[PATCHv2 for-next 16/24] block/rnbd-clt: Improve find_or_create_sess() return check
From: Gioh Kim <hidden>
Date: 2021-03-30 07:39:15
Subsystem:
block layer, rnbd block drivers, the rest · Maintainers:
Jens Axboe, Md. Haris Iqbal, Jack Wang, Linus Torvalds
From: Tom Rix <trix@redhat.com>
clang static analysis reports this problem
rnbd-clt.c:1212:11: warning: Branch condition evaluates to a
garbage value
else if (!first)
^~~~~~
This is triggered in the find_and_get_or_create_sess() call
because the variable first is not initialized and the
earlier check is specifically for
if (sess == ERR_PTR(-ENOMEM))
This is false positive.
But the if-check can be reduced by initializing first to
false and then returning if the call to find_or_creat_sess()
does not set it to true. When it remains false, either
sess will be valid or not. The not case is caught by
find_and_get_or_create_sess()'s caller rnbd_clt_map_device()
sess = find_and_get_or_create_sess(...);
if (IS_ERR(sess))
return ERR_CAST(sess);
Since find_and_get_or_create_sess() initializes first to false
setting it in find_or_create_sess() is not needed.
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Gioh Kim <redacted>
---
drivers/block/rnbd/rnbd-clt.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/drivers/block/rnbd/rnbd-clt.c b/drivers/block/rnbd/rnbd-clt.c
index 6aba7b26f260..6f955a937f40 100644
--- a/drivers/block/rnbd/rnbd-clt.c
+++ b/drivers/block/rnbd/rnbd-clt.c@@ -915,6 +915,7 @@ static struct rnbd_clt_session *__find_and_get_sess(const char *sessname) return NULL; } +/* caller is responsible for initializing 'first' to false */ static struct rnbd_clt_session *find_or_create_sess(const char *sessname, bool *first) {
@@ -930,8 +931,7 @@ rnbd_clt_session *find_or_create_sess(const char *sessname, bool *first) } list_add(&sess->list, &sess_list); *first = true; - } else - *first = false; + } mutex_unlock(&sess_lock); return sess;
@@ -1200,13 +1200,11 @@ find_and_get_or_create_sess(const char *sessname, struct rnbd_clt_session *sess; struct rtrs_attrs attrs; int err; - bool first; + bool first = false; struct rtrs_clt_ops rtrs_ops; sess = find_or_create_sess(sessname, &first); - if (sess == ERR_PTR(-ENOMEM)) - return ERR_PTR(-ENOMEM); - else if (!first) + if (!first) return sess; if (!path_cnt) {
--
2.25.1