fs/quota_v1.c

   1 #include <linux/errno.h>
   2 #include <linux/fs.h>
   3 #include <linux/quota.h>
   4 #include <linux/quotaops.h>
   5 #include <linux/dqblk_v1.h>
   6 #include <linux/quotaio_v1.h>
   7 #include <linux/kernel.h>
   8 #include <linux/init.h>
   9 #include <linux/module.h>
  10
  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 v1_disk_dqblk dqblk;
  45
  46         if (!sb_dqopt(dquot->dq_sb)->files[type])
  47                 return -EINVAL;
  48
  49         /* Set structure to 0s in case read fails/is after end of file */
  50         memset(&dqblk, 0, sizeof(struct v1_disk_dqblk));
  51         dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk, sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id));
  52
  53         v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
  54         if (dquot->dq_dqb.dqb_bhardlimit == 0 && dquot->dq_dqb.dqb_bsoftlimit == 0 &&
  55             dquot->dq_dqb.dqb_ihardlimit == 0 && dquot->dq_dqb.dqb_isoftlimit == 0)
  56                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
  57         dqstats.reads++;
  58
  59         return 0;
  60 }
  61
  62 static int v1_commit_dqblk(struct dquot *dquot)
  63 {
  64         short type = dquot->dq_type;
  65         ssize_t ret;
  66         struct v1_disk_dqblk dqblk;
  67
  68         v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
  69         if (dquot->dq_id == 0) {
  70                 dqblk.dqb_btime = sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
  71                 dqblk.dqb_itime = sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
  72         }
  73         ret = 0;
  74         if (sb_dqopt(dquot->dq_sb)->files[type])
  75                 ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type, (char *)&dqblk,
  76                                         sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id));
  77         if (ret != sizeof(struct v1_disk_dqblk)) {
  78                 printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
  79                         dquot->dq_sb->s_id);
  80                 if (ret >= 0)
  81                         ret = -EIO;
  82                 goto out;
  83         }
  84         ret = 0;
  85
  86 out:
  87         dqstats.writes++;
  88
  89         return ret;
  90 }
  91
  92 /* Magics of new quota format */
  93 #define V2_INITQMAGICS {\
  94         0xd9c01f11,     /* USRQUOTA */\
  95         0xd9c01927      /* GRPQUOTA */\
  96 }
  97
  98 /* Header of new quota format */
  99 struct v2_disk_dqheader {
 100         __le32 dqh_magic;        /* Magic number identifying file */
 101         __le32 dqh_version;      /* File version */
 102 };
 103
 104 static int v1_check_quota_file(struct super_block *sb, int type)
 105 {
 106         struct inode *inode = sb_dqopt(sb)->files[type];
 107         ulong blocks;
 108         size_t off;
 109         struct v2_disk_dqheader dqhead;
 110         ssize_t size;
 111         loff_t isize;
 112         static const uint quota_magics[] = V2_INITQMAGICS;
 113
 114         isize = i_size_read(inode);
 115         if (!isize)
 116                 return 0;
 117         blocks = isize >> BLOCK_SIZE_BITS;
 118         off = isize & (BLOCK_SIZE - 1);
 119         if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % sizeof(struct v1_disk_dqblk))
 120                 return 0;
 121         /* Doublecheck whether we didn't get file with new format - with old quotactl() this could happen */
 122         size = sb->s_op->quota_read(sb, type, (char *)&dqhead, sizeof(struct v2_disk_dqheader), 0);
 123         if (size != sizeof(struct v2_disk_dqheader))
 124                 return 1;       /* Probably not new format */
 125         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
 126                 return 1;       /* Definitely not new format */
 127         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);
 128         return 0;               /* Seems like a new format file -> refuse it */
 129 }
 130
 131 static int v1_read_file_info(struct super_block *sb, int type)
 132 {
 133         struct quota_info *dqopt = sb_dqopt(sb);
 134         struct v1_disk_dqblk dqblk;
 135         int ret;
 136
 137         if ((ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, sizeof(struct v1_disk_dqblk), v1_dqoff(0))) != sizeof(struct v1_disk_dqblk)) {
 138                 if (ret >= 0)
 139                         ret = -EIO;
 140                 goto out;
 141         }
 142         ret = 0;
 143         /* limits are stored as unsigned 32-bit data */
 144         dqopt->info[type].dqi_maxblimit = 0xffffffff;
 145         dqopt->info[type].dqi_maxilimit = 0xffffffff;
 146         dqopt->info[type].dqi_igrace = dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
 147         dqopt->info[type].dqi_bgrace = dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
 148 out:
 149         return ret;
 150 }
 151
 152 static int v1_write_file_info(struct super_block *sb, int type)
 153 {
 154         struct quota_info *dqopt = sb_dqopt(sb);
 155         struct v1_disk_dqblk dqblk;
 156         int ret;
 157
 158         dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
 159         if ((ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
 160             sizeof(struct v1_disk_dqblk), v1_dqoff(0))) != sizeof(struct v1_disk_dqblk)) {
 161                 if (ret >= 0)
 162                         ret = -EIO;
 163                 goto out;
 164         }
 165         dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
 166         dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
 167         ret = sb->s_op->quota_write(sb, type, (char *)&dqblk,
 168               sizeof(struct v1_disk_dqblk), v1_dqoff(0));
 169         if (ret == sizeof(struct v1_disk_dqblk))
 170                 ret = 0;
 171         else if (ret > 0)
 172                 ret = -EIO;
 173 out:
 174         return ret;
 175 }
 176
 177 static struct quota_format_ops v1_format_ops = {
 178         .check_quota_file       = v1_check_quota_file,
 179         .read_file_info         = v1_read_file_info,
 180         .write_file_info        = v1_write_file_info,
 181         .free_file_info         = NULL,
 182         .read_dqblk             = v1_read_dqblk,
 183         .commit_dqblk           = v1_commit_dqblk,
 184 };
 185
 186 static struct quota_format_type v1_quota_format = {
 187         .qf_fmt_id      = QFMT_VFS_OLD,
 188         .qf_ops         = &v1_format_ops,
 189         .qf_owner       = THIS_MODULE
 190 };
 191
 192 static int __init init_v1_quota_format(void)
 193 {
 194         return register_quota_format(&v1_quota_format);
 195 }
 196
 197 static void __exit exit_v1_quota_format(void)
 198 {
 199         unregister_quota_format(&v1_quota_format);
 200 }
 201
 202 module_init(init_v1_quota_format);
 203 module_exit(exit_v1_quota_format);
 204