bcache: safeguard a dangerous addressing in closure_queue
authorLiang Chen <liangchen.linux@gmail.com>
Fri, 13 Oct 2017 23:35:40 +0000 (16:35 -0700)
committerJens Axboe <axboe@kernel.dk>
Mon, 16 Oct 2017 15:07:26 +0000 (09:07 -0600)
commit6446c684f9418d0175c9c3e5134e7744fe79181a
tree0ecab99341033e1f332c05eddd6d0abbb17e19a7
parenta8500fc816b19795756d27c762daa5e19f5e1b6f
bcache: safeguard a dangerous addressing in closure_queue

The use of the union reduces the size of closure struct by taking advantage
of the current size of its members. The offset of func in work_struct
equals the size of the first three members, so that work.work_func will
just reference the forth member - fn.

This is smart but dangerous. It can be broken if work_struct or the other
structs get changed, and can be a bit difficult to debug.

Signed-off-by: Liang Chen <liangchen.linux@gmail.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/md/bcache/closure.h