• Andrew Morton's avatar
    [PATCH] loop: Fix OOM and oops · 29da03f1
    Andrew Morton authored
    The loop driver takes a copy of the data which it is writing.  When this
    happens on the try_to_free_pages() path, loop can easily consume ALL memory
    and bio_copy() will fail to allocate a page.
    
    Loop forgets to check the bio_copy() return value and oopses.
    
    Fix this by dropping PF_MEMALLOC and throttling to the block writeout speed.
    
    The patch exports blk_congestion_wait() to modules for this.  This is a
    needed export: several filesystems have a "try to allocate and yield if it
    failed" loop and blk_congestion_wait() is a more appropriate way of
    implementing the sleep in this situation.
    29da03f1
ksyms.c 16.7 KB