udev/net_id: avoid slot based names only for single function devices

If we have two or more devices that share the same slot but they are
also multifunction then it is OK to use the slot information even if it
is the same for all of them. Name conflict will be avoided because we
will append function number and form names like, ens1f1, ens1f2...

diff --git a/man/systemd.net-naming-scheme.xml b/man/systemd.net-naming-scheme.xml
index 41408411fccb0b70964f2a7fd0f11ec9a8d27f23..e5a3d7a3139dad6bf7bb888f2435ee820d2fadff 100644 (file)
--- a/man/systemd.net-naming-scheme.xml
+++ b/man/systemd.net-naming-scheme.xml
@@ -403,6 +403,18 @@
           </listitem>
         </varlistentry>
 
+        <varlistentry>
+          <term><constant>v251</constant></term>
+
+          <listitem><para>Since version <constant>v247</constant> we no longer set
+          <varname>ID_NET_NAME_SLOT</varname> if we detect that a PCI device associated with a slot is a PCI
+          bridge as that would create naming conflict when there are more child devices on that bridge. Now,
+          this is relaxed and we will use slot information to generate the name based on it but only if
+          the PCI device has multiple functions. This is safe because distinct function number is a part of
+          the device name for multifunction devices.</para>
+          </listitem>
+        </varlistentry>
+
       </variablelist>
 
     <para>Note that <constant>latest</constant> may be used to denote the latest scheme known (to this

diff --git a/src/shared/netif-naming-scheme.c b/src/shared/netif-naming-scheme.c
index a2bc4fa55ab2f7fdde1b97e93665ac424fdbfa7c..e95072e048904ab9e56fd18510acbb891972a37a 100644 (file)
--- a/src/shared/netif-naming-scheme.c
+++ b/src/shared/netif-naming-scheme.c
@@ -23,6 +23,7 @@ static const NamingScheme naming_schemes[] = {
         { "v247", NAMING_V247 },
         { "v249", NAMING_V249 },
         { "v250", NAMING_V250 },
+        { "v251", NAMING_V251 },
         /* … add more schemes here, as the logic to name devices is updated … */
 
         EXTRA_NET_NAMING_MAP

diff --git a/src/shared/netif-naming-scheme.h b/src/shared/netif-naming-scheme.h
index 16b304ce10be6f5a09470147c312f71015228209..5303348e063e832474b723b4801843b24452323f 100644 (file)
--- a/src/shared/netif-naming-scheme.h
+++ b/src/shared/netif-naming-scheme.h
@@ -22,20 +22,21 @@
  * OS versions, but not fully stabilize them. */
 typedef enum NamingSchemeFlags {
         /* First, the individual features */
-        NAMING_SR_IOV_V            = 1 << 0, /* Use "v" suffix for SR-IOV, see 609948c7043a */
-        NAMING_NPAR_ARI            = 1 << 1, /* Use NPAR "ARI", see 6bc04997b6ea */
-        NAMING_INFINIBAND          = 1 << 2, /* Use "ib" prefix for infiniband, see 938d30aa98df */
-        NAMING_ZERO_ACPI_INDEX     = 1 << 3, /* Use zero acpi_index field, see d81186ef4f6a */
-        NAMING_ALLOW_RERENAMES     = 1 << 4, /* Allow re-renaming of devices, see #9006 */
-        NAMING_STABLE_VIRTUAL_MACS = 1 << 5, /* Use device name to generate MAC, see 6d3646406560 */
-        NAMING_NETDEVSIM           = 1 << 6, /* Generate names for netdevsim devices, see eaa9d507d855 */
-        NAMING_LABEL_NOPREFIX      = 1 << 7, /* Don't prepend ID_NET_LABEL_ONBOARD with interface type prefix */
-        NAMING_NSPAWN_LONG_HASH    = 1 << 8, /* Shorten nspawn interfaces by including 24bit hash, instead of simple truncation  */
-        NAMING_BRIDGE_NO_SLOT      = 1 << 9, /* Don't use PCI hotplug slot information if the corresponding device is a PCI bridge */
-        NAMING_SLOT_FUNCTION_ID    = 1 << 10, /* Use function_id if present to identify PCI hotplug slots */
-        NAMING_16BIT_INDEX         = 1 << 11, /* Allow full 16-bit for the onboard index */
-        NAMING_REPLACE_STRICTLY    = 1 << 12, /* Use udev_replace_ifname() for NAME= rule */
-        NAMING_XEN_VIF             = 1 << 13, /* GEnerate names for Xen netfront devices */
+        NAMING_SR_IOV_V                  = 1 << 0, /* Use "v" suffix for SR-IOV, see 609948c7043a */
+        NAMING_NPAR_ARI                  = 1 << 1, /* Use NPAR "ARI", see 6bc04997b6ea */
+        NAMING_INFINIBAND                = 1 << 2, /* Use "ib" prefix for infiniband, see 938d30aa98df */
+        NAMING_ZERO_ACPI_INDEX           = 1 << 3, /* Use zero acpi_index field, see d81186ef4f6a */
+        NAMING_ALLOW_RERENAMES           = 1 << 4, /* Allow re-renaming of devices, see #9006 */
+        NAMING_STABLE_VIRTUAL_MACS       = 1 << 5, /* Use device name to generate MAC, see 6d3646406560 */
+        NAMING_NETDEVSIM                 = 1 << 6, /* Generate names for netdevsim devices, see eaa9d507d855 */
+        NAMING_LABEL_NOPREFIX            = 1 << 7, /* Don't prepend ID_NET_LABEL_ONBOARD with interface type prefix */
+        NAMING_NSPAWN_LONG_HASH          = 1 << 8, /* Shorten nspawn interfaces by including 24bit hash, instead of simple truncation  */
+        NAMING_BRIDGE_NO_SLOT            = 1 << 9, /* Don't use PCI hotplug slot information if the corresponding device is a PCI bridge */
+        NAMING_SLOT_FUNCTION_ID          = 1 << 10, /* Use function_id if present to identify PCI hotplug slots */
+        NAMING_16BIT_INDEX               = 1 << 11, /* Allow full 16-bit for the onboard index */
+        NAMING_REPLACE_STRICTLY          = 1 << 12, /* Use udev_replace_ifname() for NAME= rule */
+        NAMING_XEN_VIF                   = 1 << 13, /* Generate names for Xen netfront devices */
+        NAMING_BRIDGE_MULTIFUNCTION_SLOT = 1 << 14, /* Use PCI hotplug slot information associated with bridge, but only if PCI device is multifunction */
 
         /* And now the masks that combine the features above */
         NAMING_V238 = 0,
@@ -47,6 +48,7 @@ typedef enum NamingSchemeFlags {
         NAMING_V247 = NAMING_V245 | NAMING_BRIDGE_NO_SLOT,
         NAMING_V249 = NAMING_V247 | NAMING_SLOT_FUNCTION_ID | NAMING_16BIT_INDEX | NAMING_REPLACE_STRICTLY,
         NAMING_V250 = NAMING_V249 | NAMING_XEN_VIF,
+        NAMING_V251 = NAMING_V250 | NAMING_BRIDGE_MULTIFUNCTION_SLOT,
 
         EXTRA_NET_NAMING_SCHEMES
 

diff --git a/src/udev/udev-builtin-net_id.c b/src/udev/udev-builtin-net_id.c
index 9e4297adaf6ffd71f38a8dd5bbb329f9fe759c90..114fda663ee2139808af516c23251e6a85a2b362 100644 (file)
--- a/src/udev/udev-builtin-net_id.c
+++ b/src/udev/udev-builtin-net_id.c
@@ -451,8 +451,15 @@ static int dev_pci_slot(sd_device *dev, const LinkInfo *info, NetNames *names) {
                                  * devices that will try to claim the same index and that would create name
                                  * collision. */
                                 if (naming_scheme_has(NAMING_BRIDGE_NO_SLOT) && is_pci_bridge(hotplug_slot_dev)) {
-                                        log_device_debug(dev, "Not using slot information because the PCI device is a bridge.");
-                                        return 0;
+                                        if (naming_scheme_has(NAMING_BRIDGE_MULTIFUNCTION_SLOT) && !is_pci_multifunction(names->pcidev)) {
+                                                log_device_debug(dev, "Not using slot information because the PCI device associated with the hotplug slot is a bridge and the PCI device has single function.");
+                                                return 0;
+                                        }
+
+                                        if (!naming_scheme_has(NAMING_BRIDGE_MULTIFUNCTION_SLOT)) {
+                                                log_device_debug(dev, "Not using slot information because the PCI device is a bridge.");
+                                                return 0;
+                                        }
                                 }
 
                                 break;