No users left since the removal of the legacy request interface, we can remove all the magic bit stealing now and make it a normal field.
But use WRITE_ONCE/READ_ONCE on the new deadline field, given that we don't seem to have any mechanism to guarantee a new value actually gets seen by other threads. Signed-off-by: Christoph Hellwig <[email protected]> --- block/blk-mq.c | 4 ++-- block/blk-timeout.c | 8 +++++--- block/blk.h | 35 ----------------------------------- include/linux/blkdev.h | 4 +--- 4 files changed, 8 insertions(+), 43 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 411be60d0cb6..4c82b4b4fa3e 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -325,7 +325,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data, rq->special = NULL; /* tag was already set */ rq->extra_len = 0; - rq->__deadline = 0; + WRITE_ONCE(rq->deadline, 0); rq->timeout = 0; @@ -839,7 +839,7 @@ static bool blk_mq_req_expired(struct request *rq, unsigned long *next) if (rq->rq_flags & RQF_TIMED_OUT) return false; - deadline = blk_rq_deadline(rq); + deadline = READ_ONCE(rq->deadline); if (time_after_eq(jiffies, deadline)) return true; diff --git a/block/blk-timeout.c b/block/blk-timeout.c index 006cff4390c0..3b0179fbdd6a 100644 --- a/block/blk-timeout.c +++ b/block/blk-timeout.c @@ -84,7 +84,7 @@ void blk_abort_request(struct request *req) * immediately and that scan sees the new timeout value. * No need for fancy synchronizations. */ - blk_rq_set_deadline(req, jiffies); + WRITE_ONCE(req->deadline, jiffies); kblockd_schedule_work(&req->q->timeout_work); } EXPORT_SYMBOL_GPL(blk_abort_request); @@ -121,14 +121,16 @@ void blk_add_timer(struct request *req) req->timeout = q->rq_timeout; req->rq_flags &= ~RQF_TIMED_OUT; - blk_rq_set_deadline(req, jiffies + req->timeout); + + expiry = jiffies + req->timeout; + WRITE_ONCE(req->deadline, expiry); /* * If the timer isn't already pending or this timeout is earlier * than an existing one, modify the timer. Round up to next nearest * second. */ - expiry = blk_rq_timeout(round_jiffies_up(blk_rq_deadline(req))); + expiry = blk_rq_timeout(round_jiffies_up(expiry)); if (!timer_pending(&q->timeout) || time_before(expiry, q->timeout.expires)) { diff --git a/block/blk.h b/block/blk.h index 41b64e6e101b..08a5845b03ba 100644 --- a/block/blk.h +++ b/block/blk.h @@ -238,26 +238,6 @@ void blk_account_io_start(struct request *req, bool new_io); void blk_account_io_completion(struct request *req, unsigned int bytes); void blk_account_io_done(struct request *req, u64 now); -/* - * EH timer and IO completion will both attempt to 'grab' the request, make - * sure that only one of them succeeds. Steal the bottom bit of the - * __deadline field for this. - */ -static inline int blk_mark_rq_complete(struct request *rq) -{ - return test_and_set_bit(0, &rq->__deadline); -} - -static inline void blk_clear_rq_complete(struct request *rq) -{ - clear_bit(0, &rq->__deadline); -} - -static inline bool blk_rq_is_complete(struct request *rq) -{ - return test_bit(0, &rq->__deadline); -} - /* * Internal elevator interface */ @@ -322,21 +302,6 @@ static inline void req_set_nomerge(struct request_queue *q, struct request *req) q->last_merge = NULL; } -/* - * Steal a bit from this field for legacy IO path atomic IO marking. Note that - * setting the deadline clears the bottom bit, potentially clearing the - * completed bit. The user has to be OK with this (current ones are fine). - */ -static inline void blk_rq_set_deadline(struct request *rq, unsigned long time) -{ - rq->__deadline = time & ~0x1UL; -} - -static inline unsigned long blk_rq_deadline(struct request *rq) -{ - return rq->__deadline & ~0x1UL; -} - /* * Internal io_context interface */ diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index c92aafcde0b8..1aa94759d219 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -224,9 +224,7 @@ struct request { refcount_t ref; unsigned int timeout; - - /* access through blk_rq_set_deadline, blk_rq_deadline */ - unsigned long __deadline; + unsigned long deadline; union { struct __call_single_data csd; -- 2.19.1
