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/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, sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id));
  66
  67         v1_disk2mem_dqblk(&dquot->dq_dqb, &dqblk);
  68         if (dquot->dq_dqb.dqb_bhardlimit == 0 && dquot->dq_dqb.dqb_bsoftlimit == 0 &&
  69             dquot->dq_dqb.dqb_ihardlimit == 0 && dquot->dq_dqb.dqb_isoftlimit == 0)
  70                 set_bit(DQ_FAKE_B, &dquot->dq_flags);
  71         dqstats.reads++;
  72
  73         return 0;
  74 }
  75
  76 static int v1_commit_dqblk(struct dquot *dquot)
  77 {
  78         short type = dquot->dq_type;
  79         ssize_t ret;
  80         struct v1_disk_dqblk dqblk;
  81
  82         v1_mem2disk_dqblk(&dqblk, &dquot->dq_dqb);
  83         if (dquot->dq_id == 0) {
  84                 dqblk.dqb_btime = sb_dqopt(dquot->dq_sb)->info[type].dqi_bgrace;
  85                 dqblk.dqb_itime = sb_dqopt(dquot->dq_sb)->info[type].dqi_igrace;
  86         }
  87         ret = 0;
  88         if (sb_dqopt(dquot->dq_sb)->files[type])
  89                 ret = dquot->dq_sb->s_op->quota_write(dquot->dq_sb, type, (char *)&dqblk,
  90                                         sizeof(struct v1_disk_dqblk), v1_dqoff(dquot->dq_id));
  91         if (ret != sizeof(struct v1_disk_dqblk)) {
  92                 printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
  93                         dquot->dq_sb->s_id);
  94                 if (ret >= 0)
  95                         ret = -EIO;
  96                 goto out;
  97         }
  98         ret = 0;
  99
 100 out:
 101         dqstats.writes++;
 102
 103         return ret;
 104 }
 105
 106 /* Magics of new quota format */
 107 #define V2_INITQMAGICS {\
 108         0xd9c01f11,     /* USRQUOTA */\
 109         0xd9c01927      /* GRPQUOTA */\
 110 }
 111
 112 /* Header of new quota format */
 113 struct v2_disk_dqheader {
 114         __le32 dqh_magic;        /* Magic number identifying file */
 115         __le32 dqh_version;      /* File version */
 116 };
 117
 118 static int v1_check_quota_file(struct super_block *sb, int type)
 119 {
 120         struct inode *inode = sb_dqopt(sb)->files[type];
 121         ulong blocks;
 122         size_t off;
 123         struct v2_disk_dqheader dqhead;
 124         ssize_t size;
 125         loff_t isize;
 126         static const uint quota_magics[] = V2_INITQMAGICS;
 127
 128         isize = i_size_read(inode);
 129         if (!isize)
 130                 return 0;
 131         blocks = isize >> BLOCK_SIZE_BITS;
 132         off = isize & (BLOCK_SIZE - 1);
 133         if ((blocks % sizeof(struct v1_disk_dqblk) * BLOCK_SIZE + off) % sizeof(struct v1_disk_dqblk))
 134                 return 0;
 135         /* Doublecheck whether we didn't get file with new format - with old quotactl() this could happen */
 136         size = sb->s_op->quota_read(sb, type, (char *)&dqhead, sizeof(struct v2_disk_dqheader), 0);
 137         if (size != sizeof(struct v2_disk_dqheader))
 138                 return 1;       /* Probably not new format */
 139         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type])
 140                 return 1;       /* Definitely not new format */
 141         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);
 142         return 0;               /* Seems like a new format file -> refuse it */
 143 }
 144
 145 static int v1_read_file_info(struct super_block *sb, int type)
 146 {
 147         struct quota_info *dqopt = sb_dqopt(sb);
 148         struct v1_disk_dqblk dqblk;
 149         int ret;
 150
 151         if ((ret = sb->s_op->quota_read(sb, type, (char *)&dqblk, sizeof(struct v1_disk_dqblk), v1_dqoff(0))) != sizeof(struct v1_disk_dqblk)) {
 152                 if (ret >= 0)
 153                         ret = -EIO;
 154                 goto out;
 155         }
 156         ret = 0;
 157         /* limits are stored as unsigned 32-bit data */
 158         dqopt->info[type].dqi_maxblimit = 0xffffffff;
 159         dqopt->info[type].dqi_maxilimit = 0xffffffff;
 160         dqopt->info[type].dqi_igrace = dqblk.dqb_itime ? dqblk.dqb_itime : MAX_IQ_TIME;
 161         dqopt->info[type].dqi_bgrace = dqblk.dqb_btime ? dqblk.dqb_btime : MAX_DQ_TIME;
 162 out:
 163         return ret;
 164 }
 165
 166 static int v1_write_file_info(struct super_block *sb, int type)
 167 {
 168         struct quota_info *dqopt = sb_dqopt(sb);
 169         struct v1_disk_dqblk dqblk;
 170         int ret;
 171
 172         dqopt->info[type].dqi_flags &= ~DQF_INFO_DIRTY;
 173         if ((ret = sb->s_op->quota_read(sb, type, (char *)&dqblk,
 174             sizeof(struct v1_disk_dqblk), v1_dqoff(0))) != sizeof(struct v1_disk_dqblk)) {
 175                 if (ret >= 0)
 176                         ret = -EIO;
 177                 goto out;
 178         }
 179         dqblk.dqb_itime = dqopt->info[type].dqi_igrace;
 180         dqblk.dqb_btime = dqopt->info[type].dqi_bgrace;
 181         ret = sb->s_op->quota_write(sb, type, (char *)&dqblk,
 182               sizeof(struct v1_disk_dqblk), v1_dqoff(0));
 183         if (ret == sizeof(struct v1_disk_dqblk))
 184                 ret = 0;
 185         else if (ret > 0)
 186                 ret = -EIO;
 187 out:
 188         return ret;
 189 }
 190
 191 static struct quota_format_ops v1_format_ops = {
 192         .check_quota_file       = v1_check_quota_file,
 193         .read_file_info         = v1_read_file_info,
 194         .write_file_info        = v1_write_file_info,
 195         .free_file_info         = NULL,
 196         .read_dqblk             = v1_read_dqblk,
 197         .commit_dqblk           = v1_commit_dqblk,
 198 };
 199
 200 static struct quota_format_type v1_quota_format = {
 201         .qf_fmt_id      = QFMT_VFS_OLD,
 202         .qf_ops         = &v1_format_ops,
 203         .qf_owner       = THIS_MODULE
 204 };
 205
 206 static int __init init_v1_quota_format(void)
 207 {
 208         return register_quota_format(&v1_quota_format);
 209 }
 210
 211 static void __exit exit_v1_quota_format(void)
 212 {
 213         unregister_quota_format(&v1_quota_format);
 214 }
 215
 216 module_init(init_v1_quota_format);
 217 module_exit(exit_v1_quota_format);
 218