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                 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 quota_info *dqopt = sb_dqopt(sb);
 158         struct mem_dqinfo *info = &dqopt->info[type];
 159         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 160         ssize_t size;
 161
 162         down_write(&dqopt->dqio_sem);
 163         spin_lock(&dq_data_lock);
 164         info->dqi_flags &= ~DQF_INFO_DIRTY;
 165         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 166         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 167         /* No flags currently supported */
 168         dinfo.dqi_flags = cpu_to_le32(0);
 169         spin_unlock(&dq_data_lock);
 170         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 171         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 172         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 173         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 174                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 175         up_write(&dqopt->dqio_sem);
 176         if (size != sizeof(struct v2_disk_dqinfo)) {
 177                 quota_error(sb, "Can't write info structure");
 178                 return -1;
 179         }
 180         return 0;
 181 }
 182
 183 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
 184 {
 185         struct v2r0_disk_dqblk *d = dp, empty;
 186         struct mem_dqblk *m = &dquot->dq_dqb;
 187
 188         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 189         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 190         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 191         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 192         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 193         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 194         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 195         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 196         /* We need to escape back all-zero structure */
 197         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
 198         empty.dqb_itime = cpu_to_le64(1);
 199         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
 200                 m->dqb_itime = 0;
 201 }
 202
 203 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 204 {
 205         struct v2r0_disk_dqblk *d = dp;
 206         struct mem_dqblk *m = &dquot->dq_dqb;
 207         struct qtree_mem_dqinfo *info =
 208                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 209
 210         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 211         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 212         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 213         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 214         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 215         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 216         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 217         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 218         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 219         if (qtree_entry_unused(info, dp))
 220                 d->dqb_itime = cpu_to_le64(1);
 221 }
 222
 223 static int v2r0_is_id(void *dp, struct dquot *dquot)
 224 {
 225         struct v2r0_disk_dqblk *d = dp;
 226         struct qtree_mem_dqinfo *info =
 227                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 228
 229         if (qtree_entry_unused(info, dp))
 230                 return 0;
 231         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 232                                 le32_to_cpu(d->dqb_id)),
 233                       dquot->dq_id);
 234 }
 235
 236 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
 237 {
 238         struct v2r1_disk_dqblk *d = dp, empty;
 239         struct mem_dqblk *m = &dquot->dq_dqb;
 240
 241         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
 242         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
 243         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
 244         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 245         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
 246         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
 247         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 248         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 249         /* We need to escape back all-zero structure */
 250         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
 251         empty.dqb_itime = cpu_to_le64(1);
 252         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
 253                 m->dqb_itime = 0;
 254 }
 255
 256 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 257 {
 258         struct v2r1_disk_dqblk *d = dp;
 259         struct mem_dqblk *m = &dquot->dq_dqb;
 260         struct qtree_mem_dqinfo *info =
 261                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 262
 263         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
 264         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
 265         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
 266         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 267         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
 268         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
 269         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 270         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 271         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 272         if (qtree_entry_unused(info, dp))
 273                 d->dqb_itime = cpu_to_le64(1);
 274 }
 275
 276 static int v2r1_is_id(void *dp, struct dquot *dquot)
 277 {
 278         struct v2r1_disk_dqblk *d = dp;
 279         struct qtree_mem_dqinfo *info =
 280                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 281
 282         if (qtree_entry_unused(info, dp))
 283                 return 0;
 284         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 285                                 le32_to_cpu(d->dqb_id)),
 286                       dquot->dq_id);
 287 }
 288
 289 static int v2_read_dquot(struct dquot *dquot)
 290 {
 291         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 292         int ret;
 293
 294         down_read(&dqopt->dqio_sem);
 295         ret = qtree_read_dquot(
 296                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 297                         dquot);
 298         up_read(&dqopt->dqio_sem);
 299         return ret;
 300 }
 301
 302 static int v2_write_dquot(struct dquot *dquot)
 303 {
 304         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 305         int ret;
 306         bool alloc = false;
 307
 308         /*
 309          * If space for dquot is already allocated, we don't need any
 310          * protection as we'll only overwrite the place of dquot. We are
 311          * still protected by concurrent writes of the same dquot by
 312          * dquot->dq_lock.
 313          */
 314         if (!dquot->dq_off) {
 315                 alloc = true;
 316                 down_write(&dqopt->dqio_sem);
 317         }
 318         ret = qtree_write_dquot(
 319                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 320                         dquot);
 321         if (alloc)
 322                 up_write(&dqopt->dqio_sem);
 323         return ret;
 324 }
 325
 326 static int v2_release_dquot(struct dquot *dquot)
 327 {
 328         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 329         int ret;
 330
 331         down_write(&dqopt->dqio_sem);
 332         ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 333         up_write(&dqopt->dqio_sem);
 334
 335         return ret;
 336 }
 337
 338 static int v2_free_file_info(struct super_block *sb, int type)
 339 {
 340         kfree(sb_dqinfo(sb, type)->dqi_priv);
 341         return 0;
 342 }
 343
 344 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
 345 {
 346         struct quota_info *dqopt = sb_dqopt(sb);
 347         int ret;
 348
 349         down_read(&dqopt->dqio_sem);
 350         ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
 351         up_read(&dqopt->dqio_sem);
 352         return ret;
 353 }
 354
 355 static const struct quota_format_ops v2_format_ops = {
 356         .check_quota_file       = v2_check_quota_file,
 357         .read_file_info         = v2_read_file_info,
 358         .write_file_info        = v2_write_file_info,
 359         .free_file_info         = v2_free_file_info,
 360         .read_dqblk             = v2_read_dquot,
 361         .commit_dqblk           = v2_write_dquot,
 362         .release_dqblk          = v2_release_dquot,
 363         .get_next_id            = v2_get_next_id,
 364 };
 365
 366 static struct quota_format_type v2r0_quota_format = {
 367         .qf_fmt_id      = QFMT_VFS_V0,
 368         .qf_ops         = &v2_format_ops,
 369         .qf_owner       = THIS_MODULE
 370 };
 371
 372 static struct quota_format_type v2r1_quota_format = {
 373         .qf_fmt_id      = QFMT_VFS_V1,
 374         .qf_ops         = &v2_format_ops,
 375         .qf_owner       = THIS_MODULE
 376 };
 377
 378 static int __init init_v2_quota_format(void)
 379 {
 380         int ret;
 381
 382         ret = register_quota_format(&v2r0_quota_format);
 383         if (ret)
 384                 return ret;
 385         return register_quota_format(&v2r1_quota_format);
 386 }
 387
 388 static void __exit exit_v2_quota_format(void)
 389 {
 390         unregister_quota_format(&v2r0_quota_format);
 391         unregister_quota_format(&v2r1_quota_format);
 392 }
 393
 394 module_init(init_v2_quota_format);
 395 module_exit(exit_v2_quota_format);