block: switch on bio operation in bio_integrity_prep

Use a single switch to perform read and write specific checks and exit
early for other operations instead of having two checks using different
predicates.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20240626045950.189758-5-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Christoph Hellwig

block/bio-integrity.c

@@ -435,20 +435,19 @@ bool bio_integrity_prep(struct bio *bio)
 	if (!bi)
 		return true;
 
-	if (bio_op(bio) != REQ_OP_READ && bio_op(bio) != REQ_OP_WRITE)
-		return true;
-
 	if (!bio_sectors(bio))
 		return true;
 
 	/* Already protected? */
 	if (bio_integrity(bio))
 		return true;
 
-	if (bio_data_dir(bio) == READ) {
+	switch (bio_op(bio)) {
+	case REQ_OP_READ:
 		if (bi->flags & BLK_INTEGRITY_NOVERIFY)
 			return true;
-	} else {
+		break;
+	case REQ_OP_WRITE:
 		if (bi->flags & BLK_INTEGRITY_NOGENERATE)
 			return true;
 
@@ -459,6 +458,9 @@ bool bio_integrity_prep(struct bio *bio)
 		 */
 		if (bi->csum_type == BLK_INTEGRITY_CSUM_NONE)
 			gfp |= __GFP_ZERO;
+		break;
+	default:
+		return true;
 	}
 
 	/* Allocate kernel buffer for protection data */