• NeilBrown's avatar
    sunrpc/cache: ensure items removed from cache do not have pending upcalls. · 013920eb
    NeilBrown authored
    It is possible for a race to set CACHE_PENDING after cache_clean()
    has removed a cache entry from the cache.
    If CACHE_PENDING is still set when the entry is finally 'put',
    the cache_dequeue() will never happen and we can leak memory.
    
    So set a new flag 'CACHE_CLEANED' when we remove something from
    the cache, and don't queue any upcall if it is set.
    
    If CACHE_PENDING is set before CACHE_CLEANED, the call that
    cache_clean() makes to cache_fresh_unlocked() will free memory
    as needed.  If CACHE_PENDING is set after CACHE_CLEANED, the
    test in sunrpc_cache_pipe_upcall will ensure that the memory
    is not allocated.
    
    Reported-by: <bstroesser@ts.fujitsu.com>
    Signed-off-by: default avatarNeilBrown <neilb@suse.de>
    Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
    013920eb
cache.c 43.7 KB