Merge branch 'quota_scaling' of git://git.kernel.org/pub/scm/linux/kernel/git/jack...
[sfrench/cifs-2.6.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 = 0;
162 out:
163         up_read(&dqopt->dqio_sem);
164         return ret;
165 }
166
167 /* Write information header to quota file */
168 static int v2_write_file_info(struct super_block *sb, int type)
169 {
170         struct v2_disk_dqinfo dinfo;
171         struct quota_info *dqopt = sb_dqopt(sb);
172         struct mem_dqinfo *info = &dqopt->info[type];
173         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
174         ssize_t size;
175
176         down_write(&dqopt->dqio_sem);
177         spin_lock(&dq_data_lock);
178         info->dqi_flags &= ~DQF_INFO_DIRTY;
179         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
180         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
181         /* No flags currently supported */
182         dinfo.dqi_flags = cpu_to_le32(0);
183         spin_unlock(&dq_data_lock);
184         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
185         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
186         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
187         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
188                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
189         up_write(&dqopt->dqio_sem);
190         if (size != sizeof(struct v2_disk_dqinfo)) {
191                 quota_error(sb, "Can't write info structure");
192                 return -1;
193         }
194         return 0;
195 }
196
197 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
198 {
199         struct v2r0_disk_dqblk *d = dp, empty;
200         struct mem_dqblk *m = &dquot->dq_dqb;
201
202         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
203         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
204         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
205         m->dqb_itime = le64_to_cpu(d->dqb_itime);
206         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
207         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
208         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
209         m->dqb_btime = le64_to_cpu(d->dqb_btime);
210         /* We need to escape back all-zero structure */
211         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
212         empty.dqb_itime = cpu_to_le64(1);
213         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
214                 m->dqb_itime = 0;
215 }
216
217 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
218 {
219         struct v2r0_disk_dqblk *d = dp;
220         struct mem_dqblk *m = &dquot->dq_dqb;
221         struct qtree_mem_dqinfo *info =
222                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
223
224         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
225         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
226         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
227         d->dqb_itime = cpu_to_le64(m->dqb_itime);
228         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
229         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
230         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
231         d->dqb_btime = cpu_to_le64(m->dqb_btime);
232         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
233         if (qtree_entry_unused(info, dp))
234                 d->dqb_itime = cpu_to_le64(1);
235 }
236
237 static int v2r0_is_id(void *dp, struct dquot *dquot)
238 {
239         struct v2r0_disk_dqblk *d = dp;
240         struct qtree_mem_dqinfo *info =
241                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
242
243         if (qtree_entry_unused(info, dp))
244                 return 0;
245         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
246                                 le32_to_cpu(d->dqb_id)),
247                       dquot->dq_id);
248 }
249
250 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
251 {
252         struct v2r1_disk_dqblk *d = dp, empty;
253         struct mem_dqblk *m = &dquot->dq_dqb;
254
255         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
256         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
257         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
258         m->dqb_itime = le64_to_cpu(d->dqb_itime);
259         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
260         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
261         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
262         m->dqb_btime = le64_to_cpu(d->dqb_btime);
263         /* We need to escape back all-zero structure */
264         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
265         empty.dqb_itime = cpu_to_le64(1);
266         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
267                 m->dqb_itime = 0;
268 }
269
270 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
271 {
272         struct v2r1_disk_dqblk *d = dp;
273         struct mem_dqblk *m = &dquot->dq_dqb;
274         struct qtree_mem_dqinfo *info =
275                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
276
277         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
278         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
279         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
280         d->dqb_itime = cpu_to_le64(m->dqb_itime);
281         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
282         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
283         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
284         d->dqb_btime = cpu_to_le64(m->dqb_btime);
285         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
286         if (qtree_entry_unused(info, dp))
287                 d->dqb_itime = cpu_to_le64(1);
288 }
289
290 static int v2r1_is_id(void *dp, struct dquot *dquot)
291 {
292         struct v2r1_disk_dqblk *d = dp;
293         struct qtree_mem_dqinfo *info =
294                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
295
296         if (qtree_entry_unused(info, dp))
297                 return 0;
298         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
299                                 le32_to_cpu(d->dqb_id)),
300                       dquot->dq_id);
301 }
302
303 static int v2_read_dquot(struct dquot *dquot)
304 {
305         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
306         int ret;
307
308         down_read(&dqopt->dqio_sem);
309         ret = qtree_read_dquot(
310                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
311                         dquot);
312         up_read(&dqopt->dqio_sem);
313         return ret;
314 }
315
316 static int v2_write_dquot(struct dquot *dquot)
317 {
318         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
319         int ret;
320         bool alloc = false;
321
322         /*
323          * If space for dquot is already allocated, we don't need any
324          * protection as we'll only overwrite the place of dquot. We are
325          * still protected by concurrent writes of the same dquot by
326          * dquot->dq_lock.
327          */
328         if (!dquot->dq_off) {
329                 alloc = true;
330                 down_write(&dqopt->dqio_sem);
331         }
332         ret = qtree_write_dquot(
333                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
334                         dquot);
335         if (alloc)
336                 up_write(&dqopt->dqio_sem);
337         return ret;
338 }
339
340 static int v2_release_dquot(struct dquot *dquot)
341 {
342         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
343         int ret;
344
345         down_write(&dqopt->dqio_sem);
346         ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
347         up_write(&dqopt->dqio_sem);
348
349         return ret;
350 }
351
352 static int v2_free_file_info(struct super_block *sb, int type)
353 {
354         kfree(sb_dqinfo(sb, type)->dqi_priv);
355         return 0;
356 }
357
358 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
359 {
360         struct quota_info *dqopt = sb_dqopt(sb);
361         int ret;
362
363         down_read(&dqopt->dqio_sem);
364         ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
365         up_read(&dqopt->dqio_sem);
366         return ret;
367 }
368
369 static const struct quota_format_ops v2_format_ops = {
370         .check_quota_file       = v2_check_quota_file,
371         .read_file_info         = v2_read_file_info,
372         .write_file_info        = v2_write_file_info,
373         .free_file_info         = v2_free_file_info,
374         .read_dqblk             = v2_read_dquot,
375         .commit_dqblk           = v2_write_dquot,
376         .release_dqblk          = v2_release_dquot,
377         .get_next_id            = v2_get_next_id,
378 };
379
380 static struct quota_format_type v2r0_quota_format = {
381         .qf_fmt_id      = QFMT_VFS_V0,
382         .qf_ops         = &v2_format_ops,
383         .qf_owner       = THIS_MODULE
384 };
385
386 static struct quota_format_type v2r1_quota_format = {
387         .qf_fmt_id      = QFMT_VFS_V1,
388         .qf_ops         = &v2_format_ops,
389         .qf_owner       = THIS_MODULE
390 };
391
392 static int __init init_v2_quota_format(void)
393 {
394         int ret;
395
396         ret = register_quota_format(&v2r0_quota_format);
397         if (ret)
398                 return ret;
399         return register_quota_format(&v2r1_quota_format);
400 }
401
402 static void __exit exit_v2_quota_format(void)
403 {
404         unregister_quota_format(&v2r0_quota_format);
405         unregister_quota_format(&v2r1_quota_format);
406 }
407
408 module_init(init_v2_quota_format);
409 module_exit(exit_v2_quota_format);