79721e0a77
Currently udevd delays only events for the same DEVPATH. Example of an "add" event sequence: /block/sda /block/sda/sda1 With this change, we make sure, that the udev process handling /block/sda has finished its work (waited for all attributes, created the node) before we fork the udev event for /block/sda/sda1. This way the event for sda1 can be sure, that the node for the main device is already created (may be useful for disk labels). It will not affect any parallel device handling, only the sequence of the devices directory chain is serialized. The 10.000 disks plugged in will still run as parallel events. :) The main motivation to do this is the program execution of the dev.d/ and hotplug.d/ directory. If we don't wait for the parent event to exit, we can't be sure that the executed scripts are run in the right order. On Thu, Dec 09, 2004 at 09:18:28AM +0100, Kay Sievers wrote: > On Wed, 2004-12-08 at 19:07 -0800, David Brownell wrote: > > Could that argument apply to the underlying hardware, too? > We now make sure that the sequence of events for a device > is serialized for every device chain and the class/block > devices which have a "device" link to a physical device are > handled after the physical device is fully populated and > notified to userspace. It will only work this way on kernels > later than 2.6.10-rc1 cause it depends on the PHYSDEVPATH > value in the hotplug environment.
54 lines
1.4 KiB
C
54 lines
1.4 KiB
C
/*
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* udevd.h
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*
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* Userspace devfs
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*
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* Copyright (C) 2004 Ling, Xiaofeng <xiaofeng.ling@intel.com>
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* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
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*
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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*/
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#include "list.h"
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#define UDEV_MAGIC "udevd_" UDEV_VERSION
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#define EVENT_TIMEOUT_SEC 10
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#define UDEVD_SOCK_PATH "udevd"
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#define SEND_WAIT_MAX_SECONDS 3
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#define SEND_WAIT_LOOP_PER_SECOND 10
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/* environment buffer, should match the kernel's size in lib/kobject_uevent.h */
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#define HOTPLUG_BUFFER_SIZE 1024
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#define HOTPLUG_NUM_ENVP 32
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struct udevsend_msg {
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char magic[20];
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char envbuf[HOTPLUG_BUFFER_SIZE+256];
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};
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struct hotplug_msg {
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struct list_head list;
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pid_t pid;
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long queue_time;
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char *action;
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char *devpath;
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char *subsystem;
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unsigned long long seqnum;
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char *physdevpath;
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char *envp[HOTPLUG_NUM_ENVP+1];
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char envbuf[];
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};
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