fs/quota_v1.c

   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
  13 static 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 = ((qsize_t)d->dqb_curblocks) << QUOTABLOCK_BITS;
  21         m->dqb_itime = d->dqb_itime;
  22         m->dqb_btime = d->dqb_btime;
  23 }
  24
  25 static 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
  37 static 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         memset(&dqblk, 0, sizeof(dqblk));       /* Initialize buffer in case file is too short */
  50         /* Now we are sure filp is valid */
  51         offset = v1_dqoff(dquot->dq_id);
  52         fs = get_fs();
  53         set_fs(KERNEL_DS);
  54         filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset);
  55         set_fs(fs);
  56
  57         v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
  58         if (dquot->dq_dqb.dqb_bhardlimit == 0 && dquot->dq_dqb.dqb_bsoftlimit == 0 &&
  59             dquot->dq_dqb.dqb_ihardlimit == 0 && dquot->dq_dqb.dqb_isoftlimit == 0)
  60                 dquot->dq_flags |= DQ_FAKE;
  61         dqstats.reads++;
  62         return 0;
  63 }
  64
  65 static 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                         kdevname(dquot->dq_dev));
  96                 if (ret >= 0)
  97                         ret = -EIO;
  98                 goto out;
  99         }
 100         ret = 0;
 101
 102 out:
 103         set_fs(fs);
 104         dqstats.writes++;
 105         return ret;
 106 }
 107
 108 /* Magics of new quota format */
 109 #define V2_INITQMAGICS {\
 110         0xd9c01f11,     /* USRQUOTA */\
 111         0xd9c01927      /* GRPQUOTA */\
 112 }
 113
 114 /* Header of new quota format */
 115 struct v2_disk_dqheader {
 116         __u32 dqh_magic;        /* Magic number identifying file */
 117         __u32 dqh_version;      /* File version */
 118 };
 119
 120 static int v1_check_quota_file(struct super_block *sb, int type)
 121 {
 122         struct file *f = sb_dqopt(sb)->files[type];
 123         struct inode *inode = f->f_dentry->d_inode;
 124         ulong blocks;
 125         size_t off;
 126         struct v2_disk_dqheader dqhead;
 127         mm_segment_t fs;
 128         ssize_t size;
 129         loff_t offset = 0;
 130         static const uint quota_magics[] = V2_INITQMAGICS;
 131
 132         if (!inode->i_size)
 133                 return 0;
 134         blocks = inode->i_size >> BLOCK_SIZE_BITS;
 135         off = inode->i_size & (BLOCK_SIZE - 1);
 136         if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % sizeof(struct v1_disk_dqblk))
 137                 return 0;
 138         /* Doublecheck whether we didn't get file with new format - with old quotactl() this could happen */
 139         fs = get_fs();
 140         set_fs(KERNEL_DS);
 141         size = f->f_op->read(f, (char *)&dqhead, sizeof(struct v2_disk_dqheader), &offset);
 142         set_fs(fs);
 143         if (size != sizeof(struct v2_disk_dqheader))
 144                 return 1;       /* Probably not new format */
 145         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
 146                 return 1;       /* Definitely not new format */
 147         printk(KERN_INFO "VFS: %s: Refusing to turn on old quota format on given file. It probably contains newer quota format.\n", kdevname(sb->s_dev));
 148         return 0;               /* Seems like a new format file -> refuse it */
 149 }
 150
 151 static int v1_read_file_info(struct super_block *sb, int type)
 152 {
 153         struct quota_info *dqopt = sb_dqopt(sb);
 154         mm_segment_t fs;
 155         loff_t offset;
 156         struct file *filp = dqopt->files[type];
 157         struct v1_disk_dqblk dqblk;
 158         int ret;
 159
 160         down(&dqopt->dqio_sem);
 161         offset = v1_dqoff(0);
 162         fs = get_fs();
 163         set_fs(KERNEL_DS);
 164         if ((ret = filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset)) != sizeof(struct v1_disk_dqblk)) {
 165                 if (ret >= 0)
 166                         ret = -EIO;
 167                 goto out;
 168         }
 169         ret = 0;
 170         dqopt->info[type].dqi_igrace = dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
 171         dqopt->info[type].dqi_bgrace = dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
 172 out:
 173         up(&dqopt->dqio_sem);
 174         set_fs(fs);
 175         return ret;
 176 }
 177
 178 static int v1_write_file_info(struct super_block *sb, int type)
 179 {
 180         struct quota_info *dqopt = sb_dqopt(sb);
 181         mm_segment_t fs;
 182         struct file *filp = dqopt->files[type];
 183         struct v1_disk_dqblk dqblk;
 184         loff_t offset;
 185         int ret;
 186
 187         down(&dqopt->dqio_sem);
 188         dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
 189         offset = v1_dqoff(0);
 190         fs = get_fs();
 191         set_fs(KERNEL_DS);
 192         if ((ret = filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset)) != sizeof(struct v1_disk_dqblk)) {
 193                 if (ret >= 0)
 194                         ret = -EIO;
 195                 goto out;
 196         }
 197         dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
 198         dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
 199         offset = v1_dqoff(0);
 200         ret = filp->f_op->write(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset);
 201         if (ret == sizeof(struct v1_disk_dqblk))
 202                 ret = 0;
 203         else if (ret > 0)
 204                 ret = -EIO;
 205 out:
 206         up(&dqopt->dqio_sem);
 207         set_fs(fs);
 208         return ret;
 209 }
 210
 211 static struct quota_format_ops v1_format_ops = {
 212         check_quota_file:       v1_check_quota_file,
 213         read_file_info:         v1_read_file_info,
 214         write_file_info:        v1_write_file_info,
 215         free_file_info:         NULL,
 216         read_dqblk:             v1_read_dqblk,
 217         commit_dqblk:           v1_commit_dqblk,
 218 };
 219
 220 static struct quota_format_type v1_quota_format = {
 221         qf_fmt_id:      QFMT_VFS_OLD,
 222         qf_ops:         &v1_format_ops,
 223         qf_owner:       THIS_MODULE
 224 };
 225
 226 static int __init init_v1_quota_format(void)
 227 {
 228         return register_quota_format(&v1_quota_format);
 229 }
 230
 231 static void __exit exit_v1_quota_format(void)
 232 {
 233         unregister_quota_format(&v1_quota_format);
 234 }
 235
 236 EXPORT_NO_SYMBOLS;
 237
 238 module_init(init_v1_quota_format);
 239 module_exit(exit_v1_quota_format);
 240