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-rw-r--r--Documentation/Changes15
-rw-r--r--Documentation/DocBook/Makefile3
-rw-r--r--Documentation/DocBook/genericirq.tmpl474
-rw-r--r--Documentation/DocBook/kernel-api.tmpl5
-rw-r--r--Documentation/DocBook/mtdnand.tmpl6
-rw-r--r--Documentation/DocBook/videobook.tmpl2
-rw-r--r--Documentation/IPMI.txt4
-rw-r--r--Documentation/IRQ.txt22
-rw-r--r--Documentation/README.DAC9606
-rw-r--r--Documentation/arm/IXP4xx2
-rw-r--r--Documentation/digiepca.txt2
-rw-r--r--Documentation/feature-removal-schedule.txt84
-rw-r--r--Documentation/filesystems/configfs/configfs_example.c19
-rw-r--r--Documentation/filesystems/devfs/ChangeLog1977
-rw-r--r--Documentation/filesystems/devfs/README1959
-rw-r--r--Documentation/filesystems/devfs/ToDo40
-rw-r--r--Documentation/filesystems/devfs/boot-options65
-rw-r--r--Documentation/initrd.txt24
-rw-r--r--Documentation/ioctl-number.txt1
-rw-r--r--Documentation/kernel-parameters.txt13
-rw-r--r--Documentation/keys-request-key.txt54
-rw-r--r--Documentation/keys.txt29
-rw-r--r--Documentation/memory-barriers.txt2
-rw-r--r--Documentation/networking/pktgen.txt2
-rw-r--r--Documentation/pci.txt2
-rw-r--r--Documentation/pcmcia/crc32hash.c32
-rw-r--r--Documentation/pcmcia/devicetable.txt36
-rw-r--r--Documentation/scsi/tmscsim.txt2
-rw-r--r--Documentation/sound/alsa/ALSA-Configuration.txt106
-rw-r--r--Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl8
-rw-r--r--Documentation/sysctl/vm.txt13
-rw-r--r--Documentation/video4linux/CARDLIST.cx881
-rw-r--r--Documentation/watchdog/pcwd-watchdog.txt75
-rw-r--r--Documentation/watchdog/src/watchdog-simple.c15
-rw-r--r--Documentation/watchdog/src/watchdog-test.c68
-rw-r--r--Documentation/watchdog/watchdog-api.txt56
-rw-r--r--Documentation/watchdog/watchdog.txt23
37 files changed, 947 insertions, 4300 deletions
diff --git a/Documentation/Changes b/Documentation/Changes
index b02f476c2973..488272074c36 100644
--- a/Documentation/Changes
+++ b/Documentation/Changes
@@ -181,8 +181,8 @@ Intel IA32 microcode
181-------------------- 181--------------------
182 182
183A driver has been added to allow updating of Intel IA32 microcode, 183A driver has been added to allow updating of Intel IA32 microcode,
184accessible as both a devfs regular file and as a normal (misc) 184accessible as a normal (misc) character device. If you are not using
185character device. If you are not using devfs you may need to: 185udev you may need to:
186 186
187mkdir /dev/cpu 187mkdir /dev/cpu
188mknod /dev/cpu/microcode c 10 184 188mknod /dev/cpu/microcode c 10 184
@@ -201,7 +201,9 @@ with programs using shared memory.
201udev 201udev
202---- 202----
203udev is a userspace application for populating /dev dynamically with 203udev is a userspace application for populating /dev dynamically with
204only entries for devices actually present. udev replaces devfs. 204only entries for devices actually present. udev replaces the basic
205functionality of devfs, while allowing persistant device naming for
206devices.
205 207
206FUSE 208FUSE
207---- 209----
@@ -231,18 +233,13 @@ The PPP driver has been restructured to support multilink and to
231enable it to operate over diverse media layers. If you use PPP, 233enable it to operate over diverse media layers. If you use PPP,
232upgrade pppd to at least 2.4.0. 234upgrade pppd to at least 2.4.0.
233 235
234If you are not using devfs, you must have the device file /dev/ppp 236If you are not using udev, you must have the device file /dev/ppp
235which can be made by: 237which can be made by:
236 238
237mknod /dev/ppp c 108 0 239mknod /dev/ppp c 108 0
238 240
239as root. 241as root.
240 242
241If you use devfsd and build ppp support as modules, you will need
242the following in your /etc/devfsd.conf file:
243
244LOOKUP PPP MODLOAD
245
246Isdn4k-utils 243Isdn4k-utils
247------------ 244------------
248 245
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index 5a2882d275ba..66e1cf733571 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -10,7 +10,8 @@ DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \
10 kernel-hacking.xml kernel-locking.xml deviceiobook.xml \ 10 kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
11 procfs-guide.xml writing_usb_driver.xml \ 11 procfs-guide.xml writing_usb_driver.xml \
12 kernel-api.xml journal-api.xml lsm.xml usb.xml \ 12 kernel-api.xml journal-api.xml lsm.xml usb.xml \
13 gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml 13 gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
14 genericirq.xml
14 15
15### 16###
16# The build process is as follows (targets): 17# The build process is as follows (targets):
diff --git a/Documentation/DocBook/genericirq.tmpl b/Documentation/DocBook/genericirq.tmpl
new file mode 100644
index 000000000000..0f4a4b6321e4
--- /dev/null
+++ b/Documentation/DocBook/genericirq.tmpl
@@ -0,0 +1,474 @@
1<?xml version="1.0" encoding="UTF-8"?>
2<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
4
5<book id="Generic-IRQ-Guide">
6 <bookinfo>
7 <title>Linux generic IRQ handling</title>
8
9 <authorgroup>
10 <author>
11 <firstname>Thomas</firstname>
12 <surname>Gleixner</surname>
13 <affiliation>
14 <address>
15 <email>tglx@linutronix.de</email>
16 </address>
17 </affiliation>
18 </author>
19 <author>
20 <firstname>Ingo</firstname>
21 <surname>Molnar</surname>
22 <affiliation>
23 <address>
24 <email>mingo@elte.hu</email>
25 </address>
26 </affiliation>
27 </author>
28 </authorgroup>
29
30 <copyright>
31 <year>2005-2006</year>
32 <holder>Thomas Gleixner</holder>
33 </copyright>
34 <copyright>
35 <year>2005-2006</year>
36 <holder>Ingo Molnar</holder>
37 </copyright>
38
39 <legalnotice>
40 <para>
41 This documentation is free software; you can redistribute
42 it and/or modify it under the terms of the GNU General Public
43 License version 2 as published by the Free Software Foundation.
44 </para>
45
46 <para>
47 This program is distributed in the hope that it will be
48 useful, but WITHOUT ANY WARRANTY; without even the implied
49 warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
50 See the GNU General Public License for more details.
51 </para>
52
53 <para>
54 You should have received a copy of the GNU General Public
55 License along with this program; if not, write to the Free
56 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
57 MA 02111-1307 USA
58 </para>
59
60 <para>
61 For more details see the file COPYING in the source
62 distribution of Linux.
63 </para>
64 </legalnotice>
65 </bookinfo>
66
67<toc></toc>
68
69 <chapter id="intro">
70 <title>Introduction</title>
71 <para>
72 The generic interrupt handling layer is designed to provide a
73 complete abstraction of interrupt handling for device drivers.
74 It is able to handle all the different types of interrupt controller
75 hardware. Device drivers use generic API functions to request, enable,
76 disable and free interrupts. The drivers do not have to know anything
77 about interrupt hardware details, so they can be used on different
78 platforms without code changes.
79 </para>
80 <para>
81 This documentation is provided to developers who want to implement
82 an interrupt subsystem based for their architecture, with the help
83 of the generic IRQ handling layer.
84 </para>
85 </chapter>
86
87 <chapter id="rationale">
88 <title>Rationale</title>
89 <para>
90 The original implementation of interrupt handling in Linux is using
91 the __do_IRQ() super-handler, which is able to deal with every
92 type of interrupt logic.
93 </para>
94 <para>
95 Originally, Russell King identified different types of handlers to
96 build a quite universal set for the ARM interrupt handler
97 implementation in Linux 2.5/2.6. He distinguished between:
98 <itemizedlist>
99 <listitem><para>Level type</para></listitem>
100 <listitem><para>Edge type</para></listitem>
101 <listitem><para>Simple type</para></listitem>
102 </itemizedlist>
103 In the SMP world of the __do_IRQ() super-handler another type
104 was identified:
105 <itemizedlist>
106 <listitem><para>Per CPU type</para></listitem>
107 </itemizedlist>
108 </para>
109 <para>
110 This split implementation of highlevel IRQ handlers allows us to
111 optimize the flow of the interrupt handling for each specific
112 interrupt type. This reduces complexity in that particular codepath
113 and allows the optimized handling of a given type.
114 </para>
115 <para>
116 The original general IRQ implementation used hw_interrupt_type
117 structures and their ->ack(), ->end() [etc.] callbacks to
118 differentiate the flow control in the super-handler. This leads to
119 a mix of flow logic and lowlevel hardware logic, and it also leads
120 to unnecessary code duplication: for example in i386, there is a
121 ioapic_level_irq and a ioapic_edge_irq irq-type which share many
122 of the lowlevel details but have different flow handling.
123 </para>
124 <para>
125 A more natural abstraction is the clean separation of the
126 'irq flow' and the 'chip details'.
127 </para>
128 <para>
129 Analysing a couple of architecture's IRQ subsystem implementations
130 reveals that most of them can use a generic set of 'irq flow'
131 methods and only need to add the chip level specific code.
132 The separation is also valuable for (sub)architectures
133 which need specific quirks in the irq flow itself but not in the
134 chip-details - and thus provides a more transparent IRQ subsystem
135 design.
136 </para>
137 <para>
138 Each interrupt descriptor is assigned its own highlevel flow
139 handler, which is normally one of the generic
140 implementations. (This highlevel flow handler implementation also
141 makes it simple to provide demultiplexing handlers which can be
142 found in embedded platforms on various architectures.)
143 </para>
144 <para>
145 The separation makes the generic interrupt handling layer more
146 flexible and extensible. For example, an (sub)architecture can
147 use a generic irq-flow implementation for 'level type' interrupts
148 and add a (sub)architecture specific 'edge type' implementation.
149 </para>
150 <para>
151 To make the transition to the new model easier and prevent the
152 breakage of existing implementations, the __do_IRQ() super-handler
153 is still available. This leads to a kind of duality for the time
154 being. Over time the new model should be used in more and more
155 architectures, as it enables smaller and cleaner IRQ subsystems.
156 </para>
157 </chapter>
158 <chapter id="bugs">
159 <title>Known Bugs And Assumptions</title>
160 <para>
161 None (knock on wood).
162 </para>
163 </chapter>
164
165 <chapter id="Abstraction">
166 <title>Abstraction layers</title>
167 <para>
168 There are three main levels of abstraction in the interrupt code:
169 <orderedlist>
170 <listitem><para>Highlevel driver API</para></listitem>
171 <listitem><para>Highlevel IRQ flow handlers</para></listitem>
172 <listitem><para>Chiplevel hardware encapsulation</para></listitem>
173 </orderedlist>
174 </para>
175 <sect1>
176 <title>Interrupt control flow</title>
177 <para>
178 Each interrupt is described by an interrupt descriptor structure
179 irq_desc. The interrupt is referenced by an 'unsigned int' numeric
180 value which selects the corresponding interrupt decription structure
181 in the descriptor structures array.
182 The descriptor structure contains status information and pointers
183 to the interrupt flow method and the interrupt chip structure
184 which are assigned to this interrupt.
185 </para>
186 <para>
187 Whenever an interrupt triggers, the lowlevel arch code calls into
188 the generic interrupt code by calling desc->handle_irq().
189 This highlevel IRQ handling function only uses desc->chip primitives
190 referenced by the assigned chip descriptor structure.
191 </para>
192 </sect1>
193 <sect1>
194 <title>Highlevel Driver API</title>
195 <para>
196 The highlevel Driver API consists of following functions:
197 <itemizedlist>
198 <listitem><para>request_irq()</para></listitem>
199 <listitem><para>free_irq()</para></listitem>
200 <listitem><para>disable_irq()</para></listitem>
201 <listitem><para>enable_irq()</para></listitem>
202 <listitem><para>disable_irq_nosync() (SMP only)</para></listitem>
203 <listitem><para>synchronize_irq() (SMP only)</para></listitem>
204 <listitem><para>set_irq_type()</para></listitem>
205 <listitem><para>set_irq_wake()</para></listitem>
206 <listitem><para>set_irq_data()</para></listitem>
207 <listitem><para>set_irq_chip()</para></listitem>
208 <listitem><para>set_irq_chip_data()</para></listitem>
209 </itemizedlist>
210 See the autogenerated function documentation for details.
211 </para>
212 </sect1>
213 <sect1>
214 <title>Highlevel IRQ flow handlers</title>
215 <para>
216 The generic layer provides a set of pre-defined irq-flow methods:
217 <itemizedlist>
218 <listitem><para>handle_level_irq</para></listitem>
219 <listitem><para>handle_edge_irq</para></listitem>
220 <listitem><para>handle_simple_irq</para></listitem>
221 <listitem><para>handle_percpu_irq</para></listitem>
222 </itemizedlist>
223 The interrupt flow handlers (either predefined or architecture
224 specific) are assigned to specific interrupts by the architecture
225 either during bootup or during device initialization.
226 </para>
227 <sect2>
228 <title>Default flow implementations</title>
229 <sect3>
230 <title>Helper functions</title>
231 <para>
232 The helper functions call the chip primitives and
233 are used by the default flow implementations.
234 The following helper functions are implemented (simplified excerpt):
235 <programlisting>
236default_enable(irq)
237{
238 desc->chip->unmask(irq);
239}
240
241default_disable(irq)
242{
243 if (!delay_disable(irq))
244 desc->chip->mask(irq);
245}
246
247default_ack(irq)
248{
249 chip->ack(irq);
250}
251
252default_mask_ack(irq)
253{
254 if (chip->mask_ack) {
255 chip->mask_ack(irq);
256 } else {
257 chip->mask(irq);
258 chip->ack(irq);
259 }
260}
261
262noop(irq)
263{
264}
265
266 </programlisting>
267 </para>
268 </sect3>
269 </sect2>
270 <sect2>
271 <title>Default flow handler implementations</title>
272 <sect3>
273 <title>Default Level IRQ flow handler</title>
274 <para>
275 handle_level_irq provides a generic implementation
276 for level-triggered interrupts.
277 </para>
278 <para>
279 The following control flow is implemented (simplified excerpt):
280 <programlisting>
281desc->chip->start();
282handle_IRQ_event(desc->action);
283desc->chip->end();
284 </programlisting>
285 </para>
286 </sect3>
287 <sect3>
288 <title>Default Edge IRQ flow handler</title>
289 <para>
290 handle_edge_irq provides a generic implementation
291 for edge-triggered interrupts.
292 </para>
293 <para>
294 The following control flow is implemented (simplified excerpt):
295 <programlisting>
296if (desc->status &amp; running) {
297 desc->chip->hold();
298 desc->status |= pending | masked;
299 return;
300}
301desc->chip->start();
302desc->status |= running;
303do {
304 if (desc->status &amp; masked)
305 desc->chip->enable();
306 desc-status &amp;= ~pending;
307 handle_IRQ_event(desc->action);
308} while (status &amp; pending);
309desc-status &amp;= ~running;
310desc->chip->end();
311 </programlisting>
312 </para>
313 </sect3>
314 <sect3>
315 <title>Default simple IRQ flow handler</title>
316 <para>
317 handle_simple_irq provides a generic implementation
318 for simple interrupts.
319 </para>
320 <para>
321 Note: The simple flow handler does not call any
322 handler/chip primitives.
323 </para>
324 <para>
325 The following control flow is implemented (simplified excerpt):
326 <programlisting>
327handle_IRQ_event(desc->action);
328 </programlisting>
329 </para>
330 </sect3>
331 <sect3>
332 <title>Default per CPU flow handler</title>
333 <para>
334 handle_percpu_irq provides a generic implementation
335 for per CPU interrupts.
336 </para>
337 <para>
338 Per CPU interrupts are only available on SMP and
339 the handler provides a simplified version without
340 locking.
341 </para>
342 <para>
343 The following control flow is implemented (simplified excerpt):
344 <programlisting>
345desc->chip->start();
346handle_IRQ_event(desc->action);
347desc->chip->end();
348 </programlisting>
349 </para>
350 </sect3>
351 </sect2>
352 <sect2>
353 <title>Quirks and optimizations</title>
354 <para>
355 The generic functions are intended for 'clean' architectures and chips,
356 which have no platform-specific IRQ handling quirks. If an architecture
357 needs to implement quirks on the 'flow' level then it can do so by
358 overriding the highlevel irq-flow handler.
359 </para>
360 </sect2>
361 <sect2>
362 <title>Delayed interrupt disable</title>
363 <para>
364 This per interrupt selectable feature, which was introduced by Russell
365 King in the ARM interrupt implementation, does not mask an interrupt
366 at the hardware level when disable_irq() is called. The interrupt is
367 kept enabled and is masked in the flow handler when an interrupt event
368 happens. This prevents losing edge interrupts on hardware which does
369 not store an edge interrupt event while the interrupt is disabled at
370 the hardware level. When an interrupt arrives while the IRQ_DISABLED
371 flag is set, then the interrupt is masked at the hardware level and
372 the IRQ_PENDING bit is set. When the interrupt is re-enabled by
373 enable_irq() the pending bit is checked and if it is set, the
374 interrupt is resent either via hardware or by a software resend
375 mechanism. (It's necessary to enable CONFIG_HARDIRQS_SW_RESEND when
376 you want to use the delayed interrupt disable feature and your
377 hardware is not capable of retriggering an interrupt.)
378 The delayed interrupt disable can be runtime enabled, per interrupt,
379 by setting the IRQ_DELAYED_DISABLE flag in the irq_desc status field.
380 </para>
381 </sect2>
382 </sect1>
383 <sect1>
384 <title>Chiplevel hardware encapsulation</title>
385 <para>
386 The chip level hardware descriptor structure irq_chip
387 contains all the direct chip relevant functions, which
388 can be utilized by the irq flow implementations.
389 <itemizedlist>
390 <listitem><para>ack()</para></listitem>
391 <listitem><para>mask_ack() - Optional, recommended for performance</para></listitem>
392 <listitem><para>mask()</para></listitem>
393 <listitem><para>unmask()</para></listitem>
394 <listitem><para>retrigger() - Optional</para></listitem>
395 <listitem><para>set_type() - Optional</para></listitem>
396 <listitem><para>set_wake() - Optional</para></listitem>
397 </itemizedlist>
398 These primitives are strictly intended to mean what they say: ack means
399 ACK, masking means masking of an IRQ line, etc. It is up to the flow
400 handler(s) to use these basic units of lowlevel functionality.
401 </para>
402 </sect1>
403 </chapter>
404
405 <chapter id="doirq">
406 <title>__do_IRQ entry point</title>
407 <para>
408 The original implementation __do_IRQ() is an alternative entry
409 point for all types of interrupts.
410 </para>
411 <para>
412 This handler turned out to be not suitable for all
413 interrupt hardware and was therefore reimplemented with split
414 functionality for egde/level/simple/percpu interrupts. This is not
415 only a functional optimization. It also shortens code paths for
416 interrupts.
417 </para>
418 <para>
419 To make use of the split implementation, replace the call to
420 __do_IRQ by a call to desc->chip->handle_irq() and associate
421 the appropriate handler function to desc->chip->handle_irq().
422 In most cases the generic handler implementations should
423 be sufficient.
424 </para>
425 </chapter>
426
427 <chapter id="locking">
428 <title>Locking on SMP</title>
429 <para>
430 The locking of chip registers is up to the architecture that
431 defines the chip primitives. There is a chip->lock field that can be used
432 for serialization, but the generic layer does not touch it. The per-irq
433 structure is protected via desc->lock, by the generic layer.
434 </para>
435 </chapter>
436 <chapter id="structs">
437 <title>Structures</title>
438 <para>
439 This chapter contains the autogenerated documentation of the structures which are
440 used in the generic IRQ layer.
441 </para>
442!Iinclude/linux/irq.h
443 </chapter>
444
445 <chapter id="pubfunctions">
446 <title>Public Functions Provided</title>
447 <para>
448 This chapter contains the autogenerated documentation of the kernel API functions
449 which are exported.
450 </para>
451!Ekernel/irq/manage.c
452!Ekernel/irq/chip.c
453 </chapter>
454
455 <chapter id="intfunctions">
456 <title>Internal Functions Provided</title>
457 <para>
458 This chapter contains the autogenerated documentation of the internal functions.
459 </para>
460!Ikernel/irq/handle.c
461!Ikernel/irq/chip.c
462 </chapter>
463
464 <chapter id="credits">
465 <title>Credits</title>
466 <para>
467 The following people have contributed to this document:
468 <orderedlist>
469 <listitem><para>Thomas Gleixner<email>tglx@linutronix.de</email></para></listitem>
470 <listitem><para>Ingo Molnar<email>mingo@elte.hu</email></para></listitem>
471 </orderedlist>
472 </para>
473 </chapter>
474</book>
diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl
index 3630a0d7695f..1ae4dc0fd856 100644
--- a/Documentation/DocBook/kernel-api.tmpl
+++ b/Documentation/DocBook/kernel-api.tmpl
@@ -348,11 +348,6 @@ X!Earch/i386/kernel/mca.c
348 </sect1> 348 </sect1>
349 </chapter> 349 </chapter>
350 350
351 <chapter id="devfs">
352 <title>The Device File System</title>
353!Efs/devfs/base.c
354 </chapter>
355
356 <chapter id="sysfs"> 351 <chapter id="sysfs">
357 <title>The Filesystem for Exporting Kernel Objects</title> 352 <title>The Filesystem for Exporting Kernel Objects</title>
358!Efs/sysfs/file.c 353!Efs/sysfs/file.c
diff --git a/Documentation/DocBook/mtdnand.tmpl b/Documentation/DocBook/mtdnand.tmpl
index 6e463d0db266..999afe1ca8cb 100644
--- a/Documentation/DocBook/mtdnand.tmpl
+++ b/Documentation/DocBook/mtdnand.tmpl
@@ -189,9 +189,9 @@ static unsigned long baseaddr;
189 <sect1> 189 <sect1>
190 <title>Partition defines</title> 190 <title>Partition defines</title>
191 <para> 191 <para>
192 If you want to divide your device into parititions, then 192 If you want to divide your device into partitions, then
193 enable the configuration switch CONFIG_MTD_PARITIONS and define 193 enable the configuration switch CONFIG_MTD_PARTITIONS and define
194 a paritioning scheme suitable to your board. 194 a partitioning scheme suitable to your board.
195 </para> 195 </para>
196 <programlisting> 196 <programlisting>
197#define NUM_PARTITIONS 2 197#define NUM_PARTITIONS 2
diff --git a/Documentation/DocBook/videobook.tmpl b/Documentation/DocBook/videobook.tmpl
index fdff984a5161..b629da33951d 100644
--- a/Documentation/DocBook/videobook.tmpl
+++ b/Documentation/DocBook/videobook.tmpl
@@ -976,7 +976,7 @@ static int camera_close(struct video_device *dev)
976 <title>Interrupt Handling</title> 976 <title>Interrupt Handling</title>
977 <para> 977 <para>
978 Our example handler is for an ISA bus device. If it was PCI you would be 978 Our example handler is for an ISA bus device. If it was PCI you would be
979 able to share the interrupt and would have set SA_SHIRQ to indicate a 979 able to share the interrupt and would have set IRQF_SHARED to indicate a
980 shared IRQ. We pass the device pointer as the interrupt routine argument. We 980 shared IRQ. We pass the device pointer as the interrupt routine argument. We
981 don't need to since we only support one card but doing this will make it 981 don't need to since we only support one card but doing this will make it
982 easier to upgrade the driver for multiple devices in the future. 982 easier to upgrade the driver for multiple devices in the future.
diff --git a/Documentation/IPMI.txt b/Documentation/IPMI.txt
index bf1cf98d2a27..0256805b548f 100644
--- a/Documentation/IPMI.txt
+++ b/Documentation/IPMI.txt
@@ -10,7 +10,7 @@ standard for controlling intelligent devices that monitor a system.
10It provides for dynamic discovery of sensors in the system and the 10It provides for dynamic discovery of sensors in the system and the
11ability to monitor the sensors and be informed when the sensor's 11ability to monitor the sensors and be informed when the sensor's
12values change or go outside certain boundaries. It also has a 12values change or go outside certain boundaries. It also has a
13standardized database for field-replacable units (FRUs) and a watchdog 13standardized database for field-replaceable units (FRUs) and a watchdog
14timer. 14timer.
15 15
16To use this, you need an interface to an IPMI controller in your 16To use this, you need an interface to an IPMI controller in your
@@ -64,7 +64,7 @@ situation, you need to read the section below named 'The SI Driver' or
64IPMI defines a standard watchdog timer. You can enable this with the 64IPMI defines a standard watchdog timer. You can enable this with the
65'IPMI Watchdog Timer' config option. If you compile the driver into 65'IPMI Watchdog Timer' config option. If you compile the driver into
66the kernel, then via a kernel command-line option you can have the 66the kernel, then via a kernel command-line option you can have the
67watchdog timer start as soon as it intitializes. It also have a lot 67watchdog timer start as soon as it initializes. It also have a lot
68of other options, see the 'Watchdog' section below for more details. 68of other options, see the 'Watchdog' section below for more details.
69Note that you can also have the watchdog continue to run if it is 69Note that you can also have the watchdog continue to run if it is
70closed (by default it is disabled on close). Go into the 'Watchdog 70closed (by default it is disabled on close). Go into the 'Watchdog
diff --git a/Documentation/IRQ.txt b/Documentation/IRQ.txt
new file mode 100644
index 000000000000..1011e7175021
--- /dev/null
+++ b/Documentation/IRQ.txt
@@ -0,0 +1,22 @@
1What is an IRQ?
2
3An IRQ is an interrupt request from a device.
4Currently they can come in over a pin, or over a packet.
5Several devices may be connected to the same pin thus
6sharing an IRQ.
7
8An IRQ number is a kernel identifier used to talk about a hardware
9interrupt source. Typically this is an index into the global irq_desc
10array, but except for what linux/interrupt.h implements the details
11are architecture specific.
12
13An IRQ number is an enumeration of the possible interrupt sources on a
14machine. Typically what is enumerated is the number of input pins on
15all of the interrupt controller in the system. In the case of ISA
16what is enumerated are the 16 input pins on the two i8259 interrupt
17controllers.
18
19Architectures can assign additional meaning to the IRQ numbers, and
20are encouraged to in the case where there is any manual configuration
21of the hardware involved. The ISA IRQs are a classic example of
22assigning this kind of additional meaning.
diff --git a/Documentation/README.DAC960 b/Documentation/README.DAC960
index 98ea617a0dd6..0e8f618ab534 100644
--- a/Documentation/README.DAC960
+++ b/Documentation/README.DAC960
@@ -78,9 +78,9 @@ also known as "System Drives", and Drive Groups are also called "Packs". Both
78terms are in use in the Mylex documentation; I have chosen to standardize on 78terms are in use in the Mylex documentation; I have chosen to standardize on
79the more generic "Logical Drive" and "Drive Group". 79the more generic "Logical Drive" and "Drive Group".
80 80
81DAC960 RAID disk devices are named in the style of the Device File System 81DAC960 RAID disk devices are named in the style of the obsolete Device File
82(DEVFS). The device corresponding to Logical Drive D on Controller C is 82System (DEVFS). The device corresponding to Logical Drive D on Controller C
83referred to as /dev/rd/cCdD, and the partitions are called /dev/rd/cCdDp1 83is referred to as /dev/rd/cCdD, and the partitions are called /dev/rd/cCdDp1
84through /dev/rd/cCdDp7. For example, partition 3 of Logical Drive 5 on 84through /dev/rd/cCdDp7. For example, partition 3 of Logical Drive 5 on
85Controller 2 is referred to as /dev/rd/c2d5p3. Note that unlike with SCSI 85Controller 2 is referred to as /dev/rd/c2d5p3. Note that unlike with SCSI
86disks the device names will not change in the event of a disk drive failure. 86disks the device names will not change in the event of a disk drive failure.
diff --git a/Documentation/arm/IXP4xx b/Documentation/arm/IXP4xx
index d4c6d3aa0c25..43edb4ecf27d 100644
--- a/Documentation/arm/IXP4xx
+++ b/Documentation/arm/IXP4xx
@@ -85,7 +85,7 @@ IXP4xx provides two methods of accessing PCI memory space:
852) If > 64MB of memory space is required, the IXP4xx can be 852) If > 64MB of memory space is required, the IXP4xx can be
86 configured to use indirect registers to access PCI This allows 86 configured to use indirect registers to access PCI This allows
87 for up to 128MB (0x48000000 to 0x4fffffff) of memory on the bus. 87 for up to 128MB (0x48000000 to 0x4fffffff) of memory on the bus.
88 The disadvantadge of this is that every PCI access requires 88 The disadvantage of this is that every PCI access requires
89 three local register accesses plus a spinlock, but in some 89 three local register accesses plus a spinlock, but in some
90 cases the performance hit is acceptable. In addition, you cannot 90 cases the performance hit is acceptable. In addition, you cannot
91 mmap() PCI devices in this case due to the indirect nature 91 mmap() PCI devices in this case due to the indirect nature
diff --git a/Documentation/digiepca.txt b/Documentation/digiepca.txt
index 88820fe38dad..f2560e22f2c9 100644
--- a/Documentation/digiepca.txt
+++ b/Documentation/digiepca.txt
@@ -2,7 +2,7 @@ NOTE: This driver is obsolete. Digi provides a 2.6 driver (dgdm) at
2http://www.digi.com for PCI cards. They no longer maintain this driver, 2http://www.digi.com for PCI cards. They no longer maintain this driver,
3and have no 2.6 driver for ISA cards. 3and have no 2.6 driver for ISA cards.
4 4
5This driver requires a number of user-space tools. They can be aquired from 5This driver requires a number of user-space tools. They can be acquired from
6http://www.digi.com, but only works with 2.4 kernels. 6http://www.digi.com, but only works with 2.4 kernels.
7 7
8 8
diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 027285d0c26c..99f219a01e0e 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -6,17 +6,6 @@ be removed from this file.
6 6
7--------------------------- 7---------------------------
8 8
9What: devfs
10When: July 2005
11Files: fs/devfs/*, include/linux/devfs_fs*.h and assorted devfs
12 function calls throughout the kernel tree
13Why: It has been unmaintained for a number of years, has unfixable
14 races, contains a naming policy within the kernel that is
15 against the LSB, and can be replaced by using udev.
16Who: Greg Kroah-Hartman <greg@kroah.com>
17
18---------------------------
19
20What: RAW driver (CONFIG_RAW_DRIVER) 9What: RAW driver (CONFIG_RAW_DRIVER)
21When: December 2005 10When: December 2005
22Why: declared obsolete since kernel 2.6.3 11Why: declared obsolete since kernel 2.6.3
@@ -132,16 +121,6 @@ Who: NeilBrown <neilb@suse.de>
132 121
133--------------------------- 122---------------------------
134 123
135What: au1x00_uart driver
136When: January 2006
137Why: The 8250 serial driver now has the ability to deal with the differences
138 between the standard 8250 family of UARTs and their slightly strange
139 brother on Alchemy SOCs. The loss of features is not considered an
140 issue.
141Who: Ralf Baechle <ralf@linux-mips.org>
142
143---------------------------
144
145What: eepro100 network driver 124What: eepro100 network driver
146When: January 2007 125When: January 2007
147Why: replaced by the e100 driver 126Why: replaced by the e100 driver
@@ -177,6 +156,16 @@ Who: Jean Delvare <khali@linux-fr.org>
177 156
178--------------------------- 157---------------------------
179 158
159What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
160 (temporary transition config option provided until then)
161 The transition config option will also be removed at the same time.
162When: before 2.6.19
163Why: Unused symbols are both increasing the size of the kernel binary
164 and are often a sign of "wrong API"
165Who: Arjan van de Ven <arjan@linux.intel.com>
166
167---------------------------
168
180What: remove EXPORT_SYMBOL(tasklist_lock) 169What: remove EXPORT_SYMBOL(tasklist_lock)
181When: August 2006 170When: August 2006
182Files: kernel/fork.c 171Files: kernel/fork.c
@@ -224,3 +213,56 @@ Why: The interface no longer has any callers left in the kernel. It
224Who: Nick Piggin <npiggin@suse.de> 213Who: Nick Piggin <npiggin@suse.de>
225 214
226--------------------------- 215---------------------------
216
217What: Support for the MIPS EV96100 evaluation board
218When: September 2006
219Why: Does no longer build since at least November 15, 2003, apparently
220 no userbase left.
221Who: Ralf Baechle <ralf@linux-mips.org>
222
223---------------------------
224
225What: Support for the Momentum / PMC-Sierra Jaguar ATX evaluation board
226When: September 2006
227Why: Does no longer build since quite some time, and was never popular,
228 due to the platform being replaced by successor models. Apparently
229 no user base left. It also is one of the last users of
230 WANT_PAGE_VIRTUAL.
231Who: Ralf Baechle <ralf@linux-mips.org>
232
233---------------------------
234
235What: Support for the Momentum Ocelot, Ocelot 3, Ocelot C and Ocelot G
236When: September 2006
237Why: Some do no longer build and apparently there is no user base left
238 for these platforms.
239Who: Ralf Baechle <ralf@linux-mips.org>
240
241---------------------------
242
243What: Support for MIPS Technologies' Altas and SEAD evaluation board
244When: September 2006
245Why: Some do no longer build and apparently there is no user base left
246 for these platforms. Hardware out of production since several years.
247Who: Ralf Baechle <ralf@linux-mips.org>
248
249---------------------------
250
251What: Support for the IT8172-based platforms, ITE 8172G and Globespan IVR
252When: September 2006
253Why: Code does no longer build since at least 2.6.0, apparently there is
254 no user base left for these platforms. Hardware out of production
255 since several years and hardly a trace of the manufacturer left on
256 the net.
257Who: Ralf Baechle <ralf@linux-mips.org>
258
259---------------------------
260
261What: Interrupt only SA_* flags
262When: Januar 2007
263Why: The interrupt related SA_* flags are replaced by IRQF_* to move them
264 out of the signal namespace.
265
266Who: Thomas Gleixner <tglx@linutronix.de>
267
268---------------------------
diff --git a/Documentation/filesystems/configfs/configfs_example.c b/Documentation/filesystems/configfs/configfs_example.c
index 3d4713a6c207..2d6a14a463e0 100644
--- a/Documentation/filesystems/configfs/configfs_example.c
+++ b/Documentation/filesystems/configfs/configfs_example.c
@@ -264,6 +264,15 @@ static struct config_item_type simple_child_type = {
264}; 264};
265 265
266 266
267struct simple_children {
268 struct config_group group;
269};
270
271static inline struct simple_children *to_simple_children(struct config_item *item)
272{
273 return item ? container_of(to_config_group(item), struct simple_children, group) : NULL;
274}
275
267static struct config_item *simple_children_make_item(struct config_group *group, const char *name) 276static struct config_item *simple_children_make_item(struct config_group *group, const char *name)
268{ 277{
269 struct simple_child *simple_child; 278 struct simple_child *simple_child;
@@ -304,7 +313,13 @@ static ssize_t simple_children_attr_show(struct config_item *item,
304"items have only one attribute that is readable and writeable.\n"); 313"items have only one attribute that is readable and writeable.\n");
305} 314}
306 315
316static void simple_children_release(struct config_item *item)
317{
318 kfree(to_simple_children(item));
319}
320
307static struct configfs_item_operations simple_children_item_ops = { 321static struct configfs_item_operations simple_children_item_ops = {
322 .release = simple_children_release,
308 .show_attribute = simple_children_attr_show, 323 .show_attribute = simple_children_attr_show,
309}; 324};
310 325
@@ -345,10 +360,6 @@ static struct configfs_subsystem simple_children_subsys = {
345 * children of its own. 360 * children of its own.
346 */ 361 */
347 362
348struct simple_children {
349 struct config_group group;
350};
351
352static struct config_group *group_children_make_group(struct config_group *group, const char *name) 363static struct config_group *group_children_make_group(struct config_group *group, const char *name)
353{ 364{
354 struct simple_children *simple_children; 365 struct simple_children *simple_children;
diff --git a/Documentation/filesystems/devfs/ChangeLog b/Documentation/filesystems/devfs/ChangeLog
deleted file mode 100644
index e5aba5246d7c..000000000000
--- a/Documentation/filesystems/devfs/ChangeLog
+++ /dev/null
@@ -1,1977 +0,0 @@
1/* -*- auto-fill -*- */
2===============================================================================
3Changes for patch v1
4
5- creation of devfs
6
7- modified miscellaneous character devices to support devfs
8===============================================================================
9Changes for patch v2
10
11- bug fix with manual inode creation
12===============================================================================
13Changes for patch v3
14
15- bugfixes
16
17- documentation improvements
18
19- created a couple of scripts (one to save&restore a devfs and the
20 other to set up compatibility symlinks)
21
22- devfs support for SCSI discs. New name format is: sd_hHcCiIlL
23===============================================================================
24Changes for patch v4
25
26- bugfix for the directory reading code
27
28- bugfix for compilation with kerneld
29
30- devfs support for generic hard discs
31
32- rationalisation of the various watchdog drivers
33===============================================================================
34Changes for patch v5
35
36- support for mounting directly from entries in the devfs (it doesn't
37 need to be mounted to do this), including the root filesystem.
38 Mounting of swap partitions also works. Hence, now if you set
39 CONFIG_DEVFS_ONLY to 'Y' then you won't be able to access your discs
40 via ordinary device nodes. Naturally, the default is 'N' so that you
41 can still use your old device nodes. If you want to mount from devfs
42 entries, make sure you use: append = "root=/dev/sd_..." in your
43 lilo.conf. It seems LILO looks for the device number (major&minor)
44 and writes that into the kernel image :-(
45
46- support for character memory devices (/dev/null, /dev/zero, /dev/full
47 and so on). Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
48===============================================================================
49Changes for patch v6
50
51- support for subdirectories
52
53- support for symbolic links (created by devfs_mk_symlink(), no
54 support yet for creation via symlink(2))
55
56- SCSI disc naming now cast in stone, with the format:
57 /dev/sd/c0b1t2u3 controller=0, bus=1, ID=2, LUN=3, whole disc
58 /dev/sd/c0b1t2u3p4 controller=0, bus=1, ID=2, LUN=3, 4th partition
59
60- loop devices now appear in devfs
61
62- tty devices, console, serial ports, etc. now appear in devfs
63 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
64
65- bugs with mounting devfs-only devices now fixed
66===============================================================================
67Changes for patch v7
68
69- SCSI CD-ROMS, tapes and generic devices now appear in devfs
70===============================================================================
71Changes for patch v8
72
73- bugfix with no-rewind SCSI tapes
74
75- RAMDISCs now appear in devfs
76
77- better cleaning up of devfs entries created by various modules
78
79- interface change to <devfs_register>
80===============================================================================
81Changes for patch v9
82
83- the v8 patch was corrupted somehow, which would affect the patch for
84 linux/fs/filesystems.c
85 I've also fixed the v8 patch file on the WWW
86
87- MetaDevices (/dev/md*) should now appear in devfs
88===============================================================================
89Changes for patch v10
90
91- bugfix in meta device support for devfs
92
93- created this ChangeLog file
94
95- added devfs support to the floppy driver
96
97- added support for creating sockets in a devfs
98===============================================================================
99Changes for patch v11
100
101- added DEVFS_FL_HIDE_UNREG flag
102
103- incorporated better patch for ttyname() in libc 5.4.43 from H.J. Lu.
104
105- interface change to <devfs_mk_symlink>
106
107- support for creating symlinks with symlink(2)
108
109- parallel port printer (/dev/lp*) now appears in devfs
110===============================================================================
111Changes for patch v12
112
113- added inode check to <devfs_fill_file> function
114
115- improved devfs support when mounting from devfs
116
117- added call to <<release>> operation when removing swap areas on
118 devfs devices
119
120- increased NR_SUPER to 128 to support large numbers of devfs mounts
121 (for chroot(2) gaols)
122
123- fixed bug in SCSI disc support: was generating incorrect minors if
124 SCSI ID's did not start at 0 and increase by 1
125
126- support symlink traversal when mounting root
127===============================================================================
128Changes for patch v13
129
130- added devfs support to soundcard driver
131 Thanks to Eric Dumas <dumas@linux.eu.org> and
132 C. Scott Ananian <cananian@alumni.princeton.edu>
133
134- added devfs support to the joystick driver
135
136- loop driver now has it's own subdirectory "/dev/loop/"
137
138- created <devfs_get_flags> and <devfs_set_flags> functions
139
140- fix problem with SCSI disc compatibility names (sd{a,b,c,d,e,f})
141 which assumes ID's start at 0 and increase by 1. Also only create
142 devfs entries for SCSI disc partitions which actually exist
143 Show new names in partition check
144 Thanks to Jakub Jelinek <jj@sunsite.ms.mff.cuni.cz>
145===============================================================================
146Changes for patch v14
147
148- bug fix in floppy driver: would not compile without
149 CONFIG_DEVFS_FS='Y'
150 Thanks to Jurgen Botz <jbotz@nova.botz.org>
151
152- bug fix in loop driver
153 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
154
155- do not create devfs entries for printers not configured
156 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
157
158- do not create devfs entries for serial ports not present
159 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
160
161- ensure <tty_register_devfs> is exported from tty_io.c
162 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
163
164- allow unregistering of devfs symlink entries
165
166- fixed bug in SCSI disc naming introduced in last patch version
167===============================================================================
168Changes for patch v15
169
170- ported to kernel 2.1.81
171===============================================================================
172Changes for patch v16
173
174- created <devfs_set_symlink_destination> function
175
176- moved DEVFS_SUPER_MAGIC into header file
177
178- added DEVFS_FL_HIDE flag
179
180- created <devfs_get_maj_min>
181
182- created <devfs_get_handle_from_inode>
183
184- fixed bugs in searching by major&minor
185
186- changed interface to <devfs_unregister>, <devfs_fill_file> and
187 <devfs_find_handle>
188
189- fixed inode times when symlink created with symlink(2)
190
191- change tty driver to do auto-creation of devfs entries
192 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
193
194- fixed bug in genhd.c: whole disc (non-SCSI) was not registered to
195 devfs
196
197- updated libc 5.4.43 patch for ttyname()
198===============================================================================
199Changes for patch v17
200
201- added CONFIG_DEVFS_TTY_COMPAT
202 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
203
204- bugfix in devfs support for drivers/char/lp.c
205 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
206
207- clean up serial driver so that PCMCIA devices unregister correctly
208 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
209
210- fixed bug in genhd.c: whole disc (non-SCSI) was not registered to
211 devfs [was missing in patch v16]
212
213- updated libc 5.4.43 patch for ttyname() [was missing in patch v16]
214
215- all SCSI devices now registered in /dev/sg
216
217- support removal of devfs entries via unlink(2)
218===============================================================================
219Changes for patch v18
220
221- added floppy/?u720 floppy entry
222
223- fixed kerneld support for entries in devfs subdirectories
224
225- incorporated latest patch for ttyname() in libc 5.4.43 from H.J. Lu.
226===============================================================================
227Changes for patch v19
228
229- bug fix when looking up unregistered entries: kerneld was not called
230
231- fixes for kernel 2.1.86 (now requires 2.1.86)
232===============================================================================
233Changes for patch v20
234
235- only create available floppy entries
236 Thanks to Andrzej Krzysztofowicz <ankry@green.mif.pg.gda.pl>
237
238- new IDE naming scheme following SCSI format (i.e. /dev/id/c0b0t0u0p1
239 instead of /dev/hda1)
240 Thanks to Andrzej Krzysztofowicz <ankry@green.mif.pg.gda.pl>
241
242- new XT disc naming scheme following SCSI format (i.e. /dev/xd/c0t0p1
243 instead of /dev/xda1)
244 Thanks to Andrzej Krzysztofowicz <ankry@green.mif.pg.gda.pl>
245
246- new non-standard CD-ROM names (i.e. /dev/sbp/c#t#)
247 Thanks to Andrzej Krzysztofowicz <ankry@green.mif.pg.gda.pl>
248
249- allow symlink traversal when mounting the root filesystem
250
251- Create entries for MD devices at MD init
252 Thanks to Christophe Leroy <christophe.leroy5@capway.com>
253===============================================================================
254Changes for patch v21
255
256- ported to kernel 2.1.91
257===============================================================================
258Changes for patch v22
259
260- SCSI host number patch ("scsihosts=" kernel option)
261 Thanks to Andrzej Krzysztofowicz <ankry@green.mif.pg.gda.pl>
262===============================================================================
263Changes for patch v23
264
265- Fixed persistence bug with device numbers for manually created
266 device files
267
268- Fixed problem with recreating symlinks with different content
269
270- Added CONFIG_DEVFS_MOUNT (mount devfs on /dev at boot time)
271===============================================================================
272Changes for patch v24
273
274- Switched from CONFIG_KERNELD to CONFIG_KMOD: module autoloading
275 should now work again
276
277- Hide entries which are manually unlinked
278
279- Always invalidate devfs dentry cache when registering entries
280
281- Support removal of devfs directories via rmdir(2)
282
283- Ensure directories created by <devfs_mk_dir> are visible
284
285- Default no access for "other" for floppy device
286===============================================================================
287Changes for patch v25
288
289- Updates to CREDITS file and minor IDE numbering change
290 Thanks to Andrzej Krzysztofowicz <ankry@green.mif.pg.gda.pl>
291
292- Invalidate devfs dentry cache when making directories
293
294- Invalidate devfs dentry cache when removing entries
295
296- More informative message if root FS mount fails when devfs
297 configured
298
299- Fixed persistence bug with fifos
300===============================================================================
301Changes for patch v26
302
303- ported to kernel 2.1.97
304
305- Changed serial directory from "/dev/serial" to "/dev/tts" and
306 "/dev/consoles" to "/dev/vc" to be more friendly to new procps
307===============================================================================
308Changes for patch v27
309
310- Added support for IDE4 and IDE5
311 Thanks to Andrzej Krzysztofowicz <ankry@green.mif.pg.gda.pl>
312
313- Documented "scsihosts=" boot parameter
314
315- Print process command when debugging kerneld/kmod
316
317- Added debugging for register/unregister/change operations
318
319- Added "devfs=" boot options
320
321- Hide unregistered entries by default
322===============================================================================
323Changes for patch v28
324
325- No longer lock/unlock superblock in <devfs_put_super> (cope with
326 recent VFS interface change)
327
328- Do not automatically change ownership/protection of /dev/tty
329
330- Drop negative dentries when they are released
331
332- Manage dcache more efficiently
333===============================================================================
334Changes for patch v29
335
336- Added DEVFS_FL_AUTO_DEVNUM flag
337===============================================================================
338Changes for patch v30
339
340- No longer set unnecessary methods
341
342- Ported to kernel 2.1.99-pre3
343===============================================================================
344Changes for patch v31
345
346- Added PID display to <call_kerneld> debugging message
347
348- Added "diread" and "diwrite" options
349
350- Ported to kernel 2.1.102
351
352- Fixed persistence problem with permissions
353===============================================================================
354Changes for patch v32
355
356- Fixed devfs support in drivers/block/md.c
357===============================================================================
358Changes for patch v33
359
360- Support legacy device nodes
361
362- Fixed bug where recreated inodes were hidden
363
364- New IDE naming scheme: everything is under /dev/ide
365===============================================================================
366Changes for patch v34
367
368- Improved debugging in <get_vfs_inode>
369
370- Prevent duplicate calls to <devfs_mk_dir> in SCSI layer
371
372- No longer free old dentries in <devfs_mk_dir>
373
374- Free all dentries for a given entry when deleting inodes
375===============================================================================
376Changes for patch v35
377
378- Ported to kernel 2.1.105 (sound driver changes)
379===============================================================================
380Changes for patch v36
381
382- Fixed sound driver port
383===============================================================================
384Changes for patch v37
385
386- Minor documentation tweaks
387===============================================================================
388Changes for patch v38
389
390- More documentation tweaks
391
392- Fix for sound driver port
393
394- Removed ttyname-patch (grab libc 5.4.44 instead)
395
396- Ported to kernel 2.1.107-pre2 (loop driver fix)
397===============================================================================
398Changes for patch v39
399
400- Ported to kernel 2.1.107 (hd.c hunk broke due to spelling "fixes"). Sigh
401
402- Removed many #ifdef's, replaced with trickery in include/devfs_fs.h
403===============================================================================
404Changes for patch v40
405
406- Fix for sound driver port
407
408- Limit auto-device numbering to majors 128 to 239
409===============================================================================
410Changes for patch v41
411
412- Fixed inode times persistence problem
413===============================================================================
414Changes for patch v42
415
416- Ported to kernel 2.1.108 (drivers/scsi/hosts.c hunk broke)
417===============================================================================
418Changes for patch v43
419
420- Fixed spelling in <devfs_readlink> debug
421
422- Fixed bug in <devfs_setup> parsing "dilookup"
423
424- More #ifdef's removed
425
426- Supported Sparc keyboard (/dev/kbd)
427
428- Supported DSP56001 digital signal processor (/dev/dsp56k)
429
430- Supported Apple Desktop Bus (/dev/adb)
431
432- Supported Coda network file system (/dev/cfs*)
433===============================================================================
434Changes for patch v44
435
436- Fixed devfs inode leak when manually recreating inodes
437
438- Fixed permission persistence problem when recreating inodes
439===============================================================================
440Changes for patch v45
441
442- Ported to kernel 2.1.110
443===============================================================================
444Changes for patch v46
445
446- Ported to kernel 2.1.112-pre1
447
448- Removed harmless "unused variable" compiler warning
449
450- Fixed modes for manually recreated device nodes
451===============================================================================
452Changes for patch v47
453
454- Added NULL devfs inode warning in <devfs_read_inode>
455
456- Force all inode nlink values to 1
457===============================================================================
458Changes for patch v48
459
460- Added "dimknod" option
461
462- Set inode nlink to 0 when freeing dentries
463
464- Added support for virtual console capture devices (/dev/vcs*)
465 Thanks to Dennis Hou <smilax@mindmeld.yi.org>
466
467- Fixed modes for manually recreated symlinks
468===============================================================================
469Changes for patch v49
470
471- Ported to kernel 2.1.113
472===============================================================================
473Changes for patch v50
474
475- Fixed bugs in recreated directories and symlinks
476===============================================================================
477Changes for patch v51
478
479- Improved robustness of rc.devfs script
480 Thanks to Roderich Schupp <rsch@experteam.de>
481
482- Fixed bugs in recreated device nodes
483
484- Fixed bug in currently unused <devfs_get_handle_from_inode>
485
486- Defined new <devfs_handle_t> type
487
488- Improved debugging when getting entries
489
490- Fixed bug where directories could be emptied
491
492- Ported to kernel 2.1.115
493===============================================================================
494Changes for patch v52
495
496- Replaced dummy .epoch inode with .devfsd character device
497
498- Modified rc.devfs to take account of above change
499
500- Removed spurious driver warning messages when CONFIG_DEVFS_FS=n
501
502- Implemented devfsd protocol revision 0
503===============================================================================
504Changes for patch v53
505
506- Ported to kernel 2.1.116 (kmod change broke hunk)
507
508- Updated Documentation/Configure.help
509
510- Test and tty pattern patch for rc.devfs script
511 Thanks to Roderich Schupp <rsch@experteam.de>
512
513- Added soothing message to warning in <devfs_d_iput>
514===============================================================================
515Changes for patch v54
516
517- Ported to kernel 2.1.117
518
519- Fixed default permissions in sound driver
520
521- Added support for frame buffer devices (/dev/fb*)
522===============================================================================
523Changes for patch v55
524
525- Ported to kernel 2.1.119
526
527- Use GCC extensions for structure initialisations
528
529- Implemented async open notification
530
531- Incremented devfsd protocol revision to 1
532===============================================================================
533Changes for patch v56
534
535- Ported to kernel 2.1.120-pre3
536
537- Moved async open notification to end of <devfs_open>
538===============================================================================
539Changes for patch v57
540
541- Ported to kernel 2.1.121
542
543- Prepended "/dev/" to module load request
544
545- Renamed <call_kerneld> to <call_kmod>
546
547- Created sample modules.conf file
548===============================================================================
549Changes for patch v58
550
551- Fixed typo "AYSNC" -> "ASYNC"
552===============================================================================
553Changes for patch v59
554
555- Added open flag for files
556===============================================================================
557Changes for patch v60
558
559- Ported to kernel 2.1.123-pre2
560===============================================================================
561Changes for patch v61
562
563- Set i_blocks=0 and i_blksize=1024 in <devfs_read_inode>
564===============================================================================
565Changes for patch v62
566
567- Ported to kernel 2.1.123
568===============================================================================
569Changes for patch v63
570
571- Ported to kernel 2.1.124-pre2
572===============================================================================
573Changes for patch v64
574
575- Fixed Unix98 pty support
576
577- Increased buffer size in <get_partition_list> to avoid crash and
578 burn
579===============================================================================
580Changes for patch v65
581
582- More Unix98 pty support fixes
583
584- Added test for empty <<name>> in <devfs_find_handle>
585
586- Renamed <generate_path> to <devfs_generate_path> and published
587
588- Created /dev/root symlink
589 Thanks to Roderich Schupp <rsch@ExperTeam.de>
590 with further modifications by me
591===============================================================================
592Changes for patch v66
593
594- Yet more Unix98 pty support fixes (now tested)
595
596- Created <devfs_get_fops>
597
598- Support media change checks when CONFIG_DEVFS_ONLY=y
599
600- Abolished Unix98-style PTY names for old PTY devices
601===============================================================================
602Changes for patch v67
603
604- Added inline declaration for dummy <devfs_generate_path>
605
606- Removed spurious "unable to register... in devfs" messages when
607 CONFIG_DEVFS_FS=n
608
609- Fixed misc. devices when CONFIG_DEVFS_FS=n
610
611- Limit auto-device numbering to majors 144 to 239
612===============================================================================
613Changes for patch v68
614
615- Hide unopened virtual consoles from directory listings
616
617- Added support for video capture devices
618
619- Ported to kernel 2.1.125
620===============================================================================
621Changes for patch v69
622
623- Fix for CONFIG_VT=n
624===============================================================================
625Changes for patch v70
626
627- Added support for non-OSS/Free sound cards
628===============================================================================
629Changes for patch v71
630
631- Ported to kernel 2.1.126-pre2
632===============================================================================
633Changes for patch v72
634
635- #ifdef's for CONFIG_DEVFS_DISABLE_OLD_NAMES removed
636===============================================================================
637Changes for patch v73
638
639- CONFIG_DEVFS_DISABLE_OLD_NAMES replaced with "nocompat" boot option
640
641- CONFIG_DEVFS_BOOT_OPTIONS removed: boot options always available
642===============================================================================
643Changes for patch v74
644
645- Removed CONFIG_DEVFS_MOUNT and "mount" boot option and replaced with
646 "nomount" boot option
647
648- Documentation updates
649
650- Updated sample modules.conf
651===============================================================================
652Changes for patch v75
653
654- Updated sample modules.conf
655
656- Remount devfs after initrd finishes
657
658- Ported to kernel 2.1.127
659
660- Added support for ISDN
661 Thanks to Christophe Leroy <christophe.leroy5@capway.com>
662===============================================================================
663Changes for patch v76
664
665- Updated an email address in ChangeLog
666
667- CONFIG_DEVFS_ONLY replaced with "only" boot option
668===============================================================================
669Changes for patch v77
670
671- Added DEVFS_FL_REMOVABLE flag
672
673- Check for disc change when listing directories with removable media
674 devices
675
676- Use DEVFS_FL_REMOVABLE in sd.c
677
678- Ported to kernel 2.1.128
679===============================================================================
680Changes for patch v78
681
682- Only call <scan_dir_for_removable> on first call to <devfs_readdir>
683
684- Ported to kernel 2.1.129-pre5
685
686- ISDN support improvements
687 Thanks to Christophe Leroy <christophe.leroy5@capway.com>
688===============================================================================
689Changes for patch v79
690
691- Ported to kernel 2.1.130
692
693- Renamed miscdevice "apm" to "apm_bios" to be consistent with
694 devices.txt
695===============================================================================
696Changes for patch v80
697
698- Ported to kernel 2.1.131
699
700- Updated <devfs_rmdir> for VFS change in 2.1.131
701===============================================================================
702Changes for patch v81
703
704- Fixed permissions on /dev/ptmx
705===============================================================================
706Changes for patch v82
707
708- Ported to kernel 2.1.132-pre4
709
710- Changed initial permissions on /dev/pts/*
711
712- Created <devfs_mk_compat>
713
714- Added "symlinks" boot option
715
716- Changed devfs_register_blkdev() back to register_blkdev() for IDE
717
718- Check for partitions on removable media in <devfs_lookup>
719===============================================================================
720Changes for patch v83
721
722- Fixed support for ramdisc when using string-based root FS name
723
724- Ported to kernel 2.2.0-pre1
725===============================================================================
726Changes for patch v84
727
728- Ported to kernel 2.2.0-pre7
729===============================================================================
730Changes for patch v85
731
732- Compile fixes for driver/sound/sound_common.c (non-module) and
733 drivers/isdn/isdn_common.c
734 Thanks to Christophe Leroy <christophe.leroy5@capway.com>
735
736- Added support for registering regular files
737
738- Created <devfs_set_file_size>
739
740- Added /dev/cpu/mtrr as an alternative interface to /proc/mtrr
741
742- Update devfs inodes from entries if not changed through FS
743===============================================================================
744Changes for patch v86
745
746- Ported to kernel 2.2.0-pre9
747===============================================================================
748Changes for patch v87
749
750- Fixed bug when mounting non-devfs devices in a devfs
751===============================================================================
752Changes for patch v88
753
754- Fixed <devfs_fill_file> to only initialise temporary inodes
755
756- Trap for NULL fops in <devfs_register>
757
758- Return -ENODEV in <devfs_fill_file> for non-driver inodes
759
760- Fixed bug when unswapping non-devfs devices in a devfs
761===============================================================================
762Changes for patch v89
763
764- Switched to C data types in include/linux/devfs_fs.h
765
766- Switched from PATH_MAX to DEVFS_PATHLEN
767
768- Updated Documentation/filesystems/devfs/modules.conf to take account
769 of reverse scanning (!) by modprobe
770
771- Ported to kernel 2.2.0
772===============================================================================
773Changes for patch v90
774
775- CONFIG_DEVFS_DISABLE_OLD_TTY_NAMES replaced with "nottycompat" boot
776 option
777
778- CONFIG_DEVFS_TTY_COMPAT removed: existing "symlinks" boot option now
779 controls this. This means you must have libc 5.4.44 or later, or a
780 recent version of libc 6 if you use the "symlinks" option
781===============================================================================
782Changes for patch v91
783
784- Switch from <devfs_mk_symlink> to <devfs_mk_compat> in
785 drivers/char/vc_screen.c to fix problems with Midnight Commander
786===============================================================================
787Changes for patch v92
788
789- Ported to kernel 2.2.2-pre5
790===============================================================================
791Changes for patch v93
792
793- Modified <sd_name> in drivers/scsi/sd.c to cope with devices that
794 don't exist (which happens with new RAID autostart code printk()s)
795===============================================================================
796Changes for patch v94
797
798- Fixed bug in joystick driver: only first joystick was registered
799===============================================================================
800Changes for patch v95
801
802- Fixed another bug in joystick driver
803
804- Fixed <devfsd_read> to not overrun event buffer
805===============================================================================
806Changes for patch v96
807
808- Ported to kernel 2.2.5-2
809
810- Created <devfs_auto_unregister>
811
812- Fixed bugs: compatibility entries were not unregistered for:
813 loop driver
814 floppy driver
815 RAMDISC driver
816 IDE tape driver
817 SCSI CD-ROM driver
818 SCSI HDD driver
819===============================================================================
820Changes for patch v97
821
822- Fixed bugs: compatibility entries were not unregistered for:
823 ALSA sound driver
824 partitions in generic disc driver
825
826- Don't return unregistred entries in <devfs_find_handle>
827
828- Panic in <devfs_unregister> if entry unregistered
829
830- Don't panic in <devfs_auto_unregister> for duplicates
831===============================================================================
832Changes for patch v98
833
834- Don't unregister already unregistered entries in <unregister>
835
836- Register entry in <sd_detect>
837
838- Unregister entry in <sd_detach>
839
840- Changed to <devfs_*register_chrdev> in drivers/char/tty_io.c
841
842- Ported to kernel 2.2.7
843===============================================================================
844Changes for patch v99
845
846- Ported to kernel 2.2.8
847
848- Fixed bug in drivers/scsi/sd.c when >16 SCSI discs
849
850- Disable warning messages when unable to read partition table for
851 removable media
852===============================================================================
853Changes for patch v100
854
855- Ported to kernel 2.3.1-pre5
856
857- Added "oops-on-panic" boot option
858
859- Improved debugging in <devfs_register> and <devfs_unregister>
860
861- Register entry in <sr_detect>
862
863- Unregister entry in <sr_detach>
864
865- Register entry in <sg_detect>
866
867- Unregister entry in <sg_detach>
868
869- Added support for ALSA drivers
870===============================================================================
871Changes for patch v101
872
873- Ported to kernel 2.3.2
874===============================================================================
875Changes for patch v102
876
877- Update serial driver to register PCMCIA entries
878 Thanks to Roch-Alexandre Nomine-Beguin <roch@samarkand.infini.fr>
879
880- Updated an email address in ChangeLog
881
882- Hide virtual console capture entries from directory listings when
883 corresponding console device is not open
884===============================================================================
885Changes for patch v103
886
887- Ported to kernel 2.3.3
888===============================================================================
889Changes for patch v104
890
891- Added documentation for some functions
892
893- Added "doc" target to fs/devfs/Makefile
894
895- Added "v4l" directory for video4linux devices
896
897- Replaced call to <devfs_unregister> in <sd_detach> with call to
898 <devfs_register_partitions>
899
900- Moved registration for sr and sg drivers from detect() to attach()
901 methods
902
903- Register entries in <st_attach> and unregister in <st_detach>
904
905- Work around IDE driver treating CD-ROM as gendisk
906
907- Use <sed> instead of <tr> in rc.devfs
908
909- Updated ToDo list
910
911- Removed "oops-on-panic" boot option: now always Oops
912===============================================================================
913Changes for patch v105
914
915- Unregister SCSI host from <scsi_host_no_list> in <scsi_unregister>
916 Thanks to Zoltán Böszörményi <zboszor@mail.externet.hu>
917
918- Don't save /dev/log in rc.devfs
919
920- Ported to kernel 2.3.4-pre1
921===============================================================================
922Changes for patch v106
923
924- Fixed silly typo in drivers/scsi/st.c
925
926- Improved debugging in <devfs_register>
927===============================================================================
928Changes for patch v107
929
930- Added "diunlink" and "nokmod" boot options
931
932- Removed superfluous warning message in <devfs_d_iput>
933===============================================================================
934Changes for patch v108
935
936- Remove entries when unloading sound module
937===============================================================================
938Changes for patch v109
939
940- Ported to kernel 2.3.6-pre2
941===============================================================================
942Changes for patch v110
943
944- Took account of change to <d_alloc_root>
945===============================================================================
946Changes for patch v111
947
948- Created separate event queue for each mounted devfs
949
950- Removed <devfs_invalidate_dcache>
951
952- Created new ioctl()s for devfsd
953
954- Incremented devfsd protocol revision to 3
955
956- Fixed bug when re-creating directories: contents were lost
957
958- Block access to inodes until devfsd updates permissions
959===============================================================================
960Changes for patch v112
961
962- Modified patch so it applies against 2.3.5 and 2.3.6
963
964- Updated an email address in ChangeLog
965
966- Do not automatically change ownership/protection of /dev/tty<n>
967
968- Updated sample modules.conf
969
970- Switched to sending process uid/gid to devfsd
971
972- Renamed <call_kmod> to <try_modload>
973
974- Added DEVFSD_NOTIFY_LOOKUP event
975
976- Added DEVFSD_NOTIFY_CHANGE event
977
978- Added DEVFSD_NOTIFY_CREATE event
979
980- Incremented devfsd protocol revision to 4
981
982- Moved kernel-specific stuff to include/linux/devfs_fs_kernel.h
983===============================================================================
984Changes for patch v113
985
986- Ported to kernel 2.3.9
987
988- Restricted permissions on some block devices
989===============================================================================
990Changes for patch v114
991
992- Added support for /dev/netlink
993 Thanks to Dennis Hou <smilax@mindmeld.yi.org>
994
995- Return EISDIR rather than EINVAL for read(2) on directories
996
997- Ported to kernel 2.3.10
998===============================================================================
999Changes for patch v115
1000
1001- Added support for all remaining character devices
1002 Thanks to Dennis Hou <smilax@mindmeld.yi.org>
1003
1004- Cleaned up netlink support
1005===============================================================================
1006Changes for patch v116
1007
1008- Added support for /dev/parport%d
1009 Thanks to Tim Waugh <tim@cyberelk.demon.co.uk>
1010
1011- Fixed parallel port ATAPI tape driver
1012
1013- Fixed Atari SLM laser printer driver
1014===============================================================================
1015Changes for patch v117
1016
1017- Added support for COSA card
1018 Thanks to Dennis Hou <smilax@mindmeld.yi.org>
1019
1020- Fixed drivers/char/ppdev.c: missing #include <linux/init.h>
1021
1022- Fixed drivers/char/ftape/zftape/zftape-init.c
1023 Thanks to Vladimir Popov <mashgrad@usa.net>
1024===============================================================================
1025Changes for patch v118
1026
1027- Ported to kernel 2.3.15-pre3
1028
1029- Fixed bug in loop driver
1030
1031- Unregister /dev/lp%d entries in drivers/char/lp.c
1032 Thanks to Maciej W. Rozycki <macro@ds2.pg.gda.pl>
1033===============================================================================
1034Changes for patch v119
1035
1036- Ported to kernel 2.3.16
1037===============================================================================
1038Changes for patch v120
1039
1040- Fixed bug in drivers/scsi/scsi.c
1041
1042- Added /dev/ppp
1043 Thanks to Dennis Hou <smilax@mindmeld.yi.org>
1044
1045- Ported to kernel 2.3.17
1046===============================================================================
1047Changes for patch v121
1048
1049- Fixed bug in drivers/block/loop.c
1050
1051- Ported to kernel 2.3.18
1052===============================================================================
1053Changes for patch v122
1054
1055- Ported to kernel 2.3.19
1056===============================================================================
1057Changes for patch v123
1058
1059- Ported to kernel 2.3.20
1060===============================================================================
1061Changes for patch v124
1062
1063- Ported to kernel 2.3.21
1064===============================================================================
1065Changes for patch v125
1066
1067- Created <devfs_get_info>, <devfs_set_info>,
1068 <devfs_get_first_child> and <devfs_get_next_sibling>
1069 Added <<dir>> parameter to <devfs_register>, <devfs_mk_compat>,
1070 <devfs_mk_dir> and <devfs_find_handle>
1071 Work sponsored by SGI
1072
1073- Fixed apparent bug in COSA driver
1074
1075- Re-instated "scsihosts=" boot option
1076===============================================================================
1077Changes for patch v126
1078
1079- Always create /dev/pts if CONFIG_UNIX98_PTYS=y
1080
1081- Fixed call to <devfs_mk_dir> in drivers/block/ide-disk.c
1082 Thanks to Dennis Hou <smilax@mindmeld.yi.org>
1083
1084- Allow multiple unregistrations
1085
1086- Created /dev/scsi hierarchy
1087 Work sponsored by SGI
1088===============================================================================
1089Changes for patch v127
1090
1091Work sponsored by SGI
1092
1093- No longer disable devpts if devfs enabled (caveat emptor)
1094
1095- Added flags array to struct gendisk and removed code from
1096 drivers/scsi/sd.c
1097
1098- Created /dev/discs hierarchy
1099===============================================================================
1100Changes for patch v128
1101
1102Work sponsored by SGI
1103
1104- Created /dev/cdroms hierarchy
1105===============================================================================
1106Changes for patch v129
1107
1108Work sponsored by SGI
1109
1110- Removed compatibility entries for sound devices
1111
1112- Removed compatibility entries for printer devices
1113
1114- Removed compatibility entries for video4linux devices
1115
1116- Removed compatibility entries for parallel port devices
1117
1118- Removed compatibility entries for frame buffer devices
1119===============================================================================
1120Changes for patch v130
1121
1122Work sponsored by SGI
1123
1124- Added major and minor number to devfsd protocol
1125
1126- Incremented devfsd protocol revision to 5
1127
1128- Removed compatibility entries for SoundBlaster CD-ROMs
1129
1130- Removed compatibility entries for netlink devices
1131
1132- Removed compatibility entries for SCSI generic devices
1133
1134- Removed compatibility entries for SCSI tape devices
1135===============================================================================
1136Changes for patch v131
1137
1138Work sponsored by SGI
1139
1140- Support info pointer for all devfs entry types
1141
1142- Added <<info>> parameter to <devfs_mk_dir> and <devfs_mk_symlink>
1143
1144- Removed /dev/st hierarchy
1145
1146- Removed /dev/sg hierarchy
1147
1148- Removed compatibility entries for loop devices
1149
1150- Removed compatibility entries for IDE tape devices
1151
1152- Removed compatibility entries for SCSI CD-ROMs
1153
1154- Removed /dev/sr hierarchy
1155===============================================================================
1156Changes for patch v132
1157
1158Work sponsored by SGI
1159
1160- Removed compatibility entries for floppy devices
1161
1162- Removed compatibility entries for RAMDISCs
1163
1164- Removed compatibility entries for meta-devices
1165
1166- Removed compatibility entries for SCSI discs
1167
1168- Created <devfs_make_root>
1169
1170- Removed /dev/sd hierarchy
1171
1172- Support "../" when searching devfs namespace
1173
1174- Created /dev/ide/host* hierarchy
1175
1176- Supported IDE hard discs in /dev/ide/host* hierarchy
1177
1178- Removed compatibility entries for IDE discs
1179
1180- Removed /dev/ide/hd hierarchy
1181
1182- Supported IDE CD-ROMs in /dev/ide/host* hierarchy
1183
1184- Removed compatibility entries for IDE CD-ROMs
1185
1186- Removed /dev/ide/cd hierarchy
1187===============================================================================
1188Changes for patch v133
1189
1190Work sponsored by SGI
1191
1192- Created <devfs_get_unregister_slave>
1193
1194- Fixed bug in fs/partitions/check.c when rescanning
1195===============================================================================
1196Changes for patch v134
1197
1198Work sponsored by SGI
1199
1200- Removed /dev/sd, /dev/sr, /dev/st and /dev/sg directories
1201
1202- Removed /dev/ide/hd directory
1203
1204- Exported <devfs_get_parent>
1205
1206- Created <devfs_register_tape> and /dev/tapes hierarchy
1207
1208- Removed /dev/ide/mt hierarchy
1209
1210- Removed /dev/ide/fd hierarchy
1211
1212- Ported to kernel 2.3.25
1213===============================================================================
1214Changes for patch v135
1215
1216Work sponsored by SGI
1217
1218- Removed compatibility entries for virtual console capture devices
1219
1220- Removed unused <devfs_set_symlink_destination>
1221
1222- Removed compatibility entries for serial devices
1223
1224- Removed compatibility entries for console devices
1225
1226- Do not hide entries from devfsd or children
1227
1228- Removed DEVFS_FL_TTY_COMPAT flag
1229
1230- Removed "nottycompat" boot option
1231
1232- Removed <devfs_mk_compat>
1233===============================================================================
1234Changes for patch v136
1235
1236Work sponsored by SGI
1237
1238- Moved BSD pty devices to /dev/pty
1239
1240- Added DEVFS_FL_WAIT flag
1241===============================================================================
1242Changes for patch v137
1243
1244Work sponsored by SGI
1245
1246- Really fixed bug in fs/partitions/check.c when rescanning
1247
1248- Support new "disc" naming scheme in <get_removable_partition>
1249
1250- Allow NULL fops in <devfs_register>
1251
1252- Removed redundant name functions in SCSI disc and IDE drivers
1253===============================================================================
1254Changes for patch v138
1255
1256Work sponsored by SGI
1257
1258- Fixed old bugs in drivers/block/paride/pt.c, drivers/char/tpqic02.c,
1259 drivers/net/wan/cosa.c and drivers/scsi/scsi.c
1260 Thanks to Sergey Kubushin <ksi@ksi-linux.com>
1261
1262- Fall back to major table if NULL fops given to <devfs_register>
1263===============================================================================
1264Changes for patch v139
1265
1266Work sponsored by SGI
1267
1268- Corrected and moved <get_blkfops> and <get_chrfops> declarations
1269 from arch/alpha/kernel/osf_sys.c to include/linux/fs.h
1270
1271- Removed name function from struct gendisk
1272
1273- Updated devfs FAQ
1274===============================================================================
1275Changes for patch v140
1276
1277Work sponsored by SGI
1278
1279- Ported to kernel 2.3.27
1280===============================================================================
1281Changes for patch v141
1282
1283Work sponsored by SGI
1284
1285- Bug fix in arch/m68k/atari/joystick.c
1286
1287- Moved ISDN and capi devices to /dev/isdn
1288===============================================================================
1289Changes for patch v142
1290
1291Work sponsored by SGI
1292
1293- Bug fix in drivers/block/ide-probe.c (patch confusion)
1294===============================================================================
1295Changes for patch v143
1296
1297Work sponsored by SGI
1298
1299- Bug fix in drivers/block/blkpg.c:partition_name()
1300===============================================================================
1301Changes for patch v144
1302
1303Work sponsored by SGI
1304
1305- Ported to kernel 2.3.29
1306
1307- Removed calls to <devfs_register> from cdu31a, cm206, mcd and mcdx
1308 CD-ROM drivers: generic driver handles this now
1309
1310- Moved joystick devices to /dev/joysticks
1311===============================================================================
1312Changes for patch v145
1313
1314Work sponsored by SGI
1315
1316- Ported to kernel 2.3.30-pre3
1317
1318- Register whole-disc entry even for invalid partition tables
1319
1320- Fixed bug in mounting root FS when initrd enabled
1321
1322- Fixed device entry leak with IDE CD-ROMs
1323
1324- Fixed compile problem with drivers/isdn/isdn_common.c
1325
1326- Moved COSA devices to /dev/cosa
1327
1328- Support fifos when unregistering
1329
1330- Created <devfs_register_series> and used in many drivers
1331
1332- Moved Coda devices to /dev/coda
1333
1334- Moved parallel port IDE tapes to /dev/pt
1335
1336- Moved parallel port IDE generic devices to /dev/pg
1337===============================================================================
1338Changes for patch v146
1339
1340Work sponsored by SGI
1341
1342- Removed obsolete DEVFS_FL_COMPAT and DEVFS_FL_TOLERANT flags
1343
1344- Fixed compile problem with fs/coda/psdev.c
1345
1346- Reinstate change to <devfs_register_blkdev> in
1347 drivers/block/ide-probe.c now that fs/isofs/inode.c is fixed
1348
1349- Switched to <devfs_register_blkdev> in drivers/block/floppy.c,
1350 drivers/scsi/sr.c and drivers/block/md.c
1351
1352- Moved DAC960 devices to /dev/dac960
1353===============================================================================
1354Changes for patch v147
1355
1356Work sponsored by SGI
1357
1358- Ported to kernel 2.3.32-pre4
1359===============================================================================
1360Changes for patch v148
1361
1362Work sponsored by SGI
1363
1364- Removed kmod support: use devfsd instead
1365
1366- Moved miscellaneous character devices to /dev/misc
1367===============================================================================
1368Changes for patch v149
1369
1370Work sponsored by SGI
1371
1372- Ensure include/linux/joystick.h is OK for user-space
1373
1374- Improved debugging in <get_vfs_inode>
1375
1376- Ensure dentries created by devfsd will be cleaned up
1377===============================================================================
1378Changes for patch v150
1379
1380Work sponsored by SGI
1381
1382- Ported to kernel 2.3.34
1383===============================================================================
1384Changes for patch v151
1385
1386Work sponsored by SGI
1387
1388- Ported to kernel 2.3.35-pre1
1389
1390- Created <devfs_get_name>
1391===============================================================================
1392Changes for patch v152
1393
1394Work sponsored by SGI
1395
1396- Updated sample modules.conf
1397
1398- Ported to kernel 2.3.36-pre1
1399===============================================================================
1400Changes for patch v153
1401
1402Work sponsored by SGI
1403
1404- Ported to kernel 2.3.42
1405
1406- Removed <devfs_fill_file>
1407===============================================================================
1408Changes for patch v154
1409
1410Work sponsored by SGI
1411
1412- Took account of device number changes for /dev/fb*
1413===============================================================================
1414Changes for patch v155
1415
1416Work sponsored by SGI
1417
1418- Ported to kernel 2.3.43-pre8
1419
1420- Moved /dev/tty0 to /dev/vc/0
1421
1422- Moved sequence number formatting from <_tty_make_name> to drivers
1423===============================================================================
1424Changes for patch v156
1425
1426Work sponsored by SGI
1427
1428- Fixed breakage in drivers/scsi/sd.c due to recent SCSI changes
1429===============================================================================
1430Changes for patch v157
1431
1432Work sponsored by SGI
1433
1434- Ported to kernel 2.3.45
1435===============================================================================
1436Changes for patch v158
1437
1438Work sponsored by SGI
1439
1440- Ported to kernel 2.3.46-pre2
1441===============================================================================
1442Changes for patch v159
1443
1444Work sponsored by SGI
1445
1446- Fixed drivers/block/md.c
1447 Thanks to Mike Galbraith <mikeg@weiden.de>
1448
1449- Documentation fixes
1450
1451- Moved device registration from <lp_init> to <lp_register>
1452 Thanks to Tim Waugh <twaugh@redhat.com>
1453===============================================================================
1454Changes for patch v160
1455
1456Work sponsored by SGI
1457
1458- Fixed drivers/char/joystick/joystick.c
1459 Thanks to Vojtech Pavlik <vojtech@suse.cz>
1460
1461- Documentation updates
1462
1463- Fixed arch/i386/kernel/mtrr.c if procfs and devfs not enabled
1464
1465- Fixed drivers/char/stallion.c
1466===============================================================================
1467Changes for patch v161
1468
1469Work sponsored by SGI
1470
1471- Remove /dev/ide when ide-mod is unloaded
1472
1473- Fixed bug in drivers/block/ide-probe.c when secondary but no primary
1474
1475- Added DEVFS_FL_NO_PERSISTENCE flag
1476
1477- Used new DEVFS_FL_NO_PERSISTENCE flag for Unix98 pty slaves
1478
1479- Removed unnecessary call to <update_devfs_inode_from_entry> in
1480 <devfs_readdir>
1481
1482- Only set auto-ownership for /dev/pty/s*
1483===============================================================================
1484Changes for patch v162
1485
1486Work sponsored by SGI
1487
1488- Set inode->i_size to correct size for symlinks
1489 Thanks to Jeremy Fitzhardinge <jeremy@goop.org>
1490
1491- Only give lookup() method to directories to comply with new VFS
1492 assumptions
1493
1494- Remove unnecessary tests in symlink methods
1495
1496- Don't kill existing block ops in <devfs_read_inode>
1497
1498- Restore auto-ownership for /dev/pty/m*
1499===============================================================================
1500Changes for patch v163
1501
1502Work sponsored by SGI
1503
1504- Don't create missing directories in <devfs_find_handle>
1505
1506- Removed Documentation/filesystems/devfs/mk-devlinks
1507
1508- Updated Documentation/filesystems/devfs/README
1509===============================================================================
1510Changes for patch v164
1511
1512Work sponsored by SGI
1513
1514- Fixed CONFIG_DEVFS breakage in drivers/char/serial.c introduced in
1515 linux-2.3.99-pre6-7
1516===============================================================================
1517Changes for patch v165
1518
1519Work sponsored by SGI
1520
1521- Ported to kernel 2.3.99-pre6
1522===============================================================================
1523Changes for patch v166
1524
1525Work sponsored by SGI
1526
1527- Added CONFIG_DEVFS_MOUNT
1528===============================================================================
1529Changes for patch v167
1530
1531Work sponsored by SGI
1532
1533- Updated Documentation/filesystems/devfs/README
1534
1535- Updated sample modules.conf
1536===============================================================================
1537Changes for patch v168
1538
1539Work sponsored by SGI
1540
1541- Disabled multi-mount capability (use VFS bindings instead)
1542
1543- Updated README from master HTML file
1544===============================================================================
1545Changes for patch v169
1546
1547Work sponsored by SGI
1548
1549- Removed multi-mount code
1550
1551- Removed compatibility macros: VFS has changed too much
1552===============================================================================
1553Changes for patch v170
1554
1555Work sponsored by SGI
1556
1557- Updated README from master HTML file
1558
1559- Merged devfs inode into devfs entry
1560===============================================================================
1561Changes for patch v171
1562
1563Work sponsored by SGI
1564
1565- Updated sample modules.conf
1566
1567- Removed dead code in <devfs_register> which used to call
1568 <free_dentries>
1569
1570- Ported to kernel 2.4.0-test2-pre3
1571===============================================================================
1572Changes for patch v172
1573
1574Work sponsored by SGI
1575
1576- Changed interface to <devfs_register>
1577
1578- Changed interface to <devfs_register_series>
1579===============================================================================
1580Changes for patch v173
1581
1582Work sponsored by SGI
1583
1584- Simplified interface to <devfs_mk_symlink>
1585
1586- Simplified interface to <devfs_mk_dir>
1587
1588- Simplified interface to <devfs_find_handle>
1589===============================================================================
1590Changes for patch v174
1591
1592Work sponsored by SGI
1593
1594- Updated README from master HTML file
1595===============================================================================
1596Changes for patch v175
1597
1598Work sponsored by SGI
1599
1600- DocBook update for fs/devfs/base.c
1601 Thanks to Tim Waugh <twaugh@redhat.com>
1602
1603- Removed stale fs/tunnel.c (was never used or completed)
1604===============================================================================
1605Changes for patch v176
1606
1607Work sponsored by SGI
1608
1609- Updated ToDo list
1610
1611- Removed sample modules.conf: now distributed with devfsd
1612
1613- Updated README from master HTML file
1614
1615- Ported to kernel 2.4.0-test3-pre4 (which had devfs-patch-v174)
1616===============================================================================
1617Changes for patch v177
1618
1619- Updated README from master HTML file
1620
1621- Documentation cleanups
1622
1623- Ensure <devfs_generate_path> terminates string for root entry
1624 Thanks to Tim Jansen <tim@tjansen.de>
1625
1626- Exported <devfs_get_name> to modules
1627
1628- Make <devfs_mk_symlink> send events to devfsd
1629
1630- Cleaned up option processing in <devfs_setup>
1631
1632- Fixed bugs in handling symlinks: could leak or cause Oops
1633
1634- Cleaned up directory handling by separating fops
1635 Thanks to Alexander Viro <viro@parcelfarce.linux.theplanet.co.uk>
1636===============================================================================
1637Changes for patch v178
1638
1639- Fixed handling of inverted options in <devfs_setup>
1640===============================================================================
1641Changes for patch v179
1642
1643- Adjusted <try_modload> to account for <devfs_generate_path> fix
1644===============================================================================
1645Changes for patch v180
1646
1647- Fixed !CONFIG_DEVFS_FS stub declaration of <devfs_get_info>
1648===============================================================================
1649Changes for patch v181
1650
1651- Answered question posed by Al Viro and removed his comments from <devfs_open>
1652
1653- Moved setting of registered flag after other fields are changed
1654
1655- Fixed race between <devfsd_close> and <devfsd_notify_one>
1656
1657- Global VFS changes added bogus BKL to devfsd_close(): removed
1658
1659- Widened locking in <devfs_readlink> and <devfs_follow_link>
1660
1661- Replaced <devfsd_read> stack usage with <devfsd_ioctl> kmalloc
1662
1663- Simplified locking in <devfsd_ioctl> and fixed memory leak
1664===============================================================================
1665Changes for patch v182
1666
1667- Created <devfs_*alloc_major> and <devfs_*alloc_devnum>
1668
1669- Removed broken devnum allocation and use <devfs_alloc_devnum>
1670
1671- Fixed old devnum leak by calling new <devfs_dealloc_devnum>
1672
1673- Created <devfs_*alloc_unique_number>
1674
1675- Fixed number leak for /dev/cdroms/cdrom%d
1676
1677- Fixed number leak for /dev/discs/disc%d
1678===============================================================================
1679Changes for patch v183
1680
1681- Fixed bug in <devfs_setup> which could hang boot process
1682===============================================================================
1683Changes for patch v184
1684
1685- Documentation typo fix for fs/devfs/util.c
1686
1687- Fixed drivers/char/stallion.c for devfs
1688
1689- Added DEVFSD_NOTIFY_DELETE event
1690
1691- Updated README from master HTML file
1692
1693- Removed #include <asm/segment.h> from fs/devfs/base.c
1694===============================================================================
1695Changes for patch v185
1696
1697- Made <block_semaphore> and <char_semaphore> in fs/devfs/util.c
1698 private
1699
1700- Fixed inode table races by removing it and using inode->u.generic_ip
1701 instead
1702
1703- Moved <devfs_read_inode> into <get_vfs_inode>
1704
1705- Moved <devfs_write_inode> into <devfs_notify_change>
1706===============================================================================
1707Changes for patch v186
1708
1709- Fixed race in <devfs_do_symlink> for uni-processor
1710
1711- Updated README from master HTML file
1712===============================================================================
1713Changes for patch v187
1714
1715- Fixed drivers/char/stallion.c for devfs
1716
1717- Fixed drivers/char/rocket.c for devfs
1718
1719- Fixed bug in <devfs_alloc_unique_number>: limited to 128 numbers
1720===============================================================================
1721Changes for patch v188
1722
1723- Updated major masks in fs/devfs/util.c up to Linus' "no new majors"
1724 proclamation. Block: were 126 now 122 free, char: were 26 now 19 free
1725
1726- Updated README from master HTML file
1727
1728- Removed remnant of multi-mount support in <devfs_mknod>
1729
1730- Removed unused DEVFS_FL_SHOW_UNREG flag
1731===============================================================================
1732Changes for patch v189
1733
1734- Removed nlink field from struct devfs_inode
1735
1736- Removed auto-ownership for /dev/pty/* (BSD ptys) and used
1737 DEVFS_FL_CURRENT_OWNER|DEVFS_FL_NO_PERSISTENCE for /dev/pty/s* (just
1738 like Unix98 pty slaves) and made /dev/pty/m* rw-rw-rw- access
1739===============================================================================
1740Changes for patch v190
1741
1742- Updated README from master HTML file
1743
1744- Replaced BKL with global rwsem to protect symlink data (quick and
1745 dirty hack)
1746===============================================================================
1747Changes for patch v191
1748
1749- Replaced global rwsem for symlink with per-link refcount
1750===============================================================================
1751Changes for patch v192
1752
1753- Removed unnecessary #ifdef CONFIG_DEVFS_FS from arch/i386/kernel/mtrr.c
1754
1755- Ported to kernel 2.4.10-pre11
1756
1757- Set inode->i_mapping->a_ops for block nodes in <get_vfs_inode>
1758===============================================================================
1759Changes for patch v193
1760
1761- Went back to global rwsem for symlinks (refcount scheme no good)
1762===============================================================================
1763Changes for patch v194
1764
1765- Fixed overrun in <devfs_link> by removing function (not needed)
1766
1767- Updated README from master HTML file
1768===============================================================================
1769Changes for patch v195
1770
1771- Fixed buffer underrun in <try_modload>
1772
1773- Moved down_read() from <search_for_entry_in_dir> to <find_entry>
1774===============================================================================
1775Changes for patch v196
1776
1777- Fixed race in <devfsd_ioctl> when setting event mask
1778 Thanks to Kari Hurtta <hurtta@leija.mh.fmi.fi>
1779
1780- Avoid deadlock in <devfs_follow_link> by using temporary buffer
1781===============================================================================
1782Changes for patch v197
1783
1784- First release of new locking code for devfs core (v1.0)
1785
1786- Fixed bug in drivers/cdrom/cdrom.c
1787===============================================================================
1788Changes for patch v198
1789
1790- Discard temporary buffer, now use "%s" for dentry names
1791
1792- Don't generate path in <try_modload>: use fake entry instead
1793
1794- Use "existing" directory in <_devfs_make_parent_for_leaf>
1795
1796- Use slab cache rather than fixed buffer for devfsd events
1797===============================================================================
1798Changes for patch v199
1799
1800- Removed obsolete usage of DEVFS_FL_NO_PERSISTENCE
1801
1802- Send DEVFSD_NOTIFY_REGISTERED events in <devfs_mk_dir>
1803
1804- Fixed locking bug in <devfs_d_revalidate_wait> due to typo
1805
1806- Do not send CREATE, CHANGE, ASYNC_OPEN or DELETE events from devfsd
1807 or children
1808===============================================================================
1809Changes for patch v200
1810
1811- Ported to kernel 2.5.1-pre2
1812===============================================================================
1813Changes for patch v201
1814
1815- Fixed bug in <devfsd_read>: was dereferencing freed pointer
1816===============================================================================
1817Changes for patch v202
1818
1819- Fixed bug in <devfsd_close>: was dereferencing freed pointer
1820
1821- Added process group check for devfsd privileges
1822===============================================================================
1823Changes for patch v203
1824
1825- Use SLAB_ATOMIC in <devfsd_notify_de> from <devfs_d_delete>
1826===============================================================================
1827Changes for patch v204
1828
1829- Removed long obsolete rc.devfs
1830
1831- Return old entry in <devfs_mk_dir> for 2.4.x kernels
1832
1833- Updated README from master HTML file
1834
1835- Increment refcount on module in <check_disc_changed>
1836
1837- Created <devfs_get_handle> and exported <devfs_put>
1838
1839- Increment refcount on module in <devfs_get_ops>
1840
1841- Created <devfs_put_ops> and used where needed to fix races
1842
1843- Added clarifying comments in response to preliminary EMC code review
1844
1845- Added poisoning to <devfs_put>
1846
1847- Improved debugging messages
1848
1849- Fixed unregister bugs in drivers/md/lvm-fs.c
1850===============================================================================
1851Changes for patch v205
1852
1853- Corrected (made useful) debugging message in <unregister>
1854
1855- Moved <kmem_cache_create> in <mount_devfs_fs> to <init_devfs_fs>
1856
1857- Fixed drivers/md/lvm-fs.c to create "lvm" entry
1858
1859- Added magic number to guard against scribbling drivers
1860
1861- Only return old entry in <devfs_mk_dir> if a directory
1862
1863- Defined macros for error and debug messages
1864
1865- Updated README from master HTML file
1866===============================================================================
1867Changes for patch v206
1868
1869- Added support for multiple Compaq cpqarray controllers
1870
1871- Fixed (rare, old) race in <devfs_lookup>
1872===============================================================================
1873Changes for patch v207
1874
1875- Fixed deadlock bug in <devfs_d_revalidate_wait>
1876
1877- Tag VFS deletable in <devfs_mk_symlink> if handle ignored
1878
1879- Updated README from master HTML file
1880===============================================================================
1881Changes for patch v208
1882
1883- Added KERN_* to remaining messages
1884
1885- Cleaned up declaration of <stat_read>
1886
1887- Updated README from master HTML file
1888===============================================================================
1889Changes for patch v209
1890
1891- Updated README from master HTML file
1892
1893- Removed silently introduced calls to lock_kernel() and
1894 unlock_kernel() due to recent VFS locking changes. BKL isn't
1895 required in devfs
1896
1897- Changed <devfs_rmdir> to allow later additions if not yet empty
1898
1899- Added calls to <devfs_register_partitions> in drivers/block/blkpc.c
1900 <add_partition> and <del_partition>
1901
1902- Fixed bug in <devfs_alloc_unique_number>: was clearing beyond
1903 bitfield
1904
1905- Fixed bitfield data type for <devfs_*alloc_devnum>
1906
1907- Made major bitfield type and initialiser 64 bit safe
1908===============================================================================
1909Changes for patch v210
1910
1911- Updated fs/devfs/util.c to fix shift warning on 64 bit machines
1912 Thanks to Anton Blanchard <anton@samba.org>
1913
1914- Updated README from master HTML file
1915===============================================================================
1916Changes for patch v211
1917
1918- Do not put miscellaneous character devices in /dev/misc if they
1919 specify their own directory (i.e. contain a '/' character)
1920
1921- Copied macro for error messages from fs/devfs/base.c to
1922 fs/devfs/util.c and made use of this macro
1923
1924- Removed 2.4.x compatibility code from fs/devfs/base.c
1925===============================================================================
1926Changes for patch v212
1927
1928- Added BKL to <devfs_open> because drivers still need it
1929===============================================================================
1930Changes for patch v213
1931
1932- Protected <scan_dir_for_removable> and <get_removable_partition>
1933 from changing directory contents
1934===============================================================================
1935Changes for patch v214
1936
1937- Switched to ISO C structure field initialisers
1938
1939- Switch to set_current_state() and move before add_wait_queue()
1940
1941- Updated README from master HTML file
1942
1943- Fixed devfs entry leak in <devfs_readdir> when *readdir fails
1944===============================================================================
1945Changes for patch v215
1946
1947- Created <devfs_find_and_unregister>
1948
1949- Switched many functions from <devfs_find_handle> to
1950 <devfs_find_and_unregister>
1951
1952- Switched many functions from <devfs_find_handle> to <devfs_get_handle>
1953===============================================================================
1954Changes for patch v216
1955
1956- Switched arch/ia64/sn/io/hcl.c from <devfs_find_handle> to
1957 <devfs_get_handle>
1958
1959- Removed deprecated <devfs_find_handle>
1960===============================================================================
1961Changes for patch v217
1962
1963- Exported <devfs_find_and_unregister> and <devfs_only> to modules
1964
1965- Updated README from master HTML file
1966
1967- Fixed module unload race in <devfs_open>
1968===============================================================================
1969Changes for patch v218
1970
1971- Removed DEVFS_FL_AUTO_OWNER flag
1972
1973- Switched lingering structure field initialiser to ISO C
1974
1975- Added locking when setting/clearing flags
1976
1977- Documentation fix in fs/devfs/util.c
diff --git a/Documentation/filesystems/devfs/README b/Documentation/filesystems/devfs/README
deleted file mode 100644
index aabfba24bc2e..000000000000
--- a/Documentation/filesystems/devfs/README
+++ /dev/null
@@ -1,1959 +0,0 @@
1Devfs (Device File System) FAQ
2
3
4Linux Devfs (Device File System) FAQ
5Richard Gooch
620-AUG-2002
7
8
9Document languages:
10
11
12
13
14
15
16
17-----------------------------------------------------------------------------
18
19NOTE: the master copy of this document is available online at:
20
21http://www.atnf.csiro.au/~rgooch/linux/docs/devfs.html
22and looks much better than the text version distributed with the
23kernel sources. A mirror site is available at:
24
25http://www.ras.ucalgary.ca/~rgooch/linux/docs/devfs.html
26
27There is also an optional daemon that may be used with devfs. You can
28find out more about it at:
29
30http://www.atnf.csiro.au/~rgooch/linux/
31
32A mailing list is available which you may subscribe to. Send
33email
34to majordomo@oss.sgi.com with the following line in the
35body of the message:
36subscribe devfs
37To unsubscribe, send the message body:
38unsubscribe devfs
39instead. The list is archived at
40
41http://oss.sgi.com/projects/devfs/archive/.
42
43-----------------------------------------------------------------------------
44
45Contents
46
47
48What is it?
49
50Why do it?
51
52Who else does it?
53
54How it works
55
56Operational issues (essential reading)
57
58Instructions for the impatient
59Permissions persistence across reboots
60Dealing with drivers without devfs support
61All the way with Devfs
62Other Issues
63Kernel Naming Scheme
64Devfsd Naming Scheme
65Old Compatibility Names
66SCSI Host Probing Issues
67
68
69
70Device drivers currently ported
71
72Allocation of Device Numbers
73
74Questions and Answers
75
76Making things work
77Alternatives to devfs
78What I don't like about devfs
79How to report bugs
80Strange kernel messages
81Compilation problems with devfsd
82
83
84Other resources
85
86Translations of this document
87
88
89-----------------------------------------------------------------------------
90
91
92What is it?
93
94Devfs is an alternative to "real" character and block special devices
95on your root filesystem. Kernel device drivers can register devices by
96name rather than major and minor numbers. These devices will appear in
97devfs automatically, with whatever default ownership and
98protection the driver specified. A daemon (devfsd) can be used to
99override these defaults. Devfs has been in the kernel since 2.3.46.
100
101NOTE that devfs is entirely optional. If you prefer the old
102disc-based device nodes, then simply leave CONFIG_DEVFS_FS=n (the
103default). In this case, nothing will change. ALSO NOTE that if you do
104enable devfs, the defaults are such that full compatibility is
105maintained with the old devices names.
106
107There are two aspects to devfs: one is the underlying device
108namespace, which is a namespace just like any mounted filesystem. The
109other aspect is the filesystem code which provides a view of the
110device namespace. The reason I make a distinction is because devfs
111can be mounted many times, with each mount showing the same device
112namespace. Changes made are global to all mounted devfs filesystems.
113Also, because the devfs namespace exists without any devfs mounts, you
114can easily mount the root filesystem by referring to an entry in the
115devfs namespace.
116
117
118The cost of devfs is a small increase in kernel code size and memory
119usage. About 7 pages of code (some of that in __init sections) and 72
120bytes for each entry in the namespace. A modest system has only a
121couple of hundred device entries, so this costs a few more
122pages. Compare this with the suggestion to put /dev on a <a
123href="#why-faq-ramdisc">ramdisc.
124
125On a typical machine, the cost is under 0.2 percent. On a modest
126system with 64 MBytes of RAM, the cost is under 0.1 percent. The
127accusations of "bloatware" levelled at devfs are not justified.
128
129-----------------------------------------------------------------------------
130
131
132Why do it?
133
134There are several problems that devfs addresses. Some of these
135problems are more serious than others (depending on your point of
136view), and some can be solved without devfs. However, the totality of
137these problems really calls out for devfs.
138
139The choice is a patchwork of inefficient user space solutions, which
140are complex and likely to be fragile, or to use a simple and efficient
141devfs which is robust.
142
143There have been many counter-proposals to devfs, all seeking to
144provide some of the benefits without actually implementing devfs. So
145far there has been an absence of code and no proposed alternative has
146been able to provide all the features that devfs does. Further,
147alternative proposals require far more complexity in user-space (and
148still deliver less functionality than devfs). Some people have the
149mantra of reducing "kernel bloat", but don't consider the effects on
150user-space.
151
152A good solution limits the total complexity of kernel-space and
153user-space.
154
155
156Major&minor allocation
157
158The existing scheme requires the allocation of major and minor device
159numbers for each and every device. This means that a central
160co-ordinating authority is required to issue these device numbers
161(unless you're developing a "private" device driver), in order to
162preserve uniqueness. Devfs shifts the burden to a namespace. This may
163not seem like a huge benefit, but actually it is. Since driver authors
164will naturally choose a device name which reflects the functionality
165of the device, there is far less potential for namespace conflict.
166Solving this requires a kernel change.
167
168/dev management
169
170Because you currently access devices through device nodes, these must
171be created by the system administrator. For standard devices you can
172usually find a MAKEDEV programme which creates all these (hundreds!)
173of nodes. This means that changes in the kernel must be reflected by
174changes in the MAKEDEV programme, or else the system administrator
175creates device nodes by hand.
176
177The basic problem is that there are two separate databases of
178major and minor numbers. One is in the kernel and one is in /dev (or
179in a MAKEDEV programme, if you want to look at it that way). This is
180duplication of information, which is not good practice.
181Solving this requires a kernel change.
182
183/dev growth
184
185A typical /dev has over 1200 nodes! Most of these devices simply don't
186exist because the hardware is not available. A huge /dev increases the
187time to access devices (I'm just referring to the dentry lookup times
188and the time taken to read inodes off disc: the next subsection shows
189some more horrors).
190
191An example of how big /dev can grow is if we consider SCSI devices:
192
193host 6 bits (say up to 64 hosts on a really big machine)
194channel 4 bits (say up to 16 SCSI buses per host)
195id 4 bits
196lun 3 bits
197partition 6 bits
198TOTAL 23 bits
199
200
201This requires 8 Mega (1024*1024) inodes if we want to store all
202possible device nodes. Even if we scrap everything but id,partition
203and assume a single host adapter with a single SCSI bus and only one
204logical unit per SCSI target (id), that's still 10 bits or 1024
205inodes. Each VFS inode takes around 256 bytes (kernel 2.1.78), so
206that's 256 kBytes of inode storage on disc (assuming real inodes take
207a similar amount of space as VFS inodes). This is actually not so bad,
208because disc is cheap these days. Embedded systems would care about
209256 kBytes of /dev inodes, but you could argue that embedded systems
210would have hand-tuned /dev directories. I've had to do just that on my
211embedded systems, but I would rather just leave it to devfs.
212
213Another issue is the time taken to lookup an inode when first
214referenced. Not only does this take time in scanning through a list in
215memory, but also the seek times to read the inodes off disc.
216This could be solved in user-space using a clever programme which
217scanned the kernel logs and deleted /dev entries which are not
218available and created them when they were available. This programme
219would need to be run every time a new module was loaded, which would
220slow things down a lot.
221
222There is an existing programme called scsidev which will automatically
223create device nodes for SCSI devices. It can do this by scanning files
224in /proc/scsi. Unfortunately, to extend this idea to other device
225nodes would require significant modifications to existing drivers (so
226they too would provide information in /proc). This is a non-trivial
227change (I should know: devfs has had to do something similar). Once
228you go to this much effort, you may as well use devfs itself (which
229also provides this information). Furthermore, such a system would
230likely be implemented in an ad-hoc fashion, as different drivers will
231provide their information in different ways.
232
233Devfs is much cleaner, because it (naturally) has a uniform mechanism
234to provide this information: the device nodes themselves!
235
236
237Node to driver file_operations translation
238
239There is an important difference between the way disc-based character
240and block nodes and devfs entries make the connection between an entry
241in /dev and the actual device driver.
242
243With the current 8 bit major and minor numbers the connection between
244disc-based c&b nodes and per-major drivers is done through a
245fixed-length table of 128 entries. The various filesystem types set
246the inode operations for c&b nodes to {chr,blk}dev_inode_operations,
247so when a device is opened a few quick levels of indirection bring us
248to the driver file_operations.
249
250For miscellaneous character devices a second step is required: there
251is a scan for the driver entry with the same minor number as the file
252that was opened, and the appropriate minor open method is called. This
253scanning is done *every time* you open a device node. Potentially, you
254may be searching through dozens of misc. entries before you find your
255open method. While not an enormous performance overhead, this does
256seem pointless.
257
258Linux *must* move beyond the 8 bit major and minor barrier,
259somehow. If we simply increase each to 16 bits, then the indexing
260scheme used for major driver lookup becomes untenable, because the
261major tables (one each for character and block devices) would need to
262be 64 k entries long (512 kBytes on x86, 1 MByte for 64 bit
263systems). So we would have to use a scheme like that used for
264miscellaneous character devices, which means the search time goes up
265linearly with the average number of major device drivers on your
266system. Not all "devices" are hardware, some are higher-level drivers
267like KGI, so you can get more "devices" without adding hardware
268You can improve this by creating an ordered (balanced:-)
269binary tree, in which case your search time becomes log(N).
270Alternatively, you can use hashing to speed up the search.
271But why do that search at all if you don't have to? Once again, it
272seems pointless.
273
274Note that devfs doesn't use the major&minor system. For devfs
275entries, the connection is done when you lookup the /dev entry. When
276devfs_register() is called, an internal table is appended which has
277the entry name and the file_operations. If the dentry cache doesn't
278have the /dev entry already, this internal table is scanned to get the
279file_operations, and an inode is created. If the dentry cache already
280has the entry, there is *no lookup time* (other than the dentry scan
281itself, but we can't avoid that anyway, and besides Linux dentries
282cream other OS's which don't have them:-). Furthermore, the number of
283node entries in a devfs is only the number of available device
284entries, not the number of *conceivable* entries. Even if you remove
285unnecessary entries in a disc-based /dev, the number of conceivable
286entries remains the same: you just limit yourself in order to save
287space.
288
289Devfs provides a fast connection between a VFS node and the device
290driver, in a scalable way.
291
292/dev as a system administration tool
293
294Right now /dev contains a list of conceivable devices, most of which I
295don't have. Devfs only shows those devices available on my
296system. This means that listing /dev is a handy way of checking what
297devices are available.
298
299Major&minor size
300
301Existing major and minor numbers are limited to 8 bits each. This is
302now a limiting factor for some drivers, particularly the SCSI disc
303driver, which consumes a single major number. Only 16 discs are
304supported, and each disc may have only 15 partitions. Maybe this isn't
305a problem for you, but some of us are building huge Linux systems with
306disc arrays. With devfs an arbitrary pointer can be associated with
307each device entry, which can be used to give an effective 32 bit
308device identifier (i.e. that's like having a 32 bit minor
309number). Since this is private to the kernel, there are no C library
310compatibility issues which you would have with increasing major and
311minor number sizes. See the section on "Allocation of Device Numbers"
312for details on maintaining compatibility with userspace.
313
314Solving this requires a kernel change.
315
316Since writing this, the kernel has been modified so that the SCSI disc
317driver has more major numbers allocated to it and now supports up to
318128 discs. Since these major numbers are non-contiguous (a result of
319unplanned expansion), the implementation is a little more cumbersome
320than originally.
321
322Just like the changes to IPv4 to fix impending limitations in the
323address space, people find ways around the limitations. In the long
324run, however, solutions like IPv6 or devfs can't be put off forever.
325
326Read-only root filesystem
327
328Having your device nodes on the root filesystem means that you can't
329operate properly with a read-only root filesystem. This is because you
330want to change ownerships and protections of tty devices. Existing
331practice prevents you using a CD-ROM as your root filesystem for a
332*real* system. Sure, you can boot off a CD-ROM, but you can't change
333tty ownerships, so it's only good for installing.
334
335Also, you can't use a shared NFS root filesystem for a cluster of
336discless Linux machines (having tty ownerships changed on a common
337/dev is not good). Nor can you embed your root filesystem in a
338ROM-FS.
339
340You can get around this by creating a RAMDISC at boot time, making
341an ext2 filesystem in it, mounting it somewhere and copying the
342contents of /dev into it, then unmounting it and mounting it over
343/dev.
344
345A devfs is a cleaner way of solving this.
346
347Non-Unix root filesystem
348
349Non-Unix filesystems (such as NTFS) can't be used for a root
350filesystem because they variously don't support character and block
351special files or symbolic links. You can't have a separate disc-based
352or RAMDISC-based filesystem mounted on /dev because you need device
353nodes before you can mount these. Devfs can be mounted without any
354device nodes. Devlinks won't work because symlinks aren't supported.
355An alternative solution is to use initrd to mount a RAMDISC initial
356root filesystem (which is populated with a minimal set of device
357nodes), and then construct a new /dev in another RAMDISC, and finally
358switch to your non-Unix root filesystem. This requires clever boot
359scripts and a fragile and conceptually complex boot procedure.
360
361Devfs solves this in a robust and conceptually simple way.
362
363PTY security
364
365Current pseudo-tty (pty) devices are owned by root and read-writable
366by everyone. The user of a pty-pair cannot change
367ownership/protections without being suid-root.
368
369This could be solved with a secure user-space daemon which runs as
370root and does the actual creation of pty-pairs. Such a daemon would
371require modification to *every* programme that wants to use this new
372mechanism. It also slows down creation of pty-pairs.
373
374An alternative is to create a new open_pty() syscall which does much
375the same thing as the user-space daemon. Once again, this requires
376modifications to pty-handling programmes.
377
378The devfs solution allows a device driver to "tag" certain device
379files so that when an unopened device is opened, the ownerships are
380changed to the current euid and egid of the opening process, and the
381protections are changed to the default registered by the driver. When
382the device is closed ownership is set back to root and protections are
383set back to read-write for everybody. No programme need be changed.
384The devpts filesystem provides this auto-ownership feature for Unix98
385ptys. It doesn't support old-style pty devices, nor does it have all
386the other features of devfs.
387
388Intelligent device management
389
390Devfs implements a simple yet powerful protocol for communication with
391a device management daemon (devfsd) which runs in user space. It is
392possible to send a message (either synchronously or asynchronously) to
393devfsd on any event, such as registration/unregistration of device
394entries, opening and closing devices, looking up inodes, scanning
395directories and more. This has many possibilities. Some of these are
396already implemented. See:
397
398
399http://www.atnf.csiro.au/~rgooch/linux/
400
401Device entry registration events can be used by devfsd to change
402permissions of newly-created device nodes. This is one mechanism to
403control device permissions.
404
405Device entry registration/unregistration events can be used to run
406programmes or scripts. This can be used to provide automatic mounting
407of filesystems when a new block device media is inserted into the
408drive.
409
410Asynchronous device open and close events can be used to implement
411clever permissions management. For example, the default permissions on
412/dev/dsp do not allow everybody to read from the device. This is
413sensible, as you don't want some remote user recording what you say at
414your console. However, the console user is also prevented from
415recording. This behaviour is not desirable. With asynchronous device
416open and close events, you can have devfsd run a programme or script
417when console devices are opened to change the ownerships for *other*
418device nodes (such as /dev/dsp). On closure, you can run a different
419script to restore permissions. An advantage of this scheme over
420modifying the C library tty handling is that this works even if your
421programme crashes (how many times have you seen the utmp database with
422lingering entries for non-existent logins?).
423
424Synchronous device open events can be used to perform intelligent
425device access protections. Before the device driver open() method is
426called, the daemon must first validate the open attempt, by running an
427external programme or script. This is far more flexible than access
428control lists, as access can be determined on the basis of other
429system conditions instead of just the UID and GID.
430
431Inode lookup events can be used to authenticate module autoload
432requests. Instead of using kmod directly, the event is sent to
433devfsd which can implement an arbitrary authentication before loading
434the module itself.
435
436Inode lookup events can also be used to construct arbitrary
437namespaces, without having to resort to populating devfs with symlinks
438to devices that don't exist.
439
440Speculative Device Scanning
441
442Consider an application (like cdparanoia) that wants to find all
443CD-ROM devices on the system (SCSI, IDE and other types), whether or
444not their respective modules are loaded. The application must
445speculatively open certain device nodes (such as /dev/sr0 for the SCSI
446CD-ROMs) in order to make sure the module is loaded. This requires
447that all Linux distributions follow the standard device naming scheme
448(last time I looked RedHat did things differently). Devfs solves the
449naming problem.
450
451The same application also wants to see which devices are actually
452available on the system. With the existing system it needs to read the
453/dev directory and speculatively open each /dev/sr* device to
454determine if the device exists or not. With a large /dev this is an
455inefficient operation, especially if there are many /dev/sr* nodes. A
456solution like scsidev could reduce the number of /dev/sr* entries (but
457of course that also requires all that inefficient directory scanning).
458
459With devfs, the application can open the /dev/sr directory
460(which triggers the module autoloading if required), and proceed to
461read /dev/sr. Since only the available devices will have
462entries, there are no inefficencies in directory scanning or device
463openings.
464
465-----------------------------------------------------------------------------
466
467Who else does it?
468
469FreeBSD has a devfs implementation. Solaris and AIX each have a
470pseudo-devfs (something akin to scsidev but for all devices, with some
471unspecified kernel support). BeOS, Plan9 and QNX also have it. SGI's
472IRIX 6.4 and above also have a device filesystem.
473
474While we shouldn't just automatically do something because others do
475it, we should not ignore the work of others either. FreeBSD has a lot
476of competent people working on it, so their opinion should not be
477blithely ignored.
478
479-----------------------------------------------------------------------------
480
481
482How it works
483
484Registering device entries
485
486For every entry (device node) in a devfs-based /dev a driver must call
487devfs_register(). This adds the name of the device entry, the
488file_operations structure pointer and a few other things to an
489internal table. Device entries may be added and removed at any
490time. When a device entry is registered, it automagically appears in
491any mounted devfs'.
492
493Inode lookup
494
495When a lookup operation on an entry is performed and if there is no
496driver information for that entry devfs will attempt to call
497devfsd. If still no driver information can be found then a negative
498dentry is yielded and the next stage operation will be called by the
499VFS (such as create() or mknod() inode methods). If driver information
500can be found, an inode is created (if one does not exist already) and
501all is well.
502
503Manually creating device nodes
504
505The mknod() method allows you to create an ordinary named pipe in the
506devfs, or you can create a character or block special inode if one
507does not already exist. You may wish to create a character or block
508special inode so that you can set permissions and ownership. Later, if
509a device driver registers an entry with the same name, the
510permissions, ownership and times are retained. This is how you can set
511the protections on a device even before the driver is loaded. Once you
512create an inode it appears in the directory listing.
513
514Unregistering device entries
515
516A device driver calls devfs_unregister() to unregister an entry.
517
518Chroot() gaols
519
5202.2.x kernels
521
522The semantics of inode creation are different when devfs is mounted
523with the "explicit" option. Now, when a device entry is registered, it
524will not appear until you use mknod() to create the device. It doesn't
525matter if you mknod() before or after the device is registered with
526devfs_register(). The purpose of this behaviour is to support
527chroot(2) gaols, where you want to mount a minimal devfs inside the
528gaol. Only the devices you specifically want to be available (through
529your mknod() setup) will be accessible.
530
5312.4.x kernels
532
533As of kernel 2.3.99, the VFS has had the ability to rebind parts of
534the global filesystem namespace into another part of the namespace.
535This now works even at the leaf-node level, which means that
536individual files and device nodes may be bound into other parts of the
537namespace. This is like making links, but better, because it works
538across filesystems (unlike hard links) and works through chroot()
539gaols (unlike symbolic links).
540
541Because of these improvements to the VFS, the multi-mount capability
542in devfs is no longer needed. The administrator may create a minimal
543device tree inside a chroot(2) gaol by using VFS bindings. As this
544provides most of the features of the devfs multi-mount capability, I
545removed the multi-mount support code (after issuing an RFC). This
546yielded code size reductions and simplifications.
547
548If you want to construct a minimal chroot() gaol, the following
549command should suffice:
550
551mount --bind /dev/null /gaol/dev/null
552
553
554Repeat for other device nodes you want to expose. Simple!
555
556-----------------------------------------------------------------------------
557
558
559Operational issues
560
561
562Instructions for the impatient
563
564Nobody likes reading documentation. People just want to get in there
565and play. So this section tells you quickly the steps you need to take
566to run with devfs mounted over /dev. Skip these steps and you will end
567up with a nearly unbootable system. Subsequent sections describe the
568issues in more detail, and discuss non-essential configuration
569options.
570
571Devfsd
572OK, if you're reading this, I assume you want to play with
573devfs. First you should ensure that /usr/src/linux contains a
574recent kernel source tree. Then you need to compile devfsd, the device
575management daemon, available at
576
577http://www.atnf.csiro.au/~rgooch/linux/.
578Because the kernel has a naming scheme
579which is quite different from the old naming scheme, you need to
580install devfsd so that software and configuration files that use the
581old naming scheme will not break.
582
583Compile and install devfsd. You will be provided with a default
584configuration file /etc/devfsd.conf which will provide
585compatibility symlinks for the old naming scheme. Don't change this
586config file unless you know what you're doing. Even if you think you
587do know what you're doing, don't change it until you've followed all
588the steps below and booted a devfs-enabled system and verified that it
589works.
590
591Now edit your main system boot script so that devfsd is started at the
592very beginning (before any filesystem
593checks). /etc/rc.d/rc.sysinit is often the main boot script
594on systems with SysV-style boot scripts. On systems with BSD-style
595boot scripts it is often /etc/rc. Also check
596/sbin/rc.
597
598NOTE that the line you put into the boot
599script should be exactly:
600
601/sbin/devfsd /dev
602
603DO NOT use some special daemon-launching
604programme, otherwise the boot script may not wait for devfsd to finish
605initialising.
606
607System Libraries
608There may still be some problems because of broken software making
609assumptions about device names. In particular, some software does not
610handle devices which are symbolic links. If you are running a libc 5
611based system, install libc 5.4.44 (if you have libc 5.4.46, go back to
612libc 5.4.44, which is actually correct). If you are running a glibc
613based system, make sure you have glibc 2.1.3 or later.
614
615/etc/securetty
616PAM (Pluggable Authentication Modules) is supposed to be a flexible
617mechanism for providing better user authentication and access to
618services. Unfortunately, it's also fragile, complex and undocumented
619(check out RedHat 6.1, and probably other distributions as well). PAM
620has problems with symbolic links. Append the following lines to your
621/etc/securetty file:
622
623vc/1
624vc/2
625vc/3
626vc/4
627vc/5
628vc/6
629vc/7
630vc/8
631
632This will not weaken security. If you have a version of util-linux
633earlier than 2.10.h, please upgrade to 2.10.h or later. If you
634absolutely cannot upgrade, then also append the following lines to
635your /etc/securetty file:
636
6371
6382
6393
6404
6415
6426
6437
6448
645
646This may potentially weaken security by allowing root logins over the
647network (a password is still required, though). However, since there
648are problems with dealing with symlinks, I'm suspicious of the level
649of security offered in any case.
650
651XFree86
652While not essential, it's probably a good idea to upgrade to XFree86
6534.0, as patches went in to make it more devfs-friendly. If you don't,
654you'll probably need to apply the following patch to
655/etc/security/console.perms so that ordinary users can run
656startx. Note that not all distributions have this file (e.g. Debian),
657so if it's not present, don't worry about it.
658
659--- /etc/security/console.perms.orig Sat Apr 17 16:26:47 1999
660+++ /etc/security/console.perms Fri Feb 25 23:53:55 2000
661@@ -14,7 +14,7 @@
662 # man 5 console.perms
663
664 # file classes -- these are regular expressions
665-<console>=tty[0-9][0-9]* :[0-9]\.[0-9] :[0-9]
666+<console>=tty[0-9][0-9]* vc/[0-9][0-9]* :[0-9]\.[0-9] :[0-9]
667
668 # device classes -- these are shell-style globs
669 <floppy>=/dev/fd[0-1]*
670
671If the patch does not apply, then change the line:
672
673<console>=tty[0-9][0-9]* :[0-9]\.[0-9] :[0-9]
674
675with:
676
677<console>=tty[0-9][0-9]* vc/[0-9][0-9]* :[0-9]\.[0-9] :[0-9]
678
679
680Disable devpts
681I've had a report of devpts mounted on /dev/pts not working
682correctly. Since devfs will also manage /dev/pts, there is no
683need to mount devpts as well. You should either edit your
684/etc/fstab so devpts is not mounted, or disable devpts from
685your kernel configuration.
686
687Unsupported drivers
688Not all drivers have devfs support. If you depend on one of these
689drivers, you will need to create a script or tarfile that you can use
690at boot time to create device nodes as appropriate. There is a
691section which describes this. Another
692section lists the drivers which have
693devfs support.
694
695/dev/mouse
696
697Many disributions configure /dev/mouse to be the mouse device
698for XFree86 and GPM. I actually think this is a bad idea, because it
699adds another level of indirection. When looking at a config file, if
700you see /dev/mouse you're left wondering which mouse
701is being referred to. Hence I recommend putting the actual mouse
702device (for example /dev/psaux) into your
703/etc/X11/XF86Config file (and similarly for the GPM
704configuration file).
705
706Alternatively, use the same technique used for unsupported drivers
707described above.
708
709The Kernel
710Finally, you need to make sure devfs is compiled into your kernel. Set
711CONFIG_EXPERIMENTAL=y, CONFIG_DEVFS_FS=y and CONFIG_DEVFS_MOUNT=y by
712using favourite configuration tool (i.e. make config or
713make xconfig) and then make clean and then recompile your kernel and
714modules. At boot, devfs will be mounted onto /dev.
715
716If you encounter problems booting (for example if you forgot a
717configuration step), you can pass devfs=nomount at the kernel
718boot command line. This will prevent the kernel from mounting devfs at
719boot time onto /dev.
720
721In general, a kernel built with CONFIG_DEVFS_FS=y but without mounting
722devfs onto /dev is completely safe, and requires no
723configuration changes. One exception to take note of is when
724LABEL= directives are used in /etc/fstab. In this
725case you will be unable to boot properly. This is because the
726mount(8) programme uses /proc/partitions as part of
727the volume label search process, and the device names it finds are not
728available, because setting CONFIG_DEVFS_FS=y changes the names in
729/proc/partitions, irrespective of whether devfs is mounted.
730
731Now you've finished all the steps required. You're now ready to boot
732your shiny new kernel. Enjoy.
733
734Changing the configuration
735
736OK, you've now booted a devfs-enabled system, and everything works.
737Now you may feel like changing the configuration (common targets are
738/etc/fstab and /etc/devfsd.conf). Since you have a
739system that works, if you make any changes and it doesn't work, you
740now know that you only have to restore your configuration files to the
741default and it will work again.
742
743
744Permissions persistence across reboots
745
746If you don't use mknod(2) to create a device file, nor use chmod(2) or
747chown(2) to change the ownerships/permissions, the inode ctime will
748remain at 0 (the epoch, 12 am, 1-JAN-1970, GMT). Anything with a ctime
749later than this has had it's ownership/permissions changed. Hence, a
750simple script or programme may be used to tar up all changed inodes,
751prior to shutdown. Although effective, many consider this approach a
752kludge.
753
754A much better approach is to use devfsd to save and restore
755permissions. It may be configured to record changes in permissions and
756will save them in a database (in fact a directory tree), and restore
757these upon boot. This is an efficient method and results in immediate
758saving of current permissions (unlike the tar approach, which saves
759permissions at some unspecified future time).
760
761The default configuration file supplied with devfsd has config entries
762which you may uncomment to enable persistence management.
763
764If you decide to use the tar approach anyway, be aware that tar will
765first unlink(2) an inode before creating a new device node. The
766unlink(2) has the effect of breaking the connection between a devfs
767entry and the device driver. If you use the "devfs=only" boot option,
768you lose access to the device driver, requiring you to reload the
769module. I consider this a bug in tar (there is no real need to
770unlink(2) the inode first).
771
772Alternatively, you can use devfsd to provide more sophisticated
773management of device permissions. You can use devfsd to store
774permissions for whole groups of devices with a single configuration
775entry, rather than the conventional single entry per device entry.
776
777Permissions database stored in mounted-over /dev
778
779If you wish to save and restore your device permissions into the
780disc-based /dev while still mounting devfs onto /dev
781you may do so. This requires a 2.4.x kernel (in fact, 2.3.99 or
782later), which has the VFS binding facility. You need to do the
783following to set this up:
784
785
786
787make sure the kernel does not mount devfs at boot time
788
789
790make sure you have a correct /dev/console entry in your
791root file-system (where your disc-based /dev lives)
792
793create the /dev-state directory
794
795
796add the following lines near the very beginning of your boot
797scripts:
798
799mount --bind /dev /dev-state
800mount -t devfs none /dev
801devfsd /dev
802
803
804
805
806add the following lines to your /etc/devfsd.conf file:
807
808REGISTER ^pt[sy] IGNORE
809CREATE ^pt[sy] IGNORE
810CHANGE ^pt[sy] IGNORE
811DELETE ^pt[sy] IGNORE
812REGISTER .* COPY /dev-state/$devname $devpath
813CREATE .* COPY $devpath /dev-state/$devname
814CHANGE .* COPY $devpath /dev-state/$devname
815DELETE .* CFUNCTION GLOBAL unlink /dev-state/$devname
816RESTORE /dev-state
817
818Note that the sample devfsd.conf file contains these lines,
819as well as other sample configurations you may find useful. See the
820devfsd distribution
821
822
823reboot.
824
825
826
827
828Permissions database stored in normal directory
829
830If you are using an older kernel which doesn't support VFS binding,
831then you won't be able to have the permissions database in a
832mounted-over /dev. However, you can still use a regular
833directory to store the database. The sample /etc/devfsd.conf
834file above may still be used. You will need to create the
835/dev-state directory prior to installing devfsd. If you have
836old permissions in /dev, then just copy (or move) the device
837nodes over to the new directory.
838
839Which method is better?
840
841The best method is to have the permissions database stored in the
842mounted-over /dev. This is because you will not need to copy
843device nodes over to /dev-state, and because it allows you to
844switch between devfs and non-devfs kernels, without requiring you to
845copy permissions between /dev-state (for devfs) and
846/dev (for non-devfs).
847
848
849Dealing with drivers without devfs support
850
851Currently, not all device drivers in the kernel have been modified to
852use devfs. Device drivers which do not yet have devfs support will not
853automagically appear in devfs. The simplest way to create device nodes
854for these drivers is to unpack a tarfile containing the required
855device nodes. You can do this in your boot scripts. All your drivers
856will now work as before.
857
858Hopefully for most people devfs will have enough support so that they
859can mount devfs directly over /dev without losing most functionality
860(i.e. losing access to various devices). As of 22-JAN-1998 (devfs
861patch version 10) I am now running this way. All the devices I have
862are available in devfs, so I don't lose anything.
863
864WARNING: if your configuration requires the old-style device names
865(i.e. /dev/hda1 or /dev/sda1), you must install devfsd and configure
866it to maintain compatibility entries. It is almost certain that you
867will require this. Note that the kernel creates a compatibility entry
868for the root device, so you don't need initrd.
869
870Note that you no longer need to mount devpts if you use Unix98 PTYs,
871as devfs can manage /dev/pts itself. This saves you some RAM, as you
872don't need to compile and install devpts. Note that some versions of
873glibc have a bug with Unix98 pty handling on devfs systems. Contact
874the glibc maintainers for a fix. Glibc 2.1.3 has the fix.
875
876Note also that apart from editing /etc/fstab, other things will need
877to be changed if you *don't* install devfsd. Some software (like the X
878server) hard-wire device names in their source. It really is much
879easier to install devfsd so that compatibility entries are created.
880You can then slowly migrate your system to using the new device names
881(for example, by starting with /etc/fstab), and then limiting the
882compatibility entries that devfsd creates.
883
884IF YOU CONFIGURE TO MOUNT DEVFS AT BOOT, MAKE SURE YOU INSTALL DEVFSD
885BEFORE YOU BOOT A DEVFS-ENABLED KERNEL!
886
887Now that devfs has gone into the 2.3.46 kernel, I'm getting a lot of
888reports back. Many of these are because people are trying to run
889without devfsd, and hence some things break. Please just run devfsd if
890things break. I want to concentrate on real bugs rather than
891misconfiguration problems at the moment. If people are willing to fix
892bugs/false assumptions in other code (i.e. glibc, X server) and submit
893that to the respective maintainers, that would be great.
894
895
896All the way with Devfs
897
898The devfs kernel patch creates a rationalised device tree. As stated
899above, if you want to keep using the old /dev naming scheme,
900you just need to configure devfsd appopriately (see the man
901page). People who prefer the old names can ignore this section. For
902those of us who like the rationalised names and an uncluttered
903/dev, read on.
904
905If you don't run devfsd, or don't enable compatibility entry
906management, then you will have to configure your system to use the new
907names. For example, you will then need to edit your
908/etc/fstab to use the new disc naming scheme. If you want to
909be able to boot non-devfs kernels, you will need compatibility
910symlinks in the underlying disc-based /dev pointing back to
911the old-style names for when you boot a kernel without devfs.
912
913You can selectively decide which devices you want compatibility
914entries for. For example, you may only want compatibility entries for
915BSD pseudo-terminal devices (otherwise you'll have to patch you C
916library or use Unix98 ptys instead). It's just a matter of putting in
917the correct regular expression into /dev/devfsd.conf.
918
919There are other choices of naming schemes that you may prefer. For
920example, I don't use the kernel-supplied
921names, because they are too verbose. A common misconception is
922that the kernel-supplied names are meant to be used directly in
923configuration files. This is not the case. They are designed to
924reflect the layout of the devices attached and to provide easy
925classification.
926
927If you like the kernel-supplied names, that's fine. If you don't then
928you should be using devfsd to construct a namespace more to your
929liking. Devfsd has built-in code to construct a
930namespace that is both logical and easy to
931manage. In essence, it creates a convenient abbreviation of the
932kernel-supplied namespace.
933
934You are of course free to build your own namespace. Devfsd has all the
935infrastructure required to make this easy for you. All you need do is
936write a script. You can even write some C code and devfsd can load the
937shared object as a callable extension.
938
939
940Other Issues
941
942The init programme
943Another thing to take note of is whether your init programme
944creates a Unix socket /dev/telinit. Some versions of init
945create /dev/telinit so that the telinit programme can
946communicate with the init process. If you have such a system you need
947to make sure that devfs is mounted over /dev *before* init
948starts. In other words, you can't leave the mounting of devfs to
949/etc/rc, since this is executed after init. Other
950versions of init require a named pipe /dev/initctl
951which must exist *before* init starts. Once again, you need to
952mount devfs and then create the named pipe *before* init
953starts.
954
955The default behaviour now is not to mount devfs onto /dev at
956boot time for 2.3.x and later kernels. You can correct this with the
957"devfs=mount" boot option. This solves any problems with init,
958and also prevents the dreaded:
959
960Cannot open initial console
961
962message. For 2.2.x kernels where you need to apply the devfs patch,
963the default is to mount.
964
965If you have automatic mounting of devfs onto /dev then you
966may need to create /dev/initctl in your boot scripts. The
967following lines should suffice:
968
969mknod /dev/initctl p
970kill -SIGUSR1 1 # tell init that /dev/initctl now exists
971
972Alternatively, if you don't want the kernel to mount devfs onto
973/dev then you could use the following procedure is a
974guideline for how to get around /dev/initctl problems:
975
976# cd /sbin
977# mv init init.real
978# cat > init
979#! /bin/sh
980mount -n -t devfs none /dev
981mknod /dev/initctl p
982exec /sbin/init.real $*
983[control-D]
984# chmod a+x init
985
986Note that newer versions of init create /dev/initctl
987automatically, so you don't have to worry about this.
988
989Module autoloading
990You will need to configure devfsd to enable module
991autoloading. The following lines should be placed in your
992/etc/devfsd.conf file:
993
994LOOKUP .* MODLOAD
995
996
997As of devfsd-v1.3.10, a generic /etc/modules.devfs
998configuration file is installed, which is used by the MODLOAD
999action. This should be sufficient for most configurations. If you
1000require further configuration, edit your /etc/modules.conf
1001file. The way module autoloading work with devfs is:
1002
1003
1004a process attempts to lookup a device node (e.g. /dev/fred)
1005
1006
1007if that device node does not exist, the full pathname is passed to
1008devfsd as a string
1009
1010
1011devfsd will pass the string to the modprobe programme (provided the
1012configuration line shown above is present), and specifies that
1013/etc/modules.devfs is the configuration file
1014
1015
1016/etc/modules.devfs includes /etc/modules.conf to
1017access local configurations
1018
1019modprobe will search it's configuration files, looking for an alias
1020that translates the pathname into a module name
1021
1022
1023the translated pathname is then used to load the module.
1024
1025
1026If you wanted a lookup of /dev/fred to load the
1027mymod module, you would require the following configuration
1028line in /etc/modules.conf:
1029
1030alias /dev/fred mymod
1031
1032The /etc/modules.devfs configuration file provides many such
1033aliases for standard device names. If you look closely at this file,
1034you will note that some modules require multiple alias configuration
1035lines. This is required to support module autoloading for old and new
1036device names.
1037
1038Mounting root off a devfs device
1039If you wish to mount root off a devfs device when you pass the
1040"devfs=only" boot option, then you need to pass in the
1041"root=<device>" option to the kernel when booting. If you use
1042LILO, then you must have this in lilo.conf:
1043
1044append = "root=<device>"
1045
1046Surprised? Yep, so was I. It turns out if you have (as most people
1047do):
1048
1049root = <device>
1050
1051
1052then LILO will determine the device number of <device> and will
1053write that device number into a special place in the kernel image
1054before starting the kernel, and the kernel will use that device number
1055to mount the root filesystem. So, using the "append" variety ensures
1056that LILO passes the root filesystem device as a string, which devfs
1057can then use.
1058
1059Note that this isn't an issue if you don't pass "devfs=only".
1060
1061TTY issues
1062The ttyname(3) function in some versions of the C library makes
1063false assumptions about device entries which are symbolic links. The
1064tty(1) programme is one that depends on this function. I've
1065written a patch to libc 5.4.43 which fixes this. This has been
1066included in libc 5.4.44 and a similar fix is in glibc 2.1.3.
1067
1068
1069Kernel Naming Scheme
1070
1071The kernel provides a default naming scheme. This scheme is designed
1072to make it easy to search for specific devices or device types, and to
1073view the available devices. Some device types (such as hard discs),
1074have a directory of entries, making it easy to see what devices of
1075that class are available. Often, the entries are symbolic links into a
1076directory tree that reflects the topology of available devices. The
1077topological tree is useful for finding how your devices are arranged.
1078
1079Below is a list of the naming schemes for the most common drivers. A
1080list of reserved device names is
1081available for reference. Please send email to
1082rgooch@atnf.csiro.au to obtain an allocation. Please be
1083patient (the maintainer is busy). An alternative name may be allocated
1084instead of the requested name, at the discretion of the maintainer.
1085
1086Disc Devices
1087
1088All discs, whether SCSI, IDE or whatever, are placed under the
1089/dev/discs hierarchy:
1090
1091 /dev/discs/disc0 first disc
1092 /dev/discs/disc1 second disc
1093
1094
1095Each of these entries is a symbolic link to the directory for that
1096device. The device directory contains:
1097
1098 disc for the whole disc
1099 part* for individual partitions
1100
1101
1102CD-ROM Devices
1103
1104All CD-ROMs, whether SCSI, IDE or whatever, are placed under the
1105/dev/cdroms hierarchy:
1106
1107 /dev/cdroms/cdrom0 first CD-ROM
1108 /dev/cdroms/cdrom1 second CD-ROM
1109
1110
1111Each of these entries is a symbolic link to the real device entry for
1112that device.
1113
1114Tape Devices
1115
1116All tapes, whether SCSI, IDE or whatever, are placed under the
1117/dev/tapes hierarchy:
1118
1119 /dev/tapes/tape0 first tape
1120 /dev/tapes/tape1 second tape
1121
1122
1123Each of these entries is a symbolic link to the directory for that
1124device. The device directory contains:
1125
1126 mt for mode 0
1127 mtl for mode 1
1128 mtm for mode 2
1129 mta for mode 3
1130 mtn for mode 0, no rewind
1131 mtln for mode 1, no rewind
1132 mtmn for mode 2, no rewind
1133 mtan for mode 3, no rewind
1134
1135
1136SCSI Devices
1137
1138To uniquely identify any SCSI device requires the following
1139information:
1140
1141 controller (host adapter)
1142 bus (SCSI channel)
1143 target (SCSI ID)
1144 unit (Logical Unit Number)
1145
1146
1147All SCSI devices are placed under /dev/scsi (assuming devfs
1148is mounted on /dev). Hence, a SCSI device with the following
1149parameters: c=1,b=2,t=3,u=4 would appear as:
1150
1151 /dev/scsi/host1/bus2/target3/lun4 device directory
1152
1153
1154Inside this directory, a number of device entries may be created,
1155depending on which SCSI device-type drivers were installed.
1156
1157See the section on the disc naming scheme to see what entries the SCSI
1158disc driver creates.
1159
1160See the section on the tape naming scheme to see what entries the SCSI
1161tape driver creates.
1162
1163The SCSI CD-ROM driver creates:
1164
1165 cd
1166
1167
1168The SCSI generic driver creates:
1169
1170 generic
1171
1172
1173IDE Devices
1174
1175To uniquely identify any IDE device requires the following
1176information:
1177
1178 controller
1179 bus (aka. primary/secondary)
1180 target (aka. master/slave)
1181 unit
1182
1183
1184All IDE devices are placed under /dev/ide, and uses a similar
1185naming scheme to the SCSI subsystem.
1186
1187XT Hard Discs
1188
1189All XT discs are placed under /dev/xd. The first XT disc has
1190the directory /dev/xd/disc0.
1191
1192TTY devices
1193
1194The tty devices now appear as:
1195
1196 New name Old-name Device Type
1197 -------- -------- -----------
1198 /dev/tts/{0,1,...} /dev/ttyS{0,1,...} Serial ports
1199 /dev/cua/{0,1,...} /dev/cua{0,1,...} Call out devices
1200 /dev/vc/0 /dev/tty Current virtual console
1201 /dev/vc/{1,2,...} /dev/tty{1...63} Virtual consoles
1202 /dev/vcc/{0,1,...} /dev/vcs{1...63} Virtual consoles
1203 /dev/pty/m{0,1,...} /dev/ptyp?? PTY masters
1204 /dev/pty/s{0,1,...} /dev/ttyp?? PTY slaves
1205
1206
1207RAMDISCS
1208
1209The RAMDISCS are placed in their own directory, and are named thus:
1210
1211 /dev/rd/{0,1,2,...}
1212
1213
1214Meta Devices
1215
1216The meta devices are placed in their own directory, and are named
1217thus:
1218
1219 /dev/md/{0,1,2,...}
1220
1221
1222Floppy discs
1223
1224Floppy discs are placed in the /dev/floppy directory.
1225
1226Loop devices
1227
1228Loop devices are placed in the /dev/loop directory.
1229
1230Sound devices
1231
1232Sound devices are placed in the /dev/sound directory
1233(audio, sequencer, ...).
1234
1235
1236Devfsd Naming Scheme
1237
1238Devfsd provides a naming scheme which is a convenient abbreviation of
1239the kernel-supplied namespace. In some
1240cases, the kernel-supplied naming scheme is quite convenient, so
1241devfsd does not provide another naming scheme. The convenience names
1242that devfsd creates are in fact the same names as the original devfs
1243kernel patch created (before Linus mandated the Big Name
1244Change). These are referred to as "new compatibility entries".
1245
1246In order to configure devfsd to create these convenience names, the
1247following lines should be placed in your /etc/devfsd.conf:
1248
1249REGISTER .* MKNEWCOMPAT
1250UNREGISTER .* RMNEWCOMPAT
1251
1252This will cause devfsd to create (and destroy) symbolic links which
1253point to the kernel-supplied names.
1254
1255SCSI Hard Discs
1256
1257All SCSI discs are placed under /dev/sd (assuming devfs is
1258mounted on /dev). Hence, a SCSI disc with the following
1259parameters: c=1,b=2,t=3,u=4 would appear as:
1260
1261 /dev/sd/c1b2t3u4 for the whole disc
1262 /dev/sd/c1b2t3u4p5 for the 5th partition
1263 /dev/sd/c1b2t3u4p5s6 for the 6th slice in the 5th partition
1264
1265
1266SCSI Tapes
1267
1268All SCSI tapes are placed under /dev/st. A similar naming
1269scheme is used as for SCSI discs. A SCSI tape with the
1270parameters:c=1,b=2,t=3,u=4 would appear as:
1271
1272 /dev/st/c1b2t3u4m0 for mode 0
1273 /dev/st/c1b2t3u4m1 for mode 1
1274 /dev/st/c1b2t3u4m2 for mode 2
1275 /dev/st/c1b2t3u4m3 for mode 3
1276 /dev/st/c1b2t3u4m0n for mode 0, no rewind
1277 /dev/st/c1b2t3u4m1n for mode 1, no rewind
1278 /dev/st/c1b2t3u4m2n for mode 2, no rewind
1279 /dev/st/c1b2t3u4m3n for mode 3, no rewind
1280
1281
1282SCSI CD-ROMs
1283
1284All SCSI CD-ROMs are placed under /dev/sr. A similar naming
1285scheme is used as for SCSI discs. A SCSI CD-ROM with the
1286parameters:c=1,b=2,t=3,u=4 would appear as:
1287
1288 /dev/sr/c1b2t3u4
1289
1290
1291SCSI Generic Devices
1292
1293The generic (aka. raw) interface for all SCSI devices are placed under
1294/dev/sg. A similar naming scheme is used as for SCSI discs. A
1295SCSI generic device with the parameters:c=1,b=2,t=3,u=4 would appear
1296as:
1297
1298 /dev/sg/c1b2t3u4
1299
1300
1301IDE Hard Discs
1302
1303All IDE discs are placed under /dev/ide/hd, using a similar
1304convention to SCSI discs. The following mappings exist between the new
1305and the old names:
1306
1307 /dev/hda /dev/ide/hd/c0b0t0u0
1308 /dev/hdb /dev/ide/hd/c0b0t1u0
1309 /dev/hdc /dev/ide/hd/c0b1t0u0
1310 /dev/hdd /dev/ide/hd/c0b1t1u0
1311
1312
1313IDE Tapes
1314
1315A similar naming scheme is used as for IDE discs. The entries will
1316appear in the /dev/ide/mt directory.
1317
1318IDE CD-ROM
1319
1320A similar naming scheme is used as for IDE discs. The entries will
1321appear in the /dev/ide/cd directory.
1322
1323IDE Floppies
1324
1325A similar naming scheme is used as for IDE discs. The entries will
1326appear in the /dev/ide/fd directory.
1327
1328XT Hard Discs
1329
1330All XT discs are placed under /dev/xd. The first XT disc
1331would appear as /dev/xd/c0t0.
1332
1333
1334Old Compatibility Names
1335
1336The old compatibility names are the legacy device names, such as
1337/dev/hda, /dev/sda, /dev/rtc and so on.
1338Devfsd can be configured to create compatibility symlinks so that you
1339may continue to use the old names in your configuration files and so
1340that old applications will continue to function correctly.
1341
1342In order to configure devfsd to create these legacy names, the
1343following lines should be placed in your /etc/devfsd.conf:
1344
1345REGISTER .* MKOLDCOMPAT
1346UNREGISTER .* RMOLDCOMPAT
1347
1348This will cause devfsd to create (and destroy) symbolic links which
1349point to the kernel-supplied names.
1350
1351
1352-----------------------------------------------------------------------------
1353
1354
1355Device drivers currently ported
1356
1357- All miscellaneous character devices support devfs (this is done
1358 transparently through misc_register())
1359
1360- SCSI discs and generic hard discs
1361
1362- Character memory devices (null, zero, full and so on)
1363 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
1364
1365- Loop devices (/dev/loop?)
1366
1367- TTY devices (console, serial ports, terminals and pseudo-terminals)
1368 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
1369
1370- SCSI tapes (/dev/scsi and /dev/tapes)
1371
1372- SCSI CD-ROMs (/dev/scsi and /dev/cdroms)
1373
1374- SCSI generic devices (/dev/scsi)
1375
1376- RAMDISCS (/dev/ram?)
1377
1378- Meta Devices (/dev/md*)
1379
1380- Floppy discs (/dev/floppy)
1381
1382- Parallel port printers (/dev/printers)
1383
1384- Sound devices (/dev/sound)
1385 Thanks to Eric Dumas <dumas@linux.eu.org> and
1386 C. Scott Ananian <cananian@alumni.princeton.edu>
1387
1388- Joysticks (/dev/joysticks)
1389
1390- Sparc keyboard (/dev/kbd)
1391
1392- DSP56001 digital signal processor (/dev/dsp56k)
1393
1394- Apple Desktop Bus (/dev/adb)
1395
1396- Coda network file system (/dev/cfs*)
1397
1398- Virtual console capture devices (/dev/vcc)
1399 Thanks to Dennis Hou <smilax@mindmeld.yi.org>
1400
1401- Frame buffer devices (/dev/fb)
1402
1403- Video capture devices (/dev/v4l)
1404
1405
1406-----------------------------------------------------------------------------
1407
1408
1409Allocation of Device Numbers
1410
1411Devfs allows you to write a driver which doesn't need to allocate a
1412device number (major&minor numbers) for the internal operation of the
1413kernel. However, there are a number of userspace programmes that use
1414the device number as a unique handle for a device. An example is the
1415find programme, which uses device numbers to determine whether
1416an inode is on a different filesystem than another inode. The device
1417number used is the one for the block device which a filesystem is
1418using. To preserve compatibility with userspace programmes, block
1419devices using devfs need to have unique device numbers allocated to
1420them. Furthermore, POSIX specifies device numbers, so some kind of
1421device number needs to be presented to userspace.
1422
1423The simplest option (especially when porting drivers to devfs) is to
1424keep using the old major and minor numbers. Devfs will take whatever
1425values are given for major&minor and pass them onto userspace.
1426
1427This device number is a 16 bit number, so this leaves plenty of space
1428for large numbers of discs and partitions. This scheme can also be
1429used for character devices, in particular the tty devices, which are
1430currently limited to 256 pseudo-ttys (this limits the total number of
1431simultaneous xterms and remote logins). Note that the device number
1432is limited to the range 36864-61439 (majors 144-239), in order to
1433avoid any possible conflicts with existing official allocations.
1434
1435Please note that using dynamically allocated block device numbers may
1436break the NFS daemons (both user and kernel mode), which expect dev_t
1437for a given device to be constant over the lifetime of remote mounts.
1438
1439A final note on this scheme: since it doesn't increase the size of
1440device numbers, there are no compatibility issues with userspace.
1441
1442-----------------------------------------------------------------------------
1443
1444
1445Questions and Answers
1446
1447
1448Making things work
1449Alternatives to devfs
1450What I don't like about devfs
1451How to report bugs
1452Strange kernel messages
1453Compilation problems with devfsd
1454
1455
1456
1457Making things work
1458
1459Here are some common questions and answers.
1460
1461
1462
1463Devfsd doesn't start
1464
1465Make sure you have compiled and installed devfsd
1466Make sure devfsd is being started from your boot
1467scripts
1468Make sure you have configured your kernel to enable devfs (see
1469below)
1470Make sure devfs is mounted (see below)
1471
1472
1473Devfsd is not managing all my permissions
1474
1475Make sure you are capturing the appropriate events. For example,
1476device entries created by the kernel generate REGISTER events,
1477but those created by devfsd generate CREATE events.
1478
1479
1480Devfsd is not capturing all REGISTER events
1481
1482See the previous entry: you may need to capture CREATE events.
1483
1484
1485X will not start
1486
1487Make sure you followed the steps
1488outlined above.
1489
1490
1491Why don't my network devices appear in devfs?
1492
1493This is not a bug. Network devices have their own, completely separate
1494namespace. They are accessed via socket(2) and
1495setsockopt(2) calls, and thus require no device nodes. I have
1496raised the possibilty of moving network devices into the device
1497namespace, but have had no response.
1498
1499
1500How can I test if I have devfs compiled into my kernel?
1501
1502All filesystems built-in or currently loaded are listed in
1503/proc/filesystems. If you see a devfs entry, then
1504you know that devfs was compiled into your kernel. If you have
1505correctly configured and rebuilt your kernel, then devfs will be
1506built-in. If you think you've configured it in, but
1507/proc/filesystems doesn't show it, you've made a mistake.
1508Common mistakes include:
1509
1510Using a 2.2.x kernel without applying the devfs patch (if you
1511don't know how to patch your kernel, use 2.4.x instead, don't bother
1512asking me how to patch)
1513Forgetting to set CONFIG_EXPERIMENTAL=y
1514Forgetting to set CONFIG_DEVFS_FS=y
1515Forgetting to set CONFIG_DEVFS_MOUNT=y (if you want devfs
1516to be automatically mounted at boot)
1517Editing your .config manually, instead of using make
1518config or make xconfig
1519Forgetting to run make dep; make clean after changing the
1520configuration and before compiling
1521Forgetting to compile your kernel and modules
1522Forgetting to install your kernel
1523Forgetting to install your modules
1524
1525Please check twice that you've done all these steps before sending in
1526a bug report.
1527
1528
1529
1530How can I test if devfs is mounted on /dev?
1531
1532The device filesystem will always create an entry called
1533".devfsd", which is used to communicate with the daemon. Even
1534if the daemon is not running, this entry will exist. Testing for the
1535existence of this entry is the approved method of determining if devfs
1536is mounted or not. Note that the type of entry (i.e. regular file,
1537character device, named pipe, etc.) may change without notice. Only
1538the existence of the entry should be relied upon.
1539
1540
1541When I start devfsd, I see the error:
1542Error opening file: ".devfsd" No such file or directory?
1543
1544This means that devfs is not mounted. Make sure you have devfs mounted.
1545
1546
1547How do I mount devfs?
1548
1549First make sure you have devfs compiled into your kernel (see
1550above). Then you will either need to:
1551
1552set CONFIG_DEVFS_MOUNT=y in your kernel config
1553pass devfs=mount to your boot loader
1554mount devfs manually in your boot scripts with:
1555mount -t none devfs /dev
1556
1557
1558
1559Mount by volume LABEL=<label> doesn't work with
1560devfs
1561
1562Most probably you are not mounting devfs onto /dev. What
1563happens is that if your kernel config has CONFIG_DEVFS_FS=y
1564then the contents of /proc/partitions will have the devfs
1565names (such as scsi/host0/bus0/target0/lun0/part1). The
1566contents of /proc/partitions are used by mount(8) when
1567mounting by volume label. If devfs is not mounted on /dev,
1568then mount(8) will fail to find devices. The solution is to
1569make sure that devfs is mounted on /dev. See above for how to
1570do that.
1571
1572
1573I have extra or incorrect entries in /dev
1574
1575You may have stale entries in your dev-state area. Check for a
1576RESTORE configuration line in your devfsd configuration
1577(typically /etc/devfsd.conf). If you have this line, check
1578the contents of the specified directory for stale entries. Remove
1579any entries which are incorrect, then reboot.
1580
1581
1582I get "Unable to open initial console" messages at boot
1583
1584This usually happens when you don't have devfs automounted onto
1585/dev at boot time, and there is no valid
1586/dev/console entry on your root file-system. Create a valid
1587/dev/console device node.
1588
1589
1590
1591
1592
1593Alternatives to devfs
1594
1595I've attempted to collate all the anti-devfs proposals and explain
1596their limitations. Under construction.
1597
1598
1599Why not just pass device create/remove events to a daemon?
1600
1601Here the suggestion is to develop an API in the kernel so that devices
1602can register create and remove events, and a daemon listens for those
1603events. The daemon would then populate/depopulate /dev (which
1604resides on disc).
1605
1606This has several limitations:
1607
1608
1609it only works for modules loaded and unloaded (or devices inserted
1610and removed) after the kernel has finished booting. Without a database
1611of events, there is no way the daemon could fully populate
1612/dev
1613
1614
1615if you add a database to this scheme, the question is then how to
1616present that database to user-space. If you make it a list of strings
1617with embedded event codes which are passed through a pipe to the
1618daemon, then this is only of use to the daemon. I would argue that the
1619natural way to present this data is via a filesystem (since many of
1620the events will be of a hierarchical nature), such as devfs.
1621Presenting the data as a filesystem makes it easy for the user to see
1622what is available and also makes it easy to write scripts to scan the
1623"database"
1624
1625
1626the tight binding between device nodes and drivers is no longer
1627possible (requiring the otherwise perfectly avoidable
1628table lookups)
1629
1630
1631you cannot catch inode lookup events on /dev which means
1632that module autoloading requires device nodes to be created. This is a
1633problem, particularly for drivers where only a few inodes are created
1634from a potentially large set
1635
1636
1637this technique can't be used when the root FS is mounted
1638read-only
1639
1640
1641
1642
1643Just implement a better scsidev
1644
1645This suggestion involves taking the scsidev programme and
1646extending it to scan for all devices, not just SCSI devices. The
1647scsidev programme works by scanning /proc/scsi
1648
1649Problems:
1650
1651
1652the kernel does not currently provide a list of all devices
1653available. Not all drivers register entries in /proc or
1654generate kernel messages
1655
1656
1657there is no uniform mechanism to register devices other than the
1658devfs API
1659
1660
1661implementing such an API is then the same as the
1662proposal above
1663
1664
1665
1666
1667Put /dev on a ramdisc
1668
1669This suggestion involves creating a ramdisc and populating it with
1670device nodes and then mounting it over /dev.
1671
1672Problems:
1673
1674
1675
1676this doesn't help when mounting the root filesystem, since you
1677still need a device node to do that
1678
1679
1680if you want to use this technique for the root device node as
1681well, you need to use initrd. This complicates the booting sequence
1682and makes it significantly harder to administer and configure. The
1683initrd is essentially opaque, robbing the system administrator of easy
1684configuration
1685
1686
1687insufficient information is available to correctly populate the
1688ramdisc. So we come back to the
1689proposal above to "solve" this
1690
1691
1692a ramdisc-based solution would take more kernel memory, since the
1693backing store would be (at best) normal VFS inodes and dentries, which
1694take 284 bytes and 112 bytes, respectively, for each entry. Compare
1695that to 72 bytes for devfs
1696
1697
1698
1699
1700Do nothing: there's no problem
1701
1702Sometimes people can be heard to claim that the existing scheme is
1703fine. This is what they're ignoring:
1704
1705
1706device number size (8 bits each for major and minor) is a real
1707limitation, and must be fixed somehow. Systems with large numbers of
1708SCSI devices, for example, will continue to consume the remaining
1709unallocated major numbers. USB will also need to push beyond the 8 bit
1710minor limitation
1711
1712
1713simply increasing the device number size is insufficient. Apart
1714from causing a lot of pain, it doesn't solve the management issues
1715of a /dev with thousands or more device nodes
1716
1717
1718ignoring the problem of a huge /dev will not make it go
1719away, and dismisses the legitimacy of a large number of people who
1720want a dynamic /dev
1721
1722
1723the standard response then becomes: "write a device management
1724daemon", which brings us back to the
1725proposal above
1726
1727
1728
1729
1730What I don't like about devfs
1731
1732Here are some common complaints about devfs, and some suggestions and
1733solutions that may make it more palatable for you. I can't please
1734everybody, but I do try :-)
1735
1736I hate the naming scheme
1737
1738First, remember that no naming scheme will please everybody. You hate
1739the scheme, others love it. Who's to say who's right and who's wrong?
1740Ultimately, the person who writes the code gets to choose, and what
1741exists now is a combination of the choices made by the
1742devfs author and the
1743kernel maintainer (Linus).
1744
1745However, not all is lost. If you want to create your own naming
1746scheme, it is a simple matter to write a standalone script, hack
1747devfsd, or write a script called by devfsd. You can create whatever
1748naming scheme you like.
1749
1750Further, if you want to remove all traces of the devfs naming scheme
1751from /dev, you can mount devfs elsewhere (say
1752/devfs) and populate /dev with links into
1753/devfs. This population can be automated using devfsd if you
1754wish.
1755
1756You can even use the VFS binding facility to make the links, rather
1757than using symbolic links. This way, you don't even have to see the
1758"destination" of these symbolic links.
1759
1760Devfs puts policy into the kernel
1761
1762There's already policy in the kernel. Device numbers are in fact
1763policy (why should the kernel dictate what device numbers I use?).
1764Face it, some policy has to be in the kernel. The real difference
1765between device names as policy and device numbers as policy is that
1766no one will use device numbers directly, because device
1767numbers are devoid of meaning to humans and are ugly. At least with
1768the devfs device names, (even though you can add your own naming
1769scheme) some people will use the devfs-supplied names directly. This
1770offends some people :-)
1771
1772Devfs is bloatware
1773
1774This is not even remotely true. As shown above,
1775both code and data size are quite modest.
1776
1777
1778How to report bugs
1779
1780If you have (or think you have) a bug with devfs, please follow the
1781steps below:
1782
1783
1784
1785make sure you have enabled debugging output when configuring your
1786kernel. You will need to set (at least) the following config options:
1787
1788CONFIG_DEVFS_DEBUG=y
1789CONFIG_DEBUG_KERNEL=y
1790CONFIG_DEBUG_SLAB=y
1791
1792
1793
1794please make sure you have the latest devfs patches applied. The
1795latest kernel version might not have the latest devfs patches applied
1796yet (Linus is very busy)
1797
1798
1799save a copy of your complete kernel logs (preferably by
1800using the dmesg programme) for later inclusion in your bug
1801report. You may need to use the -s switch to increase the
1802internal buffer size so you can capture all the boot messages.
1803Don't edit or trim the dmesg output
1804
1805
1806
1807
1808try booting with devfs=dall passed to the kernel boot
1809command line (read the documentation on your bootloader on how to do
1810this), and save the result to a file. This may be quite verbose, and
1811it may overflow the messages buffer, but try to get as much of it as
1812you can
1813
1814
1815send a copy of your devfsd configuration file(s)
1816
1817send the bug report to me first.
1818Don't expect that I will see it if you post it to the linux-kernel
1819mailing list. Include all the information listed above, plus
1820anything else that you think might be relevant. Put the string
1821devfs somewhere in the subject line, so my mail filters mark
1822it as urgent
1823
1824
1825
1826
1827Here is a general guide on how to ask questions in a way that greatly
1828improves your chances of getting a reply:
1829
1830http://www.tuxedo.org/~esr/faqs/smart-questions.html. If you have
1831a bug to report, you should also read
1832
1833http://www.chiark.greenend.org.uk/~sgtatham/bugs.html.
1834
1835
1836Strange kernel messages
1837
1838You may see devfs-related messages in your kernel logs. Below are some
1839messages and what they mean (and what you should do about them, if
1840anything).
1841
1842
1843
1844devfs_register(fred): could not append to parent, err: -17
1845
1846You need to check what the error code means, but usually 17 means
1847EEXIST. This means that a driver attempted to create an entry
1848fred in a directory, but there already was an entry with that
1849name. This is often caused by flawed boot scripts which untar a bunch
1850of inodes into /dev, as a way to restore permissions. This
1851message is harmless, as the device nodes will still
1852provide access to the driver (unless you use the devfs=only
1853boot option, which is only for dedicated souls:-). If you want to get
1854rid of these annoying messages, upgrade to devfsd-v1.3.20 and use the
1855recommended RESTORE directive to restore permissions.
1856
1857
1858devfs_mk_dir(bill): using old entry in dir: c1808724 ""
1859
1860This is similar to the message above, except that a driver attempted
1861to create a directory named bill, and the parent directory
1862has an entry with the same name. In this case, to ensure that drivers
1863continue to work properly, the old entry is re-used and given to the
1864driver. In 2.5 kernels, the driver is given a NULL entry, and thus,
1865under rare circumstances, may not create the require device nodes.
1866The solution is the same as above.
1867
1868
1869
1870
1871
1872Compilation problems with devfsd
1873
1874Usually, you can compile devfsd just by typing in
1875make in the source directory, followed by a make
1876install (as root). Sometimes, you may have problems, particularly
1877on broken configurations.
1878
1879
1880
1881error messages relating to DEVFSD_NOTIFY_DELETE
1882
1883This happened because you have an ancient set of kernel headers
1884installed in /usr/include/linux or /usr/src/linux.
1885Install kernel 2.4.10 or later. You may need to pass the
1886KERNEL_DIR variable to make (if you did not install
1887the new kernel sources as /usr/src/linux), or you may copy
1888the devfs_fs.h file in the kernel source tree into
1889/usr/include/linux.
1890
1891
1892
1893
1894-----------------------------------------------------------------------------
1895
1896
1897Other resources
1898
1899
1900
1901Douglas Gilbert has written a useful document at
1902
1903http://www.torque.net/sg/devfs_scsi.html which
1904explores the SCSI subsystem and how it interacts with devfs
1905
1906
1907Douglas Gilbert has written another useful document at
1908
1909http://www.torque.net/scsi/SCSI-2.4-HOWTO/ which
1910discusses the Linux SCSI subsystem in 2.4.
1911
1912
1913Johannes Erdfelt has started a discussion paper on Linux and
1914hot-swap devices, describing what the requirements are for a scalable
1915solution and how and why he's used devfs+devfsd. Note that this is an
1916early draft only, available in plain text form at:
1917
1918http://johannes.erdfelt.com/hotswap.txt.
1919Johannes has promised a HTML version will follow.
1920
1921
1922I presented an invited
1923paper
1924at the
1925
19262nd Annual Storage Management Workshop held in Miamia, Florida,
1927U.S.A. in October 2000.
1928
1929
1930
1931
1932-----------------------------------------------------------------------------
1933
1934
1935Translations of this document
1936
1937This document has been translated into other languages.
1938
1939
1940
1941
1942The document master (in English) by rgooch@atnf.csiro.au is
1943available at
1944
1945http://www.atnf.csiro.au/~rgooch/linux/docs/devfs.html
1946
1947
1948
1949A Korean translation by viatoris@nownuri.net is available at
1950
1951http://your.destiny.pe.kr/devfs/devfs.html
1952
1953
1954
1955
1956-----------------------------------------------------------------------------
1957Most flags courtesy of ITA's
1958Flags of All Countries
1959used with permission.
diff --git a/Documentation/filesystems/devfs/ToDo b/Documentation/filesystems/devfs/ToDo
deleted file mode 100644
index afd5a8f2c19b..000000000000
--- a/Documentation/filesystems/devfs/ToDo
+++ /dev/null
@@ -1,40 +0,0 @@
1 Device File System (devfs) ToDo List
2
3 Richard Gooch <rgooch@atnf.csiro.au>
4
5 3-JUL-2000
6
7This is a list of things to be done for better devfs support in the
8Linux kernel. If you'd like to contribute to the devfs, please have a
9look at this list for anything that is unallocated. Also, if there are
10items missing (surely), please contact me so I can add them to the
11list (preferably with your name attached to them:-).
12
13
14- >256 ptys
15 Thanks to C. Scott Ananian <cananian@alumni.princeton.edu>
16
17- Amiga floppy driver (drivers/block/amiflop.c)
18
19- Atari floppy driver (drivers/block/ataflop.c)
20
21- SWIM3 (Super Woz Integrated Machine 3) floppy driver (drivers/block/swim3.c)
22
23- Amiga ZorroII ramdisc driver (drivers/block/z2ram.c)
24
25- Parallel port ATAPI CD-ROM (drivers/block/paride/pcd.c)
26
27- Parallel port ATAPI floppy (drivers/block/paride/pf.c)
28
29- AP1000 block driver (drivers/ap1000/ap.c, drivers/ap1000/ddv.c)
30
31- Archimedes floppy (drivers/acorn/block/fd1772.c)
32
33- MFM hard drive (drivers/acorn/block/mfmhd.c)
34
35- I2O block device (drivers/message/i2o/i2o_block.c)
36
37- ST-RAM device (arch/m68k/atari/stram.c)
38
39- Raw devices
40
diff --git a/Documentation/filesystems/devfs/boot-options b/Documentation/filesystems/devfs/boot-options
deleted file mode 100644
index df3d33b03e0a..000000000000
--- a/Documentation/filesystems/devfs/boot-options
+++ /dev/null
@@ -1,65 +0,0 @@
1/* -*- auto-fill -*- */
2
3 Device File System (devfs) Boot Options
4
5 Richard Gooch <rgooch@atnf.csiro.au>
6
7 18-AUG-2001
8
9
10When CONFIG_DEVFS_DEBUG is enabled, you can pass several boot options
11to the kernel to debug devfs. The boot options are prefixed by
12"devfs=", and are separated by commas. Spaces are not allowed. The
13syntax looks like this:
14
15devfs=<option1>,<option2>,<option3>
16
17and so on. For example, if you wanted to turn on debugging for module
18load requests and device registration, you would do:
19
20devfs=dmod,dreg
21
22You may prefix "no" to any option. This will invert the option.
23
24
25Debugging Options
26=================
27
28These requires CONFIG_DEVFS_DEBUG to be enabled.
29Note that all debugging options have 'd' as the first character. By
30default all options are off. All debugging output is sent to the
31kernel logs. The debugging options do not take effect until the devfs
32version message appears (just prior to the root filesystem being
33mounted).
34
35These are the options:
36
37dmod print module load requests to <request_module>
38
39dreg print device register requests to <devfs_register>
40
41dunreg print device unregister requests to <devfs_unregister>
42
43dchange print device change requests to <devfs_set_flags>
44
45dilookup print inode lookup requests
46
47diget print VFS inode allocations
48
49diunlink print inode unlinks
50
51dichange print inode changes
52
53dimknod print calls to mknod(2)
54
55dall some debugging turned on
56
57
58Other Options
59=============
60
61These control the default behaviour of devfs. The options are:
62
63mount mount devfs onto /dev at boot time
64
65only disable non-devfs device nodes for devfs-capable drivers
diff --git a/Documentation/initrd.txt b/Documentation/initrd.txt
index 7de1c80cd719..b1b6440237a6 100644
--- a/Documentation/initrd.txt
+++ b/Documentation/initrd.txt
@@ -67,8 +67,7 @@ initrd adds the following new options:
67 as the last process has closed it, all data is freed and /dev/initrd 67 as the last process has closed it, all data is freed and /dev/initrd
68 can't be opened anymore. 68 can't be opened anymore.
69 69
70 root=/dev/ram0 (without devfs) 70 root=/dev/ram0
71 root=/dev/rd/0 (with devfs)
72 71
73 initrd is mounted as root, and the normal boot procedure is followed, 72 initrd is mounted as root, and the normal boot procedure is followed,
74 with the RAM disk still mounted as root. 73 with the RAM disk still mounted as root.
@@ -90,8 +89,7 @@ you're building an install floppy), the root file system creation
90procedure should create the /initrd directory. 89procedure should create the /initrd directory.
91 90
92If initrd will not be mounted in some cases, its content is still 91If initrd will not be mounted in some cases, its content is still
93accessible if the following device has been created (note that this 92accessible if the following device has been created:
94does not work if using devfs):
95 93
96# mknod /dev/initrd b 1 250 94# mknod /dev/initrd b 1 250
97# chmod 400 /dev/initrd 95# chmod 400 /dev/initrd
@@ -119,8 +117,7 @@ We'll describe the loopback device method:
119 (if space is critical, you may want to use the Minix FS instead of Ext2) 117 (if space is critical, you may want to use the Minix FS instead of Ext2)
120 3) mount the file system, e.g. 118 3) mount the file system, e.g.
121 # mount -t ext2 -o loop initrd /mnt 119 # mount -t ext2 -o loop initrd /mnt
122 4) create the console device (not necessary if using devfs, but it can't 120 4) create the console device:
123 hurt to do it anyway):
124 # mkdir /mnt/dev 121 # mkdir /mnt/dev
125 # mknod /mnt/dev/console c 5 1 122 # mknod /mnt/dev/console c 5 1
126 5) copy all the files that are needed to properly use the initrd 123 5) copy all the files that are needed to properly use the initrd
@@ -152,12 +149,7 @@ have to be given:
152 149
153 root=/dev/ram0 init=/linuxrc rw 150 root=/dev/ram0 init=/linuxrc rw
154 151
155if not using devfs, or 152(rw is only necessary if writing to the initrd file system.)
156
157 root=/dev/rd/0 init=/linuxrc rw
158
159if using devfs. (rw is only necessary if writing to the initrd file
160system.)
161 153
162With LOADLIN, you simply execute 154With LOADLIN, you simply execute
163 155
@@ -217,9 +209,9 @@ following command:
217# exec chroot . what-follows <dev/console >dev/console 2>&1 209# exec chroot . what-follows <dev/console >dev/console 2>&1
218 210
219Where what-follows is a program under the new root, e.g. /sbin/init 211Where what-follows is a program under the new root, e.g. /sbin/init
220If the new root file system will be used with devfs and has no valid 212If the new root file system will be used with udev and has no valid
221/dev directory, devfs must be mounted before invoking chroot in order to 213/dev directory, udev must be initialized before invoking chroot in order
222provide /dev/console. 214to provide /dev/console.
223 215
224Note: implementation details of pivot_root may change with time. In order 216Note: implementation details of pivot_root may change with time. In order
225to ensure compatibility, the following points should be observed: 217to ensure compatibility, the following points should be observed:
@@ -236,7 +228,7 @@ Now, the initrd can be unmounted and the memory allocated by the RAM
236disk can be freed: 228disk can be freed:
237 229
238# umount /initrd 230# umount /initrd
239# blockdev --flushbufs /dev/ram0 # /dev/rd/0 if using devfs 231# blockdev --flushbufs /dev/ram0
240 232
241It is also possible to use initrd with an NFS-mounted root, see the 233It is also possible to use initrd with an NFS-mounted root, see the
242pivot_root(8) man page for details. 234pivot_root(8) man page for details.
diff --git a/Documentation/ioctl-number.txt b/Documentation/ioctl-number.txt
index 1543802ef53e..edc04d74ae23 100644
--- a/Documentation/ioctl-number.txt
+++ b/Documentation/ioctl-number.txt
@@ -119,7 +119,6 @@ Code Seq# Include File Comments
119'c' 00-7F linux/comstats.h conflict! 119'c' 00-7F linux/comstats.h conflict!
120'c' 00-7F linux/coda.h conflict! 120'c' 00-7F linux/coda.h conflict!
121'd' 00-FF linux/char/drm/drm/h conflict! 121'd' 00-FF linux/char/drm/drm/h conflict!
122'd' 00-1F linux/devfs_fs.h conflict!
123'd' 00-DF linux/video_decoder.h conflict! 122'd' 00-DF linux/video_decoder.h conflict!
124'd' F0-FF linux/digi1.h 123'd' F0-FF linux/digi1.h
125'e' all linux/digi1.h conflict! 124'e' all linux/digi1.h conflict!
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 0d189c93eeaf..86e9282d1c20 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -35,7 +35,6 @@ parameter is applicable:
35 APM Advanced Power Management support is enabled. 35 APM Advanced Power Management support is enabled.
36 AX25 Appropriate AX.25 support is enabled. 36 AX25 Appropriate AX.25 support is enabled.
37 CD Appropriate CD support is enabled. 37 CD Appropriate CD support is enabled.
38 DEVFS devfs support is enabled.
39 DRM Direct Rendering Management support is enabled. 38 DRM Direct Rendering Management support is enabled.
40 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled 39 EDD BIOS Enhanced Disk Drive Services (EDD) is enabled
41 EFI EFI Partitioning (GPT) is enabled 40 EFI EFI Partitioning (GPT) is enabled
@@ -440,9 +439,6 @@ running once the system is up.
440 Format: <area>[,<node>] 439 Format: <area>[,<node>]
441 See also Documentation/networking/decnet.txt. 440 See also Documentation/networking/decnet.txt.
442 441
443 devfs= [DEVFS]
444 See Documentation/filesystems/devfs/boot-options.
445
446 dhash_entries= [KNL] 442 dhash_entries= [KNL]
447 Set number of hash buckets for dentry cache. 443 Set number of hash buckets for dentry cache.
448 444
@@ -1689,9 +1685,14 @@ running once the system is up.
1689 decrease the size and leave more room for directly 1685 decrease the size and leave more room for directly
1690 mapped kernel RAM. 1686 mapped kernel RAM.
1691 1687
1692 vmhalt= [KNL,S390] 1688 vmhalt= [KNL,S390] Perform z/VM CP command after system halt.
1689 Format: <command>
1690
1691 vmpanic= [KNL,S390] Perform z/VM CP command after kernel panic.
1692 Format: <command>
1693 1693
1694 vmpoff= [KNL,S390] 1694 vmpoff= [KNL,S390] Perform z/VM CP command after power off.
1695 Format: <command>
1695 1696
1696 waveartist= [HW,OSS] 1697 waveartist= [HW,OSS]
1697 Format: <io>,<irq>,<dma>,<dma2> 1698 Format: <io>,<irq>,<dma>,<dma2>
diff --git a/Documentation/keys-request-key.txt b/Documentation/keys-request-key.txt
index 22488d791168..c1f64fdf84cb 100644
--- a/Documentation/keys-request-key.txt
+++ b/Documentation/keys-request-key.txt
@@ -3,16 +3,23 @@
3 =================== 3 ===================
4 4
5The key request service is part of the key retention service (refer to 5The key request service is part of the key retention service (refer to
6Documentation/keys.txt). This document explains more fully how that the 6Documentation/keys.txt). This document explains more fully how the requesting
7requesting algorithm works. 7algorithm works.
8 8
9The process starts by either the kernel requesting a service by calling 9The process starts by either the kernel requesting a service by calling
10request_key(): 10request_key*():
11 11
12 struct key *request_key(const struct key_type *type, 12 struct key *request_key(const struct key_type *type,
13 const char *description, 13 const char *description,
14 const char *callout_string); 14 const char *callout_string);
15 15
16or:
17
18 struct key *request_key_with_auxdata(const struct key_type *type,
19 const char *description,
20 const char *callout_string,
21 void *aux);
22
16Or by userspace invoking the request_key system call: 23Or by userspace invoking the request_key system call:
17 24
18 key_serial_t request_key(const char *type, 25 key_serial_t request_key(const char *type,
@@ -20,16 +27,26 @@ Or by userspace invoking the request_key system call:
20 const char *callout_info, 27 const char *callout_info,
21 key_serial_t dest_keyring); 28 key_serial_t dest_keyring);
22 29
23The main difference between the two access points is that the in-kernel 30The main difference between the access points is that the in-kernel interface
24interface does not need to link the key to a keyring to prevent it from being 31does not need to link the key to a keyring to prevent it from being immediately
25immediately destroyed. The kernel interface returns a pointer directly to the 32destroyed. The kernel interface returns a pointer directly to the key, and
26key, and it's up to the caller to destroy the key. 33it's up to the caller to destroy the key.
34
35The request_key_with_auxdata() call is like the in-kernel request_key() call,
36except that it permits auxiliary data to be passed to the upcaller (the default
37is NULL). This is only useful for those key types that define their own upcall
38mechanism rather than using /sbin/request-key.
27 39
28The userspace interface links the key to a keyring associated with the process 40The userspace interface links the key to a keyring associated with the process
29to prevent the key from going away, and returns the serial number of the key to 41to prevent the key from going away, and returns the serial number of the key to
30the caller. 42the caller.
31 43
32 44
45The following example assumes that the key types involved don't define their
46own upcall mechanisms. If they do, then those should be substituted for the
47forking and execution of /sbin/request-key.
48
49
33=========== 50===========
34THE PROCESS 51THE PROCESS
35=========== 52===========
@@ -40,8 +57,8 @@ A request proceeds in the following manner:
40 interface]. 57 interface].
41 58
42 (2) request_key() searches the process's subscribed keyrings to see if there's 59 (2) request_key() searches the process's subscribed keyrings to see if there's
43 a suitable key there. If there is, it returns the key. If there isn't, and 60 a suitable key there. If there is, it returns the key. If there isn't,
44 callout_info is not set, an error is returned. Otherwise the process 61 and callout_info is not set, an error is returned. Otherwise the process
45 proceeds to the next step. 62 proceeds to the next step.
46 63
47 (3) request_key() sees that A doesn't have the desired key yet, so it creates 64 (3) request_key() sees that A doesn't have the desired key yet, so it creates
@@ -62,7 +79,7 @@ A request proceeds in the following manner:
62 instantiation. 79 instantiation.
63 80
64 (7) The program may want to access another key from A's context (say a 81 (7) The program may want to access another key from A's context (say a
65 Kerberos TGT key). It just requests the appropriate key, and the keyring 82 Kerberos TGT key). It just requests the appropriate key, and the keyring
66 search notes that the session keyring has auth key V in its bottom level. 83 search notes that the session keyring has auth key V in its bottom level.
67 84
68 This will permit it to then search the keyrings of process A with the 85 This will permit it to then search the keyrings of process A with the
@@ -79,10 +96,11 @@ A request proceeds in the following manner:
79(10) The program then exits 0 and request_key() deletes key V and returns key 96(10) The program then exits 0 and request_key() deletes key V and returns key
80 U to the caller. 97 U to the caller.
81 98
82This also extends further. If key W (step 7 above) didn't exist, key W would be 99This also extends further. If key W (step 7 above) didn't exist, key W would
83created uninstantiated, another auth key (X) would be created (as per step 3) 100be created uninstantiated, another auth key (X) would be created (as per step
84and another copy of /sbin/request-key spawned (as per step 4); but the context 1013) and another copy of /sbin/request-key spawned (as per step 4); but the
85specified by auth key X will still be process A, as it was in auth key V. 102context specified by auth key X will still be process A, as it was in auth key
103V.
86 104
87This is because process A's keyrings can't simply be attached to 105This is because process A's keyrings can't simply be attached to
88/sbin/request-key at the appropriate places because (a) execve will discard two 106/sbin/request-key at the appropriate places because (a) execve will discard two
@@ -118,17 +136,17 @@ A search of any particular keyring proceeds in the following fashion:
118 136
119 (2) It considers all the non-keyring keys within that keyring and, if any key 137 (2) It considers all the non-keyring keys within that keyring and, if any key
120 matches the criteria specified, calls key_permission(SEARCH) on it to see 138 matches the criteria specified, calls key_permission(SEARCH) on it to see
121 if the key is allowed to be found. If it is, that key is returned; if 139 if the key is allowed to be found. If it is, that key is returned; if
122 not, the search continues, and the error code is retained if of higher 140 not, the search continues, and the error code is retained if of higher
123 priority than the one currently set. 141 priority than the one currently set.
124 142
125 (3) It then considers all the keyring-type keys in the keyring it's currently 143 (3) It then considers all the keyring-type keys in the keyring it's currently
126 searching. It calls key_permission(SEARCH) on each keyring, and if this 144 searching. It calls key_permission(SEARCH) on each keyring, and if this
127 grants permission, it recurses, executing steps (2) and (3) on that 145 grants permission, it recurses, executing steps (2) and (3) on that
128 keyring. 146 keyring.
129 147
130The process stops immediately a valid key is found with permission granted to 148The process stops immediately a valid key is found with permission granted to
131use it. Any error from a previous match attempt is discarded and the key is 149use it. Any error from a previous match attempt is discarded and the key is
132returned. 150returned.
133 151
134When search_process_keyrings() is invoked, it performs the following searches 152When search_process_keyrings() is invoked, it performs the following searches
@@ -153,7 +171,7 @@ The moment one succeeds, all pending errors are discarded and the found key is
153returned. 171returned.
154 172
155Only if all these fail does the whole thing fail with the highest priority 173Only if all these fail does the whole thing fail with the highest priority
156error. Note that several errors may have come from LSM. 174error. Note that several errors may have come from LSM.
157 175
158The error priority is: 176The error priority is:
159 177
diff --git a/Documentation/keys.txt b/Documentation/keys.txt
index 61c0fad2fe2f..e373f0212843 100644
--- a/Documentation/keys.txt
+++ b/Documentation/keys.txt
@@ -780,6 +780,17 @@ payload contents" for more information.
780 See also Documentation/keys-request-key.txt. 780 See also Documentation/keys-request-key.txt.
781 781
782 782
783(*) To search for a key, passing auxiliary data to the upcaller, call:
784
785 struct key *request_key_with_auxdata(const struct key_type *type,
786 const char *description,
787 const char *callout_string,
788 void *aux);
789
790 This is identical to request_key(), except that the auxiliary data is
791 passed to the key_type->request_key() op if it exists.
792
793
783(*) When it is no longer required, the key should be released using: 794(*) When it is no longer required, the key should be released using:
784 795
785 void key_put(struct key *key); 796 void key_put(struct key *key);
@@ -1031,6 +1042,24 @@ The structure has a number of fields, some of which are mandatory:
1031 as might happen when the userspace buffer is accessed. 1042 as might happen when the userspace buffer is accessed.
1032 1043
1033 1044
1045 (*) int (*request_key)(struct key *key, struct key *authkey, const char *op,
1046 void *aux);
1047
1048 This method is optional. If provided, request_key() and
1049 request_key_with_auxdata() will invoke this function rather than
1050 upcalling to /sbin/request-key to operate upon a key of this type.
1051
1052 The aux parameter is as passed to request_key_with_auxdata() or is NULL
1053 otherwise. Also passed are the key to be operated upon, the
1054 authorisation key for this operation and the operation type (currently
1055 only "create").
1056
1057 This function should return only when the upcall is complete. Upon return
1058 the authorisation key will be revoked, and the target key will be
1059 negatively instantiated if it is still uninstantiated. The error will be
1060 returned to the caller of request_key*().
1061
1062
1034============================ 1063============================
1035REQUEST-KEY CALLBACK SERVICE 1064REQUEST-KEY CALLBACK SERVICE
1036============================ 1065============================
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt
index cf0d5416a4c3..28d1bc3edb1c 100644
--- a/Documentation/memory-barriers.txt
+++ b/Documentation/memory-barriers.txt
@@ -602,7 +602,7 @@ Consider the following sequence of events:
602 602
603This sequence of events is committed to the memory coherence system in an order 603This sequence of events is committed to the memory coherence system in an order
604that the rest of the system might perceive as the unordered set of { STORE A, 604that the rest of the system might perceive as the unordered set of { STORE A,
605STORE B, STORE C } all occuring before the unordered set of { STORE D, STORE E 605STORE B, STORE C } all occurring before the unordered set of { STORE D, STORE E
606}: 606}:
607 607
608 +-------+ : : 608 +-------+ : :
diff --git a/Documentation/networking/pktgen.txt b/Documentation/networking/pktgen.txt
index 278771c9ad99..44f2f769e865 100644
--- a/Documentation/networking/pktgen.txt
+++ b/Documentation/networking/pktgen.txt
@@ -74,7 +74,7 @@ Examples:
74 pgset "pkt_size 9014" sets packet size to 9014 74 pgset "pkt_size 9014" sets packet size to 9014
75 pgset "frags 5" packet will consist of 5 fragments 75 pgset "frags 5" packet will consist of 5 fragments
76 pgset "count 200000" sets number of packets to send, set to zero 76 pgset "count 200000" sets number of packets to send, set to zero
77 for continious sends untill explicitl stopped. 77 for continuous sends until explicitly stopped.
78 78
79 pgset "delay 5000" adds delay to hard_start_xmit(). nanoseconds 79 pgset "delay 5000" adds delay to hard_start_xmit(). nanoseconds
80 80
diff --git a/Documentation/pci.txt b/Documentation/pci.txt
index 3242e5c1ee9c..2b395e478961 100644
--- a/Documentation/pci.txt
+++ b/Documentation/pci.txt
@@ -225,7 +225,7 @@ Generic flavors of pci_request_region() are request_mem_region()
225Use these for address resources that are not described by "normal" PCI 225Use these for address resources that are not described by "normal" PCI
226interfaces (e.g. BAR). 226interfaces (e.g. BAR).
227 227
228 All interrupt handlers should be registered with SA_SHIRQ and use the devid 228 All interrupt handlers should be registered with IRQF_SHARED and use the devid
229to map IRQs to devices (remember that all PCI interrupts are shared). 229to map IRQs to devices (remember that all PCI interrupts are shared).
230 230
231 231
diff --git a/Documentation/pcmcia/crc32hash.c b/Documentation/pcmcia/crc32hash.c
new file mode 100644
index 000000000000..cbc36d299af8
--- /dev/null
+++ b/Documentation/pcmcia/crc32hash.c
@@ -0,0 +1,32 @@
1/* crc32hash.c - derived from linux/lib/crc32.c, GNU GPL v2 */
2/* Usage example:
3$ ./crc32hash "Dual Speed"
4*/
5
6#include <string.h>
7#include <stdio.h>
8#include <ctype.h>
9#include <stdlib.h>
10
11unsigned int crc32(unsigned char const *p, unsigned int len)
12{
13 int i;
14 unsigned int crc = 0;
15 while (len--) {
16 crc ^= *p++;
17 for (i = 0; i < 8; i++)
18 crc = (crc >> 1) ^ ((crc & 1) ? 0xedb88320 : 0);
19 }
20 return crc;
21}
22
23int main(int argc, char **argv) {
24 unsigned int result;
25 if (argc != 2) {
26 printf("no string passed as argument\n");
27 return -1;
28 }
29 result = crc32(argv[1], strlen(argv[1]));
30 printf("0x%x\n", result);
31 return 0;
32}
diff --git a/Documentation/pcmcia/devicetable.txt b/Documentation/pcmcia/devicetable.txt
index 3351c0355143..199afd100cf2 100644
--- a/Documentation/pcmcia/devicetable.txt
+++ b/Documentation/pcmcia/devicetable.txt
@@ -27,37 +27,7 @@ pcmcia:m0149cC1ABf06pfn00fn00pa725B842DpbF1EFEE84pc0877B627pd00000000
27The hex value after "pa" is the hash of product ID string 1, after "pb" for 27The hex value after "pa" is the hash of product ID string 1, after "pb" for
28string 2 and so on. 28string 2 and so on.
29 29
30Alternatively, you can use this small tool to determine the crc32 hash. 30Alternatively, you can use crc32hash (see Documentation/pcmcia/crc32hash.c)
31simply pass the string you want to evaluate as argument to this program, 31to determine the crc32 hash. Simply pass the string you want to evaluate
32e.g. 32as argument to this program, e.g.:
33$ ./crc32hash "Dual Speed" 33$ ./crc32hash "Dual Speed"
34
35-------------------------------------------------------------------------
36/* crc32hash.c - derived from linux/lib/crc32.c, GNU GPL v2 */
37#include <string.h>
38#include <stdio.h>
39#include <ctype.h>
40#include <stdlib.h>
41
42unsigned int crc32(unsigned char const *p, unsigned int len)
43{
44 int i;
45 unsigned int crc = 0;
46 while (len--) {
47 crc ^= *p++;
48 for (i = 0; i < 8; i++)
49 crc = (crc >> 1) ^ ((crc & 1) ? 0xedb88320 : 0);
50 }
51 return crc;
52}
53
54int main(int argc, char **argv) {
55 unsigned int result;
56 if (argc != 2) {
57 printf("no string passed as argument\n");
58 return -1;
59 }
60 result = crc32(argv[1], strlen(argv[1]));
61 printf("0x%x\n", result);
62 return 0;
63}
diff --git a/Documentation/scsi/tmscsim.txt b/Documentation/scsi/tmscsim.txt
index e165229adf50..df7a02bfb5bf 100644
--- a/Documentation/scsi/tmscsim.txt
+++ b/Documentation/scsi/tmscsim.txt
@@ -109,7 +109,7 @@ than the 33.33 MHz being in the PCI spec.
109 109
110If you want to share the IRQ with another device and the driver refuses to 110If you want to share the IRQ with another device and the driver refuses to
111do so, you might succeed with changing the DC390_IRQ type in tmscsim.c to 111do so, you might succeed with changing the DC390_IRQ type in tmscsim.c to
112SA_SHIRQ | SA_INTERRUPT. 112IRQF_SHARED | IRQF_DISABLED.
113 113
114 114
1153.Features 1153.Features
diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index 87d76a5c73d0..f61af23dd85d 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -472,6 +472,22 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
472 472
473 The power-management is supported. 473 The power-management is supported.
474 474
475 Module snd-darla20
476 ------------------
477
478 Module for Echoaudio Darla20
479
480 This module supports multiple cards.
481 The driver requires the firmware loader support on kernel.
482
483 Module snd-darla24
484 ------------------
485
486 Module for Echoaudio Darla24
487
488 This module supports multiple cards.
489 The driver requires the firmware loader support on kernel.
490
475 Module snd-dt019x 491 Module snd-dt019x
476 ----------------- 492 -----------------
477 493
@@ -499,6 +515,14 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
499 515
500 The power-management is supported. 516 The power-management is supported.
501 517
518 Module snd-echo3g
519 -----------------
520
521 Module for Echoaudio 3G cards (Gina3G/Layla3G)
522
523 This module supports multiple cards.
524 The driver requires the firmware loader support on kernel.
525
502 Module snd-emu10k1 526 Module snd-emu10k1
503 ------------------ 527 ------------------
504 528
@@ -657,6 +681,22 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
657 681
658 The power-management is supported. 682 The power-management is supported.
659 683
684 Module snd-gina20
685 -----------------
686
687 Module for Echoaudio Gina20
688
689 This module supports multiple cards.
690 The driver requires the firmware loader support on kernel.
691
692 Module snd-gina24
693 -----------------
694
695 Module for Echoaudio Gina24
696
697 This module supports multiple cards.
698 The driver requires the firmware loader support on kernel.
699
660 Module snd-gusclassic 700 Module snd-gusclassic
661 --------------------- 701 ---------------------
662 702
@@ -760,12 +800,18 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
760 basic fixed pin assignment w/o SPDIF 800 basic fixed pin assignment w/o SPDIF
761 auto auto-config reading BIOS (default) 801 auto auto-config reading BIOS (default)
762 802
763 ALC882/883/885 803 ALC882/885
764 3stack-dig 3-jack with SPDIF I/O 804 3stack-dig 3-jack with SPDIF I/O
765 6stck-dig 6-jack digital with SPDIF I/O 805 6stck-dig 6-jack digital with SPDIF I/O
766 auto auto-config reading BIOS (default) 806 auto auto-config reading BIOS (default)
767 807
768 ALC861 808 ALC883/888
809 3stack-dig 3-jack with SPDIF I/O
810 6stack-dig 6-jack digital with SPDIF I/O
811 6stack-dig-demo 6-stack digital for Intel demo board
812 auto auto-config reading BIOS (default)
813
814 ALC861/660
769 3stack 3-jack 815 3stack 3-jack
770 3stack-dig 3-jack with SPDIF I/O 816 3stack-dig 3-jack with SPDIF I/O
771 6stack-dig 6-jack with SPDIF I/O 817 6stack-dig 6-jack with SPDIF I/O
@@ -937,6 +983,30 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
937 driver isn't configured properly or you want to try another 983 driver isn't configured properly or you want to try another
938 type for testing. 984 type for testing.
939 985
986 Module snd-indigo
987 -----------------
988
989 Module for Echoaudio Indigo
990
991 This module supports multiple cards.
992 The driver requires the firmware loader support on kernel.
993
994 Module snd-indigodj
995 -------------------
996
997 Module for Echoaudio Indigo DJ
998
999 This module supports multiple cards.
1000 The driver requires the firmware loader support on kernel.
1001
1002 Module snd-indigoio
1003 -------------------
1004
1005 Module for Echoaudio Indigo IO
1006
1007 This module supports multiple cards.
1008 The driver requires the firmware loader support on kernel.
1009
940 Module snd-intel8x0 1010 Module snd-intel8x0
941 ------------------- 1011 -------------------
942 1012
@@ -1036,6 +1106,22 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
1036 1106
1037 This module supports multiple cards. 1107 This module supports multiple cards.
1038 1108
1109 Module snd-layla20
1110 ------------------
1111
1112 Module for Echoaudio Layla20
1113
1114 This module supports multiple cards.
1115 The driver requires the firmware loader support on kernel.
1116
1117 Module snd-layla24
1118 ------------------
1119
1120 Module for Echoaudio Layla24
1121
1122 This module supports multiple cards.
1123 The driver requires the firmware loader support on kernel.
1124
1039 Module snd-maestro3 1125 Module snd-maestro3
1040 ------------------- 1126 -------------------
1041 1127
@@ -1056,6 +1142,14 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
1056 1142
1057 The power-management is supported. 1143 The power-management is supported.
1058 1144
1145 Module snd-mia
1146 ---------------
1147
1148 Module for Echoaudio Mia
1149
1150 This module supports multiple cards.
1151 The driver requires the firmware loader support on kernel.
1152
1059 Module snd-miro 1153 Module snd-miro
1060 --------------- 1154 ---------------
1061 1155
@@ -1088,6 +1182,14 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
1088 When no hotplug fw loader is available, you need to load the 1182 When no hotplug fw loader is available, you need to load the
1089 firmware via mixartloader utility in alsa-tools package. 1183 firmware via mixartloader utility in alsa-tools package.
1090 1184
1185 Module snd-mona
1186 ---------------
1187
1188 Module for Echoaudio Mona
1189
1190 This module supports multiple cards.
1191 The driver requires the firmware loader support on kernel.
1192
1091 Module snd-mpu401 1193 Module snd-mpu401
1092 ----------------- 1194 -----------------
1093 1195
diff --git a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl
index 635cbb94357c..69866d5997a4 100644
--- a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl
+++ b/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl
@@ -1149,7 +1149,7 @@
1149 } 1149 }
1150 chip->port = pci_resource_start(pci, 0); 1150 chip->port = pci_resource_start(pci, 0);
1151 if (request_irq(pci->irq, snd_mychip_interrupt, 1151 if (request_irq(pci->irq, snd_mychip_interrupt,
1152 SA_INTERRUPT|SA_SHIRQ, "My Chip", chip)) { 1152 IRQF_DISABLED|IRQF_SHARED, "My Chip", chip)) {
1153 printk(KERN_ERR "cannot grab irq %d\n", pci->irq); 1153 printk(KERN_ERR "cannot grab irq %d\n", pci->irq);
1154 snd_mychip_free(chip); 1154 snd_mychip_free(chip);
1155 return -EBUSY; 1155 return -EBUSY;
@@ -1323,7 +1323,7 @@
1323 <programlisting> 1323 <programlisting>
1324<![CDATA[ 1324<![CDATA[
1325 if (request_irq(pci->irq, snd_mychip_interrupt, 1325 if (request_irq(pci->irq, snd_mychip_interrupt,
1326 SA_INTERRUPT|SA_SHIRQ, "My Chip", chip)) { 1326 IRQF_DISABLED|IRQF_SHARED, "My Chip", chip)) {
1327 printk(KERN_ERR "cannot grab irq %d\n", pci->irq); 1327 printk(KERN_ERR "cannot grab irq %d\n", pci->irq);
1328 snd_mychip_free(chip); 1328 snd_mychip_free(chip);
1329 return -EBUSY; 1329 return -EBUSY;
@@ -1342,7 +1342,7 @@
1342 1342
1343 <para> 1343 <para>
1344 On the PCI bus, the interrupts can be shared. Thus, 1344 On the PCI bus, the interrupts can be shared. Thus,
1345 <constant>SA_SHIRQ</constant> is given as the interrupt flag of 1345 <constant>IRQF_SHARED</constant> is given as the interrupt flag of
1346 <function>request_irq()</function>. 1346 <function>request_irq()</function>.
1347 </para> 1347 </para>
1348 1348
@@ -3048,7 +3048,7 @@ struct _snd_pcm_runtime {
3048 </para> 3048 </para>
3049 3049
3050 <para> 3050 <para>
3051 If you aquire a spinlock in the interrupt handler, and the 3051 If you acquire a spinlock in the interrupt handler, and the
3052 lock is used in other pcm callbacks, too, then you have to 3052 lock is used in other pcm callbacks, too, then you have to
3053 release the lock before calling 3053 release the lock before calling
3054 <function>snd_pcm_period_elapsed()</function>, because 3054 <function>snd_pcm_period_elapsed()</function>, because
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index 2dc246af4885..86754eb390da 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -28,7 +28,6 @@ Currently, these files are in /proc/sys/vm:
28- block_dump 28- block_dump
29- drop-caches 29- drop-caches
30- zone_reclaim_mode 30- zone_reclaim_mode
31- zone_reclaim_interval
32- panic_on_oom 31- panic_on_oom
33 32
34============================================================== 33==============================================================
@@ -167,18 +166,6 @@ use of files and builds up large slab caches. However, the slab
167shrink operation is global, may take a long time and free slabs 166shrink operation is global, may take a long time and free slabs
168in all nodes of the system. 167in all nodes of the system.
169 168
170================================================================
171
172zone_reclaim_interval:
173
174The time allowed for off node allocations after zone reclaim
175has failed to reclaim enough pages to allow a local allocation.
176
177Time is set in seconds and set by default to 30 seconds.
178
179Reduce the interval if undesired off node allocations occur. However, too
180frequent scans will have a negative impact onoff node allocation performance.
181
182============================================================= 169=============================================================
183 170
184panic_on_oom 171panic_on_oom
diff --git a/Documentation/video4linux/CARDLIST.cx88 b/Documentation/video4linux/CARDLIST.cx88
index 6cb63ddf6163..00d9a1f2a54c 100644
--- a/Documentation/video4linux/CARDLIST.cx88
+++ b/Documentation/video4linux/CARDLIST.cx88
@@ -50,3 +50,4 @@
50 49 -> PixelView PlayTV P7000 [1554:4813] 50 49 -> PixelView PlayTV P7000 [1554:4813]
51 50 -> NPG Tech Real TV FM Top 10 [14f1:0842] 51 50 -> NPG Tech Real TV FM Top 10 [14f1:0842]
52 51 -> WinFast DTV2000 H [107d:665e] 52 51 -> WinFast DTV2000 H [107d:665e]
53 52 -> Geniatech DVB-S [14f1:0084]
diff --git a/Documentation/watchdog/pcwd-watchdog.txt b/Documentation/watchdog/pcwd-watchdog.txt
index 12187a33e310..d9ee6336c1d4 100644
--- a/Documentation/watchdog/pcwd-watchdog.txt
+++ b/Documentation/watchdog/pcwd-watchdog.txt
@@ -22,78 +22,9 @@
22 to run the program with an "&" to run it in the background!) 22 to run the program with an "&" to run it in the background!)
23 23
24 If you want to write a program to be compatible with the PC Watchdog 24 If you want to write a program to be compatible with the PC Watchdog
25 driver, simply do the following: 25 driver, simply use of modify the watchdog test program:
26 26 Documentation/watchdog/src/watchdog-test.c
27-- Snippet of code -- 27
28/*
29 * Watchdog Driver Test Program
30 */
31
32#include <stdio.h>
33#include <stdlib.h>
34#include <string.h>
35#include <unistd.h>
36#include <fcntl.h>
37#include <sys/ioctl.h>
38#include <linux/types.h>
39#include <linux/watchdog.h>
40
41int fd;
42
43/*
44 * This function simply sends an IOCTL to the driver, which in turn ticks
45 * the PC Watchdog card to reset its internal timer so it doesn't trigger
46 * a computer reset.
47 */
48void keep_alive(void)
49{
50 int dummy;
51
52 ioctl(fd, WDIOC_KEEPALIVE, &dummy);
53}
54
55/*
56 * The main program. Run the program with "-d" to disable the card,
57 * or "-e" to enable the card.
58 */
59int main(int argc, char *argv[])
60{
61 fd = open("/dev/watchdog", O_WRONLY);
62
63 if (fd == -1) {
64 fprintf(stderr, "Watchdog device not enabled.\n");
65 fflush(stderr);
66 exit(-1);
67 }
68
69 if (argc > 1) {
70 if (!strncasecmp(argv[1], "-d", 2)) {
71 ioctl(fd, WDIOC_SETOPTIONS, WDIOS_DISABLECARD);
72 fprintf(stderr, "Watchdog card disabled.\n");
73 fflush(stderr);
74 exit(0);
75 } else if (!strncasecmp(argv[1], "-e", 2)) {
76 ioctl(fd, WDIOC_SETOPTIONS, WDIOS_ENABLECARD);
77 fprintf(stderr, "Watchdog card enabled.\n");
78 fflush(stderr);
79 exit(0);
80 } else {
81 fprintf(stderr, "-d to disable, -e to enable.\n");
82 fprintf(stderr, "run by itself to tick the card.\n");
83 fflush(stderr);
84 exit(0);
85 }
86 } else {
87 fprintf(stderr, "Watchdog Ticking Away!\n");
88 fflush(stderr);
89 }
90
91 while(1) {
92 keep_alive();
93 sleep(1);
94 }
95}
96-- End snippet --
97 28
98 Other IOCTL functions include: 29 Other IOCTL functions include:
99 30
diff --git a/Documentation/watchdog/src/watchdog-simple.c b/Documentation/watchdog/src/watchdog-simple.c
new file mode 100644
index 000000000000..85cf17c48669
--- /dev/null
+++ b/Documentation/watchdog/src/watchdog-simple.c
@@ -0,0 +1,15 @@
1#include <stdlib.h>
2#include <fcntl.h>
3
4int main(int argc, const char *argv[]) {
5 int fd = open("/dev/watchdog", O_WRONLY);
6 if (fd == -1) {
7 perror("watchdog");
8 exit(1);
9 }
10 while (1) {
11 write(fd, "\0", 1);
12 fsync(fd);
13 sleep(10);
14 }
15}
diff --git a/Documentation/watchdog/src/watchdog-test.c b/Documentation/watchdog/src/watchdog-test.c
new file mode 100644
index 000000000000..65f6c19cb865
--- /dev/null
+++ b/Documentation/watchdog/src/watchdog-test.c
@@ -0,0 +1,68 @@
1/*
2 * Watchdog Driver Test Program
3 */
4
5#include <stdio.h>
6#include <stdlib.h>
7#include <string.h>
8#include <unistd.h>
9#include <fcntl.h>
10#include <sys/ioctl.h>
11#include <linux/types.h>
12#include <linux/watchdog.h>
13
14int fd;
15
16/*
17 * This function simply sends an IOCTL to the driver, which in turn ticks
18 * the PC Watchdog card to reset its internal timer so it doesn't trigger
19 * a computer reset.
20 */
21void keep_alive(void)
22{
23 int dummy;
24
25 ioctl(fd, WDIOC_KEEPALIVE, &dummy);
26}
27
28/*
29 * The main program. Run the program with "-d" to disable the card,
30 * or "-e" to enable the card.
31 */
32int main(int argc, char *argv[])
33{
34 fd = open("/dev/watchdog", O_WRONLY);
35
36 if (fd == -1) {
37 fprintf(stderr, "Watchdog device not enabled.\n");
38 fflush(stderr);
39 exit(-1);
40 }
41
42 if (argc > 1) {
43 if (!strncasecmp(argv[1], "-d", 2)) {
44 ioctl(fd, WDIOC_SETOPTIONS, WDIOS_DISABLECARD);
45 fprintf(stderr, "Watchdog card disabled.\n");
46 fflush(stderr);
47 exit(0);
48 } else if (!strncasecmp(argv[1], "-e", 2)) {
49 ioctl(fd, WDIOC_SETOPTIONS, WDIOS_ENABLECARD);
50 fprintf(stderr, "Watchdog card enabled.\n");
51 fflush(stderr);
52 exit(0);
53 } else {
54 fprintf(stderr, "-d to disable, -e to enable.\n");
55 fprintf(stderr, "run by itself to tick the card.\n");
56 fflush(stderr);
57 exit(0);
58 }
59 } else {
60 fprintf(stderr, "Watchdog Ticking Away!\n");
61 fflush(stderr);
62 }
63
64 while(1) {
65 keep_alive();
66 sleep(1);
67 }
68}
diff --git a/Documentation/watchdog/watchdog-api.txt b/Documentation/watchdog/watchdog-api.txt
index 21ed51173662..958ff3d48be3 100644
--- a/Documentation/watchdog/watchdog-api.txt
+++ b/Documentation/watchdog/watchdog-api.txt
@@ -34,22 +34,7 @@ activates as soon as /dev/watchdog is opened and will reboot unless
34the watchdog is pinged within a certain time, this time is called the 34the watchdog is pinged within a certain time, this time is called the
35timeout or margin. The simplest way to ping the watchdog is to write 35timeout or margin. The simplest way to ping the watchdog is to write
36some data to the device. So a very simple watchdog daemon would look 36some data to the device. So a very simple watchdog daemon would look
37like this: 37like this source file: see Documentation/watchdog/src/watchdog-simple.c
38
39#include <stdlib.h>
40#include <fcntl.h>
41
42int main(int argc, const char *argv[]) {
43 int fd=open("/dev/watchdog",O_WRONLY);
44 if (fd==-1) {
45 perror("watchdog");
46 exit(1);
47 }
48 while(1) {
49 write(fd, "\0", 1);
50 sleep(10);
51 }
52}
53 38
54A more advanced driver could for example check that a HTTP server is 39A more advanced driver could for example check that a HTTP server is
55still responding before doing the write call to ping the watchdog. 40still responding before doing the write call to ping the watchdog.
@@ -110,7 +95,40 @@ current timeout using the GETTIMEOUT ioctl.
110 ioctl(fd, WDIOC_GETTIMEOUT, &timeout); 95 ioctl(fd, WDIOC_GETTIMEOUT, &timeout);
111 printf("The timeout was is %d seconds\n", timeout); 96 printf("The timeout was is %d seconds\n", timeout);
112 97
113Envinronmental monitoring: 98Pretimeouts:
99
100Some watchdog timers can be set to have a trigger go off before the
101actual time they will reset the system. This can be done with an NMI,
102interrupt, or other mechanism. This allows Linux to record useful
103information (like panic information and kernel coredumps) before it
104resets.
105
106 pretimeout = 10;
107 ioctl(fd, WDIOC_SETPRETIMEOUT, &pretimeout);
108
109Note that the pretimeout is the number of seconds before the time
110when the timeout will go off. It is not the number of seconds until
111the pretimeout. So, for instance, if you set the timeout to 60 seconds
112and the pretimeout to 10 seconds, the pretimout will go of in 50
113seconds. Setting a pretimeout to zero disables it.
114
115There is also a get function for getting the pretimeout:
116
117 ioctl(fd, WDIOC_GETPRETIMEOUT, &timeout);
118 printf("The pretimeout was is %d seconds\n", timeout);
119
120Not all watchdog drivers will support a pretimeout.
121
122Get the number of seconds before reboot:
123
124Some watchdog drivers have the ability to report the remaining time
125before the system will reboot. The WDIOC_GETTIMELEFT is the ioctl
126that returns the number of seconds before reboot.
127
128 ioctl(fd, WDIOC_GETTIMELEFT, &timeleft);
129 printf("The timeout was is %d seconds\n", timeleft);
130
131Environmental monitoring:
114 132
115All watchdog drivers are required return more information about the system, 133All watchdog drivers are required return more information about the system,
116some do temperature, fan and power level monitoring, some can tell you 134some do temperature, fan and power level monitoring, some can tell you
@@ -169,6 +187,10 @@ The watchdog saw a keepalive ping since it was last queried.
169 187
170 WDIOF_SETTIMEOUT Can set/get the timeout 188 WDIOF_SETTIMEOUT Can set/get the timeout
171 189
190The watchdog can do pretimeouts.
191
192 WDIOF_PRETIMEOUT Pretimeout (in seconds), get/set
193
172 194
173For those drivers that return any bits set in the option field, the 195For those drivers that return any bits set in the option field, the
174GETSTATUS and GETBOOTSTATUS ioctls can be used to ask for the current 196GETSTATUS and GETBOOTSTATUS ioctls can be used to ask for the current
diff --git a/Documentation/watchdog/watchdog.txt b/Documentation/watchdog/watchdog.txt
index dffda29c8799..4b1ff69cc19a 100644
--- a/Documentation/watchdog/watchdog.txt
+++ b/Documentation/watchdog/watchdog.txt
@@ -65,28 +65,7 @@ The external event interfaces on the WDT boards are not currently supported.
65Minor numbers are however allocated for it. 65Minor numbers are however allocated for it.
66 66
67 67
68Example Watchdog Driver 68Example Watchdog Driver: see Documentation/watchdog/src/watchdog-simple.c
69-----------------------
70
71#include <stdio.h>
72#include <unistd.h>
73#include <fcntl.h>
74
75int main(int argc, const char *argv[])
76{
77 int fd=open("/dev/watchdog",O_WRONLY);
78 if(fd==-1)
79 {
80 perror("watchdog");
81 exit(1);
82 }
83 while(1)
84 {
85 write(fd,"\0",1);
86 fsync(fd);
87 sleep(10);
88 }
89}
90 69
91 70
92Contact Information 71Contact Information
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-22 09:00:24 -0500