[PATCH 10/12] raid5-cache: new helper: r5_reserve_log_entry
From: Christoph Hellwig <hch@lst.de>
Date: 2015-09-12 06:17:16
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
Factor out code to reserve log space. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/md/raid5-cache.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-)
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index 82a9d32..7d9fa29 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c@@ -269,6 +269,23 @@ static struct bio *r5l_bio_alloc(struct r5l_log *log, struct r5l_io_unit *io) return bio; } +static void r5_reserve_log_entry(struct r5l_log *log, struct r5l_io_unit *io) +{ + log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS); + + /* + * If we filled up the log device start from the beginning again, + * which will require a new bio. + * + * Note: for this to work properly the log size needs to me a multiple + * of BLOCK_SECTORS. + */ + if (log->log_start == 0) + io->current_bio = NULL; + + io->log_end = log->log_start; +} + static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log) { struct r5l_io_unit *io;
@@ -297,11 +314,7 @@ static struct r5l_io_unit *r5l_new_meta(struct r5l_log *log) bio_add_page(io->current_bio, io->meta_page, PAGE_SIZE, 0); log->seq++; - log->log_start = r5l_ring_add(log, log->log_start, BLOCK_SECTORS); - io->log_end = log->log_start; - /* current bio hit disk end */ - if (log->log_start == 0) - io->current_bio = NULL; + r5_reserve_log_entry(log, io); spin_lock_irq(&log->io_list_lock); list_add_tail(&io->log_sibling, &log->running_ios);
@@ -354,13 +367,8 @@ alloc_bio: io->current_bio = NULL; goto alloc_bio; } - log->log_start = r5l_ring_add(log, log->log_start, - BLOCK_SECTORS); - /* current bio hit disk end */ - if (log->log_start == 0) - io->current_bio = NULL; - io->log_end = log->log_start; + r5_reserve_log_entry(log, io); } static void r5l_log_stripe(struct r5l_log *log, struct stripe_head *sh,
--
1.9.1