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/byteorder.h>
  11
  12 MODULE_AUTHOR("Jan Kara");
  13 MODULE_DESCRIPTION("Old quota format support");
  14 MODULE_LICENSE("GPL");
  15
  16 static void v1_disk2mem_dqblk(struct mem_dqblk *m, struct v1_disk_dqblk *d)
  17 {
  18         m->dqb_ihardlimit = d->dqb_ihardlimit;
  19         m->dqb_isoftlimit = d->dqb_isoftlimit;
  20         m->dqb_curinodes = d->dqb_curinodes;
  21         m->dqb_bhardlimit = d->dqb_bhardlimit;
  22         m->dqb_bsoftlimit = d->dqb_bsoftlimit;
  23         m->dqb_curspace = ((qsize_t)d->dqb_curblocks) << QUOTABLOCK_BITS;
  24         m->dqb_itime = d->dqb_itime;
  25         m->dqb_btime = d->dqb_btime;
  26 }
  27
  28 static void v1_mem2disk_dqblk(struct v1_disk_dqblk *d, struct mem_dqblk *m)
  29 {
  30         d->dqb_ihardlimit = m->dqb_ihardlimit;
  31         d->dqb_isoftlimit = m->dqb_isoftlimit;
  32         d->dqb_curinodes = m->dqb_curinodes;
  33         d->dqb_bhardlimit = m->dqb_bhardlimit;
  34         d->dqb_bsoftlimit = m->dqb_bsoftlimit;
  35         d->dqb_curblocks = toqb(m->dqb_curspace);
  36         d->dqb_itime = m->dqb_itime;
  37         d->dqb_btime = m->dqb_btime;
  38 }
  39
  40 static int v1_read_dqblk(struct dquot *dquot)
  41 {
  42         int type = dquot->dq_type;
  43         struct v1_disk_dqblk dqblk;
  44
  45         if (!sb_dqopt(dquot->dq_sb)->files[type])
  46                 return -EINVAL;
  47
  48         /* Set structure to 0s in case read fails/is after end of file */
  49         memset(&dqblk, 0, sizeof(struct v1_disk_dqblk));
  50         dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk, sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id));
  51
  52         v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
  53         if (dquot->dq_dqb.dqb_bhardlimit == 0 && dquot->dq_dqb.dqb_bsoftlimit == 0 &&
  54             dquot->dq_dqb.dqb_ihardlimit == 0 && dquot->dq_dqb.dqb_isoftlimit == 0)
  55                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
  56         dqstats.reads++;
  57
  58         return 0;
  59 }
  60
  61 static int v1_commit_dqblk(struct dquot *dquot)
  62 {
  63         short type = dquot->dq_type;
  64         ssize_t ret;
  65         struct v1_disk_dqblk dqblk;
  66
  67         v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
  68         if (dquot->dq_id == 0) {
  69                 dqblk.dqb_btime = sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
  70                 dqblk.dqb_itime = sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
  71         }
  72         ret = 0;
  73         if (sb_dqopt(dquot->dq_sb)->files[type])
  74                 ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type, (char *)&dqblk,
  75                                         sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id));
  76         if (ret != sizeof(struct v1_disk_dqblk)) {
  77                 printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
  78                         dquot->dq_sb->s_id);
  79                 if (ret >= 0)
  80                         ret = -EIO;
  81                 goto out;
  82         }
  83         ret = 0;
  84
  85 out:
  86         dqstats.writes++;
  87
  88         return ret;
  89 }
  90
  91 /* Magics of new quota format */
  92 #define V2_INITQMAGICS {\
  93         0xd9c01f11,     /* USRQUOTA */\
  94         0xd9c01927      /* GRPQUOTA */\
  95 }
  96
  97 /* Header of new quota format */
  98 struct v2_disk_dqheader {
  99         __le32 dqh_magic;        /* Magic number identifying file */
 100         __le32 dqh_version;      /* File version */
 101 };
 102
 103 static int v1_check_quota_file(struct super_block *sb, int type)
 104 {
 105         struct inode *inode = sb_dqopt(sb)->files[type];
 106         ulong blocks;
 107         size_t off;
 108         struct v2_disk_dqheader dqhead;
 109         ssize_t size;
 110         loff_t isize;
 111         static const uint quota_magics[] = V2_INITQMAGICS;
 112
 113         isize = i_size_read(inode);
 114         if (!isize)
 115                 return 0;
 116         blocks = isize >> BLOCK_SIZE_BITS;
 117         off = isize & (BLOCK_SIZE - 1);
 118         if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % sizeof(struct v1_disk_dqblk))
 119                 return 0;
 120         /* Doublecheck whether we didn't get file with new format - with old quotactl() this could happen */
 121         size = sb->s_op->quota_read(sb, type, (char *)&dqhead, sizeof(struct v2_disk_dqheader), 0);
 122         if (size != sizeof(struct v2_disk_dqheader))
 123                 return 1;       /* Probably not new format */
 124         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
 125                 return 1;       /* Definitely not new format */
 126         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);
 127         return 0;               /* Seems like a new format file -> refuse it */
 128 }
 129
 130 static int v1_read_file_info(struct super_block *sb, int type)
 131 {
 132         struct quota_info *dqopt = sb_dqopt(sb);
 133         struct v1_disk_dqblk dqblk;
 134         int ret;
 135
 136         if ((ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, sizeof(struct v1_disk_dqblk), v1_dqoff(0))) != sizeof(struct v1_disk_dqblk)) {
 137                 if (ret >= 0)
 138                         ret = -EIO;
 139                 goto out;
 140         }
 141         ret = 0;
 142         /* limits are stored as unsigned 32-bit data */
 143         dqopt->info[type].dqi_maxblimit = 0xffffffff;
 144         dqopt->info[type].dqi_maxilimit = 0xffffffff;
 145         dqopt->info[type].dqi_igrace = dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
 146         dqopt->info[type].dqi_bgrace = dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
 147 out:
 148         return ret;
 149 }
 150
 151 static int v1_write_file_info(struct super_block *sb, int type)
 152 {
 153         struct quota_info *dqopt = sb_dqopt(sb);
 154         struct v1_disk_dqblk dqblk;
 155         int ret;
 156
 157         dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
 158         if ((ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
 159             sizeof(struct v1_disk_dqblk), v1_dqoff(0))) != sizeof(struct v1_disk_dqblk)) {
 160                 if (ret >= 0)
 161                         ret = -EIO;
 162                 goto out;
 163         }
 164         dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
 165         dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
 166         ret = sb->s_op->quota_write(sb, type, (char *)&dqblk,
 167               sizeof(struct v1_disk_dqblk), v1_dqoff(0));
 168         if (ret == sizeof(struct v1_disk_dqblk))
 169                 ret = 0;
 170         else if (ret > 0)
 171                 ret = -EIO;
 172 out:
 173         return ret;
 174 }
 175
 176 static struct quota_format_ops v1_format_ops = {
 177         .check_quota_file       = v1_check_quota_file,
 178         .read_file_info         = v1_read_file_info,
 179         .write_file_info        = v1_write_file_info,
 180         .free_file_info         = NULL,
 181         .read_dqblk             = v1_read_dqblk,
 182         .commit_dqblk           = v1_commit_dqblk,
 183 };
 184
 185 static struct quota_format_type v1_quota_format = {
 186         .qf_fmt_id      = QFMT_VFS_OLD,
 187         .qf_ops         = &v1_format_ops,
 188         .qf_owner       = THIS_MODULE
 189 };
 190
 191 static int __init init_v1_quota_format(void)
 192 {
 193         return register_quota_format(&v1_quota_format);
 194 }
 195
 196 static void __exit exit_v1_quota_format(void)
 197 {
 198         unregister_quota_format(&v1_quota_format);
 199 }
 200
 201 module_init(init_v1_quota_format);
 202 module_exit(exit_v1_quota_format);
 203