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2022-01-09docs: sysfs-block: move to stable directoryEric Biggers
The block layer sysfs ABI is widely used by userspace software and is considered stable. 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/20211209003833.6396-2-ebiggers@kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-10-19block: add documentation for inflightSteffen Maier
Complements v2.6.32 commit a9327cac440b ("Seperate read and write statistics of in_flight requests") and commit 316d315bffa4 ("block: Seperate read and write statistics of in_flight requests v2"). Signed-off-by: Steffen Maier <maier@linux.ibm.com> Reviewed-by: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/r/20211019130230.77594-1-maier@linux.ibm.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-08-02block: export diskseq in sysfsMatteo Croce
Add a new sysfs handle to export the new diskseq value. Place it in <sysfs>/block/<disk>/diskseq and document it. $ grep . /sys/class/block/*/diskseq /sys/class/block/loop0/diskseq:13 /sys/class/block/loop1/diskseq:14 /sys/class/block/loop2/diskseq:5 /sys/class/block/loop3/diskseq:6 /sys/class/block/ram0/diskseq:1 /sys/class/block/ram1/diskseq:2 /sys/class/block/vda/diskseq:7 Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Matteo Croce <mcroce@microsoft.com> Tested-by: Luca Boccassi <bluca@debian.org> Link: https://lore.kernel.org/r/20210712230530.29323-5-mcroce@linux.microsoft.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-10-30docs: ABI: testing: make the files compatible with ReST outputMauro Carvalho Chehab
Some files over there won't parse well by Sphinx. Fix them. Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for IIO Acked-by: Fabrice Gasnier <fabrice.gasnier@st.com> Acked-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/58cf3c2d611e0197fb215652719ebd82ca2658db.1604042072.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-15block: add max_active_zones to blk-sysfsNiklas Cassel
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 Cassel
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>
2019-11-21block: add iostat counters for flush requestsKonstantin Khlebnikov
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>
2019-07-15docs: admin-guide: add a series of orphaned documentsMauro Carvalho Chehab
There are lots of documents that belong to the admin-guide but are on random places (most under Documentation root dir). Move them to the admin guide. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2019-01-04block: add documentation for io_timeoutWeiping Zhang
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 Moal
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>
2017-04-08block: remove the discard_zeroes_data flagChristoph Hellwig
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>
2016-12-01block: add support for REQ_OP_WRITE_ZEROESChaitanya Kulkarni
This adds a new block layer operation to zero out a range of LBAs. This allows to implement zeroing for devices that don't use either discard with a predictable zero pattern or WRITE SAME of zeroes. The prominent example of that is NVMe with the Write Zeroes command, but in the future, this should also help with improving the way zeroing discards work. For this operation, suitable entry is exported in sysfs which indicate the number of maximum bytes allowed in one write zeroes operation by the device. Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@hgst.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-18blk-sysfs: Add 'chunk_sectors' to sysfs attributesHannes Reinecke
The queue limits already have a 'chunk_sectors' setting, so we should be presenting it via sysfs. Signed-off-by: Hannes Reinecke <hare@suse.de> [Damien: Updated Documentation/ABI/testing/sysfs-block] Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com> Tested-by: Shaun Tancheff <shaun.tancheff@seagate.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-18block: Add 'zoned' queue limitDamien Le Moal
Add the zoned queue limit to indicate the zoning model of a block device. Defined values are 0 (BLK_ZONED_NONE) for regular block devices, 1 (BLK_ZONED_HA) for host-aware zone block devices and 2 (BLK_ZONED_HM) for host-managed zone block devices. The standards defined drive managed model is not defined here since these block devices do not provide any command for accessing zone information. Drive managed model devices will be reported as BLK_ZONED_NONE. The helper functions blk_queue_zoned_model and bdev_zoned_model return the zoned limit and the functions blk_queue_is_zoned and bdev_is_zoned return a boolean for callers to test if a block device is zoned. The zoned attribute is also exported as a string to applications via sysfs. BLK_ZONED_NONE shows as "none", BLK_ZONED_HA as "host-aware" and BLK_ZONED_HM as "host-managed". Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com> Tested-by: Shaun Tancheff <shaun.tancheff@seagate.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-21block: Export integrity data interval size in sysfsMartin K. Petersen
The size of the data interval was not exported in the sysfs integrity directory. Export it so that userland apps can tell whether the interval is different from the device's logical block size. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-27block: Add a disk flag to block integrity profileMartin K. Petersen
So far we have relied on the app tag size to determine whether a disk has been formatted with T10 protection information or not. However, not all target devices provide application tag storage. Add a flag to the block integrity profile that indicates whether the disk has been formatted with protection information. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Sagi Grimberg <sagig@dev.mellanox.co.il> Signed-off-by: Jens Axboe <axboe@fb.com>
2012-09-20block: Implement support for WRITE SAMEMartin K. Petersen
The WRITE SAME command supported on some SCSI devices allows the same block to be efficiently replicated throughout a block range. Only a single logical block is transferred from the host and the storage device writes the same data to all blocks described by the I/O. This patch implements support for WRITE SAME in the block layer. The blkdev_issue_write_same() function can be used by filesystems and block drivers to replicate a buffer across a block range. This can be used to efficiently initialize software RAID devices, etc. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-11-10block: Revert "[SCSI] genhd: add a new attribute "alias" in gendisk"Tejun Heo
This reverts commit a72c5e5eb738033938ab30d6a634b74d1d060f10. The commit introduced alias for block devices which is intended to be used during logging although actual usage hasn't been committed yet. This approach adds very limited benefit (raw log might be easier to follow) which can be trivially implemented in userland but has a lot of problems. It is much worse than netif renames because it doesn't rename the actual device but just adds conveninence name which isn't used universally or enforced. Everything internal including device lookup and sysfs still uses the internal name and nothing prevents two devices from using conflicting alias - ie. sda can have sdb as its alias. This has been nacked by people working on device driver core, block layer and kernel-userland interface and shouldn't have been upstreamed. Revert it. http://thread.gmane.org/gmane.linux.kernel/1155104 http://thread.gmane.org/gmane.linux.scsi/68632 http://thread.gmane.org/gmane.linux.scsi/69776 Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Nao Nishijima <nao.nishijima.xt@hitachi.com> Cc: Alan Cox <alan@linux.intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2011-08-29[SCSI] genhd: add a new attribute "alias" in gendiskNao Nishijima
This patch allows the user to set an "alias" of the disk via sysfs interface. This patch only adds a new attribute "alias" in gendisk structure. To show the alias instead of the device name in kernel messages, we need to revise printk messages and use alias_name() in them. Example: (current) printk("disk name is %s\n", disk->disk_name); (new) printk("disk name is %s\n", alias_name(disk)); Users can use alphabets, numbers, '-' and '_' in "alias" attribute. A disk can have an "alias" which length is up to 255 bytes. This attribute is write-once. Suggested-by: James Bottomley <James.Bottomley@HansenPartnership.com> Suggested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Nao Nishijima <nao.nishijima.xt@hitachi.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-05-18block: Add sysfs documentation for the discard topology parametersMartin K. Petersen
Add documentation for the discard I/O topology parameters exported in sysfs. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-01-29block: Added in stricter no merge semantics for block I/OAlan D. Brunelle
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>
2009-12-04tree-wide: fix assorted typos all over the placeAndré Goddard Rosa
That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-08-01block: Update topology documentationMartin K. Petersen
Update topology comments and sysfs documentation based upon discussions with Neil Brown. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-22block: Export I/O topology for block devices and partitionsMartin K. Petersen
To support devices with physical block sizes bigger than 512 bytes we need to ensure proper alignment. This patch adds support for exposing I/O topology characteristics as devices are stacked. logical_block_size is the smallest unit the device can address. physical_block_size indicates the smallest I/O the device can write without incurring a read-modify-write penalty. The io_min parameter is the smallest preferred I/O size reported by the device. In many cases this is the same as the physical block size. However, the io_min parameter can be scaled up when stacking (RAID5 chunk size > physical block size). The io_opt characteristic indicates the optimal I/O size reported by the device. This is usually the stripe width for arrays. The alignment_offset parameter indicates the number of bytes the start of the device/partition is offset from the device's natural alignment. Partition tools and MD/DM utilities can use this to pad their offsets so filesystems start on proper boundaries. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-03block: Data integrity infrastructure documentationMartin K. Petersen
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-02-08Enhanced partition statistics: documentation updateJerome Marchand
Update the documentation to reflect the change in userspace interface. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>