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 = ((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 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         /* Set structure to 0s in case read fails/is after end of file */
  56         memset(&dqblk, 0, sizeof(struct v1_disk_dqblk));
  57         fs = get_fs();
  58         set_fs(KERNEL_DS);
  59         filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset);
  60         set_fs(fs);
  61
  62         v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
  63         if (dquot->dq_dqb.dqb_bhardlimit == 0 && dquot->dq_dqb.dqb_bsoftlimit == 0 &&
  64             dquot->dq_dqb.dqb_ihardlimit == 0 && dquot->dq_dqb.dqb_isoftlimit == 0)
  65                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
  66         dqstats.reads++;
  67
  68         return 0;
  69 }
  70
  71 static int v1_commit_dqblk(struct dquot *dquot)
  72 {
  73         short type = dquot->dq_type;
  74         struct file *filp;
  75         mm_segment_t fs;
  76         loff_t offset;
  77         ssize_t ret;
  78         struct v1_disk_dqblk dqblk;
  79
  80         filp = sb_dqopt(dquot->dq_sb)->files[type];
  81         offset = v1_dqoff(dquot->dq_id);
  82         fs = get_fs();
  83         set_fs(KERNEL_DS);
  84
  85         v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
  86         if (dquot->dq_id == 0) {
  87                 dqblk.dqb_btime = sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
  88                 dqblk.dqb_itime = sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
  89         }
  90         ret = 0;
  91         if (filp)
  92                 ret = filp->f_op->write(filp, (char *)&dqblk,
  93                                         sizeof(struct v1_disk_dqblk), &offset);
  94         if (ret != sizeof(struct v1_disk_dqblk)) {
  95                 printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
  96                         dquot->dq_sb->s_id);
  97                 if (ret >= 0)
  98                         ret = -EIO;
  99                 goto out;
 100         }
 101         ret = 0;
 102
 103 out:
 104         set_fs(fs);
 105         dqstats.writes++;
 106
 107         return ret;
 108 }
 109
 110 /* Magics of new quota format */
 111 #define V2_INITQMAGICS {\
 112         0xd9c01f11,     /* USRQUOTA */\
 113         0xd9c01927      /* GRPQUOTA */\
 114 }
 115
 116 /* Header of new quota format */
 117 struct v2_disk_dqheader {
 118         __u32 dqh_magic;        /* Magic number identifying file */
 119         __u32 dqh_version;      /* File version */
 120 };
 121
 122 static int v1_check_quota_file(struct super_block *sb, int type)
 123 {
 124         struct file *f = sb_dqopt(sb)->files[type];
 125         struct inode *inode = f->f_dentry->d_inode;
 126         ulong blocks;
 127         size_t off;
 128         struct v2_disk_dqheader dqhead;
 129         mm_segment_t fs;
 130         ssize_t size;
 131         loff_t offset = 0;
 132         loff_t isize;
 133         static const uint quota_magics[] = V2_INITQMAGICS;
 134
 135         isize = i_size_read(inode);
 136         if (!isize)
 137                 return 0;
 138         blocks = isize >> BLOCK_SIZE_BITS;
 139         off = isize & (BLOCK_SIZE - 1);
 140         if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % sizeof(struct v1_disk_dqblk))
 141                 return 0;
 142         /* Doublecheck whether we didn't get file with new format - with old quotactl() this could happen */
 143         fs = get_fs();
 144         set_fs(KERNEL_DS);
 145         size = f->f_op->read(f, (char *)&dqhead, sizeof(struct v2_disk_dqheader), &offset);
 146         set_fs(fs);
 147         if (size != sizeof(struct v2_disk_dqheader))
 148                 return 1;       /* Probably not new format */
 149         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
 150                 return 1;       /* Definitely not new format */
 151         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);
 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         mm_segment_t fs;
 159         loff_t offset;
 160         struct file *filp = dqopt->files[type];
 161         struct v1_disk_dqblk dqblk;
 162         int ret;
 163
 164         offset = v1_dqoff(0);
 165         fs = get_fs();
 166         set_fs(KERNEL_DS);
 167         if ((ret = filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset)) != sizeof(struct v1_disk_dqblk)) {
 168                 if (ret >= 0)
 169                         ret = -EIO;
 170                 goto out;
 171         }
 172         ret = 0;
 173         dqopt->info[type].dqi_igrace = dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
 174         dqopt->info[type].dqi_bgrace = dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
 175 out:
 176         set_fs(fs);
 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         mm_segment_t fs;
 184         struct file *filp = dqopt->files[type];
 185         struct v1_disk_dqblk dqblk;
 186         loff_t offset;
 187         int ret;
 188
 189         dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
 190         offset = v1_dqoff(0);
 191         fs = get_fs();
 192         set_fs(KERNEL_DS);
 193         if ((ret = filp->f_op->read(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset)) != sizeof(struct v1_disk_dqblk)) {
 194                 if (ret >= 0)
 195                         ret = -EIO;
 196                 goto out;
 197         }
 198         dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
 199         dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
 200         offset = v1_dqoff(0);
 201         ret = filp->f_op->write(filp, (char *)&dqblk, sizeof(struct v1_disk_dqblk), &offset);
 202         if (ret == sizeof(struct v1_disk_dqblk))
 203                 ret = 0;
 204         else if (ret > 0)
 205                 ret = -EIO;
 206 out:
 207         set_fs(fs);
 208         return ret;
 209 }
 210
 211 static struct quota_format_ops v1_format_ops = {
 212         .check_quota_file       = v1_check_quota_file,
 213         .read_file_info         = v1_read_file_info,
 214         .write_file_info        = v1_write_file_info,
 215         .free_file_info         = NULL,
 216         .read_dqblk             = v1_read_dqblk,
 217         .commit_dqblk           = v1_commit_dqblk,
 218 };
 219
 220 static struct quota_format_type v1_quota_format = {
 221         .qf_fmt_id      = QFMT_VFS_OLD,
 222         .qf_ops         = &v1_format_ops,
 223         .qf_owner       = THIS_MODULE
 224 };
 225
 226 static int __init init_v1_quota_format(void)
 227 {
 228         return register_quota_format(&v1_quota_format);
 229 }
 230
 231 static void __exit exit_v1_quota_format(void)
 232 {
 233         unregister_quota_format(&v1_quota_format);
 234 }
 235
 236 module_init(init_v1_quota_format);
 237 module_exit(exit_v1_quota_format);
 238