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 #define QUOTABLOCK_BITS 10
  18 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
  19
  20 static inline qsize_t v1_stoqb(qsize_t space)
  21 {
  22         return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
  23 }
  24
  25 static inline qsize_t v1_qbtos(qsize_t blocks)
  26 {
  27         return blocks << QUOTABLOCK_BITS;
  28 }
  29
  30 static void v1_disk2mem_dqblk(struct mem_dqblk *m, struct v1_disk_dqblk *d)
  31 {
  32         m->dqb_ihardlimit = d->dqb_ihardlimit;
  33         m->dqb_isoftlimit = d->dqb_isoftlimit;
  34         m->dqb_curinodes = d->dqb_curinodes;
  35         m->dqb_bhardlimit = v1_qbtos(d->dqb_bhardlimit);
  36         m->dqb_bsoftlimit = v1_qbtos(d->dqb_bsoftlimit);
  37         m->dqb_curspace = v1_qbtos(d->dqb_curblocks);
  38         m->dqb_itime = d->dqb_itime;
  39         m->dqb_btime = d->dqb_btime;
  40 }
  41
  42 static void v1_mem2disk_dqblk(struct v1_disk_dqblk *d, struct mem_dqblk *m)
  43 {
  44         d->dqb_ihardlimit = m->dqb_ihardlimit;
  45         d->dqb_isoftlimit = m->dqb_isoftlimit;
  46         d->dqb_curinodes = m->dqb_curinodes;
  47         d->dqb_bhardlimit = v1_stoqb(m->dqb_bhardlimit);
  48         d->dqb_bsoftlimit = v1_stoqb(m->dqb_bsoftlimit);
  49         d->dqb_curblocks = v1_stoqb(m->dqb_curspace);
  50         d->dqb_itime = m->dqb_itime;
  51         d->dqb_btime = m->dqb_btime;
  52 }
  53
  54 static int v1_read_dqblk(struct dquot *dquot)
  55 {
  56         int type = dquot->dq_type;
  57         struct v1_disk_dqblk dqblk;
  58
  59         if (!sb_dqopt(dquot->dq_sb)->files[type])
  60                 return -EINVAL;
  61
  62         /* Set structure to 0s in case read fails/is after end of file */
  63         memset(&dqblk, 0, sizeof(struct v1_disk_dqblk));
  64         dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk, sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id));
  65
  66         v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
  67         if (dquot->dq_dqb.dqb_bhardlimit == 0 && dquot->dq_dqb.dqb_bsoftlimit == 0 &&
  68             dquot->dq_dqb.dqb_ihardlimit == 0 && dquot->dq_dqb.dqb_isoftlimit == 0)
  69                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
  70         dqstats.reads++;
  71
  72         return 0;
  73 }
  74
  75 static int v1_commit_dqblk(struct dquot *dquot)
  76 {
  77         short type = dquot->dq_type;
  78         ssize_t ret;
  79         struct v1_disk_dqblk dqblk;
  80
  81         v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
  82         if (dquot->dq_id == 0) {
  83                 dqblk.dqb_btime = sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
  84                 dqblk.dqb_itime = sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
  85         }
  86         ret = 0;
  87         if (sb_dqopt(dquot->dq_sb)->files[type])
  88                 ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type, (char *)&dqblk,
  89                                         sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id));
  90         if (ret != sizeof(struct v1_disk_dqblk)) {
  91                 printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
  92                         dquot->dq_sb->s_id);
  93                 if (ret >= 0)
  94                         ret = -EIO;
  95                 goto out;
  96         }
  97         ret = 0;
  98
  99 out:
 100         dqstats.writes++;
 101
 102         return ret;
 103 }
 104
 105 /* Magics of new quota format */
 106 #define V2_INITQMAGICS {\
 107         0xd9c01f11,     /* USRQUOTA */\
 108         0xd9c01927      /* GRPQUOTA */\
 109 }
 110
 111 /* Header of new quota format */
 112 struct v2_disk_dqheader {
 113         __le32 dqh_magic;        /* Magic number identifying file */
 114         __le32 dqh_version;      /* File version */
 115 };
 116
 117 static int v1_check_quota_file(struct super_block *sb, int type)
 118 {
 119         struct inode *inode = sb_dqopt(sb)->files[type];
 120         ulong blocks;
 121         size_t off;
 122         struct v2_disk_dqheader dqhead;
 123         ssize_t size;
 124         loff_t isize;
 125         static const uint quota_magics[] = V2_INITQMAGICS;
 126
 127         isize = i_size_read(inode);
 128         if (!isize)
 129                 return 0;
 130         blocks = isize >> BLOCK_SIZE_BITS;
 131         off = isize & (BLOCK_SIZE - 1);
 132         if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % sizeof(struct v1_disk_dqblk))
 133                 return 0;
 134         /* Doublecheck whether we didn't get file with new format - with old quotactl() this could happen */
 135         size = sb->s_op->quota_read(sb, type, (char *)&dqhead, sizeof(struct v2_disk_dqheader), 0);
 136         if (size != sizeof(struct v2_disk_dqheader))
 137                 return 1;       /* Probably not new format */
 138         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
 139                 return 1;       /* Definitely not new format */
 140         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);
 141         return 0;               /* Seems like a new format file -> refuse it */
 142 }
 143
 144 static int v1_read_file_info(struct super_block *sb, int type)
 145 {
 146         struct quota_info *dqopt = sb_dqopt(sb);
 147         struct v1_disk_dqblk dqblk;
 148         int ret;
 149
 150         if ((ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, sizeof(struct v1_disk_dqblk), v1_dqoff(0))) != sizeof(struct v1_disk_dqblk)) {
 151                 if (ret >= 0)
 152                         ret = -EIO;
 153                 goto out;
 154         }
 155         ret = 0;
 156         /* limits are stored as unsigned 32-bit data */
 157         dqopt->info[type].dqi_maxblimit = 0xffffffff;
 158         dqopt->info[type].dqi_maxilimit = 0xffffffff;
 159         dqopt->info[type].dqi_igrace = dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
 160         dqopt->info[type].dqi_bgrace = dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
 161 out:
 162         return ret;
 163 }
 164
 165 static int v1_write_file_info(struct super_block *sb, int type)
 166 {
 167         struct quota_info *dqopt = sb_dqopt(sb);
 168         struct v1_disk_dqblk dqblk;
 169         int ret;
 170
 171         dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
 172         if ((ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
 173             sizeof(struct v1_disk_dqblk), v1_dqoff(0))) != sizeof(struct v1_disk_dqblk)) {
 174                 if (ret >= 0)
 175                         ret = -EIO;
 176                 goto out;
 177         }
 178         dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
 179         dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
 180         ret = sb->s_op->quota_write(sb, type, (char *)&dqblk,
 181               sizeof(struct v1_disk_dqblk), v1_dqoff(0));
 182         if (ret == sizeof(struct v1_disk_dqblk))
 183                 ret = 0;
 184         else if (ret > 0)
 185                 ret = -EIO;
 186 out:
 187         return ret;
 188 }
 189
 190 static struct quota_format_ops v1_format_ops = {
 191         .check_quota_file       = v1_check_quota_file,
 192         .read_file_info         = v1_read_file_info,
 193         .write_file_info        = v1_write_file_info,
 194         .free_file_info         = NULL,
 195         .read_dqblk             = v1_read_dqblk,
 196         .commit_dqblk           = v1_commit_dqblk,
 197 };
 198
 199 static struct quota_format_type v1_quota_format = {
 200         .qf_fmt_id      = QFMT_VFS_OLD,
 201         .qf_ops         = &v1_format_ops,
 202         .qf_owner       = THIS_MODULE
 203 };
 204
 205 static int __init init_v1_quota_format(void)
 206 {
 207         return register_quota_format(&v1_quota_format);
 208 }
 209
 210 static void __exit exit_v1_quota_format(void)
 211 {
 212         unregister_quota_format(&v1_quota_format);
 213 }
 214
 215 module_init(init_v1_quota_format);
 216 module_exit(exit_v1_quota_format);
 217