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Re: JFFS2 as root FS




ds@xxxxxxx.org said:
>  Can you (or someone) comment on whether or not JFFS2 satisfies the
> necessary criteria for a POSIX-compliant file system?  I could not
> (quickly) find a reference to what qualifies as a POSIX file system,
> otherwise I would have checked myself. 

Haven't looked at how much is required and how much is optional. We now 
support hard links, but we still don't do atime - at least, we don't update 
atime each time an inode is accessed, as we should.

Other than atime, I'm not aware of anything missing, but I haven't checked 
against a spec either.

ds@xxxxxxx.org said:
> > Note that once you realise you only need to keep a cache of
> > (dev,inode) tuples for inodes with i_nlink > 1, rather than every inode
> > you touch, and that you only need to look into that cache when you're 
> > writing out such an inode, it becomes a much more feasible task.

> That actually seems to be more complicated than checking every inode.
> That is, if you consider if(n_links>1) more complicated.

The code has two extra lines in it (including the close-brace), so it's 
slightly more complicated. However, the cache is far smaller so you don't 
need to bother with hashing it nicely, etc. The net effect is that it's 
simpler and faster.

--
dwmw2



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