kernel/linux.git/include/linux/bio.h, branch v3.13-rc5

Merge branch 'blk-mq/core' into for-3.13/core

2013-11-08T16:08:12+00:00

Signed-off-by: Jens Axboe Conflicts: block/blk-timeout.c

block: Consolidate duplicated bio_trim() implementations

2013-11-08T16:02:31+00:00

Someone cut and pasted md's md_trim_bio() into xen-blkfront.c. Come on, we should know better than this. Signed-off-by: Kent Overstreet Cc: Jens Axboe Cc: Neil Brown Cc: Konrad Rzeszutek Wilk Cc: Jeremy Fitzhardinge Signed-off-by: Jens Axboe

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

2013-10-25T10:56:00+00:00

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

xtensa: remove the second argument of __bio_kmap_atomic()

2013-07-08T08:23:15+00:00

kmap_atomic allows only one argument now, just remove the unused 'kmtype'. Signed-off-by: Zhao Hongjiang Acked-by: Geert Uytterhoeven Signed-off-by: Chris Zankel

bio-integrity: Add explicit field for owner of bip_buf

2013-03-23T21:26:34+00:00

This was the only real user of BIO_CLONED, which didn't have very clear semantics. Convert to its own flag so we can get rid of BIO_CLONED. Signed-off-by: Kent Overstreet CC: Jens Axboe CC: Martin K. Petersen

block: Add an explicit bio flag for bios that own their bvec

2013-03-23T21:26:33+00:00

This is for the new bio splitting code. When we split a bio, if the split occured on a bvec boundry we reuse the bvec for the new bio. But that means bio_free() can't free it, hence the explicit flag. Signed-off-by: Kent Overstreet CC: Jens Axboe Acked-by: Tejun Heo

block: Add bio_alloc_pages()

2013-03-23T21:26:31+00:00

More utility code to replace stuff that's getting open coded. Signed-off-by: Kent Overstreet CC: Jens Axboe CC: NeilBrown

block: Add bio_for_each_segment_all()

2013-03-23T21:26:28+00:00

__bio_for_each_segment() iterates bvecs from the specified index instead of bio->bv_idx. Currently, the only usage is to walk all the bvecs after the bio has been advanced by specifying 0 index. For immutable bvecs, we need to split these apart; bio_for_each_segment() is going to have a different implementation. This will also help document the intent of code that's using it - bio_for_each_segment_all() is only legal to use for code that owns the bio. Signed-off-by: Kent Overstreet CC: Jens Axboe CC: Neil Brown CC: Boaz Harrosh

block: Add bio_copy_data()

2013-03-23T21:15:37+00:00

This gets open coded quite a bit and it's tricky to get right, so make a generic version and convert some existing users over to it instead. Signed-off-by: Kent Overstreet CC: Jens Axboe

block: Add submit_bio_wait(), remove from md

2013-03-23T21:15:32+00:00

Random cleanup - this code was duplicated and it's not really specific to md. Also added the ability to return the actual error code. Signed-off-by: Kent Overstreet CC: Jens Axboe CC: NeilBrown Acked-by: Tejun Heo