kernel.git/block/blk.h, branch linux-6.9.y

block: support to account io_ticks precisely

2024-05-30T07:44:10Z

[ Upstream commit 99dc422335d8b2bd4d105797241d3e715bae90e9 ] Currently, io_ticks is accounted based on sampling, specifically update_io_ticks() will always account io_ticks by 1 jiffies from bdev_start_io_acct()/blk_account_io_start(), and the result can be inaccurate, for example(HZ is 250): Test script: fio -filename=/dev/sda -bs=4k -rw=write -direct=1 -name=test -thinktime=4ms Test result: util is about 90%, while the disk is really idle. This behaviour is introduced by commit 5b18b5a73760 ("block: delete part_round_stats and switch to less precise counting"), however, there was a key point that is missed that this patch also improve performance a lot: Before the commit: part_round_stats: if (part->stamp != now) stats |= 1; part_in_flight() -> there can be lots of task here in 1 jiffies. part_round_stats_single() __part_stat_add() part->stamp = now; After the commit: update_io_ticks: stamp = part->bd_stamp; if (time_after(now, stamp)) if (try_cmpxchg()) __part_stat_add() -> only one task can reach here in 1 jiffies. Hence in order to account io_ticks precisely, we only need to know if there are IO inflight at most once in one jiffies. Noted that for rq-based device, iterating tags should not be used here because 'tags->lock' is grabbed in blk_mq_find_and_get_req(), hence part_stat_lock_inc/dec() and part_in_flight() is used to trace inflight. The additional overhead is quite little: - per cpu add/dec for each IO for rq-based device; - per cpu sum for each jiffies; And it's verified by null-blk that there are no performance degration under heavy IO pressure. Fixes: 5b18b5a73760 ("block: delete part_round_stats and switch to less precise counting") Signed-off-by: Yu Kuai Link: https://lore.kernel.org/r/20240509123717.3223892-2-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: Make blk_rq_set_mixed_merge() static

2024-03-26T17:28:20Z

Since commit 8e756373d7c8 ("block: Move bio merge related functions into blk-merge.c"), blk_rq_set_mixed_merge() has only been referenced in blk-merge.c, so make it static. Signed-off-by: John Garry Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240325083501.2816408-1-john.g.garry@oracle.com Signed-off-by: Jens Axboe

block: limit block time caching to in_task() context

2024-03-13T20:12:53Z

We should not have any callers of this from non-task context, but Jakub ran [1] into one from blk-iocost. Rather than risk running into others, or future ones, just limit blk_time_get_ns() to when it is called from a task. Any other usage is invalid. [1] https://lore.kernel.org/lkml/CAHk-=wiOaBLqarS2uFhM1YdwOvCX4CZaWkeyNDY1zONpbYw2ig@mail.gmail.com/ Fixes: da4c8c3d0975 ("block: cache current nsec time in struct blk_plug") Reported-by: Jakub Kicinski Signed-off-by: Jens Axboe

Merge tag 'for-6.9/block-20240310' of git://git.kernel.dk/linux

2024-03-11T18:43:44Z

Pull block updates from Jens Axboe: - MD pull requests via Song: - Cleanup redundant checks (Yu Kuai) - Remove deprecated headers (Marc Zyngier, Song Liu) - Concurrency fixes (Li Lingfeng) - Memory leak fix (Li Nan) - Refactor raid1 read_balance (Yu Kuai, Paul Luse) - Clean up and fix for md_ioctl (Li Nan) - Other small fixes (Gui-Dong Han, Heming Zhao) - MD atomic limits (Christoph) - NVMe pull request via Keith: - RDMA target enhancements (Max) - Fabrics fixes (Max, Guixin, Hannes) - Atomic queue_limits usage (Christoph) - Const use for class_register (Ricardo) - Identification error handling fixes (Shin'ichiro, Keith) - Improvement and cleanup for cached request handling (Christoph) - Moving towards atomic queue limits. Core changes and driver bits so far (Christoph) - Fix UAF issues in aoeblk (Chun-Yi) - Zoned fix and cleanups (Damien) - s390 dasd cleanups and fixes (Jan, Miroslav) - Block issue timestamp caching (me) - noio scope guarding for zoned IO (Johannes) - block/nvme PI improvements (Kanchan) - Ability to terminate long running discard loop (Keith) - bdev revalidation fix (Li) - Get rid of old nr_queues hack for kdump kernels (Ming) - Support for async deletion of ublk (Ming) - Improve IRQ bio recycling (Pavel) - Factor in CPU capacity for remote vs local completion (Qais) - Add shared_tags configfs entry for null_blk (Shin'ichiro - Fix for a regression in page refcounts introduced by the folio unification (Tony) - Misc fixes and cleanups (Arnd, Colin, John, Kunwu, Li, Navid, Ricardo, Roman, Tang, Uwe) * tag 'for-6.9/block-20240310' of git://git.kernel.dk/linux: (221 commits) block: partitions: only define function mac_fix_string for CONFIG_PPC_PMAC block/swim: Convert to platform remove callback returning void cdrom: gdrom: Convert to platform remove callback returning void block: remove disk_stack_limits md: remove mddev->queue md: don't initialize queue limits md/raid10: use the atomic queue limit update APIs md/raid5: use the atomic queue limit update APIs md/raid1: use the atomic queue limit update APIs md/raid0: use the atomic queue limit update APIs md: add queue limit helpers md: add a mddev_is_dm helper md: add a mddev_add_trace_msg helper md: add a mddev_trace_remap helper bcache: move calculation of stripe_size and io_opt into bcache_device_init virtio_blk: Do not use disk_set_max_open/active_zones() aoe: fix the potential use-after-free problem in aoecmd_cfg_pkts block: move capacity validation to blkpg_do_ioctl() block: prevent division by zero in blk_rq_stat_sum() drbd: atomically update queue limits in drbd_reconsider_queue_parameters ...

block: remove bdev_handle completely

2024-02-25T11:05:28Z

We just need to use the holder to indicate whether a block device open was exclusive or not. We did use to do that before but had to give that up once we switched to struct bdev_handle. Before struct bdev_handle we only stashed stuff in file->private_data if this was an exclusive open but after struct bdev_handle we always set file->private_data to a struct bdev_handle and so we had to use bdev_handle->mode or bdev_handle->holder. Now that we don't use struct bdev_handle anymore we can revert back to the old behavior. Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-32-adbd023e19cc@kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner

bdev: remove bdev pointer from struct bdev_handle

2024-02-25T11:05:27Z

We can always go directly via: * I_BDEV(bdev_file->f_inode) * I_BDEV(bdev_file->f_mapping->host) So keeping struct bdev in struct bdev_handle is redundant. Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-30-adbd023e19cc@kernel.org Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

bdev: make struct bdev_handle private to the block layer

2024-02-25T11:05:27Z

Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-29-adbd023e19cc@kernel.org Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner

bdev: make bdev_{release, open_by_dev}() private to block layer

2024-02-25T11:05:27Z

Move both of them to the private block header. There's no caller in the tree anymore that uses them directly. Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-28-adbd023e19cc@kernel.org Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

block: io wait hang check helper

2024-02-24T19:46:46Z

This is the same in two places, and another will be added soon. Create a helper for it. Reviewed-by: Ming Lei Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch Reviewed-by: Chaitanya Kulkarni Link: https://lore.kernel.org/r/20240223155910.3622666-4-kbusch@meta.com Signed-off-by: Jens Axboe

block: pass a queue_limits argument to blk_alloc_queue

2024-02-13T15:56:59Z

Pass a queue_limits to blk_alloc_queue and apply it after validating and capping the values using blk_validate_limits. This will allow allocating queues with valid queue limits instead of setting the values one at a time later. Signed-off-by: Christoph Hellwig Reviewed-by: Damien Le Moal Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20240213073425.1621680-9-hch@lst.de Signed-off-by: Jens Axboe