D_SPLICE_ALIAS(9) The Linux VFS D_SPLICE_ALIAS(9)
NAME d_splice_alias - splice a disconnected dentry into the tree if one exists
SYNOPSIS struct dentry * d_splice_alias(struct inode * inode, struct dentry * dentry);
ARGUMENTS inode the inode which may have a disconnected dentry
dentry a negative dentry which we want to point to the inode.
DESCRIPTION If inode is a directory and has a ´disconnected´ dentry (i.e. IS_ROOT and DCACHE_DISCONNECTED), then d_move that in place of the given dentry and return it, else simply d_add the inode to the dentry and return NULL.
This is needed in the lookup routine of any filesystem that is exportable (via knfsd) so that we can build dcache paths to directories effectively.
If a dentry was found and moved, then it is returned. Otherwise NULL is returned. This matches the expected return value of ->lookup.
COPYRIGHT Kernel Hackers Manual 2.6. April 2016 D_SPLICE_ALIAS(9)