From 13f05c8d8e98bbdce89158bfdb2e380940695a88 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Fri, 10 Sep 2010 20:50:10 +0200 Subject: block/scsi: Provide a limit on the number of integrity segments Some controllers have a hardware limit on the number of protection information scatter-gather list segments they can handle. Introduce a max_integrity_segments limit in the block layer and provide a new scsi_host_template setting that allows HBA drivers to provide a value suitable for the hardware. Add support for honoring the integrity segment limit when merging both bios and requests. Signed-off-by: Martin K. Petersen Signed-off-by: Jens Axboe --- drivers/scsi/scsi_lib.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) (limited to 'drivers/scsi/scsi_lib.c') diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 9ade720422c..861c0b937ac 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -968,11 +968,13 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, */ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) { - int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask); + struct request *rq = cmd->request; + + int error = scsi_init_sgtable(rq, &cmd->sdb, gfp_mask); if (error) goto err_exit; - if (blk_bidi_rq(cmd->request)) { + if (blk_bidi_rq(rq)) { struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc( scsi_sdb_cache, GFP_ATOMIC); if (!bidi_sdb) { @@ -980,28 +982,28 @@ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) goto err_exit; } - cmd->request->next_rq->special = bidi_sdb; - error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb, - GFP_ATOMIC); + rq->next_rq->special = bidi_sdb; + error = scsi_init_sgtable(rq->next_rq, bidi_sdb, GFP_ATOMIC); if (error) goto err_exit; } - if (blk_integrity_rq(cmd->request)) { + if (blk_integrity_rq(rq)) { struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; int ivecs, count; BUG_ON(prot_sdb == NULL); - ivecs = blk_rq_count_integrity_sg(cmd->request); + ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) { error = BLKPREP_DEFER; goto err_exit; } - count = blk_rq_map_integrity_sg(cmd->request, + count = blk_rq_map_integrity_sg(rq->q, rq->bio, prot_sdb->table.sgl); BUG_ON(unlikely(count > ivecs)); + BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q))); cmd->prot_sdb = prot_sdb; cmd->prot_sdb->table.nents = count; @@ -1625,6 +1627,14 @@ struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, SCSI_MAX_SG_CHAIN_SEGMENTS)); + if (scsi_host_prot_dma(shost)) { + shost->sg_prot_tablesize = + min_not_zero(shost->sg_prot_tablesize, + (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); + BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); + blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); + } + blk_queue_max_hw_sectors(q, shost->max_sectors); blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); blk_queue_segment_boundary(q, shost->dma_boundary); -- cgit v1.2.3-18-g5258