The 'probe' callback in __register_blkdev() is only used under the
CONFIG_BLOCK_LEGACY_AUTOLOAD deprecation guard.

The loop_probe() function is only used for that callback, so guard it
too, accordingly.

See commit fbdee71bb5d8 ("block: deprecate autoloading based on dev_t").

Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230720143033.841001-2-mfo@canonical.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Current code supposes that it is enough to provide forward progress by
just waking up one wait queue after one completion batch is done.

Unfortunately this way isn't enough, cause waiter can be added to wait
queue just after it is woken up.

Follows one example(64 depth, wake_batch is 8)

1) all 64 tags are active

2) in each wait queue, there is only one single waiter

3) each time one completion batch(8 completions) wakes up just one
waiter in each wait queue, then immediately one new sleeper is added
to this wait queue

4) after 64 completions, 8 waiters are wakeup, and there are still 8
waiters in each wait queue

5) after another 8 active tags are completed, only one waiter can be
wakeup, and the other 7 can't be waken up anymore.

Turns out it isn't easy to fix this problem, so simply wakeup enough
waiters for single batch.

Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20230721095715.232728-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

The flush bio may have data, may have no data (empty flush), we couldn't
calculate cost for empty flush bio. So we'd better just skip it for now.

Another side effect is that empty flush bio's bio_end_sector() is 0, cause
iocg->cursor reset to 0, may break the cost calculation of other bios.

This isn't good enough, since flush bio still consume the device bandwidth,
but flush request is special, can be merged randomly in the flush state
machine, we don't know how to calculate cost for it for now.

Its completion time also has flaws, which may include the pre-flush or
post-flush completion time, but I don't know if we need to fix that and
how to fix it.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20230720121441.1408522-1-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

This counter is not used anywhere, so delete it.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230720095512.1403123-1-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We have seen rare IO stalls as follows:

* blk_mq_plug_issue_direct() is entered with an mq_list containing two
requests.
* For the first request, it sets last == false and enters the driver's
queue_rq callback.
* The driver queue_rq callback indirectly calls schedule() which calls
blk_flush_plug(). This may happen if the driver has the
BLK_MQ_F_BLOCKING flag set and is allowed to sleep in ->queue_rq.
* blk_flush_plug() handles the remaining request in the mq_list. mq_list
is now empty.
* The original call to queue_rq resumes (with last == false).
* The loop in blk_mq_plug_issue_direct() terminates because there are no
remaining requests in mq_list.

The IO is now stalled because the last request submitted to the driver
had last == false and there was no subsequent call to commit_rqs().

Fix this by returning early in blk_mq_flush_plug_list() if rq_count is 0
which it will be in the recursive case, rather than checking if the
mq_list is empty. At the same time, adjust one of the callers to skip
the mq_list empty check as it is not necessary.

Fixes: dc5fc361d891 ("block: attempt direct issue of plug list")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230714101106.3635611-1-ross.lagerwall@citrix.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

We used to insert the data commands following a pre-flush to the head
of the queue until commit 1e82fadfc6b ("blk-mq: do not do head insertions
post-pre-flush commands"). Not doing this seems to cause hangs of
such commands on NFS workloads when exported from file systems with
SATA SSDs. I have no idea why this would starve these workloads,
but doing a semantic revert of this patch (which looks quite different
due to various other changes) fixes the hangs.

Fixes: 1e82fadfc6b ("blk-mq: do not do head insertions post-pre-flush commands")
Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20230714143014.11879-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull NVMe fixes from Keith:

"nvme fixes for Linux 6.5

- Don't require quirk to use duplicate namespace identifiers
(Christoph, Sagi)
- One more BOGUS_NID quirk (Pankaj)
- IO timeout and error hanlding fixes for PCI (Keith)
- Enhanced metadata format mask fix (Ankit)
- Association race condition fix for fibre channel (Michael)
- Correct debugfs error checks (Minjie)
- Use PAGE_SECTORS_SHIFT where needed (Damien)
- Reduce kernel logs for legacy nguid attribute (Keith)
- Use correct dma direction when unmapping metadata (Ming)"

* tag 'nvme-6.5-2023-07-13' of git://git.infradead.org/nvme:
nvme-pci: fix DMA direction of unmapping integrity data
nvme: don't reject probe due to duplicate IDs for single-ported PCIe devices
nvme: ensure disabling pairs with unquiesce
nvme-fc: fix race between error recovery and creating association
nvme-fc: return non-zero status code when fails to create association
nvme: fix parameter check in nvme_fault_inject_init()
nvme: warn only once for legacy uuid attribute
nvme: fix the NVME_ID_NS_NVM_STS_MASK definition
nvmet: use PAGE_SECTORS_SHIFT
nvme: add BOGUS_NID quirk for Samsung SM953

The iocost rely on rq start_time_ns and alloc_time_ns to tell saturation
state of the block device. Most of the time request is allocated after
rq_qos_throttle() and its alloc_time_ns or start_time_ns won't be affected.

But for plug batched allocation introduced by the commit 47c122e35d7e
("block: pre-allocate requests if plug is started and is a batch"), we can
rq_qos_throttle() after the allocation of the request. This is what the
blk_mq_get_cached_request() does.

In this case, the cached request alloc_time_ns or start_time_ns is much
ahead if blocked in any qos ->throttle().

Fix it by setting alloc_time_ns and start_time_ns to now when the allocated
request is actually used.

Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230710105516.2053478-1-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>

DMA direction should be taken in dma_unmap_page() for unmapping integrity
data.

Fix this DMA direction, and reported in Guangwu's test.

Reported-by: Guangwu Zhang <guazhang@redhat.com>
Fixes: 4aedb705437f ("nvme-pci: split metadata handling from nvme_map_data / nvme_unmap_data")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

A bug was introduced in deadline_from_pos() while implementing the
suggestion to use round_down() in the following code:

pos -= bdev_offset_from_zone_start(rq->q->disk->part0, pos);

This patch makes deadline_from_pos() use round_down() such that 'pos' is
rounded down.

Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Closes: https://lore.kernel.org/all/5zthzi3lppvcdp4nemum6qck4gpqbdhvgy4k3qwguhgzxc4quj@amulvgycq67h/
Cc: Christoph Hellwig <hch@lst.de>
Cc: Damien Le Moal <dlemoal@kernel.org>
Fixes: 0effb390c4ba ("block: mq-deadline: Handle requeued requests correctly")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230712173344.2994513-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

While duplicate IDs are still very harmful, including the potential to easily
see changing devices in /dev/disk/by-id, it turn out they are extremely
common for cheap end user NVMe devices.

Relax our check for them for so that it doesn't reject the probe on
single-ported PCIe devices, but prints a big warning instead. In doubt
we'd still like to see quirk entries to disable the potential for
changing supposed stable device identifier links, but this will at least
allow users how have two (or more) of these devices to use them without
having to manually add a new PCI ID entry with the quirk through sysfs or
by patching the kernel.

Fixes: 2079f41ec6ff ("nvme: check that EUI/GUID/UUID are globally unique")
Cc: stable@vger.kernel.org # 6.0+
Co-developed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

It's no longer used. While in there, also update the comment as to why
it can coexist with the rb_node.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

If any error handling that disables the controller fails to queue the
reset work, like if the state changed to disconnected inbetween, then
the failed teardown needs to unquiesce the queues since it's no longer
paired with reset_work. Just make sure that the controller can be put
into a resetting state prior to starting the disable so that no other
handling can change the queue states while recovery is happening.

Reported-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

When a device-mapper device is passing through the inline encryption
support of an underlying device, calls to blk_crypto_evict_key() take
the blk_crypto_profile::lock of the device-mapper device, then take the
blk_crypto_profile::lock of the underlying device (nested). This isn't
a real deadlock, but it causes a lockdep report because there is only
one lock class for all instances of this lock.

Lockdep subclasses don't really work here because the hierarchy of block
devices is dynamic and could have more than 2 levels.

Instead, register a dynamic lock class for each blk_crypto_profile, and
associate that with the lock.

This avoids false-positive lockdep reports like the following:

============================================
WARNING: possible recursive locking detected
6.4.0-rc5 #2 Not tainted
--------------------------------------------
fscryptctl/1421 is trying to acquire lock:
ffffff80829ca418 (&profile->lock){++++}-{3:3}, at: __blk_crypto_evict_key+0x44/0x1c0

but task is already holding lock:
ffffff8086b68ca8 (&profile->lock){++++}-{3:3}, at: __blk_crypto_evict_key+0xc8/0x1c0

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&profile->lock);
lock(&profile->lock);

*** DEADLOCK ***

May be due to missing lock nesting notation

Fixes: 1b2628397058 ("block: Keyslot Manager for Inline Encryption")
Reported-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230610061139.212085-1-ebiggers@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

There is a small race window between nvme-fc association creation and error
recovery. Fix this race condition by protecting accessing to controller
state and ASSOC_FAILED flag under nvme-fc controller lock.

Signed-off-by: Michael Liang <mliang@purestorage.com>
Reviewed-by: Caleb Sander <csander@purestorage.com>
Reviewed-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>