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 <linux/namei.h>
  31 #include <asm/byteorder.h>
  32 #include "sysv.h"
  33
  34 /* This is only called on sync() and umount(), when s_dirt=1. */
  35 static void sysv_write_super(struct super_block *sb)
  36 {
  37         struct sysv_sb_info *sbi = SYSV_SB(sb);
  38         unsigned long time = get_seconds(), old_time;
  39
  40         lock_kernel();
  41         if (sb->s_flags & MS_RDONLY)
  42                 goto clean;
  43
  44         /*
  45          * If we are going to write out the super block,
  46          * then attach current time stamp.
  47          * But if the filesystem was marked clean, keep it clean.
  48          */
  49         old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
  50         if (sbi->s_type == FSTYPE_SYSV4) {
  51                 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
  52                         *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
  53                 *sbi->s_sb_time = cpu_to_fs32(sbi, time);
  54                 mark_buffer_dirty(sbi->s_bh2);
  55         }
  56 clean:
  57         sb->s_dirt = 0;
  58         unlock_kernel();
  59 }
  60
  61 static int sysv_remount(struct super_block *sb, int *flags, char *data)
  62 {
  63         struct sysv_sb_info *sbi = SYSV_SB(sb);
  64         lock_super(sb);
  65         if (sbi->s_forced_ro)
  66                 *flags |= MS_RDONLY;
  67         if (!(*flags & MS_RDONLY))
  68                 sb->s_dirt = 1;
  69         unlock_super(sb);
  70         return 0;
  71 }
  72
  73 static void sysv_put_super(struct super_block *sb)
  74 {
  75         struct sysv_sb_info *sbi = SYSV_SB(sb);
  76
  77         lock_kernel();
  78
  79         if (sb->s_dirt)
  80                 sysv_write_super(sb);
  81
  82         if (!(sb->s_flags & MS_RDONLY)) {
  83                 /* XXX ext2 also updates the state here */
  84                 mark_buffer_dirty(sbi->s_bh1);
  85                 if (sbi->s_bh1 != sbi->s_bh2)
  86                         mark_buffer_dirty(sbi->s_bh2);
  87         }
  88
  89         brelse(sbi->s_bh1);
  90         if (sbi->s_bh1 != sbi->s_bh2)
  91                 brelse(sbi->s_bh2);
  92
  93         kfree(sbi);
  94
  95         unlock_kernel();
  96 }
  97
  98 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
  99 {
 100         struct super_block *sb = dentry->d_sb;
 101         struct sysv_sb_info *sbi = SYSV_SB(sb);
 102         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 103
 104         buf->f_type = sb->s_magic;
 105         buf->f_bsize = sb->s_blocksize;
 106         buf->f_blocks = sbi->s_ndatazones;
 107         buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
 108         buf->f_files = sbi->s_ninodes;
 109         buf->f_ffree = sysv_count_free_inodes(sb);
 110         buf->f_namelen = SYSV_NAMELEN;
 111         buf->f_fsid.val[0] = (u32)id;
 112         buf->f_fsid.val[1] = (u32)(id >> 32);
 113         return 0;
 114 }
 115
 116 /*
 117  * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
 118  */
 119 static inline void read3byte(struct sysv_sb_info *sbi,
 120         unsigned char * from, unsigned char * to)
 121 {
 122         if (sbi->s_bytesex == BYTESEX_PDP) {
 123                 to[0] = from[0];
 124                 to[1] = 0;
 125                 to[2] = from[1];
 126                 to[3] = from[2];
 127         } else if (sbi->s_bytesex == BYTESEX_LE) {
 128                 to[0] = from[0];
 129                 to[1] = from[1];
 130                 to[2] = from[2];
 131                 to[3] = 0;
 132         } else {
 133                 to[0] = 0;
 134                 to[1] = from[0];
 135                 to[2] = from[1];
 136                 to[3] = from[2];
 137         }
 138 }
 139
 140 static inline void write3byte(struct sysv_sb_info *sbi,
 141         unsigned char * from, unsigned char * to)
 142 {
 143         if (sbi->s_bytesex == BYTESEX_PDP) {
 144                 to[0] = from[0];
 145                 to[1] = from[2];
 146                 to[2] = from[3];
 147         } else if (sbi->s_bytesex == BYTESEX_LE) {
 148                 to[0] = from[0];
 149                 to[1] = from[1];
 150                 to[2] = from[2];
 151         } else {
 152                 to[0] = from[1];
 153                 to[1] = from[2];
 154                 to[2] = from[3];
 155         }
 156 }
 157
 158 static const struct inode_operations sysv_symlink_inode_operations = {
 159         .readlink       = generic_readlink,
 160         .follow_link    = page_follow_link_light,
 161         .put_link       = page_put_link,
 162         .getattr        = sysv_getattr,
 163 };
 164
 165 void sysv_set_inode(struct inode *inode, dev_t rdev)
 166 {
 167         if (S_ISREG(inode->i_mode)) {
 168                 inode->i_op = &sysv_file_inode_operations;
 169                 inode->i_fop = &sysv_file_operations;
 170                 inode->i_mapping->a_ops = &sysv_aops;
 171         } else if (S_ISDIR(inode->i_mode)) {
 172                 inode->i_op = &sysv_dir_inode_operations;
 173                 inode->i_fop = &sysv_dir_operations;
 174                 inode->i_mapping->a_ops = &sysv_aops;
 175         } else if (S_ISLNK(inode->i_mode)) {
 176                 if (inode->i_blocks) {
 177                         inode->i_op = &sysv_symlink_inode_operations;
 178                         inode->i_mapping->a_ops = &sysv_aops;
 179                 } else {
 180                         inode->i_op = &sysv_fast_symlink_inode_operations;
 181                         nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size,
 182                                 sizeof(SYSV_I(inode)->i_data) - 1);
 183                 }
 184         } else
 185                 init_special_inode(inode, inode->i_mode, rdev);
 186 }
 187
 188 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
 189 {
 190         struct sysv_sb_info * sbi = SYSV_SB(sb);
 191         struct buffer_head * bh;
 192         struct sysv_inode * raw_inode;
 193         struct sysv_inode_info * si;
 194         struct inode *inode;
 195         unsigned int block;
 196
 197         if (!ino || ino > sbi->s_ninodes) {
 198                 printk("Bad inode number on dev %s: %d is out of range\n",
 199                        sb->s_id, ino);
 200                 return ERR_PTR(-EIO);
 201         }
 202
 203         inode = iget_locked(sb, ino);
 204         if (!inode)
 205                 return ERR_PTR(-ENOMEM);
 206         if (!(inode->i_state & I_NEW))
 207                 return inode;
 208
 209         raw_inode = sysv_raw_inode(sb, ino, &bh);
 210         if (!raw_inode) {
 211                 printk("Major problem: unable to read inode from dev %s\n",
 212                        inode->i_sb->s_id);
 213                 goto bad_inode;
 214         }
 215         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 216         inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
 217         inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
 218         inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
 219         inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
 220         inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
 221         inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
 222         inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
 223         inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
 224         inode->i_ctime.tv_nsec = 0;
 225         inode->i_atime.tv_nsec = 0;
 226         inode->i_mtime.tv_nsec = 0;
 227         inode->i_blocks = 0;
 228
 229         si = SYSV_I(inode);
 230         for (block = 0; block < 10+1+1+1; block++)
 231                 read3byte(sbi, &raw_inode->i_data[3*block],
 232                                 (u8 *)&si->i_data[block]);
 233         brelse(bh);
 234         si->i_dir_start_lookup = 0;
 235         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 236                 sysv_set_inode(inode,
 237                                old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
 238         else
 239                 sysv_set_inode(inode, 0);
 240         unlock_new_inode(inode);
 241         return inode;
 242
 243 bad_inode:
 244         iget_failed(inode);
 245         return ERR_PTR(-EIO);
 246 }
 247
 248 static struct buffer_head * sysv_update_inode(struct inode * inode)
 249 {
 250         struct super_block * sb = inode->i_sb;
 251         struct sysv_sb_info * sbi = SYSV_SB(sb);
 252         struct buffer_head * bh;
 253         struct sysv_inode * raw_inode;
 254         struct sysv_inode_info * si;
 255         unsigned int ino, block;
 256
 257         ino = inode->i_ino;
 258         if (!ino || ino > sbi->s_ninodes) {
 259                 printk("Bad inode number on dev %s: %d is out of range\n",
 260                        inode->i_sb->s_id, ino);
 261                 return NULL;
 262         }
 263         raw_inode = sysv_raw_inode(sb, ino, &bh);
 264         if (!raw_inode) {
 265                 printk("unable to read i-node block\n");
 266                 return NULL;
 267         }
 268
 269         raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
 270         raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
 271         raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
 272         raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
 273         raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
 274         raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
 275         raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
 276         raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
 277
 278         si = SYSV_I(inode);
 279         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 280                 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
 281         for (block = 0; block < 10+1+1+1; block++)
 282                 write3byte(sbi, (u8 *)&si->i_data[block],
 283                         &raw_inode->i_data[3*block]);
 284         mark_buffer_dirty(bh);
 285         return bh;
 286 }
 287
 288 int sysv_write_inode(struct inode * inode, int wait)
 289 {
 290         struct buffer_head *bh;
 291         lock_kernel();
 292         bh = sysv_update_inode(inode);
 293         brelse(bh);
 294         unlock_kernel();
 295         return 0;
 296 }
 297
 298 int sysv_sync_inode(struct inode * inode)
 299 {
 300         int err = 0;
 301         struct buffer_head *bh;
 302
 303         bh = sysv_update_inode(inode);
 304         if (bh && buffer_dirty(bh)) {
 305                 sync_dirty_buffer(bh);
 306                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
 307                         printk ("IO error syncing sysv inode [%s:%08lx]\n",
 308                                 inode->i_sb->s_id, inode->i_ino);
 309                         err = -1;
 310                 }
 311         }
 312         else if (!bh)
 313                 err = -1;
 314         brelse (bh);
 315         return err;
 316 }
 317
 318 static void sysv_delete_inode(struct inode *inode)
 319 {
 320         truncate_inode_pages(&inode->i_data, 0);
 321         inode->i_size = 0;
 322         sysv_truncate(inode);
 323         lock_kernel();
 324         sysv_free_inode(inode);
 325         unlock_kernel();
 326 }
 327
 328 static struct kmem_cache *sysv_inode_cachep;
 329
 330 static struct inode *sysv_alloc_inode(struct super_block *sb)
 331 {
 332         struct sysv_inode_info *si;
 333
 334         si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
 335         if (!si)
 336                 return NULL;
 337         return &si->vfs_inode;
 338 }
 339
 340 static void sysv_destroy_inode(struct inode *inode)
 341 {
 342         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
 343 }
 344
 345 static void init_once(void *p)
 346 {
 347         struct sysv_inode_info *si = (struct sysv_inode_info *)p;
 348
 349         inode_init_once(&si->vfs_inode);
 350 }
 351
 352 const struct super_operations sysv_sops = {
 353         .alloc_inode    = sysv_alloc_inode,
 354         .destroy_inode  = sysv_destroy_inode,
 355         .write_inode    = sysv_write_inode,
 356         .delete_inode   = sysv_delete_inode,
 357         .put_super      = sysv_put_super,
 358         .write_super    = sysv_write_super,
 359         .remount_fs     = sysv_remount,
 360         .statfs         = sysv_statfs,
 361 };
 362
 363 int __init sysv_init_icache(void)
 364 {
 365         sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
 366                         sizeof(struct sysv_inode_info), 0,
 367                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 368                         init_once);
 369         if (!sysv_inode_cachep)
 370                 return -ENOMEM;
 371         return 0;
 372 }
 373
 374 void sysv_destroy_icache(void)
 375 {
 376         kmem_cache_destroy(sysv_inode_cachep);
 377 }