[PATCH v2] md: dm-mpath: use list iterator only inside the loop

From: Xiaomeng Tong
Date: Sat Apr 02 2022 - 23:41:19 EST


To move the declare of list iterator into the list_for_each_entry_*()
macro in the future, it should be avoided to use the list iterator
variable after the loop body [1].

Because the cases (the list is empty or no entry is found) have been
checked prior to iterating m->priority_groups, it is fine to move the
bypass_pg(m, pg, bypassed); inside the loop when entry is found.

[1]: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@xxxxxxxxxxxxxx/

Signed-off-by: Xiaomeng Tong <xiam0nd.tong@xxxxxxxxx>
---

changes since v1:
- it is not a bug, have checked before (Mike Snitzer)
- tweak code to avoid dead code "return -EINVAL;" (Xiaomeng Tong)

v1: https://lore.kernel.org/lkml/20220327053742.2942-1-xiam0nd.tong@xxxxxxxxx/

---
drivers/md/dm-mpath.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index f4719b65e5e3..13c65eab32a2 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1496,11 +1496,12 @@ static int bypass_pg_num(struct multipath *m, const char *pgstr, bool bypassed)
}

list_for_each_entry(pg, &m->priority_groups, list) {
- if (!--pgnum)
+ if (!--pgnum) {
+ bypass_pg(m, pg, bypassed);
break;
+ }
}

- bypass_pg(m, pg, bypassed);
return 0;
}

--
2.17.1