The commit 85774780ef96 ("block: store a block_device pointer in struct bio")
now uses bdev unconditionally in the macro bio_set_dev() and assumes
that bdev value is not NULL which results in the following crash in
since thats where bdev is actually accessed :-
void bio_associate_blkg_from_css(struct bio *bio,
struct cgroup_subsys_state *css)
{
if (bio->bi_blkg)
blkg_put(bio->bi_blkg);
Jens Axboe [Wed, 27 Jan 2021 17:04:49 +0000 (10:04 -0700)]
mm: only make map_swap_entry available for CONFIG_HIBERNATION
Current tree spews this on compile:
mm/swapfile.c:2290:17: warning: ‘map_swap_entry’ defined but not used [-Wunused-function]
2290 | static sector_t map_swap_entry(swp_entry_t entry, struct block_device **bdev)
| ^~~~~~~~~~~~~~
if !CONFIG_HIBERNATION, as we don't use the function unless we have that
config option set.
Just reuse the block_device and sector from the swap_info structure,
just as used by the SWP_SYNCHRONOUS path. Also remove the checks for
NULL returns from bio_alloc as that can't happen for sleeping
allocations.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Refactor raid5_read_one_chunk so that all simple checks are done
before allocating the bio.
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Song Liu <song@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
md_bio_alloc_sync is never called with a NULL mddev, and ->sync_set is
initialized in md_run, so it always must be initialized as well. Just
open code the remaining call to bio_alloc_bioset.
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Song Liu <song@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Use an on-stack bio and biovec for the single page synchronous I/O.
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Song Liu <song@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
bio_alloc_mddev is never called with a NULL mddev, and ->bio_set is
initialized in md_run, so it always must be initialized as well. Just
open code the remaining call to bio_alloc_bioset.
Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Song Liu <song@kernel.org> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Open code drbd_req_make_private_bio in the two callers to prepare
for further changes. Also don't bother to initialize bi_next as the
bio code already does that that.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Given that drbd_md_io_bio_set is initialized during module initialization
and the module fails to load if the initialization fails there is no need
to fall back to plain bio_alloc.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk-crypto: use bio_kmalloc in blk_crypto_clone_bio
Use bio_kmalloc instead of open coding it.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Acked-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jan Kara [Fri, 5 Jun 2020 14:16:18 +0000 (16:16 +0200)]
bfq: Use only idle IO periods for think time calculations
Currently whenever bfq queue has a request queued we add now -
last_completion_time to the think time statistics. This is however
misleading in case the process is able to submit several requests in
parallel because e.g. if the queue has request completed at time T0 and
then queues new requests at times T1, T2, then we will add T1-T0 and
T2-T0 to think time statistics which just doesn't make any sence (the
queue's think time is penalized by the queue being able to submit more
IO). So add to think time statistics only time intervals when the queue
had no IO pending.
Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Paolo Valente <paolo.valente@linaro.org>
[axboe: fix whitespace on empty line] Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jan Kara [Fri, 5 Jun 2020 14:16:16 +0000 (16:16 +0200)]
bfq: Avoid false bfq queue merging
bfq_setup_cooperator() uses bfqd->in_serv_last_pos so detect whether it
makes sense to merge current bfq queue with the in-service queue.
However if the in-service queue is freshly scheduled and didn't dispatch
any requests yet, bfqd->in_serv_last_pos is stale and contains value
from the previously scheduled bfq queue which can thus result in a bogus
decision that the two queues should be merged. This bug can be observed
for example with the following fio jobfile:
where the 4 processes will end up in the one shared bfq queue although
they do IO to physically very distant files (for some reason I was able to
observe this only with slice_idle=1ms setting).
Fix the problem by invalidating bfqd->in_serv_last_pos when switching
in-service queue.
Fixes: 68db94066a5b ("block, bfq: fix in-service-queue check for queue merging") CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jan Kara [Thu, 7 Jan 2021 15:40:34 +0000 (16:40 +0100)]
bdev: Do not return EBUSY if bdev discard races with write
blkdev_fallocate() tries to detect whether a discard raced with an
overlapping write by calling invalidate_inode_pages2_range(). However
this check can give both false negatives (when writing using direct IO
or when writeback already writes out the written pagecache range) and
false positives (when write is not actually overlapping but ends in the
same page when blocksize < pagesize). This actually causes issues for
qemu which is getting confused by EBUSY errors.
Fix the problem by removing this conflicting write detection since it is
inherently racy and thus of little use anyway.
Reported-by: Maxim Levitsky <mlevitsk@redhat.com> CC: "Darrick J. Wong" <darrick.wong@oracle.com> Link: https://lore.kernel.org/qemu-devel/20201111153913.41840-1-mlevitsk@redhat.com Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cloned bios are can be used to on the same device, in which case we need
to inherit the BIO_REMAPPED flag to avoid a double partition remap. When
the cloned bios are used on another device, bio_set_dev will clear the flag.
Fixes: 85774780ef96 ("block: store a block_device pointer in struct bio") Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Mon, 25 Jan 2021 19:02:48 +0000 (20:02 +0100)]
block, bfq: make waker-queue detection more robust
In the presence of many parallel I/O flows, the detection of waker
bfq_queues suffers from false positives. This commits addresses this
issue by making the filtering of actual wakers more selective. In more
detail, a candidate waker must be found to meet waker requirements
three times before being promoted to actual waker.
Tested-by: Jan Kara <jack@suse.cz> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Mon, 25 Jan 2021 19:02:47 +0000 (20:02 +0100)]
block, bfq: save also injection state on queue merging
To prevent injection information from being lost on bfq_queue merging,
also the amount of service that a bfq_queue receives must be saved and
restored when the bfq_queue is merged and split, respectively.
Tested-by: Jan Kara <jack@suse.cz> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Mon, 25 Jan 2021 19:02:46 +0000 (20:02 +0100)]
block, bfq: save also weight-raised service on queue merging
To prevent weight-raising information from being lost on bfq_queue merging,
also the amount of service that a bfq_queue receives must be saved and
restored when the bfq_queue is merged and split, respectively.
Tested-by: Jan Kara <jack@suse.cz> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Mon, 25 Jan 2021 19:02:45 +0000 (20:02 +0100)]
block, bfq: fix switch back from soft-rt weitgh-raising
A bfq_queue may happen to be deemed as soft real-time while it is
still enjoying interactive weight-raising. If this happens because of
a false positive, then the bfq_queue is likely to loose its soft
real-time status soon. Upon losing such a status, the bfq_queue must
get back its interactive weight-raising, if its interactive period is
not over yet. But this case is not handled. This commit corrects this
error.
Tested-by: Jan Kara <jack@suse.cz> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Mon, 25 Jan 2021 19:02:44 +0000 (20:02 +0100)]
block, bfq: re-evaluate convenience of I/O plugging on rq arrivals
Upon an I/O-dispatch attempt, BFQ may detect that it was better to
plug I/O dispatch, and to wait for a new request to arrive for the
currently in-service queue. But the arrival of a new request for an
empty bfq_queue, and thus the switch from idle to busy of the
bfq_queue, may cause the scenario to change, and make plugging no
longer needed for service guarantees, or more convenient for
throughput. In this case, keeping I/O-dispatch plugged would certainly
lower throughput.
To address this issue, this commit makes such a check, and stops
plugging I/O if it is better to stop plugging I/O.
Tested-by: Jan Kara <jack@suse.cz> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Mon, 25 Jan 2021 19:02:43 +0000 (20:02 +0100)]
block, bfq: replace mechanism for evaluating I/O intensity
Some BFQ mechanisms make their decisions on a bfq_queue basing also on
whether the bfq_queue is I/O bound. In this respect, the current logic
for evaluating whether a bfq_queue is I/O bound is rather rough. This
commits replaces this logic with a more effective one.
The new logic measures the percentage of time during which a bfq_queue
is active, and marks the bfq_queue as I/O bound if the latter if this
percentage is above a fixed threshold.
Tested-by: Jan Kara <jack@suse.cz> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: skip bio_check_eod for partition-remapped bios
When an already remapped bio is resubmitted (e.g. by blk_queue_split),
bio_check_eod will compare the remapped bi_sector against the size
of the partition, leading to spurious I/O failures.
Skip the EOD check in this case.
Fixes: 85774780ef96 ("block: store a block_device pointer in struct bio") Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pavel Begunkov [Sat, 9 Jan 2021 16:03:03 +0000 (16:03 +0000)]
bio: don't copy bvec for direct IO
The block layer spends quite a while in blkdev_direct_IO() to copy and
initialise bio's bvec. However, if we've already got a bvec in the input
iterator it might be reused in some cases, i.e. when new
ITER_BVEC_FLAG_FIXED flag is set. Simple tests show considerable
performance boost, and it also reduces memory footprint.
Suggested-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pavel Begunkov [Sat, 9 Jan 2021 16:03:02 +0000 (16:03 +0000)]
bio: add a helper calculating nr segments to alloc
Add a helper function calculating the number of bvec segments we need to
allocate to construct a bio. It doesn't change anything functionally,
but will be used to not duplicate special cases in the future.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pavel Begunkov [Sat, 9 Jan 2021 16:03:01 +0000 (16:03 +0000)]
iov_iter: optimise bvec iov_iter_advance()
iov_iter_advance() is heavily used, but implemented through generic
means. For bvecs there is a specifically crafted function for that, so
use bvec_iter_advance() instead, it's faster and slimmer.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
target/file: allocate the bvec array as part of struct target_core_file_cmd
This saves one memory allocation, and ensures the bvecs aren't freed
before the AIO completion. This will allow the lower level code to be
optimized so that it can avoid allocating another bvec array.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pavel Begunkov [Sat, 9 Jan 2021 16:02:59 +0000 (16:02 +0000)]
block/psi: remove PSI annotations from direct IO
Direct IO does not operate on the current working set of pages managed
by the kernel, so it should not be accounted as memory stall to PSI
infrastructure.
The block layer and iomap direct IO use bio_iov_iter_get_pages()
to build bios, and they are the only users of it, so to avoid PSI
tracking for them clear out BIO_WORKINGSET flag. Do same for
dio_bio_submit() because fs/direct_io constructs bios by hand directly
calling bio_add_page().
Reported-by: Christoph Hellwig <hch@infradead.org> Suggested-by: Christoph Hellwig <hch@infradead.org> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pavel Begunkov [Sat, 9 Jan 2021 16:02:58 +0000 (16:02 +0000)]
bvec/iter: disallow zero-length segment bvecs
zero-length bvec segments are allowed in general, but not handled by bio
and down the block layer so filtered out. This inconsistency may be
confusing and prevent from optimisations. As zero-length segments are
useless and places that were generating them are patched, declare them
not allowed.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pavel Begunkov [Sat, 9 Jan 2021 16:02:57 +0000 (16:02 +0000)]
splice: don't generate zero-len segement bvecs
iter_file_splice_write() may spawn bvec segments with zero-length. In
preparation for prohibiting them, filter out by hand at splice level.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Mon, 11 Jan 2021 03:05:57 +0000 (11:05 +0800)]
bcache: don't pass BIOSET_NEED_BVECS for the 'bio_set' embedded in 'cache_set'
This bioset is just for allocating bio only from bio_next_split, and it
needn't bvecs, so remove the flag.
Cc: linux-bcache@vger.kernel.org Cc: Coly Li <colyli@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Acked-by: Coly Li <colyli@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Mon, 11 Jan 2021 03:05:56 +0000 (11:05 +0800)]
block: move three bvec helpers declaration into private helper
bvec_alloc(), bvec_free() and bvec_nr_vecs() are only used inside block
layer core functions, no need to declare them in public header.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Mon, 11 Jan 2021 03:05:55 +0000 (11:05 +0800)]
block: set .bi_max_vecs as actual allocated vector number
bvec_alloc() may allocate more bio vectors than requested, so set
.bi_max_vecs as actual allocated vector number, instead of the requested
number. This way can help fs build bigger bio because new bio often won't
be allocated until the current one becomes full.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Mon, 11 Jan 2021 03:05:54 +0000 (11:05 +0800)]
block: don't allocate inline bvecs if this bioset needn't bvecs
The inline bvecs won't be used if user needn't bvecs by not passing
BIOSET_NEED_BVECS, so don't allocate bvecs in this situation.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Tested-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Mon, 11 Jan 2021 03:05:53 +0000 (11:05 +0800)]
block: don't pass BIOSET_NEED_BVECS for q->bio_split
q->bio_split is only used by bio_split() for fast cloning bio, and no
need to allocate bvecs, so remove this flag.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Tested-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ming Lei [Mon, 11 Jan 2021 03:05:52 +0000 (11:05 +0800)]
block: manage bio slab cache by xarray
Managing bio slab cache via xarray by using slab cache size as xarray
index, and storing 'struct bio_slab' instance into xarray.
So code is simplified a lot, meantime it becomes more readable than before.
Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Tested-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jan Kara [Mon, 11 Jan 2021 16:47:17 +0000 (17:47 +0100)]
blk-mq: Improve performance of non-mq IO schedulers with multiple HW queues
Currently when non-mq aware IO scheduler (BFQ, mq-deadline) is used for
a queue with multiple HW queues, the performance it rather bad. The
problem is that these IO schedulers use queue-wide locking and their
dispatch function does not respect the hctx it is passed in and returns
any request it finds appropriate. Thus locality of request access is
broken and dispatch from multiple CPUs just contends on IO scheduler
locks. For these IO schedulers there's little point in dispatching from
multiple CPUs. Instead dispatch always only from a single CPU to limit
contention.
Below is a comparison of dbench runs on XFS filesystem where the storage
is a raid card with 64 HW queues and to it attached a single rotating
disk. BFQ is used as IO scheduler:
Numbers are times so lower is better. MQ is stock 5.10-rc6 kernel. SQ is
the same kernel with megaraid_sas.host_tagset_enable=0 so that the card
advertises just a single HW queue. MQ-Patched is a kernel with this
patch applied.
You can see multiple hardware queues heavily hurt performance in
combination with BFQ. The patch restores the performance.
Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since both mq-deadline and BFQ completely ignore hctx they are passed to
their dispatch function and dispatch whatever request they deem fit
checking whether any request for a particular hctx is queued is just
pointless since we'll very likely get a request from a different hctx
anyway. In the following commit we'll deal with lock contention in these
IO schedulers in presence of multiple HW queues in a different way.
Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Fri, 22 Jan 2021 18:19:48 +0000 (19:19 +0100)]
block, bfq: do not expire a queue when it is the only busy one
This commits preserves I/O-dispatch plugging for a special symmetric
case that may suddenly turn into asymmetric: the case where only one
bfq_queue, say bfqq, is busy. In this case, not expiring bfqq does not
cause any harm to any other queues in terms of service guarantees. In
contrast, it avoids the following unlucky sequence of events: (1) bfqq
is expired, (2) a new queue with a lower weight than bfqq becomes busy
(or more queues), (3) the new queue is served until a new request
arrives for bfqq, (4) when bfqq is finally served, there are so many
requests of the new queue in the drive that the pending requests for
bfqq take a lot of time to be served. In particular, event (2) may
case even already dispatched requests of bfqq to be delayed, inside
the drive. So, to avoid this series of events, the scenario is
preventively declared as asymmetric also if bfqq is the only busy
queues. By doing so, I/O-dispatch plugging is performed for bfqq.
Tested-by: Jan Kara <jack@suse.cz> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Fri, 22 Jan 2021 18:19:47 +0000 (19:19 +0100)]
block, bfq: avoid spurious switches to soft_rt of interactive queues
BFQ tags some bfq_queues as interactive or soft_rt if it deems that
these bfq_queues contain the I/O of, respectively, interactive or soft
real-time applications. BFQ privileges both these special types of
bfq_queues over normal bfq_queues. To privilege a bfq_queue, BFQ
mainly raises the weight of the bfq_queue. In particular, soft_rt
bfq_queues get a higher weight than interactive bfq_queues.
A bfq_queue may turn from interactive to soft_rt. And this leads to a
tricky issue. Soft real-time applications usually start with an
I/O-bound, interactive phase, in which they load themselves into main
memory. BFQ correctly detects this phase, and keeps the bfq_queues
associated with the application in interactive mode for a
while. Problems arise when the I/O pattern of the application finally
switches to soft real-time. One of the conditions for a bfq_queue to
be deemed as soft_rt is that the bfq_queue does not consume too much
bandwidth. But the bfq_queues associated with a soft real-time
application consume as much bandwidth as they can in the loading phase
of the application. So, after the application becomes truly soft
real-time, a lot of time should pass before the average bandwidth
consumed by its bfq_queues finally drops to a value acceptable for
soft_rt bfq_queues. As a consequence, there might be a time gap during
which the application is not privileged at all, because its bfq_queues
are not interactive any longer, but cannot be deemed as soft_rt yet.
To avoid this problem, BFQ pretends that an interactive bfq_queue
consumes zero bandwidth, and allows an interactive bfq_queue to switch
to soft_rt. Yet, this fake zero-bandwidth consumption easily causes
the bfq_queue to often switch to soft_rt deceptively, during its
loading phase. As in soft_rt mode, the bfq_queue gets its bandwidth
correctly computed, and therefore soon switches back to
interactive. Then it switches again to soft_rt, and so on. These
spurious fluctuations usually cause losses of throughput, because they
deceive BFQ's mechanisms for boosting throughput (injection,
I/O-plugging avoidance, ...).
This commit addresses this issue as follows:
1) It does compute actual bandwidth consumption also for interactive
bfq_queues. This avoids the above false positives.
2) When a bfq_queue switches from interactive to normal mode, the
consumed bandwidth is reset (forgotten). This allows the
bfq_queue to enjoy soft_rt very quickly. In particular, two
alternatives are possible in this switch:
- the bfq_queue still has backlog, and therefore there is a budget
already scheduled to serve the bfq_queue; in this case, the
scheduling of the current budget of the bfq_queue is not
hindered, because only the scheduling of the next budget will
be affected by the weight drop. After that, if the bfq_queue is
actually in a soft_rt phase, and becomes empty during the
service of its current budget, which is the natural behavior of
a soft_rt bfq_queue, then the bfq_queue will be considered as
soft_rt when its next I/O arrives. If, in contrast, the
bfq_queue remains constantly non-empty, then its next budget
will be scheduled with a low weight, which is the natural
treatment for an I/O-bound (non soft_rt) bfq_queue.
- the bfq_queue is empty; in this case, the bfq_queue may be
considered unjustly soft_rt when its new I/O arrives. Yet
the problem is now much smaller than before, because it is
unlikely that more than one spurious fluctuation occurs.
Tested-by: Jan Kara <jack@suse.cz> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Fri, 22 Jan 2021 18:19:46 +0000 (19:19 +0100)]
block, bfq: do not raise non-default weights
BFQ heuristics try to detect interactive I/O, and raise the weight of
the queues containing such an I/O. Yet, if also the user changes the
weight of a queue (i.e., the user changes the ioprio of the process
associated with that queue), then it is most likely better to prevent
BFQ heuristics from silently changing the same weight.
Tested-by: Jan Kara <jack@suse.cz> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Jia Cheng Hu [Fri, 22 Jan 2021 18:19:44 +0000 (19:19 +0100)]
block, bfq: set next_rq to waker_bfqq->next_rq in waker injection
Since commit c5089591c3ba ("block, bfq: detect wakers and
unconditionally inject their I/O"), when the in-service bfq_queue, say
Q, is temporarily empty, BFQ checks whether there are I/O requests to
inject (also) from the waker bfq_queue for Q. To this goal, the value
pointed by bfqq->waker_bfqq->next_rq must be controlled. However, the
current implementation mistakenly looks at bfqq->next_rq, which
instead points to the next request of the currently served queue.
This mistake evidently causes losses of throughput in scenarios with
waker bfq_queues.
This commit corrects this mistake.
Fixes: c5089591c3ba ("block, bfq: detect wakers and unconditionally inject their I/O") Signed-off-by: Jia Cheng Hu <jia.jiachenghu@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Paolo Valente [Fri, 22 Jan 2021 18:19:43 +0000 (19:19 +0100)]
block, bfq: use half slice_idle as a threshold to check short ttime
The value of the I/O plugging (idling) timeout is used also as the
think-time threshold to decide whether a process has a short think
time. In this respect, a good value of this timeout for rotational
drives is un the order of several ms. Yet, this is often too long a
time interval to be effective as a think-time threshold. This commit
mitigates this problem (by a lot, according to tests), by halving the
threshold.
Tested-by: Jan Kara <jack@suse.cz> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that no fast path lookups in the partition table are left, there is
no point in micro-optimizing the data structure for it. Just use a bog
standard xarray.
Add a helper to call kobject_uevent for the disk and all partitions, and
unexport the disk_part_iter_* helpers that are now only used in the core
block code.
Rework the I/O accounting for bio based drivers to use ->bi_bdev. This
means all drivers can now simply use bio_start_io_acct to start
accounting, and it will take partitions into account automatically. To
end I/O account either bio_end_io_acct can be used if the driver never
remaps I/O to a different device, or bio_end_io_acct_remapped if the
driver did remap the I/O.
block: do not reassig ->bi_bdev when partition remapping
There is no good reason to reassign ->bi_bdev when remapping the
partition-relative block number to the device wide one, as all the
information required by the drivers comes from the gendisk anyway.
Keeping the original ->bi_bdev alive will allow to greatly simplify
the partition-away I/O accounting.
Replace the gendisk pointer in struct bio with a pointer to the newly
improved struct block device. From that the gendisk can be trivially
accessed with an extra indirection, but it also allows to directly
look up all information related to partition remapping.
nvme: allow revalidate to set a namespace read-only
Unconditionally call set_disk_ro now that it only updates the hardware
state. This allows to properly set up the Linux devices read-only when
the controller turns a previously writable namespace read-only.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: propagate BLKROSET on the whole device to all partitions
Change the policy so that a BLKROSET on the whole device also affects
partitions. To quote Martin K. Petersen:
It's very common for database folks to twiddle the read-only state of
block devices and partitions. I know that our users will find it very
counter-intuitive that setting /dev/sda read-only won't prevent writes
to /dev/sda1.
The existing behavior is inconsistent in the sense that doing:
doesn't work either since sda1's read-only policy has been inherited
from the whole-disk device.
You need to do:
# blockdev --rereadpt
after setting the whole-disk device rw to effectuate the same change on
the partitions, otherwise they are stuck being read-only indefinitely.
However, setting the read-only policy on a partition does *not* require
the revalidate step. As a matter of fact, doing the revalidate will blow
away the policy setting you just made.
So the user needs to take different actions depending on whether they
are trying to read-protect a whole-disk device or a partition. Despite
using the same ioctl. That is really confusing.
I have lost count how many times our customers have had data clobbered
because of ambiguity of the existing whole-disk device policy. The
current behavior violates the principle of least surprise by letting the
user think they write protected the whole disk when they actually
didn't.
Suggested-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Commit 71257c65ebf9 ("scsi: sd: Keep disk read-only when re-reading
partition") addressed a long-standing problem with user read-only
policy being overridden as a result of a device-initiated revalidate.
The commit has since been reverted due to a regression that left some
USB devices read-only indefinitely.
To fix the underlying problems with revalidate we need to keep track
of hardware state and user policy separately.
The gendisk has been updated to reflect the current hardware state set
by the device driver. This is done to allow returning the device to
the hardware state once the user clears the BLKROSET flag.
The resulting semantics are as follows:
- If BLKROSET sets a given partition read-only, that partition will
remain read-only even if the underlying storage stack initiates a
revalidate. However, the BLKRRPART ioctl will cause the partition
table to be dropped and any user policy on partitions will be lost.
- If BLKROSET has not been set, both the whole disk device and any
partitions will reflect the current write-protect state of the
underlying device.
Based on a patch from Martin K. Petersen <martin.petersen@oracle.com>.
Reported-by: Oleksii Kurochko <olkuroch@cisco.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201221 Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
block: remove the NULL bdev check in bdev_read_only
Only a single caller can end up in bdev_read_only, so move the check
there.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
dm: use bdev_read_only to check if a device is read-only
dm-thin and dm-cache also work on partitions, so use the proper
interface to check if the device is read-only.
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Linus Torvalds [Sun, 24 Jan 2021 20:30:14 +0000 (12:30 -0800)]
Merge tag 'io_uring-5.11-2021-01-24' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
"Still need a final cancelation fix that isn't quite done done,
expected in the next day or two. That said, this contains:
- Wakeup fix for IOPOLL requests
- SQPOLL split close op handling fix
- Ensure that any use of io_uring fd itself is marked as inflight
- Short non-regular file read fix (Pavel)
- Fix up bad false positive warning (Pavel)
- SQPOLL fixes (Pavel)
- In-flight removal fix (Pavel)"
* tag 'io_uring-5.11-2021-01-24' of git://git.kernel.dk/linux-block:
io_uring: account io_uring internal files as REQ_F_INFLIGHT
io_uring: fix sleeping under spin in __io_clean_op
io_uring: fix short read retries for non-reg files
io_uring: fix SQPOLL IORING_OP_CLOSE cancelation state
io_uring: fix skipping disabling sqo on exec
io_uring: fix uring_flush in exit_files() warning
io_uring: fix false positive sqo warning on flush
io_uring: iopoll requests should also wake task ->in_idle state
Linus Torvalds [Sun, 24 Jan 2021 20:24:35 +0000 (12:24 -0800)]
Merge tag 'block-5.11-2021-01-24' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
- NVMe pull request from Christoph:
- fix a status code in nvmet (Chaitanya Kulkarni)
- avoid double completions in nvme-rdma/nvme-tcp (Chao Leng)
- fix the CMB support to cope with NVMe 1.4 controllers (Klaus Jensen)
- fix PRINFO handling in the passthrough ioctl (Revanth Rajashekar)
- fix a double DMA unmap in nvme-pci
* tag 'block-5.11-2021-01-24' of git://git.kernel.dk/linux-block:
lightnvm: fix memory leak when submit fails
nvme-pci: fix error unwind in nvme_map_data
nvme-pci: refactor nvme_unmap_data
md: Set prev_flush_start and flush_bio in an atomic way
nvmet: set right status on error in id-ns handler
nvme-pci: allow use of cmb on v1.4 controllers
nvme-tcp: avoid request double completion for concurrent nvme_tcp_timeout
nvme-rdma: avoid request double completion for concurrent nvme_rdma_timeout
nvme: check the PRINFO bit before deciding the host buffer length
Linus Torvalds [Sun, 24 Jan 2021 20:16:34 +0000 (12:16 -0800)]
Merge branch 'akpm' (patches from Andrew)
Merge misc fixes from Andrew Morton:
"18 patches.
Subsystems affected by this patch series: mm (pagealloc, memcg, kasan,
memory-failure, and highmem), ubsan, proc, and MAINTAINERS"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
MAINTAINERS: add a couple more files to the Clang/LLVM section
proc_sysctl: fix oops caused by incorrect command parameters
powerpc/mm/highmem: use __set_pte_at() for kmap_local()
mips/mm/highmem: use set_pte() for kmap_local()
mm/highmem: prepare for overriding set_pte_at()
sparc/mm/highmem: flush cache and TLB
mm: fix page reference leak in soft_offline_page()
ubsan: disable unsigned-overflow check for i386
kasan, mm: fix resetting page_alloc tags for HW_TAGS
kasan, mm: fix conflicts with init_on_alloc/free
kasan: fix HW_TAGS boot parameters
kasan: fix incorrect arguments passing in kasan_add_zero_shadow
kasan: fix unaligned address is unhandled in kasan_remove_zero_shadow
mm: fix numa stats for thp migration
mm: memcg: fix memcg file_dirty numa stat
mm: memcg/slab: optimize objcg stock draining
mm: fix initialization of struct page for holes in memory layout
x86/setup: don't remove E820_TYPE_RAM for pfn 0
Linus Torvalds [Sun, 24 Jan 2021 19:26:46 +0000 (11:26 -0800)]
Merge tag 'char-misc-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH:
"Here are some small char/misc driver fixes for 5.11-rc5:
- habanalabs driver fixes
- phy driver fixes
- hwtracing driver fixes
- rtsx cardreader driver fix
All of these have been in linux-next with no reported issues"
* tag 'char-misc-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
misc: rtsx: init value of aspm_enabled
habanalabs: disable FW events on device removal
habanalabs: fix backward compatibility of idle check
habanalabs: zero pci counters packet before submit to FW
intel_th: pci: Add Alder Lake-P support
stm class: Fix module init return on allocation failure
habanalabs: prevent soft lockup during unmap
habanalabs: fix reset process in case of failures
habanalabs: fix dma_addr passed to dma_mmap_coherent
phy: mediatek: allow compile-testing the dsi phy
phy: cpcap-usb: Fix warning for missing regulator_disable
PHY: Ingenic: fix unconditional build of phy-ingenic-usb
Linus Torvalds [Sun, 24 Jan 2021 19:02:01 +0000 (11:02 -0800)]
Merge tag 'staging-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging/IIO driver fixes from Greg KH:
"Here are some IIO driver fixes for 5.11-rc5 to resolve some reported
problems.
Nothing major, just a few small fixes, all of these have been in
linux-next for a while and full details are in the shortlog"
* tag 'staging-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
iio: sx9310: Fix semtech,avg-pos-strength setting when > 16
iio: common: st_sensors: fix possible infinite loop in st_sensors_irq_thread
iio: ad5504: Fix setting power-down state
counter:ti-eqep: remove floor
drivers: iio: temperature: Add delay after the addressed reset command in mlx90632.c
iio: adc: ti_am335x_adc: remove omitted iio_kfifo_free()
dt-bindings: iio: accel: bma255: Fix bmc150/bmi055 compatible
iio: sx9310: Off by one in sx9310_read_thresh()
Linus Torvalds [Sun, 24 Jan 2021 18:56:45 +0000 (10:56 -0800)]
Merge tag 'tty-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial fixes from Greg KH:
"Here are three small tty/serial fixes for 5.11-rc5 to resolve reported
problems:
- two patches to fix up writing to ttys with splice
- mvebu-uart driver fix for reported problem
All of these have been in linux-next with no reported problems"
* tag 'tty-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
tty: fix up hung_up_tty_write() conversion
tty: implement write_iter
serial: mvebu-uart: fix tx lost characters at power off
Linus Torvalds [Sun, 24 Jan 2021 18:54:54 +0000 (10:54 -0800)]
Merge tag 'usb-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
"Here are some small USB driver fixes for 5.11-rc5. They resolve:
- xhci issues for some reported problems
- ehci driver issue for one specific device
- USB gadget fixes for some reported problems
- cdns3 driver fixes for issues reported
- MAINTAINERS file update
- thunderbolt minor fix
All of these have been in linux-next with no reported issues"
* tag 'usb-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: bdc: Make bdc pci driver depend on BROKEN
xhci: tegra: Delay for disabling LFPS detector
xhci: make sure TRB is fully written before giving it to the controller
usb: udc: core: Use lock when write to soft_connect
USB: gadget: dummy-hcd: Fix errors in port-reset handling
usb: gadget: aspeed: fix stop dma register setting.
USB: ehci: fix an interrupt calltrace error
ehci: fix EHCI host controller initialization sequence
MAINTAINERS: update Peter Chen's email address
thunderbolt: Drop duplicated 0x prefix from format string
MAINTAINERS: Update address for Cadence USB3 driver
usb: cdns3: imx: improve driver .remove API
usb: cdns3: imx: fix can't create core device the second time issue
usb: cdns3: imx: fix writing read-only memory issue
Xiaoming Ni [Sun, 24 Jan 2021 05:02:16 +0000 (21:02 -0800)]
proc_sysctl: fix oops caused by incorrect command parameters
The process_sysctl_arg() does not check whether val is empty before
invoking strlen(val). If the command line parameter () is incorrectly
configured and val is empty, oops is triggered.
For example:
"hung_task_panic=1" is incorrectly written as "hung_task_panic", oops is
triggered. The call stack is as follows:
Kernel command line: .... hung_task_panic
......
Call trace:
__pi_strlen+0x10/0x98
parse_args+0x278/0x344
do_sysctl_args+0x8c/0xfc
kernel_init+0x5c/0xf4
ret_from_fork+0x10/0x30
To fix it, check whether "val" is empty when "phram" is a sysctl field.
Error codes are returned in the failure branch, and error logs are
generated by parse_args().
Link: https://lkml.kernel.org/r/20210118133029.28580-1-nixiaoming@huawei.com Fixes: 98747e1df87111e ("kernel/sysctl: support setting sysctl parameters from kernel command line") Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Iurii Zaikin <yzaikin@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Heiner Kallweit <hkallweit1@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: <stable@vger.kernel.org> [5.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Thomas Gleixner [Sun, 24 Jan 2021 05:02:11 +0000 (21:02 -0800)]
powerpc/mm/highmem: use __set_pte_at() for kmap_local()
The original PowerPC highmem mapping function used __set_pte_at() to
denote that the mapping is per CPU. This got lost with the conversion
to the generic implementation.
Override the default map function.
Link: https://lkml.kernel.org/r/20210112170411.281464308@linutronix.de Fixes: ba6b033900af ("powerpc/mm/highmem: Switch to generic kmap atomic") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Paul Cercueil <paul@crapouillou.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Thomas Gleixner [Sun, 24 Jan 2021 05:02:02 +0000 (21:02 -0800)]
mm/highmem: prepare for overriding set_pte_at()
The generic kmap_local() map function uses set_pte_at(), but MIPS requires
set_pte() and PowerPC wants __set_pte_at().
Provide arch_kmap_local_set_pte() and default it to set_pte_at().
Link: https://lkml.kernel.org/r/20210112170411.056306194@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Cercueil <paul@crapouillou.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dan Williams [Sun, 24 Jan 2021 05:01:52 +0000 (21:01 -0800)]
mm: fix page reference leak in soft_offline_page()
The conversion to move pfn_to_online_page() internal to
soft_offline_page() missed that the get_user_pages() reference taken by
the madvise() path needs to be dropped when pfn_to_online_page() fails.
Note the direct sysfs-path to soft_offline_page() does not perform a
get_user_pages() lookup.
When soft_offline_page() is handed a pfn_valid() && !pfn_to_online_page()
pfn the kernel hangs at dax-device shutdown due to a leaked reference.
Link: https://lkml.kernel.org/r/161058501210.1840162.8108917599181157327.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: 11af82241199 ("mm, soft-offline: convert parameter to pfn") Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Qian Cai <cai@lca.pw> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Sun, 24 Jan 2021 05:01:43 +0000 (21:01 -0800)]
kasan, mm: fix resetting page_alloc tags for HW_TAGS
A previous commit added resetting KASAN page tags to
kernel_init_free_pages() to avoid false-positives due to accesses to
metadata with the hardware tag-based mode.
That commit did reset page tags before the metadata access, but didn't
restore them after. As the result, KASAN fails to detect bad accesses
to page_alloc allocations on some configurations.
Fix this by recovering the tag after the metadata access.
Link: https://lkml.kernel.org/r/02b5bcd692e912c27d484030f666b350ad7e4ae4.1611074450.git.andreyknvl@google.com Fixes: 7815ec9f5f76 ("kasan, mm: reset tags when accessing metadata") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Marco Elver <elver@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrey Konovalov [Sun, 24 Jan 2021 05:01:38 +0000 (21:01 -0800)]
kasan, mm: fix conflicts with init_on_alloc/free
A few places where SLUB accesses object's data or metadata were missed
in a previous patch. This leads to false positives with hardware
tag-based KASAN when bulk allocations are used with init_on_alloc/free.
Fix the false-positives by resetting pointer tags during these accesses.
(The kasan_reset_tag call is removed from slab_alloc_node, as it's added
into maybe_wipe_obj_freeptr.)
Andrey Konovalov [Sun, 24 Jan 2021 05:01:34 +0000 (21:01 -0800)]
kasan: fix HW_TAGS boot parameters
The initially proposed KASAN command line parameters are redundant.
This change drops the complex "kasan.mode=off/prod/full" parameter and
adds a simpler kill switch "kasan=off/on" instead. The new parameter
together with the already existing ones provides a cleaner way to
express the same set of features.
The full set of parameters with this change:
kasan=off/on - whether KASAN is enabled
kasan.fault=report/panic - whether to only print a report or also panic
kasan.stacktrace=off/on - whether to collect alloc/free stack traces
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