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 = &sysv_fast_symlink_inode_operations;
 170                         nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size,
 171                                 sizeof(SYSV_I(inode)->i_data) - 1);
 172                 }
 173         } else
 174                 init_special_inode(inode, inode->i_mode, rdev);
 175 }
 176
 177 struct inode *sysv_iget(struct super_block *sb, unsigned int ino)
 178 {
 179         struct sysv_sb_info * sbi = SYSV_SB(sb);
 180         struct buffer_head * bh;
 181         struct sysv_inode * raw_inode;
 182         struct sysv_inode_info * si;
 183         struct inode *inode;
 184         unsigned int block;
 185
 186         if (!ino || ino > sbi->s_ninodes) {
 187                 printk("Bad inode number on dev %s: %d is out of range\n",
 188                        sb->s_id, ino);
 189                 return ERR_PTR(-EIO);
 190         }
 191
 192         inode = iget_locked(sb, ino);
 193         if (!inode)
 194                 return ERR_PTR(-ENOMEM);
 195         if (!(inode->i_state & I_NEW))
 196                 return inode;
 197
 198         raw_inode = sysv_raw_inode(sb, ino, &bh);
 199         if (!raw_inode) {
 200                 printk("Major problem: unable to read inode from dev %s\n",
 201                        inode->i_sb->s_id);
 202                 goto bad_inode;
 203         }
 204         /* SystemV FS: kludge permissions if ino==SYSV_ROOT_INO ?? */
 205         inode->i_mode = fs16_to_cpu(sbi, raw_inode->i_mode);
 206         i_uid_write(inode, (uid_t)fs16_to_cpu(sbi, raw_inode->i_uid));
 207         i_gid_write(inode, (gid_t)fs16_to_cpu(sbi, raw_inode->i_gid));
 208         set_nlink(inode, fs16_to_cpu(sbi, raw_inode->i_nlink));
 209         inode->i_size = fs32_to_cpu(sbi, raw_inode->i_size);
 210         inode->i_atime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_atime);
 211         inode->i_mtime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_mtime);
 212         inode->i_ctime.tv_sec = fs32_to_cpu(sbi, raw_inode->i_ctime);
 213         inode->i_ctime.tv_nsec = 0;
 214         inode->i_atime.tv_nsec = 0;
 215         inode->i_mtime.tv_nsec = 0;
 216         inode->i_blocks = 0;
 217
 218         si = SYSV_I(inode);
 219         for (block = 0; block < 10+1+1+1; block++)
 220                 read3byte(sbi, &raw_inode->i_data[3*block],
 221                                 (u8 *)&si->i_data[block]);
 222         brelse(bh);
 223         si->i_dir_start_lookup = 0;
 224         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 225                 sysv_set_inode(inode,
 226                                old_decode_dev(fs32_to_cpu(sbi, si->i_data[0])));
 227         else
 228                 sysv_set_inode(inode, 0);
 229         unlock_new_inode(inode);
 230         return inode;
 231
 232 bad_inode:
 233         iget_failed(inode);
 234         return ERR_PTR(-EIO);
 235 }
 236
 237 static int __sysv_write_inode(struct inode *inode, int wait)
 238 {
 239         struct super_block * sb = inode->i_sb;
 240         struct sysv_sb_info * sbi = SYSV_SB(sb);
 241         struct buffer_head * bh;
 242         struct sysv_inode * raw_inode;
 243         struct sysv_inode_info * si;
 244         unsigned int ino, block;
 245         int err = 0;
 246
 247         ino = inode->i_ino;
 248         if (!ino || ino > sbi->s_ninodes) {
 249                 printk("Bad inode number on dev %s: %d is out of range\n",
 250                        inode->i_sb->s_id, ino);
 251                 return -EIO;
 252         }
 253         raw_inode = sysv_raw_inode(sb, ino, &bh);
 254         if (!raw_inode) {
 255                 printk("unable to read i-node block\n");
 256                 return -EIO;
 257         }
 258
 259         raw_inode->i_mode = cpu_to_fs16(sbi, inode->i_mode);
 260         raw_inode->i_uid = cpu_to_fs16(sbi, fs_high2lowuid(i_uid_read(inode)));
 261         raw_inode->i_gid = cpu_to_fs16(sbi, fs_high2lowgid(i_gid_read(inode)));
 262         raw_inode->i_nlink = cpu_to_fs16(sbi, inode->i_nlink);
 263         raw_inode->i_size = cpu_to_fs32(sbi, inode->i_size);
 264         raw_inode->i_atime = cpu_to_fs32(sbi, inode->i_atime.tv_sec);
 265         raw_inode->i_mtime = cpu_to_fs32(sbi, inode->i_mtime.tv_sec);
 266         raw_inode->i_ctime = cpu_to_fs32(sbi, inode->i_ctime.tv_sec);
 267
 268         si = SYSV_I(inode);
 269         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode))
 270                 si->i_data[0] = cpu_to_fs32(sbi, old_encode_dev(inode->i_rdev));
 271         for (block = 0; block < 10+1+1+1; block++)
 272                 write3byte(sbi, (u8 *)&si->i_data[block],
 273                         &raw_inode->i_data[3*block]);
 274         mark_buffer_dirty(bh);
 275         if (wait) {
 276                 sync_dirty_buffer(bh);
 277                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
 278                         printk ("IO error syncing sysv inode [%s:%08x]\n",
 279                                 sb->s_id, ino);
 280                         err = -EIO;
 281                 }
 282         }
 283         brelse(bh);
 284         return 0;
 285 }
 286
 287 int sysv_write_inode(struct inode *inode, struct writeback_control *wbc)
 288 {
 289         return __sysv_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
 290 }
 291
 292 int sysv_sync_inode(struct inode *inode)
 293 {
 294         return __sysv_write_inode(inode, 1);
 295 }
 296
 297 static void sysv_evict_inode(struct inode *inode)
 298 {
 299         truncate_inode_pages_final(&inode->i_data);
 300         if (!inode->i_nlink) {
 301                 inode->i_size = 0;
 302                 sysv_truncate(inode);
 303         }
 304         invalidate_inode_buffers(inode);
 305         clear_inode(inode);
 306         if (!inode->i_nlink)
 307                 sysv_free_inode(inode);
 308 }
 309
 310 static struct kmem_cache *sysv_inode_cachep;
 311
 312 static struct inode *sysv_alloc_inode(struct super_block *sb)
 313 {
 314         struct sysv_inode_info *si;
 315
 316         si = kmem_cache_alloc(sysv_inode_cachep, GFP_KERNEL);
 317         if (!si)
 318                 return NULL;
 319         return &si->vfs_inode;
 320 }
 321
 322 static void sysv_i_callback(struct rcu_head *head)
 323 {
 324         struct inode *inode = container_of(head, struct inode, i_rcu);
 325         kmem_cache_free(sysv_inode_cachep, SYSV_I(inode));
 326 }
 327
 328 static void sysv_destroy_inode(struct inode *inode)
 329 {
 330         call_rcu(&inode->i_rcu, sysv_i_callback);
 331 }
 332
 333 static void init_once(void *p)
 334 {
 335         struct sysv_inode_info *si = (struct sysv_inode_info *)p;
 336
 337         inode_init_once(&si->vfs_inode);
 338 }
 339
 340 const struct super_operations sysv_sops = {
 341         .alloc_inode    = sysv_alloc_inode,
 342         .destroy_inode  = sysv_destroy_inode,
 343         .write_inode    = sysv_write_inode,
 344         .evict_inode    = sysv_evict_inode,
 345         .put_super      = sysv_put_super,
 346         .sync_fs        = sysv_sync_fs,
 347         .remount_fs     = sysv_remount,
 348         .statfs         = sysv_statfs,
 349 };
 350
 351 int __init sysv_init_icache(void)
 352 {
 353         sysv_inode_cachep = kmem_cache_create("sysv_inode_cache",
 354                         sizeof(struct sysv_inode_info), 0,
 355                         SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
 356                         init_once);
 357         if (!sysv_inode_cachep)
 358                 return -ENOMEM;
 359         return 0;
 360 }
 361
 362 void sysv_destroy_icache(void)
 363 {
 364         /*
 365          * Make sure all delayed rcu free inodes are flushed before we
 366          * destroy cache.
 367          */
 368         rcu_barrier();
 369         kmem_cache_destroy(sysv_inode_cachep);
 370 }