User: Password:
|
|
Subscribe / Log in / New account

a reflink would be a new type of inode

a reflink would be a new type of inode

Posted May 6, 2009 16:07 UTC (Wed) by masoncl (subscriber, #47138)
In reply to: a reflink would be a new type of inode by corbet
Parent article: The two sides of reflink()

It is more accurate to say (for both btrfs and ocfs2) that the result of the reflink is an entirely new file. It has a known starting point (the contents and permissions of the original).

The two files can be changed independently without affecting each other. One could be deleted, truncated, expanded, chmoded, have new acls set, etc.

The actual block sharing is just an implementation detail...it could be implemented as a lazy copy for example.


(Log in to post comments)

a reflink would be a new type of inode

Posted May 6, 2009 19:40 UTC (Wed) by adj (subscriber, #7401) [Link]

That leaves the "link" part of the interface name sounding terribly misleading.

Surely there's a better name for a make-a-copy-of-this-inode-and-all-its-data-and-maybe-do-some-cool-COW-magic system call. It's too bad that the "dup" family of system call names is already used for something with a completely separate meaning.

madcow()?

Posted May 6, 2009 21:47 UTC (Wed) by AnswerGuy (subscriber, #1256) [Link]

magically-allocated-data-copy-on-write ... :)


Copyright © 2017, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds