NFSv4: Eliminate nfs4_path_walk()
[linux-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 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 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                 printk(KERN_WARNING "quota_v2: Failed header read:"
67                        " expected=%zd got=%zd\n",
68                         sizeof(struct v2_disk_dqheader), size);
69                 return 0;
70         }
71         return 1;
72 }
73
74 /* Check whether given file is really vfsv0 quotafile */
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 */
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 mem_dqinfo *info = sb_dqinfo(sb, type);
95         struct qtree_mem_dqinfo *qinfo;
96         ssize_t size;
97         unsigned int version;
98
99         if (!v2_read_header(sb, type, &dqhead))
100                 return -1;
101         version = le32_to_cpu(dqhead.dqh_version);
102         if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
103             (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1))
104                 return -1;
105
106         size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
107                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
108         if (size != sizeof(struct v2_disk_dqinfo)) {
109                 printk(KERN_WARNING "quota_v2: Can't read info structure on device %s.\n",
110                         sb->s_id);
111                 return -1;
112         }
113         info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
114         if (!info->dqi_priv) {
115                 printk(KERN_WARNING
116                        "Not enough memory for quota information structure.\n");
117                 return -1;
118         }
119         qinfo = info->dqi_priv;
120         if (version == 0) {
121                 /* limits are stored as unsigned 32-bit data */
122                 info->dqi_maxblimit = 0xffffffff;
123                 info->dqi_maxilimit = 0xffffffff;
124         } else {
125                 /* used space is stored as unsigned 64-bit value */
126                 info->dqi_maxblimit = 0xffffffffffffffffULL;    /* 2^64-1 */
127                 info->dqi_maxilimit = 0xffffffffffffffffULL;
128         }
129         info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
130         info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
131         info->dqi_flags = le32_to_cpu(dinfo.dqi_flags);
132         qinfo->dqi_sb = sb;
133         qinfo->dqi_type = type;
134         qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
135         qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
136         qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
137         qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
138         qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
139         qinfo->dqi_qtree_depth = qtree_depth(qinfo);
140         if (version == 0) {
141                 qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
142                 qinfo->dqi_ops = &v2r0_qtree_ops;
143         } else {
144                 qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
145                 qinfo->dqi_ops = &v2r1_qtree_ops;
146         }
147         return 0;
148 }
149
150 /* Write information header to quota file */
151 static int v2_write_file_info(struct super_block *sb, int type)
152 {
153         struct v2_disk_dqinfo dinfo;
154         struct mem_dqinfo *info = sb_dqinfo(sb, type);
155         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
156         ssize_t size;
157
158         spin_lock(&dq_data_lock);
159         info->dqi_flags &= ~DQF_INFO_DIRTY;
160         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
161         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
162         dinfo.dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
163         spin_unlock(&dq_data_lock);
164         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
165         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
166         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
167         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
168                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
169         if (size != sizeof(struct v2_disk_dqinfo)) {
170                 printk(KERN_WARNING "Can't write info structure on device %s.\n",
171                         sb->s_id);
172                 return -1;
173         }
174         return 0;
175 }
176
177 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
178 {
179         struct v2r0_disk_dqblk *d = dp, empty;
180         struct mem_dqblk *m = &dquot->dq_dqb;
181
182         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
183         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
184         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
185         m->dqb_itime = le64_to_cpu(d->dqb_itime);
186         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
187         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
188         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
189         m->dqb_btime = le64_to_cpu(d->dqb_btime);
190         /* We need to escape back all-zero structure */
191         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
192         empty.dqb_itime = cpu_to_le64(1);
193         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
194                 m->dqb_itime = 0;
195 }
196
197 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
198 {
199         struct v2r0_disk_dqblk *d = dp;
200         struct mem_dqblk *m = &dquot->dq_dqb;
201         struct qtree_mem_dqinfo *info =
202                         sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
203
204         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
205         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
206         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
207         d->dqb_itime = cpu_to_le64(m->dqb_itime);
208         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
209         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
210         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
211         d->dqb_btime = cpu_to_le64(m->dqb_btime);
212         d->dqb_id = cpu_to_le32(dquot->dq_id);
213         if (qtree_entry_unused(info, dp))
214                 d->dqb_itime = cpu_to_le64(1);
215 }
216
217 static int v2r0_is_id(void *dp, struct dquot *dquot)
218 {
219         struct v2r0_disk_dqblk *d = dp;
220         struct qtree_mem_dqinfo *info =
221                         sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
222
223         if (qtree_entry_unused(info, dp))
224                 return 0;
225         return le32_to_cpu(d->dqb_id) == dquot->dq_id;
226 }
227
228 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
229 {
230         struct v2r1_disk_dqblk *d = dp, empty;
231         struct mem_dqblk *m = &dquot->dq_dqb;
232
233         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
234         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
235         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
236         m->dqb_itime = le64_to_cpu(d->dqb_itime);
237         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
238         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
239         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
240         m->dqb_btime = le64_to_cpu(d->dqb_btime);
241         /* We need to escape back all-zero structure */
242         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
243         empty.dqb_itime = cpu_to_le64(1);
244         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
245                 m->dqb_itime = 0;
246 }
247
248 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
249 {
250         struct v2r1_disk_dqblk *d = dp;
251         struct mem_dqblk *m = &dquot->dq_dqb;
252         struct qtree_mem_dqinfo *info =
253                         sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
254
255         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
256         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
257         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
258         d->dqb_itime = cpu_to_le64(m->dqb_itime);
259         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
260         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
261         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
262         d->dqb_btime = cpu_to_le64(m->dqb_btime);
263         d->dqb_id = cpu_to_le32(dquot->dq_id);
264         if (qtree_entry_unused(info, dp))
265                 d->dqb_itime = cpu_to_le64(1);
266 }
267
268 static int v2r1_is_id(void *dp, struct dquot *dquot)
269 {
270         struct v2r1_disk_dqblk *d = dp;
271         struct qtree_mem_dqinfo *info =
272                         sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
273
274         if (qtree_entry_unused(info, dp))
275                 return 0;
276         return le32_to_cpu(d->dqb_id) == dquot->dq_id;
277 }
278
279 static int v2_read_dquot(struct dquot *dquot)
280 {
281         return qtree_read_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
282 }
283
284 static int v2_write_dquot(struct dquot *dquot)
285 {
286         return qtree_write_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
287 }
288
289 static int v2_release_dquot(struct dquot *dquot)
290 {
291         return qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
292 }
293
294 static int v2_free_file_info(struct super_block *sb, int type)
295 {
296         kfree(sb_dqinfo(sb, type)->dqi_priv);
297         return 0;
298 }
299
300 static const struct quota_format_ops v2_format_ops = {
301         .check_quota_file       = v2_check_quota_file,
302         .read_file_info         = v2_read_file_info,
303         .write_file_info        = v2_write_file_info,
304         .free_file_info         = v2_free_file_info,
305         .read_dqblk             = v2_read_dquot,
306         .commit_dqblk           = v2_write_dquot,
307         .release_dqblk          = v2_release_dquot,
308 };
309
310 static struct quota_format_type v2r0_quota_format = {
311         .qf_fmt_id      = QFMT_VFS_V0,
312         .qf_ops         = &v2_format_ops,
313         .qf_owner       = THIS_MODULE
314 };
315
316 static struct quota_format_type v2r1_quota_format = {
317         .qf_fmt_id      = QFMT_VFS_V1,
318         .qf_ops         = &v2_format_ops,
319         .qf_owner       = THIS_MODULE
320 };
321
322 static int __init init_v2_quota_format(void)
323 {
324         int ret;
325
326         ret = register_quota_format(&v2r0_quota_format);
327         if (ret)
328                 return ret;
329         return register_quota_format(&v2r1_quota_format);
330 }
331
332 static void __exit exit_v2_quota_format(void)
333 {
334         unregister_quota_format(&v2r0_quota_format);
335         unregister_quota_format(&v2r1_quota_format);
336 }
337
338 module_init(init_v2_quota_format);
339 module_exit(exit_v2_quota_format);