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 MODULE_AUTHOR("Jan Kara");
  14 MODULE_DESCRIPTION("Old quota format support");
  15 MODULE_LICENSE("GPL");
  16
  17 static void v1_disk2mem_dqblk(struct mem_dqblk *m, struct v1_disk_dqblk *d)
  18 {
  19         m->dqb_ihardlimit = d->dqb_ihardlimit;
  20         m->dqb_isoftlimit = d->dqb_isoftlimit;
  21         m->dqb_curinodes = d->dqb_curinodes;
  22         m->dqb_bhardlimit = d->dqb_bhardlimit;
  23         m->dqb_bsoftlimit = d->dqb_bsoftlimit;
  24         m->dqb_curspace = ((qsize_t)d->dqb_curblocks) << QUOTABLOCK_BITS;
  25         m->dqb_itime = d->dqb_itime;
  26         m->dqb_btime = d->dqb_btime;
  27 }
  28
  29 static void v1_mem2disk_dqblk(struct v1_disk_dqblk *d, struct mem_dqblk *m)
  30 {
  31         d->dqb_ihardlimit = m->dqb_ihardlimit;
  32         d->dqb_isoftlimit = m->dqb_isoftlimit;
  33         d->dqb_curinodes = m->dqb_curinodes;
  34         d->dqb_bhardlimit = m->dqb_bhardlimit;
  35         d->dqb_bsoftlimit = m->dqb_bsoftlimit;
  36         d->dqb_curblocks = toqb(m->dqb_curspace);
  37         d->dqb_itime = m->dqb_itime;
  38         d->dqb_btime = m->dqb_btime;
  39 }
  40
  41 static int v1_read_dqblk(struct dquot *dquot)
  42 {
  43         int type = dquot->dq_type;
  44         struct file *filp;
  45         mm_segment_t fs;
  46         loff_t offset;
  47         struct v1_disk_dqblk dqblk;
  48
  49         filp = sb_dqopt(dquot->dq_sb)->files[type];
  50         if (filp == (struct file *)NULL)
  51                 return -EINVAL;
  52
  53         /* Now we are sure filp is valid */
  54         offset = v1_dqoff(dquot->dq_id);
  55         fs = get_fs();
  56         set_fs(KERNEL_DS);
  57         filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset);
  58         set_fs(fs);
  59
  60         v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
  61         if (dquot->dq_dqb.dqb_bhardlimit == 0 && dquot->dq_dqb.dqb_bsoftlimit == 0 &&
  62             dquot->dq_dqb.dqb_ihardlimit == 0 && dquot->dq_dqb.dqb_isoftlimit == 0)
  63                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
  64         dqstats.reads++;
  65
  66         return 0;
  67 }
  68
  69 static int v1_commit_dqblk(struct dquot *dquot)
  70 {
  71         short type = dquot->dq_type;
  72         struct file *filp;
  73         mm_segment_t fs;
  74         loff_t offset;
  75         ssize_t ret;
  76         struct v1_disk_dqblk dqblk;
  77
  78         filp = sb_dqopt(dquot->dq_sb)->files[type];
  79         offset = v1_dqoff(dquot->dq_id);
  80         fs = get_fs();
  81         set_fs(KERNEL_DS);
  82
  83         v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
  84         if (dquot->dq_id == 0) {
  85                 dqblk.dqb_btime = sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
  86                 dqblk.dqb_itime = sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
  87         }
  88         ret = 0;
  89         if (filp)
  90                 ret = filp->f_op->write(filp, (char *)&dqblk,
  91                                         sizeof(struct v1_disk_dqblk), &offset);
  92         if (ret != sizeof(struct v1_disk_dqblk)) {
  93                 printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
  94                         dquot->dq_sb->s_id);
  95                 if (ret >= 0)
  96                         ret = -EIO;
  97                 goto out;
  98         }
  99         ret = 0;
 100
 101 out:
 102         set_fs(fs);
 103         dqstats.writes++;
 104
 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         loff_t isize;
 131         static const uint quota_magics[] = V2_INITQMAGICS;
 132
 133         isize = i_size_read(inode);
 134         if (!isize)
 135                 return 0;
 136         blocks = isize >> BLOCK_SIZE_BITS;
 137         off = isize & (BLOCK_SIZE - 1);
 138         if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % sizeof(struct v1_disk_dqblk))
 139                 return 0;
 140         /* Doublecheck whether we didn't get file with new format - with old quotactl() this could happen */
 141         fs = get_fs();
 142         set_fs(KERNEL_DS);
 143         size = f->f_op->read(f, (char *)&dqhead, sizeof(struct v2_disk_dqheader), &offset);
 144         set_fs(fs);
 145         if (size != sizeof(struct v2_disk_dqheader))
 146                 return 1;       /* Probably not new format */
 147         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
 148                 return 1;       /* Definitely not new format */
 149         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);
 150         return 0;               /* Seems like a new format file -> refuse it */
 151 }
 152
 153 static int v1_read_file_info(struct super_block *sb, int type)
 154 {
 155         struct quota_info *dqopt = sb_dqopt(sb);
 156         mm_segment_t fs;
 157         loff_t offset;
 158         struct file *filp = dqopt->files[type];
 159         struct v1_disk_dqblk dqblk;
 160         int ret;
 161
 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;
 173 out:
 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         dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
 188         offset = v1_dqoff(0);
 189         fs = get_fs();
 190         set_fs(KERNEL_DS);
 191         if ((ret = filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset)) != sizeof(struct v1_disk_dqblk)) {
 192                 if (ret >= 0)
 193                         ret = -EIO;
 194                 goto out;
 195         }
 196         dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
 197         dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
 198         offset = v1_dqoff(0);
 199         ret = filp->f_op->write(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset);
 200         if (ret == sizeof(struct v1_disk_dqblk))
 201                 ret = 0;
 202         else if (ret > 0)
 203                 ret = -EIO;
 204 out:
 205         set_fs(fs);
 206         return ret;
 207 }
 208
 209 static struct quota_format_ops v1_format_ops = {
 210         .check_quota_file       = v1_check_quota_file,
 211         .read_file_info         = v1_read_file_info,
 212         .write_file_info        = v1_write_file_info,
 213         .free_file_info         = NULL,
 214         .read_dqblk             = v1_read_dqblk,
 215         .commit_dqblk           = v1_commit_dqblk,
 216 };
 217
 218 static struct quota_format_type v1_quota_format = {
 219         .qf_fmt_id      = QFMT_VFS_OLD,
 220         .qf_ops         = &v1_format_ops,
 221         .qf_owner       = THIS_MODULE
 222 };
 223
 224 static int __init init_v1_quota_format(void)
 225 {
 226         return register_quota_format(&v1_quota_format);
 227 }
 228
 229 static void __exit exit_v1_quota_format(void)
 230 {
 231         unregister_quota_format(&v1_quota_format);
 232 }
 233
 234 module_init(init_v1_quota_format);
 235 module_exit(exit_v1_quota_format);
 236