fs/sysv/inode.c

   1 /*
   2  *  linux/fs/sysv/inode.c
   3  *
   4  *  minix/inode.c
   5  *  Copyright (C) 1991, 1992  Linus Torvalds
   6  *
   7  *  xenix/inode.c
   8  *  Copyright (C) 1992  Doug Evans
   9  *
  10  *  coh/inode.c
  11  *  Copyright (C) 1993  Pascal Haible, Bruno Haible
  12  *
  13  *  sysv/inode.c
  14  *  Copyright (C) 1993  Paul B. Monday
  15  *
  16  *  sysv/inode.c
  17  *  Copyright (C) 1993  Bruno Haible
  18  *  Copyright (C) 1997, 1998  Krzysztof G. Baranowski
  19  *
  20  *  This file contains code for allocating/freeing inodes and for read/writing
  21  *  the superblock.
  22  */
  23
  24 #include <linux/fs.h>
  25 #include <linux/sysv_fs.h>
  26 #include <linux/locks.h>
  27 #include <linux/smp_lock.h>
  28 #include <linux/highuid.h>
  29 #include <asm/byteorder.h>
  30
  31 /* This is only called on sync() and umount(), when s_dirt=1. */
  32 static void sysv_write_super(struct super_block *sb)
  33 {
  34         if (!(sb->s_flags & MS_RDONLY)) {
  35                 /* If we are going to write out the super block,
  36                    then attach current time stamp.
  37                    But if the filesystem was marked clean, keep it clean. */
  38                 unsigned long time = CURRENT_TIME;
  39                 unsigned long old_time = fs32_to_cpu(sb, *sb->sv_sb_time);
  40                 if (sb->sv_type == FSTYPE_SYSV4)
  41                         if (*sb->sv_sb_state == cpu_to_fs32(sb, 0x7c269d38 - old_time))
  42                                 *sb->sv_sb_state = cpu_to_fs32(sb, 0x7c269d38 - time);
  43                 *sb->sv_sb_time = cpu_to_fs32(sb, time);
  44                 mark_buffer_dirty(sb->sv_bh2);
  45         }
  46         sb->s_dirt = 0;
  47 }
  48
  49 static void sysv_put_super(struct super_block *sb)
  50 {
  51         if (!(sb->s_flags & MS_RDONLY)) {
  52                 /* XXX ext2 also updates the state here */
  53                 mark_buffer_dirty(sb->sv_bh1);
  54                 if (sb->sv_bh1 != sb->sv_bh2)
  55                         mark_buffer_dirty(sb->sv_bh2);
  56         }
  57
  58         brelse(sb->sv_bh1);
  59         if (sb->sv_bh1 != sb->sv_bh2)
  60                 brelse(sb->sv_bh2);
  61 }
  62
  63 static int sysv_statfs(struct super_block *sb, struct statfs *buf)
  64 {
  65         buf->f_type = sb->s_magic;
  66         buf->f_bsize = sb->s_blocksize;
  67         buf->f_blocks = sb->sv_ndatazones;
  68         buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
  69         buf->f_files = sb->sv_ninodes;
  70         buf->f_ffree = sysv_count_free_inodes(sb);
  71         buf->f_namelen = SYSV_NAMELEN;
  72         return 0;
  73 }
  74
  75 /*
  76  * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
  77  */
  78 static inline void read3byte(struct super_block *sb,
  79         unsigned char * from, unsigned char * to)
  80 {
  81         if (sb->sv_bytesex == BYTESEX_PDP) {
  82                 to[0] = from[0];
  83                 to[1] = 0;
  84                 to[2] = from[1];
  85                 to[3] = from[2];
  86         } else if (sb->sv_bytesex == BYTESEX_LE) {
  87                 to[0] = from[0];
  88                 to[1] = from[1];
  89                 to[2] = from[2];
  90                 to[3] = 0;
  91         } else {
  92                 to[0] = 0;
  93                 to[1] = from[0];
  94                 to[2] = from[1];
  95                 to[3] = from[2];
  96         }
  97 }
  98
  99 static inline void write3byte(struct super_block *sb,
 100         unsigned char * from, unsigned char * to)
 101 {
 102         if (sb->sv_bytesex == BYTESEX_PDP) {
 103                 to[0] = from[0];
 104                 to[1] = from[2];
 105                 to[2] = from[3];
 106         } else if (sb->sv_bytesex == BYTESEX_LE) {
 107                 to[0] = from[0];
 108                 to[1] = from[1];
 109                 to[2] = from[2];
 110         } else {
 111                 to[0] = from[1];
 112                 to[1] = from[2];
 113                 to[2] = from[3];
 114         }
 115 }
 116
 117 static struct inode_operations sysv_symlink_inode_operations = {
 118         readlink:       page_readlink,
 119         follow_link:    page_follow_link,
 120 };
 121
 122 void sysv_set_inode(struct inode *inode, dev_t rdev)
 123 {
 124         if (S_ISREG(inode->i_mode)) {
 125                 inode->i_op = &sysv_file_inode_operations;
 126                 inode->i_fop = &sysv_file_operations;
 127                 inode->i_mapping->a_ops = &sysv_aops;
 128         } else if (S_ISDIR(inode->i_mode)) {
 129                 inode->i_op = &sysv_dir_inode_operations;
 130                 inode->i_fop = &sysv_dir_operations;
 131                 inode->i_mapping->a_ops = &sysv_aops;
 132         } else if (S_ISLNK(inode->i_mode)) {
 133                 if (inode->i_blocks) {
 134                         inode->i_op = &sysv_symlink_inode_operations;
 135                         inode->i_mapping->a_ops = &sysv_aops;
 136                 } else
 137                         inode->i_op = &sysv_fast_symlink_inode_operations;
 138         } else
 139                 init_special_inode(inode, inode->i_mode, rdev);
 140 }
 141
 142 static void sysv_read_inode(struct inode *inode)
 143 {
 144         struct super_block * sb = inode->i_sb;
 145         struct buffer_head * bh;
 146         struct sysv_inode * raw_inode;
 147         unsigned int block, ino;
 148         dev_t rdev = 0;
 149
 150         ino = inode->i_ino;
 151         if (!ino || ino > sb->sv_ninodes) {
 152                 printk("Bad inode number on dev %s"
 153                        ": %d is out of range\n",
 154                        kdevname(inode->i_dev), ino);
 155                 goto bad_inode;
 156         }
 157         raw_inode = sysv_raw_inode(sb, ino, &bh);
 158         if (!raw_inode) {
 159                 printk("Major problem: unable to read inode from dev %s\n",
 160                        bdevname(inode->i_dev));
 161                 goto bad_inode;
 162         }
 163         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 164         inode->i_mode = fs16_to_cpu(sb, raw_inode->i_mode);
 165         inode->i_uid = (uid_t)fs16_to_cpu(sb, raw_inode->i_uid);
 166         inode->i_gid = (gid_t)fs16_to_cpu(sb, raw_inode->i_gid);
 167         inode->i_nlink = fs16_to_cpu(sb, raw_inode->i_nlink);
 168         inode->i_size = fs32_to_cpu(sb, raw_inode->i_size);
 169         inode->i_atime = fs32_to_cpu(sb, raw_inode->i_atime);
 170         inode->i_mtime = fs32_to_cpu(sb, raw_inode->i_mtime);
 171         inode->i_ctime = fs32_to_cpu(sb, raw_inode->i_ctime);
 172         inode->i_blocks = inode->i_blksize = 0;
 173         for (block = 0; block < 10+1+1+1; block++)
 174                 read3byte(sb, &raw_inode->i_a.i_addb[3*block],
 175                         (unsigned char*)&inode->u.sysv_i.i_data[block]);
 176         brelse(bh);
 177         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 178                 rdev = (u16)fs32_to_cpu(sb, inode->u.sysv_i.i_data[0]);
 179         inode->u.sysv_i.i_dir_start_lookup = 0;
 180         sysv_set_inode(inode, rdev);
 181         return;
 182
 183 bad_inode:
 184         make_bad_inode(inode);
 185         return;
 186 }
 187
 188 static struct buffer_head * sysv_update_inode(struct inode * inode)
 189 {
 190         struct super_block * sb = inode->i_sb;
 191         struct buffer_head * bh;
 192         struct sysv_inode * raw_inode;
 193         unsigned int ino, block;
 194
 195         ino = inode->i_ino;
 196         if (!ino || ino > sb->sv_ninodes) {
 197                 printk("Bad inode number on dev %s: %d is out of range\n",
 198                        bdevname(inode->i_dev), ino);
 199                 return 0;
 200         }
 201         raw_inode = sysv_raw_inode(sb, ino, &bh);
 202         if (!raw_inode) {
 203                 printk("unable to read i-node block\n");
 204                 return 0;
 205         }
 206
 207         raw_inode->i_mode = cpu_to_fs16(sb, inode->i_mode);
 208         raw_inode->i_uid = cpu_to_fs16(sb, fs_high2lowuid(inode->i_uid));
 209         raw_inode->i_gid = cpu_to_fs16(sb, fs_high2lowgid(inode->i_gid));
 210         raw_inode->i_nlink = cpu_to_fs16(sb, inode->i_nlink);
 211         raw_inode->i_size = cpu_to_fs32(sb, inode->i_size);
 212         raw_inode->i_atime = cpu_to_fs32(sb, inode->i_atime);
 213         raw_inode->i_mtime = cpu_to_fs32(sb, inode->i_mtime);
 214         raw_inode->i_ctime = cpu_to_fs32(sb, inode->i_ctime);
 215         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 216                 inode->u.sysv_i.i_data[0] =
 217                         cpu_to_fs32(sb, kdev_t_to_nr(inode->i_rdev));
 218         for (block = 0; block < 10+1+1+1; block++)
 219                 write3byte(sb, (unsigned char*)&inode->u.sysv_i.i_data[block],
 220                         &raw_inode->i_a.i_addb[3*block]);
 221         mark_buffer_dirty(bh);
 222         return bh;
 223 }
 224
 225 void sysv_write_inode(struct inode * inode, int wait)
 226 {
 227         struct buffer_head *bh;
 228         lock_kernel();
 229         bh = sysv_update_inode(inode);
 230         brelse(bh);
 231         unlock_kernel();
 232 }
 233
 234 int sysv_sync_inode(struct inode * inode)
 235 {
 236         int err = 0;
 237         struct buffer_head *bh;
 238
 239         bh = sysv_update_inode(inode);
 240         if (bh && buffer_dirty(bh)) {
 241                 ll_rw_block(WRITE, 1, &bh);
 242                 wait_on_buffer(bh);
 243                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
 244                         printk ("IO error syncing sysv inode [%s:%08lx]\n",
 245                                 bdevname(inode->i_dev), inode->i_ino);
 246                         err = -1;
 247                 }
 248         }
 249         else if (!bh)
 250                 err = -1;
 251         brelse (bh);
 252         return err;
 253 }
 254
 255 static void sysv_delete_inode(struct inode *inode)
 256 {
 257         lock_kernel();
 258         inode->i_size = 0;
 259         sysv_truncate(inode);
 260         sysv_free_inode(inode);
 261         unlock_kernel();
 262 }
 263
 264 struct super_operations sysv_sops = {
 265         read_inode:     sysv_read_inode,
 266         write_inode:    sysv_write_inode,
 267         delete_inode:   sysv_delete_inode,
 268         put_super:      sysv_put_super,
 269         write_super:    sysv_write_super,
 270         statfs:         sysv_statfs,
 271 };