diff mbox series

cifs: print "Unknown" instead of bogus link speed value

Message ID 20221108181405.21810-1-ematsumiya@suse.de
State New
Headers show
Series cifs: print "Unknown" instead of bogus link speed value | expand

Commit Message

Enzo Matsumiya Nov. 8, 2022, 6:14 p.m. UTC 
The virtio driver for Linux guests will not set a link speed to its
paravirtualized NICs.  This will be shown as -1 in server settings, and
when the SMB server (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 check if the speed we got is such value, and print "Unknown"
instead.

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>
---
 fs/cifs/cifs_debug.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index 90850da390ae..6ec04869008d 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -151,12 +151,23 @@  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);
+	/*
+	 * Some servers will return an invalid (-1) link speed, e.g. virtio driver on Linux guests
+	 * When the server parses it, it's cast to an unsigned value, and the field ends with a
+	 * bogus value.
+	 * Let's not print such values to avoid confusion.
+	 */
+	if (iface->speed == ((u64)UINT_MAX * 1000 * 1000))
+		seq_printf(m, "\tSpeed: Unknown\n");
+	else
+		seq_printf(m, "\tSpeed: %zu bps\n", 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);