raid5-cache: optimize FLUSH IO with log enabled (828cbe98) · Commits · 戴 / test

drivers/md/raid5-cache.c

+18 −0

Original line number	Diff line number	Diff line
		@@ -507,6 +507,24 @@ void r5l_write_stripe_run(struct r5l_log *log)
		mutex_unlock(&log->io_mutex);
		}

		int r5l_handle_flush_request(struct r5l_log log, struct bio bio)
		{
		if (!log)
		return -ENODEV;
		/*
		* we flush log disk cache first, then write stripe data to raid disks.
		* So if bio is finished, the log disk cache is flushed already. The
		* recovery guarantees we can recovery the bio from log disk, so we
		* don't need to flush again
		*/
		if (bio->bi_iter.bi_size == 0) {
		bio_endio(bio);
		return 0;
		}
		bio->bi_rw &= ~REQ_FLUSH;
		return -EAGAIN;
		}

		/* This will run after log space is reclaimed */
		static void r5l_run_no_space_stripes(struct r5l_log *log)
		{

+9 −2

Original line number	Diff line number	Diff line
		@@ -5146,9 +5146,16 @@ static void make_request(struct mddev mddev, struct bio bi)
		bool do_prepare;

		if (unlikely(bi->bi_rw & REQ_FLUSH)) {
		int ret = r5l_handle_flush_request(conf->log, bi);

		if (ret == 0)
		return;
		if (ret == -ENODEV) {
		md_flush_request(mddev, bi);
		return;
		}
		/* ret == -EAGAIN, fallback */
		}

		md_write_start(mddev, bi);

+1 −0

Original line number	Diff line number	Diff line
		@@ -629,4 +629,5 @@ extern int r5l_write_stripe(struct r5l_log log, struct stripe_head head_sh);
		extern void r5l_write_stripe_run(struct r5l_log *log);
		extern void r5l_flush_stripe_to_raid(struct r5l_log *log);
		extern void r5l_stripe_write_finished(struct stripe_head *sh);
		extern int r5l_handle_flush_request(struct r5l_log log, struct bio bio);
		#endif