[PATCH AUTOSEL 6.1 05/15] smb/client: print "Unknown" instead of bogus link speed value

Sasha Levin
2023-08-29T13:34:49Z

From: Enzo Matsumiya <ematsumiya@suse.de>

[ Upstream commit 50e63d6db6fd30a6dd9a33c49aa5b0bba36e1a92 ]

The virtio driver for Linux guests will not set a link speed to its
paravirtualized NICs. This will be seen as -1 in the ethernet layer, and
when some servers (e.g. samba) fetches it, it's converted to an unsigned
value (and multiplied by 1000 * 1000), so in client side we end up with:

1) Speed: 4294967295000000 bps

in DebugData.

This patch introduces a helper that returns a speed string (in Mbps or
Gbps) if interface speed is valid (>= SPEED_10 and <= SPEED_800000), or
"Unknown" otherwise.

The reason to not change the value in iface->speed is because we don't
know the real speed of the HW backing the server NIC, so let's keep
considering these as the fastest NICs available.

Also print "Capabilities: None" when the interface doesn't support any.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/smb/client/cifs_debug.c | 47 +++++++++++++++++++++++++++++++++++++-
1 file changed, 46 insertions(+), 1 deletion(-)

diff --git a/fs/smb/client/cifs_debug.c b/fs/smb/client/cifs_debug.c
index e41154ad96afc..492f9b11e9ad0 100644
--- a/fs/smb/client/cifs_debug.c
+++ b/fs/smb/client/cifs_debug.c
@@ -11,6 +11,7 @@
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/uaccess.h>
+#include <uapi/linux/ethtool.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
@@ -145,18 +146,62 @@ cifs_dump_channel(struct seq_file *m, int i, struct cifs_chan *chan)
atomic_read(&server->num_waiters));
}

+static inline const char *smb_speed_to_str(size_t bps)
+{
+ size_t mbps = bps / 1000 / 1000;
+
+ switch (mbps) {
+ case SPEED_10:
+ return "10Mbps";
+ case SPEED_100:
+ return "100Mbps";
+ case SPEED_1000:
+ return "1Gbps";
+ case SPEED_2500:
+ return "2.5Gbps";
+ case SPEED_5000:
+ return "5Gbps";
+ case SPEED_10000:
+ return "10Gbps";
+ case SPEED_14000:
+ return "14Gbps";
+ case SPEED_20000:
+ return "20Gbps";
+ case SPEED_25000:
+ return "25Gbps";
+ case SPEED_40000:
+ return "40Gbps";
+ case SPEED_50000:
+ return "50Gbps";
+ case SPEED_56000:
+ return "56Gbps";
+ case SPEED_100000:
+ return "100Gbps";
+ case SPEED_200000:
+ return "200Gbps";
+ case SPEED_400000:
+ return "400Gbps";
+ case SPEED_800000:
+ return "800Gbps";
+ default:
+ return "Unknown";
+ }
+}
+
static void
cifs_dump_iface(struct seq_file *m, struct cifs_server_iface *iface)
{
struct sockaddr_in *ipv4 = (struct sockaddr_in *)&iface->sockaddr;
struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&iface->sockaddr;

- seq_printf(m, "\tSpeed: %zu bps\n", iface->speed);
+ seq_printf(m, "\tSpeed: %s\n", smb_speed_to_str(iface->speed));
seq_puts(m, "\t\tCapabilities: ");
if (iface->rdma_capable)
seq_puts(m, "rdma ");
if (iface->rss_capable)
seq_puts(m, "rss ");
+ if (!iface->rdma_capable && !iface->rss_capable)
+ seq_puts(m, "None");
seq_putc(m, '\n');
if (iface->sockaddr.ss_family == AF_INET)
seq_printf(m, "\t\tIPv4: %pI4\n", &ipv4->sin_addr);
--
2.40.1