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