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         struct qtree_mem_dqinfo *qinfo;
  75         ssize_t size;
  76
  77         size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
  78                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
  79         if (size != sizeof(struct v2_disk_dqinfo)) {
  80                 printk(KERN_WARNING "Can't read info structure on device %s.\n",
  81                         sb->s_id);
  82                 return -1;
  83         }
  84         info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
  85         if (!info->dqi_priv) {
  86                 printk(KERN_WARNING
  87                        "Not enough memory for quota information structure.\n");
  88                 return -1;
  89         }
  90         qinfo = info->dqi_priv;
  91         /* limits are stored as unsigned 32-bit data */
  92         info->dqi_maxblimit = 0xffffffff;
  93         info->dqi_maxilimit = 0xffffffff;
  94         info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
  95         info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
  96         info->dqi_flags = le32_to_cpu(dinfo.dqi_flags);
  97         qinfo->dqi_sb = sb;
  98         qinfo->dqi_type = type;
  99         qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
 100         qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
 101         qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
 102         qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
 103         qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
 104         qinfo->dqi_qtree_depth = qtree_depth(qinfo);
 105         qinfo->dqi_entry_size = sizeof(struct v2_disk_dqblk);
 106         qinfo->dqi_ops = &v2_qtree_ops;
 107         return 0;
 108 }
 109
 110 /* Write information header to quota file */
 111 static int v2_write_file_info(struct super_block *sb, int type)
 112 {
 113         struct v2_disk_dqinfo dinfo;
 114         struct mem_dqinfo *info = sb_dqinfo(sb, type);
 115         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 116         ssize_t size;
 117
 118         spin_lock(&dq_data_lock);
 119         info->dqi_flags &= ~DQF_INFO_DIRTY;
 120         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 121         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 122         dinfo.dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
 123         spin_unlock(&dq_data_lock);
 124         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 125         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 126         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 127         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 128                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 129         if (size != sizeof(struct v2_disk_dqinfo)) {
 130                 printk(KERN_WARNING "Can't write info structure on device %s.\n",
 131                         sb->s_id);
 132                 return -1;
 133         }
 134         return 0;
 135 }
 136
 137 static void v2_disk2memdqb(struct dquot *dquot, void *dp)
 138 {
 139         struct v2_disk_dqblk *d = dp, empty;
 140         struct mem_dqblk *m = &dquot->dq_dqb;
 141
 142         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 143         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 144         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 145         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 146         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 147         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 148         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 149         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 150         /* We need to escape back all-zero structure */
 151         memset(&empty, 0, sizeof(struct v2_disk_dqblk));
 152         empty.dqb_itime = cpu_to_le64(1);
 153         if (!memcmp(&empty, dp, sizeof(struct v2_disk_dqblk)))
 154                 m->dqb_itime = 0;
 155 }
 156
 157 static void v2_mem2diskdqb(void *dp, struct dquot *dquot)
 158 {
 159         struct v2_disk_dqblk *d = dp;
 160         struct mem_dqblk *m = &dquot->dq_dqb;
 161         struct qtree_mem_dqinfo *info =
 162                         sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
 163
 164         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 165         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 166         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 167         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 168         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 169         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 170         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 171         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 172         d->dqb_id = cpu_to_le32(dquot->dq_id);
 173         if (qtree_entry_unused(info, dp))
 174                 d->dqb_itime = cpu_to_le64(1);
 175 }
 176
 177 static int v2_is_id(void *dp, struct dquot *dquot)
 178 {
 179         struct v2_disk_dqblk *d = dp;
 180         struct qtree_mem_dqinfo *info =
 181                         sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
 182
 183         if (qtree_entry_unused(info, dp))
 184                 return 0;
 185         return le32_to_cpu(d->dqb_id) == dquot->dq_id;
 186 }
 187
 188 static int v2_read_dquot(struct dquot *dquot)
 189 {
 190         return qtree_read_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
 191 }
 192
 193 static int v2_write_dquot(struct dquot *dquot)
 194 {
 195         return qtree_write_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
 196 }
 197
 198 static int v2_release_dquot(struct dquot *dquot)
 199 {
 200         return qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
 201 }
 202
 203 static int v2_free_file_info(struct super_block *sb, int type)
 204 {
 205         kfree(sb_dqinfo(sb, type)->dqi_priv);
 206         return 0;
 207 }
 208
 209 static struct quota_format_ops v2_format_ops = {
 210         .check_quota_file       = v2_check_quota_file,
 211         .read_file_info         = v2_read_file_info,
 212         .write_file_info        = v2_write_file_info,
 213         .free_file_info         = v2_free_file_info,
 214         .read_dqblk             = v2_read_dquot,
 215         .commit_dqblk           = v2_write_dquot,
 216         .release_dqblk          = v2_release_dquot,
 217 };
 218
 219 static struct quota_format_type v2_quota_format = {
 220         .qf_fmt_id      = QFMT_VFS_V0,
 221         .qf_ops         = &v2_format_ops,
 222         .qf_owner       = THIS_MODULE
 223 };
 224
 225 static int __init init_v2_quota_format(void)
 226 {
 227         return register_quota_format(&v2_quota_format);
 228 }
 229
 230 static void __exit exit_v2_quota_format(void)
 231 {
 232         unregister_quota_format(&v2_quota_format);
 233 }
 234
 235 module_init(init_v2_quota_format);
 236 module_exit(exit_v2_quota_format);