kernel/linux.git/block/blk.h, branch v6.6.131

block: support to account io_ticks precisely

2024-06-12T09:11:35+00:00

[ 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 some exports for bcachefs

2023-08-14T21:40:42+00:00

- bio_set_pages_dirty(), bio_check_pages_dirty() - dio path - blk_status_to_str() - error messages - bio_add_folio() - this should definitely be exported for everyone, it's the modern version of bio_add_page() Signed-off-by: Kent Overstreet Cc: linux-block@vger.kernel.org Cc: Jens Axboe Signed-off-by: Kent Overstreet Link: https://lore.kernel.org/r/20230813182636.2966159-2-kent.overstreet@linux.dev Signed-off-by: Jens Axboe

block: make bvec_try_merge_hw_page() non-static

2023-08-09T22:05:35+00:00

This will be used for multi-page configuration for integrity payload. Cc: Christoph Hellwig Cc: Martin K. Petersen Reviewed-by: Christoph Hellwig Signed-off-by: Jinyoung Choi Tested-by: "Martin K. Petersen" Reviewed-by: "Martin K. Petersen" Link: https://lore.kernel.org/r/20230803024827epcms2p838d9e9131492c86a159fff25d195658f@epcms2p8 Signed-off-by: Jens Axboe

blk-flush: count inflight flush_data requests

2023-07-17T14:18:21+00:00

The flush state machine use a double list to link all inflight flush_data requests, to avoid issuing separate post-flushes for these flush_data requests which shared PREFLUSH. So we can't reuse rq->queuelist, this is why we need rq->flush.list In preparation of the next patch that reuse rq->queuelist for flush state machine, we change the double linked list to unsigned long counter, which count all inflight flush_data requests. This is ok since we only need to know if there is any inflight flush_data request, so unsigned long counter is good. Signed-off-by: Chengming Zhou Reviewed-by: Ming Lei Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230717040058.3993930-4-chengming.zhou@linux.dev Signed-off-by: Jens Axboe

block: remove BIO_PAGE_REFFED

2023-06-16T16:08:09+00:00

Now that all block direct I/O helpers use page pinning, this flag is unused. Signed-off-by: Christoph Hellwig Reviewed-by: Christian Brauner Reviewed-by: Johannes Thumshirn Reviewed-by: David Howells Link: https://lore.kernel.org/r/20230614140341.521331-4-hch@lst.de Signed-off-by: Jens Axboe

block: replace fmode_t with a block-specific type for block open flags

2023-06-12T14:04:05+00:00

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 Acked-by: Jack Wang [rnbd] Reviewed-by: Hannes Reinecke Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20230608110258.189493-28-hch@lst.de Signed-off-by: Jens Axboe

block: remove unused fmode_t arguments from ioctl handlers

2023-06-12T14:04:04+00:00

A few ioctl handlers have fmode_t arguments that are entirely unused, remove them. Signed-off-by: Christoph Hellwig Acked-by: Christian Brauner Reviewed-by: Hannes Reinecke Link: https://lore.kernel.org/r/20230608110258.189493-27-hch@lst.de Signed-off-by: Jens Axboe

block: move a few internal definitions out of blkdev.h

2023-06-12T14:04:04+00:00

All these helpers are only used in core block code, so move them out of the public header. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Acked-by: Christian Brauner Link: https://lore.kernel.org/r/20230608110258.189493-26-hch@lst.de Signed-off-by: Jens Axboe

block: delete partitions later in del_gendisk

2023-06-05T16:53:04+00:00

Delay dropping the block_devices for partitions in del_gendisk until after the call to blk_mark_disk_dead, so that we can implementat notification of removed devices in blk_mark_disk_dead. This requires splitting a lower-level drop_partition helper out of delete_partition and using that from del_gendisk, while having a common loop for the whole device and partitions that calls remove_inode_hash, fsync_bdev and __invalidate_device before the call to blk_mark_disk_dead. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Acked-by: Dave Chinner Reviewed-by: Dave Chinner Link: https://lore.kernel.org/r/20230601094459.1350643-8-hch@lst.de Signed-off-by: Jens Axboe

block: Add BIO_PAGE_PINNED and associated infrastructure

2023-05-24T14:42:44+00:00

Add BIO_PAGE_PINNED to indicate that the pages in a bio are pinned (FOLL_PIN) and that the pin will need removing. Signed-off-by: David Howells Reviewed-by: Christoph Hellwig Reviewed-by: John Hubbard cc: Al Viro cc: Jens Axboe cc: Jan Kara cc: Matthew Wilcox cc: Logan Gunthorpe cc: linux-block@vger.kernel.org Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20230522205744.2825689-5-dhowells@redhat.com Signed-off-by: Jens Axboe