release/src-rt-6.x.4708/linux/linux-2.6.36/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/highuid.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/buffer_head.h>
  28 #include <linux/vfs.h>
  29 #include <linux/writeback.h>
  30 #include <linux/namei.h>
  31 #include <asm/byteorder.h>
  32 #include "sysv.h"
  33
  34 static int sysv_sync_fs(struct super_block *sb, int wait)
  35 {
  36         struct sysv_sb_info *sbi = SYSV_SB(sb);
  37         unsigned long time = get_seconds(), old_time;
  38
  39         lock_super(sb);
  40
  41         /*
  42          * If we are going to write out the super block,
  43          * then attach current time stamp.
  44          * But if the filesystem was marked clean, keep it clean.
  45          */
  46         sb->s_dirt = 0;
  47         old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
  48         if (sbi->s_type == FSTYPE_SYSV4) {
  49                 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
  50                         *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
  51                 *sbi->s_sb_time = cpu_to_fs32(sbi, time);
  52                 mark_buffer_dirty(sbi->s_bh2);
  53         }
  54
  55         unlock_super(sb);
  56
  57         return 0;
  58 }
  59
  60 static void sysv_write_super(struct super_block *sb)
  61 {
  62         if (!(sb->s_flags & MS_RDONLY))
  63                 sysv_sync_fs(sb, 1);
  64         else
  65                 sb->s_dirt = 0;
  66 }
  67
  68 static int sysv_remount(struct super_block *sb, int *flags, char *data)
  69 {
  70         struct sysv_sb_info *sbi = SYSV_SB(sb);
  71         lock_super(sb);
  72         if (sbi->s_forced_ro)
  73                 *flags |= MS_RDONLY;
  74         if (*flags & MS_RDONLY)
  75                 sysv_write_super(sb);
  76         unlock_super(sb);
  77         return 0;
  78 }
  79
  80 static void sysv_put_super(struct super_block *sb)
  81 {
  82         struct sysv_sb_info *sbi = SYSV_SB(sb);
  83
  84         if (sb->s_dirt)
  85                 sysv_write_super(sb);
  86
  87         if (!(sb->s_flags & MS_RDONLY)) {
  88                 mark_buffer_dirty(sbi->s_bh1);
  89                 if (sbi->s_bh1 != sbi->s_bh2)
  90                         mark_buffer_dirty(sbi->s_bh2);
  91         }
  92
  93         brelse(sbi->s_bh1);
  94         if (sbi->s_bh1 != sbi->s_bh2)
  95                 brelse(sbi->s_bh2);
  96
  97         kfree(sbi);
  98 }
  99
 100 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
 101 {
 102         struct super_block *sb = dentry->d_sb;
 103         struct sysv_sb_info *sbi = SYSV_SB(sb);
 104         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 105
 106         buf->f_type = sb->s_magic;
 107         buf->f_bsize = sb->s_blocksize;
 108         buf->f_blocks = sbi->s_ndatazones;
 109         buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
 110         buf->f_files = sbi->s_ninodes;
 111         buf->f_ffree = sysv_count_free_inodes(sb);
 112         buf->f_namelen = SYSV_NAMELEN;
 113         buf->f_fsid.val[0] = (u32)id;
 114         buf->f_fsid.val[1] = (u32)(id >> 32);
 115         return 0;
 116 }
 117
 118 /*
 119  * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
 120  */
 121 static inline void read3byte(struct sysv_sb_info *sbi,
 122         unsigned char * from, unsigned char * to)
 123 {
 124         if (sbi->s_bytesex == BYTESEX_PDP) {
 125                 to[0] = from[0];
 126                 to[1] = 0;
 127                 to[2] = from[1];
 128                 to[3] = from[2];
 129         } else if (sbi->s_bytesex == BYTESEX_LE) {
 130                 to[0] = from[0];
 131                 to[1] = from[1];
 132                 to[2] = from[2];
 133                 to[3] = 0;
 134         } else {
 135                 to[0] = 0;
 136                 to[1] = from[0];
 137                 to[2] = from[1];
 138                 to[3] = from[2];
 139         }
 140 }
 141
 142 static inline void write3byte(struct sysv_sb_info *sbi,
 143         unsigned char * from, unsigned char * to)
 144 {
 145         if (sbi->s_bytesex == BYTESEX_PDP) {
 146                 to[0] = from[0];
 147                 to[1] = from[2];
 148                 to[2] = from[3];
 149         } else if (sbi->s_bytesex == BYTESEX_LE) {
 150                 to[0] = from[0];
 151                 to[1] = from[1];
 152                 to[2] = from[2];
 153         } else {
 154                 to[0] = from[1];
 155                 to[1] = from[2];
 156                 to[2] = from[3];
 157         }
 158 }
 159
 160 static const struct inode_operations sysv_symlink_inode_operations = {
 161         .readlink       = generic_readlink,
 162         .follow_link    = page_follow_link_light,
 163         .put_link       = page_put_link,
 164         .getattr        = sysv_getattr,
 165 };
 166
 167 void sysv_set_inode(struct inode *inode, dev_t rdev)
 168 {
 169         if (S_ISREG(inode->i_mode)) {
 170                 inode->i_op = &sysv_file_inode_operations;
 171                 inode->i_fop = &sysv_file_operations;
 172                 inode->i_mapping->a_ops = &sysv_aops;
 173         } else if (S_ISDIR(inode->i_mode)) {
 174                 inode->i_op = &sysv_dir_inode_operations;
 175                 inode->i_fop = &sysv_dir_operations;
 176                 inode->i_mapping->a_ops = &sysv_aops;
 177         } else if (S_ISLNK(inode->i_mode)) {
 178                 if (inode->i_blocks) {
 179                         inode->i_op = &sysv_symlink_inode_operations;
 180                         inode->i_mapping->a_ops = &sysv_aops;
 181                 } else {
 182                         inode->i_op = &sysv_fast_symlink_inode_operations;
 183                         nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size,
 184                                 sizeof(SYSV_I(inode)->i_data) - 1);
 185                 }
 186         } else
 187                 init_special_inode(inode, inode->i_mode, rdev);
 188 }
 189
 190 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
 191 {
 192         struct sysv_sb_info * sbi = SYSV_SB(sb);
 193         struct buffer_head * bh;
 194         struct sysv_inode * raw_inode;
 195         struct sysv_inode_info * si;
 196         struct inode *inode;
 197         unsigned int block;
 198
 199         if (!ino || ino > sbi->s_ninodes) {
 200                 printk("Bad inode number on dev %s: %d is out of range\n",
 201                        sb->s_id, ino);
 202                 return ERR_PTR(-EIO);
 203         }
 204
 205         inode = iget_locked(sb, ino);
 206         if (!inode)
 207                 return ERR_PTR(-ENOMEM);
 208         if (!(inode->i_state & I_NEW))
 209                 return inode;
 210
 211         raw_inode = sysv_raw_inode(sb, ino, &bh);
 212         if (!raw_inode) {
 213                 printk("Major problem: unable to read inode from dev %s\n",
 214                        inode->i_sb->s_id);
 215                 goto bad_inode;
 216         }
 217         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 218         inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
 219         inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
 220         inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
 221         inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
 222         inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
 223         inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
 224         inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
 225         inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
 226         inode->i_ctime.tv_nsec = 0;
 227         inode->i_atime.tv_nsec = 0;
 228         inode->i_mtime.tv_nsec = 0;
 229         inode->i_blocks = 0;
 230
 231         si = SYSV_I(inode);
 232         for (block = 0; block < 10+1+1+1; block++)
 233                 read3byte(sbi, &raw_inode->i_data[3*block],
 234                                 (u8 *)&si->i_data[block]);
 235         brelse(bh);
 236         si->i_dir_start_lookup = 0;
 237         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 238                 sysv_set_inode(inode,
 239                                old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
 240         else
 241                 sysv_set_inode(inode, 0);
 242         unlock_new_inode(inode);
 243         return inode;
 244
 245 bad_inode:
 246         iget_failed(inode);
 247         return ERR_PTR(-EIO);
 248 }
 249
 250 static int __sysv_write_inode(struct inode *inode, int wait)
 251 {
 252         struct super_block * sb = inode->i_sb;
 253         struct sysv_sb_info * sbi = SYSV_SB(sb);
 254         struct buffer_head * bh;
 255         struct sysv_inode * raw_inode;
 256         struct sysv_inode_info * si;
 257         unsigned int ino, block;
 258         int err = 0;
 259
 260         ino = inode->i_ino;
 261         if (!ino || ino > sbi->s_ninodes) {
 262                 printk("Bad inode number on dev %s: %d is out of range\n",
 263                        inode->i_sb->s_id, ino);
 264                 return -EIO;
 265         }
 266         raw_inode = sysv_raw_inode(sb, ino, &bh);
 267         if (!raw_inode) {
 268                 printk("unable to read i-node block\n");
 269                 return -EIO;
 270         }
 271
 272         raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
 273         raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
 274         raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
 275         raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
 276         raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
 277         raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
 278         raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
 279         raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
 280
 281         si = SYSV_I(inode);
 282         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 283                 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
 284         for (block = 0; block < 10+1+1+1; block++)
 285                 write3byte(sbi, (u8 *)&si->i_data[block],
 286                         &raw_inode->i_data[3*block]);
 287         mark_buffer_dirty(bh);
 288         if (wait) {
 289                 sync_dirty_buffer(bh);
 290                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
 291                         printk ("IO error syncing sysv inode [%s:%08x]\n",
 292                                 sb->s_id, ino);
 293                         err = -EIO;
 294                 }
 295         }
 296         brelse(bh);
 297         return 0;
 298 }
 299
 300 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc)
 301 {
 302         return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
 303 }
 304
 305 int sysv_sync_inode(struct inode *inode)
 306 {
 307         return __sysv_write_inode(inode, 1);
 308 }
 309
 310 static void sysv_evict_inode(struct inode *inode)
 311 {
 312         truncate_inode_pages(&inode->i_data, 0);
 313         if (!inode->i_nlink) {
 314                 inode->i_size = 0;
 315                 sysv_truncate(inode);
 316         }
 317         invalidate_inode_buffers(inode);
 318         end_writeback(inode);
 319         if (!inode->i_nlink)
 320                 sysv_free_inode(inode);
 321 }
 322
 323 static struct kmem_cache *sysv_inode_cachep;
 324
 325 static struct inode *sysv_alloc_inode(struct super_block *sb)
 326 {
 327         struct sysv_inode_info *si;
 328
 329         si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
 330         if (!si)
 331                 return NULL;
 332         return &si->vfs_inode;
 333 }
 334
 335 static void sysv_destroy_inode(struct inode *inode)
 336 {
 337         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
 338 }
 339
 340 static void init_once(void *p)
 341 {
 342         struct sysv_inode_info *si = (struct sysv_inode_info *)p;
 343
 344         inode_init_once(&si->vfs_inode);
 345 }
 346
 347 const struct super_operations sysv_sops = {
 348         .alloc_inode    = sysv_alloc_inode,
 349         .destroy_inode  = sysv_destroy_inode,
 350         .write_inode    = sysv_write_inode,
 351         .evict_inode    = sysv_evict_inode,
 352         .put_super      = sysv_put_super,
 353         .write_super    = sysv_write_super,
 354         .sync_fs        = sysv_sync_fs,
 355         .remount_fs     = sysv_remount,
 356         .statfs         = sysv_statfs,
 357 };
 358
 359 int __init sysv_init_icache(void)
 360 {
 361         sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
 362                         sizeof(struct sysv_inode_info), 0,
 363                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 364                         init_once);
 365         if (!sysv_inode_cachep)
 366                 return -ENOMEM;
 367         return 0;
 368 }
 369
 370 void sysv_destroy_icache(void)
 371 {
 372         kmem_cache_destroy(sysv_inode_cachep);
 373 }