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>

1 files changed, 1 insertions, 0 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;