Commit Graph

3136 Commits

Author SHA1 Message Date
Bart Van Assche
f3bcb0e606 blk-mq-debugfs: Add missing __acquires() / __releases() annotations
This patch avoids that sparse complains about lock imbalances.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-01 12:20:55 -07:00
Jens Axboe
12d70958a2 blk-mq: don't fail allocating driver tag for stopped hw queue
We rely on blk_mq_get_driver_tag() not failing if 'wait' is true,
but it currently fails in that case if the queue happens to be
stopped at the time of the call.

We don't need to check for stopped here, it's just assigning
the tag. If the queue is stopped, we'll handle it when
attempting to run the queue.

This fixes a stall/crash on flush intensive workloads, where
we proceed to process a flush that doesn't have a valid tag
assigned.

Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 23:32:50 -07:00
Christoph Hellwig
aebf526b53 block: fold cmd_type into the REQ_OP_ space
Instead of keeping two levels of indirection for requests types, fold it
all into the operations.  The little caveat here is that previously
cmd_type only applied to struct request, while the request and bio op
fields were set to plain REQ_OP_READ/WRITE even for passthrough
operations.

Instead this patch adds new REQ_OP_* for SCSI passthrough and driver
private requests, althought it has to add two for each so that we
can communicate the data in/out nature of the request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 14:00:44 -07:00
Christoph Hellwig
57292b58dd block: introduce blk_rq_is_passthrough
This can be used to check for fs vs non-fs requests and basically
removes all knowledge of BLOCK_PC specific from the block layer,
as well as preparing for removing the cmd_type field in struct request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 14:00:34 -07:00
Christoph Hellwig
72148aecf4 block: make scsi_request and scsi ioctl support optional
We only need this code to support scsi, ide, cciss and virtio.  And at
least for virtio it's a deprecated feature to start with.

This should shrink the kernel size for embedded device that only use,
say eMMC a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 10:53:05 -07:00
Christoph Hellwig
fb045ca25c block: don't assign cmd_flags in __blk_rq_prep_clone
These days we have the proper flags set since request allocation time.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 15:08:35 -07:00
Christoph Hellwig
82ed4db499 block: split scsi_request out of struct request
And require all drivers that want to support BLOCK_PC to allocate it
as the first thing of their private data.  To support this the legacy
IDE and BSG code is switched to set cmd_size on their queues to let
the block layer allocate the additional space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 15:08:35 -07:00
Christoph Hellwig
8ae94eb65b block/bsg: move queue creation into bsg_setup_queue
Simply the boilerplate code needed for bsg nodes a bit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 15:08:35 -07:00
Christoph Hellwig
6d247d7f71 block: allow specifying size for extra command data
This mirrors the blk-mq capabilities to allocate extra drivers-specific
data behind struct request by setting a cmd_size field, as well as having
a constructor / destructor for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 15:08:35 -07:00
Christoph Hellwig
5ea708d15a block: simplify blk_init_allocated_queue
Return an errno value instead of the passed in queue so that the callers
don't have to keep track of two queues, and move the assignment of the
request_fn and lock to the caller as passing them as argument doesn't
simplify anything.  While we're at it also remove two pointless NULL
assignments, given that the request structure is zeroed on allocation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 15:08:35 -07:00
Christoph Hellwig
e6f7f93d58 block: fix elevator init check
We can't initalize the elevator fields for flushes as flush share space
in struct request with the elevator data.  But currently we can't
communicate that a request is a flush through blk_get_request as we
can only pass READ or WRITE, and the low-level code looks at the
possible NULL bio to check for a flush.

Fix this by allowing to pass any block op and flags, and by checking for
the flush flags in __get_request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 15:08:35 -07:00
Jens Axboe
f924ba70c1 Merge branch 'for-4.11/block' into for-4.11/rq-refactor
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 15:08:31 -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
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
Keith Busch
88a7503376 blk-mq: Remove unused variable
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>
2017-01-18 15:14:15 -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
Jens Axboe
fd2d332677 blk-mq: add support for carrying internal tag information in blk_qc_t
No functional change in this patch, just in preparation for having
two types of tags available to the block layer for a single request.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:04:09 -07:00
Jens Axboe
cc71a6f438 blk-mq: abstract out helpers for allocating/freeing tag maps
Prep patch for adding an extra tag map for scheduler requests.

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 10:04:04 -07:00
Jens Axboe
4941115bef blk-mq-tag: cleanup the normal/reserved tag allocation
This is in preparation for having another tag set available. Cleanup
the parameters, and allow passing in of tags for blk_mq_put_tag().

Signed-off-by: Jens Axboe <axboe@fb.com>
[hch: even more cleanups]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:03:59 -07:00
Jens Axboe
2c3ad66790 blk-mq: export some helpers we need to the scheduling framework
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:03:53 -07:00
Jens Axboe
16a3c2a70c blk-mq: un-export blk_mq_free_hctx_request()
It's only used in blk-mq, kill it from the main exported header
and kill the symbol export as well.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:03:48 -07:00
Jens Axboe
c23ecb4260 block: move rq_ioc() to blk.h
We want to use it outside of blk-core.c.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:03:42 -07:00
Jens Axboe
c51ca6cf54 block: move existing elevator ops to union
Prep patch for adding MQ ops as well, since doing anon unions with
named initializers doesn't work on older compilers.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
2017-01-17 10:03:33 -07:00
Alden Tondettar
c5082b70ad partitions/efi: Fix integer overflow in GPT size calculation
If a GUID Partition Table claims to have more than 2**25 entries, the
calculation of the partition table size in alloc_read_gpt_entries() will
overflow a 32-bit integer and not enough space will be allocated for the
table.

Nothing seems to get written out of bounds, but later efi_partition() will
read up to 32768 bytes from a 128 byte buffer, possibly OOPSing or exposing
information to /proc/partitions and uevents.

The problem exists on both 64-bit and 32-bit platforms.

Fix the overflow and also print a meaningful debug message if the table
size is too large.

Signed-off-by: Alden Tondettar <alden.tondettar@gmail.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-17 09:02:31 -07:00
Christoph Hellwig
bef13315e9 block: don't try to discard from __blkdev_issue_zeroout
Discard can return -EIO asynchronously if the alignment for the request
isn't suitable for the driver, which makes a proper fallback to other
methods in __blkdev_issue_zeroout impossible.  Thus only issue a sync
discard from blkdev_issue_zeroout an don't try discard at all from
__blkdev_issue_zeroout as a non-invasive workaround.

One more reason why abusing discard for zeroing must die..

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Eryu Guan <eguan@redhat.com>
Fixes: e73c23ff ("block: add async variant of blkdev_issue_zeroout")
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-13 15:18:16 -07:00
Damien Le Moal
f99e86485c block: Rename blk_queue_zone_size and bdev_zone_size
All block device data fields and functions returning a number of 512B
sectors are by convention named xxx_sectors while names in the form
xxx_size are generally used for a number of bytes. The blk_queue_zone_size
and bdev_zone_size functions were not following this convention so rename
them.

No functional change is introduced by this patch.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>

Collapsed the two patches, they were nonsensically split and broke
bisection.

Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-12 07:58:32 -07:00
Jens Axboe
f8a5b12247 blk-mq: make mq_ops a const pointer
We never change it, make that clear.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
2017-01-11 20:47:44 -07:00
Linus Torvalds
62f8c40592 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
 "A set of fixes for the current series, one fixing a regression with
  block size < page cache size in the alias series from Jan. Outside of
  that, two small cleanups for wbt from Bart, a nvme pull request from
  Christoph, and a few small fixes of documentation updates"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: fix up io_poll documentation
  block: Avoid that sparse complains about context imbalance in __wbt_wait()
  block: Make wbt_wait() definition consistent with declaration
  clean_bdev_aliases: Prevent cleaning blocks that are not in block range
  genhd: remove dead and duplicated scsi code
  block: add back plugging in __blkdev_direct_IO
  nvmet/fcloop: remove some logically dead code performing redundant ret checks
  nvmet: fix KATO offset in Set Features
  nvme/fc: simplify error handling of nvme_fc_create_hw_io_queues
  nvme/fc: correct some printk information
  nvme/scsi: Remove START STOP emulation
  nvme/pci: Delete misleading queue-wrap comment
  nvme/pci: Fix whitespace problem
  nvme: simplify stripe quirk
  nvme: update maintainers information
2017-01-04 09:03:37 -08:00
Bart Van Assche
9eca53508a block: Avoid that sparse complains about context imbalance in __wbt_wait()
This patch does not change any functionality.

Fixes: e34cbd3074 ("blk-wbt: add general throttling mechanism")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-02 09:48:47 -07:00
Bart Van Assche
f2e0a0b292 block: Make wbt_wait() definition consistent with declaration
Fixes: e34cbd3074 ("blk-wbt: add general throttling mechanism")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-02 09:46:15 -07:00
Thomas Gleixner
8b0e195314 ktime: Cleanup ktime_set() usage
ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
2016-12-25 17:21:22 +01:00
Linus Torvalds
7c0f6ba682 Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24 11:46:01 -08:00
Linus Torvalds
a307d0a007 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull final vfs updates from Al Viro:
 "Assorted cleanups and fixes all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  sg_write()/bsg_write() is not fit to be called under KERNEL_DS
  ufs: fix function declaration for ufs_truncate_blocks
  fs: exec: apply CLOEXEC before changing dumpable task flags
  seq_file: reset iterator to first record for zero offset
  vfs: fix isize/pos/len checks for reflink & dedupe
  [iov_iter] fix iterate_all_kinds() on empty iterators
  move aio compat to fs/aio.c
  reorganize do_make_slave()
  clone_private_mount() doesn't need to touch namespace_sem
  remove a bogus claim about namespace_sem being held by callers of mnt_alloc_id()
2016-12-23 10:52:43 -08:00
Al Viro
128394eff3 sg_write()/bsg_write() is not fit to be called under KERNEL_DS
Both damn things interpret userland pointers embedded into the payload;
worse, they are actually traversing those.  Leaving aside the bad
API design, this is very much _not_ safe to call with KERNEL_DS.
Bail out early if that happens.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-12-22 23:03:42 -05:00
Stefan Haberland
633395b67b block: check partition alignment
Partitions that are not aligned to the blocksize of a device may cause
invalid I/O requests because the blocklayer cares only about alignment
within the partition when building requests on partitions.

device
|--------4096--------|--------4096--------|--------4096--------|
partition offset 512byte
|-512-|--------4096--------|--------4096--------|--------4096--------|

When reading/writing one 4k block of the partition this maps to
reading/writing with an offset of 512 byte of the device leading to
unaligned requests for the device which in turn may cause unexpected
behavior of the device driver.

For DASD devices we have to translate the block number into a cylinder,
head, record format. The unaligned requests lead to wrong calculation
and therefore to misdirected I/O. In a "good" case this leads to I/O
errors because the underlying hardware detects the wrong addressing.
In a worst case scenario this might destroy data on the device.

To prevent partitions that are not aligned to the physical blocksize
of a device check for the alignment in the blkpg_ioctl.

Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-19 09:20:59 -07:00
Mauricio Faria de Oliveira
25cdb64510 block: allow WRITE_SAME commands with the SG_IO ioctl
The WRITE_SAME commands are not present in the blk_default_cmd_filter
write_ok list, and thus are failed with -EPERM when the SG_IO ioctl()
is executed without CAP_SYS_RAWIO capability (e.g., unprivileged users).
[ sg_io() -> blk_fill_sghdr_rq() > blk_verify_command() -> -EPERM ]

The problem can be reproduced with the sg_write_same command

  # sg_write_same --num 1 --xferlen 512 /dev/sda
  #

  # capsh --drop=cap_sys_rawio -- -c \
    'sg_write_same --num 1 --xferlen 512 /dev/sda'
    Write same: pass through os error: Operation not permitted
  #

For comparison, the WRITE_VERIFY command does not observe this problem,
since it is in that list:

  # capsh --drop=cap_sys_rawio -- -c \
    'sg_write_verify --num 1 --ilen 512 --lba 0 /dev/sda'
  #

So, this patch adds the WRITE_SAME commands to the list, in order
for the SG_IO ioctl to finish successfully:

  # capsh --drop=cap_sys_rawio -- -c \
    'sg_write_same --num 1 --xferlen 512 /dev/sda'
  #

That case happens to be exercised by QEMU KVM guests with 'scsi-block' devices
(qemu "-device scsi-block" [1], libvirt "<disk type='block' device='lun'>" [2]),
which employs the SG_IO ioctl() and runs as an unprivileged user (libvirt-qemu).

In that scenario, when a filesystem (e.g., ext4) performs its zero-out calls,
which are translated to write-same calls in the guest kernel, and then into
SG_IO ioctls to the host kernel, SCSI I/O errors may be observed in the guest:

  [...] sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
  [...] sd 0:0:0:0: [sda] tag#0 Sense Key : Aborted Command [current]
  [...] sd 0:0:0:0: [sda] tag#0 Add. Sense: I/O process terminated
  [...] sd 0:0:0:0: [sda] tag#0 CDB: Write Same(10) 41 00 01 04 e0 78 00 00 08 00
  [...] blk_update_request: I/O error, dev sda, sector 17096824

Links:
[1] http://git.qemu.org/?p=qemu.git;a=commit;h=336a6915bc7089fb20fea4ba99972ad9a97c5f52
[2] https://libvirt.org/formatdomain.html#elementsDisks (see 'disk' -> 'device')

Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Signed-off-by: Brahadambal Srinivasan <latha@linux.vnet.ibm.com>
Reported-by: Manjunatha H R <manjuhr1@in.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-19 08:34:17 -07:00
Linus Torvalds
cf1b3341af Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block IO fixes from Jens Axboe:
 "A few fixes that I collected as post-merge.

  I was going to wait a bit with sending this out, but the O_DIRECT fix
  should really go in sooner rather than later"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq: Fix failed allocation path when mapping queues
  blk-mq: Avoid memory reclaim when remapping queues
  block_dev: don't update file access position for sync direct IO
  nvme/pci: Log PCI_STATUS when the controller dies
  block_dev: don't test bdev->bd_contains when it is not stable
2016-12-14 17:21:53 -08:00
Gabriel Krisman Bertazi
d1b1cea1e5 blk-mq: Fix failed allocation path when mapping queues
In blk_mq_map_swqueue, there is a memory optimization that frees the
tags of a queue that has gone unmapped.  Later, if that hctx is remapped
after another topology change, the tags need to be reallocated.

If this allocation fails, a simple WARN_ON triggers, but the block layer
ends up with an active hctx without any corresponding set of tags.
Then, any income IO to that hctx can trigger an Oops.

I can reproduce it consistently by running IO, flipping CPUs on and off
and eventually injecting a memory allocation failure in that path.

In the fix below, if the system experiences a failed allocation of any
hctx's tags, we remap all the ctxs of that queue to the hctx_0, which
should always keep it's tags.  There is a minor performance hit, since
our mapping just got worse after the error path, but this is
the simplest solution to handle this error path.  The performance hit
will disappear after another successful remap.

I considered dropping the memory optimization all together, but it
seemed a bad trade-off to handle this very specific error case.

This should apply cleanly on top of Jens' for-next branch.

The Oops is the one below:

SP (3fff935ce4d0) is in userspace
1:mon> e
cpu 0x1: Vector: 300 (Data Access) at [c000000fe99eb110]
    pc: c0000000005e868c: __sbitmap_queue_get+0x2c/0x180
    lr: c000000000575328: __bt_get+0x48/0xd0
    sp: c000000fe99eb390
   msr: 900000010280b033
   dar: 28
 dsisr: 40000000
  current = 0xc000000fe9966800
  paca    = 0xc000000007e80300   softe: 0        irq_happened: 0x01
    pid   = 11035, comm = aio-stress
Linux version 4.8.0-rc6+ (root@bean) (gcc version 5.4.0 20160609
(Ubuntu/IBM 5.4.0-6ubuntu1~16.04.2) ) #3 SMP Mon Oct 10 20:16:53 CDT 2016
1:mon> s
[c000000fe99eb3d0] c000000000575328 __bt_get+0x48/0xd0
[c000000fe99eb400] c000000000575838 bt_get.isra.1+0x78/0x2d0
[c000000fe99eb480] c000000000575cb4 blk_mq_get_tag+0x44/0x100
[c000000fe99eb4b0] c00000000056f6f4 __blk_mq_alloc_request+0x44/0x220
[c000000fe99eb500] c000000000570050 blk_mq_map_request+0x100/0x1f0
[c000000fe99eb580] c000000000574650 blk_mq_make_request+0xf0/0x540
[c000000fe99eb640] c000000000561c44 generic_make_request+0x144/0x230
[c000000fe99eb690] c000000000561e00 submit_bio+0xd0/0x200
[c000000fe99eb740] c0000000003ef740 ext4_io_submit+0x90/0xb0
[c000000fe99eb770] c0000000003e95d8 ext4_writepages+0x588/0xdd0
[c000000fe99eb910] c00000000025a9f0 do_writepages+0x60/0xc0
[c000000fe99eb940] c000000000246c88 __filemap_fdatawrite_range+0xf8/0x180
[c000000fe99eb9e0] c000000000246f90 filemap_write_and_wait_range+0x70/0xf0
[c000000fe99eba20] c0000000003dd844 ext4_sync_file+0x214/0x540
[c000000fe99eba80] c000000000364718 vfs_fsync_range+0x78/0x130
[c000000fe99ebad0] c0000000003dd46c ext4_file_write_iter+0x35c/0x430
[c000000fe99ebb90] c00000000038c280 aio_run_iocb+0x3b0/0x450
[c000000fe99ebce0] c00000000038dc28 do_io_submit+0x368/0x730
[c000000fe99ebe30] c000000000009404 system_call+0x38/0xec

Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: Douglas Miller <dougmill@linux.vnet.ibm.com>
Cc: linux-block@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Reviewed-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-14 13:57:47 -07:00
Linus Torvalds
a829a8445f SCSI misc on 20161213
This update includes the usual round of major driver updates (ncr5380,
 lpfc, hisi_sas, megaraid_sas, ufs, ibmvscsis, mpt3sas).  There's also
 an assortment of minor fixes, mostly in error legs or other not very
 user visible stuff.  The major change is the pci_alloc_irq_vectors
 replacement for the old pci_msix_.. calls; this effectively makes IRQ
 mapping generic for the drivers and allows blk_mq to use the
 information.
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.vnet.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This update includes the usual round of major driver updates (ncr5380,
  lpfc, hisi_sas, megaraid_sas, ufs, ibmvscsis, mpt3sas).

  There's also an assortment of minor fixes, mostly in error legs or
  other not very user visible stuff. The major change is the
  pci_alloc_irq_vectors replacement for the old pci_msix_.. calls; this
  effectively makes IRQ mapping generic for the drivers and allows
  blk_mq to use the information"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (256 commits)
  scsi: qla4xxx: switch to pci_alloc_irq_vectors
  scsi: hisi_sas: support deferred probe for v2 hw
  scsi: megaraid_sas: switch to pci_alloc_irq_vectors
  scsi: scsi_devinfo: remove synchronous ALUA for NETAPP devices
  scsi: be2iscsi: set errno on error path
  scsi: be2iscsi: set errno on error path
  scsi: hpsa: fallback to use legacy REPORT PHYS command
  scsi: scsi_dh_alua: Fix RCU annotations
  scsi: hpsa: use %phN for short hex dumps
  scsi: hisi_sas: fix free'ing in probe and remove
  scsi: isci: switch to pci_alloc_irq_vectors
  scsi: ipr: Fix runaway IRQs when falling back from MSI to LSI
  scsi: dpt_i2o: double free on error path
  scsi: cxlflash: Migrate scsi command pointer to AFU command
  scsi: cxlflash: Migrate IOARRIN specific routines to function pointers
  scsi: cxlflash: Cleanup queuecommand()
  scsi: cxlflash: Cleanup send_tmf()
  scsi: cxlflash: Remove AFU command lock
  scsi: cxlflash: Wait for active AFU commands to timeout upon tear down
  scsi: cxlflash: Remove private command pool
  ...
2016-12-14 10:49:33 -08:00
Gabriel Krisman Bertazi
36e1f3d107 blk-mq: Avoid memory reclaim when remapping queues
While stressing memory and IO at the same time we changed SMT settings,
we were able to consistently trigger deadlocks in the mm system, which
froze the entire machine.

I think that under memory stress conditions, the large allocations
performed by blk_mq_init_rq_map may trigger a reclaim, which stalls
waiting on the block layer remmaping completion, thus deadlocking the
system.  The trace below was collected after the machine stalled,
waiting for the hotplug event completion.

The simplest fix for this is to make allocations in this path
non-reclaimable, with GFP_NOIO.  With this patch, We couldn't hit the
issue anymore.

This should apply on top of Jens's for-next branch cleanly.

Changes since v1:
  - Use GFP_NOIO instead of GFP_NOWAIT.

 Call Trace:
[c000000f0160aaf0] [c000000f0160ab50] 0xc000000f0160ab50 (unreliable)
[c000000f0160acc0] [c000000000016624] __switch_to+0x2e4/0x430
[c000000f0160ad20] [c000000000b1a880] __schedule+0x310/0x9b0
[c000000f0160ae00] [c000000000b1af68] schedule+0x48/0xc0
[c000000f0160ae30] [c000000000b1b4b0] schedule_preempt_disabled+0x20/0x30
[c000000f0160ae50] [c000000000b1d4fc] __mutex_lock_slowpath+0xec/0x1f0
[c000000f0160aed0] [c000000000b1d678] mutex_lock+0x78/0xa0
[c000000f0160af00] [d000000019413cac] xfs_reclaim_inodes_ag+0x33c/0x380 [xfs]
[c000000f0160b0b0] [d000000019415164] xfs_reclaim_inodes_nr+0x54/0x70 [xfs]
[c000000f0160b0f0] [d0000000194297f8] xfs_fs_free_cached_objects+0x38/0x60 [xfs]
[c000000f0160b120] [c0000000003172c8] super_cache_scan+0x1f8/0x210
[c000000f0160b190] [c00000000026301c] shrink_slab.part.13+0x21c/0x4c0
[c000000f0160b2d0] [c000000000268088] shrink_zone+0x2d8/0x3c0
[c000000f0160b380] [c00000000026834c] do_try_to_free_pages+0x1dc/0x520
[c000000f0160b450] [c00000000026876c] try_to_free_pages+0xdc/0x250
[c000000f0160b4e0] [c000000000251978] __alloc_pages_nodemask+0x868/0x10d0
[c000000f0160b6f0] [c000000000567030] blk_mq_init_rq_map+0x160/0x380
[c000000f0160b7a0] [c00000000056758c] blk_mq_map_swqueue+0x33c/0x360
[c000000f0160b820] [c000000000567904] blk_mq_queue_reinit+0x64/0xb0
[c000000f0160b850] [c00000000056a16c] blk_mq_queue_reinit_notify+0x19c/0x250
[c000000f0160b8a0] [c0000000000f5d38] notifier_call_chain+0x98/0x100
[c000000f0160b8f0] [c0000000000c5fb0] __cpu_notify+0x70/0xe0
[c000000f0160b930] [c0000000000c63c4] notify_prepare+0x44/0xb0
[c000000f0160b9b0] [c0000000000c52f4] cpuhp_invoke_callback+0x84/0x250
[c000000f0160ba10] [c0000000000c570c] cpuhp_up_callbacks+0x5c/0x120
[c000000f0160ba60] [c0000000000c7cb8] _cpu_up+0xf8/0x1d0
[c000000f0160bac0] [c0000000000c7eb0] do_cpu_up+0x120/0x150
[c000000f0160bb40] [c0000000006fe024] cpu_subsys_online+0x64/0xe0
[c000000f0160bb90] [c0000000006f5124] device_online+0xb4/0x120
[c000000f0160bbd0] [c0000000006f5244] online_store+0xb4/0xc0
[c000000f0160bc20] [c0000000006f0a68] dev_attr_store+0x68/0xa0
[c000000f0160bc60] [c0000000003ccc30] sysfs_kf_write+0x80/0xb0
[c000000f0160bca0] [c0000000003cbabc] kernfs_fop_write+0x17c/0x250
[c000000f0160bcf0] [c00000000030fe6c] __vfs_write+0x6c/0x1e0
[c000000f0160bd90] [c000000000311490] vfs_write+0xd0/0x270
[c000000f0160bde0] [c0000000003131fc] SyS_write+0x6c/0x110
[c000000f0160be30] [c000000000009204] system_call+0x38/0xec

Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: Douglas Miller <dougmill@linux.vnet.ibm.com>
Cc: linux-block@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-14 08:15:25 -07:00
Linus Torvalds
b92e09bb5b Merge branch 'for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata
Pull libata updates from Tejun Heo:

 - Adam added opt-in ATA command priority support.

 - There are machines which hide multiple nvme devices behind an ahci
   BAR. Dan Williams proposed a solution to force-switch the mode but
   deemed too hackishd. People are gonna discuss the proper way to
   handle the situation in nvme standard meetings. For now, detect and
   warn about the situation.

 - Low level driver specific changes.

Christoph Hellwig pipes in about the hidden nvme warning:
 "I wish that was the case. We've pretty much agreed that we'll want to
  implement it as a virtual PCIe root bridge, similar to Intels other
  'innovation' VMD that we work around that way.

  But Intel management has apparently decided that they don't want to
  spend more cycles on this now that Lenovo has an optional BIOS that
  doesn't force this broken mode anymore, and no one outside of Intel
  has enough information to implement something like this.

  So for now I guess this warning is it, until Intel reconsideres and
  spends resources on fixing up the damage their Chipset people caused"

* 'for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  ahci: warn about remapped NVMe devices
  ahci-remap.h: add ahci remapping definitions
  nvme: move NVMe class code to pci_ids.h
  pata: imx: support controller modes up to PIO4
  pata: imx: add support of setting timings for PIO modes
  pata: imx: set controller PIO mode with .set_piomode callback
  pata: imx: sort headers out
  ata: set ncq_prio_enabled iff device has support
  ata: ATA Command Priority Disabled By Default
  ata: Enabling ATA Command Priorities
  block: Add iocontext priority to request
  ahci: qoriq: added ls1046a platform support
2016-12-13 13:26:24 -08:00
Linus Torvalds
36869cb93d Merge branch 'for-4.10/block' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
 "This is the main block pull request this series. Contrary to previous
  release, I've kept the core and driver changes in the same branch. We
  always ended up having dependencies between the two for obvious
  reasons, so makes more sense to keep them together. That said, I'll
  probably try and keep more topical branches going forward, especially
  for cycles that end up being as busy as this one.

  The major parts of this pull request is:

   - Improved support for O_DIRECT on block devices, with a small
     private implementation instead of using the pig that is
     fs/direct-io.c. From Christoph.

   - Request completion tracking in a scalable fashion. This is utilized
     by two components in this pull, the new hybrid polling and the
     writeback queue throttling code.

   - Improved support for polling with O_DIRECT, adding a hybrid mode
     that combines pure polling with an initial sleep. From me.

   - Support for automatic throttling of writeback queues on the block
     side. This uses feedback from the device completion latencies to
     scale the queue on the block side up or down. From me.

   - Support from SMR drives in the block layer and for SD. From Hannes
     and Shaun.

   - Multi-connection support for nbd. From Josef.

   - Cleanup of request and bio flags, so we have a clear split between
     which are bio (or rq) private, and which ones are shared. From
     Christoph.

   - A set of patches from Bart, that improve how we handle queue
     stopping and starting in blk-mq.

   - Support for WRITE_ZEROES from Chaitanya.

   - Lightnvm updates from Javier/Matias.

   - Supoort for FC for the nvme-over-fabrics code. From James Smart.

   - A bunch of fixes from a whole slew of people, too many to name
     here"

* 'for-4.10/block' of git://git.kernel.dk/linux-block: (182 commits)
  blk-stat: fix a few cases of missing batch flushing
  blk-flush: run the queue when inserting blk-mq flush
  elevator: make the rqhash helpers exported
  blk-mq: abstract out blk_mq_dispatch_rq_list() helper
  blk-mq: add blk_mq_start_stopped_hw_queue()
  block: improve handling of the magic discard payload
  blk-wbt: don't throttle discard or write zeroes
  nbd: use dev_err_ratelimited in io path
  nbd: reset the setup task for NBD_CLEAR_SOCK
  nvme-fabrics: Add FC LLDD loopback driver to test FC-NVME
  nvme-fabrics: Add target support for FC transport
  nvme-fabrics: Add host support for FC transport
  nvme-fabrics: Add FC transport LLDD api definitions
  nvme-fabrics: Add FC transport FC-NVME definitions
  nvme-fabrics: Add FC transport error codes to nvme.h
  Add type 0x28 NVME type code to scsi fc headers
  nvme-fabrics: patch target code in prep for FC transport support
  nvme-fabrics: set sqe.command_id in core not transports
  parser: add u64 number parser
  nvme-rdma: align to generic ib_event logging helper
  ...
2016-12-13 10:19:16 -08:00
Jens Axboe
9491ae4aad mm: don't cap request size based on read-ahead setting
We ran into a funky issue, where someone doing 256K buffered reads saw
128K requests at the device level.  Turns out it is read-ahead capping
the request size, since we use 128K as the default setting.  This
doesn't make a lot of sense - if someone is issuing 256K reads, they
should see 256K reads, regardless of the read-ahead setting, if the
underlying device can support a 256K read in a single command.

This patch introduces a bdi hint, io_pages.  This is the soft max IO
size for the lower level, I've hooked it up to the bdev settings here.
Read-ahead is modified to issue the maximum of the user request size,
and the read-ahead max size, but capped to the max request size on the
device side.  The latter is done to avoid reading ahead too much, if the
application asks for a huge read.  With this patch, the kernel behaves
like the application expects.

Link: http://lkml.kernel.org/r/1479498073-8657-1-git-send-email-axboe@fb.com
Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12 18:55:08 -08:00
Jens Axboe
7cd54aa843 blk-stat: fix a few cases of missing batch flushing
Everytime we need to read ->nr_samples, we should have flushed
the batch first. The non-mq read path also needs to flush the
batch.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-09 13:08:35 -07:00
Jens Axboe
c8e52ba5e2 blk-flush: run the queue when inserting blk-mq flush
Currently we pass in to run the queue async, but don't flag the
queue to be run. We don't need to run it async here, but we should
run it. So fixup the parameters.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-12-09 09:03:02 -07:00
Jens Axboe
70b3ea056f elevator: make the rqhash helpers exported
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-12-09 09:03:02 -07:00
Jens Axboe
f04c3df3ef blk-mq: abstract out blk_mq_dispatch_rq_list() helper
Takes a list of requests, and dispatches it. Moves any residual
requests to the dispatch list.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-12-09 09:03:02 -07:00
Jens Axboe
ae911c5e79 blk-mq: add blk_mq_start_stopped_hw_queue()
We have a variant for all hardware queues, but not one for a single
hardware queue.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
2016-12-09 09:03:02 -07:00
Christoph Hellwig
f9d03f96b9 block: improve handling of the magic discard payload
Instead of allocating a single unused biovec for discard requests, send
them down without any payload.  Instead we allow the driver to add a
"special" payload using a biovec embedded into struct request (unioned
over other fields never used while in the driver), and overloading
the number of segments for this case.

This has a couple of advantages:

 - we don't have to allocate the bio_vec
 - the amount of special casing for discard requests in the block
   layer is significantly reduced
 - using this same scheme for other request types is trivial,
   which will be important for implementing the new WRITE_ZEROES
   op on devices where it actually requires a payload (e.g. SCSI)
 - we can get rid of playing games with the request length, as
   we'll never touch it and completions will work just fine
 - it will allow us to support ranged discard operations in the
   future by merging non-contiguous discard bios into a single
   request
 - last but not least it removes a lot of code

This patch is the common base for my WIP series for ranges discards and to
remove discard_zeroes_data in favor of always using REQ_OP_WRITE_ZEROES,
so it would be good to get it in quickly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-09 08:30:51 -07:00
Christoph Hellwig
be07e14f96 blk-wbt: don't throttle discard or write zeroes
Both of these are metadata only commands that are not issued by the
writeback code and not directly relevant to the writeback bandwith.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-09 08:29:35 -07:00
Linus Torvalds
a0ac402cfc Don't feed anything but regular iovec's to blk_rq_map_user_iov
In theory we could map other things, but there's a reason that function
is called "user_iov".  Using anything else (like splice can do) just
confuses it.

Reported-and-tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-07 08:23:35 -08:00
Jens Axboe
6e85eaf307 blk-mq: blk_account_io_start() takes a bool
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2016-12-05 12:14:28 -07:00
Nicolai Stange
58886785db block: fix unintended fallthrough in generic_make_request_checks()
Since commit e73c23ff73 ("block: add async variant of
blkdev_issue_zeroout") messages like the following show up:

  EXT4-fs (dm-1): Delayed block allocation failed for inode 2368848 at
                  logical offset 0 with max blocks 1 with error 95
  EXT4-fs (dm-1): This should not happen!! Data will be lost

Due to the following fallthrough introduced with
commit 2d253440b5 ("block: Define zoned block device operations"),
generic_make_request_checks() would accept a REQ_OP_WRITE_SAME bio only
if the block device supports "write same" *and* is a zoned one:

  switch (bio_op(bio)) {
  [...]
  case REQ_OP_WRITE_SAME:
        if (!bdev_write_same(bio->bi_bdev))
                goto not_supported;
  case REQ_OP_ZONE_REPORT:
  case REQ_OP_ZONE_RESET:
                if (!bdev_is_zoned(bio->bi_bdev))
                        goto not_supported;
                break;
  [...]
  }

Thus, although the bio setup as done by __blkdev_issue_write_same() from
commit e73c23ff73 ("block: add async variant of blkdev_issue_zeroout")
would succeed, its actual submission would not, resulting in the
EOPNOTSUPP == 95.

Fix this by removing the fallthrough which, due to the lack of an explicit
comment, seems to be unintended anyway.

Fixes: e73c23ff73 ("block: add async variant of blkdev_issue_zeroout")
Fixes: 2d253440b5 ("block: Define zoned block device operations")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-05 07:54:39 -07:00
Shaohua Li
209200efa3 blk-stat: fix a typo
Signed-off-by: Shaohua Li <shli@fb.com>
Fixes: cf43e6be86 ("block: add scalable completion tracking of requests")
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-02 20:17:43 -07:00
Ritesh Harjani
e0c7230009 block: factor out req_set_nomerge
Factor out common code for setting REQ_NOMERGE flag which is being used
out at certain places and make it a helper instead, req_set_nomerge().

Signed-off-by: Ritesh Harjani <riteshh@codeaurora.org>

Get rid of the inline.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-01 08:36:16 -07:00
Chaitanya Kulkarni
a6f0788ec2 block: add support for REQ_OP_WRITE_ZEROES
This adds a new block layer operation to zero out a range of
LBAs. This allows to implement zeroing for devices that don't use
either discard with a predictable zero pattern or WRITE SAME of zeroes.
The prominent example of that is NVMe with the Write Zeroes command,
but in the future, this should also help with improving the way
zeroing discards work. For this operation, suitable entry is exported in
sysfs which indicate the number of maximum bytes allowed in one
write zeroes operation by the device.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-01 07:58:40 -07:00
Chaitanya Kulkarni
e73c23ff73 block: add async variant of blkdev_issue_zeroout
Similar to __blkdev_issue_discard this variant allows submitting
the final bio asynchronously and chaining multiple ranges
into a single completion.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-01 07:58:40 -07:00
Damien Le Moal
b02d8aaea1 block: Check partition alignment on zoned block devices
Both blkdev_report_zones and blkdev_reset_zones can operate on a partition of
a zoned block device. However, the first and last zones reported for a
partition make sense only if the partition start sector and size are aligned
on the device zone size. The same applies for zone reset. Resetting the first
or the last zone of a partition straddling zones may impact neighboring
partitions. Finally, if a partition start sector is not at the beginning of a
sequential zone, it will be impossible to write to the first sectors of the
partition on a host-managed device.
Avoid all these problems and incoherencies by ignoring partitions that are not
zone aligned.

Note: Even with CONFIG_BLK_DEV_ZONED disabled, bdev_is_zoned() will report the
correct disk zoning type (host-aware, host-managed or none) but
bdev_zone_size() will always return 0 for zoned block devices (i.e. the zone
size is unknown). So test this as a way to ensure that a zoned block device is
being handled as such. As a result, for a host-aware devices, unaligned zone
partitions will be accepted with CONFIG_BLK_DEV_ZONED disabled. That is, the
disk will be treated as a regular block device (as it should). If zoned block
device support is enabled, only aligned partitions will be accepted.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-01 07:56:53 -07:00
Gabriel Krisman Bertazi
415d3dab96 blk-mq: Drop explicit timeout sync in hotplug
After commit 287922eb0b ("block: defer timeouts to a workqueue"),
deleting the timeout work after freezing the queue shouldn't be
necessary, since the synchronization is already enforced by the
acquisition of a q_usage_counter reference in blk_mq_timeout_work.

Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Reviewed-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-29 08:01:08 -07:00
Jens Axboe
d62118b6dd blk-wbt: allow wbt to be enabled always through sysfs
Currently there's no way to enable wbt if it's not enabled in the
kernel config by default for a device. Allow a write to the
'wbt_lat_usec' queue sysfs file to enable wbt.

This is useful for both the kernel config case, but also if the
device is CFQ managed and it was turned off by default.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-28 10:27:03 -07:00
Jens Axboe
fa224eed2b blk-wbt: cleanup disable-by-default for CFQ
Make it clear that we are disabling wbt for the specified queued,
if it was enabled by default. This is in preparation for allowing
users to re-enable wbt, and not have it disabled automatically
again.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-28 10:27:03 -07:00
Jens Axboe
80e091d10e blk-wbt: allow reset of default latency through sysfs
Allow a write of '-1' to reset the default latency target for
a given device. This removes knowledge of the different default
settings for rotational vs non-rotational from user space.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-28 10:27:03 -07:00
Tejun Heo
e00f4f4d0f block,blkcg: use __GFP_NOWARN for best-effort allocations in blkcg
blkcg allocates some per-cgroup data structures with GFP_NOWAIT and
when that fails falls back to operations which aren't specific to the
cgroup.  Occassional failures are expected under pressure and falling
back to non-cgroup operation is the right thing to do.

Unfortunately, I forgot to add __GFP_NOWARN to these allocations and
these expected failures end up creating a lot of noise.  Add
__GFP_NOWARN.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Marc MERLIN <marc@merlins.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-22 08:59:49 -07:00
Ming Lei
3a83f46775 block: bio: pass bvec table to bio_init()
Some drivers often use external bvec table, so introduce
this helper for this case. It is always safe to access the
bio->bi_io_vec in this way for this case.

After converting to this usage, it will becomes a bit easier
to evaluate the remaining direct access to bio->bi_io_vec,
so it can help to prepare for the following multipage bvec
support.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Fixed up the new O_DIRECT cases.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-22 08:57:21 -07:00
Shaun Tancheff
778889d841 block: apply blk_partition_remap to REQ_OP_ZONE_RESET
If a ZBC device is partitioned and operations are performed on the partition
the zone information is rebased to the partition, however the zone reset
is not mapped from the partition to device as are other operations.

This causes the API (report zones / reset zone) to be unbalanced in this
regard. Checking for the zone reset op code explicitly will balance the
API.

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-21 15:08:24 -07:00
Johannes Thumshirn
a0f4bd7f2a scsi: fc: move FC transport's bsg code to bsg-lib
Now that all conversions are done, move the FibreChannel bsg code over
to the bsg library.

This patch is derived from work done by Mike Christie in 2011 [1] but
only the iscsi parts got merged back then.

[1] http://marc.info/?l=linux-scsi&m=131149780921009&w=2

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-17 20:15:26 -05:00
Johannes Thumshirn
fb6f7c8d8a block: add bsg_job_put() and bsg_job_get()
Add bsg_job_put() and bsg_job_get() so don't need to export
bsg_destroy_job() any more.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-17 20:15:26 -05:00
Johannes Thumshirn
6aa858cd33 scsi: fc: use bsg_softirq_done
bsg_softirq_done() and fc_bsg_softirq_done() are copies of each other, so
ditch the fc specific one.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-17 20:15:26 -05:00
Johannes Thumshirn
c00da4c90f scsi: fc: Use bsg_destroy_job
fc_destroy_bsgjob() and bsg_destroy_job() are now 1:1 copies, so use the
latter. As bsg_destroy_job() comes from bsg-lib we need to select it in
Kconfig once CONFOG_SCSI_FC_ATTRS is active.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-17 20:15:25 -05:00
Johannes Thumshirn
bf0f2d380f block: add reference counting for struct bsg_job
Add reference counting to 'struct bsg_job' so we can implement a reuqest
timeout handler for bsg_jobs, which is needed for Fibre Channel.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-17 20:15:25 -05:00
Jens Axboe
64f1c21e86 blk-mq: make the polling code adaptive
The previous commit introduced the hybrid sleep/poll mode. Take
that one step further, and use the completion latencies to
automatically sleep for half the mean completion time. This is
a good approximation.

This changes the 'io_poll_delay' sysfs file a bit to expose the
various options. Depending on the value, the polling code will
behave differently:

-1	Never enter hybrid sleep mode
 0	Use half of the completion mean for the sleep delay
>0	Use this specific value as the sleep delay

Signed-off-by: Jens Axboe <axboe@fb.com>
Tested-By: Stephen Bates <sbates@raithlin.com>
Reviewed-By: Stephen Bates <sbates@raithlin.com>
2016-11-17 13:34:57 -07:00
Jens Axboe
06426adf07 blk-mq: implement hybrid poll mode for sync O_DIRECT
This patch enables a hybrid polling mode. Instead of polling after IO
submission, we can induce an artificial delay, and then poll after that.
For example, if the IO is presumed to complete in 8 usecs from now, we
can sleep for 4 usecs, wake up, and then do our polling. This still puts
a sleep/wakeup cycle in the IO path, but instead of the wakeup happening
after the IO has completed, it'll happen before. With this hybrid
scheme, we can achieve big latency reductions while still using the same
(or less) amount of CPU.

Signed-off-by: Jens Axboe <axboe@fb.com>
Tested-By: Stephen Bates <sbates@raithlin.com>
Reviewed-By: Stephen Bates <sbates@raithlin.com>
2016-11-17 13:34:51 -07:00
Arnd Bergmann
4121d385f1 blk-wbt: fix old-style function declaration
The newly added driver causes a harmless warning in some configurations:

block/blk-wbt.c:250:1: error: ‘inline’ is not at beginning of declaration [-Werror=old-style-declaration]
 static bool inline stat_sample_valid(struct blk_rq_stat *stat)

This makes it use the expected format for the declaration.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-16 08:32:40 -07:00
Ming Lei
0a6219a95f block: deal with stale req count of plug list
In both legacy and mq path, req count of plug list is computed
before allocating request, so the number can be stale when falling
back to slept allocation, also the new introduced wbt can sleep
too.

This patch deals with the case by checking if plug list becomes
empty, and fixes the KASAN report of 'BUG: KASAN: stack-out-of-bounds'
which is introduced by Shaohua's patches of dispatching big request.

Fixes: 600271d900002(blk-mq: immediately dispatch big size request)
Fixes: 50d24c34403c6(block: immediately dispatch big size request)
Cc: Shaohua Li <shli@fb.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-16 08:09:51 -07:00
Bart Van Assche
dbb3ab0356 bsg: Add sparse annotations to bsg_request_fn()
Avoid that sparse complains about unbalanced lock actions.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-14 09:57:03 -07:00
Jens Axboe
382cf633ed blk-wbt: use BLK_STAT_{READ,WRITE} instead of 0/1
Since we have proper enums for the stats directions, use them.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-11 16:18:29 -07:00
Jens Axboe
8054b89f8f blk-wbt: remove stat ops
Again a leftover from when the throttling code was generic. Now that we
just have the block user, get rid of the stat ops and indirections.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-11 16:18:24 -07:00
Jens Axboe
d8a0cbfd73 blk-wbt: store queue instead of bdi
The bdi was a leftover from when the code was block layer agnostic.
Now that we just support a block layer user, store the queue directly.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-11 16:18:18 -07:00
Jens Axboe
bbd7bb7017 block: move poll code to blk-mq
The poll code is blk-mq specific, let's move it to blk-mq.c. This
is a prep patch for improving the polling code.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-11-11 13:40:25 -07:00
Jens Axboe
066a4a73ce blk-mq: blk_mq_try_issue_directly() should lookup hardware queue
A previous commit changed this to pass in the hardware queue, but
it was using the wrong hardware queue. Hence a request that was
allocated on one hardware queue ended up being issued on another
one, and that caused IO timeouts and oopses on some drivers. Since
the request holds hardware queue private resources, like a tag,
we can't just issue it on a different hardware queue.

Fixes: 2253efc850 ("blk-mq: Move more code into blk_mq_direct_issue_request()")
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-11 12:24:46 -07:00
Jens Axboe
87760e5eef block: hook up writeback throttling
Enable throttling of buffered writeback to make it a lot
more smooth, and has way less impact on other system activity.
Background writeback should be, by definition, background
activity. The fact that we flush huge bundles of it at the time
means that it potentially has heavy impacts on foreground workloads,
which isn't ideal. We can't easily limit the sizes of writes that
we do, since that would impact file system layout in the presence
of delayed allocation. So just throttle back buffered writeback,
unless someone is waiting for it.

The algorithm for when to throttle takes its inspiration in the
CoDel networking scheduling algorithm. Like CoDel, blk-wb monitors
the minimum latencies of requests over a window of time. In that
window of time, if the minimum latency of any request exceeds a
given target, then a scale count is incremented and the queue depth
is shrunk. The next monitoring window is shrunk accordingly. Unlike
CoDel, if we hit a window that exhibits good behavior, then we
simply increment the scale count and re-calculate the limits for that
scale value. This prevents us from oscillating between a
close-to-ideal value and max all the time, instead remaining in the
windows where we get good behavior.

Unlike CoDel, blk-wb allows the scale count to to negative. This
happens if we primarily have writes going on. Unlike positive
scale counts, this doesn't change the size of the monitoring window.
When the heavy writers finish, blk-bw quickly snaps back to it's
stable state of a zero scale count.

The patch registers a sysfs entry, 'wb_lat_usec'. This sets the latency
target to me met. It defaults to 2 msec for non-rotational storage, and
75 msec for rotational storage. Setting this value to '0' disables
blk-wb. Generally, a user would not have to touch this setting.

We don't enable WBT on devices that are managed with CFQ, and have
a non-root block cgroup attached. If we have a proportional share setup
on this particular disk, then the wbt throttling will interfere with
that. We don't have a strong need for wbt for that case, since we will
rely on CFQ doing that for us.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-10 13:53:40 -07:00
Jens Axboe
e34cbd3074 blk-wbt: add general throttling mechanism
We can hook this up to the block layer, to help throttle buffered
writes.

wbt registers a few trace points that can be used to track what is
happening in the system:

wbt_lat: 259:0: latency 2446318
wbt_stat: 259:0: rmean=2446318, rmin=2446318, rmax=2446318, rsamples=1,
               wmean=518866, wmin=15522, wmax=5330353, wsamples=57
wbt_step: 259:0: step down: step=1, window=72727272, background=8, normal=16, max=32

This shows a sync issue event (wbt_lat) that exceeded it's time. wbt_stat
dumps the current read/write stats for that window, and wbt_step shows a
step down event where we now scale back writes. Each trace includes the
device, 259:0 in this case.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-10 13:53:32 -07:00
Jens Axboe
cf43e6be86 block: add scalable completion tracking of requests
For legacy block, we simply track them in the request queue. For
blk-mq, we track them on a per-sw queue basis, which we can then
sum up through the hardware queues and finally to a per device
state.

The stats are tracked in, roughly, 0.1s interval windows.

Add sysfs files to display the stats.

The feature is off by default, to avoid any extra overhead. In-kernel
users of it can turn it on by setting QUEUE_FLAG_STATS in the queue
flags. We currently don't turn it on if someone just reads any of
the stats files, that is something we could add as well.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-10 13:53:26 -07:00
Tejun Heo
ebc4ff661f block: cfq_cpd_alloc() should use @gfp
cfq_cpd_alloc() which is the cpd_alloc_fn implementation for cfq was
incorrectly hard coding GFP_KERNEL instead of using the mask specified
through the @gfp parameter.  This currently doesn't cause any actual
issues because all current callers specify GFP_KERNEL.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: e4a9bde958 ("blkcg: replace blkcg_policy->cpd_size with ->cpd_alloc/free_fn() methods")
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-10 10:10:04 -07:00
Jens Axboe
ae5b2ec8ad block: set REQ_SYNC if we clear REQ_FUA|REQ_PREFLUSH
If we insert a flush request, we clear REQ_PREFLUSH and/or REQ_FUA,
depending on flush settings. Since op_is_sync() factors those flags
in for deciding whether this request is sync or not, we should
set REQ_SYNC to avoid screwing up this accounting.

This should be less fragile.

Reported-by: Logan Gunthorpe <logang@deltatee.com>
Fixes: b685d3d65a ("block: treat REQ_FUA and REQ_PREFLUSH as synchronous")
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-08 19:39:28 -07:00
Christoph Hellwig
9e5a7e2295 blk-mq: export blk_mq_map_queues
This will allow SCSI to have a single blk_mq_ops structure that either
lets the LLDD map the queues to PCIe MSIx vectors or use the default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-11-08 17:30:00 -05:00
Gabriel Krisman Bertazi
c02ebfdddb blk-mq: Always schedule hctx->next_cpu
Commit 0e87e58bf6 ("blk-mq: improve warning for running a queue on the
wrong CPU") attempts to avoid triggering the WARN_ON in
__blk_mq_run_hw_queue when the expected CPU is dead.  Problem is, in the
last batch execution before round robin, blk_mq_hctx_next_cpu can
schedule a dead CPU and also update next_cpu to the next alive CPU in
the mask, which will trigger the WARN_ON despite the previous
workaround.

The following patch fixes this scenario by always scheduling the value
in hctx->next_cpu.  This changes the moment when we round-robin the CPU
running the hctx, but it really doesn't matter, since it still executes
BLK_MQ_CPU_WORK_BATCH times in a row before switching to another CPU.

Fixes: 0e87e58bf6 ("blk-mq: improve warning for running a queue on the wrong CPU")
Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-06 14:14:41 -07:00
Jens Axboe
d278d4a889 block: add code to track actual device queue depth
For blk-mq, ->nr_requests does track queue depth, at least at init
time. But for the older queue paths, it's simply a soft setting.
On top of that, it's generally larger than the hardware setting
on purpose, to allow backup of requests for merging.

Fill a hole in struct request with a 'queue_depth' member, that
drivers can call to more closely inform the block layer of the
real queue depth.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
2016-11-05 17:09:53 -06:00
Shaohua Li
600271d900 blk-mq: immediately dispatch big size request
This is corresponding part for blk-mq. Disk with multiple hardware
queues doesn't need this as we only hold 1 request at most.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-03 22:00:38 -06:00
Shaohua Li
50d24c3440 block: immediately dispatch big size request
Currently block plug holds up to 16 non-mergeable requests. This makes
sense if the request size is small, eg, reduce lock contention. But if
request size is big enough, we don't need to worry about lock
contention. Holding such request makes no sense and it lows the disk
utilization.

In practice, this improves 10% throughput for my raid5 sequential write
workload.

The size (128k) is arbitrary right now, but it makes sure lock
contention is small. This probably could be more intelligent, eg, check
average request size holded. Since this is mainly for sequential IO,
probably not worthy.

V2: check the last request instead of the first request, so as long as
there is one big size request we flush the plug.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-03 22:00:36 -06:00
Johannes Thumshirn
46f3cc1762 block: drop q argument from bsg_validate_sgv4_hdr
bsg_validate_sgv4_hdr() doesn't care about the request_queue, so drop it
from it's arguments.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-03 07:56:14 -06:00
Bart Van Assche
2b053aca76 blk-mq: Add a kick_requeue_list argument to blk_mq_requeue_request()
Most blk_mq_requeue_request() and blk_mq_add_to_requeue_list() calls
are followed by kicking the requeue list. Hence add an argument to
these two functions that allows to kick the requeue list. This was
proposed by Christoph Hellwig.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche
6a83e74d21 blk-mq: Introduce blk_mq_quiesce_queue()
blk_mq_quiesce_queue() waits until ongoing .queue_rq() invocations
have finished. This function does *not* wait until all outstanding
requests have finished (this means invocation of request.end_io()).
The algorithm used by blk_mq_quiesce_queue() is as follows:
* Hold either an RCU read lock or an SRCU read lock around
  .queue_rq() calls. The former is used if .queue_rq() does not
  block and the latter if .queue_rq() may block.
* blk_mq_quiesce_queue() first calls blk_mq_stop_hw_queues()
  followed by synchronize_srcu() or synchronize_rcu(). The latter
  call waits for .queue_rq() invocations that started before
  blk_mq_quiesce_queue() was called.
* The blk_mq_hctx_stopped() calls that control whether or not
  .queue_rq() will be called are called with the (S)RCU read lock
  held. This is necessary to avoid race conditions against
  blk_mq_quiesce_queue().

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche
9b7dd572cc blk-mq: Remove blk_mq_cancel_requeue_work()
Since blk_mq_requeue_work() no longer restarts stopped queues
canceling requeue work is no longer needed to prevent that a
stopped queue would be restarted. Hence remove this function.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche
52d7f1b5c2 blk-mq: Avoid that requeueing starts stopped queues
Since blk_mq_requeue_work() starts stopped queues and since
execution of this function can be scheduled after a queue has
been stopped it is not possible to stop queues without using
an additional state variable to track whether or not the queue
has been stopped. Hence modify blk_mq_requeue_work() such that it
does not start stopped queues. My conclusion after a review of
the blk_mq_stop_hw_queues() and blk_mq_{delay_,}kick_requeue_list()
callers is as follows:
* In the dm driver starting and stopping queues should only happen
  if __dm_suspend() or __dm_resume() is called and not if the
  requeue list is processed.
* In the SCSI core queue stopping and starting should only be
  performed by the scsi_internal_device_block() and
  scsi_internal_device_unblock() functions but not by any other
  function. Although the blk_mq_stop_hw_queue() call in
  scsi_queue_rq() may help to reduce CPU load if a LLD queue is
  full, figuring out whether or not a queue should be restarted
  when requeueing a command would require to introduce additional
  locking in scsi_mq_requeue_cmd() to avoid a race with
  scsi_internal_device_block(). Avoid this complexity by removing
  the blk_mq_stop_hw_queue() call from scsi_queue_rq().
* In the NVMe core only the functions that call
  blk_mq_start_stopped_hw_queues() explicitly should start stopped
  queues.
* A blk_mq_start_stopped_hwqueues() call must be added in the
  xen-blkfront driver in its blkif_recover() function.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Roger Pau Monné <roger.pau@citrix.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: James Bottomley <jejb@linux.vnet.ibm.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche
2253efc850 blk-mq: Move more code into blk_mq_direct_issue_request()
Move the "hctx stopped" test and the insert request calls into
blk_mq_direct_issue_request(). Rename that function into
blk_mq_try_issue_directly() to reflect its new semantics. Pass
the hctx pointer to that function instead of looking it up a
second time. These changes avoid that code has to be duplicated
in the next patch.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche
fd00144301 blk-mq: Introduce blk_mq_queue_stopped()
The function blk_queue_stopped() allows to test whether or not a
traditional request queue has been stopped. Introduce a helper
function that allows block drivers to query easily whether or not
one or more hardware contexts of a blk-mq queue have been stopped.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche
5d1b25c1ec blk-mq: Introduce blk_mq_hctx_stopped()
Multiple functions test the BLK_MQ_S_STOPPED bit so introduce
a helper function that performs this test.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Bart Van Assche
bc27c01b5c blk-mq: Do not invoke .queue_rq() for a stopped queue
The meaning of the BLK_MQ_S_STOPPED flag is "do not call
.queue_rq()". Hence modify blk_mq_make_request() such that requests
are queued instead of issued if a queue has been stopped.

Reported-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 12:50:19 -06:00
Kent Overstreet
2cefe4dbaa block: add bio_iov_iter_get_pages()
This is a helper that pins down a range from an iov_iter and adds it to
a bio without requiring a separate memory allocation for the page array.
It will be used for upcoming direct I/O implementations for block devices
and iomap based file systems.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[hch: ported to the iov_iter interface, renamed and added comments.
      All blame should be directed to me and all fame should go to Kent
      after this!]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-02 10:50:18 -06:00
Christoph Hellwig
70fd76140a block,fs: use REQ_* flags directly
Remove the WRITE_* and READ_SYNC wrappers, and just use the flags
directly.  Where applicable this also drops usage of the
bio_set_op_attrs wrapper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-01 09:43:26 -06:00
Christoph Hellwig
a2b809672e block: replace REQ_NOIDLE with REQ_IDLE
Noidle should be the default for writes as seen by all the compounds
definitions in fs.h using it.  In fact only direct I/O really should
be using NODILE, so turn the whole flag around to get the defaults
right, which will make our life much easier especially onces the
WRITE_* defines go away.

This assumes all the existing "raw" users of REQ_SYNC for writes
want noidle behavior, which seems to be spot on from a quick audit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-01 09:43:26 -06:00
Christoph Hellwig
aa39ebd404 cfq-iosched: use op_is_sync instead of opencoding it
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-01 09:43:26 -06:00
Christoph Hellwig
ef295ecf09 block: better op and flags encoding
Now that we don't need the common flags to overflow outside the range
of a 32-bit type we can encode them the same way for both the bio and
request fields.  This in addition allows us to place the operation
first (and make some room for more ops while we're at it) and to
stop having to shift around the operation values.

In addition this allows passing around only one value in the block layer
instead of two (and eventuall also in the file systems, but we can do
that later) and thus clean up a lot of code.

Last but not least this allows decreasing the size of the cmd_flags
field in struct request to 32-bits.  Various functions passing this
value could also be updated, but I'd like to avoid the churn for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-28 08:48:16 -06:00
Christoph Hellwig
e806402130 block: split out request-only flags into a new namespace
A lot of the REQ_* flags are only used on struct requests, and only of
use to the block layer and a few drivers that dig into struct request
internals.

This patch adds a new req_flags_t rq_flags field to struct request for
them, and thus dramatically shrinks the number of common requests.  It
also removes the unfortunate situation where we have to fit the fields
from the same enum into 32 bits for struct bio and 64 bits for
struct request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-28 08:45:17 -06:00
Christoph Hellwig
8d2bbd4c82 block: replace REQ_THROTTLED with a bio flag
It's the last bio-only REQ_* flag, and we have space for it in the bio
bi_flags field.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-28 08:45:17 -06:00
Christoph Hellwig
c4aebd0332 block: remove bio_is_rw
With the addition of the zoned operations the tests in this function
became incorrect.  But I think it's much better to just open code the
allow operations in the only caller anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-28 08:45:17 -06:00
Jens Axboe
2552e3f878 blk-mq: get rid of confusing blk_map_ctx structure
We can just use struct blk_mq_alloc_data - it has a few more
members, but we allocate it further down the stack anyway. So
this cleans up the code, and reduces the stack overhead a bit.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-27 19:13:58 -06:00
Jens Axboe
7dd2fb6877 blk-mq: update hardware and software queues for sleeping alloc
If we end up sleeping due to running out of requests, we should
update the hardware and software queues in the map ctx structure.
Otherwise we could end up having rq->mq_ctx point to the pre-sleep
context, and risk corrupting ctx->rq_list since we'll be
grabbing the wrong lock when inserting the request.

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Reported-by: Chris Mason <clm@fb.com>
Tested-by: Chris Mason <clm@fb.com>
Fixes: 63581af3f3 ("blk-mq: remove non-blocking pass in blk_mq_map_request")
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-27 19:13:56 -06:00
Jens Axboe
7fe311302f blk-mq: update hardware and software queues for sleeping alloc
If we end up sleeping due to running out of requests, we should
update the hardware and software queues in the map ctx structure.
Otherwise we could end up having rq->mq_ctx point to the pre-sleep
context, and risk corrupting ctx->rq_list since we'll be
grabbing the wrong lock when inserting the request.

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Reported-by: Chris Mason <clm@fb.com>
Tested-by: Chris Mason <clm@fb.com>
Fixes: 63581af3f3 ("blk-mq: remove non-blocking pass in blk_mq_map_request")
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-27 09:56:03 -06:00
Ming Lei
94d7dea448 block: flush: fix IO hang in case of flood fua req
This patch fixes one issue reported by Kent, which can
be triggered in bcachefs over sata disk. Actually it
is a generic issue in block flush vs. blk-tag.

Cc: Christoph Hellwig <hch@infradead.org>
Reported-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-26 07:49:27 -06:00
Arnd Bergmann
3c4da75814 block: zoned: fix harmless maybe-uninitialized warning
The blkdev_report_zones produces a harmless warning when
-Wmaybe-uninitialized is set, after gcc gets a little confused
about the multiple 'goto' here:

block/blk-zoned.c: In function 'blkdev_report_zones':
block/blk-zoned.c:188:13: error: 'nz' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Moving the assignment to nr_zones makes this a little simpler
while also avoiding the warning reliably. I'm removing the
extraneous initialization of 'int ret' in the same patch, as
that is semi-related and could cause an uninitialized use of
that variable to not produce a warning.

Fixes: 6a0cb1bc10 ("block: Implement support for zoned block devices")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-24 20:51:22 -06:00
Shaohua Li
b4a1278c78 badblocks: badblocks_set/clear update unacked_exist
When bandblocks_set acknowledges a range or badblocks_clear a range,
it's possible all badblocks are acknowledged. We should update
unacked_exist if this occurs.

Signed-off-by: Shaohua Li <shli@fb.com>
Reviewed-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Tested-by: Tomasz Majchrzak <tomasz.majchrzak@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-21 15:45:47 -06:00
Linus Torvalds
ecd06f2883 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
 "A set of fixes that missed the merge window, mostly due to me being
  away around that time.

  Nothing major here, a mix of nvme cleanups and fixes, and one fix for
  the badblocks handling"

* 'for-linus' of git://git.kernel.dk/linux-block:
  nvmet: use symbolic constants for CNS values
  nvme: use symbolic constants for CNS values
  nvme.h: add an enum for cns values
  nvme.h: don't use uuid_be
  nvme.h: resync with nvme-cli
  nvme: Add tertiary number to NVME_VS
  nvme : Add sysfs entry for NVMe CMBs when appropriate
  nvme: don't schedule multiple resets
  nvme: Delete created IO queues on reset
  nvme: Stop probing a removed device
  badblocks: fix overlapping check for clearing
2016-10-21 10:54:01 -07:00
Adam Manzanares
5dc8b362a2 block: Add iocontext priority to request
Patch adds an association between iocontext ioprio and the ioprio of a
request. This is done to enable request based drivers the ability to
act on priority information stored in the request. An example being
ATA devices that support command priorities. If the ATA driver discovers
that the device supports command priorities and the request has valid
priority information indicating the request is high priority, then a high
priority command can be sent to the device. This should improve tail
latencies for high priority IO on any device that queues requests
internally and can make use of the priority information stored in the
request.

The ioprio of the request is set in blk_rq_set_prio which takes the
request and the ioc as arguments. If the ioc is valid in blk_rq_set_prio
then the iopriority of the request is set as the iopriority of the ioc.
In init_request_from_bio a check is made to see if the ioprio of the bio
is valid and if so then the request prio comes from the bio.

Signed-off-by: Adam Manzananares <adam.manzanares@wdc.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-10-19 14:34:35 -04:00
Shaun Tancheff
3ed05a987e blk-zoned: implement ioctls
Adds the new BLKREPORTZONE and BLKRESETZONE ioctls for respectively
obtaining the zone configuration of a zoned block device and resetting
the write pointer of sequential zones of a zoned block device.

The BLKREPORTZONE ioctl maps directly to a single call of the function
blkdev_report_zones. The zone information result is passed as an array
of struct blk_zone identical to the structure used internally for
processing the REQ_OP_ZONE_REPORT operation.  The BLKRESETZONE ioctl
maps to a single call of the blkdev_reset_zones function.

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-18 10:05:42 -06:00
Hannes Reinecke
6a0cb1bc10 block: Implement support for zoned block devices
Implement zoned block device zone information reporting and reset.
Zone information are reported as struct blk_zone. This implementation
does not differentiate between host-aware and host-managed device
models and is valid for both. Two functions are provided:
blkdev_report_zones for discovering the zone configuration of a
zoned block device, and blkdev_reset_zones for resetting the write
pointer of sequential zones. The helper function blk_queue_zone_size
and bdev_zone_size are also provided for, as the name suggest,
obtaining the zone size (in 512B sectors) of the zones of the device.

Signed-off-by: Hannes Reinecke <hare@suse.de>

[Damien: * Removed the zone cache
         * Implement report zones operation based on earlier proposal
           by Shaun Tancheff <shaun.tancheff@seagate.com>]
Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Tested-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-18 10:05:40 -06:00
Shaun Tancheff
2d253440b5 block: Define zoned block device operations
Define REQ_OP_ZONE_REPORT and REQ_OP_ZONE_RESET for handling zones of
host-managed and host-aware zoned block devices. With with these two
new operations, the total number of operations defined reaches 8 and
still fits with the 3 bits definition of REQ_OP_BITS.

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-18 10:02:05 -06:00
Hannes Reinecke
987b3b26eb block: update chunk_sectors in blk_stack_limits()
Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Tested-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-18 10:02:04 -06:00