linux-toradex.git/block/blk-wbt.c, branch v6.5-rc4

Merge branch 'for-6.5/block-late' into block-6.5

2023-06-28T22:08:19+00:00

* for-6.5/block-late:
  blk-sysfs: add a new attr_group for blk_mq
  blk-iocost: move wbt_enable/disable_default() out of spinlock
  blk-wbt: cleanup rwb_enabled() and wbt_disabled()
  blk-wbt: remove dead code to handle wbt enable/disable with io inflight
  blk-wbt: don't create wbt sysfs entry if CONFIG_BLK_WBT is disabled
  blk-mq: fix two misuses on RQF_USE_SCHED
  blk-throttle: Fix io statistics for cgroup v1
  bcache: Fix bcache device claiming
  bcache: Alloc holder object before async registration
  raid10: avoid spin_lock from fastpath from raid10_unplug()
  md: fix 'delete_mutex' deadlock
  md: use mddev->external to select holder in export_rdev()
  md/raid1-10: fix casting from randomized structure in raid1_submit_write()
  md/raid10: fix the condition to call bio_end_io_acct()

Merge tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux

2023-06-26T19:47:20+00:00

Pull block updates from Jens Axboe:

 - NVMe pull request via Keith:
      - Various cleanups all around (Irvin, Chaitanya, Christophe)
      - Better struct packing (Christophe JAILLET)
      - Reduce controller error logs for optional commands (Keith)
      - Support for >=64KiB block sizes (Daniel Gomez)
      - Fabrics fixes and code organization (Max, Chaitanya, Daniel
        Wagner)

 - bcache updates via Coly:
      - Fix a race at init time (Mingzhe Zou)
      - Misc fixes and cleanups (Andrea, Thomas, Zheng, Ye)

 - use page pinning in the block layer for dio (David)

 - convert old block dio code to page pinning (David, Christoph)

 - cleanups for pktcdvd (Andy)

 - cleanups for rnbd (Guoqing)

 - use the unchecked __bio_add_page() for the initial single page
   additions (Johannes)

 - fix overflows in the Amiga partition handling code (Michael)

 - improve mq-deadline zoned device support (Bart)

 - keep passthrough requests out of the IO schedulers (Christoph, Ming)

 - improve support for flush requests, making them less special to deal
   with (Christoph)

 - add bdev holder ops and shutdown methods (Christoph)

 - fix the name_to_dev_t() situation and use cases (Christoph)

 - decouple the block open flags from fmode_t (Christoph)

 - ublk updates and cleanups, including adding user copy support (Ming)

 - BFQ sanity checking (Bart)

 - convert brd from radix to xarray (Pankaj)

 - constify various structures (Thomas, Ivan)

 - more fine grained persistent reservation ioctl capability checks
   (Jingbo)

 - misc fixes and cleanups (Arnd, Azeem, Demi, Ed, Hengqi, Hou, Jan,
   Jordy, Li, Min, Yu, Zhong, Waiman)

* tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux: (266 commits)
  scsi/sg: don't grab scsi host module reference
  ext4: Fix warning in blkdev_put()
  block: don't return -EINVAL for not found names in devt_from_devname
  cdrom: Fix spectre-v1 gadget
  block: Improve kernel-doc headers
  blk-mq: don't insert passthrough request into sw queue
  bsg: make bsg_class a static const structure
  ublk: make ublk_chr_class a static const structure
  aoe: make aoe_class a static const structure
  block/rnbd: make all 'class' structures const
  block: fix the exclusive open mask in disk_scan_partitions
  block: add overflow checks for Amiga partition support
  block: change all __u32 annotations to __be32 in affs_hardblocks.h
  block: fix signed int overflow in Amiga partition support
  block: add capacity validation in bdev_add_partition()
  block: fine-granular CAP_SYS_ADMIN for Persistent Reservation
  block: disallow Persistent Reservation on partitions
  reiserfs: fix blkdev_put() warning from release_journal_dev()
  block: fix wrong mode for blkdev_get_by_dev() from disk_scan_partitions()
  block: document the holder argument to blkdev_get_by_path
  ...

blk-wbt: cleanup rwb_enabled() and wbt_disabled()

2023-06-26T15:53:36+00:00

'wb_normal' will set to 0 if 'min_lat_nsec' is 0, and 'min_lat_nsec' can
only be set to 0 through sysfs configuration where 'WBT_STATE_OFF_MANUAL'
is set together, in the meantime, they can only be cleared together
through sysfs afterwards. Hence 'wb_normal != 0' is the same as
'rwb->enable_state != WBT_STATE_OFF_MANUAL'.

The code is redundan, hence replace the checking of 'wb_normal' to
'enable_state' in rwb_enabled() and reuse rwb_enabled() for
wbt_disabled().

Signed-off-by: Yu Kuai 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20230527010644.647900-4-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe

blk-wbt: remove dead code to handle wbt enable/disable with io inflight

2023-06-26T15:53:36+00:00

enable or disable wbt is always called with queue freezed, so that wbt
can never be enabled or disabled while io is still inflight, and this
behaviour should always hold to avoid io hang(There have been reported
several times).

Therefor, the code to handle wbt enable/diskble with io inflight is not
and never will be used, hence remove such dead code.

Signed-off-by: Yu Kuai 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20230527010644.647900-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe

block/rq_qos: protect rq_qos apis with a new lock

2023-05-23T17:13:19+00:00

commit 50e34d78815e ("block: disable the elevator int del_gendisk")
move rq_qos_exit() from disk_release() to del_gendisk(), this will
introduce some problems:

1) If rq_qos_add() is triggered by enabling iocost/iolatency through
   cgroupfs, then it can concurrent with del_gendisk(), it's not safe to
   write 'q->rq_qos' concurrently.

2) Activate cgroup policy that is relied on rq_qos will call
   rq_qos_add() and blkcg_activate_policy(), and if rq_qos_exit() is
   called in the middle, null-ptr-dereference will be triggered in
   blkcg_activate_policy().

3) blkg_conf_open_bdev() can call blkdev_get_no_open() first to find the
   disk, then if rq_qos_exit() from del_gendisk() is done before
   rq_qos_add(), then memory will be leaked.

This patch add a new disk level mutex 'rq_qos_mutex':

1) The lock will protect rq_qos_exit() directly.

2) For wbt that doesn't relied on blk-cgroup, rq_qos_add() can only be
   called from disk initialization for now because wbt can't be
   destructed until rq_qos_exit(), so it's safe not to protect wbt for
   now. Hoever, in case that rq_qos dynamically destruction is supported
   in the furture, this patch also protect rq_qos_add() from wbt_init()
   directly, this is enough because blk-sysfs already synchronize
   writers with disk removal.

3) For iocost and iolatency, in order to synchronize disk removal and
   cgroup configuration, the lock is held after blkdev_get_no_open()
   from blkg_conf_open_bdev(), and is released in blkg_conf_exit().
   In order to fix the above memory leak, disk_live() is checked after
   holding the new lock.

Fixes: 50e34d78815e ("block: disable the elevator int del_gendisk")
Signed-off-by: Yu Kuai 
Acked-by: Tejun Heo 
Link: https://lore.kernel.org/r/20230414084008.2085155-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe

blk-wbt: fix that wbt can't be disabled by default

2023-05-23T17:08:53+00:00

commit b11d31ae01e6 ("blk-wbt: remove unnecessary check in
wbt_enable_default()") removes the checking of CONFIG_BLK_WBT_MQ by
mistake, which is used to control enable or disable wbt by default.

Fix the problem by adding back the checking. This patch also do a litter
cleanup to make related code more readable.

Fixes: b11d31ae01e6 ("blk-wbt: remove unnecessary check in wbt_enable_default()")
Reported-by: Lukas Bulwahn 
Link: https://lore.kernel.org/lkml/CAKXUXMzfKq_J9nKHGyr5P5rvUETY4B-fxoQD4sO+NYjFOfVtZA@mail.gmail.com/t/
Signed-off-by: Yu Kuai 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20230522121854.2928880-1-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe

blk-rq-qos: store a gendisk instead of request_queue in struct rq_qos

2023-02-03T15:20:05+00:00

This is what about half of the users already want, and it's only going to
grow more.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Andreas Herrmann 
Acked-by: Tejun Heo 
Link: https://lore.kernel.org/r/20230203150400.3199230-16-hch@lst.de
Signed-off-by: Jens Axboe

blk-rq-qos: constify rq_qos_ops

2023-02-03T15:20:05+00:00

These op vectors are constant, so mark them const.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Andreas Herrmann 
Acked-by: Tejun Heo 
Link: https://lore.kernel.org/r/20230203150400.3199230-15-hch@lst.de
Signed-off-by: Jens Axboe

blk-rq-qos: make rq_qos_add and rq_qos_del more useful

2023-02-03T15:20:05+00:00

Switch to passing a gendisk, and make rq_qos_add initialize all required
fields and drop the not required q argument from rq_qos_del.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Andreas Herrmann 
Acked-by: Tejun Heo 
Link: https://lore.kernel.org/r/20230203150400.3199230-14-hch@lst.de
Signed-off-by: Jens Axboe

blk-wbt: open code wbt_queue_depth_changed in wbt_init

2023-02-03T15:20:05+00:00

wbt_queue_depth_changed just updates a field and calls another function.
Open code it in wbt_init, so that the local queue variable can be used
instead of the one stored in the rq_qos.  This will allow delaying that
rq_qos->queue assignment in a subsequent patch.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Andreas Herrmann 
Acked-by: Tejun Heo 
Link: https://lore.kernel.org/r/20230203150400.3199230-12-hch@lst.de
Signed-off-by: Jens Axboe