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Re: JFFS2: powerfailtesting again




LANCE_N@xxxxxxx.COM said:
>  we arrived at roughly 2.5 sectors for JFFS1 empircally  - it's hard
> to tell from the documentation what it really needs to be  beyond 2,
> and agree it is not something easy to prove formally.

It's not bounded if you rename files to larger names. Actually a horrible
thought occurred to me on the way into the office this morning. 

The Linux flash drivers assert Vpp just before writing to the flash. 
Consider a situation where you have a low battery, and few milliseconds after 
you assert Vpp, the box dies. It reboots OK, right up to the time when it 
next asserts Vpp.

JFFS2 was asserting Vpp because it was writing to the flash. And it managed 
to write something (even one bit) before it died.

Watch it eat _all_ your reserved free space.

--
dwmw2



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