net/9p: show error message if user 'msize' cannot be satisfied

If user supplied a large value with the 'msize' option, then
client would silently limit that 'msize' value to the maximum
value supported by transport. That's a bit confusing for users
of not having any indication why the preferred 'msize' value
could not be satisfied.

Link: https://lkml.kernel.org/r/783ba37c1566dd715b9a67d437efa3b77e3cd1a7.1640870037.git.linux_oss@crudebyte.com
Reported-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>

diff --git a/net/9p/client.c b/net/9p/client.c
index d062f1e5bfb0e817eba5c4fd54bfca6618923c00..8bba0d9cf975417b64b0483849f9201bd7fd4d2a 100644 (file)
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1038,8 +1038,13 @@ struct p9_client *p9_client_create(const char *dev_name, char *options)
        if (err)
                goto put_trans;
 
-       if (clnt->msize > clnt->trans_mod->maxsize)
+       if (clnt->msize > clnt->trans_mod->maxsize) {
                clnt->msize = clnt->trans_mod->maxsize;
+               pr_info("Limiting 'msize' to %d as this is the maximum "
+                       "supported by transport %s\n",
+                       clnt->msize, clnt->trans_mod->name
+               );
+       }
 
        if (clnt->msize < 4096) {
                p9_debug(P9_DEBUG_ERROR,