block: Add bio_reset()
authorKent Overstreet <koverstreet@google.com>
Thu, 6 Sep 2012 22:34:58 +0000 (15:34 -0700)
committerJens Axboe <axboe@kernel.dk>
Sun, 9 Sep 2012 08:35:39 +0000 (10:35 +0200)
commitf44b48c7691be7643877d1f881b5eeace654d05d
treea862b4844b99abfa1bfb6fd437cf1ee4f055c438
parent94818742316e27d01506240cf8b07d69844d31af
block: Add bio_reset()

Reusing bios is something that's been highly frowned upon in the past,
but driver code keeps doing it anyways. If it's going to happen anyways,
we should provide a generic method.

This'll help with getting rid of bi_destructor - drivers/block/pktcdvd.c
was open coding it, by doing a bio_init() and resetting bi_destructor.

This required reordering struct bio, but the block layer is not yet
nearly fast enough for any cacheline effects to matter here.

v5: Add a define BIO_RESET_BITS, to be very explicit about what parts of
bio->bi_flags are saved.
v6: Further commenting verbosity, per Tejun
v9: Add a function comment

Signed-off-by: Kent Overstreet <koverstreet@google.com>
CC: Jens Axboe <axboe@kernel.dk>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
fs/bio.c
include/linux/bio.h
include/linux/blk_types.h