namei.c

linux 内核源代码

	if (r == 1)
		goto bail2;
	if (r == -1) {
		err = -EEXIST;
		goto bail2;
	}
	fnode->len = len;
	memcpy(fnode->name, name, len > 15 ? 15 : len);
	fnode->up = dir->i_ino;
	hpfs_set_ea(result, fnode, "SYMLINK", (char *)symlink, strlen(symlink));
	mark_buffer_dirty(bh);
	brelse(bh);

	insert_inode_hash(result);

	hpfs_write_inode_nolock(result);
	d_instantiate(dentry, result);
	mutex_unlock(&hpfs_i(dir)->i_mutex);
	unlock_kernel();
	return 0;
bail2:
	mutex_unlock(&hpfs_i(dir)->i_mutex);
	iput(result);
bail1:
	brelse(bh);
	hpfs_free_sectors(dir->i_sb, fno, 1);
bail:
	unlock_kernel();
	return err;
}

static int hpfs_unlink(struct inode *dir, struct dentry *dentry)
{
	const char *name = dentry->d_name.name;
	unsigned len = dentry->d_name.len;
	struct quad_buffer_head qbh;
	struct hpfs_dirent *de;
	struct inode *inode = dentry->d_inode;
	dnode_secno dno;
	fnode_secno fno;
	int r;
	int rep = 0;
	int err;

	lock_kernel();
	hpfs_adjust_length((char *)name, &len);
again:
	mutex_lock(&hpfs_i(inode)->i_parent_mutex);
	mutex_lock(&hpfs_i(dir)->i_mutex);
	err = -ENOENT;
	de = map_dirent(dir, hpfs_i(dir)->i_dno, (char *)name, len, &dno, &qbh);
	if (!de)
		goto out;

	err = -EPERM;
	if (de->first)
		goto out1;

	err = -EISDIR;
	if (de->directory)
		goto out1;

	fno = de->fnode;
	r = hpfs_remove_dirent(dir, dno, de, &qbh, 1);
	switch (r) {
	case 1:
		hpfs_error(dir->i_sb, "there was error when removing dirent");
		err = -EFSERROR;
		break;
	case 2:		/* no space for deleting, try to truncate file */

		err = -ENOSPC;
		if (rep++)
			break;

		mutex_unlock(&hpfs_i(dir)->i_mutex);
		mutex_unlock(&hpfs_i(inode)->i_parent_mutex);
		d_drop(dentry);
		spin_lock(&dentry->d_lock);
		if (atomic_read(&dentry->d_count) > 1 ||
		    permission(inode, MAY_WRITE, NULL) ||
		    !S_ISREG(inode->i_mode) ||
		    get_write_access(inode)) {
			spin_unlock(&dentry->d_lock);
			d_rehash(dentry);
		} else {
			struct iattr newattrs;
			spin_unlock(&dentry->d_lock);
			/*printk("HPFS: truncating file before delete.\n");*/
			newattrs.ia_size = 0;
			newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
			err = notify_change(dentry, &newattrs);
			put_write_access(inode);
			if (!err)
				goto again;
		}
		unlock_kernel();
		return -ENOSPC;
	default:
		drop_nlink(inode);
		err = 0;
	}
	goto out;

out1:
	hpfs_brelse4(&qbh);
out:
	mutex_unlock(&hpfs_i(dir)->i_mutex);
	mutex_unlock(&hpfs_i(inode)->i_parent_mutex);
	unlock_kernel();
	return err;
}

static int hpfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	const char *name = dentry->d_name.name;
	unsigned len = dentry->d_name.len;
	struct quad_buffer_head qbh;
	struct hpfs_dirent *de;
	struct inode *inode = dentry->d_inode;
	dnode_secno dno;
	fnode_secno fno;
	int n_items = 0;
	int err;
	int r;

	hpfs_adjust_length((char *)name, &len);
	lock_kernel();
	mutex_lock(&hpfs_i(inode)->i_parent_mutex);
	mutex_lock(&hpfs_i(dir)->i_mutex);
	err = -ENOENT;
	de = map_dirent(dir, hpfs_i(dir)->i_dno, (char *)name, len, &dno, &qbh);
	if (!de)
		goto out;

	err = -EPERM;
	if (de->first)
		goto out1;

	err = -ENOTDIR;
	if (!de->directory)
		goto out1;

	hpfs_count_dnodes(dir->i_sb, hpfs_i(inode)->i_dno, NULL, NULL, &n_items);
	err = -ENOTEMPTY;
	if (n_items)
		goto out1;

	fno = de->fnode;
	r = hpfs_remove_dirent(dir, dno, de, &qbh, 1);
	switch (r) {
	case 1:
		hpfs_error(dir->i_sb, "there was error when removing dirent");
		err = -EFSERROR;
		break;
	case 2:
		err = -ENOSPC;
		break;
	default:
		drop_nlink(dir);
		clear_nlink(inode);
		err = 0;
	}
	goto out;
out1:
	hpfs_brelse4(&qbh);
out:
	mutex_unlock(&hpfs_i(dir)->i_mutex);
	mutex_unlock(&hpfs_i(inode)->i_parent_mutex);
	unlock_kernel();
	return err;
}

static int hpfs_symlink_readpage(struct file *file, struct page *page)
{
	char *link = kmap(page);
	struct inode *i = page->mapping->host;
	struct fnode *fnode;
	struct buffer_head *bh;
	int err;

	err = -EIO;
	lock_kernel();
	if (!(fnode = hpfs_map_fnode(i->i_sb, i->i_ino, &bh)))
		goto fail;
	err = hpfs_read_ea(i->i_sb, fnode, "SYMLINK", link, PAGE_SIZE);
	brelse(bh);
	if (err)
		goto fail;
	unlock_kernel();
	SetPageUptodate(page);
	kunmap(page);
	unlock_page(page);
	return 0;

fail:
	unlock_kernel();
	SetPageError(page);
	kunmap(page);
	unlock_page(page);
	return err;
}

const struct address_space_operations hpfs_symlink_aops = {
	.readpage	= hpfs_symlink_readpage
};
	
static int hpfs_rename(struct inode *old_dir, struct dentry *old_dentry,
		struct inode *new_dir, struct dentry *new_dentry)
{
	char *old_name = (char *)old_dentry->d_name.name;
	int old_len = old_dentry->d_name.len;
	char *new_name = (char *)new_dentry->d_name.name;
	int new_len = new_dentry->d_name.len;
	struct inode *i = old_dentry->d_inode;
	struct inode *new_inode = new_dentry->d_inode;
	struct quad_buffer_head qbh, qbh1;
	struct hpfs_dirent *dep, *nde;
	struct hpfs_dirent de;
	dnode_secno dno;
	int r;
	struct buffer_head *bh;
	struct fnode *fnode;
	int err;
	if ((err = hpfs_chk_name((char *)new_name, &new_len))) return err;
	err = 0;
	hpfs_adjust_length((char *)old_name, &old_len);

	lock_kernel();
	/* order doesn't matter, due to VFS exclusion */
	mutex_lock(&hpfs_i(i)->i_parent_mutex);
	if (new_inode)
		mutex_lock(&hpfs_i(new_inode)->i_parent_mutex);
	mutex_lock(&hpfs_i(old_dir)->i_mutex);
	if (new_dir != old_dir)
		mutex_lock(&hpfs_i(new_dir)->i_mutex);
	
	/* Erm? Moving over the empty non-busy directory is perfectly legal */
	if (new_inode && S_ISDIR(new_inode->i_mode)) {
		err = -EINVAL;
		goto end1;
	}

	if (!(dep = map_dirent(old_dir, hpfs_i(old_dir)->i_dno, (char *)old_name, old_len, &dno, &qbh))) {
		hpfs_error(i->i_sb, "lookup succeeded but map dirent failed");
		err = -ENOENT;
		goto end1;
	}
	copy_de(&de, dep);
	de.hidden = new_name[0] == '.';

	if (new_inode) {
		int r;
		if ((r = hpfs_remove_dirent(old_dir, dno, dep, &qbh, 1)) != 2) {
			if ((nde = map_dirent(new_dir, hpfs_i(new_dir)->i_dno, (char *)new_name, new_len, NULL, &qbh1))) {
				clear_nlink(new_inode);
				copy_de(nde, &de);
				memcpy(nde->name, new_name, new_len);
				hpfs_mark_4buffers_dirty(&qbh1);
				hpfs_brelse4(&qbh1);
				goto end;
			}
			hpfs_error(new_dir->i_sb, "hpfs_rename: could not find dirent");
			err = -EFSERROR;
			goto end1;
		}
		err = r == 2 ? -ENOSPC : r == 1 ? -EFSERROR : 0;
		goto end1;
	}

	if (new_dir == old_dir) hpfs_brelse4(&qbh);

	hpfs_lock_creation(i->i_sb);
	if ((r = hpfs_add_dirent(new_dir, new_name, new_len, &de, 1))) {
		hpfs_unlock_creation(i->i_sb);
		if (r == -1) hpfs_error(new_dir->i_sb, "hpfs_rename: dirent already exists!");
		err = r == 1 ? -ENOSPC : -EFSERROR;
		if (new_dir != old_dir) hpfs_brelse4(&qbh);
		goto end1;
	}
	
	if (new_dir == old_dir)
		if (!(dep = map_dirent(old_dir, hpfs_i(old_dir)->i_dno, (char *)old_name, old_len, &dno, &qbh))) {
			hpfs_unlock_creation(i->i_sb);
			hpfs_error(i->i_sb, "lookup succeeded but map dirent failed at #2");
			err = -ENOENT;
			goto end1;
		}

	if ((r = hpfs_remove_dirent(old_dir, dno, dep, &qbh, 0))) {
		hpfs_unlock_creation(i->i_sb);
		hpfs_error(i->i_sb, "hpfs_rename: could not remove dirent");
		err = r == 2 ? -ENOSPC : -EFSERROR;
		goto end1;
	}
	hpfs_unlock_creation(i->i_sb);
	
	end:
	hpfs_i(i)->i_parent_dir = new_dir->i_ino;
	if (S_ISDIR(i->i_mode)) {
		inc_nlink(new_dir);
		drop_nlink(old_dir);
	}
	if ((fnode = hpfs_map_fnode(i->i_sb, i->i_ino, &bh))) {
		fnode->up = new_dir->i_ino;
		fnode->len = new_len;
		memcpy(fnode->name, new_name, new_len>15?15:new_len);
		if (new_len < 15) memset(&fnode->name[new_len], 0, 15 - new_len);
		mark_buffer_dirty(bh);
		brelse(bh);
	}
	hpfs_i(i)->i_conv = hpfs_sb(i->i_sb)->sb_conv;
	hpfs_decide_conv(i, (char *)new_name, new_len);
end1:
	if (old_dir != new_dir)
		mutex_unlock(&hpfs_i(new_dir)->i_mutex);
	mutex_unlock(&hpfs_i(old_dir)->i_mutex);
	mutex_unlock(&hpfs_i(i)->i_parent_mutex);
	if (new_inode)
		mutex_unlock(&hpfs_i(new_inode)->i_parent_mutex);
	unlock_kernel();
	return err;
}

const struct inode_operations hpfs_dir_iops =
{
	.create		= hpfs_create,
	.lookup		= hpfs_lookup,
	.unlink		= hpfs_unlink,
	.symlink	= hpfs_symlink,
	.mkdir		= hpfs_mkdir,
	.rmdir		= hpfs_rmdir,
	.mknod		= hpfs_mknod,
	.rename		= hpfs_rename,
	.setattr	= hpfs_notify_change,
};