[PATCH v3 07/15] md/raid5: Drop the do_prepare flag in raid5_make_request()
From: Logan Gunthorpe <logang@deltatee.com>
Date: 2022-06-16 19:20:57
Also in:
lkml
Subsystem:
software raid (multiple disks) support, the rest · Maintainers:
Song Liu, Yu Kuai, Linus Torvalds
prepare_to_wait() can be reasonably called after schedule instead of setting a flag and preparing in the next loop iteration. This means that prepare_to_wait() will be called before read_seqcount_begin(), but there shouldn't be any reason that the order matters here. On the first iteration of the loop prepare_to_wait() is already called first. Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Guoqing Jiang <redacted> --- drivers/md/raid5.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 26ef292842de..c58e70db204a 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c@@ -5918,7 +5918,6 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) const int rw = bio_data_dir(bi); enum stripe_result res; DEFINE_WAIT(w); - bool do_prepare; if (unlikely(bi->bi_opf & REQ_PREFLUSH)) { int ret = log_handle_flush_request(conf, bi);
@@ -5976,12 +5975,8 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) for (; logical_sector < last_sector; logical_sector += RAID5_STRIPE_SECTORS(conf)) { int seq; - do_prepare = false; retry: seq = read_seqcount_begin(&conf->gen_lock); - if (do_prepare) - prepare_to_wait(&conf->wait_for_overlap, &w, - TASK_UNINTERRUPTIBLE); res = make_stripe_request(mddev, conf, &ctx, logical_sector, bi, seq);
@@ -5993,7 +5988,8 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) if (res == STRIPE_SCHEDULE_AND_RETRY) { schedule(); - do_prepare = true; + prepare_to_wait(&conf->wait_for_overlap, &w, + TASK_UNINTERRUPTIBLE); goto retry; } }
--
2.30.2