scsi: make sure that scsi_init_shared_tag_map() doesn't overwrite existing map
Right now callers have to check whether scsi_host->bqt is already
set up, it's much cleaner to just have scsi_init_shared_tag_map()
does this check on its own.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index cf4c219..1723138 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -140,8 +140,18 @@
*/
static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
{
- shost->bqt = blk_init_tags(depth);
- return shost->bqt ? 0 : -ENOMEM;
+ /*
+ * If the shared tag map isn't already initialized, do it now.
+ * This saves callers from having to check ->bqt when setting up
+ * devices on the shared host (for libata)
+ */
+ if (!shost->bqt) {
+ shost->bqt = blk_init_tags(depth);
+ if (!shost->bqt)
+ return -ENOMEM;
+ }
+
+ return 0;
}
/**