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                 return 0;
  69         }
  70         return 1;
  71 }
  72
  73 /* Check whether given file is really vfsv0 quotafile */
  74 static int v2_check_quota_file(struct super_block *sb, int type)
  75 {
  76         struct v2_disk_dqheader dqhead;
  77         static const uint quota_magics[] = V2_INITQMAGICS;
  78         static const uint quota_versions[] = V2_INITQVERSIONS;
  79
  80         if (!v2_read_header(sb, type, &dqhead))
  81                 return 0;
  82         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
  83             le32_to_cpu(dqhead.dqh_version) > quota_versions[type])
  84                 return 0;
  85         return 1;
  86 }
  87
  88 /* Read information header from quota file */
  89 static int v2_read_file_info(struct super_block *sb, int type)
  90 {
  91         struct v2_disk_dqinfo dinfo;
  92         struct v2_disk_dqheader dqhead;
  93         struct mem_dqinfo *info = sb_dqinfo(sb, type);
  94         struct qtree_mem_dqinfo *qinfo;
  95         ssize_t size;
  96         unsigned int version;
  97
  98         if (!v2_read_header(sb, type, &dqhead))
  99                 return -1;
 100         version = le32_to_cpu(dqhead.dqh_version);
 101         if ((info->dqi_fmt_id == QFMT_VFS_V0 && version != 0) ||
 102             (info->dqi_fmt_id == QFMT_VFS_V1 && version != 1))
 103                 return -1;
 104
 105         size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
 106                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 107         if (size != sizeof(struct v2_disk_dqinfo)) {
 108                 quota_error(sb, "Can't read info structure");
 109                 return -1;
 110         }
 111         info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
 112         if (!info->dqi_priv)
 113                 return -ENOMEM;
 114
 115         qinfo = info->dqi_priv;
 116         if (version == 0) {
 117                 /* limits are stored as unsigned 32-bit data */
 118                 info->dqi_max_spc_limit = 0xffffffffLL << QUOTABLOCK_BITS;
 119                 info->dqi_max_ino_limit = 0xffffffff;
 120         } else {
 121                 /*
 122                  * Used space is stored as unsigned 64-bit value in bytes but
 123                  * quota core supports only signed 64-bit values so use that
 124                  * as a limit
 125                  */
 126                 info->dqi_max_spc_limit = 0x7fffffffffffffffLL; /* 2^63-1 */
 127                 info->dqi_max_ino_limit = 0x7fffffffffffffffLL;
 128         }
 129         info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
 130         info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
 131         /* No flags currently supported */
 132         info->dqi_flags = 0;
 133         qinfo->dqi_sb = sb;
 134         qinfo->dqi_type = type;
 135         qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
 136         qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
 137         qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
 138         qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
 139         qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
 140         qinfo->dqi_qtree_depth = qtree_depth(qinfo);
 141         if (version == 0) {
 142                 qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
 143                 qinfo->dqi_ops = &v2r0_qtree_ops;
 144         } else {
 145                 qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
 146                 qinfo->dqi_ops = &v2r1_qtree_ops;
 147         }
 148         return 0;
 149 }
 150
 151 /* Write information header to quota file */
 152 static int v2_write_file_info(struct super_block *sb, int type)
 153 {
 154         struct v2_disk_dqinfo dinfo;
 155         struct mem_dqinfo *info = sb_dqinfo(sb, type);
 156         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 157         ssize_t size;
 158
 159         spin_lock(&dq_data_lock);
 160         info->dqi_flags &= ~DQF_INFO_DIRTY;
 161         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 162         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 163         /* No flags currently supported */
 164         dinfo.dqi_flags = cpu_to_le32(0);
 165         spin_unlock(&dq_data_lock);
 166         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 167         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 168         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 169         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 170                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 171         if (size != sizeof(struct v2_disk_dqinfo)) {
 172                 quota_error(sb, "Can't write info structure");
 173                 return -1;
 174         }
 175         return 0;
 176 }
 177
 178 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
 179 {
 180         struct v2r0_disk_dqblk *d = dp, empty;
 181         struct mem_dqblk *m = &dquot->dq_dqb;
 182
 183         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 184         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 185         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 186         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 187         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 188         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 189         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 190         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 191         /* We need to escape back all-zero structure */
 192         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
 193         empty.dqb_itime = cpu_to_le64(1);
 194         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
 195                 m->dqb_itime = 0;
 196 }
 197
 198 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 199 {
 200         struct v2r0_disk_dqblk *d = dp;
 201         struct mem_dqblk *m = &dquot->dq_dqb;
 202         struct qtree_mem_dqinfo *info =
 203                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 204
 205         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 206         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 207         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 208         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 209         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 210         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 211         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 212         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 213         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 214         if (qtree_entry_unused(info, dp))
 215                 d->dqb_itime = cpu_to_le64(1);
 216 }
 217
 218 static int v2r0_is_id(void *dp, struct dquot *dquot)
 219 {
 220         struct v2r0_disk_dqblk *d = dp;
 221         struct qtree_mem_dqinfo *info =
 222                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 223
 224         if (qtree_entry_unused(info, dp))
 225                 return 0;
 226         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 227                                 le32_to_cpu(d->dqb_id)),
 228                       dquot->dq_id);
 229 }
 230
 231 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
 232 {
 233         struct v2r1_disk_dqblk *d = dp, empty;
 234         struct mem_dqblk *m = &dquot->dq_dqb;
 235
 236         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
 237         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
 238         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
 239         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 240         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
 241         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
 242         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 243         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 244         /* We need to escape back all-zero structure */
 245         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
 246         empty.dqb_itime = cpu_to_le64(1);
 247         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
 248                 m->dqb_itime = 0;
 249 }
 250
 251 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 252 {
 253         struct v2r1_disk_dqblk *d = dp;
 254         struct mem_dqblk *m = &dquot->dq_dqb;
 255         struct qtree_mem_dqinfo *info =
 256                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 257
 258         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
 259         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
 260         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
 261         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 262         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
 263         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
 264         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 265         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 266         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 267         if (qtree_entry_unused(info, dp))
 268                 d->dqb_itime = cpu_to_le64(1);
 269 }
 270
 271 static int v2r1_is_id(void *dp, struct dquot *dquot)
 272 {
 273         struct v2r1_disk_dqblk *d = dp;
 274         struct qtree_mem_dqinfo *info =
 275                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 276
 277         if (qtree_entry_unused(info, dp))
 278                 return 0;
 279         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 280                                 le32_to_cpu(d->dqb_id)),
 281                       dquot->dq_id);
 282 }
 283
 284 static int v2_read_dquot(struct dquot *dquot)
 285 {
 286         return qtree_read_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 287 }
 288
 289 static int v2_write_dquot(struct dquot *dquot)
 290 {
 291         return qtree_write_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 292 }
 293
 294 static int v2_release_dquot(struct dquot *dquot)
 295 {
 296         return qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 297 }
 298
 299 static int v2_free_file_info(struct super_block *sb, int type)
 300 {
 301         kfree(sb_dqinfo(sb, type)->dqi_priv);
 302         return 0;
 303 }
 304
 305 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
 306 {
 307         return qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
 308 }
 309
 310 static const struct quota_format_ops v2_format_ops = {
 311         .check_quota_file       = v2_check_quota_file,
 312         .read_file_info         = v2_read_file_info,
 313         .write_file_info        = v2_write_file_info,
 314         .free_file_info         = v2_free_file_info,
 315         .read_dqblk             = v2_read_dquot,
 316         .commit_dqblk           = v2_write_dquot,
 317         .release_dqblk          = v2_release_dquot,
 318         .get_next_id            = v2_get_next_id,
 319 };
 320
 321 static struct quota_format_type v2r0_quota_format = {
 322         .qf_fmt_id      = QFMT_VFS_V0,
 323         .qf_ops         = &v2_format_ops,
 324         .qf_owner       = THIS_MODULE
 325 };
 326
 327 static struct quota_format_type v2r1_quota_format = {
 328         .qf_fmt_id      = QFMT_VFS_V1,
 329         .qf_ops         = &v2_format_ops,
 330         .qf_owner       = THIS_MODULE
 331 };
 332
 333 static int __init init_v2_quota_format(void)
 334 {
 335         int ret;
 336
 337         ret = register_quota_format(&v2r0_quota_format);
 338         if (ret)
 339                 return ret;
 340         return register_quota_format(&v2r1_quota_format);
 341 }
 342
 343 static void __exit exit_v2_quota_format(void)
 344 {
 345         unregister_quota_format(&v2r0_quota_format);
 346         unregister_quota_format(&v2r1_quota_format);
 347 }
 348
 349 module_init(init_v2_quota_format);
 350 module_exit(exit_v2_quota_format);