suse man page for d_obtain_alias

D_OBTAIN_ALIAS(9)						   The Linux VFS						 D_OBTAIN_ALIAS(9)

NAME
       d_obtain_alias - find or allocate a dentry for a given inode

SYNOPSIS
       struct dentry * d_obtain_alias(struct inode * inode);

ARGUMENTS
       inode
	   inode to allocate the dentry for

DESCRIPTION
       Obtain a dentry for an inode resulting from NFS filehandle conversion or similar open by handle operations. The returned dentry may be
       anonymous, or may have a full name (if the inode was already in the cache).

       When called on a directory inode, we must ensure that the inode only ever has one dentry. If a dentry is found, that is returned instead of
       allocating a new one.

       On successful return, the reference to the inode has been transferred to the dentry. In case of an error the reference on the inode is
       released. To make it easier to use in export operations a NULL or IS_ERR inode may be passed in and will be the error will be propagate to
       the return value, with a NULL inode replaced by ERR_PTR(-ESTALE).

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010							 D_OBTAIN_ALIAS(9)