Move the cache control settings into the queue_limits so that the flags
can be set atomically with the device queue frozen.

Add new features and flags field for the driver set flags, and internal
(usually sysfs-controlled) flags in the block layer.  Note that we'll
eventually remove enough field from queue_limits to bring it back to the
previous size.

The disable flag is inverted compared to the previous meaning, which
means it now survives a rescan, similar to the max_sectors and
max_discard_sectors user limits.

The FLUSH and FUA flags are now inherited by blk_stack_limits, which
simplified the code in dm a lot, but also causes a slight behavior
change in that dm-switch and dm-unstripe now advertise a write cache
despite setting num_flush_bios to 0.  The I/O path will handle this
gracefully, but as far as I can tell the lack of num_flush_bios
and thus flush support is a pre-existing data integrity bug in those
targets that really needs fixing, after which a non-zero num_flush_bios
should be required in dm for targets that map to underlying devices.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-14-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Fold blk_flush_policy into the only caller to prepare for pending changes
to it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240617060532.127975-13-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

queue_attr_store updates attributes used to control generating I/O, and
can cause malformed bios if changed with I/O in flight.  Freeze the queue
in common code instead of adding it to almost every attribute.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240617060532.127975-12-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Move setting the cache control flags in nbd in preparation for moving
these flags into the queue_limits structure.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-11-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

virtblk_update_cache_mode boils down to a single call to
blk_queue_write_cache.  Remove it in preparation for moving the cache
control flags into the queue_limits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240617060532.127975-10-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

This prepares for moving the rotational flag into the queue_limits and
also fixes it for the case where the loop device is backed by a block
device.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240617060532.127975-9-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Fix the code in loop_reconfigure_limits to pick a default block size for
O_DIRECT file descriptors to also work when the loop device sits on top
of a block device and not just on a regular file on a block device based
file system.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240617060532.127975-8-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

The LOOP_CONFIGURE path automatically upgrades the block size to that
of the underlying file for O_DIRECT file descriptors, but the
LOOP_SET_BLOCK_SIZE path does not.  Fix this by lifting the code to
pick the block size into common code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240617060532.127975-7-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Simplify loop_reconfigure_limits by always updating the discard limits.
This adds a little more work to loop_set_block_size, but doesn't change
the outcome as the discard flag won't change.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240617060532.127975-6-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

__loop_clr_fd wants to clear all settings on the device.  Prepare for
moving more settings into the block limits by open coding
loop_reconfigure_limits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240617060532.127975-5-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Move a bit of code that sets up the zone flag and the write granularity
into sd_zbc_read_zones to be with the rest of the zoned limits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Since commit 7437bb73 ("block: remove support for the host aware zone
model"), only ZBC devices expose a zoned access model.  sd_is_zoned is
used to check for that and thus return false for host aware devices.

Replace the helper with the simple open coded TYPE_ZBC check to fix this.

Fixes: 7437bb73 ("block: remove support for the host aware zone model")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240617060532.127975-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

blkfront always had a robust negotiation protocol for detecting a write
cache.  Stop simply disabling cache flushes in the block layer as the
flags handling is moving to the atomic queue limits API that needs
user context to freeze the queue for that.  Instead handle the case
of the feature flags cleared inside of blkfront.  This removes old
debug code to check for such a mismatch which was previously impossible
to hit, including the check for passthrough requests that blkfront
never used to start with.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240617060532.127975-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Move the integrity information into the queue limits so that it can be
set atomically with other queue limits, and that the sysfs changes to
the read_verify and write_generate flags are properly synchronized.
This also allows to provide a more useful helper to stack the integrity
fields, although it still is separate from the main stacking function
as not all stackable devices want to inherit the integrity settings.
Even with that it greatly simplifies the code in md and dm.

Note that the integrity field is moved as-is into the queue limits.
While there are good arguments for removing the separate blk_integrity
structure, this would cause a lot of churn and might better be done at a
later time if desired.  However the integrity field in the queue_limits
structure is now unconditional so that various ifdefs can be avoided or
replaced with IS_ENABLED().  Given that tiny size of it that seems like
a worthwhile trade off.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-13-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Invert the flags so that user set values will be able to persist
revalidating the integrity information once we switch the integrity
information to queue_limits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-12-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Currently registering a checksum-enabled (aka PI) integrity profile sets
the QUEUE_FLAG_STABLE_WRITE flag, and unregistering it clears the flag.
This can incorrectly clear the flag when the driver requires stable
writes even without PI, e.g. in case of iSCSI or NVMe/TCP with data
digest enabled.

Fix this by looking at the csum_type directly in bdev_stable_writes and
not setting the queue flag.  Also remove the blk_queue_stable_writes
helper as the only user in nvme wants to only look at the actual
QUEUE_FLAG_STABLE_WRITE flag as it inherits the integrity configuration
by other means.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240613084839.1044015-11-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Non-PI metadata doesn't contain checksums and thus doesn't require
stable pages.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240613084839.1044015-10-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Use the text to integer helper that has error handling and doesn't modify
the input pointer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-9-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Factor the duplicate code for the generate and verify attributes into
common helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240613084839.1044015-8-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Now that there are no indirect calls for PI processing there is no
way to dereference a NULL pointer here.  Additionally drivers now always
freeze the queue (or in case of stacking drivers use their internal
equivalent) around changing the integrity profile.

This is effectively a revert of commit 3df49967 ("block: flush the
integrity workqueue in blk_integrity_unregister").
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240613084839.1044015-7-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Block layer integrity configuration is a bit complex right now, as it
indirects through operation vectors for a simple two-dimensional
configuration:

 a) the checksum type of none, ip checksum, crc, crc64
 b) the presence or absence of a reference tag

Remove the integrity profile, and instead add a separate csum_type flag
which replaces the existing ip-checksum field and a new flag that
indicates the presence of the reference tag.

This removes up to two layers of indirect calls, remove the need to
offload the no-op verification of non-PI metadata to a workqueue and
generally simplifies the code. The downside is that block/t10-pi.c now
has to be built into the kernel when CONFIG_BLK_DEV_INTEGRITY is
supported.  Given that both nvme and SCSI require t10-pi.ko, it is loaded
for all usual configurations that enabled CONFIG_BLK_DEV_INTEGRITY
already, though.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-6-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Use the block layer built-in nop profile instead of duplicating it.

Tested by:

$ dd if=/dev/urandom of=key.bin bs=512 count=1

$ cryptsetup luksFormat -q --type luks2 --integrity hmac-sha256 \
 	--integrity-no-wipe /dev/nvme0n1 key.bin
$ cryptsetup luksOpen /dev/nvme0n1 luks-integrity --key-file key.bin

and then doing mkfs.xfs and simple I/O on the mount file system.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Milan Broz <gmazyland@gmail.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-5-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

The core md code calls the ->free method which already frees conf.

Fixes: 07f1a685 ("md/raid1: fail run raid1 array when active disk less than one")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

The core md code calls the ->free method which already frees conf.

Fixes: 0c031fd3 ("md: Move alloc/free acct bioset in to personality")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Metadata added by bio_integrity_prep is using plain kmalloc, which leads
to random kernel memory being written media.  For PI metadata this is
limited to the app tag that isn't used by kernel generated metadata,
but for non-PI metadata the entire buffer leaks kernel memory.

Fix this by adding the __GFP_ZERO flag to allocations for writes.

Fixes: 7ba1ba12 ("block: Block layer data integrity support")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240613084839.1044015-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

A few drivers optimistically try to support discard, write zeroes and
secure erase and disable the features from the I/O completion handler
if the hardware can't support them.  This disable can't be done using
the atomic queue limits API because the I/O completion handlers can't
take sleeping locks or freeze the queue.  Keep the existing clearing
of the relevant field to zero, but replace the old blk_queue_max_*
APIs with new disable APIs that force the value to 0.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-15-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Remove all APIs that are unused now that sd and sr have been converted
to the atomic queue limits API.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-14-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Assign all queue limits through a local queue_limits variable and
queue_limits_commit_update so that we can't race updating them from
multiple places, and free the queue when updating them so that
in-progress I/O submissions don't see half-updated limits.

Also use the chance to clean up variable names to standard ones.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-13-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Assign all queue limits through a local queue_limits variable and
queue_limits_commit_update so that we can't race updating them from
multiple places, and freeze the queue when updating them so that
in-progress I/O submissions don't see half-updated limits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-12-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Consolidate setting zone-related queue limits in sd_zbc_read_zones
instead of splitting them between sd_zbc_revalidate_zones and
sd_zbc_read_zones, and move the early_zone_information initialization
in sd_zbc_read_zones above setting up the queue limits.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-11-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Split the logic to pick the right discard mode into a little helper
to prepare for further changes.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-10-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Fall through to the main call to blk_queue_max_discard_sectors given that
max_blocks has been initialized to zero above instead of duplicating the
call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-9-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Add helper to disable WRITE SAME when it is not supported and use it
instead of sd_config_write_same in the I/O completion handler.  This
avoids touching more fields than required in the I/O completion handler
and  prepares for converting sd to use the atomic queue limits API.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-8-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Add helper to disable discard when it is not supported and use it
instead of sd_config_discard in the I/O completion handler.  This avoids
touching more fields than required in the I/O completion handler and
prepares for converting sd to use the atomic queue limits API.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-7-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Don't reset the discard settings to no-op over and over when a user
writes to the provisioning attribute as that is already the default
mode for ZBC devices.  In hindsight we should have made writing to
the attribute fail for ZBC devices, but the code has probably been
around for far too long to change this now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-6-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

The soft max_sectors limit is normally capped by the hardware limits and
an arbitrary upper limit enforced by the kernel, but can be modified by
the user.  A few drivers want to increase this limit (nbd, rbd) or
adjust it up or down based on hardware capabilities (sd).

Change blk_validate_limits to default max_sectors to the optimal I/O
size, or upgrade it to the preferred minimal I/O size if that is
larger than the kernel default if no optimal I/O size is provided based
on the logic in the SD driver.

This keeps the existing kernel default for drivers that do not provide
an io_opt or very big io_min value, but picks a much more useful
default for those who provide these hints, and allows to remove the
hacks to set the user max_sectors limit in nbd, rbd and sd.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Acked-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-5-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Commit 16d80c54 ("rbd: set io_min, io_opt and discard_granularity to
alloc_size") lowered the io_opt size for rbd from objset_bytes which is
4MB for typical setup to alloc_size which is typically 64KB.

The commit mostly talks about discard behavior and does mention io_min
in passing.  Reducing io_opt means reducing the readahead size, which
seems counter-intuitive given that rbd currently abuses the user
max_sectors setting to actually increase the I/O size.  Switch back
to the old setting to allow larger reads (the readahead size despite it's
name actually limits the size of any buffered read) and to prepare
for using io_opt in the max_sectors calculation and getting drivers out
of the business of overriding the max_user_sectors value.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Discard and Write Zeroes are different operation and implemented
by different fallocate opcodes for ubd.  If one fails the other one
can work and vice versa.

Split the code to disable the operations in ubd_handler to only
disable the operation that actually failed.

Fixes: 50109b5a ("um: Add support for DISCARD in the UBD Driver")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Instead of a separate handler function that leaves no work in the
interrupt hanler itself, split out a per-request end I/O helper and
clean up the coding style and variable naming while we're at it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Link: https://lore.kernel.org/r/20240531074837.1648501-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>