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