Re: [PATCH 4/5] block: move the bdi from the request_queue to the gendisk
flat view
From: Jan Kara <jack@suse.cz>
Date: 2021-08-09 15:47:33
Also in:
cgroups, linux-fsdevel, linux-mm
On Mon 09-08-21 16:17:43, Christoph Hellwig wrote:
The backing device information only makes sense for file system I/O, and thus belongs into the gendisk and not the lower level request_queue structure. Move it there. Signed-off-by: Christoph Hellwig <hch@lst.de>
Looks mostly good. I'm just unsure whether some queue_to_disk() calls are safe.
quoted hunk ↗ jump to hunk
diff --git a/block/blk-mq.c b/block/blk-mq.c index 2c4ac51e54eb..d2725f94491d 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c@@ -525,7 +525,7 @@ void blk_mq_free_request(struct request *rq) __blk_mq_dec_active_requests(hctx); if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq))) - laptop_io_completion(q->backing_dev_info); + laptop_io_completion(queue_to_disk(q)->bdi);
E.g. cannot this get called for a queue that is without a disk?
quoted hunk ↗ jump to hunk
diff --git a/block/blk-wbt.c b/block/blk-wbt.c index 3ed71b8da887..31086afaad9c 100644 --- a/block/blk-wbt.c +++ b/block/blk-wbt.c@@ -97,7 +97,7 @@ static void wb_timestamp(struct rq_wb *rwb, unsigned long *var) */ static bool wb_recent_wait(struct rq_wb *rwb) { - struct bdi_writeback *wb = &rwb->rqos.q->backing_dev_info->wb; + struct bdi_writeback *wb = &queue_to_disk(rwb->rqos.q)->bdi->wb; return time_before(jiffies, wb->dirty_sleep + HZ); }@@ -234,7 +234,7 @@ enum { static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat) { - struct backing_dev_info *bdi = rwb->rqos.q->backing_dev_info; + struct backing_dev_info *bdi = queue_to_disk(rwb->rqos.q)->bdi; struct rq_depth *rqd = &rwb->rq_depth; u64 thislat;@@ -287,7 +287,7 @@ static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat) static void rwb_trace_step(struct rq_wb *rwb, const char *msg) { - struct backing_dev_info *bdi = rwb->rqos.q->backing_dev_info; + struct backing_dev_info *bdi = queue_to_disk(rwb->rqos.q)->bdi; struct rq_depth *rqd = &rwb->rq_depth; trace_wbt_step(bdi, msg, rqd->scale_step, rwb->cur_win_nsec,@@ -359,8 +359,8 @@ static void wb_timer_fn(struct blk_stat_callback *cb) status = latency_exceeded(rwb, cb->stat); - trace_wbt_timer(rwb->rqos.q->backing_dev_info, status, rqd->scale_step, - inflight); + trace_wbt_timer(queue_to_disk(rwb->rqos.q)->bdi, status, + rqd->scale_step, inflight); /* * If we exceeded the latency target, step down. If we did not,
Or all these calls - is wbt guaranteed to only be setup for a queue with disk? Honza -- Jan Kara [off-list ref] SUSE Labs, CR