xfs
[Top] [All Lists]

Atomicity of xfs_fsr -- also isolation?

To: linux-xfs@xxxxxxxxxxx
Subject: Atomicity of xfs_fsr -- also isolation?
From: Florian Weimer <fw@xxxxxxxxxxxxx>
Date: Wed, 16 Feb 2005 11:04:41 +0100
Sender: linux-xfs-bounce@xxxxxxxxxxx
The xfs_fsr manpage contains the following notes:

| xfs_fsr improves the layout of extents for each file by copying the
| entire file to a temporary location and then interchanging the data
| extents of the target and temporary files in an atomic manner.  This
| method requires that enough free disk space be available to copy any
| given file and that the space be less fragmented then the original
| file.  It also requires the owner of the file to have enough
| remaining filespace quota to do the copy on systems running quotas.
| xfs_fsr generates a warning message if space is not suffi- cient to
| improve the target file.

Is it safe to run xfs_fsr on a file which is regularly updated?  It
seems that if a copy is made and later linked as the original, updates
to the file might be lost.  Is this really the case?


<Prev in Thread] Current Thread [Next in Thread>