Commit Graph

648309 Commits

Author SHA1 Message Date
Keith Busch
7bf7d77862 nvme/pci: Don't mark IOD as aborted if abort wasn't sent
This patch sets the aborted flag only if an abort was sent, reducing
excessive kernel message spamming for completed IO that wasn't actually
aborted.

Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:34:47 -07:00
Javier González
9a69b0ed62 lightnvm: allow targets to use sysfs
In order to register through the sysfs interface, a driver needs to know
its kobject. On a disk structure, this happens when the partition
information is added (device_add_disk), which for lightnvm takes place
after the target has been initialized. This means that on target
initialization, the kboject has not been created yet.

This patch adds a target function to let targets initialize their own
kboject as a child of the disk kobject.

Signed-off-by: Javier González <javier@cnexlabs.com>
Added exit typedef and passed gendisk instead of void pointer for exit.
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Javier González
deccf5a52e lightnvm: free properly on target creation error
Fix a memory leak when target creation fails. More specifically, free
the entire device structure given to the target (tgt_dev).

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Javier González
38ea2f7656 lightnvm: Add CRC read error
Let the host differentiate between a read error and a CRC check error on
the device side.

Signed-off-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Matias Bjørling
06894efea7 lightnvm: use end_io callback instead of instance
When the lightnvm core had the "gennvm" layer between the device and the
target, there was a need for the core to be able to figure out which
target it should send an end_io callback to. Leading to a "double"
end_io, first for the media manager instance, and then for the target
instance. Now that core and gennvm is merged, there is no longer a need
for this, and a single end_io callback will do.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Matias Bjørling
84d4add793 lightnvm: add ioctls for vector I/Os
Enable user-space to issue vector I/O commands through ioctls. To issue
a vector I/O, the ppa list with addresses is also required and must be
mapped for the controller to access.

For each ioctl, the result and status bits are returned as well, such
that user-space can retrieve the open-channel SSD completion bits.

The implementation covers the traditional use-cases of bad block
management, and vectored read/write/erase.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Metadata implementation, test, and fixes.
Signed-off-by: Simon A.F. Lund <slund@cnexlabs.com>
Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Matias Bjørling
19bd6fe73c lightnvm: reduce number of nvm_id groups to one
The number of configuration groups has been limited to one in current
code, even if there is support for up to four. With the introduction
of the open-channel SSD 1.3 specification, only a single
group is exposed onwards. Reflect this in the nvm_id structure.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Matias Bjørling
dab8ee9e8a lightnvm: cleanup nvm transformation functions
Going from target specific ppa addresses to device was accomplished by
first converting target to generic ppa addresses and generic to device
addresses. The conversion was either open-coded or used the built-in
nvm_trans_* and nvm_map_* functions for conversion. Simplify the
interface and cleanup the calls to provide clean functions that now
either take a list of ppas or a nvm_rq, and is exposed through:

 void nvm_ppa_* - target to/from device with a list of PPAs,
 void nvm_rq_* - target to/from device with a nvm_rq.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Matias Bjørling
61a561d8d7 lightnvm: make nvm_map_* return void
The only check there was done was a debugging check. Remove it and
replace the return value with void to reduce error checking.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Matias Bjørling
8f4fe008fb lightnvm: remove nvm_get_bb_tbl and nvm_set_bb_tbl
Since the merge of gennvm and core, there is no longer a need for the
device specific bad block functions.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Matias Bjørling
583b7058b2 lightnvm: remove nvm_submit_ppa* functions
The nvm_submit_ppa* functions are no longer needed after gennvm and core
have been merged.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Matias Bjørling
10995c3dc9 lightnvm: collapse nvm_erase_ppa and nvm_erase_blk
After gennvm and core have been merged, there are no more callers to
nvm_erase_ppa. Therefore collapse the device specific and target
specific erase functions.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Matias Bjørling
ade69e2432 lightnvm: merge gennvm with core
For the first iteration of Open-Channel SSDs, it was anticipated that
there could be various media managers on top of an open-channel SSD,
such to allow vendors to plug in their own host-side FTLs, without the
media manager in between.

Now that an Open-Channel SSD is exposed as a traditional block device,
there is no longer a need for this. Therefore lets merge the gennvm code
with core and simplify the stack.

Signed-off-by: Matias Bjørling <matias@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 08:32:13 -07:00
Omar Sandoval
400f73b23f blk-mq: fix debugfs compilation issues
This fixes a couple of problems:

1. In the !CONFIG_DEBUG_FS case, the stub definitions were bogus.
2. In the !CONFIG_BLOCK case, blk-mq-debugfs.c shouldn't be compiled at
   all.

Fix the stub definitions and add a CONFIG_BLK_DEBUG_FS Kconfig option.

Fixes: 07e4fead45 ("blk-mq: create debugfs directory tree")
Signed-off-by: Omar Sandoval <osandov@fb.com>

Augment Kconfig description.

Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 15:03:01 -07:00
Jens Axboe
f3a8ab7d55 block: cleanup remaining manual checks for PREFLUSH|FUA
Use op_is_flush() where applicable.

Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 09:08:23 -07:00
Jens Axboe
bd6737f1ae blk-mq-sched: add flush insertion into blk_mq_sched_insert_request()
Instead of letting the caller check this and handle the details
of inserting a flush request, put the logic in the scheduler
insertion function. This fixes direct flush insertion outside
of the usual make_request_fn calls, like from dm via
blk_insert_cloned_request().

Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 09:03:14 -07:00
Christoph Hellwig
f73f44eb00 block: add a op_is_flush helper
This centralizes the checks for bios that needs to be go into the flush
state machine.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 09:01:45 -07:00
Jens Axboe
c13660a08c blk-mq-sched: change ->dispatch_requests() to ->dispatch_request()
When we invoke dispatch_requests(), the scheduler empties everything
into the passed in list. This isn't always a good thing, since it
means that we remove items that we could have potentially merged
with.

Change the function to dispatch single requests at the time. If
we do that, we can backoff exactly at the point where the device
can't consume more IO, and leave the rest with the scheduler for
better merging and future dispatch decision making.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Tested-by: Hannes Reinecke <hare@suse.com>
2017-01-27 08:20:35 -07:00
Jens Axboe
50e1dab86a blk-mq-sched: fix starvation for multiple hardware queues and shared tags
If we have both multiple hardware queues and shared tag map between
devices, we need to ensure that we propagate the hardware queue
restart bit higher up. This is because we can get into a situation
where we don't have any IO pending on a hardware queue, yet we fail
getting a tag to start new IO. If that happens, it's not enough to
mark the hardware queue as needing a restart, we need to bubble
that up to the higher level queue as well.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Tested-by: Hannes Reinecke <hare@suse.com>
2017-01-27 08:20:34 -07:00
Jens Axboe
99cf1dc580 blk-mq: release driver tag on a requeue event
We don't want to hold on to this resource when we have a scheduler
attached.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Tested-by: Hannes Reinecke <hare@suse.com>
2017-01-27 08:20:32 -07:00
Jens Axboe
3c782d67c1 blk-mq: fix potential race in queue restart and driver tag allocation
Once we mark the queue as needing a restart, re-check if we can
get a driver tag. This fixes a theoretical issue where the needed
IO completes _after_ blk_mq_get_driver_tag() fails, but before we
manage to set the restart bit.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Tested-by: Hannes Reinecke <hare@suse.com>
2017-01-27 08:20:31 -07:00
Jens Axboe
0abad77412 blk-mq: improve scheduler queue sync/async running
We'll use the same criteria for whether we need to run the queue sync
or async when we have a scheduler, as we do without one.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Tested-by: Hannes Reinecke <hare@suse.com>
2017-01-27 08:20:30 -07:00
Omar Sandoval
4a46f05ebf blk-mq: move hctx and ctx counters from sysfs to debugfs
These counters aren't as out-of-place in sysfs as the other stuff, but
debugfs is a slightly better home for them.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 08:17:44 -07:00
Omar Sandoval
be21547318 blk-mq: move hctx io_poll, stats, and dispatched from sysfs to debugfs
These statistics _might_ be useful to userspace, but it's better not to
commit to an ABI for these yet. Also, the dispatched file in sysfs
couldn't be cleared, so make it clearable like the others in debugfs.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 08:17:44 -07:00
Omar Sandoval
d7e3621ad1 blk-mq: add tags and sched_tags bitmaps to debugfs
These can be used to debug issues like tag leaks and stuck requests.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 08:17:44 -07:00
Omar Sandoval
d96b37c0af blk-mq: move tags and sched_tags info from sysfs to debugfs
These are very tied to the blk-mq tag implementation, so exposing them
to sysfs isn't a great idea. Move the debugging information to debugfs
and add basic entries for the number of tags and the number of reserved
tags to sysfs.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 08:17:44 -07:00
Omar Sandoval
0bfa5288a7 blk-mq: export software queue pending map to debugfs
This is useful for debugging problems where we've gotten stuck with
requests in the software queues.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 08:17:44 -07:00
Omar Sandoval
24af1ccfe1 sbitmap: add helpers for dumping to a seq_file
This is useful debugging information that will be used in the blk-mq
debugfs directory.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>

Changed 'weight' to 'busy'.

Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 08:17:44 -07:00
Omar Sandoval
7b3938524c blk-mq: add extra request information to debugfs
The request pointers by themselves aren't super useful.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 08:17:44 -07:00
Omar Sandoval
950cd7e9ff blk-mq: move hctx->dispatch and ctx->rq_list from sysfs to debugfs
These lists are only useful for debugging; they definitely don't belong
in sysfs. Putting them in debugfs also removes the limitation of a
single page of output.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 08:17:44 -07:00
Omar Sandoval
9abb2ad21e blk-mq: add hctx->{state,flags} to debugfs
hctx->state could come in handy for bugs where the hardware queue gets
stuck in the stopped state, and hctx->flags is just useful to know.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 08:17:44 -07:00
Omar Sandoval
07e4fead45 blk-mq: create debugfs directory tree
In preparation for putting blk-mq debugging information in debugfs,
create a directory tree mirroring the one in sysfs:

    # tree -d /sys/kernel/debug/block
    /sys/kernel/debug/block
    |-- nvme0n1
    |   `-- mq
    |       |-- 0
    |       |   `-- cpu0
    |       |-- 1
    |       |   `-- cpu1
    |       |-- 2
    |       |   `-- cpu2
    |       `-- 3
    |           `-- cpu3
    `-- vda
        `-- mq
            `-- 0
                |-- cpu0
                |-- cpu1
                |-- cpu2
                `-- cpu3

Also add the scaffolding for the actual files that will go in here,
either under the hardware queue or software queue directories.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 08:17:44 -07:00
Jens Axboe
b48fda0976 blk-mq-sched: check for successful allocation before assigning tag
We don't trigger this from the normal IO path, since we always use
blocking allocations from there. But Bart saw it testing multipath
dm, since that is a heavy user of atomic request allocations in
the map and clone path.

Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-26 14:52:20 -07:00
Jens Axboe
5a797e00dc blk-mq: don't lose flags passed in to blk_mq_alloc_request()
If we come in from blk_mq_alloc_requst() with NOWAIT set in flags,
we must ensure that we don't later overwrite that in
blk_mq_sched_get_request(). Initialize alloc_data->flags before
passing it in.

Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-26 12:22:11 -07:00
Jens Axboe
200e86b337 blk-mq: only apply active queue tag throttling for driver tags
If we have a scheduler attached, we have two sets of tags. We don't
want to apply our active queue throttling for the scheduler side
of tags, that only applies to driver tags since that's the resource
we need to dispatch an IO.

Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-25 08:11:38 -07:00
Markus Elfring
1cf4175303 cfq-iosched: Adjust one function call together with a variable assignment
The script "checkpatch.pl" pointed information out like the following.

ERROR: do not use assignment in if condition

Thus fix the affected source code place.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-23 08:32:18 -07:00
Markus Elfring
d609af3a13 blk-throttle: Adjust two function calls together with a variable assignment
The script "checkpatch.pl" pointed information out like the following.

ERROR: do not use assignment in if condition

Thus fix the affected source code places.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-23 08:32:15 -07:00
Alexander Potapenko
4d608baac5 block: Initialize cfqq->ioprio_class in cfq_get_queue()
KMSAN (KernelMemorySanitizer, a new error detection tool) reports use of
uninitialized memory in cfq_init_cfqq():

==================================================================
BUG: KMSAN: use of unitialized memory
...
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff8202ac97>] dump_stack+0x157/0x1d0 lib/dump_stack.c:51
 [<ffffffff813e9b65>] kmsan_report+0x205/0x360 ??:?
 [<ffffffff813eabbb>] __msan_warning+0x5b/0xb0 ??:?
 [<     inline     >] cfq_init_cfqq block/cfq-iosched.c:3754
 [<ffffffff8201e110>] cfq_get_queue+0xc80/0x14d0 block/cfq-iosched.c:3857
...
origin:
 [<ffffffff8103ab37>] save_stack_trace+0x27/0x50 arch/x86/kernel/stacktrace.c:67
 [<ffffffff813e836b>] kmsan_internal_poison_shadow+0xab/0x150 ??:?
 [<ffffffff813e88ab>] kmsan_poison_slab+0xbb/0x120 ??:?
 [<     inline     >] allocate_slab mm/slub.c:1627
 [<ffffffff813e533f>] new_slab+0x3af/0x4b0 mm/slub.c:1641
 [<     inline     >] new_slab_objects mm/slub.c:2407
 [<ffffffff813e0ef3>] ___slab_alloc+0x323/0x4a0 mm/slub.c:2564
 [<     inline     >] __slab_alloc mm/slub.c:2606
 [<     inline     >] slab_alloc_node mm/slub.c:2669
 [<ffffffff813dfb42>] kmem_cache_alloc_node+0x1d2/0x1f0 mm/slub.c:2746
 [<ffffffff8201d90d>] cfq_get_queue+0x47d/0x14d0 block/cfq-iosched.c:3850
...
==================================================================
(the line numbers are relative to 4.8-rc6, but the bug persists
upstream)

The uninitialized struct cfq_queue is created by kmem_cache_alloc_node()
and then passed to cfq_init_cfqq(), which accesses cfqq->ioprio_class
before it's initialized.

Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-23 08:30:28 -07:00
Jens Axboe
70f36b6001 blk-mq: allow resize of scheduler requests
Add support for growing the tags associated with a hardware queue, for
the scheduler tags. Currently we only support resizing within the
limits of the original depth, change that so we can grow it as well by
allocating and replacing the existing scheduler tag set.

This is similar to how we could increase the software queue depth with
the legacy IO stack and schedulers.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-20 09:05:53 -07:00
Jens Axboe
7e79dadce2 blk-mq: stop hardware queue in blk_mq_delay_queue()
The run handler we register for the delayed work requires that the
queue be stopped, yet we leave that up to the caller. Let's move
it into blk_mq_delay_queue() itself, so that the API is sane.

This fixes a stall with SCSI, where it calls blk_mq_delay_queue()
without having stopped the queue. Hence the queue is never run.

Reported-by: Hannes Reinecke <hare@suse.com>
Fixes: 70f4db639c ("blk-mq: add blk_mq_delay_queue")
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-19 08:01:55 -07:00
Jens Axboe
8cecb07d70 blk-mq-tag: remove redundant check for 'data->hctx' being non-NULL
We used to pass in NULL for hctx for reserved tags, but we don't
do that anymore. Hence the check for whether hctx is NULL or not
is now redundant, kill it.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: a642a158aec6 ("blk-mq-tag: cleanup the normal/reserved tag allocation")
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-19 07:43:05 -07:00
Jens Axboe
610d886c0c elevator: fix unnecessary put of elevator in failure case
We already checked that e is NULL, so no point in calling
elevator_put() to free it.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: dc877dbd088f ("blk-mq-sched: add framework for MQ capable IO schedulers")
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-19 07:43:05 -07:00
Jens Axboe
38dbb7dd4d blk-cgroup: don't quiesce the queue on policy activate/deactivate
There's no potential harm in quiescing the queue, but it also doesn't
buy us anything. And we can't run the queue async for policy
deactivate, since we could be in the path of tearing the queue down.
If we schedule an async run of the queue at that time, we're racing
with queue teardown AFTER having we've already torn most of it down.

Reported-by: Omar Sandoval <osandov@fb.com>
Fixes: 4d199c6f1c ("blk-cgroup: ensure that we clear the stop bit on quiesced queues")
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-18 15:37:27 -07:00
Omar Sandoval
6c0ca7ae29 sbitmap: fix wakeup hang after sbq resize
When we resize a struct sbitmap_queue, we update the wakeup batch size,
but we don't update the wait count in the struct sbq_wait_states. If we
resized down from a size which could use a bigger batch size, these
counts could be too large and cause us to miss necessary wakeups. To fix
this, update the wait counts when we resize (ensuring some careful
memory ordering so that it's safe w.r.t. concurrent clears).

This also fixes a theoretical issue where two threads could end up
bumping the wait count up by the batch size, which could also
potentially lead to hangs.

Reported-by: Martin Raiber <martin@urbackup.org>
Fixes: e3a2b3f931 ("blk-mq: allow changing of queue depth through sysfs")
Fixes: 2971c35f35 ("blk-mq: bitmap tag: fix race on blk_mq_bitmap_tags::wake_cnt")
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-18 13:41:55 -07:00
Omar Sandoval
f66227de59 sbitmap: use smp_mb__after_atomic() in sbq_wake_up()
We always do an atomic clear_bit() right before we call sbq_wake_up(),
so we can use smp_mb__after_atomic(). While we're here, comment the
memory barriers in here a little more.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-18 13:41:49 -07:00
Jens Axboe
4d199c6f1c blk-cgroup: ensure that we clear the stop bit on quiesced queues
If we call blk_mq_quiesce_queue() on a queue, we must remember to
pair that with something that clears the stopped by on the
queues later on.

Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-18 07:43:26 -07:00
Jens Axboe
d348499138 blk-mq-sched: allow setting of default IO scheduler
Add Kconfig entries to manage what devices get assigned an MQ
scheduler, and add a blk-mq flag for drivers to opt out of scheduling.
The latter is useful for admin type queues that still allocate a blk-mq
queue and tag set, but aren't use for normal IO.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:04:31 -07:00
Jens Axboe
945ffb60c1 mq-deadline: add blk-mq adaptation of the deadline IO scheduler
This is basically identical to deadline-iosched, except it registers
as a MQ capable scheduler. This is still a single queue design.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:04:25 -07:00
Jens Axboe
bd166ef183 blk-mq-sched: add framework for MQ capable IO schedulers
This adds a set of hooks that intercepts the blk-mq path of
allocating/inserting/issuing/completing requests, allowing
us to develop a scheduler within that framework.

We reuse the existing elevator scheduler API on the registration
side, but augment that with the scheduler flagging support for
the blk-mq interfce, and with a separate set of ops hooks for MQ
devices.

We split driver and scheduler tags, so we can run the scheduling
independently of device queue depth.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:04:20 -07:00
Jens Axboe
2af8cbe305 blk-mq: split tag ->rqs[] into two
This is in preparation for having two sets of tags available. For
that we need a static index, and a dynamically assignable one.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:04:15 -07:00