diff --git a/block/blk-flush.c b/block/blk-flush.c
index 83b7d5b41c79..4938bec8cfef 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -1,12 +1,12 @@
 /*
- * Functions to sequence FLUSH and FUA writes.
+ * Functions to sequence PREFLUSH and FUA writes.
  *
  * Copyright (C) 2011		Max Planck Institute for Gravitational Physics
  * Copyright (C) 2011		Tejun Heo <tj@kernel.org>
  *
  * This file is released under the GPLv2.
  *
- * REQ_{FLUSH|FUA} requests are decomposed to sequences consisted of three
+ * REQ_{PREFLUSH|FUA} requests are decomposed to sequences consisted of three
  * optional steps - PREFLUSH, DATA and POSTFLUSH - according to the request
  * properties and hardware capability.
  *
@@ -16,9 +16,9 @@
  * REQ_FUA means that the data must be on non-volatile media on request
  * completion.
  *
- * If the device doesn't have writeback cache, FLUSH and FUA don't make any
- * difference.  The requests are either completed immediately if there's no
- * data or executed as normal requests otherwise.
+ * If the device doesn't have writeback cache, PREFLUSH and FUA don't make any
+ * difference.  The requests are either completed immediately if there's no data
+ * or executed as normal requests otherwise.
  *
  * If the device has writeback cache and supports FUA, REQ_PREFLUSH is
  * translated to PREFLUSH but REQ_FUA is passed down directly with DATA.
@@ -31,7 +31,7 @@
  * fq->flush_queue[fq->flush_pending_idx].  Once certain criteria are met, a
  * REQ_OP_FLUSH is issued and the pending_idx is toggled.  When the flush
  * completes, all the requests which were pending are proceeded to the next
- * step.  This allows arbitrary merging of different types of FLUSH/FUA
+ * step.  This allows arbitrary merging of different types of PREFLUSH/FUA
  * requests.
  *
  * Currently, the following conditions are used to determine when to issue
@@ -47,19 +47,19 @@
  * C3. The second condition is ignored if there is a request which has
  *     waited longer than FLUSH_PENDING_TIMEOUT.  This is to avoid
  *     starvation in the unlikely case where there are continuous stream of
- *     FUA (without FLUSH) requests.
+ *     FUA (without PREFLUSH) requests.
  *
  * For devices which support FUA, it isn't clear whether C2 (and thus C3)
  * is beneficial.
  *
- * Note that a sequenced FLUSH/FUA request with DATA is completed twice.
+ * Note that a sequenced PREFLUSH/FUA request with DATA is completed twice.
  * Once while executing DATA and again after the whole sequence is
  * complete.  The first completion updates the contained bio but doesn't
  * finish it so that the bio submitter is notified only after the whole
  * sequence is complete.  This is implemented by testing RQF_FLUSH_SEQ in
  * req_bio_endio().
  *
- * The above peculiarity requires that each FLUSH/FUA request has only one
+ * The above peculiarity requires that each PREFLUSH/FUA request has only one
  * bio attached to it, which is guaranteed as they aren't allowed to be
  * merged in the usual way.
  */
@@ -76,7 +76,7 @@
 #include "blk-mq-tag.h"
 #include "blk-mq-sched.h"
 
-/* FLUSH/FUA sequences */
+/* PREFLUSH/FUA sequences */
 enum {
 	REQ_FSEQ_PREFLUSH	= (1 << 0), /* pre-flushing in progress */
 	REQ_FSEQ_DATA		= (1 << 1), /* data write in progress */
@@ -148,7 +148,7 @@ static bool blk_flush_queue_rq(struct request *rq, bool add_front)
 
 /**
  * blk_flush_complete_seq - complete flush sequence
- * @rq: FLUSH/FUA request being sequenced
+ * @rq: PREFLUSH/FUA request being sequenced
  * @fq: flush queue
  * @seq: sequences to complete (mask of %REQ_FSEQ_*, can be zero)
  * @error: whether an error occurred
@@ -406,7 +406,7 @@ static void mq_flush_data_end_io(struct request *rq, blk_status_t error)
 }
 
 /**
- * blk_insert_flush - insert a new FLUSH/FUA request
+ * blk_insert_flush - insert a new PREFLUSH/FUA request
  * @rq: request to insert
  *
  * To be called from __elv_add_request() for %ELEVATOR_INSERT_FLUSH insertions.