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         mutex_lock(&sbi->s_lock);
  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         old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
  47         if (sbi->s_type == FSTYPE_SYSV4) {
  48                 if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
  49                         *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
  50                 *sbi->s_sb_time = cpu_to_fs32(sbi, time);
  51                 mark_buffer_dirty(sbi->s_bh2);
  52         }
  53
  54         mutex_unlock(&sbi->s_lock);
  55
  56         return 0;
  57 }
  58
  59 static int sysv_remount(struct super_block *sb, int *flags, char *data)
  60 {
  61         struct sysv_sb_info *sbi = SYSV_SB(sb);
  62
  63         sync_filesystem(sb);
  64         if (sbi->s_forced_ro)
  65                 *flags |= MS_RDONLY;
  66         return 0;
  67 }
  68
  69 static void sysv_put_super(struct super_block *sb)
  70 {
  71         struct sysv_sb_info *sbi = SYSV_SB(sb);
  72
  73         if (!(sb->s_flags & MS_RDONLY)) {
  74                 /* XXX ext2 also updates the state here */
  75                 mark_buffer_dirty(sbi->s_bh1);
  76                 if (sbi->s_bh1 != sbi->s_bh2)
  77                         mark_buffer_dirty(sbi->s_bh2);
  78         }
  79
  80         brelse(sbi->s_bh1);
  81         if (sbi->s_bh1 != sbi->s_bh2)
  82                 brelse(sbi->s_bh2);
  83
  84         kfree(sbi);
  85 }
  86
  87 static int sysv_statfs(struct dentry *dentry, struct kstatfs *buf)
  88 {
  89         struct super_block *sb = dentry->d_sb;
  90         struct sysv_sb_info *sbi = SYSV_SB(sb);
  91         u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
  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         buf->f_fsid.val[0] = (u32)id;
 101         buf->f_fsid.val[1] = (u32)(id >> 32);
 102         return 0;
 103 }
 104
 105 /*
 106  * NXI <-> N0XI for PDP, XIN <-> XIN0 for le32, NIX <-> 0NIX for be32
 107  */
 108 static inline void read3byte(struct sysv_sb_info *sbi,
 109         unsigned char * from, unsigned char * to)
 110 {
 111         if (sbi->s_bytesex == BYTESEX_PDP) {
 112                 to[0] = from[0];
 113                 to[1] = 0;
 114                 to[2] = from[1];
 115                 to[3] = from[2];
 116         } else if (sbi->s_bytesex == BYTESEX_LE) {
 117                 to[0] = from[0];
 118                 to[1] = from[1];
 119                 to[2] = from[2];
 120                 to[3] = 0;
 121         } else {
 122                 to[0] = 0;
 123                 to[1] = from[0];
 124                 to[2] = from[1];
 125                 to[3] = from[2];
 126         }
 127 }
 128
 129 static inline void write3byte(struct sysv_sb_info *sbi,
 130         unsigned char * from, unsigned char * to)
 131 {
 132         if (sbi->s_bytesex == BYTESEX_PDP) {
 133                 to[0] = from[0];
 134                 to[1] = from[2];
 135                 to[2] = from[3];
 136         } else if (sbi->s_bytesex == BYTESEX_LE) {
 137                 to[0] = from[0];
 138                 to[1] = from[1];
 139                 to[2] = from[2];
 140         } else {
 141                 to[0] = from[1];
 142                 to[1] = from[2];
 143                 to[2] = from[3];
 144         }
 145 }
 146
 147 static const struct inode_operations sysv_symlink_inode_operations = {
 148         .readlink       = generic_readlink,
 149         .follow_link    = page_follow_link_light,
 150         .put_link       = page_put_link,
 151         .getattr        = sysv_getattr,
 152 };
 153
 154 void sysv_set_inode(struct inode *inode, dev_t rdev)
 155 {
 156         if (S_ISREG(inode->i_mode)) {
 157                 inode->i_op = &sysv_file_inode_operations;
 158                 inode->i_fop = &sysv_file_operations;
 159                 inode->i_mapping->a_ops = &sysv_aops;
 160         } else if (S_ISDIR(inode->i_mode)) {
 161                 inode->i_op = &sysv_dir_inode_operations;
 162                 inode->i_fop = &sysv_dir_operations;
 163                 inode->i_mapping->a_ops = &sysv_aops;
 164         } else if (S_ISLNK(inode->i_mode)) {
 165                 if (inode->i_blocks) {
 166                         inode->i_op = &sysv_symlink_inode_operations;
 167                         inode->i_mapping->a_ops = &sysv_aops;
 168                 } else {
 169                         inode->i_op = &simple_symlink_inode_operations;
 170                         inode->i_link = (char *)SYSV_I(inode)->i_data;
 171                         nd_terminate_link(inode->i_link, inode->i_size,
 172                                 sizeof(SYSV_I(inode)->i_data) - 1);
 173                 }
 174         } else
 175                 init_special_inode(inode, inode->i_mode, rdev);
 176 }
 177
 178 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
 179 {
 180         struct sysv_sb_info * sbi = SYSV_SB(sb);
 181         struct buffer_head * bh;
 182         struct sysv_inode * raw_inode;
 183         struct sysv_inode_info * si;
 184         struct inode *inode;
 185         unsigned int block;
 186
 187         if (!ino || ino > sbi->s_ninodes) {
 188                 printk("Bad inode number on dev %s: %d is out of range\n",
 189                        sb->s_id, ino);
 190                 return ERR_PTR(-EIO);
 191         }
 192
 193         inode = iget_locked(sb, ino);
 194         if (!inode)
 195                 return ERR_PTR(-ENOMEM);
 196         if (!(inode->i_state & I_NEW))
 197                 return inode;
 198
 199         raw_inode = sysv_raw_inode(sb, ino, &bh);
 200         if (!raw_inode) {
 201                 printk("Major problem: unable to read inode from dev %s\n",
 202                        inode->i_sb->s_id);
 203                 goto bad_inode;
 204         }
 205         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 206         inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
 207         i_uid_write(inode, (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid));
 208         i_gid_write(inode, (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid));
 209         set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink));
 210         inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
 211         inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
 212         inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
 213         inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
 214         inode->i_ctime.tv_nsec = 0;
 215         inode->i_atime.tv_nsec = 0;
 216         inode->i_mtime.tv_nsec = 0;
 217         inode->i_blocks = 0;
 218
 219         si = SYSV_I(inode);
 220         for (block = 0; block < 10+1+1+1; block++)
 221                 read3byte(sbi, &raw_inode->i_data[3*block],
 222                                 (u8 *)&si->i_data[block]);
 223         brelse(bh);
 224         si->i_dir_start_lookup = 0;
 225         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 226                 sysv_set_inode(inode,
 227                                old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
 228         else
 229                 sysv_set_inode(inode, 0);
 230         unlock_new_inode(inode);
 231         return inode;
 232
 233 bad_inode:
 234         iget_failed(inode);
 235         return ERR_PTR(-EIO);
 236 }
 237
 238 static int __sysv_write_inode(struct inode *inode, int wait)
 239 {
 240         struct super_block * sb = inode->i_sb;
 241         struct sysv_sb_info * sbi = SYSV_SB(sb);
 242         struct buffer_head * bh;
 243         struct sysv_inode * raw_inode;
 244         struct sysv_inode_info * si;
 245         unsigned int ino, block;
 246         int err = 0;
 247
 248         ino = inode->i_ino;
 249         if (!ino || ino > sbi->s_ninodes) {
 250                 printk("Bad inode number on dev %s: %d is out of range\n",
 251                        inode->i_sb->s_id, ino);
 252                 return -EIO;
 253         }
 254         raw_inode = sysv_raw_inode(sb, ino, &bh);
 255         if (!raw_inode) {
 256                 printk("unable to read i-node block\n");
 257                 return -EIO;
 258         }
 259
 260         raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
 261         raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(i_uid_read(inode)));
 262         raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(i_gid_read(inode)));
 263         raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
 264         raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
 265         raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
 266         raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
 267         raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
 268
 269         si = SYSV_I(inode);
 270         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 271                 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
 272         for (block = 0; block < 10+1+1+1; block++)
 273                 write3byte(sbi, (u8 *)&si->i_data[block],
 274                         &raw_inode->i_data[3*block]);
 275         mark_buffer_dirty(bh);
 276         if (wait) {
 277                 sync_dirty_buffer(bh);
 278                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
 279                         printk ("IO error syncing sysv inode [%s:%08x]\n",
 280                                 sb->s_id, ino);
 281                         err = -EIO;
 282                 }
 283         }
 284         brelse(bh);
 285         return 0;
 286 }
 287
 288 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc)
 289 {
 290         return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
 291 }
 292
 293 int sysv_sync_inode(struct inode *inode)
 294 {
 295         return __sysv_write_inode(inode, 1);
 296 }
 297
 298 static void sysv_evict_inode(struct inode *inode)
 299 {
 300         truncate_inode_pages_final(&inode->i_data);
 301         if (!inode->i_nlink) {
 302                 inode->i_size = 0;
 303                 sysv_truncate(inode);
 304         }
 305         invalidate_inode_buffers(inode);
 306         clear_inode(inode);
 307         if (!inode->i_nlink)
 308                 sysv_free_inode(inode);
 309 }
 310
 311 static struct kmem_cache *sysv_inode_cachep;
 312
 313 static struct inode *sysv_alloc_inode(struct super_block *sb)
 314 {
 315         struct sysv_inode_info *si;
 316
 317         si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
 318         if (!si)
 319                 return NULL;
 320         return &si->vfs_inode;
 321 }
 322
 323 static void sysv_i_callback(struct rcu_head *head)
 324 {
 325         struct inode *inode = container_of(head, struct inode, i_rcu);
 326         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
 327 }
 328
 329 static void sysv_destroy_inode(struct inode *inode)
 330 {
 331         call_rcu(&inode->i_rcu, sysv_i_callback);
 332 }
 333
 334 static void init_once(void *p)
 335 {
 336         struct sysv_inode_info *si = (struct sysv_inode_info *)p;
 337
 338         inode_init_once(&si->vfs_inode);
 339 }
 340
 341 const struct super_operations sysv_sops = {
 342         .alloc_inode    = sysv_alloc_inode,
 343         .destroy_inode  = sysv_destroy_inode,
 344         .write_inode    = sysv_write_inode,
 345         .evict_inode    = sysv_evict_inode,
 346         .put_super      = sysv_put_super,
 347         .sync_fs        = sysv_sync_fs,
 348         .remount_fs     = sysv_remount,
 349         .statfs         = sysv_statfs,
 350 };
 351
 352 int __init sysv_init_icache(void)
 353 {
 354         sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
 355                         sizeof(struct sysv_inode_info), 0,
 356                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 357                         init_once);
 358         if (!sysv_inode_cachep)
 359                 return -ENOMEM;
 360         return 0;
 361 }
 362
 363 void sysv_destroy_icache(void)
 364 {
 365         /*
 366          * Make sure all delayed rcu free inodes are flushed before we
 367          * destroy cache.
 368          */
 369         rcu_barrier();
 370         kmem_cache_destroy(sysv_inode_cachep);
 371 }