Replace the semi-open coded request list helpers with a proper rq_list
type that mirrors the bio_list and has head and tail pointers. Besides
better type safety this actually allows to insert at the tail of the
list, which will be useful soon.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241113152050.157179-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
max_zone_append_sectors differs from all other queue limits in that the
final value used is not stored in the queue_limits but needs to be
obtained using queue_limits_max_zone_append_sectors helper. This not
only adds (tiny) extra overhead to the I/O path, but also can be easily
forgotten in file system code.
Add a new max_hw_zone_append_sectors value to queue_limits which is
set by the driver, and calculate max_zone_append_sectors from that and
the other inputs in blk_validate_zoned_limits, similar to how
max_sectors is calculated to fix this.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241104073955.112324-3-hch@lst.de
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20241108154657.845768-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
max_zone_append_sectors differs from all other queue limits in that the
final value used is not stored in the queue_limits but needs to be
obtained using queue_limits_max_zone_append_sectors helper. This not
only adds (tiny) extra overhead to the I/O path, but also can be easily
forgotten in file system code.
Add a new max_hw_zone_append_sectors value to queue_limits which is
set by the driver, and calculate max_zone_append_sectors from that and
the other inputs in blk_validate_zoned_limits, similar to how
max_sectors is calculated to fix this.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241104073955.112324-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The block queue limits validation does this for us now.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://lore.kernel.org/r/20240708091651.177447-4-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Now that device mapper can handle resetting all zones of a mapped zoned
device using REQ_OP_ZONE_RESET_ALL, all zoned block device drivers
support this operation. With this, the request queue feature
BLK_FEAT_ZONE_RESETALL is not necessary and the emulation code in
blk-zone.c can be removed.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240704052816.623865-5-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Allow creating a zoned null_blk device with the initial state of its
sequential write required zones to be FULL. This is convenient to avoid
having to first write these zones to perform read performance evaluation
or test zone management operations such as zone reset (and zone reset
all).
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240704052816.623865-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The description of the fua module parameter is defined using
MODULE_PARM_DESC() with the first argument passed being "zoned". That is
the wrong name, obviously. Fix that by using the correct "fua" parameter
name so that "modinfo null_blk" displays correct information.
Fixes: f4f84586c8 ("null_blk: Introduce fua attribute")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240702073234.206458-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In null_register_zoned_dev(), there is no need to set disk->nr_zones as
the now uncoditional call to blk_revalidate_disk_zones() will do that.
So remove the assignment using bdev_nr_zones().
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240621031506.759397-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the zone_resetall flag into the queue_limits feature field so that
it can be set atomically with the queue frozen.
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/20240617060532.127975-24-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the zoned flags into the features field to reclaim a little
bit of space.
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/20240617060532.127975-23-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the nonrot flag into the queue_limits feature field so that it can
be set atomically with the queue frozen.
Use the chance to switch to defaulting to non-rotational and require
the driver to opt into rotational, which matches the polarity of the
sysfs interface.
For the z2ram, ps3vram, 2x memstick, ubiblock and dcssblk the new
rotational flag is not set as they clearly are not rotational despite
this being a behavior change. There are some other drivers that
unconditionally set the rotational flag to keep the existing behavior
as they arguably can be used on rotational devices even if that is
probably not their main use today (e.g. virtio_blk and drbd).
The flag is automatically inherited in blk_stack_limits matching the
existing behavior in dm and md.
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/20240617060532.127975-15-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Block size should be between 512 and PAGE_SIZE and be a power of 2. The current
check does not validate this, so update the check.
Without this patch, null_blk would Oops due to a null pointer deref when
loaded with bs=1536 [1].
Link: https://lore.kernel.org/all/87wmn8mocd.fsf@metaspace.dk/
Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20240603192645.977968-1-nmi@metaspace.dk
[axboe: remove unnecessary braces and != 0 check]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
A zoned device with a smaller last zone together with a zone capacity
smaller than the zone size does make any sense as that does not
correspond to any possible setup for a real device:
1) For ZNS and zoned UFS devices, all zones are always the same size.
2) For SMR HDDs, all zones always have the same capacity.
In other words, if we have a smaller last runt zone, then this zone
capacity should always be equal to the zone size.
Add a check in null_init_zoned_dev() to prevent a configuration to have
both a smaller zone size and a zone capacity smaller than the zone size.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240530054035.491497-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When changing the maximum number of open zones, print that number
instead of the total number of zones.
Fixes: dc4d137ee3 ("null_blk: add support for max open/active zone limit for zoned devices")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Link: https://lore.kernel.org/r/20240528062852.437599-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When powering on a null_blk device that is not already on, the return
value ret that is initialized to be count is reused to check the return
value of null_add_dev(), leading to nullb_device_power_store() to return
null_add_dev() return value (0 on success) instead of "count".
So make sure to set ret to be equal to count when there are no errors.
Fixes: a2db328b08 ("null_blk: fix null-ptr-dereference while configuring 'power' and 'submit_queues'")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20240527043445.235267-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Writing 'power' and 'submit_queues' concurrently will trigger kernel
panic:
Test script:
modprobe null_blk nr_devices=0
mkdir -p /sys/kernel/config/nullb/nullb0
while true; do echo 1 > submit_queues; echo 4 > submit_queues; done &
while true; do echo 1 > power; echo 0 > power; done
Test result:
BUG: kernel NULL pointer dereference, address: 0000000000000148
Oops: 0000 [#1] PREEMPT SMP
RIP: 0010:__lock_acquire+0x41d/0x28f0
Call Trace:
<TASK>
lock_acquire+0x121/0x450
down_write+0x5f/0x1d0
simple_recursive_removal+0x12f/0x5c0
blk_mq_debugfs_unregister_hctxs+0x7c/0x100
blk_mq_update_nr_hw_queues+0x4a3/0x720
nullb_update_nr_hw_queues+0x71/0xf0 [null_blk]
nullb_device_submit_queues_store+0x79/0xf0 [null_blk]
configfs_write_iter+0x119/0x1e0
vfs_write+0x326/0x730
ksys_write+0x74/0x150
This is because del_gendisk() can concurrent with
blk_mq_update_nr_hw_queues():
nullb_device_power_store nullb_apply_submit_queues
null_del_dev
del_gendisk
nullb_update_nr_hw_queues
if (!dev->nullb)
// still set while gendisk is deleted
return 0
blk_mq_update_nr_hw_queues
dev->nullb = NULL
Fix this problem by resuing the global mutex to protect
nullb_device_power_store() and nullb_update_nr_hw_queues() from configfs.
Fixes: 45919fbfe1 ("null_blk: Enable modifying 'submit_queues' after an instance has been configured")
Reported-and-tested-by: Yi Zhang <yi.zhang@redhat.com>
Closes: https://lore.kernel.org/all/CAHj4cs9LgsHLnjg8z06LQ3Pr5cax-+Ps+xT7AP7TPnEjStuwZA@mail.gmail.com/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Link: https://lore.kernel.org/r/20240523153934.1937851-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Fix the following sparse warnings:
drivers/block/null_blk/main.c:1243:35: warning: incorrect type in return expression (different base types)
drivers/block/null_blk/main.c:1243:35: expected int
drivers/block/null_blk/main.c:1243:35: got restricted blk_status_t
drivers/block/null_blk/main.c:1291:30: warning: incorrect type in return expression (different base types)
drivers/block/null_blk/main.c:1291:30: expected restricted blk_status_t
drivers/block/null_blk/main.c:1291:30: got int
Cc: Christoph Hellwig <hch@lst.de>
Cc: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240510201816.24921-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-6.10/block-20240511' of git://git.kernel.dk/linux
Pull block updates from Jens Axboe:
- Add a partscan attribute in sysfs, fixing an issue with systemd
relying on an internal interface that went away.
- Attempt #2 at making long running discards interruptible. The
previous attempt went into 6.9, but we ended up mostly reverting it
as it had issues.
- Remove old ida_simple API in bcache
- Support for zoned write plugging, greatly improving the performance
on zoned devices.
- Remove the old throttle low interface, which has been experimental
since 2017 and never made it beyond that and isn't being used.
- Remove page->index debugging checks in brd, as it hasn't caught
anything and prepares us for removing in struct page.
- MD pull request from Song
- Don't schedule block workers on isolated CPUs
* tag 'for-6.10/block-20240511' of git://git.kernel.dk/linux: (84 commits)
blk-throttle: delay initialization until configuration
blk-throttle: remove CONFIG_BLK_DEV_THROTTLING_LOW
block: fix that util can be greater than 100%
block: support to account io_ticks precisely
block: add plug while submitting IO
bcache: fix variable length array abuse in btree_iter
bcache: Remove usage of the deprecated ida_simple_xx() API
md: Revert "md: Fix overflow in is_mddev_idle"
blk-lib: check for kill signal in ioctl BLKDISCARD
block: add a bio_await_chain helper
block: add a blk_alloc_discard_bio helper
block: add a bio_chain_and_submit helper
block: move discard checks into the ioctl handler
block: remove the discard_granularity check in __blkdev_issue_discard
block/ioctl: prefer different overflow check
null_blk: Fix the WARNING: modpost: missing MODULE_DESCRIPTION()
block: fix and simplify blkdevparts= cmdline parsing
block: refine the EOF check in blkdev_iomap_begin
block: add a partscan sysfs attribute for disks
block: add a disk_has_partscan helper
...
When a mutex lock is not used any more, the function mutex_destroy
should be called to mark the mutex lock uninitialized.
Fixes: f2298c0403 ("null_blk: multi queue aware block test driver")
Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Link: https://lore.kernel.org/r/20240425171635.4227-1-yanjun.zhu@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In null_zone_write, we do not need to first check if the target zone
condition is FULL, READONLY or OFFLINE: for theses conditions, the check
of the command sector against the zone write pointer will always result
in the command failing. Remove these checks.
We still however need to check that the target zone write pointer is not
invalid for zone append operations. To do so, add the macro
NULL_ZONE_INVALID_WP and use it in null_set_zone_cond() when changing a
zone to READONLY or OFFLINE condition.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240411085502.728558-4-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
For zoned null_blk devices setup without any limit on the maximum number
of open and active zones, there is no need to count the number of zones
that are implicitly open, explicitly open and closed. This is indicated
by the boolean field need_zone_res_mgmt of sturct nullb_device.
Modify the zone management functions null_reset_zone(),
null_finish_zone(), null_open_zone() and null_close_zone() to manage
the zone condition counters only if the device need_zone_res_mgmt field
is true. With this change, the function __null_close_zone() is removed
and integrated into the 2 caller sites directly, with the
null_close_imp_open_zone() call site greatly simplified as this function
closes zones that are known to be in the implicit open condition.
null_zone_write() is modified in a similar manner to do zone condition
accouting only when the device need_zone_res_mgmt field is true.
With these changes, the inline helpers null_lock_zone_res() and
null_unlock_zone_res() are removed and replaced with direct calls to
spin_lock()/spin_unlock().
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240411085502.728558-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Modify the null_handle_flush() and null_handle_rq() functions to return
a blk_status_t instead of an errno to simplify the call sites of these
functions and to be consistant with other null_handle_xxx() functions.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Nitesh Shetty <nj.shetty@samsung.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240411085502.728558-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The only user of blk_revalidate_disk_zones() second argument was the
SCSI disk driver (sd). Now that this driver does not require this
update_driver_data argument, remove it to simplify the interface of
blk_revalidate_disk_zones(). Also update the function kdoc comment to
be more accurate (i.e. there is no gendisk ->revalidate method).
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-21-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add the fua configfs attribute and module parameter to allow
configuring if the device supports FUA or not. Using this attribute
has an effect on the null_blk device only if memory backing is enabled
together with a write cache (cache_size option).
This new attribute allows configuring a null_blk device with a write
cache but without FUA support. This is convenient to test the block
layer flush machinery.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-18-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add the zone_append_max_sectors configfs attribute and module parameter
to allow configuring the maximum number of 512B sectors of zone append
operations. This attribute is meaningful only for zoned null block
devices.
If not specified, the default is unchanged and the zoned device max
append sectors limit is set to the device max sectors limit.
If a non 0 value is used for this attribute, which is the default,
then native support for zone append operations is enabled.
Setting a 0 value disables native zone append operations support to
instead use the block layer emulation.
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-17-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
With zone write plugging enabled at the block layer level, a zoned
device can only ever see at most a single write operation per zone.
There is thus no need to request a block scheduler with strick per-zone
sequential write ordering control through the ELEVATOR_F_ZBD_SEQ_WRITE
feature. Removing this allows using a zoned null_blk device with any
scheduler, including "none".
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Tested-by: Hans Holmberg <hans.holmberg@wdc.com>
Tested-by: Dennis Maisenbacher <dennis.maisenbacher@wdc.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240408014128.205141-16-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In null_add_dev(), if an error happen after initializing the resources
for a zoned null block device, we must free these resources before
exiting the function. To ensure this, move the out_cleanup_zone label
after out_cleanup_disk as we jump to this latter label if an error
happens after calling null_init_zoned_dev().
Fixes: e440626b1c ("null_blk: pass queue_limits to blk_mq_alloc_disk")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240330005300.1503252-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since commit 8b631f9cf0 ("null_blk: remove the bio based I/O path"),
struct nullb members queue_depth and nr_queues are only ever written, so
delete them.
With that, null_exit_hctx() can also be deleted.
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20240222083420.6026-1-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pass the queue limits directly to blk_mq_alloc_disk instead of
setting them one at a time.
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: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240220093248.3290292-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
null_gendisk_register isn't a very useful abstraction given that it
doesn't even allocate the gendisk. Merge it into the only caller
instead.
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: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240220093248.3290292-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Move the tagset initialization out of null_add_dev into a new
null_setup_tagset helper, and move the shared vs local differences
out of null_init_tag_set into the callers.
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: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240220093248.3290292-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Otherwise it will be reset to the always same value when initializing a
device using the shared tag_set.
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: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240220093248.3290292-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The bio based I/O path complicates null_blk and also make various
data structures, including the per-command one way bigger than
required for the main request based interface. As the bio-based
path is mostly used by stacking drivers and simple memory based
drivers, and brd is a good example driver for the latter there is
no need to have a bio based path in null_blk. Remove the path
to simplify the driver and make future block layer API changes
simpler by not having to deal with the complex two API setup in
null_blk.
Note that the queue_mode field in struct nullb_device is kept as
that is simpler than having two different places to check the
value and fully open coding the debugfs helpers as the existing
ones won't work without a named struct member.
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: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240220093248.3290292-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pass a queue_limits to blk_alloc_disk and apply it if non-NULL. This
will allow allocating queues with valid queue limits instead of setting
the values one at a time later.
Also change blk_alloc_disk to return an ERR_PTR instead of just NULL
which can't distinguish errors.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Link: https://lore.kernel.org/r/20240215071055.2201424-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pass a queue_limits to blk_mq_alloc_disk and apply it if non-NULL. This
will allow allocating queues with valid queue limits instead of setting
the values one at a time later.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20240213073425.1621680-11-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Allow setting shared_tags through configfs, which could only be set as a
module parameter. For that purpose, delay tag_set initialization from
null_init() to null_add_dev(). Refer tag_set.ops as the flag to check if
tag_set is initialized or not.
The following parameters can not be set through configfs yet:
timeout
requeue
init_hctx
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20240130042134.2463659-1-shinichiro.kawasaki@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The discard granularity now defaults to a single sector, so don't set
that value explicitly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231228075545.362768-7-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
null_blk has some rather odd capping of the max_hw_sectors value to
BLK_DEF_MAX_SECTORS, which doesn't make sense - max_hw_sector is the
hardware limit, and BLK_DEF_MAX_SECTORS despite the confusing name is the
default cap for the max_sectors field used for normal file system I/O.
Remove all the capping, and simply leave it to the block layer or
user to take up or not all of that for file system I/O.
Fixes: ea17fd354c ("null_blk: Allow controlling max_hw_sectors limit")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20231227092305.279567-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Only use disk_set_zoned to actually enable zoned device support.
For clearing it, call disk_clear_zoned, which is renamed from
disk_clear_zone_settings and now directly clears the zoned flag as
well.
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/20231217165359.604246-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When zones were first added the SCSI and ATA specs, two different
models were supported (in addition to the drive managed one that
is invisible to the host):
- host managed where non-conventional zones there is strict requirement
to write at the write pointer, or else an error is returned
- host aware where a write point is maintained if writes always happen
at it, otherwise it is left in an under-defined state and the
sequential write preferred zones behave like conventional zones
(probably very badly performing ones, though)
Not surprisingly this lukewarm model didn't prove to be very useful and
was finally removed from the ZBC and SBC specs (NVMe never implemented
it). Due to to the easily disappearing write pointer host software
could never rely on the write pointer to actually be useful for say
recovery.
Fortunately only a few HDD prototypes shipped using this model which
never made it to mass production. Drop the support before it is too
late. Note that any such host aware prototype HDD can still be used
with Linux as we'll now treat it as a conventional HDD.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20231217165359.604246-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION is enabled, null_queue_rq()
would return BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE for the request,
which has been marked as MQ_RQ_IN_FLIGHT by blk_mq_start_request().
Then null_queue_rqs() put these requests in the rqlist, return back to
the block layer core, which would try to queue them individually again,
so the warning in blk_mq_start_request() triggered.
Fix it by splitting the null_queue_rq() into two parts: the first is the
preparation of request, the second is the handling of request. We put
the blk_mq_start_request() after the preparation part, which may fail
and return back to the block layer core.
The throttling also belongs to the preparation part, so move it before
blk_mq_start_request(). And change the return type of null_handle_cmd()
to void, since it always return BLK_STS_OK now.
Reported-by: <syzbot+fcc47ba2476570cbbeb0@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/all/0000000000000e6aac06098aee0c@google.com/
Fixes: d78bfa1346 ("block/null_blk: add queue_rqs() support")
Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Link: https://lore.kernel.org/r/20231120032521.1012037-1-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
`strncpy` is deprecated for use on NUL-terminated destination strings [1].
We should favor a more robust and less ambiguous interface.
We expect that both `nullb->disk_name` and `disk->disk_name` be
NUL-terminated:
| snprintf(nullb->disk_name, sizeof(nullb->disk_name),
| "%s", config_item_name(&dev->group.cg_item));
...
| pr_info("disk %s created\n", nullb->disk_name);
It seems like NUL-padding may be required due to __assign_disk_name()
utilizing a memcpy as opposed to a `str*cpy` api.
| static inline void __assign_disk_name(char *name, struct gendisk *disk)
| {
| if (disk)
| memcpy(name, disk->disk_name, DISK_NAME_LEN);
| else
| memset(name, 0, DISK_NAME_LEN);
| }
Then we go and print it with `__print_disk_name` which wraps `nullb_trace_disk_name()`.
| #define __print_disk_name(name) nullb_trace_disk_name(p, name)
This function obviously expects a NUL-terminated string.
| const char *nullb_trace_disk_name(struct trace_seq *p, char *name)
| {
| const char *ret = trace_seq_buffer_ptr(p);
|
| if (name && *name)
| trace_seq_printf(p, "disk=%s, ", name);
| trace_seq_putc(p, 0);
|
| return ret;
| }
>From the above, we need both 1) a NUL-terminated string and 2) a
NUL-padded string. So, let's use strscpy_pad() as per Kees' suggestion
from v1.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230919-strncpy-drivers-block-null_blk-main-c-v3-1-10cf0a87a2c3@google.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add batched mq_ops.queue_rqs() support in null_blk for testing. The
implementation is much easy since null_blk doesn't have commit_rqs().
We simply handle each request one by one, if errors are encountered,
leave them in the passed in list and return back.
There is about 3.6% improvement in IOPS of fio/t/io_uring on null_blk
with hw_queue_depth=256 on my test VM, from 1.09M to 1.13M.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230913151616.3164338-6-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When doing io_uring benchmark on /dev/nullb0, it's easy to crash the
kernel if poll requests timeout triggered, as reported by David. [1]
BUG: kernel NULL pointer dereference, address: 0000000000000008
Workqueue: kblockd blk_mq_timeout_work
RIP: 0010:null_timeout_rq+0x4e/0x91
Call Trace:
? null_timeout_rq+0x4e/0x91
blk_mq_handle_expired+0x31/0x4b
bt_iter+0x68/0x84
? bt_tags_iter+0x81/0x81
__sbitmap_for_each_set.constprop.0+0xb0/0xf2
? __blk_mq_complete_request_remote+0xf/0xf
bt_for_each+0x46/0x64
? __blk_mq_complete_request_remote+0xf/0xf
? percpu_ref_get_many+0xc/0x2a
blk_mq_queue_tag_busy_iter+0x14d/0x18e
blk_mq_timeout_work+0x95/0x127
process_one_work+0x185/0x263
worker_thread+0x1b5/0x227
This is indeed a race problem between null_timeout_rq() and null_poll().
null_poll() null_timeout_rq()
spin_lock(&nq->poll_lock)
list_splice_init(&nq->poll_list, &list)
spin_unlock(&nq->poll_lock)
while (!list_empty(&list))
req = list_first_entry()
list_del_init()
...
blk_mq_add_to_batch()
// req->rq_next = NULL
spin_lock(&nq->poll_lock)
// rq->queuelist->next == NULL
list_del_init(&rq->queuelist)
spin_unlock(&nq->poll_lock)
Fix these problems by setting requests state to MQ_RQ_COMPLETE under
nq->poll_lock protection, in which null_timeout_rq() can safely detect
this race and early return.
Note this patch just fix the kernel panic when request timeout happen.
[1] https://lore.kernel.org/all/3893581.1691785261@warthog.procyon.org.uk/
Fixes: 0a593fbbc2 ("null_blk: poll queue support")
Reported-by: David Howells <dhowells@redhat.com>
Tested-by: David Howells <dhowells@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Link: https://lore.kernel.org/r/20230901120306.170520-2-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
