<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/block/pktcdvd.c, branch v4.5</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>Merge branch 'for-4.4/io-poll' of git://git.kernel.dk/linux-block</title>
<updated>2015-11-11T01:23:49+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-11-11T01:23:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3419b45039c6b799c974a8019361c045e7ca232c'/>
<id>3419b45039c6b799c974a8019361c045e7ca232c</id>
<content type='text'>
Pull block IO poll support from Jens Axboe:
 "Various groups have been doing experimentation around IO polling for
  (really) fast devices.  The code has been reviewed and has been
  sitting on the side for a few releases, but this is now good enough
  for coordinated benchmarking and further experimentation.

  Currently O_DIRECT sync read/write are supported.  A framework is in
  the works that allows scalable stats tracking so we can auto-tune
  this.  And we'll add libaio support as well soon.  Fow now, it's an
  opt-in feature for test purposes"

* 'for-4.4/io-poll' of git://git.kernel.dk/linux-block:
  direct-io: be sure to assign dio-&gt;bio_bdev for both paths
  directio: add block polling support
  NVMe: add blk polling support
  block: add block polling support
  blk-mq: return tag/queue combo in the make_request_fn handlers
  block: change -&gt;make_request_fn() and users to return a queue cookie
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull block IO poll support from Jens Axboe:
 "Various groups have been doing experimentation around IO polling for
  (really) fast devices.  The code has been reviewed and has been
  sitting on the side for a few releases, but this is now good enough
  for coordinated benchmarking and further experimentation.

  Currently O_DIRECT sync read/write are supported.  A framework is in
  the works that allows scalable stats tracking so we can auto-tune
  this.  And we'll add libaio support as well soon.  Fow now, it's an
  opt-in feature for test purposes"

* 'for-4.4/io-poll' of git://git.kernel.dk/linux-block:
  direct-io: be sure to assign dio-&gt;bio_bdev for both paths
  directio: add block polling support
  NVMe: add blk polling support
  block: add block polling support
  blk-mq: return tag/queue combo in the make_request_fn handlers
  block: change -&gt;make_request_fn() and users to return a queue cookie
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2015-11-07T22:32:45+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-11-07T22:32:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ad804a0b2a769a0eed29015c53fe395449c09d13'/>
<id>ad804a0b2a769a0eed29015c53fe395449c09d13</id>
<content type='text'>
Merge second patch-bomb from Andrew Morton:

 - most of the rest of MM

 - procfs

 - lib/ updates

 - printk updates

 - bitops infrastructure tweaks

 - checkpatch updates

 - nilfs2 update

 - signals

 - various other misc bits: coredump, seqfile, kexec, pidns, zlib, ipc,
   dma-debug, dma-mapping, ...

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (102 commits)
  ipc,msg: drop dst nil validation in copy_msg
  include/linux/zutil.h: fix usage example of zlib_adler32()
  panic: release stale console lock to always get the logbuf printed out
  dma-debug: check nents in dma_sync_sg*
  dma-mapping: tidy up dma_parms default handling
  pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode
  kexec: use file name as the output message prefix
  fs, seqfile: always allow oom killer
  seq_file: reuse string_escape_str()
  fs/seq_file: use seq_* helpers in seq_hex_dump()
  coredump: change zap_threads() and zap_process() to use for_each_thread()
  coredump: ensure all coredumping tasks have SIGNAL_GROUP_COREDUMP
  signal: remove jffs2_garbage_collect_thread()-&gt;allow_signal(SIGCONT)
  signal: introduce kernel_signal_stop() to fix jffs2_garbage_collect_thread()
  signal: turn dequeue_signal_lock() into kernel_dequeue_signal()
  signals: kill block_all_signals() and unblock_all_signals()
  nilfs2: fix gcc uninitialized-variable warnings in powerpc build
  nilfs2: fix gcc unused-but-set-variable warnings
  MAINTAINERS: nilfs2: add header file for tracing
  nilfs2: add tracepoints for analyzing reading and writing metadata files
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge second patch-bomb from Andrew Morton:

 - most of the rest of MM

 - procfs

 - lib/ updates

 - printk updates

 - bitops infrastructure tweaks

 - checkpatch updates

 - nilfs2 update

 - signals

 - various other misc bits: coredump, seqfile, kexec, pidns, zlib, ipc,
   dma-debug, dma-mapping, ...

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (102 commits)
  ipc,msg: drop dst nil validation in copy_msg
  include/linux/zutil.h: fix usage example of zlib_adler32()
  panic: release stale console lock to always get the logbuf printed out
  dma-debug: check nents in dma_sync_sg*
  dma-mapping: tidy up dma_parms default handling
  pidns: fix set/getpriority and ioprio_set/get in PRIO_USER mode
  kexec: use file name as the output message prefix
  fs, seqfile: always allow oom killer
  seq_file: reuse string_escape_str()
  fs/seq_file: use seq_* helpers in seq_hex_dump()
  coredump: change zap_threads() and zap_process() to use for_each_thread()
  coredump: ensure all coredumping tasks have SIGNAL_GROUP_COREDUMP
  signal: remove jffs2_garbage_collect_thread()-&gt;allow_signal(SIGCONT)
  signal: introduce kernel_signal_stop() to fix jffs2_garbage_collect_thread()
  signal: turn dequeue_signal_lock() into kernel_dequeue_signal()
  signals: kill block_all_signals() and unblock_all_signals()
  nilfs2: fix gcc uninitialized-variable warnings in powerpc build
  nilfs2: fix gcc unused-but-set-variable warnings
  MAINTAINERS: nilfs2: add header file for tracing
  nilfs2: add tracepoints for analyzing reading and writing metadata files
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial</title>
<updated>2015-11-07T21:05:44+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2015-11-07T21:05:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=75021d28594d9b6fb4d05bbc41f77948a0db0e02'/>
<id>75021d28594d9b6fb4d05bbc41f77948a0db0e02</id>
<content type='text'>
Pull trivial updates from Jiri Kosina:
 "Trivial stuff from trivial tree that can be trivially summed up as:

   - treewide drop of spurious unlikely() before IS_ERR() from Viresh
     Kumar

   - cosmetic fixes (that don't really affect basic functionality of the
     driver) for pktcdvd and bcache, from Julia Lawall and Petr Mladek

   - various comment / printk fixes and updates all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  bcache: Really show state of work pending bit
  hwmon: applesmc: fix comment typos
  Kconfig: remove comment about scsi_wait_scan module
  class_find_device: fix reference to argument "match"
  debugfs: document that debugfs_remove*() accepts NULL and error values
  net: Drop unlikely before IS_ERR(_OR_NULL)
  mm: Drop unlikely before IS_ERR(_OR_NULL)
  fs: Drop unlikely before IS_ERR(_OR_NULL)
  drivers: net: Drop unlikely before IS_ERR(_OR_NULL)
  drivers: misc: Drop unlikely before IS_ERR(_OR_NULL)
  UBI: Update comments to reflect UBI_METAONLY flag
  pktcdvd: drop null test before destroy functions
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull trivial updates from Jiri Kosina:
 "Trivial stuff from trivial tree that can be trivially summed up as:

   - treewide drop of spurious unlikely() before IS_ERR() from Viresh
     Kumar

   - cosmetic fixes (that don't really affect basic functionality of the
     driver) for pktcdvd and bcache, from Julia Lawall and Petr Mladek

   - various comment / printk fixes and updates all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  bcache: Really show state of work pending bit
  hwmon: applesmc: fix comment typos
  Kconfig: remove comment about scsi_wait_scan module
  class_find_device: fix reference to argument "match"
  debugfs: document that debugfs_remove*() accepts NULL and error values
  net: Drop unlikely before IS_ERR(_OR_NULL)
  mm: Drop unlikely before IS_ERR(_OR_NULL)
  fs: Drop unlikely before IS_ERR(_OR_NULL)
  drivers: net: Drop unlikely before IS_ERR(_OR_NULL)
  drivers: misc: Drop unlikely before IS_ERR(_OR_NULL)
  UBI: Update comments to reflect UBI_METAONLY flag
  pktcdvd: drop null test before destroy functions
</pre>
</div>
</content>
</entry>
<entry>
<title>block: change -&gt;make_request_fn() and users to return a queue cookie</title>
<updated>2015-11-07T17:40:46+00:00</updated>
<author>
<name>Jens Axboe</name>
<email>axboe@fb.com</email>
</author>
<published>2015-11-05T17:41:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=dece16353ef47d8d33f5302bc158072a9d65e26f'/>
<id>dece16353ef47d8d33f5302bc158072a9d65e26f</id>
<content type='text'>
No functional changes in this patch, but it prepares us for returning
a more useful cookie related to the IO that was queued up.

Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
Acked-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Keith Busch &lt;keith.busch@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
No functional changes in this patch, but it prepares us for returning
a more useful cookie related to the IO that was queued up.

Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
Acked-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Keith Busch &lt;keith.busch@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM</title>
<updated>2015-11-07T01:50:42+00:00</updated>
<author>
<name>Mel Gorman</name>
<email>mgorman@techsingularity.net</email>
</author>
<published>2015-11-07T00:28:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=71baba4b92dc1fa1bc461742c6ab1942ec6034e9'/>
<id>71baba4b92dc1fa1bc461742c6ab1942ec6034e9</id>
<content type='text'>
__GFP_WAIT was used to signal that the caller was in atomic context and
could not sleep.  Now it is possible to distinguish between true atomic
context and callers that are not willing to sleep.  The latter should
clear __GFP_DIRECT_RECLAIM so kswapd will still wake.  As clearing
__GFP_WAIT behaves differently, there is a risk that people will clear the
wrong flags.  This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
indicate what it does -- setting it allows all reclaim activity, clearing
them prevents it.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Acked-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: Vitaly Wool &lt;vitalywool@gmail.com&gt;
Cc: Rik van Riel &lt;riel@redhat.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>
__GFP_WAIT was used to signal that the caller was in atomic context and
could not sleep.  Now it is possible to distinguish between true atomic
context and callers that are not willing to sleep.  The latter should
clear __GFP_DIRECT_RECLAIM so kswapd will still wake.  As clearing
__GFP_WAIT behaves differently, there is a risk that people will clear the
wrong flags.  This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
indicate what it does -- setting it allows all reclaim activity, clearing
them prevents it.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Acked-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Cc: Christoph Lameter &lt;cl@linux.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: Vitaly Wool &lt;vitalywool@gmail.com&gt;
Cc: Rik van Riel &lt;riel@redhat.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>pktcdvd: drop null test before destroy functions</title>
<updated>2015-09-29T13:01:47+00:00</updated>
<author>
<name>Julia Lawall</name>
<email>Julia.Lawall@lip6.fr</email>
</author>
<published>2015-09-13T12:15:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0220531a13b83d0049dcf1391a5a0cb10346962f'/>
<id>0220531a13b83d0049dcf1391a5a0cb10346962f</id>
<content type='text'>
Remove unneeded NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// &lt;smpl&gt;
@@ expression x; @@
-if (x != NULL)
  \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
// &lt;/smpl&gt;

Signed-off-by: Julia Lawall &lt;Julia.Lawall@lip6.fr&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove unneeded NULL test.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// &lt;smpl&gt;
@@ expression x; @@
-if (x != NULL)
  \(kmem_cache_destroy\|mempool_destroy\|dma_pool_destroy\)(x);
// &lt;/smpl&gt;

Signed-off-by: Julia Lawall &lt;Julia.Lawall@lip6.fr&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: kill merge_bvec_fn() completely</title>
<updated>2015-08-13T18:31:57+00:00</updated>
<author>
<name>Kent Overstreet</name>
<email>kent.overstreet@gmail.com</email>
</author>
<published>2015-04-28T06:48:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8ae126660fddbeebb9251a174e6fa45b6ad8f932'/>
<id>8ae126660fddbeebb9251a174e6fa45b6ad8f932</id>
<content type='text'>
As generic_make_request() is now able to handle arbitrarily sized bios,
it's no longer necessary for each individual block driver to define its
own -&gt;merge_bvec_fn() callback. Remove every invocation completely.

Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Lars Ellenberg &lt;drbd-dev@lists.linbit.com&gt;
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina &lt;jkosina@suse.cz&gt;
Cc: Yehuda Sadeh &lt;yehuda@inktank.com&gt;
Cc: Sage Weil &lt;sage@inktank.com&gt;
Cc: Alex Elder &lt;elder@kernel.org&gt;
Cc: ceph-devel@vger.kernel.org
Cc: Alasdair Kergon &lt;agk@redhat.com&gt;
Cc: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: dm-devel@redhat.com
Cc: Neil Brown &lt;neilb@suse.de&gt;
Cc: linux-raid@vger.kernel.org
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: "Martin K. Petersen" &lt;martin.petersen@oracle.com&gt;
Acked-by: NeilBrown &lt;neilb@suse.de&gt; (for the 'md' bits)
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Kent Overstreet &lt;kent.overstreet@gmail.com&gt;
[dpark: also remove -&gt;merge_bvec_fn() in dm-thin as well as
 dm-era-target, and resolve merge conflicts]
Signed-off-by: Dongsu Park &lt;dpark@posteo.net&gt;
Signed-off-by: Ming Lin &lt;ming.l@ssi.samsung.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As generic_make_request() is now able to handle arbitrarily sized bios,
it's no longer necessary for each individual block driver to define its
own -&gt;merge_bvec_fn() callback. Remove every invocation completely.

Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Lars Ellenberg &lt;drbd-dev@lists.linbit.com&gt;
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina &lt;jkosina@suse.cz&gt;
Cc: Yehuda Sadeh &lt;yehuda@inktank.com&gt;
Cc: Sage Weil &lt;sage@inktank.com&gt;
Cc: Alex Elder &lt;elder@kernel.org&gt;
Cc: ceph-devel@vger.kernel.org
Cc: Alasdair Kergon &lt;agk@redhat.com&gt;
Cc: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: dm-devel@redhat.com
Cc: Neil Brown &lt;neilb@suse.de&gt;
Cc: linux-raid@vger.kernel.org
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: "Martin K. Petersen" &lt;martin.petersen@oracle.com&gt;
Acked-by: NeilBrown &lt;neilb@suse.de&gt; (for the 'md' bits)
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Kent Overstreet &lt;kent.overstreet@gmail.com&gt;
[dpark: also remove -&gt;merge_bvec_fn() in dm-thin as well as
 dm-era-target, and resolve merge conflicts]
Signed-off-by: Dongsu Park &lt;dpark@posteo.net&gt;
Signed-off-by: Ming Lin &lt;ming.l@ssi.samsung.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: make generic_make_request handle arbitrarily sized bios</title>
<updated>2015-08-13T18:31:33+00:00</updated>
<author>
<name>Kent Overstreet</name>
<email>kent.overstreet@gmail.com</email>
</author>
<published>2015-04-24T05:37:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=54efd50bfd873e2dbf784e0b21a8027ba4299a3e'/>
<id>54efd50bfd873e2dbf784e0b21a8027ba4299a3e</id>
<content type='text'>
The way the block layer is currently written, it goes to great lengths
to avoid having to split bios; upper layer code (such as bio_add_page())
checks what the underlying device can handle and tries to always create
bios that don't need to be split.

But this approach becomes unwieldy and eventually breaks down with
stacked devices and devices with dynamic limits, and it adds a lot of
complexity. If the block layer could split bios as needed, we could
eliminate a lot of complexity elsewhere - particularly in stacked
drivers. Code that creates bios can then create whatever size bios are
convenient, and more importantly stacked drivers don't have to deal with
both their own bio size limitations and the limitations of the
(potentially multiple) devices underneath them.  In the future this will
let us delete merge_bvec_fn and a bunch of other code.

We do this by adding calls to blk_queue_split() to the various
make_request functions that need it - a few can already handle arbitrary
size bios. Note that we add the call _after_ any call to
blk_queue_bounce(); this means that blk_queue_split() and
blk_recalc_rq_segments() don't need to be concerned with bouncing
affecting segment merging.

Some make_request_fn() callbacks were simple enough to audit and verify
they don't need blk_queue_split() calls. The skipped ones are:

 * nfhd_make_request (arch/m68k/emu/nfblock.c)
 * axon_ram_make_request (arch/powerpc/sysdev/axonram.c)
 * simdisk_make_request (arch/xtensa/platforms/iss/simdisk.c)
 * brd_make_request (ramdisk - drivers/block/brd.c)
 * mtip_submit_request (drivers/block/mtip32xx/mtip32xx.c)
 * loop_make_request
 * null_queue_bio
 * bcache's make_request fns

Some others are almost certainly safe to remove now, but will be left
for future patches.

Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Ming Lei &lt;ming.lei@canonical.com&gt;
Cc: Neil Brown &lt;neilb@suse.de&gt;
Cc: Alasdair Kergon &lt;agk@redhat.com&gt;
Cc: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: dm-devel@redhat.com
Cc: Lars Ellenberg &lt;drbd-dev@lists.linbit.com&gt;
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina &lt;jkosina@suse.cz&gt;
Cc: Geoff Levand &lt;geoff@infradead.org&gt;
Cc: Jim Paris &lt;jim@jtan.com&gt;
Cc: Philip Kelleher &lt;pjk1939@linux.vnet.ibm.com&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: Nitin Gupta &lt;ngupta@vflare.org&gt;
Cc: Oleg Drokin &lt;oleg.drokin@intel.com&gt;
Cc: Andreas Dilger &lt;andreas.dilger@intel.com&gt;
Acked-by: NeilBrown &lt;neilb@suse.de&gt; (for the 'md/md.c' bits)
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: Kent Overstreet &lt;kent.overstreet@gmail.com&gt;
[dpark: skip more mq-based drivers, resolve merge conflicts, etc.]
Signed-off-by: Dongsu Park &lt;dpark@posteo.net&gt;
Signed-off-by: Ming Lin &lt;ming.l@ssi.samsung.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The way the block layer is currently written, it goes to great lengths
to avoid having to split bios; upper layer code (such as bio_add_page())
checks what the underlying device can handle and tries to always create
bios that don't need to be split.

But this approach becomes unwieldy and eventually breaks down with
stacked devices and devices with dynamic limits, and it adds a lot of
complexity. If the block layer could split bios as needed, we could
eliminate a lot of complexity elsewhere - particularly in stacked
drivers. Code that creates bios can then create whatever size bios are
convenient, and more importantly stacked drivers don't have to deal with
both their own bio size limitations and the limitations of the
(potentially multiple) devices underneath them.  In the future this will
let us delete merge_bvec_fn and a bunch of other code.

We do this by adding calls to blk_queue_split() to the various
make_request functions that need it - a few can already handle arbitrary
size bios. Note that we add the call _after_ any call to
blk_queue_bounce(); this means that blk_queue_split() and
blk_recalc_rq_segments() don't need to be concerned with bouncing
affecting segment merging.

Some make_request_fn() callbacks were simple enough to audit and verify
they don't need blk_queue_split() calls. The skipped ones are:

 * nfhd_make_request (arch/m68k/emu/nfblock.c)
 * axon_ram_make_request (arch/powerpc/sysdev/axonram.c)
 * simdisk_make_request (arch/xtensa/platforms/iss/simdisk.c)
 * brd_make_request (ramdisk - drivers/block/brd.c)
 * mtip_submit_request (drivers/block/mtip32xx/mtip32xx.c)
 * loop_make_request
 * null_queue_bio
 * bcache's make_request fns

Some others are almost certainly safe to remove now, but will be left
for future patches.

Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Ming Lei &lt;ming.lei@canonical.com&gt;
Cc: Neil Brown &lt;neilb@suse.de&gt;
Cc: Alasdair Kergon &lt;agk@redhat.com&gt;
Cc: Mike Snitzer &lt;snitzer@redhat.com&gt;
Cc: dm-devel@redhat.com
Cc: Lars Ellenberg &lt;drbd-dev@lists.linbit.com&gt;
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina &lt;jkosina@suse.cz&gt;
Cc: Geoff Levand &lt;geoff@infradead.org&gt;
Cc: Jim Paris &lt;jim@jtan.com&gt;
Cc: Philip Kelleher &lt;pjk1939@linux.vnet.ibm.com&gt;
Cc: Minchan Kim &lt;minchan@kernel.org&gt;
Cc: Nitin Gupta &lt;ngupta@vflare.org&gt;
Cc: Oleg Drokin &lt;oleg.drokin@intel.com&gt;
Cc: Andreas Dilger &lt;andreas.dilger@intel.com&gt;
Acked-by: NeilBrown &lt;neilb@suse.de&gt; (for the 'md/md.c' bits)
Acked-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Reviewed-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
Signed-off-by: Kent Overstreet &lt;kent.overstreet@gmail.com&gt;
[dpark: skip more mq-based drivers, resolve merge conflicts, etc.]
Signed-off-by: Dongsu Park &lt;dpark@posteo.net&gt;
Signed-off-by: Ming Lin &lt;ming.l@ssi.samsung.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>block: add a bi_error field to struct bio</title>
<updated>2015-07-29T14:55:15+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2015-07-20T13:29:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4246a0b63bd8f56a1469b12eafeb875b1041a451'/>
<id>4246a0b63bd8f56a1469b12eafeb875b1041a451</id>
<content type='text'>
Currently we have two different ways to signal an I/O error on a BIO:

 (1) by clearing the BIO_UPTODATE flag
 (2) by returning a Linux errno value to the bi_end_io callback

The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario.  Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.

So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.de&gt;
Reviewed-by: NeilBrown &lt;neilb@suse.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently we have two different ways to signal an I/O error on a BIO:

 (1) by clearing the BIO_UPTODATE flag
 (2) by returning a Linux errno value to the bi_end_io callback

The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario.  Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.

So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.

Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.de&gt;
Reviewed-by: NeilBrown &lt;neilb@suse.com&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>writeback: separate out include/linux/backing-dev-defs.h</title>
<updated>2015-06-02T14:33:34+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2015-05-22T21:13:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=66114cad64bf76a155fec1f0fff0de771cf909d5'/>
<id>66114cad64bf76a155fec1f0fff0de771cf909d5</id>
<content type='text'>
With the planned cgroup writeback support, backing-dev related
declarations will be more widely used across block and cgroup;
unfortunately, including backing-dev.h from include/linux/blkdev.h
makes cyclic include dependency quite likely.

This patch separates out backing-dev-defs.h which only has the
essential definitions and updates blkdev.h to include it.  c files
which need access to more backing-dev details now include
backing-dev.h directly.  This takes backing-dev.h off the common
include dependency chain making it a lot easier to use it across block
and cgroup.

v2: fs/fat build failure fixed.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With the planned cgroup writeback support, backing-dev related
declarations will be more widely used across block and cgroup;
unfortunately, including backing-dev.h from include/linux/blkdev.h
makes cyclic include dependency quite likely.

This patch separates out backing-dev-defs.h which only has the
essential definitions and updates blkdev.h to include it.  c files
which need access to more backing-dev details now include
backing-dev.h directly.  This takes backing-dev.h off the common
include dependency chain making it a lot easier to use it across block
and cgroup.

v2: fs/fat build failure fixed.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reviewed-by: Jan Kara &lt;jack@suse.cz&gt;
Cc: Jens Axboe &lt;axboe@kernel.dk&gt;
Signed-off-by: Jens Axboe &lt;axboe@fb.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
