tree 68d3bf447201d86cc46ca0b8292d803c2a728b12
parent b8314f9303a985354f445763960c0db2d7948891
author Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> 1400327798 +0900
committer Al Viro <viro@zeniv.linux.org.uk> 1412836742 -0400

fs: Fix theoretical division by 0 in super_cache_scan().

total_objects could be 0 and is used as a denom.

While total_objects is a "long", total_objects == 0 unlikely happens for
3.12 and later kernels because 32-bit architectures would not be able to
hold (1 << 32) objects. However, total_objects == 0 may happen for kernels
between 3.1 and 3.11 because total_objects in prune_super() was an "int"
and (e.g.) x86_64 architecture might be able to hold (1 << 32) objects.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable <stable@kernel.org> # 3.1+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>