Commit Graph

639 Commits

Author SHA1 Message Date
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 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 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 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
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
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
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
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
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
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
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 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 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
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
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
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 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
Stephen Bates 6e219353af block: add poll_considered statistic
In order to help determine the effectiveness of polling in a running
system it is usful to determine the ratio of how often the poll
function is called vs how often the completion is checked. For this
reason we add a poll_considered variable and add it to the sysfs entry
for io_poll.

Signed-off-by: Stephen Bates <sbates@raithlin.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-14 08:41:21 -06:00
Jens Axboe 27489a3c82 blk-mq: turn hctx->run_work into a regular work struct
We don't need the larger delayed work struct, since we always run it
immediately.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-29 08:13:21 -06:00
Jens Axboe ee63cfa7fc block: add kblockd_schedule_work_on()
Add a helper to schedule a regular struct work on a particular CPU.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-29 08:13:21 -06:00
Bart Van Assche 1b85608681 block: Fix race triggered by blk_set_queue_dying()
blk_set_queue_dying() can be called while another thread is
submitting I/O or changing queue flags, e.g. through dm_stop_queue().
Hence protect the QUEUE_FLAG_DYING flag change with locking.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-16 19:36:14 -06:00
Jens Axboe 1eff9d322a block: rename bio bi_rw to bi_opf
Since commit 63a4cc2486, bio->bi_rw contains flags in the lower
portion and the op code in the higher portions. This means that
old code that relies on manually setting bi_rw is most likely
going to be broken. Instead of letting that brokeness linger,
rename the member, to force old and out-of-tree code to break
at compile time instead of at runtime.

No intended functional changes in this commit.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-07 14:41:02 -06:00
Linus Torvalds 3fc9d69093 Merge branch 'for-4.8/drivers' of git://git.kernel.dk/linux-block
Pull block driver updates from Jens Axboe:
 "This branch also contains core changes.  I've come to the conclusion
  that from 4.9 and forward, I'll be doing just a single branch.  We
  often have dependencies between core and drivers, and it's hard to
  always split them up appropriately without pulling core into drivers
  when that happens.

  That said, this contains:

   - separate secure erase type for the core block layer, from
     Christoph.

   - set of discard fixes, from Christoph.

   - bio shrinking fixes from Christoph, as a followup up to the
     op/flags change in the core branch.

   - map and append request fixes from Christoph.

   - NVMeF (NVMe over Fabrics) code from Christoph.  This is pretty
     exciting!

   - nvme-loop fixes from Arnd.

   - removal of ->driverfs_dev from Dan, after providing a
     device_add_disk() helper.

   - bcache fixes from Bhaktipriya and Yijing.

   - cdrom subchannel read fix from Vchannaiah.

   - set of lightnvm updates from Wenwei, Matias, Johannes, and Javier.

   - set of drbd updates and fixes from Fabian, Lars, and Philipp.

   - mg_disk error path fix from Bart.

   - user notification for failed device add for loop, from Minfei.

   - NVMe in general:
        + NVMe delay quirk from Guilherme.
        + SR-IOV support and command retry limits from Keith.
        + fix for memory-less NUMA node from Masayoshi.
        + use UINT_MAX for discard sectors, from Minfei.
        + cancel IO fixes from Ming.
        + don't allocate unused major, from Neil.
        + error code fixup from Dan.
        + use constants for PSDT/FUSE from James.
        + variable init fix from Jay.
        + fabrics fixes from Ming, Sagi, and Wei.
        + various fixes"

* 'for-4.8/drivers' of git://git.kernel.dk/linux-block: (115 commits)
  nvme/pci: Provide SR-IOV support
  nvme: initialize variable before logical OR'ing it
  block: unexport various bio mapping helpers
  scsi/osd: open code blk_make_request
  target: stop using blk_make_request
  block: simplify and export blk_rq_append_bio
  block: ensure bios return from blk_get_request are properly initialized
  virtio_blk: use blk_rq_map_kern
  memstick: don't allow REQ_TYPE_BLOCK_PC requests
  block: shrink bio size again
  block: simplify and cleanup bvec pool handling
  block: get rid of bio_rw and READA
  block: don't ignore -EOPNOTSUPP blkdev_issue_write_same
  block: introduce BLKDEV_DISCARD_ZERO to fix zeroout
  NVMe: don't allocate unused nvme_major
  nvme: avoid crashes when node 0 is memoryless node.
  nvme: Limit command retries
  loop: Make user notify for adding loop device failed
  nvme-loop: fix nvme-loop Kconfig dependencies
  nvmet: fix return value check in nvmet_subsys_alloc()
  ...
2016-07-26 15:37:51 -07:00
Christoph Hellwig 4613c5f1df scsi/osd: open code blk_make_request
I wish the OSD code could simply use blk_rq_map_* helpers like
everyone else, but the complex nature of deciding if we have
DATA IN and/or DATA OUT buffers might make this impossible
(at least for a mere human like me).

But using blk_rq_append_bio at least allows sharing the setup code
between request with or without dat a buffers, and given that this
is the last user of blk_make_request it allows getting rid of that
somewhat awkward interface.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Boaz Harrosh <ooo@electrozaur.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20 17:38:35 -06:00
Christoph Hellwig 98d61d5b1a block: simplify and export blk_rq_append_bio
The target SCSI passthrough backend is much better served with the low-level
blk_rq_append_bio construct then the helpers built on top of it, so export it.

Also use the opportunity to remove the pointless request_queue argument and
make the code flow a little more readable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20 17:38:32 -06:00
Christoph Hellwig 0c4de0f33b block: ensure bios return from blk_get_request are properly initialized
blk_get_request is used for BLOCK_PC and similar passthrough requests.
Currently we always need to call blk_rq_set_block_pc or an open coded
version of it to allow appending bios using the request mapping helpers
later on, which is a somewhat awkward API.  Instead move the
initialization part of blk_rq_set_block_pc into blk_get_request, so that
we always have a safe to use request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20 17:38:30 -06:00
Sagi Grimberg 9645c1a233 block: Export blk_poll
The new NVMe over fabrics target will make use of this outside from a
module.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-05 11:30:31 -06:00
Jens Axboe b8269db456 cfq-iosched: temporarily boost queue priority for idle classes
If we're queuing REQ_PRIO IO and the task is running at an idle IO
class, then temporarily boost the priority. This prevents livelocks
due to priority inversion, when a low priority task is holding file
system resources while attempting to do IO.

An example of that is shown below. An ioniced idle task is holding
the directory mutex, while a normal priority task is trying to do
a directory lookup.

[478381.198925] ------------[ cut here ]------------
[478381.200315] INFO: task ionice:1168369 blocked for more than 120 seconds.
[478381.201324]       Not tainted 4.0.9-38_fbk5_hotfix1_2936_g85409c6 #1
[478381.202278] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[478381.203462] ionice          D ffff8803692736a8     0 1168369      1 0x00000080
[478381.203466]  ffff8803692736a8 ffff880399c21300 ffff880276adcc00 ffff880369273698
[478381.204589]  ffff880369273fd8 0000000000000000 7fffffffffffffff 0000000000000002
[478381.205752]  ffffffff8177d5e0 ffff8803692736c8 ffffffff8177cea7 0000000000000000
[478381.206874] Call Trace:
[478381.207253]  [<ffffffff8177d5e0>] ? bit_wait_io_timeout+0x80/0x80
[478381.208175]  [<ffffffff8177cea7>] schedule+0x37/0x90
[478381.208932]  [<ffffffff8177f5fc>] schedule_timeout+0x1dc/0x250
[478381.209805]  [<ffffffff81421c17>] ? __blk_run_queue+0x37/0x50
[478381.210706]  [<ffffffff810ca1c5>] ? ktime_get+0x45/0xb0
[478381.211489]  [<ffffffff8177c407>] io_schedule_timeout+0xa7/0x110
[478381.212402]  [<ffffffff810a8c2b>] ? prepare_to_wait+0x5b/0x90
[478381.213280]  [<ffffffff8177d616>] bit_wait_io+0x36/0x50
[478381.214063]  [<ffffffff8177d325>] __wait_on_bit+0x65/0x90
[478381.214961]  [<ffffffff8177d5e0>] ? bit_wait_io_timeout+0x80/0x80
[478381.215872]  [<ffffffff8177d47c>] out_of_line_wait_on_bit+0x7c/0x90
[478381.216806]  [<ffffffff810a89f0>] ? wake_atomic_t_function+0x40/0x40
[478381.217773]  [<ffffffff811f03aa>] __wait_on_buffer+0x2a/0x30
[478381.218641]  [<ffffffff8123c557>] ext4_bread+0x57/0x70
[478381.219425]  [<ffffffff8124498c>] __ext4_read_dirblock+0x3c/0x380
[478381.220467]  [<ffffffff8124665d>] ext4_dx_find_entry+0x7d/0x170
[478381.221357]  [<ffffffff8114c49e>] ? find_get_entry+0x1e/0xa0
[478381.222208]  [<ffffffff81246bd4>] ext4_find_entry+0x484/0x510
[478381.223090]  [<ffffffff812471a2>] ext4_lookup+0x52/0x160
[478381.223882]  [<ffffffff811c401d>] lookup_real+0x1d/0x60
[478381.224675]  [<ffffffff811c4698>] __lookup_hash+0x38/0x50
[478381.225697]  [<ffffffff817745bd>] lookup_slow+0x45/0xab
[478381.226941]  [<ffffffff811c690e>] link_path_walk+0x7ae/0x820
[478381.227880]  [<ffffffff811c6a42>] path_init+0xc2/0x430
[478381.228677]  [<ffffffff813e6e26>] ? security_file_alloc+0x16/0x20
[478381.229776]  [<ffffffff811c8c57>] path_openat+0x77/0x620
[478381.230767]  [<ffffffff81185c6e>] ? page_add_file_rmap+0x2e/0x70
[478381.232019]  [<ffffffff811cb253>] do_filp_open+0x43/0xa0
[478381.233016]  [<ffffffff8108c4a9>] ? creds_are_invalid+0x29/0x70
[478381.234072]  [<ffffffff811c0cb0>] do_open_execat+0x70/0x170
[478381.235039]  [<ffffffff811c1bf8>] do_execveat_common.isra.36+0x1b8/0x6e0
[478381.236051]  [<ffffffff811c214c>] do_execve+0x2c/0x30
[478381.236809]  [<ffffffff811ca392>] ? getname+0x12/0x20
[478381.237564]  [<ffffffff811c23be>] SyS_execve+0x2e/0x40
[478381.238338]  [<ffffffff81780a1d>] stub_execve+0x6d/0xa0
[478381.239126] ------------[ cut here ]------------
[478381.239915] ------------[ cut here ]------------
[478381.240606] INFO: task python2.7:1168375 blocked for more than 120 seconds.
[478381.242673]       Not tainted 4.0.9-38_fbk5_hotfix1_2936_g85409c6 #1
[478381.243653] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[478381.244902] python2.7       D ffff88005cf8fb98     0 1168375 1168248 0x00000080
[478381.244904]  ffff88005cf8fb98 ffff88016c1f0980 ffffffff81c134c0 ffff88016c1f11a0
[478381.246023]  ffff88005cf8ffd8 ffff880466cd0cbc ffff88016c1f0980 00000000ffffffff
[478381.247138]  ffff880466cd0cc0 ffff88005cf8fbb8 ffffffff8177cea7 ffff88005cf8fcc8
[478381.248252] Call Trace:
[478381.248630]  [<ffffffff8177cea7>] schedule+0x37/0x90
[478381.249382]  [<ffffffff8177d08e>] schedule_preempt_disabled+0xe/0x10
[478381.250465]  [<ffffffff8177e892>] __mutex_lock_slowpath+0x92/0x100
[478381.251409]  [<ffffffff8177e91b>] mutex_lock+0x1b/0x2f
[478381.252199]  [<ffffffff817745ae>] lookup_slow+0x36/0xab
[478381.253023]  [<ffffffff811c690e>] link_path_walk+0x7ae/0x820
[478381.253877]  [<ffffffff811aeb41>] ? try_charge+0xc1/0x700
[478381.254690]  [<ffffffff811c6a42>] path_init+0xc2/0x430
[478381.255525]  [<ffffffff813e6e26>] ? security_file_alloc+0x16/0x20
[478381.256450]  [<ffffffff811c8c57>] path_openat+0x77/0x620
[478381.257256]  [<ffffffff8115b2fb>] ? lru_cache_add_active_or_unevictable+0x2b/0xa0
[478381.258390]  [<ffffffff8117b623>] ? handle_mm_fault+0x13f3/0x1720
[478381.259309]  [<ffffffff811cb253>] do_filp_open+0x43/0xa0
[478381.260139]  [<ffffffff811d7ae2>] ? __alloc_fd+0x42/0x120
[478381.260962]  [<ffffffff811b95ac>] do_sys_open+0x13c/0x230
[478381.261779]  [<ffffffff81011393>] ? syscall_trace_enter_phase1+0x113/0x170
[478381.262851]  [<ffffffff811b96c2>] SyS_open+0x22/0x30
[478381.263598]  [<ffffffff81780532>] system_call_fastpath+0x12/0x17
[478381.264551] ------------[ cut here ]------------
[478381.265377] ------------[ cut here ]------------

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
2016-06-09 16:15:01 -06:00
Christoph Hellwig 288dab8a35 block: add a separate operation type for secure erase
Instead of overloading the discard support with the REQ_SECURE flag.
Use the opportunity to rename the queue flag as well, and remove the
dead checks for this flag in the RAID 1 and RAID 10 drivers that don't
claim support for secure erase.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-09 09:52:25 -06:00
Mike Christie 28a8f0d317 block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH
To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 6296b9604f block, drivers, fs: shrink bi_rw from long to int
We don't need bi_rw to be so large on 64 bit archs, so
reduce it to unsigned int.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie d9d8c5c489 block: convert is_sync helpers to use REQ_OPs.
This patch converts the is_sync helpers to use separate variables
for the operation and flags.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 8fe0d473f5 block: convert merge/insert code to check for REQ_OPs.
This patch converts the block layer merging code to use separate variables
for the operation and flags, and to check req_op for the REQ_OP.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie ba568ea0a2 block: prepare elevator to use REQ_OPs.
This patch converts the elevator code to use separate variables
for the operation and flags, and to check req_op for the REQ_OP.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie e6a40b096e block: prepare request creation/destruction code to use REQ_OPs
This patch prepares *_get_request/*_put_request and freed_request,
to use separate variables for the operation and flags. In the
next patches the struct request users will be converted like
was done for bios where the op and flags are set separately.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 4993b77d3f block: copy bio op to request op
The bio users should now always be setting up the bio op. This patch
has the block layer copy that to the request.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 95fe6c1a20 block, fs, mm, drivers: use bio set/get op accessors
This patch converts the simple bi_rw use cases in the block,
drivers, mm and fs code to set/get the bio operation using
bio_set_op_attrs/bio_op

These should be simple one or two liner cases, so I just did them
in one patch. The next patches handle the more complicated
cases in a module per patch.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie a8ebb056a8 block, drivers, cgroup: use op_is_write helper instead of checking for REQ_WRITE
We currently set REQ_WRITE/WRITE for all non READ IOs
like discard, flush, writesame, etc. In the next patches where we
no longer set up the op as a bitmap, we will not be able to
detect a operation direction like writesame by testing if REQ_WRITE is
set.

This patch converts the drivers and cgroup to use the
op_is_write helper. This should just cover the simple
cases. I did dm, md and bcache in their own patches
because they were more involved.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 4e49ea4a3d block/fs/drivers: remove rw argument from submit_bio
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw
instead of passing it in. This makes that use the same as
generic_make_request and how we set the other bio fields.

Signed-off-by: Mike Christie <mchristi@redhat.com>

Fixed up fs/ext4/crypto.c

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Jens Axboe c888a8f95a block: kill off q->flush_flags
Now that we converted everything to the newer block write cache
interface, kill off the queue flush_flags and queueable flush
entries.

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-04-13 13:33:19 -06:00
Ming Lin 37e58237a1 block: add offset in blk_add_request_payload()
We could kmalloc() the payload, so need the offset in page.

Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-04-12 13:13:23 -06:00
Kirill A. Shutemov 09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

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

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

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

The changes are pretty straight-forward:

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

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

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

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

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

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

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

virtual patch

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

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

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

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

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

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

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00
Linus Torvalds fcab86add7 Merge branch 'for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata
Pull libata updates from Tejun Heo:

 - ahci grew runtime power management support so that the controller can
   be turned off if no devices are attached.

 - sata_via isn't dead yet.  It got hotplug support and more refined
   workaround for certain WD drives.

 - Misc cleanups.  There's a merge from for-4.5-fixes to avoid confusing
   conflicts in ahci PCI ID table.

* 'for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  ata: ahci_xgene: dereferencing uninitialized pointer in probe
  AHCI: Remove obsolete Intel Lewisburg SATA RAID device IDs
  ata: sata_rcar: Use ARCH_RENESAS
  sata_via: Implement hotplug for VT6421
  sata_via: Apply WD workaround only when needed on VT6421
  ahci: Add runtime PM support for the host controller
  ahci: Add functions to manage runtime PM of AHCI ports
  ahci: Convert driver to use modern PM hooks
  ahci: Cache host controller version
  scsi: Drop runtime PM usage count after host is added
  scsi: Set request queue runtime PM status back to active on resume
  block: Add blk_set_runtime_active()
  ata: ahci_mvebu: add support for Armada 3700 variant
  libata: fix unbalanced spin_lock_irqsave/spin_unlock_irq() in ata_scsi_park_show()
  libata: support AHCI on OCTEON platform
2016-03-18 20:06:46 -07:00
Mike Snitzer 6acfe68bac dm: fix excessive dm-mq context switching
Request-based DM's blk-mq support (dm-mq) was reported to be 50% slower
than if an underlying null_blk device were used directly.  One of the
reasons for this drop in performance is that blk_insert_clone_request()
was calling blk_mq_insert_request() with @async=true.  This forced the
use of kblockd_schedule_delayed_work_on() to run the blk-mq hw queues
which ushered in ping-ponging between process context (fio in this case)
and kblockd's kworker to submit the cloned request.  The ftrace
function_graph tracer showed:

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

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

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

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

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

    In my testing against a really fast null_blk device there was no benefit
    to running blk_mq_run_hw_queues() on completion (and no other blk-mq
    driver does this).  So hopefully this change doesn't induce the need for
    yet another revert like commit 621739b00e !

2)  use blk_mq_complete_request() in dm_complete_request()

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

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

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

Fixes: 7fb4898e0 ("block: add blk-mq support to blk_insert_cloned_request()")
Fixes: bfebd1cdb ("dm: add full blk-mq support to request-based DM")
Cc: stable@vger.kernel.org # 4.1+
Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
2016-02-22 11:04:40 -05:00
Mika Westerberg d07ab6d114 block: Add blk_set_runtime_active()
If block device is left runtime suspended during system suspend, resume
hook of the driver typically corrects runtime PM status of the device back
to "active" after it is resumed. However, this is not enough as queue's
runtime PM status is still "suspended". As long as it is in this state
blk_pm_peek_request() returns NULL and thus prevents new requests to be
processed.

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

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-02-19 10:52:45 -05:00
James Bottomley 12ffbbe94d Merge remote-tracking branch 'mkp-scsi/4.5/scsi-fixes' into fixes 2016-02-04 21:37:52 -08:00
Martin K. Petersen 0fb5b1fb30 block/sd: Return -EREMOTEIO when WRITE SAME and DISCARD are disabled
When a storage device rejects a WRITE SAME command we will disable write
same functionality for the device and return -EREMOTEIO to the block
layer. -EREMOTEIO will in turn prevent DM from retrying the I/O and/or
failing the path.

Yiwen Jiang discovered a small race where WRITE SAME requests issued
simultaneously would cause -EIO to be returned. This happened because
any requests being prepared after WRITE SAME had been disabled for the
device caused us to return BLKPREP_KILL. The latter caused the block
layer to return -EIO upon completion.

To overcome this we introduce BLKPREP_INVALID which indicates that this
is an invalid request for the device. blk_peek_request() is modified to
return -EREMOTEIO in that case.

Reported-by: Yiwen Jiang <jiangyiwen@huawei.com>
Suggested-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-02-04 22:42:58 -05:00
Linus Torvalds 3e1e21c7bf Merge branch 'for-4.5/nvme' of git://git.kernel.dk/linux-block
Pull NVMe updates from Jens Axboe:
 "Last branch for this series is the nvme changes.  It's in a separate
  branch to avoid splitting too much between core and NVMe changes,
  since NVMe is still helping drive some blk-mq changes.  That said, not
  a huge amount of core changes in here.  The grunt of the work is the
  continued split of the code"

* 'for-4.5/nvme' of git://git.kernel.dk/linux-block: (67 commits)
  uapi: update install list after nvme.h rename
  NVMe: Export NVMe attributes to sysfs group
  NVMe: Shutdown controller only for power-off
  NVMe: IO queue deletion re-write
  NVMe: Remove queue freezing on resets
  NVMe: Use a retryable error code on reset
  NVMe: Fix admin queue ring wrap
  nvme: make SG_IO support optional
  nvme: fixes for NVME_IOCTL_IO_CMD on the char device
  nvme: synchronize access to ctrl->namespaces
  nvme: Move nvme_freeze/unfreeze_queues to nvme core
  PCI/AER: include header file
  NVMe: Export namespace attributes to sysfs
  NVMe: Add pci error handlers
  block: remove REQ_NO_TIMEOUT flag
  nvme: merge iod and cmd_info
  nvme: meta_sg doesn't have to be an array
  nvme: properly free resources for cancelled command
  nvme: simplify completion handling
  nvme: special case AEN requests
  ...
2016-01-21 19:58:02 -08:00
Linus Torvalds 7c24d9f3b2 Merge branch 'for-4.5/core' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe:
 "We don't have a lot of core changes this time around, it's mostly in
  drivers, which will come in a subsequent pull.

  The cores changes include:

   - blk-mq
        - Prep patch from Christoph, changing blk_mq_alloc_request() to
          take flags instead of just using gfp_t for sleep/nosleep.
        - Doc patch from me, clarifying the difference between legacy
          and blk-mq for timer usage.
        - Fixes from Raghavendra for memory-less numa nodes, and a reuse
          of CPU masks.

   - Cleanup from Geliang Tang, using offset_in_page() instead of open
     coding it.

   - From Ilya, rename request_queue slab to it reflects what it holds,
     and a fix for proper use of bdgrab/put.

   - A real fix for the split across stripe boundaries from Keith.  We
     yanked a broken version of this from 4.4-rc final, this one works.

   - From Mike Krinkin, emit a trace message when we split.

   - From Wei Tang, two small cleanups, not explicitly clearing memory
     that is already cleared"

* 'for-4.5/core' of git://git.kernel.dk/linux-block:
  block: use bd{grab,put}() instead of open-coding
  block: split bios to max possible length
  block: add call to split trace point
  blk-mq: Avoid memoryless numa node encoded in hctx numa_node
  blk-mq: Reuse hardware context cpumask for tags
  blk-mq: add a flags parameter to blk_mq_alloc_request
  Revert "blk-flush: Queue through IO scheduler when flush not required"
  block: clarify blk_add_timer() use case for blk-mq
  bio: use offset_in_page macro
  block: do not initialise statics to 0 or NULL
  block: do not initialise globals to 0 or NULL
  block: rename request_queue slab cache
2016-01-19 15:03:34 -08:00
Jens Axboe 21491412f2 block: add blk_start_queue_async()
We currently only have an inline/sync helper to restart a stopped
queue. If drivers need an async version, they have to roll their
own. Add a generic helper instead.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-28 13:07:07 -07:00
Junichi Nomura 23688bf4f8 block: ensure to split after potentially bouncing a bio
blk_queue_bio() does split then bounce, which makes the segment
counting based on pages before bouncing and could go wrong. Move
the split to after bouncing, like we do for blk-mq, and the we
fix the issue of having the bio count for segments be wrong.

Fixes: 54efd50bfd ("block: make generic_make_request handle arbitrarily sized bios")
Cc: stable@vger.kernel.org
Tested-by: Artem S. Tashkinov <t.artem@lycos.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-22 10:26:53 -07:00
Christoph Hellwig 287922eb0b block: defer timeouts to a workqueue
Timer context is not very useful for drivers to perform any meaningful abort
action from.  So instead of calling the driver from this useless context
defer it to a workqueue as soon as possible.

Note that while a delayed_work item would seem the right thing here I didn't
dare to use it due to the magic in blk_add_timer that pokes deep into timer
internals.  But maybe this encourages Tejun to add a sensible API for that to
the workqueue API and we'll all be fine in the end :)

Contains a major update from Keith Bush:

"This patch removes synchronizing the timeout work so that the timer can
 start a freeze on its own queue. The timer enters the queue, so timer
 context can only start a freeze, but not wait for frozen."

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-22 09:38:16 -07:00
Ken Xue 4fd41a8552 SCSI: Fix NULL pointer dereference in runtime PM
The routines in scsi_pm.c assume that if a runtime-PM callback is
invoked for a SCSI device, it can only mean that the device's driver
has asked the block layer to handle the runtime power management (by
calling blk_pm_runtime_init(), which among other things sets q->dev).

However, this assumption turns out to be wrong for things like the ses
driver.  Normally ses devices are not allowed to do runtime PM, but
userspace can override this setting.  If this happens, the kernel gets
a NULL pointer dereference when blk_post_runtime_resume() tries to use
the uninitialized q->dev pointer.

This patch fixes the problem by checking q->dev in block layer before
handle runtime PM. Since ses doesn't define any PM callbacks and call
blk_pm_runtime_init(), the crash won't occur.

This fixes Bugzilla #101371.
https://bugzilla.kernel.org/show_bug.cgi?id=101371

More discussion can be found from below link.
http://marc.info/?l=linux-scsi&m=144163730531875&w=2

Signed-off-by: Ken Xue <Ken.Xue@amd.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Xiangliang Yu <Xiangliang.Yu@amd.com>
Cc: James E.J. Bottomley <JBottomley@odin.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Terry <Michael.terry@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-03 20:35:02 -07:00
Christoph Hellwig 6f3b0e8bcf blk-mq: add a flags parameter to blk_mq_alloc_request
We already have the reserved flag, and a nowait flag awkwardly encoded as
a gfp_t.  Add a real flags argument to make the scheme more extensible and
allow for a nicer calling convention.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-01 10:53:59 -07:00
Hannes Reinecke bf4e6b4e75 block: Always check queue limits for cloned requests
When a cloned request is retried on other queues it always needs
to be checked against the queue limits of that queue.
Otherwise the calculations for nr_phys_segments might be wrong,
leading to a crash in scsi_init_sgtable().

To clarify this the patch renames blk_rq_check_limits()
to blk_cloned_rq_check_limits() and removes the symbol
export, as the new function should only be used for
cloned requests and never exported.

Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Ewan Milne <emilne@redhat.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Fixes: e2a60da74 ("block: Clean up special command handling logic")
Cc: stable@vger.kernel.org # 3.7+
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-29 14:37:27 -07:00
Wei Tang d674d4145e block: do not initialise globals to 0 or NULL
This patch fixes the checkpatch.pl error to blk-exec.c:

ERROR: do not initialise globals to 0 or NULL

Signed-off-by: Wei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-24 15:24:25 -07:00
Ilya Dryomov c2789bd403 block: rename request_queue slab cache
Name the cache after the actual name of the struct.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-24 15:24:25 -07:00
Randy Dunlap ccc2600b8a block: fix blk-core.c kernel-doc warning
Fix kernel-doc warning in blk-core.c:

Warning(..//block/blk-core.c:1549): No description found for parameter 'same_queue_rq'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-11 09:36:57 -07:00
Linus Torvalds 3419b45039 Merge branch 'for-4.4/io-poll' of git://git.kernel.dk/linux-block
Pull block IO poll support from Jens Axboe:
 "Various groups have been doing experimentation around IO polling for
  (really) fast devices.  The code has been reviewed and has been
  sitting on the side for a few releases, but this is now good enough
  for coordinated benchmarking and further experimentation.

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

* 'for-4.4/io-poll' of git://git.kernel.dk/linux-block:
  direct-io: be sure to assign dio->bio_bdev for both paths
  directio: add block polling support
  NVMe: add blk polling support
  block: add block polling support
  blk-mq: return tag/queue combo in the make_request_fn handlers
  block: change ->make_request_fn() and users to return a queue cookie
2015-11-10 17:23:49 -08:00
Jens Axboe 05229beedd block: add block polling support
Add basic support for polling for specific IO to complete. This uses
the cookie that blk-mq passes back, which enables the block layer
to pass this cookie to the driver to spin for a specific request.

This will be combined with request latency tracking, so we can make
qualified decisions about when to poll and when not to. For now, for
benchmark purposes, we add a sysfs file that controls whether polling
is enabled or not.

Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
2015-11-07 10:40:47 -07:00
Jens Axboe dece16353e block: change ->make_request_fn() and users to return a queue cookie
No functional changes in this patch, but it prepares us for returning
a more useful cookie related to the IO that was queued up.

Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
2015-11-07 10:40:46 -07:00
Mel Gorman 71baba4b92 mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM
__GFP_WAIT was used to signal that the caller was in atomic context and
could not sleep.  Now it is possible to distinguish between true atomic
context and callers that are not willing to sleep.  The latter should
clear __GFP_DIRECT_RECLAIM so kswapd will still wake.  As clearing
__GFP_WAIT behaves differently, there is a risk that people will clear the
wrong flags.  This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
indicate what it does -- setting it allows all reclaim activity, clearing
them prevents it.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
Mel Gorman d0164adc89 mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts.  They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve".  __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".

Over time, callers had a requirement to not block when fallback options
were available.  Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.

This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative.  High priority users continue to use
__GFP_HIGH.  __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim.  __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim.  __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.

This patch then converts a number of sites

o __GFP_ATOMIC is used by callers that are high priority and have memory
  pools for those requests. GFP_ATOMIC uses this flag.

o Callers that have a limited mempool to guarantee forward progress clear
  __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
  into this category where kswapd will still be woken but atomic reserves
  are not used as there is a one-entry mempool to guarantee progress.

o Callers that are checking if they are non-blocking should use the
  helper gfpflags_allow_blocking() where possible. This is because
  checking for __GFP_WAIT as was done historically now can trigger false
  positives. Some exceptions like dm-crypt.c exist where the code intent
  is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
  flag manipulations.

o Callers that built their own GFP flags instead of starting with GFP_KERNEL
  and friends now also need to specify __GFP_KSWAPD_RECLAIM.

The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.

The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL.  They may
now wish to specify __GFP_KSWAPD_RECLAIM.  It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
Linus Torvalds 527d1529e3 Merge branch 'for-4.4/integrity' of git://git.kernel.dk/linux-block
Pull block integrity updates from Jens Axboe:
 ""This is the joint work of Dan and Martin, cleaning up and improving
  the support for block data integrity"

* 'for-4.4/integrity' of git://git.kernel.dk/linux-block:
  block, libnvdimm, nvme: provide a built-in blk_integrity nop profile
  block: blk_flush_integrity() for bio-based drivers
  block: move blk_integrity to request_queue
  block: generic request_queue reference counting
  nvme: suspend i/o during runtime blk_integrity_unregister
  md: suspend i/o during runtime blk_integrity_unregister
  md, dm, scsi, nvme, libnvdimm: drop blk_integrity_unregister() at shutdown
  block: Inline blk_integrity in struct gendisk
  block: Export integrity data interval size in sysfs
  block: Reduce the size of struct blk_integrity
  block: Consolidate static integrity profile properties
  block: Move integrity kobject to struct gendisk
2015-11-04 20:51:48 -08:00
Linus Torvalds d9734e0d1c Merge branch 'for-4.4/core' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe:
 "This is the core block pull request for 4.4.  I've got a few more
  topic branches this time around, some of them will layer on top of the
  core+drivers changes and will come in a separate round.  So not a huge
  chunk of changes in this round.

  This pull request contains:

   - Enable blk-mq page allocation tracking with kmemleak, from Catalin.

   - Unused prototype removal in blk-mq from Christoph.

   - Cleanup of the q->blk_trace exchange, using cmpxchg instead of two
     xchg()'s, from Davidlohr.

   - A plug flush fix from Jeff.

   - Also from Jeff, a fix that means we don't have to update shared tag
     sets at init time unless we do a state change.  This cuts down boot
     times on thousands of devices a lot with scsi/blk-mq.

   - blk-mq waitqueue barrier fix from Kosuke.

   - Various fixes from Ming:

        - Fixes for segment merging and splitting, and checks, for
          the old core and blk-mq.

        - Potential blk-mq speedup by marking ctx pending at the end
          of a plug insertion batch in blk-mq.

        - direct-io no page dirty on kernel direct reads.

   - A WRITE_SYNC fix for mpage from Roman"

* 'for-4.4/core' of git://git.kernel.dk/linux-block:
  blk-mq: avoid excessive boot delays with large lun counts
  blktrace: re-write setting q->blk_trace
  blk-mq: mark ctx as pending at batch in flush plug path
  blk-mq: fix for trace_block_plug()
  block: check bio_mergeable() early before merging
  blk-mq: check bio_mergeable() early before merging
  block: avoid to merge splitted bio
  block: setup bi_phys_segments after splitting
  block: fix plug list flushing for nomerge queues
  blk-mq: remove unused blk_mq_clone_flush_request prototype
  blk-mq: fix waitqueue_active without memory barrier in block/blk-mq-tag.c
  fs: direct-io: don't dirtying pages for ITER_BVEC/ITER_KVEC direct read
  fs/mpage.c: forgotten WRITE_SYNC in case of data integrity write
  block: kmemleak: Track the page allocations for struct request
2015-11-04 20:28:10 -08:00
Jeff Moyer 0809e3ac62 block: fix plug list flushing for nomerge queues
Request queues with merging disabled will not flush the plug list after
BLK_MAX_REQUEST_COUNT requests have been queued, since the code relies
on blk_attempt_plug_merge to compute the request_count.  Fix this by
computing the number of queued requests even for nomerge queues.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 15:00:48 -06:00
Dan Williams 5a48fc147d block: blk_flush_integrity() for bio-based drivers
Since they lack requests to pin the request_queue active, synchronous
bio-based drivers may have in-flight integrity work from
bio_integrity_endio() that is not flushed by blk_freeze_queue().  Flush
that work to prevent races to free the queue and the final usage of the
blk_integrity profile.

This is temporary unless/until bio-based drivers start to generically
take a q_usage_counter reference while a bio is in-flight.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
[martin: fix the CONFIG_BLK_DEV_INTEGRITY=n case]
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:43:44 -06:00
Dan Williams 3ef28e83ab block: generic request_queue reference counting
Allow pmem, and other synchronous/bio-based block drivers, to fallback
on a per-cpu reference count managed by the core for tracking queue
live/dead state.

The existing per-cpu reference count for the blk_mq case is promoted to
be used in all block i/o scenarios.  This involves initializing it by
default, waiting for it to drop to zero at exit, and holding a live
reference over the invocation of q->make_request_fn() in
generic_make_request().  The blk_mq code continues to take its own
reference per blk_mq request and retains the ability to freeze the
queue, but the check that the queue is frozen is moved to
generic_make_request().

This fixes crash signatures like the following:

 BUG: unable to handle kernel paging request at ffff880140000000
 [..]
 Call Trace:
  [<ffffffff8145e8bf>] ? copy_user_handle_tail+0x5f/0x70
  [<ffffffffa004e1e0>] pmem_do_bvec.isra.11+0x70/0xf0 [nd_pmem]
  [<ffffffffa004e331>] pmem_make_request+0xd1/0x200 [nd_pmem]
  [<ffffffff811c3162>] ? mempool_alloc+0x72/0x1a0
  [<ffffffff8141f8b6>] generic_make_request+0xd6/0x110
  [<ffffffff8141f966>] submit_bio+0x76/0x170
  [<ffffffff81286dff>] submit_bh_wbc+0x12f/0x160
  [<ffffffff81286e62>] submit_bh+0x12/0x20
  [<ffffffff813395bd>] jbd2_write_superblock+0x8d/0x170
  [<ffffffff8133974d>] jbd2_mark_journal_empty+0x5d/0x90
  [<ffffffff813399cb>] jbd2_journal_destroy+0x24b/0x270
  [<ffffffff810bc4ca>] ? put_pwq_unlocked+0x2a/0x30
  [<ffffffff810bc6f5>] ? destroy_workqueue+0x225/0x250
  [<ffffffff81303494>] ext4_put_super+0x64/0x360
  [<ffffffff8124ab1a>] generic_shutdown_super+0x6a/0xf0

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:43:41 -06:00
Tejun Heo b02176f30c block: don't release bdi while request_queue has live references
bdi's are initialized in two steps, bdi_init() and bdi_register(), but
destroyed in a single step by bdi_destroy() which, for a bdi embedded
in a request_queue, is called during blk_cleanup_queue() which makes
the queue invisible and starts the draining of remaining usages.

A request_queue's user can access the congestion state of the embedded
bdi as long as it holds a reference to the queue.  As such, it may
access the congested state of a queue which finished
blk_cleanup_queue() but hasn't reached blk_release_queue() yet.
Because the congested state was embedded in backing_dev_info which in
turn is embedded in request_queue, accessing the congested state after
bdi_destroy() was called was fine.  The bdi was destroyed but the
memory region for the congested state remained accessible till the
queue got released.

a13f35e871 ("writeback: don't embed root bdi_writeback_congested in
bdi_writeback") changed the situation.  Now, the root congested state
which is expected to be pinned while request_queue remains accessible
is separately reference counted and the base ref is put during
bdi_destroy().  This means that the root congested state may go away
prematurely while the queue is between bdi_dstroy() and
blk_cleanup_queue(), which was detected by Andrey's KASAN tests.

The root cause of this problem is that bdi doesn't distinguish the two
steps of destruction, unregistration and release, and now the root
congested state actually requires a separate release step.  To fix the
issue, this patch separates out bdi_unregister() and bdi_exit() from
bdi_destroy().  bdi_unregister() is called from blk_cleanup_queue()
and bdi_exit() from blk_release_queue().  bdi_destroy() is now just a
simple wrapper calling the two steps back-to-back.

While at it, the prototype of bdi_destroy() is moved right below
bdi_setup_and_register() so that the counterpart operations are
located together.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: a13f35e871 ("writeback: don't embed root bdi_writeback_congested in bdi_writeback")
Cc: stable@vger.kernel.org # v4.2+
Reported-and-tested-by: Andrey Konovalov <andreyknvl@google.com>
Link: http://lkml.kernel.org/g/CAAeHK+zUJ74Zn17=rOyxacHU18SgCfC6bsYW=6kCY5GXJBwGfQ@mail.gmail.com
Reviewed-by: Jan Kara <jack@suse.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-15 09:53:28 -06:00
Linus Torvalds b0a1ea51bd Merge branch 'for-4.3/blkcg' of git://git.kernel.dk/linux-block
Pull blk-cg updates from Jens Axboe:
 "A bit later in the cycle, but this has been in the block tree for a a
  while.  This is basically four patchsets from Tejun, that improve our
  buffered cgroup writeback.  It was dependent on the other cgroup
  changes, but they went in earlier in this cycle.

  Series 1 is set of 5 patches that has cgroup writeback updates:

   - bdi_writeback iteration fix which could lead to some wb's being
     skipped or repeated during e.g. sync under memory pressure.

   - Simplification of wb work wait mechanism.

   - Writeback tracepoints updated to report cgroup.

  Series 2 is is a set of updates for the CFQ cgroup writeback handling:

     cfq has always charged all async IOs to the root cgroup.  It didn't
     have much choice as writeback didn't know about cgroups and there
     was no way to tell who to blame for a given writeback IO.
     writeback finally grew support for cgroups and now tags each
     writeback IO with the appropriate cgroup to charge it against.

     This patchset updates cfq so that it follows the blkcg each bio is
     tagged with.  Async cfq_queues are now shared across cfq_group,
     which is per-cgroup, instead of per-request_queue cfq_data.  This
     makes all IOs follow the weight based IO resource distribution
     implemented by cfq.

     - Switched from GFP_ATOMIC to GFP_NOWAIT as suggested by Jeff.

     - Other misc review points addressed, acks added and rebased.

  Series 3 is the blkcg policy cleanup patches:

     This patchset contains assorted cleanups for blkcg_policy methods
     and blk[c]g_policy_data handling.

     - alloc/free added for blkg_policy_data.  exit dropped.

     - alloc/free added for blkcg_policy_data.

     - blk-throttle's async percpu allocation is replaced with direct
       allocation.

     - all methods now take blk[c]g_policy_data instead of blkcg_gq or
       blkcg.

  And finally, series 4 is a set of patches cleaning up the blkcg stats
  handling:

    blkcg's stats have always been somwhat of a mess.  This patchset
    tries to improve the situation a bit.

     - The following patches added to consolidate blkcg entry point and
       blkg creation.  This is in itself is an improvement and helps
       colllecting common stats on bio issue.

     - per-blkg stats now accounted on bio issue rather than request
       completion so that bio based and request based drivers can behave
       the same way.  The issue was spotted by Vivek.

     - cfq-iosched implements custom recursive stats and blk-throttle
       implements custom per-cpu stats.  This patchset make blkcg core
       support both by default.

     - cfq-iosched and blk-throttle keep track of the same stats
       multiple times.  Unify them"

* 'for-4.3/blkcg' of git://git.kernel.dk/linux-block: (45 commits)
  blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchy
  blkcg: s/CFQ_WEIGHT_*/CFQ_WEIGHT_LEGACY_*/
  blkcg: implement interface for the unified hierarchy
  blkcg: misc preparations for unified hierarchy interface
  blkcg: separate out tg_conf_updated() from tg_set_conf()
  blkcg: move body parsing from blkg_conf_prep() to its callers
  blkcg: mark existing cftypes as legacy
  blkcg: rename subsystem name from blkio to io
  blkcg: refine error codes returned during blkcg configuration
  blkcg: remove unnecessary NULL checks from __cfqg_set_weight_device()
  blkcg: reduce stack usage of blkg_rwstat_recursive_sum()
  blkcg: remove cfqg_stats->sectors
  blkcg: move io_service_bytes and io_serviced stats into blkcg_gq
  blkcg: make blkg_[rw]stat_recursive_sum() to be able to index into blkcg_gq
  blkcg: make blkcg_[rw]stat per-cpu
  blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it
  blkcg: consolidate blkg creation in blkcg_bio_issue_check()
  blk-throttle: improve queue bypass handling
  blkcg: move root blkg lookup optimization from throtl_lookup_tg() to __blkg_lookup()
  blkcg: inline [__]blkg_lookup()
  ...
2015-09-10 18:56:14 -07:00
Tejun Heo ae11889636 blkcg: consolidate blkg creation in blkcg_bio_issue_check()
blkg (blkcg_gq) currently is created by blkcg policies invoking
blkg_lookup_create() which ends up repeating about the same code in
different policies.  Theoretically, this can avoid the overhead of
looking and/or creating blkg's if blkcg is enabled but no policy is in
use; however, the cost of blkg lookup / creation is very low
especially if only the root blkcg is in use which is highly likely if
no blkcg policy is in active use - it boils down to a single very
predictable conditional and surrounding RCU protection.

This patch consolidates blkg creation to a new function
blkcg_bio_issue_check() which is called during bio issue from
generic_make_request_checks().  blkcg_bio_issue_check() is now the
only function which tries to create missing blkg's.  The subsequent
policy and request_list operations just perform blkg_lookup() and if
missing falls back to the root.

* blk_get_rl() no longer tries to create blkg.  It uses blkg_lookup()
  instead of blkg_lookup_create().

* blk_throtl_bio() is now called from blkcg_bio_issue_check() with rcu
  read locked and blkg already looked up.  Both throtl_lookup_tg() and
  throtl_lookup_create_tg() are dropped.

* cfq is similarly updated.  cfq_lookup_create_cfqg() is replaced with
  cfq_lookup_cfqg()which uses blkg_lookup().

This consolidates blkg handling and avoids unnecessary blkg creation
retries under memory pressure.  In addition, this provides a common
bio entry point into blkcg where things like common accounting can be
performed.

v2: Build fixes for !CONFIG_CFQ_GROUP_IOSCHED and
    !CONFIG_BLK_DEV_THROTTLING.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Arianna Avanzini <avanzini.arianna@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-18 15:49:17 -07:00
Kent Overstreet 54efd50bfd block: make generic_make_request handle arbitrarily sized bios
The way the block layer is currently written, it goes to great lengths
to avoid having to split bios; upper layer code (such as bio_add_page())
checks what the underlying device can handle and tries to always create
bios that don't need to be split.

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

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

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

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

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

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Jim Paris <jim@jtan.com>
Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Acked-by: NeilBrown <neilb@suse.de> (for the 'md/md.c' bits)
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[dpark: skip more mq-based drivers, resolve merge conflicts, etc.]
Signed-off-by: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-13 12:31:33 -06:00
Jens Axboe b7c44ed9d2 block: manipulate bio->bi_flags through helpers
Some places use helpers now, others don't. We only have the 'is set'
helper, add helpers for setting and clearing flags too.

It was a bit of a mess of atomic vs non-atomic access. With
BIO_UPTODATE gone, we don't have any risk of concurrent access to the
flags. So relax the restriction and don't make any of them atomic. The
flags that do have serialization issues (reffed and chained), we
already handle those separately.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-29 08:55:20 -06:00
Christoph Hellwig 4246a0b63b block: add a bi_error field to struct bio
Currently we have two different ways to signal an I/O error on a BIO:

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

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

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-29 08:55:15 -06:00
Maninder Singh 0762b23d23 block: use FIELD_SIZEOF to calculate size of a field
use FIELD_SIZEOF instead of open coding

Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-07 07:47:37 -06:00
Linus Torvalds 22165fa798 - Revert block and DM core changes the removed request-based DM's
ability to handle partial request completions -- otherwise with the
   current SCSI LLDs these changes could lead to silent data corruption.
 
 - Fix two DM version bumps that were missing from the initial 4.2 DM
   pull request (enabled userspace lvm2 to know certain changes have been
   made).
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Merge tag 'dm-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:
 "Apologies for not pressing this request-based DM partial completion
  issue further, it was an oversight on my part.  We'll have to get it
  fixed up properly and revisit for a future release.

   - Revert block and DM core changes the removed request-based DM's
     ability to handle partial request completions -- otherwise with the
     current SCSI LLDs these changes could lead to silent data
     corruption.

   - Fix two DM version bumps that were missing from the initial 4.2 DM
     pull request (enabled userspace lvm2 to know certain changes have
     been made)"

* tag 'dm-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm cache policy smq: fix "default" version to be 1.4.0
  dm: bump the ioctl version to 4.32.0
  Revert "block, dm: don't copy bios for request clones"
  Revert "dm: do not allocate any mempools for blk-mq request-based DM"
2015-06-26 12:35:01 -07:00
Mike Snitzer 78d8e58a08 Revert "block, dm: don't copy bios for request clones"
This reverts commit 5f1b670d0b.

Justification for revert as reported in this dm-devel post:
https://www.redhat.com/archives/dm-devel/2015-June/msg00160.html

this change should not be pushed to mainline yet.

Firstly, Christoph has a newer version of the patch that fixes silent
data corruption problem:
  https://www.redhat.com/archives/dm-devel/2015-May/msg00229.html

And the new version still depends on LLDDs to always complete requests
to the end when error happens, while block API doesn't enforce such a
requirement. If the assumption is ever broken, the inconsistency between
request and bio (e.g. rq->__sector and rq->bio) will cause silent data
corruption:
  https://www.redhat.com/archives/dm-devel/2015-June/msg00022.html

Reported-by: Junichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-06-26 10:11:58 -04:00
Linus Torvalds e4bc13adfd Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block
Pull cgroup writeback support from Jens Axboe:
 "This is the big pull request for adding cgroup writeback support.

  This code has been in development for a long time, and it has been
  simmering in for-next for a good chunk of this cycle too.  This is one
  of those problems that has been talked about for at least half a
  decade, finally there's a solution and code to go with it.

  Also see last weeks writeup on LWN:

        http://lwn.net/Articles/648292/"

* 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits)
  writeback, blkio: add documentation for cgroup writeback support
  vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB
  writeback: do foreign inode detection iff cgroup writeback is enabled
  v9fs: fix error handling in v9fs_session_init()
  bdi: fix wrong error return value in cgwb_create()
  buffer: remove unusued 'ret' variable
  writeback: disassociate inodes from dying bdi_writebacks
  writeback: implement foreign cgroup inode bdi_writeback switching
  writeback: add lockdep annotation to inode_to_wb()
  writeback: use unlocked_inode_to_wb transaction in inode_congested()
  writeback: implement unlocked_inode_to_wb transaction and use it for stat updates
  writeback: implement [locked_]inode_to_wb_and_lock_list()
  writeback: implement foreign cgroup inode detection
  writeback: make writeback_control track the inode being written back
  writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb()
  mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use
  writeback: implement memcg writeback domain based throttling
  writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes
  writeback: implement memcg wb_domain
  writeback: update wb_over_bg_thresh() to use wb_domain aware operations
  ...
2015-06-25 16:00:17 -07:00
Linus Torvalds bfffa1cc9d Merge branch 'for-4.2/core' of git://git.kernel.dk/linux-block
Pull core block IO update from Jens Axboe:
 "Nothing really major in here, mostly a collection of smaller
  optimizations and cleanups, mixed with various fixes.  In more detail,
  this contains:

   - Addition of policy specific data to blkcg for block cgroups.  From
     Arianna Avanzini.

   - Various cleanups around command types from Christoph.

   - Cleanup of the suspend block I/O path from Christoph.

   - Plugging updates from Shaohua and Jeff Moyer, for blk-mq.

   - Eliminating atomic inc/dec of both remaining IO count and reference
     count in a bio.  From me.

   - Fixes for SG gap and chunk size support for data-less (discards)
     IO, so we can merge these better.  From me.

   - Small restructuring of blk-mq shared tag support, freeing drivers
     from iterating hardware queues.  From Keith Busch.

   - A few cfq-iosched tweaks, from Tahsin Erdogan and me.  Makes the
     IOPS mode the default for non-rotational storage"

* 'for-4.2/core' of git://git.kernel.dk/linux-block: (35 commits)
  cfq-iosched: fix other locations where blkcg_to_cfqgd() can return NULL
  cfq-iosched: fix sysfs oops when attempting to read unconfigured weights
  cfq-iosched: move group scheduling functions under ifdef
  cfq-iosched: fix the setting of IOPS mode on SSDs
  blktrace: Add blktrace.c to BLOCK LAYER in MAINTAINERS file
  block, cgroup: implement policy-specific per-blkcg data
  block: Make CFQ default to IOPS mode on SSDs
  block: add blk_set_queue_dying() to blkdev.h
  blk-mq: Shared tag enhancements
  block: don't honor chunk sizes for data-less IO
  block: only honor SG gap prevention for merges that contain data
  block: fix returnvar.cocci warnings
  block, dm: don't copy bios for request clones
  block: remove management of bi_remaining when restoring original bi_end_io
  block: replace trylock with mutex_lock in blkdev_reread_part()
  block: export blkdev_reread_part() and __blkdev_reread_part()
  suspend: simplify block I/O handling
  block: collapse bio bit space
  block: remove unused BIO_RW_BLOCK and BIO_EOF flags
  block: remove BIO_EOPNOTSUPP
  ...
2015-06-25 14:29:53 -07:00
Tejun Heo 482cf79cdf writeback, blkcg: propagate non-root blkcg congestion state
Now that bdi layer can handle per-blkcg bdi_writeback_congested state,
blk_{set|clear}_congested() can propagate non-root blkcg congestion
state to them.

This can be easily achieved by disabling the root_rl tests in
blk_{set|clear}_congested().  Note that we still need those tests when
!CONFIG_CGROUP_WRITEBACK as otherwise we'll end up flipping root blkcg
wb's congestion state for events happening on other blkcgs.

v2: Updated for bdi_writeback_congested.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:35 -06:00
Tejun Heo d40f75a06d writeback, blkcg: restructure blk_{set|clear}_queue_congested()
blk_{set|clear}_queue_congested() take @q and set or clear,
respectively, the congestion state of its bdi's root wb.  Because bdi
used to be able to handle congestion state only on the root wb, the
callers of those functions tested whether the congestion is on the
root blkcg and skipped if not.

This is cumbersome and makes implementation of per cgroup
bdi_writeback congestion state propagation difficult.  This patch
renames blk_{set|clear}_queue_congested() to
blk_{set|clear}_congested(), and makes them take request_list instead
of request_queue and test whether the specified request_list is the
root one before updating bdi_writeback congestion state.  This makes
the tests in the callers unnecessary and simplifies them.

As there are no external users of these functions, the definitions are
moved from include/linux/blkdev.h to block/blk-core.c.

This patch doesn't introduce any noticeable behavior difference.

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

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

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

This patch moves bdi->state into wb.

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

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

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

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: drbd-dev@lists.linbit.com
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
Tejun Heo eea8f41cc5 blkcg: move block/blk-cgroup.h to include/linux/blk-cgroup.h
cgroup aware writeback support will require exposing some of blkcg
details.  In preprataion, move block/blk-cgroup.h to
include/linux/blk-cgroup.h.  This patch is pure file move.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:33 -06:00
Mike Snitzer 183f7802e7 Merge remote-tracking branch 'jens/for-4.2/core' into dm-4.2 2015-05-29 14:17:16 -04:00
Christoph Hellwig 5f1b670d0b block, dm: don't copy bios for request clones
Currently dm-multipath has to clone the bios for every request sent
to the lower devices, which wastes cpu cycles and ties down memory.

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

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-22 08:58:57 -06:00
Christoph Hellwig 97ca223c3b block: remove unused BIO_RW_BLOCK and BIO_EOF flags
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-19 09:17:05 -06:00
Mike Snitzer 336b7e1f23 block: remove export for blk_queue_bio
With commit ff36ab345 ("dm: remove request-based logic from
make_request_fn wrapper") DM no longer calls blk_queue_bio() directly,
so remove its export.  Doing so required a forward declaration in
blk-core.c.

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

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

Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-08 14:17:23 -06:00
Shaohua Li dd6cf3e18d blk: clean up plug
Current code looks like inner plug gets flushed with a
blk_finish_plug(). Actually it's a nop. All requests/callbacks are added
to current->plug, while only outmost plug is assigned to current->plug.
So inner plug always has empty request/callback list, which makes
blk_flush_plug_list() a nop. This tries to make the code more clear.

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-05 13:40:42 -06:00
NeilBrown 6cd18e711d block: destroy bdi before blockdev is unregistered.
Because of the peculiar way that md devices are created (automatically
when the device node is opened), a new device can be created and
registered immediately after the
	blk_unregister_region(disk_devt(disk), disk->minors);
call in del_gendisk().

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

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

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

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

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

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

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

Fixes: c4db59d31e
Reported-by: Azat Khuzhin <a3at.mail@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org (v4.0)
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-27 10:27:20 -06:00
David Rientjes 271508dba2 block: allocate request memory local to request queue
blk_init_rl() allocates a mempool using mempool_create_node() with node
local memory.  This only allocates the mempool and element list locally
to the requeue queue node.

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

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-24 20:00:07 -06:00
Linus Torvalds 3e12cefbe1 Merge branch 'for-3.20/core' of git://git.kernel.dk/linux-block
Pull core block IO changes from Jens Axboe:
 "This contains:

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

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

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

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

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

* 'for-3.20/core' of git://git.kernel.dk/linux-block: (27 commits)
  block: remove unused function blk_bio_map_sg
  block: handle the null_mapped flag correctly in blk_rq_map_user_iov
  blk-mq: fix double-free in error path
  block: prevent request-to-request merging with gaps if not allowed
  blk-mq: make blk_mq_run_queues() static
  dm: fix multipath regression due to initializing wrong request
  cfq-iosched: handle failure of cfq group allocation
  block: Quiesce zeroout wrapper
  block: rewrite and split __bio_copy_iov()
  block: merge __bio_map_user_iov into bio_map_user_iov
  block: merge __bio_map_kern into bio_map_kern
  block: pass iov_iter to the BLOCK_PC mapping functions
  block: add a helper to free bio bounce buffer pages
  block: use blk_rq_map_user_iov to implement blk_rq_map_user
  block: simplify bio_map_kern
  block: mark blk-mq devices as stackable
  block: keep established cmd_flags when cloning into a blk-mq request
  block: add blk-mq support to blk_insert_cloned_request()
  block: require blk_rq_prep_clone() be given an initialized clone request
  blk-mq: add tag allocation policy
  ...
2015-02-12 14:13:23 -08:00
Keith Busch 77a0868901 block: keep established cmd_flags when cloning into a blk-mq request
blk_mq_alloc_request() may establish REQ_MQ_INFLIGHT in addition to
incrementing the hctx->nr_active count.  Any cmd_flags that are
established in the newly allocated clone request must be preserved in
addition to the cmd_flags that are later copied over from the original
request as part of blk_rq_prep_clone().

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

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

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

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

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-28 09:44:11 -07:00
Christoph Hellwig b4caecd480 fs: introduce f_op->mmap_capabilities for nommu mmap support
Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:02:58 -07:00
Jens Axboe aed3ea94bd block: wake up waiters when a queue is marked dying
If it's dying, we can't expect new request to complete and come
in an wake up other tasks waiting for requests. So after we
have marked it as dying, wake up everybody currently waiting
for a request. Once they wake, they will retry their allocation
and fail appropriately due to the state of the queue.

Tested-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-31 09:39:16 -07:00
Linus Torvalds caf292ae5b Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-block
Pull block driver core update from Jens Axboe:
 "This is the pull request for the core block IO changes for 3.19.  Not
  a huge round this time, mostly lots of little good fixes:

   - Fix a bug in sysfs blktrace interface causing a NULL pointer
     dereference, when enabled/disabled through that API.  From Arianna
     Avanzini.

   - Various updates/fixes/improvements for blk-mq:

        - A set of updates from Bart, mostly fixing buts in the tag
          handling.

        - Cleanup/code consolidation from Christoph.

        - Extend queue_rq API to be able to handle batching issues of IO
          requests. NVMe will utilize this shortly. From me.

        - A few tag and request handling updates from me.

        - Cleanup of the preempt handling for running queues from Paolo.

        - Prevent running of unmapped hardware queues from Ming Lei.

        - Move the kdump memory limiting check to be in the correct
          location, from Shaohua.

        - Initialize all software queues at init time from Takashi. This
          prevents a kobject warning when CPUs are brought online that
          weren't online when a queue was registered.

   - Single writeback fix for I_DIRTY clearing from Tejun.  Queued with
     the core IO changes, since it's just a single fix.

   - Version X of the __bio_add_page() segment addition retry from
     Maurizio.  Hope the Xth time is the charm.

   - Documentation fixup for IO scheduler merging from Jan.

   - Introduce (and use) generic IO stat accounting helpers for non-rq
     drivers, from Gu Zheng.

   - Kill off artificial limiting of max sectors in a request from
     Christoph"

* 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits)
  bio: modify __bio_add_page() to accept pages that don't start a new segment
  blk-mq: Fix uninitialized kobject at CPU hotplugging
  blktrace: don't let the sysfs interface remove trace from running list
  blk-mq: Use all available hardware queues
  blk-mq: Micro-optimize bt_get()
  blk-mq: Fix a race between bt_clear_tag() and bt_get()
  blk-mq: Avoid that __bt_get_word() wraps multiple times
  blk-mq: Fix a use-after-free
  blk-mq: prevent unmapped hw queue from being scheduled
  blk-mq: re-check for available tags after running the hardware queue
  blk-mq: fix hang in bt_get()
  blk-mq: move the kdump check to blk_mq_alloc_tag_set
  blk-mq: cleanup tag free handling
  blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map
  blk: introduce generic io stat accounting help function
  blk-mq: handle the single queue case in blk_mq_hctx_next_cpu
  genhd: check for int overflow in disk_expand_part_tbl()
  blk-mq: add blk_mq_free_hctx_request()
  blk-mq: export blk_mq_free_request()
  blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable
  ...
2014-12-13 14:14:23 -08:00
Linus Torvalds 92a578b064 ACPI and power management updates for 3.19-rc1
This time we have some more new material than we used to have during
 the last couple of development cycles.
 
 The most important part of it to me is the introduction of a unified
 interface for accessing device properties provided by platform
 firmware.  It works with Device Trees and ACPI in a uniform way and
 drivers using it need not worry about where the properties come
 from as long as the platform firmware (either DT or ACPI) makes
 them available.  It covers both devices and "bare" device node
 objects without struct device representation as that turns out to
 be necessary in some cases.  This has been in the works for quite
 a few months (and development cycles) and has been approved by
 all of the relevant maintainers.
 
 On top of that, some drivers are switched over to the new interface
 (at25, leds-gpio, gpio_keys_polled) and some additional changes are
 made to the core GPIO subsystem to allow device drivers to manipulate
 GPIOs in the "canonical" way on platforms that provide GPIO information
 in their ACPI tables, but don't assign names to GPIO lines (in which
 case the driver needs to do that on the basis of what it knows about
 the device in question).  That also has been approved by the GPIO
 core maintainers and the rfkill driver is now going to use it.
 
 Second is support for hardware P-states in the intel_pstate driver.
 It uses CPUID to detect whether or not the feature is supported by
 the processor in which case it will be enabled by default.  However,
 it can be disabled entirely from the kernel command line if necessary.
 
 Next is support for a platform firmware interface based on ACPI
 operation regions used by the PMIC (Power Management Integrated
 Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
 That interface is used for manipulating power resources and for
 thermal management: sensor temperature reporting, trip point setting
 and so on.
 
 Also the ACPI core is now going to support the _DEP configuration
 information in a limited way.  Basically, _DEP it supposed to reflect
 off-the-hierarchy dependencies between devices which may be very
 indirect, like when AML for one device accesses locations in an
 operation region handled by another device's driver (usually, the
 device depended on this way is a serial bus or GPIO controller).
 The support added this time is sufficient to make the ACPI battery
 driver work on Asus T100A, but it is general enough to be able to
 cover some other use cases in the future.
 
 Finally, we have a new cpufreq driver for the Loongson1B processor.
 
 In addition to the above, there are fixes and cleanups all over the
 place as usual and a traditional ACPICA update to a recent upstream
 release.
 
 As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver
 for Intel platforms should be able to handle power management of
 the DMA engine correctly, the cpufreq-dt driver should interact
 with the thermal subsystem in a better way and the ACPI backlight
 driver should handle some more corner cases, among other things.
 
 On top of the ACPICA update there are fixes for race conditions
 in the ACPICA's interrupt handling code which might lead to some
 random and strange looking failures on some systems.
 
 In the cleanups department the most visible part is the series
 of commits targeted at getting rid of the CONFIG_PM_RUNTIME
 configuration option.  That was triggered by a discussion
 regarding the generic power domains code during which we realized
 that trying to support certain combinations of PM config options
 was painful and not really worth it, because nobody would use them
 in production anyway.  For this reason, we decided to make
 CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and that lead to the
 conclusion that the latter became redundant and CONFIG_PM could
 be used instead of it.  The material here makes that replacement
 in a major part of the tree, but there will be at least one more
 batch of that in the second part of the merge window.
 
 Specifics:
 
  - Support for retrieving device properties information from ACPI
    _DSD device configuration objects and a unified device properties
    interface for device drivers (and subsystems) on top of that.
    As stated above, this works with Device Trees and ACPI and allows
    device drivers to be written in a platform firmware (DT or ACPI)
    agnostic way.  The at25, leds-gpio and gpio_keys_polled drivers
    are now going to use this new interface and the GPIO subsystem
    is additionally modified to allow device drivers to assign names
    to GPIO resources returned by ACPI _CRS objects (in case _DSD is
    not present or does not provide the expected data).  The changes
    in this set are mostly from Mika Westerberg, Rafael J Wysocki,
    Aaron Lu, and Darren Hart with some fixes from others (Fabio Estevam,
    Geert Uytterhoeven).
 
  - Support for Hardware Managed Performance States (HWP) as described
    in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
    driver.  CPUID is used to detect whether or not the feature is
    supported by the processor.  If supported, it will be enabled
    automatically unless the intel_pstate=no_hwp switch is present in
    the kernel command line.  From Dirk Brandewie.
 
  - New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).
 
  - Support for firmware interface based on ACPI operation regions
    used by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
    platforms for power resource control and thermal management
    (Aaron Lu).
 
  - Limited support for retrieving off-the-hierarchy dependencies
    between devices from ACPI _DEP device configuration objects
    and deferred probing support for the ACPI battery driver based
    on the _DEP information to make that driver work on Asus T100A
    (Lan Tianyu).
 
  - New cpufreq driver for the Loongson1B processor (Kelvin Cheung).
 
  - ACPICA update to upstream revision 20141107 which only affects
    tools (Bob Moore).
 
  - Fixes for race conditions in the ACPICA's interrupt handling
    code and in the ACPI code related to system suspend and resume
    (Lv Zheng and Rafael J Wysocki).
 
  - ACPI core fix for an RCU-related issue in the ioremap() regions
    management code that slowed down significantly after CPUs had
    been allowed to enter idle states even if they'd had RCU callbakcs
    queued and triggered some problems in certain proprietary graphics
    driver (and elsewhere).  The fix replaces synchronize_rcu() in
    that code with synchronize_rcu_expedited() which makes the issue
    go away.  From Konstantin Khlebnikov.
 
  - ACPI LPSS (Low-Power Subsystem) driver fix to handle power
    management of the DMA engine included into the LPSS correctly.
    The problem is that the DMA engine doesn't have ACPI PM support
    of its own and it simply is turned off when the last LPSS device
    having ACPI PM support goes into D3cold.  To work around that,
    the PM domain used by the ACPI LPSS driver is redesigned so at
    least one device with ACPI PM support will be on as long as the
    DMA engine is in use.  From Andy Shevchenko.
 
  - ACPI backlight driver fix to avoid using it on "Win8-compatible"
    systems where it doesn't work and where it was used by default by
    mistake (Aaron Lu).
 
  - Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
    Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and
    Ashwin Chaugule (mostly related to the upcoming ARM64 support).
 
  - Intel RAPL (Running Average Power Limit) power capping driver
    fixes and improvements including new processor IDs (Jacob Pan).
 
  - Generic power domains modification to power up domains after
    attaching devices to them to meet the expectations of device
    drivers and bus types assuming devices to be accessible at
    probe time (Ulf Hansson).
 
  - Preliminary support for controlling device clocks from the
    generic power domains core code and modifications of the
    ARM/shmobile platform to use that feature (Ulf Hansson).
 
  - Assorted minor fixes and cleanups of the generic power
    domains core code (Ulf Hansson, Geert Uytterhoeven).
 
  - Assorted minor fixes and cleanups of the device clocks control
    code in the PM core (Geert Uytterhoeven, Grygorii Strashko).
 
  - Consolidation of device power management Kconfig options by making
    CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
    which is now redundant (Rafael J Wysocki and Kevin Hilman).  That
    is the first batch of the changes needed for this purpose.
 
  - Core device runtime power management support code cleanup related
    to the execution of callbacks (Andrzej Hajda).
 
  - cpuidle ARM support improvements (Lorenzo Pieralisi).
 
  - cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and
    a new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
    Bartlomiej Zolnierkiewicz).
 
  - New cpufreq driver callback (->ready) to be executed when the
    cpufreq core is ready to use a given policy object and cpufreq-dt
    driver modification to use that callback for cooling device
    registration (Viresh Kumar).
 
  - cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu,
    James Geboski, Tomeu Vizoso).
 
  - Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
    cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
    Stefan Wahren, Petr Cvek).
 
  - OPP (Operating Performance Points) framework modification to
    allow OPPs to be removed too and update of a few cpufreq drivers
    (cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
    during initialization) on driver removal (Viresh Kumar).
 
  - Hibernation core fixes and cleanups (Tina Ruchandani and
    Markus Elfring).
 
  - PM Kconfig fix related to CPU power management (Pankaj Dubey).
 
  - cpupower tool fix (Prarit Bhargava).
 
 /
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Merge tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael Wysocki:
 "This time we have some more new material than we used to have during
  the last couple of development cycles.

  The most important part of it to me is the introduction of a unified
  interface for accessing device properties provided by platform
  firmware.  It works with Device Trees and ACPI in a uniform way and
  drivers using it need not worry about where the properties come from
  as long as the platform firmware (either DT or ACPI) makes them
  available.  It covers both devices and "bare" device node objects
  without struct device representation as that turns out to be necessary
  in some cases.  This has been in the works for quite a few months (and
  development cycles) and has been approved by all of the relevant
  maintainers.

  On top of that, some drivers are switched over to the new interface
  (at25, leds-gpio, gpio_keys_polled) and some additional changes are
  made to the core GPIO subsystem to allow device drivers to manipulate
  GPIOs in the "canonical" way on platforms that provide GPIO
  information in their ACPI tables, but don't assign names to GPIO lines
  (in which case the driver needs to do that on the basis of what it
  knows about the device in question).  That also has been approved by
  the GPIO core maintainers and the rfkill driver is now going to use
  it.

  Second is support for hardware P-states in the intel_pstate driver.
  It uses CPUID to detect whether or not the feature is supported by the
  processor in which case it will be enabled by default.  However, it
  can be disabled entirely from the kernel command line if necessary.

  Next is support for a platform firmware interface based on ACPI
  operation regions used by the PMIC (Power Management Integrated
  Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
  That interface is used for manipulating power resources and for
  thermal management: sensor temperature reporting, trip point setting
  and so on.

  Also the ACPI core is now going to support the _DEP configuration
  information in a limited way.  Basically, _DEP it supposed to reflect
  off-the-hierarchy dependencies between devices which may be very
  indirect, like when AML for one device accesses locations in an
  operation region handled by another device's driver (usually, the
  device depended on this way is a serial bus or GPIO controller).  The
  support added this time is sufficient to make the ACPI battery driver
  work on Asus T100A, but it is general enough to be able to cover some
  other use cases in the future.

  Finally, we have a new cpufreq driver for the Loongson1B processor.

  In addition to the above, there are fixes and cleanups all over the
  place as usual and a traditional ACPICA update to a recent upstream
  release.

  As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver for
  Intel platforms should be able to handle power management of the DMA
  engine correctly, the cpufreq-dt driver should interact with the
  thermal subsystem in a better way and the ACPI backlight driver should
  handle some more corner cases, among other things.

  On top of the ACPICA update there are fixes for race conditions in the
  ACPICA's interrupt handling code which might lead to some random and
  strange looking failures on some systems.

  In the cleanups department the most visible part is the series of
  commits targeted at getting rid of the CONFIG_PM_RUNTIME configuration
  option.  That was triggered by a discussion regarding the generic
  power domains code during which we realized that trying to support
  certain combinations of PM config options was painful and not really
  worth it, because nobody would use them in production anyway.  For
  this reason, we decided to make CONFIG_PM_SLEEP select
  CONFIG_PM_RUNTIME and that lead to the conclusion that the latter
  became redundant and CONFIG_PM could be used instead of it.  The
  material here makes that replacement in a major part of the tree, but
  there will be at least one more batch of that in the second part of
  the merge window.

  Specifics:

   - Support for retrieving device properties information from ACPI _DSD
     device configuration objects and a unified device properties
     interface for device drivers (and subsystems) on top of that.  As
     stated above, this works with Device Trees and ACPI and allows
     device drivers to be written in a platform firmware (DT or ACPI)
     agnostic way.  The at25, leds-gpio and gpio_keys_polled drivers are
     now going to use this new interface and the GPIO subsystem is
     additionally modified to allow device drivers to assign names to
     GPIO resources returned by ACPI _CRS objects (in case _DSD is not
     present or does not provide the expected data).  The changes in
     this set are mostly from Mika Westerberg, Rafael J Wysocki, Aaron
     Lu, and Darren Hart with some fixes from others (Fabio Estevam,
     Geert Uytterhoeven).

   - Support for Hardware Managed Performance States (HWP) as described
     in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
     driver.  CPUID is used to detect whether or not the feature is
     supported by the processor.  If supported, it will be enabled
     automatically unless the intel_pstate=no_hwp switch is present in
     the kernel command line.  From Dirk Brandewie.

   - New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).

   - Support for firmware interface based on ACPI operation regions used
     by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
     platforms for power resource control and thermal management (Aaron
     Lu).

   - Limited support for retrieving off-the-hierarchy dependencies
     between devices from ACPI _DEP device configuration objects and
     deferred probing support for the ACPI battery driver based on the
     _DEP information to make that driver work on Asus T100A (Lan
     Tianyu).

   - New cpufreq driver for the Loongson1B processor (Kelvin Cheung).

   - ACPICA update to upstream revision 20141107 which only affects
     tools (Bob Moore).

   - Fixes for race conditions in the ACPICA's interrupt handling code
     and in the ACPI code related to system suspend and resume (Lv Zheng
     and Rafael J Wysocki).

   - ACPI core fix for an RCU-related issue in the ioremap() regions
     management code that slowed down significantly after CPUs had been
     allowed to enter idle states even if they'd had RCU callbakcs
     queued and triggered some problems in certain proprietary graphics
     driver (and elsewhere).  The fix replaces synchronize_rcu() in that
     code with synchronize_rcu_expedited() which makes the issue go
     away.  From Konstantin Khlebnikov.

   - ACPI LPSS (Low-Power Subsystem) driver fix to handle power
     management of the DMA engine included into the LPSS correctly.  The
     problem is that the DMA engine doesn't have ACPI PM support of its
     own and it simply is turned off when the last LPSS device having
     ACPI PM support goes into D3cold.  To work around that, the PM
     domain used by the ACPI LPSS driver is redesigned so at least one
     device with ACPI PM support will be on as long as the DMA engine is
     in use.  From Andy Shevchenko.

   - ACPI backlight driver fix to avoid using it on "Win8-compatible"
     systems where it doesn't work and where it was used by default by
     mistake (Aaron Lu).

   - Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
     Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and Ashwin
     Chaugule (mostly related to the upcoming ARM64 support).

   - Intel RAPL (Running Average Power Limit) power capping driver fixes
     and improvements including new processor IDs (Jacob Pan).

   - Generic power domains modification to power up domains after
     attaching devices to them to meet the expectations of device
     drivers and bus types assuming devices to be accessible at probe
     time (Ulf Hansson).

   - Preliminary support for controlling device clocks from the generic
     power domains core code and modifications of the ARM/shmobile
     platform to use that feature (Ulf Hansson).

   - Assorted minor fixes and cleanups of the generic power domains core
     code (Ulf Hansson, Geert Uytterhoeven).

   - Assorted minor fixes and cleanups of the device clocks control code
     in the PM core (Geert Uytterhoeven, Grygorii Strashko).

   - Consolidation of device power management Kconfig options by making
     CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
     which is now redundant (Rafael J Wysocki and Kevin Hilman).  That
     is the first batch of the changes needed for this purpose.

   - Core device runtime power management support code cleanup related
     to the execution of callbacks (Andrzej Hajda).

   - cpuidle ARM support improvements (Lorenzo Pieralisi).

   - cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and a
     new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
     Bartlomiej Zolnierkiewicz).

   - New cpufreq driver callback (->ready) to be executed when the
     cpufreq core is ready to use a given policy object and cpufreq-dt
     driver modification to use that callback for cooling device
     registration (Viresh Kumar).

   - cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu, James
     Geboski, Tomeu Vizoso).

   - Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
     cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
     Stefan Wahren, Petr Cvek).

   - OPP (Operating Performance Points) framework modification to allow
     OPPs to be removed too and update of a few cpufreq drivers
     (cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
     during initialization) on driver removal (Viresh Kumar).

   - Hibernation core fixes and cleanups (Tina Ruchandani and Markus
     Elfring).

   - PM Kconfig fix related to CPU power management (Pankaj Dubey).

   - cpupower tool fix (Prarit Bhargava)"

* tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (120 commits)
  i2c-omap / PM: Drop CONFIG_PM_RUNTIME from i2c-omap.c
  dmaengine / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tools: cpupower: fix return checks for sysfs_get_idlestate_count()
  drivers: sh / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  e1000e / igb / PM: Eliminate CONFIG_PM_RUNTIME
  MMC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  MFD / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  misc / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  media / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  input / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  leds: leds-gpio: Fix multiple instances registration without 'label' property
  iio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hsi / OMAP / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  i2c-hid / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  drm / exynos / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  gpio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hwrandom / exynos / PM: Use CONFIG_PM in #ifdef
  block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  USB / PM: Drop CONFIG_PM_RUNTIME from the USB core
  PM: Merge the SET*_RUNTIME_PM_OPS() macros
  ...
2014-12-10 21:17:00 -08:00
Bart Van Assche 45a9c9d909 blk-mq: Fix a use-after-free
blk-mq users are allowed to free the memory request_queue.tag_set
points at after blk_cleanup_queue() has finished but before
blk_release_queue() has started. This can happen e.g. in the SCSI
core. The SCSI core namely embeds the tag_set structure in a SCSI
host structure. The SCSI host structure is freed by
scsi_host_dev_release(). This function is called after
blk_cleanup_queue() finished but can be called before
blk_release_queue().

This means that it is not safe to access request_queue.tag_set from
inside blk_release_queue(). Hence remove the blk_sync_queue() call
from blk_release_queue(). This call is not necessary - outstanding
requests must have finished before blk_release_queue() is
called. Additionally, move the blk_mq_free_queue() call from
blk_release_queue() to blk_cleanup_queue() to avoid that struct
request_queue.tag_set gets accessed after it has been freed.

This patch avoids that the following kernel oops can be triggered
when deleting a SCSI host for which scsi-mq was enabled:

Call Trace:
 [<ffffffff8109a7c4>] lock_acquire+0xc4/0x270
 [<ffffffff814ce111>] mutex_lock_nested+0x61/0x380
 [<ffffffff812575f0>] blk_mq_free_queue+0x30/0x180
 [<ffffffff8124d654>] blk_release_queue+0x84/0xd0
 [<ffffffff8126c29b>] kobject_cleanup+0x7b/0x1a0
 [<ffffffff8126c140>] kobject_put+0x30/0x70
 [<ffffffff81245895>] blk_put_queue+0x15/0x20
 [<ffffffff8125c409>] disk_release+0x99/0xd0
 [<ffffffff8133d056>] device_release+0x36/0xb0
 [<ffffffff8126c29b>] kobject_cleanup+0x7b/0x1a0
 [<ffffffff8126c140>] kobject_put+0x30/0x70
 [<ffffffff8125a78a>] put_disk+0x1a/0x20
 [<ffffffff811d4cb5>] __blkdev_put+0x135/0x1b0
 [<ffffffff811d56a0>] blkdev_put+0x50/0x160
 [<ffffffff81199eb4>] kill_block_super+0x44/0x70
 [<ffffffff8119a2a4>] deactivate_locked_super+0x44/0x60
 [<ffffffff8119a87e>] deactivate_super+0x4e/0x70
 [<ffffffff811b9833>] cleanup_mnt+0x43/0x90
 [<ffffffff811b98d2>] __cleanup_mnt+0x12/0x20
 [<ffffffff8107252c>] task_work_run+0xac/0xe0
 [<ffffffff81002c01>] do_notify_resume+0x61/0xa0
 [<ffffffff814d2c58>] int_signal+0x12/0x17

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robert Elliott <elliott@hp.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Alexander Gordeev <agordeev@redhat.com>
Cc: <stable@vger.kernel.org> # v3.13+
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-09 09:07:13 -07:00
Rafael J. Wysocki 47fafbc701 block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
After commit b2b49ccbdd (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so #ifdef blocks
depending on CONFIG_PM_RUNTIME may now be changed to depend on
CONFIG_PM.

Replace CONFIG_PM_RUNTIME with CONFIG_PM in the block device core.

Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-04 01:00:23 +01:00
Christoph Hellwig 125c99bc8b scsi: add new scsi-command flag for tagged commands
Currently scsi piggy backs on the block layer to define the concept
of a tagged command.  But we want to be able to have block-level host-wide
tags assigned even for untagged commands like the initial INQUIRY, so add
a new SCSI-level flag for commands that are tagged at the scsi level, so
that even commands without that set can have tags assigned to them.  Note
that this alredy is the case for the blk-mq code path, and this just lets
the old path catch up with it.

We also set this flag based upon sdev->simple_tags instead of the block
queue flag, so that it is entirely independent of the block layer tagging,
and thus always correct even if a driver doesn't use block level tagging
yet.

Also remove the old blk_rq_tagged; it was only used by SCSI drivers, and
removing it forces them to look for the proper replacement.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-12 11:19:40 +01:00
Linus Torvalds d3dc366bba Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block
Pull core block layer changes from Jens Axboe:
 "This is the core block IO pull request for 3.18.  Apart from the new
  and improved flush machinery for blk-mq, this is all mostly bug fixes
  and cleanups.

   - blk-mq timeout updates and fixes from Christoph.

   - Removal of REQ_END, also from Christoph.  We pass it through the
     ->queue_rq() hook for blk-mq instead, freeing up one of the request
     bits.  The space was overly tight on 32-bit, so Martin also killed
     REQ_KERNEL since it's no longer used.

   - blk integrity updates and fixes from Martin and Gu Zheng.

   - Update to the flush machinery for blk-mq from Ming Lei.  Now we
     have a per hardware context flush request, which both cleans up the
     code should scale better for flush intensive workloads on blk-mq.

   - Improve the error printing, from Rob Elliott.

   - Backing device improvements and cleanups from Tejun.

   - Fixup of a misplaced rq_complete() tracepoint from Hannes.

   - Make blk_get_request() return error pointers, fixing up issues
     where we NULL deref when a device goes bad or missing.  From Joe
     Lawrence.

   - Prep work for drastically reducing the memory consumption of dm
     devices from Junichi Nomura.  This allows creating clone bio sets
     without preallocating a lot of memory.

   - Fix a blk-mq hang on certain combinations of queue depths and
     hardware queues from me.

   - Limit memory consumption for blk-mq devices for crash dump
     scenarios and drivers that use crazy high depths (certain SCSI
     shared tag setups).  We now just use a single queue and limited
     depth for that"

* 'for-3.18/core' of git://git.kernel.dk/linux-block: (58 commits)
  block: Remove REQ_KERNEL
  blk-mq: allocate cpumask on the home node
  bio-integrity: remove the needless fail handle of bip_slab creating
  block: include func name in __get_request prints
  block: make blk_update_request print prefix match ratelimited prefix
  blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio
  block: fix alignment_offset math that assumes io_min is a power-of-2
  blk-mq: Make bt_clear_tag() easier to read
  blk-mq: fix potential hang if rolling wakeup depth is too high
  block: add bioset_create_nobvec()
  block: use bio_clone_fast() in blk_rq_prep_clone()
  block: misplaced rq_complete tracepoint
  sd: Honor block layer integrity handling flags
  block: Replace strnicmp with strncasecmp
  block: Add T10 Protection Information functions
  block: Don't merge requests if integrity flags differ
  block: Integrity checksum flag
  block: Relocate bio integrity flags
  block: Add a disk flag to block integrity profile
  block: Add prefix to block integrity profile flags
  ...
2014-10-18 11:53:51 -07:00
Robert Elliott 7b2b10e0e2 block: include func name in __get_request prints
In __get_request calls to printk_ratelimited, include the function name so
the callbacks suppressed message matches the messages that are printed,
and add "dev" before the device name so it matches other block layer
messages.

Signed-off-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-13 08:34:23 -06:00
Robert Elliott ef3ecb66bc block: make blk_update_request print prefix match ratelimited prefix
In blk_update_request, change the printk_ratelimited
prefix from end_request to blk_update_request so it
matches the name printed if rate limiting occurs.

Old:
[10234.933106] blk_update_request: 174 callbacks suppressed
[10234.934940] end_request: critical target error, dev sdr, sector 16
[10234.949788] end_request: critical target error, dev sdr, sector 16

New:
[16863.445173] blk_update_request: 398 callbacks suppressed
[16863.447029] blk_update_request: critical target error, dev sdr, sector
1442066176
[16863.449383] blk_update_request: critical target error, dev sdr, sector
802802888
[16863.451680] blk_update_request: critical target error, dev sdr, sector
1609535456

Signed-off-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-13 08:34:21 -06:00
Linus Torvalds 28596c9722 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull "trivial tree" updates from Jiri Kosina:
 "Usual pile from trivial tree everyone is so eagerly waiting for"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  Remove MN10300_PROC_MN2WS0038
  mei: fix comments
  treewide: Fix typos in Kconfig
  kprobes: update jprobe_example.c for do_fork() change
  Documentation: change "&" to "and" in Documentation/applying-patches.txt
  Documentation: remove obsolete pcmcia-cs from Changes
  Documentation: update links in Changes
  Documentation: Docbook: Fix generated DocBook/kernel-api.xml
  score: Remove GENERIC_HAS_IOMAP
  gpio: fix 'CONFIG_GPIO_IRQCHIP' comments
  tty: doc: Fix grammar in serial/tty
  dma-debug: modify check_for_stack output
  treewide: fix errors in printk
  genirq: fix reference in devm_request_threaded_irq comment
  treewide: fix synchronize_rcu() in comments
  checkstack.pl: port to AArch64
  doc: queue-sysfs: minor fixes
  init/do_mounts: better syntax description
  MIPS: fix comment spelling
  powerpc/simpleboot: fix comment
  ...
2014-10-07 21:16:26 -04:00
Junichi Nomura 11dfce509e block: use bio_clone_fast() in blk_rq_prep_clone()
Request cloning clones bios in the request to track the completion
of each bio.
For that purpose, we can use bio_clone_fast() instead of bio_clone()
to avoid unnecessary allocation and copy of bvecs.

This patch reduces memory footprint of request-based device-mapper
(about 1-4KB for each request) and is a preparation for further
reduction of memory usage by removing unused bvec mempool.

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-03 15:28:16 -06:00
Hannes Reinecke 4a0efdc933 block: misplaced rq_complete tracepoint
The rq_complete tracepoint was never issued for empty requests,
causing the resulting blktrace information to never show any
completion for those request.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-01 08:17:42 -06:00
Ming Lei f70ced0917 blk-mq: support per-distpatch_queue flush machinery
This patch supports to run one single flush machinery for
each blk-mq dispatch queue, so that:

- current init_request and exit_request callbacks can
cover flush request too, then the buggy copying way of
initializing flush request's pdu can be fixed

- flushing performance gets improved in case of multi hw-queue

In fio sync write test over virtio-blk(4 hw queues, ioengine=sync,
iodepth=64, numjobs=4, bs=4K), it is observed that througput gets
increased a lot over my test environment:
	- throughput: +70% in case of virtio-blk over null_blk
	- throughput: +30% in case of virtio-blk over SSD image

The multi virtqueue feature isn't merged to QEMU yet, and patches for
the feature can be found in below tree:

	git://kernel.ubuntu.com/ming/qemu.git  	v2.1.0-mq.4

And simply passing 'num_queues=4 vectors=5' should be enough to
enable multi queue(quad queue) feature for QEMU virtio-blk.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-25 15:22:45 -06:00
Ming Lei e97c293cdf block: introduce 'blk_mq_ctx' parameter to blk_get_flush_queue
This patch adds 'blk_mq_ctx' parameter to blk_get_flush_queue(),
so that this function can find the corresponding blk_flush_queue
bound with current mq context since the flush queue will become
per hw-queue.

For legacy queue, the parameter can be simply 'NULL'.

For multiqueue case, the parameter should be set as the context
from which the related request is originated. With this context
info, the hw queue and related flush queue can be found easily.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-25 15:22:44 -06:00
Ming Lei ba483388e3 block: remove blk_init_flush() and its pair
Now mission of the two helpers is over, and just call
blk_alloc_flush_queue() and blk_free_flush_queue() directly.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-25 15:22:41 -06:00
Ming Lei 7c94e1c157 block: introduce blk_flush_queue to drive flush machinery
This patch introduces 'struct blk_flush_queue' and puts all
flush machinery related fields into this structure, so that

	- flush implementation details aren't exposed to driver
	- it is easy to convert to per dispatch-queue flush machinery

This patch is basically a mechanical replacement.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-25 15:22:40 -06:00
Ming Lei 3c09676c12 block: move flush initialization to blk_flush_init
These fields are always used with the flush request, so
initialize them together.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-25 15:22:37 -06:00
Ming Lei f355265571 block: introduce blk_init_flush and its pair
These two temporary functions are introduced for holding flush
initialization and de-initialization, so that we can
introduce 'flush queue' easier in the following patch. And
once 'flush queue' and its allocation/free functions are ready,
they will be removed for sake of code readability.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-25 15:22:35 -06:00
Jens Axboe b207892b06 Merge branch 'for-linus' into for-3.18/core
A bit of churn on the for-linus side that would be nice to have
in the core bits for 3.18, so pull it in to catch us up and make
forward progress easier.

Signed-off-by: Jens Axboe <axboe@fb.com>

Conflicts:
	block/scsi_ioctl.c
2014-09-11 09:31:18 -06:00
Masanari Iida da3dae54e4 Documentation: Docbook: Fix generated DocBook/kernel-api.xml
This patch fix spelling typo found in DocBook/kernel-api.xml.
It is because the file is generated from the source comments,
I have to fix the comments in source codes.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-09-09 10:34:56 +02:00
Tejun Heo ff9ea32381 block, bdi: an active gendisk always has a request_queue associated with it
bdev_get_queue() returns the request_queue associated with the
specified block_device.  blk_get_backing_dev_info() makes use of
bdev_get_queue() to determine the associated bdi given a block_device.

All the callers of bdev_get_queue() including
blk_get_backing_dev_info() assume that bdev_get_queue() may return
NULL and implement NULL handling; however, bdev_get_queue() requires
the passed in block_device is opened and attached to its gendisk.
Because an active gendisk always has a valid request_queue associated
with it, bdev_get_queue() can never return NULL and neither can
blk_get_backing_dev_info().

Make it clear that neither of the two functions can return NULL and
remove NULL handling from all the callers.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chris Mason <clm@fb.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-08 10:00:35 -06:00
Joe Lawrence a492f07545 block,scsi: fixup blk_get_request dead queue scenarios
The blk_get_request function may fail in low-memory conditions or during
device removal (even if __GFP_WAIT is set). To distinguish between these
errors, modify the blk_get_request call stack to return the appropriate
ERR_PTR. Verify that all callers check the return status and consider
IS_ERR instead of a simple NULL pointer check.

For consistency, make a similar change to the blk_mq_alloc_request leg
of blk_get_request.  It may fail if the queue is dead, or the caller was
unwilling to wait.

Signed-off-by: Joe Lawrence <joe.lawrence@stratus.com>
Acked-by: Jiri Kosina <jkosina@suse.cz> [for pktdvd]
Acked-by: Boaz Harrosh <bharrosh@panasas.com> [for osd]
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-08-28 10:03:46 -06:00
Tony Battersby 6f4a16266f scsi-mq: fix requests that use a separate CDB buffer
This patch fixes code such as the following with scsi-mq enabled:

    rq = blk_get_request(...);
    blk_rq_set_block_pc(rq);

    rq->cmd = my_cmd_buffer; /* separate CDB buffer */

    blk_execute_rq_nowait(...);

Code like this appears in e.g. sg_start_req() in drivers/scsi/sg.c (for
large CDBs only).  Without this patch, scsi_mq_prep_fn() will set
rq->cmd back to rq->__cmd, causing the wrong CDB to be sent to the device.

Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-08-22 15:04:31 -05:00
Tejun Heo 780db2071a blk-mq: decouble blk-mq freezing from generic bypassing
blk_mq freezing is entangled with generic bypassing which bypasses
blkcg and io scheduler and lets IO requests fall through the block
layer to the drivers in FIFO order.  This allows forward progress on
IOs with the advanced features disabled so that those features can be
configured or altered without worrying about stalling IO which may
lead to deadlock through memory allocation.

However, generic bypassing doesn't quite fit blk-mq.  blk-mq currently
doesn't make use of blkcg or ioscheds and it maps bypssing to
freezing, which blocks request processing and drains all the in-flight
ones.  This causes problems as bypassing assumes that request
processing is online.  blk-mq works around this by conditionally
allowing request processing for the problem case - during queue
initialization.

Another weirdity is that except for during queue cleanup, bypassing
started on the generic side prevents blk-mq from processing new
requests but doesn't drain the in-flight ones.  This shouldn't break
anything but again highlights that something isn't quite right here.

The root cause is conflating blk-mq freezing and generic bypassing
which are two different mechanisms.  The only intersecting purpose
that they serve is during queue cleanup.  Let's properly separate
blk-mq freezing from generic bypassing and simply use it where
necessary.

* request_queue->mq_freeze_depth is added and
  blk_mq_[un]freeze_queue() now operate on this counter instead of
  ->bypass_depth.  The replacement for QUEUE_FLAG_BYPASS isn't added
  but the counter is tested directly.  This will be further updated by
  later changes.

* blk_mq_drain_queue() is dropped and "__" prefix is dropped from
  blk_mq_freeze_queue().  Queue cleanup path now calls
  blk_mq_freeze_queue() directly.

* blk_queue_enter()'s fast path condition is simplified to simply
  check @q->mq_freeze_depth.  Previously, the condition was

	!blk_queue_dying(q) &&
	    (!blk_queue_bypass(q) || !blk_queue_init_done(q))

  mq_freeze_depth is incremented right after dying is set and
  blk_queue_init_done() exception isn't necessary as blk-mq doesn't
  start frozen, which only leaves the blk_queue_bypass() test which
  can be replaced by @q->mq_freeze_depth test.

This change simplifies the code and reduces confusion in the area.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-07-01 10:31:13 -06:00
Tejun Heo 776687bce4 block, blk-mq: draining can't be skipped even if bypass_depth was non-zero
Currently, both blk_queue_bypass_start() and blk_mq_freeze_queue()
skip queue draining if bypass_depth was already above zero.  The
assumption is that the one which bumped the bypass_depth should have
performed draining already; however, there's nothing which prevents a
new instance of bypassing/freezing from starting before the previous
one finishes draining.  The current code may allow the later
bypassing/freezing instances to complete while there still are
in-flight requests which haven't finished draining.

Fix it by draining regardless of bypass_depth.  We still skip draining
from blk_queue_bypass_start() while the queue is initializing to avoid
introducing excessive delays during boot.  INIT_DONE setting is moved
above the initial blk_queue_bypass_end() so that bypassing attempts
can't slip inbetween.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-07-01 10:29:17 -06:00
Linus Torvalds f1d702487b Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
 "A smaller collection of fixes for the block core that would be nice to
  have in -rc2.  This pull request contains:

   - Fixes for races in the wait/wakeup logic used in blk-mq from
     Alexander.  No issues have been observed, but it is definitely a
     bit flakey currently.  Alternatively, we may drop the cyclic
     wakeups going forward, but that needs more testing.

   - Some cleanups from Christoph.

   - Fix for an oops in null_blk if queue_mode=1 and softirq completions
     are used.  From me.

   - A fix for a regression caused by the chunk size setting.  It
     inadvertently used max_hw_sectors instead of max_sectors, which is
     incorrect, and causes hangs on btrfs multi-disk setups (where hw
     sectors apparently isn't set).  From me.

   - Removal of WQ_POWER_EFFICIENT in the kblockd creation.  This was a
     recent addition as well, but it actually breaks blk-mq which relies
     on strict scheduling.  If the workqueue power_efficient mode is
     turned on, this breaks blk-mq.  From Matias.

   - null_blk module parameter description fix from Mike"

* 'for-linus' of git://git.kernel.dk/linux-block:
  blk-mq: bitmap tag: fix races in bt_get() function
  blk-mq: bitmap tag: fix race on blk_mq_bitmap_tags::wake_cnt
  blk-mq: bitmap tag: fix races on shared ::wake_index fields
  block: blk_max_size_offset() should check ->max_sectors
  null_blk: fix softirq completions for queue_mode == 1
  blk-mq: merge blk_mq_drain_queue and __blk_mq_drain_queue
  blk-mq: properly drain stopped queues
  block: remove WQ_POWER_EFFICIENT from kblockd
  null_blk: fix name and description of 'queue_mode' module parameter
  block: remove elv_abort_queue and blk_abort_flushes
2014-06-19 17:56:43 -10:00
Linus Torvalds b55b390202 Merge git://git.infradead.org/users/willy/linux-nvme
Pull NVMe update from Matthew Wilcox:
 "Mostly bugfixes again for the NVMe driver.  I'd like to call out the
  exported tracepoint in the block layer; I believe Keith has cleared
  this with Jens.

  We've had a few reports from people who're really pounding on NVMe
  devices at scale, hence the timeout changes (and new module
  parameters), hotplug cpu deadlock, tracepoints, and minor performance
  tweaks"

[ Jens hadn't seen that tracepoint thing, but is ok with it - it will
  end up going away when mq conversion happens ]

* git://git.infradead.org/users/willy/linux-nvme: (22 commits)
  NVMe: Fix START_STOP_UNIT Scsi->NVMe translation.
  NVMe: Use Log Page constants in SCSI emulation
  NVMe: Define Log Page constants
  NVMe: Fix hot cpu notification dead lock
  NVMe: Rename io_timeout to nvme_io_timeout
  NVMe: Use last bytes of f/w rev SCSI Inquiry
  NVMe: Adhere to request queue block accounting enable/disable
  NVMe: Fix nvme get/put queue semantics
  NVMe: Delete NVME_GET_FEAT_TEMP_THRESH
  NVMe: Make admin timeout a module parameter
  NVMe: Make iod bio timeout a parameter
  NVMe: Prevent possible NULL pointer dereference
  NVMe: Fix the buffer size passed in GetLogPage(CDW10.NUMD)
  NVMe: Update data structures for NVMe 1.2
  NVMe: Enable BUILD_BUG_ON checks
  NVMe: Update namespace and controller identify structures to the 1.1a spec
  NVMe: Flush with data support
  NVMe: Configure support for block flush
  NVMe: Add tracepoints
  NVMe: Protect against badly formatted CQEs
  ...
2014-06-15 15:58:03 -10:00
Matias Bjørling 28747fcd22 block: remove WQ_POWER_EFFICIENT from kblockd
blk-mq issues async requests through kblockd. To issue a work request on
a specific CPU, kblockd_schedule_delayed_work_on is used. However, the
specific CPU choice may not be honored, if the power_efficient option
for workqueues is set. blk-mq requires that we have strict per-cpu
scheduling, so it wont work properly if kblockd is marked
POWER_EFFICIENT and power_efficient is set.

Remove the kblockd WQ_POWER_EFFICIENT flag to prevent this behavior.
This essentially reverts part of commit 695588f945, which added
the WQ_POWER_EFFICIENT marker to kblockd.

Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-06-11 15:53:39 -06:00
Jens Axboe f27b087b81 block: add blk_rq_set_block_pc()
With the optimizations around not clearing the full request at alloc
time, we are leaving some of the needed init for REQ_TYPE_BLOCK_PC
up to the user allocating the request.

Add a blk_rq_set_block_pc() that sets the command type to
REQ_TYPE_BLOCK_PC, and properly initializes the members associated
with this type of request. Update callers to use this function instead
of manipulating rq->cmd_type directly.

Includes fixes from Christoph Hellwig <hch@lst.de> for my half-assed
attempt.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-06-06 07:57:37 -06:00
Jens Axboe 4d92a9beb3 block: remove 'magic' from struct blk_plug
I don't think we've ever caught any bugs with this, and there's the
list poisoning for the plug lists to catch uninitialized cases.
So remove the magic member and save 8 bytes in the struct.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-29 08:09:00 -06:00
Christoph Hellwig 4ce01dd1a0 blk-mq: merge blk_mq_alloc_reserved_request into blk_mq_alloc_request
Instead of having two almost identical copies of the same code just let
the callers pass in the reserved flag directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-28 09:49:19 -06:00
Ming Lei 3d2936f457 block: only allocate/free mq_usage_counter in blk-mq
The percpu counter is only used for blk-mq, so move
its allocation and free inside blk-mq, and don't
allocate it for legacy queue device.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-27 09:37:08 -06:00
Robert Elliott da41a589f5 blk-mq: Micro-optimize blk_queue_nomerges() check
In blk_mq_make_request(), do the blk_queue_nomerges() check
outside the call to blk_attempt_plug_merge() to eliminate
function call overhead when nomerges=2 (disabled)

Signed-off-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-20 15:49:03 -06:00
Jens Axboe e3a2b3f931 blk-mq: allow changing of queue depth through sysfs
For request_fn based devices, the block layer exports a 'nr_requests'
file through sysfs to allow adjusting of queue depth on the fly.
Currently this returns -EINVAL for blk-mq, since it's not wired up.
Wire this up for blk-mq, so that it now also always dynamic
adjustments of the allowed queue depth for any given block device
managed by blk-mq.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-20 11:49:02 -06:00
Jens Axboe 7276d02e24 block: only calculate part_in_flight() once
We first check if we have inflight IO, then retrieve that
same number again. Usually this isn't that costly since the
chance of having the data dirtied in between is small, but
there's no reason for calling part_in_flight() twice.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-09 15:48:23 -06:00
Keith Busch 3291fa57cb NVMe: Add tracepoints
Adding tracepoints for bio_complete and block_split into nvme to help
with gathering IO info using blktrace and blkparse.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
2014-05-05 10:41:26 -04:00
Christoph Hellwig 12120077b2 block: export blk_finish_request
This allows to mirror the blk-mq code flow for more a more readable I/O
completion handler in SCSI.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-16 14:15:25 -06:00
Christoph Hellwig 70f4db639c blk-mq: add blk_mq_delay_queue
Add a blk-mq equivalent to blk_delay_queue so that the scsi layer can ask
to be kicked again after a delay.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Modified by me to kill the unnecessary preempt disable/enable
in the delayed workqueue handler.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-16 14:15:25 -06:00
Jens Axboe b4f42e2831 block: remove struct request buffer member
This was used in the olden days, back when onions were proper
yellow. Basically it mapped to the current buffer to be
transferred. With highmem being added more than a decade ago,
most drivers map pages out of a bio, and rq->buffer isn't
pointing at anything valid.

Convert old style drivers to just use bio_data().

For the discard payload use case, just reference the page
in the bio.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-15 14:03:02 -06:00
Jens Axboe f89e0dd9d1 Linux 3.15-rc1
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Merge tag 'v3.15-rc1' into for-3.16/core

We don't like this, but things have diverged with the blk-mq fixes
in 3.15-rc1. So merge it in.
2014-04-15 14:02:24 -06:00
Duan Jiong 21f9fcd815 block: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
This patch fixes coccinelle error regarding usage of IS_ERR and
PTR_ERR instead of PTR_ERR_OR_ZERO.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-11 08:09:47 -06:00
Jens Axboe 360f92c244 block: fix regression with block enabled tagging
Martin reported that his test system would not boot with
current git, it oopsed with this:

BUG: unable to handle kernel paging request at ffff88046c6c9e80
IP: [<ffffffff812971e0>] blk_queue_start_tag+0x90/0x150
PGD 1ddf067 PUD 1de2067 PMD 47fc7d067 PTE 800000046c6c9060
Oops: 0002 [#1] SMP DEBUG_PAGEALLOC
Modules linked in: sd_mod lpfc(+) scsi_transport_fc scsi_tgt oracleasm
rpcsec_gss_krb5 ipv6 igb dca i2c_algo_bit i2c_core hwmon
CPU: 3 PID: 87 Comm: kworker/u17:1 Not tainted 3.14.0+ #246
Hardware name: Supermicro X9DRX+-F/X9DRX+-F, BIOS 3.00 07/09/2013
Workqueue: events_unbound async_run_entry_fn
task: ffff8802743c2150 ti: ffff880273d02000 task.ti: ffff880273d02000
RIP: 0010:[<ffffffff812971e0>]  [<ffffffff812971e0>]
blk_queue_start_tag+0x90/0x150
RSP: 0018:ffff880273d03a58  EFLAGS: 00010092
RAX: ffff88046c6c9e78 RBX: ffff880077208e78 RCX: 00000000fffc8da6
RDX: 00000000fffc186d RSI: 0000000000000009 RDI: 00000000fffc8d9d
RBP: ffff880273d03a88 R08: 0000000000000001 R09: ffff8800021c2410
R10: 0000000000000005 R11: 0000000000015b30 R12: ffff88046c5bb8a0
R13: ffff88046c5c0890 R14: 000000000000001e R15: 000000000000001e
FS:  0000000000000000(0000) GS:ffff880277b00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88046c6c9e80 CR3: 00000000018f6000 CR4: 00000000000407e0
Stack:
 ffff880273d03a98 ffff880474b18800 0000000000000000 ffff880474157000
 ffff88046c5c0890 ffff880077208e78 ffff880273d03ae8 ffffffff813b9e62
 ffff880200000010 ffff880474b18968 ffff880474b18848 ffff88046c5c0cd8
Call Trace:
 [<ffffffff813b9e62>] scsi_request_fn+0xf2/0x510
 [<ffffffff81293167>] __blk_run_queue+0x37/0x50
 [<ffffffff8129ac43>] blk_execute_rq_nowait+0xb3/0x130
 [<ffffffff8129ad24>] blk_execute_rq+0x64/0xf0
 [<ffffffff8108d2b0>] ? bit_waitqueue+0xd0/0xd0
 [<ffffffff813bba35>] scsi_execute+0xe5/0x180
 [<ffffffff813bbe4a>] scsi_execute_req_flags+0x9a/0x110
 [<ffffffffa01b1304>] sd_spinup_disk+0x94/0x460 [sd_mod]
 [<ffffffff81160000>] ? __unmap_hugepage_range+0x200/0x2f0
 [<ffffffffa01b2b9a>] sd_revalidate_disk+0xaa/0x3f0 [sd_mod]
 [<ffffffffa01b2fb8>] sd_probe_async+0xd8/0x200 [sd_mod]
 [<ffffffff8107703f>] async_run_entry_fn+0x3f/0x140
 [<ffffffff8106a1c5>] process_one_work+0x175/0x410
 [<ffffffff8106b373>] worker_thread+0x123/0x400
 [<ffffffff8106b250>] ? manage_workers+0x160/0x160
 [<ffffffff8107104e>] kthread+0xce/0xf0
 [<ffffffff81070f80>] ? kthread_freezable_should_stop+0x70/0x70
 [<ffffffff815f0bac>] ret_from_fork+0x7c/0xb0
 [<ffffffff81070f80>] ? kthread_freezable_should_stop+0x70/0x70
Code: 48 0f ab 11 72 db 48 81 4b 40 00 00 10 00 89 83 08 01 00 00 48 89
df 49 8b 04 24 48 89 1c d0 e8 f7 a8 ff ff 49 8b 85 28 05 00 00 <48> 89
58 08 48 89 03 49 8d 85 28 05 00 00 48 89 43 08 49 89 9d
RIP  [<ffffffff812971e0>] blk_queue_start_tag+0x90/0x150
 RSP <ffff880273d03a58>
CR2: ffff88046c6c9e80

Martin bisected and found this to be the problem patch;

	commit 6d113398dc
	Author: Jan Kara <jack@suse.cz>
	Date:   Mon Feb 24 16:39:54 2014 +0100

	    block: Stop abusing rq->csd.list in blk-softirq

and the problem was immediately apparent. The patch states that
it is safe to reuse queuelist at completion time, since it is
no longer used. However, that is not true if a device is using
block enabled tagging. If that is the case, then the queuelist
is reused to keep track of busy tags. If a device also ended
up using softirq completions, we'd reuse ->queuelist for the
IPI handling while block tagging was still using it. Boom.

Fix this by adding a new ipi_list list head, and share the
memory used with the request hash table. The hash table is
never used after the request is moved to the dispatch list,
which happens long before any potential completion of the
request. Add a new request bit for this, so we don't have
cases that check rq->hash while it could potentially have
been reused for the IPI completion.

Reported-by: Martin K. Petersen <martin.petersen@oracle.com>
Tested-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-09 21:54:06 -06:00
Jens Axboe 8ab14595b6 block: add kblockd_schedule_delayed_work_on()
Same function as kblockd_schedule_delayed_work(), but allow the
caller to pass in a CPU that the work should be executed on. This
just directly extends and maps into the workqueue API, and will
be used to make the blk-mq mappings more strict.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-09 10:17:03 -06:00
Jens Axboe 59c3d45e48 block: remove 'q' parameter from kblockd_schedule_*_work()
The queue parameter is never used, just get rid of it.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-09 10:17:00 -06:00
Linus Torvalds 159d8133d0 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull trivial tree updates from Jiri Kosina:
 "Usual rocket science -- mostly documentation and comment updates"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  sparse: fix comment
  doc: fix double words
  isdn: capi: fix "CAPI_VERSION" comment
  doc: DocBook: Fix typos in xml and template file
  Bluetooth: add module name for btwilink
  driver core: unexport static function create_syslog_header
  mmc: core: typo fix in printk specifier
  ARM: spear: clean up editing mistake
  net-sysfs: fix comment typo 'CONFIG_SYFS'
  doc: Insert MODULE_ in module-signing macros
  Documentation: update URL to hfsplus Technote 1150
  gpio: update path to documentation
  ixgbe: Fix format string in ixgbe_fcoe.
  Kconfig: Remove useless "default N" lines
  user_namespace.c: Remove duplicated word in comment
  CREDITS: fix formatting
  treewide: Fix typo in Documentation/DocBook
  mm: Fix warning on make htmldocs caused by slab.c
  ata: ata-samsung_cf: cleanup in header file
  idr: remove unused prototype of idr_free()
2014-04-02 16:23:38 -07:00
Linus Torvalds 7a48837732 Merge branch 'for-3.15/core' of git://git.kernel.dk/linux-block
Pull core block layer updates from Jens Axboe:
 "This is the pull request for the core block IO bits for the 3.15
  kernel.  It's a smaller round this time, it contains:

   - Various little blk-mq fixes and additions from Christoph and
     myself.

   - Cleanup of the IPI usage from the block layer, and associated
     helper code.  From Frederic Weisbecker and Jan Kara.

   - Duplicate code cleanup in bio-integrity from Gu Zheng.  This will
     give you a merge conflict, but that should be easy to resolve.

   - blk-mq notify spinlock fix for RT from Mike Galbraith.

   - A blktrace partial accounting bug fix from Roman Pen.

   - Missing REQ_SYNC detection fix for blk-mq from Shaohua Li"

* 'for-3.15/core' of git://git.kernel.dk/linux-block: (25 commits)
  blk-mq: add REQ_SYNC early
  rt,blk,mq: Make blk_mq_cpu_notify_lock a raw spinlock
  blk-mq: support partial I/O completions
  blk-mq: merge blk_mq_insert_request and blk_mq_run_request
  blk-mq: remove blk_mq_alloc_rq
  blk-mq: don't dump CPU -> hw queue map on driver load
  blk-mq: fix wrong usage of hctx->state vs hctx->flags
  blk-mq: allow blk_mq_init_commands() to return failure
  block: remove old blk_iopoll_enabled variable
  blktrace: fix accounting of partially completed requests
  smp: Rename __smp_call_function_single() to smp_call_function_single_async()
  smp: Remove wait argument from __smp_call_function_single()
  watchdog: Simplify a little the IPI call
  smp: Move __smp_call_function_single() below its safe version
  smp: Consolidate the various smp_call_function_single() declensions
  smp: Teach __smp_call_function_single() to check for offline cpus
  smp: Remove unused list_head from csd
  smp: Iterate functions through llist_for_each_entry_safe()
  block: Stop abusing rq->csd.list in blk-softirq
  block: Remove useless IPI struct initialization
  ...
2014-04-01 19:19:15 -07:00
Dave Jones 708f04d2ab block: free q->flush_rq in blk_init_allocated_queue error paths
Commit 7982e90c3a ("block: fix q->flush_rq NULL pointer crash on
dm-mpath flush") moved an allocation to blk_init_allocated_queue(), but
neglected to free that allocation on the error paths that follow.

Signed-off-by: Dave Jones <davej@fedoraproject.org>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-20 22:32:06 -07:00