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/highuid.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/buffer_head.h>
  28 #include <linux/vfs.h>
  29 #include <linux/namei.h>
  30 #include <asm/byteorder.h>
  31 #include "sysv.h"
  32
  33 static int sysv_sync_fs(struct super_block *sb, int wait)
  34 {
  35         struct sysv_sb_info *sbi = SYSV_SB(sb);
  36         unsigned long time = get_seconds(), old_time;
  37
  38         lock_super(sb);
  39
  40         /*
  41          * If we are going to write out the super block,
  42          * then attach current time stamp.
  43          * But if the filesystem was marked clean, keep it clean.
  44          */
  45         old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
  46         if (sbi->s_type == FSTYPE_SYSV4) {
  47                 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
  48                         *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
  49                 *sbi->s_sb_time = cpu_to_fs32(sbi, time);
  50                 mark_buffer_dirty(sbi->s_bh2);
  51         }
  52
  53         unlock_super(sb);
  54
  55         return 0;
  56 }
  57
  58 static void sysv_write_super(struct super_block *sb)
  59 {
  60         if (!(sb->s_flags & MS_RDONLY))
  61                 sysv_sync_fs(sb, 1);
  62         else
  63                 sb->s_dirt = 0;
  64 }
  65
  66 static int sysv_remount(struct super_block *sb, int *flags, char *data)
  67 {
  68         struct sysv_sb_info *sbi = SYSV_SB(sb);
  69         lock_super(sb);
  70         if (sbi->s_forced_ro)
  71                 *flags |= MS_RDONLY;
  72         if (!(*flags & MS_RDONLY))
  73                 sb->s_dirt = 1;
  74         unlock_super(sb);
  75         return 0;
  76 }
  77
  78 static void sysv_put_super(struct super_block *sb)
  79 {
  80         struct sysv_sb_info *sbi = SYSV_SB(sb);
  81
  82         if (sb->s_dirt)
  83                 sysv_write_super(sb);
  84
  85         if (!(sb->s_flags & MS_RDONLY)) {
  86                 /* XXX ext2 also updates the state here */
  87                 mark_buffer_dirty(sbi->s_bh1);
  88                 if (sbi->s_bh1 != sbi->s_bh2)
  89                         mark_buffer_dirty(sbi->s_bh2);
  90         }
  91
  92         brelse(sbi->s_bh1);
  93         if (sbi->s_bh1 != sbi->s_bh2)
  94                 brelse(sbi->s_bh2);
  95
  96         kfree(sbi);
  97 }
  98
  99 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
 100 {
 101         struct super_block *sb = dentry->d_sb;
 102         struct sysv_sb_info *sbi = SYSV_SB(sb);
 103         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 104
 105         buf->f_type = sb->s_magic;
 106         buf->f_bsize = sb->s_blocksize;
 107         buf->f_blocks = sbi->s_ndatazones;
 108         buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
 109         buf->f_files = sbi->s_ninodes;
 110         buf->f_ffree = sysv_count_free_inodes(sb);
 111         buf->f_namelen = SYSV_NAMELEN;
 112         buf->f_fsid.val[0] = (u32)id;
 113         buf->f_fsid.val[1] = (u32)(id >> 32);
 114         return 0;
 115 }
 116
 117 /*
 118  * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
 119  */
 120 static inline void read3byte(struct sysv_sb_info *sbi,
 121         unsigned char * from, unsigned char * to)
 122 {
 123         if (sbi->s_bytesex == BYTESEX_PDP) {
 124                 to[0] = from[0];
 125                 to[1] = 0;
 126                 to[2] = from[1];
 127                 to[3] = from[2];
 128         } else if (sbi->s_bytesex == BYTESEX_LE) {
 129                 to[0] = from[0];
 130                 to[1] = from[1];
 131                 to[2] = from[2];
 132                 to[3] = 0;
 133         } else {
 134                 to[0] = 0;
 135                 to[1] = from[0];
 136                 to[2] = from[1];
 137                 to[3] = from[2];
 138         }
 139 }
 140
 141 static inline void write3byte(struct sysv_sb_info *sbi,
 142         unsigned char * from, unsigned char * to)
 143 {
 144         if (sbi->s_bytesex == BYTESEX_PDP) {
 145                 to[0] = from[0];
 146                 to[1] = from[2];
 147                 to[2] = from[3];
 148         } else if (sbi->s_bytesex == BYTESEX_LE) {
 149                 to[0] = from[0];
 150                 to[1] = from[1];
 151                 to[2] = from[2];
 152         } else {
 153                 to[0] = from[1];
 154                 to[1] = from[2];
 155                 to[2] = from[3];
 156         }
 157 }
 158
 159 static const struct inode_operations sysv_symlink_inode_operations = {
 160         .readlink       = generic_readlink,
 161         .follow_link    = page_follow_link_light,
 162         .put_link       = page_put_link,
 163         .getattr        = sysv_getattr,
 164 };
 165
 166 void sysv_set_inode(struct inode *inode, dev_t rdev)
 167 {
 168         if (S_ISREG(inode->i_mode)) {
 169                 inode->i_op = &sysv_file_inode_operations;
 170                 inode->i_fop = &sysv_file_operations;
 171                 inode->i_mapping->a_ops = &sysv_aops;
 172         } else if (S_ISDIR(inode->i_mode)) {
 173                 inode->i_op = &sysv_dir_inode_operations;
 174                 inode->i_fop = &sysv_dir_operations;
 175                 inode->i_mapping->a_ops = &sysv_aops;
 176         } else if (S_ISLNK(inode->i_mode)) {
 177                 if (inode->i_blocks) {
 178                         inode->i_op = &sysv_symlink_inode_operations;
 179                         inode->i_mapping->a_ops = &sysv_aops;
 180                 } else {
 181                         inode->i_op = &sysv_fast_symlink_inode_operations;
 182                         nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size,
 183                                 sizeof(SYSV_I(inode)->i_data) - 1);
 184                 }
 185         } else
 186                 init_special_inode(inode, inode->i_mode, rdev);
 187 }
 188
 189 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
 190 {
 191         struct sysv_sb_info * sbi = SYSV_SB(sb);
 192         struct buffer_head * bh;
 193         struct sysv_inode * raw_inode;
 194         struct sysv_inode_info * si;
 195         struct inode *inode;
 196         unsigned int block;
 197
 198         if (!ino || ino > sbi->s_ninodes) {
 199                 printk("Bad inode number on dev %s: %d is out of range\n",
 200                        sb->s_id, ino);
 201                 return ERR_PTR(-EIO);
 202         }
 203
 204         inode = iget_locked(sb, ino);
 205         if (!inode)
 206                 return ERR_PTR(-ENOMEM);
 207         if (!(inode->i_state & I_NEW))
 208                 return inode;
 209
 210         raw_inode = sysv_raw_inode(sb, ino, &bh);
 211         if (!raw_inode) {
 212                 printk("Major problem: unable to read inode from dev %s\n",
 213                        inode->i_sb->s_id);
 214                 goto bad_inode;
 215         }
 216         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 217         inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
 218         inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
 219         inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
 220         inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
 221         inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
 222         inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
 223         inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
 224         inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
 225         inode->i_ctime.tv_nsec = 0;
 226         inode->i_atime.tv_nsec = 0;
 227         inode->i_mtime.tv_nsec = 0;
 228         inode->i_blocks = 0;
 229
 230         si = SYSV_I(inode);
 231         for (block = 0; block < 10+1+1+1; block++)
 232                 read3byte(sbi, &raw_inode->i_data[3*block],
 233                                 (u8 *)&si->i_data[block]);
 234         brelse(bh);
 235         si->i_dir_start_lookup = 0;
 236         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 237                 sysv_set_inode(inode,
 238                                old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
 239         else
 240                 sysv_set_inode(inode, 0);
 241         unlock_new_inode(inode);
 242         return inode;
 243
 244 bad_inode:
 245         iget_failed(inode);
 246         return ERR_PTR(-EIO);
 247 }
 248
 249 int sysv_write_inode(struct inode *inode, int wait)
 250 {
 251         struct super_block * sb = inode->i_sb;
 252         struct sysv_sb_info * sbi = SYSV_SB(sb);
 253         struct buffer_head * bh;
 254         struct sysv_inode * raw_inode;
 255         struct sysv_inode_info * si;
 256         unsigned int ino, block;
 257         int err = 0;
 258
 259         ino = inode->i_ino;
 260         if (!ino || ino > sbi->s_ninodes) {
 261                 printk("Bad inode number on dev %s: %d is out of range\n",
 262                        inode->i_sb->s_id, ino);
 263                 return -EIO;
 264         }
 265         raw_inode = sysv_raw_inode(sb, ino, &bh);
 266         if (!raw_inode) {
 267                 printk("unable to read i-node block\n");
 268                 return -EIO;
 269         }
 270
 271         raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
 272         raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
 273         raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
 274         raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
 275         raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
 276         raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
 277         raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
 278         raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
 279
 280         si = SYSV_I(inode);
 281         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 282                 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
 283         for (block = 0; block < 10+1+1+1; block++)
 284                 write3byte(sbi, (u8 *)&si->i_data[block],
 285                         &raw_inode->i_data[3*block]);
 286         mark_buffer_dirty(bh);
 287         if (wait) {
 288                 sync_dirty_buffer(bh);
 289                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
 290                         printk ("IO error syncing sysv inode [%s:%08x]\n",
 291                                 sb->s_id, ino);
 292                         err = -EIO;
 293                 }
 294         }
 295         brelse(bh);
 296         return 0;
 297 }
 298
 299 int sysv_sync_inode(struct inode *inode)
 300 {
 301         return sysv_write_inode(inode, 1);
 302 }
 303
 304 static void sysv_delete_inode(struct inode *inode)
 305 {
 306         truncate_inode_pages(&inode->i_data, 0);
 307         inode->i_size = 0;
 308         sysv_truncate(inode);
 309         sysv_free_inode(inode);
 310 }
 311
 312 static struct kmem_cache *sysv_inode_cachep;
 313
 314 static struct inode *sysv_alloc_inode(struct super_block *sb)
 315 {
 316         struct sysv_inode_info *si;
 317
 318         si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
 319         if (!si)
 320                 return NULL;
 321         return &si->vfs_inode;
 322 }
 323
 324 static void sysv_destroy_inode(struct inode *inode)
 325 {
 326         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
 327 }
 328
 329 static void init_once(void *p)
 330 {
 331         struct sysv_inode_info *si = (struct sysv_inode_info *)p;
 332
 333         inode_init_once(&si->vfs_inode);
 334 }
 335
 336 const struct super_operations sysv_sops = {
 337         .alloc_inode    = sysv_alloc_inode,
 338         .destroy_inode  = sysv_destroy_inode,
 339         .write_inode    = sysv_write_inode,
 340         .delete_inode   = sysv_delete_inode,
 341         .put_super      = sysv_put_super,
 342         .write_super    = sysv_write_super,
 343         .sync_fs        = sysv_sync_fs,
 344         .remount_fs     = sysv_remount,
 345         .statfs         = sysv_statfs,
 346 };
 347
 348 int __init sysv_init_icache(void)
 349 {
 350         sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
 351                         sizeof(struct sysv_inode_info), 0,
 352                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 353                         init_once);
 354         if (!sysv_inode_cachep)
 355                 return -ENOMEM;
 356         return 0;
 357 }
 358
 359 void sysv_destroy_icache(void)
 360 {
 361         kmem_cache_destroy(sysv_inode_cachep);
 362 }