kernel.git/block/genhd.c, 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: add a partscan sysfs attribute for disks

2024-05-25T14:30:56Z

commit a4217c6740dc64a3eb6815868a9260825e8c68c6 upstream. Userspace had been unknowingly relying on a non-stable interface of kernel internals to determine if partition scanning is enabled for a given disk. Provide a stable interface for this purpose instead. Cc: stable@vger.kernel.org # 6.3+ Depends-on: 140ce28dd3be ("block: add a disk_has_partscan helper") Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/linux-block/ZhQJf8mzq_wipkBH@gardel-login/ Link: https://lore.kernel.org/r/20240502130033.1958492-3-hch@lst.de [axboe: add links and commit message from Keith] Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: add a disk_has_partscan helper

2024-05-25T14:30:56Z

commit 140ce28dd3bee8e53acc27f123ae474d69ef66f0 upstream. Add a helper to check if partition scanning is enabled instead of open coding the check in a few places. This now always checks for the hidden flag even if all but one of the callers are never reachable for hidden gendisks. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240502130033.1958492-2-hch@lst.de Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

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: make block_class constant

2024-03-06T15:29:20Z

Since commit 43a7206b0963 ("driver core: class: make class_register() take a const *"), the driver core allows for struct class to be in read-only memory, so move the block_class structure to be declared at build time placing it into read-only memory, instead of having to be dynamically allocated at boot time. Cc: Greg Kroah-Hartman Suggested-by: Greg Kroah-Hartman Signed-off-by: Ricardo B. Marliere Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240305-class_cleanup-block-v1-1-130bb27b9c72@marliere.net Signed-off-by: Jens Axboe

block/genhd: port disk_scan_partitions() to file

2024-02-25T11:05:22Z

This may run from a kernel thread via device_add_disk(). So this could also use __fput_sync() if we were worried about EBUSY. But when it is called from a kernel thread it's always BLK_OPEN_READ so EBUSY can't really happen even if we do BLK_OPEN_RESTRICT_WRITES or BLK_OPEN_EXCL. Otherwise it's called from an ioctl on the block device which is only called from userspace and can rely on task work. Link: https://lore.kernel.org/r/20240123-vfs-bdev-file-v2-3-adbd023e19cc@kernel.org Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Christian Brauner

block: pass a queue_limits argument to blk_alloc_disk

2024-02-19T23:58:23Z

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 Reviewed-by: Dan Williams Reviewed-by: Himanshu Madhani Link: https://lore.kernel.org/r/20240215071055.2201424-2-hch@lst.de 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

block: add check of 'minors' and 'first_minor' in device_add_disk()

2023-12-19T15:23:12Z

'first_minor' represents the starting minor number of disks, and 'minors' represents the number of partitions in the device. Neither of them can be greater than MINORMASK + 1. Commit e338924bd05d ("block: check minor range in device_add_disk()") only added the check of 'first_minor + minors'. However, their sum might be less than MINORMASK but their values are wrong. Complete the checks now. Fixes: e338924bd05d ("block: check minor range in device_add_disk()") Signed-off-by: Li Nan Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20231219075942.840255-1-linan666@huaweicloud.com Signed-off-by: Jens Axboe

block: Set memalloc_noio to false on device_add_disk() error path

2023-12-13T15:17:02Z

On the error path of device_add_disk(), device's memalloc_noio flag was set but not cleared. As the comment of pm_runtime_set_memalloc_noio(), "The function should be called between device_add() and device_del()". Clear this flag before device_del() now. Fixes: 25e823c8c37d ("block/genhd.c: apply pm_runtime_set_memalloc_noio on block devices") Signed-off-by: Li Nan Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20231211075356.1839282-1-linan666@huaweicloud.com Signed-off-by: Jens Axboe