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 = 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                 dquot->dq_flags |= DQ_FAKE;
  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         /*
  84          * Note: clear the DQ_MOD flag unconditionally,
  85          * so we don't loop forever on failure.
  86          */
  87         v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
  88         dquot->dq_flags &= ~DQ_MOD;
  89         if (dquot->dq_id == 0) {
  90                 dqblk.dqb_btime = sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
  91                 dqblk.dqb_itime = sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
  92         }
  93         ret = 0;
  94         if (filp)
  95                 ret = filp->f_op->write(filp, (char *)&dqblk,
  96                                         sizeof(struct v1_disk_dqblk), &offset);
  97         if (ret != sizeof(struct v1_disk_dqblk)) {
  98                 printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
  99                         dquot->dq_sb->s_id);
 100                 if (ret >= 0)
 101                         ret = -EIO;
 102                 goto out;
 103         }
 104         ret = 0;
 105
 106 out:
 107         set_fs(fs);
 108         dqstats.writes++;
 109
 110         return ret;
 111 }
 112
 113 /* Magics of new quota format */
 114 #define V2_INITQMAGICS {\
 115         0xd9c01f11,     /* USRQUOTA */\
 116         0xd9c01927      /* GRPQUOTA */\
 117 }
 118
 119 /* Header of new quota format */
 120 struct v2_disk_dqheader {
 121         __u32 dqh_magic;        /* Magic number identifying file */
 122         __u32 dqh_version;      /* File version */
 123 };
 124
 125 static int v1_check_quota_file(struct super_block *sb, int type)
 126 {
 127         struct file *f = sb_dqopt(sb)->files[type];
 128         struct inode *inode = f->f_dentry->d_inode;
 129         ulong blocks;
 130         size_t off;
 131         struct v2_disk_dqheader dqhead;
 132         mm_segment_t fs;
 133         ssize_t size;
 134         loff_t offset = 0;
 135         static const uint quota_magics[] = V2_INITQMAGICS;
 136
 137         if (!inode->i_size)
 138                 return 0;
 139         blocks = inode->i_size >> BLOCK_SIZE_BITS;
 140         off = inode->i_size & (BLOCK_SIZE - 1);
 141         if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % sizeof(struct v1_disk_dqblk))
 142                 return 0;
 143         /* Doublecheck whether we didn't get file with new format - with old quotactl() this could happen */
 144         fs = get_fs();
 145         set_fs(KERNEL_DS);
 146         size = f->f_op->read(f, (char *)&dqhead, sizeof(struct v2_disk_dqheader), &offset);
 147         set_fs(fs);
 148         if (size != sizeof(struct v2_disk_dqheader))
 149                 return 1;       /* Probably not new format */
 150         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
 151                 return 1;       /* Definitely not new format */
 152         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);
 153         return 0;               /* Seems like a new format file -> refuse it */
 154 }
 155
 156 static int v1_read_file_info(struct super_block *sb, int type)
 157 {
 158         struct quota_info *dqopt = sb_dqopt(sb);
 159         mm_segment_t fs;
 160         loff_t offset;
 161         struct file *filp = dqopt->files[type];
 162         struct v1_disk_dqblk dqblk;
 163         int ret;
 164
 165         down(&dqopt->dqio_sem);
 166         offset = v1_dqoff(0);
 167         fs = get_fs();
 168         set_fs(KERNEL_DS);
 169         if ((ret = filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset)) != sizeof(struct v1_disk_dqblk)) {
 170                 if (ret >= 0)
 171                         ret = -EIO;
 172                 goto out;
 173         }
 174         ret = 0;
 175         dqopt->info[type].dqi_igrace = dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
 176         dqopt->info[type].dqi_bgrace = dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
 177 out:
 178         up(&dqopt->dqio_sem);
 179         set_fs(fs);
 180         return ret;
 181 }
 182
 183 static int v1_write_file_info(struct super_block *sb, int type)
 184 {
 185         struct quota_info *dqopt = sb_dqopt(sb);
 186         mm_segment_t fs;
 187         struct file *filp = dqopt->files[type];
 188         struct v1_disk_dqblk dqblk;
 189         loff_t offset;
 190         int ret;
 191
 192         down(&dqopt->dqio_sem);
 193         dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
 194         offset = v1_dqoff(0);
 195         fs = get_fs();
 196         set_fs(KERNEL_DS);
 197         if ((ret = filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset)) != sizeof(struct v1_disk_dqblk)) {
 198                 if (ret >= 0)
 199                         ret = -EIO;
 200                 goto out;
 201         }
 202         dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
 203         dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
 204         offset = v1_dqoff(0);
 205         ret = filp->f_op->write(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset);
 206         if (ret == sizeof(struct v1_disk_dqblk))
 207                 ret = 0;
 208         else if (ret > 0)
 209                 ret = -EIO;
 210 out:
 211         up(&dqopt->dqio_sem);
 212         set_fs(fs);
 213         return ret;
 214 }
 215
 216 static struct quota_format_ops v1_format_ops = {
 217         .check_quota_file       = v1_check_quota_file,
 218         .read_file_info         = v1_read_file_info,
 219         .write_file_info        = v1_write_file_info,
 220         .free_file_info         = NULL,
 221         .read_dqblk             = v1_read_dqblk,
 222         .commit_dqblk           = v1_commit_dqblk,
 223 };
 224
 225 static struct quota_format_type v1_quota_format = {
 226         .qf_fmt_id      = QFMT_VFS_OLD,
 227         .qf_ops         = &v1_format_ops,
 228         .qf_owner       = THIS_MODULE
 229 };
 230
 231 static int __init init_v1_quota_format(void)
 232 {
 233         return register_quota_format(&v1_quota_format);
 234 }
 235
 236 static void __exit exit_v1_quota_format(void)
 237 {
 238         unregister_quota_format(&v1_quota_format);
 239 }
 240
 241 module_init(init_v1_quota_format);
 242 module_exit(exit_v1_quota_format);
 243