Commit Graph

2639 Commits

Author SHA1 Message Date
Linus Torvalds
69234acee5 Merge branch 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
 "The cgroup core saw several significant updates this cycle:

   - percpu_rwsem for threadgroup locking is reinstated.  This was
     temporarily dropped due to down_write latency issues.  Oleg's
     rework of percpu_rwsem which is scheduled to be merged in this
     merge window resolves the issue.

   - On the v2 hierarchy, when controllers are enabled and disabled, all
     operations are atomic and can fail and revert cleanly.  This allows
     ->can_attach() failure which is necessary for cpu RT slices.

   - Tasks now stay associated with the original cgroups after exit
     until released.  This allows tracking resources held by zombies
     (e.g.  pids) and makes it easy to find out where zombies came from
     on the v2 hierarchy.  The pids controller was broken before these
     changes as zombies escaped the limits; unfortunately, updating this
     behavior required too many invasive changes and I don't think it's
     a good idea to backport them, so the pids controller on 4.3, the
     first version which included the pids controller, will stay broken
     at least until I'm sure about the cgroup core changes.

   - Optimization of a couple common tests using static_key"

* 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (38 commits)
  cgroup: fix race condition around termination check in css_task_iter_next()
  blkcg: don't create "io.stat" on the root cgroup
  cgroup: drop cgroup__DEVEL__legacy_files_on_dfl
  cgroup: replace error handling in cgroup_init() with WARN_ON()s
  cgroup: add cgroup_subsys->free() method and use it to fix pids controller
  cgroup: keep zombies associated with their original cgroups
  cgroup: make css_set_rwsem a spinlock and rename it to css_set_lock
  cgroup: don't hold css_set_rwsem across css task iteration
  cgroup: reorganize css_task_iter functions
  cgroup: factor out css_set_move_task()
  cgroup: keep css_set and task lists in chronological order
  cgroup: make cgroup_destroy_locked() test cgroup_is_populated()
  cgroup: make css_sets pin the associated cgroups
  cgroup: relocate cgroup_[try]get/put()
  cgroup: move check_for_release() invocation
  cgroup: replace cgroup_has_tasks() with cgroup_is_populated()
  cgroup: make cgroup->nr_populated count the number of populated css_sets
  cgroup: remove an unused parameter from cgroup_task_migrate()
  cgroup: fix too early usage of static_branch_disable()
  cgroup: make cgroup_update_dfl_csses() migrate all target processes atomically
  ...
2015-11-05 14:51:32 -08:00
Linus Torvalds
ccf21b69a8 Merge branch 'for-4.4/reservations' of git://git.kernel.dk/linux-block
Pull block reservation support from Jens Axboe:
 "This adds support for persistent reservations, both at the core level,
  as well as for sd and NVMe"

[ Background from the docs: "Persistent Reservations allow restricting
  access to block devices to specific initiators in a shared storage
  setup.  All implementations are expected to ensure the reservations
  survive a power loss and cover all connections in a multi path
  environment" ]

* 'for-4.4/reservations' of git://git.kernel.dk/linux-block:
  NVMe: Precedence error in nvme_pr_clear()
  nvme: add missing endianess annotations in nvme_pr_command
  NVMe: Add persistent reservation ops
  sd: implement the Persistent Reservation API
  block: add an API for Persistent Reservations
  block: cleanup blkdev_ioctl
2015-11-04 21:01:27 -08:00
Linus Torvalds
527d1529e3 Merge branch 'for-4.4/integrity' of git://git.kernel.dk/linux-block
Pull block integrity updates from Jens Axboe:
 ""This is the joint work of Dan and Martin, cleaning up and improving
  the support for block data integrity"

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

  This pull request contains:

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

   - Unused prototype removal in blk-mq from Christoph.

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

   - A plug flush fix from Jeff.

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

   - blk-mq waitqueue barrier fix from Kosuke.

   - Various fixes from Ming:

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

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

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

   - A WRITE_SYNC fix for mpage from Roman"

* 'for-4.4/core' of git://git.kernel.dk/linux-block:
  blk-mq: avoid excessive boot delays with large lun counts
  blktrace: re-write setting q->blk_trace
  blk-mq: mark ctx as pending at batch in flush plug path
  blk-mq: fix for trace_block_plug()
  block: check bio_mergeable() early before merging
  blk-mq: check bio_mergeable() early before merging
  block: avoid to merge splitted bio
  block: setup bi_phys_segments after splitting
  block: fix plug list flushing for nomerge queues
  blk-mq: remove unused blk_mq_clone_flush_request prototype
  blk-mq: fix waitqueue_active without memory barrier in block/blk-mq-tag.c
  fs: direct-io: don't dirtying pages for ITER_BVEC/ITER_KVEC direct read
  fs/mpage.c: forgotten WRITE_SYNC in case of data integrity write
  block: kmemleak: Track the page allocations for struct request
2015-11-04 20:28:10 -08:00
Jeff Moyer
2404e607a9 blk-mq: avoid excessive boot delays with large lun counts
Hi,

Zhangqing Luo reported long boot times on a system with thousands of
LUNs when scsi-mq was enabled.  He narrowed the problem down to
blk_mq_add_queue_tag_set, where every queue is frozen in order to set
the BLK_MQ_F_TAG_SHARED flag.  Each added device will freeze all queues
added before it in sequence, which involves waiting for an RCU grace
period for each one.  We don't need to do this.  After the second queue
is added, only new queues need to be initialized with the shared tag.
We can do that by percolating the flag up to the blk_mq_tag_set, and
updating the newly added queue's hctxs if the flag is set.

This problem was introduced by commit 0d2602ca30 (blk-mq: improve
support for shared tags maps).

Reported-and-tested-by: Jason Luo <zhangqing.luo@oracle.com>
Reviewed-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-03 08:42:19 -07:00
Ming Lin
a22c4d7e34 block: re-add discard_granularity and alignment checks
In commit b49a087("block: remove split code in
blkdev_issue_{discard,write_same}"), discard_granularity and alignment
checks were removed. Ideally, with bio late splitting, the upper layers
shouldn't need to depend on device's limits.

Christoph reported a discard regression on the HGST Ultrastar SN100 NVMe
device when mkfs.xfs. We have not found the root cause yet.

This patch re-adds discard_granularity and alignment checks by reverting
the related changes in commit b49a087. The good thing is now we can
remove the 2G discard size cap and just use UINT_MAX to avoid bi_size
overflow.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-28 09:12:58 +09:00
Tejun Heo
ca0752c5e3 blkcg: don't create "io.stat" on the root cgroup
The stat files on the root cgroup shows stats for the whole system and
usually don't contain any information which isn't available through
the usual system monitoring mechanisms.  Some controllers skip
collecting these duplicate stats to optimize cases where cgroup isn't
used and later try to emulate the result on demand.

This leads to complexities and subtle differences in the information
shown through different channels.  This is entirely unnecessary and
cgroup v2 is dropping stat files which are duplicate from all
controllers.  This patch removes "io.stat" from the root hierarchy.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Vivek Goyal <vgoyal@redhat.com>
2015-10-22 17:58:26 +09:00
Ming Lei
cfd0c552a8 blk-mq: mark ctx as pending at batch in flush plug path
Most of times, flush plug should be the hottest I/O path,
so mark ctx as pending after all requests in the list are
inserted.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 15:00:58 -06:00
Ming Lei
676d06077f blk-mq: fix for trace_block_plug()
The trace point is for tracing plug event of each request
queue instead of each task, so we should check the request
count in the plug list from current queue instead of
current task.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 15:00:56 -06:00
Ming Lei
7460d389c0 block: check bio_mergeable() early before merging
After bio splitting is introduced, one bio can be splitted
and it is marked as NOMERGE because it is too fat to be merged,
so check bio_mergeable() earlier to avoid to try to merge it
unnecessarily.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 15:00:54 -06:00
Ming Lei
e18378a60e blk-mq: check bio_mergeable() early before merging
It isn't necessary to try to merge the bio which is marked
as NOMERGE.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 15:00:53 -06:00
Ming Lei
6ac45aeb6b block: avoid to merge splitted bio
The splitted bio has been already too fat to merge, so mark it
as NOMERGE.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 15:00:51 -06:00
Ming Lei
bdced438ac block: setup bi_phys_segments after splitting
The number of bio->bi_phys_segments is always obtained
during bio splitting, so it is natural to setup it
just after bio splitting, then we can avoid to compute
nr_segment again during merge.

Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 15:00:50 -06:00
Jeff Moyer
0809e3ac62 block: fix plug list flushing for nomerge queues
Request queues with merging disabled will not flush the plug list after
BLK_MAX_REQUEST_COUNT requests have been queued, since the code relies
on blk_attempt_plug_merge to compute the request_count.  Fix this by
computing the number of queued requests even for nomerge queues.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 15:00:48 -06:00
Christoph Hellwig
bbd3e06436 block: add an API for Persistent Reservations
This commits adds a driver API and ioctls for controlling Persistent
Reservations s/genericly/generically/ at the block layer.  Persistent
Reservations are supported by SCSI and NVMe and allow controlling who gets
access to a device in a shared storage setup.

Note that we add a pr_ops structure to struct block_device_operations
instead of adding the members directly to avoid bloating all instances
of devices that will never support Persistent Reservations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:46:56 -06:00
Christoph Hellwig
d8e4bb8103 block: cleanup blkdev_ioctl
Split out helpers for all non-trivial ioctls to make this function simpler,
and also start passing around a pointer version of the argument, as that's
what most ioctl handlers actually need.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:46:55 -06:00
Dan Williams
4125a09b0a block, libnvdimm, nvme: provide a built-in blk_integrity nop profile
The libnvidmm-btt and nvme drivers use blk_integrity to reserve space
for per-sector metadata, but sometimes without protection checksums.
This property is generically useful, so teach the block core to
internally specify a nop profile if one is not provided at registration
time.

Cc: Keith Busch <keith.busch@intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
[hch: kill the local nvme nop profile as well]
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:43:45 -06:00
Dan Williams
5a48fc147d block: blk_flush_integrity() for bio-based drivers
Since they lack requests to pin the request_queue active, synchronous
bio-based drivers may have in-flight integrity work from
bio_integrity_endio() that is not flushed by blk_freeze_queue().  Flush
that work to prevent races to free the queue and the final usage of the
blk_integrity profile.

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

Cc: Martin K. Petersen <martin.petersen@oracle.com>
[martin: fix the CONFIG_BLK_DEV_INTEGRITY=n case]
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:43:44 -06:00
Dan Williams
ac6fc48c9f block: move blk_integrity to request_queue
A trace like the following proceeds a crash in bio_integrity_process()
when it goes to use an already freed blk_integrity profile.

 BUG: unable to handle kernel paging request at ffff8800d31b10d8
 IP: [<ffff8800d31b10d8>] 0xffff8800d31b10d8
 PGD 2f65067 PUD 21fffd067 PMD 80000000d30001e3
 Oops: 0011 [] SMP
 Dumping ftrace buffer:
 ---------------------------------
    ndctl-2222    2.... 44526245us : disk_release: pmem1s
 systemd--2223    4.... 44573945us : bio_integrity_endio: pmem1s
    <...>-409     4.... 44574005us : bio_integrity_process: pmem1s
 ---------------------------------
[..]
  Call Trace:
  [<ffffffff8144e0f9>] ? bio_integrity_process+0x159/0x2d0
  [<ffffffff8144e4f6>] bio_integrity_verify_fn+0x36/0x60
  [<ffffffff810bd2dc>] process_one_work+0x1cc/0x4e0

Given that a request_queue is pinned while i/o is in flight and that a
gendisk is allowed to have a shorter lifetime, move blk_integrity to
request_queue to satisfy requests arriving after the gendisk has been
torn down.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
[martin: fix the CONFIG_BLK_DEV_INTEGRITY=n case]
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:43:42 -06:00
Dan Williams
3ef28e83ab block: generic request_queue reference counting
Allow pmem, and other synchronous/bio-based block drivers, to fallback
on a per-cpu reference count managed by the core for tracking queue
live/dead state.

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

This fixes crash signatures like the following:

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

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:43:41 -06:00
Martin K. Petersen
25520d55cd block: Inline blk_integrity in struct gendisk
Up until now the_integrity profile has been dynamically allocated and
attached to struct gendisk after the disk has been made active.

This causes problems because NVMe devices need to register the profile
prior to the partition table being read due to a mandatory metadata
buffer requirement. In addition, DM goes through hoops to deal with
preallocating, but not initializing integrity profiles.

Since the integrity profile is small (4 bytes + a pointer), Christoph
suggested moving it to struct gendisk proper. This requires several
changes:

 - Moving the blk_integrity definition to genhd.h.

 - Inlining blk_integrity in struct gendisk.

 - Removing the dynamic allocation code.

 - Adding helper functions which allow gendisk to set up and tear down
   the integrity sysfs dir when a disk is added/deleted.

 - Adding a blk_integrity_revalidate() callback for updating the stable
   pages bdi setting.

 - The calls that depend on whether a device has an integrity profile or
   not now key off of the bi->profile pointer.

 - Simplifying the integrity support routines in DM (Mike Snitzer).

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:42:42 -06:00
Martin K. Petersen
4c241d08db block: Export integrity data interval size in sysfs
The size of the data interval was not exported in the sysfs integrity
directory. Export it so that userland apps can tell whether the interval
is different from the device's logical block size.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:42:41 -06:00
Martin K. Petersen
a48f041d91 block: Reduce the size of struct blk_integrity
The per-device properties in the blk_integrity structure were previously
unsigned short. However, most of the values fit inside a char. The only
exception is the data interval size and we can work around that by
storing it as a power of two.

This cuts the size of the dynamic portion of blk_integrity in half.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:42:39 -06:00
Martin K. Petersen
0f8087ecde block: Consolidate static integrity profile properties
We previously made a complete copy of a device's data integrity profile
even though several of the fields inside the blk_integrity struct are
pointers to fixed template entries in t10-pi.c.

Split the static and per-device portions so that we can reference the
template directly.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:42:38 -06:00
Martin K. Petersen
aff34e192e block: Move integrity kobject to struct gendisk
The integrity kobject purely exists to support the integrity
subdirectory in sysfs and doesn't really have anything to do with the
blk_integrity data structure. Move the kobject to struct gendisk where
it belongs.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21 14:42:36 -06:00
Tejun Heo
b02176f30c block: don't release bdi while request_queue has live references
bdi's are initialized in two steps, bdi_init() and bdi_register(), but
destroyed in a single step by bdi_destroy() which, for a bdi embedded
in a request_queue, is called during blk_cleanup_queue() which makes
the queue invisible and starts the draining of remaining usages.

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

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

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

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

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: a13f35e871 ("writeback: don't embed root bdi_writeback_congested in bdi_writeback")
Cc: stable@vger.kernel.org # v4.2+
Reported-and-tested-by: Andrey Konovalov <andreyknvl@google.com>
Link: http://lkml.kernel.org/g/CAAeHK+zUJ74Zn17=rOyxacHU18SgCfC6bsYW=6kCY5GXJBwGfQ@mail.gmail.com
Reviewed-by: Jan Kara <jack@suse.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-15 09:53:28 -06:00
Junichi Nomura
f42d79ab67 blk-mq: fix use-after-free in blk_mq_free_tag_set()
tags is freed in blk_mq_free_rq_map() and should not be used after that.
The problem doesn't manifest if CONFIG_CPUMASK_OFFSTACK is false because
free_cpumask_var() is nop.

tags->cpumask is allocated in blk_mq_init_tags() so it's natural to
free cpumask in its counter part, blk_mq_free_tags().

Fixes: f26cdc8536 ("blk-mq: Shared tag enhancements")
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Keith Busch <keith.busch@intel.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-15 08:45:58 -06:00
Christoph Hellwig
3380f4589f blk-mq: remove unused blk_mq_clone_flush_request prototype
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-09 11:16:39 -06:00
Kosuke Tatsukawa
8ee1b7b9d8 blk-mq: fix waitqueue_active without memory barrier in block/blk-mq-tag.c
blk_mq_tag_update_depth() seems to be missing a memory barrier which
might cause the waker to not notice the waiter and fail to send a
wake_up as in the following figure.

	blk_mq_tag_update_depth			bt_get
------------------------------------------------------------------------
if (waitqueue_active(&bs->wait))
/* The CPU might reorder the test for
   the waitqueue up here, before
   prior writes complete */
					prepare_to_wait(&bs->wait, &wait,
					  TASK_UNINTERRUPTIBLE);
					tag = __bt_get(hctx, bt, last_tag,
					  tags);
					/* Value set in bt_update_count not
					   visible yet */
bt_update_count(&tags->bitmap_tags, tdepth);
/* blk_mq_tag_wakeup_all(tags, false); */
 bt = &tags->bitmap_tags;
 wake_index = atomic_read(&bt->wake_index);
					...
					io_schedule();
------------------------------------------------------------------------

This patch adds the missing memory barrier.

I found this issue when I was looking through the linux source code
for places calling waitqueue_active() before wake_up*(), but without
preceding memory barriers, after sending a patch to fix a similar
issue in drivers/tty/n_tty.c  (Details about the original issue can be
found here: https://lkml.org/lkml/2015/9/28/849).

Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-09 10:52:46 -06:00
Jens Axboe
fd48ca3849 Linux 4.3-rc4
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Merge tag 'v4.3-rc4' into for-4.4/core

Linux 4.3-rc4

Pulling in v4.3-rc4 to avoid conflicts with NVMe fixes that have gone
in since for-4.4/core was based.
2015-10-09 10:08:39 -06:00
Christoph Hellwig
0bf6cd5b95 blk-mq: factor out a helper to iterate all tags for a request_queue
And replace the blk_mq_tag_busy_iter with it - the driver use has been
replaced with a new helper a while ago, and internal to the block we
only need the new version.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-01 10:10:57 +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
Akinobu Mita
60de074ba1 blk-mq: fix deadlock when reading cpu_list
CPU hotplug handling for blk-mq (blk_mq_queue_reinit) acquires
all_q_mutex in blk_mq_queue_reinit_notify() and then removes sysfs
entries by blk_mq_sysfs_unregister().  Removing sysfs entry needs to
be blocked until the active reference of the kernfs_node to be zero.

On the other hand, reading blk_mq_hw_sysfs_cpu sysfs entry (e.g.
/sys/block/nullb0/mq/0/cpu_list) acquires all_q_mutex in
blk_mq_hw_sysfs_cpus_show().

If these happen at the same time, a deadlock can happen.  Because one
can wait for the active reference to be zero with holding all_q_mutex,
and the other tries to acquire all_q_mutex with holding the active
reference.

The reason that all_q_mutex is acquired in blk_mq_hw_sysfs_cpus_show()
is to avoid reading an imcomplete hctx->cpumask.  Since reading sysfs
entry for blk-mq needs to acquire q->sysfs_lock, we can avoid deadlock
and reading an imcomplete hctx->cpumask by protecting q->sysfs_lock
while hctx->cpumask is being updated.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-29 11:32:51 -06:00
Akinobu Mita
5778322e67 blk-mq: avoid inserting requests before establishing new mapping
Notifier callbacks for CPU_ONLINE action can be run on the other CPU
than the CPU which was just onlined.  So it is possible for the
process running on the just onlined CPU to insert request and run
hw queue before establishing new mapping which is done by
blk_mq_queue_reinit_notify().

This can cause a problem when the CPU has just been onlined first time
since the request queue was initialized.  At this time ctx->index_hw
for the CPU, which is the index in hctx->ctxs[] for this ctx, is still
zero before blk_mq_queue_reinit_notify() is called by notifier
callbacks for CPU_ONLINE action.

For example, there is a single hw queue (hctx) and two CPU queues
(ctx0 for CPU0, and ctx1 for CPU1).  Now CPU1 is just onlined and
a request is inserted into ctx1->rq_list and set bit0 in pending
bitmap as ctx1->index_hw is still zero.

And then while running hw queue, flush_busy_ctxs() finds bit0 is set
in pending bitmap and tries to retrieve requests in
hctx->ctxs[0]->rq_list.  But htx->ctxs[0] is a pointer to ctx0, so the
request in ctx1->rq_list is ignored.

Fix it by ensuring that new mapping is established before onlined cpu
starts running.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-29 11:32:50 -06:00
Akinobu Mita
0e62636820 blk-mq: fix q->mq_usage_counter access race
CPU hotplug handling for blk-mq (blk_mq_queue_reinit) accesses
q->mq_usage_counter while freezing all request queues in all_q_list.
On the other hand, q->mq_usage_counter is deinitialized in
blk_mq_free_queue() before deleting the queue from all_q_list.

So if CPU hotplug event occurs in the window, percpu_ref_kill() is
called with q->mq_usage_counter which has already been marked dead,
and it triggers warning.  Fix it by deleting the queue from all_q_list
earlier than destroying q->mq_usage_counter.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-29 11:32:48 -06:00
Akinobu Mita
a723bab3d7 blk-mq: Fix use after of free q->mq_map
CPU hotplug handling for blk-mq (blk_mq_queue_reinit) updates
q->mq_map by blk_mq_update_queue_map() for all request queues in
all_q_list.  On the other hand, q->mq_map is released before deleting
the queue from all_q_list.

So if CPU hotplug event occurs in the window, invalid memory access
can happen.  Fix it by releasing q->mq_map in blk_mq_release() to make
it happen latter than removal from all_q_list.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Suggested-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-29 11:32:46 -06:00
Akinobu Mita
4593fdbe7a blk-mq: fix sysfs registration/unregistration race
There is a race between cpu hotplug handling and adding/deleting
gendisk for blk-mq, where both are trying to register and unregister
the same sysfs entries.

null_add_dev
    --> blk_mq_init_queue
        --> blk_mq_init_allocated_queue
            --> add to 'all_q_list' (*)
    --> add_disk
        --> blk_register_queue
            --> blk_mq_register_disk (++)

null_del_dev
    --> del_gendisk
        --> blk_unregister_queue
            --> blk_mq_unregister_disk (--)
    --> blk_cleanup_queue
        --> blk_mq_free_queue
            --> del from 'all_q_list' (*)

blk_mq_queue_reinit
    --> blk_mq_sysfs_unregister (-)
    --> blk_mq_sysfs_register (+)

While the request queue is added to 'all_q_list' (*),
blk_mq_queue_reinit() can be called for the queue anytime by CPU
hotplug callback.  But blk_mq_sysfs_unregister (-) and
blk_mq_sysfs_register (+) in blk_mq_queue_reinit must not be called
before blk_mq_register_disk (++) and after blk_mq_unregister_disk (--)
is finished.  Because '/sys/block/*/mq/' is not exists.

There has already been BLK_MQ_F_SYSFS_UP flag in hctx->flags which can
be used to track these sysfs stuff, but it is only fixing this issue
partially.

In order to fix it completely, we just need per-queue flag instead of
per-hctx flag with appropriate locking.  So this introduces
q->mq_sysfs_init_done which is properly protected with all_q_mutex.

Also, we need to ensure that blk_mq_map_swqueue() is called with
all_q_mutex is held.  Since hctx->nr_ctx is reset temporarily and
updated in blk_mq_map_swqueue(), so we should avoid
blk_mq_register_hctx() seeing the temporary hctx->nr_ctx value
in CPU hotplug handling or adding/deleting gendisk .

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Ming Lei <tom.leiming@gmail.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-29 11:32:45 -06:00
Akinobu Mita
1356aae083 blk-mq: avoid setting hctx->tags->cpumask before allocation
When unmapped hw queue is remapped after CPU topology is changed,
hctx->tags->cpumask has to be set after hctx->tags is setup in
blk_mq_map_swqueue(), otherwise it causes null pointer dereference.

Fixes: f26cdc8536 ("blk-mq: Shared tag enhancements")
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-29 11:32:43 -06:00
Catalin Marinas
f75782e4e0 block: kmemleak: Track the page allocations for struct request
The pages allocated for struct request contain pointers to other slab
allocations (via ops->init_request). Since kmemleak does not track/scan
page allocations, the slab objects will be reported as leaks (false
positives). This patch adds kmemleak callbacks to allow tracking of such
pages.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Bart Van Assche<bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-23 11:00:57 -06:00
Linus Torvalds
133bb59585 Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
 "This is a bit bigger than it should be, but I could (did) not want to
  send it off last week due to both wanting extra testing, and expecting
  a fix for the bounce regression as well.  In any case, this contains:

   - Fix for the blk-merge.c compilation warning on gcc 5.x from me.

   - A set of back/front SG gap merge fixes, from me and from Sagi.
     This ensures that we honor SG gapping for integrity payloads as
     well.

   - Two small fixes for null_blk from Matias, fixing a leak and a
     capacity propagation issue.

   - A blkcg fix from Tejun, fixing a NULL dereference.

   - A fast clone optimization from Ming, fixing a performance
     regression since the arbitrarily sized bio's were introduced.

   - Also from Ming, a regression fix for bouncing IOs"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: fix bounce_end_io
  block: blk-merge: fast-clone bio when splitting rw bios
  block: blkg_destroy_all() should clear q->root_blkg and ->root_rl.blkg
  block: Copy a user iovec if it includes gaps
  block: Refuse adding appending a gapped integrity page to a bio
  block: Refuse request/bio merges with gaps in the integrity payload
  block: Check for gaps on front and back merges
  null_blk: fix wrong capacity when bs is not 512 bytes
  null_blk: fix memory leak on cleanup
  block: fix bogus compiler warnings in blk-merge.c
2015-09-19 18:57:09 -07:00
Tejun Heo
9e10a130d9 cgroup: replace cgroup_on_dfl() tests in controllers with cgroup_subsys_on_dfl()
cgroup_on_dfl() tests whether the cgroup's root is the default
hierarchy; however, an individual controller is only interested in
whether the controller is attached to the default hierarchy and never
tests a cgroup which doesn't belong to the hierarchy that the
controller is attached to.

This patch replaces cgroup_on_dfl() tests in controllers with faster
static_key based cgroup_subsys_on_dfl().  This leaves cgroup core as
the only user of cgroup_on_dfl() and the function is moved from the
header file to cgroup.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Zefan Li <lizefan@huawei.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
2015-09-18 11:56:28 -04:00
Ming Lei
9945187999 block: fix bounce_end_io
When bio bounce is involved, one new bio and its biovecs are
cloned from the comming bio, which can be one fast-cloned bio
from upper layer(such as dm).

So it is obviously wrong to assume the start index of the coming(
original) bio's io vector is zero, which can be any value between
0 and (bi_max_vecs - 1), especially in case of bio split.

This patch fixes Fedora's booting oops on i386, often with the
following kernel log together:

> [    9.026738] systemd[1]: Switching root.
> [    9.036467] systemd-journald[149]: Received SIGTERM from PID 1
> (systemd).
> [    9.082262] BUG: Bad page state in process kworker/u5:1  pfn:372ac
> [    9.083989] page:f3d32ae0 count:0 mapcount:0 mapping:f2252178
> index:0x16a
> [    9.085755] flags: 0x40020021(locked|lru|mappedtodisk)
> [    9.087284] page dumped because: page still charged to cgroup
> [    9.088772] bad because of flags:
> [    9.089731] flags: 0x21(locked|lru)
> [    9.090818] page->mem_cgroup:f2c3e400

Reported-by: Josh Boyer <jwboyer@fedoraproject.org>
Tested-by: Adam Williamson <awilliam@redhat.com>
Cc: Ming Lin <mlin@kernel.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-17 10:07:04 -06:00
Ming Lei
52cc6eead9 block: blk-merge: fast-clone bio when splitting rw bios
biovecs has become immutable since v3.13, so it isn't necessary
to allocate biovecs for the new cloned bios, then we can save
one extra biovecs allocation/copy, and the allocation is often
not fixed-length and a bit more expensive.

For example, if the 'max_sectors_kb' of null blk's queue is set
as 16(32 sectors) via sysfs just for making more splits, this patch
can increase throught about ~70% in the sequential read test over
null_blk(direct io, bs: 1M).

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Ming Lin <ming.l@ssi.samsung.com>
Cc: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lei <ming.lei@canonical.com>

This fixes a performance regression introduced by commit 54efd50bfd,
and allows us to take full advantage of the fact that we have immutable
bio_vecs. Hand applied, as it rejected violently with commit
5014c311ba.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-17 09:58:38 -06:00
Tejun Heo
6fe810bda0 block: blkg_destroy_all() should clear q->root_blkg and ->root_rl.blkg
While making the root blkg unconditional, ec13b1d6f0 ("blkcg: always
create the blkcg_gq for the root blkcg") removed the part which clears
q->root_blkg and ->root_rl.blkg during q exit.  This leaves the two
pointers dangling after blkg_destroy_all().  blk-throttle exit path
performs blkg traversals and dereferences ->root_blkg and can lead to
the following oops.

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000558
 IP: [<ffffffff81389746>] __blkg_lookup+0x26/0x70
 ...
 task: ffff88001b4e2580 ti: ffff88001ac0c000 task.ti: ffff88001ac0c000
 RIP: 0010:[<ffffffff81389746>]  [<ffffffff81389746>] __blkg_lookup+0x26/0x70
 ...
 Call Trace:
  [<ffffffff8138d14a>] blk_throtl_drain+0x5a/0x110
  [<ffffffff8138a108>] blkcg_drain_queue+0x18/0x20
  [<ffffffff81369a70>] __blk_drain_queue+0xc0/0x170
  [<ffffffff8136a101>] blk_queue_bypass_start+0x61/0x80
  [<ffffffff81388c59>] blkcg_deactivate_policy+0x39/0x100
  [<ffffffff8138d328>] blk_throtl_exit+0x38/0x50
  [<ffffffff8138a14e>] blkcg_exit_queue+0x3e/0x50
  [<ffffffff8137016e>] blk_release_queue+0x1e/0xc0
 ...

While the bug is a straigh-forward use-after-free bug, it is tricky to
reproduce because blkg release is RCU protected and the rest of exit
path usually finishes before RCU grace period.

This patch fixes the bug by updating blkg_destro_all() to clear
q->root_blkg and ->root_rl.blkg.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Richard W.M. Jones" <rjones@redhat.com>
Reported-by: Josh Boyer <jwboyer@fedoraproject.org>
Link: http://lkml.kernel.org/g/CA+5PVA5rzQ0s4723n5rHBcxQa9t0cW8BPPBekr_9aMRoWt2aYg@mail.gmail.com
Fixes: ec13b1d6f0 ("blkcg: always create the blkcg_gq for the root blkcg")
Cc: stable@vger.kernel.org # v4.2+
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-11 09:03:50 -06:00
Sagi Grimberg
46348456c1 block: Copy a user iovec if it includes gaps
For drivers that don't support gaps in the SG lists handed to
them we must bounce (copy the user buffers) and pass a bio that
does not include gaps. This doesn't matter for any current user,
but will help to allow iser which can't handle gaps to use the
block virtual boundary instead of using driver-local bounce
buffering when handling SG_IO commands.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-11 09:03:50 -06:00
Sagi Grimberg
87a816df53 block: Refuse adding appending a gapped integrity page to a bio
This is only theoretical at the moment given that the only
subsystems that generate integrity payloads are the block layer
itself and the scsi target (which generate well aligned integrity
payloads). But when we will expose integrity meta-data to user-space,
we'll need to refuse appending a page with a gap (if the queue
virtual boundary is set).

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-11 09:03:45 -06:00
Sagi Grimberg
7f39add3b0 block: Refuse request/bio merges with gaps in the integrity payload
If a driver sets the block queue virtual boundary mask, it means that
it cannot handle gaps so we must not allow those in the integrity
payload as well.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>

Fixed up by me to have duplicate integrity merge functions, depending
on whether block integrity is enabled or not. Fixes a compilations
issue with CONFIG_BLK_DEV_INTEGRITY unset.

Signed-off-by: Jens Axboe <axboe@fb.com>
2015-09-11 09:03:04 -06:00
Linus Torvalds
b0a1ea51bd Merge branch 'for-4.3/blkcg' of git://git.kernel.dk/linux-block
Pull blk-cg updates from Jens Axboe:
 "A bit later in the cycle, but this has been in the block tree for a a
  while.  This is basically four patchsets from Tejun, that improve our
  buffered cgroup writeback.  It was dependent on the other cgroup
  changes, but they went in earlier in this cycle.

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

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

   - Simplification of wb work wait mechanism.

   - Writeback tracepoints updated to report cgroup.

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

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

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

     - Switched from GFP_ATOMIC to GFP_NOWAIT as suggested by Jeff.

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

  Series 3 is the blkcg policy cleanup patches:

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

     - alloc/free added for blkg_policy_data.  exit dropped.

     - alloc/free added for blkcg_policy_data.

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

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

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

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

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

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

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

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

* 'for-4.3/blkcg' of git://git.kernel.dk/linux-block: (45 commits)
  blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchy
  blkcg: s/CFQ_WEIGHT_*/CFQ_WEIGHT_LEGACY_*/
  blkcg: implement interface for the unified hierarchy
  blkcg: misc preparations for unified hierarchy interface
  blkcg: separate out tg_conf_updated() from tg_set_conf()
  blkcg: move body parsing from blkg_conf_prep() to its callers
  blkcg: mark existing cftypes as legacy
  blkcg: rename subsystem name from blkio to io
  blkcg: refine error codes returned during blkcg configuration
  blkcg: remove unnecessary NULL checks from __cfqg_set_weight_device()
  blkcg: reduce stack usage of blkg_rwstat_recursive_sum()
  blkcg: remove cfqg_stats->sectors
  blkcg: move io_service_bytes and io_serviced stats into blkcg_gq
  blkcg: make blkg_[rw]stat_recursive_sum() to be able to index into blkcg_gq
  blkcg: make blkcg_[rw]stat per-cpu
  blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it
  blkcg: consolidate blkg creation in blkcg_bio_issue_check()
  blk-throttle: improve queue bypass handling
  blkcg: move root blkg lookup optimization from throtl_lookup_tg() to __blkg_lookup()
  blkcg: inline [__]blkg_lookup()
  ...
2015-09-10 18:56:14 -07:00
Linus Torvalds
e31fb9e005 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull ext3 removal, quota & udf fixes from Jan Kara:
 "The biggest change in the pull is the removal of ext3 filesystem
  driver (~28k lines removed).  Ext4 driver is a full featured
  replacement these days and both RH and SUSE use it for several years
  without issues.  Also there are some workarounds in VM & block layer
  mainly for ext3 which we could eventually get rid of.

  Other larger change is addition of proper error handling for
  dquot_initialize().  The rest is small fixes and cleanups"

[ I wasn't convinced about the ext3 removal and worried about things
  falling through the cracks for legacy users, but ext4 maintainers
  piped up and were all unanimously in favor of removal, and maintaining
  all legacy ext3 support inside ext4.   - Linus ]

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  udf: Don't modify filesystem for read-only mounts
  quota: remove an unneeded condition
  ext4: memory leak on error in ext4_symlink()
  mm/Kconfig: NEED_BOUNCE_POOL: clean-up condition
  ext4: Improve ext4 Kconfig test
  block: Remove forced page bouncing under IO
  fs: Remove ext3 filesystem driver
  doc: Update doc about journalling layer
  jfs: Handle error from dquot_initialize()
  reiserfs: Handle error from dquot_initialize()
  ocfs2: Handle error from dquot_initialize()
  ext4: Handle error from dquot_initialize()
  ext2: Handle error from dquot_initalize()
  quota: Propagate error from ->acquire_dquot()
2015-09-03 12:28:30 -07:00
Jens Axboe
5e7c4274a7 block: Check for gaps on front and back merges
We are checking for gaps to previous bio_vec, which can
only detect back merges gaps. Moreover, at the point where
we check for a gap, we don't know if we will attempt a back
or a front merge. Thus, check for gap to prev in a back merge
attempt and check for a gap to next in a front merge attempt.

Signed-off-by: Jens Axboe <axboe@fb.com>
[sagig: Minor rename change]
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
2015-09-03 10:33:09 -06:00