fs/quota/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,
  58                                     sizeof(struct v2_disk_dqheader), 0);
  59         if (size != sizeof(struct v2_disk_dqheader)) {
  60                 printk("quota_v2: failed read expected=%zd got=%zd\n",
  61                         sizeof(struct v2_disk_dqheader), size);
  62                 return 0;
  63         }
  64         if (le32_to_cpu(dqhead.dqh_magic) != quota_magics[type] ||
  65             le32_to_cpu(dqhead.dqh_version) != quota_versions[type])
  66                 return 0;
  67         return 1;
  68 }
  69
  70 /* Read information header from quota file */
  71 static int v2_read_file_info(struct super_block *sb, int type)
  72 {
  73         struct v2_disk_dqinfo dinfo;
  74         struct mem_dqinfo *info = sb_dqinfo(sb, type);
  75         struct qtree_mem_dqinfo *qinfo;
  76         ssize_t size;
  77
  78         size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
  79                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
  80         if (size != sizeof(struct v2_disk_dqinfo)) {
  81                 printk(KERN_WARNING "Can't read info structure on device %s.\n",
  82                         sb->s_id);
  83                 return -1;
  84         }
  85         info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
  86         if (!info->dqi_priv) {
  87                 printk(KERN_WARNING
  88                        "Not enough memory for quota information structure.\n");
  89                 return -1;
  90         }
  91         qinfo = info->dqi_priv;
  92         /* limits are stored as unsigned 32-bit data */
  93         info->dqi_maxblimit = 0xffffffff;
  94         info->dqi_maxilimit = 0xffffffff;
  95         info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
  96         info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
  97         info->dqi_flags = le32_to_cpu(dinfo.dqi_flags);
  98         qinfo->dqi_sb = sb;
  99         qinfo->dqi_type = type;
 100         qinfo->dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
 101         qinfo->dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
 102         qinfo->dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
 103         qinfo->dqi_blocksize_bits = V2_DQBLKSIZE_BITS;
 104         qinfo->dqi_usable_bs = 1 << V2_DQBLKSIZE_BITS;
 105         qinfo->dqi_qtree_depth = qtree_depth(qinfo);
 106         qinfo->dqi_entry_size = sizeof(struct v2_disk_dqblk);
 107         qinfo->dqi_ops = &v2_qtree_ops;
 108         return 0;
 109 }
 110
 111 /* Write information header to quota file */
 112 static int v2_write_file_info(struct super_block *sb, int type)
 113 {
 114         struct v2_disk_dqinfo dinfo;
 115         struct mem_dqinfo *info = sb_dqinfo(sb, type);
 116         struct qtree_mem_dqinfo *qinfo = info->dqi_priv;
 117         ssize_t size;
 118
 119         spin_lock(&dq_data_lock);
 120         info->dqi_flags &= ~DQF_INFO_DIRTY;
 121         dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
 122         dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
 123         dinfo.dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
 124         spin_unlock(&dq_data_lock);
 125         dinfo.dqi_blocks = cpu_to_le32(qinfo->dqi_blocks);
 126         dinfo.dqi_free_blk = cpu_to_le32(qinfo->dqi_free_blk);
 127         dinfo.dqi_free_entry = cpu_to_le32(qinfo->dqi_free_entry);
 128         size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
 129                sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
 130         if (size != sizeof(struct v2_disk_dqinfo)) {
 131                 printk(KERN_WARNING "Can't write info structure on device %s.\n",
 132                         sb->s_id);
 133                 return -1;
 134         }
 135         return 0;
 136 }
 137
 138 static void v2_disk2memdqb(struct dquot *dquot, void *dp)
 139 {
 140         struct v2_disk_dqblk *d = dp, empty;
 141         struct mem_dqblk *m = &dquot->dq_dqb;
 142
 143         m->dqb_ihardlimit = le32_to_cpu(d->dqb_ihardlimit);
 144         m->dqb_isoftlimit = le32_to_cpu(d->dqb_isoftlimit);
 145         m->dqb_curinodes = le32_to_cpu(d->dqb_curinodes);
 146         m->dqb_itime = le64_to_cpu(d->dqb_itime);
 147         m->dqb_bhardlimit = v2_qbtos(le32_to_cpu(d->dqb_bhardlimit));
 148         m->dqb_bsoftlimit = v2_qbtos(le32_to_cpu(d->dqb_bsoftlimit));
 149         m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
 150         m->dqb_btime = le64_to_cpu(d->dqb_btime);
 151         /* We need to escape back all-zero structure */
 152         memset(&empty, 0, sizeof(struct v2_disk_dqblk));
 153         empty.dqb_itime = cpu_to_le64(1);
 154         if (!memcmp(&empty, dp, sizeof(struct v2_disk_dqblk)))
 155                 m->dqb_itime = 0;
 156 }
 157
 158 static void v2_mem2diskdqb(void *dp, struct dquot *dquot)
 159 {
 160         struct v2_disk_dqblk *d = dp;
 161         struct mem_dqblk *m = &dquot->dq_dqb;
 162         struct qtree_mem_dqinfo *info =
 163                         sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
 164
 165         d->dqb_ihardlimit = cpu_to_le32(m->dqb_ihardlimit);
 166         d->dqb_isoftlimit = cpu_to_le32(m->dqb_isoftlimit);
 167         d->dqb_curinodes = cpu_to_le32(m->dqb_curinodes);
 168         d->dqb_itime = cpu_to_le64(m->dqb_itime);
 169         d->dqb_bhardlimit = cpu_to_le32(v2_stoqb(m->dqb_bhardlimit));
 170         d->dqb_bsoftlimit = cpu_to_le32(v2_stoqb(m->dqb_bsoftlimit));
 171         d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
 172         d->dqb_btime = cpu_to_le64(m->dqb_btime);
 173         d->dqb_id = cpu_to_le32(dquot->dq_id);
 174         if (qtree_entry_unused(info, dp))
 175                 d->dqb_itime = cpu_to_le64(1);
 176 }
 177
 178 static int v2_is_id(void *dp, struct dquot *dquot)
 179 {
 180         struct v2_disk_dqblk *d = dp;
 181         struct qtree_mem_dqinfo *info =
 182                         sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
 183
 184         if (qtree_entry_unused(info, dp))
 185                 return 0;
 186         return le32_to_cpu(d->dqb_id) == dquot->dq_id;
 187 }
 188
 189 static int v2_read_dquot(struct dquot *dquot)
 190 {
 191         return qtree_read_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
 192 }
 193
 194 static int v2_write_dquot(struct dquot *dquot)
 195 {
 196         return qtree_write_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
 197 }
 198
 199 static int v2_release_dquot(struct dquot *dquot)
 200 {
 201         return qtree_release_dquot(sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv, dquot);
 202 }
 203
 204 static int v2_free_file_info(struct super_block *sb, int type)
 205 {
 206         kfree(sb_dqinfo(sb, type)->dqi_priv);
 207         return 0;
 208 }
 209
 210 static struct quota_format_ops v2_format_ops = {
 211         .check_quota_file       = v2_check_quota_file,
 212         .read_file_info         = v2_read_file_info,
 213         .write_file_info        = v2_write_file_info,
 214         .free_file_info         = v2_free_file_info,
 215         .read_dqblk             = v2_read_dquot,
 216         .commit_dqblk           = v2_write_dquot,
 217         .release_dqblk          = v2_release_dquot,
 218 };
 219
 220 static struct quota_format_type v2_quota_format = {
 221         .qf_fmt_id      = QFMT_VFS_V0,
 222         .qf_ops         = &v2_format_ops,
 223         .qf_owner       = THIS_MODULE
 224 };
 225
 226 static int __init init_v2_quota_format(void)
 227 {
 228         return register_quota_format(&v2_quota_format);
 229 }
 230
 231 static void __exit exit_v2_quota_format(void)
 232 {
 233         unregister_quota_format(&v2_quota_format);
 234 }
 235
 236 module_init(init_v2_quota_format);
 237 module_exit(exit_v2_quota_format);