[PATCH 5.15 121/279] net/smc: Make sure the link_id is unique

Greg Kroah-Hartman
2021-11-24T13:53:22Z

From: Wen Gu <guwen@linux.alibaba.com>

[ Upstream commit cf4f5530bb55ef7d5a91036b26676643b80b1616 ]

The link_id is supposed to be unique, but smcr_next_link_id() doesn't
skip the used link_id as expected. So the patch fixes this.

Fixes: 026c381fb477 ("net/smc: introduce link_idx for link group array")
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/smc/smc_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index d2206743dc714..d672c0f0e247f 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -665,13 +665,14 @@ static u8 smcr_next_link_id(struct smc_link_group *lgr)
int i;

while (1) {
+again:
link_id = ++lgr->next_link_id;
if (!link_id) /* skip zero as link_id */
link_id = ++lgr->next_link_id;
for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
if (smc_link_usable(&lgr->lnk[i]) &&
lgr->lnk[i].link_id == link_id)
- continue;
+ goto again;
}
break;
}
--
2.33.0