From defd94b75409b983f94548ea2f52ff5787ddb848 Mon Sep 17 00:00:00 2001 From: Mike Christie Date: Mon, 5 Dec 2005 02:37:06 -0600 Subject: [SCSI] seperate max_sectors from max_hw_sectors - export __blk_put_request and blk_execute_rq_nowait needed for async REQ_BLOCK_PC requests - seperate max_hw_sectors and max_sectors for block/scsi_ioctl.c and SG_IO bio.c helpers per Jens's last comments. Since block/scsi_ioctl.c SG_IO was already testing against max_sectors and SCSI-ml was setting max_sectors and max_hw_sectors to the same value this does not change any scsi SG_IO behavior. It only prepares ll_rw_blk.c, scsi_ioctl.c and bio.c for when SCSI-ml begins to set a valid max_hw_sectors for all LLDs. Today if a LLD does not set it SCSI-ml sets it to a safe default and some LLDs set it to a artificial low value to overcome memory and feedback issues. Note: Since we now cap max_sectors to BLK_DEF_MAX_SECTORS, which is 1024, drivers that used to call blk_queue_max_sectors with a large value of max_sectors will now see the fs requests capped to BLK_DEF_MAX_SECTORS. Signed-off-by: Mike Christie Signed-off-by: James Bottomley --- block/ll_rw_blk.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) (limited to 'block/ll_rw_blk.c') diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index c525b5a2b59..d4beb9a89ee 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -239,7 +239,7 @@ void blk_queue_make_request(request_queue_t * q, make_request_fn * mfn) q->backing_dev_info.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; q->backing_dev_info.state = 0; q->backing_dev_info.capabilities = BDI_CAP_MAP_COPY; - blk_queue_max_sectors(q, MAX_SECTORS); + blk_queue_max_sectors(q, SAFE_MAX_SECTORS); blk_queue_hardsect_size(q, 512); blk_queue_dma_alignment(q, 511); blk_queue_congestion_threshold(q); @@ -555,7 +555,12 @@ void blk_queue_max_sectors(request_queue_t *q, unsigned short max_sectors) printk("%s: set to minimum %d\n", __FUNCTION__, max_sectors); } - q->max_sectors = q->max_hw_sectors = max_sectors; + if (BLK_DEF_MAX_SECTORS > max_sectors) + q->max_hw_sectors = q->max_sectors = max_sectors; + else { + q->max_sectors = BLK_DEF_MAX_SECTORS; + q->max_hw_sectors = max_sectors; + } } EXPORT_SYMBOL(blk_queue_max_sectors); @@ -657,8 +662,8 @@ EXPORT_SYMBOL(blk_queue_hardsect_size); void blk_queue_stack_limits(request_queue_t *t, request_queue_t *b) { /* zero is "infinity" */ - t->max_sectors = t->max_hw_sectors = - min_not_zero(t->max_sectors,b->max_sectors); + t->max_sectors = min_not_zero(t->max_sectors,b->max_sectors); + t->max_hw_sectors = min_not_zero(t->max_hw_sectors,b->max_hw_sectors); t->max_phys_segments = min(t->max_phys_segments,b->max_phys_segments); t->max_hw_segments = min(t->max_hw_segments,b->max_hw_segments); @@ -1293,9 +1298,15 @@ static inline int ll_new_hw_segment(request_queue_t *q, static int ll_back_merge_fn(request_queue_t *q, struct request *req, struct bio *bio) { + unsigned short max_sectors; int len; - if (req->nr_sectors + bio_sectors(bio) > q->max_sectors) { + if (unlikely(blk_pc_request(req))) + max_sectors = q->max_hw_sectors; + else + max_sectors = q->max_sectors; + + if (req->nr_sectors + bio_sectors(bio) > max_sectors) { req->flags |= REQ_NOMERGE; if (req == q->last_merge) q->last_merge = NULL; @@ -1325,9 +1336,16 @@ static int ll_back_merge_fn(request_queue_t *q, struct request *req, static int ll_front_merge_fn(request_queue_t *q, struct request *req, struct bio *bio) { + unsigned short max_sectors; int len; - if (req->nr_sectors + bio_sectors(bio) > q->max_sectors) { + if (unlikely(blk_pc_request(req))) + max_sectors = q->max_hw_sectors; + else + max_sectors = q->max_sectors; + + + if (req->nr_sectors + bio_sectors(bio) > max_sectors) { req->flags |= REQ_NOMERGE; if (req == q->last_merge) q->last_merge = NULL; @@ -2144,7 +2162,7 @@ int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf, struct bio *bio; int reading; - if (len > (q->max_sectors << 9)) + if (len > (q->max_hw_sectors << 9)) return -EINVAL; if (!len || !ubuf) return -EINVAL; @@ -2259,7 +2277,7 @@ int blk_rq_map_kern(request_queue_t *q, struct request *rq, void *kbuf, { struct bio *bio; - if (len > (q->max_sectors << 9)) + if (len > (q->max_hw_sectors << 9)) return -EINVAL; if (!len || !kbuf) return -EINVAL; -- cgit v1.2.3-18-g5258