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>

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>
Jens Axboe
1 parent 1d63e72640
Showing 1 changed file with 12 additions and 2 deletions Side-by-side Diff
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;
 }
  
 /**
...	...	@@ -140,8 +140,18 @@
140	140	*/
141	141	static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
142	142	{
143		- shost->bqt = blk_init_tags(depth);
144		- return shost->bqt ? 0 : -ENOMEM;
	143	+ /*
	144	+ * If the shared tag map isn't already initialized, do it now.
	145	+ * This saves callers from having to check ->bqt when setting up
	146	+ * devices on the shared host (for libata)
	147	+ */
	148	+ if (!shost->bqt) {
	149	+ shost->bqt = blk_init_tags(depth);
	150	+ if (!shost->bqt)
	151	+ return -ENOMEM;
	152	+ }
	153	+
	154	+ return 0;
145	155	}
146	156
147	157	/**