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 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         lock_kernel();
  41
  42         /*
  43          * If we are going to write out the super block,
  44          * then attach current time stamp.
  45          * But if the filesystem was marked clean, keep it clean.
  46          */
  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_kernel();
  56         unlock_super(sb);
  57
  58         return 0;
  59 }
  60
  61 static void sysv_write_super(struct super_block *sb)
  62 {
  63         if (!(sb->s_flags & MS_RDONLY))
  64                 sysv_sync_fs(sb, 1);
  65         else
  66                 sb->s_dirt = 0;
  67 }
  68
  69 static int sysv_remount(struct super_block *sb, int *flags, char *data)
  70 {
  71         struct sysv_sb_info *sbi = SYSV_SB(sb);
  72         lock_super(sb);
  73         if (sbi->s_forced_ro)
  74                 *flags |= MS_RDONLY;
  75         if (!(*flags & MS_RDONLY))
  76                 sb->s_dirt = 1;
  77         unlock_super(sb);
  78         return 0;
  79 }
  80
  81 static void sysv_put_super(struct super_block *sb)
  82 {
  83         struct sysv_sb_info *sbi = SYSV_SB(sb);
  84
  85         lock_kernel();
  86
  87         if (sb->s_dirt)
  88                 sysv_write_super(sb);
  89
  90         if (!(sb->s_flags & MS_RDONLY)) {
  91                 /* XXX ext2 also updates the state here */
  92                 mark_buffer_dirty(sbi->s_bh1);
  93                 if (sbi->s_bh1 != sbi->s_bh2)
  94                         mark_buffer_dirty(sbi->s_bh2);
  95         }
  96
  97         brelse(sbi->s_bh1);
  98         if (sbi->s_bh1 != sbi->s_bh2)
  99                 brelse(sbi->s_bh2);
 100
 101         kfree(sbi);
 102
 103         unlock_kernel();
 104 }
 105
 106 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
 107 {
 108         struct super_block *sb = dentry->d_sb;
 109         struct sysv_sb_info *sbi = SYSV_SB(sb);
 110         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 111
 112         buf->f_type = sb->s_magic;
 113         buf->f_bsize = sb->s_blocksize;
 114         buf->f_blocks = sbi->s_ndatazones;
 115         buf->f_bavail = buf->f_bfree = sysv_count_free_blocks(sb);
 116         buf->f_files = sbi->s_ninodes;
 117         buf->f_ffree = sysv_count_free_inodes(sb);
 118         buf->f_namelen = SYSV_NAMELEN;
 119         buf->f_fsid.val[0] = (u32)id;
 120         buf->f_fsid.val[1] = (u32)(id >> 32);
 121         return 0;
 122 }
 123
 124 /*
 125  * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
 126  */
 127 static inline void read3byte(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] = 0;
 133                 to[2] = from[1];
 134                 to[3] = from[2];
 135         } else if (sbi->s_bytesex == BYTESEX_LE) {
 136                 to[0] = from[0];
 137                 to[1] = from[1];
 138                 to[2] = from[2];
 139                 to[3] = 0;
 140         } else {
 141                 to[0] = 0;
 142                 to[1] = from[0];
 143                 to[2] = from[1];
 144                 to[3] = from[2];
 145         }
 146 }
 147
 148 static inline void write3byte(struct sysv_sb_info *sbi,
 149         unsigned char * from, unsigned char * to)
 150 {
 151         if (sbi->s_bytesex == BYTESEX_PDP) {
 152                 to[0] = from[0];
 153                 to[1] = from[2];
 154                 to[2] = from[3];
 155         } else if (sbi->s_bytesex == BYTESEX_LE) {
 156                 to[0] = from[0];
 157                 to[1] = from[1];
 158                 to[2] = from[2];
 159         } else {
 160                 to[0] = from[1];
 161                 to[1] = from[2];
 162                 to[2] = from[3];
 163         }
 164 }
 165
 166 static const struct inode_operations sysv_symlink_inode_operations = {
 167         .readlink       = generic_readlink,
 168         .follow_link    = page_follow_link_light,
 169         .put_link       = page_put_link,
 170         .getattr        = sysv_getattr,
 171 };
 172
 173 void sysv_set_inode(struct inode *inode, dev_t rdev)
 174 {
 175         if (S_ISREG(inode->i_mode)) {
 176                 inode->i_op = &sysv_file_inode_operations;
 177                 inode->i_fop = &sysv_file_operations;
 178                 inode->i_mapping->a_ops = &sysv_aops;
 179         } else if (S_ISDIR(inode->i_mode)) {
 180                 inode->i_op = &sysv_dir_inode_operations;
 181                 inode->i_fop = &sysv_dir_operations;
 182                 inode->i_mapping->a_ops = &sysv_aops;
 183         } else if (S_ISLNK(inode->i_mode)) {
 184                 if (inode->i_blocks) {
 185                         inode->i_op = &sysv_symlink_inode_operations;
 186                         inode->i_mapping->a_ops = &sysv_aops;
 187                 } else {
 188                         inode->i_op = &sysv_fast_symlink_inode_operations;
 189                         nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size,
 190                                 sizeof(SYSV_I(inode)->i_data) - 1);
 191                 }
 192         } else
 193                 init_special_inode(inode, inode->i_mode, rdev);
 194 }
 195
 196 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
 197 {
 198         struct sysv_sb_info * sbi = SYSV_SB(sb);
 199         struct buffer_head * bh;
 200         struct sysv_inode * raw_inode;
 201         struct sysv_inode_info * si;
 202         struct inode *inode;
 203         unsigned int block;
 204
 205         if (!ino || ino > sbi->s_ninodes) {
 206                 printk("Bad inode number on dev %s: %d is out of range\n",
 207                        sb->s_id, ino);
 208                 return ERR_PTR(-EIO);
 209         }
 210
 211         inode = iget_locked(sb, ino);
 212         if (!inode)
 213                 return ERR_PTR(-ENOMEM);
 214         if (!(inode->i_state & I_NEW))
 215                 return inode;
 216
 217         raw_inode = sysv_raw_inode(sb, ino, &bh);
 218         if (!raw_inode) {
 219                 printk("Major problem: unable to read inode from dev %s\n",
 220                        inode->i_sb->s_id);
 221                 goto bad_inode;
 222         }
 223         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 224         inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
 225         inode->i_uid = (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid);
 226         inode->i_gid = (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid);
 227         inode->i_nlink = fs16_to_cpu(sbi, raw_inode->i_nlink);
 228         inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
 229         inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
 230         inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
 231         inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
 232         inode->i_ctime.tv_nsec = 0;
 233         inode->i_atime.tv_nsec = 0;
 234         inode->i_mtime.tv_nsec = 0;
 235         inode->i_blocks = 0;
 236
 237         si = SYSV_I(inode);
 238         for (block = 0; block < 10+1+1+1; block++)
 239                 read3byte(sbi, &raw_inode->i_data[3*block],
 240                                 (u8 *)&si->i_data[block]);
 241         brelse(bh);
 242         si->i_dir_start_lookup = 0;
 243         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 244                 sysv_set_inode(inode,
 245                                old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
 246         else
 247                 sysv_set_inode(inode, 0);
 248         unlock_new_inode(inode);
 249         return inode;
 250
 251 bad_inode:
 252         iget_failed(inode);
 253         return ERR_PTR(-EIO);
 254 }
 255
 256 int sysv_write_inode(struct inode *inode, int wait)
 257 {
 258         struct super_block * sb = inode->i_sb;
 259         struct sysv_sb_info * sbi = SYSV_SB(sb);
 260         struct buffer_head * bh;
 261         struct sysv_inode * raw_inode;
 262         struct sysv_inode_info * si;
 263         unsigned int ino, block;
 264         int err = 0;
 265
 266         ino = inode->i_ino;
 267         if (!ino || ino > sbi->s_ninodes) {
 268                 printk("Bad inode number on dev %s: %d is out of range\n",
 269                        inode->i_sb->s_id, ino);
 270                 return -EIO;
 271         }
 272         raw_inode = sysv_raw_inode(sb, ino, &bh);
 273         if (!raw_inode) {
 274                 printk("unable to read i-node block\n");
 275                 return -EIO;
 276         }
 277
 278         lock_kernel();
 279         raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
 280         raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(inode->i_uid));
 281         raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(inode->i_gid));
 282         raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
 283         raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
 284         raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
 285         raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
 286         raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
 287
 288         si = SYSV_I(inode);
 289         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 290                 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
 291         for (block = 0; block < 10+1+1+1; block++)
 292                 write3byte(sbi, (u8 *)&si->i_data[block],
 293                         &raw_inode->i_data[3*block]);
 294         unlock_kernel();
 295         mark_buffer_dirty(bh);
 296         if (wait) {
 297                 sync_dirty_buffer(bh);
 298                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
 299                         printk ("IO error syncing sysv inode [%s:%08x]\n",
 300                                 sb->s_id, ino);
 301                         err = -EIO;
 302                 }
 303         }
 304         brelse(bh);
 305         return 0;
 306 }
 307
 308 int sysv_sync_inode(struct inode *inode)
 309 {
 310         return sysv_write_inode(inode, 1);
 311 }
 312
 313 static void sysv_delete_inode(struct inode *inode)
 314 {
 315         truncate_inode_pages(&inode->i_data, 0);
 316         inode->i_size = 0;
 317         sysv_truncate(inode);
 318         lock_kernel();
 319         sysv_free_inode(inode);
 320         unlock_kernel();
 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         .delete_inode   = sysv_delete_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 }