<feed xmlns='http://www.w3.org/2005/Atom'>
<title>litmus-rt.git/arch/um/drivers, branch linux-tip</title>
<subtitle>The LITMUS^RT kernel.</subtitle>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/'/>
<entry>
<title>uml: disable winch irq before freeing handler data</title>
<updated>2010-11-24T21:50:39+00:00</updated>
<author>
<name>Will Newton</name>
<email>will.newton@gmail.com</email>
</author>
<published>2010-11-24T20:56:55+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=69e83dad5207f8f03c9699e57e1febb114383cb8'/>
<id>69e83dad5207f8f03c9699e57e1febb114383cb8</id>
<content type='text'>
Disable the winch irq early to make sure we don't take an interrupt part
way through the freeing of the handler data, resulting in a crash on
shutdown:

  winch_interrupt : read failed, errno = 9
  fd 13 is losing SIGWINCH support
  ------------[ cut here ]------------
  WARNING: at lib/list_debug.c:48 list_del+0xc6/0x100()
  list_del corruption, next is LIST_POISON1 (00100100)
  082578c8:  [&lt;081fd77f&gt;] dump_stack+0x22/0x24
  082578e0:  [&lt;0807a18a&gt;] warn_slowpath_common+0x5a/0x80
  08257908:  [&lt;0807a23e&gt;] warn_slowpath_fmt+0x2e/0x30
  08257920:  [&lt;08172196&gt;] list_del+0xc6/0x100
  08257940:  [&lt;08060244&gt;] free_winch+0x14/0x80
  08257958:  [&lt;080606fb&gt;] winch_interrupt+0xdb/0xe0
  08257978:  [&lt;080a65b5&gt;] handle_IRQ_event+0x35/0xe0
  08257998:  [&lt;080a8717&gt;] handle_edge_irq+0xb7/0x170
  082579bc:  [&lt;08059bc4&gt;] do_IRQ+0x34/0x50
  082579d4:  [&lt;08059e1b&gt;] sigio_handler+0x5b/0x80
  082579ec:  [&lt;0806a374&gt;] sig_handler_common+0x44/0xb0
  08257a68:  [&lt;0806a538&gt;] sig_handler+0x38/0x50
  08257a78:  [&lt;0806a77c&gt;] handle_signal+0x5c/0xa0
  08257a9c:  [&lt;0806be28&gt;] hard_handler+0x18/0x20
  08257aac:  [&lt;00c14400&gt;] 0xc14400

Signed-off-by: Will Newton &lt;will.newton@gmail.com&gt;
Acked-by: WANG Cong &lt;xiyou.wangcong@gmail.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: &lt;stable@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Disable the winch irq early to make sure we don't take an interrupt part
way through the freeing of the handler data, resulting in a crash on
shutdown:

  winch_interrupt : read failed, errno = 9
  fd 13 is losing SIGWINCH support
  ------------[ cut here ]------------
  WARNING: at lib/list_debug.c:48 list_del+0xc6/0x100()
  list_del corruption, next is LIST_POISON1 (00100100)
  082578c8:  [&lt;081fd77f&gt;] dump_stack+0x22/0x24
  082578e0:  [&lt;0807a18a&gt;] warn_slowpath_common+0x5a/0x80
  08257908:  [&lt;0807a23e&gt;] warn_slowpath_fmt+0x2e/0x30
  08257920:  [&lt;08172196&gt;] list_del+0xc6/0x100
  08257940:  [&lt;08060244&gt;] free_winch+0x14/0x80
  08257958:  [&lt;080606fb&gt;] winch_interrupt+0xdb/0xe0
  08257978:  [&lt;080a65b5&gt;] handle_IRQ_event+0x35/0xe0
  08257998:  [&lt;080a8717&gt;] handle_edge_irq+0xb7/0x170
  082579bc:  [&lt;08059bc4&gt;] do_IRQ+0x34/0x50
  082579d4:  [&lt;08059e1b&gt;] sigio_handler+0x5b/0x80
  082579ec:  [&lt;0806a374&gt;] sig_handler_common+0x44/0xb0
  08257a68:  [&lt;0806a538&gt;] sig_handler+0x38/0x50
  08257a78:  [&lt;0806a77c&gt;] handle_signal+0x5c/0xa0
  08257a9c:  [&lt;0806be28&gt;] hard_handler+0x18/0x20
  08257aac:  [&lt;00c14400&gt;] 0xc14400

Signed-off-by: Will Newton &lt;will.newton@gmail.com&gt;
Acked-by: WANG Cong &lt;xiyou.wangcong@gmail.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: &lt;stable@kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl</title>
<updated>2010-10-22T17:52:56+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2010-10-22T17:52:56+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=092e0e7e520a1fca03e13c9f2d157432a8657ff2'/>
<id>092e0e7e520a1fca03e13c9f2d157432a8657ff2</id>
<content type='text'>
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl</title>
<updated>2010-10-22T17:43:11+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2010-10-22T17:43:11+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=5704e44d283e907623e3775c1262f206a2c48cf3'/>
<id>5704e44d283e907623e3775c1262f206a2c48cf3</id>
<content type='text'>
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  BKL: introduce CONFIG_BKL.
  dabusb: remove the BKL
  sunrpc: remove the big kernel lock
  init/main.c: remove BKL notations
  blktrace: remove the big kernel lock
  rtmutex-tester: make it build without BKL
  dvb-core: kill the big kernel lock
  dvb/bt8xx: kill the big kernel lock
  tlclk: remove big kernel lock
  fix rawctl compat ioctls breakage on amd64 and itanic
  uml: kill big kernel lock
  parisc: remove big kernel lock
  cris: autoconvert trivial BKL users
  alpha: kill big kernel lock
  isapnp: BKL removal
  s390/block: kill the big kernel lock
  hpet: kill BKL, add compat_ioctl
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  BKL: introduce CONFIG_BKL.
  dabusb: remove the BKL
  sunrpc: remove the big kernel lock
  init/main.c: remove BKL notations
  blktrace: remove the big kernel lock
  rtmutex-tester: make it build without BKL
  dvb-core: kill the big kernel lock
  dvb/bt8xx: kill the big kernel lock
  tlclk: remove big kernel lock
  fix rawctl compat ioctls breakage on amd64 and itanic
  uml: kill big kernel lock
  parisc: remove big kernel lock
  cris: autoconvert trivial BKL users
  alpha: kill big kernel lock
  isapnp: BKL removal
  s390/block: kill the big kernel lock
  hpet: kill BKL, add compat_ioctl
</pre>
</div>
</content>
</entry>
<entry>
<title>uml: kill big kernel lock</title>
<updated>2010-10-19T09:29:42+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2010-09-11T16:38:03+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=9a181c58617134822ae596339dbea076ef9b5cf7'/>
<id>9a181c58617134822ae596339dbea076ef9b5cf7</id>
<content type='text'>
Three uml device drivers still use the big kernel lock,
but all of them can be safely converted to using
a per-driver mutex instead. Most likely this is not
even necessary, so after further review these can
and should be removed as well.

The exec system call no longer requires the BKL either,
so remove it from there, too.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: user-mode-linux-devel@lists.sourceforge.net
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Three uml device drivers still use the big kernel lock,
but all of them can be safely converted to using
a per-driver mutex instead. Most likely this is not
even necessary, so after further review these can
and should be removed as well.

The exec system call no longer requires the BKL either,
so remove it from there, too.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: user-mode-linux-devel@lists.sourceforge.net
</pre>
</div>
</content>
</entry>
<entry>
<title>uml: fix build</title>
<updated>2010-10-15T21:42:24+00:00</updated>
<author>
<name>FUJITA Tomonori</name>
<email>fujita.tomonori@lab.ntt.co.jp</email>
</author>
<published>2010-10-15T21:34:13+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=e3c6cf61815b0af0c697aeed4c6f11762f913002'/>
<id>e3c6cf61815b0af0c697aeed4c6f11762f913002</id>
<content type='text'>
Fix a build error introduced by d6d1b650ae6acce73d55dd024 ("param: simple
locking for sysfs-writable charp parameters").

    CC      arch/um/kernel/trap.o
  arch/um/drivers/hostaudio_kern.c: In function 'hostaudio_open':
  arch/um/drivers/hostaudio_kern.c:204: error: '__param_dsp' undeclared (first use in this function)
  arch/um/drivers/hostaudio_kern.c:204: error: (Each undeclared identifier is reported only once
  arch/um/drivers/hostaudio_kern.c:204: error: for each function it appears in.)
  arch/um/drivers/hostaudio_kern.c: In function 'hostmixer_open_mixdev':
  arch/um/drivers/hostaudio_kern.c:265: error: '__param_mixer' undeclared (first use in this function)
  arch/um/drivers/hostaudio_kern.c:272: error: '__param_dsp' undeclared (first use in this function)

Reported-by: Toralf Förster &lt;toralf.foerster@gmx.de&gt;
Tested-by: Toralf Förster &lt;toralf.foerster@gmx.de&gt;
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Cc: Takashi Iwai &lt;tiwai@suse.de&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fix a build error introduced by d6d1b650ae6acce73d55dd024 ("param: simple
locking for sysfs-writable charp parameters").

    CC      arch/um/kernel/trap.o
  arch/um/drivers/hostaudio_kern.c: In function 'hostaudio_open':
  arch/um/drivers/hostaudio_kern.c:204: error: '__param_dsp' undeclared (first use in this function)
  arch/um/drivers/hostaudio_kern.c:204: error: (Each undeclared identifier is reported only once
  arch/um/drivers/hostaudio_kern.c:204: error: for each function it appears in.)
  arch/um/drivers/hostaudio_kern.c: In function 'hostmixer_open_mixdev':
  arch/um/drivers/hostaudio_kern.c:265: error: '__param_mixer' undeclared (first use in this function)
  arch/um/drivers/hostaudio_kern.c:272: error: '__param_dsp' undeclared (first use in this function)

Reported-by: Toralf Förster &lt;toralf.foerster@gmx.de&gt;
Tested-by: Toralf Förster &lt;toralf.foerster@gmx.de&gt;
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Cc: Takashi Iwai &lt;tiwai@suse.de&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>llseek: automatically add .llseek fop</title>
<updated>2010-10-15T13:53:27+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2010-08-15T16:52:59+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=6038f373a3dc1f1c26496e60b6c40b164716f07e'/>
<id>6038f373a3dc1f1c26496e60b6c40b164716f07e</id>
<content type='text'>
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
&lt;+...
nonseekable_open(...)
...+&gt;
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
&lt;+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+&gt;
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
&lt;+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+&gt;
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
&lt;+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+&gt;
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek &amp;&amp; has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 &amp;&amp; !fops2 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 &amp;&amp; !fops2 &amp;&amp; !fops3 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write &amp;&amp; !has_read &amp;&amp; !fops1 &amp;&amp; !fops2 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read &amp;&amp; !has_write &amp;&amp; !fops1 &amp;&amp; !fops2 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read &amp;&amp; !has_write &amp;&amp; !fops1 &amp;&amp; !fops2 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Julia Lawall &lt;julia@diku.dk&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
&lt;+...
nonseekable_open(...)
...+&gt;
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
&lt;+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+&gt;
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
&lt;+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+&gt;
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
&lt;+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+&gt;
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek &amp;&amp; has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 &amp;&amp; !fops2 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 &amp;&amp; !fops2 &amp;&amp; !fops3 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write &amp;&amp; !has_read &amp;&amp; !fops1 &amp;&amp; !fops2 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read &amp;&amp; !has_write &amp;&amp; !fops1 &amp;&amp; !fops2 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read &amp;&amp; !has_write &amp;&amp; !fops1 &amp;&amp; !fops2 &amp;&amp; !has_llseek &amp;&amp; !nonseekable1 &amp;&amp; !nonseekable2 &amp;&amp; !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Julia Lawall &lt;julia@diku.dk&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ubd: fix incorrect sector handling during request restart</title>
<updated>2010-10-15T10:56:21+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2010-10-15T10:56:21+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=47526903feb52f4c26a6350370bdf74e337fcdb1'/>
<id>47526903feb52f4c26a6350370bdf74e337fcdb1</id>
<content type='text'>
Commit f81f2f7c (ubd: drop unnecessary rq-&gt;sector manipulation)
dropped request-&gt;sector manipulation in preparation for global request
handling cleanup; unfortunately, it incorrectly assumed that the
updated sector wasn't being used.

ubd tries to issue as many requests as possible to io_thread.  When
issuing fails due to memory pressure or other reasons, the device is
put on the restart list and issuing stops.  On IO completion, devices
on the restart list are scanned and IO issuing is restarted.

ubd issues IOs sg-by-sg and issuing can be stopped in the middle of a
request, so each device on the restart queue needs to remember where
to restart in its current request.  ubd needs to keep track of the
issue position itself because,

* blk_rq_pos(req) is now updated by the block layer to keep track of
  _completion_ position.

* Multiple io_req's for the current request may be in flight, so it's
  difficult to tell where blk_rq_pos(req) currently is.

Add ubd-&gt;rq_pos to keep track of the issue position and use it to
correctly restart io_req issue.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Richard Weinberger &lt;richard@nod.at&gt;
Tested-by: Richard Weinberger &lt;richard@nod.at&gt;
Tested-by: Chris Frey &lt;cdfrey@foursquare.net&gt;
Cc: stable@kernel.org
Signed-off-by: Jens Axboe &lt;jaxboe@fusionio.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit f81f2f7c (ubd: drop unnecessary rq-&gt;sector manipulation)
dropped request-&gt;sector manipulation in preparation for global request
handling cleanup; unfortunately, it incorrectly assumed that the
updated sector wasn't being used.

ubd tries to issue as many requests as possible to io_thread.  When
issuing fails due to memory pressure or other reasons, the device is
put on the restart list and issuing stops.  On IO completion, devices
on the restart list are scanned and IO issuing is restarted.

ubd issues IOs sg-by-sg and issuing can be stopped in the middle of a
request, so each device on the restart queue needs to remember where
to restart in its current request.  ubd needs to keep track of the
issue position itself because,

* blk_rq_pos(req) is now updated by the block layer to keep track of
  _completion_ position.

* Multiple io_req's for the current request may be in flight, so it's
  difficult to tell where blk_rq_pos(req) currently is.

Add ubd-&gt;rq_pos to keep track of the issue position and use it to
correctly restart io_req issue.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Richard Weinberger &lt;richard@nod.at&gt;
Tested-by: Richard Weinberger &lt;richard@nod.at&gt;
Tested-by: Chris Frey &lt;cdfrey@foursquare.net&gt;
Cc: stable@kernel.org
Signed-off-by: Jens Axboe &lt;jaxboe@fusionio.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>um: Proper Fix for f25c80a4: remove duplicate structure field initialization</title>
<updated>2010-09-30T02:30:11+00:00</updated>
<author>
<name>Boaz Harrosh</name>
<email>bharrosh@panasas.com</email>
</author>
<published>2010-09-29T08:34:27+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=9337057d4335053dc14934a60d9c3e8fe4e32039'/>
<id>9337057d4335053dc14934a60d9c3e8fe4e32039</id>
<content type='text'>
uml_net_set_mac() was broken and luckily it was never used, before.
What it was trying to do is spin_lock before memcopy the mac address.
Linus attempted to fix it in assumption that someone decided the
lock was needed. But since it was never ever used at all, and was
just dead code, I think we can assume that it is not needed, after
all.

On the other hand patch [f25c80a4] was trying to use eth_mac_addr()
in eth_configure(), *which was the real fallout*. Because of state
checks done inside eth_mac_addr() the address was never set. I have
not reintroduced the memcpy wrapper, but I've put a comment for future
cats.

The code now is back to exactly as it was before [f25c80a4]. With
the cleanup applied. If the spin_lock is indeed needed then a contender
should supply a test case that fails, then fix it with the proper
locking, as a separate unrelated patch.

CC: Julia Lawall &lt;julia@diku.dk&gt;
CC: David S. Miller &lt;davem@davemloft.net&gt;
CC: Andrew Morton &lt;akpm@linux-foundation.org&gt;
CC: Al Viro &lt;viro@ZenIV.linux.org.uk&gt;
Tested-by: Boaz Harrosh &lt;bharrosh@panasas.com&gt;
Signed-off-by: Boaz Harrosh &lt;bharrosh@panasas.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
uml_net_set_mac() was broken and luckily it was never used, before.
What it was trying to do is spin_lock before memcopy the mac address.
Linus attempted to fix it in assumption that someone decided the
lock was needed. But since it was never ever used at all, and was
just dead code, I think we can assume that it is not needed, after
all.

On the other hand patch [f25c80a4] was trying to use eth_mac_addr()
in eth_configure(), *which was the real fallout*. Because of state
checks done inside eth_mac_addr() the address was never set. I have
not reintroduced the memcpy wrapper, but I've put a comment for future
cats.

The code now is back to exactly as it was before [f25c80a4]. With
the cleanup applied. If the spin_lock is indeed needed then a contender
should supply a test case that fails, then fix it with the proper
locking, as a separate unrelated patch.

CC: Julia Lawall &lt;julia@diku.dk&gt;
CC: David S. Miller &lt;davem@davemloft.net&gt;
CC: Andrew Morton &lt;akpm@linux-foundation.org&gt;
CC: Al Viro &lt;viro@ZenIV.linux.org.uk&gt;
Tested-by: Boaz Harrosh &lt;bharrosh@panasas.com&gt;
Signed-off-by: Boaz Harrosh &lt;bharrosh@panasas.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Input: sysrq - drop tty argument form handle_sysrq()</title>
<updated>2010-08-21T07:34:45+00:00</updated>
<author>
<name>Dmitry Torokhov</name>
<email>dmitry.torokhov@gmail.com</email>
</author>
<published>2010-08-18T04:15:47+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=f335397d177c906256ee1bba28e8c49e8ec63817'/>
<id>f335397d177c906256ee1bba28e8c49e8ec63817</id>
<content type='text'>
Sysrq operations do not accept tty argument anymore so no need to pass
it to us.

[Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;: fix build breakage in drm code
 caused by sysrq using bool but not including linux/types.h]

[Sachin Sant &lt;sachinp@in.ibm.com&gt;: fix build breakage in s390 keyboadr
 driver]

Acked-by: Alan Cox &lt;alan@lxorguk.ukuu.org.uk&gt;
Acked-by: Jason Wessel &lt;jason.wessel@windriver.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
Signed-off-by: Dmitry Torokhov &lt;dtor@mail.ru&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Sysrq operations do not accept tty argument anymore so no need to pass
it to us.

[Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;: fix build breakage in drm code
 caused by sysrq using bool but not including linux/types.h]

[Sachin Sant &lt;sachinp@in.ibm.com&gt;: fix build breakage in s390 keyboadr
 driver]

Acked-by: Alan Cox &lt;alan@lxorguk.ukuu.org.uk&gt;
Acked-by: Jason Wessel &lt;jason.wessel@windriver.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
Signed-off-by: Dmitry Torokhov &lt;dtor@mail.ru&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>param: simple locking for sysfs-writable charp parameters</title>
<updated>2010-08-11T13:34:31+00:00</updated>
<author>
<name>Rusty Russell</name>
<email>rusty@rustcorp.com.au</email>
</author>
<published>2010-08-12T05:04:27+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=d6d1b650ae6acce73d55dd0246de22180303ae73'/>
<id>d6d1b650ae6acce73d55dd0246de22180303ae73</id>
<content type='text'>
Since the writing to sysfs can free the old one, we need to block that
when we access the charp variables.

Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Reviewed-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Tested-by: Phil Carmody &lt;ext-phil.2.carmody@nokia.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: Dan Williams &lt;dcbw@redhat.com&gt;
Cc: John W. Linville &lt;linville@tuxdriver.com&gt;
Cc: Jing Huang &lt;huangj@brocade.com&gt;
Cc: James E.J. Bottomley &lt;James.Bottomley@suse.de&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
Cc: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: libertas-dev@lists.infradead.org
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-usb@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since the writing to sysfs can free the old one, we need to block that
when we access the charp variables.

Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Reviewed-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Tested-by: Phil Carmody &lt;ext-phil.2.carmody@nokia.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: Dan Williams &lt;dcbw@redhat.com&gt;
Cc: John W. Linville &lt;linville@tuxdriver.com&gt;
Cc: Jing Huang &lt;huangj@brocade.com&gt;
Cc: James E.J. Bottomley &lt;James.Bottomley@suse.de&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
Cc: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: libertas-dev@lists.infradead.org
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-usb@vger.kernel.org
</pre>
</div>
</content>
</entry>
</feed>
