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 unsigned int memalloc;
100 int ret;
101
102 down_read(sem: &dqopt->dqio_sem);
103 memalloc = memalloc_nofs_save();
104 ret = v2_read_header(sb, type, dqhead: &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_KERNEL);
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(info: 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 = -EUCLEAN;
163 /* Some sanity checks of the read headers... */
164 if ((loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits >
165 i_size_read(inode: sb_dqopt(sb)->files[type])) {
166 quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).",
167 (loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits,
168 i_size_read(sb_dqopt(sb)->files[type]));
169 goto out_free;
170 }
171 if (qinfo->dqi_free_blk && (qinfo->dqi_free_blk <= QT_TREEOFF ||
172 qinfo->dqi_free_blk >= qinfo->dqi_blocks)) {
173 quota_error(sb, "Free block number %u out of range (%u, %u).",
174 qinfo->dqi_free_blk, QT_TREEOFF, qinfo->dqi_blocks);
175 goto out_free;
176 }
177 if (qinfo->dqi_free_entry && (qinfo->dqi_free_entry <= QT_TREEOFF ||
178 qinfo->dqi_free_entry >= qinfo->dqi_blocks)) {
179 quota_error(sb, "Block with free entry %u out of range (%u, %u).",
180 qinfo->dqi_free_entry, QT_TREEOFF,
181 qinfo->dqi_blocks);
182 goto out_free;
183 }
184 ret = 0;
185out_free:
186 if (ret) {
187 kfree(objp: info->dqi_priv);
188 info->dqi_priv = NULL;
189 }
190out:
191 memalloc_nofs_restore(flags: memalloc);
192 up_read(sem: &dqopt->dqio_sem);
193 return ret;
194}
195
196/* Write information header to quota file */
197static int v2_write_file_info(struct super_block *sb, int type)
198{
199 struct v2_disk_dqinfo dinfo;
200 struct quota_info *dqopt = sb_dqopt(sb);
201 struct mem_dqinfo *info = &dqopt->info[type];
202 struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
203 ssize_t size;
204 unsigned int memalloc;
205
206 down_write(sem: &dqopt->dqio_sem);
207 memalloc = memalloc_nofs_save();
208 spin_lock(lock: &dq_data_lock);
209 info->dqi_flags &= ~DQF_INFO_DIRTY;
210 dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
211 dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
212 /* No flags currently supported */
213 dinfo.dqi_flags = cpu_to_le32(0);
214 spin_unlock(lock: &dq_data_lock);
215 dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
216 dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
217 dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
218 size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
219 sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
220 memalloc_nofs_restore(flags: memalloc);
221 up_write(sem: &dqopt->dqio_sem);
222 if (size != sizeof(struct v2_disk_dqinfo)) {
223 quota_error(sb, "Can't write info structure");
224 return size < 0 ? size : -EIO;
225 }
226 return 0;
227}
228
229static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
230{
231 struct v2r0_disk_dqblk *d = dp, empty;
232 struct mem_dqblk *m = &dquot->dq_dqb;
233
234 m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
235 m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
236 m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
237 m->dqb_itime = le64_to_cpu(d->dqb_itime);
238 m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
239 m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
240 m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
241 m->dqb_btime = le64_to_cpu(d->dqb_btime);
242 /* We need to escape back all-zero structure */
243 memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
244 empty.dqb_itime = cpu_to_le64(1);
245 if (!memcmp(p: &empty, q: dp, size: sizeof(struct v2r0_disk_dqblk)))
246 m->dqb_itime = 0;
247}
248
249static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
250{
251 struct v2r0_disk_dqblk *d = dp;
252 struct mem_dqblk *m = &dquot->dq_dqb;
253 struct qtree_mem_dqinfo *info =
254 sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv;
255
256 d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
257 d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
258 d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
259 d->dqb_itime = cpu_to_le64(m->dqb_itime);
260 d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
261 d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
262 d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
263 d->dqb_btime = cpu_to_le64(m->dqb_btime);
264 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
265 if (qtree_entry_unused(info, disk: dp))
266 d->dqb_itime = cpu_to_le64(1);
267}
268
269static int v2r0_is_id(void *dp, struct dquot *dquot)
270{
271 struct v2r0_disk_dqblk *d = dp;
272 struct qtree_mem_dqinfo *info =
273 sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv;
274
275 if (qtree_entry_unused(info, disk: dp))
276 return 0;
277 return qid_eq(left: make_kqid(from: &init_user_ns, type: dquot->dq_id.type,
278 le32_to_cpu(d->dqb_id)),
279 right: dquot->dq_id);
280}
281
282static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
283{
284 struct v2r1_disk_dqblk *d = dp, empty;
285 struct mem_dqblk *m = &dquot->dq_dqb;
286
287 m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
288 m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
289 m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
290 m->dqb_itime = le64_to_cpu(d->dqb_itime);
291 m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
292 m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
293 m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
294 m->dqb_btime = le64_to_cpu(d->dqb_btime);
295 /* We need to escape back all-zero structure */
296 memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
297 empty.dqb_itime = cpu_to_le64(1);
298 if (!memcmp(p: &empty, q: dp, size: sizeof(struct v2r1_disk_dqblk)))
299 m->dqb_itime = 0;
300}
301
302static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
303{
304 struct v2r1_disk_dqblk *d = dp;
305 struct mem_dqblk *m = &dquot->dq_dqb;
306 struct qtree_mem_dqinfo *info =
307 sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv;
308
309 d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
310 d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
311 d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
312 d->dqb_itime = cpu_to_le64(m->dqb_itime);
313 d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
314 d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
315 d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
316 d->dqb_btime = cpu_to_le64(m->dqb_btime);
317 d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
318 d->dqb_pad = 0;
319 if (qtree_entry_unused(info, disk: dp))
320 d->dqb_itime = cpu_to_le64(1);
321}
322
323static int v2r1_is_id(void *dp, struct dquot *dquot)
324{
325 struct v2r1_disk_dqblk *d = dp;
326 struct qtree_mem_dqinfo *info =
327 sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv;
328
329 if (qtree_entry_unused(info, disk: dp))
330 return 0;
331 return qid_eq(left: make_kqid(from: &init_user_ns, type: dquot->dq_id.type,
332 le32_to_cpu(d->dqb_id)),
333 right: dquot->dq_id);
334}
335
336static int v2_read_dquot(struct dquot *dquot)
337{
338 struct quota_info *dqopt = sb_dqopt(sb: dquot->dq_sb);
339 int ret;
340 unsigned int memalloc;
341
342 down_read(sem: &dqopt->dqio_sem);
343 memalloc = memalloc_nofs_save();
344 ret = qtree_read_dquot(
345 info: sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv,
346 dquot);
347 memalloc_nofs_restore(flags: memalloc);
348 up_read(sem: &dqopt->dqio_sem);
349 return ret;
350}
351
352static int v2_write_dquot(struct dquot *dquot)
353{
354 struct quota_info *dqopt = sb_dqopt(sb: dquot->dq_sb);
355 int ret;
356 bool alloc = false;
357 unsigned int memalloc;
358
359 /*
360 * If space for dquot is already allocated, we don't need any
361 * protection as we'll only overwrite the place of dquot. We are
362 * still protected by concurrent writes of the same dquot by
363 * dquot->dq_lock.
364 */
365 if (!dquot->dq_off) {
366 alloc = true;
367 down_write(sem: &dqopt->dqio_sem);
368 } else {
369 down_read(sem: &dqopt->dqio_sem);
370 }
371 memalloc = memalloc_nofs_save();
372 ret = qtree_write_dquot(
373 info: sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv,
374 dquot);
375 memalloc_nofs_restore(flags: memalloc);
376 if (alloc)
377 up_write(sem: &dqopt->dqio_sem);
378 else
379 up_read(sem: &dqopt->dqio_sem);
380 return ret;
381}
382
383static int v2_release_dquot(struct dquot *dquot)
384{
385 struct quota_info *dqopt = sb_dqopt(sb: dquot->dq_sb);
386 unsigned int memalloc;
387 int ret;
388
389 down_write(sem: &dqopt->dqio_sem);
390 memalloc = memalloc_nofs_save();
391 ret = qtree_release_dquot(info: sb_dqinfo(sb: dquot->dq_sb, type: dquot->dq_id.type)->dqi_priv, dquot);
392 memalloc_nofs_restore(flags: memalloc);
393 up_write(sem: &dqopt->dqio_sem);
394
395 return ret;
396}
397
398static int v2_free_file_info(struct super_block *sb, int type)
399{
400 kfree(objp: sb_dqinfo(sb, type)->dqi_priv);
401 return 0;
402}
403
404static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
405{
406 struct quota_info *dqopt = sb_dqopt(sb);
407 unsigned int memalloc;
408 int ret;
409
410 down_read(sem: &dqopt->dqio_sem);
411 memalloc = memalloc_nofs_save();
412 ret = qtree_get_next_id(info: sb_dqinfo(sb, type: qid->type)->dqi_priv, qid);
413 memalloc_nofs_restore(flags: memalloc);
414 up_read(sem: &dqopt->dqio_sem);
415 return ret;
416}
417
418static const struct quota_format_ops v2_format_ops = {
419 .check_quota_file = v2_check_quota_file,
420 .read_file_info = v2_read_file_info,
421 .write_file_info = v2_write_file_info,
422 .free_file_info = v2_free_file_info,
423 .read_dqblk = v2_read_dquot,
424 .commit_dqblk = v2_write_dquot,
425 .release_dqblk = v2_release_dquot,
426 .get_next_id = v2_get_next_id,
427};
428
429static struct quota_format_type v2r0_quota_format = {
430 .qf_fmt_id = QFMT_VFS_V0,
431 .qf_ops = &v2_format_ops,
432 .qf_owner = THIS_MODULE
433};
434
435static struct quota_format_type v2r1_quota_format = {
436 .qf_fmt_id = QFMT_VFS_V1,
437 .qf_ops = &v2_format_ops,
438 .qf_owner = THIS_MODULE
439};
440
441static int __init init_v2_quota_format(void)
442{
443 register_quota_format(fmt: &v2r0_quota_format);
444 register_quota_format(fmt: &v2r1_quota_format);
445 return 0;
446}
447
448static void __exit exit_v2_quota_format(void)
449{
450 unregister_quota_format(fmt: &v2r0_quota_format);
451 unregister_quota_format(fmt: &v2r1_quota_format);
452}
453
454module_init(init_v2_quota_format);
455module_exit(exit_v2_quota_format);
456

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