LXR linux-bk/fs/quota

   1#include <linux/errno.h>
   2#include <linux/fs.h>
   3#include <linux/quota.h>
   4#include <linux/dqblk_v1.h>
   5#include <linux/quotaio_v1.h>
   6#include <linux/kernel.h>
   7#include <linux/init.h>
   8#include <linux/module.h>
   9
  10#include <asm/uaccess.h>
  11#include <asm/byteorder.h>
  12
  13static void v1_disk2mem_dqblk(struct mem_dqblk *m, struct v1_disk_dqblk *d)
  14{
  15        m->dqb_ihardlimit = d->dqb_ihardlimit;
  16        m->dqb_isoftlimit = d->dqb_isoftlimit;
  17        m->dqb_curinodes = d->dqb_curinodes;
  18        m->dqb_bhardlimit = d->dqb_bhardlimit;
  19        m->dqb_bsoftlimit = d->dqb_bsoftlimit;
  20        m->dqb_curspace = d->dqb_curblocks << QUOTABLOCK_BITS;
  21        m->dqb_itime = d->dqb_itime;
  22        m->dqb_btime = d->dqb_btime;
  23}
  24
  25static void v1_mem2disk_dqblk(struct v1_disk_dqblk *d, struct mem_dqblk *m)
  26{
  27        d->dqb_ihardlimit = m->dqb_ihardlimit;
  28        d->dqb_isoftlimit = m->dqb_isoftlimit;
  29        d->dqb_curinodes = m->dqb_curinodes;
  30        d->dqb_bhardlimit = m->dqb_bhardlimit;
  31        d->dqb_bsoftlimit = m->dqb_bsoftlimit;
  32        d->dqb_curblocks = toqb(m->dqb_curspace);
  33        d->dqb_itime = m->dqb_itime;
  34        d->dqb_btime = m->dqb_btime;
  35}
  36
  37static int v1_read_dqblk(struct dquot *dquot)
  38{
  39        int type = dquot->dq_type;
  40        struct file *filp;
  41        mm_segment_t fs;
  42        loff_t offset;
  43        struct v1_disk_dqblk dqblk;
  44
  45        filp = sb_dqopt(dquot->dq_sb)->files[type];
  46        if (filp == (struct file *)NULL)
  47                return -EINVAL;
  48
  49        /* Now we are sure filp is valid */
  50        offset = v1_dqoff(dquot->dq_id);
  51        fs = get_fs();
  52        set_fs(KERNEL_DS);
  53        filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset);
  54        set_fs(fs);
  55
  56        v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
  57        if (dquot->dq_dqb.dqb_bhardlimit == 0 && dquot->dq_dqb.dqb_bsoftlimit == 0 &&
  58            dquot->dq_dqb.dqb_ihardlimit == 0 && dquot->dq_dqb.dqb_isoftlimit == 0)
  59                dquot->dq_flags |= DQ_FAKE;
  60        dqstats.reads++;
  61
  62        return 0;
  63}
  64
  65static int v1_commit_dqblk(struct dquot *dquot)
  66{
  67        short type = dquot->dq_type;
  68        struct file *filp;
  69        mm_segment_t fs;
  70        loff_t offset;
  71        ssize_t ret;
  72        struct v1_disk_dqblk dqblk;
  73
  74        filp = sb_dqopt(dquot->dq_sb)->files[type];
  75        offset = v1_dqoff(dquot->dq_id);
  76        fs = get_fs();
  77        set_fs(KERNEL_DS);
  78
  79        /*
  80         * Note: clear the DQ_MOD flag unconditionally,
  81         * so we don't loop forever on failure.
  82         */
  83        v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
  84        dquot->dq_flags &= ~DQ_MOD;
  85        if (dquot->dq_id == 0) {
  86                dqblk.dqb_btime = sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
  87                dqblk.dqb_itime = sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
  88        }
  89        ret = 0;
  90        if (filp)
  91                ret = filp->f_op->write(filp, (char *)&dqblk,
  92                                        sizeof(struct v1_disk_dqblk), &offset);
  93        if (ret != sizeof(struct v1_disk_dqblk)) {
  94                printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
  95                        dquot->dq_sb->s_id);
  96                if (ret >= 0)
  97                        ret = -EIO;
  98                goto out;
  99        }
 100        ret = 0;
 101
 102out:
 103        set_fs(fs);
 104        dqstats.writes++;
 105
 106        return ret;
 107}
 108
 109/* Magics of new quota format */
 110#define V2_INITQMAGICS {\
 111        0xd9c01f11,     /* USRQUOTA */\
 112        0xd9c01927      /* GRPQUOTA */\
 113}
 114
 115/* Header of new quota format */
 116struct v2_disk_dqheader {
 117        __u32 dqh_magic;        /* Magic number identifying file */
 118        __u32 dqh_version;      /* File version */
 119};
 120
 121static int v1_check_quota_file(struct super_block *sb, int type)
 122{
 123        struct file *f = sb_dqopt(sb)->files[type];
 124        struct inode *inode = f->f_dentry->d_inode;
 125        ulong blocks;
 126        size_t off; 
 127        struct v2_disk_dqheader dqhead;
 128        mm_segment_t fs;
 129        ssize_t size;
 130        loff_t offset = 0;
 131        static const uint quota_magics[] = V2_INITQMAGICS;
 132
 133        if (!inode->i_size)
 134                return 0;
 135        blocks = inode->i_size >> BLOCK_SIZE_BITS;
 136        off = inode->i_size & (BLOCK_SIZE - 1);
 137        if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % sizeof(struct v1_disk_dqblk))
 138                return 0;
 139        /* Doublecheck whether we didn't get file with new format - with old quotactl() this could happen */
 140        fs = get_fs();
 141        set_fs(KERNEL_DS);
 142        size = f->f_op->read(f, (char *)&dqhead, sizeof(struct v2_disk_dqheader), &offset);
 143        set_fs(fs);
 144        if (size != sizeof(struct v2_disk_dqheader))
 145                return 1;       /* Probably not new format */
 146        if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
 147                return 1;       /* Definitely not new format */
 148        printk(KERN_INFO "VFS: %s: Refusing to turn on old quota format on given file. It probably contains newer quota format.\n", sb->s_id);
 149        return 0;               /* Seems like a new format file -> refuse it */
 150}
 151
 152static int v1_read_file_info(struct super_block *sb, int type)
 153{
 154        struct quota_info *dqopt = sb_dqopt(sb);
 155        mm_segment_t fs;
 156        loff_t offset;
 157        struct file *filp = dqopt->files[type];
 158        struct v1_disk_dqblk dqblk;
 159        int ret;
 160
 161        down(&dqopt->dqio_sem);
 162        offset = v1_dqoff(0);
 163        fs = get_fs();
 164        set_fs(KERNEL_DS);
 165        if ((ret = filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset)) != sizeof(struct v1_disk_dqblk)) {
 166                if (ret >= 0)
 167                        ret = -EIO;
 168                goto out;
 169        }
 170        ret = 0;
 171        dqopt->info[type].dqi_igrace = dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
 172        dqopt->info[type].dqi_bgrace = dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
 173out:
 174        up(&dqopt->dqio_sem);
 175        set_fs(fs);
 176        return ret;
 177}
 178
 179static int v1_write_file_info(struct super_block *sb, int type)
 180{
 181        struct quota_info *dqopt = sb_dqopt(sb);
 182        mm_segment_t fs;
 183        struct file *filp = dqopt->files[type];
 184        struct v1_disk_dqblk dqblk;
 185        loff_t offset;
 186        int ret;
 187
 188        down(&dqopt->dqio_sem);
 189        dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
 190        offset = v1_dqoff(0);
 191        fs = get_fs();
 192        set_fs(KERNEL_DS);
 193        if ((ret = filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset)) != sizeof(struct v1_disk_dqblk)) {
 194                if (ret >= 0)
 195                        ret = -EIO;
 196                goto out;
 197        }
 198        dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
 199        dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
 200        offset = v1_dqoff(0);
 201        ret = filp->f_op->write(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset);
 202        if (ret == sizeof(struct v1_disk_dqblk))
 203                ret = 0;
 204        else if (ret > 0)
 205                ret = -EIO;
 206out:
 207        up(&dqopt->dqio_sem);
 208        set_fs(fs);
 209        return ret;
 210}
 211
 212static struct quota_format_ops v1_format_ops = {
 213        .check_quota_file       = v1_check_quota_file,
 214        .read_file_info         = v1_read_file_info,
 215        .write_file_info        = v1_write_file_info,
 216        .free_file_info         = NULL,
 217        .read_dqblk             = v1_read_dqblk,
 218        .commit_dqblk           = v1_commit_dqblk,
 219};
 220
 221static struct quota_format_type v1_quota_format = {
 222        .qf_fmt_id      = QFMT_VFS_OLD,
 223        .qf_ops         = &v1_format_ops,
 224        .qf_owner       = THIS_MODULE
 225};
 226
 227static int __init init_v1_quota_format(void)
 228{
 229        return register_quota_format(&v1_quota_format);
 230}
 231
 232static void __exit exit_v1_quota_format(void)
 233{
 234        unregister_quota_format(&v1_quota_format);
 235}
 236
 237EXPORT_NO_SYMBOLS;
 238
 239module_init(init_v1_quota_format);
 240module_exit(exit_v1_quota_format);
 241
 242