From bb6114af097da0cd9c5081e42db718559130687f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Michal=20Sekleta=CC=81r?= Date: Mon, 19 Oct 2020 11:10:31 +0200 Subject: [PATCH] udev/net_id: don't generate slot based names if multiple devices might claim the same slot (cherry picked from commit 2c8ec0095e6fd2e72879d4915ff8a9e5c0664d0b) Resolves: #1827462 --- man/systemd.net-naming-scheme.xml | 15 ++++++++++- src/udev/udev-builtin-net_id.c | 41 ++++++++++++++++++++++++++----- 2 files changed, 49 insertions(+), 7 deletions(-) diff --git a/man/systemd.net-naming-scheme.xml b/man/systemd.net-naming-scheme.xml index a12cc3c460..10e71dcb15 100644 --- a/man/systemd.net-naming-scheme.xml +++ b/man/systemd.net-naming-scheme.xml @@ -176,7 +176,10 @@ SR-IOV virtual devices are named based on the name of the parent interface, with a suffix of v and the virtual device number, with any leading zeros removed. The bus - number is ignored. This device type is found in IBM PowerVMs. + number is ignored. + + In some configurations a parent PCI bridge of a given network controller may be associated + with a slot. In such case we don't generate this device property to avoid possible naming conflicts. @@ -288,6 +291,16 @@ Same as naming scheme rhel-8.0. + + rhel-8.4 + + If the PCI slot is assocated with PCI bridge and that has multiple child network + controllers then all of them might derive the same value of ID_NET_NAME_SLOT + property. That could cause naming conflict if the property is selected as a device name. Now, we detect the + situation, slot - bridge relation, and we don't produce the ID_NET_NAME_SLOT property to + avoid possible naming conflict. + + Note that latest may be used to denote the latest scheme known (to this particular version of systemd. diff --git a/src/udev/udev-builtin-net_id.c b/src/udev/udev-builtin-net_id.c index ede24dee41..d8c56b62bb 100644 --- a/src/udev/udev-builtin-net_id.c +++ b/src/udev/udev-builtin-net_id.c @@ -124,6 +124,7 @@ typedef enum NamingSchemeFlags { /* First, the individual features */ NAMING_SR_IOV_V = 1 << 0, /* Use "v" suffix for SR-IOV, see 609948c7043a40008b8299529c978ed8e11de8f6*/ NAMING_NPAR_ARI = 1 << 1, /* Use NPAR "ARI", see 6bc04997b6eab35d1cb9fa73889892702c27be09 */ + NAMING_BRIDGE_NO_SLOT = 1 << 9, /* Don't use PCI hotplug slot information if the corresponding device is a PCI bridge */ /* And now the masks that combine the features above */ NAMING_V238 = 0, @@ -132,6 +133,7 @@ typedef enum NamingSchemeFlags { NAMING_RHEL_8_1 = NAMING_V239, NAMING_RHEL_8_2 = NAMING_V239, NAMING_RHEL_8_3 = NAMING_V239, + NAMING_RHEL_8_4 = NAMING_V239|NAMING_BRIDGE_NO_SLOT, _NAMING_SCHEME_FLAGS_INVALID = -1, } NamingSchemeFlags; @@ -389,6 +391,26 @@ static bool is_pci_ari_enabled(struct udev_device *dev) { return streq_ptr(udev_device_get_sysattr_value(dev, "ari_enabled"), "1"); } +static bool is_pci_bridge(struct udev_device *dev) { + const char *v, *p; + + v = udev_device_get_sysattr_value(dev, "modalias"); + if (!v) + return false; + + if (!startswith(v, "pci:")) + return false; + + p = strrchr(v, 's'); + if (!p) + return false; + if (p[1] != 'c') + return false; + + /* PCI device subclass 04 corresponds to PCI bridge */ + return strneq(p + 2, "04", 2); +} + static int dev_pci_slot(struct udev_device *dev, struct netnames *names) { struct udev *udev = udev_device_get_udev(names->pcidev); unsigned domain, bus, slot, func, dev_port = 0; @@ -461,16 +483,23 @@ static int dev_pci_slot(struct udev_device *dev, struct netnames *names) { if (r < 0 || i <= 0) continue; + /* match slot address with device by stripping the function */ if (snprintf_ok(str, sizeof str, "%s/%s/address", slots, dent->d_name) && - read_one_line_file(str, &address) >= 0) - /* match slot address with device by stripping the function */ - if (startswith(udev_device_get_sysname(hotplug_slot_dev), address)) - hotplug_slot = i; + read_one_line_file(str, &address) >= 0 && + startswith(udev_device_get_sysname(hotplug_slot_dev), address)) { + hotplug_slot = i; + + /* We found the match between PCI device and slot. However, we won't use the + * slot index if the device is a PCI bridge, because it can have other child + * 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)) + hotplug_slot = 0; - if (hotplug_slot > 0) break; + } } - if (hotplug_slot > 0) + if (hotplug_slot >= 0) break; rewinddir(dir); hotplug_slot_dev = udev_device_get_parent_with_subsystem_devtype(hotplug_slot_dev, "pci", NULL);