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4 years agobcache: Fix an error code in bch_dump_read()
Dan Carpenter [Tue, 3 Sep 2019 13:25:44 +0000 (21:25 +0800)]
bcache: Fix an error code in bch_dump_read()

The copy_to_user() function returns the number of bytes remaining to be
copied, but the intention here was to return -EFAULT if the copy fails.

Fixes: cafe56359144 ("bcache: A block layer cache")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobcache: add cond_resched() in __bch_cache_cmp()
Shile Zhang [Tue, 3 Sep 2019 13:25:43 +0000 (21:25 +0800)]
bcache: add cond_resched() in __bch_cache_cmp()

Read /sys/fs/bcache/<uuid>/cacheN/priority_stats can take very long
time with huge cache after long run.

Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Tested-by: Heitor Alves de Siqueira <halves@canonical.com>
Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoDocumentation:kernel-per-CPU-kthreads.txt: Remove reference to elevator=
Marcos Paulo de Souza [Tue, 3 Sep 2019 14:05:37 +0000 (08:05 -0600)]
Documentation:kernel-per-CPU-kthreads.txt: Remove reference to elevator=

This argument was not being considered since blk-mq was set by default,
so removed this documentation to avoid confusion.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
.txt file is now .rst

Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoDocumenation: switching-sched: Remove notes about elevator argument
Marcos Paulo de Souza [Tue, 3 Sep 2019 14:04:02 +0000 (08:04 -0600)]
Documenation: switching-sched: Remove notes about elevator argument

This argument was ignored since blk-mq was set as default, so remove it
from documentation.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
.txt file is now .rst

Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: elevator.c: Remove now unused elevator= argument
Marcos Paulo de Souza [Wed, 28 Aug 2019 01:19:27 +0000 (22:19 -0300)]
block: elevator.c: Remove now unused elevator= argument

Since the inclusion of blk-mq, elevator argument was not being
considered anymore, and it's utility died long with the legacy IO path,
now removed too.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
Fold with doc removal patch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: mq-deadline: Fix queue restart handling
Damien Le Moal [Wed, 28 Aug 2019 04:40:20 +0000 (13:40 +0900)]
block: mq-deadline: Fix queue restart handling

Commit 7211aef86f79 ("block: mq-deadline: Fix write completion
handling") added a call to blk_mq_sched_mark_restart_hctx() in
dd_dispatch_request() to make sure that write request dispatching does
not stall when all target zones are locked. This fix left a subtle race
when a write completion happens during a dispatch execution on another
CPU:

CPU 0: Dispatch CPU1: write completion

dd_dispatch_request()
    lock(&dd->lock);
    ...
    lock(&dd->zone_lock); dd_finish_request()
    rq = find request lock(&dd->zone_lock);
    unlock(&dd->zone_lock);
     zone write unlock
unlock(&dd->zone_lock);
...
__blk_mq_free_request
                                      check restart flag (not set)
      -> queue not run
    ...
    if (!rq && have writes)
        blk_mq_sched_mark_restart_hctx()
    unlock(&dd->lock)

Since the dispatch context finishes after the write request completion
handling, marking the queue as needing a restart is not seen from
__blk_mq_free_request() and blk_mq_sched_restart() not executed leading
to the dispatch stall under 100% write workloads.

Fix this by moving the call to blk_mq_sched_mark_restart_hctx() from
dd_dispatch_request() into dd_finish_request() under the zone lock to
ensure full mutual exclusion between write request dispatch selection
and zone unlock on write request completion.

Fixes: 7211aef86f79 ("block: mq-deadline: Fix write completion handling")
Cc: stable@vger.kernel.org
Reported-by: Hans Holmberg <Hans.Holmberg@wdc.com>
Reviewed-by: Hans Holmberg <hans.holmberg@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agowriteback: don't access page->mapping directly in track_foreign_dirty TP
Tejun Heo [Fri, 30 Aug 2019 23:39:54 +0000 (16:39 -0700)]
writeback: don't access page->mapping directly in track_foreign_dirty TP

page->mapping may encode different values in it and page_mapping()
should always be used to access the mapping pointer.
track_foreign_dirty tracepoint was incorrectly accessing page->mapping
directly.  Use page_mapping() instead.  Also, add NULL checks while at
it.

Fixes: 3a8e9ac89e6a ("writeback: add tracepoints for cgroup foreign writebacks")
Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoMerge branch 'nvme-5.4' of git://git.infradead.org/nvme into for-5.4/block
Jens Axboe [Fri, 30 Aug 2019 20:21:27 +0000 (14:21 -0600)]
Merge branch 'nvme-5.4' of git://git.infradead.org/nvme into for-5.4/block

Pull NVMe changes from Sagi:

"The nvme updates include:
 - ana log parse fix from Anton
 - nvme quirks support for Apple devices from Ben
 - fix missing bio completion tracing for multipath stack devices from
   Hannes and Mikhail
 - IP TOS settings for nvme rdma and tcp transports from Israel
 - rq_dma_dir cleanups from Israel
 - tracing for Get LBA Status command from Minwoo
 - Some nvme-tcp cleanups from Minwoo, Potnuri and Myself
 - Some consolidation between the fabrics transports for handling the CAP
   register
 - reset race with ns scanning fix for fabrics (move fabrics commands to
   a dedicated request queue with a different lifetime from the admin
   request queue)."

* 'nvme-5.4' of git://git.infradead.org/nvme: (30 commits)
  nvme-rdma: Use rq_dma_dir macro
  nvme-fc: Use rq_dma_dir macro
  nvme-pci: Tidy up nvme_unmap_data
  nvme: make fabrics command run on a separate request queue
  nvme-pci: Support shared tags across queues for Apple 2018 controllers
  nvme-pci: Add support for Apple 2018+ models
  nvme-pci: Add support for variable IO SQ element size
  nvme-pci: Pass the queue to SQ_SIZE/CQ_SIZE macros
  nvme: trace bio completion
  nvme-multipath: fix ana log nsid lookup when nsid is not found
  nvmet-tcp: Add TOS for tcp transport
  nvme-tcp: Add TOS for tcp transport
  nvme-tcp: Use struct nvme_ctrl directly
  nvme-rdma: Add TOS for rdma transport
  nvme-fabrics: Add type of service (TOS) configuration
  nvmet-tcp: fix possible memory leak
  nvmet-tcp: fix possible NULL deref
  nvmet: trace: parse Get LBA Status command in detail
  nvme: trace: parse Get LBA Status command in detail
  nvme: trace: support for Get LBA Status opcode parsed
  ...

4 years agowriteback: add tracepoints for cgroup foreign writebacks
Tejun Heo [Thu, 29 Aug 2019 22:47:19 +0000 (15:47 -0700)]
writeback: add tracepoints for cgroup foreign writebacks

cgroup foreign inode handling has quite a bit of heuristics and
internal states which sometimes makes it difficult to understand
what's going on.  Add tracepoints to improve visibility.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblkcg: add missing NULL check in ioc_cpd_alloc()
Tejun Heo [Fri, 30 Aug 2019 13:10:58 +0000 (06:10 -0700)]
blkcg: add missing NULL check in ioc_cpd_alloc()

ioc_cpd_alloc() forgot to check NULL return from kzalloc().  Add it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonvme-rdma: Use rq_dma_dir macro
Israel Rukshin [Wed, 28 Aug 2019 11:11:50 +0000 (14:11 +0300)]
nvme-rdma: Use rq_dma_dir macro

Remove code duplication.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-fc: Use rq_dma_dir macro
Israel Rukshin [Wed, 28 Aug 2019 11:11:49 +0000 (14:11 +0300)]
nvme-fc: Use rq_dma_dir macro

Remove code duplication.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-pci: Tidy up nvme_unmap_data
Israel Rukshin [Wed, 28 Aug 2019 11:11:48 +0000 (14:11 +0300)]
nvme-pci: Tidy up nvme_unmap_data

Remove pointless local variable and use rq_dma_dir macro.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme: make fabrics command run on a separate request queue
Sagi Grimberg [Sat, 3 Aug 2019 02:33:59 +0000 (19:33 -0700)]
nvme: make fabrics command run on a separate request queue

We have a fundamental issue that fabric commands use the admin_q.
The reason is, that admin-connect, register reads and writes and
admin commands cannot be guaranteed ordering while we are running
controller resets.

For example, when we reset a controller we perform:
1. disable the controller
2. teardown the admin queue
3. re-establish the admin queue
4. enable the controller

In order to perform (3), we need to unquiesce the admin queue, however
we may have some admin commands that are already pending on the
quiesced admin_q and will immediate execute when we unquiesce it before
we execute (4). The host must not send admin commands to the controller
before enabling the controller.

To fix this, we have the fabric commands (admin connect and property
get/set, but not I/O queue connect) use a separate fabrics_q and make
sure to quiesce the admin_q before we disable the controller, and
unquiesce it only after we enable the controller.

This fixes the error prints from nvmet in a controller reset storm test:
kernel: nvmet: got cmd 6 while CC.EN == 0 on qid = 0
Which indicate that the host is sending an admin command when the
controller is not enabled.

Reviewed-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-pci: Support shared tags across queues for Apple 2018 controllers
Benjamin Herrenschmidt [Wed, 7 Aug 2019 07:51:22 +0000 (17:51 +1000)]
nvme-pci: Support shared tags across queues for Apple 2018 controllers

Another issue with the Apple T2 based 2018 controllers seem to be
that they blow up (and shut the machine down) if there's a tag
collision between the IO queue and the Admin queue.

My suspicion is that they use our tags for their internal tracking
and don't mix them with the queue id. They also seem to not like
when tags go beyond the IO queue depth, ie 128 tags.

This adds a quirk that marks tags 0..31 of the IO queue reserved

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-pci: Add support for Apple 2018+ models
Benjamin Herrenschmidt [Wed, 7 Aug 2019 07:51:21 +0000 (17:51 +1000)]
nvme-pci: Add support for Apple 2018+ models

Based on reverse engineering and original patch by

Paul Pawlowski <paul@mrarm.io>

This adds support for Apple weird implementation of NVME in their
2018 or later machines. It accounts for the twice-as-big SQ entries
for the IO queues, and the fact that only interrupt vector 0 appears
to function properly.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-pci: Add support for variable IO SQ element size
Benjamin Herrenschmidt [Wed, 7 Aug 2019 07:51:20 +0000 (17:51 +1000)]
nvme-pci: Add support for variable IO SQ element size

The size of a submission queue element should always be 6 (64 bytes)
by spec.

However some controllers such as Apple's are not properly implementing
the standard and require a different size.

This provides the ground work for the subsequent quirks for these
controllers.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-pci: Pass the queue to SQ_SIZE/CQ_SIZE macros
Benjamin Herrenschmidt [Wed, 7 Aug 2019 07:51:19 +0000 (17:51 +1000)]
nvme-pci: Pass the queue to SQ_SIZE/CQ_SIZE macros

This will make it easier to handle variable queue entry sizes
later. No functional change.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme: trace bio completion
Hannes Reinecke [Wed, 24 Jul 2019 13:47:55 +0000 (15:47 +0200)]
nvme: trace bio completion

When native multipathing is enabled we cannot enable blktrace for
the underlying paths, so any completion is never traced.

Signed-off-by: Hannes Reinecke <hare@suse.com>
[fixed-up by Mikhail for non-multipath-build]
Signed-off-by: Mikhail Skorzhinskii <mskorzhinskiy@solarflare.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-multipath: fix ana log nsid lookup when nsid is not found
Anton Eidelman [Fri, 16 Aug 2019 20:00:10 +0000 (13:00 -0700)]
nvme-multipath: fix ana log nsid lookup when nsid is not found

ANA log parsing invokes nvme_update_ana_state() per ANA group desc.
This updates the state of namespaces with nsids in desc->nsids[].

Both ctrl->namespaces list and desc->nsids[] array are sorted by nsid.
Hence nvme_update_ana_state() performs a single walk over ctrl->namespaces:
- if current namespace matches the current desc->nsids[n],
  this namespace is updated, and n is incremented.
- the process stops when it encounters the end of either
  ctrl->namespaces end or desc->nsids[]

In case desc->nsids[n] does not match any of ctrl->namespaces,
the remaining nsids following desc->nsids[n] will not be updated.
Such situation was considered abnormal and generated WARN_ON_ONCE.

However ANA log MAY contain nsids not (yet) found in ctrl->namespaces.
For example, lets consider the following scenario:
- nvme0 exposes namespaces with nsids = [2, 3] to the host
- a new namespace nsid = 1 is added dynamically
- also, a ANA topology change is triggered
- NS_CHANGED aen is generated and triggers scan_work
- before scan_work discovers nsid=1 and creates a namespace, a NOTICE_ANA
  aen was issues and ana_work receives ANA log with nsids=[1, 2, 3]

Result: ana_work fails to update ANA state on existing namespaces [2, 3]

Solution:
Change the way nvme_update_ana_state() namespace list walk
checks the current namespace against desc->nsids[n] as follows:
a) ns->head->ns_id < desc->nsids[n]: keep walking ctrl->namespaces.
b) ns->head->ns_id == desc->nsids[n]: match, update the namespace
c) ns->head->ns_id >= desc->nsids[n]: skip to desc->nsids[n+1]

This enables correct operation in the scenario described above.
This also allows ANA log to contain nsids currently invisible
to the host, i.e. inactive nsids.

Signed-off-by: Anton Eidelman <anton@lightbitslabs.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvmet-tcp: Add TOS for tcp transport
Israel Rukshin [Sun, 18 Aug 2019 09:08:55 +0000 (12:08 +0300)]
nvmet-tcp: Add TOS for tcp transport

Set the outgoing packets type of service (TOS) according to the
receiving TOS.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Suggested-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-tcp: Add TOS for tcp transport
Israel Rukshin [Sun, 18 Aug 2019 09:08:54 +0000 (12:08 +0300)]
nvme-tcp: Add TOS for tcp transport

TOS provide clients the ability to segregate traffic flows for
different type of data.
One of the TOS usage is bandwidth management which allows setting bandwidth
limits for QoS classes, e.g. 80% bandwidth to controllers at QoS class A
and 20% to controllers at QoS class B.

usage examples:
nvme connect --tos=0 --transport=tcp --traddr=10.0.1.1 --nqn=test-nvme

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-tcp: Use struct nvme_ctrl directly
Israel Rukshin [Sun, 18 Aug 2019 09:08:53 +0000 (12:08 +0300)]
nvme-tcp: Use struct nvme_ctrl directly

This patch doesn't change any functionality.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-rdma: Add TOS for rdma transport
Israel Rukshin [Sun, 18 Aug 2019 09:08:52 +0000 (12:08 +0300)]
nvme-rdma: Add TOS for rdma transport

For RDMA transports, TOS is an extension of IB QoS to provide clients
the ability to segregate traffic flows for different type of data.
RDMA CM abstract it for ULPs using rdma_set_service_type().
Internally, each traffic flow is represented by a connection with all of
its independent resources like that of a normal connection, and is
differentiated by service type. In other words, there can be multiple qp
connections between an IP pair and each supports a unique service type.

One of the TOS usage is bandwidth management which allows setting bandwidth
limits for QoS classes, e.g. 80% bandwidth to controllers at QoS class A
and 20% to controllers at QoS class B.

Note: In addition to the TOS configuration, QOS must be configured on the
relevant HCA on the target (send RDMA commands) and initiator to effect
the traffic.

usage examples:
nvme connect --tos=0 --transport=rdma --traddr=10.0.1.1 --nqn=test-nvme

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-fabrics: Add type of service (TOS) configuration
Israel Rukshin [Sun, 18 Aug 2019 09:08:51 +0000 (12:08 +0300)]
nvme-fabrics: Add type of service (TOS) configuration

TOS is user-defined and needs to be configured via nvme-cli.
It must be set before initiating any traffic and once set the TOS
cannot be changed.

Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvmet-tcp: fix possible memory leak
Sagi Grimberg [Sat, 3 Aug 2019 03:29:11 +0000 (20:29 -0700)]
nvmet-tcp: fix possible memory leak

when we uninit a command in error flow we also need to
free an iovec if it was allocated.

Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvmet-tcp: fix possible NULL deref
Sagi Grimberg [Sat, 3 Aug 2019 03:23:38 +0000 (20:23 -0700)]
nvmet-tcp: fix possible NULL deref

We must only call sgl_free for sgl that we actually
allocated.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvmet: trace: parse Get LBA Status command in detail
Minwoo Im [Sun, 4 Aug 2019 07:50:50 +0000 (16:50 +0900)]
nvmet: trace: parse Get LBA Status command in detail

Four different fields are in CDWs of Get LBA Status command which means
it would be great if we can see in detail when tracing in target side
also.

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme: trace: parse Get LBA Status command in detail
Minwoo Im [Sun, 4 Aug 2019 07:50:49 +0000 (16:50 +0900)]
nvme: trace: parse Get LBA Status command in detail

Four different fields are in CDWs of Get LBA Status command which means
it would be great if we can see in detail when tracing.

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme: trace: support for Get LBA Status opcode parsed
Minwoo Im [Sun, 4 Aug 2019 07:50:48 +0000 (16:50 +0900)]
nvme: trace: support for Get LBA Status opcode parsed

This patch adds Get LBA Status command's opcode to the macro that is
used by the trace feature.  Now we can see "get_lba_status" instead of
the opcode value itself.

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme: add Get LBA Status command opcode
Minwoo Im [Sun, 4 Aug 2019 07:50:47 +0000 (16:50 +0900)]
nvme: add Get LBA Status command opcode

NVMe 1.4 added Get LBA Status command with opcode 0x86.

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvmet: fix data units read and written counters in SMART log
Tom Wu [Thu, 8 Aug 2019 02:22:36 +0000 (02:22 +0000)]
nvmet: fix data units read and written counters in SMART log

In nvme spec 1.3 there is a definition for data write/read counters
from SMART log, (See section 5.14.1.2):
This value is reported in thousands (i.e., a value of 1
corresponds to 1000 units of 512 bytes read) and is rounded up.

However, in nvme target where value is reported with actual units,
but not thousands of units as the spec requires.

Signed-off-by: Tom Wu <tomwu@mellanox.com>
Reviewed-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-tcp: support simple polling
Sagi Grimberg [Wed, 3 Jul 2019 21:08:04 +0000 (14:08 -0700)]
nvme-tcp: support simple polling

Simple polling support via socket busy_poll interface.
Although we do not shutdown interrupts but simply hammer
the socket poll, we can sometimes find completions faster
than the normal interrupt driven RX path.

We add per queue nr_cqe counter that resets every time
RX path is invoked such that .poll callback can return it
to stay consistent with the semantics.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme: tcp: selects CRYPTO_CRC32C for nvme-tcp
Minwoo Im [Sun, 14 Jul 2019 08:18:42 +0000 (17:18 +0900)]
nvme: tcp: selects CRYPTO_CRC32C for nvme-tcp

The tcp host module is now taking those APIs from crypto ahash:
(1) crypto_ahash_final()
(2) crypto_ahash_digest()
(3) crypto_alloc_ahash()

nvme-tcp should depends on CRYPTO_CRC32C.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Jens Axboe <axboe@fb.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme: don't pass cap to nvme_disable_ctrl
Sagi Grimberg [Tue, 23 Jul 2019 00:06:54 +0000 (17:06 -0700)]
nvme: don't pass cap to nvme_disable_ctrl

All seem to call it with ctrl->cap so no need to pass it
at all.

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme: move sqsize setting to the core
Sagi Grimberg [Tue, 23 Jul 2019 00:06:53 +0000 (17:06 -0700)]
nvme: move sqsize setting to the core

nvme_enable_ctrl reads the cap register right after, so
no need to do that locally in the transport driver. Have
sqsize setting in nvme_init_identify.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-pci: set ctrl sqsize to the device q_depth
Sagi Grimberg [Thu, 22 Aug 2019 17:51:17 +0000 (10:51 -0700)]
nvme-pci: set ctrl sqsize to the device q_depth

Align with what the rest of the transports are doing.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme: have nvme_init_identify set ctrl->cap
Sagi Grimberg [Tue, 23 Jul 2019 00:06:52 +0000 (17:06 -0700)]
nvme: have nvme_init_identify set ctrl->cap

No need to use a stack cap variable.

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-tcp: Use protocol specific operations while reading socket
Potnuri Bharat Teja [Mon, 8 Jul 2019 09:52:00 +0000 (15:22 +0530)]
nvme-tcp: Use protocol specific operations while reading socket

Using socket specific read_sock() calls instead of directly calling
tcp_read_sock() helps lld module registered handlers if any, to be called
from nvme-tcp host.
This patch therefore replaces the tcp_read_sock() with socket specific
prot_ops.

Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agonvme-tcp: cleanup nvme_tcp_recv_pdu
Sagi Grimberg [Fri, 19 Jul 2019 19:46:46 +0000 (12:46 -0700)]
nvme-tcp: cleanup nvme_tcp_recv_pdu

Can return directly in the switch statement

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
4 years agoblkcg: fix missing free on error path of blk_iocost_init()
Tejun Heo [Thu, 29 Aug 2019 15:53:06 +0000 (08:53 -0700)]
blkcg: fix missing free on error path of blk_iocost_init()

blk_iocost_init() forgot to free its percpu stat on the error path.
Fix it.

Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost")
Reported-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblkcg: blk-iocost: predeclare used structs
Stephen Rothwell [Thu, 29 Aug 2019 15:43:34 +0000 (09:43 -0600)]
blkcg: blk-iocost: predeclare used structs

Fixes: 7caa47151ab2 ("blkcg: implement blk-iocost")
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblkcg: add tools/cgroup/iocost_coef_gen.py
Tejun Heo [Wed, 28 Aug 2019 22:06:00 +0000 (15:06 -0700)]
blkcg: add tools/cgroup/iocost_coef_gen.py

Add a script which can be used to generate device-specific iocost
linear model coefficients.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblkcg: add tools/cgroup/iocost_monitor.py
Tejun Heo [Wed, 28 Aug 2019 22:05:59 +0000 (15:05 -0700)]
blkcg: add tools/cgroup/iocost_monitor.py

Instead of mucking with debugfs and ->pd_stat(), add drgn based
monitoring script.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblkcg: implement blk-iocost
Tejun Heo [Wed, 28 Aug 2019 22:05:58 +0000 (15:05 -0700)]
blkcg: implement blk-iocost

This patchset implements IO cost model based work-conserving
proportional controller.

While io.latency provides the capability to comprehensively prioritize
and protect IOs depending on the cgroups, its protection is binary -
the lowest latency target cgroup which is suffering is protected at
the cost of all others.  In many use cases including stacking multiple
workload containers in a single system, it's necessary to distribute
IO capacity with better granularity.

One challenge of controlling IO resources is the lack of trivially
observable cost metric.  The most common metrics - bandwidth and iops
- can be off by orders of magnitude depending on the device type and
IO pattern.  However, the cost isn't a complete mystery.  Given
several key attributes, we can make fairly reliable predictions on how
expensive a given stream of IOs would be, at least compared to other
IO patterns.

The function which determines the cost of a given IO is the IO cost
model for the device.  This controller distributes IO capacity based
on the costs estimated by such model.  The more accurate the cost
model the better but the controller adapts based on IO completion
latency and as long as the relative costs across differents IO
patterns are consistent and sensible, it'll adapt to the actual
performance of the device.

Currently, the only implemented cost model is a simple linear one with
a few sets of default parameters for different classes of device.
This covers most common devices reasonably well.  All the
infrastructure to tune and add different cost models is already in
place and a later patch will also allow using bpf progs for cost
models.

Please see the top comment in blk-iocost.c and documentation for
more details.

v2: Rebased on top of RQ_ALLOC_TIME changes and folded in Rik's fix
    for a divide-by-zero bug in current_hweight() triggered by zero
    inuse_sum.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andy Newell <newella@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Rik van Riel <riel@surriel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblk-mq: add optional request->alloc_time_ns
Tejun Heo [Wed, 28 Aug 2019 22:05:57 +0000 (15:05 -0700)]
blk-mq: add optional request->alloc_time_ns

There are currently two start time timestamps - start_time_ns and
io_start_time_ns.  The former marks the request allocation and and the
second issue-to-device time.  The planned io.weight controller needs
to measure the total time bios take to execute after it leaves rq_qos
including the time spent waiting for request to become available,
which can easily dominate on saturated devices.

This patch adds request->alloc_time_ns which records when the request
allocation attempt started.  As it isn't used for the usual stats,
make it optional behind CONFIG_BLK_RQ_ALLOC_TIME and
QUEUE_FLAG_RQ_ALLOC_TIME so that it can be compiled out when there are
no users and it's active only on queues which need it even when
compiled in.

v2: s/pre_start_time/alloc_time/ and add CONFIG_BLK_RQ_ALLOC_TIME
    gating as suggested by Jens.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblkcg: s/RQ_QOS_CGROUP/RQ_QOS_LATENCY/
Tejun Heo [Wed, 28 Aug 2019 22:05:56 +0000 (15:05 -0700)]
blkcg: s/RQ_QOS_CGROUP/RQ_QOS_LATENCY/

io.weight is gonna be another rq_qos cgroup mechanism.  Let's rename
RQ_QOS_CGROUP which is being used by io.latency to RQ_QOS_LATENCY in
preparation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock/rq_qos: implement rq_qos_ops->queue_depth_changed()
Tejun Heo [Wed, 28 Aug 2019 22:05:55 +0000 (15:05 -0700)]
block/rq_qos: implement rq_qos_ops->queue_depth_changed()

wbt already gets queue depth changed notification through
wbt_set_queue_depth().  Generalize it into
rq_qos_ops->queue_depth_changed() so that other rq_qos policies can
easily hook into the events too.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock/rq_qos: add rq_qos_merge()
Tejun Heo [Wed, 28 Aug 2019 22:05:54 +0000 (15:05 -0700)]
block/rq_qos: add rq_qos_merge()

Add a merge hook for rq_qos.  This will be used by io.weight.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblkcg: separate blkcg_conf_get_disk() out of blkg_conf_prep()
Tejun Heo [Wed, 28 Aug 2019 22:05:53 +0000 (15:05 -0700)]
blkcg: separate blkcg_conf_get_disk() out of blkg_conf_prep()

Separate out blkcg_conf_get_disk() so that it can be used by blkcg
policy interface file input parsers before the policy is actually
enabled.  This doesn't introduce any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblkcg: make ->cpd_init_fn() optional
Tejun Heo [Wed, 28 Aug 2019 22:05:52 +0000 (15:05 -0700)]
blkcg: make ->cpd_init_fn() optional

For policies which can do enough initialization from ->cpd_alloc_fn(),
make ->cpd_init_fn() optional.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn()
Tejun Heo [Wed, 28 Aug 2019 22:05:51 +0000 (15:05 -0700)]
blkcg: pass @q and @blkcg into blkcg_pol_alloc_pd_fn()

Instead of @node, pass in @q and @blkcg so that the alloc function has
more context.  This doesn't cause any behavior change and will be used
by io.weight implementation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoMerge branch 'md-next' of git://git.kernel.org/pub/scm/linux/kernel/git/song/md into...
Jens Axboe [Tue, 27 Aug 2019 19:56:59 +0000 (13:56 -0600)]
Merge branch 'md-next' of git://git./linux/kernel/git/song/md into for-5.4/block

Pull MD fixes from Song.

* 'md-next' of git://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  raid5 improve too many read errors msg by adding limits
  md: don't report active array_state until after revalidate_disk() completes.
  md: only call set_in_sync() when it is expected to succeed.

4 years agoraid5 improve too many read errors msg by adding limits
Nigel Croxon [Wed, 21 Aug 2019 13:27:08 +0000 (09:27 -0400)]
raid5 improve too many read errors msg by adding limits

Often limits can be changed by admin. When discussing such things
it helps if you can provide "self-sustained" facts. Also
sometimes the admin thinks he changed a limit, but it did not
take effect for some reason or he changed the wrong thing.

V3: Only pr_warn when Faulty is 0.
V2: Add read_errors value to pr_warn.

Signed-off-by: Nigel Croxon <ncroxon@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
4 years agomd: don't report active array_state until after revalidate_disk() completes.
NeilBrown [Tue, 20 Aug 2019 00:21:09 +0000 (10:21 +1000)]
md: don't report active array_state until after revalidate_disk() completes.

Until revalidate_disk() has completed, the size of a new md array will
appear to be zero.
So we shouldn't report, through array_state, that the array is active
until that time.
udev rules check array_state to see if the array is ready.  As soon as
it appear to be zero, fsck can be run.  If it find the size to be
zero, it will fail.

So add a new flag to provide an interlock between do_md_run() and
array_state_show().  This flag is set while do_md_run() is active and
it prevents array_state_show() from reporting that the array is
active.

Before do_md_run() is called, ->pers will be NULL so array is
definitely not active.
After do_md_run() is called, revalidate_disk() will have run and the
array will be completely ready.

We also move various sysfs_notify*() calls out of md_run() into
do_md_run() after MD_NOT_READY is cleared.  This ensure the
information is ready before the notification is sent.

Prior to v4.12, array_state_show() was called with the
mddev->reconfig_mutex held, which provided exclusion with do_md_run().

Note that MD_NOT_READY cleared twice.  This is deliberate to cover
both success and error paths with minimal noise.

Fixes: b7b17c9b67e5 ("md: remove mddev_lock() from md_attr_show()")
Cc: stable@vger.kernel.org (v4.12++)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
4 years agomd: only call set_in_sync() when it is expected to succeed.
NeilBrown [Tue, 20 Aug 2019 00:21:09 +0000 (10:21 +1000)]
md: only call set_in_sync() when it is expected to succeed.

Since commit 4ad23a976413 ("MD: use per-cpu counter for
writes_pending"), set_in_sync() is substantially more expensive: it
can wait for a full RCU grace period which can be 10s of milliseconds.

So we should only call it when the cost is justified.

md_check_recovery() currently calls set_in_sync() every time it finds
anything to do (on non-external active arrays).  For an array
performing resync or recovery, this will be quite often.
Each call will introduce a delay to the md thread, which can noticeable
affect IO submission latency.

In md_check_recovery() we only need to call set_in_sync() if
'safemode' was non-zero at entry, meaning that there has been not
recent IO.  So we save this "safemode was nonzero" state, and only
call set_in_sync() if it was non-zero.

This measurably reduces mean and maximum IO submission latency during
resync/recovery.

Reported-and-tested-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Fixes: 4ad23a976413 ("MD: use per-cpu counter for writes_pending")
Cc: stable@vger.kernel.org (v4.12+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
4 years agoblock: split .sysfs_lock into two locks
Ming Lei [Tue, 27 Aug 2019 11:01:48 +0000 (19:01 +0800)]
block: split .sysfs_lock into two locks

The kernfs built-in lock of 'kn->count' is held in sysfs .show/.store
path. Meantime, inside block's .show/.store callback, q->sysfs_lock is
required.

However, when mq & iosched kobjects are removed via
blk_mq_unregister_dev() & elv_unregister_queue(), q->sysfs_lock is held
too. This way causes AB-BA lock because the kernfs built-in lock of
'kn-count' is required inside kobject_del() too, see the lockdep warning[1].

On the other hand, it isn't necessary to acquire q->sysfs_lock for
both blk_mq_unregister_dev() & elv_unregister_queue() because
clearing REGISTERED flag prevents storing to 'queue/scheduler'
from being happened. Also sysfs write(store) is exclusive, so no
necessary to hold the lock for elv_unregister_queue() when it is
called in switching elevator path.

So split .sysfs_lock into two: one is still named as .sysfs_lock for
covering sync .store, the other one is named as .sysfs_dir_lock
for covering kobjects and related status change.

sysfs itself can handle the race between add/remove kobjects and
showing/storing attributes under kobjects. For switching scheduler
via storing to 'queue/scheduler', we use the queue flag of
QUEUE_FLAG_REGISTERED with .sysfs_lock for avoiding the race, then
we can avoid to hold .sysfs_lock during removing/adding kobjects.

[1]  lockdep warning
    ======================================================
    WARNING: possible circular locking dependency detected
    5.3.0-rc3-00044-g73277fc75ea0 #1380 Not tainted
    ------------------------------------------------------
    rmmod/777 is trying to acquire lock:
    00000000ac50e981 (kn->count#202){++++}, at: kernfs_remove_by_name_ns+0x59/0x72

    but task is already holding lock:
    00000000fb16ae21 (&q->sysfs_lock){+.+.}, at: blk_unregister_queue+0x78/0x10b

    which lock already depends on the new lock.

    the existing dependency chain (in reverse order) is:

    -> #1 (&q->sysfs_lock){+.+.}:
           __lock_acquire+0x95f/0xa2f
           lock_acquire+0x1b4/0x1e8
           __mutex_lock+0x14a/0xa9b
           blk_mq_hw_sysfs_show+0x63/0xb6
           sysfs_kf_seq_show+0x11f/0x196
           seq_read+0x2cd/0x5f2
           vfs_read+0xc7/0x18c
           ksys_read+0xc4/0x13e
           do_syscall_64+0xa7/0x295
           entry_SYSCALL_64_after_hwframe+0x49/0xbe

    -> #0 (kn->count#202){++++}:
           check_prev_add+0x5d2/0xc45
           validate_chain+0xed3/0xf94
           __lock_acquire+0x95f/0xa2f
           lock_acquire+0x1b4/0x1e8
           __kernfs_remove+0x237/0x40b
           kernfs_remove_by_name_ns+0x59/0x72
           remove_files+0x61/0x96
           sysfs_remove_group+0x81/0xa4
           sysfs_remove_groups+0x3b/0x44
           kobject_del+0x44/0x94
           blk_mq_unregister_dev+0x83/0xdd
           blk_unregister_queue+0xa0/0x10b
           del_gendisk+0x259/0x3fa
           null_del_dev+0x8b/0x1c3 [null_blk]
           null_exit+0x5c/0x95 [null_blk]
           __se_sys_delete_module+0x204/0x337
           do_syscall_64+0xa7/0x295
           entry_SYSCALL_64_after_hwframe+0x49/0xbe

    other info that might help us debug this:

     Possible unsafe locking scenario:

           CPU0                    CPU1
           ----                    ----
      lock(&q->sysfs_lock);
                                   lock(kn->count#202);
                                   lock(&q->sysfs_lock);
      lock(kn->count#202);

     *** DEADLOCK ***

    2 locks held by rmmod/777:
     #0: 00000000e69bd9de (&lock){+.+.}, at: null_exit+0x2e/0x95 [null_blk]
     #1: 00000000fb16ae21 (&q->sysfs_lock){+.+.}, at: blk_unregister_queue+0x78/0x10b

    stack backtrace:
    CPU: 0 PID: 777 Comm: rmmod Not tainted 5.3.0-rc3-00044-g73277fc75ea0 #1380
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS ?-20180724_192412-buildhw-07.phx4
    Call Trace:
     dump_stack+0x9a/0xe6
     check_noncircular+0x207/0x251
     ? print_circular_bug+0x32a/0x32a
     ? find_usage_backwards+0x84/0xb0
     check_prev_add+0x5d2/0xc45
     validate_chain+0xed3/0xf94
     ? check_prev_add+0xc45/0xc45
     ? mark_lock+0x11b/0x804
     ? check_usage_forwards+0x1ca/0x1ca
     __lock_acquire+0x95f/0xa2f
     lock_acquire+0x1b4/0x1e8
     ? kernfs_remove_by_name_ns+0x59/0x72
     __kernfs_remove+0x237/0x40b
     ? kernfs_remove_by_name_ns+0x59/0x72
     ? kernfs_next_descendant_post+0x7d/0x7d
     ? strlen+0x10/0x23
     ? strcmp+0x22/0x44
     kernfs_remove_by_name_ns+0x59/0x72
     remove_files+0x61/0x96
     sysfs_remove_group+0x81/0xa4
     sysfs_remove_groups+0x3b/0x44
     kobject_del+0x44/0x94
     blk_mq_unregister_dev+0x83/0xdd
     blk_unregister_queue+0xa0/0x10b
     del_gendisk+0x259/0x3fa
     ? disk_events_poll_msecs_store+0x12b/0x12b
     ? check_flags+0x1ea/0x204
     ? mark_held_locks+0x1f/0x7a
     null_del_dev+0x8b/0x1c3 [null_blk]
     null_exit+0x5c/0x95 [null_blk]
     __se_sys_delete_module+0x204/0x337
     ? free_module+0x39f/0x39f
     ? blkcg_maybe_throttle_current+0x8a/0x718
     ? rwlock_bug+0x62/0x62
     ? __blkcg_punt_bio_submit+0xd0/0xd0
     ? trace_hardirqs_on_thunk+0x1a/0x20
     ? mark_held_locks+0x1f/0x7a
     ? do_syscall_64+0x4c/0x295
     do_syscall_64+0xa7/0x295
     entry_SYSCALL_64_after_hwframe+0x49/0xbe
    RIP: 0033:0x7fb696cdbe6b
    Code: 73 01 c3 48 8b 0d 1d 20 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 008
    RSP: 002b:00007ffec9588788 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
    RAX: ffffffffffffffda RBX: 0000559e589137c0 RCX: 00007fb696cdbe6b
    RDX: 000000000000000a RSI: 0000000000000800 RDI: 0000559e58913828
    RBP: 0000000000000000 R08: 00007ffec9587701 R09: 0000000000000000
    R10: 00007fb696d4eae0 R11: 0000000000000206 R12: 00007ffec95889b0
    R13: 00007ffec95896b3 R14: 0000559e58913260 R15: 0000559e589137c0

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: add helper for checking if queue is registered
Ming Lei [Tue, 27 Aug 2019 11:01:47 +0000 (19:01 +0800)]
block: add helper for checking if queue is registered

There are 4 users which check if queue is registered, so add one helper
to check it.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblk-mq: don't hold q->sysfs_lock in blk_mq_map_swqueue
Ming Lei [Tue, 27 Aug 2019 11:01:46 +0000 (19:01 +0800)]
blk-mq: don't hold q->sysfs_lock in blk_mq_map_swqueue

blk_mq_map_swqueue() is called from blk_mq_init_allocated_queue()
and blk_mq_update_nr_hw_queues(). For the former caller, the kobject
isn't exposed to userspace yet. For the latter caller, hctx sysfs entries
and debugfs are un-registered before updating nr_hw_queues.

On the other hand, commit 2f8f1336a48b ("blk-mq: always free hctx after
request queue is freed") moves freeing hctx into queue's release
handler, so there won't be race with queue release path too.

So don't hold q->sysfs_lock in blk_mq_map_swqueue().

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: don't hold q->sysfs_lock in elevator_init_mq
Ming Lei [Tue, 27 Aug 2019 11:01:45 +0000 (19:01 +0800)]
block: don't hold q->sysfs_lock in elevator_init_mq

The original comment says:

q->sysfs_lock must be held to provide mutual exclusion between
elevator_switch() and here.

Which is simply wrong. elevator_init_mq() is only called from
blk_mq_init_allocated_queue, which is always called before the request
queue is registered via blk_register_queue(), for dm-rq or normal rq
based driver. However, queue's kobject is only exposed and added to sysfs
in blk_register_queue(). So there isn't such race between elevator_switch()
and elevator_init_mq().

So avoid to hold q->sysfs_lock in elevator_init_mq().

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: Remove blk_mq_register_dev()
Bart Van Assche [Tue, 27 Aug 2019 11:01:44 +0000 (19:01 +0800)]
block: Remove blk_mq_register_dev()

This function has no callers. Hence remove it.

Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agowriteback, memcg: Implement foreign dirty flushing
Tejun Heo [Mon, 26 Aug 2019 16:06:56 +0000 (09:06 -0700)]
writeback, memcg: Implement foreign dirty flushing

There's an inherent mismatch between memcg and writeback.  The former
trackes ownership per-page while the latter per-inode.  This was a
deliberate design decision because honoring per-page ownership in the
writeback path is complicated, may lead to higher CPU and IO overheads
and deemed unnecessary given that write-sharing an inode across
different cgroups isn't a common use-case.

Combined with inode majority-writer ownership switching, this works
well enough in most cases but there are some pathological cases.  For
example, let's say there are two cgroups A and B which keep writing to
different but confined parts of the same inode.  B owns the inode and
A's memory is limited far below B's.  A's dirty ratio can rise enough
to trigger balance_dirty_pages() sleeps but B's can be low enough to
avoid triggering background writeback.  A will be slowed down without
a way to make writeback of the dirty pages happen.

This patch implements foreign dirty recording and foreign mechanism so
that when a memcg encounters a condition as above it can trigger
flushes on bdi_writebacks which can clean its pages.  Please see the
comment on top of mem_cgroup_track_foreign_dirty_slowpath() for
details.

A reproducer follows.

write-range.c::

  #include <stdio.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <sys/types.h>

  static const char *usage = "write-range FILE START SIZE\n";

  int main(int argc, char **argv)
  {
  int fd;
  unsigned long start, size, end, pos;
  char *endp;
  char buf[4096];

  if (argc < 4) {
  fprintf(stderr, usage);
  return 1;
  }

  fd = open(argv[1], O_WRONLY);
  if (fd < 0) {
  perror("open");
  return 1;
  }

  start = strtoul(argv[2], &endp, 0);
  if (*endp != '\0') {
  fprintf(stderr, usage);
  return 1;
  }

  size = strtoul(argv[3], &endp, 0);
  if (*endp != '\0') {
  fprintf(stderr, usage);
  return 1;
  }

  end = start + size;

  while (1) {
  for (pos = start; pos < end; ) {
  long bread, bwritten = 0;

  if (lseek(fd, pos, SEEK_SET) < 0) {
  perror("lseek");
  return 1;
  }

  bread = read(0, buf, sizeof(buf) < end - pos ?
       sizeof(buf) : end - pos);
  if (bread < 0) {
  perror("read");
  return 1;
  }
  if (bread == 0)
  return 0;

  while (bwritten < bread) {
  long this;

  this = write(fd, buf + bwritten,
       bread - bwritten);
  if (this < 0) {
  perror("write");
  return 1;
  }

  bwritten += this;
  pos += bwritten;
  }
  }
  }
  }

repro.sh::

  #!/bin/bash

  set -e
  set -x

  sysctl -w vm.dirty_expire_centisecs=300000
  sysctl -w vm.dirty_writeback_centisecs=300000
  sysctl -w vm.dirtytime_expire_seconds=300000
  echo 3 > /proc/sys/vm/drop_caches

  TEST=/sys/fs/cgroup/test
  A=$TEST/A
  B=$TEST/B

  mkdir -p $A $B
  echo "+memory +io" > $TEST/cgroup.subtree_control
  echo $((1<<30)) > $A/memory.high
  echo $((32<<30)) > $B/memory.high

  rm -f testfile
  touch testfile
  fallocate -l 4G testfile

  echo "Starting B"

  (echo $BASHPID > $B/cgroup.procs
   pv -q --rate-limit 70M < /dev/urandom | ./write-range testfile $((2<<30)) $((2<<30))) &

  echo "Waiting 10s to ensure B claims the testfile inode"
  sleep 5
  sync
  sleep 5
  sync
  echo "Starting A"

  (echo $BASHPID > $A/cgroup.procs
   pv < /dev/urandom | ./write-range testfile 0 $((2<<30)))

v2: Added comments explaining why the specific intervals are being used.

v3: Use 0 @nr when calling cgroup_writeback_by_id() to use best-effort
    flushing while avoding possible livelocks.

v4: Use get_jiffies_64() and time_before/after64() instead of raw
    jiffies_64 and arthimetic comparisons as suggested by Jan.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agowriteback, memcg: Implement cgroup_writeback_by_id()
Tejun Heo [Mon, 26 Aug 2019 16:06:55 +0000 (09:06 -0700)]
writeback, memcg: Implement cgroup_writeback_by_id()

Implement cgroup_writeback_by_id() which initiates cgroup writeback
from bdi and memcg IDs.  This will be used by memcg foreign inode
flushing.

v2: Use wb_get_lookup() instead of wb_get_create() to avoid creating
    spurious wbs.

v3: Interpret 0 @nr as 1.25 * nr_dirty to implement best-effort
    flushing while avoding possible livelocks.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agowriteback: Separate out wb_get_lookup() from wb_get_create()
Tejun Heo [Mon, 26 Aug 2019 16:06:54 +0000 (09:06 -0700)]
writeback: Separate out wb_get_lookup() from wb_get_create()

Separate out wb_get_lookup() which doesn't try to create one if there
isn't already one from wb_get_create().  This will be used by later
patches.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agobdi: Add bdi->id
Tejun Heo [Mon, 26 Aug 2019 16:06:53 +0000 (09:06 -0700)]
bdi: Add bdi->id

There currently is no way to universally identify and lookup a bdi
without holding a reference and pointer to it.  This patch adds an
non-recycling bdi->id and implements bdi_get_by_id() which looks up
bdis by their ids.  This will be used by memcg foreign inode flushing.

I left bdi_list alone for simplicity and because while rb_tree does
support rcu assignment it doesn't seem to guarantee lossless walk when
walk is racing aginst tree rebalance operations.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agowriteback: Generalize and expose wb_completion
Tejun Heo [Mon, 26 Aug 2019 16:06:52 +0000 (09:06 -0700)]
writeback: Generalize and expose wb_completion

wb_completion is used to track writeback completions.  We want to use
it from memcg side for foreign inode flushes.  This patch updates it
to remember the target waitq instead of assuming bdi->wb_waitq and
expose it outside of fs-writeback.c.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonull_blk: fix inline misuse
Jens Axboe [Fri, 23 Aug 2019 18:49:00 +0000 (12:49 -0600)]
null_blk: fix inline misuse

You can't magically mark a function inline and expect that to work.

Fixes: fceb5d1b19cb ("null_blk: create a helper for zoned devices")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonull_blk: create a helper for req completion
Chaitanya Kulkarni [Fri, 23 Aug 2019 04:45:19 +0000 (21:45 -0700)]
null_blk: create a helper for req completion

This patch creates a helper function for handling the request
completion in the null_handle_cmd().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonull_blk: create a helper for zoned devices
Chaitanya Kulkarni [Fri, 23 Aug 2019 04:45:18 +0000 (21:45 -0700)]
null_blk: create a helper for zoned devices

This patch creates a helper function for handling zoned block device
operations.

This patch also restructured the code for null_blk_zoned.c and uses the
pattern to return blk_status_t and catch the error in the function
null_handle_cmd() into cmd->error variable instead of setting it up in
the deeper layer just like the way it is done for flush, badblocks and
memory backed case in the null_handle_cmd(). We also move
null_handle_zoned() to the null_blk_zoned.c to keep the zoned code
separate.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonull_blk: create a helper for mem-backed ops
Chaitanya Kulkarni [Fri, 23 Aug 2019 04:45:17 +0000 (21:45 -0700)]
null_blk: create a helper for mem-backed ops

This patch creates a helper for handling requests when null_blk is
memory backed in the null_handle_cmd(). Although the helper is very
simple right now, it makes the code flow consistent with the rest of
code in the null_handle_cmd() and provides a uniform code structure
for future code.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonull_blk: create a helper for badblocks
Chaitanya Kulkarni [Fri, 23 Aug 2019 04:45:16 +0000 (21:45 -0700)]
null_blk: create a helper for badblocks

This patch creates a helper for handling badblocks code in the
null_handle_cmd().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonull_blk: create a helper for throttling
Chaitanya Kulkarni [Fri, 23 Aug 2019 04:45:15 +0000 (21:45 -0700)]
null_blk: create a helper for throttling

This patch creates a helper for handling throttling code in the
null_handle_cmd().

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonull_blk: move duplicate code to callers
Chaitanya Kulkarni [Fri, 23 Aug 2019 04:45:14 +0000 (21:45 -0700)]
null_blk: move duplicate code to callers

This is a preparation patch which moves the duplicate code for sectors
and nr_sectors calculations for bio vs request mode into their
respective callers (null_queue_bio(), null_qeueue_req()). Now the core
function only deals with the respective actions and commands instead of
having to calculte the bio vs req operations and different sector
related variables. We also move the flush command handling at the top
which significantly simplifies the rest of the code.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: move same page handling from __bio_add_pc_page to the callers
Christoph Hellwig [Mon, 12 Aug 2019 15:39:58 +0000 (17:39 +0200)]
block: move same page handling from __bio_add_pc_page to the callers

Hiding page refcount manipulation inside a low-level bio helper is
somewhat awkward.  Instead return the same page information to the
callers, where it fits in much better.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: create a bio_try_merge_pc_page helper
Christoph Hellwig [Mon, 12 Aug 2019 15:39:57 +0000 (17:39 +0200)]
block: create a bio_try_merge_pc_page helper

Passsthrough bio handling should be the same as normal bio handling,
except that we need to take hardware limitations into account.  Thus
use the common try_merge implementation after checking the hardware
limits.  This changes behavior in that we now also check segment
and dma boundary settings for same page merges, which is a little
more work but has no effect as those need to be larger than the
page size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: improve the gap check in __bio_add_pc_page
Christoph Hellwig [Mon, 12 Aug 2019 15:39:56 +0000 (17:39 +0200)]
block: improve the gap check in __bio_add_pc_page

If we can add more data into an existing segment we do not create a gap
per definition, so move the check for a gap after the attempt to merge
into the segment.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonbd: fix max number of supported devs
Mike Christie [Sun, 4 Aug 2019 19:10:06 +0000 (14:10 -0500)]
nbd: fix max number of supported devs

This fixes a bug added in 4.10 with commit:

commit 9561a7ade0c205bc2ee035a2ac880478dcc1a024
Author: Josef Bacik <jbacik@fb.com>
Date:   Tue Nov 22 14:04:40 2016 -0500

    nbd: add multi-connection support

that limited the number of devices to 256. Before the patch we could
create 1000s of devices, but the patch switched us from using our
own thread to using a work queue which has a default limit of 256
active works.

The problem is that our recv_work function sits in a loop until
disconnection but only handles IO for one connection. The work is
started when the connection is started/restarted, but if we end up
creating 257 or more connections, the queue_work call just queues
connection257+'s recv_work and that waits for connection 1 - 256's
recv_work to be disconnected and that work instance completing.

Instead of reverting back to kthreads, this has us allocate a
workqueue_struct per device, so we can block in the work.

Cc: stable@vger.kernel.org
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonbd: fix zero cmd timeout handling v2
Mike Christie [Tue, 13 Aug 2019 16:39:52 +0000 (11:39 -0500)]
nbd: fix zero cmd timeout handling v2

This fixes a regression added in 4.9 with commit:

commit 0eadf37afc2500e1162c9040ec26a705b9af8d47
Author: Josef Bacik <jbacik@fb.com>
Date:   Thu Sep 8 12:33:40 2016 -0700

    nbd: allow block mq to deal with timeouts

where before the patch userspace would set the timeout to 0 to disable
it. With the above patch, a zero timeout tells the block layer to use
the default value of 30 seconds. For setups where commands can take a
long time or experience transient issues like network disruptions this
then results in IO errors being sent to the application.

To fix this, the patch still uses the common block layer timeout
framework, but if zero is set, nbd just logs a message and then resets
the timer when it expires.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonbd: add missing config put
Mike Christie [Tue, 13 Aug 2019 16:39:51 +0000 (11:39 -0500)]
nbd: add missing config put

Fix bug added with the patch:

commit 8f3ea35929a0806ad1397db99a89ffee0140822a
Author: Josef Bacik <josef@toxicpanda.com>
Date:   Mon Jul 16 12:11:35 2018 -0400

    nbd: handle unexpected replies better

where if the timeout handler runs when the completion path is and we fail
to grab the mutex in the timeout handler we will leave a config reference
and cannot free the config later.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonbd: add function to convert blk req op to nbd cmd
Mike Christie [Tue, 13 Aug 2019 16:39:50 +0000 (11:39 -0500)]
nbd: add function to convert blk req op to nbd cmd

This adds a helper function to convert a block req op to a nbd cmd type.
It will be used in the last patch to log the type in the timeout
handler.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agonbd: add set cmd timeout helper
Mike Christie [Tue, 13 Aug 2019 16:39:49 +0000 (11:39 -0500)]
nbd: add set cmd timeout helper

Add a helper to set the cmd timeout. It does not really do a lot now,
but will be more useful in the next patches.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: sed-opal: Removed duplicate OPAL_METHOD_LENGTH definition
Revanth Rajashekar [Tue, 20 Aug 2019 15:30:51 +0000 (09:30 -0600)]
block: sed-opal: Removed duplicate OPAL_METHOD_LENGTH definition

The original commit adding the sed-opal library by mistake added two
definitions of OPAL_METHOD_LENGTH, remove one of them.

Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: sed-opal: Remove always false conditional statement
Revanth Rajashekar [Tue, 20 Aug 2019 15:30:50 +0000 (09:30 -0600)]
block: sed-opal: Remove always false conditional statement

In the function 'response_parse', num_entries will never be 0 as
slen is checked for 0. Hence, the condition 'if (num_entries == 0)'
can never be true.

Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: sed-opal: Add/remove spaces
Revanth Rajashekar [Tue, 20 Aug 2019 15:30:49 +0000 (09:30 -0600)]
block: sed-opal: Add/remove spaces

Signed-off-by: Revanth Rajashekar <revanth.rajashekar@intel.com>
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>
Reviewed-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: remove struct request_queue queue_head
Junxiao Bi [Fri, 16 Aug 2019 21:12:33 +0000 (14:12 -0700)]
block: remove struct request_queue queue_head

The dispatch list is not used any more, as the legacy block IO stack
has been removed.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agowriteback, cgroup: inode_switch_wbs() shouldn't give up on wb_switch_rwsem trylock...
Tejun Heo [Fri, 2 Aug 2019 19:08:13 +0000 (12:08 -0700)]
writeback, cgroup: inode_switch_wbs() shouldn't give up on wb_switch_rwsem trylock fail

As inode wb switching may make sync(2) miss some inodes, they're
synchronized using wb_switch_rwsem so that no wb switching happens
while sync(2) is in progress.  In addition to synchronizing the actual
switching, the rwsem is also used to prevent queueing new switch
attempts while sync(2) is in progress.  This is to avoid queueing too
many instances while the rwsem is held by sync(2).  Unfortunately,
this is too agressive and can block wb switching for a long time if
sync(2) is frequent.

The goal is avoiding expolding the number of scheduled switches, not
avoiding scheduling anything.  Let's use wb_switch_rwsem only for
synchronizing the actual switching and sync(2) and use
isw_nr_in_flight instead for limiting the maximum number of scheduled
switches.  The limit is set to 1024 which should be more than enough
while still avoiding extreme situations.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agowriteback, cgroup: Adjust WB_FRN_TIME_CUT_DIV to accelerate foreign inode switching
Tejun Heo [Thu, 15 Aug 2019 19:25:28 +0000 (12:25 -0700)]
writeback, cgroup: Adjust WB_FRN_TIME_CUT_DIV to accelerate foreign inode switching

WB_FRN_TIME_CUT_DIV is used to tell the foreign inode detection logic
to ignore short writeback rounds to prevent getting confused by a
burst of short writebacks.  The parameter is currently 2 meaning that
anything smaller than half of the running average writback duration
will be ignored.

This is unnecessarily aggressive.  The detection logic uses 16 history
slots and is already reasonably protected against some short bursts
confusing it and the current parameter can lead to tens of seconds of
missed detection depending on the writeback pattern.

Let's change the parameter to 8, so that it only ignores writeback
with are smaller than 12.5% of the current running average.

v2: Add comment explaining what's going on with the foreign detection
    parameters.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblock: annotate refault stalls from IO submission
Johannes Weiner [Thu, 8 Aug 2019 19:03:00 +0000 (15:03 -0400)]
block: annotate refault stalls from IO submission

psi tracks the time tasks wait for refaulting pages to become
uptodate, but it does not track the time spent submitting the IO. The
submission part can be significant if backing storage is contended or
when cgroup throttling (io.latency) is in effect - a lot of time is
spent in submit_bio(). In that case, we underreport memory pressure.

Annotate submit_bio() to account submission time as memory stall when
the bio is reading userspace workingset pages.

Tested-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoblk-mq: Fix memory leak in blk_mq_init_allocated_queue error handling
zhengbin [Tue, 23 Jul 2019 14:10:42 +0000 (22:10 +0800)]
blk-mq: Fix memory leak in blk_mq_init_allocated_queue error handling

If blk_mq_init_allocated_queue->elevator_init_mq fails, need to release
the previously requested resources.

Fixes: d34849913819 ("blk-mq-sched: allow setting of default IO scheduler")
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agofloppy: fix usercopy direction
Jann Horn [Tue, 26 Mar 2019 22:03:48 +0000 (23:03 +0100)]
floppy: fix usercopy direction

As sparse points out, these two copy_from_user() should actually be
copy_to_user().

Fixes: 229b53c9bf4e ("take floppy compat ioctls to sodding floppy.c")
Cc: stable@vger.kernel.org
Acked-by: Alexander Popov <alex.popov@linux.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agolightnvm: remove unused 'geo' variable
Jens Axboe [Fri, 9 Aug 2019 04:11:28 +0000 (22:11 -0600)]
lightnvm: remove unused 'geo' variable

A previous commit correctly removed set-but-not-read variables, but
this left two new variables now unused. Kill them.

Fixes: ba6f7da99aaf ("lightnvm: remove set but not used variables 'data_len' and 'rq_len'")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoloop: Add LOOP_SET_DIRECT_IO to compat ioctl
Alessio Balsini [Wed, 7 Aug 2019 00:48:28 +0000 (01:48 +0100)]
loop: Add LOOP_SET_DIRECT_IO to compat ioctl

Enabling Direct I/O with loop devices helps reducing memory usage by
avoiding double caching.  32 bit applications running on 64 bits systems
are currently not able to request direct I/O because is missing from the
lo_compat_ioctl.

This patch fixes the compatibility issue mentioned above by exporting
LOOP_SET_DIRECT_IO as additional lo_compat_ioctl() entry.
The input argument for this ioctl is a single long converted to a 1-bit
boolean, so compatibility is preserved.

Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Alessio Balsini <balsini@android.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agolib: scatterlist: Fix to support no mapped sg
Zhou Wang [Wed, 24 Jul 2019 03:54:23 +0000 (11:54 +0800)]
lib: scatterlist: Fix to support no mapped sg

In function sg_split, the second sg_calculate_split will return -EINVAL
when in_mapped_nents is 0.

Indeed there is no need to do second sg_calculate_split and sg_split_mapped
when in_mapped_nents is 0, as in_mapped_nents indicates no mapped entry in
original sgl.

Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agolightnvm: remove set but not used variables 'data_len' and 'rq_len'
YueHaibing [Wed, 7 Aug 2019 13:18:47 +0000 (21:18 +0800)]
lightnvm: remove set but not used variables 'data_len' and 'rq_len'

drivers/lightnvm/pblk-read.c: In function pblk_submit_read_gc:
drivers/lightnvm/pblk-read.c:423:6: warning: variable data_len set but not used [-Wunused-but-set-variable]
drivers/lightnvm/pblk-recovery.c: In function pblk_recov_scan_oob:
drivers/lightnvm/pblk-recovery.c:368:15: warning: variable rq_len set but not used [-Wunused-but-set-variable]

They are not used since commit 48e5da725581 ("lightnvm:
move metadata mapping to lower level driver")

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
4 years agoMerge branch 'md-next' of https://github.com/liu-song-6/linux into for-5.4/block
Jens Axboe [Wed, 7 Aug 2019 18:26:53 +0000 (12:26 -0600)]
Merge branch 'md-next' of https://github.com/liu-song-6/linux into for-5.4/block

Pull MD changes from Song.

* 'md-next' of https://github.com/liu-song-6/linux:
  raid1: factor out a common routine to handle the completion of sync write
  md: don't call spare_active in md_reap_sync_thread if all member devices can't work
  md: don't set In_sync if array is frozen
  md: allow last device to be forcibly removed from RAID1/RAID10.
  md: Convert to use int_pow()
  md/raid10: end bio when the device faulty
  md/raid1: end bio when the device faulty
  md/raid6: Set R5_ReadError when there is read failure on parity disk
  raid1: use an int as the return value of raise_barrier()

4 years agoraid1: factor out a common routine to handle the completion of sync write
Hou Tao [Sat, 27 Jul 2019 06:02:58 +0000 (14:02 +0800)]
raid1: factor out a common routine to handle the completion of sync write

It's just code clean-up.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
4 years agomd: don't call spare_active in md_reap_sync_thread if all member devices can't work
Guoqing Jiang [Wed, 24 Jul 2019 09:09:21 +0000 (11:09 +0200)]
md: don't call spare_active in md_reap_sync_thread if all member devices can't work

When add one disk to array, the md_reap_sync_thread is responsible
to activate the spare and set In_sync flag for the new member in
spare_active().

But if raid1 has one member disk A, and disk B is added to the array.
Then we offline A before all the datas are synchronized from A to B,
obviously B doesn't have the latest data as A, but B is still marked
with In_sync flag.

So let's not call spare_active under the condition, otherwise B is
still showed with 'U' state which is not correct.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
4 years agomd: don't set In_sync if array is frozen
Guoqing Jiang [Wed, 24 Jul 2019 09:09:20 +0000 (11:09 +0200)]
md: don't set In_sync if array is frozen

When a disk is added to array, the following path is called in mdadm.

Manage_subdevs -> sysfs_freeze_array
               -> Manage_add
               -> sysfs_set_str(&info, NULL, "sync_action","idle")

Then from kernel side, Manage_add invokes the path (add_new_disk ->
validate_super = super_1_validate) to set In_sync flag.

Since In_sync means "device is in_sync with rest of array", and the new
added disk need to resync thread to help the synchronization of data.
And md_reap_sync_thread would call spare_active to set In_sync for the
new added disk finally. So don't set In_sync if array is in frozen.

Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
4 years agomd: allow last device to be forcibly removed from RAID1/RAID10.
Guoqing Jiang [Wed, 24 Jul 2019 09:09:19 +0000 (11:09 +0200)]
md: allow last device to be forcibly removed from RAID1/RAID10.

When the 'last' device in a RAID1 or RAID10 reports an error,
we do not mark it as failed.  This would serve little purpose
as there is no risk of losing data beyond that which is obviously
lost (as there is with RAID5), and there could be other sectors
on the device which are readable, and only readable from this device.
This in general this maximises access to data.

However the current implementation also stops an admin from removing
the last device by direct action.  This is rarely useful, but in many
case is not harmful and can make automation easier by removing special
cases.

Also, if an attempt to write metadata fails the device must be marked
as faulty, else an infinite loop will result, attempting to update
the metadata on all non-faulty devices.

So add 'fail_last_dev' member to 'struct mddev', then we can bypasses
the 'last disk' checks for RAID1 and RAID10, and control the behavior
per array by change sysfs node.

Signed-off-by: NeilBrown <neilb@suse.de>
[add sysfs node for fail_last_dev by Guoqing]
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
4 years agomd: Convert to use int_pow()
Andy Shevchenko [Tue, 23 Jul 2019 20:41:55 +0000 (23:41 +0300)]
md: Convert to use int_pow()

Instead of linear approach to calculate power of 10, use generic int_pow()
which does it better.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>