• Al Viro's avatar
    make sure that __dentry_kill() always invalidates d_seq, unhashed or not · 4c0d7cd5
    Al Viro authored
    RCU pathwalk relies upon the assumption that anything that changes
    ->d_inode of a dentry will invalidate its ->d_seq.  That's almost
    true - the one exception is that the final dput() of already unhashed
    dentry does *not* touch ->d_seq at all.  Unhashing does, though,
    so for anything we'd found by RCU dcache lookup we are fine.
    Unfortunately, we can *start* with an unhashed dentry or jump into
    We could try and be careful in the (few) places where that could
    happen.  Or we could just make the final dput() invalidate the damn
    thing, unhashed or not.  The latter is much simpler and easier to
    backport, so let's do it that way.
    Reported-by: default avatar"Dae R. Jeong" <threeearcat@gmail.com>
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
dcache.c 83.4 KB