fs/quota_v2.c

   1 /*
   2  *      vfsv0 quota IO operations on file
   3  */
   4
   5 #include <linux/errno.h>
   6 #include <linux/fs.h>
   7 #include <linux/mount.h>
   8 #include <linux/dqblk_v2.h>
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/slab.h>
  13 #include <linux/quotaops.h>
  14
  15 #include <asm/byteorder.h>
  16
  17 #include "quota_tree.h"
  18 #include "quotaio_v2.h"
  19
  20 MODULE_AUTHOR("Jan Kara");
  21 MODULE_DESCRIPTION("Quota format v2 support");
  22 MODULE_LICENSE("GPL");
  23
  24 #define __QUOTA_V2_PARANOIA
  25
  26 static void v2_mem2diskdqb(void *dp, struct dquot *dquot);
  27 static void v2_disk2memdqb(struct dquot *dquot, void *dp);
  28 static int v2_is_id(void *dp, struct dquot *dquot);
  29
  30 static struct qtree_fmt_operations v2_qtree_ops = {
  31         .mem2disk_dqblk = v2_mem2diskdqb,
  32         .disk2mem_dqblk = v2_disk2memdqb,
  33         .is_id = v2_is_id,
  34 };
  35
  36 #define QUOTABLOCK_BITS 10
  37 #define QUOTABLOCK_SIZE (1 << QUOTABLOCK_BITS)
  38
  39 static inline qsize_t v2_stoqb(qsize_t space)
  40 {
  41         return (space + QUOTABLOCK_SIZE - 1) >> QUOTABLOCK_BITS;
  42 }
  43
  44 static inline qsize_t v2_qbtos(qsize_t blocks)
  45 {
  46         return blocks << QUOTABLOCK_BITS;
  47 }
  48
  49 /* Check whether given file is really vfsv0 quotafile */
  50 static int v2_check_quota_file(struct super_block *sb, int type)
  51 {
  52         struct v2_disk_dqheader dqhead;
  53         ssize_t size;
  54         static const uint quota_magics[] = V2_INITQMAGICS;
  55         static const uint quota_versions[] = V2_INITQVERSIONS;
  56
  57         size = sb->s_op->quota_read(sb, type, (char *)&dqhead, sizeof(struct v2_disk_dqheader), 0);
  58         if (size != sizeof(struct v2_disk_dqheader)) {
  59                 printk("quota_v2: failed read expected=%zd got=%zd\n",
  60                         sizeof(struct v2_disk_dqheader), size);
  61                 return 0;
  62         }
  63         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
  64             le32_to_cpu(dqhead.dqh_version) != quota_versions[type])
  65                 return 0;
  66         return 1;
  67 }
  68
  69 /* Read information header from quota file */
  70 static int v2_read_file_info(struct super_block *sb, int type)
  71 {
  72         struct v2_disk_dqinfo dinfo;
  73         struct mem_dqinfo *info = sb_dqinfo(sb, type);
  74         ssize_t size;
  75
  76         size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
  77                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
  78         if (size != sizeof(struct v2_disk_dqinfo)) {
  79                 printk(KERN_WARNING "Can't read info structure on device %s.\n",
  80                         sb->s_id);
  81                 return -1;
  82         }
  83         /* limits are stored as unsigned 32-bit data */
  84         info->dqi_maxblimit = 0xffffffff;
  85         info->dqi_maxilimit = 0xffffffff;
  86         info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
  87         info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
  88         info->dqi_flags = le32_to_cpu(dinfo.dqi_flags);
  89         info->u.v2_i.i.dqi_sb = sb;
  90         info->u.v2_i.i.dqi_type = type;
  91         info->u.v2_i.i.dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
  92         info->u.v2_i.i.dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
  93         info->u.v2_i.i.dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
  94         info->u.v2_i.i.dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
  95         info->u.v2_i.i.dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
  96         info->u.v2_i.i.dqi_qtree_depth = qtree_depth(&info->u.v2_i.i);
  97         info->u.v2_i.i.dqi_entry_size = sizeof(struct v2_disk_dqblk);
  98         info->u.v2_i.i.dqi_ops = &v2_qtree_ops;
  99         return 0;
 100 }
 101
 102 /* Write information header to quota file */
 103 static int v2_write_file_info(struct super_block *sb, int type)
 104 {
 105         struct v2_disk_dqinfo dinfo;
 106         struct mem_dqinfo *info = sb_dqinfo(sb, type);
 107         ssize_t size;
 108
 109         spin_lock(&dq_data_lock);
 110         info->dqi_flags &= ~DQF_INFO_DIRTY;
 111         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 112         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 113         dinfo.dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
 114         spin_unlock(&dq_data_lock);
 115         dinfo.dqi_blocks = cpu_to_le32(info->u.v2_i.i.dqi_blocks);
 116         dinfo.dqi_free_blk = cpu_to_le32(info->u.v2_i.i.dqi_free_blk);
 117         dinfo.dqi_free_entry = cpu_to_le32(info->u.v2_i.i.dqi_free_entry);
 118         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 119                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 120         if (size != sizeof(struct v2_disk_dqinfo)) {
 121                 printk(KERN_WARNING "Can't write info structure on device %s.\n",
 122                         sb->s_id);
 123                 return -1;
 124         }
 125         return 0;
 126 }
 127
 128 static void v2_disk2memdqb(struct dquot *dquot, void *dp)
 129 {
 130         struct v2_disk_dqblk *d = dp, empty;
 131         struct mem_dqblk *m = &dquot->dq_dqb;
 132
 133         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 134         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 135         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 136         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 137         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 138         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 139         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 140         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 141         /* We need to escape back all-zero structure */
 142         memset(&empty, 0, sizeof(struct v2_disk_dqblk));
 143         empty.dqb_itime = cpu_to_le64(1);
 144         if (!memcmp(&empty, dp, sizeof(struct v2_disk_dqblk)))
 145                 m->dqb_itime = 0;
 146 }
 147
 148 static void v2_mem2diskdqb(void *dp, struct dquot *dquot)
 149 {
 150         struct v2_disk_dqblk *d = dp;
 151         struct mem_dqblk *m = &dquot->dq_dqb;
 152         struct qtree_mem_dqinfo *info =
 153                         &sb_dqinfo(dquot->dq_sb, dquot->dq_type)->u.v2_i.i;
 154
 155         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 156         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 157         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 158         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 159         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 160         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 161         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 162         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 163         d->dqb_id = cpu_to_le32(dquot->dq_id);
 164         if (qtree_entry_unused(info, dp))
 165                 d->dqb_itime = cpu_to_le64(1);
 166 }
 167
 168 static int v2_is_id(void *dp, struct dquot *dquot)
 169 {
 170         struct v2_disk_dqblk *d = dp;
 171         struct qtree_mem_dqinfo *info =
 172                         &sb_dqinfo(dquot->dq_sb, dquot->dq_type)->u.v2_i.i;
 173
 174         if (qtree_entry_unused(info, dp))
 175                 return 0;
 176         return le32_to_cpu(d->dqb_id) == dquot->dq_id;
 177 }
 178
 179 static int v2_read_dquot(struct dquot *dquot)
 180 {
 181         return qtree_read_dquot(&sb_dqinfo(dquot->dq_sb, dquot->dq_type)->u.v2_i.i, dquot);
 182 }
 183
 184 static int v2_write_dquot(struct dquot *dquot)
 185 {
 186         return qtree_write_dquot(&sb_dqinfo(dquot->dq_sb, dquot->dq_type)->u.v2_i.i, dquot);
 187 }
 188
 189 static int v2_release_dquot(struct dquot *dquot)
 190 {
 191         return qtree_release_dquot(&sb_dqinfo(dquot->dq_sb, dquot->dq_type)->u.v2_i.i, dquot);
 192 }
 193
 194 static struct quota_format_ops v2_format_ops = {
 195         .check_quota_file       = v2_check_quota_file,
 196         .read_file_info         = v2_read_file_info,
 197         .write_file_info        = v2_write_file_info,
 198         .free_file_info         = NULL,
 199         .read_dqblk             = v2_read_dquot,
 200         .commit_dqblk           = v2_write_dquot,
 201         .release_dqblk          = v2_release_dquot,
 202 };
 203
 204 static struct quota_format_type v2_quota_format = {
 205         .qf_fmt_id      = QFMT_VFS_V0,
 206         .qf_ops         = &v2_format_ops,
 207         .qf_owner       = THIS_MODULE
 208 };
 209
 210 static int __init init_v2_quota_format(void)
 211 {
 212         return register_quota_format(&v2_quota_format);
 213 }
 214
 215 static void __exit exit_v2_quota_format(void)
 216 {
 217         unregister_quota_format(&v2_quota_format);
 218 }
 219
 220 module_init(init_v2_quota_format);
 221 module_exit(exit_v2_quota_format);