Commit Graph

2696 Commits

Author SHA1 Message Date
Linus Torvalds
7c24d9f3b2 Merge branch 'for-4.5/core' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe:
 "We don't have a lot of core changes this time around, it's mostly in
  drivers, which will come in a subsequent pull.

  The cores changes include:

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

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

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

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

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

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

* 'for-4.5/core' of git://git.kernel.dk/linux-block:
  block: use bd{grab,put}() instead of open-coding
  block: split bios to max possible length
  block: add call to split trace point
  blk-mq: Avoid memoryless numa node encoded in hctx numa_node
  blk-mq: Reuse hardware context cpumask for tags
  blk-mq: add a flags parameter to blk_mq_alloc_request
  Revert "blk-flush: Queue through IO scheduler when flush not required"
  block: clarify blk_add_timer() use case for blk-mq
  bio: use offset_in_page macro
  block: do not initialise statics to 0 or NULL
  block: do not initialise globals to 0 or NULL
  block: rename request_queue slab cache
2016-01-19 15:03:34 -08:00
Linus Torvalds
d080827f85 libnvdimm for 4.5
1/ Media error handling: The 'badblocks' implementation that originated
    in md-raid is up-levelled to a generic capability of a block device.
    This initial implementation is limited to being consulted in the pmem
    block-i/o path.  Later, 'badblocks' will be consulted when creating
    dax mappings.
 
 2/ Raw block device dax: For virtualization and other cases that want
    large contiguous mappings of persistent memory, add the capability to
    dax-mmap a block device directly.
 
 3/ Increased /dev/mem restrictions: Add an option to treat all io-memory
    as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access while a driver is
    actively using an address range.  This behavior is controlled via the
    new CONFIG_IO_STRICT_DEVMEM option and can be overridden by the
    existing "iomem=relaxed" kernel command line option.
 
 4/ Miscellaneous fixes include a 'pfn'-device huge page alignment fix,
    block device shutdown crash fix, and other small libnvdimm fixes.
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Merge tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "The bulk of this has appeared in -next and independently received a
  build success notification from the kbuild robot.  The 'for-4.5/block-
  dax' topic branch was rebased over the weekend to drop the "block
  device end-of-life" rework that Al would like to see re-implemented
  with a notifier, and to address bug reports against the badblocks
  integration.

  There is pending feedback against "libnvdimm: Add a poison list and
  export badblocks" received last week.  Linda identified some localized
  fixups that we will handle incrementally.

  Summary:

   - Media error handling: The 'badblocks' implementation that
     originated in md-raid is up-levelled to a generic capability of a
     block device.  This initial implementation is limited to being
     consulted in the pmem block-i/o path.  Later, 'badblocks' will be
     consulted when creating dax mappings.

   - Raw block device dax: For virtualization and other cases that want
     large contiguous mappings of persistent memory, add the capability
     to dax-mmap a block device directly.

   - Increased /dev/mem restrictions: Add an option to treat all
     io-memory as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access
     while a driver is actively using an address range.  This behavior
     is controlled via the new CONFIG_IO_STRICT_DEVMEM option and can be
     overridden by the existing "iomem=relaxed" kernel command line
     option.

   - Miscellaneous fixes include a 'pfn'-device huge page alignment fix,
     block device shutdown crash fix, and other small libnvdimm fixes"

* tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (32 commits)
  block: kill disk_{check|set|clear|alloc}_badblocks
  libnvdimm, pmem: nvdimm_read_bytes() badblocks support
  pmem, dax: disable dax in the presence of bad blocks
  pmem: fail io-requests to known bad blocks
  libnvdimm: convert to statically allocated badblocks
  libnvdimm: don't fail init for full badblocks list
  block, badblocks: introduce devm_init_badblocks
  block: clarify badblocks lifetime
  badblocks: rename badblocks_free to badblocks_exit
  libnvdimm, pmem: move definition of nvdimm_namespace_add_poison to nd.h
  libnvdimm: Add a poison list and export badblocks
  nfit_test: Enable DSMs for all test NFITs
  md: convert to use the generic badblocks code
  block: Add badblock management for gendisks
  badblocks: Add core badblock management code
  block: fix del_gendisk() vs blkdev_ioctl crash
  block: enable dax for raw block devices
  block: introduce bdev_file_inode()
  restrict /dev/mem to idle io memory ranges
  arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug
  ...
2016-01-13 19:15:14 -08:00
Keith Busch
e36f620428 block: split bios to max possible length
This splits bio in the middle of a vector to form the largest possible
bio at the h/w's desired alignment, and guarantees the bio being split
will have some data.

The criteria for splitting is changed from the max sectors to the h/w's
optimal sector alignment if it is provided. For h/w that advertise their
block storage's underlying chunk size, it's a big performance win to not
submit commands that cross them. If sector alignment is not provided,
this patch uses the max sectors as before.

This addresses the performance issue commit d380561113 attempted to
fix, but was reverted due to splitting logic error.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: <stable@vger.kernel.org> # 4.4.x-
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-01-12 15:10:56 -07:00
Dan Williams
55f5560d8c block: kill disk_{check|set|clear|alloc}_badblocks
These actions are completely managed by a block driver or can use the
badblocks api directly.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 22:42:31 -08:00
Dan Williams
57f7f317ab pmem, dax: disable dax in the presence of bad blocks
Longer term teach dax to punch "error" holes in mapping requests and
deliver SIGBUS to applications that consume a bad pmem page.  For now,
simply disable the dax performance optimization in the presence of known
errors.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 22:42:31 -08:00
Dan Williams
16263ff6c7 block, badblocks: introduce devm_init_badblocks
Provide a devres interface for initializing a badblocks instance.  The
pmem driver has several scenarios where it will be beneficial to have
this structure automatically freed when the device is disabled / fails
probe.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 08:39:04 -08:00
Dan Williams
20a308f09e block: clarify badblocks lifetime
The badblocks list attached to a gendisk is allocated by the driver
which equates to the driver owning the lifetime of the object.  Do not
automatically free it in del_gendisk(). This is in preparation for
expanding the use of badblocks in libnvdimm drivers and introducing
devm_init_badblocks().

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 08:39:04 -08:00
Dan Williams
d3b407fb3f badblocks: rename badblocks_free to badblocks_exit
For symmetry with badblocks_init() make it clear that this path only
destroys incremental allocations of a badblocks instance, and does not
free the badblocks instance itself.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 08:39:04 -08:00
Vishal Verma
99e6608c9e block: Add badblock management for gendisks
NVDIMM devices, which can behave more like DRAM rather than block
devices, may develop bad cache lines, or 'poison'. A block device
exposed by the pmem driver can then consume poison via a read (or
write), and cause a machine check. On platforms without machine
check recovery features, this would mean a crash.

The block device maintaining a runtime list of all known sectors that
have poison can directly avoid this, and also provide a path forward
to enable proper handling/recovery for DAX faults on such a device.

Use the new badblock management interfaces to add a badblocks list to
gendisks.

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 08:36:51 -08:00
Vishal Verma
9e0e252a04 badblocks: Add core badblock management code
Take the core badblocks implementation from md, and make it generally
available. This follows the same style as kernel implementations of
linked lists, rb-trees etc, where you can have a structure that can be
embedded anywhere, and accessor functions to manipulate the data.

The only changes in this copy of the code are ones to generalize
function/variable names from md-specific ones. Also add init and free
functions.

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 06:35:12 -08:00
Dan Williams
ac34f15e0c block: fix del_gendisk() vs blkdev_ioctl crash
When tearing down a block device early in its lifetime, userspace may
still be performing discovery actions like blkdev_ioctl() to re-read
partitions.

The nvdimm_revalidate_disk() implementation depends on
disk->driverfs_dev to be valid at entry.  However, it is set to NULL in
del_gendisk() and fatally this is happening *before* the disk device is
deleted from userspace view.

There's no reason for del_gendisk() to clear ->driverfs_dev.  That
device is the parent of the disk.  It is guaranteed to not be freed
until the disk, as a child, drops its ->parent reference.

We could also fix this issue locally in nvdimm_revalidate_disk() by
using disk_to_dev(disk)->parent, but lets fix it globally since
->driverfs_dev follows the lifetime of the parent.  Longer term we
should probably just add a @parent parameter to add_disk(), and stop
carrying this pointer in the gendisk.

 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: [<ffffffffa00340a8>] nvdimm_revalidate_disk+0x18/0x90 [libnvdimm]
 CPU: 2 PID: 538 Comm: systemd-udevd Tainted: G           O    4.4.0-rc5 #2257
 [..]
 Call Trace:
  [<ffffffff8143e5c7>] rescan_partitions+0x87/0x2c0
  [<ffffffff810f37f9>] ? __lock_is_held+0x49/0x70
  [<ffffffff81438c62>] __blkdev_reread_part+0x72/0xb0
  [<ffffffff81438cc5>] blkdev_reread_part+0x25/0x40
  [<ffffffff8143982d>] blkdev_ioctl+0x4fd/0x9c0
  [<ffffffff811246c9>] ? current_kernel_time64+0x69/0xd0
  [<ffffffff812916dd>] block_ioctl+0x3d/0x50
  [<ffffffff81264c38>] do_vfs_ioctl+0x308/0x560
  [<ffffffff8115dbd1>] ? __audit_syscall_entry+0xb1/0x100
  [<ffffffff810031d6>] ? do_audit_syscall_entry+0x66/0x70
  [<ffffffff81264f09>] SyS_ioctl+0x79/0x90
  [<ffffffff81902672>] entry_SYSCALL_64_fastpath+0x12/0x76

Reported-by: Robert Hu <robert.hu@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 06:35:12 -08:00
Dan Williams
5a023cdba5 block: enable dax for raw block devices
If an application wants exclusive access to all of the persistent memory
provided by an NVDIMM namespace it can use this raw-block-dax facility
to forgo establishing a filesystem.  This capability is targeted
primarily to hypervisors wanting to provision persistent memory for
guests.  It can be disabled / enabled dynamically via the new BLKDAXSET
ioctl.

Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reviewed-by: Jan Kara <jack@suse.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 06:30:49 -08:00
Jens Axboe
6126eb2483 Revert "block: Split bios on chunk boundaries"
This reverts commit d380561113.

If we end up splitting on the first segment, we don't adjust
the sector count. That results in hitting a BUG() with attempting
to split 0 sectors.

As this is just a performance issue and not a regression since
4.3 release, let's just rever this change. That gives us more
time to test a real fix for 4.5, which would be marked for
stable anyway.
2016-01-08 09:00:29 -07:00
Jens Axboe
21491412f2 block: add blk_start_queue_async()
We currently only have an inline/sync helper to restart a stopped
queue. If drivers need an async version, they have to roll their
own. Add a generic helper instead.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-28 13:07:07 -07:00
Keith Busch
d380561113 block: Split bios on chunk boundaries
For h/w that advertise their block storage's underlying chunk size, it's
a big performance win to not submit commands that cross them. This patch
uses that criteria if it is provided. If it is not provided, this patch
uses the max sectors as before.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-22 17:19:25 -07:00
Linus Torvalds
24bc3ea5df Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
 "Three small fixes for 4.4 final. Specifically:

   - The segment issue fix from Junichi, where the old IO path does a
     bio limit split before potentially bouncing the pages.  We need to
     do that in the right order, to ensure that limitations are met.

   - A NVMe surprise removal IO hang fix from Keith.

   - A use-after-free in null_blk, introduced by a previous patch in
     this series.  From Mike Krinkin"

* 'for-linus' of git://git.kernel.dk/linux-block:
  null_blk: fix use-after-free error
  block: ensure to split after potentially bouncing a bio
  NVMe: IO ending fixes on surprise removal
2015-12-22 16:00:25 -08:00
Junichi Nomura
23688bf4f8 block: ensure to split after potentially bouncing a bio
blk_queue_bio() does split then bounce, which makes the segment
counting based on pages before bouncing and could go wrong. Move
the split to after bouncing, like we do for blk-mq, and the we
fix the issue of having the bio count for segments be wrong.

Fixes: 54efd50bfd ("block: make generic_make_request handle arbitrarily sized bios")
Cc: stable@vger.kernel.org
Tested-by: Artem S. Tashkinov <t.artem@lycos.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-22 10:26:53 -07:00
Linus Torvalds
7807563183 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
 "A set of fixes for the current series.  This contains:

   - A bunch of fixes for lightnvm, should be the last round for this
     series.  From Matias and Wenwei.

   - A writeback detach inode fix from Ilya, also marked for stable.

   - A block (though it says SCSI) fix for an OOPS in SCSI runtime power
     management.

   - Module init error path fixes for null_blk from Minfei"

* 'for-linus' of git://git.kernel.dk/linux-block:
  null_blk: Fix error path in module initialization
  lightnvm: do not compile in debugging by default
  lightnvm: prevent gennvm module unload on use
  lightnvm: fix media mgr registration
  lightnvm: replace req queue with nvmdev for lld
  lightnvm: comments on constants
  lightnvm: check mm before use
  lightnvm: refactor spin_unlock in gennvm_get_blk
  lightnvm: put blks when luns configure failed
  lightnvm: use flags in rrpc_get_blk
  block: detach bdev inode from its wb in __blkdev_put()
  SCSI: Fix NULL pointer dereference in runtime PM
2015-12-12 10:24:00 -08:00
Tejun Heo
0b98f0c042 Merge branch 'master' into for-4.4-fixes
The following commit which went into mainline through networking tree

  3b13758f51 ("cgroups: Allow dynamically changing net_classid")

conflicts in net/core/netclassid_cgroup.c with the following pending
fix in cgroup/for-4.4-fixes.

  1f7dd3e5a6 ("cgroup: fix handling of multi-destination migration from subtree_control enabling")

The former separates out update_classid() from cgrp_attach() and
updates it to walk all fds of all tasks in the target css so that it
can be used from both migration and config change paths.  The latter
drops @css from cgrp_attach().

Resolve the conflict by making cgrp_attach() call update_classid()
with the css from the first task.  We can revive @tset walking in
cgrp_attach() but given that net_cls is v1 only where there always is
only one target css during migration, this is fine.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Nina Schiff <ninasc@fb.com>
2015-12-07 10:09:03 -05:00
Linus Torvalds
19190f5ea9 SCSI fixes on 20151205
This is quite a bumper crop of fixes: Three from Arnd correcting various build
 issues in some configurations, a lock recursion in qla2xxx.  Two potentially
 exploitable issues in hpsa and mvsas, a potential null deref in st, A revert
 of a bdi registration fix that turned out to cause even more problems, a set
 of fixes to allow people who only defined MPT2SAS to still work after the
 mpt2/mpt3sas merger and a couple of fixes for issues turned up by the hyper-v
 storvsc driver.
 
 Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
 "This is quite a bumper crop of fixes: three from Arnd correcting
  various build issues in some configurations, a lock recursion in
  qla2xxx.  Two potentially exploitable issues in hpsa and mvsas, a
  potential null deref in st, a revert of a bdi registration fix that
  turned out to cause even more problems, a set of fixes to allow people
  who only defined MPT2SAS to still work after the mpt2/mpt3sas merger
  and a couple of fixes for issues turned up by the hyper-v storvsc
  driver"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  mpt3sas: fix Kconfig dependency problem for mpt2sas back compatibility
  Revert "scsi: Fix a bdi reregistration race"
  mpt3sas: Add dummy Kconfig option for backwards compatibility
  Fix a memory leak in scsi_host_dev_release()
  block/sd: Fix device-imposed transfer length limits
  scsi_debug: fix prevent_allow+verify regressions
  MAINTAINERS: Add myself as co-maintainer of the SCSI subsystem.
  sd: Make discard granularity match logical block size when LBPRZ=1
  scsi: hpsa: select CONFIG_SCSI_SAS_ATTR
  scsi: advansys needs ISA dma api for ISA support
  scsi_sysfs: protect against double execution of __scsi_remove_device()
  st: fix potential null pointer dereference.
  scsi: report 'INQUIRY result too short' once per host
  advansys: fix big-endian builds
  qla2xxx: Fix rwlock recursion
  hpsa: logical vs bitwise AND typo
  mvsas: don't allow negative timeouts
  mpt3sas: Fix use sas_is_tlr_enabled API before enabling MPI2_SCSIIO_CONTROL_TLR_ON flag
2015-12-06 08:02:25 -08:00
Ken Xue
4fd41a8552 SCSI: Fix NULL pointer dereference in runtime PM
The routines in scsi_pm.c assume that if a runtime-PM callback is
invoked for a SCSI device, it can only mean that the device's driver
has asked the block layer to handle the runtime power management (by
calling blk_pm_runtime_init(), which among other things sets q->dev).

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

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

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

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

Signed-off-by: Ken Xue <Ken.Xue@amd.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Xiangliang Yu <Xiangliang.Yu@amd.com>
Cc: James E.J. Bottomley <JBottomley@odin.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michael Terry <Michael.terry@canonical.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-03 20:35:02 -07:00
James Bottomley
be9e2f775f Merge branch 'mkp-fixes' into fixes 2015-12-03 09:32:33 -08:00
Mike Krinkin
cda22646ad block: add call to split trace point
There is a split tracepoint that is supposed to be called when
bio is splitted, and it was called in bio_split function until
commit 4b1faf9316 ("block: Kill bio_pair_split()").
But now, no one reports splits, so this patch adds call to
trace_block_split back in blk_queue_split right after split.

Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-03 10:18:44 -07:00
Raghavendra K T
bffed45716 blk-mq: Avoid memoryless numa node encoded in hctx numa_node
In architecture like powerpc, we can have cpus without any local memory
attached to it (a.k.a memoryless nodes). In such cases cpu to node mapping
can result in memory allocation hints for block hctx->numa_node populated
with node values which does not have real memory.

Instead use local_memory_node(), which is guaranteed to have memory.
local_memory_node is a noop in other architectures that does not support
memoryless nodes.

Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-03 09:56:27 -07:00
Raghavendra K T
e0e827b9fc blk-mq: Reuse hardware context cpumask for tags
hctx->cpumask is already populated and let the tag cpumask follow that
instead of going through a new for loop.

Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-03 09:56:25 -07:00
Tejun Heo
1f7dd3e5a6 cgroup: fix handling of multi-destination migration from subtree_control enabling
Consider the following v2 hierarchy.

  P0 (+memory) --- P1 (-memory) --- A
                                 \- B
       
P0 has memory enabled in its subtree_control while P1 doesn't.  If
both A and B contain processes, they would belong to the memory css of
P1.  Now if memory is enabled on P1's subtree_control, memory csses
should be created on both A and B and A's processes should be moved to
the former and B's processes the latter.  IOW, enabling controllers
can cause atomic migrations into different csses.

The core cgroup migration logic has been updated accordingly but the
controller migration methods haven't and still assume that all tasks
migrate to a single target css; furthermore, the methods were fed the
css in which subtree_control was updated which is the parent of the
target csses.  pids controller depends on the migration methods to
move charges and this made the controller attribute charges to the
wrong csses often triggering the following warning by driving a
counter negative.

 WARNING: CPU: 1 PID: 1 at kernel/cgroup_pids.c:97 pids_cancel.constprop.6+0x31/0x40()
 Modules linked in:
 CPU: 1 PID: 1 Comm: systemd Not tainted 4.4.0-rc1+ #29
 ...
  ffffffff81f65382 ffff88007c043b90 ffffffff81551ffc 0000000000000000
  ffff88007c043bc8 ffffffff810de202 ffff88007a752000 ffff88007a29ab00
  ffff88007c043c80 ffff88007a1d8400 0000000000000001 ffff88007c043bd8
 Call Trace:
  [<ffffffff81551ffc>] dump_stack+0x4e/0x82
  [<ffffffff810de202>] warn_slowpath_common+0x82/0xc0
  [<ffffffff810de2fa>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8118e031>] pids_cancel.constprop.6+0x31/0x40
  [<ffffffff8118e0fd>] pids_can_attach+0x6d/0xf0
  [<ffffffff81188a4c>] cgroup_taskset_migrate+0x6c/0x330
  [<ffffffff81188e05>] cgroup_migrate+0xf5/0x190
  [<ffffffff81189016>] cgroup_attach_task+0x176/0x200
  [<ffffffff8118949d>] __cgroup_procs_write+0x2ad/0x460
  [<ffffffff81189684>] cgroup_procs_write+0x14/0x20
  [<ffffffff811854e5>] cgroup_file_write+0x35/0x1c0
  [<ffffffff812e26f1>] kernfs_fop_write+0x141/0x190
  [<ffffffff81265f88>] __vfs_write+0x28/0xe0
  [<ffffffff812666fc>] vfs_write+0xac/0x1a0
  [<ffffffff81267019>] SyS_write+0x49/0xb0
  [<ffffffff81bcef32>] entry_SYSCALL_64_fastpath+0x12/0x76

This patch fixes the bug by removing @css parameter from the three
migration methods, ->can_attach, ->cancel_attach() and ->attach() and
updating cgroup_taskset iteration helpers also return the destination
css in addition to the task being migrated.  All controllers are
updated accordingly.

* Controllers which don't care whether there are one or multiple
  target csses can be converted trivially.  cpu, io, freezer, perf,
  netclassid and netprio fall in this category.

* cpuset's current implementation assumes that there's single source
  and destination and thus doesn't support v2 hierarchy already.  The
  only change made by this patchset is how that single destination css
  is obtained.

* memory migration path already doesn't do anything on v2.  How the
  single destination css is obtained is updated and the prep stage of
  mem_cgroup_can_attach() is reordered to accomodate the change.

* pids is the only controller which was affected by this bug.  It now
  correctly handles multi-destination migrations and no longer causes
  counter underflow from incorrect accounting.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Cc: Aleksa Sarai <cyphar@cyphar.com>
2015-12-03 10:18:21 -05:00
Christoph Hellwig
6f3b0e8bcf blk-mq: add a flags parameter to blk_mq_alloc_request
We already have the reserved flag, and a nowait flag awkwardly encoded as
a gfp_t.  Add a real flags argument to make the scheme more extensible and
allow for a nicer calling convention.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-12-01 10:53:59 -07:00
Ming Lei
a88d32af18 blk-merge: fix computing bio->bi_seg_front_size in case of single segment
When bio has only one physical segment, we should set bio's
bi_seg_front_size as the real(final) size of the single segment.

Fixes: 02e707424c2ea(blk-merge: fix blk_bio_segment_split)
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-30 13:02:36 -07:00
Hannes Reinecke
bf4e6b4e75 block: Always check queue limits for cloned requests
When a cloned request is retried on other queues it always needs
to be checked against the queue limits of that queue.
Otherwise the calculations for nr_phys_segments might be wrong,
leading to a crash in scsi_init_sgtable().

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

Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Ewan Milne <emilne@redhat.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Fixes: e2a60da74 ("block: Clean up special command handling logic")
Cc: stable@vger.kernel.org # 3.7+
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-29 14:37:27 -07:00
Eric Sandeen
77032ca66f Return EBUSY from BLKRRPART for mounted whole-dev fs
Today, blockdev --rereadpt /dev/sda will fail with EBUSY if any
partition of sda is mounted (and will fail with EINVAL if pointed
at a partition).  But it will pass if the entire block device is
formatted with a filesystem and mounted.  I don't think this makes
sense; partitioning should surely not ever change out from under
a mounted device.

So check for bdev->bd_super, and fail that with -EBUSY as well.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-25 20:49:24 -07:00
Martin K. Petersen
ca369d51b3 block/sd: Fix device-imposed transfer length limits
Commit 4f258a4634 ("sd: Fix maximum I/O size for BLOCK_PC requests")
had the unfortunate side-effect of removing an implicit clamp to
BLK_DEF_MAX_SECTORS for REQ_TYPE_FS requests in the block layer
code. This caused problems for some SMR drives.

Debugging this issue revealed a few problems with the existing
infrastructure since the block layer didn't know how to deal with
device-imposed limits, only limits set by the I/O controller.

 - Introduce a new queue limit, max_dev_sectors, which is used by the
   ULD to signal the maximum sectors for a REQ_TYPE_FS request.

 - Ensure that max_dev_sectors is correctly stacked and taken into
   account when overriding max_sectors through sysfs.

 - Rework sd_read_block_limits() so it saves the max_xfer and opt_xfer
   values for later processing.

 - In sd_revalidate() set the queue's max_dev_sectors based on the
   MAXIMUM TRANSFER LENGTH value in the Block Limits VPD. If this value
   is not reported, fall back to a cap based on the CDB TRANSFER LENGTH
   field size.

 - In sd_revalidate(), use OPTIMAL TRANSFER LENGTH from the Block Limits
   VPD--if reported and sane--to signal the preferred device transfer
   size for FS requests. Otherwise use BLK_DEF_MAX_SECTORS.

 - blk_limits_max_hw_sectors() is no longer used and can be removed.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=93581
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: sweeneygj@gmx.com
Tested-by: Arzeets <anatol.pomozov@gmail.com>
Tested-by: David Eisner <david.eisner@oriel.oxon.org>
Tested-by: Mario Kicherer <dev@kicherer.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2015-11-25 21:38:58 -05:00
Jens Axboe
d7cf931dd9 Revert "blk-flush: Queue through IO scheduler when flush not required"
This reverts commit 1b2ff19e6a.

Jan writes:

--

Thanks for report! After some investigation I found out we allocate
elevator specific data in __get_request() only for non-flush requests. And
this is actually required since the flush machinery uses the space in
struct request for something else. Doh. So my patch is just wrong and not
easy to fix since at the time __get_request() is called we are not sure
whether the flush machinery will be used in the end. Jens, please revert
1b2ff19e6a. Thanks!

I'm somewhat surprised that you can reliably hit the race where flushing
gets disabled for the device just while the request is in flight. But I
guess during boot it makes some sense.

--

So let's just revert it, we can fix the queue run manually after the
fact. This race is rare enough that it didn't trigger in testing, it
requires the specific disable-while-in-flight scenario to trigger.
2015-11-25 11:02:02 -07:00
Jens Axboe
dcd8376c36 Revert "blk-flush: Queue through IO scheduler when flush not required"
This reverts commit 1b2ff19e6a.

Jan writes:

--

Thanks for report! After some investigation I found out we allocate
elevator specific data in __get_request() only for non-flush requests. And
this is actually required since the flush machinery uses the space in
struct request for something else. Doh. So my patch is just wrong and not
easy to fix since at the time __get_request() is called we are not sure
whether the flush machinery will be used in the end. Jens, please revert
1b2ff19e6a. Thanks!

I'm somewhat surprised that you can reliably hit the race where flushing
gets disabled for the device just while the request is in flight. But I
guess during boot it makes some sense.

--

So let's just revert it, we can fix the queue run manually after the
fact. This race is rare enough that it didn't trigger in testing, it
requires the specific disable-while-in-flight scenario to trigger.
2015-11-25 10:12:54 -07:00
Jens Axboe
3b627a3f93 block: clarify blk_add_timer() use case for blk-mq
Just a comment update on not needing queue_lock, and that we aren't
really adding the request to a timeout list for !mq.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-24 15:58:53 -07:00
Geliang Tang
bd5cecea43 bio: use offset_in_page macro
Use offset_in_page macro instead of (addr & ~PAGE_MASK).

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-24 15:24:25 -07:00
Wei Tang
1fe8f34841 block: do not initialise statics to 0 or NULL
This patch fixes the checkpatch.pl error to genhd.c:

ERROR: do not initialise statics to 0 or NULL

Signed-off-by: Wei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-24 15:24:25 -07:00
Wei Tang
d674d4145e block: do not initialise globals to 0 or NULL
This patch fixes the checkpatch.pl error to blk-exec.c:

ERROR: do not initialise globals to 0 or NULL

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

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-24 15:24:25 -07:00
Christoph Hellwig
55ce0da1da block: fix blk_abort_request for blk-mq drivers
We only added the request to the request list for the !blk-mq case,
so we should only delete it in that case as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-24 15:24:10 -07:00
Linus Torvalds
4ce01c518e Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block layer fixes from Jens Axboe:
 "A round of fixes/updates for the current series.

  This looks a little bigger than it is, but that's mainly because we
  pushed the lightnvm enabled null_blk change out of the merge window so
  it could be updated a bit.  The rest of the volume is also mostly
  lightnvm.  In particular:

   - Lightnvm.  Various fixes, additions, updates from Matias and
     Javier, as well as from Wenwei Tao.

   - NVMe:
        - Fix for potential arithmetic overflow from Keith.
        - Also from Keith, ensure that we reap pending completions from
          a completion queue before deleting it.  Fixes kernel crashes
          when resetting a device with IO pending.
        - Various little lightnvm related tweaks from Matias.

   - Fixup flushes to go through the IO scheduler, for the cases where a
     flush is not required.  Fixes a case in CFQ where we would be
     idling and not see this request, hence not break the idling.  From
     Jan Kara.

   - Use list_{first,prev,next} in elevator.c for cleaner code.  From
     Gelian Tang.

   - Fix for a warning trigger on btrfs and raid on single queue blk-mq
     devices, where we would flush plug callbacks with preemption
     disabled.  From me.

   - A mac partition validation fix from Kees Cook.

   - Two merge fixes from Ming, marked stable.  A third part is adding a
     new warning so we'll notice this quicker in the future, if we screw
     up the accounting.

   - Cleanup of thread name/creation in mtip32xx from Rasmus Villemoes"

* 'for-linus' of git://git.kernel.dk/linux-block: (32 commits)
  blk-merge: warn if figured out segment number is bigger than nr_phys_segments
  blk-merge: fix blk_bio_segment_split
  block: fix segment split
  blk-mq: fix calling unplug callbacks with preempt disabled
  mac: validate mac_partition is within sector
  mtip32xx: use formatting capability of kthread_create_on_node
  NVMe: reap completion entries when deleting queue
  lightnvm: add free and bad lun info to show luns
  lightnvm: keep track of block counts
  nvme: lightnvm: use admin queues for admin cmds
  lightnvm: missing free on init error
  lightnvm: wrong return value and redundant free
  null_blk: do not del gendisk with lightnvm
  null_blk: use device addressing mode
  null_blk: use ppa_cache pool
  NVMe: Fix possible arithmetic overflow for max segments
  blk-flush: Queue through IO scheduler when flush not required
  null_blk: register as a LightNVM device
  elevator: use list_{first,prev,next}_entry
  lightnvm: cleanup queue before target removal
  ...
2015-11-24 10:26:30 -08:00
Ming Lei
12e57f59ca blk-merge: warn if figured out segment number is bigger than nr_phys_segments
We had seen lots of reports of this kind issue, so add one
warnning in blk-merge, then it can be triggered easily and
avoid to depend on warning/bug from drivers.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-23 20:16:55 -07:00
Ming Lei
02e707424c blk-merge: fix blk_bio_segment_split
Commit bdced438acd83a(block: setup bi_phys_segments after
splitting) introduces function of computing bio->bi_phys_segments
during bio splitting.

Unfortunately both bio->bi_seg_front_size and bio->bi_seg_back_size
arn't computed, so too many physical segments may be obtained
for one request since both the two are used to check if one segment
across two bios can be possible.

This patch fixes the issue by computing the two variables in
blk_bio_segment_split().

Fixes: bdced438acd83a(block: setup bi_phys_segments after splitting)
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Mark Salter <msalter@redhat.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-23 20:16:53 -07:00
Ming Lei
578270bfbd block: fix segment split
Inside blk_bio_segment_split(), previous bvec pointer(bvprvp)
always points to the iterator local variable, which is obviously
wrong, so fix it by pointing to the local variable of 'bvprv'.

Fixes: 5014c311baa2b(block: fix bogus compiler warnings in blk-merge.c)
Cc: stable@kernel.org #4.3
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Mark Salter <msalter@redhat.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-23 20:16:51 -07:00
Jens Axboe
b094f89ca4 blk-mq: fix calling unplug callbacks with preempt disabled
Liu reported that running certain parts of xfstests threw the
following error:

BUG: sleeping function called from invalid context at mm/page_alloc.c:3190
in_atomic(): 1, irqs_disabled(): 0, pid: 6, name: kworker/u16:0
3 locks held by kworker/u16:0/6:
 #0:  ("writeback"){++++.+}, at: [<ffffffff8107f083>] process_one_work+0x173/0x730
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff8107f083>] process_one_work+0x173/0x730
 #2:  (&type->s_umount_key#44){+++++.}, at: [<ffffffff811e6805>] trylock_super+0x25/0x60
CPU: 5 PID: 6 Comm: kworker/u16:0 Tainted: G           OE   4.3.0+ #3
Hardware name: Red Hat KVM, BIOS Bochs 01/01/2011
Workqueue: writeback wb_workfn (flush-btrfs-108)
 ffffffff81a3abab ffff88042e282ba8 ffffffff8130191b ffffffff81a3abab
 0000000000000c76 ffff88042e282ba8 ffff88042e27c180 ffff88042e282bd8
 ffffffff8108ed95 ffff880400000004 0000000000000000 0000000000000c76
Call Trace:
 [<ffffffff8130191b>] dump_stack+0x4f/0x74
 [<ffffffff8108ed95>] ___might_sleep+0x185/0x240
 [<ffffffff8108eea2>] __might_sleep+0x52/0x90
 [<ffffffff811817e8>] __alloc_pages_nodemask+0x268/0x410
 [<ffffffff8109a43c>] ? sched_clock_local+0x1c/0x90
 [<ffffffff8109a6d1>] ? local_clock+0x21/0x40
 [<ffffffff810b9eb0>] ? __lock_release+0x420/0x510
 [<ffffffff810b534c>] ? __lock_acquired+0x16c/0x3c0
 [<ffffffff811ca265>] alloc_pages_current+0xc5/0x210
 [<ffffffffa0577105>] ? rbio_is_full+0x55/0x70 [btrfs]
 [<ffffffff810b7ed8>] ? mark_held_locks+0x78/0xa0
 [<ffffffff81666d50>] ? _raw_spin_unlock_irqrestore+0x40/0x60
 [<ffffffffa0578c0a>] full_stripe_write+0x5a/0xc0 [btrfs]
 [<ffffffffa0578ca9>] __raid56_parity_write+0x39/0x60 [btrfs]
 [<ffffffffa0578deb>] run_plug+0x11b/0x140 [btrfs]
 [<ffffffffa0578e33>] btrfs_raid_unplug+0x23/0x70 [btrfs]
 [<ffffffff812d36c2>] blk_flush_plug_list+0x82/0x1f0
 [<ffffffff812e0349>] blk_sq_make_request+0x1f9/0x740
 [<ffffffff812ceba2>] ? generic_make_request_checks+0x222/0x7c0
 [<ffffffff812cf264>] ? blk_queue_enter+0x124/0x310
 [<ffffffff812cf1d2>] ? blk_queue_enter+0x92/0x310
 [<ffffffff812d0ae2>] generic_make_request+0x172/0x2c0
 [<ffffffff812d0ad4>] ? generic_make_request+0x164/0x2c0
 [<ffffffff812d0ca0>] submit_bio+0x70/0x140
 [<ffffffffa0577b29>] ? rbio_add_io_page+0x99/0x150 [btrfs]
 [<ffffffffa0578a89>] finish_rmw+0x4d9/0x600 [btrfs]
 [<ffffffffa0578c4c>] full_stripe_write+0x9c/0xc0 [btrfs]
 [<ffffffffa057ab7f>] raid56_parity_write+0xef/0x160 [btrfs]
 [<ffffffffa052bd83>] btrfs_map_bio+0xe3/0x2d0 [btrfs]
 [<ffffffffa04fbd6d>] btrfs_submit_bio_hook+0x8d/0x1d0 [btrfs]
 [<ffffffffa05173c4>] submit_one_bio+0x74/0xb0 [btrfs]
 [<ffffffffa0517f55>] submit_extent_page+0xe5/0x1c0 [btrfs]
 [<ffffffffa0519b18>] __extent_writepage_io+0x408/0x4c0 [btrfs]
 [<ffffffffa05179c0>] ? alloc_dummy_extent_buffer+0x140/0x140 [btrfs]
 [<ffffffffa051dc88>] __extent_writepage+0x218/0x3a0 [btrfs]
 [<ffffffff810b7ed8>] ? mark_held_locks+0x78/0xa0
 [<ffffffffa051e2c9>] extent_write_cache_pages.clone.0+0x2f9/0x400 [btrfs]
 [<ffffffffa051e422>] extent_writepages+0x52/0x70 [btrfs]
 [<ffffffffa05001f0>] ? btrfs_set_inode_index+0x70/0x70 [btrfs]
 [<ffffffffa04fcc17>] btrfs_writepages+0x27/0x30 [btrfs]
 [<ffffffff81184df3>] do_writepages+0x23/0x40
 [<ffffffff81212229>] __writeback_single_inode+0x89/0x4d0
 [<ffffffff81212a60>] ? writeback_sb_inodes+0x260/0x480
 [<ffffffff81212a60>] ? writeback_sb_inodes+0x260/0x480
 [<ffffffff8121295f>] ? writeback_sb_inodes+0x15f/0x480
 [<ffffffff81212ad2>] writeback_sb_inodes+0x2d2/0x480
 [<ffffffff810b1397>] ? down_read_trylock+0x57/0x60
 [<ffffffff811e6805>] ? trylock_super+0x25/0x60
 [<ffffffff810d629f>] ? rcu_read_lock_sched_held+0x4f/0x90
 [<ffffffff81212d0c>] __writeback_inodes_wb+0x8c/0xc0
 [<ffffffff812130b5>] wb_writeback+0x2b5/0x500
 [<ffffffff810b7ed8>] ? mark_held_locks+0x78/0xa0
 [<ffffffff810660a8>] ? __local_bh_enable_ip+0x68/0xc0
 [<ffffffff81213362>] ? wb_do_writeback+0x62/0x310
 [<ffffffff812133c1>] wb_do_writeback+0xc1/0x310
 [<ffffffff8107c3d9>] ? set_worker_desc+0x79/0x90
 [<ffffffff81213842>] wb_workfn+0x92/0x330
 [<ffffffff8107f133>] process_one_work+0x223/0x730
 [<ffffffff8107f083>] ? process_one_work+0x173/0x730
 [<ffffffff8108035f>] ? worker_thread+0x18f/0x430
 [<ffffffff810802ed>] worker_thread+0x11d/0x430
 [<ffffffff810801d0>] ? maybe_create_worker+0xf0/0xf0
 [<ffffffff810801d0>] ? maybe_create_worker+0xf0/0xf0
 [<ffffffff810858df>] kthread+0xef/0x110
 [<ffffffff8108f74e>] ? schedule_tail+0x1e/0xd0
 [<ffffffff810857f0>] ? __init_kthread_worker+0x70/0x70
 [<ffffffff816673bf>] ret_from_fork+0x3f/0x70
 [<ffffffff810857f0>] ? __init_kthread_worker+0x70/0x70

The issue is that we've got the software context pinned while
calling blk_flush_plug_list(), which flushes callbacks that
are allowed to sleep. btrfs and raid has such callbacks.

Flip the checks around a bit, so we can enable preempt a bit
earlier and flush plugs without having preempt disabled.

This only affects blk-mq driven devices, and only those that
register a single queue.

Reported-by: Liu Bo <bo.li.liu@oracle.com>
Tested-by: Liu Bo <bo.li.liu@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-20 20:29:45 -07:00
Kees Cook
02e2a5bfeb mac: validate mac_partition is within sector
If md->signature == MAC_DRIVER_MAGIC and md->block_size == 1023, a single
512 byte sector would be read (secsize / 512). However the partition
structure would be located past the end of the buffer (secsize % 512).

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-20 08:49:28 -07:00
Dan Williams
2e6edc9538 block: protect rw_page against device teardown
Fix use after free crashes like the following:

 general protection fault: 0000 [#1] SMP
 Call Trace:
  [<ffffffffa0050216>] ? pmem_do_bvec.isra.12+0xa6/0xf0 [nd_pmem]
  [<ffffffffa0050ba2>] pmem_rw_page+0x42/0x80 [nd_pmem]
  [<ffffffff8128fd90>] bdev_read_page+0x50/0x60
  [<ffffffff812972f0>] do_mpage_readpage+0x510/0x770
  [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
  [<ffffffff811d86dc>] ? lru_cache_add+0x1c/0x50
  [<ffffffff81297657>] mpage_readpages+0x107/0x170
  [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
  [<ffffffff8128fd20>] ? I_BDEV+0x20/0x20
  [<ffffffff8129058d>] blkdev_readpages+0x1d/0x20
  [<ffffffff811d615f>] __do_page_cache_readahead+0x28f/0x310
  [<ffffffff811d6039>] ? __do_page_cache_readahead+0x169/0x310
  [<ffffffff811c5abd>] ? pagecache_get_page+0x2d/0x1d0
  [<ffffffff811c76f6>] filemap_fault+0x396/0x530
  [<ffffffff811f816e>] __do_fault+0x4e/0xf0
  [<ffffffff811fce7d>] handle_mm_fault+0x11bd/0x1b50

Cc: <stable@vger.kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Reported-by: kbuild test robot <lkp@intel.com>
Acked-by: Matthew Wilcox <willy@linux.intel.com>
[willy: symmetry fixups]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-11-19 13:47:10 -08:00
Jan Kara
1b2ff19e6a blk-flush: Queue through IO scheduler when flush not required
Currently blk_insert_flush() just adds flush request to q->queue_head
when flush is not required. That completely bypasses IO scheduler so
e.g. CFQ can be idling waiting for new request to arrive and will idle
through the whole window unnecessarily. Luckily this only happens in
rare cases as usually checks in generic_make_request_checks() clear
FLUSH and FUA flags early if they are not needed.

When no flushing is actually required, we can easily fix the problem by
properly queueing the request through the IO scheduler. Ideally IO
scheduler should be also made aware of requests queued via
blk_flush_queue_rq(). However inserting flush request through IO
scheduler can have unwanted side-effects since due to flush batching
delaying the flush request in IO scheduler will delay all flush requests
possibly coming from other processes. So we keep adding the request
directly to q->queue_head.

Signed-off-by: Jan Kara <jack@suse.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-16 15:23:51 -07:00
Geliang Tang
4736346bb4 elevator: use list_{first,prev,next}_entry
To make the intention clearer, use list_{first,prev,next}_entry
instead of list_entry.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-16 15:21:48 -07:00
Randy Dunlap
ccc2600b8a block: fix blk-core.c kernel-doc warning
Fix kernel-doc warning in blk-core.c:

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

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-11 09:36:57 -07:00
Jens Axboe
1fa8cc52f4 blk-mq: mark __blk_mq_complete_request() static
It's no longer used outside of blk-mq core.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-11 09:36:56 -07:00