• Richard Weinberger's avatar
    UBI: Fastmap: Fix race in ubi_eba_atomic_leb_change() · 36a87e44
    Richard Weinberger authored
    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: default avatarRichard Weinberger <richard@nod.at>
    36a87e44
eba.c 39.9 KB