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  1. Jun 07, 2016
  3. Jun 02, 2016
  5. May 26, 2016
  7. May 21, 2016
  9. May 20, 2016
  11. May 17, 2016
    • Toshi Kani's avatar
      block: Update blkdev_dax_capable() for consistency · a8078b1f
      Toshi Kani authored 
      blkdev_dax_capable() is similar to bdev_dax_supported(), but needs
to remain as a separate interface for checking dax capability of
a raw block device.

Rename and relocate blkdev_dax_capable() to keep them maintained
consistently, and call bdev_direct_access() for the dax capability
check.

There is no change in the behavior.

Link: https://lkml.org/lkml/2016/5/9/950


Signed-off-by: default avatarToshi Kani <toshi.kani@hpe.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@fb.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Boaz Harrosh <boaz@plexistor.com>
Signed-off-by: default avatarVishal Verma <vishal.l.verma@intel.com>
      a8078b1f
  13. May 16, 2016
  15. May 10, 2016
  17. May 05, 2016
    • Mike Snitzer's avatar
      block: make bio_inc_remaining() interface accessible again · 0ef5a50c
      Mike Snitzer authored 
      Commit 326e1dbb

 ("block: remove management of bi_remaining when
restoring original bi_end_io") made bio_inc_remaining() private to bio.c
because the only use-case that made sense was confined to the
bio_chain() interface.

Since that time DM thinp went on to use bio_chain() in its relatively
complex implementation of async discard support.  That implementation,
even when converted over to use the new async __blkdev_issue_discard()
interface, depends on deferred completion of the original discard bio --
which is most appropriately implemented using bio_inc_remaining().

DM thinp foolishly duplicated bio_inc_remaining(), local to dm-thin.c as
__bio_inc_remaining(), so re-exporting bio_inc_remaining() allows us to
put an end to that foolishness.

All said, bio_inc_remaining() should really only be used in conjunction
with bio_chain().  It isn't intended for generic bio reference counting.

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Acked-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      0ef5a50c
    • Mike Snitzer's avatar
      block: reinstate early return of -EOPNOTSUPP from blkdev_issue_discard · bbd848e0
      Mike Snitzer authored 
      Commit 38f25255 ("block: add __blkdev_issue_discard") incorrectly
disallowed the early return of -EOPNOTSUPP if the device doesn't support
discard (or secure discard).  This early return of -EOPNOTSUPP has
always been part of blkdev_issue_discard() interface so there isn't a
good reason to break that behaviour -- especially when it can be easily
reinstated.

The nuance of allowing early return of -EOPNOTSUPP vs disallowing late
return of -EOPNOTSUPP is: if the overall device never advertised support
for discards and one is issued to the device it is beneficial to inform
the caller that discards are not supported via -EOPNOTSUPP.  But if a
device advertises discard support it means that at least a subset of the
device does have discard support -- but it could be that discards issued
to some regions of a stacked device will not be supported.  In that case
the late return of -EOPNOTSUPP must be disallowed.

Fixes: 38f25255

 ("block: add __blkdev_issue_discard")
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      bbd848e0
  19. May 03, 2016
  21. May 02, 2016
  23. Apr 18, 2016
  25. Apr 13, 2016
  27. Apr 12, 2016
  29. Apr 08, 2016
  31. Apr 04, 2016
    • Kirill A. Shutemov's avatar
      mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage · ea1754a0
      Kirill A. Shutemov authored 
      
Mostly direct substitution with occasional adjustment or removing
outdated comments.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ea1754a0
    • Kirill A. Shutemov's avatar
      mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros · 09cbfeaf
      Kirill A. Shutemov authored 
      
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      09cbfeaf
  33. Mar 29, 2016
  35. Mar 20, 2016
  37. Mar 15, 2016
  39. Mar 14, 2016
  41. Mar 03, 2016
  43. Feb 27, 2016
  45. Feb 22, 2016
    • Mike Snitzer's avatar
      dm: fix excessive dm-mq context switching · 6acfe68b
      Mike Snitzer authored 
      Request-based DM's blk-mq support (dm-mq) was reported to be 50% slower
than if an underlying null_blk device were used directly.  One of the
reasons for this drop in performance is that blk_insert_clone_request()
was calling blk_mq_insert_request() with @async=true.  This forced the
use of kblockd_schedule_delayed_work_on() to run the blk-mq hw queues
which ushered in ping-ponging between process context (fio in this case)
and kblockd's kworker to submit the cloned request.  The ftrace
function_graph tracer showed:

  kworker-2013  =>   fio-12190
  fio-12190    =>  kworker-2013
  ...
  kworker-2013  =>   fio-12190
  fio-12190    =>  kworker-2013
  ...

Fixing blk_insert_clone_request()'s blk_mq_insert_request() call to
_not_ use kblockd to submit the cloned requests isn't enough to
eliminate the observed context switches.

In addition to this dm-mq specific blk-core fix, there are 2 DM core
fixes to dm-mq that (when paired with the blk-core fix) completely
eliminate the observed context switching:

1)  don't blk_mq_run_hw_queues in blk-mq request completion

    Motivated by desire to reduce overhead of dm-mq, punting to kblockd
    just increases context switches.

    In my testing against a really fast null_blk device there was no benefit
    to running blk_mq_run_hw_queues() on completion (and no other blk-mq
    driver does this).  So hopefully this change doesn't induce the need for
    yet another revert like commit 621739b0 !

2)  use blk_mq_complete_request() in dm_complete_request()

    blk_complete_request() doesn't offer the traditional q->mq_ops vs
    .request_fn branching pattern that other historic block interfaces
    do (e.g. blk_get_request).  Using blk_mq_complete_request() for
    blk-mq requests is important for performance.  It should be noted
    that, like blk_complete_request(), blk_mq_complete_request() doesn't
    natively handle partial completions -- but the request-based
    DM-multipath target does provide the required partial completion
    support by dm.c:end_clone_bio() triggering requeueing of the request
    via dm-mpath.c:multipath_end_io()'s return of DM_ENDIO_REQUEUE.

dm-mq fix #2 is _much_ more important than #1 for eliminating the
context switches.
Before: cpu          : usr=15.10%, sys=59.39%, ctx=7905181, majf=0, minf=475
After:  cpu          : usr=20.60%, sys=79.35%, ctx=2008, majf=0, minf=472

With these changes multithreaded async read IOPs improved from ~950K
to ~1350K for this dm-mq stacked on null_blk test-case.  The raw read
IOPs of the underlying null_blk device for the same workload is ~1950K.

Fixes: 7fb4898e ("block: add blk-mq support to blk_insert_cloned_request()")
Fixes: bfebd1cd

 ("dm: add full blk-mq support to request-based DM")
Cc: stable@vger.kernel.org # 4.1+
Reported-by: default avatarSagi Grimberg <sagig@dev.mellanox.co.il>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Acked-by: default avatarJens Axboe <axboe@kernel.dk>
      6acfe68b
  47. Feb 19, 2016
    • Mika Westerberg's avatar
      block: Add blk_set_runtime_active() · d07ab6d1
      Mika Westerberg authored 
      
If block device is left runtime suspended during system suspend, resume
hook of the driver typically corrects runtime PM status of the device back
to "active" after it is resumed. However, this is not enough as queue's
runtime PM status is still "suspended". As long as it is in this state
blk_pm_peek_request() returns NULL and thus prevents new requests to be
processed.

Add new function blk_set_runtime_active() that can be used to force the
queue status back to "active" as needed.

Signed-off-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: default avatarJens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      d07ab6d1
  49. Feb 17, 2016
  51. Feb 14, 2016
    • Ming Lei's avatar
      blk-mq: mark request queue as mq asap · 66841672
      Ming Lei authored 
      Currently q->mq_ops is used widely to decide if the queue
is mq or not, so we should set the 'flag' asap so that both
block core and drivers can get the correct mq info.

For example, commit 868f2f0b

(blk-mq: dynamic h/w context count)
moves the hctx's initialization before setting q->mq_ops in
blk_mq_init_allocated_queue(), then cause blk_alloc_flush_queue()
to think the queue is non-mq and don't allocate command size
for the per-hctx flush rq.

This patches should fix the problem reported by Sasha.

Cc: Keith Busch <keith.busch@intel.com>
Reported-by: default avatarSasha Levin <sasha.levin@oracle.com>
Signed-off-by: default avatarMing Lei <tom.leiming@gmail.com>
Fixes: 868f2f0b

 ("blk-mq: dynamic h/w context count")
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      66841672
  53. Feb 12, 2016
    • Hannes Reinecke's avatar
      bio: return EINTR if copying to user space got interrupted · 2d99b55d
      Hannes Reinecke authored 
      Commit 35dc2483 introduced a check for
current->mm to see if we have a user space context and only copies data
if we do. Now if an IO gets interrupted by a signal data isn't copied
into user space any more (as we don't have a user space context) but
user space isn't notified about it.

This patch modifies the behaviour to return -EINTR from bio_uncopy_user()
to notify userland that a signal has interrupted the syscall, otherwise
it could lead to a situation where the caller may get a buffer with
no data returned.

This can be reproduced by issuing SG_IO ioctl()s in one thread while
constantly sending signals to it.

Fixes: 35dc2483

 [SCSI] sg: Fix user memory corruption when SG_IO is interrupted by a signal
Signed-off-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
Cc: stable@vger.kernel.org # v.3.11+
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      2d99b55d

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