mirror of
https://github.com/systemd/systemd.git
synced 2024-12-23 21:35:11 +03:00
warn when renaming kernel-provided nodes instead of adding symlinks
This commit is contained in:
parent
2d01980f1a
commit
75cb1ac51e
11
NEWS
11
NEWS
@ -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
|
||||
========
|
||||
|
@ -1263,17 +1263,6 @@ EOF
|
||||
KERNEL=="ttyACM[0-9]*", SYMLINK+="one"
|
||||
KERNEL=="ttyACM[0-9]*", SYMLINK+="two"
|
||||
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
|
||||
},
|
||||
{
|
||||
|
@ -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);
|
||||
|
@ -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;
|
||||
|
@ -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>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>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>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>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>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>
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user