GNU Linux-libre 4.19.211-gnu1
[releases.git] / fs / quota / quota_v2.c
1 /*
2  *      vfsv0 quota IO operations on file
3  */
4
5 #include <linux/errno.h>
6 #include <linux/fs.h>
7 #include <linux/mount.h>
8 #include <linux/dqblk_v2.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/quotaops.h>
14
15 #include <asm/byteorder.h>
16
17 #include "quota_tree.h"
18 #include "quotaio_v2.h"
19
20 MODULE_AUTHOR("Jan Kara");
21 MODULE_DESCRIPTION("Quota format v2 support");
22 MODULE_LICENSE("GPL");
23
24 #define __QUOTA_V2_PARANOIA
25
26 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
27 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
28 static int v2r0_is_id(void *dp, struct dquot *dquot);
29 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
30 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
31 static int v2r1_is_id(void *dp, struct dquot *dquot);
32
33 static const struct qtree_fmt_operations v2r0_qtree_ops = {
34         .mem2disk_dqblk = v2r0_mem2diskdqb,
35         .disk2mem_dqblk = v2r0_disk2memdqb,
36         .is_id = v2r0_is_id,
37 };
38
39 static const struct qtree_fmt_operations v2r1_qtree_ops = {
40         .mem2disk_dqblk = v2r1_mem2diskdqb,
41         .disk2mem_dqblk = v2r1_disk2memdqb,
42         .is_id = v2r1_is_id,
43 };
44
45 #define QUOTABLOCK_BITS 10
46 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
47
48 static inline qsize_t v2_stoqb(qsize_t space)
49 {
50         return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
51 }
52
53 static inline qsize_t v2_qbtos(qsize_t blocks)
54 {
55         return blocks << QUOTABLOCK_BITS;
56 }
57
58 static int v2_read_header(struct super_block *sb, int type,
59                           struct v2_disk_dqheader *dqhead)
60 {
61         ssize_t size;
62
63         size = sb->s_op->quota_read(sb, type, (char *)dqhead,
64                                     sizeof(struct v2_disk_dqheader), 0);
65         if (size != sizeof(struct v2_disk_dqheader)) {
66                 quota_error(sb, "Failed header read: expected=%zd got=%zd",
67                             sizeof(struct v2_disk_dqheader), size);
68                 if (size < 0)
69                         return size;
70                 return -EIO;
71         }
72         return 0;
73 }
74
75 /* Check whether given file is really vfsv0 quotafile */
76 static int v2_check_quota_file(struct super_block *sb, int type)
77 {
78         struct v2_disk_dqheader dqhead;
79         static const uint quota_magics[] = V2_INITQMAGICS;
80         static const uint quota_versions[] = V2_INITQVERSIONS;
81  
82         if (v2_read_header(sb, type, &dqhead))
83                 return 0;
84         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
85             le32_to_cpu(dqhead.dqh_version) > quota_versions[type])
86                 return 0;
87         return 1;
88 }
89
90 /* Read information header from quota file */
91 static int v2_read_file_info(struct super_block *sb, int type)
92 {
93         struct v2_disk_dqinfo dinfo;
94         struct v2_disk_dqheader dqhead;
95         struct quota_info *dqopt = sb_dqopt(sb);
96         struct mem_dqinfo *info = &dqopt->info[type];
97         struct qtree_mem_dqinfo *qinfo;
98         ssize_t size;
99         unsigned int version;
100         int ret;
101
102         down_read(&dqopt->dqio_sem);
103         ret = v2_read_header(sb, type, &dqhead);
104         if (ret < 0)
105                 goto out;
106         version = le32_to_cpu(dqhead.dqh_version);
107         if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
108             (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1)) {
109                 ret = -EINVAL;
110                 goto out;
111         }
112
113         size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
114                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
115         if (size != sizeof(struct v2_disk_dqinfo)) {
116                 quota_error(sb, "Can't read info structure");
117                 if (size < 0)
118                         ret = size;
119                 else
120                         ret = -EIO;
121                 goto out;
122         }
123         info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
124         if (!info->dqi_priv) {
125                 ret = -ENOMEM;
126                 goto out;
127         }
128         qinfo = info->dqi_priv;
129         if (version == 0) {
130                 /* limits are stored as unsigned 32-bit data */
131                 info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
132                 info->dqi_max_ino_limit = 0xffffffff;
133         } else {
134                 /*
135                  * Used space is stored as unsigned 64-bit value in bytes but
136                  * quota core supports only signed 64-bit values so use that
137                  * as a limit
138                  */
139                 info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
140                 info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
141         }
142         info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
143         info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
144         /* No flags currently supported */
145         info->dqi_flags = 0;
146         qinfo->dqi_sb = sb;
147         qinfo->dqi_type = type;
148         qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
149         qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
150         qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
151         qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
152         qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
153         qinfo->dqi_qtree_depth = qtree_depth(qinfo);
154         if (version == 0) {
155                 qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
156                 qinfo->dqi_ops = &v2r0_qtree_ops;
157         } else {
158                 qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
159                 qinfo->dqi_ops = &v2r1_qtree_ops;
160         }
161         ret = -EUCLEAN;
162         /* Some sanity checks of the read headers... */
163         if ((loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits >
164             i_size_read(sb_dqopt(sb)->files[type])) {
165                 quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).",
166                     (loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits,
167                     i_size_read(sb_dqopt(sb)->files[type]));
168                 goto out_free;
169         }
170         if (qinfo->dqi_free_blk >= qinfo->dqi_blocks) {
171                 quota_error(sb, "Free block number too big (%u >= %u).",
172                             qinfo->dqi_free_blk, qinfo->dqi_blocks);
173                 goto out_free;
174         }
175         if (qinfo->dqi_free_entry >= qinfo->dqi_blocks) {
176                 quota_error(sb, "Block with free entry too big (%u >= %u).",
177                             qinfo->dqi_free_entry, qinfo->dqi_blocks);
178                 goto out_free;
179         }
180         ret = 0;
181 out_free:
182         if (ret) {
183                 kfree(info->dqi_priv);
184                 info->dqi_priv = NULL;
185         }
186 out:
187         up_read(&dqopt->dqio_sem);
188         return ret;
189 }
190
191 /* Write information header to quota file */
192 static int v2_write_file_info(struct super_block *sb, int type)
193 {
194         struct v2_disk_dqinfo dinfo;
195         struct quota_info *dqopt = sb_dqopt(sb);
196         struct mem_dqinfo *info = &dqopt->info[type];
197         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
198         ssize_t size;
199
200         down_write(&dqopt->dqio_sem);
201         spin_lock(&dq_data_lock);
202         info->dqi_flags &= ~DQF_INFO_DIRTY;
203         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
204         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
205         /* No flags currently supported */
206         dinfo.dqi_flags = cpu_to_le32(0);
207         spin_unlock(&dq_data_lock);
208         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
209         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
210         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
211         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
212                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
213         up_write(&dqopt->dqio_sem);
214         if (size != sizeof(struct v2_disk_dqinfo)) {
215                 quota_error(sb, "Can't write info structure");
216                 return -1;
217         }
218         return 0;
219 }
220
221 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
222 {
223         struct v2r0_disk_dqblk *d = dp, empty;
224         struct mem_dqblk *m = &dquot->dq_dqb;
225
226         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
227         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
228         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
229         m->dqb_itime = le64_to_cpu(d->dqb_itime);
230         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
231         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
232         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
233         m->dqb_btime = le64_to_cpu(d->dqb_btime);
234         /* We need to escape back all-zero structure */
235         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
236         empty.dqb_itime = cpu_to_le64(1);
237         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
238                 m->dqb_itime = 0;
239 }
240
241 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
242 {
243         struct v2r0_disk_dqblk *d = dp;
244         struct mem_dqblk *m = &dquot->dq_dqb;
245         struct qtree_mem_dqinfo *info =
246                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
247
248         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
249         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
250         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
251         d->dqb_itime = cpu_to_le64(m->dqb_itime);
252         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
253         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
254         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
255         d->dqb_btime = cpu_to_le64(m->dqb_btime);
256         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
257         if (qtree_entry_unused(info, dp))
258                 d->dqb_itime = cpu_to_le64(1);
259 }
260
261 static int v2r0_is_id(void *dp, struct dquot *dquot)
262 {
263         struct v2r0_disk_dqblk *d = dp;
264         struct qtree_mem_dqinfo *info =
265                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
266
267         if (qtree_entry_unused(info, dp))
268                 return 0;
269         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
270                                 le32_to_cpu(d->dqb_id)),
271                       dquot->dq_id);
272 }
273
274 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
275 {
276         struct v2r1_disk_dqblk *d = dp, empty;
277         struct mem_dqblk *m = &dquot->dq_dqb;
278
279         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
280         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
281         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
282         m->dqb_itime = le64_to_cpu(d->dqb_itime);
283         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
284         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
285         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
286         m->dqb_btime = le64_to_cpu(d->dqb_btime);
287         /* We need to escape back all-zero structure */
288         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
289         empty.dqb_itime = cpu_to_le64(1);
290         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
291                 m->dqb_itime = 0;
292 }
293
294 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
295 {
296         struct v2r1_disk_dqblk *d = dp;
297         struct mem_dqblk *m = &dquot->dq_dqb;
298         struct qtree_mem_dqinfo *info =
299                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
300
301         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
302         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
303         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
304         d->dqb_itime = cpu_to_le64(m->dqb_itime);
305         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
306         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
307         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
308         d->dqb_btime = cpu_to_le64(m->dqb_btime);
309         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
310         d->dqb_pad = 0;
311         if (qtree_entry_unused(info, dp))
312                 d->dqb_itime = cpu_to_le64(1);
313 }
314
315 static int v2r1_is_id(void *dp, struct dquot *dquot)
316 {
317         struct v2r1_disk_dqblk *d = dp;
318         struct qtree_mem_dqinfo *info =
319                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
320
321         if (qtree_entry_unused(info, dp))
322                 return 0;
323         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
324                                 le32_to_cpu(d->dqb_id)),
325                       dquot->dq_id);
326 }
327
328 static int v2_read_dquot(struct dquot *dquot)
329 {
330         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
331         int ret;
332
333         down_read(&dqopt->dqio_sem);
334         ret = qtree_read_dquot(
335                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
336                         dquot);
337         up_read(&dqopt->dqio_sem);
338         return ret;
339 }
340
341 static int v2_write_dquot(struct dquot *dquot)
342 {
343         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
344         int ret;
345         bool alloc = false;
346
347         /*
348          * If space for dquot is already allocated, we don't need any
349          * protection as we'll only overwrite the place of dquot. We are
350          * still protected by concurrent writes of the same dquot by
351          * dquot->dq_lock.
352          */
353         if (!dquot->dq_off) {
354                 alloc = true;
355                 down_write(&dqopt->dqio_sem);
356         } else {
357                 down_read(&dqopt->dqio_sem);
358         }
359         ret = qtree_write_dquot(
360                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
361                         dquot);
362         if (alloc)
363                 up_write(&dqopt->dqio_sem);
364         else
365                 up_read(&dqopt->dqio_sem);
366         return ret;
367 }
368
369 static int v2_release_dquot(struct dquot *dquot)
370 {
371         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
372         int ret;
373
374         down_write(&dqopt->dqio_sem);
375         ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
376         up_write(&dqopt->dqio_sem);
377
378         return ret;
379 }
380
381 static int v2_free_file_info(struct super_block *sb, int type)
382 {
383         kfree(sb_dqinfo(sb, type)->dqi_priv);
384         return 0;
385 }
386
387 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
388 {
389         struct quota_info *dqopt = sb_dqopt(sb);
390         int ret;
391
392         down_read(&dqopt->dqio_sem);
393         ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
394         up_read(&dqopt->dqio_sem);
395         return ret;
396 }
397
398 static const struct quota_format_ops v2_format_ops = {
399         .check_quota_file       = v2_check_quota_file,
400         .read_file_info         = v2_read_file_info,
401         .write_file_info        = v2_write_file_info,
402         .free_file_info         = v2_free_file_info,
403         .read_dqblk             = v2_read_dquot,
404         .commit_dqblk           = v2_write_dquot,
405         .release_dqblk          = v2_release_dquot,
406         .get_next_id            = v2_get_next_id,
407 };
408
409 static struct quota_format_type v2r0_quota_format = {
410         .qf_fmt_id      = QFMT_VFS_V0,
411         .qf_ops         = &v2_format_ops,
412         .qf_owner       = THIS_MODULE
413 };
414
415 static struct quota_format_type v2r1_quota_format = {
416         .qf_fmt_id      = QFMT_VFS_V1,
417         .qf_ops         = &v2_format_ops,
418         .qf_owner       = THIS_MODULE
419 };
420
421 static int __init init_v2_quota_format(void)
422 {
423         int ret;
424
425         ret = register_quota_format(&v2r0_quota_format);
426         if (ret)
427                 return ret;
428         return register_quota_format(&v2r1_quota_format);
429 }
430
431 static void __exit exit_v2_quota_format(void)
432 {
433         unregister_quota_format(&v2r0_quota_format);
434         unregister_quota_format(&v2r1_quota_format);
435 }
436
437 module_init(init_v2_quota_format);
438 module_exit(exit_v2_quota_format);