<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/fs/proc/proc_misc.c, branch v2.6.20.3</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>[PATCH] fix linux banner format string</title>
<updated>2007-01-10T17:33:59+00:00</updated>
<author>
<name>Roman Zippel</name>
<email>zippel@linux-m68k.org</email>
</author>
<published>2007-01-10T13:45:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3eb3c740f51c2126b53c2dde974c1c57e634aa7b'/>
<id>3eb3c740f51c2126b53c2dde974c1c57e634aa7b</id>
<content type='text'>
Revert previous attempts at messing with the linux banner string and
simply use a separate format string for proc.

Signed-off-by: Roman Zippel &lt;zippel@linux-m68k.org&gt;
Acked-by: Olaf Hering &lt;olaf@aepfle.de&gt;
Acked-by: Jean Delvare &lt;khali@linux-fr.org&gt;
Cc: Andrey Borzenkov &lt;arvidjaar@mail.ru&gt;
Cc: Andrew Morton &lt;akpm@osdl.org&gt;
Cc: Andy Whitcroft &lt;apw@shadowen.org&gt;
Cc: Herbert Poetzl &lt;herbert@13thfloor.at&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Revert previous attempts at messing with the linux banner string and
simply use a separate format string for proc.

Signed-off-by: Roman Zippel &lt;zippel@linux-m68k.org&gt;
Acked-by: Olaf Hering &lt;olaf@aepfle.de&gt;
Acked-by: Jean Delvare &lt;khali@linux-fr.org&gt;
Cc: Andrey Borzenkov &lt;arvidjaar@mail.ru&gt;
Cc: Andrew Morton &lt;akpm@osdl.org&gt;
Cc: Andy Whitcroft &lt;apw@shadowen.org&gt;
Cc: Herbert Poetzl &lt;herbert@13thfloor.at&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Make SLES9 "get_kernel_version" work on the kernel binary again</title>
<updated>2006-12-11T19:34:11+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@woody.osdl.org</email>
</author>
<published>2006-12-11T17:28:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8993780a6e44fb4e7ed34e33458506a775356c6e'/>
<id>8993780a6e44fb4e7ed34e33458506a775356c6e</id>
<content type='text'>
As reported by Andy Whitcroft, at least the SLES9 initrd build process
depends on getting the kernel version from the kernel binary.  It does
that by simply trawling the binary and looking for the signature of the
"linux_banner" string (the string "Linux version " to be exact. Which
is really broken in itself, but whatever..)

That got broken when the string was changed to allow /proc/version to
change the UTS release information dynamically, and "get_kernel_version"
thus returned "%s" (see commit a2ee8649ba6d71416712e798276bf7c40b64e6e5:
"[PATCH] Fix linux banner utsname information").

This just restores "linux_banner" as a static string, which should fix
the version finding.  And /proc/version simply uses a different string.

To avoid wasting even that miniscule amount of memory, the early boot
string should really be marked __initdata, but that just causes the same
bug in SLES9 to re-appear, since it will then find other occurrences of
"Linux version " first.

Cc: Andy Whitcroft &lt;apw@shadowen.org&gt;
Acked-by: Herbert Poetzl &lt;herbert@13thfloor.at&gt;
Cc: Andi Kleen &lt;ak@suse.de&gt;
Cc: Andrew Morton &lt;akpm@osdl.org&gt;
Cc: Steve Fox &lt;drfickle@us.ibm.com&gt;
Acked-by: Olaf Hering &lt;olaf@aepfle.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As reported by Andy Whitcroft, at least the SLES9 initrd build process
depends on getting the kernel version from the kernel binary.  It does
that by simply trawling the binary and looking for the signature of the
"linux_banner" string (the string "Linux version " to be exact. Which
is really broken in itself, but whatever..)

That got broken when the string was changed to allow /proc/version to
change the UTS release information dynamically, and "get_kernel_version"
thus returned "%s" (see commit a2ee8649ba6d71416712e798276bf7c40b64e6e5:
"[PATCH] Fix linux banner utsname information").

This just restores "linux_banner" as a static string, which should fix
the version finding.  And /proc/version simply uses a different string.

To avoid wasting even that miniscule amount of memory, the early boot
string should really be marked __initdata, but that just causes the same
bug in SLES9 to re-appear, since it will then find other occurrences of
"Linux version " first.

Cc: Andy Whitcroft &lt;apw@shadowen.org&gt;
Acked-by: Herbert Poetzl &lt;herbert@13thfloor.at&gt;
Cc: Andi Kleen &lt;ak@suse.de&gt;
Cc: Andrew Morton &lt;akpm@osdl.org&gt;
Cc: Steve Fox &lt;drfickle@us.ibm.com&gt;
Acked-by: Olaf Hering &lt;olaf@aepfle.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] proc_misc build fix</title>
<updated>2006-12-08T16:29:09+00:00</updated>
<author>
<name>Andrew Morton</name>
<email>akpm@osdl.org</email>
</author>
<published>2006-12-08T10:41:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7bf65382caeecea4ae7206138e92e732b676d6e5'/>
<id>7bf65382caeecea4ae7206138e92e732b676d6e5</id>
<content type='text'>
fs/proc/proc_misc.c: In function `version_read_proc':
fs/proc/proc_misc.c:256: warning: implicit declaration of function `utsname'

Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
fs/proc/proc_misc.c: In function `version_read_proc':
fs/proc/proc_misc.c:256: warning: implicit declaration of function `utsname'

Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] use current-&gt;nsproxy-&gt;pid_ns</title>
<updated>2006-12-08T16:28:52+00:00</updated>
<author>
<name>Cedric Le Goater</name>
<email>clg@fr.ibm.com</email>
</author>
<published>2006-12-08T10:38:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6cc1b22a4acef3816eaa5f8c227d93d749b23195'/>
<id>6cc1b22a4acef3816eaa5f8c227d93d749b23195</id>
<content type='text'>
Signed-off-by: Cedric Le Goater &lt;clg@fr.ibm.com&gt;
Cc: Kirill Korotaev &lt;dev@openvz.org&gt;
Cc: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Cc: Herbert Poetzl &lt;herbert@13thfloor.at&gt;
Cc: Sukadev Bhattiprolu &lt;sukadev@us.ibm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Cedric Le Goater &lt;clg@fr.ibm.com&gt;
Cc: Kirill Korotaev &lt;dev@openvz.org&gt;
Cc: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Cc: Herbert Poetzl &lt;herbert@13thfloor.at&gt;
Cc: Sukadev Bhattiprolu &lt;sukadev@us.ibm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] rename struct pspace to struct pid_namespace</title>
<updated>2006-12-08T16:28:52+00:00</updated>
<author>
<name>Sukadev Bhattiprolu</name>
<email>sukadev@us.ibm.com</email>
</author>
<published>2006-12-08T10:37:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=61a58c6c238cc81f7742b8cc84212cc55fb57747'/>
<id>61a58c6c238cc81f7742b8cc84212cc55fb57747</id>
<content type='text'>
Rename struct pspace to struct pid_namespace for consistency with other
namespaces (uts_namespace and ipc_namespace).  Also rename
include/linux/pspace.h to include/linux/pid_namespace.h and variables from
pspace to pid_ns.

Signed-off-by: Sukadev Bhattiprolu &lt;sukadev@us.ibm.com&gt;
Signed-off-by: Cedric Le Goater &lt;clg@fr.ibm.com&gt;
Cc: Kirill Korotaev &lt;dev@openvz.org&gt;
Cc: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Cc: Herbert Poetzl &lt;herbert@13thfloor.at&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Rename struct pspace to struct pid_namespace for consistency with other
namespaces (uts_namespace and ipc_namespace).  Also rename
include/linux/pspace.h to include/linux/pid_namespace.h and variables from
pspace to pid_ns.

Signed-off-by: Sukadev Bhattiprolu &lt;sukadev@us.ibm.com&gt;
Signed-off-by: Cedric Le Goater &lt;clg@fr.ibm.com&gt;
Cc: Kirill Korotaev &lt;dev@openvz.org&gt;
Cc: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Cc: Herbert Poetzl &lt;herbert@13thfloor.at&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] Fix linux banner utsname information</title>
<updated>2006-12-08T16:28:37+00:00</updated>
<author>
<name>Herbert Poetzl</name>
<email>herbert@13thfloor.at</email>
</author>
<published>2006-12-08T10:36:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a2ee8649ba6d71416712e798276bf7c40b64e6e5'/>
<id>a2ee8649ba6d71416712e798276bf7c40b64e6e5</id>
<content type='text'>
utsname information is shown in the linux banner, which also is used for
/proc/version (which can have different utsname values inside a uts
namespaces).  this patch makes the varying data arguments and changes the
string to a format string, using those arguments.

Signed-off-by: Herbert Poetzl &lt;herbert@13thfloor.at&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
utsname information is shown in the linux banner, which also is used for
/proc/version (which can have different utsname values inside a uts
namespaces).  this patch makes the varying data arguments and changes the
string to a format string, using those arguments.

Signed-off-by: Herbert Poetzl &lt;herbert@13thfloor.at&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] remove the syslog interface when printk is disabled</title>
<updated>2006-12-07T16:39:38+00:00</updated>
<author>
<name>Mike Galbraith</name>
<email>efault@gmx.de</email>
</author>
<published>2006-12-07T04:37:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c36264dfb2d6fa6383082de0a1bba8e12b477da1'/>
<id>c36264dfb2d6fa6383082de0a1bba8e12b477da1</id>
<content type='text'>
Attempts to read() from the non-existent dmesg buffer will return zero and
userspace tends to get stuck in a busyloop.

So just remove /dev/kmsg altogether if CONFIG_PRINTK=n.

Signed-off-by: Mike Galbraith &lt;efault@gmx.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Attempts to read() from the non-existent dmesg buffer will return zero and
userspace tends to get stuck in a busyloop.

So just remove /dev/kmsg altogether if CONFIG_PRINTK=n.

Signed-off-by: Mike Galbraith &lt;efault@gmx.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>IRQ: Maintain regs pointer globally rather than passing to IRQ handlers</title>
<updated>2006-10-05T14:10:12+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2006-10-05T13:55:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7d12e780e003f93433d49ce78cfedf4b4c52adc5'/>
<id>7d12e780e003f93433d49ce78cfedf4b4c52adc5</id>
<content type='text'>
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells &lt;dhowells@redhat.com&gt;
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells &lt;dhowells@redhat.com&gt;
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] Define struct pspace</title>
<updated>2006-10-02T14:57:15+00:00</updated>
<author>
<name>Sukadev Bhattiprolu</name>
<email>sukadev@us.ibm.com</email>
</author>
<published>2006-10-02T09:17:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3fbc96486459324e182717b03c50c90c880be6ec'/>
<id>3fbc96486459324e182717b03c50c90c880be6ec</id>
<content type='text'>
Define a per-container pid space object.  And create one instance of this
object, init_pspace, to define the entire pid space.  Subsequent patches
will provide/use interfaces to create/destroy pid spaces.

Its a subset/rework of Eric Biederman's patch
http://lkml.org/lkml/2006/2/6/285 .

Signed-off-by: Eric Biederman &lt;ebiederm@xmission.com&gt;
Signed-off-by: Sukadev Bhattiprolu &lt;sukadev@us.ibm.com&gt;
Cc: Dave Hansen &lt;haveblue@us.ibm.com&gt;
Cc: Serge Hallyn &lt;serue@us.ibm.com&gt;
Cc: Cedric Le Goater &lt;clg@fr.ibm.com&gt;
Cc: Kirill Korotaev &lt;dev@sw.ru&gt;
Cc: Andrey Savochkin &lt;saw@sw.ru&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Define a per-container pid space object.  And create one instance of this
object, init_pspace, to define the entire pid space.  Subsequent patches
will provide/use interfaces to create/destroy pid spaces.

Its a subset/rework of Eric Biederman's patch
http://lkml.org/lkml/2006/2/6/285 .

Signed-off-by: Eric Biederman &lt;ebiederm@xmission.com&gt;
Signed-off-by: Sukadev Bhattiprolu &lt;sukadev@us.ibm.com&gt;
Cc: Dave Hansen &lt;haveblue@us.ibm.com&gt;
Cc: Serge Hallyn &lt;serue@us.ibm.com&gt;
Cc: Cedric Le Goater &lt;clg@fr.ibm.com&gt;
Cc: Kirill Korotaev &lt;dev@sw.ru&gt;
Cc: Andrey Savochkin &lt;saw@sw.ru&gt;
Signed-off-by: Andrew Morton &lt;akpm@osdl.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@osdl.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>[PATCH] BLOCK: Make it possible to disable the block layer [try #6]</title>
<updated>2006-09-30T18:52:31+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2006-09-30T18:45:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9361401eb7619c033e2394e4f9f6d410d6719ac7'/>
<id>9361401eb7619c033e2394e4f9f6d410d6719ac7</id>
<content type='text'>
Make it possible to disable the block layer.  Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.

This patch does the following:

 (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
     support.

 (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
     an item that uses the block layer.  This includes:

     (*) Block I/O tracing.

     (*) Disk partition code.

     (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.

     (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
     	 block layer to do scheduling.  Some drivers that use SCSI facilities -
     	 such as USB storage - end up disabled indirectly from this.

     (*) Various block-based device drivers, such as IDE and the old CDROM
     	 drivers.

     (*) MTD blockdev handling and FTL.

     (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
     	 taking a leaf out of JFFS2's book.

 (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
     linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
     however, still used in places, and so is still available.

 (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
     parts of linux/fs.h.

 (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.

 (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.

 (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
     is not enabled.

 (*) fs/no-block.c is created to hold out-of-line stubs and things that are
     required when CONFIG_BLOCK is not set:

     (*) Default blockdev file operations (to give error ENODEV on opening).

 (*) Makes some /proc changes:

     (*) /proc/devices does not list any blockdevs.

     (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.

 (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.

 (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
     given command other than Q_SYNC or if a special device is specified.

 (*) In init/do_mounts.c, no reference is made to the blockdev routines if
     CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.

 (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
     error ENOSYS by way of cond_syscall if so).

 (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
     CONFIG_BLOCK is not set, since they can't then happen.

Signed-Off-By: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Make it possible to disable the block layer.  Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.

This patch does the following:

 (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
     support.

 (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
     an item that uses the block layer.  This includes:

     (*) Block I/O tracing.

     (*) Disk partition code.

     (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.

     (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
     	 block layer to do scheduling.  Some drivers that use SCSI facilities -
     	 such as USB storage - end up disabled indirectly from this.

     (*) Various block-based device drivers, such as IDE and the old CDROM
     	 drivers.

     (*) MTD blockdev handling and FTL.

     (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
     	 taking a leaf out of JFFS2's book.

 (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
     linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
     however, still used in places, and so is still available.

 (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
     parts of linux/fs.h.

 (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.

 (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.

 (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
     is not enabled.

 (*) fs/no-block.c is created to hold out-of-line stubs and things that are
     required when CONFIG_BLOCK is not set:

     (*) Default blockdev file operations (to give error ENODEV on opening).

 (*) Makes some /proc changes:

     (*) /proc/devices does not list any blockdevs.

     (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.

 (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.

 (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
     given command other than Q_SYNC or if a special device is specified.

 (*) In init/do_mounts.c, no reference is made to the blockdev routines if
     CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.

 (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
     error ENOSYS by way of cond_syscall if so).

 (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
     CONFIG_BLOCK is not set, since they can't then happen.

Signed-Off-By: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
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