[PATCH] net/9p: fix potential refcnt problem of trans module

[Chengguang Xu]

When specifying trans_mod multiple times in a mount,
it may cause inaccurate refcount of trans module. Also,
in the error case of option parsing, we should put the
trans module if we have already got.

Signed-off-by: Chengguang Xu <cgxu...@gmx.com>
---
 net/9p/client.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/9p/client.c b/net/9p/client.c
index b433aff..7ccfb4b 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -190,7 +190,9 @@ static int parse_opts(char *opts, struct p9_client *clnt)
                                p9_debug(P9_DEBUG_ERROR,
                                         "problem allocating copy of trans 
arg\n");
                                goto free_and_return;
-                        }
+                       }
+
+                       v9fs_put_trans(clnt->trans_mod);
                        clnt->trans_mod = v9fs_get_trans_by_name(s);
                        if (clnt->trans_mod == NULL) {
                                pr_info("Could not find request transport: 
%s\n",
@@ -226,6 +228,7 @@ static int parse_opts(char *opts, struct p9_client *clnt)
        }
 
 free_and_return:
+       v9fs_put_trans(clnt->trans_mod);
        kfree(tmp_options);
        return ret;
 }
-- 
1.8.3.1