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