SG: work with the SCSI fixed maximum allocations.
SCSI sg table allocation has a maximum size (of SCSI_MAX_SG_SEGMENTS,
currently 128) and this will cause a BUG_ON() in SCSI if something
tries an allocation over it. This patch adds a size limit to the
chaining allocator to allow the specification of the maximum
allocation size for chaining, so we always chain in units of the
maximum SCSI allocation size.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 3b5121c..eb4911a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -761,9 +761,11 @@
BUG_ON(!cmd->use_sg);
- ret = __sg_alloc_table(&cmd->sg_table, cmd->use_sg, gfp_mask, scsi_sg_alloc);
+ ret = __sg_alloc_table(&cmd->sg_table, cmd->use_sg,
+ SCSI_MAX_SG_SEGMENTS, gfp_mask, scsi_sg_alloc);
if (unlikely(ret))
- __sg_free_table(&cmd->sg_table, scsi_sg_free);
+ __sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS,
+ scsi_sg_free);
cmd->request_buffer = cmd->sg_table.sgl;
return ret;
@@ -773,7 +775,7 @@
void scsi_free_sgtable(struct scsi_cmnd *cmd)
{
- __sg_free_table(&cmd->sg_table, scsi_sg_free);
+ __sg_free_table(&cmd->sg_table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);
}
EXPORT_SYMBOL(scsi_free_sgtable);
