blkcg-qos is going to do essentially what wbt does, only on a cgroup
basis. Break out the common code that will be shared between blkcg-qos
and wbt into blk-rq-qos.* so they can both utilize the same
infrastructure.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We need to use blk_rq_stat in the blkcg qos stuff, so export some of
these helpers so they can be used by other things.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since IO can be issued from literally anywhere it's almost impossible to
do throttling without having some sort of adverse effect somewhere else
in the system because of locking or other dependencies. The best way to
solve this is to do the throttling when we know we aren't holding any
other kernel resources. Do this by tracking throttling in a per-blkg
basis, and if we require throttling flag the task that it needs to check
before it returns to user space and possibly sleep there.
This is to address the case where a process is doing work that is
generating IO that can't be throttled, whether that is directly with a
lot of REQ_META IO, or indirectly by allocating so much memory that it
is swamping the disk with REQ_SWAP. We can't use task_add_work as we
don't want to induce a memory allocation in the IO path, so simply
saving the request queue in the task and flagging it to do the
notify_resume thing achieves the same result without the overhead of a
memory allocation.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For backcharging we need to know who the page belongs to when swapping
it out. We don't worry about things that do ->rw_page (zram etc) at the
moment, we're only worried about pages that actually go to a block
device.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk-iolatency has a few stats that it would like to print out, and
instead of adding a bunch of crap to the generic code just provide a
helper so that controllers can add stuff to the stat line if they want
to.
Hide it behind a boot option since it changes the output of io.stat from
normal, and these stats are only interesting to developers.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently io.low uses a bi_cg_private to stash its private data for the
blkg, however other blkcg policies may want to use this as well. Since
we can get the private data out of the blkg, move this to bi_blkg in the
bio and make it generic, then we can use bio_associate_blkg() to attach
the blkg to the bio.
Theoretically we could simply replace the bi_css with this since we can
get to all the same information from the blkg, however you have to
lookup the blkg, so for example wbc_init_bio() would have to lookup and
possibly allocate the blkg for the css it was trying to attach to the
bio. This could be problematic and result in us either not attaching
the css at all to the bio, or falling back to the root blkcg if we are
unable to allocate the corresponding blkg.
So for now do this, and in the future if possible we could just replace
the bi_css with bi_blkg and update the helpers to do the correct
translation.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It won't be efficient to dequeue request one by one from sw queue,
but we have to do that when queue is busy for better merge performance.
This patch takes the Exponential Weighted Moving Average(EWMA) to figure
out if queue is busy, then only dequeue request one by one from sw queue
when queue is busy.
Fixes: b347689ffb ("blk-mq-sched: improve dispatching from sw queue")
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Reported-by: Kashyap Desai <kashyap.desai@broadcom.com>
Tested-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Only attempt to merge bio iff the ctx->rq_list isn't empty, because:
1) for high-performance SSD, most of times dispatch may succeed, then
there may be nothing left in ctx->rq_list, so don't try to merge over
sw queue if it is empty, then we can save one acquiring of ctx->lock
2) we can't expect good merge performance on per-cpu sw queue, and missing
one merge on sw queue won't be a big deal since tasks can be scheduled from
one CPU to another.
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Tested-by: Kashyap Desai <kashyap.desai@broadcom.com>
Reported-by: Kashyap Desai <kashyap.desai@broadcom.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
list_splice_tail_init() is much more faster than inserting each
request one by one, given all requets in 'list' belong to
same sw queue and ctx->lock is required to insert requests.
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Tested-by: Kashyap Desai <kashyap.desai@broadcom.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fix typo in a function blk_mq_alloc_tag_set() comment.
if if it too large -> if it's too large.
Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
set->mq_map is now currently cleared if something goes wrong when
establishing a queue map in blk-mq-pci.c. It's also cleared before
updating a queue map in blk_mq_update_queue_map().
This patch provides an API to clear set->mq_map to make it clear.
Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pointer dgrp is being assigned but is never used hence it is redundant
and can be removed.
Cleans up clang warning:
warning: variable 'dgrp' set but not used [-Wunused-but-set-variable]
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Once one cgroup has io.low configured, @low_valid becomes true and other
cgroups won't switch it back whatsoever.
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The payload of struct request is stored in the request.bio chain if
the RQF_SPECIAL_PAYLOAD flag is not set and in request.special_vec if
RQF_SPECIAL_PAYLOAD has been set. However, blk_update_request()
iterates over req->bio whether or not RQF_SPECIAL_PAYLOAD has been
set. Additionally, the RQF_SPECIAL_PAYLOAD flag is ignored by
blk_rq_bytes() which means that the value returned by that function
is incorrect if the RQF_SPECIAL_PAYLOAD flag has been set. It is not
clear to me whether this is an oversight or whether this happened on
purpose. Anyway, document that it is known that both functions ignore
RQF_SPECIAL_PAYLOAD. See also commit f9d03f96b9 ("block: improve
handling of the magic discard payload").
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
SCSI probing may synchronously create and destroy a lot of request_queues
for non-existent devices. Any synchronize_rcu() in queue creation or
destroy path may introduce long latency during booting, see detailed
description in comment of blk_register_queue().
This patch removes one synchronize_rcu() inside blk_cleanup_queue()
for this case, commit c2856ae2f315d75(blk-mq: quiesce queue before freeing queue)
needs synchronize_rcu() for implementing blk_mq_quiesce_queue(), but
when queue isn't initialized, it isn't necessary to do that since
only pass-through requests are involved, no original issue in
scsi_execute() at all.
Without this patch and previous one, it may take more 20+ seconds for
virtio-scsi to complete disk probe. With the two patches, the time becomes
less than 100ms.
Fixes: c2856ae2f3 ("blk-mq: quiesce queue before freeing queue")
Reported-by: Andrew Jones <drjones@redhat.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: linux-scsi@vger.kernel.org
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Tested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We have to remove synchronize_rcu() from blk_queue_cleanup(),
otherwise long delay can be caused during lun probe. For removing
it, we have to avoid to iterate the set->tag_list in IO path, eg,
blk_mq_sched_restart().
This patch reverts 5b79413946d (Revert "blk-mq: don't handle
TAG_SHARED in restart"). Given we have fixed enough IO hang issue,
and there isn't any reason to restart all queues in one tags any more,
see the following reasons:
1) blk-mq core can deal with shared-tags case well via blk_mq_get_driver_tag(),
which can wake up queues waiting for driver tag.
2) SCSI is a bit special because it may return BLK_STS_RESOURCE if queue,
target or host is ready, but SCSI built-in restart can cover all these well,
see scsi_end_request(), queue will be rerun after any request initiated from
this host/target is completed.
In my test on scsi_debug(8 luns), this patch may improve IOPS by 20% ~ 30%
when running I/O on these 8 luns concurrently.
Fixes: 705cda97ee ("blk-mq: Make it safe to use RCU to iterate over blk_mq_tag_set.tag_list")
Cc: Omar Sandoval <osandov@fb.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Reported-by: Andrew Jones <drjones@redhat.com>
Tested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now hctx->lock is only acquired when adding hctx->dispatch_wait to
one wait queue, but not held when removing it from the wait queue.
IO hang can be observed easily if SCHED RESTART is disabled, that means
now RESTART exits just for fixing the issue in blk_mq_mark_tag_wait().
This patch fixes the issue by introducing hctx->dispatch_wait_lock and
holding it for removing hctx->dispatch_wait in blk_mq_dispatch_wake(),
since we need to avoid acquiring hctx->lock in irq context.
Fixes: eb619fdb2d ("blk-mq: fix issue with shared tag queue re-running")
Cc: Christoph Hellwig <hch@lst.de>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Tested-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
'hctx' won't be changed at all, so not necessary to pass
'**hctx' to blk_mq_mark_tag_wait().
Cc: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Tested-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We never pass 'wait' as true to blk_mq_get_driver_tag(), and hence
we never change '**hctx' as well. The last use of these went away
with the flush cleanup, commit 0c2a6fe4dc.
So cleanup the usage and remove the two extra parameters.
Cc: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Tested-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The actual goal of the function bfq_bfqq_may_idle is to tell whether
it is better to perform device idling (more precisely: I/O-dispatch
plugging) for the input bfq_queue, either to boost throughput or to
preserve service guarantees. This commit improves the name of the
function accordingly.
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If
- a bfq_queue Q preempts another queue, because one request of Q
arrives in time,
- but, after this preemption, Q is not the queue that is set in service,
then Q->entity.service is set to 0 when Q is eventually set in
service. But Q should have continued receiving service with its old
budget (which is why preemption has occurred) and its old service.
This commit addresses this issue by resetting service on queue real
expiration.
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For some bfq_queues, BFQ plugs I/O dispatching when the queue becomes
idle, and keeps the plug until a new request of the queue arrives, or
a timeout fires. BFQ does so either to boost throughput or to preserve
service guarantees for the queue.
More precisely, for such a queue, plugging starts when the queue
happens to have either no request enqueued, or no request in flight,
that is, no request already dispatched but not yet completed.
On the opposite end, BFQ may happen to expire a queue with no request
enqueued, without doing any plugging, if the queue still has some
request in flight. Unfortunately, such a premature expiration causes
the queue to lose its chance to enjoy dispatch plugging a moment
later, i.e., when its in-flight requests finally get completed. This
breaks service guarantees for the queue.
This commit prevents BFQ from expiring an empty queue if the latter
still has in-flight requests.
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
To keep I/O throughput high as often as possible, BFQ performs
I/O-dispatch plugging (aka device idling) only when beneficial exactly
for throughput, or when needed for service guarantees (low latency,
fairness). An important case where the latter condition holds is when
the scenario is 'asymmetric' in terms of weights: i.e., when some
bfq_queue or whole group of queues has a higher weight, and thus has
to receive more service, than other queues or groups. Without dispatch
plugging, lower-weight queues/groups may unjustly steal bandwidth to
higher-weight queues/groups.
To detect asymmetric scenarios, BFQ checks some sufficient
conditions. One of these conditions is that active groups have
different weights. BFQ controls this condition by maintaining a
special set of unique weights of active groups
(group_weights_tree). To this purpose, in the function
bfq_active_insert/bfq_active_extract BFQ adds/removes the weight of a
group to/from this set.
Unfortunately, the function bfq_active_extract may happen to be
invoked also for a group that is still active (to preserve the correct
update of the next queue to serve, see comments in function
bfq_no_longer_next_in_service() for details). In this case, removing
the weight of the group makes the set group_weights_tree
inconsistent. Service-guarantee violations follow.
This commit addresses this issue by moving group_weights_tree
insertions from their previous location (in bfq_active_insert) into
the function __bfq_activate_entity, and by moving group_weights_tree
extractions from bfq_active_extract to when the entity that represents
a group remains throughly idle, i.e., with no request either enqueued
or dispatched.
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Exclude zoned block device members from struct request_queue for
CONFIG_BLK_DEV_ZONED == n. Avoid breaking the build by only building
the code that uses these struct request_queue members if
CONFIG_BLK_DEV_ZONED != n.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Matias Bjorling <mb@lightnvm.io>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since the implementation of blk_queue_nr_zones() is trivial and since
it only has a single caller, inline this function.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Matias Bjorling <mb@lightnvm.io>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No cast is necessary when assigning a non-void pointer to a void
pointer.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Matias Bjorling <mb@lightnvm.io>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-linus-20180629' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"Small set of fixes for this series. Mostly just minor fixes, the only
oddball in here is the sg change.
The sg change came out of the stall fix for NVMe, where we added a
mempool and limited us to a single page allocation. CONFIG_SG_DEBUG
sort-of ruins that, since we'd need to account for that. That's
actually a generic problem, since lots of drivers need to allocate SG
lists. So this just removes support for CONFIG_SG_DEBUG, which I added
back in 2007 and to my knowledge it was never useful.
Anyway, outside of that, this pull contains:
- clone of request with special payload fix (Bart)
- drbd discard handling fix (Bart)
- SATA blk-mq stall fix (me)
- chunk size fix (Keith)
- double free nvme rdma fix (Sagi)"
* tag 'for-linus-20180629' of git://git.kernel.dk/linux-block:
sg: remove ->sg_magic member
drbd: Fix drbd_request_prepare() discard handling
blk-mq: don't queue more if we get a busy return
block: Fix cloning of requests with a special payload
nvme-rdma: fix possible double free of controller async event buffer
block: Fix transfer when chunk sectors exceeds max
Some devices have different queue limits depending on the type of IO. A
classic case is SATA NCQ, where some commands can queue, but others
cannot. If we have NCQ commands inflight and encounter a non-queueable
command, the driver returns busy. Currently we attempt to dispatch more
from the scheduler, if we were able to queue some commands. But for the
case where we ended up stopping due to BUSY, we should not attempt to
retrieve more from the scheduler. If we do, we can get into a situation
where we attempt to queue a non-queueable command, get BUSY, then
successfully retrieve more commands from that scheduler and queue those.
This can repeat forever, starving the non-queuable command indefinitely.
Fix this by NOT attempting to pull more commands from the scheduler, if
we get a BUSY return. This should also be more optimal in terms of
letting requests stay in the scheduler for as long as possible, if we
get a BUSY due to the regular out-of-tags condition.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This patch avoids that removing a path controlled by the dm-mpath driver
while mkfs is running triggers the following kernel bug:
kernel BUG at block/blk-core.c:3347!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 20 PID: 24369 Comm: mkfs.ext4 Not tainted 4.18.0-rc1-dbg+ #2
RIP: 0010:blk_end_request_all+0x68/0x70
Call Trace:
<IRQ>
dm_softirq_done+0x326/0x3d0 [dm_mod]
blk_done_softirq+0x19b/0x1e0
__do_softirq+0x128/0x60d
irq_exit+0x100/0x110
smp_call_function_single_interrupt+0x90/0x330
call_function_single_interrupt+0xf/0x20
</IRQ>
Fixes: f9d03f96b9 ("block: improve handling of the magic discard payload")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-linus-20180623' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
- Further timeout fixes. We aren't quite there yet, so expect another
round of fixes for that to completely close some of the IRQ vs
completion races. (Christoph/Bart)
- Set of NVMe fixes from the usual suspects, mostly error handling
- Two off-by-one fixes (Dan)
- Another bdi race fix (Jan)
- Fix nbd reconfigure with NBD_DISCONNECT_ON_CLOSE (Doron)
* tag 'for-linus-20180623' of git://git.kernel.dk/linux-block:
blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE
bdi: Fix another oops in wb_workfn()
lightnvm: Remove depends on HAS_DMA in case of platform dependency
nvme-pci: limit max IO size and segments to avoid high order allocations
nvme-pci: move nvme_kill_queues to nvme_remove_dead_ctrl
nvme-fc: release io queues to allow fast fail
nbd: Add the nbd NBD_DISCONNECT_ON_CLOSE config flag.
block: sed-opal: Fix a couple off by one bugs
blk-mq-debugfs: Off by one in blk_mq_rq_state_name()
nvmet: reset keep alive timer in controller enable
nvme-rdma: don't override opts->queue_size
nvme-rdma: Fix command completion race at error recovery
nvme-rdma: fix possible free of a non-allocated async event buffer
nvme-rdma: fix possible double free condition when failing to create a controller
Revert "block: Add warning for bi_next not NULL in bio_endio()"
block: fix timeout changes for legacy request drivers
Make sure that RQF_TIMED_OUT is cleared when a request is reused
after a block driver timeout handler has returned BLK_EH_DONE.
Fixes: da66126739 ("blk-mq: don't time out requests again that are in the timeout handler")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jianchao Wang <jianchao.w.wang@oracle.com>
Cc: Andrew Randrianasulu <randrianasulu@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
resp->num is the number of tokens in resp->tok[]. It gets set in
response_parse(). So if n == resp->num then we're reading beyond the
end of the data.
Fixes: 455a7b238c ("block: Add Sed-opal library")
Reviewed-by: Scott Bauer <scott.bauer@intel.com>
Tested-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If rq_state == ARRAY_SIZE() then we read one element beyond the end of
the blk_mq_rq_state_name_array[] array.
Fixes: ec6dcf63c5 ("blk-mq-debugfs: Show more request state information")
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 0ba99ca483 ("block: Add warning for bi_next not NULL in
bio_endio()") breaks the dm driver. end_clone_bio() detects whether
or not a bio is the last bio associated with a request by checking
the .bi_next field. Commit 0ba99ca483 clears that field before
end_clone_bio() has had a chance to inspect that field. Hence revert
commit 0ba99ca483.
This patch avoids that KASAN reports the following complaint when
running the srp-test software (srp-test/run_tests -c -d -r 10 -t 02-mq):
==================================================================
BUG: KASAN: use-after-free in bio_advance+0x11b/0x1d0
Read of size 4 at addr ffff8801300e06d0 by task ksoftirqd/0/9
CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 4.18.0-rc1-dbg+ #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
Call Trace:
dump_stack+0xa4/0xf5
print_address_description+0x6f/0x270
kasan_report+0x241/0x360
__asan_load4+0x78/0x80
bio_advance+0x11b/0x1d0
blk_update_request+0xa7/0x5b0
scsi_end_request+0x56/0x320 [scsi_mod]
scsi_io_completion+0x7d6/0xb20 [scsi_mod]
scsi_finish_command+0x1c0/0x280 [scsi_mod]
scsi_softirq_done+0x19a/0x230 [scsi_mod]
blk_mq_complete_request+0x160/0x240
scsi_mq_done+0x50/0x1a0 [scsi_mod]
srp_recv_done+0x515/0x1330 [ib_srp]
__ib_process_cq+0xa0/0xf0 [ib_core]
ib_poll_handler+0x38/0xa0 [ib_core]
irq_poll_softirq+0xe8/0x1f0
__do_softirq+0x128/0x60d
run_ksoftirqd+0x3f/0x60
smpboot_thread_fn+0x352/0x460
kthread+0x1c1/0x1e0
ret_from_fork+0x24/0x30
Allocated by task 1918:
save_stack+0x43/0xd0
kasan_kmalloc+0xad/0xe0
kasan_slab_alloc+0x11/0x20
kmem_cache_alloc+0xfe/0x350
mempool_alloc_slab+0x15/0x20
mempool_alloc+0xfb/0x270
bio_alloc_bioset+0x244/0x350
submit_bh_wbc+0x9c/0x2f0
__block_write_full_page+0x299/0x5a0
block_write_full_page+0x16b/0x180
blkdev_writepage+0x18/0x20
__writepage+0x42/0x80
write_cache_pages+0x376/0x8a0
generic_writepages+0xbe/0x110
blkdev_writepages+0xe/0x10
do_writepages+0x9b/0x180
__filemap_fdatawrite_range+0x178/0x1c0
file_write_and_wait_range+0x59/0xc0
blkdev_fsync+0x46/0x80
vfs_fsync_range+0x66/0x100
do_fsync+0x3d/0x70
__x64_sys_fsync+0x21/0x30
do_syscall_64+0x77/0x230
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 9:
save_stack+0x43/0xd0
__kasan_slab_free+0x137/0x190
kasan_slab_free+0xe/0x10
kmem_cache_free+0xd3/0x380
mempool_free_slab+0x17/0x20
mempool_free+0x63/0x160
bio_free+0x81/0xa0
bio_put+0x59/0x60
end_bio_bh_io_sync+0x5d/0x70
bio_endio+0x1a7/0x360
blk_update_request+0xd0/0x5b0
end_clone_bio+0xa3/0xd0 [dm_mod]
bio_endio+0x1a7/0x360
blk_update_request+0xd0/0x5b0
scsi_end_request+0x56/0x320 [scsi_mod]
scsi_io_completion+0x7d6/0xb20 [scsi_mod]
scsi_finish_command+0x1c0/0x280 [scsi_mod]
scsi_softirq_done+0x19a/0x230 [scsi_mod]
blk_mq_complete_request+0x160/0x240
scsi_mq_done+0x50/0x1a0 [scsi_mod]
srp_recv_done+0x515/0x1330 [ib_srp]
__ib_process_cq+0xa0/0xf0 [ib_core]
ib_poll_handler+0x38/0xa0 [ib_core]
irq_poll_softirq+0xe8/0x1f0
__do_softirq+0x128/0x60d
The buggy address belongs to the object at ffff8801300e0640
which belongs to the cache bio-0 of size 200
The buggy address is located 144 bytes inside of
200-byte region [ffff8801300e0640, ffff8801300e0708)
The buggy address belongs to the page:
page:ffffea0004c03800 count:1 mapcount:0 mapping:ffff88015a563a00 index:0x0 compound_mapcount: 0
flags: 0x8000000000008100(slab|head)
raw: 8000000000008100 dead000000000100 dead000000000200 ffff88015a563a00
raw: 0000000000000000 0000000000330033 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8801300e0580: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc
ffff8801300e0600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff8801300e0680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8801300e0700: fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8801300e0780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Fixes: 0ba99ca483 ("block: Add warning for bi_next not NULL in bio_endio()")
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_mq_complete_request can only be called for blk-mq drivers, but when
removing the BLK_EH_HANDLED return value, two legacy request timeout
methods incorrectly got switched to call blk_mq_complete_request.
Call __blk_complete_request instead to reinstance the previous behavior.
For that __blk_complete_request needs to be exported.
Fixes: 1fc2b62e ("scsi_transport_fc: complete requests from ->timeout")
Fixes: 0df0bb08 ("null_blk: complete requests from ->timeout")
Reported-by: Jianchao Wang <jianchao.w.wang@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-linus-20180616' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"A collection of fixes that should go into -rc1. This contains:
- bsg_open vs bsg_unregister race fix (Anatoliy)
- NVMe pull request from Christoph, with fixes for regressions in
this window, FC connect/reconnect path code unification, and a
trace point addition.
- timeout fix (Christoph)
- remove a few unused functions (Christoph)
- blk-mq tag_set reinit fix (Roman)"
* tag 'for-linus-20180616' of git://git.kernel.dk/linux-block:
bsg: fix race of bsg_open and bsg_unregister
block: remov blk_queue_invalidate_tags
nvme-fabrics: fix and refine state checks in __nvmf_check_ready
nvme-fabrics: handle the admin-only case properly in nvmf_check_ready
nvme-fabrics: refactor queue ready check
blk-mq: remove blk_mq_tagset_iter
nvme: remove nvme_reinit_tagset
nvme-fc: fix nulling of queue data on reconnect
nvme-fc: remove reinit_request routine
blk-mq: don't time out requests again that are in the timeout handler
nvme-fc: change controllers first connect to use reconnect path
nvme: don't rely on the changed namespace list log
nvmet: free smart-log buffer after use
nvme-rdma: fix error flow during mapping request data
nvme: add bio remapping tracepoint
nvme: fix NULL pointer dereference in nvme_init_subsystem
blk-mq: reinit q->tag_set_list entry only after grace period
As we move stuff around, some doc references are broken. Fix some of
them via this script:
./scripts/documentation-file-ref-check --fix
Manually checked if the produced result is valid, removing a few
false-positives.
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
The existing implementation allows races between bsg_unregister and
bsg_open paths. bsg_unregister and request_queue cleanup and deletion
may start and complete right after bsg_get_device (in bsg_open path)
retrieves bsg_class_device and releases the mutex. Then bsg_open path
touches freed memory of bsg_class_device and request_queue.
One possible fix is to hold the mutex all the way through bsg_get_device
instead of releasing it after bsg_class_device retrieval.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-Off-By: Anatoliy Glagolev <glagolig@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This function is entirely unused, so remove it and the tag_queue_busy
member of struct request_queue.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull NVMe fixes from Christoph:
"Fix various little regressions introduced in this merge window, plus
a rework of the fibre channel connect and reconnect path to share the
code instead of having separate sets of bugs. Last but not least a
trivial trace point addition from Hannes."
* 'nvme-4.18' of git://git.infradead.org/nvme:
nvme-fabrics: fix and refine state checks in __nvmf_check_ready
nvme-fabrics: handle the admin-only case properly in nvmf_check_ready
nvme-fabrics: refactor queue ready check
blk-mq: remove blk_mq_tagset_iter
nvme: remove nvme_reinit_tagset
nvme-fc: fix nulling of queue data on reconnect
nvme-fc: remove reinit_request routine
nvme-fc: change controllers first connect to use reconnect path
nvme: don't rely on the changed namespace list log
nvmet: free smart-log buffer after use
nvme-rdma: fix error flow during mapping request data
nvme: add bio remapping tracepoint
nvme: fix NULL pointer dereference in nvme_init_subsystem
We can currently call the timeout handler again on a request that has
already been handed over to the timeout handler. Prevent that with a new
flag.
Fixes: 12f5b931 ("blk-mq: Remove generation seqeunce")
Reported-by: Andrew Randrianasulu <randrianasulu@gmail.com>
Tested-by: Andrew Randrianasulu <randrianasulu@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It is not allowed to reinit q->tag_set_list list entry while RCU grace
period has not completed yet, otherwise the following soft lockup in
blk_mq_sched_restart() happens:
[ 1064.252652] watchdog: BUG: soft lockup - CPU#12 stuck for 23s! [fio:9270]
[ 1064.254445] task: ffff99b912e8b900 task.stack: ffffa6d54c758000
[ 1064.254613] RIP: 0010:blk_mq_sched_restart+0x96/0x150
[ 1064.256510] Call Trace:
[ 1064.256664] <IRQ>
[ 1064.256824] blk_mq_free_request+0xea/0x100
[ 1064.256987] msg_io_conf+0x59/0xd0 [ibnbd_client]
[ 1064.257175] complete_rdma_req+0xf2/0x230 [ibtrs_client]
[ 1064.257340] ? ibtrs_post_recv_empty+0x4d/0x70 [ibtrs_core]
[ 1064.257502] ibtrs_clt_rdma_done+0xd1/0x1e0 [ibtrs_client]
[ 1064.257669] ib_create_qp+0x321/0x380 [ib_core]
[ 1064.257841] ib_process_cq_direct+0xbd/0x120 [ib_core]
[ 1064.258007] irq_poll_softirq+0xb7/0xe0
[ 1064.258165] __do_softirq+0x106/0x2a2
[ 1064.258328] irq_exit+0x92/0xa0
[ 1064.258509] do_IRQ+0x4a/0xd0
[ 1064.258660] common_interrupt+0x7a/0x7a
[ 1064.258818] </IRQ>
Meanwhile another context frees other queue but with the same set of
shared tags:
[ 1288.201183] INFO: task bash:5910 blocked for more than 180 seconds.
[ 1288.201833] bash D 0 5910 5820 0x00000000
[ 1288.202016] Call Trace:
[ 1288.202315] schedule+0x32/0x80
[ 1288.202462] schedule_timeout+0x1e5/0x380
[ 1288.203838] wait_for_completion+0xb0/0x120
[ 1288.204137] __wait_rcu_gp+0x125/0x160
[ 1288.204287] synchronize_sched+0x6e/0x80
[ 1288.204770] blk_mq_free_queue+0x74/0xe0
[ 1288.204922] blk_cleanup_queue+0xc7/0x110
[ 1288.205073] ibnbd_clt_unmap_device+0x1bc/0x280 [ibnbd_client]
[ 1288.205389] ibnbd_clt_unmap_dev_store+0x169/0x1f0 [ibnbd_client]
[ 1288.205548] kernfs_fop_write+0x109/0x180
[ 1288.206328] vfs_write+0xb3/0x1a0
[ 1288.206476] SyS_write+0x52/0xc0
[ 1288.206624] do_syscall_64+0x68/0x1d0
[ 1288.206774] entry_SYSCALL_64_after_hwframe+0x3d/0xa2
What happened is the following:
1. There are several MQ queues with shared tags.
2. One queue is about to be freed and now task is in
blk_mq_del_queue_tag_set().
3. Other CPU is in blk_mq_sched_restart() and loops over all queues in
tag list in order to find hctx to restart.
Because linked list entry was modified in blk_mq_del_queue_tag_set()
without proper waiting for a grace period, blk_mq_sched_restart()
never ends, spining in list_for_each_entry_rcu_rr(), thus soft lockup.
Fix is simple: reinit list entry after an RCU grace period elapsed.
Fixes: Fixes: 705cda97ee ("blk-mq: Make it safe to use RCU to iterate over blk_mq_tag_set.tag_list")
Cc: stable@vger.kernel.org
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: linux-block@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Roman Pen <roman.penyaev@profitbricks.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A recent commit reused the original request flags for the flush
queue handling. However, for some of the kick flush cases, the
original request was already completed. This caused a use after
free, if blk-mq wasn't used.
Fixes: 84fca1b0c4 ("block: pass failfast and driver-specific flags to flush requests")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Josef Bacik