From 6a15674d1e90917f1723a814e2e8c949000440f7 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 9 Nov 2017 10:49:54 -0800 Subject: block: Introduce blk_get_request_flags() A side effect of this patch is that the GFP mask that is passed to several allocation functions in the legacy block layer is changed from GFP_KERNEL into __GFP_DIRECT_RECLAIM. Signed-off-by: Bart Van Assche Reviewed-by: Hannes Reinecke Tested-by: Martin Steigerwald Tested-by: Oleksandr Natalenko Cc: Christoph Hellwig Cc: Ming Lei Cc: Johannes Thumshirn Signed-off-by: Jens Axboe --- block/blk-core.c | 50 +++++++++++++++++++++++++++++++++++--------------- 1 file changed, 35 insertions(+), 15 deletions(-) (limited to 'block') diff --git a/block/blk-core.c b/block/blk-core.c index a4362849059a..0f7093dfc010 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -1160,7 +1160,7 @@ int blk_update_nr_requests(struct request_queue *q, unsigned int nr) * @rl: request list to allocate from * @op: operation and flags * @bio: bio to allocate request for (can be %NULL) - * @gfp_mask: allocation mask + * @flags: BLQ_MQ_REQ_* flags * * Get a free request from @q. This function may fail under memory * pressure or if @q is dead. @@ -1170,7 +1170,7 @@ int blk_update_nr_requests(struct request_queue *q, unsigned int nr) * Returns request pointer on success, with @q->queue_lock *not held*. */ static struct request *__get_request(struct request_list *rl, unsigned int op, - struct bio *bio, gfp_t gfp_mask) + struct bio *bio, unsigned int flags) { struct request_queue *q = rl->q; struct request *rq; @@ -1179,6 +1179,8 @@ static struct request *__get_request(struct request_list *rl, unsigned int op, struct io_cq *icq = NULL; const bool is_sync = op_is_sync(op); int may_queue; + gfp_t gfp_mask = flags & BLK_MQ_REQ_NOWAIT ? GFP_ATOMIC : + __GFP_DIRECT_RECLAIM; req_flags_t rq_flags = RQF_ALLOCED; lockdep_assert_held(q->queue_lock); @@ -1339,7 +1341,7 @@ rq_starved: * @q: request_queue to allocate request from * @op: operation and flags * @bio: bio to allocate request for (can be %NULL) - * @gfp_mask: allocation mask + * @flags: BLK_MQ_REQ_* flags. * * Get a free request from @q. If %__GFP_DIRECT_RECLAIM is set in @gfp_mask, * this function keeps retrying under memory pressure and fails iff @q is dead. @@ -1349,7 +1351,7 @@ rq_starved: * Returns request pointer on success, with @q->queue_lock *not held*. */ static struct request *get_request(struct request_queue *q, unsigned int op, - struct bio *bio, gfp_t gfp_mask) + struct bio *bio, unsigned int flags) { const bool is_sync = op_is_sync(op); DEFINE_WAIT(wait); @@ -1361,7 +1363,7 @@ static struct request *get_request(struct request_queue *q, unsigned int op, rl = blk_get_rl(q, bio); /* transferred to @rq on success */ retry: - rq = __get_request(rl, op, bio, gfp_mask); + rq = __get_request(rl, op, bio, flags); if (!IS_ERR(rq)) return rq; @@ -1370,7 +1372,7 @@ retry: return ERR_PTR(-EAGAIN); } - if (!gfpflags_allow_blocking(gfp_mask) || unlikely(blk_queue_dying(q))) { + if ((flags & BLK_MQ_REQ_NOWAIT) || unlikely(blk_queue_dying(q))) { blk_put_rl(rl); return rq; } @@ -1397,10 +1399,13 @@ retry: goto retry; } +/* flags: BLK_MQ_REQ_PREEMPT and/or BLK_MQ_REQ_NOWAIT. */ static struct request *blk_old_get_request(struct request_queue *q, - unsigned int op, gfp_t gfp_mask) + unsigned int op, unsigned int flags) { struct request *rq; + gfp_t gfp_mask = flags & BLK_MQ_REQ_NOWAIT ? GFP_ATOMIC : + __GFP_DIRECT_RECLAIM; int ret = 0; WARN_ON_ONCE(q->mq_ops); @@ -1413,7 +1418,7 @@ static struct request *blk_old_get_request(struct request_queue *q, if (ret) return ERR_PTR(ret); spin_lock_irq(q->queue_lock); - rq = get_request(q, op, NULL, gfp_mask); + rq = get_request(q, op, NULL, flags); if (IS_ERR(rq)) { spin_unlock_irq(q->queue_lock); blk_queue_exit(q); @@ -1427,25 +1432,40 @@ static struct request *blk_old_get_request(struct request_queue *q, return rq; } -struct request *blk_get_request(struct request_queue *q, unsigned int op, - gfp_t gfp_mask) +/** + * blk_get_request_flags - allocate a request + * @q: request queue to allocate a request for + * @op: operation (REQ_OP_*) and REQ_* flags, e.g. REQ_SYNC. + * @flags: BLK_MQ_REQ_* flags, e.g. BLK_MQ_REQ_NOWAIT. + */ +struct request *blk_get_request_flags(struct request_queue *q, unsigned int op, + unsigned int flags) { struct request *req; + WARN_ON_ONCE(op & REQ_NOWAIT); + WARN_ON_ONCE(flags & ~BLK_MQ_REQ_NOWAIT); + if (q->mq_ops) { - req = blk_mq_alloc_request(q, op, - (gfp_mask & __GFP_DIRECT_RECLAIM) ? - 0 : BLK_MQ_REQ_NOWAIT); + req = blk_mq_alloc_request(q, op, flags); if (!IS_ERR(req) && q->mq_ops->initialize_rq_fn) q->mq_ops->initialize_rq_fn(req); } else { - req = blk_old_get_request(q, op, gfp_mask); + req = blk_old_get_request(q, op, flags); if (!IS_ERR(req) && q->initialize_rq_fn) q->initialize_rq_fn(req); } return req; } +EXPORT_SYMBOL(blk_get_request_flags); + +struct request *blk_get_request(struct request_queue *q, unsigned int op, + gfp_t gfp_mask) +{ + return blk_get_request_flags(q, op, gfp_mask & __GFP_DIRECT_RECLAIM ? + 0 : BLK_MQ_REQ_NOWAIT); +} EXPORT_SYMBOL(blk_get_request); /** @@ -1871,7 +1891,7 @@ get_rq: * Returns with the queue unlocked. */ blk_queue_enter_live(q); - req = get_request(q, bio->bi_opf, bio, GFP_NOIO); + req = get_request(q, bio->bi_opf, bio, 0); if (IS_ERR(req)) { blk_queue_exit(q); __wbt_done(q->rq_wb, wb_acct); -- cgit v1.2.3