[dm-devel] [PATCH 08/30] block: rename blk-barrier.c to blk-flush.c

[Tejun Heo <tj kernel org>]

Without ordering requirements, barrier and ordering are minomers.
Rename block/blk-barrier.c to block/blk-flush.c.  Rename of symbols
will follow.

Signed-off-by: Tejun Heo <tj kernel org>
Cc: Christoph Hellwig <hch infradead org>
---
 block/Makefile      |    2 +-
 block/blk-barrier.c |  248 ---------------------------------------------------
 block/blk-flush.c   |  248 +++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 249 insertions(+), 249 deletions(-)
 delete mode 100644 block/blk-barrier.c
 create mode 100644 block/blk-flush.c

diff --git a/block/Makefile b/block/Makefile
index 0bb499a..f627e4b 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -3,7 +3,7 @@
 #
 
 obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \
-			blk-barrier.o blk-settings.o blk-ioc.o blk-map.o \
+			blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
 			blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
 			blk-iopoll.o blk-lib.o ioctl.o genhd.o scsi_ioctl.o
 
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
deleted file mode 100644
index e8b2e5c..0000000
--- a/block/blk-barrier.c
+++ /dev/null
@@ -1,248 +0,0 @@
-/*
- * Functions related to barrier IO handling
- */
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/bio.h>
-#include <linux/blkdev.h>
-#include <linux/gfp.h>
-
-#include "blk.h"
-
-static struct request *queue_next_ordseq(struct request_queue *q);
-
-/*
- * Cache flushing for ordered writes handling
- */
-unsigned blk_ordered_cur_seq(struct request_queue *q)
-{
-	if (!q->ordseq)
-		return 0;
-	return 1 << ffz(q->ordseq);
-}
-
-static struct request *blk_ordered_complete_seq(struct request_queue *q,
-						unsigned seq, int error)
-{
-	struct request *next_rq = NULL;
-
-	if (error && !q->orderr)
-		q->orderr = error;
-
-	BUG_ON(q->ordseq & seq);
-	q->ordseq |= seq;
-
-	if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
-		/* not complete yet, queue the next ordered sequence */
-		next_rq = queue_next_ordseq(q);
-	} else {
-		/* complete this barrier request */
-		__blk_end_request_all(q->orig_bar_rq, q->orderr);
-		q->orig_bar_rq = NULL;
-		q->ordseq = 0;
-
-		/* dispatch the next barrier if there's one */
-		if (!list_empty(&q->pending_barriers)) {
-			next_rq = list_entry_rq(q->pending_barriers.next);
-			list_move(&next_rq->queuelist, &q->queue_head);
-		}
-	}
-	return next_rq;
-}
-
-static void pre_flush_end_io(struct request *rq, int error)
-{
-	elv_completed_request(rq->q, rq);
-	blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
-}
-
-static void bar_end_io(struct request *rq, int error)
-{
-	elv_completed_request(rq->q, rq);
-	blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
-}
-
-static void post_flush_end_io(struct request *rq, int error)
-{
-	elv_completed_request(rq->q, rq);
-	blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
-}
-
-static void queue_flush(struct request_queue *q, struct request *rq,
-			rq_end_io_fn *end_io)
-{
-	blk_rq_init(q, rq);
-	rq->cmd_type = REQ_TYPE_FS;
-	rq->cmd_flags = REQ_FLUSH;
-	rq->rq_disk = q->orig_bar_rq->rq_disk;
-	rq->end_io = end_io;
-
-	elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
-}
-
-static struct request *queue_next_ordseq(struct request_queue *q)
-{
-	struct request *rq = &q->bar_rq;
-
-	switch (blk_ordered_cur_seq(q)) {
-	case QUEUE_ORDSEQ_PREFLUSH:
-		queue_flush(q, rq, pre_flush_end_io);
-		break;
-
-	case QUEUE_ORDSEQ_BAR:
-		/* initialize proxy request and queue it */
-		blk_rq_init(q, rq);
-		init_request_from_bio(rq, q->orig_bar_rq->bio);
-		rq->cmd_flags &= ~REQ_HARDBARRIER;
-		if (q->ordered & QUEUE_ORDERED_DO_FUA)
-			rq->cmd_flags |= REQ_FUA;
-		rq->end_io = bar_end_io;
-
-		elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
-		break;
-
-	case QUEUE_ORDSEQ_POSTFLUSH:
-		queue_flush(q, rq, post_flush_end_io);
-		break;
-
-	default:
-		BUG();
-	}
-	return rq;
-}
-
-struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
-{
-	unsigned skip = 0;
-
-	if (!(rq->cmd_flags & REQ_HARDBARRIER))
-		return rq;
-
-	if (q->ordseq) {
-		/*
-		 * Barrier is already in progress and they can't be
-		 * processed in parallel.  Queue for later processing.
-		 */
-		list_move_tail(&rq->queuelist, &q->pending_barriers);
-		return NULL;
-	}
-
-	if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
-		/*
-		 * Queue ordering not supported.  Terminate
-		 * with prejudice.
-		 */
-		blk_dequeue_request(rq);
-		__blk_end_request_all(rq, -EOPNOTSUPP);
-		return NULL;
-	}
-
-	/*
-	 * Start a new ordered sequence
-	 */
-	q->orderr = 0;
-	q->ordered = q->next_ordered;
-	q->ordseq |= QUEUE_ORDSEQ_STARTED;
-
-	/*
-	 * For an empty barrier, there's no actual BAR request, which
-	 * in turn makes POSTFLUSH unnecessary.  Mask them off.
-	 */
-	if (!blk_rq_sectors(rq))
-		q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
-				QUEUE_ORDERED_DO_POSTFLUSH);
-
-	/* stash away the original request */
-	blk_dequeue_request(rq);
-	q->orig_bar_rq = rq;
-
-	if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
-		skip |= QUEUE_ORDSEQ_PREFLUSH;
-
-	if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
-		skip |= QUEUE_ORDSEQ_BAR;
-
-	if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
-		skip |= QUEUE_ORDSEQ_POSTFLUSH;
-
-	/* complete skipped sequences and return the first sequence */
-	return blk_ordered_complete_seq(q, skip, 0);
-}
-
-static void bio_end_empty_barrier(struct bio *bio, int err)
-{
-	if (err) {
-		if (err == -EOPNOTSUPP)
-			set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
-		clear_bit(BIO_UPTODATE, &bio->bi_flags);
-	}
-	if (bio->bi_private)
-		complete(bio->bi_private);
-	bio_put(bio);
-}
-
-/**
- * blkdev_issue_flush - queue a flush
- * @bdev:	blockdev to issue flush for
- * @gfp_mask:	memory allocation flags (for bio_alloc)
- * @error_sector:	error sector
- * @flags:	BLKDEV_IFL_* flags to control behaviour
- *
- * Description:
- *    Issue a flush for the block device in question. Caller can supply
- *    room for storing the error offset in case of a flush error, if they
- *    wish to. If WAIT flag is not passed then caller may check only what
- *    request was pushed in some internal queue for later handling.
- */
-int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
-		sector_t *error_sector, unsigned long flags)
-{
-	DECLARE_COMPLETION_ONSTACK(wait);
-	struct request_queue *q;
-	struct bio *bio;
-	int ret = 0;
-
-	if (bdev->bd_disk == NULL)
-		return -ENXIO;
-
-	q = bdev_get_queue(bdev);
-	if (!q)
-		return -ENXIO;
-
-	/*
-	 * some block devices may not have their queue correctly set up here
-	 * (e.g. loop device without a backing file) and so issuing a flush
-	 * here will panic. Ensure there is a request function before issuing
-	 * the barrier.
-	 */
-	if (!q->make_request_fn)
-		return -ENXIO;
-
-	bio = bio_alloc(gfp_mask, 0);
-	bio->bi_end_io = bio_end_empty_barrier;
-	bio->bi_bdev = bdev;
-	if (test_bit(BLKDEV_WAIT, &flags))
-		bio->bi_private = &wait;
-
-	bio_get(bio);
-	submit_bio(WRITE_BARRIER, bio);
-	if (test_bit(BLKDEV_WAIT, &flags)) {
-		wait_for_completion(&wait);
-		/*
-		 * The driver must store the error location in ->bi_sector, if
-		 * it supports it. For non-stacked drivers, this should be
-		 * copied from blk_rq_pos(rq).
-		 */
-		if (error_sector)
-			*error_sector = bio->bi_sector;
-	}
-
-	if (bio_flagged(bio, BIO_EOPNOTSUPP))
-		ret = -EOPNOTSUPP;
-	else if (!bio_flagged(bio, BIO_UPTODATE))
-		ret = -EIO;
-
-	bio_put(bio);
-	return ret;
-}
-EXPORT_SYMBOL(blkdev_issue_flush);
diff --git a/block/blk-flush.c b/block/blk-flush.c
new file mode 100644
index 0000000..e8b2e5c
--- /dev/null
+++ b/block/blk-flush.c
@@ -0,0 +1,248 @@
+/*
+ * Functions related to barrier IO handling
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/gfp.h>
+
+#include "blk.h"
+
+static struct request *queue_next_ordseq(struct request_queue *q);
+
+/*
+ * Cache flushing for ordered writes handling
+ */
+unsigned blk_ordered_cur_seq(struct request_queue *q)
+{
+	if (!q->ordseq)
+		return 0;
+	return 1 << ffz(q->ordseq);
+}
+
+static struct request *blk_ordered_complete_seq(struct request_queue *q,
+						unsigned seq, int error)
+{
+	struct request *next_rq = NULL;
+
+	if (error && !q->orderr)
+		q->orderr = error;
+
+	BUG_ON(q->ordseq & seq);
+	q->ordseq |= seq;
+
+	if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE) {
+		/* not complete yet, queue the next ordered sequence */
+		next_rq = queue_next_ordseq(q);
+	} else {
+		/* complete this barrier request */
+		__blk_end_request_all(q->orig_bar_rq, q->orderr);
+		q->orig_bar_rq = NULL;
+		q->ordseq = 0;
+
+		/* dispatch the next barrier if there's one */
+		if (!list_empty(&q->pending_barriers)) {
+			next_rq = list_entry_rq(q->pending_barriers.next);
+			list_move(&next_rq->queuelist, &q->queue_head);
+		}
+	}
+	return next_rq;
+}
+
+static void pre_flush_end_io(struct request *rq, int error)
+{
+	elv_completed_request(rq->q, rq);
+	blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
+}
+
+static void bar_end_io(struct request *rq, int error)
+{
+	elv_completed_request(rq->q, rq);
+	blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
+}
+
+static void post_flush_end_io(struct request *rq, int error)
+{
+	elv_completed_request(rq->q, rq);
+	blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
+}
+
+static void queue_flush(struct request_queue *q, struct request *rq,
+			rq_end_io_fn *end_io)
+{
+	blk_rq_init(q, rq);
+	rq->cmd_type = REQ_TYPE_FS;
+	rq->cmd_flags = REQ_FLUSH;
+	rq->rq_disk = q->orig_bar_rq->rq_disk;
+	rq->end_io = end_io;
+
+	elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+}
+
+static struct request *queue_next_ordseq(struct request_queue *q)
+{
+	struct request *rq = &q->bar_rq;
+
+	switch (blk_ordered_cur_seq(q)) {
+	case QUEUE_ORDSEQ_PREFLUSH:
+		queue_flush(q, rq, pre_flush_end_io);
+		break;
+
+	case QUEUE_ORDSEQ_BAR:
+		/* initialize proxy request and queue it */
+		blk_rq_init(q, rq);
+		init_request_from_bio(rq, q->orig_bar_rq->bio);
+		rq->cmd_flags &= ~REQ_HARDBARRIER;
+		if (q->ordered & QUEUE_ORDERED_DO_FUA)
+			rq->cmd_flags |= REQ_FUA;
+		rq->end_io = bar_end_io;
+
+		elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
+		break;
+
+	case QUEUE_ORDSEQ_POSTFLUSH:
+		queue_flush(q, rq, post_flush_end_io);
+		break;
+
+	default:
+		BUG();
+	}
+	return rq;
+}
+
+struct request *blk_do_ordered(struct request_queue *q, struct request *rq)
+{
+	unsigned skip = 0;
+
+	if (!(rq->cmd_flags & REQ_HARDBARRIER))
+		return rq;
+
+	if (q->ordseq) {
+		/*
+		 * Barrier is already in progress and they can't be
+		 * processed in parallel.  Queue for later processing.
+		 */
+		list_move_tail(&rq->queuelist, &q->pending_barriers);
+		return NULL;
+	}
+
+	if (unlikely(q->next_ordered == QUEUE_ORDERED_NONE)) {
+		/*
+		 * Queue ordering not supported.  Terminate
+		 * with prejudice.
+		 */
+		blk_dequeue_request(rq);
+		__blk_end_request_all(rq, -EOPNOTSUPP);
+		return NULL;
+	}
+
+	/*
+	 * Start a new ordered sequence
+	 */
+	q->orderr = 0;
+	q->ordered = q->next_ordered;
+	q->ordseq |= QUEUE_ORDSEQ_STARTED;
+
+	/*
+	 * For an empty barrier, there's no actual BAR request, which
+	 * in turn makes POSTFLUSH unnecessary.  Mask them off.
+	 */
+	if (!blk_rq_sectors(rq))
+		q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
+				QUEUE_ORDERED_DO_POSTFLUSH);
+
+	/* stash away the original request */
+	blk_dequeue_request(rq);
+	q->orig_bar_rq = rq;
+
+	if (!(q->ordered & QUEUE_ORDERED_DO_PREFLUSH))
+		skip |= QUEUE_ORDSEQ_PREFLUSH;
+
+	if (!(q->ordered & QUEUE_ORDERED_DO_BAR))
+		skip |= QUEUE_ORDSEQ_BAR;
+
+	if (!(q->ordered & QUEUE_ORDERED_DO_POSTFLUSH))
+		skip |= QUEUE_ORDSEQ_POSTFLUSH;
+
+	/* complete skipped sequences and return the first sequence */
+	return blk_ordered_complete_seq(q, skip, 0);
+}
+
+static void bio_end_empty_barrier(struct bio *bio, int err)
+{
+	if (err) {
+		if (err == -EOPNOTSUPP)
+			set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+		clear_bit(BIO_UPTODATE, &bio->bi_flags);
+	}
+	if (bio->bi_private)
+		complete(bio->bi_private);
+	bio_put(bio);
+}
+
+/**
+ * blkdev_issue_flush - queue a flush
+ * @bdev:	blockdev to issue flush for
+ * @gfp_mask:	memory allocation flags (for bio_alloc)
+ * @error_sector:	error sector
+ * @flags:	BLKDEV_IFL_* flags to control behaviour
+ *
+ * Description:
+ *    Issue a flush for the block device in question. Caller can supply
+ *    room for storing the error offset in case of a flush error, if they
+ *    wish to. If WAIT flag is not passed then caller may check only what
+ *    request was pushed in some internal queue for later handling.
+ */
+int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
+		sector_t *error_sector, unsigned long flags)
+{
+	DECLARE_COMPLETION_ONSTACK(wait);
+	struct request_queue *q;
+	struct bio *bio;
+	int ret = 0;
+
+	if (bdev->bd_disk == NULL)
+		return -ENXIO;
+
+	q = bdev_get_queue(bdev);
+	if (!q)
+		return -ENXIO;
+
+	/*
+	 * some block devices may not have their queue correctly set up here
+	 * (e.g. loop device without a backing file) and so issuing a flush
+	 * here will panic. Ensure there is a request function before issuing
+	 * the barrier.
+	 */
+	if (!q->make_request_fn)
+		return -ENXIO;
+
+	bio = bio_alloc(gfp_mask, 0);
+	bio->bi_end_io = bio_end_empty_barrier;
+	bio->bi_bdev = bdev;
+	if (test_bit(BLKDEV_WAIT, &flags))
+		bio->bi_private = &wait;
+
+	bio_get(bio);
+	submit_bio(WRITE_BARRIER, bio);
+	if (test_bit(BLKDEV_WAIT, &flags)) {
+		wait_for_completion(&wait);
+		/*
+		 * The driver must store the error location in ->bi_sector, if
+		 * it supports it. For non-stacked drivers, this should be
+		 * copied from blk_rq_pos(rq).
+		 */
+		if (error_sector)
+			*error_sector = bio->bi_sector;
+	}
+
+	if (bio_flagged(bio, BIO_EOPNOTSUPP))
+		ret = -EOPNOTSUPP;
+	else if (!bio_flagged(bio, BIO_UPTODATE))
+		ret = -EIO;
+
+	bio_put(bio);
+	return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_flush);
-- 
1.7.1