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