diff options
| -rw-r--r-- | NEWS | 11 | ||||
| -rwxr-xr-x | test/udev-test.pl | 11 | ||||
| -rw-r--r-- | udev/udev-event.c | 27 | ||||
| -rw-r--r-- | udev/udev-rules.c | 10 | ||||
| -rw-r--r-- | udev/udev.xml | 91 |
5 files changed, 72 insertions, 78 deletions
@@ -1,5 +1,16 @@ udev 154 ======== +Bugfixes. + +Udev now gradually starts to pass control over the primary device nodes +and their names to the kernel, and will in the end only manage the +permissions of the node, and possibly create additional symlinks. +As a first step NAME="" will be ignored, and NAME= setings with names +other than the kernel provided name will result in a logged warning. +Kernels that don't provide device names, or devtmpfs is not used, will +still work as they did before, but it is strongly recommended to use +only the same names for the primary device node as the recent kernel +provides for all devices. udev 153 ======== diff --git a/test/udev-test.pl b/test/udev-test.pl index a4d3a728f7..24e62b4d66 100755 --- a/test/udev-test.pl +++ b/test/udev-test.pl @@ -1266,17 +1266,6 @@ KERNEL=="ttyACM[0-9]*", SYMLINK="three" EOF }, { - desc => "test empty NAME", - subsys => "tty", - devpath => "/devices/pci0000:00/0000:00:1d.7/usb5/5-2/5-2:1.0/tty/ttyACM0", - exp_name => "<none>", - not_exp_name => "ttyACM0", - exp_add_error => "yes", - rules => <<EOF -KERNEL=="ttyACM[0-9]*", NAME="" -EOF - }, - { desc => "test empty SYMLINK+ (empty override)", subsys => "tty", devpath => "/devices/pci0000:00/0000:00:1d.7/usb5/5-2/5-2:1.0/tty/ttyACM0", diff --git a/udev/udev-event.c b/udev/udev-event.c index 1e7a2ea34c..1be3f74ea3 100644 --- a/udev/udev-event.c +++ b/udev/udev-event.c @@ -617,15 +617,20 @@ int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules) } } - if (event->name == NULL) { - /* things went wrong */ + if (event->name == NULL || event->name[0] == '\0') { udev_device_delete_db(dev); udev_device_tag_index(dev, NULL, false); udev_device_unref(event->dev_db); err = -ENOMEM; + err(event->udev, "no node name, something went wrong, ignoring\n"); goto out; } + if (udev_device_get_knodename(dev) != NULL && strcmp(udev_device_get_knodename(dev), event->name) != 0) + err(event->udev, "kernel-provided name '%s' and NAME= '%s' disagree, " + "please use SYMLINK+= or change the kernel to provide the proper name\n", + udev_device_get_knodename(dev), event->name); + /* set device node name */ util_strscpyl(filename, sizeof(filename), udev_get_dev_path(event->udev), "/", event->name, NULL); udev_device_set_devnode(dev, filename); @@ -639,23 +644,7 @@ int udev_event_execute_rules(struct udev_event *event, struct udev_rules *rules) if (event->dev_db != NULL) udev_node_update_old_links(dev, event->dev_db); - if (event->name[0] != '\0') - err = udev_node_add(dev, event->mode, event->uid, event->gid); - else - info(event->udev, "device node creation suppressed\n"); - - /* remove kernel-created node, if needed */ - if (udev_device_get_knodename(dev) != NULL && strcmp(event->name, udev_device_get_knodename(dev)) != 0) { - struct stat stats; - char filename[UTIL_PATH_SIZE]; - - util_strscpyl(filename, sizeof(filename), udev_get_dev_path(event->udev), "/", udev_device_get_knodename(dev), NULL); - if (lstat(filename, &stats) == 0 && stats.st_rdev == udev_device_get_devnum(dev)) { - info(event->udev, "remove kernel created node '%s'\n", udev_device_get_knodename(dev)); - util_unlink_secure(event->udev, filename); - util_delete_path(event->udev, filename); - } - } + err = udev_node_add(dev, event->mode, event->uid, event->gid); } udev_device_unref(event->dev_db); diff --git a/udev/udev-rules.c b/udev/udev-rules.c index eb73221fa9..59fdb71853 100644 --- a/udev/udev-rules.c +++ b/udev/udev-rules.c @@ -1468,9 +1468,13 @@ static int add_rule(struct udev_rules *rules, char *line, if (op < OP_MATCH_MAX) { rule_add_key(&rule_tmp, TK_M_NAME, op, value, NULL); } else { - if (strcmp(value, "%k") == 0) - err(rules->udev, "NAME=\"%%k\" is superfluous and breaks " - "kernel supplied names, please remove it from %s:%u\n", filename, lineno); + if (strcmp(value, "%k") == 0) { + err(rules->udev, "NAME=\"%%k\" is ignored because it breaks kernel supplied names, " + "please remove it from %s:%u\n", filename, lineno); + continue; + } + if (value[0] == '\0') + continue; rule_add_key(&rule_tmp, TK_A_NAME, op, value, NULL); } rule_tmp.rule.rule.flags = 1; diff --git a/udev/udev.xml b/udev/udev.xml index d2277c93d0..678023c373 100644 --- a/udev/udev.xml +++ b/udev/udev.xml @@ -18,23 +18,28 @@ <refnamediv> <refname>udev</refname> - <refpurpose>dynamic device management</refpurpose> + <refpurpose>Linux dynamic device management</refpurpose> </refnamediv> <refsect1><title>DESCRIPTION</title> - <para>udev provides a dynamic device directory containing only the files for - actually present devices. It creates or removes device node files in the - <filename>/dev</filename> directory, or it renames network interfaces.</para> - - <para>Usually udev runs as <citerefentry><refentrytitle>udevd</refentrytitle> - <manvolnum>8</manvolnum></citerefentry> and receives uevents directly from the - kernel if a device is added or removed from the system.</para> - - <para>If udev receives a device event, it matches its configured rules - against the available device attributes provided in sysfs to identify the device. - Rules that match may provide additional device information or specify a device - node name and multiple symlink names and instruct udev to run additional programs - as part of the device event handling.</para> + <para>udev supplies the system software with device events, manages permissions + of device nodes and may create additional symlinks in the <filename>/dev</filename> + directory, or renames network interfaces. The kernel usually just assigns unpredictable + device names based on the order of discovery. Meaningful symlinks or network device + names provide a way to reliably identify devices based on their properties or + current configuration.</para> + + <para>The udev daemon <citerefentry><refentrytitle>udevd</refentrytitle> + <manvolnum>8</manvolnum></citerefentry> receives device uevents directly from + the kernel whenever a device is added or removed from the system, or it changes its + state. When udev receives a device event, it matches its configured set of rules + against various device attributes to identify the device. Rules that match, may + provide additional device information to be stored in the udev database, or information + to be used to create meaningful symlink names.</para> + + <para>All device information udev processes, is stored in the udev database and + sent out to possible event subscribers. Access to all stored data and the event + sources are provided by the library libudev.</para> </refsect1> <refsect1><title>CONFIGURATION</title> @@ -84,9 +89,9 @@ If all match keys are matching against its value, the rule gets applied and the assign keys get the specified value assigned.</para> - <para>A matching rule may specify the name of the device node, add a symlink - pointing to the node, or run a specified program as part of the event handling. - If no matching rule is found, the default device node name is used.</para> + <para>A matching rule may rename a network interface, add symlinks + pointing to the device node, or run a specified program as part of + the event handling.</para> <para>A rule consists of a list of one or more key value pairs separated by a comma. Each key has a distinct operation, depending on the used operator. Valid @@ -304,13 +309,17 @@ <varlistentry> <term><option>NAME</option></term> <listitem> - <para>The name, a network interface should be renamed to, or the name - a device node should be named. Usually the kernel provides the defined - node name, or even creates and removes the node before udev receives - any event. Changing the node name from the kernel's default may result - in unexpected behavior and is not supported. Udev is only expected to - handle device node permissions and to create additional symlinks, which - do not conflict with the kernel device node names.</para> + <para>The name, a network interface should be renamed to. Or as + a temporary workaraound, the name a device node should be named. + Usually the kernel provides the defined node name, or even creates + and removes the node before udev even receives any event. Changing + the node name from the kernel's default creates inconsistencies + and is not supported. If the kernel and NAME specify different names, + an error will be logged. Udev is only expected to handle device node + permissions and to create additional symlinks, not to change + kernel-provided device node names. Instead of renaming a device node, + SYMLINK should be used. Symlink names must never conflict with + device node names, it will result in unpredictable behavior.</para> </listitem> </varlistentry> @@ -318,15 +327,15 @@ <term><option>SYMLINK</option></term> <listitem> <para>The name of a symlink targeting the node. Every matching rule will add - this value to the list of symlinks to be created along with the device node. - Multiple symlinks may be specified by separating the names by the space - character. In case multiple devices claim the same name, the link will - always point to the device with the highest link_priority. If the current device - goes away, the links will be re-evaluated and the device with the next highest - link_priority will own the link. If no link_priority is specified, the order - of the devices, and which of them will own the link, is undefined. Claiming - the same name for a node and links may result in unexpected behavior and is - not supported. + this value to the list of symlinks to be created. Multiple symlinks may be + specified by separating the names by the space character. In case multiple + devices claim the same name, the link will always point to the device with + the highest link_priority. If the current device goes away, the links will + be re-evaluated and the device with the next highest link_priority will own + the link. If no link_priority is specified, the order of the devices, and + which one of them will own the link, is undefined. Claiming the same name for + a symlink, which is or might be used for a device node, may result in + unexpected behavior and is not supported. </para> </listitem> </varlistentry> @@ -379,18 +388,10 @@ <option>RUN{<replaceable>fail_event_on_error</replaceable>}</option> is specified, and the executed program returns non-zero, the event will be marked as failed for a possible later handling.</para> - <para>If no path is given, the program must be in - <filename>/lib/udev</filename>, otherwise the full path must be - specified.</para> - <para>If the specified string starts with - <option>socket:<replaceable>path</replaceable></option>, all current event - values will be passed to the specified socket, as a message in the same - format the kernel sends an uevent. If the first character of the specified path - is an @ character, an abstract namespace socket is used, instead of an existing - socket file.</para> - <para>Program name and arguments are separated with spaces. To - include spaces in an argument, use single quotes. Please note - that this does not run through a shell.</para> + <para>If no absolute path is given, the program is expected to live in + <filename>/lib/udev</filename>, otherwise the absolute path must be + specified. Program name and arguments are separated by spaces. Single quotes + can be used to specify arguments with spaces.</para> </listitem> </varlistentry> |