Avoid ARC buffer transfrom operations in prefetch

This change will prevent prefetch to perform unnecessary ARC buffer
fill when reading from disk.

Reviewed-by: Alexander Motin <[email protected]>
Signed-off-by: Jaydeep Kshirsagar <[email protected]>
Co-authored-by: Alexander Motin <[email protected]>
Closes openzfs#17013

Author: 2 people

module/zfs/arc.c

@@ -5916,6 +5916,7 @@ arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
 		acb->acb_compressed = compressed_read;
 		acb->acb_encrypted = encrypted_read;
 		acb->acb_noauth = noauth_read;
+		acb->acb_nobuf = no_buf;
 		acb->acb_zb = *zb;
 
 		ASSERT3P(hdr->b_l1hdr.b_acb, ==, NULL);