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authorMartin K. Petersen <martin.petersen@oracle.com>2010-09-10 20:50:10 +0200
committerJens Axboe <axboe@carl.home.kernel.dk>2010-09-10 20:50:10 +0200
commit13f05c8d8e98bbdce89158bfdb2e380940695a88 (patch)
tree055215e7e2b1bdc684ead64daa61b30b35eaa3c5 /drivers/scsi
parentc8bf1336824ebd698d37b71763e1c43190f2229a (diff)
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 <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/hosts.c1
-rw-r--r--drivers/scsi/scsi_lib.c26
-rw-r--r--drivers/scsi/scsi_sysfs.c2
3 files changed, 21 insertions, 8 deletions
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 8a8f803439e1..10478153641b 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -376,6 +376,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
shost->this_id = sht->this_id;
shost->can_queue = sht->can_queue;
shost->sg_tablesize = sht->sg_tablesize;
+ shost->sg_prot_tablesize = sht->sg_prot_tablesize;
shost->cmd_per_lun = sht->cmd_per_lun;
shost->unchecked_isa_dma = sht->unchecked_isa_dma;
shost->use_clustering = sht->use_clustering;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 9ade720422c6..861c0b937ac9 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);
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index c3f67373a4f8..20ad59dff730 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -251,6 +251,7 @@ shost_rd_attr(host_busy, "%hu\n");
shost_rd_attr(cmd_per_lun, "%hd\n");
shost_rd_attr(can_queue, "%hd\n");
shost_rd_attr(sg_tablesize, "%hu\n");
+shost_rd_attr(sg_prot_tablesize, "%hu\n");
shost_rd_attr(unchecked_isa_dma, "%d\n");
shost_rd_attr(prot_capabilities, "%u\n");
shost_rd_attr(prot_guard_type, "%hd\n");
@@ -262,6 +263,7 @@ static struct attribute *scsi_sysfs_shost_attrs[] = {
&dev_attr_cmd_per_lun.attr,
&dev_attr_can_queue.attr,
&dev_attr_sg_tablesize.attr,
+ &dev_attr_sg_prot_tablesize.attr,
&dev_attr_unchecked_isa_dma.attr,
&dev_attr_proc_name.attr,
&dev_attr_scan.attr,