linux.git/drivers/block/nbd.c, branch v6.13

nbd: correct the maximum value for discard sectors

2024-09-06T14:31:40+00:00

The version of the NBD protocol implemented by the kernel driver
currently has a 32 bit field for length values. As the NBD protocol uses
bytes as a unit of length, length values larger than 2^32 bytes cannot
be expressed.

Update the max_hw_discard_sectors field to match that.

Signed-off-by: Wouter Verhelst 
Fixes: 268283244c0f ("nbd: use the atomic queue limits API in nbd_set_size")
Reviewed-by: Damien Le Moal 
Cc: Eric Blake 
Link: https://lore.kernel.org/r/20240812133032.115134-8-w@uter.be
Signed-off-by: Jens Axboe

nbd: nbd_bg_flags_show: add NBD_FLAG_ROTATIONAL

2024-09-06T14:31:40+00:00

Also handle NBD_FLAG_ROTATIONAL in our debug helper function

Signed-off-by: Wouter Verhelst 
Cc: Eric Blake 
Link: https://lore.kernel.org/r/20240812133032.115134-6-w@uter.be
Signed-off-by: Jens Axboe

nbd: implement the WRITE_ZEROES command

2024-09-06T14:31:40+00:00

The NBD protocol defines a message for zeroing out a region of an export

Add support to the kernel driver for that message.

Signed-off-by: Wouter Verhelst 
Cc: Eric Blake 
Reviewed-by: Damien Le Moal 
Link: https://lore.kernel.org/r/20240812133032.115134-3-w@uter.be
Signed-off-by: Jens Axboe

nbd: fix race between timeout and normal completion

2024-08-30T20:46:59+00:00

If request timetout is handled by nbd_requeue_cmd(), normal completion
has to be stopped for avoiding to complete this requeued request, other
use-after-free can be triggered.

Fix the race by clearing NBD_CMD_INFLIGHT in nbd_requeue_cmd(), meantime
make sure that cmd->lock is grabbed for clearing the flag and the
requeue.

Cc: Josef Bacik 
Cc: Yu Kuai 
Fixes: 2895f1831e91 ("nbd: don't clear 'NBD_CMD_INFLIGHT' flag if request is not completed")
Signed-off-by: Ming Lei 
Reviewed-by: Yu Kuai 
Link: https://lore.kernel.org/r/20240830034145.1827742-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe

nbd: add support for rotational devices

2024-07-28T22:47:52+00:00

The NBD protocol defines the flag NBD_FLAG_ROTATIONAL to flag that the
export in use should be treated as a rotational device.

Add support for that flag to the kernel driver.

Signed-off-by: Wouter Verhelst 
Reviewed-by: Eric Blake 
Link: https://lore.kernel.org/r/20240725164536.1275851-1-w@uter.be
Signed-off-by: Jens Axboe

Merge tag 'for-6.11/block-20240710' of git://git.kernel.dk/linux

2024-07-15T21:20:22+00:00

Pull block updates from Jens Axboe:

 - NVMe updates via Keith:
     - Device initialization memory leak fixes (Keith)
     - More constants defined (Weiwen)
     - Target debugfs support (Hannes)
     - PCIe subsystem reset enhancements (Keith)
     - Queue-depth multipath policy (Redhat and PureStorage)
     - Implement get_unique_id (Christoph)
     - Authentication error fixes (Gaosheng)

 - MD updates via Song
     - sync_action fix and refactoring (Yu Kuai)
     - Various small fixes (Christoph Hellwig, Li Nan, and Ofir Gal, Yu
       Kuai, Benjamin Marzinski, Christophe JAILLET, Yang Li)

 - Fix loop detach/open race (Gulam)

 - Fix lower control limit for blk-throttle (Yu)

 - Add module descriptions to various drivers (Jeff)

 - Add support for atomic writes for block devices, and statx reporting
   for same. Includes SCSI and NVMe (John, Prasad, Alan)

 - Add IO priority information to block trace points (Dongliang)

 - Various zone improvements and tweaks (Damien)

 - mq-deadline tag reservation improvements (Bart)

 - Ignore direct reclaim swap writes in writeback throttling (Baokun)

 - Block integrity improvements and fixes (Anuj)

 - Add basic support for rust based block drivers. Has a dummy null_blk
   variant for now (Andreas)

 - Series converting driver settings to queue limits, and cleanups and
   fixes related to that (Christoph)

 - Cleanup for poking too deeply into the bvec internals, in preparation
   for DMA mapping API changes (Christoph)

 - Various minor tweaks and fixes (Jiapeng, John, Kanchan, Mikulas,
   Ming, Zhu, Damien, Christophe, Chaitanya)

* tag 'for-6.11/block-20240710' of git://git.kernel.dk/linux: (206 commits)
  floppy: add missing MODULE_DESCRIPTION() macro
  loop: add missing MODULE_DESCRIPTION() macro
  ublk_drv: add missing MODULE_DESCRIPTION() macro
  xen/blkback: add missing MODULE_DESCRIPTION() macro
  block/rnbd: Constify struct kobj_type
  block: take offset into account in blk_bvec_map_sg again
  block: fix get_max_segment_size() warning
  loop: Don't bother validating blocksize
  virtio_blk: Don't bother validating blocksize
  null_blk: Don't bother validating blocksize
  block: Validate logical block size in blk_validate_limits()
  virtio_blk: Fix default logical block size fallback
  nvmet-auth: fix nvmet_auth hash error handling
  nvme: implement ->get_unique_id
  block: pass a phys_addr_t to get_max_segment_size
  block: add a bvec_phys helper
  blk-lib: check for kill signal in ioctl BLKZEROOUT
  block: limit the Write Zeroes to manually writing zeroes fallback
  block: refacto blkdev_issue_zeroout
  block: move read-only and supported checks into (__)blkdev_issue_zeroout
  ...

block: move the nonrot flag to queue_limits

2024-06-19T13:58:28+00:00

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 
Reviewed-by: Damien Le Moal 
Reviewed-by: Hannes Reinecke 
Link: https://lore.kernel.org/r/20240617060532.127975-15-hch@lst.de
Signed-off-by: Jens Axboe

block: move cache control settings out of queue->flags

2024-06-19T13:58:28+00:00

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 
Acked-by: Ulf Hansson 
Reviewed-by: Damien Le Moal 
Reviewed-by: Hannes Reinecke 
Link: https://lore.kernel.org/r/20240617060532.127975-14-hch@lst.de
Signed-off-by: Jens Axboe

nbd: move setting the cache control flags to __nbd_set_size

2024-06-19T13:58:28+00:00

Move setting the cache control flags in nbd in preparation for moving
these flags into the queue_limits structure.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Bart Van Assche 
Reviewed-by: Josef Bacik 
Reviewed-by: Damien Le Moal 
Reviewed-by: Hannes Reinecke 
Link: https://lore.kernel.org/r/20240617060532.127975-11-hch@lst.de
Signed-off-by: Jens Axboe

block: take io_opt and io_min into account for max_sectors

2024-06-14T16:19:44+00:00

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 
Reviewed-by: Bart Van Assche 
Reviewed-by: Damien Le Moal 
Acked-by: Ilya Dryomov 
Reviewed-by: Martin K. Petersen 
Link: https://lore.kernel.org/r/20240531074837.1648501-5-hch@lst.de
Signed-off-by: Jens Axboe