Commit graph

307 commits

Author SHA1 Message Date
Jens Axboe
5c61ee2cd5 Linux 5.1-rc6
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Merge tag 'v5.1-rc6' into for-5.2/block

Pull in v5.1-rc6 to resolve two conflicts. One is in BFQ, in just a
comment, and is trivial. The other one is a conflict due to a later fix
in the bio multi-page work, and needs a bit more care.

* tag 'v5.1-rc6': (770 commits)
  Linux 5.1-rc6
  block: make sure that bvec length can't be overflow
  block: kill all_q_node in request_queue
  x86/cpu/intel: Lower the "ENERGY_PERF_BIAS: Set to normal" message's log priority
  coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping
  mm/kmemleak.c: fix unused-function warning
  init: initialize jump labels before command line option parsing
  kernel/watchdog_hld.c: hard lockup message should end with a newline
  kcov: improve CONFIG_ARCH_HAS_KCOV help text
  mm: fix inactive list balancing between NUMA nodes and cgroups
  mm/hotplug: treat CMA pages as unmovable
  proc: fixup proc-pid-vm test
  proc: fix map_files test on F29
  mm/vmstat.c: fix /proc/vmstat format for CONFIG_DEBUG_TLBFLUSH=y CONFIG_SMP=n
  mm/memory_hotplug: do not unlock after failing to take the device_hotplug_lock
  mm: swapoff: shmem_unuse() stop eviction without igrab()
  mm: swapoff: take notice of completion sooner
  mm: swapoff: remove too limiting SWAP_UNUSE_MAX_TRIES
  mm: swapoff: shmem_find_swap_entries() filter out other types
  slab: store tagged freelist for off-slab slabmgmt
  ...

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-22 09:47:36 -06:00
Dongli Zhang
bf348f9b78 virtio-blk: limit number of hw queues by nr_cpu_ids
When tag_set->nr_maps is 1, the block layer limits the number of hw queues
by nr_cpu_ids. No matter how many hw queues are used by virtio-blk, as it
has (tag_set->nr_maps == 1), it can use at most nr_cpu_ids hw queues.

In addition, specifically for pci scenario, when the 'num-queues' specified
by qemu is more than maxcpus, virtio-blk would not be able to allocate more
than maxcpus vectors in order to have a vector for each queue. As a result,
it falls back into MSI-X with one vector for config and one shared for
queues.

Considering above reasons, this patch limits the number of hw queues used
by virtio-blk by nr_cpu_ids.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-10 08:18:24 -06:00
Dongli Zhang
9bc00750f5 virtio_blk: replace 0 by HCTX_TYPE_DEFAULT to index blk_mq_tag_set->map
Use HCTX_TYPE_DEFAULT instead of 0 to avoid hardcoding.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-08 08:08:29 -06:00
Joerg Roedel
fd1068e186 virtio-blk: Consider virtio_max_dma_size() for maximum segment size
Segments can't be larger than the maximum DMA mapping size
supported on the platform. Take that into account when
setting the maximum segment size for a block device.

Cc: stable@vger.kernel.org
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-03-06 11:19:26 -05:00
Linus Torvalds
d548e65904 virtio, vhost: features, fixes, cleanups
discard in virtio blk
 misc fixes and cleanups
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio/vhost updates from Michael Tsirkin:
"Features, fixes, cleanups:

   - discard in virtio blk

   - misc fixes and cleanups"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: correct the related warning message
  vhost: split structs into a separate header file
  virtio: remove deprecated VIRTIO_PCI_CONFIG()
  vhost/vsock: switch to a mutex for vhost_vsock_hash
  virtio_blk: add discard and write zeroes support
2019-01-02 18:54:45 -08:00
Changpeng Liu
1f23816b8e virtio_blk: add discard and write zeroes support
In commit 88c85538, "virtio-blk: add discard and write zeroes features
to specification" (https://github.com/oasis-tcs/virtio-spec), the virtio
block specification has been extended to add VIRTIO_BLK_T_DISCARD and
VIRTIO_BLK_T_WRITE_ZEROES commands.  This patch enables support for
discard and write zeroes in the virtio-blk driver when the device
advertises the corresponding features, VIRTIO_BLK_F_DISCARD and
VIRTIO_BLK_F_WRITE_ZEROES.

Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Signed-off-by: Daniel Verkamp <dverkamp@chromium.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-12-19 18:23:49 -05:00
Jens Axboe
944e7c8796 virtio_blk: implement mq_ops->commit_rqs() hook
We need this for blk-mq to kick things into gear, if we told it that
we had more IO coming, but then failed to deliver on that promise.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-29 10:12:22 -07:00
Jens Axboe
ed76e329d7 blk-mq: abstract out queue map
This is in preparation for allowing multiple sets of maps per
queue, if so desired.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-07 13:44:59 -07:00
Hannes Reinecke
e982c4d0a2 virtio-blk: modernize sysfs attribute creation
Use new-style DEVICE_ATTR_RO/DEVICE_ATTR_RW to create the sysfs attributes
and register the disk with default sysfs attribute groups.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-28 08:30:33 -06:00
Hannes Reinecke
fef912bf86 block: genhd: add 'groups' argument to device_add_disk
Update device_add_disk() to take an 'groups' argument so that
individual drivers can register a device with additional sysfs
attributes.
This avoids race condition the driver would otherwise have if these
groups were to be created with sysfs_add_groups().

Signed-off-by: Martin Wilck <martin.wilck@suse.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-28 08:30:28 -06:00
Joe Perches
5657a819a8 block drivers/block: Use octal not symbolic permissions
Convert the S_<FOO> symbolic permissions to their octal equivalents as
using octal and not symbolic permissions is preferred by many as more
readable.

see: https://lkml.org/lkml/2016/8/2/1945

Done with automated conversion via:
$ ./scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace <files...>

Miscellanea:

o Wrapped modified multi-line calls to a single line where appropriate
o Realign modified multi-line calls to open parenthesis

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-24 13:38:59 -06:00
Christoph Hellwig
ff005a0662 block: sanitize blk_get_request calling conventions
Switch everyone to blk_get_request_flags, and then rename
blk_get_request_flags to blk_get_request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-14 08:55:12 -06:00
Linus Torvalds
846ade7dd2 virtio, vhost: fixes, cleanups, features
This includes the disk/cache memory stats for for the virtio balloon,
 as well as multiple fixes and cleanups.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio/vhost updates from Michael Tsirkin:
 "virtio, vhost: fixes, cleanups, features

  This includes the disk/cache memory stats for for the virtio balloon,
  as well as multiple fixes and cleanups"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: don't hold onto file pointer for VHOST_SET_LOG_FD
  vhost: don't hold onto file pointer for VHOST_SET_VRING_ERR
  vhost: don't hold onto file pointer for VHOST_SET_VRING_CALL
  ringtest: ring.c malloc & memset to calloc
  virtio_vop: don't kfree device on register failure
  virtio_pci: don't kfree device on register failure
  virtio: split device_register into device_initialize and device_add
  vhost: remove unused lock check flag in vhost_dev_cleanup()
  vhost: Remove the unused variable.
  virtio_blk: print capacity at probe time
  virtio: make VIRTIO a menuconfig to ease disabling it all
  virtio/ringtest: virtio_ring: fix up need_event math
  virtio/ringtest: fix up need_event math
  virtio: virtio_mmio: make of_device_ids const.
  firmware: Use PTR_ERR_OR_ZERO()
  virtio-mmio: Use PTR_ERR_OR_ZERO()
  vhost/scsi: Improve a size determination in four functions
  virtio_balloon: include disk/file caches memory statistics
2018-02-08 10:41:00 -08:00
Stefan Hajnoczi
daf2a50169 virtio_blk: print capacity at probe time
Print the capacity of the block device when the driver is probed.  Many
users expect this since SCSI disks (sd) do it.  Moreover, kernel dmesg
output is the primary source of troubleshooting information so it's
helpful to include the disk size there.

The capacity is already printed by virtio_blk when a resize event
occurs.  Extract the code and reuse it from virtblk_probe().

This patch also adds the block device name to the message so it can be
correlated with a specific device:

  virtio_blk virtio0: [vda] 20971520 512-byte logical blocks (10.7 GB/10.0 GiB)

Cc: Rodrigo A B Freire <rfreire@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-02-01 16:26:43 +02:00
Ming Lei
86ff7c2a80 blk-mq: introduce BLK_STS_DEV_RESOURCE
This status is returned from driver to block layer if device related
resource is unavailable, but driver can guarantee that IO dispatch
will be triggered in future when the resource is available.

Convert some drivers to return BLK_STS_DEV_RESOURCE.  Also, if driver
returns BLK_STS_RESOURCE and SCHED_RESTART is set, rerun queue after
a delay (BLK_MQ_DELAY_QUEUE) to avoid IO stalls.  BLK_MQ_DELAY_QUEUE is
3 ms because both scsi-mq and nvmefc are using that magic value.

If a driver can make sure there is in-flight IO, it is safe to return
BLK_STS_DEV_RESOURCE because:

1) If all in-flight IOs complete before examining SCHED_RESTART in
blk_mq_dispatch_rq_list(), SCHED_RESTART must be cleared, so queue
is run immediately in this case by blk_mq_dispatch_rq_list();

2) if there is any in-flight IO after/when examining SCHED_RESTART
in blk_mq_dispatch_rq_list():
- if SCHED_RESTART isn't set, queue is run immediately as handled in 1)
- otherwise, this request will be dispatched after any in-flight IO is
  completed via blk_mq_sched_restart()

3) if SCHED_RESTART is set concurently in context because of
BLK_STS_RESOURCE, blk_mq_delay_run_hw_queue() will cover the above two
cases and make sure IO hang can be avoided.

One invariant is that queue will be rerun if SCHED_RESTART is set.

Suggested-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-01-30 20:18:28 -07:00
Bart Van Assche
efea2abcb0 virtio_blk: Fix an SG_IO regression
Avoid that submitting an SG_IO ioctl triggers a kernel oops that
is preceded by:

usercopy: kernel memory overwrite attempt detected to (null) (<null>) (6 bytes)
kernel BUG at mm/usercopy.c:72!

Reported-by: Dann Frazier <dann.frazier@canonical.com>
Fixes: commit ca18d6f769 ("block: Make most scsi_req_init() calls implicit")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Dann Frazier <dann.frazier@canonical.com>
Cc: <stable@vger.kernel.org> # v4.13
Reviewed-by: Christoph Hellwig <hch@lst.de>

Moved virtblk_initialize_rq() inside CONFIG_VIRTIO_BLK_SCSI.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-27 08:23:21 -06:00
Linus Torvalds
a0725ab0c7 Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
 "This is the first pull request for 4.14, containing most of the code
  changes. It's a quiet series this round, which I think we needed after
  the churn of the last few series. This contains:

   - Fix for a registration race in loop, from Anton Volkov.

   - Overflow complaint fix from Arnd for DAC960.

   - Series of drbd changes from the usual suspects.

   - Conversion of the stec/skd driver to blk-mq. From Bart.

   - A few BFQ improvements/fixes from Paolo.

   - CFQ improvement from Ritesh, allowing idling for group idle.

   - A few fixes found by Dan's smatch, courtesy of Dan.

   - A warning fixup for a race between changing the IO scheduler and
     device remova. From David Jeffery.

   - A few nbd fixes from Josef.

   - Support for cgroup info in blktrace, from Shaohua.

   - Also from Shaohua, new features in the null_blk driver to allow it
     to actually hold data, among other things.

   - Various corner cases and error handling fixes from Weiping Zhang.

   - Improvements to the IO stats tracking for blk-mq from me. Can
     drastically improve performance for fast devices and/or big
     machines.

   - Series from Christoph removing bi_bdev as being needed for IO
     submission, in preparation for nvme multipathing code.

   - Series from Bart, including various cleanups and fixes for switch
     fall through case complaints"

* 'for-4.14/block' of git://git.kernel.dk/linux-block: (162 commits)
  kernfs: checking for IS_ERR() instead of NULL
  drbd: remove BIOSET_NEED_RESCUER flag from drbd_{md_,}io_bio_set
  drbd: Fix allyesconfig build, fix recent commit
  drbd: switch from kmalloc() to kmalloc_array()
  drbd: abort drbd_start_resync if there is no connection
  drbd: move global variables to drbd namespace and make some static
  drbd: rename "usermode_helper" to "drbd_usermode_helper"
  drbd: fix race between handshake and admin disconnect/down
  drbd: fix potential deadlock when trying to detach during handshake
  drbd: A single dot should be put into a sequence.
  drbd: fix rmmod cleanup, remove _all_ debugfs entries
  drbd: Use setup_timer() instead of init_timer() to simplify the code.
  drbd: fix potential get_ldev/put_ldev refcount imbalance during attach
  drbd: new disk-option disable-write-same
  drbd: Fix resource role for newly created resources in events2
  drbd: mark symbols static where possible
  drbd: Send P_NEG_ACK upon write error in protocol != C
  drbd: add explicit plugging when submitting batches
  drbd: change list_for_each_safe to while(list_first_entry_or_null)
  drbd: introduce drbd_recv_header_maybe_unplug
  ...
2017-09-07 11:59:42 -07:00
Stefan Hajnoczi
1046d30490 virtio_blk: fix incorrect message when disk is resized
The message printed on disk resize is incorrect.  The following is
printed when resizing to 2 GiB:

  $ truncate -s 1G test.img
  $ qemu -device virtio-blk-pci,logical_block_size=4096,...
  (qemu) block_resize drive1 2G

  virtio_blk virtio0: new size: 4194304 4096-byte logical blocks (17.2 GB/16.0 GiB)

The virtio_blk capacity config field is in 512-byte sector units
regardless of logical_block_size as per the VIRTIO specification.
Therefore the message should read:

  virtio_blk virtio0: new size: 524288 4096-byte logical blocks (2.15 GB/2.0 GiB)

Note that this only affects the printed message.  Thankfully the actual
block device has the correct size because the block layer expects
capacity in sectors.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-08-25 21:37:15 +03:00
Bart Van Assche
6e9fe8dddb virtio_blk: Use blk_rq_is_scsi()
This patch does not change any functionality.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-18 08:36:58 -06:00
Andy Shevchenko
f53d5aa050 virtio_blk: Use sysfs_match_string() helper
Use sysfs_match_string() helper instead of open coded variant.

Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
2017-07-25 16:37:34 +03:00
Sagi Grimberg
9b3e990584 virtio_blk: quiesce/unquiesce live IO when entering PM states
Without it its not guaranteed that no .queue_rq is inflight.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: virtio-dev@lists.oasis-open.org
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
2017-07-06 09:49:34 +03:00
Christoph Hellwig
46685d1a95 blk-mq: don't bounce by default
For historical reasons we default to bouncing highmem pages for all block
queues.  But the blk-mq drivers are easy to audit to ensure that we don't
need this - scsi and mtip32xx set explicit limits and everyone else doesn't
have any particular ones.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-27 12:13:45 -06:00
Christoph Hellwig
fc17b6534e blk-mq: switch ->queue_rq return value to blk_status_t
Use the same values for use for request completion errors as the return
value from ->queue_rq.  BLK_STS_RESOURCE is special cased to cause
a requeue, and all the others are completed as-is.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Christoph Hellwig
2a842acab1 block: introduce new block status code type
Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Linus Torvalds
c44b594303 virtio: fixes, cleanups, performance
A bunch of changes to virtio, most affecting virtio net.
 ptr_ring batched zeroing - first of batching enhancements
 that seems ready.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio updates from Michael Tsirkin:
 "Fixes, cleanups, performance

  A bunch of changes to virtio, most affecting virtio net. Also ptr_ring
  batched zeroing - first of batching enhancements that seems ready."

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  s390/virtio: change maintainership
  tools/virtio: fix spelling mistake: "wakeus" -> "wakeups"
  virtio_net: tidy a couple debug statements
  ptr_ring: support testing different batching sizes
  ringtest: support test specific parameters
  ptr_ring: batch ring zeroing
  virtio: virtio_driver doc
  virtio_net: don't reset twice on XDP on/off
  virtio_net: fix support for small rings
  virtio_net: reduce alignment for buffers
  virtio_net: rework mergeable buffer handling
  virtio_net: allow specifying context for rx
  virtio: allow extra context per descriptor
  tools/virtio: fix build breakage
  virtio: add context flag to find vqs
  virtio: wrap find_vqs
  ringtest: fix an assert statement
2017-05-10 11:33:08 -07:00
Michael S. Tsirkin
9b2bbdb227 virtio: wrap find_vqs
We are going to add more parameters to find_vqs, let's wrap the call so
we don't need to tweak all drivers every time.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-05-02 23:41:42 +03:00
Christoph Hellwig
d6296d39e9 blk-mq: update ->init_request and ->exit_request prototypes
Remove the request_idx parameter, which can't be used safely now that we
support I/O schedulers with blk-mq.  Except for a superflous check in
mtip32xx it was unused anyway.

Also pass the tag_set instead of just the driver data - this allows drivers
to avoid some code duplication in a follow on cleanup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-02 07:52:08 -06:00
Christoph Hellwig
08e0029aa2 blk-mq: remove the error argument to blk_mq_complete_request
Now that all drivers that call blk_mq_complete_requests have a
->complete callback we can remove the direct call to blk_mq_end_request,
as well as the error argument to blk_mq_complete_request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:16:10 -06:00
Christoph Hellwig
17d5363b83 scsi: introduce a result field in struct scsi_request
This passes on the scsi_cmnd result field to users of passthrough
requests.  Currently we abuse req->errors for this purpose, but that
field will go away in its current form.

Note that the old IDE code abuses the errors field in very creative
ways and stores all kinds of different values in it.  I didn't dare
to touch this magic, so the abuses are brought forward 1:1.

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>
2017-04-20 12:16:10 -06:00
Christoph Hellwig
d19633d537 virtio_blk: don't use req->errors
Remove passing req->errors (which at that point is always 0) to
blk_mq_complete_request, and rely on the virtio status code for the
serial number passthrough request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:16:10 -06:00
Christoph Hellwig
a1a6e62b79 virtio: fix spelling of virtblk_scsi_request_done
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:16:10 -06:00
Christoph Hellwig
b7819b9259 block: remove the blk_execute_rq return value
The function only returns -EIO if rq->errors is non-zero, which is not
very useful and lets a large number of callers ignore the return value.

Just let the callers figure out their error themselves.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:16:10 -06:00
Eric Biggers
f363b089be blk-mq: constify struct blk_mq_ops
Constify all instances of blk_mq_ops, as they are never modified.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-31 08:28:58 -06:00
Linus Torvalds
54d7989f47 virtio, vhost: optimizations, fixes
Looks like a quiet cycle for vhost/virtio, just a couple of minor
 tweaks. Most notable is automatic interrupt affinity for blk and scsi.
 Hopefully other devices are not far behind.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull vhost updates from Michael Tsirkin:
 "virtio, vhost: optimizations, fixes

  Looks like a quiet cycle for vhost/virtio, just a couple of minor
  tweaks. Most notable is automatic interrupt affinity for blk and scsi.
  Hopefully other devices are not far behind"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio-console: avoid DMA from stack
  vhost: introduce O(1) vq metadata cache
  virtio_scsi: use virtio IRQ affinity
  virtio_blk: use virtio IRQ affinity
  blk-mq: provide a default queue mapping for virtio device
  virtio: provide a method to get the IRQ affinity mask for a virtqueue
  virtio: allow drivers to request IRQ affinity when creating VQs
  virtio_pci: simplify MSI-X setup
  virtio_pci: don't duplicate the msix_enable flag in struct pci_dev
  virtio_pci: use shared interrupts for virtqueues
  virtio_pci: remove struct virtio_pci_vq_info
  vhost: try avoiding avail index access when getting descriptor
  virtio_mmio: expose header to userspace
2017-03-02 13:53:13 -08:00
Christoph Hellwig
ad71473d9c virtio_blk: use virtio IRQ affinity
Use automatic IRQ affinity assignment in the virtio layer if available,
and build the blk-mq queues based on it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-02-27 20:54:05 +02:00
Christoph Hellwig
fb5e31d970 virtio: allow drivers to request IRQ affinity when creating VQs
Add a struct irq_affinity pointer to the find_vqs methods, which if set
is used to tell the PCI layer to create the MSI-X vectors for our I/O
virtqueues with the proper affinity from the start.  Compared to after
the fact affinity hints this gives us an instantly working setup and
allows to allocate the irq descritors node-local and avoid interconnect
traffic.  Last but not least this will allow blk-mq queues are created
based on the interrupt affinity for storage drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-02-27 20:54:04 +02:00
Linus Torvalds
772c8f6f3b for-4.11/linus-merge-signed
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Merge tag 'for-4.11/linus-merge-signed' of git://git.kernel.dk/linux-block

Pull block layer updates from Jens Axboe:

 - blk-mq scheduling framework from me and Omar, with a port of the
   deadline scheduler for this framework. A port of BFQ from Paolo is in
   the works, and should be ready for 4.12.

 - Various fixups and improvements to the above scheduling framework
   from Omar, Paolo, Bart, me, others.

 - Cleanup of the exported sysfs blk-mq data into debugfs, from Omar.
   This allows us to export more information that helps debug hangs or
   performance issues, without cluttering or abusing the sysfs API.

 - Fixes for the sbitmap code, the scalable bitmap code that was
   migrated from blk-mq, from Omar.

 - Removal of the BLOCK_PC support in struct request, and refactoring of
   carrying SCSI payloads in the block layer. This cleans up the code
   nicely, and enables us to kill the SCSI specific parts of struct
   request, shrinking it down nicely. From Christoph mainly, with help
   from Hannes.

 - Support for ranged discard requests and discard merging, also from
   Christoph.

 - Support for OPAL in the block layer, and for NVMe as well. Mainly
   from Scott Bauer, with fixes/updates from various others folks.

 - Error code fixup for gdrom from Christophe.

 - cciss pci irq allocation cleanup from Christoph.

 - Making the cdrom device operations read only, from Kees Cook.

 - Fixes for duplicate bdi registrations and bdi/queue life time
   problems from Jan and Dan.

 - Set of fixes and updates for lightnvm, from Matias and Javier.

 - A few fixes for nbd from Josef, using idr to name devices and a
   workqueue deadlock fix on receive. Also marks Josef as the current
   maintainer of nbd.

 - Fix from Josef, overwriting queue settings when the number of
   hardware queues is updated for a blk-mq device.

 - NVMe fix from Keith, ensuring that we don't repeatedly mark and IO
   aborted, if we didn't end up aborting it.

 - SG gap merging fix from Ming Lei for block.

 - Loop fix also from Ming, fixing a race and crash between setting loop
   status and IO.

 - Two block race fixes from Tahsin, fixing request list iteration and
   fixing a race between device registration and udev device add
   notifiations.

 - Double free fix from cgroup writeback, from Tejun.

 - Another double free fix in blkcg, from Hou Tao.

 - Partition overflow fix for EFI from Alden Tondettar.

* tag 'for-4.11/linus-merge-signed' of git://git.kernel.dk/linux-block: (156 commits)
  nvme: Check for Security send/recv support before issuing commands.
  block/sed-opal: allocate struct opal_dev dynamically
  block/sed-opal: tone down not supported warnings
  block: don't defer flushes on blk-mq + scheduling
  blk-mq-sched: ask scheduler for work, if we failed dispatching leftovers
  blk-mq: don't special case flush inserts for blk-mq-sched
  blk-mq-sched: don't add flushes to the head of requeue queue
  blk-mq: have blk_mq_dispatch_rq_list() return if we queued IO or not
  block: do not allow updates through sysfs until registration completes
  lightnvm: set default lun range when no luns are specified
  lightnvm: fix off-by-one error on target initialization
  Maintainers: Modify SED list from nvme to block
  Move stack parameters for sed_ioctl to prevent oversized stack with CONFIG_KASAN
  uapi: sed-opal fix IOW for activate lsp to use correct struct
  cdrom: Make device operations read-only
  elevator: fix loading wrong elevator type for blk-mq devices
  cciss: switch to pci_irq_alloc_vectors
  block/loop: fix race between I/O and set_status
  blk-mq-sched: don't hold queue_lock when calling exit_icq
  block: set make_request_fn manually in blk_mq_update_nr_hw_queues
  ...
2017-02-21 10:57:33 -08:00
Linus Torvalds
42e1b14b6e Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Implement wraparound-safe refcount_t and kref_t types based on
     generic atomic primitives (Peter Zijlstra)

   - Improve and fix the ww_mutex code (Nicolai Hähnle)

   - Add self-tests to the ww_mutex code (Chris Wilson)

   - Optimize percpu-rwsems with the 'rcuwait' mechanism (Davidlohr
     Bueso)

   - Micro-optimize the current-task logic all around the core kernel
     (Davidlohr Bueso)

   - Tidy up after recent optimizations: remove stale code and APIs,
     clean up the code (Waiman Long)

   - ... plus misc fixes, updates and cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (50 commits)
  fork: Fix task_struct alignment
  locking/spinlock/debug: Remove spinlock lockup detection code
  lockdep: Fix incorrect condition to print bug msgs for MAX_LOCKDEP_CHAIN_HLOCKS
  lkdtm: Convert to refcount_t testing
  kref: Implement 'struct kref' using refcount_t
  refcount_t: Introduce a special purpose refcount type
  sched/wake_q: Clarify queue reinit comment
  sched/wait, rcuwait: Fix typo in comment
  locking/mutex: Fix lockdep_assert_held() fail
  locking/rtmutex: Flip unlikely() branch to likely() in __rt_mutex_slowlock()
  locking/rwsem: Reinit wake_q after use
  locking/rwsem: Remove unnecessary atomic_long_t casts
  jump_labels: Move header guard #endif down where it belongs
  locking/atomic, kref: Implement kref_put_lock()
  locking/ww_mutex: Turn off __must_check for now
  locking/atomic, kref: Avoid more abuse
  locking/atomic, kref: Use kref_get_unless_zero() more
  locking/atomic, kref: Kill kref_sub()
  locking/atomic, kref: Add kref_read()
  locking/atomic, kref: Add KREF_INIT()
  ...
2017-02-20 13:23:30 -08:00
Christoph Hellwig
aebf526b53 block: fold cmd_type into the REQ_OP_ space
Instead of keeping two levels of indirection for requests types, fold it
all into the operations.  The little caveat here is that previously
cmd_type only applied to struct request, while the request and bio op
fields were set to plain REQ_OP_READ/WRITE even for passthrough
operations.

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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 14:00:44 -07:00
Christoph Hellwig
97b50a654d virtio_blk: make SCSI passthrough support configurable
The SCSI passthrough idea was a a bad idea to start with (guess who came
up with it?), and has been removed from the virtio 1.O spec, and is not
enabled by defauly by any host I know of.  Add a separate config option
for it so that we don't need to enable it for most setups.  That way
any bugs related to it (like the one recently fixed for vmapped stacks)
do not affect other users, and the size of the virtblk_req structure
also shrinks significantly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 10:53:10 -07:00
Christoph Hellwig
85dada09ee virtio_blk: remove struct request backpointer from virtblk_req
We can simply use blk_mq_rq_from_pdu to get back at the request at
I/O completion time.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 10:53:08 -07:00
Christoph Hellwig
82ed4db499 block: split scsi_request out of struct request
And require all drivers that want to support BLOCK_PC to allocate it
as the first thing of their private data.  To support this the legacy
IDE and BSG code is switched to set cmd_size on their queues to let
the block layer allocate the additional space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 15:08:35 -07:00
Peter Zijlstra
2c935bc572 locking/atomic, kref: Add kref_read()
Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

	atomic_read(&kref->refcount)
	kref->refcount.counter

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-14 11:37:18 +01:00
Omar Sandoval
6bf6b0aa3d virtio_blk: fix panic in initialization error path
If blk_mq_init_queue() returns an error, it gets assigned to
vblk->disk->queue. Then, when we call put_disk(), we end up calling
blk_put_queue() with the ERR_PTR, causing a bad dereference. Fix it by
only assigning to vblk->disk->queue on success.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-10 13:30:50 -07:00
Christoph Hellwig
a14d749fce virtio_blk: avoid DMA to stack for the sense buffer
Most users of BLOCK_PC requests allocate the sense buffer on the stack,
so to avoid DMA to the stack copy them to a field in the heap allocated
virtblk_req structure.  Without that any attempt at SCSI passthrough I/O,
including the SG_IO ioctl from userspace will crash the kernel.  Note that
this includes running tools like hdparm even when the host does not have
SCSI passthrough enabled.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-10 13:30:50 -07:00
Markus Elfring
2ff98449ee virtio_blk: Delete an unnecessary initialisation in init_vq()
The local variable "err" will be set to an appropriate value
by a following statement.
Thus omit the explicit initialisation at the beginning.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-31 00:21:47 +02:00
Markus Elfring
668866b6e8 virtio_blk: Use kmalloc_array() in init_vq()
Multiplications for the size determination of memory allocations
indicated that array data structures should be processed.
Thus use the corresponding function "kmalloc_array".

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-10-31 00:21:46 +02:00
Christoph Hellwig
7d7e0f90b7 blk-mq: remove ->map_queue
All drivers use the default, so provide an inline version of it.  If we
ever need other queue mapping we can add an optional method back,
although supporting will also require major changes to the queue setup
code.

This provides better code generation, and better debugability as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-15 08:42:03 -06:00
Minfei Huang
347a529398 virtio_blk: Fix a slient kernel panic
We do a lot of memory allocation in function init_vq, and don't handle
the allocation failure properly. Then this function will return 0,
although initialization fails due to lacking memory. At that moment,
kernel will panic in guest machine, if virtio is used to drive disk.

To fix this bug, we should take care of allocation failure, and return
correct value to let caller know what happen.

Tested-by: Chao Fan <fanc.fnst@cn.fujitsu.com>
Signed-off-by: Minfei Huang <mnghuan@gmail.com>
Signed-off-by: Minfei Huang <minfei.hmf@alibaba-inc.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-08-09 13:42:39 +03:00
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
Christoph Hellwig
f9596695be virtio_blk: use blk_rq_map_kern
Similar to how SCSI and NVMe prepare passthrough requests.  This avoids
poking into request internals too much.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20 17:38:29 -06:00
Dan Williams
0d52c756a6 block: convert to device_add_disk()
For block drivers that specify a parent device, convert them to use
device_add_disk().

This conversion was done with the following semantic patch:

    @@
    struct gendisk *disk;
    expression E;
    @@

    - disk->driverfs_dev = E;
    ...
    - add_disk(disk);
    + device_add_disk(E, disk);

    @@
    struct gendisk *disk;
    expression E1, E2;
    @@

    - disk->driverfs_dev = E1;
    ...
    E2 = disk;
    ...
    - add_disk(E2);
    + device_add_disk(E1, E2);

...plus some manual fixups for a few missed conversions.

Cc: Jens Axboe <axboe@fb.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-06-27 12:26:08 -07:00
Mike Christie
3a5e02ced1 block, drivers: add REQ_OP_FLUSH operation
This adds a REQ_OP_FLUSH operation that is sent to request_fn
based drivers by the block layer's flush code, instead of
sending requests with the request->cmd_flags REQ_FLUSH bit set.

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
Jens Axboe
ad9126ac72 virtio_blk: switch to using blk_queue_write_cache()
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-04-12 16:00:39 -06:00
Michael S. Tsirkin
592002f55e virtio_blk: VIRTIO_BLK_F_WCE->VIRTIO_BLK_F_FLUSH
Latest virtio spec says the feature bit name is VIRTIO_BLK_F_FLUSH,
VIRTIO_BLK_F_WCE is the legacy name.  virtio blk header says exactly the
reverse - fix that and update driver code to match.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-03-02 17:01:59 +02:00
Christoph Hellwig
f4829a9b7a blk-mq: fix racy updates of rq->errors
blk_mq_complete_request may be a no-op if the request has already
been completed by others means (e.g. a timeout or cancellation), but
currently drivers have to set rq->errors before calling
blk_mq_complete_request, which might leave us with the wrong error value.

Add an error parameter to blk_mq_complete_request so that we can
defer setting rq->errors until we known we won the race to complete the
request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-01 10:10:55 +02:00
Fam Zheng
5fa3142da1 virtio-blk: Allow extended partitions
This will allow up to DISK_MAX_PARTS (256) partitions, with for example
GPT in the guest. Otherwise, the partition scan code will only discover
the first 15 partitions.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-09-08 13:31:07 +03:00
Paolo Bonzini
53eab6fd27 virtio-blk: use VIRTIO_BLK_F_WCE and VIRTIO_BLK_F_CONFIG_WCE in virtio1
VIRTIO_BLK_F_CONFIG_WCE is important in order to achieve good performance
(up to 2x, though more realistically +30-40%) in latency-bound workloads.
However, it was removed by mistake together with VIRTIO_BLK_F_FLUSH.

It will be restored in the next revision of the virtio 1.0 standard, so
do the same in Linux.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2015-09-08 13:29:14 +03:00
Christoph Hellwig
4f8c9510ba block: rename REQ_TYPE_SPECIAL to REQ_TYPE_DRV_PRIV
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-05 13:40:03 -06:00
James Bottomley
b9f28d8635 sd, mmc, virtio_blk, string_helpers: fix block size units
The current string_get_size() overflows when the device size goes over
2^64 bytes because the string helper routine computes the suffix from
the size in bytes.  However, the entirety of Linux thinks in terms of
blocks, not bytes, so this will artificially induce an overflow on very
large devices.  Fix this by making the function string_get_size() take
blocks and the block size instead of bytes.  This should allow us to
keep working until the current SCSI standard overflows.

Also fix virtio_blk and mmc (both of which were also artificially
multiplying by the block size to pass a byte side to string_get_size()).

The mathematics of this is pretty simple:  we're taking a product of
size in blocks (S) and block size (B) and trying to re-express this in
exponential form: S*B = R*N^E (where N, the exponent is either 1000 or
1024) and R < N.  Mathematically, S = RS*N^ES and B=RB*N^EB, so if RS*RB
< N it's easy to see that S*B = RS*RB*N^(ES+EB).  However, if RS*BS > N,
we can see that this can be re-expressed as RS*BS = R*N (where R =
RS*BS/N < N) so the whole exponent becomes R*N^(ES+EB+1)

[jejb: fix incorrect 32 bit do_div spotted by kbuild test robot <fengguang.wu@intel.com>]
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-04-10 16:27:48 -07:00
Michael S. Tsirkin
bb6ec57600 virtio_blk: coding style fixes
Most of our code has
struct foo {
}

Fix two instances where blk is inconsistent.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21 16:28:57 +10:30
Michael S. Tsirkin
a4379fd841 virtio/blk: verify device has config space
Some devices might not implement config space access
(e.g. remoteproc used not to - before 3.9).
virtio/blk needs config space access so make it
fail gracefully if not there.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-21 16:28:45 +10:30
Ming Lei
35b489d32f block: fix checking return value of blk_mq_init_queue
Check IS_ERR_OR_NULL(return value) instead of just return value.

Signed-off-by: Ming Lei <ming.lei@canonical.com>

Reduced to IS_ERR() by me, we never return NULL.
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-02 10:32:02 -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
Michael S. Tsirkin
51cdc3815f virtio: drop VIRTIO_F_VERSION_1 from drivers
Core activates this bit automatically now,
drop it from drivers that set it explicitly.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-12-09 12:06:32 +02:00
Michael S. Tsirkin
38f37b578f virtio_blk: fix race at module removal
If a device appears while module is being removed,
driver will get a callback after we've given up
on the major number.

In theory this means this major number can get reused
by something else, resulting in a conflict.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2014-12-09 12:05:27 +02:00
Michael S. Tsirkin
393c525b5b virtio_blk: make serial attribute static
It's never declared so no need to make it extern.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2014-12-09 12:05:27 +02:00
Michael S. Tsirkin
19c1c5a64c virtio_blk: v1.0 support
Based on patch by Cornelia Huck.

Note: for consistency, and to avoid sparse errors,
      convert all fields, even those no longer in use
      for virtio v1.0.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2014-12-09 12:05:26 +02:00
Jens Axboe
74c450521d blk-mq: add a 'list' parameter to ->queue_rq()
Since we have the notion of a 'last' request in a chain, we can use
this to have the hardware optimize the issuing of requests. Add
a list_head parameter to queue_rq that the driver can use to
temporarily store hw commands for issue when 'last' is true. If we
are doing a chain of requests, pass in a NULL list for the first
request to force issue of that immediately, then batch the remainder
for deferred issue until the last request has been sent.

Instead of adding yet another argument to the hot ->queue_rq path,
encapsulate the passed arguments in a blk_mq_queue_data structure.
This is passed as a constant, and has been tested as faster than
passing 4 (or even 3) args through ->queue_rq. Update drivers for
the new ->queue_rq() prototype. There are no functional changes
in this patch for drivers - if they don't use the passed in list,
then they will just queue requests individually like before.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-29 11:14:52 -06:00
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
Michael S. Tsirkin
6d62c37f19 virtio_blk: enable VQs early on restore
virtio spec requires drivers to set DRIVER_OK before using VQs.
This is set automatically after restore returns, virtio block violated
this rule on restore by restarting queues, which might in theory
cause the VQ to be used directly within restore.

To fix, call virtio_device_ready before using starting queues.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-10-15 10:25:07 +10:30
Michael S. Tsirkin
7a11370e5e virtio_blk: enable VQs early
virtio spec requires drivers to set DRIVER_OK before using VQs.
This is set automatically after probe returns, virtio block violated this
rule by calling add_disk, which causes the VQ to be used directly within
probe.

To fix, call virtio_device_ready before using VQs.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-10-15 10:25:02 +10:30
Michael S. Tsirkin
1f54b0c055 virtio-blk: drop config_mutex
config_mutex served two purposes: prevent multiple concurrent config
change handlers, and synchronize access to config_enable flag.

Since commit dbf2576e37
    workqueue: make all workqueues non-reentrant
all workqueues are non-reentrant, and config_enable
is now gone.

Get rid of the unnecessary lock.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-10-15 10:24:57 +10:30
Michael S. Tsirkin
cc74f71934 virtio_blk: drop config_enable
Now that virtio core ensures config changes don't
arrive during probing, drop config_enable flag
in virtio blk.
On removal, flush is now sufficient to guarantee that
no change work is queued.

This help simplify the driver, and will allow
setting DRIVER_OK earlier without losing config
change notifications.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-10-15 10:24:56 +10:30
Christoph Hellwig
c8a446ad69 blk-mq: rename blk_mq_end_io to blk_mq_end_request
Now that we've changed the driver API on the submission side use the
opportunity to fix up the name on the completion side to fit into the
general scheme.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-22 12:00:07 -06:00
Christoph Hellwig
e2490073cd blk-mq: call blk_mq_start_request from ->queue_rq
When we call blk_mq_start_request from the core blk-mq code before calling into
->queue_rq there is a racy window where the timeout handler can hit before we've
fully set up the driver specific part of the command.

Move the call to blk_mq_start_request into the driver so the driver can start
the request only once it is fully set up.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-22 12:00:07 -06:00
Christoph Hellwig
bf57229745 blk-mq: remove REQ_END
Pass an explicit parameter for the last request in a batch to ->queue_rq
instead of using a request flag.  Besides being a cleaner and non-stateful
interface this is also required for the next patch, which fixes the blk-mq
I/O submission code to not start a time too early.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-22 12:00:07 -06:00
Ming Lei
6a27b656fc block: virtio-blk: support multi virt queues per virtio-blk device
Firstly this patch supports more than one virtual queues for virtio-blk
device.

Secondly this patch maps the virtual queue to blk-mq's hardware queue.

With this approach, both scalability and performance can be improved.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-07-01 10:51:03 -06:00
Ming Lei
e8edca6f7f block: virtio_blk: don't hold spin lock during world switch
Firstly, it isn't necessary to hold lock of vblk->vq_lock
when notifying hypervisor about queued I/O.

Secondly, virtqueue_notify() will cause world switch and
it may take long time on some hypervisors(such as, qemu-arm),
so it isn't good to hold the lock and block other vCPUs.

On arm64 quad core VM(qemu-kvm), the patch can increase I/O
performance a lot with VIRTIO_RING_F_EVENT_IDX enabled:
	- without the patch: 14K IOPS
	- with the patch: 34K IOPS

fio script:
	[global]
	direct=1
	bsrange=4k-4k
	timeout=10
	numjobs=4
	ioengine=libaio
	iodepth=64

	filename=/dev/vdc
	group_reporting=1

	[f1]
	rw=randread

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org # 3.13+
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-30 08:19:39 -06:00
Jens Axboe
0fb662e225 Merge branch 'for-3.16/core' into for-3.16/drivers
Pull in core changes (again), since we got rid of the alloc/free
hctx mq_ops hooks and mtip32xx then needed updating again.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-28 10:18:51 -06:00
Christoph Hellwig
cdef54dd85 blk-mq: remove alloc_hctx and free_hctx methods
There is no need for drivers to control hardware context allocation
now that we do the context to node mapping in common code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-28 10:18:31 -06:00
Ming Lei
0c29e93eae virtio_blk: fix race between start and stop queue
When there isn't enough vring descriptor for adding to vq,
blk-mq will be put as stopped state until some of pending
descriptors are completed & freed.

Unfortunately, the vq's interrupt may come just before
blk-mq's BLK_MQ_S_STOPPED flag is set, so the blk-mq will
still be kept as stopped even though lots of descriptors
are completed and freed in the interrupt handler. The worst
case is that all pending descriptors are freed in the
interrupt handler, and the queue is kept as stopped forever.

This patch fixes the problem by starting/stopping blk-mq
with holding vq_lock.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-05-16 09:40:31 -06:00
Christoph Hellwig
1b4a325858 blk-mq: add async parameter to blk_mq_start_stopped_hw_queues
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
24d2f90309 blk-mq: split out tag initialization, support shared tags
Add a new blk_mq_tag_set structure that gets set up before we initialize
the queue.  A single blk_mq_tag_set structure can be shared by multiple
queues.

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

Modular export of blk_mq_{alloc,free}_tagset added by me.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-15 14:18:02 -06:00
Christoph Hellwig
e9b267d91f blk-mq: add ->init_request and ->exit_request methods
The current blk_mq_init_commands/blk_mq_free_commands interface has a
two problems:

 1) Because only the constructor is passed to blk_mq_init_commands there
    is no easy way to clean up when a comman initialization failed.  The
    current code simply leaks the allocations done in the constructor.

 2) There is no good place to call blk_mq_free_commands: before
    blk_cleanup_queue there is no guarantee that all outstanding
    commands have completed, so we can't free them yet.  After
    blk_cleanup_queue the queue has usually been freed.  This can be
    worked around by grabbing an unconditional reference before calling
    blk_cleanup_queue and dropping it after blk_mq_free_commands is
    done, although that's not exatly pretty and driver writers are
    guaranteed to get it wrong sooner or later.

Both issues are easily fixed by making the request constructor and
destructor normal blk_mq_ops methods.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-15 14:03:03 -06:00
Christoph Hellwig
9d74e25737 blk-mq: do not initialize req->special
Drivers can reach their private data easily using the blk_mq_rq_to_pdu
helper and don't need req->special.  By not initializing it code can
be simplified nicely, and we also shave off a few more instructions from
the I/O path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-04-15 14:03:02 -06:00
Linus Torvalds
64056a9425 Nothing exciting: virtio-blk users might see a bit of a boost from the
doubling of the default queue length though.
 
 Cheers,
 Rusty.
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Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio updates from Rusty Russell:
 "Nothing exciting: virtio-blk users might see a bit of a boost from the
  doubling of the default queue length though"

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  virtio-blk: base queue-depth on virtqueue ringsize or module param
  Revert a02bbb1ccf: MAINTAINERS: add virtio-dev ML for virtio
  virtio: fail adding buffer on broken queues.
  virtio-rng: don't crash if virtqueue is broken.
  virtio_balloon: don't crash if virtqueue is broken.
  virtio_blk: don't crash, report error if virtqueue is broken.
  virtio_net: don't crash if virtqueue is broken.
  virtio_balloon: don't softlockup on huge balloon changes.
  virtio: Use pci_enable_msix_exact() instead of pci_enable_msix()
  MAINTAINERS: virtio-dev is subscribers only
  tools/virtio: add a missing )
  tools/virtio: fix missing kmemleak_ignore symbol
  tools/virtio: update internal copies of headers
2014-04-02 14:43:17 -07:00
Rusty Russell
fc4324b459 virtio-blk: base queue-depth on virtqueue ringsize or module param
Venkatash spake thus:

  virtio-blk set the default queue depth to 64 requests, which was
  insufficient for high-IOPS devices. Instead set the blk-queue depth to
  the device's virtqueue depth divided by two (each I/O requires at least
  two VQ entries).

But behold, Ted added a module parameter:

  Also allow the queue depth to be something which can be set at module
  load time or via a kernel boot-time parameter, for
  testing/benchmarking purposes.

And I rewrote it substantially, mainly to take
VIRTIO_RING_F_INDIRECT_DESC into account.

As QEMU sets the vq size for PCI to 128, Venkatash's patch wouldn't
have made a change.  This version does (since QEMU also offers
VIRTIO_RING_F_INDIRECT_DESC.

Inspired-by: "Theodore Ts'o" <tytso@mit.edu>
Based-on-the-true-story-of: Venkatesh Srinivas <venkateshs@google.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: virtio-dev@lists.oasis-open.org
Cc: virtualization@lists.linux-foundation.org
Cc: Frank Swiderski <fes@google.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-03-24 12:20:18 +10:30
Jens Axboe
95363efde1 blk-mq: allow blk_mq_init_commands() to return failure
If drivers do dynamic allocation in the hardware command init
path, then we need to be able to handle and return failures.

And if they do allocations or mappings in the init command path,
then we need a cleanup function to free up that space at exit
time. So add blk_mq_free_commands() as the cleanup function.

This is required for the mtip32xx driver conversion to blk-mq.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-03-14 10:43:15 -06:00
Rusty Russell
5261b85e58 virtio_blk: don't crash, report error if virtqueue is broken.
A bad implementation of virtio might cause us to mark the virtqueue
broken: we'll dev_err() in that case, and the device is useless, but
let's not BUG_ON().

ENOMEM or ENOSPC implies the ring is full, and we should try again
later (-ENOMEM is documented to happen, but doesn't, as we fall
through to ENOSPC).

EIO means it's broken.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-03-13 11:27:56 +10:30
Christoph Hellwig
5124c28579 virtio_blk: use blk_mq_complete_request
Make sure to complete requests on the submitting CPU.  Previously this
was done in blk_mq_end_io, but the responsibility shifted to the drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-02-10 09:27:31 -07:00
Shaohua Li
f02b9ac35a virtio-blk: virtqueue_kick() must be ordered with other virtqueue operations
It isn't safe to call it without holding the vblk->vq_lock.

Reported-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Shaohua Li <shli@fusionio.com>

Fixed another condition of virtqueue_kick() not holding the lock.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-19 19:00:45 -07:00
Linus Torvalds
f412f2c60b Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull second round of block driver updates from Jens Axboe:
 "As mentioned in the original pull request, the bcache bits were pulled
  because of their dependency on the immutable bio vecs.  Kent re-did
  this part and resubmitted it, so here's the 2nd round of (mostly)
  driver updates for 3.13.  It contains:

 - The bcache work from Kent.

 - Conversion of virtio-blk to blk-mq.  This removes the bio and request
   path, and substitutes with the blk-mq path instead.  The end result
   almost 200 deleted lines.  Patch is acked by Asias and Christoph, who
   both did a bunch of testing.

 - A removal of bootmem.h include from Grygorii Strashko, part of a
   larger series of his killing the dependency on that header file.

 - Removal of __cpuinit from blk-mq from Paul Gortmaker"

* 'for-linus' of git://git.kernel.dk/linux-block: (56 commits)
  virtio_blk: blk-mq support
  blk-mq: remove newly added instances of __cpuinit
  bcache: defensively handle format strings
  bcache: Bypass torture test
  bcache: Delete some slower inline asm
  bcache: Use ida for bcache block dev minor
  bcache: Fix sysfs splat on shutdown with flash only devs
  bcache: Better full stripe scanning
  bcache: Have btree_split() insert into parent directly
  bcache: Move spinlock into struct time_stats
  bcache: Kill sequential_merge option
  bcache: Kill bch_next_recurse_key()
  bcache: Avoid deadlocking in garbage collection
  bcache: Incremental gc
  bcache: Add make_btree_freeing_key()
  bcache: Add btree_node_write_sync()
  bcache: PRECEDING_KEY()
  bcache: bch_(btree|extent)_ptr_invalid()
  bcache: Don't bother with bucket refcount for btree node allocations
  bcache: Debug code improvements
  ...
2013-11-15 16:33:41 -08:00
Jens Axboe
1cf7e9c68f virtio_blk: blk-mq support
Switch virtio-blk from the dual support for old-style requests and bios
to use the block-multiqueue.

Acked-by: Asias He <asias@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2013-11-14 08:40:44 -07:00
Heinz Graalfs
7f03b17d5c virtio_blk: verify if queue is broken after virtqueue_get_buf()
In case virtqueue_get_buf() returned with a NULL pointer verify if the
virtqueue is broken in order to leave while loop.

Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-10-29 11:28:17 +10:30
Rusty Russell
855e0c5288 virtio: use size-based config accessors.
This lets the transport do endian conversion if necessary, and insulates
the drivers from the difference.

Most drivers can use the simple helpers virtio_cread() and virtio_cwrite().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-10-17 10:55:37 +10:30
Aaron Lu
8910700039 virtio: pm: use CONFIG_PM_SLEEP instead of CONFIG_PM
The freeze and restore functions defined in virtio drivers are used
for suspend and hibernate, so CONFIG_PM_SLEEP is more appropriate than
CONFIG_PM. This patch replace all CONFIG_PM with CONFIG_PM_SLEEP for
virtio drivers that implement freeze and restore callbacks.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Reviewed-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-09-23 15:45:58 +09:30
Jonghwan Choi
2a647bfe1b virtio_blk: Add missing 'static' qualifiers
Add missing 'static' qualifiers

Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-05-20 12:09:23 +09:30
Rusty Russell
0a11cc36f7 virtio_blk: remove nents member.
It's simply a flag as to whether we have data now, so make it an
explicit function parameter rather than a member of struct
virtblk_req.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Asias He <asias@redhat.com>
2013-03-20 15:44:58 +10:30
Paolo Bonzini
20af3cfd20 virtio-blk: use virtqueue_add_sgs on req path
(This is a respin of Paolo Bonzini's patch, but it calls
virtqueue_add_sgs() instead of his multi-part API).

This is similar to the previous patch, but a bit more radical
because the bio and req paths now share the buffer construction
code.  Because the req path doesn't use vbr->sg, however, we
need to add a couple of arguments to __virtblk_add_req.

We also need to teach __virtblk_add_req how to build SCSI command
requests.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Asias He <asias@redhat.com>
2013-03-20 15:44:55 +10:30
Paolo Bonzini
8f39db9d37 virtio-blk: use virtqueue_add_sgs on bio path
(This is a respin of Paolo Bonzini's patch, but it calls
virtqueue_add_sgs() instead of his multi-part API).

Move the creation of the request header and response footer to
__virtblk_add_req.  vbr->sg only contains the data scatterlist,
the header/footer are added separately using virtqueue_add_sgs().

With this change, virtio-blk (with use_bio) is not relying anymore on
the virtio functions ignoring the end markers in a scatterlist.
The next patch will do the same for the other path.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Asias He <asias@redhat.com>
2013-03-20 15:44:54 +10:30
Paolo Bonzini
5ee21a52c0 virtio-blk: reorganize virtblk_add_req
Right now, both virtblk_add_req and virtblk_add_req_wait call
virtqueue_add_buf.  To prepare for the next patches, abstract the call
to virtqueue_add_buf into a new function __virtblk_add_req, and include
the waiting logic directly in virtblk_add_req.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-03-20 15:44:54 +10:30
Milos Vyletel
9d9598b81c virtio-blk: emit udev event when device is resized
When virtio-blk device is resized from host (using block_resize from QEMU) emit
KOBJ_CHANGE uevent to notify guest about such change. This allows user to have
custom udev rules which would take whatever action if such event occurs. As a
proof of concept I've created simple udev rule that automatically resize
filesystem on virtio-blk device.

ACTION=="change", KERNEL=="vd*", \
        ENV{RESIZE}=="1", \
        ENV{ID_FS_TYPE}=="ext[3-4]", \
        RUN+="/sbin/resize2fs /dev/%k"
ACTION=="change", KERNEL=="vd*", \
        ENV{RESIZE}=="1", \
        ENV{ID_FS_TYPE}=="LVM2_member", \
        RUN+="/sbin/pvresize /dev/%k"

Signed-off-by: Milos Vyletel <milos.vyletel@sde.cz>
Tested-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (minor simplification)
2013-03-12 15:44:55 +10:30
Linus Torvalds
226364766f Various minor fixes, but a slightly more complex one to fix the per-cpu overload
problem introduced recently by kvm id changes.
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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module fixes and a virtio block fix from Rusty Russell:
 "Various minor fixes, but a slightly more complex one to fix the
  per-cpu overload problem introduced recently by kvm id changes."

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  module: put modules in list much earlier.
  module: add new state MODULE_STATE_UNFORMED.
  module: prevent warning when finit_module a 0 sized file
  virtio-blk: Don't free ida when disk is in use
2013-01-20 16:44:28 -08:00
Greg Kroah-Hartman
8d85fce77e Drivers: block: remove __dev* attributes.
CONFIG_HOTPLUG is going away as an option.  As a result, the __dev*
markings need to be removed.

This change removes the use of __devinit, __devexit_p, __devinitdata,
__devinitconst, and __devexit from these drivers.

Based on patches originally written by Bill Pemberton, but redone by me
in order to handle some of the coding style issues better, by hand.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Cc: Mike Miller <mike.miller@hp.com>
Cc: Chirag Kantharia <chirag.kantharia@hp.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Jim Paris <jim@jtan.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: NeilBrown <neilb@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Tao Guo <Tao.Guo@emc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-03 15:57:15 -08:00
Alexander Graf
f4953fe6c4 virtio-blk: Don't free ida when disk is in use
When a file system is mounted on a virtio-blk disk, we then remove it
and then reattach it, the reattached disk gets the same disk name and
ids as the hot removed one.

This leads to very nasty effects - mostly rendering the newly attached
device completely unusable.

Trying what happens when I do the same thing with a USB device, I saw
that the sd node simply doesn't get free'd when a device gets forcefully
removed.

Imitate the same behavior for vd devices. This way broken vd devices
simply are never free'd and newly attached ones keep working just fine.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
2013-01-02 15:37:58 +10:30
Asias He
bb8111086c virtio-blk: Disable callback in virtblk_done()
This reduces unnecessary interrupts that host could send to guest while
guest is in the progress of irq handling.

If one vcpu is handling the irq, while another interrupt comes, in
handle_edge_irq(), the guest will mask the interrupt via mask_msi_irq()
which is a very heavy operation that goes all the way down to host.

 Here are some performance numbers on qemu:

 Before:
 -------------------------------------
   seq-read  : io=0 B, bw=269730KB/s, iops=67432 , runt= 62200msec
   seq-write : io=0 B, bw=339716KB/s, iops=84929 , runt= 49386msec
   rand-read : io=0 B, bw=270435KB/s, iops=67608 , runt= 62038msec
   rand-write: io=0 B, bw=354436KB/s, iops=88608 , runt= 47335msec
     clat (usec): min=101 , max=138052 , avg=14822.09, stdev=11771.01
     clat (usec): min=96 , max=81543 , avg=11798.94, stdev=7735.60
     clat (usec): min=128 , max=140043 , avg=14835.85, stdev=11765.33
     clat (usec): min=109 , max=147207 , avg=11337.09, stdev=5990.35
   cpu          : usr=15.93%, sys=60.37%, ctx=7764972, majf=0, minf=54
   cpu          : usr=32.73%, sys=120.49%, ctx=7372945, majf=0, minf=1
   cpu          : usr=18.84%, sys=58.18%, ctx=7775420, majf=0, minf=1
   cpu          : usr=24.20%, sys=59.85%, ctx=8307886, majf=0, minf=0
   vdb: ios=8389107/8368136, merge=0/0, ticks=19457874/14616506,
 in_queue=34206098, util=99.68%
  43: interrupt in total: 887320
 fio --exec_prerun="echo 3 > /proc/sys/vm/drop_caches" --group_reporting
 --ioscheduler=noop --thread --bs=4k --size=512MB --direct=1 --numjobs=16
 --ioengine=libaio --iodepth=64 --loops=3 --ramp_time=0
 --filename=/dev/vdb --name=seq-read --stonewall --rw=read
 --name=seq-write --stonewall --rw=write --name=rnd-read --stonewall
 --rw=randread --name=rnd-write --stonewall --rw=randwrite

 After:
 -------------------------------------
   seq-read  : io=0 B, bw=309503KB/s, iops=77375 , runt= 54207msec
   seq-write : io=0 B, bw=448205KB/s, iops=112051 , runt= 37432msec
   rand-read : io=0 B, bw=311254KB/s, iops=77813 , runt= 53902msec
   rand-write: io=0 B, bw=377152KB/s, iops=94287 , runt= 44484msec
     clat (usec): min=81 , max=90588 , avg=12946.06, stdev=9085.94
     clat (usec): min=57 , max=72264 , avg=8967.97, stdev=5951.04
     clat (usec): min=29 , max=101046 , avg=12889.95, stdev=9067.91
     clat (usec): min=52 , max=106152 , avg=10660.56, stdev=4778.19
   cpu          : usr=15.05%, sys=57.92%, ctx=7710941, majf=0, minf=54
   cpu          : usr=26.78%, sys=101.40%, ctx=7387891, majf=0, minf=2
   cpu          : usr=19.03%, sys=58.17%, ctx=7681976, majf=0, minf=8
   cpu          : usr=24.65%, sys=58.34%, ctx=8442632, majf=0, minf=4
   vdb: ios=8389086/8361888, merge=0/0, ticks=17243780/12742010,
 in_queue=30078377, util=99.59%
  43: interrupt in total: 1259639
 fio --exec_prerun="echo 3 > /proc/sys/vm/drop_caches" --group_reporting
 --ioscheduler=noop --thread --bs=4k --size=512MB --direct=1 --numjobs=16
 --ioengine=libaio --iodepth=64 --loops=3 --ramp_time=0
 --filename=/dev/vdb --name=seq-read --stonewall --rw=read
 --name=seq-write --stonewall --rw=write --name=rnd-read --stonewall
 --rw=randread --name=rnd-write --stonewall --rw=randwrite

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-28 15:05:16 +09:30
Dan Carpenter
f22cf8eb48 virtio-blk: fix NULL checking in virtblk_alloc_req()
Smatch complains about the inconsistent NULL checking here.  Fix it to
return NULL on failure.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (fixed accidental deletion)
2012-09-28 15:05:14 +09:30
Asias He
c85a1f91b3 virtio-blk: Add REQ_FLUSH and REQ_FUA support to bio path
We need to support both REQ_FLUSH and REQ_FUA for bio based path since
it does not get the sequencing of REQ_FUA into REQ_FLUSH that request
based drivers can request.

REQ_FLUSH is emulated by:
A) If the bio has no data to write:
1. Send VIRTIO_BLK_T_FLUSH to device,
2. In the flush I/O completion handler, finish the bio

B) If the bio has data to write:
1. Send VIRTIO_BLK_T_FLUSH to device
2. In the flush I/O completion handler, send the actual write data to device
3. In the write I/O completion handler, finish the bio

REQ_FUA is emulated by:
1. Send the actual write data to device
2. In the write I/O completion handler, send VIRTIO_BLK_T_FLUSH to device
3. In the flush I/O completion handler, finish the bio

Changes in v7:
- Using vbr->flags to trace request type
- Dropped unnecessary struct virtio_blk *vblk parameter
- Reuse struct virtblk_req in bio done function

Cahnges in v6:
- Reworked REQ_FLUSH and REQ_FUA emulatation order

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-28 15:05:14 +09:30
Asias He
a98755c559 virtio-blk: Add bio-based IO path for virtio-blk
This patch introduces bio-based IO path for virtio-blk.

Compared to request-based IO path, bio-based IO path uses driver
provided ->make_request_fn() method to bypasses the IO scheduler. It
handles the bio to device directly without allocating a request in block
layer. This reduces the IO path in guest kernel to achieve high IOPS
and lower latency. The downside is that guest can not use the IO
scheduler to merge and sort requests. However, this is not a big problem
if the backend disk in host side uses faster disk device.

When the bio-based IO path is not enabled, virtio-blk still uses the
original request-based IO path, no performance difference is observed.

Using a slow device e.g. normal SATA disk, the bio-based IO path for
sequential read and write are slower than req-based IO path due to lack
of merge in guest kernel. So we make the bio-based path optional.

Performance evaluation:
-----------------------------
1) Fio test is performed in a 8 vcpu guest with ramdisk based guest using
kvm tool.

Short version:
 With bio-based IO path, sequential read/write, random read/write
 IOPS boost         : 28%, 24%, 21%, 16%
 Latency improvement: 32%, 17%, 21%, 16%

Long version:
 With bio-based IO path:
  seq-read  : io=2048.0MB, bw=116996KB/s, iops=233991 , runt= 17925msec
  seq-write : io=2048.0MB, bw=100829KB/s, iops=201658 , runt= 20799msec
  rand-read : io=3095.7MB, bw=112134KB/s, iops=224268 , runt= 28269msec
  rand-write: io=3095.7MB, bw=96198KB/s,  iops=192396 , runt= 32952msec
    clat (usec): min=0 , max=2631.6K, avg=58716.99, stdev=191377.30
    clat (usec): min=0 , max=1753.2K, avg=66423.25, stdev=81774.35
    clat (usec): min=0 , max=2915.5K, avg=61685.70, stdev=120598.39
    clat (usec): min=0 , max=1933.4K, avg=76935.12, stdev=96603.45
  cpu : usr=74.08%, sys=703.84%, ctx=29661403, majf=21354, minf=22460954
  cpu : usr=70.92%, sys=702.81%, ctx=77219828, majf=13980, minf=27713137
  cpu : usr=72.23%, sys=695.37%, ctx=88081059, majf=18475, minf=28177648
  cpu : usr=69.69%, sys=654.13%, ctx=145476035, majf=15867, minf=26176375
 With request-based IO path:
  seq-read  : io=2048.0MB, bw=91074KB/s, iops=182147 , runt= 23027msec
  seq-write : io=2048.0MB, bw=80725KB/s, iops=161449 , runt= 25979msec
  rand-read : io=3095.7MB, bw=92106KB/s, iops=184211 , runt= 34416msec
  rand-write: io=3095.7MB, bw=82815KB/s, iops=165630 , runt= 38277msec
    clat (usec): min=0 , max=1932.4K, avg=77824.17, stdev=170339.49
    clat (usec): min=0 , max=2510.2K, avg=78023.96, stdev=146949.15
    clat (usec): min=0 , max=3037.2K, avg=74746.53, stdev=128498.27
    clat (usec): min=0 , max=1363.4K, avg=89830.75, stdev=114279.68
  cpu : usr=53.28%, sys=724.19%, ctx=37988895, majf=17531, minf=23577622
  cpu : usr=49.03%, sys=633.20%, ctx=205935380, majf=18197, minf=27288959
  cpu : usr=55.78%, sys=722.40%, ctx=101525058, majf=19273, minf=28067082
  cpu : usr=56.55%, sys=690.83%, ctx=228205022, majf=18039, minf=26551985

2) Fio test is performed in a 8 vcpu guest with Fusion-IO based guest using
kvm tool.

Short version:
 With bio-based IO path, sequential read/write, random read/write
 IOPS boost         : 11%, 11%, 13%, 10%
 Latency improvement: 10%, 10%, 12%, 10%
Long Version:
 With bio-based IO path:
  read : io=2048.0MB, bw=58920KB/s, iops=117840 , runt= 35593msec
  write: io=2048.0MB, bw=64308KB/s, iops=128616 , runt= 32611msec
  read : io=3095.7MB, bw=59633KB/s, iops=119266 , runt= 53157msec
  write: io=3095.7MB, bw=62993KB/s, iops=125985 , runt= 50322msec
    clat (usec): min=0 , max=1284.3K, avg=128109.01, stdev=71513.29
    clat (usec): min=94 , max=962339 , avg=116832.95, stdev=65836.80
    clat (usec): min=0 , max=1846.6K, avg=128509.99, stdev=89575.07
    clat (usec): min=0 , max=2256.4K, avg=121361.84, stdev=82747.25
  cpu : usr=56.79%, sys=421.70%, ctx=147335118, majf=21080, minf=19852517
  cpu : usr=61.81%, sys=455.53%, ctx=143269950, majf=16027, minf=24800604
  cpu : usr=63.10%, sys=455.38%, ctx=178373538, majf=16958, minf=24822612
  cpu : usr=62.04%, sys=453.58%, ctx=226902362, majf=16089, minf=23278105
 With request-based IO path:
  read : io=2048.0MB, bw=52896KB/s, iops=105791 , runt= 39647msec
  write: io=2048.0MB, bw=57856KB/s, iops=115711 , runt= 36248msec
  read : io=3095.7MB, bw=52387KB/s, iops=104773 , runt= 60510msec
  write: io=3095.7MB, bw=57310KB/s, iops=114619 , runt= 55312msec
    clat (usec): min=0 , max=1532.6K, avg=142085.62, stdev=109196.84
    clat (usec): min=0 , max=1487.4K, avg=129110.71, stdev=114973.64
    clat (usec): min=0 , max=1388.6K, avg=145049.22, stdev=107232.55
    clat (usec): min=0 , max=1465.9K, avg=133585.67, stdev=110322.95
  cpu : usr=44.08%, sys=590.71%, ctx=451812322, majf=14841, minf=17648641
  cpu : usr=48.73%, sys=610.78%, ctx=418953997, majf=22164, minf=26850689
  cpu : usr=45.58%, sys=581.16%, ctx=714079216, majf=21497, minf=22558223
  cpu : usr=48.40%, sys=599.65%, ctx=656089423, majf=16393, minf=23824409

3) Fio test is performed in a 8 vcpu guest with normal SATA based guest
using kvm tool.

Short version:
 With bio-based IO path, sequential read/write, random read/write
 IOPS boost         : -10%, -10%, 4.4%, 0.5%
 Latency improvement: -12%, -15%, 2.5%, 0.8%
Long Version:
 With bio-based IO path:
  read : io=124812KB, bw=36537KB/s, iops=9060 , runt=  3416msec
  write: io=169180KB, bw=24406KB/s, iops=6065 , runt=  6932msec
  read : io=256200KB, bw=2089.3KB/s, iops=520 , runt=122630msec
  write: io=257988KB, bw=1545.7KB/s, iops=384 , runt=166910msec
    clat (msec): min=1 , max=1527 , avg=28.06, stdev=89.54
    clat (msec): min=2 , max=344 , avg=41.12, stdev=38.70
    clat (msec): min=8 , max=1984 , avg=490.63, stdev=207.28
    clat (msec): min=33 , max=4131 , avg=659.19, stdev=304.71
  cpu          : usr=4.85%, sys=17.15%, ctx=31593, majf=0, minf=7
  cpu          : usr=3.04%, sys=11.45%, ctx=39377, majf=0, minf=0
  cpu          : usr=0.47%, sys=1.59%, ctx=262986, majf=0, minf=16
  cpu          : usr=0.47%, sys=1.46%, ctx=337410, majf=0, minf=0

 With request-based IO path:
  read : io=150120KB, bw=40420KB/s, iops=10037 , runt=  3714msec
  write: io=194932KB, bw=27029KB/s, iops=6722 , runt=  7212msec
  read : io=257136KB, bw=2001.1KB/s, iops=498 , runt=128443msec
  write: io=258276KB, bw=1537.2KB/s, iops=382 , runt=168028msec
    clat (msec): min=1 , max=1542 , avg=24.84, stdev=32.45
    clat (msec): min=3 , max=628 , avg=35.62, stdev=39.71
    clat (msec): min=8 , max=2540 , avg=503.28, stdev=236.97
    clat (msec): min=41 , max=4398 , avg=653.88, stdev=302.61
  cpu          : usr=3.91%, sys=15.75%, ctx=26968, majf=0, minf=23
  cpu          : usr=2.50%, sys=10.56%, ctx=19090, majf=0, minf=0
  cpu          : usr=0.16%, sys=0.43%, ctx=20159, majf=0, minf=16
  cpu          : usr=0.18%, sys=0.53%, ctx=81364, majf=0, minf=0

How to use:
-----------------------------
Add 'virtio_blk.use_bio=1' to kernel cmdline or 'modprobe virtio_blk
use_bio=1' to enable ->make_request_fn() based I/O path.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-09-28 15:05:13 +09:30
Paolo Bonzini
cd5d503862 virtio-blk: allow toggling host cache between writeback and writethrough
This patch adds support for the new VIRTIO_BLK_F_CONFIG_WCE feature,
which exposes the cache mode in the configuration space and lets the
driver modify it.  The cache mode is exposed via sysfs.

Even if the host does not support the new feature, the cache mode is
visible (thanks to the existing VIRTIO_BLK_F_WCE), but not modifiable.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-07-30 13:30:52 +09:30
Asias He
2c95a32909 virtio-blk: Use block layer provided spinlock
Block layer will allocate a spinlock for the queue if the driver does
not provide one in blk_init_queue().

The reason to use the internal spinlock is that blk_cleanup_queue() will
switch to use the internal spinlock in the cleanup code path.

        if (q->queue_lock != &q->__queue_lock)
                q->queue_lock = &q->__queue_lock;

However, processes which are in D state might have taken the driver
provided spinlock, when the processes wake up, they would release the
block provided spinlock.

=====================================
[ BUG: bad unlock balance detected! ]
3.4.0-rc7+ #238 Not tainted
-------------------------------------
fio/3587 is trying to release lock (&(&q->__queue_lock)->rlock) at:
[<ffffffff813274d2>] blk_queue_bio+0x2a2/0x380
but there are no more locks to release!

other info that might help us debug this:
1 lock held by fio/3587:
 #0:  (&(&vblk->lock)->rlock){......}, at:
[<ffffffff8132661a>] get_request_wait+0x19a/0x250

Other drivers use block layer provided spinlock as well, e.g. SCSI.

Switching to the block layer provided spinlock saves a bit of memory and
does not increase lock contention. Performance test shows no real
difference is observed before and after this patch.

Changes in v2: Improve commit log as Michael suggested.

Cc: virtualization@lists.linux-foundation.org
Cc: kvm@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-07-30 13:30:51 +09:30
Asias He
483001c765 virtio-blk: Reset device after blk_cleanup_queue()
blk_cleanup_queue() will call blk_drian_queue() to drain all the
requests before queue DEAD marking. If we reset the device before
blk_cleanup_queue() the drain would fail.

1) if the queue is stopped in do_virtblk_request() because device is
full, the q->request_fn() will not be called.

blk_drain_queue() {
   while(true) {
      ...
      if (!list_empty(&q->queue_head))
        __blk_run_queue(q) {
	    if (queue is not stoped)
		q->request_fn()
	}
      ...
   }
}

Do no reset the device before blk_cleanup_queue() gives the chance to
start the queue in interrupt handler blk_done().

2) In commit b79d866c8b, We abort requests
dispatched to driver before blk_cleanup_queue(). There is a race if
requests are dispatched to driver after the abort and before the queue
DEAD mark. To fix this, instead of aborting the requests explicitly, we
can just reset the device after after blk_cleanup_queue so that the
device can complete all the requests before queue DEAD marking in the
drain process.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: virtualization@lists.linux-foundation.org
Cc: kvm@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-07-30 13:30:51 +09:30
Asias He
02e2b12494 virtio-blk: Call del_gendisk() before disable guest kick
del_gendisk() might not return due to failing to remove the
/sys/block/vda/serial sysfs entry when another thread (udev) is
trying to read it.

virtblk_remove()
  vdev->config->reset() : guest will not kick us through interrupt
    del_gendisk()
      device_del()
        kobject_del(): got stuck, sysfs entry ref count non zero

sysfs_open_file(): user space process read /sys/block/vda/serial
   sysfs_get_active() : got sysfs entry ref count
      dev_attr_show()
        virtblk_serial_show()
           blk_execute_rq() : got stuck, interrupt is disabled
                              request cannot be finished

This patch fixes it by calling del_gendisk() before we disable guest's
interrupt so that the request sent in virtblk_serial_show() will be
finished and del_gendisk() will success.

This fixes another race in hot-unplug process.

It is save to call del_gendisk(vblk->disk) before
flush_work(&vblk->config_work) which might access vblk->disk, because
vblk->disk is not freed until put_disk(vblk->disk).

Cc: virtualization@lists.linux-foundation.org
Cc: kvm@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-07-30 13:30:51 +09:30
Asias He
f65ca1dc6a virtio_blk: Drop unused request tracking list
Benchmark shows small performance improvement on fusion io device.

Before:
  seq-read : io=1,024MB, bw=19,982KB/s, iops=39,964, runt= 52475msec
  seq-write: io=1,024MB, bw=20,321KB/s, iops=40,641, runt= 51601msec
  rnd-read : io=1,024MB, bw=15,404KB/s, iops=30,808, runt= 68070msec
  rnd-write: io=1,024MB, bw=14,776KB/s, iops=29,552, runt= 70963msec

After:
  seq-read : io=1,024MB, bw=20,343KB/s, iops=40,685, runt= 51546msec
  seq-write: io=1,024MB, bw=20,803KB/s, iops=41,606, runt= 50404msec
  rnd-read : io=1,024MB, bw=16,221KB/s, iops=32,442, runt= 64642msec
  rnd-write: io=1,024MB, bw=15,199KB/s, iops=30,397, runt= 68991msec

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-05-22 12:16:14 +09:30
Asias He
b79d866c8b virtio-blk: Fix hot-unplug race in remove method
If we reset the virtio-blk device before the requests already dispatched
to the virtio-blk driver from the block layer are finised, we will stuck
in blk_cleanup_queue() and the remove will fail.

blk_cleanup_queue() calls blk_drain_queue() to drain all requests queued
before DEAD marking. However it will never success if the device is
already stopped. We'll have q->in_flight[] > 0, so the drain will not
finish.

How to reproduce the race:
1. hot-plug a virtio-blk device
2. keep reading/writing the device in guest
3. hot-unplug while the device is busy serving I/O

Test:
~1000 rounds of hot-plug/hot-unplug test passed with this patch.

Changes in v3:
- Drop blk_abort_queue and blk_abort_request
- Use __blk_end_request_all to complete request dispatched to driver

Changes in v2:
- Drop req_in_flight
- Use virtqueue_detach_unused_buf to get request dispatched to driver

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-05-22 12:16:13 +09:30
Linus Torvalds
cdd5983063 virtio: fixes on top of 3.4-rc2
Here are some virtio fixes for 3.4:
 a test build fix, a patch by Ren fixing naming for systems with a massive
 number of virtio blk devices, and balloon fixes for powerpc
 by David Gibson.
 
 There was some discussion about Ren's patch for virtio disc naming: some people
 wanted to move the legacy name mangling function to the block core.  But
 there's no concensus on that yet, and we can always deduplicate later.
 Added comments in the hope that this will stop people from
 copying this legacy naming scheme into future drivers.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio fixes from Michael S. Tsirkin:
 "Here are some virtio fixes for 3.4: a test build fix, a patch by Ren
  fixing naming for systems with a massive number of virtio blk devices,
  and balloon fixes for powerpc by David Gibson.

  There was some discussion about Ren's patch for virtio disc naming:
  some people wanted to move the legacy name mangling function to the
  block core.  But there's no concensus on that yet, and we can always
  deduplicate later.  Added comments in the hope that this will stop
  people from copying this legacy naming scheme into future drivers."

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_balloon: fix handling of PAGE_SIZE != 4k
  virtio_balloon: Fix endian bug
  virtio_blk: helper function to format disk names
  tools/virtio: fix up vhost/test module build
2012-04-16 18:34:12 -07:00
Ren Mingxin
c0aa3e0916 virtio_blk: helper function to format disk names
The current virtio block's naming algorithm just supports 18278
(26^3 + 26^2 + 26) disks. If there are more virtio blocks,
there will be disks with the same name.

Based on commit 3e1a7ff8a0, add
a function "virtblk_name_format()" for virtio block to support mass
of disks naming.

Notes:
- Our naming scheme is ugly. We are stuck with it
  for virtio but don't use it for any new driver:
  new drivers should name their devices PREFIX%d
  where the sequence number can be allocated by ida
- sd_format_disk_name has exactly the same logic.
  Moving it to a central place was deferred over worries
  that this will make people keep using the legacy naming
  in new drivers.
  We kept code idential in case someone wants to deduplicate later.

Signed-off-by: Ren Mingxin <renmx@cn.fujitsu.com>
Acked-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-04-12 10:37:05 +03:00
Vivek Goyal
e9986f303d virtio-blk: Call revalidate_disk() upon online disk resize
If a virtio disk is open in guest and a disk resize operation is done,
(virsh blockresize), new size is not visible to tools like "fdisk -l".
This seems to be happening as we update only part->nr_sects and not
bdev->bd_inode size.

Call revalidate_disk() which should take care of it. I tested growing disk
size of already open disk and it works for me.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-03-29 10:09:44 +02:00
Paolo Bonzini
577ebb374c block: add and use scsi_blk_cmd_ioctl
Introduce a wrapper around scsi_cmd_ioctl that takes a block device.

The function will then be enhanced to detect partition block devices
and, in that case, subject the ioctls to whitelisting.

Cc: linux-scsi@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: James Bottomley <JBottomley@parallels.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-14 15:07:24 -08:00
Amit Shah
f8fb5bc23a virtio: blk: Add freeze, restore handlers to support S4
Delete the vq and flush any pending requests from the block queue on the
freeze callback to prepare for hibernation.

Re-create the vq in the restore callback to resume normal function.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12 15:44:45 +10:30
Amit Shah
6abd6e5a44 virtio: blk: Move vq initialization to separate function
The probe and PM restore functions will share this code.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12 15:44:45 +10:30
Michael S. Tsirkin
4678d6f970 virtio_blk: fix config handler race
Fix a theoretical race related to config work
handler: a config interrupt might happen
after we flush config work but before we
reset the device. It will then cause the
config work to run during or after reset.

Two problems with this:
- if this runs after device is gone we will get use after free
- access of config while reset is in progress is racy
(as layout is changing).

As a solution
1. flush after reset when we know there will be no more interrupts
2. add a flag to disable config access before reset

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-12 15:44:44 +10:30
Rusty Russell
f96fde41f7 virtio: rename virtqueue_add_buf_gfp to virtqueue_add_buf
Remove wrapper functions. This makes the allocation type explicit in
all callers; I used GPF_KERNEL where it seemed obvious, left it at
GFP_ATOMIC otherwise.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2012-01-12 15:44:42 +10:30
Linus Torvalds
32aaeffbd4 Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include <linux/module.h>
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include <linux/module.h>
  net: sch_generic remove redundant use of <linux/module.h>
  net: inet_timewait_sock doesnt need <linux/module.h>
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h
2011-11-06 19:44:47 -08:00
Michael S. Tsirkin
5087a50e66 virtio-blk: use ida to allocate disk index
Based on a patch by Mark Wu <dwu@redhat.com>

Current index allocation in virtio-blk is based on a monotonically
increasing variable "index". This means we'll run out of numbers
after a while.  It also could cause confusion about the disk
name in the case of hot-plugging disks.
Change virtio-blk to use ida to allocate index, instead.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-11-02 11:41:02 +10:30
Paul Gortmaker
0c8d44f239 block: Fix files that are modules and hence need module.h
We want to remove the implicit everywhere presence of module.h
so fix up the people relying on that implicit presence in advance.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:13 -04:00
Liu Yuan
6917f83ffe drivers, block: virtio_blk: Replace cryptic number with the macro
It is easier to figure out the context by reading SCSI_SENSE_BUFFERSIZE
instead of plain '96'.

Signed-off-by: Liu Yuan <tailai.ly@taobao.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-05-30 11:14:13 +09:30
Christoph Hellwig
7a7c924cf0 virtio_blk: allow re-reading config space at runtime
Wire up the virtio_driver config_changed method to get notified about
config changes raised by the host.  For now we just re-read the device
size to support online resizing of devices, but once we add more
attributes that might be changeable they could be added as well.

Note that the config_changed method is called from irq context, so
we'll have to use the workqueue infrastructure to provide us a proper
user context for our changes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-05-30 11:14:13 +09:30
Linus Torvalds
a2887097f2 Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits)
  xen-blkfront: disable barrier/flush write support
  Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c
  block: remove BLKDEV_IFL_WAIT
  aic7xxx_old: removed unused 'req' variable
  block: remove the BH_Eopnotsupp flag
  block: remove the BLKDEV_IFL_BARRIER flag
  block: remove the WRITE_BARRIER flag
  swap: do not send discards as barriers
  fat: do not send discards as barriers
  ext4: do not send discards as barriers
  jbd2: replace barriers with explicit flush / FUA usage
  jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier
  jbd: replace barriers with explicit flush / FUA usage
  nilfs2: replace barriers with explicit flush / FUA usage
  reiserfs: replace barriers with explicit flush / FUA usage
  gfs2: replace barriers with explicit flush / FUA usage
  btrfs: replace barriers with explicit flush / FUA usage
  xfs: replace barriers with explicit flush / FUA usage
  block: pass gfp_mask and flags to sb_issue_discard
  dm: convey that all flushes are processed as empty
  ...
2010-10-22 17:07:18 -07:00
Christoph Hellwig
fe5a50a10c virtio_blk: remove BKL leftovers
Remove the BKL usage added in "block: push down BKL into .locked_ioctl".
Virtio-blk doesn't use the BKL for anything, and doesn't implement any
ioctl command by itself, but only uses the generic scsi_cmd_ioctl
which is fine without the BKL.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-10-21 17:44:05 +10:30
Jens Axboe
fa251f8990 Merge branch 'v2.6.36-rc8' into for-2.6.37/barrier
Conflicts:
	block/blk-core.c
	drivers/block/loop.c
	mm/swapfile.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-19 09:13:04 +02:00
Mike Snitzer
e4c4776dea virtio-blk: fix request leak.
Must drop reference taken by blk_make_request().

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org # .35.x
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-09 11:42:37 -07:00
Tejun Heo
02c42b7a68 virtio_blk: drop REQ_HARDBARRIER support
Remove now unused REQ_HARDBARRIER support.  virtio_blk already
supports REQ_FLUSH and the usefulness of REQ_FUA for virtio_blk is
questionable at this point, so there's nothing else to do to support
new REQ_FLUSH/FUA interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:37 +02:00
Tejun Heo
4913efe456 block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush()
Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA
requests.  Deprecate barrier.  All REQ_HARDBARRIERs are failed with
-EOPNOTSUPP and blk_queue_ordered() is replaced with simpler
blk_queue_flush().

blk_queue_flush() takes combinations of REQ_FLUSH and FUA.  If a
device has write cache and can flush it, it should set REQ_FLUSH.  If
the device can handle FUA writes, it should also set REQ_FUA.

All blk_queue_ordered() users are converted.

* ORDERED_DRAIN is mapped to 0 which is the default value.
* ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH.
* ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:36 +02:00
Tejun Heo
6958f14545 block: kill QUEUE_ORDERED_BY_TAG
Nobody is making meaningful use of ORDERED_BY_TAG now and queue
draining for barrier requests will be removed soon which will render
the advantage of tag ordering moot.  Kill ORDERED_BY_TAG.  The
following users are affected.

* brd: converted to ORDERED_DRAIN.
* virtio_blk: ORDERED_TAG path was already marked deprecated.  Removed.
* xen-blkfront: ORDERED_TAG case dropped.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:36 +02:00
Linus Torvalds
2f9e825d3e Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits)
  block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n
  xen-blkfront: fix missing out label
  blkdev: fix blkdev_issue_zeroout return value
  block: update request stacking methods to support discards
  block: fix missing export of blk_types.h
  writeback: fix bad _bh spinlock nesting
  drbd: revert "delay probes", feature is being re-implemented differently
  drbd: Initialize all members of sync_conf to their defaults [Bugz 315]
  drbd: Disable delay probes for the upcomming release
  writeback: cleanup bdi_register
  writeback: add new tracepoints
  writeback: remove unnecessary init_timer call
  writeback: optimize periodic bdi thread wakeups
  writeback: prevent unnecessary bdi threads wakeups
  writeback: move bdi threads exiting logic to the forker thread
  writeback: restructure bdi forker loop a little
  writeback: move last_active to bdi
  writeback: do not remove bdi from bdi_list
  writeback: simplify bdi code a little
  writeback: do not lose wake-ups in bdi threads
  ...

Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and
drivers/scsi/scsi_error.c as per Jens.
2010-08-10 15:22:42 -07:00
Arnd Bergmann
8a6cfeb6de block: push down BKL into .locked_ioctl
As a preparation for the removal of the big kernel
lock in the block layer, this removes the BKL
from the common ioctl handling code, moving it
into every single driver still using it.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:25:00 +02:00
FUJITA Tomonori
00fff26539 block: remove q->prepare_flush_fn completely
This removes q->prepare_flush_fn completely (changes the
blk_queue_ordered API).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:24:15 +02:00
FUJITA Tomonori
dd40e456a4 virtio_blk: stop using q->prepare_flush_fn
use REQ_FLUSH flag instead.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:24:14 +02:00
Jens Axboe
15fa6e8165 virtio_blk: add default case to cmd type switch
On compilation, gcc correctly detects that we do not handle
all types:

In function ‘blk_done’:
warning: enumeration value ‘REQ_TYPE_FS’ not handled in switch
warning: enumeration value ‘REQ_TYPE_SENSE’ not handled in switch
warning: enumeration value ‘REQ_TYPE_PM_SUSPEND’ not handled in switch
warning: enumeration value ‘REQ_TYPE_PM_RESUME’ not handled in switch
warning: enumeration value ‘REQ_TYPE_PM_SHUTDOWN’ not handled in switch
warning: enumeration value ‘REQ_TYPE_LINUX_BLOCK’ not handled in switch
warning: enumeration value ‘REQ_TYPE_ATA_TASKFILE’ not handled in switch
warning: enumeration value ‘REQ_TYPE_ATA_PC’ not handled in switch

which is a bit pointless since this is at the end of the request
processessing. Add a default case that just breaks out.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:22:26 +02:00
Christoph Hellwig
33659ebbae block: remove wrappers for request type/flags
Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests.  This allows much easier grepping for different request
types instead of unwinding through macros.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:17:56 +02:00
Ryan Harper
6c99a8528f virtio_blk: Remove VBID ioctl
With the availablility of a sysfs device attribute for examining disk serial
numbers the ioctl is no longer needed.  The user-space changes for this aren't
upstream yet so we don't have any users to worry about.

Signed-off-by: Ryan Harper <ryanh@us.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 13:05:31 +09:30
Ryan Harper
a5eb9e4ff1 virtio_blk: Add 'serial' attribute to virtio-blk devices (v2)
Create a new attribute for virtio-blk devices that will fetch the serial number
of the block device.  This attribute can be used by udev to create disk/by-id
symlinks for devices that don't have a UUID (filesystem) associated with them.

ATA_IDENTIFY strings are special in that they can be up to 20 chars long
and aren't required to be nul-terminated.  The buffer is also zero-padded
meaning that if the serial is 19 chars or less that we get a nul-terminated
string.  When copying this value into a string buffer, we must be careful to
copy up to the nul (if it present) and only 20 if it is longer and not to
attempt to nul terminate; this isn't needed.

Changes since v1:
- Added BUILD_BUG_ON() for PAGE_SIZE check
- Removed min() since BUILD_BUG_ON() handles the check
- Replaced serial_sysfs() by copying id directly to buffer

Signed-off-by: Ryan Harper <ryanh@us.ibm.com>
Signed-off-by: john cooper <john.cooper@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 13:05:30 +09:30
Christoph Hellwig
10bc310c27 virtio_blk: support barriers without FLUSH feature
If we want to support barriers with the cache=writethrough mode in qemu
we need to tell the block layer that we only need queue drains to
implement a barrier.  Follow the model set by SCSI and IDE and assume
that there is no volatile write cache if the host doesn't advertize it.
While this might imply working barriers on old qemu versions or other
hypervisors that actually have a volatile write cache this is only a
cosmetic issue - these hypervisors don't guarantee any data integrity
with or without this patch, but with the patch we at least provide
data ordering.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-05 13:05:29 +09:30
Christoph Hellwig
a5b365a652 virtio-blk: fix minimum number of S/G elements
We need at least one S/G element to operate properly, as does the block
layer which increments it to one anyway.  We hit this due to a qemu
bug which advertises a sg_elements of 0 under some circumstances.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (tweaked logic)
2010-06-03 22:39:18 +09:30
Michael S. Tsirkin
09ec6b69d2 virtio_blk: use virtqueue_xxx wrappers
Switch virtio_blk to new virtqueue_xxx wrappers.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-05-19 22:15:42 +09:30
Rusty Russell
bdb4a13057 virtio_blk: remove multichar constant.
drivers/block/virtio_blk.c:228:13: warning: multi-character character constant

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: john cooper <john.cooper@redhat.com>
2010-05-19 22:15:41 +09:30
john cooper
234f2725a5 Add virtio disk identification ioctl
Return serial string to the guest application via
ioctl driver call.

Note this form of interface to the guest userland
was the consensus when the prior version using
the ATA_IDENTIFY came under dispute.

Signed-off-by: john cooper <john.cooper@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-05-19 22:15:40 +09:30
john cooper
4cb2ea28c5 Add virtio disk identification support
Add virtio-blk device id (s/n) support via virtio request.

Signed-off-by: john cooper <john.cooper@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-05-19 22:15:40 +09:30