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/smp_lock.h>
  25 #include <linux/highuid.h>
  26 #include <linux/slab.h>
  27 #include <linux/init.h>
  28 #include <linux/buffer_head.h>
  29 #include <linux/vfs.h>
  30 #include <asm/byteorder.h>
  31 #include "sysv.h"
  32
  33 /* This is only called on sync() and umount(), when s_dirt=1. */
  34 static void sysv_write_super(struct super_block *sb)
  35 {
  36         struct sysv_sb_info *sbi = SYSV_SB(sb);
  37         unsigned long time = get_seconds(), old_time;
  38
  39         lock_kernel();
  40         if (sb->s_flags & MS_RDONLY)
  41                 goto clean;
  42
  43         /*
  44          * If we are going to write out the super block,
  45          * then attach current time stamp.
  46          * But if the filesystem was marked clean, keep it clean.
  47          */
  48         old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
  49         if (sbi->s_type == FSTYPE_SYSV4) {
  50                 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
  51                         *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
  52                 *sbi->s_sb_time = cpu_to_fs32(sbi, time);
  53                 mark_buffer_dirty(sbi->s_bh2);
  54         }
  55 clean:
  56         sb->s_dirt = 0;
  57         unlock_kernel();
  58 }
  59
  60 static void sysv_put_super(struct super_block *sb)
  61 {
  62         struct sysv_sb_info *sbi = SYSV_SB(sb);
  63
  64         if (!(sb->s_flags & MS_RDONLY)) {
  65                 /* XXX ext2 also updates the state here */
  66                 mark_buffer_dirty(sbi->s_bh1);
  67                 if (sbi->s_bh1 != sbi->s_bh2)
  68                         mark_buffer_dirty(sbi->s_bh2);
  69         }
  70
  71         brelse(sbi->s_bh1);
  72         if (sbi->s_bh1 != sbi->s_bh2)
  73                 brelse(sbi->s_bh2);
  74
  75         kfree(sbi);
  76 }
  77
  78 static int sysv_statfs(struct super_block *sb, struct kstatfs *buf)
  79 {
  80         struct sysv_sb_info *sbi = SYSV_SB(sb);
  81
  82         buf->f_type = sb->s_magic;
  83         buf->f_bsize = sb->s_blocksize;
  84         buf->f_blocks = sbi->s_ndatazones;
  85         buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
  86         buf->f_files = sbi->s_ninodes;
  87         buf->f_ffree = sysv_count_free_inodes(sb);
  88         buf->f_namelen = SYSV_NAMELEN;
  89         return 0;
  90 }
  91
  92 /*
  93  * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
  94  */
  95 static inline void read3byte(struct sysv_sb_info *sbi,
  96         unsigned char * from, unsigned char * to)
  97 {
  98         if (sbi->s_bytesex == BYTESEX_PDP) {
  99                 to[0] = from[0];
 100                 to[1] = 0;
 101                 to[2] = from[1];
 102                 to[3] = from[2];
 103         } else if (sbi->s_bytesex == BYTESEX_LE) {
 104                 to[0] = from[0];
 105                 to[1] = from[1];
 106                 to[2] = from[2];
 107                 to[3] = 0;
 108         } else {
 109                 to[0] = 0;
 110                 to[1] = from[0];
 111                 to[2] = from[1];
 112                 to[3] = from[2];
 113         }
 114 }
 115
 116 static inline void write3byte(struct sysv_sb_info *sbi,
 117         unsigned char * from, unsigned char * to)
 118 {
 119         if (sbi->s_bytesex == BYTESEX_PDP) {
 120                 to[0] = from[0];
 121                 to[1] = from[2];
 122                 to[2] = from[3];
 123         } else if (sbi->s_bytesex == BYTESEX_LE) {
 124                 to[0] = from[0];
 125                 to[1] = from[1];
 126                 to[2] = from[2];
 127         } else {
 128                 to[0] = from[1];
 129                 to[1] = from[2];
 130                 to[2] = from[3];
 131         }
 132 }
 133
 134 static struct inode_operations sysv_symlink_inode_operations = {
 135         .readlink       = page_readlink,
 136         .follow_link    = page_follow_link,
 137         .getattr        = sysv_getattr,
 138 };
 139
 140 void sysv_set_inode(struct inode *inode, dev_t rdev)
 141 {
 142         if (S_ISREG(inode->i_mode)) {
 143                 inode->i_op = &sysv_file_inode_operations;
 144                 inode->i_fop = &sysv_file_operations;
 145                 inode->i_mapping->a_ops = &sysv_aops;
 146         } else if (S_ISDIR(inode->i_mode)) {
 147                 inode->i_op = &sysv_dir_inode_operations;
 148                 inode->i_fop = &sysv_dir_operations;
 149                 inode->i_mapping->a_ops = &sysv_aops;
 150         } else if (S_ISLNK(inode->i_mode)) {
 151                 if (inode->i_blocks) {
 152                         inode->i_op = &sysv_symlink_inode_operations;
 153                         inode->i_mapping->a_ops = &sysv_aops;
 154                 } else
 155                         inode->i_op = &sysv_fast_symlink_inode_operations;
 156         } else
 157                 init_special_inode(inode, inode->i_mode, rdev);
 158 }
 159
 160 static void sysv_read_inode(struct inode *inode)
 161 {
 162         struct super_block * sb = inode->i_sb;
 163         struct sysv_sb_info * sbi = SYSV_SB(sb);
 164         struct buffer_head * bh;
 165         struct sysv_inode * raw_inode;
 166         struct sysv_inode_info * si;
 167         unsigned int block, ino = inode->i_ino;
 168
 169         if (!ino || ino > sbi->s_ninodes) {
 170                 printk("Bad inode number on dev %s: %d is out of range\n",
 171                        inode->i_sb->s_id, ino);
 172                 goto bad_inode;
 173         }
 174         raw_inode = sysv_raw_inode(sb, ino, &bh);
 175         if (!raw_inode) {
 176                 printk("Major problem: unable to read inode from dev %s\n",
 177                        inode->i_sb->s_id);
 178                 goto bad_inode;
 179         }
 180         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 181         inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
 182         inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
 183         inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
 184         inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
 185         inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
 186         inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
 187         inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
 188         inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
 189         inode->i_ctime.tv_nsec = 0;
 190         inode->i_atime.tv_nsec = 0;
 191         inode->i_mtime.tv_nsec = 0;
 192         inode->i_blocks = inode->i_blksize = 0;
 193
 194         si = SYSV_I(inode);
 195         for (block = 0; block < 10+1+1+1; block++)
 196                 read3byte(sbi, &raw_inode->i_data[3*block],
 197                                 (u8 *)&si->i_data[block]);
 198         brelse(bh);
 199         si->i_dir_start_lookup = 0;
 200         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 201                 sysv_set_inode(inode,
 202                                old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
 203         else
 204                 sysv_set_inode(inode, 0);
 205         return;
 206
 207 bad_inode:
 208         make_bad_inode(inode);
 209         return;
 210 }
 211
 212 static struct buffer_head * sysv_update_inode(struct inode * inode)
 213 {
 214         struct super_block * sb = inode->i_sb;
 215         struct sysv_sb_info * sbi = SYSV_SB(sb);
 216         struct buffer_head * bh;
 217         struct sysv_inode * raw_inode;
 218         struct sysv_inode_info * si;
 219         unsigned int ino, block;
 220
 221         ino = inode->i_ino;
 222         if (!ino || ino > sbi->s_ninodes) {
 223                 printk("Bad inode number on dev %s: %d is out of range\n",
 224                        inode->i_sb->s_id, ino);
 225                 return 0;
 226         }
 227         raw_inode = sysv_raw_inode(sb, ino, &bh);
 228         if (!raw_inode) {
 229                 printk("unable to read i-node block\n");
 230                 return 0;
 231         }
 232
 233         raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
 234         raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
 235         raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
 236         raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
 237         raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
 238         raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
 239         raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
 240         raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
 241
 242         si = SYSV_I(inode);
 243         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 244                 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
 245         for (block = 0; block < 10+1+1+1; block++)
 246                 write3byte(sbi, (u8 *)&si->i_data[block],
 247                         &raw_inode->i_data[3*block]);
 248         mark_buffer_dirty(bh);
 249         return bh;
 250 }
 251
 252 void sysv_write_inode(struct inode * inode, int wait)
 253 {
 254         struct buffer_head *bh;
 255         lock_kernel();
 256         bh = sysv_update_inode(inode);
 257         brelse(bh);
 258         unlock_kernel();
 259 }
 260
 261 int sysv_sync_inode(struct inode * inode)
 262 {
 263         int err = 0;
 264         struct buffer_head *bh;
 265
 266         bh = sysv_update_inode(inode);
 267         if (bh && buffer_dirty(bh)) {
 268                 sync_dirty_buffer(bh);
 269                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
 270                         printk ("IO error syncing sysv inode [%s:%08lx]\n",
 271                                 inode->i_sb->s_id, inode->i_ino);
 272                         err = -1;
 273                 }
 274         }
 275         else if (!bh)
 276                 err = -1;
 277         brelse (bh);
 278         return err;
 279 }
 280
 281 static void sysv_delete_inode(struct inode *inode)
 282 {
 283         inode->i_size = 0;
 284         sysv_truncate(inode);
 285         lock_kernel();
 286         sysv_free_inode(inode);
 287         unlock_kernel();
 288 }
 289
 290 static kmem_cache_t *sysv_inode_cachep;
 291
 292 static struct inode *sysv_alloc_inode(struct super_block *sb)
 293 {
 294         struct sysv_inode_info *si;
 295
 296         si = kmem_cache_alloc(sysv_inode_cachep, SLAB_KERNEL);
 297         if (!si)
 298                 return NULL;
 299         return &si->vfs_inode;
 300 }
 301
 302 static void sysv_destroy_inode(struct inode *inode)
 303 {
 304         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
 305 }
 306
 307 static void init_once(void *p, kmem_cache_t *cachep, unsigned long flags)
 308 {
 309         struct sysv_inode_info *si = (struct sysv_inode_info *)p;
 310
 311         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 312                         SLAB_CTOR_CONSTRUCTOR)
 313                 inode_init_once(&si->vfs_inode);
 314 }
 315
 316 struct super_operations sysv_sops = {
 317         .alloc_inode    = sysv_alloc_inode,
 318         .destroy_inode  = sysv_destroy_inode,
 319         .read_inode     = sysv_read_inode,
 320         .write_inode    = sysv_write_inode,
 321         .delete_inode   = sysv_delete_inode,
 322         .put_super      = sysv_put_super,
 323         .write_super    = sysv_write_super,
 324         .statfs         = sysv_statfs,
 325 };
 326
 327 int __init sysv_init_icache(void)
 328 {
 329         sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
 330                         sizeof(struct sysv_inode_info), 0,
 331                         SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
 332                         init_once, NULL);
 333         if (!sysv_inode_cachep)
 334                 return -ENOMEM;
 335         return 0;
 336 }
 337
 338 void sysv_destroy_icache(void)
 339 {
 340         kmem_cache_destroy(sysv_inode_cachep);
 341 }