Re: [PATCH 5/6] xfs: move non-inline symlinks to the pagecache

[Al Viro <viro@xxxxxxxxxxxxxxxxxx>]

On Sat, Apr 25, 2015 at 04:16:12PM +0200, Christoph Hellwig wrote:
> Al, what do you think about adding a new
> 
> i_link member to the union of i_pipe, i_bdev and i_cdev.  That we
> we can cache a link acquired by any way for direct use in the VFS.
> 
> This has a few use cases:  inline links can be set up directly
> when reading the inode, and we never need to call into ->follow_link.
> 
> Formats like the XFS v5 symlinks can be read in once by whatever
> way we want, and following accesses can be done RCU safe and
> without calling into the filesystem.
> 
> Note that caching the symlink in a kmalloc'ed buffer might be
> more efficient than the pagecache for most cases anyway.

Hmm...  When would you free the sucker?