release/src-rt-6.x.4708/linux/linux-2.6.36/fs/quota/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/kernel.h>
   7 #include <linux/init.h>
   8 #include <linux/module.h>
   9
  10 #include <asm/byteorder.h>
  11
  12 #include "quotaio_v1.h"
  13
  14 MODULE_AUTHOR("Jan Kara");
  15 MODULE_DESCRIPTION("Old quota format support");
  16 MODULE_LICENSE("GPL");
  17
  18 #define QUOTABLOCK_BITS 10
  19 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
  20
  21 static inline qsize_t v1_stoqb(qsize_t space)
  22 {
  23         return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
  24 }
  25
  26 static inline qsize_t v1_qbtos(qsize_t blocks)
  27 {
  28         return blocks << QUOTABLOCK_BITS;
  29 }
  30
  31 static void v1_disk2mem_dqblk(struct mem_dqblk *m, struct v1_disk_dqblk *d)
  32 {
  33         m->dqb_ihardlimit = d->dqb_ihardlimit;
  34         m->dqb_isoftlimit = d->dqb_isoftlimit;
  35         m->dqb_curinodes = d->dqb_curinodes;
  36         m->dqb_bhardlimit = v1_qbtos(d->dqb_bhardlimit);
  37         m->dqb_bsoftlimit = v1_qbtos(d->dqb_bsoftlimit);
  38         m->dqb_curspace = v1_qbtos(d->dqb_curblocks);
  39         m->dqb_itime = d->dqb_itime;
  40         m->dqb_btime = d->dqb_btime;
  41 }
  42
  43 static void v1_mem2disk_dqblk(struct v1_disk_dqblk *d, struct mem_dqblk *m)
  44 {
  45         d->dqb_ihardlimit = m->dqb_ihardlimit;
  46         d->dqb_isoftlimit = m->dqb_isoftlimit;
  47         d->dqb_curinodes = m->dqb_curinodes;
  48         d->dqb_bhardlimit = v1_stoqb(m->dqb_bhardlimit);
  49         d->dqb_bsoftlimit = v1_stoqb(m->dqb_bsoftlimit);
  50         d->dqb_curblocks = v1_stoqb(m->dqb_curspace);
  51         d->dqb_itime = m->dqb_itime;
  52         d->dqb_btime = m->dqb_btime;
  53 }
  54
  55 static int v1_read_dqblk(struct dquot *dquot)
  56 {
  57         int type = dquot->dq_type;
  58         struct v1_disk_dqblk dqblk;
  59
  60         if (!sb_dqopt(dquot->dq_sb)->files[type])
  61                 return -EINVAL;
  62
  63         /* Set structure to 0s in case read fails/is after end of file */
  64         memset(&dqblk, 0, sizeof(struct v1_disk_dqblk));
  65         dquot->dq_sb->s_op->quota_read(dquot->dq_sb, type, (char *)&dqblk,
  66                         sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id));
  67
  68         v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
  69         if (dquot->dq_dqb.dqb_bhardlimit == 0 &&
  70             dquot->dq_dqb.dqb_bsoftlimit == 0 &&
  71             dquot->dq_dqb.dqb_ihardlimit == 0 &&
  72             dquot->dq_dqb.dqb_isoftlimit == 0)
  73                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
  74         dqstats_inc(DQST_READS);
  75
  76         return 0;
  77 }
  78
  79 static int v1_commit_dqblk(struct dquot *dquot)
  80 {
  81         short type = dquot->dq_type;
  82         ssize_t ret;
  83         struct v1_disk_dqblk dqblk;
  84
  85         v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
  86         if (dquot->dq_id == 0) {
  87                 dqblk.dqb_btime =
  88                         sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
  89                 dqblk.dqb_itime =
  90                         sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
  91         }
  92         ret = 0;
  93         if (sb_dqopt(dquot->dq_sb)->files[type])
  94                 ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type,
  95                         (char *)&dqblk, sizeof(struct v1_disk_dqblk),
  96                         v1_dqoff(dquot->dq_id));
  97         if (ret != sizeof(struct v1_disk_dqblk)) {
  98                 quota_error(dquot->dq_sb, "dquota write failed");
  99                 if (ret >= 0)
 100                         ret = -EIO;
 101                 goto out;
 102         }
 103         ret = 0;
 104
 105 out:
 106         dqstats_inc(DQST_WRITES);
 107
 108         return ret;
 109 }
 110
 111 /* Magics of new quota format */
 112 #define V2_INITQMAGICS {\
 113         0xd9c01f11,     /* USRQUOTA */\
 114         0xd9c01927      /* GRPQUOTA */\
 115 }
 116
 117 /* Header of new quota format */
 118 struct v2_disk_dqheader {
 119         __le32 dqh_magic;        /* Magic number identifying file */
 120         __le32 dqh_version;      /* File version */
 121 };
 122
 123 static int v1_check_quota_file(struct super_block *sb, int type)
 124 {
 125         struct inode *inode = sb_dqopt(sb)->files[type];
 126         ulong blocks;
 127         size_t off;
 128         struct v2_disk_dqheader dqhead;
 129         ssize_t size;
 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) %
 139             sizeof(struct v1_disk_dqblk))
 140                 return 0;
 141         /* Doublecheck whether we didn't get file with new format - with old
 142          * quotactl() this could happen */
 143         size = sb->s_op->quota_read(sb, type, (char *)&dqhead,
 144                                     sizeof(struct v2_disk_dqheader), 0);
 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
 150                "VFS: %s: Refusing to turn on old quota format on given file."
 151                " It probably contains newer quota format.\n", sb->s_id);
 152         return 0;               /* Seems like a new format file -> refuse it */
 153 }
 154
 155 static int v1_read_file_info(struct super_block *sb, int type)
 156 {
 157         struct quota_info *dqopt = sb_dqopt(sb);
 158         struct v1_disk_dqblk dqblk;
 159         int ret;
 160
 161         ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
 162                                 sizeof(struct v1_disk_dqblk), v1_dqoff(0));
 163         if (ret != sizeof(struct v1_disk_dqblk)) {
 164                 if (ret >= 0)
 165                         ret = -EIO;
 166                 goto out;
 167         }
 168         ret = 0;
 169         /* limits are stored as unsigned 32-bit data */
 170         dqopt->info[type].dqi_maxblimit = 0xffffffff;
 171         dqopt->info[type].dqi_maxilimit = 0xffffffff;
 172         dqopt->info[type].dqi_igrace =
 173                         dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
 174         dqopt->info[type].dqi_bgrace =
 175                         dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
 176 out:
 177         return ret;
 178 }
 179
 180 static int v1_write_file_info(struct super_block *sb, int type)
 181 {
 182         struct quota_info *dqopt = sb_dqopt(sb);
 183         struct v1_disk_dqblk dqblk;
 184         int ret;
 185
 186         dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
 187         ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
 188                                 sizeof(struct v1_disk_dqblk), v1_dqoff(0));
 189         if (ret != sizeof(struct v1_disk_dqblk)) {
 190                 if (ret >= 0)
 191                         ret = -EIO;
 192                 goto out;
 193         }
 194         dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
 195         dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
 196         ret = sb->s_op->quota_write(sb, type, (char *)&dqblk,
 197               sizeof(struct v1_disk_dqblk), v1_dqoff(0));
 198         if (ret == sizeof(struct v1_disk_dqblk))
 199                 ret = 0;
 200         else if (ret > 0)
 201                 ret = -EIO;
 202 out:
 203         return ret;
 204 }
 205
 206 static const struct quota_format_ops v1_format_ops = {
 207         .check_quota_file       = v1_check_quota_file,
 208         .read_file_info         = v1_read_file_info,
 209         .write_file_info        = v1_write_file_info,
 210         .free_file_info         = NULL,
 211         .read_dqblk             = v1_read_dqblk,
 212         .commit_dqblk           = v1_commit_dqblk,
 213 };
 214
 215 static struct quota_format_type v1_quota_format = {
 216         .qf_fmt_id      = QFMT_VFS_OLD,
 217         .qf_ops         = &v1_format_ops,
 218         .qf_owner       = THIS_MODULE
 219 };
 220
 221 static int __init init_v1_quota_format(void)
 222 {
 223         return register_quota_format(&v1_quota_format);
 224 }
 225
 226 static void __exit exit_v1_quota_format(void)
 227 {
 228         unregister_quota_format(&v1_quota_format);
 229 }
 230
 231 module_init(init_v1_quota_format);
 232 module_exit(exit_v1_quota_format);