summaryrefslogtreecommitdiffstats
path: root/block/blk-merge.c
Commit message (Collapse)AuthorAgeFilesLines
* block: get rid of likely/unlikely predictions in merge logicJens Axboe2008-05-071-6/+6
| | | | | | | They tend to depend a lot on the workload, so not a clear-cut likely or unlikely fit. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: make queue flags non-atomicNick Piggin2008-04-291-3/+3
| | | | | | | We can save some atomic ops in the IO path, if we clearly define the rules of how to modify the queue flags. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: move the padding adjustment to blk_rq_map_sgFUJITA Tomonori2008-04-211-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | blk_rq_map_user adjusts bi_size of the last bio. It breaks the rule that req->data_len (the true data length) is equal to sum(bio). It broke the scsi command completion code. commit e97a294ef6938512b655b1abf17656cf2b26f709 was introduced to fix the above issue. However, the partial completion code doesn't work with it. The commit is also a layer violation (scsi mid-layer should not know about the block layer's padding). This patch moves the padding adjustment to blk_rq_map_sg (suggested by James). The padding works like the drain buffer. This patch breaks the rule that req->data_len is equal to sum(sg), however, the drain buffer already broke it. So this patch just restores the rule that req->data_len is equal to sub(bio) without breaking anything new. Now when a low level driver needs padding, blk_rq_map_user and blk_rq_map_user_iov guarantee there's enough room for padding. blk_rq_map_sg can safely extend the last entry of a scatter list. blk_rq_map_sg must extend the last entry of a scatter list only for a request that got through bio_copy_user_iov. This patches introduces new REQ_COPY_USER flag. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Tejun Heo <htejun@gmail.com> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: restore the meaning of rq->data_len to the true data lengthFUJITA Tomonori2008-03-041-1/+1
| | | | | | | | | | | | | | | | | | The meaning of rq->data_len was changed to the length of an allocated buffer from the true data length. It breaks SG_IO friends and bsg. This patch restores the meaning of rq->data_len to the true data length and adds rq->extra_len to store an extended length (due to drain buffer and padding). This patch also removes the code to update bio in blk_rq_map_user introduced by the commit 40b01b9bbdf51ae543a04744283bf2d56c4a6afa. The commit adjusts bio according to memory alignment (queue_dma_alignment). However, memory alignment is NOT padding alignment. This adjustment also breaks SG_IO friends and bsg. Padding alignment needs to be fixed in a proper way (by a separate patch). Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
* block: clear drain buffer if draining for write commandTejun Heo2008-02-191-0/+3
| | | | | | | | Clear drain buffer before chaining if the command in question is a write. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: implement request_queue->dma_drain_neededTejun Heo2008-02-191-1/+1
| | | | | | | | | | | Draining shouldn't be done for commands where overflow may indicate data integrity issues. Add dma_drain_needed callback to request_queue. Drain buffer is appened iff this function returns non-zero. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: add request->raw_data_lenTejun Heo2008-02-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | With padding and draining moved into it, block layer now may extend requests as directed by queue parameters, so now a request has two sizes - the original request size and the extended size which matches the size of area pointed to by bios and later by sgs. The latter size is what lower layers are primarily interested in when allocating, filling up DMA tables and setting up the controller. Both padding and draining extend the data area to accomodate controller characteristics. As any controller which speaks SCSI can handle underflows, feeding larger data area is safe. So, this patch makes the primary data length field, request->data_len, indicate the size of full data area and add a separate length field, request->raw_data_len, for the unmodified request size. The latter is used to report to higher layer (userland) and where the original request size should be fed to the controller or device. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Enhanced partition statistics: update partition statiticsJerome Marchand2008-02-081-0/+6
| | | | | | | | Updates the enhanced partition statistics in generic block layer besides the disk statistics. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: make core bits checkpatch compliantJens Axboe2008-02-011-6/+6
| | | | Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* block: ll_rw_blk.c split, add blk-merge.cJens Axboe2008-01-291-0/+485
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
OpenPOWER on IntegriCloud