Re: directory order of files

[Alexander Viro]

On Fri, 29 Jun 2001, Alan Cox wrote:

> > With Linux ext2, and some other systems, when you create files in a
> > new directory, the file system remembers their order:
> 
> No - it merely seems too. 
> 
> > $ touch one two three four
> > $ ls -U
> > one  two  three  four
> 
> Then try 'rm three; touch five'

Moreover, it isn't true even for the case when we create a list of files
in empty directory. Example: assuming that /tmp has 1Kb blocks,

mkdir /tmp/A
cd A
touch `perl -e 'print "a"x255'`
touch `perl -e 'print "b"x255'`
touch `perl -e 'print "c"x255'`
touch `perl -e 'print "d"x255'`
touch A
ls -U

will give you (lots of a) (lots of b) (lots of c) A (lots of d).

With 4Kb blocks you'll need 16 long names instead of 4 - the effect
will be the same.

The reason is quite simple - at some point you get no space for long
name and it goes into the next directory block, but there's still enough
for a short name, so it gets created in the first block.

IOW, there's no warranties at all.