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