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2024-01-18Documentation: block: ioprio: Update schedulersChristian Loehle1-7/+6
This doc hasn't been touched in a while, in the meantime some new io schedulers were added (e.g. all of mq), some with ioprio support. Also reword the introduction to remove reference to CFQ and the limitation that io priorities only work on reads, which is no longer true. Signed-off-by: Christian Loehle <christian.loehle@arm.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/a86cfdc8-016f-40f1-8b58-0cb15d2a792c@arm.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-11-01Merge tag 'docs-6.7' of git://git.lwn.net/linuxLinus Torvalds1-1/+1
Pull documentation updates from Jonathan Corbet: "The number of commits for documentation is not huge this time around, but there are some significant changes nonetheless: - Some more Spanish-language and Chinese translations - The much-discussed documentation of the confidential-computing threat model - Powerpc and RISCV documentation move under Documentation/arch - these complete this particular bit of documentation churn - A large traditional-Chinese documentation update - A new document on backporting and conflict resolution - Some kernel-doc and Sphinx fixes Plus the usual smattering of smaller updates and typo fixes" * tag 'docs-6.7' of git://git.lwn.net/linux: (40 commits) scripts/kernel-doc: Fix the regex for matching -Werror flag docs: backporting: address feedback Documentation: driver-api: pps: Update PPS generator documentation speakup: Document USB support doc: blk-ioprio: Bring the doc in line with the implementation docs: usb: fix reference to nonexistent file in UVC Gadget docs: doc-guide: mention 'make refcheckdocs' Documentation: fix typo in dynamic-debug howto scripts/kernel-doc: match -Werror flag strictly Documentation/sphinx: Remove the repeated word "the" in comments. docs: sparse: add SPDX-License-Identifier docs/zh_CN: Add subsystem-apis Chinese translation docs/zh_TW: update contents for zh_TW docs: submitting-patches: encourage direct notifications to commenters docs: add backporting and conflict resolution document docs: move riscv under arch docs: update link to powerpc/vmemmap_dedup.rst mm/memory-hotplug: fix typo in documentation docs: move powerpc under arch PCI: Update the devres documentation regarding to pcim_*() ...
2023-09-22docs: block: blk-mq.rst: correct places -> placeKuan-Wei Chiu1-1/+1
Corrected a typo in the blk-mq.rst documentation where 'places' was incorrectly used instead of 'place'. Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Message-ID: <20230902164121.2653109-1-visitorckw@gmail.com>
2023-09-11Documentation: Drop or replace remaining mentions of IA64Ard Biesheuvel1-3/+0
Drop or update mentions of IA64, as appropriate. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2023-08-30Merge tag 'docs-6.6' of git://git.lwn.net/linuxLinus Torvalds2-2/+2
Pull documentation updates from Jonathan Corbet: "Documentation work keeps chugging along; this includes: - Work from Carlos Bilbao to integrate rustdoc output into the generated HTML documentation. This took some work to figure out how to do it without slowing the docs build and without creating people who don't have Rust installed, but Carlos got there - Move the loongarch and mips architecture documentation under Documentation/arch/ - Some more maintainer documentation from Jakub ... plus the usual assortment of updates, translations, and fixes" * tag 'docs-6.6' of git://git.lwn.net/linux: (56 commits) Docu: genericirq.rst: fix irq-example input: docs: pxrc: remove reference to phoenix-sim Documentation: serial-console: Fix literal block marker docs/mm: remove references to hmm_mirror ops and clean typos docs/zh_CN: correct regi_chg(),regi_add() to region_chg(),region_add() Documentation: Fix typos Documentation/ABI: Fix typos scripts: kernel-doc: fix macro handling in enums scripts: kernel-doc: parse DEFINE_DMA_UNMAP_[ADDR|LEN] Documentation: riscv: Update boot image header since EFI stub is supported Documentation: riscv: Add early boot document Documentation: arm: Add bootargs to the table of added DT parameters docs: kernel-parameters: Refer to the correct bitmap function doc: update params of memhp_default_state= docs: Add book to process/kernel-docs.rst docs: sparse: fix invalid link addresses docs: vfs: clean up after the iterate() removal docs: Add a section on surveys to the researcher guidelines docs: move mips under arch docs: move loongarch under arch ...
2023-08-18Documentation: Fix typosBjorn Helgaas2-2/+2
Fix typos in Documentation. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Link: https://lore.kernel.org/r/20230814212822.193684-4-helgaas@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2023-08-18mm/page_io: introduce bio_first_folio_all()ZhangPeng1-0/+1
Introduce bio_first_folio_all() to return a folio, which makes it easier to use. Link: https://lkml.kernel.org/r/20230721034451.16412-4-zhangpeng362@huawei.com Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Suggested-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-05-12Documentation/block: drop the request.rst fileRandy Dunlap2-100/+0
Documentation/block/request.rst is outdated and should be removed. Also delete its entry in the block/index.rst file. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Link: https://lore.kernel.org/r/20230507182606.12647-1-rdunlap@infradead.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-16blk-crypto: remove blk_crypto_insert_cloned_request()Eric Biggers1-2/+1
blk_crypto_insert_cloned_request() is the same as blk_crypto_rq_get_keyslot(), so just use that directly. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20230315183907.53675-2-ebiggers@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-02-06block: stub out and deprecated the capability attribute on the gendiskChristoph Hellwig2-11/+0
The capability attribute was added in 2017 to expose the kernel internal GENHD_FL_MEDIA_CHANGE_NOTIFY to userspace without ever adding a value to an UAPI header, and without ever setting it in any driver until it was finally removed in Linux 5.7. Deprecate the file and always return 0 instead of exposing the other internal and frequently renumbered other gendisk flags. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Link: https://lore.kernel.org/r/20230203150209.3199115-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29block: ublk: fix doc build warningMing Lei1-0/+6
Fix the following warning: Documentation/block/ublk.rst:157: WARNING: Enumerated list ends without a blank line; unexpected unindent. Documentation/block/ublk.rst:171: WARNING: Enumerated list ends without a blank line; unexpected unindent. Fixes: 56f5160bc1b8 ("ublk_drv: add mechanism for supporting unprivileged ublk device") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20230118042318.127900-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-01-29ublk_drv: add mechanism for supporting unprivileged ublk deviceMing Lei1-9/+40
unprivileged ublk device is helpful for container use case, such as: ublk device created in one unprivileged container can be controlled and accessed by this container only. Implement this feature by adding flag of UBLK_F_UNPRIVILEGED_DEV, and if this flag isn't set, any control command has been run from privileged user. Otherwise, any control command can be sent from any unprivileged user, but the user has to be permitted to access the ublk char device to be controlled. In case of UBLK_F_UNPRIVILEGED_DEV: 1) for command UBLK_CMD_ADD_DEV, it is always allowed, and user needs to provide owner's uid/gid in this command, so that udev can set correct ownership for the created ublk device, since the device owner uid/gid can be queried via command of UBLK_CMD_GET_DEV_INFO. 2) for other control commands, they can only be run successfully if the current user is allowed to access the specified ublk char device, for running the permission check, path of the ublk char device has to be provided by these commands. Also add one control of command UBLK_CMD_GET_DEV_INFO2 which always include the char dev path in payload since userspace may not have knowledge if this device is created in unprivileged mode. For applying this mechanism, system administrator needs to take the following policies: 1) chmod 0666 /dev/ublk-control 2) change ownership of ublkcN & ublkbN - chown owner_uid:owner_gid /dev/ublkcN - chown owner_uid:owner_gid /dev/ublkbN Both can be done via one simple udev rule. Userspace: https://github.com/ming1/ubdsrv/tree/unprivileged-ublk 'ublk add -t $TYPE --un_privileged=1' is for creating one un-privileged ublk device if the user is un-privileged. Link: https://lore.kernel.org/linux-block/YoOr6jBfgVm8GvWg@stefanha-x1.localdomain/ Suggested-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20230106041711.914434-7-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-21blk-crypto: don't use struct request_queue for public interfacesChristoph Hellwig1-6/+6
Switch all public blk-crypto interfaces to use struct block_device arguments to specify the device they operate on instead of th request_queue, which is a block layer implementation detail. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20221114042944.1009870-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-10-18Documentation: document ublk user recovery featureZiyangZhang1-0/+36
Add documentation for user recovery feature of ublk subsystem. Signed-off-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/20221018045346.99706-2-ZiyangZhang@linux.alibaba.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-02Documentation: document ublkMing Lei2-0/+254
Add documentation for ublk subsystem. It was supposed to be documented when merging the driver, but missing at that time. Cc: Bagas Sanjaya <bagasdotme@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Richard W.M. Jones <rjones@redhat.com> Cc: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> [axboe: correct MAINTAINERS addition] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-08-02null_blk: add module parameters for 4 optionsVincent Fu1-0/+22
Add as module parameters these options: memory_backed discard mbps cache_size Previously these could only be set via configfs. Still missing is bad_blocks. The kernel test robot found a documentation formatting issue in v1 of this patch. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Vincent Fu <vincent.fu@samsung.com> Link: https://lore.kernel.org/r/20220708174943.87787-2-vincent.fu@samsung.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-15block: remove biodoc.rstChristoph Hellwig2-1156/+0
This document is completely out of date and extremely misleading. In general the existing kerneldoc comment serve as a much better documentation of the still existing functionality, while the history blurbs are pretty much irrelevant today. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20220215081047.3693582-1-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-11docs: block: biodoc.rst: Drop the obsolete and incorrect contentBarry Song1-5/+1
Since commit 7eaceaccab5f ("block: remove per-queue plugging"), kernel has removed blk_run_address_space(), blk_unplug() and sync_buffer(), and moved to on-stack plugging. The document has been obsolete for years. Given that there is no obvious counterparts in the new mechinism to replace old APIs, this patch drops the content directly. Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Link: https://lore.kernel.org/r/20220207074931.20067-1-song.bao.hua@hisilicon.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-04block: pass a block_device to bio_clone_fastChristoph Hellwig1-5/+0
Pass a block_device to bio_clone_fast and __bio_clone_fast and give the functions more suitable names. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Link: https://lore.kernel.org/r/20220202160109.108149-14-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-02-02block: remove genhd.hChristoph Hellwig1-1/+1
There is no good reason to keep genhd.h separate from the main blkdev.h header that includes it. So fold the contents of genhd.h into blkdev.h and remove genhd.h entirely. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Link: https://lore.kernel.org/r/20220124093913.742411-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-01-09docs: block: remove queue-sysfs.rstEric Biggers2-322/+0
This has been replaced by Documentation/ABI/stable/sysfs-block, which is the correct place for sysfs documentation. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20211209003833.6396-8-ebiggers@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-02Merge tag 'docs-5.16' of git://git.lwn.net/linuxLinus Torvalds1-4/+5
Pull documentation updates from Jonathan Corbet: "This is a relatively unexciting cycle for documentation. - Some small scripts/kerneldoc fixes - More Chinese translation work, but at a much reduced rate. - The tip-tree maintainer's handbook ...plus the usual array of build fixes, typo fixes, etc" * tag 'docs-5.16' of git://git.lwn.net/linux: (53 commits) kernel-doc: support DECLARE_PHY_INTERFACE_MASK() docs/zh_CN: add core-api xarray translation docs/zh_CN: add core-api assoc_array translation speakup: Fix typo in documentation "boo" -> "boot" docs: submitting-patches: make section about the Link: tag more explicit docs: deprecated.rst: Clarify open-coded arithmetic with literals scripts: documentation-file-ref-check: fix bpf selftests path scripts: documentation-file-ref-check: ignore hidden files coding-style.rst: trivial: fix location of driver model macros docs: f2fs: fix text alignment docs/zh_CN add PCI pci.rst translation docs/zh_CN add PCI index.rst translation docs: translations: zh_CN: memory-hotplug.rst: fix a typo docs: translations: zn_CN: irq-affinity.rst: add a missing extension block: add documentation for inflight scripts: kernel-doc: Ignore __alloc_size() attribute docs: pdfdocs: Adjust \headheight for fancyhdr docs: UML: user_mode_linux_howto_v2 edits docs: use the lore redirector everywhere docs: proc.rst: mountinfo: align columns ...
2021-11-01Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscryptLinus Torvalds1-0/+2
Pull fscrypt updates from Eric Biggers: "Some cleanups for fs/crypto/: - Allow 256-bit master keys with AES-256-XTS - Improve documentation and comments - Remove unneeded field fscrypt_operations::max_namelen" * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt: fscrypt: improve a few comments fscrypt: allow 256-bit master keys with AES-256-XTS fscrypt: improve documentation for inline encryption fscrypt: clean up comments in bio.c fscrypt: remove fscrypt_operations::max_namelen
2021-10-26doc: Fix typo in request queue sysfs documentationDamien Le Moal1-1/+1
Fix a typo (are -> as) in the introduction paragraph of Documentation/block/queue-sysfs.rst. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20211027022223.183838-6-damien.lemoal@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-26doc: document sysfs queue/independent_access_ranges attributesDamien Le Moal1-0/+31
Update the file Documentation/block/queue-sysfs.rst to add a description of a device queue sysfs entries related to independent access ranges (e.g. concurrent positioning ranges for multi-actuator hard-disks). Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/20211027022223.183838-5-damien.lemoal@wdc.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-21blk-crypto: update inline encryption documentationEric Biggers1-206/+245
Rework most of inline-encryption.rst to be easier to follow, to correct some information, to add some important details and remove some unimportant details, and to take into account the renaming from blk_keyslot_manager to blk_crypto_profile. Reviewed-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20211018180453.40441-5-ebiggers@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-20fscrypt: improve documentation for inline encryptionEric Biggers1-0/+2
Currently the fscrypt inline encryption support is documented in the "Implementation details" section, and it doesn't go into much detail. It's really more than just an "implementation detail" though, as there is a user-facing mount option. Also, hardware-wrapped key support (an upcoming feature) will depend on inline encryption and will affect the on-disk format; by definition that's not just an implementation detail. Therefore, move this documentation into its own section and expand it. Link: https://lore.kernel.org/r/20210916174928.65529-4-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2021-09-14docs: block: fix discard_max_bytes referencesStephen Kitt1-4/+5
When discard_max_hw_bytes was introduced, in commit 0034af036554 ("block: make /sys/block/<dev>/queue/discard_max_bytes writeable"), the discard_max_bytes documentation section was renamed to discard_max_hw_bytes, but the references it contains to discard_max_bytes weren't updated. This patch refers to discard_max_hw_bytes instead. It also reflows the paragraph so that sentences end lines. Signed-off-by: Stephen Kitt <steve@sk2.org> Link: https://lore.kernel.org/r/20210910105142.2116749-1-steve@sk2.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-08-24Documentation: block: blk-mq: Fix small typo in multi-queue docsJinay Jain1-1/+1
Fixed a small typo in the documentation for multi-queue block IO. Signed-off-by: Jinay Jain <jinaybjain@gmail.com> Link: https://lore.kernel.org/r/20210812152528.300668-1-jinaybjain@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-06-30Merge tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-blockLinus Torvalds1-11/+27
Pull core block updates from Jens Axboe: - disk events cleanup (Christoph) - gendisk and request queue allocation simplifications (Christoph) - bdev_disk_changed cleanups (Christoph) - IO priority improvements (Bart) - Chained bio completion trace fix (Edward) - blk-wbt fixes (Jan) - blk-wbt enable/disable fix (Zhang) - Scheduler dispatch improvements (Jan, Ming) - Shared tagset scheduler improvements (John) - BFQ updates (Paolo, Luca, Pietro) - BFQ lock inversion fix (Jan) - Documentation improvements (Kir) - CLONE_IO block cgroup fix (Tejun) - Remove of ancient and deprecated block dump feature (zhangyi) - Discard merge fix (Ming) - Misc fixes or followup fixes (Colin, Damien, Dan, Long, Max, Thomas, Yang) * tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block: (129 commits) block: fix discard request merge block/mq-deadline: Remove a WARN_ON_ONCE() call blk-mq: update hctx->dispatch_busy in case of real scheduler blk: Fix lock inversion between ioc lock and bfqd lock bfq: Remove merged request already in bfq_requests_merged() block: pass a gendisk to bdev_disk_changed block: move bdev_disk_changed block: add the events* attributes to disk_attrs block: move the disk events code to a separate file block: fix trace completion for chained bio block/partitions/msdos: Fix typo inidicator -> indicator block, bfq: reset waker pointer with shared queues block, bfq: check waker only for queues with no in-flight I/O block, bfq: avoid delayed merge of async queues block, bfq: boost throughput by extending queue-merging times block, bfq: consider also creation time in delayed stable merge block, bfq: fix delayed stable merge check block, bfq: let also stably merged queues enjoy weight raising blk-wbt: make sure throttle is enabled properly blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled() ...
2021-06-17docs: block: biodoc.rst: avoid using ReST :doc:`foo` markupMauro Carvalho Chehab1-1/+1
The :doc:`foo` tag is auto-generated via automarkup.py. So, use the filename at the sources, instead of :doc:`foo`. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/1d26256b305e02da82a6a990910a5b5fb9a0355e.1623824363.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-06-16docs: block/bfq: describe per-device weightKir Kolyshkin1-11/+27
The functionality of setting per-device weight for BFQ was added in v5.4 (commit 795fe54c2a828099), but the documentation was never updated. While at it, improve formatting a bit. Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com> Link: https://lore.kernel.org/r/20210614214109.207430-1-kolyshkin@gmail.com Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-04docs: block: fix stat.rst document errorGao Mingfei1-1/+1
Update the description of the device stat files to include the proper number of fields. Signed-off-by: Gao Mingfei <g199209@gmail.com> Link: https://lore.kernel.org/r/20210601085145.3273-1-g199209@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-05-20docs: block: blk-mq.rst: correct drive -> driverYue Hu1-2/+2
It is 'driver' to complete the request. Also remove a redundant space. Signed-off-by: Yue Hu <huyue2@yulong.com> Link: https://lore.kernel.org/r/20210520074225.1989-1-zbestahu@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-05-10Documentation: drop optional BOMsRandy Dunlap1-1/+1
A few of the Documentation .rst files begin with a Unicode byte order mark (BOM). The BOM may signify endianess for 16-bit or 32-bit encodings or indicate that the text stream is indeed Unicode. We don't need it for either of those uses. It may also interfere with (confuse) some software. Since we don't need it and its use is optional, just delete the uses of it in Documentation/. https://en.wikipedia.org/wiki/Byte_order_mark Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Link: https://lore.kernel.org/r/20210506231907.14359-1-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-03-02block/bfq: update comments and default value in docs for fifo_expireJoseph Qi1-2/+2
Correct the comments since bfq_fifo_expire[0] is for async request, while bfq_fifo_expire[1] is for sync request. Also update docs, according the source code, the default fifo_expire_async is 250ms, and fifo_expire_sync is 125ms. Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com> Acked-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-22Merge tag 'mmc-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmcLinus Torvalds1-6/+6
Pull MMC updates from Ulf Hansson: "MMC core: - Add support for eMMC inline encryption - Add a helper function to parse DT properties for clock phases - Some improvements and cleanups for the mmc_test module MMC host: - android-goldfish: Remove driver - cqhci: Add support for eMMC inline encryption - dw_mmc-zx: Remove driver - meson-gx: Extend support for scatter-gather to allow SD_IO_RW_EXTENDED - mmci: Add support for probing bus voltage level translator - mtk-sd: Address race condition for request timeouts - sdhci_am654: Add Support for the variant on TI's AM64 SoC - sdhci-esdhc-imx: Prevent kernel panic at ->remove() - sdhci-iproc: Add ACPI bindings for the RPi to enable SD and WiFi on RPi4 - sdhci-msm: Add Inline Crypto Engine support - sdhci-msm: Use actual_clock to improve timeout calculations - sdhci-of-aspeed: Add Andrew Jeffery as maintainer - sdhci-of-aspeed: Extend clock support for the AST2600 variant - sdhci-pci-gli: Increase idle period for low power state for GL9763E - sdhci-pci-o2micro: Make tuning for SDR104 HW more robust - sdhci-sirf: Remove driver - sdhci-xenon: Add support for the AP807 variant - sunxi-mmc: Add support for the A100 variant - sunxi-mmc: Ensure host is suspended during system sleep - tmio: Add detection of data timeout errors - tmio/renesas_sdhi: Extend support for retuning - renesas_sdhi_internal_dmac: Add support for the ->pre|post_req() ops" * tag 'mmc-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc: (86 commits) mmc: sdhci-esdhc-imx: fix kernel panic when remove module mmc: host: Retire MMC_GOLDFISH mmc: cb710: Use new tasklet API mmc: sdhci-pci-o2micro: Bug fix for SDR104 HW tuning failure mmc: mmc_test: use erase_arg for mmc_erase command mmc: wbsd: Use new tasklet API mmc: via-sdmmc: Use new tasklet API mmc: uniphier-sd: Use new tasklet API mmc: tifm_sd: Use new tasklet API mmc: s3cmci: Use new tasklet API mmc: omap: Use new tasklet API mmc: dw_mmc: Use new tasklet API mmc: au1xmmc: Use new tasklet API mmc: atmel-mci: Use new tasklet API mmc: cavium: Replace spin_lock_irqsave with spin_lock in hard IRQ mmc: queue: Remove unused define mmc: core: Drop redundant bouncesz from struct mmc_card mmc: core: Drop redundant member in struct mmc host mmc: core: Use host instead of card argument to mmc_spi_send_csd() mmc: core: Exclude unnecessary header file ...
2021-02-10block: introduce zone_write_granularity limitDamien Le Moal1-0/+7
Per ZBC and ZAC specifications, host-managed SMR hard-disks mandate that all writes into sequential write required zones be aligned to the device physical block size. However, NVMe ZNS does not have this constraint and allows write operations into sequential zones to be aligned to the device logical block size. This inconsistency does not help with software portability across device types. To solve this, introduce the zone_write_granularity queue limit to indicate the alignment constraint, in bytes, of write operations into zones of a zoned block device. This new limit is exported as a read-only sysfs queue attribute and the helper blk_queue_zone_write_granularity() introduced for drivers to set this limit. The function blk_queue_set_zoned() is modified to set this new limit to the device logical block size by default. NVMe ZNS devices as well as zoned nullb devices use this default value as is. The scsi disk driver is modified to execute the blk_queue_zone_write_granularity() helper to set the zone write granularity of host-managed SMR disks to the disk physical block size. The accessor functions queue_zone_write_granularity() and bdev_zone_write_granularity() are also introduced. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@edc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-10block: document zone_append_max_bytes attributeDamien Le Moal1-0/+6
The description of the zone_append_max_bytes sysfs queue attribute is missing from Documentation/block/queue-sysfs.rst. Add it. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@edc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-02-01block/keyslot-manager: introduce devm_blk_ksm_init()Eric Biggers1-6/+6
Add a resource-managed variant of blk_ksm_init() so that drivers don't have to worry about calling blk_ksm_destroy(). Note that the implementation uses a custom devres action to call blk_ksm_destroy() rather than switching the two allocations to be directly devres-managed, e.g. with devm_kmalloc(). This is because we need to keep zeroing the memory containing the keyslots when it is freed, and also because we want to continue using kvmalloc() (and there is no devm_kvmalloc()). Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Satya Tangirala <satyat@google.com> Acked-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20210121082155.111333-2-ebiggers@kernel.org Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2021-01-25bvec/iter: disallow zero-length segment bvecsPavel Begunkov1-0/+2
zero-length bvec segments are allowed in general, but not handled by bio and down the block layer so filtered out. This inconsistency may be confusing and prevent from optimisations. As zero-length segments are useless and places that were generating them are patched, declare them not allowed. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-24Merge tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-blockLinus Torvalds1-0/+8
Pull block fixes from Jens Axboe: - NVMe pull request from Christoph - rdma error handling fixes (Chao Leng) - fc error handling and reconnect fixes (James Smart) - fix the qid displace when tracing ioctl command (Keith Busch) - don't use BLK_MQ_REQ_NOWAIT for passthru (Chaitanya Kulkarni) - fix MTDT for passthru (Logan Gunthorpe) - blacklist Write Same on more devices (Kai-Heng Feng) - fix an uninitialized work struct (zhenwei pi)" - lightnvm out-of-bounds fix (Colin) - SG allocation leak fix (Doug) - rnbd fixes (Gioh, Guoqing, Jack) - zone error translation fixes (Keith) - kerneldoc markup fix (Mauro) - zram lockdep fix (Peter) - Kill unused io_context members (Yufen) - NUMA memory allocation cleanup (Xianting) - NBD config wakeup fix (Xiubo) * tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block: (27 commits) block: blk-mq: fix a kernel-doc markup nvme-fc: shorten reconnect delay if possible for FC nvme-fc: wait for queues to freeze before calling update_hr_hw_queues nvme-fc: fix error loop in create_hw_io_queues nvme-fc: fix io timeout to abort I/O null_blk: use zone status for max active/open nvmet: don't use BLK_MQ_REQ_NOWAIT for passthru nvmet: cleanup nvmet_passthru_map_sg() nvmet: limit passthru MTDS by BIO_MAX_PAGES nvmet: fix uninitialized work for zero kato nvme-pci: disable Write Zeroes on Sandisk Skyhawk nvme: use queuedata for nvme_req_qid nvme-rdma: fix crash due to incorrect cqe nvme-rdma: fix crash when connect rejected block: remove unused members for io_context blk-mq: remove the calling of local_memory_node() zram: Fix __zram_bvec_{read,write}() locking order skd_main: remove unused including <linux/version.h> sgl_alloc_order: fix memory leak lightnvm: fix out-of-bounds write to array devices->info[] ...
2020-10-15docs: block: blk-mq.rst: get rid of :c:typeMauro Carvalho Chehab1-2/+2
The :c:type macros are not used properly there, as reported by Sphinx 3: ./Documentation/block/blk-mq.rst:112: WARNING: Unparseable C cross-reference: 'hctx->dispatch' Invalid C declaration: Expected end of definition. [error at 4] hctx->dispatch ----^ Also, they won't be generating any cross references. So, replace them by a literal markup. Reviewed-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-15docs: get rid of :c:type explicit declarations for structsMauro Carvalho Chehab2-8/+8
The :c:type:`foo` only works properly with structs before Sphinx 3.x. On Sphinx 3.x, structs should now be declared using the .. c:struct, and referenced via :c:struct tag. As we now have the automarkup.py macro, that automatically convert: struct foo into cross-references, let's get rid of that, solving several warnings when building docs with Sphinx 3.x. Reviewed-by: André Almeida <andrealmeid@collabora.com> # blk-mq.rst Reviewed-by: Takashi Iwai <tiwai@suse.de> # sound Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-13block: add zone specific block statusesKeith Busch1-0/+8
A zoned device with limited resources to open or activate zones may return an error when the host exceeds those limits. The same command may be successful if retried later, but the host needs to wait for specific zone states before it should expect a retry to succeed. Have the block layer provide an appropriate status for these conditions so applications can distinuguish this error for special handling. Cc: linux-api@vger.kernel.org Cc: Niklas Cassel <niklas.cassel@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-08-05Merge tag 'for-5.9/drivers-20200803' of git://git.kernel.dk/linux-blockLinus Torvalds1-0/+14
Pull block driver updates from Jens Axboe: - NVMe: - ZNS support (Aravind, Keith, Matias, Niklas) - Misc cleanups, optimizations, fixes (Baolin, Chaitanya, David, Dongli, Max, Sagi) - null_blk zone capacity support (Aravind) - MD: - raid5/6 fixes (ChangSyun) - Warning fixes (Damien) - raid5 stripe fixes (Guoqing, Song, Yufen) - sysfs deadlock fix (Junxiao) - raid10 deadlock fix (Vitaly) - struct_size conversions (Gustavo) - Set of bcache updates/fixes (Coly) * tag 'for-5.9/drivers-20200803' of git://git.kernel.dk/linux-block: (117 commits) md/raid5: Allow degraded raid6 to do rmw md/raid5: Fix Force reconstruct-write io stuck in degraded raid5 raid5: don't duplicate code for different paths in handle_stripe raid5-cache: hold spinlock instead of mutex in r5c_journal_mode_show md: print errno in super_written md/raid5: remove the redundant setting of STRIPE_HANDLE md: register new md sysfs file 'uuid' read-only md: fix max sectors calculation for super 1.0 nvme-loop: remove extra variable in create ctrl nvme-loop: set ctrl state connecting after init nvme-multipath: do not fall back to __nvme_find_path() for non-optimized paths nvme-multipath: fix logic for non-optimized paths nvme-rdma: fix controller reset hang during traffic nvme-tcp: fix controller reset hang during traffic nvmet: introduce the passthru Kconfig option nvmet: introduce the passthru configfs interface nvmet: Add passthru enable/disable helpers nvmet: add passthru code to process commands nvme: export nvme_find_get_ns() and nvme_put_ns() nvme: introduce nvme_ctrl_get_by_path() ...
2020-08-04Merge tag 'docs-5.9' of git://git.lwn.net/linuxLinus Torvalds4-2/+156
Pull documentation updates from Jonathan Corbet: "It's been a busy cycle for documentation - hopefully the busiest for a while to come. Changes include: - Some new Chinese translations - Progress on the battle against double words words and non-HTTPS URLs - Some block-mq documentation - More RST conversions from Mauro. At this point, that task is essentially complete, so we shouldn't see this kind of churn again for a while. Unless we decide to switch to asciidoc or something...:) - Lots of typo fixes, warning fixes, and more" * tag 'docs-5.9' of git://git.lwn.net/linux: (195 commits) scripts/kernel-doc: optionally treat warnings as errors docs: ia64: correct typo mailmap: add entry for <alobakin@marvell.com> doc/zh_CN: add cpu-load Chinese version Documentation/admin-guide: tainted-kernels: fix spelling mistake MAINTAINERS: adjust kprobes.rst entry to new location devices.txt: document rfkill allocation PCI: correct flag name docs: filesystems: vfs: correct flag name docs: filesystems: vfs: correct sync_mode flag names docs: path-lookup: markup fixes for emphasis docs: path-lookup: more markup fixes docs: path-lookup: fix HTML entity mojibake CREDITS: Replace HTTP links with HTTPS ones docs: process: Add an example for creating a fixes tag doc/zh_CN: add Chinese translation prefer section doc/zh_CN: add clearing-warn-once Chinese version doc/zh_CN: add admin-guide index doc:it_IT: process: coding-style.rst: Correct __maybe_unused compiler label futex: MAINTAINERS: Re-add selftests directory ...
2020-08-03Merge tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-blockLinus Torvalds2-2/+2
Pull core block updates from Jens Axboe: "Good amount of cleanups and tech debt removals in here, and as a result, the diffstat shows a nice net reduction in code. - Softirq completion cleanups (Christoph) - Stop using ->queuedata (Christoph) - Cleanup bd claiming (Christoph) - Use check_events, moving away from the legacy media change (Christoph) - Use inode i_blkbits consistently (Christoph) - Remove old unused writeback congestion bits (Christoph) - Cleanup/unify submission path (Christoph) - Use bio_uninit consistently, instead of bio_disassociate_blkg (Christoph) - sbitmap cleared bits handling (John) - Request merging blktrace event addition (Jan) - sysfs add/remove race fixes (Luis) - blk-mq tag fixes/optimizations (Ming) - Duplicate words in comments (Randy) - Flush deferral cleanup (Yufen) - IO context locking/retry fixes (John) - struct_size() usage (Gustavo) - blk-iocost fixes (Chengming) - blk-cgroup IO stats fixes (Boris) - Various little fixes" * tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-block: (135 commits) block: blk-timeout: delete duplicated word block: blk-mq-sched: delete duplicated word block: blk-mq: delete duplicated word block: genhd: delete duplicated words block: elevator: delete duplicated word and fix typos block: bio: delete duplicated words block: bfq-iosched: fix duplicated word iocost_monitor: start from the oldest usage index iocost: Fix check condition of iocg abs_vdebt block: Remove callback typedefs for blk_mq_ops block: Use non _rcu version of list functions for tag_set_list blk-cgroup: show global disk stats in root cgroup io.stat blk-cgroup: make iostat functions visible to stat printing block: improve discard bio alignment in __blkdev_issue_discard() block: change REQ_OP_ZONE_RESET and REQ_OP_ZONE_RESET_ALL to be odd numbers block: defer flush request no matter whether we have elevator block: make blk_timeout_init() static block: remove retry loop in ioc_release_fn() block: remove unnecessary ioc nested locking block: integrate bd_start_claiming into __blkdev_get ...
2020-07-15block: add max_active_zones to blk-sysfsNiklas Cassel1-0/+7
Add a new max_active zones definition in the sysfs documentation. This definition will be common for all devices utilizing the zoned block device support in the kernel. Export max_active_zones according to this new definition for NVMe Zoned Namespace devices, ZAC ATA devices (which are treated as SCSI devices by the kernel), and ZBC SCSI devices. Add the new max_active_zones member to struct request_queue, rather than as a queue limit, since this property cannot be split across stacking drivers. For SCSI devices, even though max active zones is not part of the ZBC/ZAC spec, export max_active_zones as 0, signifying "no limit". Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-15block: add max_open_zones to blk-sysfsNiklas Cassel1-0/+7
Add a new max_open_zones definition in the sysfs documentation. This definition will be common for all devices utilizing the zoned block device support in the kernel. Export max open zones according to this new definition for NVMe Zoned Namespace devices, ZAC ATA devices (which are treated as SCSI devices by the kernel), and ZBC SCSI devices. Add the new max_open_zones member to struct request_queue, rather than as a queue limit, since this property cannot be split across stacking drivers. Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> Reviewed-by: Javier González <javier@javigon.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-13Documentation: block: eliminate duplicated wordRandy Dunlap1-1/+1
Change the doubled word "the" to "to the". Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Link: https://lore.kernel.org/r/20200707180414.10467-3-rdunlap@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-07-06docs: block: update and fix tiny error for bfqYufen Yu1-8/+1
The max value of blkio.bfq.weight is 1000, rather than 10000. And 'weights' have been remove from /sys/block/XXX/queue/iosched. Signed-off-by: Yufen Yu <yuyufen@huawei.com> Acked-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01block: rename generic_make_request to submit_bio_noacctChristoph Hellwig1-1/+1
generic_make_request has always been very confusingly misnamed, so rename it to submit_bio_noacct to make it clear that it is submit_bio minus accounting and a few checks. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-07-01block: move ->make_request_fn to struct block_device_operationsChristoph Hellwig2-2/+2
The make_request_fn is a little weird in that it sits directly in struct request_queue instead of an operation vector. Replace it with a block_device_operations method called submit_bio (which describes much better what it does). Also remove the request_queue argument to it, as the queue can be derived pretty trivially from the bio. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-06-26docs: fix references for DMA*.txt filesMauro Carvalho Chehab1-1/+1
As we moved those files to core-api, fix references to point to their newer locations. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/37b2fd159fbc7655dbf33b3eb1215396a25f6344.1592895969.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-22docs: block: Create blk-mq documentationAndré Almeida2-0/+154
Create a documentation providing a background and explanation around the operation of the Multi-Queue Block IO Queueing Mechanism (blk-mq). The reference for writing this documentation was the source code and "Linux Block IO: Introducing Multi-queue SSD Access on Multi-core Systems", by Axboe et al. Signed-off-by: André Almeida <andrealmeid@collabora.com> Reviewed-by: Jens Axboe <axboe@kernel.dk> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20200620002036.113000-1-andrealmeid@collabora.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-02Merge tag 'for-5.8-tag' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs updates from David Sterba: "Highlights: - speedup dead root detection during orphan cleanup, eg. when there are many deleted subvolumes waiting to be cleaned, the trees are now looked up in radix tree instead of a O(N^2) search - snapshot creation with inherited qgroup will mark the qgroup inconsistent, requires a rescan - send will emit file capabilities after chown, this produces a stream that does not need postprocessing to set the capabilities again - direct io ported to iomap infrastructure, cleaned up and simplified code, notably removing last use of struct buffer_head in btrfs code Core changes: - factor out backreference iteration, to be used by ordinary backreferences and relocation code - improved global block reserve utilization * better logic to serialize requests * increased maximum available for unlink * improved handling on large pages (64K) - direct io cleanups and fixes * simplify layering, where cloned bios were unnecessarily created for some cases * error handling fixes (submit, endio) * remove repair worker thread, used to avoid deadlocks during repair - refactored block group reading code, preparatory work for new type of block group storage that should improve mount time on large filesystems Cleanups: - cleaned up (and slightly sped up) set/get helpers for metadata data structure members - root bit REF_COWS got renamed to SHAREABLE to reflect the that the blocks of the tree get shared either among subvolumes or with the relocation trees Fixes: - when subvolume deletion fails due to ENOSPC, the filesystem is not turned read-only - device scan deals with devices from other filesystems that changed ownership due to overwrite (mkfs) - fix a race between scrub and block group removal/allocation - fix long standing bug of a runaway balance operation, printing the same line to the syslog, caused by a stale status bit on a reloc tree that prevented progress - fix corrupt log due to concurrent fsync of inodes with shared extents - fix space underflow for NODATACOW and buffered writes when it for some reason needs to fallback to COW mode" * tag 'for-5.8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (133 commits) btrfs: fix space_info bytes_may_use underflow during space cache writeout btrfs: fix space_info bytes_may_use underflow after nocow buffered write btrfs: fix wrong file range cleanup after an error filling dealloc range btrfs: remove redundant local variable in read_block_for_search btrfs: open code key_search btrfs: split btrfs_direct_IO to read and write part btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK fs: remove dio_end_io() btrfs: switch to iomap_dio_rw() for dio iomap: remove lockdep_assert_held() iomap: add a filesystem hook for direct I/O bio submission fs: export generic_file_buffered_read() btrfs: turn space cache writeout failure messages into debug messages btrfs: include error on messages about failure to write space/inode caches btrfs: remove useless 'fail_unlock' label from btrfs_csum_file_blocks() btrfs: do not ignore error from btrfs_next_leaf() when inserting checksums btrfs: make checksum item extension more efficient btrfs: fix corrupt log due to concurrent fsync of inodes with shared extents btrfs: unexport btrfs_compress_set_level() btrfs: simplify iget helpers ...
2020-05-25block: add bio_for_each_bvec_all()Omar Sandoval1-0/+2
An upcoming Btrfs fix needs to know the original size of a non-cloned bios. Rather than accessing the bvec table directly, let's add a bio_for_each_bvec_all() accessor. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-05-14Documentation: Document the blk-crypto frameworkSatya Tangirala2-0/+264
The blk-crypto framework adds support for inline encryption. There are numerous changes throughout the storage stack. This patch documents the main design choices in the block layer, the API presented to users of the block layer (like fscrypt or layered devices) and the API presented to drivers for adding support for inline encryption. Signed-off-by: Satya Tangirala <satyat@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-12block: Document genhd capability flagsStephen Kitt1-12/+4
The kernel documentation includes a brief section about genhd capabilities, but it turns out that the only documented capability (GENHD_FL_MEDIA_CHANGE_NOTIFY) isn't used any more. This patch removes that flag, and documents the rest, based on my understanding of the current uses of these flags in the kernel. The documentation is kept in the header file, alongside the declarations, in the hope that it will be kept up-to-date in future; the kernel documentation is changed to include the documentation generated from the header file. Because the ultimate goal is to provide some end-user documentation (or end-administrator documentation), the comments are perhaps more user-oriented than might be expected. Since the values are shown to users in hexadecimal, the documentation lists them in hexadecimal, and the constant declarations are adjusted to match. Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Stephen Kitt <steve@sk2.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-10docs: block/biovecs: update the location of bio.cGuoqing Jiang1-1/+1
Replace fs with block since bio.c had been moved to block folder. Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Link: https://lore.kernel.org/r/20200106103735.10327-1-guoqing.jiang@cloud.ionos.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-11-21block: add iostat counters for flush requestsKonstantin Khlebnikov1-2/+12
Requests that triggers flushing volatile writeback cache to disk (barriers) have significant effect to overall performance. Block layer has sophisticated engine for combining several flush requests into one. But there is no statistics for actual flushes executed by disk. Requests which trigger flushes usually are barriers - zero-size writes. This patch adds two iostat counters into /sys/class/block/$dev/stat and /proc/diskstats - count of completed flush requests and their total time. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-11docs: block: null_blk: enhance document styleAndré Almeida1-15/+18
Use proper ReST syntax for chapters. Add more information to enhance standardization in the file and to make the rendering more homogeneous. Add a SPDX identifier. Mark single-queue mode as deprecated. Signed-off-by: André Almeida <andrealmeid@collabora.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-09-03Documenation: switching-sched: Remove notes about elevator argumentMarcos Paulo de Souza1-4/+0
This argument was ignored since blk-mq was set as default, so remove it from documentation. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com> .txt file is now .rst Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-16Merge tag 'docs/v5.3-1' of ↵Linus Torvalds18-335/+536
git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media Pull rst conversion of docs from Mauro Carvalho Chehab: "As agreed with Jon, I'm sending this big series directly to you, c/c him, as this series required a special care, in order to avoid conflicts with other trees" * tag 'docs/v5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (77 commits) docs: kbuild: fix build with pdf and fix some minor issues docs: block: fix pdf output docs: arm: fix a breakage with pdf output docs: don't use nested tables docs: gpio: add sysfs interface to the admin-guide docs: locking: add it to the main index docs: add some directories to the main documentation index docs: add SPDX tags to new index files docs: add a memory-devices subdir to driver-api docs: phy: place documentation under driver-api docs: serial: move it to the driver-api docs: driver-api: add remaining converted dirs to it docs: driver-api: add xilinx driver API documentation docs: driver-api: add a series of orphaned documents docs: admin-guide: add a series of orphaned documents docs: cgroup-v1: add it to the admin-guide book docs: aoe: add it to the driver-api book docs: add some documentation dirs to the driver-api book docs: driver-model: move it to the driver-api book docs: lp855x-driver.rst: add it to the driver-api book ...
2019-07-15docs: block: fix pdf outputMauro Carvalho Chehab1-4/+5
Add an extra blank line and use a markup for the enumberated list, in order to make it possible to build the block book on pdf format. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: cgroup-v1: add it to the admin-guide bookMauro Carvalho Chehab1-1/+1
Those files belong to the admin guide, so add them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: add some documentation dirs to the driver-api bookMauro Carvalho Chehab1-1/+1
Those are subsystem docs, with a mix of kABI and user-faced docs. While they're not split, keep the dirs where they are, adding just a pointer to the main index. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-15docs: block: convert to ReSTMauro Carvalho Chehab18-332/+532
Rename the block documentation files to ReST, add an index for them and adjust in order to produce a nice html output via the Sphinx build system. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-07-10block: Remove unused definitionsDamien Le Moal1-5/+0
The ELV_MQUEUE_XXX definitions in include/linux/elevator.h are unused since the removal of elevator_may_queue_fn in kernel 5.0. Remove these definitions and also remove the documentation of elevator_may_queue_fn in Documentiation/block/biodoc.txt. Acked-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-07-09Merge tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-blockLinus Torvalds3-28/+49
Pull block updates from Jens Axboe: "This is the main block updates for 5.3. Nothing earth shattering or major in here, just fixes, additions, and improvements all over the map. This contains: - Series of documentation fixes (Bart) - Optimization of the blk-mq ctx get/put (Bart) - null_blk removal race condition fix (Bob) - req/bio_op() cleanups (Chaitanya) - Series cleaning up the segment accounting, and request/bio mapping (Christoph) - Series cleaning up the page getting/putting for bios (Christoph) - block cgroup cleanups and moving it to where it is used (Christoph) - block cgroup fixes (Tejun) - Series of fixes and improvements to bcache, most notably a write deadlock fix (Coly) - blk-iolatency STS_AGAIN and accounting fixes (Dennis) - Series of improvements and fixes to BFQ (Douglas, Paolo) - debugfs_create() return value check removal for drbd (Greg) - Use struct_size(), where appropriate (Gustavo) - Two lighnvm fixes (Heiner, Geert) - MD fixes, including a read balance and corruption fix (Guoqing, Marcos, Xiao, Yufen) - block opal shadow mbr additions (Jonas, Revanth) - sbitmap compare-and-exhange improvemnts (Pavel) - Fix for potential bio->bi_size overflow (Ming) - NVMe pull requests: - improved PCIe suspent support (Keith Busch) - error injection support for the admin queue (Akinobu Mita) - Fibre Channel discovery improvements (James Smart) - tracing improvements including nvmetc tracing support (Minwoo Im) - misc fixes and cleanups (Anton Eidelman, Minwoo Im, Chaitanya Kulkarni)" - Various little fixes and improvements to drivers and core" * tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-block: (153 commits) blk-iolatency: fix STS_AGAIN handling block: nr_phys_segments needs to be zero for REQ_OP_WRITE_ZEROES blk-mq: simplify blk_mq_make_request() blk-mq: remove blk_mq_put_ctx() sbitmap: Replace cmpxchg with xchg block: fix .bi_size overflow block: sed-opal: check size of shadow mbr block: sed-opal: ioctl for writing to shadow mbr block: sed-opal: add ioctl for done-mark of shadow mbr block: never take page references for ITER_BVEC direct-io: use bio_release_pages in dio_bio_complete block_dev: use bio_release_pages in bio_unmap_user block_dev: use bio_release_pages in blkdev_bio_end_io iomap: use bio_release_pages in iomap_dio_bio_end_io block: use bio_release_pages in bio_map_user_iov block: use bio_release_pages in bio_unmap_user block: optionally mark pages dirty in bio_release_pages block: move the BIO_NO_PAGE_REF check into bio_release_pages block: skd_main.c: Remove call to memset after dma_alloc_coherent block: mtip32xx: Remove call to memset after dma_alloc_coherent ...
2019-07-08Merge branch 'for-5.3' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "Documentation updates and the addition of cgroup_parse_float() which will be used by new controllers including blk-iocost" * 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: docs: cgroup-v1: convert docs to ReST and rename to *.rst cgroup: Move cgroup_parse_float() implementation out of CONFIG_SYSFS cgroup: add cgroup_parse_float()
2019-06-29block, documentation: Document discard_zeroes_data, fua, ↵Bart Van Assche1-0/+20
max_discard_segments and write_zeroes_max_bytes Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-29block, documentation: Explain the word 'segments'Bart Van Assche1-4/+6
Several block layer users who are not kernel developers do not know that the word 'segment' refers to an element in a DMA scatter/gather list. Make the block layer documentation easier to understand by stating explicitly what the word 'segment' stands for. Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-29block, documentation: Sort queue sysfs attribute names alphabeticallyBart Van Assche1-15/+15
Commit f9824952ee1c ("block: update sysfs documentation") # v5.0 broke the alphabetical order of the sysfs attribute names. List queue sysfs attribute names alphabetically. Cc: Damien Le Moal <damien.lemoal@wdc.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-29block, documentation: Fix wbt_lat_usec documentationBart Van Assche1-2/+2
Fix the spelling of the wbt_lat_usec sysfs attribute. Fixes: 87760e5eef35 ("block: hook up writeback throttling") # v4.10. Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: rename CONFIG_DEBUG_BLK_CGROUP to CONFIG_BFQ_CGROUP_DEBUGChristoph Hellwig1-6/+6
This option is entirely bfq specific, give it an appropinquate name. Also make it depend on CONFIG_BFQ_GROUP_IOSCHED in Kconfig, as all the functionality already does so anyway. Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-20block: remove the bi_phys_segments field in struct bioChristoph Hellwig1-1/+0
We only need the number of segments in the blk-mq submission path. Remove the field from struct bio, and return it from a variant of blk_queue_split instead of that it can passed as an argument to those functions that need the value. This also means we stop recounting segments except for cloning and partial segments. To keep the number of arguments in this how path down remove pointless struct request_queue arguments from any of the functions that had it and grew a nr_segs argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-06-14docs: cgroup-v1: convert docs to ReST and rename to *.rstMauro Carvalho Chehab1-1/+1
Convert the cgroup-v1 files to ReST format, in order to allow a later addition to the admin-guide. The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2019-06-13block/switching-sched.txt: Update to blk-mq schedulersAndreas Herrmann1-10/+8
Remove references to CFQ and legacy block layer which are gone. Update example with what's available under blk-mq. Signed-off-by: Andreas Herrmann <aherrmann@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-09block: null: Add documentation for "zone_nr_conv" paramMinwoo Im1-0/+4
zone_nr_conv module parameter was introduced by a commit ea2c18e1("null_blk: Add conventional zone configuration for zoned support"). This patch describes "zone_nr_conv" module parameter to the document. Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-04-01doc, block, bfq: add information on bfq execution timePaolo Valente1-7/+22
The execution time of BFQ has been slightly lowered. Report the new execution time in BFQ documentation. Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15block: document usage of bio iterator helpersMing Lei1-0/+25
Now multi-page bvec is supported, some helpers may return page by page, meantime some may return segment by segment, this patch documents the usage. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-09block: doc: add slice_idle_us to bfq documentationJohn Pittman1-0/+7
Of the tunables available for the bfq I/O scheduler, the only one missing from the documentation in 'Documentation/block/bfq-iosched.txt' is slice_idle_us. Add this tunable to the documentation and a short explanation of its purpose. Acked-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: John Pittman <jpittman@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-06null_blk: add zoned config support informationJohn Pittman1-1/+2
If the kernel is built without CONFIG_BLK_DEV_ZONED, a modprobe of the null_blk driver with zoned=1 fails with 'Invalid argument'. This can be confusing to users, prompting a search as to why the parameter is invalid. To assist in that search, add a bit more information to the failure, additionally adding to the documentation that CONFIG_BLK_DEV_ZONED is needed for zoned=1. Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: John Pittman <jpittman@redhat.com> Added null_blk prefix to error message. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-01-04block: add documentation for io_timeoutWeiping Zhang1-0/+7
Add documentation for /sys/block/<disk>/queue/io_timeout. Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Weiping Zhang <zhangweiping@didiglobal.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-16block: update sysfs documentationDamien Le Moal1-1/+28
Add the description of the zoned, nr_zones and chunk_sectors sysfs queue attributes to Documentation/block/queue-sysfs.txt. The description of the zoned and chunk_sector attributes are mostly copied from ABI/testing/sysfs-block (added a typo fix). While at it, also fix a typo in the description of the io_poll_delay attribute. nr_zones description is also added to ABI/testing/sysfs-block and contact email address updated for the zoned attribute. Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-07block: remove legacy IO schedulersJens Axboe1-291/+0
Retain the deadline documentation, as that carries over to mq-deadline as well. Tested-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-11-07block: remove legacy rq taggingJens Axboe1-88/+0
It's now unused, kill it. Reviewed-by: Hannes Reinecke <hare@suse.com> Tested-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-09Drop all 00-INDEX files from Documentation/Henrik Austad1-34/+0
This is a respin with a wider audience (all that get_maintainer returned) and I know this spams a *lot* of people. Not sure what would be the correct way, so my apologies for ruining your inbox. The 00-INDEX files are supposed to give a summary of all files present in a directory, but these files are horribly out of date and their usefulness is brought into question. Often a simple "ls" would reveal the same information as the filenames are generally quite descriptive as a short introduction to what the file covers (it should not surprise anyone what Documentation/sched/sched-design-CFS.txt covers) A few years back it was mentioned that these files were no longer really needed, and they have since then grown further out of date, so perhaps it is time to just throw them out. A short status yields the following _outdated_ 00-INDEX files, first counter is files listed in 00-INDEX but missing in the directory, last is files present but not listed in 00-INDEX. List of outdated 00-INDEX: Documentation: (4/10) Documentation/sysctl: (0/1) Documentation/timers: (1/0) Documentation/blockdev: (3/1) Documentation/w1/slaves: (0/1) Documentation/locking: (0/1) Documentation/devicetree: (0/5) Documentation/power: (1/1) Documentation/powerpc: (0/5) Documentation/arm: (1/0) Documentation/x86: (0/9) Documentation/x86/x86_64: (1/1) Documentation/scsi: (4/4) Documentation/filesystems: (2/9) Documentation/filesystems/nfs: (0/2) Documentation/cgroup-v1: (0/2) Documentation/kbuild: (0/4) Documentation/spi: (1/0) Documentation/virtual/kvm: (1/0) Documentation/scheduler: (0/2) Documentation/fb: (0/1) Documentation/block: (0/1) Documentation/networking: (6/37) Documentation/vm: (1/3) Then there are 364 subdirectories in Documentation/ with several files that are missing 00-INDEX alltogether (and another 120 with a single file and no 00-INDEX). I don't really have an opinion to whether or not we /should/ have 00-INDEX, but the above 00-INDEX should either be removed or be kept up to date. If we should keep the files, I can try to keep them updated, but I rather not if we just want to delete them anyway. As a starting point, remove all index-files and references to 00-INDEX and see where the discussion is going. Signed-off-by: Henrik Austad <henrik@austad.us> Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Just-do-it-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: [Almost everybody else] Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-07-18block: Track DISCARD statistics and output them in stat and diskstatMichael Callahan1-12/+16
Add tracking of REQ_OP_DISCARD ios to the partition statistics and append them to the various stat files in /sys as well as /proc/diskstats. These are tracked with the same four stats as reads and writes: Number of discard ios completed. Number of discard ios merged Number of discard sectors completed Milliseconds spent on discard requests This is done via adding a new STAT_DISCARD define to genhd.h and then using it to index that stat field for discard requests. tj: Refreshed on top of v4.17 and other previous updates. Signed-off-by: Michael Callahan <michaelcallahan@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Andy Newell <newella@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-09null_blk: add zone supportMatias Bjørling1-0/+7
Adds support for exposing a null_blk device through the zone device interface. The interface is managed with the parameters zoned and zone_size. If zoned is set, the null_blk instance registers as a zoned block device. The zone_size parameter defines how big each zone will be. Signed-off-by: Matias Bjørling <matias.bjorling@wdc.com> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-06-15block: remov blk_queue_invalidate_tagsChristoph Hellwig1-14/+1
This function is entirely unused, so remove it and the tag_queue_busy member of struct request_queue. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-06-04Merge tag 'docs-4.18' of git://git.lwn.net/linuxLinus Torvalds1-7/+14
Pull documentation updates from Jonathan Corbet: "There's been a fair amount of work in the docs tree this time around, including: - Extensive RST conversions and organizational work in the memory-management docs thanks to Mike Rapoport. - An update of Documentation/features from Andrea Parri and a script to keep it updated. - Various LICENSES updates from Thomas, along with a script to check SPDX tags. - Work to fix dangling references to documentation files; this involved a fair number of one-liner comment changes outside of Documentation/ ... and the usual list of documentation improvements, typo fixes, etc" * tag 'docs-4.18' of git://git.lwn.net/linux: (103 commits) Documentation: document hung_task_panic kernel parameter docs/admin-guide/mm: add high level concepts overview docs/vm: move ksm and transhuge from "user" to "internals" section. docs: Use the kerneldoc comments for memalloc_no*() doc: document scope NOFS, NOIO APIs docs: update kernel versions and dates in tables docs/vm: transhuge: split userspace bits to admin-guide/mm/transhuge docs/vm: transhuge: minor updates docs/vm: transhuge: change sections order Documentation: arm: clean up Marvell Berlin family info Documentation: gpio: driver: Fix a typo and some odd grammar docs: ranoops.rst: fix location of ramoops.txt scripts/documentation-file-ref-check: rewrite it in perl with auto-fix mode docs: uio-howto.rst: use a code block to solve a warning mm, THP, doc: Add document for thp_swpout/thp_swpout_fallback w1: w1_io.c: fix a kernel-doc warning Documentation/process/posting: wrap text at 80 cols docs: admin-guide: add cgroup-v2 documentation Revert "Documentation/features/vm: Remove arch support status file for 'pte_special'" Documentation: refcount-vs-atomic: Update reference to LKMM doc. ...
2018-05-25null_blk: add blocking description and remove lightnvmLiu Bo1-3/+6
- The description of 'blocking' is missing in null_blk.txt - The 'lightnvm' parameter has been removed in null_blk.c This updates both in null_blk.txt. Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-08Documentation: block: cmdline-partition.txt fixes and additionsRandy Dunlap1-7/+14
Make the description of the kernel command line option "blkdevparts" a bit more flowing and readable. Fix a few typos. Add the optional <size> and <offset> suffixes. Note that size can be "-" to indicate all of the remaining space. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Cai Zhiyong <caizhiyong@huawei.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-11-14block, bfq: move debug blkio stats behind CONFIG_DEBUG_BLK_CGROUPLuca Miccio1-6/+32
BFQ currently creates, and updates, its own instance of the whole set of blkio statistics that cfq creates. Yet, from the comments of Tejun Heo in [1], it turned out that most of these statistics are meant/useful only for debugging. This commit makes BFQ create the latter, debugging statistics only if the option CONFIG_DEBUG_BLK_CGROUP is set. By doing so, this commit also enables BFQ to enjoy a high perfomance boost. The reason is that, if CONFIG_DEBUG_BLK_CGROUP is not set, then BFQ has to update far fewer statistics, and, in particular, not the heaviest to update. To give an idea of the benefits, if CONFIG_DEBUG_BLK_CGROUP is not set, then, on an Intel i7-4850HQ, and with 8 threads doing random I/O in parallel on null_blk (configured with 0 latency), the throughput of BFQ grows from 310 to 400 KIOPS (+30%). We have measured similar or even much higher boosts with other CPUs: e.g., +45% with an ARM CortexTM-A53 Octa-core. Our results have been obtained and can be reproduced very easily with the script in [1]. [1] https://www.spinics.net/lists/linux-block/msg18943.html Suggested-by: Tejun Heo <tj@kernel.org> Suggested-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Lee Tibbert <lee.tibbert@gmail.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Luca Miccio <lucmiccio@gmail.com> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-14block, bfq: update blkio stats outside the scheduler lockPaolo Valente1-3/+3
bfq invokes various blkg_*stats_* functions to update the statistics contained in the special files blkio.bfq.* in the blkio controller groups, i.e., the I/O accounting related to the proportional-share policy provided by bfq. The execution of these functions takes a considerable percentage, about 40%, of the total per-request execution time of bfq (i.e., of the sum of the execution time of all the bfq functions that have to be executed to process an I/O request from its creation to its destruction). This reduces the request-processing rate sustainable by bfq noticeably, even on a multicore CPU. In fact, the bfq functions that invoke blkg_*stats_* functions cannot be executed in parallel with the rest of the code of bfq, because both are executed under the same same per-device scheduler lock. To reduce this slowdown, this commit moves, wherever possible, the invocation of these functions (more precisely, of the bfq functions that invoke blkg_*stats_* functions) outside the critical sections protected by the scheduler lock. With this change, and with all blkio.bfq.* statistics enabled, the throughput grows, e.g., from 250 to 310 KIOPS (+25%) on an Intel i7-4850HQ, in case of 8 threads doing random I/O in parallel on null_blk, with the latter configured with 0 latency. We obtained the same or higher throughput boosts, up to +30%, with other processors (some figures are reported in the documentation). For our tests, we used the script [1], with which our results can be easily reproduced. NOTE. This commit still protects the invocation of blkg_*stats_* functions with the request_queue lock, because the group these functions are invoked on may otherwise disappear before or while these functions are executed. Fortunately, tests without even this lock show, by difference, that the serialization caused by this lock has a little impact (at most ~5% of throughput reduction). [1] https://github.com/Algodev-github/IOSpeed Tested-by: Lee Tibbert <lee.tibbert@gmail.com> Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Luca Miccio <lucmiccio@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-14doc, block, bfq: update max IOPS sustainable with BFQPaolo Valente1-6/+11
We have investigated more deeply the performance of BFQ, in terms of number of IOPS that can be processed by the CPU when BFQ is used as I/O scheduler. In more detail, using the script [1], we have measured the number of IOPS reached on top of a null block device configured with zero latency, as a function of the workload (sequential read, sequential write, random read, random write) and of the system (we considered desktops, laptops and embedded systems). Basing on the resulting figures, with this commit we update the current, conservative IOPS range reported in BFQ documentation. In particular, the documentation now reports, for each of three different systems, the lowest number of IOPS obtained for that system with the above test (namely, the value obtained with the workload leading to the lowest IOPS). [1] https://github.com/Algodev-github/IOSpeed Reviewed-by: Lee Tibbert <lee.tibbert@gmail.com> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Luca Miccio <lucmiccio@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10block: remove __bio_kmap_atomicChristoph Hellwig1-6/+5
This helper doesn't buy us much over calling kmap_atomic directly. In fact in the only caller it does a bit of useless work as the caller already has the bvec at hand, and said caller would even buggy for a multi-segment bio due to the use of this helper. So just remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-10block: kill bio_kmap/kunmap_irq()Jens Axboe1-2/+2
There are no users of it anymore. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-07null_blk: add an usage for shared tags in documentationMinwoo Im1-0/+5
Add usage explanation for a shared_tags, introduced by commit: 82f402fefa50 ("null_blk: add support for shared tags") Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com> Reworded slightly. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-07null_blk: fix default values in documentationMinwoo Im1-2/+2
null_blk.c has initial value of (1) nr_devices as 1. (2) completion_nsec as 10,000ns, not 10.000ns. documentation should be updated for fixes above. Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13null_blk: add usage hints for no_schedweiping zhang1-0/+4
This parameter provide an option to disable io scheduler when nullb* in multi-queue mode. Signed-off-by: weiping zhang <zhangweiping@didichuxing.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-13null_blk: update usage hints for submit_queuesweiping zhang1-3/+3
update the range of submits_queues, and correct usage hints. Signed-off-by: weiping zhang <zhangweiping@didichuxing.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31doc, block, bfq: better describe how to properly configure bfqPaolo Valente1-24/+54
Many users have reported the lack of an HOWTO for properly configuring bfq as a function of the goal one wants to achieve (max responsiveness, max throughput, ...). In fact, all needed details are already provided in the documentation file bfq-iosched.txt. Yet the document lacks guidance on which parameter descriptions to look at. This commit adds some simple direction. Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Reviewed-by: Jeremy Hickman <jeremywh7@gmail.com> Reviewed-by: Laurentiu Nicola <lnicola@dend.ro> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-31doc, block, bfq: fix some typos and remove stale stuffPaolo Valente1-56/+10
In addition to containing some typos and stale sentences, the file bfq-iosched.txt still mentioned a set of sysfs parameters that have been removed from this version of bfq. This commit fixes all these issues. Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Reviewed-by: Jeremy Hickman <jeremywh7@gmail.com> Reviewed-by: Laurentiu Nicola <lnicola@dend.ro> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-03bio-integrity: fold bio_integrity_enabled to bio_integrity_prepDmitry Monakhov1-4/+2
Currently all integrity prep hooks are open-coded, and if prepare fails we ignore it's code and fail bio with EIO. Let's return real error to upper layer, so later caller may react accordingly. In fact no one want to use bio_integrity_prep() w/o bio_integrity_enabled, so it is reasonable to fold it in to one function. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> [hch: merged with the latest block tree, return bool from bio_integrity_prep] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-18block: remove bio_clone() and all references.NeilBrown1-1/+1
bio_clone() is no longer used. Only bio_clone_bioset() or bio_clone_fast(). This is for the best, as bio_clone() used fs_bio_set, and filesystems are unlikely to want to use bio_clone(). So remove bio_clone() and all references. This includes a fix to some incorrect documentation. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-05-10block, bfq: stress that low_latency must be off to get max throughputPaolo Valente1-1/+16
The introduction of the BFQ and Kyber I/O schedulers has triggered a new wave of I/O benchmarks. Unfortunately, comments and discussions on these benchmarks confirm that there is still little awareness that it is very hard to achieve, at the same time, a low latency and a high throughput. In particular, virtually all benchmarks measure throughput, or throughput-related figures of merit, but, for BFQ, they use the scheduler in its default configuration. This configuration is geared, instead, toward a low latency. This is evidently a sign that BFQ documentation is still too unclear on this important aspect. This commit addresses this issue by stressing how BFQ configuration must be (easily) changed if the only goal is maximum throughput. Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-19block, bfq: improve responsivenessPaolo Valente1-0/+9
This patch introduces a simple heuristic to load applications quickly, and to perform the I/O requested by interactive applications just as quickly. To this purpose, both a newly-created queue and a queue associated with an interactive application (we explain in a moment how BFQ decides whether the associated application is interactive), receive the following two special treatments: 1) The weight of the queue is raised. 2) The queue unconditionally enjoys device idling when it empties; in fact, if the requests of a queue are sync, then performing device idling for the queue is a necessary condition to guarantee that the queue receives a fraction of the throughput proportional to its weight (see [1] for details). For brevity, we call just weight-raising the combination of these two preferential treatments. For a newly-created queue, weight-raising starts immediately and lasts for a time interval that: 1) depends on the device speed and type (rotational or non-rotational), and 2) is equal to the time needed to load (start up) a large-size application on that device, with cold caches and with no additional workload. Finally, as for guaranteeing a fast execution to interactive, I/O-related tasks (such as opening a file), consider that any interactive application blocks and waits for user input both after starting up and after executing some task. After a while, the user may trigger new operations, after which the application stops again, and so on. Accordingly, the low-latency heuristic weight-raises again a queue in case it becomes backlogged after being idle for a sufficiently long (configurable) time. The weight-raising then lasts for the same time as for a just-created queue. According to our experiments, the combination of this low-latency heuristic and of the improvements described in the previous patch allows BFQ to guarantee a high application responsiveness. [1] P. Valente, A. Avanzini, "Evolution of the BFQ Storage I/O Scheduler", Proceedings of the First Workshop on Mobile System Technologies (MST-2015), May 2015. http://algogroup.unimore.it/people/paolo/disk_sched/mst-2015.pdf Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-19block, bfq: add full hierarchical scheduling and cgroups supportArianna Avanzini1-6/+11
Add complete support for full hierarchical scheduling, with a cgroups interface. Full hierarchical scheduling is implemented through the 'entity' abstraction: both bfq_queues, i.e., the internal BFQ queues associated with processes, and groups are represented in general by entities. Given the bfq_queues associated with the processes belonging to a given group, the entities representing these queues are sons of the entity representing the group. At higher levels, if a group, say G, contains other groups, then the entity representing G is the parent entity of the entities representing the groups in G. Hierarchical scheduling is performed as follows: if the timestamps of a leaf entity (i.e., of a bfq_queue) change, and such a change lets the entity become the next-to-serve entity for its parent entity, then the timestamps of the parent entity are recomputed as a function of the budget of its new next-to-serve leaf entity. If the parent entity belongs, in its turn, to a group, and its new timestamps let it become the next-to-serve for its parent entity, then the timestamps of the latter parent entity are recomputed as well, and so on. When a new bfq_queue must be set in service, the reverse path is followed: the next-to-serve highest-level entity is chosen, then its next-to-serve child entity, and so on, until the next-to-serve leaf entity is reached, and the bfq_queue that this entity represents is set in service. Writeback is accounted for on a per-group basis, i.e., for each group, the async I/O requests of the processes of the group are enqueued in a distinct bfq_queue, and the entity associated with this queue is a child of the entity associated with the group. Weights can be assigned explicitly to groups and processes through the cgroups interface, differently from what happens, for single processes, if the cgroups interface is not used (as explained in the description of the previous patch). In particular, since each node has a full scheduler, each group can be assigned its own weight. Signed-off-by: Fabio Checconi <fchecconi@gmail.com> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-19block, bfq: introduce the BFQ-v0 I/O scheduler as an extra schedulerPaolo Valente2-0/+519
We tag as v0 the version of BFQ containing only BFQ's engine plus hierarchical support. BFQ's engine is introduced by this commit, while hierarchical support is added by next commit. We use the v0 tag to distinguish this minimal version of BFQ from the versions containing also the features and the improvements added by next commits. BFQ-v0 coincides with the version of BFQ submitted a few years ago [1], apart from the introduction of preemption, described below. BFQ is a proportional-share I/O scheduler, whose general structure, plus a lot of code, are borrowed from CFQ. - Each process doing I/O on a device is associated with a weight and a (bfq_)queue. - BFQ grants exclusive access to the device, for a while, to one queue (process) at a time, and implements this service model by associating every queue with a budget, measured in number of sectors. - After a queue is granted access to the device, the budget of the queue is decremented, on each request dispatch, by the size of the request. - The in-service queue is expired, i.e., its service is suspended, only if one of the following events occurs: 1) the queue finishes its budget, 2) the queue empties, 3) a "budget timeout" fires. - The budget timeout prevents processes doing random I/O from holding the device for too long and dramatically reducing throughput. - Actually, as in CFQ, a queue associated with a process issuing sync requests may not be expired immediately when it empties. In contrast, BFQ may idle the device for a short time interval, giving the process the chance to go on being served if it issues a new request in time. Device idling typically boosts the throughput on rotational devices, if processes do synchronous and sequential I/O. In addition, under BFQ, device idling is also instrumental in guaranteeing the desired throughput fraction to processes issuing sync requests (see [2] for details). - With respect to idling for service guarantees, if several processes are competing for the device at the same time, but all processes (and groups, after the following commit) have the same weight, then BFQ guarantees the expected throughput distribution without ever idling the device. Throughput is thus as high as possible in this common scenario. - Queues are scheduled according to a variant of WF2Q+, named B-WF2Q+, and implemented using an augmented rb-tree to preserve an O(log N) overall complexity. See [2] for more details. B-WF2Q+ is also ready for hierarchical scheduling. However, for a cleaner logical breakdown, the code that enables and completes hierarchical support is provided in the next commit, which focuses exactly on this feature. - B-WF2Q+ guarantees a tight deviation with respect to an ideal, perfectly fair, and smooth service. In particular, B-WF2Q+ guarantees that each queue receives a fraction of the device throughput proportional to its weight, even if the throughput fluctuates, and regardless of: the device parameters, the current workload and the budgets assigned to the queue. - The last, budget-independence, property (although probably counterintuitive in the first place) is definitely beneficial, for the following reasons: - First, with any proportional-share scheduler, the maximum deviation with respect to an ideal service is proportional to the maximum budget (slice) assigned to queues. As a consequence, BFQ can keep this deviation tight not only because of the accurate service of B-WF2Q+, but also because BFQ *does not* need to assign a larger budget to a queue to let the queue receive a higher fraction of the device throughput. - Second, BFQ is free to choose, for every process (queue), the budget that best fits the needs of the process, or best leverages the I/O pattern of the process. In particular, BFQ updates queue budgets with a simple feedback-loop algorithm that allows a high throughput to be achieved, while still providing tight latency guarantees to time-sensitive applications. When the in-service queue expires, this algorithm computes the next budget of the queue so as to: - Let large budgets be eventually assigned to the queues associated with I/O-bound applications performing sequential I/O: in fact, the longer these applications are served once got access to the device, the higher the throughput is. - Let small budgets be eventually assigned to the queues associated with time-sensitive applications (which typically perform sporadic and short I/O), because, the smaller the budget assigned to a queue waiting for service is, the sooner B-WF2Q+ will serve that queue (Subsec 3.3 in [2]). - Weights can be assigned to processes only indirectly, through I/O priorities, and according to the relation: weight = 10 * (IOPRIO_BE_NR - ioprio). The next patch provides, instead, a cgroups interface through which weights can be assigned explicitly. - If several processes are competing for the device at the same time, but all processes and groups have the same weight, then BFQ guarantees the expected throughput distribution without ever idling the device. It uses preemption instead. Throughput is then much higher in this common scenario. - ioprio classes are served in strict priority order, i.e., lower-priority queues are not served as long as there are higher-priority queues. Among queues in the same class, the bandwidth is distributed in proportion to the weight of each queue. A very thin extra bandwidth is however guaranteed to the Idle class, to prevent it from starving. - If the strict_guarantees parameter is set (default: unset), then BFQ - always performs idling when the in-service queue becomes empty; - forces the device to serve one I/O request at a time, by dispatching a new request only if there is no outstanding request. In the presence of differentiated weights or I/O-request sizes, both the above conditions are needed to guarantee that every queue receives its allotted share of the bandwidth (see Documentation/block/bfq-iosched.txt for more details). Setting strict_guarantees may evidently affect throughput. [1] https://lkml.org/lkml/2008/4/1/234 https://lkml.org/lkml/2008/11/11/148 [2] P. Valente and M. Andreolini, "Improving Application Responsiveness with the BFQ Disk I/O Scheduler", Proceedings of the 5th Annual International Systems and Storage Conference (SYSTOR '12), June 2012. Slightly extended version: http://algogroup.unimore.it/people/paolo/disk_sched/bfq-v1-suite- results.pdf Signed-off-by: Fabio Checconi <fchecconi@gmail.com> Signed-off-by: Paolo Valente <paolo.valente@linaro.org> Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-14blk-mq: introduce Kyber multiqueue I/O schedulerOmar Sandoval1-0/+14
The Kyber I/O scheduler is an I/O scheduler for fast devices designed to scale to multiple queues. Users configure only two knobs, the target read and synchronous write latencies, and the scheduler tunes itself to achieve that latency goal. The implementation is based on "tokens", built on top of the scalable bitmap library. Tokens serve as a mechanism for limiting requests. There are two tiers of tokens: queueing tokens and dispatch tokens. A queueing token is required to allocate a request. In fact, these tokens are actually the blk-mq internal scheduler tags, but the scheduler manages the allocation directly in order to implement its policy. Dispatch tokens are device-wide and split up into two scheduling domains: reads vs. writes. Each hardware queue dispatches batches round-robin between the scheduling domains as long as tokens are available for that domain. These tokens can be used as the mechanism to enable various policies. The policy Kyber uses is inspired by active queue management techniques for network routing, similar to blk-wbt. The scheduler monitors latencies and scales the number of dispatch tokens accordingly. Queueing tokens are used to prevent starvation of synchronous requests by asynchronous requests. Various extensions are possible, including better heuristics and ionice support. The new scheduler isn't set as the default yet. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-08block: remove the discard_zeroes_data flagChristoph Hellwig1-5/+0
Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can kill this hack. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-28blk-throttle: make throtl_slice tunableShaohua Li1-0/+6
throtl_slice is important for blk-throttling. It's called slice internally but it really is a time window blk-throttling samples data. blk-throttling will make decision based on the samplings. An example is bandwidth measurement. A cgroup's bandwidth is measured in the time interval of throtl_slice. A small throtl_slice meanse cgroups have smoother throughput but burn more CPUs. It has 100ms default value, which is not appropriate for all disks. A fast SSD can dispatch a lot of IOs in 100ms. This patch makes it tunable. Since throtl_slice isn't a time slice, the sysfs name 'throttle_sample_time' reflects its character better. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-22Merge tag 'docs-4.11' of git://git.lwn.net/linuxLinus Torvalds1-1/+1
Pull documentation updates from Jonathan Corbet: "A slightly quieter cycle for documentation this time around. Three more DocBook template files have been converted to RST; only 21 to go. There are various build improvements and the usual array of documentation improvements and fixes" * tag 'docs-4.11' of git://git.lwn.net/linux: (44 commits) docs / driver-api: Fix structure references in device_link.rst PM / docs: Fix structure references in device.rst Add a target to check broken external links in the Documentation Documentation: Fix linux-api list typo Documentation: DocBook/Makefile comment typo Improve sparse documentation Documentation: make Makefile.sphinx no-ops quieter Documentation: DMA-ISA-LPC.txt Documentation: input: fix path to input code definitions docs: Remove the copyright year from conf.py docs: Fix a warning in the Korean HOWTO.rst translation PM / sleep / docs: Convert PM notifiers document to reST PM / core / docs: Convert sleep states API document to reST PM / core: Update kerneldoc comments in pm.h doc-rst: Fix recursive make invocation from macros doc-rst: Delete output of failed dot-SVG conversion doc-rst: Break shell command sequences on failure Documentation/sphinx: make targets independent of Sphinx work for HAVE_SPHINX=0 doc-rst: fixed cleandoc target when used with O=dir Documentation/sphinx: prevent generation of .pyc files in the source tree ...
2017-01-26Doc: Fix double words in DocumentationMasanari Iida1-1/+1
This patch fix some double words found in Documentation. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-01-03block: fix up io_poll documentationJeff Moyer1-3/+3
/sys/block/<dev>/queue/io_poll is a boolean. Fix the docs. Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-28blk-wbt: allow reset of default latency through sysfsJens Axboe1-1/+3
Allow a write of '-1' to reset the default latency target for a given device. This removes knowledge of the different default settings for rotational vs non-rotational from user space. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-17block: document the 'io_poll_delay' queue sysfs fileJens Axboe1-0/+14
This was documented in the original commit, 64f1c21e86f7, but it never made it into the proper location for queue sysfs files. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-16null_blk: add usage hints for NVMYasuaki Ishimatsu1-1/+1
If CONFIG_NVM is disabled, loading null_block module with use_lightnvm=1 fails. But there are no messages and documents related to the failure. Add the appropriate error message. Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Massaged the text a bit. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-10block: hook up writeback throttlingJens Axboe1-0/+7
Enable throttling of buffered writeback to make it a lot more smooth, and has way less impact on other system activity. Background writeback should be, by definition, background activity. The fact that we flush huge bundles of it at the time means that it potentially has heavy impacts on foreground workloads, which isn't ideal. We can't easily limit the sizes of writes that we do, since that would impact file system layout in the presence of delayed allocation. So just throttle back buffered writeback, unless someone is waiting for it. The algorithm for when to throttle takes its inspiration in the CoDel networking scheduling algorithm. Like CoDel, blk-wb monitors the minimum latencies of requests over a window of time. In that window of time, if the minimum latency of any request exceeds a given target, then a scale count is incremented and the queue depth is shrunk. The next monitoring window is shrunk accordingly. Unlike CoDel, if we hit a window that exhibits good behavior, then we simply increment the scale count and re-calculate the limits for that scale value. This prevents us from oscillating between a close-to-ideal value and max all the time, instead remaining in the windows where we get good behavior. Unlike CoDel, blk-wb allows the scale count to to negative. This happens if we primarily have writes going on. Unlike positive scale counts, this doesn't change the size of the monitoring window. When the heavy writers finish, blk-bw quickly snaps back to it's stable state of a zero scale count. The patch registers a sysfs entry, 'wb_lat_usec'. This sets the latency target to me met. It defaults to 2 msec for non-rotational storage, and 75 msec for rotational storage. Setting this value to '0' disables blk-wb. Generally, a user would not have to touch this setting. We don't enable WBT on devices that are managed with CFQ, and have a non-root block cgroup attached. If we have a proportional share setup on this particular disk, then the wbt throttling will interfere with that. We don't have a strong need for wbt for that case, since we will rely on CFQ doing that for us. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-01block: replace REQ_NOIDLE with REQ_IDLEChristoph Hellwig1-16/+16
Noidle should be the default for writes as seen by all the compounds definitions in fs.h using it. In fact only direct I/O really should be using NODILE, so turn the whole flag around to get the defaults right, which will make our life much easier especially onces the WRITE_* defines go away. This assumes all the existing "raw" users of REQ_SYNC for writes want noidle behavior, which seems to be spot on from a quick audit. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-28block: better op and flags encodingChristoph Hellwig1-2/+2
Now that we don't need the common flags to overflow outside the range of a 32-bit type we can encode them the same way for both the bio and request fields. This in addition allows us to place the operation first (and make some room for more ops while we're at it) and to stop having to shift around the operation values. In addition this allows passing around only one value in the block layer instead of two (and eventuall also in the file systems, but we can do that later) and thus clean up a lot of code. Last but not least this allows decreasing the size of the cmd_flags field in struct request to 32-bits. Various functions passing this value could also be updated, but I'd like to avoid the churn for now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-28block: split out request-only flags into a new namespaceChristoph Hellwig1-1/+1
A lot of the REQ_* flags are only used on struct requests, and only of use to the block layer and a few drivers that dig into struct request internals. This patch adds a new req_flags_t rq_flags field to struct request for them, and thus dramatically shrinks the number of common requests. It also removes the unfortunate situation where we have to fit the fields from the same enum into 32 bits for struct bio and 64 bits for struct request. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-09-14block: remove remnant refs to hardsectLinus Walleij1-2/+2
commit e1defc4ff0cf57aca6c5e3ff99fa503f5943c1f1 "block: Do away with the notion of hardsect_size" removed the notion of "hardware sector size" from the kernel in favor of logical block size, but references remain in comments and documentation. Update the remaining sites mentioning hardsect. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-11doc: update block/queue-sysfs.txt entriesJoe Lawrence1-0/+18
Add descriptions for dax, io_poll, and write_same_max_bytes files. Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-07block: rename bio bi_rw to bi_opfJens Axboe1-2/+2
Since commit 63a4cc24867d, bio->bi_rw contains flags in the lower portion and the op code in the higher portions. This means that old code that relies on manually setting bi_rw is most likely going to be broken. Instead of letting that brokeness linger, rename the member, to force old and out-of-tree code to break at compile time instead of at runtime. No intended functional changes in this commit. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-28Merge branch 'work.misc' of ↵Linus Torvalds1-2/+1
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "Assorted cleanups and fixes. Probably the most interesting part long-term is ->d_init() - that will have a bunch of followups in (at least) ceph and lustre, but we'll need to sort the barrier-related rules before it can get used for really non-trivial stuff. Another fun thing is the merge of ->d_iput() callers (dentry_iput() and dentry_unlink_inode()) and a bunch of ->d_compare() ones (all except the one in __d_lookup_lru())" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits) fs/dcache.c: avoid soft-lockup in dput() vfs: new d_init method vfs: Update lookup_dcache() comment bdev: get rid of ->bd_inodes Remove last traces of ->sync_page new helper: d_same_name() dentry_cmp(): use lockless_dereference() instead of smp_read_barrier_depends() vfs: clean up documentation vfs: document ->d_real() vfs: merge .d_select_inode() into .d_real() unify dentry_iput() and dentry_unlink_inode() binfmt_misc: ->s_root is not going anywhere drop redundant ->owner initializations ufs: get rid of redundant checks orangefs: constify inode_operations missed comment updates from ->direct_IO() prototype change file_inode(f)->i_mapping is f->f_mapping trim fsnotify hooks a bit 9p: new helper - v9fs_parent_fid() debugfs: ->d_parent is never NULL or negative ...
2016-06-30Remove last traces of ->sync_pageMatthew Wilcox1-2/+1
Commit 7eaceaccab5f removed ->sync_page, but a few mentions of it still existed in documentation and comments, Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-28Doc: block: Fix a typo in queue-sysfs.txtMasanari Iida1-1/+1
This patch fix a spelling typo found in queue-sysfs.txt. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSHMike Christie1-11/+11
To avoid confusion between REQ_OP_FLUSH, which is handled by request_fn drivers, and upper layers requesting the block layer perform a flush sequence along with possibly a WRITE, this patch renames REQ_FLUSH to REQ_PREFLUSH. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block, drivers: add REQ_OP_FLUSH operationMike Christie1-3/+3
This adds a REQ_OP_FLUSH operation that is sent to request_fn based drivers by the block layer's flush code, instead of sending requests with the request->cmd_flags REQ_FLUSH bit set. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-05-19Merge tag 'docs-for-linus' of git://git.lwn.net/linuxLinus Torvalds1-0/+4
Pull Documentation updates from Jon Corbet: "A bit busier this time around. The most interesting thing (IMO) this time around is some beginning infrastructural work to allow documents to be written using restructured text. Maybe someday, in a galaxy far far away, we'll be able to eliminate the DocBook dependency and have a much better integrated set of kernel docs. Someday. Beyond that, there's a new document on security hardening from Kees, the movement of some sample code over to samples/, a number of improvements to the serial docs from Geert, and the usual collection of corrections, typo fixes, etc" * tag 'docs-for-linus' of git://git.lwn.net/linux: (55 commits) doc: self-protection: provide initial details serial: doc: Use port->state instead of info serial: doc: Always refer to tty_port->mutex Documentation: vm: Spelling s/paltform/platform/g Documentation/memcg: update kmem limit doc as codes behavior docproc: print a comment about autogeneration for rst output docproc: add support for reStructuredText format via --rst option docproc: abstract terminating lines at first space docproc: abstract docproc directive detection docproc: reduce unnecessary indentation docproc: add variables for subcommand and filename kernel-doc: use rst C domain directives and references for types kernel-doc: produce RestructuredText output kernel-doc: rewrite usage description, remove duplicated comments Doc: correct the location of sysrq.c Documentation: fix common spelling mistakes samples: v4l: from Documentation to samples directory samples: connector: from Documentation to samples directory Documentation: xillybus: fix spelling mistake Documentation: x86: fix spelling mistakes ...
2016-04-12block: kill blk_queue_flush()Jens Axboe1-2/+2
We don't have any drivers left using it, so kill it off. Update documentation to use the newer blk_queue_write_cache(). Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-04-12block: add ability to flag write back caching on a deviceJens Axboe1-0/+9
Add an internal helper and flag for setting whether a queue has write back caching, or write through (or none). Add a sysfs file to show this as well, and make it changeable from user space. This will replace the (awkward) blk_queue_flush() interface that drivers currently use to inform the block layer of write cache state and capabilities. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-03-31Documentation: update missing index files in block/00-INDEXWei Fang1-0/+4
Update missing index files in block/00-INDEX. Signed-off-by: Wei Fang <fangwei1@huawei.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2016-01-17Merge tag 'docs-4.5' of git://git.lwn.net/linuxLinus Torvalds1-8/+7
Pull documentation updates from Jon Corbet: "A relatively boring cycle in the docs tree. There's a few kernel-doc fixes and various document tweaks. One patch reaches out of the documentation subtree to fix a comment in init/do_mounts_rd.c. There didn't seem to be anybody more appropriate to take that one, so I accepted it" * tag 'docs-4.5' of git://git.lwn.net/linux: (29 commits) thermal: add description for integral_cutoff unit Documentation: update libhugetlbfs site url Documentation: Explain pci=conf1,conf2 more verbosely DMA-API: fix confusing sentence in Documentation/DMA-API.txt Documentation: translations: update linux cross reference link Documentation: fix typo in CodingStyle init, Documentation: Remove ramdisk_blocksize mentions Documentation-getdelays: Apply a recommendation from "checkpatch.pl" in main() Documentation: HOWTO: update versions from 3.x to 4.x Documentation: remove outdated references from translations Doc: treewide: Fix grammar "a" to "an" Documentation: cpu-hotplug: Fix sysfs mount instructions can-doc: Add hint about getting timestamps Fix CFQ I/O scheduler parameter name in documentation Documentation: arm: remove dead links from Marvell Berlin docs Documentation: HOWTO: update code cross reference link Doc: Docbook/iio: Fix typo in iio.tmpl DocBook: make index.html generation less verbose by default DocBook: Cleanup: remove an unused $(call) line DocBook: Add a help message for DOCBOOKS env var ...
2015-12-10Fix CFQ I/O scheduler parameter name in documentationLibor Pechacek1-8/+7
As seen in block/cfq-iosched.c, the parameter name is low_latency. Signed-off-by: Libor Pechacek <lpechacek@suse.cz> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-11-16null_blk: register as a LightNVM deviceMatias Bjørling1-0/+3
Add support for registering as a LightNVM device. This allows us to evaluate the performance of the LightNVM subsystem. In /drivers/Makefile, LightNVM is moved above block device drivers to make sure that the LightNVM media managers have been initialized before drivers under /drivers/block are initialized. Signed-off-by: Matias Bjørling <m@bjorling.me> Fix by Jens Axboe to remove unneeded slab cache and the following memory leak. Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21block: add an API for Persistent ReservationsChristoph Hellwig1-0/+119
This commits adds a driver API and ioctls for controlling Persistent Reservations s/genericly/generically/ at the block layer. Persistent Reservations are supported by SCSI and NVMe and allow controlling who gets access to a device in a shared storage setup. Note that we add a pr_ops structure to struct block_device_operations instead of adding the members directly to avoid bloating all instances of devices that will never support Persistent Reservations. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-13Documentation: update notes in biovecs about arbitrarily sized biosDongsu Park1-1/+9
Update block/biovecs.txt so that it includes a note on what kind of effects arbitrarily sized bios would bring to the block layer. Also fix a trivial typo, bio_iter_iovec. Cc: Christoph Hellwig <hch@infradead.org> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig1-1/+1
Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-17block: make /sys/block/<dev>/queue/discard_max_bytes writeableJens Axboe1-1/+9
Lots of devices support huge discard sizes these days. Depending on how the device handles them internally, huge discards can introduce massive latencies (hundreds of msec) on the device side. We have a sysfs file, discard_max_bytes, that advertises the max hardware supported discard size. Make this writeable, and split the settings into a soft and hard limit. This can be set from 'discard_granularity' and up to the hardware limit. Add a new sysfs file, 'discard_max_hw_bytes', that shows the hw set limit. Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-03-20Documentation: Remove mentioning of block barriersLeonid V. Fedorenchik1-27/+9
Remove mentioning of block barriers since they were removed. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Leonid V. Fedorenchik <leonidsbox@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2014-12-13Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+5
Pull block driver core update from Jens Axboe: "This is the pull request for the core block IO changes for 3.19. Not a huge round this time, mostly lots of little good fixes: - Fix a bug in sysfs blktrace interface causing a NULL pointer dereference, when enabled/disabled through that API. From Arianna Avanzini. - Various updates/fixes/improvements for blk-mq: - A set of updates from Bart, mostly fixing buts in the tag handling. - Cleanup/code consolidation from Christoph. - Extend queue_rq API to be able to handle batching issues of IO requests. NVMe will utilize this shortly. From me. - A few tag and request handling updates from me. - Cleanup of the preempt handling for running queues from Paolo. - Prevent running of unmapped hardware queues from Ming Lei. - Move the kdump memory limiting check to be in the correct location, from Shaohua. - Initialize all software queues at init time from Takashi. This prevents a kobject warning when CPUs are brought online that weren't online when a queue was registered. - Single writeback fix for I_DIRTY clearing from Tejun. Queued with the core IO changes, since it's just a single fix. - Version X of the __bio_add_page() segment addition retry from Maurizio. Hope the Xth time is the charm. - Documentation fixup for IO scheduler merging from Jan. - Introduce (and use) generic IO stat accounting helpers for non-rq drivers, from Gu Zheng. - Kill off artificial limiting of max sectors in a request from Christoph" * 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits) bio: modify __bio_add_page() to accept pages that don't start a new segment blk-mq: Fix uninitialized kobject at CPU hotplugging blktrace: don't let the sysfs interface remove trace from running list blk-mq: Use all available hardware queues blk-mq: Micro-optimize bt_get() blk-mq: Fix a race between bt_clear_tag() and bt_get() blk-mq: Avoid that __bt_get_word() wraps multiple times blk-mq: Fix a use-after-free blk-mq: prevent unmapped hw queue from being scheduled blk-mq: re-check for available tags after running the hardware queue blk-mq: fix hang in bt_get() blk-mq: move the kdump check to blk_mq_alloc_tag_set blk-mq: cleanup tag free handling blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map blk: introduce generic io stat accounting help function blk-mq: handle the single queue case in blk_mq_hctx_next_cpu genhd: check for int overflow in disk_expand_part_tbl() blk-mq: add blk_mq_free_hctx_request() blk-mq: export blk_mq_free_request() blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable ...
2014-11-12scsi: add new scsi-command flag for tagged commandsChristoph Hellwig1-4/+0
Currently scsi piggy backs on the block layer to define the concept of a tagged command. But we want to be able to have block-level host-wide tags assigned even for untagged commands like the initial INQUIRY, so add a new SCSI-level flag for commands that are tagged at the scsi level, so that even commands without that set can have tags assigned to them. Note that this alredy is the case for the blk-mq code path, and this just lets the old path catch up with it. We also set this flag based upon sdev->simple_tags instead of the block queue flag, so that it is entirely independent of the block layer tagging, and thus always correct even if a driver doesn't use block level tagging yet. Also remove the old blk_rq_tagged; it was only used by SCSI drivers, and removing it forces them to look for the proper replacement. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mike Christie <michaelc@cs.wisc.edu> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-04block: Expand a bit documentation about elevator_allow_merge_fnJan Kara1-1/+5
Explain that two requests can be merged without elevator_allow_merge_fn() being called. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-18Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-49/+5
Pull core block layer changes from Jens Axboe: "This is the core block IO pull request for 3.18. Apart from the new and improved flush machinery for blk-mq, this is all mostly bug fixes and cleanups. - blk-mq timeout updates and fixes from Christoph. - Removal of REQ_END, also from Christoph. We pass it through the ->queue_rq() hook for blk-mq instead, freeing up one of the request bits. The space was overly tight on 32-bit, so Martin also killed REQ_KERNEL since it's no longer used. - blk integrity updates and fixes from Martin and Gu Zheng. - Update to the flush machinery for blk-mq from Ming Lei. Now we have a per hardware context flush request, which both cleans up the code should scale better for flush intensive workloads on blk-mq. - Improve the error printing, from Rob Elliott. - Backing device improvements and cleanups from Tejun. - Fixup of a misplaced rq_complete() tracepoint from Hannes. - Make blk_get_request() return error pointers, fixing up issues where we NULL deref when a device goes bad or missing. From Joe Lawrence. - Prep work for drastically reducing the memory consumption of dm devices from Junichi Nomura. This allows creating clone bio sets without preallocating a lot of memory. - Fix a blk-mq hang on certain combinations of queue depths and hardware queues from me. - Limit memory consumption for blk-mq devices for crash dump scenarios and drivers that use crazy high depths (certain SCSI shared tag setups). We now just use a single queue and limited depth for that" * 'for-3.18/core' of git://git.kernel.dk/linux-block: (58 commits) block: Remove REQ_KERNEL blk-mq: allocate cpumask on the home node bio-integrity: remove the needless fail handle of bip_slab creating block: include func name in __get_request prints block: make blk_update_request print prefix match ratelimited prefix blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio block: fix alignment_offset math that assumes io_min is a power-of-2 blk-mq: Make bt_clear_tag() easier to read blk-mq: fix potential hang if rolling wakeup depth is too high block: add bioset_create_nobvec() block: use bio_clone_fast() in blk_rq_prep_clone() block: misplaced rq_complete tracepoint sd: Honor block layer integrity handling flags block: Replace strnicmp with strncasecmp block: Add T10 Protection Information functions block: Don't merge requests if integrity flags differ block: Integrity checksum flag block: Relocate bio integrity flags block: Add a disk flag to block integrity profile block: Add prefix to block integrity profile flags ...
2014-09-27block: Remove integrity tagging functionsMartin K. Petersen1-34/+0
None of the filesystems appear interested in using the integrity tagging feature. Potentially because very few storage devices actually permit using the application tag space. Remove the tagging functions. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-27block: Replace bi_integrity with bi_specialMartin K. Petersen1-5/+5
For commands like REQ_COPY we need a way to pass extra information along with each bio. Like integrity metadata this information must be available at the bottom of the stack so bi_private does not suffice. Rename the existing bi_integrity field to bi_special and make it a union so we can have different bio extensions for each class of command. We previously used bi_integrity != NULL as a way to identify whether a bio had integrity metadata or not. Introduce a REQ_INTEGRITY to be the indicator now that bi_special can contain different things. In addition, bio_integrity(bio) will now return a pointer to the integrity payload (when applicable). Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-27block: Get rid of bdev_integrity_enabled()Martin K. Petersen1-10/+0
bdev_integrity_enabled() is only used by bio_integrity_enabled(). Combine these two functions. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-08-28doc: queue-sysfs: minor fixesArnd Hannemann1-3/+3
This patches fixes a typo, and for consistency use "IO" in upper case in the block/queue-sysfs.txt documentation. Signed-off-by: Arnd Hannemann <arnd@arndnet.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-08-26Documentation: Fix null_blk parameter irq_mode to irqmodeFam Zheng1-2/+2
To match the real module parameter name we implemented. Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-02-10Documentation/: update 00-INDEX filesHenrik Austad1-0/+2
Some of the 00-INDEX files are somewhat outdated and some folders does not contain 00-INDEX at all. Only outdated (with the notably exception of spi) indexes are touched here, the 169 folders without 00-INDEX has not been touched. New 00-INDEX - spi/* was added in a series of commits dating back to 2006 Added files (missing in (*/)00-INDEX) - dmatest.txt was added by commit 851b7e16a07d ("dmatest: run test via debugfs") - this_cpu_ops.txt was added by commit a1b2a555d637 ("percpu: add documentation on this_cpu operations") - ww-mutex-design.txt was added by commit 040a0a371005 ("mutex: Add support for wound/wait style locks") - bcache.txt was added by commit cafe56359144 ("bcache: A block layer cache") - kernel-per-CPU-kthreads.txt was added by commit 49717cb40410 ("kthread: Document ways of reducing OS jitter due to per-CPU kthreads") - phy.txt was added by commit ff764963479a ("drivers: phy: add generic PHY framework") - block/null_blk was added by commit 12f8f4fc0314 ("null_blk: documentation") - module-signing.txt was added by commit 3cafea307642 ("Add Documentation/module-signing.txt file") - assoc_array.txt was added by commit 3cb989501c26 ("Add a generic associative array implementation.") - arm/IXP4xx was part of the initial repo - arm/cluster-pm-race-avoidance.txt was added by commit 7fe31d28e839 ("ARM: mcpm: introduce helpers for platform coherency exit/setup") - arm/firmware.txt was added by commit 7366b92a77fc ("ARM: Add interface for registering and calling firmware-specific operations") - arm/kernel_mode_neon.txt was added by commit 2afd0a05241d ("ARM: 7825/1: document the use of NEON in kernel mode") - arm/tcm.txt was added by commit bc581770cfdd ("ARM: 5580/2: ARM TCM (Tightly-Coupled Memory) support v3") - arm/vlocks.txt was added by commit 9762f12d3e05 ("ARM: mcpm: Add baremetal voting mutexes") - blackfin/gptimers-example.c, Makefile was added by commit 4b60779d5ea7 ("Blackfin: add an example showing how to use the gptimers API") - devicetree/usage-model.txt was added by commit 31134efc681a ("dt: Linux DT usage model documentation") - fb/api.txt was added by commit fb21c2f42879 ("fbdev: Add FOURCC-based format configuration API") - fb/sm501.txt was added by commit e6a049807105 ("video, sm501: add edid and commandline support") - fb/udlfb.txt was added by commit 96f8d864afd6 ("fbdev: move udlfb out of staging.") - filesystems/Makefile was added by commit 1e0051ae48a2 ("Documentation/fs/: split txt and source files") - filesystems/nfs/nfsd-admin-interfaces.txt was added by commit 8a4c6e19cfed ("nfsd: document kernel interfaces for nfsd configuration") - ide/warm-plug-howto.txt was added by commit f74c91413ec6 ("ide: add warm-plug support for IDE devices (take 2)") - laptops/Makefile was added by commit d49129accc21 ("Documentation/laptop/: split txt and source files") - leds/leds-blinkm.txt was added by commit b54cf35a7f65 ("LEDS: add BlinkM RGB LED driver, documentation and update MAINTAINERS") - leds/ledtrig-oneshot.txt was added by commit 5e417281cde2 ("leds: add oneshot trigger") - leds/ledtrig-transient.txt was added by commit 44e1e9f8e705 ("leds: add new transient trigger for one shot timer activation") - m68k/README.buddha was part of the initial repo - networking/LICENSE.(qla3xxx|qlcnic|qlge) was added by commits 40839129f779, c4e84bde1d59, 5a4faa873782 - networking/Makefile was added by commit 3794f3e812ef ("docsrc: build Documentation/ sources") - networking/i40evf.txt was added by commit 105bf2fe6b32 ("i40evf: add driver to kernel build system") - networking/ipsec.txt was added by commit b3c6efbc36e2 ("xfrm: Add file to document IPsec corner case") - networking/mac80211-auth-assoc-deauth.txt was added by commit 3cd7920a2be8 ("mac80211: add auth/assoc/deauth flow diagram") - networking/netlink_mmap.txt was added by commit 5683264c3981 ("netlink: add documentation for memory mapped I/O") - networking/nf_conntrack-sysctl.txt was added by commit c9f9e0e1597f ("netfilter: doc: add nf_conntrack sysctl api documentation") lan) - networking/team.txt was added by commit 3d249d4ca7d0 ("net: introduce ethernet teaming device") - networking/vxlan.txt was added by commit d342894c5d2f ("vxlan: virtual extensible lan") - power/runtime_pm.txt was added by commit 5e928f77a09a ("PM: Introduce core framework for run-time PM of I/O devices (rev. 17)") - power/charger-manager.txt was added by commit 3bb3dbbd56ea ("power_supply: Add initial Charger-Manager driver") - RCU/lockdep-splat.txt was added by commit d7bd2d68aa2e ("rcu: Document interpretation of RCU-lockdep splats") - s390/kvm.txt was added by 5ecee4b (KVM: s390: API documentation) - s390/qeth.txt was added by commit b4d72c08b358 ("qeth: bridgeport support - basic control") - scheduler/sched-bwc.txt was added by commit 88ebc08ea9f7 ("sched: Add documentation for bandwidth control") - scsi/advansys.txt was added by commit 4bd6d7f35661 ("[SCSI] advansys: Move documentation to Documentation/scsi") - scsi/bfa.txt was added by commit 1ec90174bdb4 ("[SCSI] bfa: add readme file") - scsi/bnx2fc.txt was added by commit 12b8fc10eaf4 ("[SCSI] bnx2fc: Add driver documentation") - scsi/cxgb3i.txt was added by commit c3673464ebc0 ("[SCSI] cxgb3i: Add cxgb3i iSCSI driver.") - scsi/hpsa.txt was added by commit 992ebcf14f3c ("[SCSI] hpsa: Add hpsa.txt to Documentation/scsi") - scsi/link_power_management_policy.txt was added by commit ca77329fb713 ("[libata] Link power management infrastructure") - scsi/osd.txt was added by commit 78e0c621deca ("[SCSI] osd: Documentation for OSD library") - scsi/scsi-parameter.txt was created/moved by commit 163475fb111c ("Documentation: move SCSI parameters to their own text file") - serial/driver was part of the initial repo - serial/n_gsm.txt was added by commit 323e84122ec6 ("n_gsm: add a documentation") - timers/Makefile was added by commit 3794f3e812ef ("docsrc: build Documentation/ sources") - virt/kvm/s390.txt was added by commit d9101fca3d57 ("KVM: s390: diagnose call documentation") - vm/split_page_table_lock was added by commit 49076ec2ccaf ("mm: dynamically allocate page->ptl if it cannot be embedded to struct page") - w1/slaves/w1_ds28e04 was added by commit fbf7f7b4e2ae ("w1: Add 1-wire slave device driver for DS28E04-100") - w1/masters/omap-hdq was added by commit e0a29382c6f5 ("hdq: documentation for OMAP HDQ") - x86/early-microcode.txt was added by commit 0d91ea86a895 ("x86, doc: Documentation for early microcode loading") - x86/earlyprintk.txt was added by commit a1aade478862 ("x86/doc: mini-howto for using earlyprintk=dbgp") - x86/entry_64.txt was added by commit 8b4777a4b50c ("x86-64: Document some of entry_64.S") - x86/pat.txt was added by commit d27554d874c7 ("x86: PAT documentation") Moved files - arm/kernel_user_helpers.txt was moved out of arch/arm/kernel by commit 37b8304642c7 ("ARM: kuser: move interface documentation out of the source code") - efi-stub.txt was moved out of x86/ and down into Documentation/ in commit 4172fe2f8a47 ("EFI stub documentation updates") - laptops/hpfall.c was moved out of hwmon/ and into laptops/ in commit efcfed9bad88 ("Move hp_accel to drivers/platform/x86") - commit 5616c23ad9cd ("x86: doc: move x86-generic documentation from Doc/x86/i386"): * x86/usb-legacy-support.txt * x86/boot.txt * x86/zero_page.txt - power/video_extension.txt was moved to acpi in commit 70e66e4df191 ("ACPI / video: move video_extension.txt to Documentation/acpi") Removed files (left in 00-INDEX) - memory.txt was removed by commit 00ea8990aadf ("memory.txt: remove stray information") - gpio.txt was moved to gpio/ in commit fd8e198cfcaa ("Documentation: gpiolib: document new interface") - networking/DLINK.txt was removed by commit 168e06ae26dd ("drivers/net: delete old parallel port de600/de620 drivers") - serial/hayes-esp.txt was removed by commit f53a2ade0bb9 ("tty: esp: remove broken driver") - s390/TAPE was removed by commit 9e280f669308 ("[S390] remove tape block docu") - vm/locking was removed by commit 57ea8171d2bc ("mm: documentation: remove hopelessly out-of-date locking doc") - laptops/acer-wmi.txt was remvoed by commit 020036678e81 ("acer-wmi: Delete out-of-date documentation") Typos/misc issues - rpc-server-gss.txt was added as knfsd-rpcgss.txt in commit 030d794bf498 ("SUNRPC: Use gssproxy upcall for server RPCGSS authentication.") - commit b88cf73d9278 ("net: add missing entries to Documentation/networking/00-INDEX") * generic-hdlc.txt was added as generic_hdlc.txt * spider_net.txt was added as spider-net.txt - w1/master/mxc-w1 was added as mxc_w1 by commit a5fd9139f74c ("w1: add 1-wire master driver for i.MX27 / i.MX31") - s390/zfcpdump.txt was added as zfcpdump by commit 6920c12a407e ("[S390] Add Documentation/s390/00-INDEX.") Signed-off-by: Henrik Austad <henrik@austad.us> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> [rcu bits] Acked-by: Rob Landley <rob@landley.net> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Rob Herring <robh+dt@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Mark Brown <broonie@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Gleb Natapov <gleb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Len Brown <len.brown@intel.com> Cc: James Bottomley <JBottomley@parallels.com> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-31Merge tag 'v3.13-rc6' into for-3.14/coreJens Axboe1-0/+72
Needed to bring blk-mq uptodate, since changes have been going in since for-3.14/core was established. Fixup merge issues related to the immutable biovec changes. Signed-off-by: Jens Axboe <axboe@kernel.dk> Conflicts: block/blk-flush.c fs/btrfs/check-integrity.c fs/btrfs/extent_io.c fs/btrfs/scrub.c fs/logfs/dev_bdev.c
2013-12-21null_blk: set use_per_node_hctx param to falseMatias Bjørling1-4/+5
The defaults for the module is to instantiate itself with blk-mq and a submit queue for each CPU node in the system. To save resources, initialize instead with a single submit queue. Signed-off-by: Matias Bjorling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-12-21null_blk: corrections to documentationMatias Bjørling1-10/+10
Randy Dunlap reported a couple of grammar errors and unfortunate usages of socket/node/core. Signed-off-by: Matias Bjorling <m@bjorling.me> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-12-19null_blk: documentationMatias Bjorling1-0/+71
Add description of module and its parameters. Signed-off-by: Matias Bjorling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-11-23block: Immutable bio vecsKent Overstreet1-0/+111
This adds a mechanism by which we can advance a bio by an arbitrary number of bytes without modifying the biovec: bio->bi_iter.bi_bvec_done indicates the number of bytes completed in the current bvec. Various driver code still needs to be updated to not refer to the bvec directly before we can use this for interesting things, like efficient bio splitting. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Paul Clements <Paul.Clements@steeleye.com> Cc: drbd-user@lists.linbit.com Cc: nbd-general@lists.sourceforge.net
2013-11-23block: Abstract out bvec iteratorKent Overstreet1-4/+3
Immutable biovecs are going to require an explicit iterator. To implement immutable bvecs, a later patch is going to add a bi_bvec_done member to this struct; for now, this patch effectively just renames things. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: "Ed L. Cashin" <ecashin@coraid.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@inktank.com> Cc: ceph-devel@vger.kernel.org Cc: Joshua Morris <josh.h.morris@us.ibm.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux390@de.ibm.com Cc: Boaz Harrosh <bharrosh@panasas.com> Cc: Benny Halevy <bhalevy@tonian.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@fusionio.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Joern Engel <joern@logfs.org> Cc: Prasad Joshi <prasadjoshi.linux@gmail.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Ben Myers <bpm@sgi.com> Cc: xfs@oss.sgi.com Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Len Brown <len.brown@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Guo Chao <yan@linux.vnet.ibm.com> Cc: Tejun Heo <tj@kernel.org> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: "Roger Pau Monné" <roger.pau@citrix.com> Cc: Jan Beulich <jbeulich@suse.com> Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Cc: Ian Campbell <Ian.Campbell@citrix.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Jerome Marchand <jmarchand@redhat.com> Cc: Joe Perches <joe@perches.com> Cc: Peng Tao <tao.peng@emc.com> Cc: Andy Adamson <andros@netapp.com> Cc: fanchaoting <fanchaoting@cn.fujitsu.com> Cc: Jie Liu <jeff.liu@oracle.com> Cc: Sunil Mushran <sunil.mushran@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Pankaj Kumar <pankaj.km@samsung.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Mel Gorman <mgorman@suse.de>6
2013-09-30block: change config option name for cmdline partition parsingPaul Gortmaker2-4/+6
Recently commit bab55417b10c ("block: support embedded device command line partition") introduced CONFIG_CMDLINE_PARSER. However, that name is too generic and sounds like it enables/disables generic kernel boot arg processing, when it really is block specific. Before this option becomes a part of a full/final release, add the BLK_ prefix to it so that it is clear in absence of any other context that it is block specific. In addition, fix up the following less critical items: - help text was not really at all helpful. - index file for Documentation was not updated - add the new arg to Documentation/kernel-parameters.txt - clarify wording in source comments Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Cai Zhiyong <caizhiyong@huawei.com> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11block: support embedded device command line partitionCai Zhiyong1-0/+39
Read block device partition table from command line. The partition used for fixed block device (eMMC) embedded device. It is no MBR, save storage space. Bootloader can be easily accessed by absolute address of data on the block device. Users can easily change the partition. This code reference MTD partition, source "drivers/mtd/cmdlinepart.c" About the partition verbose reference "Documentation/block/cmdline-partition.txt" [akpm@linux-foundation.org: fix printk text] [yongjun_wei@trendmicro.com.cn: fix error return code in parse_parts()] Signed-off-by: Cai Zhiyong <caizhiyong@huawei.com> Cc: Karel Zak <kzak@redhat.com> Cc: "Wanglin (Albert)" <albert.wanglin@huawei.com> Cc: Marius Groeger <mag@sysgo.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Artem Bityutskiy <dedekind@infradead.org> Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-25doc: Fix typo in doucmentationsMasanari Iida1-1/+1
Correct typo (double words) in documentations. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-05-28doc: fix misspellings with 'codespell' toolAnatol Pomozov1-1/+1
Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-04-09Documentation: cfq-iosched: update documentation help for cfq tunablesNamjae Jeon1-3/+44
Add the documentation text for latency, target_latency & group_idle tunnable parameters in the block/cfq-iosched.txt. Also fix few typo(spelling) mistakes. Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Language somewhat modified by Jens. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-01-09cfq-iosched: enable full blkcg hierarchy supportTejun Heo1-0/+58
With the previous two patches, all cfqg scheduling decisions are based on vfraction and ready for hierarchy support. The only thing which keeps the behavior flat is cfqg_flat_parent() which makes vfraction calculation consider all non-root cfqgs children of the root cfqg. Replace it with cfqg_parent() which returns the real parent. This enables full blkcg hierarchy support for cfq-iosched. For example, consider the following hierarchy. root / \ A:500 B:250 / \ AA:500 AB:1000 For simplicity, let's say all the leaf nodes have active tasks and are on service tree. For each leaf node, vfraction would be AA: (500 / 1500) * (500 / 750) =~ 0.2222 AB: (1000 / 1500) * (500 / 750) =~ 0.4444 B: (250 / 750) =~ 0.3333 and vdisktime will be distributed accordingly. For more detail, please refer to Documentation/block/cfq-iosched.txt. v2: cfq-iosched.txt updated to describe group scheduling as suggested by Vivek. v3: blkio-controller.txt updated. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com>
2012-09-09block: Kill bi_destructorKent Overstreet1-5/+0
Now that we've got generic code for freeing bios allocated from bio pools, this isn't needed anymore. This patch also makes bio_free() static, since without bi_destructor there should be no need for it to be called anywhere else. bio_free() is now only called from bio_put, so we can refactor those a bit - move some code from bio_put() to bio_free() and kill the redundant bio->bi_next = NULL. v5: Switch to BIO_KMALLOC_POOL ((void *)~0), per Boaz v6: BIO_KMALLOC_POOL now NULL, drop bio_free's EXPORT_SYMBOL v7: No #define BIO_KMALLOC_POOL anymore Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-08-09Documentation: update tunable options in block/cfq-iosched.txtNamjae Jeon1-0/+64
Update tunable options in block/cfq-iosched.txt. Signed-off-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-08-09Documentation: update tunable options in block/cfq-iosched.txtNamjae Jeon1-0/+77
Update tunable options in block/cfq-iosched.txt. Signed-off-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-08-09Documentation: update missing index files in block/00-INDEXNamjae Jeon1-2/+8
Update missing index files in block/00-INDEX. Signed-off-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-06-26blkcg: implement per-blkg request allocationTejun Heo1-0/+7
Currently, request_queue has one request_list to allocate requests from regardless of blkcg of the IO being issued. When the unified request pool is used up, cfq proportional IO limits become meaningless - whoever grabs the next request being freed wins the race regardless of the configured weights. This can be easily demonstrated by creating a blkio cgroup w/ very low weight, put a program which can issue a lot of random direct IOs there and running a sequential IO from a different cgroup. As soon as the request pool is used up, the sequential IO bandwidth crashes. This patch implements per-blkg request_list. Each blkg has its own request_list and any IO allocates its request from the matching blkg making blkcgs completely isolated in terms of request allocation. * Root blkcg uses the request_list embedded in each request_queue, which was renamed to @q->root_rl from @q->rq. While making blkcg rl handling a bit harier, this enables avoiding most overhead for root blkcg. * Queue fullness is properly per request_list but bdi isn't blkcg aware yet, so congestion state currently just follows the root blkcg. As writeback isn't aware of blkcg yet, this works okay for async congestion but readahead may get the wrong signals. It's better than blkcg completely collapsing with shared request_list but needs to be improved with future changes. * After this change, each block cgroup gets a full request pool making resource consumption of each cgroup higher. This makes allowing non-root users to create cgroups less desirable; however, note that allowing non-root users to directly manage cgroups is already severely broken regardless of this patch - each block cgroup consumes kernel memory and skews IO weight (IO weights are not hierarchical). v2: queue-sysfs.txt updated and patch description udpated as suggested by Vivek. v3: blk_get_rl() wasn't checking error return from blkg_lookup_create() and may cause oops on lookup failure. Fix it by falling back to root_rl on blkg lookup failures. This problem was spotted by Rakesh Iyer <rni@google.com>. v4: Updated to accomodate 458f27a982 "block: Avoid missed wakeup in request waitqueue". blk_drain_queue() now wakes up waiters on all blkg->rl on the target queue. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-11-04Documentation: drop as block elevator reference in switching-sched.txtWang Sheng-Hui1-2/+2
Remove 'as' for as is no longer supported, and we can not use 'elevator=as' any more. Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com> Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-27doc: fix broken referencesPaul Bolle1-1/+1
There are numerous broken references to Documentation files (in other Documentation files, in comments, etc.). These broken references are caused by typo's in the references, and by renames or removals of the Documentation files. Some broken references are simply odd. Fix these broken references, sometimes by dropping the irrelevant text they were part of. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-08-05cfq-iosched: Add documentation about idlingVivek Goyal1-0/+71
There are always questions about why CFQ is idling on various conditions. Recent ones is Christoph asking again why to idle on REQ_NOIDLE. His assertion is that XFS is relying more and more on workqueues and is concerned that CFQ idling on IO from every workqueue will impact XFS badly. So he suggested that I add some more documentation about CFQ idling and that can provide more clarity on the topic and also gives an opprotunity to poke a hole in theory and lead to improvements. So here is my attempt at that. Any comments are welcome. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-07-23block: strict rq_affinityDan Williams1-3/+7
Some systems benefit from completions always being steered to the strict requester cpu rather than the looser "per-socket" steering that blk_cpu_to_group() attempts by default. This is because the first CPU in the group mask ends up being completely overloaded with work, while the others (including the original submitter) has power left to spare. Allow the strict mode to be set by writing '2' to the sysfs control file. This is identical to the scheme used for the nomerges file, where '2' is a more aggressive setting than just being turned on. echo 2 > /sys/block/<bdev>/queue/rq_affinity Cc: Christoph Hellwig <hch@infradead.org> Cc: Roland Dreier <roland@purestorage.com> Tested-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-31Fix common misspellingsLucas De Marchi1-2/+2
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-10block: remove per-queue pluggingJens Axboe1-5/+0
Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-11-11Documentation: remove anticipatory scheduler infoRandy Dunlap1-4/+4
Remove anticipatory block I/O scheduler info from Documentation/ since the code has been deleted. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Reported-by: "Robert P. J. Day" <rpjday@crashcourse.ca> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-19Merge branch 'v2.6.36-rc8' into for-2.6.37/barrierJens Axboe1-0/+45
Conflicts: block/blk-core.c drivers/block/loop.c mm/swapfile.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10block: update documentation for REQ_FLUSH / REQ_FUAChristoph Hellwig3-263/+88
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-23cfq-iosched: Documentation help for new tunablesVivek Goyal1-0/+45
Some documentation to provide help with tunables. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-05nick piggin: change email addressNick Piggin1-1/+1
Signed-off-by: Nick Piggin <npiggin@kernel.dk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-08Documentation: fix block/biodoc.txt dma mapping descriptionFUJITA Tomonori1-2/+2
- It looks incorrect to use blk_rq_map_sg with pci_map_page here about DMA mappings. dma_map_sg? - better to use dma_map_page instead of pci_map_page. http://marc.info/?l=linux-kernel&m=126596737604808&w=2 Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-02-22Merge branch 'master' into for-2.6.34Jens Axboe1-1/+1
2010-01-29block: Added in stricter no merge semantics for block I/OAlan D. Brunelle1-5/+5
Updated 'nomerges' tunable to accept a value of '2' - indicating that _no_ merges at all are to be attempted (not even the simple one-hit cache). The following table illustrates the additional benefit - 5 minute runs of a random I/O load were applied to a dozen devices on a 16-way x86_64 system. nomerges Throughput %System Improvement (tput / %sys) -------- ------------ ----------- ------------------------- 0 12.45 MB/sec 0.669365609 1 12.50 MB/sec 0.641519199 0.40% / 2.71% 2 12.52 MB/sec 0.639849750 0.56% / 2.96% Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-01-02Documentation: Rename Documentation/DMA-mapping.txtKusanagi Kouichi1-1/+1
It seems that Documentation/DMA-mapping.txt was supposed to be renamed to Documentation/PCI/PCI-DMA-mapping.txt. Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-18block: remove Documentation/block/as-iosched.txtFUJITA Tomonori2-174/+0
Commit 492af6350a5ccf087e4964104a276ed358811458 removed the AS IO scheduler, so remove its documentation too. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-07-01Trivial typo fixes in Documentation/block/data-integrity.txt.Andre Noll1-2/+2
Signed-off-by: Andre Noll <maan@systemlinux.org> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-06-12trivial: Miscellaneous documentation typo fixesMatt LaPlante1-1/+1
Fix various typos in documentation txts. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-06-02Removed reference to non-existing file Documentation/PCI/PCI-DMA-mapping.txtvibi sreenivasan1-1/+1
File Documentation/PCI/PCI-DMA-mapping.txt does not exist. Documentation/DMA-mapping.txt contains DMA Mapping details Signed-off-by: vibi sreenivasan <vibi_sreenivasan@cms.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-04-15block: update biodoc.txt on pluggingJens Axboe1-13/+6
We do per-device plugging, get rid of any references to tq_disk as that has been dead since 2.6.5 or so. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-26block: Repeated lines in switching-sched.txtAvishay Traeger1-6/+0
These lines appear in this file twice - removed one occurrence. Signed-off-by: Avishay Traeger <avishay@il.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-02block: add text file detailing queue/ sysfs filesJens Axboe1-0/+63
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30Mark mandatory elevator functions in the biodoc.txtNikanth Karthikesan1-3/+3
biodoc.txt mentions that elevator functions marked with * are mandatory, but no function is marked with *. Mark the 3 functions which should be implemented by any io scheduler. Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-29Documentation: move DMA-mapping.txt to Doc/PCI/Randy Dunlap1-2/+3
Move DMA-mapping.txt to Documentation/PCI/. DMA-mapping.txt was supposed to be moved from Documentation/ to Documentation/PCI/. The 00-INDEX files in those two directories were updated, along with a few other text files, but the file itself somehow escaped being moved, so move it and update more text files and source files with its new location. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-12-29Documentation: remove reference to ll_rw_blk.c and moved ↵Nikanth Karthikesan1-3/+3
drivers/block/elevator.c The drivers/block/ll_rw_block.c has been split and organized in the block/ directory, and also drivers/block/elevator.c has been moved to the block/ directory. Update Documentation/block/biodoc.txt accordingly Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-10-16Merge branch 'docs' of git://git.lwn.net/linux-2.6Linus Torvalds1-2/+2
* 'docs' of git://git.lwn.net/linux-2.6: Document panic_on_unrecovered_nmi sysctl Add a reference to paper to SubmittingPatches Add kerneldoc documentation for new printk format extensions Remove videobook.tmpl doc: Test-by? Add the development process document Documentation/block/data-integrity.txt: Fix section numbers
2008-10-16Documentation/block/data-integrity.txt: Fix section numbersAlberto Bertogli1-2/+2
Signed-off-by: Alberto Bertogli <albertito@blitiri.com.ar> Signed-off-by: Jonathan Corbet <corbet@lwn.net>