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 = -EUCLEAN;
 162         /* Some sanity checks of the read headers... */
 163         if ((loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits >
 164             i_size_read(sb_dqopt(sb)->files[type])) {
 165                 quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).",
 166                     (loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits,
 167                     i_size_read(sb_dqopt(sb)->files[type]));
 168                 goto out_free;
 169         }
 170         if (qinfo->dqi_free_blk >= qinfo->dqi_blocks) {
 171                 quota_error(sb, "Free block number too big (%u >= %u).",
 172                             qinfo->dqi_free_blk, qinfo->dqi_blocks);
 173                 goto out_free;
 174         }
 175         if (qinfo->dqi_free_entry >= qinfo->dqi_blocks) {
 176                 quota_error(sb, "Block with free entry too big (%u >= %u).",
 177                             qinfo->dqi_free_entry, qinfo->dqi_blocks);
 178                 goto out_free;
 179         }
 180         ret = 0;
 181 out_free:
 182         if (ret) {
 183                 kfree(info->dqi_priv);
 184                 info->dqi_priv = NULL;
 185         }
 186 out:
 187         up_read(&dqopt->dqio_sem);
 188         return ret;
 189 }
 190
 191 /* Write information header to quota file */
 192 static int v2_write_file_info(struct super_block *sb, int type)
 193 {
 194         struct v2_disk_dqinfo dinfo;
 195         struct quota_info *dqopt = sb_dqopt(sb);
 196         struct mem_dqinfo *info = &dqopt->info[type];
 197         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 198         ssize_t size;
 199
 200         down_write(&dqopt->dqio_sem);
 201         spin_lock(&dq_data_lock);
 202         info->dqi_flags &= ~DQF_INFO_DIRTY;
 203         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 204         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 205         /* No flags currently supported */
 206         dinfo.dqi_flags = cpu_to_le32(0);
 207         spin_unlock(&dq_data_lock);
 208         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 209         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 210         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 211         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 212                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 213         up_write(&dqopt->dqio_sem);
 214         if (size != sizeof(struct v2_disk_dqinfo)) {
 215                 quota_error(sb, "Can't write info structure");
 216                 return -1;
 217         }
 218         return 0;
 219 }
 220
 221 static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
 222 {
 223         struct v2r0_disk_dqblk *d = dp, empty;
 224         struct mem_dqblk *m = &dquot->dq_dqb;
 225
 226         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 227         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 228         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 229         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 230         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 231         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 232         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 233         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 234         /* We need to escape back all-zero structure */
 235         memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
 236         empty.dqb_itime = cpu_to_le64(1);
 237         if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
 238                 m->dqb_itime = 0;
 239 }
 240
 241 static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 242 {
 243         struct v2r0_disk_dqblk *d = dp;
 244         struct mem_dqblk *m = &dquot->dq_dqb;
 245         struct qtree_mem_dqinfo *info =
 246                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 247
 248         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 249         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 250         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 251         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 252         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 253         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 254         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 255         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 256         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 257         if (qtree_entry_unused(info, dp))
 258                 d->dqb_itime = cpu_to_le64(1);
 259 }
 260
 261 static int v2r0_is_id(void *dp, struct dquot *dquot)
 262 {
 263         struct v2r0_disk_dqblk *d = dp;
 264         struct qtree_mem_dqinfo *info =
 265                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 266
 267         if (qtree_entry_unused(info, dp))
 268                 return 0;
 269         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 270                                 le32_to_cpu(d->dqb_id)),
 271                       dquot->dq_id);
 272 }
 273
 274 static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
 275 {
 276         struct v2r1_disk_dqblk *d = dp, empty;
 277         struct mem_dqblk *m = &dquot->dq_dqb;
 278
 279         m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
 280         m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
 281         m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
 282         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 283         m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
 284         m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
 285         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 286         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 287         /* We need to escape back all-zero structure */
 288         memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
 289         empty.dqb_itime = cpu_to_le64(1);
 290         if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
 291                 m->dqb_itime = 0;
 292 }
 293
 294 static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 295 {
 296         struct v2r1_disk_dqblk *d = dp;
 297         struct mem_dqblk *m = &dquot->dq_dqb;
 298         struct qtree_mem_dqinfo *info =
 299                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 300
 301         d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
 302         d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
 303         d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
 304         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 305         d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
 306         d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
 307         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 308         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 309         d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 310         d->dqb_pad = 0;
 311         if (qtree_entry_unused(info, dp))
 312                 d->dqb_itime = cpu_to_le64(1);
 313 }
 314
 315 static int v2r1_is_id(void *dp, struct dquot *dquot)
 316 {
 317         struct v2r1_disk_dqblk *d = dp;
 318         struct qtree_mem_dqinfo *info =
 319                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 320
 321         if (qtree_entry_unused(info, dp))
 322                 return 0;
 323         return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 324                                 le32_to_cpu(d->dqb_id)),
 325                       dquot->dq_id);
 326 }
 327
 328 static int v2_read_dquot(struct dquot *dquot)
 329 {
 330         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 331         int ret;
 332
 333         down_read(&dqopt->dqio_sem);
 334         ret = qtree_read_dquot(
 335                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 336                         dquot);
 337         up_read(&dqopt->dqio_sem);
 338         return ret;
 339 }
 340
 341 static int v2_write_dquot(struct dquot *dquot)
 342 {
 343         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 344         int ret;
 345         bool alloc = false;
 346
 347         /*
 348          * If space for dquot is already allocated, we don't need any
 349          * protection as we'll only overwrite the place of dquot. We are
 350          * still protected by concurrent writes of the same dquot by
 351          * dquot->dq_lock.
 352          */
 353         if (!dquot->dq_off) {
 354                 alloc = true;
 355                 down_write(&dqopt->dqio_sem);
 356         } else {
 357                 down_read(&dqopt->dqio_sem);
 358         }
 359         ret = qtree_write_dquot(
 360                         sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv,
 361                         dquot);
 362         if (alloc)
 363                 up_write(&dqopt->dqio_sem);
 364         else
 365                 up_read(&dqopt->dqio_sem);
 366         return ret;
 367 }
 368
 369 static int v2_release_dquot(struct dquot *dquot)
 370 {
 371         struct quota_info *dqopt = sb_dqopt(dquot->dq_sb);
 372         int ret;
 373
 374         down_write(&dqopt->dqio_sem);
 375         ret = qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 376         up_write(&dqopt->dqio_sem);
 377
 378         return ret;
 379 }
 380
 381 static int v2_free_file_info(struct super_block *sb, int type)
 382 {
 383         kfree(sb_dqinfo(sb, type)->dqi_priv);
 384         return 0;
 385 }
 386
 387 static int v2_get_next_id(struct super_block *sb, struct kqid *qid)
 388 {
 389         struct quota_info *dqopt = sb_dqopt(sb);
 390         int ret;
 391
 392         down_read(&dqopt->dqio_sem);
 393         ret = qtree_get_next_id(sb_dqinfo(sb, qid->type)->dqi_priv, qid);
 394         up_read(&dqopt->dqio_sem);
 395         return ret;
 396 }
 397
 398 static const struct quota_format_ops v2_format_ops = {
 399         .check_quota_file       = v2_check_quota_file,
 400         .read_file_info         = v2_read_file_info,
 401         .write_file_info        = v2_write_file_info,
 402         .free_file_info         = v2_free_file_info,
 403         .read_dqblk             = v2_read_dquot,
 404         .commit_dqblk           = v2_write_dquot,
 405         .release_dqblk          = v2_release_dquot,
 406         .get_next_id            = v2_get_next_id,
 407 };
 408
 409 static struct quota_format_type v2r0_quota_format = {
 410         .qf_fmt_id      = QFMT_VFS_V0,
 411         .qf_ops         = &v2_format_ops,
 412         .qf_owner       = THIS_MODULE
 413 };
 414
 415 static struct quota_format_type v2r1_quota_format = {
 416         .qf_fmt_id      = QFMT_VFS_V1,
 417         .qf_ops         = &v2_format_ops,
 418         .qf_owner       = THIS_MODULE
 419 };
 420
 421 static int __init init_v2_quota_format(void)
 422 {
 423         int ret;
 424
 425         ret = register_quota_format(&v2r0_quota_format);
 426         if (ret)
 427                 return ret;
 428         return register_quota_format(&v2r1_quota_format);
 429 }
 430
 431 static void __exit exit_v2_quota_format(void)
 432 {
 433         unregister_quota_format(&v2r0_quota_format);
 434         unregister_quota_format(&v2r1_quota_format);
 435 }
 436
 437 module_init(init_v2_quota_format);
 438 module_exit(exit_v2_quota_format);