Commit Graph

2550 Commits

Author SHA1 Message Date
Tejun Heo
52ebea749a writeback: make backing_dev_info host cgroup-specific bdi_writebacks
For the planned cgroup writeback support, on each bdi
(backing_dev_info), each memcg will be served by a separate wb
(bdi_writeback).  This patch updates bdi so that a bdi can host
multiple wbs (bdi_writebacks).

On the default hierarchy, blkcg implicitly enables memcg.  This allows
using memcg's page ownership for attributing writeback IOs, and every
memcg - blkcg combination can be served by its own wb by assigning a
dedicated wb to each memcg.  This means that there may be multiple
wb's of a bdi mapped to the same blkcg.  As congested state is per
blkcg - bdi combination, those wb's should share the same congested
state.  This is achieved by tracking congested state via
bdi_writeback_congested structs which are keyed by blkcg.

bdi->wb remains unchanged and will keep serving the root cgroup.
cgwb's (cgroup wb's) for non-root cgroups are created on-demand or
looked up while dirtying an inode according to the memcg of the page
being dirtied or current task.  Each cgwb is indexed on bdi->cgwb_tree
by its memcg id.  Once an inode is associated with its wb, it can be
retrieved using inode_to_wb().

Currently, none of the filesystems has FS_CGROUP_WRITEBACK and all
pages will keep being associated with bdi->wb.

v3: inode_attach_wb() in account_page_dirtied() moved inside
    mapping_cap_account_dirty() block where it's known to be !NULL.
    Also, an unnecessary NULL check before kfree() removed.  Both
    detected by the kbuild bot.

v2: Updated so that wb association is per inode and wb is per memcg
    rather than blkcg.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: kbuild test robot <fengguang.wu@intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:35 -06:00
Tejun Heo
89e9b9e07a writeback: add {CONFIG|BDI_CAP|FS}_CGROUP_WRITEBACK
cgroup writeback requires support from both bdi and filesystem sides.
Add BDI_CAP_CGROUP_WRITEBACK and FS_CGROUP_WRITEBACK to indicate
support and enable BDI_CAP_CGROUP_WRITEBACK on block based bdi's by
default.  Also, define CONFIG_CGROUP_WRITEBACK which is enabled if
both MEMCG and BLK_CGROUP are enabled.

inode_cgwb_enabled() which determines whether a given inode's both bdi
and fs support cgroup writeback is added.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:35 -06:00
Tejun Heo
66114cad64 writeback: separate out include/linux/backing-dev-defs.h
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 <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
Tejun Heo
4452226ea2 writeback: move backing_dev_info->state into bdi_writeback
Currently, a bdi (backing_dev_info) embeds single wb (bdi_writeback)
and the role of the separation is unclear.  For cgroup support for
writeback IOs, a bdi will be updated to host multiple wb's where each
wb serves writeback IOs of a different cgroup on the bdi.  To achieve
that, a wb should carry all states necessary for servicing writeback
IOs for a cgroup independently.

This patch moves bdi->state into wb.

* enum bdi_state is renamed to wb_state and the prefix of all enums is
  changed from BDI_ to WB_.

* Explicit zeroing of bdi->state is removed without adding zeoring of
  wb->state as the whole data structure is zeroed on init anyway.

* As there's still only one bdi_writeback per backing_dev_info, all
  uses of bdi->state are mechanically replaced with bdi->wb.state
  introducing no behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: drbd-dev@lists.linbit.com
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
Tejun Heo
1d933cf096 blkcg: implement bio_associate_blkcg()
Currently, a bio can only be associated with the io_context and blkcg
of %current using bio_associate_current().  This is too restrictive
for cgroup writeback support.  Implement bio_associate_blkcg() which
associates a bio with the specified blkcg.

bio_associate_blkcg() leaves the io_context unassociated.
bio_associate_current() is updated so that it considers a bio as
already associated if it has a blkcg_css, instead of an io_context,
associated with it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
Tejun Heo
ec438699a9 cgroup, block: implement task_get_css() and use it in bio_associate_current()
bio_associate_current() currently open codes task_css() and
css_tryget_online() to find and pin $current's blkcg css.  Abstract it
into task_get_css() which is implemented from cgroup side.  As a task
is always associated with an online css for every subsystem except
while the css_set update is propagating, task_get_css() retries till
css_tryget_online() succeeds.

This is a cleanup and shouldn't lead to noticeable behavior changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
Tejun Heo
496d5e7560 blkcg: add blkcg_root_css
Add global constant blkcg_root_css which points to &blkcg_root.css.
This will be used by cgroup writeback support.  If blkcg is disabled,
it's defined as ERR_PTR(-EINVAL).

v2: The declarations moved to include/linux/blk-cgroup.h as suggested
    by Vivek.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:33 -06:00
Tejun Heo
ec13b1d6f0 blkcg: always create the blkcg_gq for the root blkcg
Currently, blkcg does a minor optimization where the root blkcg is
created when the first blkcg policy is activated on a queue and
destroyed on the deactivation of the last.  On systems where blkcg is
configured but not used, this saves one blkcg_gq struct per queue.  On
systems where blkcg is actually used, there's no difference.  The only
case where this can lead to any meaninful, albeit still minute, save
in memory consumption is when all blkcg policies are deactivated after
being widely used in the system, which is a hihgly unlikely scenario.

The conditional existence of root blkcg_gq has already created several
bugs in blkcg and became an issue once again for the new per-cgroup
wb_congested mechanism for cgroup writeback support leading to a NULL
dereference when no blkcg policy is active.  This is really not worth
bothering with.  This patch makes blkcg always allocate and link the
root blkcg_gq and release it only on queue destruction.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:33 -06:00
Tejun Heo
eea8f41cc5 blkcg: move block/blk-cgroup.h to include/linux/blk-cgroup.h
cgroup aware writeback support will require exposing some of blkcg
details.  In preprataion, move block/blk-cgroup.h to
include/linux/blk-cgroup.h.  This patch is pure file move.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:33 -06:00
Ingo Molnar
f407a82586 Merge branch 'linus' into sched/core, to resolve conflict
Conflicts:
	arch/sparc/include/asm/topology_64.h

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-02 08:05:42 +02:00
Keith Busch
f26cdc8536 blk-mq: Shared tag enhancements
Storage controllers may expose multiple block devices that share hardware
resources managed by blk-mq. This patch enhances the shared tags so a
low-level driver can access the shared resources not tied to the unshared
h/w contexts. This way the LLD can dynamically add and delete disks and
request queues without having to track all the request_queue hctx's to
iterate outstanding tags.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-01 14:35:56 -06:00
Jens Axboe
beefa6ba7b block: only honor SG gap prevention for merges that contain data
We can safely merge anything that wont generate an SG list entry,
so if the bio is data-less (discard), don't look at potential
SG gaps.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-29 13:10:23 -06:00
Mike Snitzer
183f7802e7 Merge remote-tracking branch 'jens/for-4.2/core' into dm-4.2 2015-05-29 14:17:16 -04:00
NeilBrown
aad653a0bc block: discard bdi_unregister() in favour of bdi_destroy()
bdi_unregister() now contains very little functionality.

It contains a "WARN_ON" if bdi->dev is NULL.  This warning is of no
real consequence as bdi->dev isn't needed by anything else in the function,
and it triggers if
   blk_cleanup_queue() -> bdi_destroy()
is called before bdi_unregister, which happens since
  Commit: 6cd18e711d ("block: destroy bdi before blockdev is unregistered.")

So this isn't wanted.

It also calls bdi_set_min_ratio().  This needs to be called after
writes through the bdi have all been flushed, and before the bdi is destroyed.
Calling it early is better than calling it late as it frees up a global
resource.

Calling it immediately after bdi_wb_shutdown() in bdi_destroy()
perfectly fits these requirements.

So bdi_unregister() can be discarded with the important content moved to
bdi_destroy(), as can the
  writeback_bdi_unregister
event which is already not used.

Reported-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org (v4.0)
Fixes: c4db59d31e ("fs: don't reassign dirty inodes to default_backing_dev_info")
Fixes: 6cd18e711d ("block: destroy bdi before blockdev is unregistered.")
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Nicholas Moulin <nicholas.w.moulin@linux.intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-28 10:12:42 -06:00
Bartosz Golaszewski
06931e6224 sched/topology: Rename topology_thread_cpumask() to topology_sibling_cpumask()
Rename topology_thread_cpumask() to topology_sibling_cpumask()
for more consistency with scheduler code.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Benoit Cousson <bcousson@baylibre.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Link: http://lkml.kernel.org/r/1432645896-12588-2-git-send-email-bgolaszewski@baylibre.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27 15:22:15 +02:00
Christoph Hellwig
5f1b670d0b block, dm: don't copy bios for request clones
Currently dm-multipath has to clone the bios for every request sent
to the lower devices, which wastes cpu cycles and ties down memory.

This patch instead adds a new REQ_CLONE flag that instructs req_bio_endio
to not complete bios attached to a request, which we set on clone
requests similar to bios in a flush sequence.  With this change I/O
errors on a path failure only get propagated to dm-multipath, which
can then either resubmit the I/O or complete the bios on the original
request.

I've done some basic testing of this on a Linux target with ALUA support,
and it survives path failures during I/O nicely.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-22 08:58:57 -06:00
Mike Snitzer
326e1dbb57 block: remove management of bi_remaining when restoring original bi_end_io
Commit c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for
non-chains") regressed all existing callers that followed this pattern:
 1) saving a bio's original bi_end_io
 2) wiring up an intermediate bi_end_io
 3) restoring the original bi_end_io from intermediate bi_end_io
 4) calling bio_endio() to execute the restored original bi_end_io

The regression was due to BIO_CHAIN only ever getting set if
bio_inc_remaining() is called.  For the above pattern it isn't set until
step 3 above (step 2 would've needed to establish BIO_CHAIN).  As such
the first bio_endio(), in step 2 above, never decremented __bi_remaining
before calling the intermediate bi_end_io -- leaving __bi_remaining with
the value 1 instead of 0.  When bio_inc_remaining() occurred during step
3 it brought it to a value of 2.  When the second bio_endio() was
called, in step 4 above, it should've called the original bi_end_io but
it didn't because there was an extra reference that wasn't dropped (due
to atomic operations being optimized away since BIO_CHAIN wasn't set
upfront).

Fix this issue by removing the __bi_remaining management complexity for
all callers that use the above pattern -- bio_chain() is the only
interface that _needs_ to be concerned with __bi_remaining.  For the
above pattern callers just expect the bi_end_io they set to get called!
Remove bio_endio_nodec() and also remove all bio_inc_remaining() calls
that aren't associated with the bio_chain() interface.

Also, the bio_inc_remaining() interface has been moved local to bio.c.

Fixes: c4cf5261 ("bio: skip atomic inc/dec of ->bi_remaining for non-chains")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-22 08:58:55 -06:00
Ming Lei
b04a5636a6 block: replace trylock with mutex_lock in blkdev_reread_part()
The only possible problem of using mutex_lock() instead of trylock
is about deadlock.

If there aren't any locks held before calling blkdev_reread_part(),
deadlock can't be caused by this conversion.

If there are locks held before calling blkdev_reread_part(),
and if these locks arn't required in open, close handler and I/O
path, deadlock shouldn't be caused too.

Both user space's ioctl(BLKRRPART) and md_setup_drive() from
init/do_mounts_md.c belongs to the 1st case, so the conversion is safe
for the two cases.

For loop, the previous patches in this pathset has fixed the ABBA lock
dependency, so the conversion is OK.

For nbd, tx_lock is held when calling the function:

	- both open and release won't hold the lock
	- when blkdev_reread_part() is run, I/O thread has been stopped
	already, so tx_lock won't be acquired in I/O path at that time.
	- so the conversion won't cause deadlock for nbd

For dasd, both dasd_open(), dasd_release() and request function don't
acquire any mutex/semphone, so the conversion should be safe.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-20 09:05:45 -06:00
Jarod Wilson
be32417796 block: export blkdev_reread_part() and __blkdev_reread_part()
This patch exports blkdev_reread_part() for block drivers, also
introduce __blkdev_reread_part().

For some drivers, such as loop, reread of partitions can be run
from the release path, and bd_mutex may already be held prior to
calling ioctl_by_bdev(bdev, BLKRRPART, 0), so introduce
__blkdev_reread_part for use in such cases.

CC: Christoph Hellwig <hch@lst.de>
CC: Jens Axboe <axboe@kernel.dk>
CC: Tejun Heo <tj@kernel.org>
CC: Alexander Viro <viro@zeniv.linux.org.uk>
CC: Markus Pargmann <mpa@pengutronix.de>
CC: Stefan Weinhuber <wein@de.ibm.com>
CC: Stefan Haberland <stefan.haberland@de.ibm.com>
CC: Sebastian Ott <sebott@linux.vnet.ibm.com>
CC: Fabian Frederick <fabf@skynet.be>
CC: Ming Lei <ming.lei@canonical.com>
CC: David Herrmann <dh.herrmann@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: nbd-general@lists.sourceforge.net
CC: linux-s390@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-20 09:05:42 -06:00
Christoph Hellwig
97ca223c3b block: remove unused BIO_RW_BLOCK and BIO_EOF flags
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-19 09:17:05 -06:00
Christoph Hellwig
b25de9d6da block: remove BIO_EOPNOTSUPP
Since the big barrier rewrite/removal in 2007 we never fail FLUSH or
FUA requests, which means we can remove the magic BIO_EOPNOTSUPP flag
to help propagating those to the buffer_head layer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-19 09:17:03 -06:00
Christoph Hellwig
4ecd4fef3a block: use an atomic_t for mq_freeze_depth
lockdep gets unhappy about the not disabling irqs when using the queue_lock
around it.  Instead of trying to fix that up just switch to an atomic_t
and get rid of the lock.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-19 09:12:59 -06:00
Mike Snitzer
336b7e1f23 block: remove export for blk_queue_bio
With commit ff36ab345 ("dm: remove request-based logic from
make_request_fn wrapper") DM no longer calls blk_queue_bio() directly,
so remove its export.  Doing so required a forward declaration in
blk-core.c.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-12 17:21:22 -04:00
Shaohua Li
5b3f341f09 blk-mq: make plug work for mutiple disks and queues
Last patch makes plug work for multiple queue case. However it only
works for single disk case, because it assumes only one request in the
plug list. If a task is accessing multiple disks, eg MD/DM, the
assumption is wrong. Let blk_attempt_plug_merge() record request from
the same queue.

V2: use NULL parameter in !mq case. Fix a bug. Add comments in
blk_attempt_plug_merge to make it less (hopefully) confusion.

Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-08 14:17:23 -06:00
Shaohua Li
f984df1f0f blk-mq: do limited block plug for multiple queue case
plug is still helpful for workload with IO merge, but it can be harmful
otherwise especially with multiple hardware queues, as there is
(supposed) no lock contention in this case and plug can introduce
latency. For multiple queues, we do limited plug, eg plug only if there
is request merge. If a request doesn't have merge with following
request, the requet will be dispatched immediately.

V2: check blk_queue_nomerges() as suggested by Jeff.

Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-08 14:17:21 -06:00
Shaohua Li
239ad215f0 blk-mq: avoid re-initialize request which is failed in direct dispatch
If we directly issue a request and it fails, we use
blk_mq_merge_queue_io(). But we already assigned bio to a request in
blk_mq_bio_to_request. blk_mq_merge_queue_io shouldn't run
blk_mq_bio_to_request again.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-08 14:17:19 -06:00
Jeff Moyer
e6c4438ba7 blk-mq: fix plugging in blk_sq_make_request
The following appears in blk_sq_make_request:

	/*
	 * If we have multiple hardware queues, just go directly to
	 * one of those for sync IO.
	 */

We clearly don't have multiple hardware queues, here!  This comment was
introduced with this commit 07068d5b8e (blk-mq: split make request
handler for multi and single queue):

    We want slightly different behavior from them:

    - On single queue devices, we currently use the per-process plug
      for deferred IO and for merging.

    - On multi queue devices, we don't use the per-process plug, but
      we want to go straight to hardware for SYNC IO.

The old code had this:

        use_plug = !is_flush_fua && ((q->nr_hw_queues == 1) || !is_sync);

and that was converted to:

	use_plug = !is_flush_fua && !is_sync;

which is not equivalent.  For the single queue case, that second half of
the && expression is always true.  So, what I think was actually inteded
follows (and this more closely matches what is done in blk_queue_bio).

V2: delete the 'likely', which should not be a big deal

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-08 14:17:17 -06:00
Shaohua Li
dd6cf3e18d blk: clean up plug
Current code looks like inner plug gets flushed with a
blk_finish_plug(). Actually it's a nop. All requests/callbacks are added
to current->plug, while only outmost plug is assigned to current->plug.
So inner plug always has empty request/callback list, which makes
blk_flush_plug_list() a nop. This tries to make the code more clear.

Signed-off-by: Shaohua Li <shli@fb.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-08 14:17:14 -06:00
Christoph Hellwig
a7928c1578 block: move PM request support to IDE
This removes the request types and hacks from the block code and into the
old IDE driver.  There is a small amunt of code duplication due to this,
but it's not too bad.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-05 13:40:42 -06:00
Jens Axboe
dac56212e8 bio: skip atomic inc/dec of ->bi_cnt for most use cases
Struct bio has a reference count that controls when it can be freed.
Most uses cases is allocating the bio, which then returns with a
single reference to it, doing IO, and then dropping that single
reference. We can remove this atomic_dec_and_test() in the completion
path, if nobody else is holding a reference to the bio.

If someone does call bio_get() on the bio, then we flag the bio as
now having valid count and that we must properly honor the reference
count when it's being put.

Tested-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-05 13:32:49 -06:00
Jens Axboe
c4cf5261f8 bio: skip atomic inc/dec of ->bi_remaining for non-chains
Struct bio has an atomic ref count for chained bio's, and we use this
to know when to end IO on the bio. However, most bio's are not chained,
so we don't need to always introduce this atomic operation as part of
ending IO.

Add a helper to elevate the bi_remaining count, and flag the bio as
now actually needing the decrement at end_io time. Rename the field
to __bi_remaining to catch any current users of this doing the
incrementing manually.

For high IOPS workloads, this reduces the overhead of bio_endio()
substantially.

Tested-by: Robert Elliott <elliott@hp.com>
Acked-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-05 13:32:47 -06:00
Shaohua Li
9ba52e5812 blk-mq: don't lose requests if a stopped queue restarts
Normally if driver is busy to dispatch a request the logic is like below:
block layer:					driver:
	__blk_mq_run_hw_queue
a.						blk_mq_stop_hw_queue
b.	rq add to ctx->dispatch

later:
1.						blk_mq_start_hw_queue
2.	__blk_mq_run_hw_queue

But it's possible step 1-2 runs between a and b. And since rq isn't in
ctx->dispatch yet, step 2 will not run rq. The rq might get lost if
there are no subsequent requests kick in.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-04 14:32:48 -06:00
NeilBrown
6cd18e711d block: destroy bdi before blockdev is unregistered.
Because of the peculiar way that md devices are created (automatically
when the device node is opened), a new device can be created and
registered immediately after the
	blk_unregister_region(disk_devt(disk), disk->minors);
call in del_gendisk().

Therefore it is important that all visible artifacts of the previous
device are removed before this call.  In particular, the 'bdi'.

Since:
commit c4db59d31e
Author: Christoph Hellwig <hch@lst.de>
    fs: don't reassign dirty inodes to default_backing_dev_info

moved the
   device_unregister(bdi->dev);
call from bdi_unregister() to bdi_destroy() it has been quite easy to
lose a race and have a new (e.g.) "md127" be created after the
blk_unregister_region() call and before bdi_destroy() is ultimately
called by the final 'put_disk', which must come after del_gendisk().

The new device finds that the bdi name is already registered in sysfs
and complains

> [ 9627.630029] WARNING: CPU: 18 PID: 3330 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x5a/0x70()
> [ 9627.630032] sysfs: cannot create duplicate filename '/devices/virtual/bdi/9:127'

We can fix this by moving the bdi_destroy() call out of
blk_release_queue() (which can happen very late when a refcount
reaches zero) and into blk_cleanup_queue() - which happens exactly when the md
device driver calls it.

Then it is only necessary for md to call blk_cleanup_queue() before
del_gendisk().  As loop.c devices are also created on demand by
opening the device node, we make the same change there.

Fixes: c4db59d31e
Reported-by: Azat Khuzhin <a3at.mail@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org (v4.0)
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-27 10:27:20 -06:00
Wang YanQing
393a339705 block:bounce: fix call inc_|dec_zone_page_state on different pages confuse value of NR_BOUNCE
Commit d2c5e30c9a
("[PATCH] zoned vm counters: conversion of nr_bounce to per zone counter")
convert statistic of nr_bounce to per zone and one global value in vm_stat,
but it call inc_|dec_zone_page_state on different pages, then different
zones, and cause us to get unexpected value of NR_BOUNCE.

Below is the result on my machine:
Mar  2 09:26:08 udknight kernel: [144766.778265] Mem-Info:
Mar  2 09:26:08 udknight kernel: [144766.778266] DMA per-cpu:
Mar  2 09:26:08 udknight kernel: [144766.778268] CPU    0: hi:    0, btch:   1 usd:   0
Mar  2 09:26:08 udknight kernel: [144766.778269] CPU    1: hi:    0, btch:   1 usd:   0
Mar  2 09:26:08 udknight kernel: [144766.778270] Normal per-cpu:
Mar  2 09:26:08 udknight kernel: [144766.778271] CPU    0: hi:  186, btch:  31 usd:   0
Mar  2 09:26:08 udknight kernel: [144766.778273] CPU    1: hi:  186, btch:  31 usd:   0
Mar  2 09:26:08 udknight kernel: [144766.778274] HighMem per-cpu:
Mar  2 09:26:08 udknight kernel: [144766.778275] CPU    0: hi:  186, btch:  31 usd:   0
Mar  2 09:26:08 udknight kernel: [144766.778276] CPU    1: hi:  186, btch:  31 usd:   0
Mar  2 09:26:08 udknight kernel: [144766.778279] active_anon:46926 inactive_anon:287406 isolated_anon:0
Mar  2 09:26:08 udknight kernel: [144766.778279]  active_file:105085 inactive_file:139432 isolated_file:0
Mar  2 09:26:08 udknight kernel: [144766.778279]  unevictable:653 dirty:0 writeback:0 unstable:0
Mar  2 09:26:08 udknight kernel: [144766.778279]  free:178957 slab_reclaimable:6419 slab_unreclaimable:9966
Mar  2 09:26:08 udknight kernel: [144766.778279]  mapped:4426 shmem:305277 pagetables:784 bounce:0
Mar  2 09:26:08 udknight kernel: [144766.778279]  free_cma:0
Mar  2 09:26:08 udknight kernel: [144766.778286] DMA free:3324kB min:68kB low:84kB high:100kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15976kB managed:15900kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? yes
Mar  2 09:26:08 udknight kernel: [144766.778287] lowmem_reserve[]: 0 822 3754 3754
Mar  2 09:26:08 udknight kernel: [144766.778293] Normal free:26828kB min:3632kB low:4540kB high:5448kB active_anon:4872kB inactive_anon:68kB active_file:1796kB inactive_file:1796kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:892920kB managed:842560kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:4144kB slab_reclaimable:25676kB slab_unreclaimable:39864kB kernel_stack:1944kB pagetables:3136kB unstable:0kB bounce:0kB free_cma:0kB writeback_tmp:0kB pages_scanned:2412612 all_unreclaimable? yes
Mar  2 09:26:08 udknight kernel: [144766.778294] lowmem_reserve[]: 0 0 23451 23451
Mar  2 09:26:08 udknight kernel: [144766.778299] HighMem free:685676kB min:512kB low:3748kB high:6984kB active_anon:182832kB inactive_anon:1149556kB active_file:418544kB inactive_file:555932kB unevictable:2612kB isolated(anon):0kB isolated(file):0kB present:3001732kB managed:3001732kB mlocked:0kB dirty:0kB writeback:0kB mapped:17704kB shmem:1216964kB slab_reclaimable:0kB slab_unreclaimable:0kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:75771152kB free_cma:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no
Mar  2 09:26:08 udknight kernel: [144766.778300] lowmem_reserve[]: 0 0 0 0

You can see bounce:75771152kB for HighMem, but bounce:0 for lowmem and global.

This patch fix it.

Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-27 09:24:07 -06:00
Chao Yu
8406a4d56e elevator: fix double release of elevator module
Our issue is descripted in below call path:
->elevator_init
 ->elevator_init_fn
  ->{cfq,deadline,noop}_init_queue
   ->elevator_alloc
    ->kzalloc_node
   fail to call kzalloc_node and then put module in elevator_alloc;
fail to call elevator_init_fn and then put module again in elevator_init.

Remove elevator_put invoking in error path of elevator_alloc to avoid
double release issue.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-23 10:47:44 -06:00
Ming Lei
2a34c0872a blk-mq: fix CPU hotplug handling
hctx->tags has to be set as NULL in case that it is to be unmapped
no matter if set->tags[hctx->queue_num] is NULL or not in blk_mq_map_swqueue()
because shared tags can be freed already from another request queue.

The same situation has to be considered during handling CPU online too.
Unmapped hw queue can be remapped after CPU topo is changed, so we need
to allocate tags for the hw queue in blk_mq_map_swqueue(). Then tags
allocation for hw queue can be removed in hctx cpu online notifier, and it
is reasonable to do that after mapping is updated.

Cc: <stable@vger.kernel.org>
Reported-by: Dongsu Park <dongsu.park@profitbricks.com>
Tested-by: Dongsu Park <dongsu.park@profitbricks.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-23 10:27:38 -06:00
Ming Lei
f054b56c95 blk-mq: fix race between timeout and CPU hotplug
Firstly during CPU hotplug, even queue is freezed, timeout
handler still may come and access hctx->tags, which may cause
use after free, so this patch deactivates timeout handler
inside CPU hotplug notifier.

Secondly, tags can be shared by more than one queues, so we
have to check if the hctx has been unmapped, otherwise
still use-after-free on tags can be triggered.

Cc: <stable@vger.kernel.org>
Reported-by: Dongsu Park <dongsu.park@profitbricks.com>
Tested-by: Dongsu Park <dongsu.park@profitbricks.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-23 10:27:35 -06:00
Jens Axboe
569fd0ce96 blk-mq: fix iteration of busy bitmap
Commit 889fa31f00 was a bit too eager in reducing the loop count,
so we ended up missing queues in some configurations. Ensure that
our division rounds up, so that's not the case.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 889fa31f00 ("blk-mq: reduce unnecessary software queue looping")
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-17 08:31:12 -06:00
Linus Torvalds
d82312c808 Merge branch 'for-4.1/core' of git://git.kernel.dk/linux-block
Pull block layer core bits from Jens Axboe:
 "This is the core pull request for 4.1.  Not a lot of stuff in here for
  this round, mostly little fixes or optimizations.  This pull request
  contains:

   - An optimization that speeds up queue runs on blk-mq, especially for
     the case where there's a large difference between nr_cpu_ids and
     the actual mapped software queues on a hardware queue.  From Chong
     Yuan.

   - Honor node local allocations for requests on legacy devices.  From
     David Rientjes.

   - Cleanup of blk_mq_rq_to_pdu() from me.

   - exit_aio() fixup from me, greatly speeding up exiting multiple IO
     contexts off exit_group().  For my particular test case, fio exit
     took ~6 seconds.  A typical case of both exposing RCU grace periods
     to user space, and serializing exit of them.

   - Make blk_mq_queue_enter() honor the gfp mask passed in, so we only
     wait if __GFP_WAIT is set.  From Keith Busch.

   - blk-mq exports and two added helpers from Mike Snitzer, which will
     be used by the dm-mq code.

   - Cleanups of blk-mq queue init from Wei Fang and Xiaoguang Wang"

* 'for-4.1/core' of git://git.kernel.dk/linux-block:
  blk-mq: reduce unnecessary software queue looping
  aio: fix serial draining in exit_aio()
  blk-mq: cleanup blk_mq_rq_to_pdu()
  blk-mq: put blk_queue_rq_timeout together in blk_mq_init_queue()
  block: remove redundant check about 'set->nr_hw_queues' in blk_mq_alloc_tag_set()
  block: allocate request memory local to request queue
  blk-mq: don't wait in blk_mq_queue_enter() if __GFP_WAIT isn't set
  blk-mq: export blk_mq_run_hw_queues
  blk-mq: add blk_mq_init_allocated_queue and export blk_mq_register_disk
2015-04-16 21:49:16 -04:00
Chong Yuan
889fa31f00 blk-mq: reduce unnecessary software queue looping
In flush_busy_ctxs() and blk_mq_hctx_has_pending(), regardless of how many
ctxs assigned to one hctx, they will all loop hctx->ctx_map.map_size
times. Here hctx->ctx_map.map_size is a const ALIGN(nr_cpu_ids, 8) / 8.
Especially, flush_busy_ctxs() is in hot code path. And it's unnecessary.
Change ->map_size to contain the actually mapped software queues, so we
only loop for as many iterations as we have to.

And remove cpumask setting and nr_ctx count in blk_mq_init_cpu_queues()
since they are all re-done in blk_mq_map_swqueue().
blk_mq_map_swqueue().

Signed-off-by: Chong Yuan <chong.yuan@memblaze.com>
Reviewed-by: Wenbo Wang <wenbo.wang@memblaze.com>

Updated by me for formatting and commenting.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-15 11:39:29 -06:00
Linus Torvalds
ca2ec32658 Merge branch 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs update from Al Viro:
 "Part one:

   - struct filename-related cleanups

   - saner iov_iter_init() replacements (and switching the syscalls to
     use of those)

   - ntfs switch to ->write_iter() (Anton)

   - aio cleanups and splitting iocb into common and async parts
     (Christoph)

   - assorted fixes (me, bfields, Andrew Elble)

  There's a lot more, including the completion of switchover to
  ->{read,write}_iter(), d_inode/d_backing_inode annotations, f_flags
  race fixes, etc, but that goes after #for-davem merge.  David has
  pulled it, and once it's in I'll send the next vfs pull request"

* 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (35 commits)
  sg_start_req(): use import_iovec()
  sg_start_req(): make sure that there's not too many elements in iovec
  blk_rq_map_user(): use import_single_range()
  sg_io(): use import_iovec()
  process_vm_access: switch to {compat_,}import_iovec()
  switch keyctl_instantiate_key_common() to iov_iter
  switch {compat_,}do_readv_writev() to {compat_,}import_iovec()
  aio_setup_vectored_rw(): switch to {compat_,}import_iovec()
  vmsplice_to_user(): switch to import_iovec()
  kill aio_setup_single_vector()
  aio: simplify arguments of aio_setup_..._rw()
  aio: lift iov_iter_init() into aio_setup_..._rw()
  lift iov_iter into {compat_,}do_readv_writev()
  NFS: fix BUG() crash in notify_change() with patch to chown_common()
  dcache: return -ESTALE not -EBUSY on distributed fs race
  NTFS: Version 2.1.32 - Update file write from aio_write to write_iter.
  VFS: Add iov_iter_fault_in_multipages_readable()
  drop bogus check in file_open_root()
  switch security_inode_getattr() to struct path *
  constify tomoyo_realpath_from_path()
  ...
2015-04-14 15:31:03 -07:00
Al Viro
8f7e885a4c blk_rq_map_user(): use import_single_range()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:27:13 -04:00
Al Viro
e272b89ff8 sg_io(): use import_iovec()
... and don't skip access_ok() validation.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:27:13 -04:00
Linus Torvalds
ac2111753c blk-mq: initialize 'struct request' and associated data to zero
Jan Engelhardt reports a strange oops with an invalid ->sense_buffer
pointer in scsi_init_cmd_errh() with the blk-mq code.

The sense_buffer pointer should have been initialized by the call to
scsi_init_request() from blk_mq_init_rq_map(), but there seems to be
some non-repeatable memory corruptor.

This patch makes sure we initialize the whole struct request allocation
(and the associated 'struct scsi_cmnd' for the SCSI case) to zero, by
using __GFP_ZERO in the allocation.  The old code initialized a couple
of individual fields, leaving the rest undefined (although many of them
are then initialized in later phases, like blk_mq_rq_ctx_init() etc.

It's not entirely clear why this matters, but it's the rigth thing to do
regardless, and with 4.0 imminent this is the defensive "let's just make
sure everything is initialized properly" patch.

Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-11 13:42:16 -07:00
Mike Snitzer
e9637415a9 block: fix blk_stack_limits() regression due to lcm() change
Linux 3.19 commit 69c953c ("lib/lcm.c: lcm(n,0)=lcm(0,n) is 0, not n")
caused blk_stack_limits() to not properly stack queue_limits for stacked
devices (e.g. DM).

Fix this regression by establishing lcm_not_zero() and switching
blk_stack_limits() over to using it.

DM uses blk_set_stacking_limits() to establish the initial top-level
queue_limits that are then built up based on underlying devices' limits
using blk_stack_limits().  In the case of optimal_io_size (io_opt)
blk_set_stacking_limits() establishes a default value of 0.  With commit
69c953c, lcm(0, n) is no longer n, which compromises proper stacking of
the underlying devices' io_opt.

Test:
$ modprobe scsi_debug dev_size_mb=10 num_tgts=1 opt_blks=1536
$ cat /sys/block/sde/queue/optimal_io_size
786432
$ dmsetup create node --table "0 100 linear /dev/sde 0"

Before this fix:
$ cat /sys/block/dm-5/queue/optimal_io_size
0

After this fix:
$ cat /sys/block/dm-5/queue/optimal_io_size
786432

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 3.19+
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-31 09:45:50 -06:00
Wei Fang
c76cbbcf40 blk-mq: put blk_queue_rq_timeout together in blk_mq_init_queue()
Don't assign ->rq_timeout twice.

Signed-off-by: Wei Fang <fangwei1@huawei.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-30 09:07:00 -06:00
Xiaoguang Wang
f9018ac930 block: remove redundant check about 'set->nr_hw_queues' in blk_mq_alloc_tag_set()
At the beginning of blk_mq_alloc_tag_set(), we have already checked whether
'set->nr_hw_queues' is zero, so here remove this redundant check.

Signed-off-by: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-30 09:04:27 -06:00
David Rientjes
271508dba2 block: allocate request memory local to request queue
blk_init_rl() allocates a mempool using mempool_create_node() with node
local memory.  This only allocates the mempool and element list locally
to the requeue queue node.

What we really want to do is allocate the request itself local to the
queue.  To do this, we need our own alloc and free functions that will
allocate from request_cachep and pass the request queue node in to prefer
node local memory.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-24 20:00:07 -06:00
Wenbo Wang
7ee8e4f398 Fix bug in blk_rq_merge_ok
Use the right array index to reference the last
element of rq->biotail->bi_io_vec[]

Signed-off-by: Wenbo Wang <wenbo.wang@memblaze.com>
Reviewed-by: Chong Yuan <chong.yuan@memblaze.com>
Fixes: 66cb45aa41 ("block: add support for limiting gaps in SG lists")
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-20 08:50:41 -06:00
Sam Bradshaw
bc188d818e blkmq: Fix NULL pointer deref when all reserved tags in
When allocating from the reserved tags pool, bt_get() is called with
a NULL hctx.  If all tags are in use, the hw queue is kicked to push
out any pending IO, potentially freeing tags, and tag allocation is
retried.  The problem is that blk_mq_run_hw_queue() doesn't check for
a NULL hctx.  So we avoid it with a simple NULL hctx test.

Tested by hammering mtip32xx with concurrent smartctl/hdparm.

Signed-off-by: Sam Bradshaw <sbradshaw@micron.com>
Signed-off-by: Selvan Mani <smani@micron.com>
Fixes: b32232073e ("blk-mq: fix hang in bt_get()")
Cc: stable@kernel.org

Added appropriate comment.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-18 17:06:18 -06:00
Keith Busch
bfd343aa17 blk-mq: don't wait in blk_mq_queue_enter() if __GFP_WAIT isn't set
Return -EBUSY if we're unable to enter a queue immediately when
allocating a blk-mq request without __GFP_WAIT.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-13 08:30:55 -06:00
Mike Snitzer
b94ec29640 blk-mq: export blk_mq_run_hw_queues
Rename blk_mq_run_queues to blk_mq_run_hw_queues, add async argument,
and export it.

DM's suspend support must be able to run the queue without starting
stopped hw queues.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-13 08:28:33 -06:00
Mike Snitzer
b62c21b71f blk-mq: add blk_mq_init_allocated_queue and export blk_mq_register_disk
Add a variant of blk_mq_init_queue that allows a previously allocated
queue to be initialized.  blk_mq_init_allocated_queue models
blk_init_allocated_queue -- which was also created for DM's use.

DM's approach to device creation requires a placeholder request_queue be
allocated for use with alloc_dev() but the decision about what type of
request_queue will be ultimately created is deferred until all component
devices referenced in the DM table are processed to determine the table
type (request-based, blk-mq request-based, or bio-based).

Also, because of DM's late finalization of the request_queue type
the call to blk_mq_register_disk() doesn't happen during alloc_dev().
Must export blk_mq_register_disk() so that DM can backfill the 'mq' dir
once the blk-mq queue is fully allocated.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-13 08:26:53 -06:00
Mike Snitzer
9a30b096b5 blk-mq: fix use of incorrect goto label in blk_mq_init_queue error path
If percpu_ref_init() fails the allocated q and hctxs must get cleaned
up; using 'err_map' doesn't allow that to happen.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@canonical.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-13 08:22:32 -06:00
Thadeu Lima de Souza Cascardo
045c47ca30 blk-throttle: check stats_cpu before reading it from sysfs
When reading blkio.throttle.io_serviced in a recently created blkio
cgroup, it's possible to race against the creation of a throttle policy,
which delays the allocation of stats_cpu.

Like other functions in the throttle code, just checking for a NULL
stats_cpu prevents the following oops caused by that race.

[ 1117.285199] Unable to handle kernel paging request for data at address 0x7fb4d0020
[ 1117.285252] Faulting instruction address: 0xc0000000003efa2c
[ 1137.733921] Oops: Kernel access of bad area, sig: 11 [#1]
[ 1137.733945] SMP NR_CPUS=2048 NUMA PowerNV
[ 1137.734025] Modules linked in: bridge stp llc kvm_hv kvm binfmt_misc autofs4
[ 1137.734102] CPU: 3 PID: 5302 Comm: blkcgroup Not tainted 3.19.0 #5
[ 1137.734132] task: c000000f1d188b00 ti: c000000f1d210000 task.ti: c000000f1d210000
[ 1137.734167] NIP: c0000000003efa2c LR: c0000000003ef9f0 CTR: c0000000003ef980
[ 1137.734202] REGS: c000000f1d213500 TRAP: 0300   Not tainted  (3.19.0)
[ 1137.734230] MSR: 9000000000009032 <SF,HV,EE,ME,IR,DR,RI>  CR: 42008884  XER: 20000000
[ 1137.734325] CFAR: 0000000000008458 DAR: 00000007fb4d0020 DSISR: 40000000 SOFTE: 0
GPR00: c0000000003ed3a0 c000000f1d213780 c000000000c59538 0000000000000000
GPR04: 0000000000000800 0000000000000000 0000000000000000 0000000000000000
GPR08: ffffffffffffffff 00000007fb4d0020 00000007fb4d0000 c000000000780808
GPR12: 0000000022000888 c00000000fdc0d80 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 000001003e120200 c000000f1d5b0cc0 0000000000000200 0000000000000000
GPR24: 0000000000000001 c000000000c269e0 0000000000000020 c000000f1d5b0c80
GPR28: c000000000ca3a08 c000000000ca3dec c000000f1c667e00 c000000f1d213850
[ 1137.734886] NIP [c0000000003efa2c] .tg_prfill_cpu_rwstat+0xac/0x180
[ 1137.734915] LR [c0000000003ef9f0] .tg_prfill_cpu_rwstat+0x70/0x180
[ 1137.734943] Call Trace:
[ 1137.734952] [c000000f1d213780] [d000000005560520] 0xd000000005560520 (unreliable)
[ 1137.734996] [c000000f1d2138a0] [c0000000003ed3a0] .blkcg_print_blkgs+0xe0/0x1a0
[ 1137.735039] [c000000f1d213960] [c0000000003efb50] .tg_print_cpu_rwstat+0x50/0x70
[ 1137.735082] [c000000f1d2139e0] [c000000000104b48] .cgroup_seqfile_show+0x58/0x150
[ 1137.735125] [c000000f1d213a70] [c0000000002749dc] .kernfs_seq_show+0x3c/0x50
[ 1137.735161] [c000000f1d213ae0] [c000000000218630] .seq_read+0xe0/0x510
[ 1137.735197] [c000000f1d213bd0] [c000000000275b04] .kernfs_fop_read+0x164/0x200
[ 1137.735240] [c000000f1d213c80] [c0000000001eb8e0] .__vfs_read+0x30/0x80
[ 1137.735276] [c000000f1d213cf0] [c0000000001eb9c4] .vfs_read+0x94/0x1b0
[ 1137.735312] [c000000f1d213d90] [c0000000001ebb38] .SyS_read+0x58/0x100
[ 1137.735349] [c000000f1d213e30] [c000000000009218] syscall_exit+0x0/0x98
[ 1137.735383] Instruction dump:
[ 1137.735405] 7c6307b4 7f891800 409d00b8 60000000 60420000 3d420004 392a63b0 786a1f24
[ 1137.735471] 7d49502a e93e01c8 7d495214 7d2ad214 <7cead02a> e9090008 e9490010 e9290018

And here is one code that allows to easily reproduce this, although this
has first been found by running docker.

void run(pid_t pid)
{
	int n;
	int status;
	int fd;
	char *buffer;
	buffer = memalign(BUFFER_ALIGN, BUFFER_SIZE);
	n = snprintf(buffer, BUFFER_SIZE, "%d\n", pid);
	fd = open(CGPATH "/test/tasks", O_WRONLY);
	write(fd, buffer, n);
	close(fd);
	if (fork() > 0) {
		fd = open("/dev/sda", O_RDONLY | O_DIRECT);
		read(fd, buffer, 512);
		close(fd);
		wait(&status);
	} else {
		fd = open(CGPATH "/test/blkio.throttle.io_serviced", O_RDONLY);
		n = read(fd, buffer, BUFFER_SIZE);
		close(fd);
	}
	free(buffer);
	exit(0);
}

void test(void)
{
	int status;
	mkdir(CGPATH "/test", 0666);
	if (fork() > 0)
		wait(&status);
	else
		run(getpid());
	rmdir(CGPATH "/test");
}

int main(int argc, char **argv)
{
	int i;
	for (i = 0; i < NR_TESTS; i++)
		test();
	return 0;
}

Reported-by: Ricardo Marin Matinata <rmm@br.ibm.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-20 22:11:58 -08:00
Linus Torvalds
8494bcf5b7 Merge branch 'for-3.20/drivers' of git://git.kernel.dk/linux-block
Pull block driver changes from Jens Axboe:
 "This contains:

   - The 4k/partition fixes for brd from Boaz/Matthew.

   - A few xen front/back block fixes from David Vrabel and Roger Pau
     Monne.

   - Floppy changes from Takashi, cleaning the device file creation.

   - Switching libata to use the new blk-mq tagging policy, removing
     code (and a suboptimal implementation) from libata.  This will
     throw you a merge conflict, since a bug in the original libata
     tagging code was fixed since this code was branched.  Trivial.
     From Shaohua.

   - Conversion of loop to blk-mq, from Ming Lei.

   - Cleanup of the io_schedule() handling in bsg from Peter Zijlstra.
     He claims it improves on unreadable code, which will cost him a
     beer.

   - Maintainer update or NDB, now handled by Markus Pargmann.

   - NVMe:
        - Optimization from me that avoids a kmalloc/kfree per IO for
          smaller (<= 8KB) IO. This cuts about 1% of high IOPS CPU
          overhead.
        - Removal of (now) dead RCU code, a relic from before NVMe was
          converted to blk-mq"

* 'for-3.20/drivers' of git://git.kernel.dk/linux-block:
  xen-blkback: default to X86_32 ABI on x86
  xen-blkfront: fix accounting of reqs when migrating
  xen-blkback,xen-blkfront: add myself as maintainer
  block: Simplify bsg complete all
  floppy: Avoid manual call of device_create_file()
  NVMe: avoid kmalloc/kfree for smaller IO
  MAINTAINERS: Update NBD maintainer
  libata: make sata_sil24 use fifo tag allocator
  libata: move sas ata tag allocation to libata-scsi.c
  libata: use blk taging
  NVMe: within nvme_free_queues(), delete RCU sychro/deferred free
  null_blk: suppress invalid partition info
  brd: Request from fdisk 4k alignment
  brd: Fix all partitions BUGs
  axonram: Fix bug in direct_access
  loop: add blk-mq.h include
  block: loop: don't handle REQ_FUA explicitly
  block: loop: introduce lo_discard() and lo_req_flush()
  block: loop: say goodby to bio
  block: loop: improve performance via blk-mq
2015-02-12 14:30:53 -08:00
Linus Torvalds
3e12cefbe1 Merge branch 'for-3.20/core' of git://git.kernel.dk/linux-block
Pull core block IO changes from Jens Axboe:
 "This contains:

   - A series from Christoph that cleans up and refactors various parts
     of the REQ_BLOCK_PC handling.  Contributions in that series from
     Dongsu Park and Kent Overstreet as well.

   - CFQ:
        - A bug fix for cfq for realtime IO scheduling from Jeff Moyer.
        - A stable patch fixing a potential crash in CFQ in OOM
          situations.  From Konstantin Khlebnikov.

   - blk-mq:
        - Add support for tag allocation policies, from Shaohua. This is
          a prep patch enabling libata (and other SCSI parts) to use the
          blk-mq tagging, instead of rolling their own.
        - Various little tweaks from Keith and Mike, in preparation for
          DM blk-mq support.
        - Minor little fixes or tweaks from me.
        - A double free error fix from Tony Battersby.

   - The partition 4k issue fixes from Matthew and Boaz.

   - Add support for zero+unprovision for blkdev_issue_zeroout() from
     Martin"

* 'for-3.20/core' of git://git.kernel.dk/linux-block: (27 commits)
  block: remove unused function blk_bio_map_sg
  block: handle the null_mapped flag correctly in blk_rq_map_user_iov
  blk-mq: fix double-free in error path
  block: prevent request-to-request merging with gaps if not allowed
  blk-mq: make blk_mq_run_queues() static
  dm: fix multipath regression due to initializing wrong request
  cfq-iosched: handle failure of cfq group allocation
  block: Quiesce zeroout wrapper
  block: rewrite and split __bio_copy_iov()
  block: merge __bio_map_user_iov into bio_map_user_iov
  block: merge __bio_map_kern into bio_map_kern
  block: pass iov_iter to the BLOCK_PC mapping functions
  block: add a helper to free bio bounce buffer pages
  block: use blk_rq_map_user_iov to implement blk_rq_map_user
  block: simplify bio_map_kern
  block: mark blk-mq devices as stackable
  block: keep established cmd_flags when cloning into a blk-mq request
  block: add blk-mq support to blk_insert_cloned_request()
  block: require blk_rq_prep_clone() be given an initialized clone request
  blk-mq: add tag allocation policy
  ...
2015-02-12 14:13:23 -08:00
Linus Torvalds
6bec003528 Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block
Pull backing device changes from Jens Axboe:
 "This contains a cleanup of how the backing device is handled, in
  preparation for a rework of the life time rules.  In this part, the
  most important change is to split the unrelated nommu mmap flags from
  it, but also removing a backing_dev_info pointer from the
  address_space (and inode), and a cleanup of other various minor bits.

  Christoph did all the work here, I just fixed an oops with pages that
  have a swap backing.  Arnd fixed a missing export, and Oleg killed the
  lustre backing_dev_info from staging.  Last patch was from Al,
  unexporting parts that are now no longer needed outside"

* 'for-3.20/bdi' of git://git.kernel.dk/linux-block:
  Make super_blocks and sb_lock static
  mtd: export new mtd_mmap_capabilities
  fs: make inode_to_bdi() handle NULL inode
  staging/lustre/llite: get rid of backing_dev_info
  fs: remove default_backing_dev_info
  fs: don't reassign dirty inodes to default_backing_dev_info
  nfs: don't call bdi_unregister
  ceph: remove call to bdi_unregister
  fs: remove mapping->backing_dev_info
  fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info
  nilfs2: set up s_bdi like the generic mount_bdev code
  block_dev: get bdev inode bdi directly from the block device
  block_dev: only write bdev inode on close
  fs: introduce f_op->mmap_capabilities for nommu mmap support
  fs: kill BDI_CAP_SWAP_BACKED
  fs: deduplicate noop_backing_dev_info
2015-02-12 13:50:21 -08:00
Christoph Hellwig
d427e3c82e block: remove unused function blk_bio_map_sg
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-11 11:24:14 -07:00
Christoph Hellwig
a0763b27bf block: handle the null_mapped flag correctly in blk_rq_map_user_iov
The tape drivers (and the sg driver in a special case that doesn't matter
here) use the null_mapped flag to tell blk_rq_map_user to not copy around
any data into or out of the bounce buffers.  blk_rq_map_user_iov never
got that treatment, which didn't matter until I refactored blk_rq_map_user
to be implemented in terms of blk_rq_map_user_iov.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Fixes: ddad8dd0a1 ("block: use blk_rq_map_user_iov to implement blk_rq_map_user")
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-11 11:24:12 -07:00
Tony Battersby
564e559f2b blk-mq: fix double-free in error path
If the allocation of bt->bs fails, then bt->map can be freed twice, once
in blk_mq_init_bitmap_tags() -> bt_alloc(), and once in
blk_mq_init_bitmap_tags() -> bt_free().  Fix by setting the pointer to
NULL after the first free.

Cc: <stable@vger.kernel.org>
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-11 09:35:21 -07:00
Keith Busch
854fbb9c69 block: prevent request-to-request merging with gaps if not allowed
If the queue has SG_GAPS set, we must not merge across an sg gap.
This is caught for the bio case, but currently not for the
more rare case of merging two requests directly.

Signed-off-by: Keith Busch <keith.busch@intel.com>

Cut the dm bits, those will go through the dm tree, and fixed
the test_bit() test.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-11 09:23:52 -07:00
Jens Axboe
201f201c33 blk-mq: make blk_mq_run_queues() static
We no longer use it outside of blk-mq.c, so we can make it static
and stop exporting it. Additionally, kill the 'async' argument, as
there's only one used of it.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-10 13:31:34 -07:00
Linus Torvalds
072bc448cc Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Ingo Molnar:
 "Main changes:

   - Move efivarfs from the misc filesystem section to pseudo filesystem

   - Expose firmware platform size in sysfs

   - Improve robustness of get_memory_map() by removing assumptions on
     the size of efi_memory_desc_t.

  - various cleanups and fixes

  The biggest risk is the get_memory_map() change, which changes the way
  that both the arm64 and x86 EFI boot stub build the early memory map.
  There are no known regressions with it at the moment, BYMMV"

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Don't look for chosen@0 node on DT platforms
  firmware: efi: Remove unneeded guid unparse
  efi/libstub: Call get_memory_map() to obtain map and desc sizes
  efi: Small leak on error in runtime map code
  efi: rtc-efi: Mark UIE as unsupported
  arm64/efi: efistub: Apply __init annotation
  efi: Expose underlying UEFI firmware platform size to userland
  efi: Rename efi_guid_unparse to efi_guid_to_str
  efi: Update the URLs for efibootmgr
  fs: Make efivarfs a pseudo filesystem, built by default with EFI
2015-02-09 17:53:53 -08:00
Konstantin Khlebnikov
69abaffec7 cfq-iosched: handle failure of cfq group allocation
Cfq_lookup_create_cfqg() allocates struct blkcg_gq using GFP_ATOMIC.
In cfq_find_alloc_queue() possible allocation failure is not handled.
As a result kernel oopses on NULL pointer dereference when
cfq_link_cfqq_cfqg() calls cfqg_get() for NULL pointer.

Bug was introduced in v3.5 in commit cd1604fab4 ("blkcg: factor
out blkio_group creation"). Prior to that commit cfq group lookup
had returned pointer to root group as fallback.

This patch handles this error using existing fallback oom_cfqq.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Fixes: cd1604fab4 ("blkcg: factor out blkio_group creation")
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-09 10:22:39 -07:00
Martin K. Petersen
9f9ee1f2b2 block: Quiesce zeroout wrapper
blkdev_issue_zeroout() printed a warning if a device failed a discard or
write same request despite advertising support for these. That's fine
for SCSI since we'll disable these commands if we get an error back from
the disk saying that they are not supported. And consequently the
warning only gets printed once.

There are other types of block devices that support discard, however,
and these may return -EOPNOTSUPP for each command but leave discard
enabled in the queue limits. This will cause a warning message for every
blkdev_issue_zeroout() invocation.

Remove the offending warning messages.

Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-05 10:14:54 -07:00
Dongsu Park
9124d3fe21 block: rewrite and split __bio_copy_iov()
Rewrite __bio_copy_iov using the copy_page_{from,to}_iter helpers, and
split it into two simpler functions.

This commit should contain only literal replacements, without
functional changes.

Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dongsu Park <dongsu.park@profitbricks.com>
[hch: removed the __bio_copy_iov wrapper]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-05 09:30:44 -07:00
Christoph Hellwig
37f19e57a0 block: merge __bio_map_user_iov into bio_map_user_iov
And also remove the unused bdev argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-05 09:30:43 -07:00
Christoph Hellwig
75c72b8366 block: merge __bio_map_kern into bio_map_kern
This saves a little code, and allow to simplify the error handling.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-05 09:30:42 -07:00
Kent Overstreet
26e49cfc7e block: pass iov_iter to the BLOCK_PC mapping functions
Make use of a new interface provided by iov_iter, backed by
scatter-gather list of iovec, instead of the old interface based on
sg_iovec. Also use iov_iter_advance() instead of manual iteration.

This commit should contain only literal replacements, without
functional changes.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
[dpark: add more description in commit message]
Signed-off-by: Dongsu Park <dongsu.park@profitbricks.com>
[hch: fixed to do a deep clone of the iov_iter, and to properly use
      the iov_iter direction]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-05 09:30:40 -07:00
Christoph Hellwig
1dfa0f68c0 block: add a helper to free bio bounce buffer pages
The code sniplet to walk all bio_vecs and free their pages is opencoded in
way to many places, so factor it into a helper.  Also convert the slightly
more complex cases in bio_kern_endio and __bio_copy_iov where we break
the freeing from an existing loop into a separate one.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-05 09:30:39 -07:00
Christoph Hellwig
ddad8dd0a1 block: use blk_rq_map_user_iov to implement blk_rq_map_user
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-05 09:30:37 -07:00
Christoph Hellwig
42d2683a27 block: simplify bio_map_kern
Just open code the trivial mapping from a kernel virtual address to
a bio instead of going through the complex user address mapping
machinery.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-05 09:30:35 -07:00
Peter Zijlstra
2c56124652 block: Simplify bsg complete all
It took me a few tries to figure out what this code did; lets rewrite
it into a more regular form.

The thing that makes this one 'special' is the BSG_F_BLOCK flag, if
that is not set we're not supposed/allowed to block and should spin
wait for completion.

The (new) io_wait_event() will never see a false condition in case of
the spinning and we will therefore not block.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-04 09:57:52 -07:00
Ingo Molnar
3c01b74e81 * Move efivarfs from the misc filesystem section to pseudo filesystem,
since that's a more logical and accurate place - Leif Lindholm
 
  * Update efibootmgr URL in Kconfig help - Peter Jones
 
  * Improve accuracy of EFI guid function names - Borislav Petkov
 
  * Expose firmware platform size in sysfs for the benefit of EFI boot
    loader installers and other utilities - Steve McIntyre
 
  * Cleanup __init annotations for arm64/efi code - Ard Biesheuvel
 
  * Mark the UIE as unsupported for rtc-efi - Ard Biesheuvel
 
  * Fix memory leak in error code path of runtime map code - Dan Carpenter
 
  * Improve robustness of get_memory_map() by removing assumptions on the
    size of efi_memory_desc_t (which could change in future spec
    versions) and querying the firmware instead of guessing about the
    memmap size - Ard Biesheuvel
 
  * Remove superfluous guid unparse calls - Ivan Khoronzhuk
 
  * Delete unnecessary chosen@0 DT node FDT code since was duplicated
    from code in drivers/of and is entirely unnecessary - Leif Lindholm
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJUv69oAAoJEC84WcCNIz1VEYgP/1b27WRfCXs4q/8FP+UheSDS
 nAFbGe9PjVPnxo5pA9VwPP6eNQ2zYiyNGEK1BlbQlFPZdSD1updIraA78CiF5iys
 iSYyG9xVIcTB23RZI8aJLnBXbosIUKPJZ3FORv1LPhI6Mz1rCpraEaaUlv67rUKr
 FLBG9cR7t9f/f+fJw6LOAAISGIG/4s0wQdA5/noaYkj5R5bICl2UTGtbwa0oNstb
 NUO93aKDgaG/VljpIEeG6XV96Ioz7cHjQsEaX8sTrvT0n7nPNIqSDjFJOqWKJOXl
 RsFrzyl8fFIbMuQatYv1f3efPvyH+iKOfHnHrvcjUNje0xhm7F0Bd86BkOw1a3JQ
 pNb0YUWecI0Z/8GSzN8X0JQ7cowa3wI15Z/Hfs03odTXiM6VqwFAhuz/s5DEUdKS
 U+rOPjU0ezt3G4oBB/VGgF9w5JWKfsMcsHgmLX9P+JYzKFrxggo1SXAtXUeRAqQp
 agKmUB+k6Y1baQO8efkoM7rKL2F0q1SR9QiK+16BHCCkevD23v7IFGrHm2r1xKil
 kvWlY4MkRVa4KGPxEFEDVty0HjXxImwYsxTaYVHTS7SMeoP41f6koHKB19NaB3No
 5fqn/rT1KcJuhQj/I+vAixIX4WMJkX/MQVbtKfqSaKlAiRg3eRY6ONYr0jOglfF6
 gaMuvmDd0HlV6UJvH/9L
 =iPpM
 -----END PGP SIGNATURE-----

Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/efi

Pull EFI updates from Matt Fleming:

" - Move efivarfs from the misc filesystem section to pseudo filesystem,
    since that's a more logical and accurate place - Leif Lindholm

  - Update efibootmgr URL in Kconfig help - Peter Jones

  - Improve accuracy of EFI guid function names - Borislav Petkov

  - Expose firmware platform size in sysfs for the benefit of EFI boot
    loader installers and other utilities - Steve McIntyre

  - Cleanup __init annotations for arm64/efi code - Ard Biesheuvel

  - Mark the UIE as unsupported for rtc-efi - Ard Biesheuvel

  - Fix memory leak in error code path of runtime map code - Dan Carpenter

  - Improve robustness of get_memory_map() by removing assumptions on the
    size of efi_memory_desc_t (which could change in future spec
    versions) and querying the firmware instead of guessing about the
    memmap size - Ard Biesheuvel

  - Remove superfluous guid unparse calls - Ivan Khoronzhuk

  - Delete unnecessary chosen@0 DT node FDT code since was duplicated
    from code in drivers/of and is entirely unnecessary - Leif Lindholm

   There's nothing super scary, mainly cleanups, and a merge from Ricardo who
   kindly picked up some patches from the linux-efi mailing list while I
   was out on annual leave in December.

   Perhaps the biggest risk is the get_memory_map() change from Ard, which
   changes the way that both the arm64 and x86 EFI boot stub build the
   early memory map. It would be good to have it bake in linux-next for a
   while.
"

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-01-29 19:16:40 +01:00
Ming Lei
e09aae7ede blk-mq: release mq's kobjects in blk_release_queue()
The kobject memory inside blk-mq hctx/ctx shouldn't have been freed
before the kobject is released because driver core can access it freely
before its release.

We can't do that in all ctx/hctx/mq_kobj's release handler because
it can be run before blk_cleanup_queue().

Given mq_kobj shouldn't have been introduced, this patch simply moves
mq's release into blk_release_queue().

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-29 08:30:51 -08:00
Ming Lei
74170118b2 Revert "blk-mq: fix hctx/ctx kobject use-after-free"
This reverts commit 76d697d107.

The commit 76d697d107 causes general protection fault
reported from Bart Van Assche:

	https://lkml.org/lkml/2015/1/28/334

Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-29 08:30:49 -08:00
Keith Busch
77a0868901 block: keep established cmd_flags when cloning into a blk-mq request
blk_mq_alloc_request() may establish REQ_MQ_INFLIGHT in addition to
incrementing the hctx->nr_active count.  Any cmd_flags that are
established in the newly allocated clone request must be preserved in
addition to the cmd_flags that are later copied over from the original
request as part of blk_rq_prep_clone().

Otherwise, if REQ_MQ_INFLIGHT isn't set in the clone request the
hctx->nr_active count won't get decremented via blk_mq_free_request().

The only consumer of blk_rq_prep_clone() is request-based DM, which uses
blk_rq_init() prior to calling blk_rq_prep_clone() for the non-blk-mq
case.  Given the cloned request's cmd_flags will be 0 it is safe to OR
them with the original request's cmd_flags for both the non-blk-mq and
blk-mq cases.

Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-28 09:44:15 -07:00
Keith Busch
7fb4898e0c block: add blk-mq support to blk_insert_cloned_request()
If the request passed to blk_insert_cloned_request() was allocated by
a blk-mq device it must be submitted using blk_mq_insert_request().

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-28 09:44:13 -07:00
Keith Busch
febf71588c block: require blk_rq_prep_clone() be given an initialized clone request
Prepare to allow blk_rq_prep_clone() to accept clone requests that were
allocated from blk-mq request queues.  As such the blk_rq_prep_clone()
caller must first initialize the clone request.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-28 09:44:11 -07:00
Shaohua Li
24391c0dc5 blk-mq: add tag allocation policy
This is the blk-mq part to support tag allocation policy. The default
allocation policy isn't changed (though it's not a strict FIFO). The new
policy is round-robin for libata. But it's a try-best implementation. If
multiple tasks are competing, the tags returned will be mixed (which is
unavoidable even with !mq, as requests from different tasks can be
mixed in queue)

Cc: Jens Axboe <axboe@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-23 14:18:00 -07:00
Shaohua Li
ee1b6f7aff block: support different tag allocation policy
The libata tag allocation is using a round-robin policy. Next patch will
make libata use block generic tag allocation, so let's add a policy to
tag allocation.

Currently two policies: FIFO (default) and round-robin.

Cc: Jens Axboe <axboe@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-23 14:15:46 -07:00
Boaz Harrosh
bb5c3cdda3 block: Remove annoying "unknown partition table" message
As Christoph put it:
  Can we just get rid of the warnings?  It's fairly annoying as devices
  without partitions are perfectly fine and very useful.

Me too I see this message every VM boot for ages on all my
devices. Would love to just remove it. For me a partition-table
is only needed for a booting BIOS, grub, and stuff.

CC: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Boaz Harrosh <boaz@plexistor.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-22 08:03:52 -07:00
Martin K. Petersen
d93ba7a5a9 block: Add discard flag to blkdev_issue_zeroout() function
blkdev_issue_discard() will zero a given block range. This is done by
way of explicit writing, thus provisioning or allocating the blocks on
disk.

There are use cases where the desired behavior is to zero the blocks but
unprovision them if possible. The blocks must deterministically contain
zeroes when they are subsequently read back.

This patch adds a flag to blkdev_issue_zeroout() that provides this
variant. If the discard flag is set and a block device guarantees
discard_zeroes_data we will use REQ_DISCARD to clear the block range. If
the device does not support discard_zeroes_data or if the discard
request fails we will fall back to first REQ_WRITE_SAME and then a
regular REQ_WRITE.

Also update the callers of blkdev_issue_zero() to reflect the new flag
and make sb_issue_zeroout() prefer the discard approach.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-21 10:41:46 -07:00
Jeff Moyer
c6ce194325 cfq-iosched: fix incorrect filing of rt async cfqq
Hi,

If you can manage to submit an async write as the first async I/O from
the context of a process with realtime scheduling priority, then a
cfq_queue is allocated, but filed into the wrong async_cfqq bucket.  It
ends up in the best effort array, but actually has realtime I/O
scheduling priority set in cfqq->ioprio.

The reason is that cfq_get_queue assumes the default scheduling class and
priority when there is no information present (i.e. when the async cfqq
is created):

static struct cfq_queue *
cfq_get_queue(struct cfq_data *cfqd, bool is_sync, struct cfq_io_cq *cic,
	      struct bio *bio, gfp_t gfp_mask)
{
	const int ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio);
	const int ioprio = IOPRIO_PRIO_DATA(cic->ioprio);

cic->ioprio starts out as 0, which is "invalid".  So, class of 0
(IOPRIO_CLASS_NONE) is passed to cfq_async_queue_prio like so:

		async_cfqq = cfq_async_queue_prio(cfqd, ioprio_class, ioprio);

static struct cfq_queue **
cfq_async_queue_prio(struct cfq_data *cfqd, int ioprio_class, int ioprio)
{
        switch (ioprio_class) {
        case IOPRIO_CLASS_RT:
                return &cfqd->async_cfqq[0][ioprio];
        case IOPRIO_CLASS_NONE:
                ioprio = IOPRIO_NORM;
                /* fall through */
        case IOPRIO_CLASS_BE:
                return &cfqd->async_cfqq[1][ioprio];
        case IOPRIO_CLASS_IDLE:
                return &cfqd->async_idle_cfqq;
        default:
                BUG();
        }
}

Here, instead of returning a class mapped from the process' scheduling
priority, we get back the bucket associated with IOPRIO_CLASS_BE.

Now, there is no queue allocated there yet, so we create it:

		cfqq = cfq_find_alloc_queue(cfqd, is_sync, cic, bio, gfp_mask);

That function ends up doing this:

			cfq_init_cfqq(cfqd, cfqq, current->pid, is_sync);
			cfq_init_prio_data(cfqq, cic);

cfq_init_cfqq marks the priority as having changed.  Then, cfq_init_prio
data does this:

	ioprio_class = IOPRIO_PRIO_CLASS(cic->ioprio);
	switch (ioprio_class) {
	default:
		printk(KERN_ERR "cfq: bad prio %x\n", ioprio_class);
	case IOPRIO_CLASS_NONE:
		/*
		 * no prio set, inherit CPU scheduling settings
		 */
		cfqq->ioprio = task_nice_ioprio(tsk);
		cfqq->ioprio_class = task_nice_ioclass(tsk);
		break;

So we basically have two code paths that treat IOPRIO_CLASS_NONE
differently, which results in an RT async cfqq filed into a best effort
bucket.

Attached is a patch which fixes the problem.  I'm not sure how to make
it cleaner.  Suggestions would be welcome.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Tested-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-21 10:38:30 -07:00
Christoph Hellwig
b4caecd480 fs: introduce f_op->mmap_capabilities for nommu mmap support
Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.

Introduce a new nommu-only file operation to provide this information to
the nommu mmap code instead.  Splitting this from the backing_dev_info
structure allows to remove lots of backing_dev_info instance that aren't
otherwise needed, and entirely gets rid of the concept of providing a
backing_dev_info for a character device.  It also removes the need for
the mtd_inodefs filesystem.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:02:58 -07:00
Ming Lei
76d697d107 blk-mq: fix hctx/ctx kobject use-after-free
The kobject memory shouldn't have been freed before the kobject
is released because driver core can access it freely before its
release.

This patch frees hctx in its release callback. For ctx, they
share one single per-cpu variable which is associated with
the request queue, so free ctx in q->mq_kobj's release handler.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
(fix ctx kobjects)
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 09:28:33 -07:00
Jens Axboe
0bf364984c blk-mq: fix false negative out-of-tags condition
The blk-mq tagging tries to maintain some locality between CPUs and
the tags issued. The tags are split into groups of words, and the
words may not be fully populated. When searching for a new free tag,
blk-mq may look at partial words, hence it passes in an offset/size
to find_next_zero_bit(). However, it does that wrong, the size must
always be the full length of the number of tags in that word,
otherwise we'll potentially miss some near the end.

Another issue is when __bt_get() goes from one word set to the next.
It bumps the index, but not the last_tag associated with the
previous index. Bump that to be in the range of the new word.

Finally, clean up __bt_get() and __bt_get_word() a bit and get
rid of the goto in there, and the unnecessary 'wrap' variable.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-14 08:49:55 -07:00
Keith Busch
eb130dbfc4 blk-mq: End unstarted requests on a dying queue
Requests that haven't been started prior to a queue dying can be ended
in error without waiting for them to start and time out.

Signed-off-by: Keith Busch <keith.busch@intel.com>

Added code comment to explain why this is done.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-08 08:59:53 -07:00
Keith Busch
5b3f25fc34 blk-mq: Allow requests to never expire
Some types of requests may be started that are not gauranteed to ever
complete. This adds a request flag that a driver can use so mark the
request as such.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-08 08:59:01 -07:00
Jens Axboe
1885b24d23 blk-mq: Add helper to abort requeued requests
Adds a helper function a driver can use to abort requeued requests in
case any are pending when h/w queues are being removed.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-08 08:55:53 -07:00
Keith Busch
c68ed59f53 blk-mq: Let drivers cancel requeue_work
Kicking requeued requests will start h/w queues in a work_queue, which
may alter the driver's requested state to temporarily stop them. This
patch exports a method to cancel the q->requeue_work so a driver can be
assured stopped h/w queues won't be started up before it is ready.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-08 08:55:40 -07:00
Keith Busch
973c01919b blk-mq: Export if requests were started
Drivers can iterate over all allocated request tags, but their callback
needs a way to know if the driver started the request in the first place.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-08 08:55:27 -07:00
Keith Busch
3fd5940cb2 blk-mq: Wake tasks entering queue on dying
When the queue is set to dying, wake up tasks that are waiting on frozen
queue so they realize it is dying and abandon their request.

Signed-off-by: Keith Busch <keith.busch@intel.com>

Modified by me to add a code comment on the need for the wakeup.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-08 08:53:56 -07:00
Borislav Petkov
26e022727f efi: Rename efi_guid_unparse to efi_guid_to_str
Call it what it does - "unparse" is plain-misleading.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
2015-01-07 19:07:44 -08:00
Jens Axboe
17ded32070 blk-mq: get rid of ->cmd_size in the hardware queue
We store it in the tag set, we don't need it in the hardware queue.
While removing cmd_size, place ->queue_num further down to avoid
a hole on 64-bit archs. It's not used in any fast paths, so we
can safely move it.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-07 10:44:04 -07:00
Jens Axboe
c761d96b07 blk-mq: export blk_mq_freeze_queue()
Commit b4c6a02877 exported the start and unfreeze, but we need
the regular blk_mq_freeze_queue() for the loop conversion.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-02 15:05:12 -07:00
Jens Axboe
aed3ea94bd block: wake up waiters when a queue is marked dying
If it's dying, we can't expect new request to complete and come
in an wake up other tasks waiting for requests. So after we
have marked it as dying, wake up everybody currently waiting
for a request. Once they wake, they will retry their allocation
and fail appropriately due to the state of the queue.

Tested-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-31 09:39:16 -07:00
Keith Busch
b4c6a02877 blk-mq: Export freeze/unfreeze functions
Let drivers prevent entering a queue that isn't available.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-20 10:34:15 -07:00
Keith Busch
c76541a932 blk-mq: Exit queue on alloc failure
Fixes usage counter when a request could not be allocated.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-20 10:33:53 -07:00