tree 5450192a84593b98bcefbddd59dbb394397bee27
parent d2158f69a7d469c21c37f7028c18aa8c54707de3
author Richard Weinberger <richard@nod.at> 1412692282 +0200
committer Richard Weinberger <richard@nod.at> 1427406358 +0100

UBI: Fastmap: Fix race in ubi_eba_atomic_leb_change()

This function a) requests a new PEB, b) writes data to it,
c) returns the old PEB and d) registers the new PEB in the EBA table.

For the non-fastmap case this works perfectly fine and is powercut safe.
Is fastmap enabled this can lead to issues.
If a new fastmap is written between a) and c) the freshly requested PEB
is no longer in a pool and will not be scanned upon attaching.
If now a powercut happens between c) and d) the freshly requested PEB
will not be scanned and the old one got already scheduled for erase.
After attaching the EBA table will point to a erased PEB.

Fix this issue by swapping steps c) and d).

Signed-off-by: Richard Weinberger <richard@nod.at>