Paolo Valente [Sat, 13 Jan 2018 11:05:18 +0000 (12:05 +0100)]
block, bfq: limit sectors served with interactive weight raising
To maximise responsiveness, BFQ raises the weight, and performs device
idling, for bfq_queues associated with processes deemed as
interactive. In particular, weight raising has a maximum duration,
equal to the time needed to start a large application. If a
weight-raised process goes on doing I/O beyond this maximum duration,
it loses weight-raising.
This mechanism is evidently vulnerable to the following false
positives: I/O-bound applications that will go on doing I/O for much
longer than the duration of weight-raising. These applications have
basically no benefit from being weight-raised at the beginning of
their I/O. On the opposite end, while being weight-raised, these
applications
a) unjustly steal throughput to applications that may truly need
low latency;
b) make BFQ uselessly perform device idling; device idling results
in loss of device throughput with most flash-based storage, and may
increase latencies when used purposelessly.
This commit adds a countermeasure to reduce both the above
problems. To introduce this countermeasure, we provide the following
extra piece of information (full details in the comments added by this
commit). During the start-up of the large application used as a
reference to set the duration of weight-raising, involved processes
transfer at most ~110K sectors each. Accordingly, a process initially
deemed as interactive has no right to be weight-raised any longer,
once transferred 110K sectors or more.
Basing on this consideration, this commit early-ends weight-raising
for a bfq_queue if the latter happens to have received an amount of
service at least equal to 110K sectors (actually, a little bit more,
to keep a safety margin). I/O-bound applications that reach a high
throughput, such as file copy, get to this threshold much before the
allowed weight-raising period finishes. Thus this early ending of
weight-raising reduces the amount of time during which these
applications cause the problems described above.
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Sat, 13 Jan 2018 11:05:17 +0000 (12:05 +0100)]
block, bfq: limit tags for writes and async I/O
Asynchronous I/O can easily starve synchronous I/O (both sync reads
and sync writes), by consuming all request tags. Similarly, storms of
synchronous writes, such as those that sync(2) may trigger, can starve
synchronous reads. In their turn, these two problems may also cause
BFQ to loose control on latency for interactive and soft real-time
applications. For example, on a PLEXTOR PX-256M5S SSD, LibreOffice
Writer takes 0.6 seconds to start if the device is idle, but it takes
more than 45 seconds (!) if there are sequential writes in the
background.
This commit addresses this issue by limiting the maximum percentage of
tags that asynchronous I/O requests and synchronous write requests can
consume. In particular, this commit grants a higher threshold to
synchronous writes, to prevent the latter from being starved by
asynchronous I/O.
According to the above test, LibreOffice Writer now starts in about
1.2 seconds on average, regardless of the background workload, and
apart from some rare outlier. To check this improvement, run, e.g.,
sudo ./comm_startup_lat.sh bfq 5 5 seq 10 "lowriter --terminate_after_init"
for the comm_startup_lat benchmark in the S suite [1].
[1] https://github.com/Algodev-github/S
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Thu, 18 Jan 2018 04:06:59 +0000 (12:06 +0800)]
blk-mq: don't dispatch request in blk_mq_request_direct_issue if queue is busy
If we run into blk_mq_request_direct_issue(), when queue is busy, we
don't want to dispatch this request into hctx->dispatch_list, and
what we need to do is to return the queue busy info to caller, so
that caller can deal with it well.
Fixes: 396eaf21ee ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback")
Reported-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 16 Jan 2018 18:31:39 +0000 (10:31 -0800)]
block: Fix __bio_integrity_endio() documentation
Fixes: 4246a0b63bd8 ("block: add a bi_error field to struct bio")
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Mike Snitzer [Wed, 17 Jan 2018 16:25:58 +0000 (11:25 -0500)]
blk-mq-sched: remove unused 'can_block' arg from blk_mq_sched_insert_request
After commit:
923218f6166a ("blk-mq: don't allocate driver tag upfront for flush rq")
we no longer use the 'can_block' argument in
blk_mq_sched_insert_request(). Kill it.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Added actual commit message as to why it's being removed.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Wed, 17 Jan 2018 16:25:57 +0000 (11:25 -0500)]
blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback
blk_insert_cloned_request() is called in the fast path of a dm-rq driver
(e.g. blk-mq request-based DM mpath). blk_insert_cloned_request() uses
blk_mq_request_bypass_insert() to directly append the request to the
blk-mq hctx->dispatch_list of the underlying queue.
1) This way isn't efficient enough because the hctx spinlock is always
used.
2) With blk_insert_cloned_request(), we completely bypass underlying
queue's elevator and depend on the upper-level dm-rq driver's elevator
to schedule IO. But dm-rq currently can't get the underlying queue's
dispatch feedback at all. Without knowing whether a request was issued
or not (e.g. due to underlying queue being busy) the dm-rq elevator will
not be able to provide effective IO merging (as a side-effect of dm-rq
currently blindly destaging a request from its elevator only to requeue
it after a delay, which kills any opportunity for merging). This
obviously causes very bad sequential IO performance.
Fix this by updating blk_insert_cloned_request() to use
blk_mq_request_direct_issue(). blk_mq_request_direct_issue() allows a
request to be issued directly to the underlying queue and returns the
dispatch feedback (blk_status_t). If blk_mq_request_direct_issue()
returns BLK_SYS_RESOURCE the dm-rq driver will now use DM_MAPIO_REQUEUE
to _not_ destage the request. Whereby preserving the opportunity to
merge IO.
With this, request-based DM's blk-mq sequential IO performance is vastly
improved (as much as 3X in mpath/virtio-scsi testing).
Signed-off-by: Ming Lei <ming.lei@redhat.com>
[blk-mq.c changes heavily influenced by Ming Lei's initial solution, but
they were refactored to make them less fragile and easier to read/review]
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Mike Snitzer [Wed, 17 Jan 2018 16:25:56 +0000 (11:25 -0500)]
blk-mq: factor out a few helpers from __blk_mq_try_issue_directly
No functional change. Just makes code flow more logically.
In following commit, __blk_mq_try_issue_directly() will be used to
return the dispatch result (blk_status_t) to DM. DM needs this
information to improve IO merging.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Wed, 17 Jan 2018 16:41:52 +0000 (00:41 +0800)]
blk-mq: turn WARN_ON in __blk_mq_run_hw_queue into printk
We know this WARN_ON is harmless and in reality it may be trigged,
so convert it to printk() and dump_stack() to avoid to confusing
people.
Also add comment about two releated races here.
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "jianchao.wang" <jianchao.w.wang@oracle.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Wed, 17 Jan 2018 16:41:51 +0000 (00:41 +0800)]
blk-mq: make sure hctx->next_cpu is set correctly
When hctx->next_cpu is set from possible online CPUs, there is one
race in which hctx->next_cpu may be set as >= nr_cpu_ids, and finally
break workqueue.
The race can be triggered in the following two sitations:
1) when one CPU is becoming DEAD, blk_mq_hctx_notify_dead() is called
to dispatch requests from the DEAD cpu context, but at that
time, this DEAD CPU has been cleared from 'cpu_online_mask', so all
CPUs in hctx->cpumask may become offline, and cause hctx->next_cpu set
a bad value.
2) blk_mq_delay_run_hw_queue() is called from CPU B, and found the queue
should be run on the other CPU A, then CPU A may become offline at the
same time and all CPUs in hctx->cpumask become offline.
This patch deals with this issue by re-selecting next CPU, and making
sure it is set correctly.
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reported-by: "jianchao.wang" <jianchao.w.wang@oracle.com>
Tested-by: "jianchao.wang" <jianchao.w.wang@oracle.com>
Fixes: 20e4d81393 ("blk-mq: simplify queue mapping & schedule with each possisble CPU")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tina Ruchandani [Wed, 17 Jan 2018 15:30:39 +0000 (16:30 +0100)]
aoe: use ktime_t instead of timeval
'struct frame' uses two variables to store the sent timestamp - 'struct
timeval' and jiffies. jiffies is used to avoid discrepancies caused by
updates to system time. 'struct timeval' is deprecated because it uses
32-bit representation for seconds which will overflow in year 2038.
This patch does the following:
- Replace the use of 'struct timeval' and jiffies with ktime_t, which
is the recommended type for timestamping
- ktime_t provides both long range (like jiffies) and high resolution
(like timeval). Using ktime_get (monotonic time) instead of wall-clock
time prevents any discprepancies caused by updates to system time.
[updates by Arnd below]
The original patch from Tina never went anywhere as we discussed how
to keep the impact on performance minimal. I've started over now but
arrived at basically the same patch that she had originally, except for
an slightly improved tsince_hr() function. I'm making it more robust
against overflows, and also optimize explicitly for the common case
in which a frame is less than 4.2 seconds old, using only a 32-bit
division in that case.
This should make the new version more efficient than the old code,
since we replace the existing two 32-bit division in do_gettimeofday()
plus one multiplication with a single single 32-bit division in
tsince_hr() and drop the double bookkeeping. It's also more efficient
than the ktime_get_us() API we discussed before, since that would
also rely on multiple divisions.
Link: https://lists.linaro.org/pipermail/y2038/2015-May/000276.html
Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
Cc: Ed Cashin <ed.cashin@acm.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Arnd Bergmann [Tue, 16 Jan 2018 15:01:36 +0000 (16:01 +0100)]
blkcg: simplify statistic accumulation code
Some older compilers (gcc-4.4 through 4.6 in particular) struggle
with the way that blkg_rwstat_read() returns a structure, leading
to excessive stack usage and rather inefficient code:
block/blk-cgroup.c: In function 'blkg_destroy':
block/blk-cgroup.c:354:1: error: the frame size of 1296 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
block/cfq-iosched.c: In function 'cfqg_stats_add_aux':
block/cfq-iosched.c:753:1: error: the frame size of 1928 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
block/bfq-cgroup.c: In function 'bfqg_stats_add_aux':
block/bfq-cgroup.c:299:1: error: the frame size of 1928 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
I also notice that there is no point in using atomic accesses
for the local variables, so storing the temporaries in simple 'u64'
variables not only avoids the stack usage on older compilers but
also improves the object code on modern versions.
Fixes: e6269c445467 ("blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it")
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Mike Snitzer [Tue, 9 Jan 2018 01:03:04 +0000 (20:03 -0500)]
dm: fix incomplete request_queue initialization
DM is no longer prone to having its request_queue be improperly
initialized.
Summary of changes:
- defer DM's blk_register_queue() from add_disk()-time until
dm_setup_md_queue() by using add_disk_no_queue_reg() in alloc_dev().
- dm_setup_md_queue() is updated to fully initialize DM's request_queue
(_after_ all table loads have occurred and the request_queue's type,
features and limits are known).
A very welcome side-effect of these changes is DM no longer needs to:
1) backfill the "mq" sysfs entry (because historically DM didn't
initialize the request_queue to use blk-mq until _after_
blk_register_queue() was called via add_disk()).
2) call elv_register_queue() to get .request_fn request-based DM
device's "iosched" exposed in syfs.
In addition, blk-mq debugfs support is now made available because
request-based DM's blk-mq request_queue is now properly initialized
before dm_setup_md_queue() calls blk_register_queue().
These changes also stave off the need to introduce new DM-specific
workarounds in block core, e.g. this proposal:
https://patchwork.kernel.org/patch/
10067961/
In the end DM devices should be less unicorn in nature (relative to
initialization and availability of block core infrastructure provided by
the request_queue).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Douglas Gilbert [Sun, 14 Jan 2018 22:00:48 +0000 (17:00 -0500)]
blk_rq_map_user_iov: fix error override
During stress tests by syzkaller on the sg driver the block layer
infrequently returns EINVAL. Closer inspection shows the block
layer was trying to return ENOMEM (which is much more
understandable) but for some reason overroad that useful error.
Patch below does not show this (unchanged) line:
ret =__blk_rq_map_user_iov(rq, map_data, &i, gfp_mask, copy);
That 'ret' was being overridden when that function failed.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Mike Snitzer [Tue, 9 Jan 2018 03:01:13 +0000 (22:01 -0500)]
block: allow gendisk's request_queue registration to be deferred
Since I can remember DM has forced the block layer to allow the
allocation and initialization of the request_queue to be distinct
operations. Reason for this is block/genhd.c:add_disk() has requires
that the request_queue (and associated bdi) be tied to the gendisk
before add_disk() is called -- because add_disk() also deals with
exposing the request_queue via blk_register_queue().
DM's dynamic creation of arbitrary device types (and associated
request_queue types) requires the DM device's gendisk be available so
that DM table loads can establish a master/slave relationship with
subordinate devices that are referenced by loaded DM tables -- using
bd_link_disk_holder(). But until these DM tables, and their associated
subordinate devices, are known DM cannot know what type of request_queue
it needs -- nor what its queue_limits should be.
This chicken and egg scenario has created all manner of problems for DM
and, at times, the block layer.
Summary of changes:
- Add device_add_disk_no_queue_reg() and add_disk_no_queue_reg() variant
that drivers may use to add a disk without also calling
blk_register_queue(). Driver must call blk_register_queue() once its
request_queue is fully initialized.
- Return early from blk_unregister_queue() if QUEUE_FLAG_REGISTERED
is not set. It won't be set if driver used add_disk_no_queue_reg()
but driver encounters an error and must del_gendisk() before calling
blk_register_queue().
- Export blk_register_queue().
These changes allow DM to use add_disk_no_queue_reg() to anchor its
gendisk as the "master" for master/slave relationships DM must establish
with subordinate devices referenced in DM tables that get loaded. Once
all "slave" devices for a DM device are known its request_queue can be
properly initialized and then advertised via sysfs -- important
improvement being that no request_queue resource initialization
performed by blk_register_queue() is missed for DM devices anymore.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Mike Snitzer [Thu, 11 Jan 2018 19:11:01 +0000 (14:11 -0500)]
block: properly protect the 'queue' kobj in blk_unregister_queue
The original commit
e9a823fb34a8b (block: fix warning when I/O elevator
is changed as request_queue is being removed) is pretty conflated.
"conflated" because the resource being protected by q->sysfs_lock isn't
the queue_flags (it is the 'queue' kobj).
q->sysfs_lock serializes __elevator_change() (via elv_iosched_store)
from racing with blk_unregister_queue():
1) By holding q->sysfs_lock first, __elevator_change() can complete
before a racing blk_unregister_queue().
2) Conversely, __elevator_change() is testing for QUEUE_FLAG_REGISTERED
in case elv_iosched_store() loses the race with blk_unregister_queue(),
it needs a way to know the 'queue' kobj isn't there.
Expand the scope of blk_unregister_queue()'s q->sysfs_lock use so it is
held until after the 'queue' kobj is removed.
To do so blk_mq_unregister_dev() must not also take q->sysfs_lock. So
rename __blk_mq_unregister_dev() to blk_mq_unregister_dev().
Also, blk_unregister_queue() should use q->queue_lock to protect against
any concurrent writes to q->queue_flags -- even though chances are the
queue is being cleaned up so no concurrent writes are likely.
Fixes: e9a823fb34a8b ("block: fix warning when I/O elevator is changed as request_queue is being removed")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Mike Snitzer [Wed, 10 Jan 2018 01:46:49 +0000 (20:46 -0500)]
block: only bdi_unregister() in del_gendisk() if !GENHD_FL_HIDDEN
device_add_disk() will only call bdi_register_owner() if
!GENHD_FL_HIDDEN, so it follows that del_gendisk() should only call
bdi_unregister() if !GENHD_FL_HIDDEN.
Found with code inspection. bdi_unregister() won't do any harm if
bdi_register_owner() wasn't used but best to avoid the unnecessary
call to bdi_unregister().
Fixes: 8ddcd65325 ("block: introduce GENHD_FL_HIDDEN")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Sun, 14 Jan 2018 17:40:45 +0000 (10:40 -0700)]
blk-mq: fix bad clear of RQF_MQ_INFLIGHT in blk_mq_ct_ctx_init()
A previous commit moved the clearing of rq->rq_flags later,
but we may have already set RQF_MQ_INFLIGHT when that happens.
Ensure that we correctly initialize rq->rq_flags to the
right value.
This is based on an original fix by Ming, just rewritten to not
require a conditional.
Fixes: 7c3fb70f0341 ("block: rearrange a few request fields for better cache layout")
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Fri, 12 Jan 2018 21:47:57 +0000 (14:47 -0700)]
blk-mq: add missing RQF_STARTED to debugfs
Looking at debug output, we see:
./
000000009ddfa913/requeue_list:
000000009646711c {.op=READ, .state=idle, gen=0x1
18, abort_gen=0x0, .cmd_flags=, .rq_flags=SORTED|1|SOFTBARRIER|IO_STAT, complete
=0, .tag=-1, .internal_tag=217}
Note the '1' between SORTED and SOFTBARRIER - that's because no name
as defined for RQF_STARTED. Fixed that.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Christoph Hellwig [Fri, 12 Jan 2018 02:53:06 +0000 (10:53 +0800)]
blk-mq: simplify queue mapping & schedule with each possisble CPU
The previous patch assigns interrupt vectors to all possible CPUs, so
now hctx can be mapped to possible CPUs, this patch applies this fact
to simplify queue mapping & schedule so that we don't need to handle
CPU hotplug for dealing with physical CPU plug & unplug. With this
simplication, we can work well on physical CPU plug & unplug, which
is a normal use case for VM at least.
Make sure we allocate blk_mq_ctx structures for all possible CPUs, and
set hctx->numa_node for possible CPUs which are mapped to this hctx. And
only choose the online CPUs for schedule.
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fixes: 4b855ad37194 ("blk-mq: Create hctx for each present CPU")
(merged the three into one because any single one may not work, and fix
selecting online CPUs for scheduler)
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Christoph Hellwig [Fri, 12 Jan 2018 02:53:05 +0000 (10:53 +0800)]
genirq/affinity: assign vectors to all possible CPUs
Currently we assign managed interrupt vectors to all present CPUs. This
works fine for systems were we only online/offline CPUs. But in case of
systems that support physical CPU hotplug (or the virtualized version of
it) this means the additional CPUs covered for in the ACPI tables or on
the command line are not catered for. To fix this we'd either need to
introduce new hotplug CPU states just for this case, or we can start
assining vectors to possible but not present CPUs.
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Fixes: 4b855ad37194 ("blk-mq: Create hctx for each present CPU")
Cc: linux-kernel@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Wed, 10 Jan 2018 21:41:21 +0000 (13:41 -0800)]
blk-mq: Reduce the number of if-statements in blk_mq_mark_tag_wait()
This patch does not change any functionality but makes the
blk_mq_mark_tag_wait() code slightly easier to read.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Arnd Bergmann [Thu, 11 Jan 2018 10:31:25 +0000 (11:31 +0100)]
null_blk: remove explicit 'select FAULT_INJECTION'
Selecting FAULT_INJECTION causes a Kconfig warning when CONFIG_DEBUG_KERNEL
is not set:
warning: (BLK_DEV_NULL_BLK && DRM_I915_SELFTEST) selects FAULT_INJECTION which has unmet direct dependencies (DEBUG_KERNEL)
The other drivers that use FAULT_INJECTION tend to have a separate
Kconfig symbol for turning on that feature, so let's do the same
thing here. This may add a bit more complexity than we like, but
it avoids the warning and is more consistent with the rest of the
kernel.
Fixes: 93b570464cce ("null_blk: add option for managing IO timeouts")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Wed, 10 Jan 2018 19:34:27 +0000 (11:34 -0800)]
blk-mq: Add locking annotations to hctx_lock() and hctx_unlock()
This patch avoids that sparse reports the following:
block/blk-mq.c:637:33: warning: context imbalance in 'hctx_unlock' - unexpected unlock
block/blk-mq.c:642:9: warning: context imbalance in 'hctx_lock' - wrong count at exit
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Bonzini [Wed, 10 Jan 2018 15:54:52 +0000 (16:54 +0100)]
block: silently forbid sending any ioctl to a partition
After the first few months, the message has not led to many bug reports.
It's been almost five years now, and in practice the main source of
it seems to be MTIOCGET that someone is using to detect tape devices.
While we could whitelist it just like CDROM_GET_CAPABILITY, this patch
just removes the message altogether.
The patch also removes the "safe but not very useful" ioctl whitelist,
as suggested by Christoph. I doubt anything is using most of those
ioctls _in general_, let alone on a partition.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Wed, 10 Jan 2018 18:46:39 +0000 (11:46 -0700)]
block: rearrange a few request fields for better cache layout
Move completion related items (like the call single data) near the
end of the struct, instead of mixing them in with the initial
queueing related fields.
Move queuelist below the bio structures. Then we have all
queueing related bits in the first cache line.
This yields a 1.5-2% increase in IOPS for a null_blk test, both for
sync and for high thread count access. Sync test goes form 975K to
992K, 32-thread case from 20.8M to 21.2M IOPS.
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Wed, 10 Jan 2018 18:34:25 +0000 (11:34 -0700)]
block: convert REQ_ATOM_COMPLETE to stealing rq->__deadline bit
We only have one atomic flag left. Instead of using an entire
unsigned long for that, steal the bottom bit of the deadline
field that we already reserved.
Remove ->atomic_flags, since it's now unused.
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 9 Jan 2018 21:23:42 +0000 (14:23 -0700)]
block: add accessors for setting/querying request deadline
We reduce the resolution of request expiry, but since we're already
using jiffies for this where resolution depends on the kernel
configuration and since the timeout resolution is coarse anyway,
that should be fine.
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Wed, 10 Jan 2018 18:30:56 +0000 (11:30 -0700)]
block: remove REQ_ATOM_POLL_SLEPT
We don't need this to be an atomic flag, it can be a regular
flag. We either end up on the same CPU for the polling, in which
case the state is sane, or we did the sleep which would imply
the needed barrier to ensure we see the right state.
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Wed, 10 Jan 2018 18:30:08 +0000 (11:30 -0700)]
blk-mq: add a few missing debugfs RQF_ flags
We are missing ZONE_WRITE_LOCKED and MQ_TIMEOUT_EXPIRED, add them
so the debugfs bits can decode them.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Tue, 9 Jan 2018 19:04:18 +0000 (12:04 -0700)]
dm mpath: Use blk_path_error
Uses common code for determining if an error should be retried on
alternate path.
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Tue, 9 Jan 2018 19:04:17 +0000 (12:04 -0700)]
nvme/multipath: Use blk_path_error
Uses common code for determining if an error should be retried on
alternate path.
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Tue, 9 Jan 2018 19:04:16 +0000 (12:04 -0700)]
block: Provide blk_status_t decoding for path errors
This patch provides a common decoder for block status path related errors
that may be retried so various entities wishing to consult this do not
have to duplicate this decision.
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Tue, 9 Jan 2018 19:04:15 +0000 (12:04 -0700)]
nvme/multipath: Consult blk_status_t for failover
This removes nvme multipath's specific status decoding to see if failover
is needed, using the generic blk_status_t that was decoded earlier. This
abstraction from the raw NVMe status means all status decoding exists
in one place.
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Keith Busch [Tue, 9 Jan 2018 19:04:14 +0000 (12:04 -0700)]
nvme: Add more command status translation
This adds more NVMe status code translations to blk_status_t values,
and captures all the current status codes NVMe multipath uses.
Acked-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Wed, 10 Jan 2018 16:33:33 +0000 (08:33 -0800)]
blk-mq: Explain when 'active_queues' is decremented
It is nontrivial to derive from the blk-mq source code when
blk_mq_tags.active_queues is decremented. Hence add a comment that
explains this.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Richard Narron [Wed, 10 Jan 2018 16:12:16 +0000 (09:12 -0700)]
partitions/msdos: Unable to mount UFS 44bsd partitions
UFS partitions from newer versions of FreeBSD 10 and 11 use relative
addressing for their subpartitions. But older versions of FreeBSD still
use absolute addressing just like OpenBSD and NetBSD.
Instead of simply testing for a FreeBSD partition, the code needs to
also test if the starting offset of the C subpartition is zero.
https://bugzilla.kernel.org/show_bug.cgi?id=197733
Signed-off-by: Richard Narron <comet.berkeley@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Wed, 10 Jan 2018 16:06:23 +0000 (09:06 -0700)]
null_blk: add option for managing IO timeouts
Use the fault injection framework to provide a way for null_blk
to configure timeouts. This only works for queue_mode 1 and 2,
since the bio mode doesn't have code for tracking timeouts.
Let's say you want to have a 10% chance of timing out every
100,000 requests, and for 5 total timeouts, you could do:
modprobe null_blk timeout="100000,10,0,5"
This is useful for adding blktests to test that IO timeouts
are handled appropriately.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Chiara Bruschi [Mon, 18 Dec 2017 16:21:59 +0000 (16:21 +0000)]
block, bfq: fix occurrences of request finish method's old name
Commit '
7b9e93616399' ("blk-mq-sched: unify request finished methods")
changed the old name of current bfq_finish_request method, but left it
unchanged elsewhere in the code (related comments, part of function
name bfq_put_rq_priv_body).
This commit fixes all occurrences of the old name of this method by
changing them into the current name.
Fixes: 7b9e93616399 ("blk-mq-sched: unify request finished methods")
Reviewed-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Federico Motta <federico@willer.it>
Signed-off-by: Chiara Bruschi <bruschi.chiara@outlook.it>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Wed, 10 Jan 2018 02:51:29 +0000 (10:51 +0800)]
Revert "block: blk-merge: try to make front segments in full size"
This reverts commit
a2d37968d784363842f87820a21e106741d28004.
If max segment size isn't 512-aligned, this patch won't work well.
Also once multipage bvec is enabled, adjacent bvecs won't be physically
contiguous if page is added via bio_add_page(), so we don't need this
kind of complicated logic.
Reported-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 9 Jan 2018 19:47:24 +0000 (12:47 -0700)]
null_blk: wire up timeouts
This is needed to ensure that we actually handle timeouts.
Without it, the queue_mode=1 path will never call blk_add_timer(),
and the queue_mode=2 path will continually just return
EH_RESET_TIMER and we never actually complete the offending request.
This was used to test the new timeout code, and the changes around
killing off REQ_ATOM_COMPLETE.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 9 Jan 2018 19:20:51 +0000 (12:20 -0700)]
bfq-iosched: don't call bfqg_and_blkg_put for !CONFIG_BFQ_GROUP_IOSCHED
It's not available if we don't have group io scheduling set, and
there's no need to call it.
Fixes: 0d52af590552 ("block, bfq: release oom-queue ref to root group on exit")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Michael Lyle [Tue, 9 Jan 2018 19:13:23 +0000 (11:13 -0800)]
bcache: closures: move control bits one bit right
Otherwise, architectures that do negated adds of atomics (e.g. s390)
to do atomic_sub fail in closure_set_stopped.
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 9 Jan 2018 18:11:00 +0000 (10:11 -0800)]
block: Fix kernel-doc warnings reported when building with W=1
Commit
3a025e1d1c2e ("Add optional check for bad kernel-doc comments")
causes W=1 the kernel-doc script to be run and thereby causes several
new warnings to appear when building the kernel with W=1. Fix the
block layer kernel-doc headers such that the block layer again builds
cleanly with W=1.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Tue, 9 Jan 2018 18:09:15 +0000 (10:09 -0800)]
blk-mq: Fix spelling in a source code comment
Change "nedeing" into "needing" and "caes" into "cases".
Fixes: commit f906a6a0f426 ("blk-mq: improve tag waiting setup for non-shared tags")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 9 Jan 2018 16:32:25 +0000 (09:32 -0700)]
blk-mq: silence false positive warnings in hctx_unlock()
In some stupider versions of gcc, it complains:
block/blk-mq.c: In function ‘blk_mq_complete_request’:
./include/linux/srcu.h:175:2: warning: ‘srcu_idx’ may be used uninitialized in this function [-Wmaybe-uninitialized]
__srcu_read_unlock(sp, idx);
^
block/blk-mq.c:620:6: note: ‘srcu_idx’ was declared here
int srcu_idx;
^
which is completely bogus, since we only use srcu_idx when
hctx->flags & BLK_MQ_F_BLOCKING is set, and that's the case where
hctx_lock() has initialized it.
Just set it to '0' in the normal path in hctx_lock() to silence
this annoying warning.
Fixes: 04ced159cec8 ("blk-mq: move hctx lock/unlock into a helper")
Fixes: 5197c05e16b4 ("blk-mq: protect completion path with RCU")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tejun Heo [Tue, 9 Jan 2018 16:29:53 +0000 (08:29 -0800)]
blk-mq: rename blk_mq_hw_ctx->queue_rq_srcu to ->srcu
The RCU protection has been expanded to cover both queueing and
completion paths making ->queue_rq_srcu a misnomer. Rename it to
->srcu as suggested by Bart.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bart Van Assche <Bart.VanAssche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tejun Heo [Tue, 9 Jan 2018 16:29:52 +0000 (08:29 -0800)]
blk-mq: remove REQ_ATOM_STARTED
After the recent updates to use generation number and state based
synchronization, we can easily replace REQ_ATOM_STARTED usages by
adding an extra state to distinguish completed but not yet freed
state.
Add MQ_RQ_COMPLETE and replace REQ_ATOM_STARTED usages with
blk_mq_rq_state() tests. REQ_ATOM_STARTED no longer has any users
left and is removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tejun Heo [Tue, 9 Jan 2018 16:29:51 +0000 (08:29 -0800)]
blk-mq: remove REQ_ATOM_COMPLETE usages from blk-mq
After the recent updates to use generation number and state based
synchronization, blk-mq no longer depends on REQ_ATOM_COMPLETE except
to avoid firing the same timeout multiple times.
Remove all REQ_ATOM_COMPLETE usages and use a new rq_flags flag
RQF_MQ_TIMEOUT_EXPIRED to avoid firing the same timeout multiple
times. This removes atomic bitops from hot paths too.
v2: Removed blk_clear_rq_complete() from blk_mq_rq_timed_out().
v3: Added RQF_MQ_TIMEOUT_EXPIRED flag.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "jianchao.wang" <jianchao.w.wang@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tejun Heo [Tue, 9 Jan 2018 16:29:50 +0000 (08:29 -0800)]
blk-mq: make blk_abort_request() trigger timeout path
With issue/complete and timeout paths now using the generation number
and state based synchronization, blk_abort_request() is the only one
which depends on REQ_ATOM_COMPLETE for arbitrating completion.
There's no reason for blk_abort_request() to be a completely separate
path. This patch makes blk_abort_request() piggyback on the timeout
path instead of trying to terminate the request directly.
This removes the last dependency on REQ_ATOM_COMPLETE in blk-mq.
Note that this makes blk_abort_request() asynchronous - it initiates
abortion but the actual termination will happen after a short while,
even when the caller owns the request. AFAICS, SCSI and ATA should be
fine with that and I think mtip32xx and dasd should be safe but not
completely sure. It'd be great if people who know the drivers take a
look.
v2: - Add comment explaining the lack of synchronization around
->deadline update as requested by Bart.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Asai Thambi SP <asamymuthupa@micron.com>
Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Cc: Jan Hoeppner <hoeppner@linux.vnet.ibm.com>
Cc: Bart Van Assche <Bart.VanAssche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tejun Heo [Tue, 9 Jan 2018 16:29:49 +0000 (08:29 -0800)]
blk-mq: use blk_mq_rq_state() instead of testing REQ_ATOM_COMPLETE
blk_mq_check_inflight() and blk_mq_poll_hybrid_sleep() test
REQ_ATOM_COMPLETE to determine the request state. Both uses are
speculative and we can test REQ_ATOM_STARTED and blk_mq_rq_state() for
equivalent results. Replace the tests. This will allow removing
REQ_ATOM_COMPLETE usages from blk-mq.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tejun Heo [Tue, 9 Jan 2018 16:29:48 +0000 (08:29 -0800)]
blk-mq: replace timeout synchronization with a RCU and generation based scheme
Currently, blk-mq timeout path synchronizes against the usual
issue/completion path using a complex scheme involving atomic
bitflags, REQ_ATOM_*, memory barriers and subtle memory coherence
rules. Unfortunately, it contains quite a few holes.
There's a complex dancing around REQ_ATOM_STARTED and
REQ_ATOM_COMPLETE between issue/completion and timeout paths; however,
they don't have a synchronization point across request recycle
instances and it isn't clear what the barriers add.
blk_mq_check_expired() can easily read STARTED from N-2'th iteration,
deadline from N-1'th, blk_mark_rq_complete() against Nth instance.
In fact, it's pretty easy to make blk_mq_check_expired() terminate a
later instance of a request. If we induce 5 sec delay before
time_after_eq() test in blk_mq_check_expired(), shorten the timeout to
2s, and issue back-to-back large IOs, blk-mq starts timing out
requests spuriously pretty quickly. Nothing actually timed out. It
just made the call on a recycle instance of a request and then
terminated a later instance long after the original instance finished.
The scenario isn't theoretical either.
This patch replaces the broken synchronization mechanism with a RCU
and generation number based one.
1. Each request has a u64 generation + state value, which can be
updated only by the request owner. Whenever a request becomes
in-flight, the generation number gets bumped up too. This provides
the basis for the timeout path to distinguish different recycle
instances of the request.
Also, marking a request in-flight and setting its deadline are
protected with a seqcount so that the timeout path can fetch both
values coherently.
2. The timeout path fetches the generation, state and deadline. If
the verdict is timeout, it records the generation into a dedicated
request abortion field and does RCU wait.
3. The completion path is also protected by RCU (from the previous
patch) and checks whether the current generation number and state
match the abortion field. If so, it skips completion.
4. The timeout path, after RCU wait, scans requests again and
terminates the ones whose generation and state still match the ones
requested for abortion.
By now, the timeout path knows that either the generation number
and state changed if it lost the race or the completion will yield
to it and can safely timeout the request.
While it's more lines of code, it's conceptually simpler, doesn't
depend on direct use of subtle memory ordering or coherence, and
hopefully doesn't terminate the wrong instance.
While this change makes REQ_ATOM_COMPLETE synchronization unnecessary
between issue/complete and timeout paths, REQ_ATOM_COMPLETE isn't
removed yet as it's still used in other places. Future patches will
move all state tracking to the new mechanism and remove all bitops in
the hot paths.
Note that this patch adds a comment explaining a race condition in
BLK_EH_RESET_TIMER path. The race has always been there and this
patch doesn't change it. It's just documenting the existing race.
v2: - Fixed BLK_EH_RESET_TIMER handling as pointed out by Jianchao.
- s/request->gstate_seqc/request->gstate_seq/ as suggested by Peter.
- READ_ONCE() added in blk_mq_rq_update_state() as suggested by Peter.
v3: - Fixed possible extended seqcount / u64_stats_sync read looping
spotted by Peter.
- MQ_RQ_IDLE was incorrectly being set in complete_request instead
of free_request. Fixed.
v4: - Rebased on top of hctx_lock() refactoring patch.
- Added comment explaining the use of hctx_lock() in completion path.
v5: - Added comments requested by Bart.
- Note the addition of BLK_EH_RESET_TIMER race condition in the
commit message.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "jianchao.wang" <jianchao.w.wang@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <Bart.VanAssche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tejun Heo [Tue, 9 Jan 2018 16:29:47 +0000 (08:29 -0800)]
blk-mq: protect completion path with RCU
Currently, blk-mq protects only the issue path with RCU. This patch
puts the completion path under the same RCU protection. This will be
used to synchronize issue/completion against timeout by later patches,
which will also add the comments.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Tue, 9 Jan 2018 16:29:46 +0000 (08:29 -0800)]
blk-mq: move hctx lock/unlock into a helper
Move the RCU vs SRCU logic into lock/unlock helpers, which makes
the actual functional bits within the locked region much easier
to read.
tj: Reordered in front of timeout revamp patches and added the missing
blk_mq_run_hw_queue() conversion.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Tue, 9 Jan 2018 09:27:59 +0000 (10:27 +0100)]
block, bfq: release oom-queue ref to root group on exit
On scheduler init, a reference to the root group, and a reference to
its corresponding blkg are taken for the oom queue. Yet these
references are not released on scheduler exit, which prevents these
objects from be freed. This commit adds the missing reference
releases.
Reported-by: Davide Ferrari <davideferrari8@gmail.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Tue, 9 Jan 2018 09:27:58 +0000 (10:27 +0100)]
block, bfq: put async queues for root bfq groups too
For each pair [device for which bfq is selected as I/O scheduler,
group in blkio/io], bfq maintains a corresponding bfq group. Each such
bfq group contains a set of async queues, with each async queue
created on demand, i.e., when some I/O request arrives for it. On
creation, an async queue gets an extra reference, to make sure that
the queue is not freed as long as its bfq group exists. Accordingly,
to allow the queue to be freed after the group exited, this extra
reference must released on group exit.
The above holds also for a bfq root group, i.e., for the bfq group
corresponding to the root blkio/io root for a given device. Yet, by
mistake, the references to the existing async queues of a root group
are not released when the latter exits. This causes a memory leak when
the instance of bfq for a given device exits. In a similar vein,
bfqg_stats_xfer_dead is not executed for a root group.
This commit fixes bfq_pd_offline so that the latter executes the above
missing operations for a root group too.
Reported-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Reported-by: Guoqing Jiang <gqjiang@suse.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Davide Ferrari <davideferrari8@gmail.com>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Tue, 9 Jan 2018 13:28:29 +0000 (21:28 +0800)]
blk-mq: fix kernel oops in blk_mq_tag_idle()
HW queues may be unmapped in some cases, such as blk_mq_update_nr_hw_queues(),
then we need to check it before calling blk_mq_tag_idle(), otherwise
the following kernel oops can be triggered, so fix it by checking if
the hw queue is unmapped since it doesn't make sense to idle the tags
any more after hw queues are unmapped.
[ 440.771298] Workqueue: nvme-wq nvme_rdma_del_ctrl_work [nvme_rdma]
[ 440.779104] task:
ffff894bae755ee0 ti:
ffff893bf9bc8000 task.ti:
ffff893bf9bc8000
[ 440.788359] RIP: 0010:[<
ffffffffb730e2b4>] [<
ffffffffb730e2b4>] __blk_mq_tag_idle+0x24/0x40
[ 440.798697] RSP: 0018:
ffff893bf9bcbd10 EFLAGS:
00010286
[ 440.805538] RAX:
0000000000000000 RBX:
ffff895bb131dc00 RCX:
000000000000011f
[ 440.814426] RDX:
00000000ffffffff RSI:
0000000000000120 RDI:
ffff895bb131dc00
[ 440.823301] RBP:
ffff893bf9bcbd10 R08:
000000000001b860 R09:
4a51d361c00c0000
[ 440.832193] R10:
b5907f32b4cc7003 R11:
ffffd6cabfb57000 R12:
ffff894bafd1e008
[ 440.841091] R13:
0000000000000001 R14:
ffff895baf770000 R15:
0000000000000080
[ 440.849988] FS:
0000000000000000(0000) GS:
ffff894bbdcc0000(0000) knlGS:
0000000000000000
[ 440.859955] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[ 440.867274] CR2:
0000000000000008 CR3:
000000103d098000 CR4:
00000000001407e0
[ 440.876169] Call Trace:
[ 440.879818] [<
ffffffffb7309d68>] blk_mq_exit_hctx+0xd8/0xe0
[ 440.887051] [<
ffffffffb730dc40>] blk_mq_free_queue+0xf0/0x160
[ 440.894465] [<
ffffffffb72ff679>] blk_cleanup_queue+0xd9/0x150
[ 440.901881] [<
ffffffffc08a802b>] nvme_ns_remove+0x5b/0xb0 [nvme_core]
[ 440.910068] [<
ffffffffc08a811b>] nvme_remove_namespaces+0x3b/0x60 [nvme_core]
[ 440.919026] [<
ffffffffc08b817b>] __nvme_rdma_remove_ctrl+0x2b/0xb0 [nvme_rdma]
[ 440.928079] [<
ffffffffc08b8237>] nvme_rdma_del_ctrl_work+0x17/0x20 [nvme_rdma]
[ 440.937126] [<
ffffffffb70ab58a>] process_one_work+0x17a/0x440
[ 440.944517] [<
ffffffffb70ac3a8>] worker_thread+0x278/0x3c0
[ 440.951607] [<
ffffffffb70ac130>] ? manage_workers.isra.24+0x2a0/0x2a0
[ 440.959760] [<
ffffffffb70b352f>] kthread+0xcf/0xe0
[ 440.966055] [<
ffffffffb70b3460>] ? insert_kthread_work+0x40/0x40
[ 440.973715] [<
ffffffffb76d8658>] ret_from_fork+0x58/0x90
[ 440.980586] [<
ffffffffb70b3460>] ? insert_kthread_work+0x40/0x40
[ 440.988229] Code: 5b 41 5c 5d c3 66 90 0f 1f 44 00 00 48 8b 87 20 01 00 00 f0 0f ba 77 40 01 19 d2 85 d2 75 08 c3 0f 1f 80 00 00 00 00 55 48 89 e5 <f0> ff 48 08 48 8d 78 10 e8 7f 0f 05 00 5d c3 0f 1f 00 66 2e 0f
[ 441.011620] RIP [<
ffffffffb730e2b4>] __blk_mq_tag_idle+0x24/0x40
[ 441.019301] RSP <
ffff893bf9bcbd10>
[ 441.024052] CR2:
0000000000000008
Reported-by: Zhang Yi <yizhan@redhat.com>
Tested-by: Zhang Yi <yizhan@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Michael Lyle [Mon, 8 Jan 2018 20:21:30 +0000 (12:21 -0800)]
bcache: fix writeback target calc on large devices
Bcache needs to scale the dirty data in the cache over the multiple
backing disks in order to calculate writeback rates for each.
The previous code did this by multiplying the target number of dirty
sectors by the backing device size, and expected it to fit into a
uint64_t; this blows up on relatively small backing devices.
The new approach figures out the bdev's share in 16384ths of the overall
cached data. This is chosen to cope well when bdevs drastically vary in
size and to ensure that bcache can cross the petabyte boundary for each
backing device.
This has been improved based on Tang Junhui's feedback to ensure that
every device gets a share of dirty data, no matter how small it is
compared to the total backing pool.
The existing mechanism is very limited; this is purely a bug fix to
remove limits on volume size. However, there still needs to be change
to make this "fair" over many volumes where some are idle.
Reported-by: Jack Douglas <jack@douglastechnology.co.uk>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Coly Li [Mon, 8 Jan 2018 20:21:29 +0000 (12:21 -0800)]
bcache: fix misleading error message in bch_count_io_errors()
Bcache only does recoverable I/O for read operations by calling
cached_dev_read_error(). For write opertions there is no I/O recovery for
failed requests.
But in bch_count_io_errors() no matter read or write I/Os, before errors
counter reaches io error limit, pr_err() always prints "IO error on %,
recoverying". For write requests this information is misleading, because
there is no I/O recovery at all.
This patch adds a parameter 'is_read' to bch_count_io_errors(), and only
prints "recovering" by pr_err() when the bio direction is READ.
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Coly Li [Mon, 8 Jan 2018 20:21:28 +0000 (12:21 -0800)]
bcache: reduce cache_set devices iteration by devices_max_used
Member devices of struct cache_set is used to reference all attached
bcache devices to this cache set. If it is treated as array of pointers,
size of devices[] is indicated by member nr_uuids of struct cache_set.
nr_uuids is calculated in drivers/md/super.c:bch_cache_set_alloc(),
bucket_bytes(c) / sizeof(struct uuid_entry)
Bucket size is determined by user space tool "make-bcache", by default it
is 1024 sectors (defined in bcache-tools/make-bcache.c:main()). So default
nr_uuids value is 4096 from the above calculation.
Every time when bcache code iterates bcache devices of a cache set, all
the 4096 pointers are checked even only 1 bcache device is attached to the
cache set, that's a wast of time and unncessary.
This patch adds a member devices_max_used to struct cache_set. Its value
is 1 + the maximum used index of devices[] in a cache set. When iterating
all valid bcache devices of a cache set, use c->devices_max_used in
for-loop may reduce a lot of useless checking.
Personally, my motivation of this patch is not for performance, I use it
in bcache debugging, which helps me to narrow down the scape to check
valid bcached devices of a cache set.
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Zhai Zhaoxuan [Mon, 8 Jan 2018 20:21:27 +0000 (12:21 -0800)]
bcache: fix unmatched generic_end_io_acct() & generic_start_io_acct()
The function cached_dev_make_request() and flash_dev_make_request() call
generic_start_io_acct() with (struct bcache_device)->disk when they start a
closure. Then the function bio_complete() calls generic_end_io_acct() with
(struct search)->orig_bio->bi_disk when the closure has done.
Since the `bi_disk` is not the bcache device, the generic_end_io_acct() is
called with a wrong device queue.
It causes the "inflight" (in struct hd_struct) counter keep increasing
without decreasing.
This patch fix the problem by calling generic_end_io_acct() with
(struct bcache_device)->disk.
Signed-off-by: Zhai Zhaoxuan <kxuanobj@gmail.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Coly Li <colyli@suse.de>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Kent Overstreet [Mon, 8 Jan 2018 20:21:26 +0000 (12:21 -0800)]
bcache: mark closure_sync() __sched
[edit by mlyle: include sched/debug.h to get __sched]
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Kent Overstreet [Mon, 8 Jan 2018 20:21:25 +0000 (12:21 -0800)]
bcache: Fix, improve efficiency of closure_sync()
Eliminates cases where sync can race and fail to complete / get stuck.
Removes many status flags and simplifies entering-and-exiting closure
sleeping behaviors.
[mlyle: fixed conflicts due to changed return behavior in mainline.
extended commit comment, and squashed down two commits that were mostly
contradictory to get to this state. Changed __set_current_state to
set_current_state per Jens review comment]
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Michael Lyle [Mon, 8 Jan 2018 20:21:24 +0000 (12:21 -0800)]
bcache: allow quick writeback when backing idle
If the control system would wait for at least half a second, and there's
been no reqs hitting the backing disk for awhile: use an alternate mode
where we have at most one contiguous set of writebacks in flight at a
time. (But don't otherwise delay). If front-end IO appears, it will
still be quick, as it will only have to contend with one real operation
in flight. But otherwise, we'll be sending data to the backing disk as
quickly as it can accept it (with one op at a time).
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Michael Lyle [Mon, 8 Jan 2018 20:21:23 +0000 (12:21 -0800)]
bcache: writeback: properly order backing device IO
Writeback keys are presently iterated and dispatched for writeback in
order of the logical block address on the backing device. Multiple may
be, in parallel, read from the cache device and then written back
(especially when there are contiguous I/O).
However-- there was no guarantee with the existing code that the writes
would be issued in LBA order, as the reads from the cache device are
often re-ordered. In turn, when writing back quickly, the backing disk
often has to seek backwards-- this slows writeback and increases
utilization.
This patch introduces an ordering mechanism that guarantees that the
original order of issue is maintained for the write portion of the I/O.
Performance for writeback is significantly improved when there are
multiple contiguous keys or high writeback rates.
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Reviewed-by: Tang Junhui <tang.junhui@zte.com.cn>
Tested-by: Tang Junhui <tang.junhui@zte.com.cn>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tang Junhui [Mon, 8 Jan 2018 20:21:22 +0000 (12:21 -0800)]
bcache: fix wrong return value in bch_debug_init()
in bch_debug_init(), ret is always 0, and the return value is useless,
change it to return 0 if be success after calling debugfs_create_dir(),
else return a non-zero value.
Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tang Junhui [Mon, 8 Jan 2018 20:21:21 +0000 (12:21 -0800)]
bcache: segregate flash only volume write streams
In such scenario that there are some flash only volumes
, and some cached devices, when many tasks request these devices in
writeback mode, the write IOs may fall to the same bucket as bellow:
| cached data | flash data | cached data | cached data| flash data|
then after writeback of these cached devices, the bucket would
be like bellow bucket:
| free | flash data | free | free | flash data |
So, there are many free space in this bucket, but since data of flash
only volumes still exists, so this bucket cannot be reclaimable,
which would cause waste of bucket space.
In this patch, we segregate flash only volume write streams from
cached devices, so data from flash only volumes and cached devices
can store in different buckets.
Compare to v1 patch, this patch do not add a additionally open bucket
list, and it is try best to segregate flash only volume write streams
from cached devices, sectors of flash only volumes may still be mixed
with dirty sectors of cached device, but the number is very small.
[mlyle: fixed commit log formatting, permissions, line endings]
Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Vasyl Gomonovych [Mon, 8 Jan 2018 20:21:20 +0000 (12:21 -0800)]
bcache: Use PTR_ERR_OR_ZERO()
Fix ptr_ret.cocci warnings:
drivers/md/bcache/btree.c:1800:1-3: WARNING: PTR_ERR_OR_ZERO can be used
Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR
Generated by: scripts/coccinelle/api/ptr_ret.cocci
Signed-off-by: Vasyl Gomonovych <gomonovych@gmail.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tang Junhui [Mon, 8 Jan 2018 20:21:19 +0000 (12:21 -0800)]
bcache: stop writeback thread after detaching
Currently, when a cached device detaching from cache, writeback thread is
not stopped, and writeback_rate_update work is not canceled. For example,
after the following command:
echo 1 >/sys/block/sdb/bcache/detach
you can still see the writeback thread. Then you attach the device to the
cache again, bcache will create another writeback thread, for example,
after below command:
echo
ba0fb5cd-658a-4533-9806-
6ce166d883b9 > /sys/block/sdb/bcache/attach
then you will see 2 writeback threads.
This patch stops writeback thread and cancels writeback_rate_update work
when cached device detaching from cache.
Compare with patch v1, this v2 patch moves code down into the register
lock for safety in case of any future changes as Coly and Mike suggested.
[edit by mlyle: commit log spelling/formatting]
Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Rui Hua [Mon, 8 Jan 2018 20:21:18 +0000 (12:21 -0800)]
bcache: ret IOERR when read meets metadata error
The read request might meet error when searching the btree, but the error
was not handled in cache_lookup(), and this kind of metadata failure will
not go into cached_dev_read_error(), finally, the upper layer will receive
bi_status=0. In this patch we judge the metadata error by the return
value of bch_btree_map_keys(), there are two potential paths give rise to
the error:
1. Because the btree is not totally cached in memery, we maybe get error
when read btree node from cache device (see bch_btree_node_get()), the
likely errno is -EIO, -ENOMEM
2. When read miss happens, bch_btree_insert_check_key() will be called to
insert a "replace_key" to btree(see cached_dev_cache_miss(), just for
doing preparatory work before insert the missed data to cache device),
a failure can also happen in this situation, the likely errno is
-ENOMEM
bch_btree_map_keys() will return MAP_DONE in normal scenario, but we will
get either -EIO or -ENOMEM in above two cases. if this happened, we should
NOT recover data from backing device (when cache device is dirty) because
we don't know whether bkeys the read request covered are all clean. And
after that happened, s->iop.status is still its initially value(0) before
we submit s->bio.bio, we set it to BLK_STS_IOERR, so it can go into
cached_dev_read_error(), and finally it can be passed to upper layer, or
recovered by reread from backing device.
[edit by mlyle: patch formatting, word-wrap, comment spelling,
commit log format]
Signed-off-by: Hua Rui <huarui.dev@gmail.com>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Mon, 8 Jan 2018 19:19:41 +0000 (12:19 -0700)]
Merge branch 'nvme-4.16' of git://git.infradead.org/nvme into for-4.16/block
Pull NVMe fixes from Christoph:
"Below are the pending nvme updates for Linux 4.16. Just fixes and
cleanups from various contributors this time around."
Israel Rukshin [Thu, 4 Jan 2018 15:56:14 +0000 (17:56 +0200)]
nvme: fix subsystem multiple controllers support check
There is a problem when another module (e.g. nvmet) takes a reference on
the nvme block device and the physical nvme drive is removed. In that
case nvme_free_ctrl() will not be called and the controller state will be
"deleting" or "dead" unless nvmet module releases the block device.
Later on, the same nvme drive probes back and nvme_init_subsystem() will
be called and fail due to duplicate subnqn (if the nvme device doesn't
support subsystem with multiple controllers). This will cause a probe
failure. This commit changes the check of multiple controllers support
at nvme_init_subsystem() by not counting all the controllers at "dead" or
"deleting" state (this is safe because controllers at this state will
never be active again).
Fixes: ab9e00cc72fa ("nvme: track subsystems")
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Nitzan Carmi [Thu, 4 Jan 2018 15:56:13 +0000 (17:56 +0200)]
nvme: take refcount on transport module
The block device is backed by the transport so we must ensure that the
transport driver will not be removed until all references are released.
Otherwise, we might end up referencing freed memory.
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Nitzan Carmi <nitzanc@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Jianchao Wang [Sat, 6 Jan 2018 00:01:58 +0000 (08:01 +0800)]
nvme-pci: fix NULL pointer reference in nvme_alloc_ns
When the io queues setup or tagset allocation failed, ctrl.tagset is
NULL. But the scan work will still be queued and executed, then panic
comes up due to NULL pointer reference of ctrl.tagset.
To fix this, add a new ctrl state NVME_CTRL_ADMIN_ONLY to inidcate only
admin queue is live. When non io queues or tagset allocation failed, ctrl
enters into this state, scan work will not be started. But async event
work and nvme dev ioctl will be still available. This will be helpful to
do further investigation and recovery.
Suggested-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Max Gurtovoy [Sun, 31 Dec 2017 13:33:27 +0000 (15:33 +0200)]
nvme: modify the debug level for setting shutdown timeout
When an NVMe controller reports RTD3 Entry Latency larger than the value
of shutdown_timeout module parameter, we update the shutdown_timeout
accordingly to honor RTD3 Entry Latency. Use an informational debug level
instead of a warning level for it.
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Sagi Grimberg [Sun, 31 Dec 2017 12:01:19 +0000 (14:01 +0200)]
nvme-pci: don't open-code nvme_reset_ctrl
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Israel Rukshin [Mon, 13 Nov 2017 12:29:41 +0000 (12:29 +0000)]
nvmet: rearrange nvmet_ctrl_free()
Make it symmetric to nvmet_alloc_ctrl().
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Israel Rukshin [Mon, 13 Nov 2017 12:29:40 +0000 (12:29 +0000)]
nvmet: fix error flow in nvmet_alloc_ctrl()
Remove the allocated id on error.
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Minwoo Im [Mon, 4 Dec 2017 20:23:54 +0000 (05:23 +0900)]
nvme-pci: remove an unnecessary initialization in HMB code
The local variable __size__ will be set a bit later in a for-loop.
Remove the explicit initialization at the beginning of this function.
Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Roy Shterman [Mon, 25 Dec 2017 12:18:30 +0000 (14:18 +0200)]
nvme-fabrics: protect against module unload during create_ctrl
NVMe transport driver module unload may (and usually does) trigger
iteration over the active controllers and delete them all (sometimes
under a mutex). However, a controller can be created concurrently with
module unload which can lead to leakage of resources (most important char
device node leakage) in case the controller creation occured after the
unload delete and drain sequence. To protect against this, we take a
module reference to guarantee that the nvme transport driver is not
unloaded while creating a controller.
Signed-off-by: Roy Shterman <roys@lightbitslabs.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
James Smart [Wed, 29 Nov 2017 23:11:55 +0000 (15:11 -0800)]
nvmet-fc: cleanup nvmet add_port/remove_port
The current fc transport add_port routine validates that there is a
matching port to the target port config. It then takes a reference
on the targetport. The del_port removes the reference.
Unfortunately, if the LLDD undergoes a hw reset or driver unload and
wants to unreg the targetport, due to the reference, the targetport
effectively can't be removed. It requires the admin to remove the
port from the nvmet config first, which calls the del_port.
Note: it appears nvmetcli clear skips over the del_port call (I'm
not attempting to change that).
There's no real reason to take the reference. With FC, there is nothing
to enable or disable as the presence of the FC targetport implicitly
means its enabled, and removal of the targtport means its disabled.
Change add_port to simply validate and change remove_port to a noop.
No references are taken on the targetport.
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
James Smart [Thu, 30 Nov 2017 00:47:33 +0000 (16:47 -0800)]
nvme_fcloop: refactor host/target io job access
The split between what the host accesses on its flows vs what the
target side accesses was flawed. Abort handling didn't properly
clear initiator vs target structure cross-reference and locks
weren't used for synchronization. Thus, there were issues of
freeing structures too soon and access after free.
A couple of these existed pre the IN_ISR mods, but when the
target upcalls were converted to work items, thus adding delays
between the 2 sides of accesses, the problems became pronounced.
Resolve by:
- tracking io state mainly in the tgt-side io structure.
- make the tgt-side io structure released by reference not by
code flow.
- when changing initiator structures, use locks for
synchronization
- aborts are clearly tracked for which side saw the abort, and
after seeing the abort, cross-references are cleared under lock.
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
James Smart [Thu, 30 Nov 2017 00:47:32 +0000 (16:47 -0800)]
nvme_fcloop: rework to remove xxx_IN_ISR feature flags
The existing fcloop driver expects the target side upcalls to
the transport to context switch, thus the calls into the nvmet layer
are not done in the calling context of the host/initiator down calls.
The xxx_IN_ISR feature flags are used to select this logic.
The xxx_IN_ISR feature flags should go away in the nvmet_fc transport
as no other lldd utilizes them. Both Broadcom and Cavium lldds have their
own non-ISR deferred handlers thus the nvmet calls can be made directly.
This patch converts the paths that make the target upcalls (command
receive, abort receive) such that they schedule a work item rather
than expecting the transport to schedule the work item.
The patch also cleans up the following:
- The completion path from target to host scheduled a host work
element called "work". Rename it "tio_done_work" for code clarity.
- The abort io path called a iniwork item to call the host side
io done. This is no longer needed as the abort routine can make
the same call.
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
James Smart [Thu, 30 Nov 2017 00:47:31 +0000 (16:47 -0800)]
nvme_fcloop: disassocate local port structs
The current fcloop driver gets its lport structure from the private
area co-allocated with the fc_localport. All is fine except the
teardown path, which wants to wait on the completion, which is marked
complete by the delete_localport callback performed after
unregister_localport. The issue is, the nvme_fc transport frees the
localport structure immediately after delete_localport is called,
meaning the original routine is trying to wait on a complete that
was just freed.
Change such that a lport struct is allocated coincident with the
addition and registration of a localport. The private area of the
localport now contains just a backpointer to the real lport struct.
Now, the completion can be waited for, and after completing, the
new structure can be kfree'd.
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
James Smart [Thu, 30 Nov 2017 00:47:30 +0000 (16:47 -0800)]
nvme_fcloop: fix abort race condition
A test case revealed a race condition of an i/o completing on a thread
parallel to the delete_association generating the aborts for the
outstanding ios on the controller. The i/o completion was freeing the
target fcloop context, thus the abort task referenced the just-freed
memory.
Correct by clearing the target/initiator cross pointers in the io
completion and abort tasks before calling the callbacks. On aborts
that detect already finished io's, ensure the complete context is
called.
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Sagi Grimberg [Mon, 4 Dec 2017 08:47:09 +0000 (10:47 +0200)]
nvmet: lower log level for each queue creation
It is a bit chatty to report on each queue, log it only for debug
purposes.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Sagi Grimberg [Mon, 4 Dec 2017 08:47:10 +0000 (10:47 +0200)]
nvmet-rdma: lowering log level for chatty debug messages
It is a bit chatty to report on every deleted queue, so keep it for debug
purposes only.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Sagi Grimberg [Mon, 13 Nov 2017 21:29:05 +0000 (23:29 +0200)]
nvmet-rdma: removed queue cleanup from module exit
We already do that when we are notified in device removal
which is triggered when unregistering as an ib client.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Ming Lei [Sat, 6 Jan 2018 08:27:40 +0000 (16:27 +0800)]
blk-mq: fix race between updating nr_hw_queues and switching io sched
In both elevator_switch_mq() and blk_mq_update_nr_hw_queues(), sched tags
can be allocated, and q->nr_hw_queue is used, and race is inevitable, for
example: blk_mq_init_sched() may trigger use-after-free on hctx, which is
freed in blk_mq_realloc_hw_ctxs() when nr_hw_queues is decreased.
This patch fixes the race be holding q->sysfs_lock.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Sat, 6 Jan 2018 08:27:39 +0000 (16:27 +0800)]
blk-mq: avoid to map CPU into stale hw queue
blk_mq_pci_map_queues() may not map one CPU into any hw queue, but its
previous map isn't cleared yet, and may point to one stale hw queue
index.
This patch fixes the following issue by clearing the mapping table before
setting it up in blk_mq_pci_map_queues().
This patches fixes this following issue reported by Zhang Yi:
[ 101.202734] BUG: unable to handle kernel NULL pointer dereference at
0000000094d3013f
[ 101.211487] IP: blk_mq_map_swqueue+0xbc/0x200
[ 101.216346] PGD 0 P4D 0
[ 101.219171] Oops: 0000 [#1] SMP
[ 101.222674] Modules linked in: sunrpc ipmi_ssif vfat fat intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel intel_cstate intel_uncore mxm_wmi intel_rapl_perf iTCO_wdt ipmi_si ipmi_devintf pcspkr iTCO_vendor_support sg dcdbas ipmi_msghandler wmi mei_me lpc_ich shpchp mei acpi_power_meter dm_multipath ip_tables xfs libcrc32c sd_mod mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm ahci libahci crc32c_intel libata tg3 nvme nvme_core megaraid_sas ptp i2c_core pps_core dm_mirror dm_region_hash dm_log dm_mod
[ 101.284881] CPU: 0 PID: 504 Comm: kworker/u25:5 Not tainted 4.15.0-rc2 #1
[ 101.292455] Hardware name: Dell Inc. PowerEdge R730xd/072T6D, BIOS 2.5.5 08/16/2017
[ 101.301001] Workqueue: nvme-wq nvme_reset_work [nvme]
[ 101.306636] task:
00000000f2c53190 task.stack:
000000002da874f9
[ 101.313241] RIP: 0010:blk_mq_map_swqueue+0xbc/0x200
[ 101.318681] RSP: 0018:
ffffc9000234fd70 EFLAGS:
00010282
[ 101.324511] RAX:
ffff88047ffc9480 RBX:
ffff88047e130850 RCX:
0000000000000000
[ 101.332471] RDX:
ffffe8ffffd40580 RSI:
ffff88047e509b40 RDI:
ffff88046f37a008
[ 101.340432] RBP:
000000000000000b R08:
ffff88046f37a008 R09:
0000000011f94280
[ 101.348392] R10:
ffff88047ffd4d00 R11:
0000000000000000 R12:
ffff88046f37a008
[ 101.356353] R13:
ffff88047e130f38 R14:
000000000000000b R15:
ffff88046f37a558
[ 101.364314] FS:
0000000000000000(0000) GS:
ffff880277c00000(0000) knlGS:
0000000000000000
[ 101.373342] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[ 101.379753] CR2:
0000000000000098 CR3:
000000047f409004 CR4:
00000000001606f0
[ 101.387714] Call Trace:
[ 101.390445] blk_mq_update_nr_hw_queues+0xbf/0x130
[ 101.395791] nvme_reset_work+0x6f4/0xc06 [nvme]
[ 101.400848] ? pick_next_task_fair+0x290/0x5f0
[ 101.405807] ? __switch_to+0x1f5/0x430
[ 101.409988] ? put_prev_entity+0x2f/0xd0
[ 101.414365] process_one_work+0x141/0x340
[ 101.418836] worker_thread+0x47/0x3e0
[ 101.422921] kthread+0xf5/0x130
[ 101.426424] ? rescuer_thread+0x380/0x380
[ 101.430896] ? kthread_associate_blkcg+0x90/0x90
[ 101.436048] ret_from_fork+0x1f/0x30
[ 101.440034] Code: 48 83 3c ca 00 0f 84 2b 01 00 00 48 63 cd 48 8b 93 10 01 00 00 8b 0c 88 48 8b 83 20 01 00 00 4a 03 14 f5 60 04 af 81 48 8b 0c c8 <48> 8b 81 98 00 00 00 f0 4c 0f ab 30 8b 81 f8 00 00 00 89 42 44
[ 101.461116] RIP: blk_mq_map_swqueue+0xbc/0x200 RSP:
ffffc9000234fd70
[ 101.468205] CR2:
0000000000000098
[ 101.471907] ---[ end trace
5fe710f98228a3ca ]---
[ 101.482489] Kernel panic - not syncing: Fatal exception
[ 101.488505] Kernel Offset: disabled
[ 101.497752] ---[ end Kernel panic - not syncing: Fatal exception
Reviewed-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Christoph Hellwig <hch@lst.de>
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Sat, 6 Jan 2018 08:27:38 +0000 (16:27 +0800)]
blk-mq: quiesce queue during switching io sched and updating nr_requests
Dispatch may still be in-progress after queue is frozen, so we have to
quiesce queue before switching IO scheduler and updating nr_requests.
Also when switching io schedulers, blk_mq_run_hw_queue() may still be
called somewhere(such as from nvme_reset_work()), and io scheduler's
per-hctx data may not be setup yet, so cause oops even inside
blk_mq_hctx_has_pending(), such as it can be run just between:
ret = e->ops.mq.init_sched(q, e);
AND
ret = e->ops.mq.init_hctx(hctx, i)
inside blk_mq_init_sched().
This reverts commit
7a148c2fcff8330(block: don't call blk_mq_quiesce_queue()
after queue is frozen) basically, and makes sure blk_mq_hctx_has_pending
won't be called if queue is quiesced.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Fixes: 7a148c2fcff83309(block: don't call blk_mq_quiesce_queue() after queue is frozen)
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Sat, 6 Jan 2018 08:27:37 +0000 (16:27 +0800)]
blk-mq: quiesce queue before freeing queue
After queue is frozen, dispatch still may happen, for example:
1) requests are submitted from several contexts
2) requests from all these contexts are inserted to queue, but may dispatch
to LLD in one of these paths, but other paths sill need to move on even all
these requests are completed(that means blk_mq_freeze_queue_wait() returns
at that time)
3) dispatch after queue freezing still moves on and causes use-after-free,
because request queue is freed
This patch quiesces queue after it is frozen, and makes sure all
in-progress dispatch are completed.
This patch fixes the following kernel crash when running heavy IOs vs.
deleting device:
[ 36.719251] BUG: unable to handle kernel NULL pointer dereference at
0000000000000008
[ 36.720318] IP: kyber_has_work+0x14/0x40
[ 36.720847] PGD
254bf5067 P4D
254bf5067 PUD
255e6a067 PMD 0
[ 36.721584] Oops: 0000 [#1] PREEMPT SMP
[ 36.722105] Dumping ftrace buffer:
[ 36.722570] (ftrace buffer empty)
[ 36.723057] Modules linked in: scsi_debug ebtable_filter ebtables ip6table_filter ip6_tables tcm_loop iscsi_target_mod target_core_file target_core_iblock target_core_pscsi target_core_mod xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack libcrc32c bridge stp llc fuse iptable_filter ip_tables sd_mod sg btrfs xor zstd_decompress zstd_compress xxhash raid6_pq mptsas mptscsih bcache crc32c_intel ahci mptbase libahci serio_raw scsi_transport_sas nvme libata shpchp lpc_ich virtio_scsi nvme_core binfmt_misc dm_mod iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi null_blk configs
[ 36.733438] CPU: 2 PID: 2374 Comm: fio Not tainted 4.15.0-rc2.blk_mq_quiesce+ #714
[ 36.735143] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.9.3-1.fc25 04/01/2014
[ 36.736688] RIP: 0010:kyber_has_work+0x14/0x40
[ 36.737515] RSP: 0018:
ffffc9000209bca0 EFLAGS:
00010202
[ 36.738431] RAX:
0000000000000008 RBX:
ffff88025578bfc8 RCX:
ffff880257bf4ed0
[ 36.739581] RDX:
0000000000000038 RSI:
ffffffff81a98c6d RDI:
ffff88025578bfc8
[ 36.740730] RBP:
ffff880253cebfc8 R08:
ffffc9000209bda0 R09:
ffff8802554f3480
[ 36.741885] R10:
ffffc9000209be60 R11:
ffff880263f72538 R12:
ffff88025573e9e8
[ 36.743036] R13:
ffff88025578bfd0 R14:
0000000000000001 R15:
0000000000000000
[ 36.744189] FS:
00007f9b9bee67c0(0000) GS:
ffff88027fc80000(0000) knlGS:
0000000000000000
[ 36.746617] CS: 0010 DS: 0000 ES: 0000 CR0:
0000000080050033
[ 36.748483] CR2:
0000000000000008 CR3:
0000000254bf4001 CR4:
00000000003606e0
[ 36.750164] DR0:
0000000000000000 DR1:
0000000000000000 DR2:
0000000000000000
[ 36.751455] DR3:
0000000000000000 DR6:
00000000fffe0ff0 DR7:
0000000000000400
[ 36.752796] Call Trace:
[ 36.753992] blk_mq_do_dispatch_sched+0x7f/0xe0
[ 36.755110] blk_mq_sched_dispatch_requests+0x119/0x190
[ 36.756179] __blk_mq_run_hw_queue+0x83/0x90
[ 36.757144] __blk_mq_delay_run_hw_queue+0xaf/0x110
[ 36.758046] blk_mq_run_hw_queue+0x24/0x70
[ 36.758845] blk_mq_flush_plug_list+0x1e7/0x270
[ 36.759676] blk_flush_plug_list+0xd6/0x240
[ 36.760463] blk_finish_plug+0x27/0x40
[ 36.761195] do_io_submit+0x19b/0x780
[ 36.761921] ? entry_SYSCALL_64_fastpath+0x1a/0x7d
[ 36.762788] entry_SYSCALL_64_fastpath+0x1a/0x7d
[ 36.763639] RIP: 0033:0x7f9b9699f697
[ 36.764352] RSP: 002b:
00007ffc10f991b8 EFLAGS:
00000206 ORIG_RAX:
00000000000000d1
[ 36.765773] RAX:
ffffffffffffffda RBX:
00000000008f6f00 RCX:
00007f9b9699f697
[ 36.766965] RDX:
0000000000a5e6c0 RSI:
0000000000000001 RDI:
00007f9b8462a000
[ 36.768377] RBP:
0000000000000000 R08:
0000000000000001 R09:
00000000008f6420
[ 36.769649] R10:
00007f9b846e5000 R11:
0000000000000206 R12:
00007f9b795d6a70
[ 36.770807] R13:
00007f9b795e4140 R14:
00007f9b795e3fe0 R15:
0000000100000000
[ 36.771955] Code: 83 c7 10 e9 3f 68 d1 ff 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 8b 97 b0 00 00 00 48 8d 42 08 48 83 c2 38 <48> 3b 00 74 06 b8 01 00 00 00 c3 48 3b 40 08 75 f4 48 83 c0 10
[ 36.775004] RIP: kyber_has_work+0x14/0x40 RSP:
ffffc9000209bca0
[ 36.776012] CR2:
0000000000000008
[ 36.776690] ---[ end trace
4045cbce364ff2a4 ]---
[ 36.777527] Kernel panic - not syncing: Fatal exception
[ 36.778526] Dumping ftrace buffer:
[ 36.779313] (ftrace buffer empty)
[ 36.780081] Kernel Offset: disabled
[ 36.780877] ---[ end Kernel panic - not syncing: Fatal exception
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jens Axboe [Sat, 6 Jan 2018 16:23:11 +0000 (09:23 -0700)]
mq-deadline: make it clear that __dd_dispatch_request() works on all hw queues
Don't pass in the hardware queue to __dd_dispatch_request(), since it
leads the reader to believe that we are returning a request for that
specific hardware queue. That's not how mq-deadline works, the state
for determining which request to serve next is shared across all
hardware queues for a device.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Fri, 5 Jan 2018 16:26:50 +0000 (08:26 -0800)]
target: Use sgl_alloc_order() and sgl_free()
Use the sgl_alloc_order() and sgl_free() functions instead of open
coding these functions.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Fri, 5 Jan 2018 16:26:49 +0000 (08:26 -0800)]
nvmet/rdma: Use sgl_alloc() and sgl_free()
Use the sgl_alloc() and sgl_free() functions instead of open coding
these functions.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Fri, 5 Jan 2018 16:26:48 +0000 (08:26 -0800)]
nvmet/fc: Use sgl_alloc() and sgl_free()
Use the sgl_alloc() and sgl_free() functions instead of open coding
these functions.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Fri, 5 Jan 2018 16:26:47 +0000 (08:26 -0800)]
crypto: scompress - use sgl_alloc() and sgl_free()
Use the sgl_alloc() and sgl_free() functions instead of open coding
these functions.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Bart Van Assche [Fri, 5 Jan 2018 16:26:46 +0000 (08:26 -0800)]
lib/scatterlist: Introduce sgl_alloc() and sgl_free()
Many kernel drivers contain code that allocates and frees both a
scatterlist and the pages that populate that scatterlist.
Introduce functions in lib/scatterlist.c that perform these tasks
instead of duplicating this functionality in multiple drivers.
Only include these functions in the build if CONFIG_SGL_ALLOC=y
to avoid that the kernel size increases if this functionality is
not used.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Wang Long [Tue, 5 Dec 2017 12:23:19 +0000 (07:23 -0500)]
writeback: update comment in inode_io_list_move_locked
The @head can be wb->b_dirty_time, so update the comment.
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Wang Long <wanglong19@meituan.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Arnd Bergmann [Mon, 11 Dec 2017 12:11:17 +0000 (13:11 +0100)]
DAC960: split up ioctl function to reduce stack size
When CONFIG_KASAN is set, all the local variables in this function are
allocated on the stack together, leading to a warning about possible
kernel stack overflow:
drivers/block/DAC960.c: In function 'DAC960_gam_ioctl':
drivers/block/DAC960.c:7061:1: error: the frame size of 2240 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
By splitting up the function into smaller chunks, we can avoid that and
make the code slightly more readable at the same time. The coding style
in this file is completely nonstandard, and I chose to not touch that
at all, leaving the unconventional intendation unchanged to make it
easier to review the diff.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Mon, 18 Dec 2017 12:22:16 +0000 (20:22 +0800)]
block: blk-merge: remove unnecessary check
In this case, 'sectors' can't be zero at all, so remove the check
and let the bio be split.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
projects / openwrt / staging / blogic.git / log