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