linux/fs/quota/quota_v2.c
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   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
  20MODULE_AUTHOR("Jan Kara");
  21MODULE_DESCRIPTION("Quota format v2 support");
  22MODULE_LICENSE("GPL");
  23
  24#define __QUOTA_V2_PARANOIA
  25
  26static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot);
  27static void v2r0_disk2memdqb(struct dquot *dquot, void *dp);
  28static int v2r0_is_id(void *dp, struct dquot *dquot);
  29static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot);
  30static void v2r1_disk2memdqb(struct dquot *dquot, void *dp);
  31static int v2r1_is_id(void *dp, struct dquot *dquot);
  32
  33static 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
  39static 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
  48static inline qsize_t v2_stoqb(qsize_t space)
  49{
  50        return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
  51}
  52
  53static inline qsize_t v2_qbtos(qsize_t blocks)
  54{
  55        return blocks << QUOTABLOCK_BITS;
  56}
  57
  58static 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 */
  74static 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 */
  89static 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_maxblimit = 0xffffffff;
 121                info->dqi_maxilimit = 0xffffffff;
 122        } else {
 123                /* used space is stored as unsigned 64-bit value */
 124                info->dqi_maxblimit = 0xffffffffffffffffULL;    /* 2^64-1 */
 125                info->dqi_maxilimit = 0xffffffffffffffffULL;
 126        }
 127        info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
 128        info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
 129        info->dqi_flags = le32_to_cpu(dinfo.dqi_flags);
 130        qinfo->dqi_sb = sb;
 131        qinfo->dqi_type = type;
 132        qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
 133        qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
 134        qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
 135        qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
 136        qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
 137        qinfo->dqi_qtree_depth = qtree_depth(qinfo);
 138        if (version == 0) {
 139                qinfo->dqi_entry_size = sizeof(struct v2r0_disk_dqblk);
 140                qinfo->dqi_ops = &v2r0_qtree_ops;
 141        } else {
 142                qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk);
 143                qinfo->dqi_ops = &v2r1_qtree_ops;
 144        }
 145        return 0;
 146}
 147
 148/* Write information header to quota file */
 149static int v2_write_file_info(struct super_block *sb, int type)
 150{
 151        struct v2_disk_dqinfo dinfo;
 152        struct mem_dqinfo *info = sb_dqinfo(sb, type);
 153        struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 154        ssize_t size;
 155
 156        spin_lock(&dq_data_lock);
 157        info->dqi_flags &= ~DQF_INFO_DIRTY;
 158        dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 159        dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 160        dinfo.dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
 161        spin_unlock(&dq_data_lock);
 162        dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 163        dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 164        dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 165        size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 166               sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 167        if (size != sizeof(struct v2_disk_dqinfo)) {
 168                quota_error(sb, "Can't write info structure");
 169                return -1;
 170        }
 171        return 0;
 172}
 173
 174static void v2r0_disk2memdqb(struct dquot *dquot, void *dp)
 175{
 176        struct v2r0_disk_dqblk *d = dp, empty;
 177        struct mem_dqblk *m = &dquot->dq_dqb;
 178
 179        m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 180        m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 181        m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 182        m->dqb_itime = le64_to_cpu(d->dqb_itime);
 183        m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 184        m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 185        m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 186        m->dqb_btime = le64_to_cpu(d->dqb_btime);
 187        /* We need to escape back all-zero structure */
 188        memset(&empty, 0, sizeof(struct v2r0_disk_dqblk));
 189        empty.dqb_itime = cpu_to_le64(1);
 190        if (!memcmp(&empty, dp, sizeof(struct v2r0_disk_dqblk)))
 191                m->dqb_itime = 0;
 192}
 193
 194static void v2r0_mem2diskdqb(void *dp, struct dquot *dquot)
 195{
 196        struct v2r0_disk_dqblk *d = dp;
 197        struct mem_dqblk *m = &dquot->dq_dqb;
 198        struct qtree_mem_dqinfo *info =
 199                        sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 200
 201        d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 202        d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 203        d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 204        d->dqb_itime = cpu_to_le64(m->dqb_itime);
 205        d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 206        d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 207        d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 208        d->dqb_btime = cpu_to_le64(m->dqb_btime);
 209        d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 210        if (qtree_entry_unused(info, dp))
 211                d->dqb_itime = cpu_to_le64(1);
 212}
 213
 214static int v2r0_is_id(void *dp, struct dquot *dquot)
 215{
 216        struct v2r0_disk_dqblk *d = dp;
 217        struct qtree_mem_dqinfo *info =
 218                        sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 219
 220        if (qtree_entry_unused(info, dp))
 221                return 0;
 222        return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 223                                le32_to_cpu(d->dqb_id)),
 224                      dquot->dq_id);
 225}
 226
 227static void v2r1_disk2memdqb(struct dquot *dquot, void *dp)
 228{
 229        struct v2r1_disk_dqblk *d = dp, empty;
 230        struct mem_dqblk *m = &dquot->dq_dqb;
 231
 232        m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
 233        m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
 234        m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
 235        m->dqb_itime = le64_to_cpu(d->dqb_itime);
 236        m->dqb_bhardlimit = v2_qbtos(le64_to_cpu(d->dqb_bhardlimit));
 237        m->dqb_bsoftlimit = v2_qbtos(le64_to_cpu(d->dqb_bsoftlimit));
 238        m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 239        m->dqb_btime = le64_to_cpu(d->dqb_btime);
 240        /* We need to escape back all-zero structure */
 241        memset(&empty, 0, sizeof(struct v2r1_disk_dqblk));
 242        empty.dqb_itime = cpu_to_le64(1);
 243        if (!memcmp(&empty, dp, sizeof(struct v2r1_disk_dqblk)))
 244                m->dqb_itime = 0;
 245}
 246
 247static void v2r1_mem2diskdqb(void *dp, struct dquot *dquot)
 248{
 249        struct v2r1_disk_dqblk *d = dp;
 250        struct mem_dqblk *m = &dquot->dq_dqb;
 251        struct qtree_mem_dqinfo *info =
 252                        sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 253
 254        d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
 255        d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
 256        d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
 257        d->dqb_itime = cpu_to_le64(m->dqb_itime);
 258        d->dqb_bhardlimit = cpu_to_le64(v2_stoqb(m->dqb_bhardlimit));
 259        d->dqb_bsoftlimit = cpu_to_le64(v2_stoqb(m->dqb_bsoftlimit));
 260        d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 261        d->dqb_btime = cpu_to_le64(m->dqb_btime);
 262        d->dqb_id = cpu_to_le32(from_kqid(&init_user_ns, dquot->dq_id));
 263        if (qtree_entry_unused(info, dp))
 264                d->dqb_itime = cpu_to_le64(1);
 265}
 266
 267static int v2r1_is_id(void *dp, struct dquot *dquot)
 268{
 269        struct v2r1_disk_dqblk *d = dp;
 270        struct qtree_mem_dqinfo *info =
 271                        sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv;
 272
 273        if (qtree_entry_unused(info, dp))
 274                return 0;
 275        return qid_eq(make_kqid(&init_user_ns, dquot->dq_id.type,
 276                                le32_to_cpu(d->dqb_id)),
 277                      dquot->dq_id);
 278}
 279
 280static int v2_read_dquot(struct dquot *dquot)
 281{
 282        return qtree_read_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 283}
 284
 285static int v2_write_dquot(struct dquot *dquot)
 286{
 287        return qtree_write_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 288}
 289
 290static int v2_release_dquot(struct dquot *dquot)
 291{
 292        return qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_id.type)->dqi_priv, dquot);
 293}
 294
 295static int v2_free_file_info(struct super_block *sb, int type)
 296{
 297        kfree(sb_dqinfo(sb, type)->dqi_priv);
 298        return 0;
 299}
 300
 301static const struct quota_format_ops v2_format_ops = {
 302        .check_quota_file       = v2_check_quota_file,
 303        .read_file_info         = v2_read_file_info,
 304        .write_file_info        = v2_write_file_info,
 305        .free_file_info         = v2_free_file_info,
 306        .read_dqblk             = v2_read_dquot,
 307        .commit_dqblk           = v2_write_dquot,
 308        .release_dqblk          = v2_release_dquot,
 309};
 310
 311static struct quota_format_type v2r0_quota_format = {
 312        .qf_fmt_id      = QFMT_VFS_V0,
 313        .qf_ops         = &v2_format_ops,
 314        .qf_owner       = THIS_MODULE
 315};
 316
 317static struct quota_format_type v2r1_quota_format = {
 318        .qf_fmt_id      = QFMT_VFS_V1,
 319        .qf_ops         = &v2_format_ops,
 320        .qf_owner       = THIS_MODULE
 321};
 322
 323static int __init init_v2_quota_format(void)
 324{
 325        int ret;
 326
 327        ret = register_quota_format(&v2r0_quota_format);
 328        if (ret)
 329                return ret;
 330        return register_quota_format(&v2r1_quota_format);
 331}
 332
 333static void __exit exit_v2_quota_format(void)
 334{
 335        unregister_quota_format(&v2r0_quota_format);
 336        unregister_quota_format(&v2r1_quota_format);
 337}
 338
 339module_init(init_v2_quota_format);
 340module_exit(exit_v2_quota_format);
 341
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