1
Commit Graph

116 Commits

Author SHA1 Message Date
Linus Torvalds
3e78198862 for-6.11/block-20240710
-----BEGIN PGP SIGNATURE-----
 
 iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAmaOTd8QHGF4Ym9lQGtl
 cm5lbC5kawAKCRD301j7KXHgppqIEACUr8Vv2FtezvT3OfVSlYWHHLXzkRhwEG5s
 vdk0o7Ow6U54sMjfymbHTgLD0ZOJf3uJ6BI95FQuW41jPzDFVbx4Hy8QzqonMkw9
 1D/YQ4zrVL2mOKBzATbKpoGJzMOzGeoXEueFZ1AYPAX7RrDtP4xPQNfrcfkdE2zF
 LycJN70Vp6lrZZMuI9yb9ts1tf7TFzK0HJANxOAKTgSiPmBmxesjkJlhrdUrgkAU
 qDVyjj7u/ssndBJAb9i6Bl95Do8s9t4DeJq5/6wgKqtf5hClMXzPVB8Wy084gr6E
 rTRsCEhOug3qEZSqfAgAxnd3XFRNc/p2KMUe5YZ4mAqux4hpSmIQQDM/5X5K9vEv
 f4MNqUGlqyqntZx+KPyFpf7kLHFYS1qK4ub0FojWJEY4GrbBPNjjncLJ9+ozR0c8
 kNDaFjMNAjalBee1FxNNH8LdVcd28rrCkPxRLEfO/gvBMUmvJf4ZyKmSED0v5DhY
 vZqKlBqG+wg0EXvdiWEHMDh9Y+q/2XBIkS6NN/Bhh61HNu+XzC838ts1X7lR+4o2
 AM5Vapw+v0q6kFBMRP3IcJI/c0UcIU8EQU7axMyzWtvhog8kx8x01hIj1L4UyYYr
 rUdWrkugBVXJbywFuH/QIJxWxS/z4JdSw5VjASJLIrXy+aANmmG9Wonv95eyhpUv
 5iv+EdRSNA==
 =wVi8
 -----END PGP SIGNATURE-----

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

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
  ...
2024-07-15 14:20:22 -07:00
Damien Le Moal
2f20872ed4 block: Remove blk_alloc_zone_bitmap()
Remove the helper function blk_alloc_zone_bitmap() and replace its
single call site with a call to bitmap_alloc(). To be consistent with
this change, use bitmap_free() to free a disk convnetional zone bitmap.

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/20240704052816.623865-6-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-07-05 00:42:04 -06:00
Damien Le Moal
f2a7bea237 block: Remove REQ_OP_ZONE_RESET_ALL emulation
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>
2024-07-05 00:42:04 -06:00
Damien Le Moal
b6cfe2287d block: Define bdev_nr_zones() as an inline function
There is no need for bdev_nr_zones() to be an exported function
calculating the number of zones of a block device. Instead, given that
all callers use this helper with a fully initialized block device that
has a gendisk, we can redefine this function as an inline helper in
blkdev.h.

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/20240621031506.759397-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-21 08:26:35 -06:00
Damien Le Moal
e21d12c7cd block: Improve checks on zone resource limits
Make sure that the zone resource limits of a zoned block device are
correct by checking that:
(a) If the device has a max active zones limit, make sure that the max
    open zones limit is lower than the max active zones limit.
(b) If the device has zone resource limits, check that the limits
    values are lower than the number of sequential zones of the device.
    If it is not, assume that the zoned device has no limits by setting
    the limits to 0.

For (a), a check is added to blk_validate_zoned_limits() and an error
returned if the max open zones limit exceeds the value of the max active
zone limit (if there is one).

For (b), given that we need the number of sequential zones of the zoned
device, this check is added to disk_update_zone_resources(). This is
safe to do as that function is executed with the disk queue frozen and
the check executed after queue_limits_start_update() which takes the
queue limits lock. Of note is that the early return in this function
for zoned devices that do not use zone write plugging (e.g. DM devices
using native zone append) is moved to after the new check and adjustment
of the zone resource limits so that the check applies to any zoned
device.

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: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
Link: https://lore.kernel.org/r/20240611023639.89277-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-15 20:42:20 -06:00
Damien Le Moal
1933192a91 block: Optimize disk zone resource cleanup
For zoned block devices using zone write plugging, an rcu_barrier() call
is needed in disk_free_zone_resources() to synchronize freeing of zone
write plugs and the destrution of the mempool used to allocate the
plugs. The barrier call does slow down a little teardown of zoned block
devices but should not affect teardown of regular block devices or zoned
block devices that do not use zone write plugging (e.g. zoned DM devices
that do not require zone append emulation).

Modify disk_free_zone_resources() to return early if we do not have a
mempool to start with, that is, if the device does not use zone write
plugging. This avoids the costly rcu_barrier() and speeds up disk
teardown.

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: dd291d77cc ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Link: https://lore.kernel.org/r/20240607002126.104227-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-06-12 10:56:45 -06:00
Damien Le Moal
29459c3eaa block: Fix zone write plugging handling of devices with a runt zone
A zoned device may have a last sequential write required zone that is
smaller than other zones. However, all tests to check if a zone write
plug write offset exceeds the zone capacity use the same capacity
value stored in the gendisk zone_capacity field. This is incorrect for a
zoned device with a last runt (smaller) zone.

Add the new field last_zone_capacity to struct gendisk to store the
capacity of the last zone of the device. blk_revalidate_seq_zone() and
blk_revalidate_conv_zone() are both modified to get this value when
disk_zone_is_last() returns true. Similarly to zone_capacity, the value
is first stored using the last_zone_capacity field of struct
blk_revalidate_zone_args. Once zone revalidation of all zones is done,
this is used to set the gendisk last_zone_capacity field.

The checks to determine if a zone is full or if a sector offset in a
zone exceeds the zone capacity in disk_should_remove_zone_wplug(),
disk_zone_wplug_abort_unaligned(), blk_zone_write_plug_init_request(),
and blk_zone_wplug_prepare_bio() are modified to use the new helper
functions disk_zone_is_full() and disk_zone_wplug_is_full().
disk_zone_is_full() uses the zone index to determine if the zone being
tested is the last one of the disk and uses the either the disk
zone_capacity or last_zone_capacity accordingly.

Fixes: dd291d77cc ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Link: https://lore.kernel.org/r/20240530054035.491497-4-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-30 15:03:52 -06:00
Damien Le Moal
cd63999368 block: Fix validation of zoned device with a runt zone
Commit ecfe43b11b ("block: Remember zone capacity when revalidating
zones") introduced checks to ensure that the capacity of the zones of
a zoned device is constant for all zones. However, this check ignores
the possibility that a zoned device has a smaller last zone with a size
not equal to the capacity of other zones. Such device correspond in
practice to an SMR drive with a smaller last zone and all zones with a
capacity equal to the zone size, leading to the last zone capacity being
different than the capacity of other zones.

Correctly handle such device by fixing the check for the constant zone
capacity in blk_revalidate_seq_zone() using the new helper function
disk_zone_is_last(). This helper function is also used in
blk_revalidate_zone_cb() when checking the zone size.

Fixes: ecfe43b11b ("block: Remember zone capacity when revalidating zones")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
Link: https://lore.kernel.org/r/20240530054035.491497-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-30 15:03:52 -06:00
Linus Torvalds
3413efa888 Compactifying bdev flags
We can easily have up to 24 flags with sane
 atomicity, _without_ pushing anything out
 of the first cacheline of struct block_device.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCZkznRwAKCRBZ7Krx/gZQ
 69XpAQDOZCyvYOZ/dlMOKKLf2vAojC/h++E/NjvGt3erbvVN2wEArXMi13ECsoCw
 JYJA3MsmvjuY6VNcm24icf2/p4TMIgo=
 =JyYi
 -----END PGP SIGNATURE-----

Merge tag 'pull-bd_flags-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull bdev flags update from Al Viro:
 "Compactifying bdev flags.

  We can easily have up to 24 flags with sane atomicity, _without_
  pushing anything out of the first cacheline of struct block_device"

* tag 'pull-bd_flags-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  bdev: move ->bd_make_it_fail to ->__bd_flags
  bdev: move ->bd_ro_warned to ->__bd_flags
  bdev: move ->bd_has_subit_bio to ->__bd_flags
  bdev: move ->bd_write_holder into ->__bd_flags
  bdev: move ->bd_read_only to ->__bd_flags
  bdev: infrastructure for flags
  wrapper for access to ->bd_partno
  Use bdev_is_paritition() instead of open-coding it
2024-05-21 13:02:56 -07:00
Linus Torvalds
38da32ee70 bd_inode series
Replacement of bdev->bd_inode with sane(r) set of primitives.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQQqUNBr3gm4hGXdBJlZ7Krx/gZQ6wUCZkwjlgAKCRBZ7Krx/gZQ
 66OmAP9nhZLASn/iM2+979I6O0GW+vid+uLh48uW3d+LbsmVIgD9GYpR+cuLQ/xj
 mJESWfYKOVSpFFSrqlzKg9PQlU/GFgs=
 =6LRp
 -----END PGP SIGNATURE-----

Merge tag 'pull-bd_inode-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull bdev bd_inode updates from Al Viro:
 "Replacement of bdev->bd_inode with sane(r) set of primitives by me and
  Yu Kuai"

* tag 'pull-bd_inode-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RIP ->bd_inode
  dasd_format(): killing the last remaining user of ->bd_inode
  nilfs_attach_log_writer(): use ->bd_mapping->host instead of ->bd_inode
  block/bdev.c: use the knowledge of inode/bdev coallocation
  gfs2: more obvious initializations of mapping->host
  fs/buffer.c: massage the remaining users of ->bd_inode to ->bd_mapping
  blk_ioctl_{discard,zeroout}(): we only want ->bd_inode->i_mapping here...
  grow_dev_folio(): we only want ->bd_inode->i_mapping there
  use ->bd_mapping instead of ->bd_inode->i_mapping
  block_device: add a pointer to struct address_space (page cache of bdev)
  missing helpers: bdev_unhash(), bdev_drop()
  block: move two helpers into bdev.c
  block2mtd: prevent direct access of bd_inode
  dm-vdo: use bdev_nr_bytes(bdev) instead of i_size_read(bdev->bd_inode)
  blkdev_write_iter(): saner way to get inode and bdev
  bcachefs: remove dead function bdev_sectors()
  ext4: remove block_device_ejected()
  erofs_buf: store address_space instead of inode
  erofs: switch erofs_bread() to passing offset instead of block number
2024-05-21 09:51:42 -07:00
Al Viro
224941e837 use ->bd_mapping instead of ->bd_inode->i_mapping
Just the low-hanging fruit...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lore.kernel.org/r/20240411145346.2516848-2-viro@zeniv.linux.org.uk
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-05-03 02:36:51 -04:00
Damien Le Moal
d7580149ef block: Cleanup blk_revalidate_zone_cb()
Define the code for checking conventional and sequential write required
zones suing the functions blk_revalidate_conv_zone() and
blk_revalidate_seq_zone() respectively. This simplifies the zone type
switch-case in blk_revalidate_zone_cb().

No functional changes.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240501110907.96950-15-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:43 -06:00
Damien Le Moal
c9c8aea03c block: Simplify zone write plug BIO abort
When BIOs plugged in a zone write plug are aborted,
blk_zone_wplug_bio_io_error() clears the BIO BIO_ZONE_WRITE_PLUGGING
flag so that bio_io_error(bio) does not end up calling
blk_zone_write_plug_bio_endio() and we thus need to manually drop the
reference on the zone write plug held by the aborted BIO.

Move the call to disk_put_zone_wplug() that is alwasy following the call
to blk_zone_wplug_bio_io_error() inside that function to simplify the
code.

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/20240501110907.96950-14-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:43 -06:00
Damien Le Moal
b5a64ec2ea block: Simplify blk_zone_write_plug_bio_endio()
We already have the disk variable obtained from the bio when calling
disk_get_zone_wplug(). So use that variable instead of dereferencing the
bio bdev again for the disk argument of disk_get_zone_wplug().

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/20240501110907.96950-13-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:43 -06:00
Damien Le Moal
347bde9da1 block: Improve zone write request completion handling
blk_zone_complete_request() must be called to handle the completion of a
zone write request handled with zone write plugging. This function is
called from blk_complete_request(), blk_update_request() and also in
blk_mq_submit_bio() error path. Improve this by moving this function
call into blk_mq_finish_request() as all requests are processed with
this function when they complete as well as when they are freed without
being executed. This also improves blk_update_request() used by scsi
devices as these may repeatedly call this function to handle partial
completions.

To be consistent with this change, blk_zone_complete_request() is
renamed to blk_zone_finish_request() and
blk_zone_write_plug_complete_request() is renamed to
blk_zone_write_plug_finish_request().

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/20240501110907.96950-12-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:43 -06:00
Damien Le Moal
c4c3ffdab2 block: Improve blk_zone_write_plug_bio_merged()
Improve blk_zone_write_plug_bio_merged() to check that we succefully get
a reference on the zone write plug of the merged BIO, as expected since
for a merge we already have at least one request and one BIO referencing
the zone write plug. Comments in this function are also improved to
better explain the references to the BIO zone write plug.

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/20240501110907.96950-11-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:43 -06:00
Damien Le Moal
096bc7ea33 block: Fix handling of non-empty flush write requests to zones
Zone write plugging ignores empty (no data) flush operations but handles
flush BIOs that have data to ensure that the flush machinery generated
write is processed in order. However, the call to
blk_zone_write_plug_attempt_merge() which sets a request
RQF_ZONE_WRITE_PLUGGING flag is called after blk_insert_flush(), thus
missing indicating that a non empty flush request completion needs
handling by zone write plugging.

Fix this by moving the call to blk_zone_write_plug_attempt_merge()
before blk_insert_flush(). And while at it, rename that function as
blk_zone_write_plug_init_request() to be clear that it is not just about
merging plugged BIOs in the request. While at it, also add a WARN_ONCE()
check that the zone write plug for the request is not NULL.

Fixes: dd291d77cc ("block: Introduce zone write plugging")
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/20240501110907.96950-10-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:43 -06:00
Damien Le Moal
7b29518728 block: Do not remove zone write plugs still in use
Large write BIOs that span a zone boundary are split in
blk_mq_submit_bio() before being passed to blk_zone_plug_bio() for zone
write plugging. Such split BIO will be chained with one fragment
targeting one zone and the remainder of the BIO targeting the next
zone. The two BIOs can be executed in parallel, without a predetermine
order relative to eachother and their completion may be reversed: the
remainder first completing and the first fragment then completing. In
such case, bio_endio() will not immediately execute
blk_zone_write_plug_bio_endio() for the parent BIO (the remainder of the
split BIO) as the BIOs are chained. blk_zone_write_plug_bio_endio() for
the parent BIO will be executed only once the first fragment completes.

In the case of a device with small zones and very large BIOs, uch
completion pattern can lead to disk_should_remove_zone_wplug() to return
true for the zone of the parent BIO when the parent BIO request
completes and blk_zone_write_plug_complete_request() is executed. This
triggers the removal of the zone write plug from the hash table using
disk_remove_zone_wplug(). With the zone write plug of the parent BIO
missing, the call to disk_get_zone_wplug() in
blk_zone_write_plug_bio_endio() returns NULL and triggers a warning.

This patterns can be recreated fairly easily using a scsi_debug device
with small zone and btrfs. E.g.

modprobe scsi_debug delay=0 dev_size_mb=1024 sector_size=4096 \
	zbc=host-managed zone_cap_mb=3 zone_nr_conv=0 zone_size_mb=4
mkfs.btrfs -f -O zoned /dev/sda
mount -t btrfs /dev/sda /mnt
fio --name=wrtest --rw=randwrite --direct=1 --ioengine=libaio \
	--bs=4k --iodepth=16 --size=1M --directory=/mnt --time_based \
	--runtime=10
umount /dev/sda

Will result in the warning:

[   29.035538] WARNING: CPU: 3 PID: 37 at block/blk-zoned.c:1207 blk_zone_write_plug_bio_endio+0xee/0x1e0
...
[   29.058682] Call Trace:
[   29.059095]  <TASK>
[   29.059473]  ? __warn+0x80/0x120
[   29.059983]  ? blk_zone_write_plug_bio_endio+0xee/0x1e0
[   29.060728]  ? report_bug+0x160/0x190
[   29.061283]  ? handle_bug+0x36/0x70
[   29.061830]  ? exc_invalid_op+0x17/0x60
[   29.062399]  ? asm_exc_invalid_op+0x1a/0x20
[   29.063025]  ? blk_zone_write_plug_bio_endio+0xee/0x1e0
[   29.063760]  bio_endio+0xb7/0x150
[   29.064280]  btrfs_clone_write_end_io+0x2b/0x60 [btrfs]
[   29.065049]  blk_update_request+0x17c/0x500
[   29.065666]  scsi_end_request+0x27/0x1a0 [scsi_mod]
[   29.066356]  scsi_io_completion+0x5b/0x690 [scsi_mod]
[   29.067077]  blk_complete_reqs+0x3a/0x50
[   29.067692]  __do_softirq+0xcf/0x2b3
[   29.068248]  ? sort_range+0x20/0x20
[   29.068791]  run_ksoftirqd+0x1c/0x30
[   29.069339]  smpboot_thread_fn+0xcc/0x1b0
[   29.069936]  kthread+0xcf/0x100
[   29.070438]  ? kthread_complete_and_exit+0x20/0x20
[   29.071314]  ret_from_fork+0x31/0x50
[   29.071873]  ? kthread_complete_and_exit+0x20/0x20
[   29.072563]  ret_from_fork_asm+0x11/0x20
[   29.073146]  </TASK>

either when fio executes or when unmount is executed.

Fix this by modifying disk_should_remove_zone_wplug() to check that the
reference count to a zone write plug is not larger than 2, that is, that
the only references left on the zone are the caller held reference
(blk_zone_write_plug_complete_request()) and the initial extra reference
for the zone write plug taken when it was initialized (and that is
dropped when the zone write plug is removed from the hash table).

To be consistent with this change, make sure to drop the request or BIO
held reference to the zone write plug before calling
disk_zone_wplug_unplug_bio(). All references are also dropped using
disk_put_zone_wplug() instead of atomic_dec() to ensure that the zone
write plug is freed if it needs to be.

Comments are also improved to clarify zone write plugs reference
handling.

Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Fixes: dd291d77cc ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20240501110907.96950-8-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:43 -06:00
Damien Le Moal
79ae35a423 block: Unhash a zone write plug only if needed
Fix disk_remove_zone_wplug() to ensure that a zone write plug already
removed from a disk hash table of zone write plugs is not removed
again. Do this by checking the BLK_ZONE_WPLUG_UNHASHED flag of the plug
and calling hlist_del_init_rcu() only if the flag is not set.

Furthermore, since BIO completions can happen at any time, that is,
decrementing of the zone write plug reference count can happen at any
time, make sure to use disk_put_zone_wplug() instead of atomic_dec() to
ensure that the zone write plug is freed when its last reference is
dropped. In order to do this, disk_remove_zone_wplug() is moved after
the definition of disk_put_zone_wplug(). disk_should_remove_zone_wplug()
is moved as well to keep it together with disk_remove_zone_wplug().

To be consistent with this change, add a check in disk_put_zone_wplug()
to ensure that a zone write plug being freed was already removed from
the disk hash table.

Fixes: dd291d77cc ("block: Introduce zone write plugging")
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/20240501110907.96950-7-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:43 -06:00
Damien Le Moal
9e78c38ab3 block: Hold a reference on zone write plugs to schedule submission
Since a zone write plug BIO work is a field of struct blk_zone_wplug, we
must ensure that a zone write plug is never freed when its BIO
submission work is queued or running. Do this by holding a reference on
the zone write plug when the submission work is scheduled for execution
with queue_work() and releasing the reference at the end of the
execution of the work function blk_zone_wplug_bio_work().
The helper function disk_zone_wplug_schedule_bio_work() is introduced to
get a reference on a zone write plug and queue its work. This helper is
used in disk_zone_wplug_unplug_bio() and disk_zone_wplug_handle_error().

Fixes: dd291d77cc ("block: Introduce zone write plugging")
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/20240501110907.96950-6-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:43 -06:00
Damien Le Moal
19aad274c2 block: Fix reference counting for zone write plugs in error state
When zone is reset or finished, disk_zone_wplug_set_wp_offset() is
called to update the zone write plug write pointer offset and to clear
the zone error state (BLK_ZONE_WPLUG_ERROR flag) if it is set.
However, this processing is missing dropping the reference to the zone
write plug that was taken in disk_zone_wplug_set_error() when the error
flag was first set. Furthermore, the error state handling must release
the zone write plug lock to first execute a report zones command. When
the report zone races with a reset or finish operation that clears the
error, we can end up decrementing the zone write plug reference count
twice: once in disk_zone_wplug_set_wp_offset() for the reset/finish
operation and one more time in disk_zone_wplugs_work() once
disk_zone_wplug_handle_error() completes.

Fix this by introducing disk_zone_wplug_clear_error() as the symmetric
function of disk_zone_wplug_set_error(). disk_zone_wplug_clear_error()
decrements the zone write plug reference count obtained in
disk_zone_wplug_set_error() only if the error handling has not started
yet, that is, only if disk_zone_wplugs_work() has not yet taken the zone
write plug off the error list. This ensure that either
disk_zone_wplug_clear_error() or disk_zone_wplugs_work() drop the zone
write plug reference count.

Fixes: dd291d77cc ("block: Introduce zone write plugging")
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/20240501110907.96950-5-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:43 -06:00
Damien Le Moal
74b7ae5f48 block: Fix zone write plug initialization from blk_revalidate_zone_cb()
When revalidating the zones of a zoned block device,
blk_revalidate_zone_cb() must allocate a zone write plug for any
sequential write required zone that is not empty nor full. However, the
current code tests the latter case by comparing the zone write pointer
offset to the zone size instead of the zone capacity. Furthermore,
disk_get_and_lock_zone_wplug() is called with a sector argument equal to
the zone start instead of the current zone write pointer position.
This commit fixes both issues by calling disk_get_and_lock_zone_wplug()
for a zone that is not empty and with a write pointer offset lower than
the zone capacity and use the zone capacity sector as the sector
argument for disk_get_and_lock_zone_wplug().

Fixes: dd291d77cc ("block: Introduce zone write plugging")
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/20240501110907.96950-4-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:42 -06:00
Damien Le Moal
6b7593b5fb block: Exclude conventional zones when faking max open limit
For a device that has no limits for the maximum number of open and
active zones, we default to using the number of zones, limited to
BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE (128), for the maximum number of open
zones indicated to the user. However, for a device that has conventional
zones and less zones than BLK_ZONE_WPLUG_DEFAULT_POOL_SIZE, we should
not account conventional zones and set the limit to the number of
sequential write required zones. Furthermore, for cases where the limit
is equal to the number of sequential write required zones, we can
advertize a limit of 0 to indicate "no limits".

Fix this by moving the zone write plug mempool resizing from
disk_revalidate_zone_resources() to disk_update_zone_resources() where
we can safely compute the number of conventional zones and update the
limits.

Fixes: 843283e96e ("block: Fake max open zones limit when there is no limit")
Reported-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
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/20240501110907.96950-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-01 08:08:42 -06:00
Johannes Thumshirn
57787fa42f block: check if zone_wplugs_hash exists in queue_zone_wplugs_show
Changhui reported a kernel crash when running this simple shell
reproducer:
 # cd /sys/kernel/debug/block && find  . -type f   -exec grep -aH . {} \;

The above results in a NULL pointer dereference if a device does not have
a zone_wplugs_hash allocated.

To fix this, return early if we don't have a zone_wplugs_hash.

Reported-by: Changhui Zhong <czhong@redhat.com>
Fixes: a98b05b02f ("block: Replace zone_wlock debugfs entry with zone_wplugs entry")
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/e5fec079dfca448cc21c425cfa5d7b291f5faa67.1714046443.git.johannes.thumshirn@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-25 07:47:46 -06:00
Damien Le Moal
a8f59e5a5d block: use a per disk workqueue for zone write plugging
A zone write plug BIO work function blk_zone_wplug_bio_work() calls
submit_bio_noacct_nocheck() to execute the next unplugged BIO. This
function may block. So executing zone plugs BIO works using the block
layer global kblockd workqueue can potentially lead to preformance or
latency issues as the number of concurrent work for a workqueue is
limited to WQ_DFL_ACTIVE (256).
1) For a system with a large number of zoned disks, issuing write
   requests to otherwise unused zones may be delayed wiating for a work
   thread to become available.
2) Requeue operations which use kblockd but are independent of zone
   write plugging may alsoi end up being delayed.

To avoid these potential performance issues, create a workqueue per
zoned device to execute zone plugs BIO work. The workqueue max active
parameter is set to the maximum number of zone write plugs allocated
with the zone write plug mempool. This limit is equal to the maximum
number of open zones of the disk and defaults to 128 for disks that do
not have a limit on the number of open zones.

Fixes: dd291d77cc ("block: Introduce zone write plugging")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240420075811.1276893-3-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-23 09:46:34 -06:00
Damien Le Moal
02ccd7c360 block: Remove zone write locking
Zone write locking is now unused and replaced with zone write plugging.
Remove all code that was implementing zone write locking, that is, the
various helper functions controlling request zone write locking and
the gendisk attached zone bitmaps.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
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/20240408014128.205141-27-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 08:44:03 -06:00
Damien Le Moal
a98b05b02f block: Replace zone_wlock debugfs entry with zone_wplugs entry
In preparation to completely remove zone write locking, replace the
"zone_wlock" mq-debugfs entry that was listing zones that are
write-locked with the zone_wplugs entry which lists the zones that
currently have a write plug allocated.

The write plug information provided is: the zone number, the zone write
plug flags, the zone write plug write pointer offset and the number of
BIOs currently waiting for execution in the zone write plug BIO list.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
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/20240408014128.205141-26-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 08:44:03 -06:00
Damien Le Moal
d9f1439a30 block: Move zone related debugfs attribute to blk-zoned.c
block/blk-mq-debugfs-zone.c contains a single debugfs attribute
function. Defining this outside of block/blk-zoned.c does not really
help in any way, so move this zone related debugfs attribute to
block/blk-zoned.c and delete block/blk-mq-debugfs-zone.c.

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/20240408014128.205141-25-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 08:44:03 -06:00
Damien Le Moal
9b3c08b90f block: Simplify blk_revalidate_disk_zones() interface
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>
2024-04-17 08:44:03 -06:00
Damien Le Moal
946dd71ed8 block: Allow BIO-based drivers to use blk_revalidate_disk_zones()
In preparation for allowing BIO based device drivers to use zone write
plugging and its zone append emulation, allow these drivers to call
blk_revalidate_disk_zones() so that all zone resources necessary to zone
write plugging can be initialized.

To do so, remove the check in blk_revalidate_disk_zones() restricting
the use of this function to mq request-based drivers to allow also
BIO-based drivers to use it. This is safe to do as long as the
BIO-based block device queue is already setup and usable, as it should,
and can be safely frozen.

The helper function disk_need_zone_resources() is added to control the
allocation and initialization of the zone write plug hash table and
of the conventional zone bitmap only for mq devices and for BIO-based
devices that require zone append emulation.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.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/20240408014128.205141-12-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 08:44:03 -06:00
Damien Le Moal
9b1ce7f0c6 block: Implement zone append emulation
Given that zone write plugging manages all writes to zones of a zoned
block device and tracks the write pointer position of all zones that are
not full nor empty, emulating zone append operations using regular
writes can be implemented generically, without relying on the underlying
device driver to implement such emulation. This is needed for devices
that do not natively support the zone append command (e.g. SMR
hard-disks).

A device may request zone append emulation by setting its
max_zone_append_sectors queue limit to 0. For such device, the function
blk_zone_wplug_prepare_bio() changes zone append BIOs into
non-mergeable regular write BIOs. Modified zone append BIOs are flagged
with the new BIO flag BIO_EMULATES_ZONE_APPEND. This flag is checked
on completion of the BIO in blk_zone_write_plug_bio_endio() to restore
the original REQ_OP_ZONE_APPEND operation code of the BIO.

The block layer internal inline helper function bio_is_zone_append() is
added to test if a BIO is either a native zone append operation
(REQ_OP_ZONE_APPEND operation code) or if it is flagged with
BIO_EMULATES_ZONE_APPEND. Given that both native and emulated zone
append BIO completion handling should be similar, The functions
blk_update_request() and blk_zone_complete_request_bio() are modified to
use bio_is_zone_append() to execute blk_zone_update_request_bio() for
both native and emulated zone append operations.

This commit contains contributions from Christoph Hellwig <hch@lst.de>.

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/20240408014128.205141-11-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 08:44:03 -06:00
Damien Le Moal
ccdbf0aad2 block: Allow zero value of max_zone_append_sectors queue limit
In preparation for adding a generic zone append emulation using zone
write plugging, allow device drivers supporting zoned block device to
set a the max_zone_append_sectors queue limit of a device to 0 to
indicate the lack of native support for zone append operations and that
the block layer should emulate these operations using regular write
operations.

blk_queue_max_zone_append_sectors() is modified to allow passing 0 as
the max_zone_append_sectors argument. The function
queue_max_zone_append_sectors() is also modified to ensure that the
minimum of the max_hw_sectors and chunk_sectors limit is used whenever
the max_zone_append_sectors limit is 0. This minimum is consistent with
the value set for the max_zone_append_sectors limit by the function
blk_validate_zoned_limits() when limits for a queue are validated.

The helper functions queue_emulates_zone_append() and
bdev_emulates_zone_append() are added to test if a queue (or block
device) emulates zone append operations.

In order for blk_revalidate_disk_zones() to accept zoned block devices
relying on zone append emulation, the direct check to the
max_zone_append_sectors queue limit of the disk is replaced by a check
using the value returned by queue_max_zone_append_sectors(). Similarly,
queue_zone_append_max_show() is modified to use the same accessor so
that the sysfs attribute advertizes the non-zero limit that will be
used, regardless if it is for native or emulated commands.

For stacking drivers, a top device should not need to care if the
underlying devices have native or emulated zone append operations.
blk_stack_limits() is thus modified to set the top device
max_zone_append_sectors limit using the new accessor
queue_limits_max_zone_append_sectors(). queue_max_zone_append_sectors()
is modified to use this function as well. Stacking drivers that require
zone append emulation, e.g. dm-crypt, can still request this feature by
calling blk_queue_max_zone_append_sectors() with a 0 limit.

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/20240408014128.205141-10-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 08:44:03 -06:00
Damien Le Moal
843283e96e block: Fake max open zones limit when there is no limit
For a zoned block device that has no limit on the number of open zones
and no limit on the number of active zones, the zone write plug mempool
is created with a size of 128 zone write plugs. For such case, set the
device max_open_zones queue limit to this value to indicate to the user
the potential performance penalty that may happen when writing
simultaneously to more zones than the mempool size.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.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/20240408014128.205141-9-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 08:44:03 -06:00
Damien Le Moal
dd291d77cc block: Introduce zone write plugging
Zone write plugging implements a per-zone "plug" for write operations
to control the submission and execution order of write operations to
sequential write required zones of a zoned block device. Per-zone
plugging guarantees that at any time there is at most only one write
request per zone being executed. This mechanism is intended to replace
zone write locking which implements a similar per-zone write throttling
at the scheduler level, but is implemented only by mq-deadline.

Unlike zone write locking which operates on requests, zone write
plugging operates on BIOs. A zone write plug is simply a BIO list that
is atomically manipulated using a spinlock and a kblockd submission
work. A write BIO to a zone is "plugged" to delay its execution if a
write BIO for the same zone was already issued, that is, if a write
request for the same zone is being executed. The next plugged BIO is
unplugged and issued once the write request completes.

This mechanism allows to:
 - Untangle zone write ordering from block IO schedulers. This allows
   removing the restriction on using mq-deadline for writing to zoned
   block devices. Any block IO scheduler, including "none" can be used.
 - Zone write plugging operates on BIOs instead of requests. Plugged
   BIOs waiting for execution thus do not hold scheduling tags and thus
   are not preventing other BIOs from executing (reads or writes to
   other zones). Depending on the workload, this can significantly
   improve the device use (higher queue depth operation) and
   performance.
 - Both blk-mq (request based) zoned devices and BIO-based zoned devices
   (e.g.  device mapper) can use zone write plugging. It is mandatory
   for the former but optional for the latter. BIO-based drivers can
   use zone write plugging to implement write ordering guarantees, or
   the drivers can implement their own if needed.
 - The code is less invasive in the block layer and is mostly limited to
   blk-zoned.c with some small changes in blk-mq.c, blk-merge.c and
   bio.c.

Zone write plugging is implemented using struct blk_zone_wplug. This
structure includes a spinlock, a BIO list and a work structure to
handle the submission of plugged BIOs. Zone write plugs structures are
managed using a per-disk hash table.

Plugging of zone write BIOs is done using the function
blk_zone_write_plug_bio() which returns false if a BIO execution does
not need to be delayed and true otherwise. This function is called
from blk_mq_submit_bio() after a BIO is split to avoid large BIOs
spanning multiple zones which would cause mishandling of zone write
plugs. This ichange enables by default zone write plugging for any mq
request-based block device. BIO-based device drivers can also use zone
write plugging by expliclty calling blk_zone_write_plug_bio() in their
->submit_bio method. For such devices, the driver must ensure that a
BIO passed to blk_zone_write_plug_bio() is already split and not
straddling zone boundaries.

Only write and write zeroes BIOs are plugged. Zone write plugging does
not introduce any significant overhead for other operations. A BIO that
is being handled through zone write plugging is flagged using the new
BIO flag BIO_ZONE_WRITE_PLUGGING. A request handling a BIO flagged with
this new flag is flagged with the new RQF_ZONE_WRITE_PLUGGING flag.
The completion of BIOs and requests flagged trigger respectively calls
to the functions blk_zone_write_bio_endio() and
blk_zone_write_complete_request(). The latter function is used to
trigger submission of the next plugged BIO using the zone plug work.
blk_zone_write_bio_endio() does the same for BIO-based devices.
This ensures that at any time, at most one request (blk-mq devices) or
one BIO (BIO-based devices) is being executed for any zone. The
handling of zone write plugs using a per-zone plug spinlock maximizes
parallelism and device usage by allowing multiple zones to be writen
simultaneously without lock contention.

Zone write plugging ignores flush BIOs without data. Hovever, any flush
BIO that has data is always plugged so that the write part of the flush
sequence is serialized with other regular writes.

Given that any BIO handled through zone write plugging will be the only
BIO in flight for the target zone when it is executed, the unplugging
and submission of a BIO will have no chance of successfully merging with
plugged requests or requests in the scheduler. To overcome this
potential performance degradation, blk_mq_submit_bio() calls the
function blk_zone_write_plug_attempt_merge() to try to merge other
plugged BIOs with the one just unplugged and submitted. Successful
merging is signaled using blk_zone_write_plug_bio_merged(), called from
bio_attempt_back_merge(). Furthermore, to avoid recalculating the number
of segments of plugged BIOs to attempt merging, the number of segments
of a plugged BIO is saved using the new struct bio field
__bi_nr_segments. To avoid growing the size of struct bio, this field is
added as a union with the bio_cookie field. This is safe to do as
polling is always disabled for plugged BIOs.

When BIOs are plugged in a zone write plug, the device request queue
usage counter is always incremented. This reference is kept and reused
for blk-mq devices when the plugged BIO is unplugged and submitted
again using submit_bio_noacct_nocheck(). For this case, the unplugged
BIO is already flagged with BIO_ZONE_WRITE_PLUGGING and
blk_mq_submit_bio() proceeds directly to allocating a new request for
the BIO, re-using the usage reference count taken when the BIO was
plugged. This extra reference count is dropped in
blk_zone_write_plug_attempt_merge() for any plugged BIO that is
successfully merged. Given that BIO-based devices will not take this
path, the extra reference is dropped after a plugged BIO is unplugged
and submitted.

Zone write plugs are dynamically allocated and managed using a hash
table (an array of struct hlist_head) with RCU protection.
A zone write plug is allocated when a write BIO is received for the
zone and not freed until the zone is fully written, reset or finished.
To detect when a zone write plug can be freed, the write state of each
zone is tracked using a write pointer offset which corresponds to the
offset of a zone write pointer relative to the zone start. Write
operations always increment this write pointer offset. Zone reset
operations set it to 0 and zone finish operations set it to the zone
size.

If a write error happens, the wp_offset value of a zone write plug may
become incorrect and out of sync with the device managed write pointer.
This is handled using the zone write plug flag BLK_ZONE_WPLUG_ERROR.
The function blk_zone_wplug_handle_error() is called from the new disk
zone write plug work when this flag is set. This function executes a
report zone to update the zone write pointer offset to the current
value as indicated by the device. The disk zone write plug work is
scheduled whenever a BIO flagged with BIO_ZONE_WRITE_PLUGGING completes
with an error or when bio_zone_wplug_prepare_bio() detects an unaligned
write. Once scheduled, the disk zone write plugs work keeps running
until all zone errors are handled.

To match the new data structures used for zoned disks, the function
disk_free_zone_bitmaps() is renamed to the more generic
disk_free_zone_resources(). The function disk_init_zone_resources() is
also introduced to initialize zone write plugs resources when a gendisk
is allocated.

In order to guarantee that the user can simultaneously write up to a
number of zones equal to a device max active zone limit or max open zone
limit, zone write plugs are allocated using a mempool sized to the
maximum of these 2 device limits. For a device that does not have
active and open zone limits, 128 is used as the default mempool size.

If a change to the device active and open zone limits is detected, the
disk mempool is resized when blk_revalidate_disk_zones() is executed.

This commit contains contributions from Christoph Hellwig <hch@lst.de>.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
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>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240408014128.205141-8-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 08:44:03 -06:00
Damien Le Moal
ecfe43b11b block: Remember zone capacity when revalidating zones
In preparation for adding zone write plugging, modify
blk_revalidate_disk_zones() to get the capacity of zones of a zoned
block device. This capacity value as a number of 512B sectors is stored
in the gendisk zone_capacity field.

Given that host-managed SMR disks (including zoned UFS drives) and all
known NVMe ZNS devices have the same zone capacity for all zones
blk_revalidate_disk_zones() returns an error if different capacities are
detected for different zones.

This also adds check to verify that the values reported by the device
for zone capacities are correct, that is, that the zone capacity is
never 0, does not exceed the zone size and is equal to the zone size for
conventional zones.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.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>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20240408014128.205141-7-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-04-17 08:44:02 -06:00
Damien Le Moal
522d73526f block: Do not include rbtree.h in blk-zoned.c
The block zone code does not use RB-tree. So remove the include of
linux/rbtree.h as it is not needed.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240222131724.1803520-2-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-22 10:35:18 -07:00
Johannes Thumshirn
71f4ecdbb4 block: remove gfp_flags from blkdev_zone_mgmt
Now that all callers pass in GFP_KERNEL to blkdev_zone_mgmt() and use
memalloc_no{io,fs}_{save,restore}() to define the allocation scope, we can
drop the gfp_mask parameter from blkdev_zone_mgmt() as well as
blkdev_zone_reset_all() and blkdev_zone_reset_all_emulated().

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20240128-zonefs_nofs-v3-5-ae3b7c8def61@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-12 08:41:16 -07:00
Damien Le Moal
587371ed78 block: Treat sequential write preferred zone type as invalid
With the removal of the support for host-aware zoned devices,
blk_revalidate_zone_cb() should never see the zone type
BLK_ZONE_TYPE_SEQWRITE_PREF (sequential write preffered zones). Treat
this zone type as being invalid.

Fixes: 7437bb73f0 ("block: remove support for the host aware zone model")
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240107072212.1071080-1-dlemoal@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-08 08:34:24 -07:00
Christoph Hellwig
4e33b071bb block: remove disk_clear_zoned
disk_clear_zoned is unused now that the last warts of the host-aware
model support in sd are gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20231228075141.362560-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-01-08 08:27:22 -07:00
Jens Axboe
5165799f0d block: export disk_clear_zoned()
A previous commit split disk_set_zoned(..., bool) into not taking an
argument for whether to set or clear, and instead added
disk_clear_zoned() as the counterpart. However, that commit neglected
to export the new symbol, causing failures for modular drivers that
used it.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: d73e93b4df ("block: simplify disk_set_zoned")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-12-20 20:32:12 -07:00
Christoph Hellwig
d73e93b4df block: simplify disk_set_zoned
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>
2023-12-19 20:17:43 -07:00
Martin K. Petersen
e96277a570 Merge branch '6.5/scsi-staging' into 6.5/scsi-fixes
Pull in the currently staged SCSI fixes for 6.5.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-07-11 12:15:15 -04:00
Damien Le Moal
03e51c4a74 scsi: block: Improve checks in blk_revalidate_disk_zones()
blk_revalidate_disk_zones() implements checks of the zones of a zoned
block device, verifying that the zone size is a power of 2 number of
sectors, that all zones (except possibly the last one) have the same
size and that zones cover the entire addressing space of the device.

While these checks are appropriate to verify that well tested hardware
devices have an adequate zone configurations, they lack in certain areas
which may result in issues with emulated devices implemented with user
drivers such as ublk or tcmu. Specifically, this function does not
check if the device driver indicated support for the mandatory zone
append writes, that is, if the device max_zone_append_sectors queue
limit is set to a non-zero value. Additionally, invalid zones such as
a zero length zone with a start sector equal to the device capacity will
not be detected and result in out of bounds use of the zone bitmaps
prepared with the callback function blk_revalidate_zone_cb().

Improve blk_revalidate_disk_zones() to address these inadequate checks,
relying on the fact that all device drivers supporting zoned block
devices must set the device zone size (chunk_sectors queue limit) and
the max_zone_append_sectors queue limit before executing this function.

The check for a non-zero max_zone_append_sectors value is done in
blk_revalidate_disk_zones() before executing the zone report. The zone
report callback function blk_revalidate_zone_cb() is also modified to
add a check that a zone start is below the device capacity.

The check that the zone size is a power of 2 number of sectors is moved
to blk_revalidate_disk_zones() as the zone size is already known.
Similarly, the number of zones of the device can be calculated in
blk_revalidate_disk_zones() before executing the zone report.

The kdoc comment for blk_revalidate_disk_zones() is also updated to
mention that device drivers must set the device zone size and the
max_zone_append_sectors queue limit before calling this function.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230703024812.76778-6-dlemoal@kernel.org
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-07-05 21:58:10 -04:00
Christoph Hellwig
05bdb99653 block: replace fmode_t with a block-specific type for block open flags
The only overlap between the block open flags mapped into the fmode_t and
other uses of fmode_t are FMODE_READ and FMODE_WRITE.  Define a new
blk_mode_t instead for use in blkdev_get_by_{dev,path}, ->open and
->ioctl and stop abusing fmode_t.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jack Wang <jinpu.wang@ionos.com>		[rnbd]
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12 08:04:05 -06:00
Christoph Hellwig
5e4ea83467 block: remove unused fmode_t arguments from ioctl handlers
A few ioctl handlers have fmode_t arguments that are entirely unused,
remove them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20230608110258.189493-27-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-06-12 08:04:04 -06:00
Bart Van Assche
19821fee3e block: Introduce blk_rq_is_seq_zoned_write()
Introduce the function blk_rq_is_seq_zoned_write(). This function will
be used in later patches to preserve the order of zoned writes that
require write serialization.

This patch includes an optimization: instead of using
rq->q->disk->part0->bd_queue to check whether or not the queue is
associated with a zoned block device, use rq->q->disk->queue.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20230517174230.897144-6-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-18 19:47:49 -06:00
Bart Van Assche
4f51644ccf block: Simplify blk_req_needs_zone_write_lock()
Remove the blk_rq_is_passthrough() check because it is redundant:
blk_req_needs_zone_write_lock() also calls bdev_op_is_zoned_write()
and the latter function returns false for pass-through requests.

Reviewed-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>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230517174230.897144-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-18 19:47:49 -06:00
Juhyung Park
9e0c7efa5e block: remove more NULL checks after bdev_get_queue()
bdev_get_queue() never returns NULL. Several commits [1][2] have been made
before to remove such superfluous checks, but some still remained.

For places where bdev_get_queue() is called solely for NULL checks, it is
removed entirely.

[1] commit ec9fd2a13d ("blk-lib: don't check bdev_get_queue() NULL check")
[2] commit fea127b36c ("block: remove superfluous check for request queue in bdev_is_zoned()")

Signed-off-by: Juhyung Park <qkrwngud825@gmail.com>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20230203024029.48260-1-qkrwngud825@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-21 09:23:22 -07:00
Pankaj Raghav
e29b210021 block: add a new helper bdev_{is_zone_start, offset_from_zone_start}
Instead of open coding to check for zone start, add a helper to improve
readability and store the logic in one place.

Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230110143635.77300-3-p.raghav@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29 15:18:34 -07:00
Pankaj Raghav
8cafdb5ab9 block: adapt blk_mq_plug() to not plug for writes that require a zone lock
The current implementation of blk_mq_plug() disables plugging for all
operations that involves a transfer to the device as we just check if
the last bit in op_is_write() function.

Modify blk_mq_plug() to disable plugging only for REQ_OP_WRITE and
REQ_OP_WRITE_ZEROS as they might require a zone lock.

Suggested-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20220929074745.103073-2-p.raghav@samsung.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-29 07:45:47 -06:00