<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/block/bsg.c, branch v2.6.35</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h</title>
<updated>2010-03-30T13:02:32+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2010-03-24T08:04:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5a0e3ad6af8660be21ca98a971cd00f331318c05'/>
<id>5a0e3ad6af8660be21ca98a971cd00f331318c05</id>
<content type='text'>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -&gt; slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Guess-its-ok-by: Christoph Lameter &lt;cl@linux-foundation.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Lee Schermerhorn &lt;Lee.Schermerhorn@hp.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -&gt; slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Guess-its-ok-by: Christoph Lameter &lt;cl@linux-foundation.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Lee Schermerhorn &lt;Lee.Schermerhorn@hp.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tree-wide: Assorted spelling fixes</title>
<updated>2010-02-09T10:13:56+00:00</updated>
<author>
<name>Daniel Mack</name>
<email>daniel@caiaq.de</email>
</author>
<published>2010-02-03T00:01:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3ad2f3fbb961429d2aa627465ae4829758bc7e07'/>
<id>3ad2f3fbb961429d2aa627465ae4829758bc7e07</id>
<content type='text'>
In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.

Signed-off-by: Daniel Mack &lt;daniel@caiaq.de&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Junio C Hamano &lt;gitster@pobox.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In particular, several occurances of funny versions of 'success',
'unknown', 'therefore', 'acknowledge', 'argument', 'achieve', 'address',
'beginning', 'desirable', 'separate' and 'necessary' are fixed.

Signed-off-by: Daniel Mack &lt;daniel@caiaq.de&gt;
Cc: Joe Perches &lt;joe@perches.com&gt;
Cc: Junio C Hamano &lt;gitster@pobox.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: jiffies fixes</title>
<updated>2009-11-11T12:47:45+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>randy.dunlap@oracle.com</email>
</author>
<published>2009-11-11T12:47:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ad5ebd2fa2557b04a653bb3c3377a47da8f9b8e9'/>
<id>ad5ebd2fa2557b04a653bb3c3377a47da8f9b8e9</id>
<content type='text'>
Use HZ-independent calculation of milliseconds.
Add jiffies.h where it was missing since functions or macros
from it are used.

Signed-off-by: Randy Dunlap &lt;randy.dunlap@oracle.com&gt;
Signed-off-by: Jens Axboe &lt;jens.axboe@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use HZ-independent calculation of milliseconds.
Add jiffies.h where it was missing since functions or macros
from it are used.

Signed-off-by: Randy Dunlap &lt;randy.dunlap@oracle.com&gt;
Signed-off-by: Jens Axboe &lt;jens.axboe@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Driver-Core: extend devnode callbacks to provide permissions</title>
<updated>2009-09-19T19:50:38+00:00</updated>
<author>
<name>Kay Sievers</name>
<email>kay.sievers@vrfy.org</email>
</author>
<published>2009-09-18T21:01:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e454cea20bdcff10ee698d11b8882662a0153a47'/>
<id>e454cea20bdcff10ee698d11b8882662a0153a47</id>
<content type='text'>
This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.

This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

Signed-off-by: Kay Sievers &lt;kay.sievers@vrfy.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.

This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

Signed-off-by: Kay Sievers &lt;kay.sievers@vrfy.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: get rid of queue-private command filter</title>
<updated>2009-07-01T08:56:26+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>jens.axboe@oracle.com</email>
</author>
<published>2009-06-26T14:27:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=018e0446890661504783f92388ecce7138c1566d'/>
<id>018e0446890661504783f92388ecce7138c1566d</id>
<content type='text'>
The initial patches to support this through sysfs export were broken
and have been if 0'ed out in any release. So lets just kill the code
and reclaim some space in struct request_queue, if anyone would later
like to fixup the sysfs bits, the git history can easily restore
the removed bits.

Signed-off-by: Jens Axboe &lt;jens.axboe@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The initial patches to support this through sysfs export were broken
and have been if 0'ed out in any release. So lets just kill the code
and reclaim some space in struct request_queue, if anyone would later
like to fixup the sysfs bits, the git history can easily restore
the removed bits.

Signed-off-by: Jens Axboe &lt;jens.axboe@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: revert "bsg: setting rq-&gt;bio to NULL"</title>
<updated>2009-06-21T15:52:42+00:00</updated>
<author>
<name>FUJITA Tomonori</name>
<email>fujita.tomonori@lab.ntt.co.jp</email>
</author>
<published>2009-06-17T06:10:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=111986593561fc4c94a1fba3f3cd84476fb40b22'/>
<id>111986593561fc4c94a1fba3f3cd84476fb40b22</id>
<content type='text'>
The SMP handler (sas_smp_request) was fixed to use the block API
properly, so we don't need this workaround to avoid blk_put_request()
warning.

Signed-off-by: FUJITA Tomonori &lt;fujita.tomonori@lab.ntt.co.jp&gt;
Signed-off-by: James Bottomley &lt;James.Bottomley@HansenPartnership.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The SMP handler (sas_smp_request) was fixed to use the block API
properly, so we don't need this workaround to avoid blk_put_request()
warning.

Signed-off-by: FUJITA Tomonori &lt;fujita.tomonori@lab.ntt.co.jp&gt;
Signed-off-by: James Bottomley &lt;James.Bottomley@HansenPartnership.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Driver Core: bsg: add nodename for bsg driver</title>
<updated>2009-06-16T04:30:26+00:00</updated>
<author>
<name>Kay Sievers</name>
<email>kay.sievers@vrfy.org</email>
</author>
<published>2009-04-30T13:23:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2bdf914915e98fe82495d05741a57e37f4b604e8'/>
<id>2bdf914915e98fe82495d05741a57e37f4b604e8</id>
<content type='text'>
This adds support to the BSG driver to report the proper device name to
userspace for the bsg devices.

Signed-off-by: Kay Sievers &lt;kay.sievers@vrfy.org&gt;
Signed-off-by: Jan Blunck &lt;jblunck@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This adds support to the BSG driver to report the proper device name to
userspace for the bsg devices.

Signed-off-by: Kay Sievers &lt;kay.sievers@vrfy.org&gt;
Signed-off-by: Jan Blunck &lt;jblunck@suse.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block</title>
<updated>2009-06-11T18:10:35+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2009-06-11T17:52:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c9059598ea8981d02356eead3188bf7fa4d717b8'/>
<id>c9059598ea8981d02356eead3188bf7fa4d717b8</id>
<content type='text'>
* 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block: (153 commits)
  block: add request clone interface (v2)
  floppy: fix hibernation
  ramdisk: remove long-deprecated "ramdisk=" boot-time parameter
  fs/bio.c: add missing __user annotation
  block: prevent possible io_context-&gt;refcount overflow
  Add serial number support for virtio_blk, V4a
  block: Add missing bounce_pfn stacking and fix comments
  Revert "block: Fix bounce limit setting in DM"
  cciss: decode unit attention in SCSI error handling code
  cciss: Remove no longer needed sendcmd reject processing code
  cciss: change SCSI error handling routines to work with interrupts enabled.
  cciss: separate error processing and command retrying code in sendcmd_withirq_core()
  cciss: factor out fix target status processing code from sendcmd functions
  cciss: simplify interface of sendcmd() and sendcmd_withirq()
  cciss: factor out core of sendcmd_withirq() for use by SCSI error handling code
  cciss: Use schedule_timeout_uninterruptible in SCSI error handling code
  block: needs to set the residual length of a bidi request
  Revert "block: implement blkdev_readpages"
  block: Fix bounce limit setting in DM
  Removed reference to non-existing file Documentation/PCI/PCI-DMA-mapping.txt
  ...

Manually fix conflicts with tracing updates in:
	block/blk-sysfs.c
	drivers/ide/ide-atapi.c
	drivers/ide/ide-cd.c
	drivers/ide/ide-floppy.c
	drivers/ide/ide-tape.c
	include/trace/events/block.h
	kernel/trace/blktrace.c
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block: (153 commits)
  block: add request clone interface (v2)
  floppy: fix hibernation
  ramdisk: remove long-deprecated "ramdisk=" boot-time parameter
  fs/bio.c: add missing __user annotation
  block: prevent possible io_context-&gt;refcount overflow
  Add serial number support for virtio_blk, V4a
  block: Add missing bounce_pfn stacking and fix comments
  Revert "block: Fix bounce limit setting in DM"
  cciss: decode unit attention in SCSI error handling code
  cciss: Remove no longer needed sendcmd reject processing code
  cciss: change SCSI error handling routines to work with interrupts enabled.
  cciss: separate error processing and command retrying code in sendcmd_withirq_core()
  cciss: factor out fix target status processing code from sendcmd functions
  cciss: simplify interface of sendcmd() and sendcmd_withirq()
  cciss: factor out core of sendcmd_withirq() for use by SCSI error handling code
  cciss: Use schedule_timeout_uninterruptible in SCSI error handling code
  block: needs to set the residual length of a bidi request
  Revert "block: implement blkdev_readpages"
  block: Fix bounce limit setting in DM
  Removed reference to non-existing file Documentation/PCI/PCI-DMA-mapping.txt
  ...

Manually fix conflicts with tracing updates in:
	block/blk-sysfs.c
	drivers/ide/ide-atapi.c
	drivers/ide/ide-cd.c
	drivers/ide/ide-floppy.c
	drivers/ide/ide-tape.c
	include/trace/events/block.h
	kernel/trace/blktrace.c
</pre>
</div>
</content>
</entry>
<entry>
<title>bsg: setting rq-&gt;bio to NULL</title>
<updated>2009-06-09T13:17:37+00:00</updated>
<author>
<name>FUJITA Tomonori</name>
<email>fujita.tomonori@lab.ntt.co.jp</email>
</author>
<published>2009-06-09T13:17:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c1d4c41f2fdfe66dea957b76d005affba3e56b26'/>
<id>c1d4c41f2fdfe66dea957b76d005affba3e56b26</id>
<content type='text'>
Due to commit 1cd96c242a829d52f7a5ae98f554ca9775429685 ("block: WARN
in __blk_put_request() for potential bio leak"), BSG SMP requests get
the false warnings:

WARNING: at block/blk-core.c:1068 __blk_put_request+0x52/0xc0()

This sets rq-&gt;bio to NULL to avoid that false warnings.

Signed-off-by: FUJITA Tomonori &lt;fujita.tomonori@lab.ntt.co.jp&gt;
Signed-off-by: Jens Axboe &lt;jens.axboe@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Due to commit 1cd96c242a829d52f7a5ae98f554ca9775429685 ("block: WARN
in __blk_put_request() for potential bio leak"), BSG SMP requests get
the false warnings:

WARNING: at block/blk-core.c:1068 __blk_put_request+0x52/0xc0()

This sets rq-&gt;bio to NULL to avoid that false warnings.

Signed-off-by: FUJITA Tomonori &lt;fujita.tomonori@lab.ntt.co.jp&gt;
Signed-off-by: Jens Axboe &lt;jens.axboe@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: add rq-&gt;resid_len</title>
<updated>2009-05-11T07:50:53+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2009-05-07T13:24:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c3a4d78c580de4edc9ef0f7c59812fb02ceb037f'/>
<id>c3a4d78c580de4edc9ef0f7c59812fb02ceb037f</id>
<content type='text'>
rq-&gt;data_len served two purposes - the length of data buffer on issue
and the residual count on completion.  This duality creates some
headaches.

First of all, block layer and low level drivers can't really determine
what rq-&gt;data_len contains while a request is executing.  It could be
the total request length or it coulde be anything else one of the
lower layers is using to keep track of residual count.  This
complicates things because blk_rq_bytes() and thus
[__]blk_end_request_all() relies on rq-&gt;data_len for PC commands.
Drivers which want to report residual count should first cache the
total request length, update rq-&gt;data_len and then complete the
request with the cached data length.

Secondly, it makes requests default to reporting full residual count,
ie. reporting that no data transfer occurred.  The residual count is
an exception not the norm; however, the driver should clear
rq-&gt;data_len to zero to signify the normal cases while leaving it
alone means no data transfer occurred at all.  This reverse default
behavior complicates code unnecessarily and renders block PC on some
drivers (ide-tape/floppy) unuseable.

This patch adds rq-&gt;resid_len which is used only for residual count.

While at it, remove now unnecessasry blk_rq_bytes() caching in
ide_pc_intr() as rq-&gt;data_len is not changed anymore.

Boaz	: spotted missing conversion in osd
Sergei	: spotted too early conversion to blk_rq_bytes() in ide-tape

[ Impact: cleanup residual count handling, report 0 resid by default ]

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Cc: James Bottomley &lt;James.Bottomley@HansenPartnership.com&gt;
Cc: Bartlomiej Zolnierkiewicz &lt;bzolnier@gmail.com&gt;
Cc: Borislav Petkov &lt;petkovbb@googlemail.com&gt;
Cc: Sergei Shtylyov &lt;sshtylyov@ru.mvista.com&gt;
Cc: Mike Miller &lt;mike.miller@hp.com&gt;
Cc: Eric Moore &lt;Eric.Moore@lsi.com&gt;
Cc: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: FUJITA Tomonori &lt;fujita.tomonori@lab.ntt.co.jp&gt;
Cc: Doug Gilbert &lt;dgilbert@interlog.com&gt;
Cc: Mike Miller &lt;mike.miller@hp.com&gt;
Cc: Eric Moore &lt;Eric.Moore@lsi.com&gt;
Cc: Darrick J. Wong &lt;djwong@us.ibm.com&gt;
Cc: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Cc: Boaz Harrosh &lt;bharrosh@panasas.com&gt;
Signed-off-by: Jens Axboe &lt;jens.axboe@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
rq-&gt;data_len served two purposes - the length of data buffer on issue
and the residual count on completion.  This duality creates some
headaches.

First of all, block layer and low level drivers can't really determine
what rq-&gt;data_len contains while a request is executing.  It could be
the total request length or it coulde be anything else one of the
lower layers is using to keep track of residual count.  This
complicates things because blk_rq_bytes() and thus
[__]blk_end_request_all() relies on rq-&gt;data_len for PC commands.
Drivers which want to report residual count should first cache the
total request length, update rq-&gt;data_len and then complete the
request with the cached data length.

Secondly, it makes requests default to reporting full residual count,
ie. reporting that no data transfer occurred.  The residual count is
an exception not the norm; however, the driver should clear
rq-&gt;data_len to zero to signify the normal cases while leaving it
alone means no data transfer occurred at all.  This reverse default
behavior complicates code unnecessarily and renders block PC on some
drivers (ide-tape/floppy) unuseable.

This patch adds rq-&gt;resid_len which is used only for residual count.

While at it, remove now unnecessasry blk_rq_bytes() caching in
ide_pc_intr() as rq-&gt;data_len is not changed anymore.

Boaz	: spotted missing conversion in osd
Sergei	: spotted too early conversion to blk_rq_bytes() in ide-tape

[ Impact: cleanup residual count handling, report 0 resid by default ]

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Cc: James Bottomley &lt;James.Bottomley@HansenPartnership.com&gt;
Cc: Bartlomiej Zolnierkiewicz &lt;bzolnier@gmail.com&gt;
Cc: Borislav Petkov &lt;petkovbb@googlemail.com&gt;
Cc: Sergei Shtylyov &lt;sshtylyov@ru.mvista.com&gt;
Cc: Mike Miller &lt;mike.miller@hp.com&gt;
Cc: Eric Moore &lt;Eric.Moore@lsi.com&gt;
Cc: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: FUJITA Tomonori &lt;fujita.tomonori@lab.ntt.co.jp&gt;
Cc: Doug Gilbert &lt;dgilbert@interlog.com&gt;
Cc: Mike Miller &lt;mike.miller@hp.com&gt;
Cc: Eric Moore &lt;Eric.Moore@lsi.com&gt;
Cc: Darrick J. Wong &lt;djwong@us.ibm.com&gt;
Cc: Pete Zaitcev &lt;zaitcev@redhat.com&gt;
Cc: Boaz Harrosh &lt;bharrosh@panasas.com&gt;
Signed-off-by: Jens Axboe &lt;jens.axboe@oracle.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
