[PATCH 1/2] blktrace: correct remap names

[PATCH 1/2] blktrace: correct remap names

[Alan D. Brunelle]

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[-- Attachment #2: 0001-blktrace-correct-remap-names.patch --]
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This attempts to clarify names utilized during block I/O remap
operations (partition, volume manager). It correctly matches up the
/from/ information for both device & sector. This takes in the concept
from Kosaki Motohiro and extends it to include better naming for the
"device_from" field.

Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
---
 include/linux/blktrace_api.h |    4 ++--
 include/trace/block.h        |    4 ++--
 kernel/trace/blktrace.c      |   24 ++++++++++++------------
 3 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index d960889..da1a14e 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -116,9 +116,9 @@ struct blk_io_trace {
  * The remap event
  */
 struct blk_io_trace_remap {
-	__be32 device;
 	__be32 device_from;
-	__be64 sector;
+	__be32 device_to;
+	__be64 sector_from;
 };
 
 enum {
diff --git a/include/trace/block.h b/include/trace/block.h
index 25b7068..87f6456 100644
--- a/include/trace/block.h
+++ b/include/trace/block.h
@@ -70,7 +70,7 @@ DECLARE_TRACE(block_split,
 
 DECLARE_TRACE(block_remap,
 	TP_PROTO(struct request_queue *q, struct bio *bio, dev_t dev,
-		 sector_t from, sector_t to),
-	      TP_ARGS(q, bio, dev, from, to));
+		 sector_t to, sector_t from),
+	      TP_ARGS(q, bio, dev, to, from));
 
 #endif
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 921ef5d..bc72d53 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -808,8 +808,8 @@ static void blk_add_trace_split(struct request_queue *q, struct bio *bio,
  * @q:		queue the io is for
  * @bio:	the source bio
  * @dev:	target device
- * @from:	source sector
  * @to:		target sector
+ * @from:	source sector
  *
  * Description:
  *     Device mapper or raid target sometimes need to split a bio because
@@ -817,7 +817,7 @@ static void blk_add_trace_split(struct request_queue *q, struct bio *bio,
  *
  **/
 static void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
-				       dev_t dev, sector_t from, sector_t to)
+				       dev_t dev, sector_t to, sector_t from)
 {
 	struct blk_trace *bt = q->blk_trace;
 	struct blk_io_trace_remap r;
@@ -825,9 +825,9 @@ static void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
 	if (likely(!bt))
 		return;
 
-	r.device = cpu_to_be32(dev);
-	r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);
-	r.sector = cpu_to_be64(to);
+	r.device_from = cpu_to_be32(dev);
+	r.device_to   = cpu_to_be32(bio->bi_bdev->bd_dev);
+	r.sector_from = cpu_to_be64(from);
 
 	__blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP,
 			!bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
@@ -996,11 +996,11 @@ static void get_pdu_remap(const struct trace_entry *ent,
 			  struct blk_io_trace_remap *r)
 {
 	const struct blk_io_trace_remap *__r = pdu_start(ent);
-	__u64 sector = __r->sector;
+	__u64 sector_from = __r->sector_from;
 
-	r->device = be32_to_cpu(__r->device);
 	r->device_from = be32_to_cpu(__r->device_from);
-	r->sector = be64_to_cpu(sector);
+	r->device_to   = be32_to_cpu(__r->device_to);
+	r->sector_from = be64_to_cpu(sector_from);
 }
 
 typedef int (blk_log_action_t) (struct trace_iterator *iter, const char *act);
@@ -1054,13 +1054,13 @@ static int blk_log_with_error(struct trace_seq *s,
 
 static int blk_log_remap(struct trace_seq *s, const struct trace_entry *ent)
 {
-	struct blk_io_trace_remap r = { .device = 0, };
+	struct blk_io_trace_remap r = { .device_from = 0, };
 
 	get_pdu_remap(ent, &r);
 	return trace_seq_printf(s, "%llu + %u <- (%d,%d) %llu\n",
-			       t_sector(ent),
-			       t_sec(ent), MAJOR(r.device), MINOR(r.device),
-			       (unsigned long long)r.sector);
+				t_sector(ent), t_sec(ent),
+				MAJOR(r.device_from), MINOR(r.device_from),
+				(unsigned long long)r.sector_from);
 }
 
 static int blk_log_plug(struct trace_seq *s, const struct trace_entry *ent)
-- 
1.6.0.4

[PATCH 2/2] from-sector redundant in trace_block_remap

[Alan D. Brunelle]

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[-- Attachment #2: 0002-from-sector-redundant-in-trace_block_remap.patch --]
[-- Type: text/x-diff, Size: 3385 bytes --]

Removed redundant from-sector parameter: it's /always/ the bio's sector
passed in.

Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
---
 block/blk-core.c        |    5 ++---
 drivers/md/dm.c         |    3 +--
 include/trace/block.h   |    4 ++--
 kernel/trace/blktrace.c |    8 ++++----
 4 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 2998fe3..d028baf 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1277,7 +1277,7 @@ static inline void blk_partition_remap(struct bio *bio)
 		bio->bi_bdev = bdev->bd_contains;
 
 		trace_block_remap(bdev_get_queue(bio->bi_bdev), bio,
-				    bdev->bd_dev, bio->bi_sector,
+				    bdev->bd_dev,
 				    bio->bi_sector - p->start_sect);
 	}
 }
@@ -1446,8 +1446,7 @@ static inline void __generic_make_request(struct bio *bio)
 			goto end_io;
 
 		if (old_sector != -1)
-			trace_block_remap(q, bio, old_dev, bio->bi_sector,
-					    old_sector);
+			trace_block_remap(q, bio, old_dev, old_sector);
 
 		trace_block_bio_queue(q, bio);
 
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 424f7b0..e2ee4a7 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -656,8 +656,7 @@ static void __map_bio(struct dm_target *ti, struct bio *clone,
 		/* the bio has been remapped so dispatch it */
 
 		trace_block_remap(bdev_get_queue(clone->bi_bdev), clone,
-				    tio->io->bio->bi_bdev->bd_dev,
-				    clone->bi_sector, sector);
+				    tio->io->bio->bi_bdev->bd_dev, sector);
 
 		generic_make_request(clone);
 	} else if (r < 0 || r == DM_MAPIO_REQUEUE) {
diff --git a/include/trace/block.h b/include/trace/block.h
index 87f6456..8ac945b 100644
--- a/include/trace/block.h
+++ b/include/trace/block.h
@@ -70,7 +70,7 @@ DECLARE_TRACE(block_split,
 
 DECLARE_TRACE(block_remap,
 	TP_PROTO(struct request_queue *q, struct bio *bio, dev_t dev,
-		 sector_t to, sector_t from),
-	      TP_ARGS(q, bio, dev, to, from));
+		 sector_t to),
+	      TP_ARGS(q, bio, dev, to));
 
 #endif
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index bc72d53..4c1ed52 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -808,7 +808,6 @@ static void blk_add_trace_split(struct request_queue *q, struct bio *bio,
  * @q:		queue the io is for
  * @bio:	the source bio
  * @dev:	target device
- * @to:		target sector
  * @from:	source sector
  *
  * Description:
@@ -817,7 +816,7 @@ static void blk_add_trace_split(struct request_queue *q, struct bio *bio,
  *
  **/
 static void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
-				       dev_t dev, sector_t to, sector_t from)
+				       dev_t dev, sector_t from)
 {
 	struct blk_trace *bt = q->blk_trace;
 	struct blk_io_trace_remap r;
@@ -829,8 +828,9 @@ static void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
 	r.device_to   = cpu_to_be32(bio->bi_bdev->bd_dev);
 	r.sector_from = cpu_to_be64(from);
 
-	__blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP,
-			!bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
+	__blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw,
+			BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE),
+			sizeof(r), &r);
 }
 
 /**
-- 
1.6.0.4

[PATCH] blktrace: from-sector redundant in trace_block_remap, fix

[Li Zefan]

> Removed redundant from-sector parameter: it's /always/ the bio's sector
> passed in.
> 
> Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
> Cc: Jens Axboe <jens.axboe@oracle.com>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>

I reviewed the older version of this patch, but didn't review it again when
Alan sent out this revised one, and I just found a typo in it...

> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
...
>  DECLARE_TRACE(block_remap,
>  	TP_PROTO(struct request_queue *q, struct bio *bio, dev_t dev,
> -		 sector_t to, sector_t from),
> -	      TP_ARGS(q, bio, dev, to, from));
> +		 sector_t to),
> +	      TP_ARGS(q, bio, dev, to));

It should be 'from', not 'to'.


=======


From: Li Zefan <lizf@cn.fujitsu.com>
Subject: [PATCH] blktrace: from-sector redundant in trace_block_remap, fix

The last argument of block_remap prober is the original sector
before remap, so it should be 'from', not 'to'.

[ Impact: clean up ]

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
 include/trace/block.h |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/trace/block.h b/include/trace/block.h
index 8ac945b..5b12efa 100644
--- a/include/trace/block.h
+++ b/include/trace/block.h
@@ -70,7 +70,7 @@ DECLARE_TRACE(block_split,
 
 DECLARE_TRACE(block_remap,
 	TP_PROTO(struct request_queue *q, struct bio *bio, dev_t dev,
-		 sector_t to),
-	      TP_ARGS(q, bio, dev, to));
+		 sector_t from),
+	      TP_ARGS(q, bio, dev, from));
 
 #endif
-- 
1.5.4.rc3