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