super.c

linux 内核源代码

			s->s_root = NULL;
			goto error;
		}

		if ((errval = reiserfs_xattr_init(s, s->s_flags))) {
			dput(s->s_root);
			s->s_root = NULL;
			goto error;
		}

		/* look for files which were to be removed in previous session */
		finish_unfinished(s);
	} else {
		if (old_format_only(s) && !silent) {
			reiserfs_info(s, "using 3.5.x disk format\n");
		}

		if ((errval = reiserfs_xattr_init(s, s->s_flags))) {
			dput(s->s_root);
			s->s_root = NULL;
			goto error;
		}
	}
	// mark hash in super block: it could be unset. overwrite should be ok
	set_sb_hash_function_code(rs, function2code(sbi->s_hash_function));

	handle_attrs(s);

	reiserfs_proc_info_init(s);

	init_waitqueue_head(&(sbi->s_wait));
	spin_lock_init(&sbi->bitmap_lock);

	return (0);

      error:
	if (jinit_done) {	/* kill the commit thread, free journal ram */
		journal_release_error(NULL, s);
	}

	reiserfs_free_bitmap_cache(s);
	if (SB_BUFFER_WITH_SB(s))
		brelse(SB_BUFFER_WITH_SB(s));
#ifdef CONFIG_QUOTA
	{
		int j;
		for (j = 0; j < MAXQUOTAS; j++) {
			kfree(sbi->s_qf_names[j]);
			sbi->s_qf_names[j] = NULL;
		}
	}
#endif
	kfree(sbi);

	s->s_fs_info = NULL;
	return errval;
}

static int reiserfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct reiserfs_super_block *rs = SB_DISK_SUPER_BLOCK(dentry->d_sb);

	buf->f_namelen = (REISERFS_MAX_NAME(s->s_blocksize));
	buf->f_bfree = sb_free_blocks(rs);
	buf->f_bavail = buf->f_bfree;
	buf->f_blocks = sb_block_count(rs) - sb_bmap_nr(rs) - 1;
	buf->f_bsize = dentry->d_sb->s_blocksize;
	/* changed to accommodate gcc folks. */
	buf->f_type = REISERFS_SUPER_MAGIC;
	return 0;
}

#ifdef CONFIG_QUOTA
static int reiserfs_dquot_initialize(struct inode *inode, int type)
{
	struct reiserfs_transaction_handle th;
	int ret, err;

	/* We may create quota structure so we need to reserve enough blocks */
	reiserfs_write_lock(inode->i_sb);
	ret =
	    journal_begin(&th, inode->i_sb,
			  2 * REISERFS_QUOTA_INIT_BLOCKS(inode->i_sb));
	if (ret)
		goto out;
	ret = dquot_initialize(inode, type);
	err =
	    journal_end(&th, inode->i_sb,
			2 * REISERFS_QUOTA_INIT_BLOCKS(inode->i_sb));
	if (!ret && err)
		ret = err;
      out:
	reiserfs_write_unlock(inode->i_sb);
	return ret;
}

static int reiserfs_dquot_drop(struct inode *inode)
{
	struct reiserfs_transaction_handle th;
	int ret, err;

	/* We may delete quota structure so we need to reserve enough blocks */
	reiserfs_write_lock(inode->i_sb);
	ret =
	    journal_begin(&th, inode->i_sb,
			  2 * REISERFS_QUOTA_DEL_BLOCKS(inode->i_sb));
	if (ret)
		goto out;
	ret = dquot_drop(inode);
	err =
	    journal_end(&th, inode->i_sb,
			2 * REISERFS_QUOTA_DEL_BLOCKS(inode->i_sb));
	if (!ret && err)
		ret = err;
      out:
	reiserfs_write_unlock(inode->i_sb);
	return ret;
}

static int reiserfs_write_dquot(struct dquot *dquot)
{
	struct reiserfs_transaction_handle th;
	int ret, err;

	reiserfs_write_lock(dquot->dq_sb);
	ret =
	    journal_begin(&th, dquot->dq_sb,
			  REISERFS_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
	if (ret)
		goto out;
	ret = dquot_commit(dquot);
	err =
	    journal_end(&th, dquot->dq_sb,
			REISERFS_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
	if (!ret && err)
		ret = err;
      out:
	reiserfs_write_unlock(dquot->dq_sb);
	return ret;
}

static int reiserfs_acquire_dquot(struct dquot *dquot)
{
	struct reiserfs_transaction_handle th;
	int ret, err;

	reiserfs_write_lock(dquot->dq_sb);
	ret =
	    journal_begin(&th, dquot->dq_sb,
			  REISERFS_QUOTA_INIT_BLOCKS(dquot->dq_sb));
	if (ret)
		goto out;
	ret = dquot_acquire(dquot);
	err =
	    journal_end(&th, dquot->dq_sb,
			REISERFS_QUOTA_INIT_BLOCKS(dquot->dq_sb));
	if (!ret && err)
		ret = err;
      out:
	reiserfs_write_unlock(dquot->dq_sb);
	return ret;
}

static int reiserfs_release_dquot(struct dquot *dquot)
{
	struct reiserfs_transaction_handle th;
	int ret, err;

	reiserfs_write_lock(dquot->dq_sb);
	ret =
	    journal_begin(&th, dquot->dq_sb,
			  REISERFS_QUOTA_DEL_BLOCKS(dquot->dq_sb));
	if (ret) {
		/* Release dquot anyway to avoid endless cycle in dqput() */
		dquot_release(dquot);
		goto out;
	}
	ret = dquot_release(dquot);
	err =
	    journal_end(&th, dquot->dq_sb,
			REISERFS_QUOTA_DEL_BLOCKS(dquot->dq_sb));
	if (!ret && err)
		ret = err;
      out:
	reiserfs_write_unlock(dquot->dq_sb);
	return ret;
}

static int reiserfs_mark_dquot_dirty(struct dquot *dquot)
{
	/* Are we journalling quotas? */
	if (REISERFS_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
	    REISERFS_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
		dquot_mark_dquot_dirty(dquot);
		return reiserfs_write_dquot(dquot);
	} else
		return dquot_mark_dquot_dirty(dquot);
}

static int reiserfs_write_info(struct super_block *sb, int type)
{
	struct reiserfs_transaction_handle th;
	int ret, err;

	/* Data block + inode block */
	reiserfs_write_lock(sb);
	ret = journal_begin(&th, sb, 2);
	if (ret)
		goto out;
	ret = dquot_commit_info(sb, type);
	err = journal_end(&th, sb, 2);
	if (!ret && err)
		ret = err;
      out:
	reiserfs_write_unlock(sb);
	return ret;
}

/*
 * Turn on quotas during mount time - we need to find the quota file and such...
 */
static int reiserfs_quota_on_mount(struct super_block *sb, int type)
{
	return vfs_quota_on_mount(sb, REISERFS_SB(sb)->s_qf_names[type],
				  REISERFS_SB(sb)->s_jquota_fmt, type);
}

/*
 * Standard function to be called on quota_on
 */
static int reiserfs_quota_on(struct super_block *sb, int type, int format_id,
			     char *path)
{
	int err;
	struct nameidata nd;

	if (!(REISERFS_SB(sb)->s_mount_opt & (1 << REISERFS_QUOTA)))
		return -EINVAL;
	err = path_lookup(path, LOOKUP_FOLLOW, &nd);
	if (err)
		return err;
	/* Quotafile not on the same filesystem? */
	if (nd.mnt->mnt_sb != sb) {
		path_release(&nd);
		return -EXDEV;
	}
	/* We must not pack tails for quota files on reiserfs for quota IO to work */
	if (!REISERFS_I(nd.dentry->d_inode)->i_flags & i_nopack_mask) {
		reiserfs_warning(sb,
				 "reiserfs: Quota file must have tail packing disabled.");
		path_release(&nd);
		return -EINVAL;
	}
	/* Not journalling quota? No more tests needed... */
	if (!REISERFS_SB(sb)->s_qf_names[USRQUOTA] &&
	    !REISERFS_SB(sb)->s_qf_names[GRPQUOTA]) {
		path_release(&nd);
		return vfs_quota_on(sb, type, format_id, path);
	}
	/* Quotafile not of fs root? */
	if (nd.dentry->d_parent->d_inode != sb->s_root->d_inode)
		reiserfs_warning(sb,
				 "reiserfs: Quota file not on filesystem root. "
				 "Journalled quota will not work.");
	path_release(&nd);
	return vfs_quota_on(sb, type, format_id, path);
}

/* Read data from quotafile - avoid pagecache and such because we cannot afford
 * acquiring the locks... As quota files are never truncated and quota code
 * itself serializes the operations (and noone else should touch the files)
 * we don't have to be afraid of races */
static ssize_t reiserfs_quota_read(struct super_block *sb, int type, char *data,
				   size_t len, loff_t off)
{
	struct inode *inode = sb_dqopt(sb)->files[type];
	unsigned long blk = off >> sb->s_blocksize_bits;
	int err = 0, offset = off & (sb->s_blocksize - 1), tocopy;
	size_t toread;
	struct buffer_head tmp_bh, *bh;
	loff_t i_size = i_size_read(inode);

	if (off > i_size)
		return 0;
	if (off + len > i_size)
		len = i_size - off;
	toread = len;
	while (toread > 0) {
		tocopy =
		    sb->s_blocksize - offset <
		    toread ? sb->s_blocksize - offset : toread;
		tmp_bh.b_state = 0;
		/* Quota files are without tails so we can safely use this function */
		reiserfs_write_lock(sb);
		err = reiserfs_get_block(inode, blk, &tmp_bh, 0);
		reiserfs_write_unlock(sb);
		if (err)
			return err;
		if (!buffer_mapped(&tmp_bh))	/* A hole? */
			memset(data, 0, tocopy);
		else {
			bh = sb_bread(sb, tmp_bh.b_blocknr);
			if (!bh)
				return -EIO;
			memcpy(data, bh->b_data + offset, tocopy);
			brelse(bh);
		}
		offset = 0;
		toread -= tocopy;
		data += tocopy;
		blk++;
	}
	return len;
}

/* Write to quotafile (we know the transaction is already started and has
 * enough credits) */
static ssize_t reiserfs_quota_write(struct super_block *sb, int type,
				    const char *data, size_t len, loff_t off)
{
	struct inode *inode = sb_dqopt(sb)->files[type];
	unsigned long blk = off >> sb->s_blocksize_bits;
	int err = 0, offset = off & (sb->s_blocksize - 1), tocopy;
	int journal_quota = REISERFS_SB(sb)->s_qf_names[type] != NULL;
	size_t towrite = len;
	struct buffer_head tmp_bh, *bh;

	if (!current->journal_info) {
		printk(KERN_WARNING "reiserfs: Quota write (off=%Lu, len=%Lu)"
			" cancelled because transaction is not started.\n",
			(unsigned long long)off, (unsigned long long)len);
		return -EIO;
	}
	mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
	while (towrite > 0) {
		tocopy = sb->s_blocksize - offset < towrite ?
		    sb->s_blocksize - offset : towrite;
		tmp_bh.b_state = 0;
		err = reiserfs_get_block(inode, blk, &tmp_bh, GET_BLOCK_CREATE);
		if (err)
			goto out;
		if (offset || tocopy != sb->s_blocksize)
			bh = sb_bread(sb, tmp_bh.b_blocknr);
		else
			bh = sb_getblk(sb, tmp_bh.b_blocknr);
		if (!bh) {
			err = -EIO;
			goto out;
		}
		lock_buffer(bh);
		memcpy(bh->b_data + offset, data, tocopy);
		flush_dcache_page(bh->b_page);
		set_buffer_uptodate(bh);
		unlock_buffer(bh);
		reiserfs_prepare_for_journal(sb, bh, 1);
		journal_mark_dirty(current->journal_info, sb, bh);
		if (!journal_quota)
			reiserfs_add_ordered_list(inode, bh);
		brelse(bh);
		offset = 0;
		towrite -= tocopy;
		data += tocopy;
		blk++;
	}
out:
	if (len == towrite)
		return err;
	if (inode->i_size < off + len - towrite)
		i_size_write(inode, off + len - towrite);
	inode->i_version++;
	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	mark_inode_dirty(inode);
	mutex_unlock(&inode->i_mutex);
	return len - towrite;
}

#endif

static int get_super_block(struct file_system_type *fs_type,
			   int flags, const char *dev_name,
			   void *data, struct vfsmount *mnt)
{
	return get_sb_bdev(fs_type, flags, dev_name, data, reiserfs_fill_super,
			   mnt);
}

static int __init init_reiserfs_fs(void)
{
	int ret;

	if ((ret = init_inodecache())) {
		return ret;
	}

	if ((ret = reiserfs_xattr_register_handlers()))
		goto failed_reiserfs_xattr_register_handlers;

	reiserfs_proc_info_global_init();
	reiserfs_proc_register_global("version",
				      reiserfs_global_version_in_proc);

	ret = register_filesystem(&reiserfs_fs_type);

	if (ret == 0) {
		return 0;
	}

	reiserfs_xattr_unregister_handlers();

      failed_reiserfs_xattr_register_handlers:
	reiserfs_proc_unregister_global("version");
	reiserfs_proc_info_global_done();
	destroy_inodecache();

	return ret;
}

static void __exit exit_reiserfs_fs(void)
{
	reiserfs_xattr_unregister_handlers();
	reiserfs_proc_unregister_global("version");
	reiserfs_proc_info_global_done();
	unregister_filesystem(&reiserfs_fs_type);
	destroy_inodecache();
}

struct file_system_type reiserfs_fs_type = {
	.owner = THIS_MODULE,
	.name = "reiserfs",
	.get_sb = get_super_block,
	.kill_sb = reiserfs_kill_sb,
	.fs_flags = FS_REQUIRES_DEV,
};

MODULE_DESCRIPTION("ReiserFS journaled filesystem");
MODULE_AUTHOR("Hans Reiser <[e-mail]>");
MODULE_LICENSE("GPL");

module_init(init_reiserfs_fs);
module_exit(exit_reiserfs_fs);