super.c

ARM 嵌入式 系统 设计与实例开发 实验教材 二源码

  reiserfs_proc_unregister( s, "per-level" );
  reiserfs_proc_unregister( s, "super" );
  reiserfs_proc_unregister( s, "version" );
  reiserfs_proc_info_done( s );
  return;
}

/* we don't mark inodes dirty, we just log them */
static void reiserfs_dirty_inode (struct inode * inode) {
    struct reiserfs_transaction_handle th ;

    if (inode->i_sb->s_flags & MS_RDONLY) {
        reiserfs_warning("clm-6006: writing inode %lu on readonly FS\n", 
	                  inode->i_ino) ;
        return ;
    }
    lock_kernel() ;

    /* this is really only used for atime updates, so they don't have
    ** to be included in O_SYNC or fsync
    */
    journal_begin(&th, inode->i_sb, 1) ;
    reiserfs_update_sd (&th, inode);
    journal_end(&th, inode->i_sb, 1) ;
    unlock_kernel() ;
}

struct super_operations reiserfs_sops = 
{
  read_inode: reiserfs_read_inode,
  read_inode2: reiserfs_read_inode2,
  write_inode: reiserfs_write_inode,
  dirty_inode: reiserfs_dirty_inode,
  delete_inode: reiserfs_delete_inode,
  put_super: reiserfs_put_super,
  write_super: reiserfs_write_super,
  write_super_lockfs: reiserfs_write_super_lockfs,
  unlockfs: reiserfs_unlockfs,
  statfs: reiserfs_statfs,
  remount_fs: reiserfs_remount,

  fh_to_dentry: reiserfs_fh_to_dentry,
  dentry_to_fh: reiserfs_dentry_to_fh,

};

/* this was (ext2)parse_options */
static int parse_options (char * options, unsigned long * mount_options, unsigned long * blocks)
{
    char * this_char;
    char * value;
  
    *blocks = 0;
    if (!options)
	/* use default configuration: create tails, journaling on, no
           conversion to newest format */
	return 1;
    for (this_char = strtok (options, ","); this_char != NULL; this_char = strtok (NULL, ",")) {
	if ((value = strchr (this_char, '=')) != NULL)
	    *value++ = 0;
	if (!strcmp (this_char, "notail")) {
	    set_bit (NOTAIL, mount_options);
	} else if (!strcmp (this_char, "conv")) {
	    // if this is set, we update super block such that
	    // the partition will not be mounable by 3.5.x anymore
	    set_bit (REISERFS_CONVERT, mount_options);
	} else if (!strcmp (this_char, "noborder")) {
				/* this is used for benchmarking
                                   experimental variations, it is not
                                   intended for users to use, only for
                                   developers who want to casually
                                   hack in something to test */
	    set_bit (REISERFS_NO_BORDER, mount_options);
	} else if (!strcmp (this_char, "no_unhashed_relocation")) {
	    set_bit (REISERFS_NO_UNHASHED_RELOCATION, mount_options);
	} else if (!strcmp (this_char, "hashed_relocation")) {
	    set_bit (REISERFS_HASHED_RELOCATION, mount_options);
	} else if (!strcmp (this_char, "test4")) {
	    set_bit (REISERFS_TEST4, mount_options);
	} else if (!strcmp (this_char, "nolog")) {
	    reiserfs_warning("reiserfs: nolog mount option not supported yet\n");
	} else if (!strcmp (this_char, "replayonly")) {
	    set_bit (REPLAYONLY, mount_options);
	} else if (!strcmp (this_char, "resize")) {
	    if (value && *value){
		*blocks = simple_strtoul (value, &value, 0);
	    } else {
	  	printk("reiserfs: resize option requires a value\n");
		return 0;
	    }
	} else if (!strcmp (this_char, "hash")) {
	    if (value && *value) {
		/* if they specify any hash option, we force detection
		** to make sure they aren't using the wrong hash
		*/
	        if (!strcmp(value, "rupasov")) {
		    set_bit (FORCE_RUPASOV_HASH, mount_options);
		    set_bit (FORCE_HASH_DETECT, mount_options);
		} else if (!strcmp(value, "tea")) {
		    set_bit (FORCE_TEA_HASH, mount_options);
		    set_bit (FORCE_HASH_DETECT, mount_options);
		} else if (!strcmp(value, "r5")) {
		    set_bit (FORCE_R5_HASH, mount_options);
		    set_bit (FORCE_HASH_DETECT, mount_options);
		} else if (!strcmp(value, "detect")) {
		    set_bit (FORCE_HASH_DETECT, mount_options);
		} else {
		    printk("reiserfs: invalid hash function specified\n") ;
		    return 0 ;
		}
	    } else {
	  	printk("reiserfs: hash option requires a value\n");
		return 0 ;
	    }
	} else {
	    printk ("reiserfs: Unrecognized mount option %s\n", this_char);
	    return 0;
	}
    }
    return 1;
}


int reiserfs_is_super(struct super_block *s) {
   return (s->s_dev != 0 && s->s_op == &reiserfs_sops) ;
}


//
// a portion of this function, particularly the VFS interface portion,
// was derived from minix or ext2's analog and evolved as the
// prototype did. You should be able to tell which portion by looking
// at the ext2 code and comparing. It's subfunctions contain no code
// used as a template unless they are so labeled.
//
static int reiserfs_remount (struct super_block * s, int * flags, char * data)
{
  struct reiserfs_super_block * rs;
  struct reiserfs_transaction_handle th ;
  unsigned long blocks;
  unsigned long mount_options;

  rs = SB_DISK_SUPER_BLOCK (s);

  if (!parse_options(data, &mount_options, &blocks))
  	return 0;

  if(blocks) {
      int rc = reiserfs_resize(s, blocks);
      if (rc != 0)
	  return rc;
  }

  if ((unsigned long)(*flags & MS_RDONLY) == (s->s_flags & MS_RDONLY)) {
    /* there is nothing to do to remount read-only fs as read-only fs */
    return 0;
  }
  
  if (*flags & MS_RDONLY) {
    /* try to remount file system with read-only permissions */
    if (sb_state(rs) == REISERFS_VALID_FS || s->u.reiserfs_sb.s_mount_state != REISERFS_VALID_FS) {
      return 0;
    }

    journal_begin(&th, s, 10) ;
    /* Mounting a rw partition read-only. */
    reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1) ;
    set_sb_state( rs, s->u.reiserfs_sb.s_mount_state );
    journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB (s));
    s->s_dirt = 0;
  } else {
    s->u.reiserfs_sb.s_mount_state = sb_state(rs) ;
    s->s_flags &= ~MS_RDONLY ; /* now it is safe to call journal_begin */
    journal_begin(&th, s, 10) ;

    /* Mount a partition which is read-only, read-write */
    reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1) ;
    s->u.reiserfs_sb.s_mount_state = sb_state(rs);
    s->s_flags &= ~MS_RDONLY;
    set_sb_state( rs, REISERFS_ERROR_FS );
    /* mark_buffer_dirty (SB_BUFFER_WITH_SB (s), 1); */
    journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB (s));
    s->s_dirt = 0;
    s->u.reiserfs_sb.s_mount_state = REISERFS_VALID_FS ;
  }
  /* this will force a full flush of all journal lists */
  SB_JOURNAL(s)->j_must_wait = 1 ;
  journal_end(&th, s, 10) ;

  if (!( *flags & MS_RDONLY ) )
    finish_unfinished( s );

  return 0;
}


static int read_bitmaps (struct super_block * s)
{
    int i, bmp, dl ;
    struct reiserfs_super_block * rs = SB_DISK_SUPER_BLOCK(s);

    SB_AP_BITMAP (s) = reiserfs_kmalloc (sizeof (struct buffer_head *) * sb_bmap_nr(rs), GFP_NOFS, s);
    if (SB_AP_BITMAP (s) == 0)
	return 1;
    memset (SB_AP_BITMAP (s), 0, sizeof (struct buffer_head *) * sb_bmap_nr(rs));

    /* reiserfs leaves the first 64k unused so that any partition
       labeling scheme currently used will have enough space. Then we
       need one block for the super.  -Hans */
    bmp = (REISERFS_DISK_OFFSET_IN_BYTES / s->s_blocksize) + 1;	/* first of bitmap blocks */
    SB_AP_BITMAP (s)[0] = reiserfs_bread (s, bmp, s->s_blocksize);
    if(!SB_AP_BITMAP(s)[0])
	return 1;
    for (i = 1, bmp = dl = s->s_blocksize * 8; i < sb_bmap_nr(rs); i ++) {
	SB_AP_BITMAP (s)[i] = reiserfs_bread (s, bmp, s->s_blocksize);
	if (!SB_AP_BITMAP (s)[i])
	    return 1;
	bmp += dl;
    }

    return 0;
}

static int read_old_bitmaps (struct super_block * s)
{
  int i ;
  struct reiserfs_super_block * rs = SB_DISK_SUPER_BLOCK(s);
  int bmp1 = (REISERFS_OLD_DISK_OFFSET_IN_BYTES / s->s_blocksize) + 1;  /* first of bitmap blocks */

  /* read true bitmap */
  SB_AP_BITMAP (s) = reiserfs_kmalloc (sizeof (struct buffer_head *) * sb_bmap_nr(rs), GFP_NOFS, s);
  if (SB_AP_BITMAP (s) == 0)
    return 1;

  memset (SB_AP_BITMAP (s), 0, sizeof (struct buffer_head *) * sb_bmap_nr(rs));

  for (i = 0; i < sb_bmap_nr(rs); i ++) {
    SB_AP_BITMAP (s)[i] = reiserfs_bread (s, bmp1 + i, s->s_blocksize);
    if (!SB_AP_BITMAP (s)[i])
      return 1;
  }

  return 0;
}

void check_bitmap (struct super_block * s)
{
  int i = 0;
  int free = 0;
  char * buf;

  while (i < SB_BLOCK_COUNT (s)) {
    buf = SB_AP_BITMAP (s)[i / (s->s_blocksize * 8)]->b_data;
    if (!reiserfs_test_le_bit (i % (s->s_blocksize * 8), buf))
      free ++;
    i ++;
  }

  if (free != SB_FREE_BLOCKS (s))
    reiserfs_warning ("vs-4000: check_bitmap: %d free blocks, must be %d\n",
		      free, SB_FREE_BLOCKS (s));
}

static int read_super_block (struct super_block * s, int size, int offset)
{
    struct buffer_head * bh;
    struct reiserfs_super_block * rs;
 

    bh = bread (s->s_dev, offset / size, size);
    if (!bh) {
      printk ("read_super_block: "
              "bread failed (dev %s, block %d, size %d)\n",
              kdevname (s->s_dev), offset / size, size);
      return 1;
    }
 
    rs = (struct reiserfs_super_block *)bh->b_data;
    if (!is_reiserfs_magic_string (rs)) {
      printk ("read_super_block: "
              "can't find a reiserfs filesystem on (dev %s, block %lu, size %d)\n",
              kdevname(s->s_dev), bh->b_blocknr, size);
      brelse (bh);
      return 1;
    }
 
    //
    // ok, reiserfs signature (old or new) found in at the given offset
    //    
    s->s_blocksize = sb_blocksize(rs);
    s->s_blocksize_bits = 0;
    while ((1 << s->s_blocksize_bits) != s->s_blocksize)
	s->s_blocksize_bits ++;

    brelse (bh);
    
    if (s->s_blocksize != size)
	set_blocksize (s->s_dev, s->s_blocksize);

    bh = reiserfs_bread (s, offset / s->s_blocksize, s->s_blocksize);
    if (!bh) {
	printk("read_super_block: "
                "bread failed (dev %s, block %d, size %d)\n",
                kdevname (s->s_dev), offset / size, size);
	return 1;
    }
    
    rs = (struct reiserfs_super_block *)bh->b_data;
    if (!is_reiserfs_magic_string (rs) ||
	sb_blocksize(rs) != s->s_blocksize) {
	printk ("read_super_block: "
		"can't find a reiserfs filesystem on (dev %s, block %lu, size %d)\n",
		kdevname(s->s_dev), bh->b_blocknr, size);
	brelse (bh);
	printk ("read_super_block: can't find a reiserfs filesystem on dev %s.\n", kdevname(s->s_dev));
	return 1;
    }
    /* must check to be sure we haven't pulled an old format super out
    ** of the old format's log.  This is a kludge of a check, but it
    ** will work.  If block we've just read in is inside the
    ** journal for that super, it can't be valid.  
    */
    if (bh->b_blocknr >= sb_journal_block(rs) && 
	bh->b_blocknr < (sb_journal_block(rs) + JOURNAL_BLOCK_COUNT)) {
	brelse(bh) ;
	printk("super-459: read_super_block: "
	       "super found at block %lu is within its own log. "
	       "It must not be of this format type.\n", bh->b_blocknr) ;
	return 1 ;
    }
    SB_BUFFER_WITH_SB (s) = bh;
    SB_DISK_SUPER_BLOCK (s) = rs;
    s->s_op = &reiserfs_sops;

    /* new format is limited by the 32 bit wide i_blocks field, want to
    ** be one full block below that.
    */
    s->s_maxbytes = (512LL << 32) - s->s_blocksize ;
    return 0;
}



/* after journal replay, reread all bitmap and super blocks */
static int reread_meta_blocks(struct super_block *s) {
  int i ;
  ll_rw_block(READ, 1, &(SB_BUFFER_WITH_SB(s))) ;
  wait_on_buffer(SB_BUFFER_WITH_SB(s)) ;
  if (!buffer_uptodate(SB_BUFFER_WITH_SB(s))) {
    printk("reread_meta_blocks, error reading the super\n") ;
    return 1 ;
  }

  for (i = 0; i < SB_BMAP_NR(s) ; i++) {
    ll_rw_block(READ, 1, &(SB_AP_BITMAP(s)[i])) ;
    wait_on_buffer(SB_AP_BITMAP(s)[i]) ;
    if (!buffer_uptodate(SB_AP_BITMAP(s)[i])) {
      printk("reread_meta_blocks, error reading bitmap block number %d at %ld\n", i, SB_AP_BITMAP(s)[i]->b_blocknr) ;
      return 1 ;
    }
  }
  return 0 ;

}


/////////////////////////////////////////////////////
// hash detection stuff


// if root directory is empty - we set default - Yura's - hash and
// warn about it
// FIXME: we look for only one name in a directory. If tea and yura
// bith have the same value - we ask user to send report to the
// mailing list
__u32 find_hash_out (struct super_block * s)