kernel.git/block/blk-flush.c, branch linux-5.12.y

block: avoid double io accounting for flush request

2021-07-14T14:59:40Z

[ Upstream commit 84da7acc3ba53af26f15c4b0ada446127b7a7836 ] For flush request, rq->end_io() may be called two times, one is from timeout handling(blk_mq_check_expired()), another is from normal completion(__blk_mq_end_request()). Move blk_account_io_flush() after flush_rq->ref drops to zero, so io accounting can be done just once for flush request. Fixes: b68663186577 ("block: add iostat counters for flush requests") Reviewed-by: Bart Van Assche Reviewed-by: Christoph Hellwig Tested-by: John Garry Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20210511152236.763464-2-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

block: use an on-stack bio in blkdev_issue_flush

2021-01-27T16:51:48Z

There is no point in allocating memory for a synchronous flush. Signed-off-by: Christoph Hellwig Reviewed-by: Johannes Thumshirn Reviewed-by: Chaitanya Kulkarni Acked-by: Damien Le Moal Signed-off-by: Jens Axboe

Merge tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block

2020-12-16T20:57:51Z

Pull block updates from Jens Axboe: "Another series of killing more code than what is being added, again thanks to Christoph's relentless cleanups and tech debt tackling. This contains: - blk-iocost improvements (Baolin Wang) - part0 iostat fix (Jeffle Xu) - Disable iopoll for split bios (Jeffle Xu) - block tracepoint cleanups (Christoph Hellwig) - Merging of struct block_device and hd_struct (Christoph Hellwig) - Rework/cleanup of how block device sizes are updated (Christoph Hellwig) - Simplification of gendisk lookup and removal of block device aliasing (Christoph Hellwig) - Block device ioctl cleanups (Christoph Hellwig) - Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig) - Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig) - sbitmap improvements (Pavel Begunkov) - Hybrid polling fix (Pavel Begunkov) - bvec iteration improvements (Pavel Begunkov) - Zone revalidation fixes (Damien Le Moal) - blk-throttle limit fix (Yu Kuai) - Various little fixes" * tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits) blk-mq: fix msec comment from micro to milli seconds blk-mq: update arg in comment of blk_mq_map_queue blk-mq: add helper allocating tagset->tags Revert "block: Fix a lockdep complaint triggered by request queue flushing" nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class blk-mq: add new API of blk_mq_hctx_set_fq_lock_class block: disable iopoll for split bio block: Improve blk_revalidate_disk_zones() checks sbitmap: simplify wrap check sbitmap: replace CAS with atomic and sbitmap: remove swap_lock sbitmap: optimise sbitmap_deferred_clear() blk-mq: skip hybrid polling if iopoll doesn't spin blk-iocost: Factor out the base vrate change into a separate function blk-iocost: Factor out the active iocgs' state check into a separate function blk-iocost: Move the usage ratio calculation to the correct place blk-iocost: Remove unnecessary advance declaration blk-iocost: Fix some typos in comments blktrace: fix up a kerneldoc comment block: remove the request_queue to argument request based tracepoints ...

Revert "block: Fix a lockdep complaint triggered by request queue flushing"

2020-12-08T03:30:19Z

This reverts commit b3c6a59975415bde29cfd76ff1ab008edbf614a9. Now we can avoid nvme-loop lockdep warning of 'lockdep possible recursive locking' by nvme-loop's lock class, no need to apply dynamically allocated lock class key, so revert commit b3c6a5997541("block: Fix a lockdep complaint triggered by request queue flushing"). This way fixes horrible SCSI probe delay issue on megaraid_sas, and it is reported the whole probe may take more than half an hour. Tested-by: Kashyap Desai Reported-by: Qian Cai Reviewed-by: Christoph Hellwig Cc: Sumit Saxena Cc: John Garry Cc: Kashyap Desai Cc: Bart Van Assche Cc: Hannes Reinecke Signed-off-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

blk-mq: add new API of blk_mq_hctx_set_fq_lock_class

2020-12-08T03:30:19Z

flush_end_io() may be called recursively from some driver, such as nvme-loop, so lockdep may complain 'possible recursive locking'. Commit b3c6a5997541("block: Fix a lockdep complaint triggered by request queue flushing") tried to address this issue by assigning dynamically allocated per-flush-queue lock class. This solution adds synchronize_rcu() for each hctx's release handler, and causes horrible SCSI MQ probe delay(more than half an hour on megaraid sas). Add new API of blk_mq_hctx_set_fq_lock_class() for these drivers, so we just need to use driver specific lock class for avoiding the lockdep warning of 'possible recursive locking'. Tested-by: Kashyap Desai Reported-by: Qian Cai Cc: Sumit Saxena Cc: John Garry Cc: Kashyap Desai Cc: Bart Van Assche Cc: Hannes Reinecke Signed-off-by: Ming Lei Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

block: switch partition lookup to use struct block_device

2020-12-01T21:53:40Z

Use struct block_device to lookup partitions on a disk. This removes all usage of struct hd_struct from the I/O path. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Hannes Reinecke Acked-by: Coly Li [bcache] Acked-by: Chao Yu [f2fs] Signed-off-by: Jens Axboe

block: allocate struct hd_struct as part of struct bdev_inode

2020-12-01T21:53:40Z

Allocate hd_struct together with struct block_device to pre-load the lifetime rule changes in preparation of merging the two structures. Note that part0 was previously embedded into struct gendisk, but is a separate allocation now, and already points to the block_device instead of the hd_struct. The lifetime of struct gendisk is still controlled by the struct device embedded in the part0 hd_struct. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

block: mark flush request as IDLE when it is really finished

2020-11-13T21:24:16Z

For avoiding use-after-free on flush request, we call its .end_io() from both timeout code path and __blk_mq_end_request(). When flush request's ref doesn't drop to zero, it is still used, we can't mark it as IDLE, so fix it by marking IDLE when its refcount drops to zero really. Fixes: 65ff5cd04551 ("blk-mq: mark flush request as IDLE in flush_end_io()") Signed-off-by: Ming Lei Cc: Yi Zhang Signed-off-by: Jens Axboe

blk-mq: mark flush request as IDLE in flush_end_io()

2020-10-30T14:33:49Z

Mark flush request as IDLE in its .end_io(), aligning it with how normal requests behave. The flush request stays in in-flight tags if we're not using an IO scheduler, so we need to change its state into IDLE. Otherwise, we will hang in blk_mq_tagset_wait_completed_request() during error recovery because flush the request state is kept as COMPLETED. Reported-by: Yi Zhang Signed-off-by: Ming Lei Tested-by: Yi Zhang Cc: Chao Leng Cc: Sagi Grimberg Signed-off-by: Jens Axboe

block: fix double account of flush request's driver tag

2020-08-11T19:53:32Z

In case of none scheduler, we share data request's driver tag for flush request, so have to mark the flush request as INFLIGHT for avoiding double account of this driver tag. Fixes: 568f27006577 ("blk-mq: centralise related handling into blk_mq_get_driver_tag") Reported-by: Matthew Wilcox Signed-off-by: Ming Lei Tested-by: Matthew Wilcox Cc: Christoph Hellwig Signed-off-by: Jens Axboe