David Woodhouse wrote:

I keep receiving requests from users to allow space saving by making holes 
in files. For people using JFFS2, a compressed file system designed for use 
on fairly small solid state storage devices, this is a fairly reasonable 
request, and it's also fairly simple to implement. It's only the interface 
I'm concerned about.

I've been resisting these requests because I really don't want to do it 
with an ioctl on the file. Only if we can have a generic sys_perforate() 
would I really want to do it.

Apparently it's hard to implement on block-based file systems. I don't 
really care about that though -- just falling back to writing zeroes to the 
offending range (or indeed returning -EINVAL) would be perfectly sufficient 
until/unless it gets implemented for other file systems. All I want is an 
interface that doesn't make me feel dirty :)

Comments? 

Could you elaborate on the difference between what you want to do and 
sparse files?

Eli
--------------------. "If it ain't broke now,
Eli Carter           \                  it will be soon." -- crypto-gram
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