock(lock: &dq_data_lock);
207 dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
208 dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
209 dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
210 size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
211 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
212 up_write(sem: &dqopt->dqio_sem);
213 if (size != sizeof(struct v2_disk_dqinfo)) {
214 quota_error(sb, "Can't write info structure");
215 return size < 0 ? size : -EIO;
216 }
217 return 0;
218}
219
220static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
221{
222 struct v2r0_disk_dqblk *d = dp, empty;
223 struct mem_dqblk *m = &dquot->dq_dqb;
224
225 m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
226 m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
227 m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
228 m->dqb_itime = le64_to_cpu(d->dqb_itime);
229 m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
230 m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
231 m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
232 m->dqb_btime = le64_to_cpu(d->dqb_btime);
233 /* We need to escape back all-zero structure */
234 memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
235 empty.dqb_itime = cpu_to_le64(1);
236 if (!memcmp(p: &empty, q: dp, size: sizeof(struct v2r0_disk_dqblk)))
237 m->dqb_itime = 0;
238}
239
240static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
241{
242 struct v2r0_disk_dqblk *d = dp;
243 struct mem_dqblk *m = &dquot->dq_dqb;
244 struct qtree_mem_dqinfo *info =
245 sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv;
246
247 d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
248 d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
249 d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
250 d->dqb_itime = cpu_to_le64(m->dqb_itime);
251 d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
252 d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
253 d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
254 d->dqb_btime = cpu_to_le64(m->dqb_btime);
255 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
256 if (qtree_entry_unused(info, disk: dp))
257 d->dqb_itime = cpu_to_le64(1);
258}
259
260static int v2r0_is_id(void *dp, struct dquot *dquot)
261{
262 struct v2r0_disk_dqblk *d = dp;
263 struct qtree_mem_dqinfo *info =
264 sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv;
265
266 if (qtree_entry_unused(info, disk: dp))
267 return 0;
268 return qid_eq(left: make_kqid(from: &init_user_ns, type: dquot->dq_id.type,
269 le32_to_cpu(d->dqb_id)),
270 right: dquot->dq_id);
271}
272
273static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
274{
275 struct v2r1_disk_dqblk *d = dp, empty;
276 struct mem_dqblk *m = &dquot->dq_dqb;
277
278 m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
279 m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
280 m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
281 m->dqb_itime = le64_to_cpu(d->dqb_itime);
282 m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
283 m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
284 m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
285 m->dqb_btime = le64_to_cpu(d->dqb_btime);
286 /* We need to escape back all-zero structure */
287 memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
288 empty.dqb_itime = cpu_to_le64(1);
289 if (!memcmp(p: &empty, q: dp, size: sizeof(struct v2r1_disk_dqblk)))
290 m->dqb_itime = 0;
291}
292
293static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
294{
295 struct v2r1_disk_dqblk *d = dp;
296 struct mem_dqblk *m = &dquot->dq_dqb;
297 struct qtree_mem_dqinfo *info =
298 sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv;
299
300 d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
301 d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
302 d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
303 d->dqb_itime = cpu_to_le64(m->dqb_itime);
304 d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
305 d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
306 d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
307 d->dqb_btime = cpu_to_le64(m->dqb_btime);
308 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
309 d->dqb_pad = 0;
310 if (qtree_entry_unused(info, disk: dp))
311 d->dqb_itime = cpu_to_le64(1);
312}
313
314static int v2r1_is_id(void *dp, struct dquot *dquot)
315{
316 struct v2r1_disk_dqblk *d = dp;
317 struct qtree_mem_dqinfo *info =
318 sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv;
319
320 if (qtree_entry_unused(info, disk: dp))
321 return 0;
322 return qid_eq(left: make_kqid(from: &init_user_ns, type: dquot->dq_id.type,
323 le32_to_cpu(d->dqb_id)),
324 right: dquot->dq_id);
325}
326
327static int v2_read_dquot(struct dquot *dquot)
328{
329 struct quota_info *dqopt = sb_dqopt(sb: dquot->dq_sb);
330 int ret;
331
332 down_read(sem: &dqopt->dqio_sem);
333 ret = qtree_read_dquot(
334 info: sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv,
335 dquot);
336 up_read(sem: &dqopt->dqio_sem);
337 return ret;
338}
339
340static int v2_write_dquot(struct dquot *dquot)
341{
342 struct quota_info *dqopt = sb_dqopt(sb: dquot->dq_sb);
343 int ret;
344 bool alloc = false;
345
346 /*
347 * If space for dquot is already allocated, we don't need any
348 * protection as we'll only overwrite the place of dquot. We are
349 * still protected by concurrent writes of the same dquot by
350 * dquot->dq_lock.
351 */
352 if (!dquot->dq_off) {
353 alloc = true;
354 down_write(sem: &dqopt->dqio_sem);
355 } else {
356 down_read(sem: &dqopt->dqio_sem);
357 }
358 ret = qtree_write_dquot(
359 info: sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv,
360 dquot);
361 if (alloc)
362 up_write(sem: &dqopt->dqio_sem);
363 else
364 up_read(sem: &dqopt->dqio_sem);
365 return ret;
366}
367
368static int v2_release_dquot(struct dquot *dquot)
369{
370 struct quota_info *dqopt = sb_dqopt(sb: dquot->dq_sb);
371 int ret;
372
373 down_write(sem: &dqopt->dqio_sem);
374 ret = qtree_release_dquot(info: sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv, dquot);
375 up_write(sem: &dqopt->dqio_sem);
376
377 return ret;
378}
379
380static int v2_free_file_info(struct super_block *sb, int type)
381{
382 kfree(objp: sb_dqinfo(sb, type)->dqi_priv);
383 return 0;
384}
385
386static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
387{
388 struct quota_info *dqopt = sb_dqopt(sb);
389 int ret;
390
391 down_read(sem: &dqopt->dqio_sem);
392 ret = qtree_get_next_id(info: sb_dqinfo(sb, type: qid->type)->dqi_priv, qid);
393 up_read(sem: &dqopt->dqio_sem);
394 return ret;
395}
396
397static const struct quota_format_ops v2_format_ops = {
398 .check_quota_file = v2_check_quota_file,
399 .read_file_info = v2_read_file_info,
400 .write_file_info = v2_write_file_info,
401 .free_file_info = v2_free_file_info,
402 .read_dqblk = v2_read_dquot,
403 .commit_dqblk = v2_write_dquot,
404 .release_dqblk = v2_release_dquot,
405 .get_next_id = v2_get_next_id,
406};
407
408static struct quota_format_type v2r0_quota_format = {
409 .qf_fmt_id = QFMT_VFS_V0,
410 .qf_ops = &v2_format_ops,
411 .qf_owner = THIS_MODULE
412};
413
414static struct quota_format_type v2r1_quota_format = {
415 .qf_fmt_id = QFMT_VFS_V1,
416 .qf_ops = &v2_format_ops,
417 .qf_owner = THIS_MODULE
418};
419
420static int __init init_v2_quota_format(void)
421{
422 int ret;
423
424 ret = register_quota_format(fmt: &v2r0_quota_format);
425 if (ret)
426 return ret;
427 return register_quota_format(fmt: &v2r1_quota_format);
428}
429
430static void __exit exit_v2_quota_format(void)
431{
432 unregister_quota_format(fmt: &v2r0_quota_format);
433 unregister_quota_format(fmt: &v2r1_quota_format);
434}
435
436module_init(init_v2_quota_format);
437module_exit(exit_v2_quota_format);
438

source code of linux/fs/quota/quota_v2.c