In this preparation patch, we add helpers to convert lbas to sectors &
sectors to lba. This is needed to eliminate code duplication in the ZBD
backend.

Use these helpers in the block device backend.
Signed-off-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NDamien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

We remove the extra local variable struct nvmet_ns in
nvmet_execute_identify_ns() since req already has ns member that can be
reused, this also eliminates the explicit call to nvmet_put_namespace()
which is already present in the request completion path.
Signed-off-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

We remove the extra local variable struct nvmet_ns in
nvmet_execute_identify_desclist() since req already has ns member that
can be reused, this also eliminates the explicit call to
nvmet_put_namespace() which is already present in the request
completion path.
Signed-off-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

We remove the extra local variable struct nvmet_ns in
nvmet_get_smart_log_nsid() since req already has ns member that can be
reused, this also eliminates the explicit call to nvmet_put_namespace()
which is already present in the request completion path.
Signed-off-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Just for current code in nvme_cleanup_cmd(), we don't have to get
namespace instance, but we need controller instance.

Controller instance can be retrieved by namespace instance, but it can
be directly accessed by nvme_request instance from request.

	ctrl = nvme_req(req)->ctrl;

We don't have to go around namespace instance from request instance
through gendisk.
Signed-off-by: NMinwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

iov_iter uses the right helpers so we should be able
to pass in a multipage bvec. Right now the iov_iter is
initialized with more segments that it needs which doesn't
fail because the iov_iter is capped by byte count, but it
is better to use a full multipage bvec iter.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

We might set the iov_iter direction wrong, which is harmless for this
use-case, but get it right. Also this makes the code slightly cleaner.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The controller can request a delay retrying a failed command by setting
the Command Retry Delay (CRD) field in the Completion Queue Entry.

Currentlty this features is only applied to commands on the I/O queue, but
not to commands on the admin queue.  Retreive the nvme_ctrl from the
request so that no namespace is required and apply the feature to all
commands.
Signed-off-by: NMinwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The only usage of these is to put their addresses in arrays of pointers
to const attribute_groups. Make them const to allow the compiler to put
them in read-only memory.
Signed-off-by: NRikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

searching assoc_list protected by rcu_read_lock if list not changed inline.
and according to the rcu list rules.

queue array embedded into nvmet_fc_tgt_assoc protected by rcu_read_lock
according to rcu dereference/assign rules.

queue and assoc object freed after grace period by call_rcu.

tgtport lock taken for changing assoc_list.
Reviewed-by: NEldad Zinger <Eldad.Zinger@dell.com>
Reviewed-by: NElad Grupi <Elad.Grupi@dell.com>
Reviewed-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NLeonid Ravich <Leonid.Ravich@emc.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Remove extra tab.
Signed-off-by: NIsrael Rukshin <israelr@nvidia.com>
Reviewed-by: NMax Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Remove code duplication.
Signed-off-by: NIsrael Rukshin <israelr@nvidia.com>
Reviewed-by: NMax Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Use semicolons and braces.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Fix below warnings reported by coccicheck:
./drivers/block/rsxx/dma.c:948:3-8: WARNING: NULL check
before some freeing functions is not needed.
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NYang Li <abaci-bugfix@linux.alibaba.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

fixed the below warning:
/drivers/block/zram/zram_drv.c:534:2-8: WARNING: NULL check
before some freeing functions is not needed.
Signed-off-by: NTian Tao <tiantao6@hisilicon.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We can remove start_jif since it is not used by drbd_request_prepare,
then remove it from __drbd_make_request further.

Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: drbd-dev@lists.linbit.com
Signed-off-by: NGuoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Replace pci_read_config_word() with pcie_capability_read_word().

pcie_capability_read_word() takes care of a few special cases when reading
the PCIe capability.  See 8c0d3a02 ("PCI: Add accessors for PCI Express
Capability").
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Use PCI #defines for PCIe Device Control register values instead of
hard-coding bit positions.  No functional change intended.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Currently, loop device has only one global lock: loop_ctl_mutex.

This becomes hot in scenarios where many loop devices are used.

Scale it by introducing per-device lock: lo_mutex that protects
modifications of all fields in struct loop_device.

Keep loop_ctl_mutex to protect global data: loop_index_idr, loop_lookup,
loop_add.

The new lock ordering requirement is that loop_ctl_mutex must be taken
before lo_mutex.
Signed-off-by: NPavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: NTyler Hicks <tyhicks@linux.microsoft.com>
Reviewed-by: NPetr Vorel <pvorel@suse.cz>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NMaxim Levitsky <mlevitsk@redhat.com>
CC: "Darrick J. Wong" <darrick.wong@oracle.com>
Link: https://lore.kernel.org/qemu-devel/20201111153913.41840-1-mlevitsk@redhat.comSigned-off-by: NJan Kara <jack@suse.cz>
Reviewed-by: NMaxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens 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: 309dca30 ("block: store a block_device pointer in struct bio")
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Always use the bio_set_dev helper to assign ->bi_bdev to make sure
other state related to the device is uptodate.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Always use the bio_set_dev helper to assign ->bi_bdev to make sure
other state related to the device is uptodate.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

It's only used in the same file, mark is appropriately static.

Fixes: 71217df3 ("block, bfq: make waker-queue detection more robust")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NJan Kara <jack@suse.cz>
Signed-off-by: NPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NJan Kara <jack@suse.cz>
Signed-off-by: NPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NJan Kara <jack@suse.cz>
Signed-off-by: NPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NJan Kara <jack@suse.cz>
Signed-off-by: NPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NJan Kara <jack@suse.cz>
Signed-off-by: NPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NJan Kara <jack@suse.cz>
Signed-off-by: NPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: 309dca30 ("block: store a block_device pointer in struct bio")
Reported-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NChristoph Hellwig <hch@infradead.org>
Suggested-by: NChristoph Hellwig <hch@infradead.org>
Suggested-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Reviewed-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We can remove 'q' from blk_execute_rq as well after the previous change
in blk_execute_rq_nowait.

And more importantly it never really was needed to start with given
that we can trivial derive it from struct request.

Cc: linux-scsi@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: linux-ide@vger.kernel.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-nvme@lists.infradead.org
Cc: linux-nfs@vger.kernel.org
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: NGuoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>