Commit ea17481f authored by Song Liu's avatar Song Liu Committed by Shaohua Li
Browse files

md/r5cache: generate R5LOG_PAYLOAD_FLUSH 



In r5c_finish_stripe_write_out(), R5LOG_PAYLOAD_FLUSH is append to
log->current_io.

Appending R5LOG_PAYLOAD_FLUSH in quiesce needs extra writes to
journal. To simplify the logic, we just skip R5LOG_PAYLOAD_FLUSH in
quiesce.

Even R5LOG_PAYLOAD_FLUSH supports multiple stripes per payload.
However, current implementation is one stripe per R5LOG_PAYLOAD_FLUSH,
which is simpler.

Signed-off-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 2d4f4687

drivers/md/raid5-cache.c

+42 −3
Original line number Diff line number Diff line
@@ -593,7 +593,7 @@ static void r5l_log_endio(struct bio *bio) 


	spin_lock_irqsave(&log->io_list_lock, flags);

	__r5l_set_io_unit_state(io, IO_UNIT_IO_END);

	if (log->need_cache_flush)

	if (log->need_cache_flush && !list_empty(&io->stripe_list))

		r5l_move_to_end_ios(log);

	else

		r5l_log_run_stripes(log);
@@ -621,10 +621,12 @@ static void r5l_log_endio(struct bio *bio) 
			bio_endio(bi);

			atomic_dec(&io->pending_stripe);

		}

	}



	/* finish flush only io_unit and PAYLOAD_FLUSH only io_unit */

	if (atomic_read(&io->pending_stripe) == 0)

		__r5l_stripe_write_finished(io);

}

}



static void r5l_do_submit_io(struct r5l_log *log, struct r5l_io_unit *io)

{
@@ -845,6 +847,41 @@ static void r5l_append_payload_page(struct r5l_log *log, struct page *page) 
	r5_reserve_log_entry(log, io);

}



static void r5l_append_flush_payload(struct r5l_log *log, sector_t sect)

{

	struct mddev *mddev = log->rdev->mddev;

	struct r5conf *conf = mddev->private;

	struct r5l_io_unit *io;

	struct r5l_payload_flush *payload;

	int meta_size;



	/*

	 * payload_flush requires extra writes to the journal.

	 * To avoid handling the extra IO in quiesce, just skip

	 * flush_payload

	 */

	if (conf->quiesce)

		return;



	mutex_lock(&log->io_mutex);

	meta_size = sizeof(struct r5l_payload_flush) + sizeof(__le64);



	if (r5l_get_meta(log, meta_size)) {

		mutex_unlock(&log->io_mutex);

		return;

	}



	/* current implementation is one stripe per flush payload */

	io = log->current_io;

	payload = page_address(io->meta_page) + io->meta_offset;

	payload->header.type = cpu_to_le16(R5LOG_PAYLOAD_FLUSH);

	payload->header.flags = cpu_to_le16(0);

	payload->size = cpu_to_le32(sizeof(__le64));

	payload->flush_stripes[0] = cpu_to_le64(sect);

	io->meta_offset += meta_size;

	mutex_unlock(&log->io_mutex);

}



static int r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,

			   int data_pages, int parity_pages)

{
@@ -2784,6 +2821,8 @@ void r5c_finish_stripe_write_out(struct r5conf *conf, 
		atomic_dec(&conf->r5c_flushing_full_stripes);

		atomic_dec(&conf->r5c_cached_full_stripes);

	}



	r5l_append_flush_payload(log, sh->sector);

}



int r5c_cache_data(struct r5l_log *log, struct stripe_head *sh)

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