From 08a17828812adbe965b7af9a0e3e6a6024460cc8 Mon Sep 17 00:00:00 2001
From: Coly Li <colyli@suse.de>
Date: Thu, 1 Oct 2020 14:50:53 +0800
Subject: [PATCH] bcache: don't check seq numbers in register_cache_set()
Git-commit: 08a17828812adbe965b7af9a0e3e6a6024460cc8
Patch-mainline: v5.10-rc1
References: git-fixes

In order to update the partial super block of cache set, the seq numbers
of cache and cache set are checked in register_cache_set(). If cache's
seq number is larger than cache set's seq number, cache set must update
its partial super block from cache's super block. It is unncessary when
the embedded struct cache_sb is removed from struct cache set.

This patch removed the seq numbers checking from register_cache_set(),
because later there will be no such partial super block in struct cache
set, the cache set will directly reference in-memory super block from
struct cache. This is a preparation patch for removing embedded struct
cache_sb from struct cache_set.

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

---
 drivers/md/bcache/super.c | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 3a79790f5fab..291a3d4a4591 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -2175,21 +2175,6 @@ static const char *register_cache_set(struct cache *ca)
 	    sysfs_create_link(&c->kobj, &ca->kobj, buf))
 		goto err;
 
-	/*
-	 * A special case is both ca->sb.seq and c->sb.seq are 0,
-	 * such condition happens on a new created cache device whose
-	 * super block is never flushed yet. In this case c->sb.version
-	 * and other members should be updated too, otherwise we will
-	 * have a mistaken super block version in cache set.
-	 */
-	if (ca->sb.seq > c->sb.seq || c->sb.seq == 0) {
-		c->sb.version		= ca->sb.version;
-		memcpy(c->set_uuid, ca->sb.set_uuid, 16);
-		c->sb.flags             = ca->sb.flags;
-		c->sb.seq		= ca->sb.seq;
-		pr_debug("set version = %llu\n", c->sb.version);
-	}
-
 	kobject_get(&ca->kobj);
 	ca->set = c;
 	ca->set->cache = ca;
-- 
2.26.2