xfs_iops.c

来自「优龙2410linux2.6.8内核源代码」· C语言 代码 · 共 712 行 · 第 1/2 页

	vnode_t		*tvp;	/* target directory */
	int		error;

	fvp = LINVFS_GET_VP(odir);
	tvp = LINVFS_GET_VP(ndir);

	VOP_RENAME(fvp, odentry, tvp, ndentry, NULL, error);
	if (error)
		return -error;

	if (new_inode)
		validate_fields(new_inode);

	validate_fields(odir);
	if (ndir != odir)
		validate_fields(ndir);
	return 0;
}

STATIC int
linvfs_readlink(
	struct dentry	*dentry,
	char		*buf,
	int		size)
{
	vnode_t		*vp = LINVFS_GET_VP(dentry->d_inode);
	uio_t		uio;
	iovec_t		iov;
	int		error;

	iov.iov_base = buf;
	iov.iov_len = size;

	uio.uio_iov = &iov;
	uio.uio_offset = 0;
	uio.uio_segflg = UIO_USERSPACE;
	uio.uio_resid = size;
	uio.uio_iovcnt = 1;

	VOP_READLINK(vp, &uio, 0, NULL, error);
	if (error)
		return -error;

	return (size - uio.uio_resid);
}

/*
 * careful here - this function can get called recursively, so
 * we need to be very careful about how much stack we use.
 * uio is kmalloced for this reason...
 */
STATIC int
linvfs_follow_link(
	struct dentry		*dentry,
	struct nameidata	*nd)
{
	vnode_t			*vp;
	uio_t			*uio;
	iovec_t			iov;
	int			error;
	char			*link;

	ASSERT(dentry);
	ASSERT(nd);

	link = (char *)kmalloc(MAXNAMELEN+1, GFP_KERNEL);
	if (!link) {
		nd_set_link(nd, ERR_PTR(-ENOMEM));
		return 0;
	}

	uio = (uio_t *)kmalloc(sizeof(uio_t), GFP_KERNEL);
	if (!uio) {
		kfree(link);
		nd_set_link(nd, ERR_PTR(-ENOMEM));
		return 0;
	}

	vp = LINVFS_GET_VP(dentry->d_inode);

	iov.iov_base = link;
	iov.iov_len = MAXNAMELEN;

	uio->uio_iov = &iov;
	uio->uio_offset = 0;
	uio->uio_segflg = UIO_SYSSPACE;
	uio->uio_resid = MAXNAMELEN;
	uio->uio_iovcnt = 1;

	VOP_READLINK(vp, uio, 0, NULL, error);
	if (error) {
		kfree(link);
		link = ERR_PTR(-error);
	} else {
		link[MAXNAMELEN - uio->uio_resid] = '\0';
	}
	kfree(uio);

	nd_set_link(nd, link);
	return 0;
}

static void linvfs_put_link(struct dentry *dentry, struct nameidata *nd)
{
	char *s = nd_get_link(nd);
	if (!IS_ERR(s))
		kfree(s);
}

#ifdef CONFIG_XFS_POSIX_ACL
STATIC int
linvfs_permission(
	struct inode	*inode,
	int		mode,
	struct nameidata *nd)
{
	vnode_t		*vp = LINVFS_GET_VP(inode);
	int		error;

	mode <<= 6;		/* convert from linux to vnode access bits */
	VOP_ACCESS(vp, mode, NULL, error);
	return -error;
}
#else
#define linvfs_permission NULL
#endif

STATIC int
linvfs_getattr(
	struct vfsmount	*mnt,
	struct dentry	*dentry,
	struct kstat	*stat)
{
	struct inode	*inode = dentry->d_inode;
	vnode_t		*vp = LINVFS_GET_VP(inode);
	int		error = 0;

	if (unlikely(vp->v_flag & VMODIFIED))
		error = vn_revalidate(vp);
	if (!error)
		generic_fillattr(inode, stat);
	return 0;
}

STATIC int
linvfs_setattr(
	struct dentry	*dentry,
	struct iattr	*attr)
{
	struct inode	*inode = dentry->d_inode;
	unsigned int	ia_valid = attr->ia_valid;
	vnode_t		*vp = LINVFS_GET_VP(inode);
	vattr_t		vattr;
	int		flags = 0;
	int		error;

	memset(&vattr, 0, sizeof(vattr_t));
	if (ia_valid & ATTR_UID) {
		vattr.va_mask |= XFS_AT_UID;
		vattr.va_uid = attr->ia_uid;
	}
	if (ia_valid & ATTR_GID) {
		vattr.va_mask |= XFS_AT_GID;
		vattr.va_gid = attr->ia_gid;
	}
	if (ia_valid & ATTR_SIZE) {
		vattr.va_mask |= XFS_AT_SIZE;
		vattr.va_size = attr->ia_size;
	}
	if (ia_valid & ATTR_ATIME) {
		vattr.va_mask |= XFS_AT_ATIME;
		vattr.va_atime = attr->ia_atime;
	}
	if (ia_valid & ATTR_MTIME) {
		vattr.va_mask |= XFS_AT_MTIME;
		vattr.va_mtime = attr->ia_mtime;
	}
	if (ia_valid & ATTR_CTIME) {
		vattr.va_mask |= XFS_AT_CTIME;
		vattr.va_ctime = attr->ia_ctime;
	}
	if (ia_valid & ATTR_MODE) {
		vattr.va_mask |= XFS_AT_MODE;
		vattr.va_mode = attr->ia_mode;
		if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
			inode->i_mode &= ~S_ISGID;
	}

	if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET))
		flags |= ATTR_UTIME;
#ifdef ATTR_NO_BLOCK
	if ((ia_valid & ATTR_NO_BLOCK))
		flags |= ATTR_NONBLOCK;
#endif

	VOP_SETATTR(vp, &vattr, flags, NULL, error);
	if (error)
		return -error;
	vn_revalidate(vp);
	return error;
}

STATIC void
linvfs_truncate(
	struct inode	*inode)
{
	block_truncate_page(inode->i_mapping, inode->i_size, linvfs_get_block);
}

STATIC int
linvfs_setxattr(
	struct dentry	*dentry,
	const char	*name,
	const void	*data,
	size_t		size,
	int		flags)
{
	vnode_t		*vp = LINVFS_GET_VP(dentry->d_inode);
	char		*attr = (char *)name;
	attrnames_t	*namesp;
	int		xflags = 0;
	int		error;

	namesp = attr_lookup_namespace(attr, attr_namespaces, ATTR_NAMECOUNT);
	if (!namesp)
		return -EOPNOTSUPP;
	attr += namesp->attr_namelen;
	error = namesp->attr_capable(vp, NULL);
	if (error)
		return error;

	/* Convert Linux syscall to XFS internal ATTR flags */
	if (flags & XATTR_CREATE)
		xflags |= ATTR_CREATE;
	if (flags & XATTR_REPLACE)
		xflags |= ATTR_REPLACE;
	xflags |= namesp->attr_flag;
	return namesp->attr_set(vp, attr, (void *)data, size, xflags);
}

STATIC ssize_t
linvfs_getxattr(
	struct dentry	*dentry,
	const char	*name,
	void		*data,
	size_t		size)
{
	vnode_t		*vp = LINVFS_GET_VP(dentry->d_inode);
	char		*attr = (char *)name;
	attrnames_t	*namesp;
	int		xflags = 0;
	ssize_t		error;

	namesp = attr_lookup_namespace(attr, attr_namespaces, ATTR_NAMECOUNT);
	if (!namesp)
		return -EOPNOTSUPP;
	attr += namesp->attr_namelen;
	error = namesp->attr_capable(vp, NULL);
	if (error)
		return error;

	/* Convert Linux syscall to XFS internal ATTR flags */
	if (!size) {
		xflags |= ATTR_KERNOVAL;
		data = NULL;
	}
	xflags |= namesp->attr_flag;
	return namesp->attr_get(vp, attr, (void *)data, size, xflags);
}

STATIC ssize_t
linvfs_listxattr(
	struct dentry		*dentry,
	char			*data,
	size_t			size)
{
	vnode_t			*vp = LINVFS_GET_VP(dentry->d_inode);
	int			error, xflags = ATTR_KERNAMELS;
	ssize_t			result;

	if (!size)
		xflags |= ATTR_KERNOVAL;
	xflags |= capable(CAP_SYS_ADMIN) ? ATTR_KERNFULLS : ATTR_KERNORMALS;

	error = attr_generic_list(vp, data, size, xflags, &result);
	if (error < 0)
		return error;
	return result;
}

STATIC int
linvfs_removexattr(
	struct dentry	*dentry,
	const char	*name)
{
	vnode_t		*vp = LINVFS_GET_VP(dentry->d_inode);
	char		*attr = (char *)name;
	attrnames_t	*namesp;
	int		xflags = 0;
	int		error;

	namesp = attr_lookup_namespace(attr, attr_namespaces, ATTR_NAMECOUNT);
	if (!namesp)
		return -EOPNOTSUPP;
	attr += namesp->attr_namelen;
	error = namesp->attr_capable(vp, NULL);
	if (error)
		return error;
	xflags |= namesp->attr_flag;
	return namesp->attr_remove(vp, attr, xflags);
}


struct inode_operations linvfs_file_inode_operations = {
	.permission		= linvfs_permission,
	.truncate		= linvfs_truncate,
	.getattr		= linvfs_getattr,
	.setattr		= linvfs_setattr,
	.setxattr		= linvfs_setxattr,
	.getxattr		= linvfs_getxattr,
	.listxattr		= linvfs_listxattr,
	.removexattr		= linvfs_removexattr,
};

struct inode_operations linvfs_dir_inode_operations = {
	.create			= linvfs_create,
	.lookup			= linvfs_lookup,
	.link			= linvfs_link,
	.unlink			= linvfs_unlink,
	.symlink		= linvfs_symlink,
	.mkdir			= linvfs_mkdir,
	.rmdir			= linvfs_rmdir,
	.mknod			= linvfs_mknod,
	.rename			= linvfs_rename,
	.permission		= linvfs_permission,
	.getattr		= linvfs_getattr,
	.setattr		= linvfs_setattr,
	.setxattr		= linvfs_setxattr,
	.getxattr		= linvfs_getxattr,
	.listxattr		= linvfs_listxattr,
	.removexattr		= linvfs_removexattr,
};

struct inode_operations linvfs_symlink_inode_operations = {
	.readlink		= linvfs_readlink,
	.follow_link		= linvfs_follow_link,
	.put_link		= linvfs_put_link,
	.permission		= linvfs_permission,
	.getattr		= linvfs_getattr,
	.setattr		= linvfs_setattr,
	.setxattr		= linvfs_setxattr,
	.getxattr		= linvfs_getxattr,
	.listxattr		= linvfs_listxattr,
	.removexattr		= linvfs_removexattr,
};