From 3514da58be9c40b4e377d73a21a56e89145f2843 Mon Sep 17 00:00:00 2001
From: Logan Gunthorpe <logang@deltatee.com>
Date: Wed, 27 Jul 2022 15:05:57 -0600
Subject: [PATCH] md/raid5: Make is_inactive_blocked() helper
Git-commit: 3514da58be9c40b4e377d73a21a56e89145f2843
Patch-mainline: v6.0-rc1
References: jsc#PED-2766

The logic to wait_for_stripe is difficult to parse being on so many
lines and with confusing operator precedence. Move it to a helper
function to make it easier to read.

No functional changes intended.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>
---
 drivers/md/raid5.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 97e8d4baf3fc..33a364ee6b20 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -755,6 +755,24 @@ static bool has_failed(struct r5conf *conf)
 	return degraded > conf->max_degraded;
 }
 
+/*
+ * Block until another thread clears R5_INACTIVE_BLOCKED or
+ * there are fewer than 3/4 the maximum number of active stripes
+ * and there is an inactive stripe available.
+ */
+static bool is_inactive_blocked(struct r5conf *conf, int hash)
+{
+	int active = atomic_read(&conf->active_stripes);
+
+	if (list_empty(conf->inactive_list + hash))
+		return false;
+
+	if (!test_bit(R5_INACTIVE_BLOCKED, &conf->cache_state))
+		return true;
+
+	return active < (conf->max_nr_stripes * 3 / 4);
+}
+
 struct stripe_head *
 raid5_get_active_stripe(struct r5conf *conf, sector_t sector,
 			int previous, int noblock, int noquiesce)
@@ -796,11 +814,7 @@ raid5_get_active_stripe(struct r5conf *conf, sector_t sector,
 	set_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);
 	r5l_wake_reclaim(conf->log, 0);
 	wait_event_lock_irq(conf->wait_for_stripe,
-			    !list_empty(conf->inactive_list + hash) &&
-			    (atomic_read(&conf->active_stripes)
-				  < (conf->max_nr_stripes * 3 / 4)
-				 || !test_bit(R5_INACTIVE_BLOCKED,
-					      &conf->cache_state)),
+			    is_inactive_blocked(conf, hash),
 			    *(conf->hash_locks + hash));
 	clear_bit(R5_INACTIVE_BLOCKED, &conf->cache_state);
 	goto retry;
-- 
2.35.3