Re: [RFC] Support for stackable file systems on top of nfs

[Nikita Danilov <nikita@clusterfs.com>]

Bryan Henderson writes:

[...]

 > 
 > I've always been irritated by the fact that filesystem drivers see struct 
 > file at all.  struct file ought to live in a higher 
 > filesystem-type-independent layer, with the filesystem driver seeing just 
 > inodes.  

This is how *BSD VFS works, and it is a pain in the neck. For example,
implementing file-system-type specific read-ahead algorithm requires
jumping through all kinds of loops, because such algorithm works with
data (read-ahead window parameters) that naturally tend to be stored in
the file descriptor, and the latter is invisible to the file-system
code.

 >          Why are credentials cached in the struct file?  Is that a natural 
 > place for it or just what's available?
 > 
 > --
 > Bryan Henderson                     IBM Almaden Research Center
 > San Jose CA                         Filesystems

Nikita.