linux/block/Makefile, branch v4.2

block: Add T10 Protection Information functions

2014-09-27T15:14:59Z

The T10 Protection Information format is also used by some devices that do not go through the SCSI layer (virtual block devices, NVMe). Relocate the relevant functions to a block layer library that can be used without involving SCSI. Signed-off-by: Martin K. Petersen Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: move mm/bounce.c to block/

2014-05-20T02:01:52Z

Continue moving some of the block files that are scattered around. bounce.c contains only code for bouncing the contents of a bio. It's block proper code, not mm code. Suggested-by: Ming Lei Signed-off-by: Jens Axboe

block: move ioprio.c from fs/ to block/

2014-05-19T17:02:18Z

Like commit f9c78b2b, move this block related file outside of fs/ and into the core block directory, block/. Signed-off-by: Jens Axboe

block: move bio.c and bio-integrity.c from fs/ to block/

2014-05-19T14:34:46Z

They really belong in block/, especially now since it's not in drivers/block/ anymore. Additionally, the get_maintainer script gets it wrong when in fs/. Suggested-by: Christoph Hellwig Acked-by: Al Viro Signed-off-by: Jens Axboe

blk-mq: new multi-queue block IO queueing mechanism

2013-10-25T10:56:00Z

Linux currently has two models for block devices: - The classic request_fn based approach, where drivers use struct request units for IO. The block layer provides various helper functionalities to let drivers share code, things like tag management, timeout handling, queueing, etc. - The "stacked" approach, where a driver squeezes in between the block layer and IO submitter. Since this bypasses the IO stack, driver generally have to manage everything themselves. With drivers being written for new high IOPS devices, the classic request_fn based driver doesn't work well enough. The design dates back to when both SMP and high IOPS was rare. It has problems with scaling to bigger machines, and runs into scaling issues even on smaller machines when you have IOPS in the hundreds of thousands per device. The stacked approach is then most often selected as the model for the driver. But this means that everybody has to re-invent everything, and along with that we get all the problems again that the shared approach solved. This commit introduces blk-mq, block multi queue support. The design is centered around per-cpu queues for queueing IO, which then funnel down into x number of hardware submission queues. We might have a 1:1 mapping between the two, or it might be an N:M mapping. That all depends on what the hardware supports. blk-mq provides various helper functions, which include: - Scalable support for request tagging. Most devices need to be able to uniquely identify a request both in the driver and to the hardware. The tagging uses per-cpu caches for freed tags, to enable cache hot reuse. - Timeout handling without tracking request on a per-device basis. Basically the driver should be able to get a notification, if a request happens to fail. - Optional support for non 1:1 mappings between issue and submission queues. blk-mq can redirect IO completions to the desired location. - Support for per-request payloads. Drivers almost always need to associate a request structure with some driver private command structure. Drivers can tell blk-mq this at init time, and then any request handed to the driver will have the required size of memory associated with it. - Support for merging of IO, and plugging. The stacked model gets neither of these. Even for high IOPS devices, merging sequential IO reduces per-command overhead and thus increases bandwidth. For now, this is provided as a potential 3rd queueing model, with the hope being that, as it matures, it can replace both the classic and stacked model. That would get us back to having just 1 real model for block devices, leaving the stacked approach to dm/md devices (as it was originally intended). Contributions in this patch from the following people: Shaohua Li Alexander Gordeev Christoph Hellwig Mike Christie Matias Bjorling Jeff Moyer Acked-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: change config option name for cmdline partition parsing

2013-09-30T21:31:02Z

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 Cc: Jens Axboe Cc: Cai Zhiyong Cc: Wei Yongjun Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

block: support embedded device command line partition

2013-09-11T22:56:57Z

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 Cc: Karel Zak Cc: "Wanglin (Albert)" Cc: Marius Groeger Cc: David Woodhouse Cc: Jens Axboe Cc: Brian Norris Cc: Artem Bityutskiy Signed-off-by: Wei Yongjun Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

separate partition format handling from generic code

2012-01-04T03:54:06Z

Signed-off-by: Al Viro

move fs/partitions to block/

2012-01-04T03:54:06Z

Signed-off-by: Al Viro

block: add bsg helper library

2011-07-31T20:05:09Z

This moves the FC classes bsg code to the block layer and makes it a lib so that other classes like iscsi and SAS can use it. It is helpful because working with the request queue, bios, creating scatterlists, etc are a pain that the LLD does not have to worry about with normal IOs and should not have to worry about for bsg requests. Signed-off-by: Mike Christie Signed-off-by: Jens Axboe