kernel/linux.git/block/blk-core.c, branch v6.19.11

block: fix typos in comments and strings in blk-core

2025-11-25T17:39:49+00:00

This patch fixes multiple spelling mistakes in comments and documentation in the file block/blk-core.c. No functional changes intended. Suggested-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Signed-off-by: shechenglong Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

Merge tag 'for-6.18/block-20250929' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

2025-10-02T17:16:56+00:00

Pull block updates from Jens Axboe: - NVMe pull request via Keith: - FC target fixes (Daniel) - Authentication fixes and updates (Martin, Chris) - Admin controller handling (Kamaljit) - Target lockdep assertions (Max) - Keep-alive updates for discovery (Alastair) - Suspend quirk (Georg) - MD pull request via Yu: - Add support for a lockless bitmap. A key feature for the new bitmap are that the IO fastpath is lockless. If a user issues lots of write IO to the same bitmap bit in a short time, only the first write has additional overhead to update bitmap bit, no additional overhead for the following writes. By supporting only resync or recover written data, means in the case creating new array or replacing with a new disk, there is no need to do a full disk resync/recovery. - Switch ->getgeo() and ->bios_param() to using struct gendisk rather than struct block_device. - Rust block changes via Andreas. This series adds configuration via configfs and remote completion to the rnull driver. The series also includes a set of changes to the rust block device driver API: a few cleanup patches, and a few features supporting the rnull changes. The series removes the raw buffer formatting logic from `kernel::block` and improves the logic available in `kernel::string` to support the same use as the removed logic. - floppy arch cleanups - Reduce the number of dereferencing needed for ublk commands - Restrict supported sockets for nbd. Mostly done to eliminate a class of issues perpetually reported by syzbot, by using nonsensical socket setups. - A few s390 dasd block fixes - Fix a few issues around atomic writes - Improve DMA interation for integrity requests - Improve how iovecs are treated with regards to O_DIRECT aligment constraints. We used to require each segment to adhere to the constraints, now only the request as a whole needs to. - Clean up and improve p2p support, enabling use of p2p for metadata payloads - Improve locking of request lookup, using SRCU where appropriate - Use page references properly for brd, avoiding very long RCU sections - Fix ordering of recursively submitted IOs - Clean up and improve updating nr_requests for a live device - Various fixes and cleanups * tag 'for-6.18/block-20250929' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (164 commits) s390/dasd: enforce dma_alignment to ensure proper buffer validation s390/dasd: Return BLK_STS_INVAL for EINVAL from do_dasd_request ublk: remove redundant zone op check in ublk_setup_iod() nvme: Use non zero KATO for persistent discovery connections nvmet: add safety check for subsys lock nvme-core: use nvme_is_io_ctrl() for I/O controller check nvme-core: do ioccsz/iorcsz validation only for I/O controllers nvme-core: add method to check for an I/O controller blk-cgroup: fix possible deadlock while configuring policy blk-mq: fix null-ptr-deref in blk_mq_free_tags() from error path blk-mq: Fix more tag iteration function documentation selftests: ublk: fix behavior when fio is not installed ublk: don't access ublk_queue in ublk_unmap_io() ublk: pass ublk_io to __ublk_complete_rq() ublk: don't access ublk_queue in ublk_need_complete_req() ublk: don't access ublk_queue in ublk_check_commit_and_fetch() ublk: don't pass ublk_queue to ublk_fetch() ublk: don't access ublk_queue in ublk_config_io_buf() ublk: don't access ublk_queue in ublk_check_fetch_buf() ublk: pass q_id and tag to __ublk_check_and_get_req() ...

block: fix EOD return for device with nr_sectors == 0

2025-09-22T15:35:24+00:00

A recent commit skipped dumping the usual "attempt to access beyond end of device" message if the device size is 0 sectors, as that's a common pattern for devices that have been hot removed. But while it stopped that message, it also prevented returning -EIO for that condition. Reinstate the -EIO return, while retaining the quiet operation for triggering EOD for a device with 0 sectors. Reported-by: syzbot+4b12286339fe4c2700c1@syzkaller.appspotmail.com Reported-by: Sahil Chandna Fixes: d0a2b527d8c3 ("block: tone down bio_check_eod") Tested-by: Sahil Chandna Signed-off-by: Jens Axboe

block: fix ordering of recursive split IO

2025-09-10T11:23:46+00:00

Currently, split bio will be chained to original bio, and original bio will be resubmitted to the tail of current->bio_list, waiting for split bio to be issued. However, if split bio get split again, the IO order will be messed up. This problem, on the one hand, will cause performance degradation, especially for mdraid with large IO size; on the other hand, will cause write errors for zoned block devices[1]. For example, in raid456 IO will first be split by max_sector from md_submit_bio(), and then later be split again by chunksize for internal handling: For example, assume max_sectors is 1M, and chunksize is 512k 1) issue a 2M IO: bio issuing: 0+2M current->bio_list: NULL 2) md_submit_bio() split by max_sector: bio issuing: 0+1M current->bio_list: 1M+1M 3) chunk_aligned_read() split by chunksize: bio issuing: 0+512k current->bio_list: 1M+1M -> 512k+512k 4) after first bio issued, __submit_bio_noacct() will contuine issuing next bio: bio issuing: 1M+1M current->bio_list: 512k+512k bio issued: 0+512k 5) chunk_aligned_read() split by chunksize: bio issuing: 1M+512k current->bio_list: 512k+512k -> 1536k+512k bio issued: 0+512k 6) no split afterwards, finally the issue order is: 0+512k -> 1M+512k -> 512k+512k -> 1536k+512k This behaviour will cause large IO read on raid456 endup to be small discontinuous IO in underlying disks. Fix this problem by placing split bio to the head of current->bio_list. Test script: test on 8 disk raid5 with 64k chunksize dd if=/dev/md0 of=/dev/null bs=4480k iflag=direct Test results: Before this patch 1) iostat results: Device r/s rMB/s rrqm/s %rrqm r_await rareq-sz aqu-sz %util md0 52430.00 3276.87 0.00 0.00 0.62 64.00 32.60 80.10 sd* 4487.00 409.00 2054.00 31.40 0.82 93.34 3.68 71.20 2) blktrace G stage: 8,0 0 486445 11.357392936 843 G R 14071424 + 128 [dd] 8,0 0 486451 11.357466360 843 G R 14071168 + 128 [dd] 8,0 0 486454 11.357515868 843 G R 14071296 + 128 [dd] 8,0 0 486468 11.357968099 843 G R 14072192 + 128 [dd] 8,0 0 486474 11.358031320 843 G R 14071936 + 128 [dd] 8,0 0 486480 11.358096298 843 G R 14071552 + 128 [dd] 8,0 0 486490 11.358303858 843 G R 14071808 + 128 [dd] 3) io seek for sdx: Noted io seek is the result from blktrace D stage, statistic of: ABS((offset of next IO) - (offset + len of previous IO)) Read|Write seek cnt 55175, zero cnt 25079 >=(KB) .. <(KB) : count ratio |distribution | 0 .. 1 : 25079 45.5% |########################################| 1 .. 2 : 0 0.0% | | 2 .. 4 : 0 0.0% | | 4 .. 8 : 0 0.0% | | 8 .. 16 : 0 0.0% | | 16 .. 32 : 0 0.0% | | 32 .. 64 : 12540 22.7% |##################### | 64 .. 128 : 2508 4.5% |##### | 128 .. 256 : 0 0.0% | | 256 .. 512 : 10032 18.2% |################# | 512 .. 1024 : 5016 9.1% |######### | After this patch: 1) iostat results: Device r/s rMB/s rrqm/s %rrqm r_await rareq-sz aqu-sz %util md0 87965.00 5271.88 0.00 0.00 0.16 61.37 14.03 90.60 sd* 6020.00 658.44 5117.00 45.95 0.44 112.00 2.68 86.50 2) blktrace G stage: 8,0 0 206296 5.354894072 664 G R 7156992 + 128 [dd] 8,0 0 206305 5.355018179 664 G R 7157248 + 128 [dd] 8,0 0 206316 5.355204438 664 G R 7157504 + 128 [dd] 8,0 0 206319 5.355241048 664 G R 7157760 + 128 [dd] 8,0 0 206333 5.355500923 664 G R 7158016 + 128 [dd] 8,0 0 206344 5.355837806 664 G R 7158272 + 128 [dd] 8,0 0 206353 5.355960395 664 G R 7158528 + 128 [dd] 8,0 0 206357 5.356020772 664 G R 7158784 + 128 [dd] 3) io seek for sdx Read|Write seek cnt 28644, zero cnt 21483 >=(KB) .. <(KB) : count ratio |distribution | 0 .. 1 : 21483 75.0% |########################################| 1 .. 2 : 0 0.0% | | 2 .. 4 : 0 0.0% | | 4 .. 8 : 0 0.0% | | 8 .. 16 : 0 0.0% | | 16 .. 32 : 0 0.0% | | 32 .. 64 : 7161 25.0% |############## | BTW, this looks like a long term problem from day one, and large sequential IO read is pretty common case like video playing. And even with this patch, in this test case IO is merged to at most 128k is due to block layer plug limit BLK_PLUG_FLUSH_SIZE, increase such limit can get even better performance. However, we'll figure out how to do this properly later. [1] https://lore.kernel.org/all/e40b076d-583d-406b-b223-005910a9f46f@acm.org/ Fixes: d89d87965dcb ("When stacked block devices are in-use (e.g. md or dm), the recursive calls") Reported-by: Tie Ren Closes: https://lore.kernel.org/all/7dro5o7u5t64d6bgiansesjavxcuvkq5p2pok7dtwkav7b7ape@3isfr44b6352/ Signed-off-by: Yu Kuai Reviewed-by: Bart Van Assche Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: skip unnecessary checks for split bio

2025-09-10T11:23:46+00:00

Lots of checks are already done while submitting this bio the first time, and there is no need to check them again when this bio is resubmitted after split. Hence open code should_fail_bio() and blk_throtl_bio() that are still necessary from submit_bio_split_bioset(). Signed-off-by: Yu Kuai Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: initialize bio issue time in blk_mq_submit_bio()

2025-09-10T11:23:45+00:00

bio->issue_time_ns is only used by blk-iolatency, which can only be enabled for rq-based disk, hence it's not necessary to initialize the time for bio-based disk. Meanwhile, if bio is split by blk_crypto_fallback_split_bio_if_needed(), the issue time is not initialized for new split bio, this can be fixed as well. Noted the next patch will optimize better that bio issue time will only be used when blk-iolatency is really enabled by the disk. Fixes: 488f6682c832 ("block: blk-crypto-fallback for Inline Encryption") Signed-off-by: Yu Kuai Signed-off-by: Jens Axboe

block: tone down bio_check_eod

2025-08-18T19:27:05+00:00

bdev_nr_sectors() == 0 is a pattern used for block devices that have been hot removed, don't spam the log about them. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20250818101102.1604551-1-hch@lst.de Signed-off-by: Jens Axboe

treewide, timers: Rename from_timer() to timer_container_of()

2025-06-08T07:07:37+00:00

Move this API to the canonical timer_*() namespace. [ tglx: Redone against pre rc1 ] Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com

block: export API to get the number of bdev inflight IO

2025-05-10T08:11:49+00:00

- rename part_in_{flight, flight_rw} to bdev_count_{inflight, inflight_rw} - export bdev_count_inflight, to fix a problem in mdraid that foreground IO can be starved by background sync IO in later patches Link: https://lore.kernel.org/linux-raid/20250506124903.2540268-6-yukuai1@huaweicloud.com Signed-off-by: Yu Kuai Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar