Read only forced on jffs2 by mtd layer?

[Josh Boyer]

On 3/10/06, Artem B. Bityutskiy <dedekind at yandex.ru> wrote:
> Josh Boyer wrote:
> > Also, does your JFFS2 filesystem have free space available?  If a
> > minimum amount of free eraseblocks are not present, JFFS2 will mark
> > itself as read-only no matter what you do.
> >
> Hmm, is this sane behaviour?

Sorta.  If there isn't enough physical space to write nodes out, then
you can't really have a writeable filesystem.  It'll actually just
return -ENOSPC for everything instead of -EROFS, but the effect is the
same.

Take a look at jffs2_calc_trigger_levels in build.c. 
c->resv_blocks_deletion is the number of blocks needed to delete
something.  c->resv_blocks_write is the number of blocks needed to
write something.

josh