This is a resend of three ll_rw_blk patches related to tagged queuing.

Currently blk_queue_free_tags cannot be called with ops outstanding.  The
scsi_tcq API defined to LLD scsi drivers allows for scsi_deactivate_tcq to
be called (which calls blk_queue_free_tags) with ops outstanding.  Change
blk_queue_free_tags to no longer free the tags, but rather just disable
tagged queuing and also modify blk_queue_init_tags to handle re-enabling
tagged queuing after it has been disabled.
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>