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2007-10-16block: Initial support for data-less (or empty) barrier supportJens Axboe1-0/+6
This implements functionality to pass down or insert a barrier in a queue, without having data attached to it. The ->prepare_flush_fn() infrastructure from data barriers are reused to provide this functionality. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-10Drop 'size' argument from bio_endio and bi_end_ioNeilBrown1-20/+5
As bi_end_io is only called once when the reqeust is complete, the 'size' argument is now redundant. Remove it. Now there is no need for bio_endio to subtract the size completed from bi_size. So don't do that either. While we are at it, change bi_end_io to return void. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-07-24[BLOCK] Get rid of request_queue_t typedefJens Axboe1-2/+2
Some of the code has been gradually transitioned to using the proper struct request_queue, but there's lots left. So do a full sweet of the kernel and get rid of this typedef and replace its uses with the proper type. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-03-27block: blk_max_pfn is somtimes wrongVasily Tarasov1-1/+1
There is a small problem in handling page bounce. At the moment blk_max_pfn equals max_pfn, which is in fact not maximum possible _number_ of a page frame, but the _amount_ of page frames. For example for the 32bit x86 node with 4Gb RAM, max_pfn = 0x100000, but not 0xFFFF. request_queue structure has a member q->bounce_pfn and queue needs bounce pages for the pages _above_ this limit. This routine is handled by blk_queue_bounce(), where the following check is produced: if (q->bounce_pfn >= blk_max_pfn) return; Assume, that a driver has set q->bounce_pfn to 0xFFFF, but blk_max_pfn equals 0x10000. In such situation the check above fails and for each bio we always fall down for iterating over pages tied to the bio. I want to notice, that for quite a big range of device drivers (ide, md, ...) such problem doesn't happen because they use BLK_BOUNCE_ANY for bounce_pfn. BLK_BOUNCE_ANY is defined as blk_max_pfn << PAGE_SHIFT, and then the check above doesn't fail. But for other drivers, which obtain reuired value from drivers, it fails. For example sata_nv uses ATA_DMA_MASK or dev->dma_mask. I propose to use (max_pfn - 1) for blk_max_pfn. And the same for blk_max_low_pfn. The patch also cleanses some checks related with bounce_pfn. Signed-off-by: Vasily Tarasov <vtaras@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-01-12[PATCH] blktrace: only add a bounce trace when we really bounceJens Axboe1-2/+2
Currently we issue a bounce trace when __blk_queue_bounce() is called, but that merely means that the device has a lower dma mask than the higher pages in the system. The bio itself may still be lower pages. So move the bounce trace into __blk_queue_bounce(), when we know there will actually be page bouncing. Signed-off-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-30[PATCH] BLOCK: Separate the bounce buffering code from the highmem code [try #6]David Howells1-0/+302
Move the bounce buffer code from mm/highmem.c to mm/bounce.c so that it can be more easily disabled when the block layer is disabled. !!!NOTE!!! There may be a bug in this code: Should init_emergency_pool() be contingent on CONFIG_HIGHMEM? Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>