Commit b0da3f0d authored by Jun'ichi Nomura's avatar Jun'ichi Nomura Committed by Jens Axboe

Add a tracepoint for block request remapping

Since 2.6.31 now has request-based device-mapper, it's useful to have
a tracepoint for request-remapping as well as bio-remapping.
This patch adds a tracepoint for request-remapping, trace_block_rq_remap().
Signed-off-by: default avatarKiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: default avatarJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent 67efc925
......@@ -34,6 +34,7 @@
#include "blk.h"
EXPORT_TRACEPOINT_SYMBOL_GPL(block_remap);
EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
static int __make_request(struct request_queue *q, struct bio *bio);
......
......@@ -212,7 +212,7 @@ extern struct attribute_group blk_trace_attr_group;
# define blk_trace_startstop(q, start) (-ENOTTY)
# define blk_trace_remove(q) (-ENOTTY)
# define blk_add_trace_msg(q, fmt, ...) do { } while (0)
# define blk_trace_remove_sysfs(struct device *dev) do { } while (0)
# define blk_trace_remove_sysfs(dev) do { } while (0)
static inline int blk_trace_init_sysfs(struct device *dev)
{
return 0;
......
......@@ -488,6 +488,39 @@ TRACE_EVENT(block_remap,
(unsigned long long)__entry->old_sector)
);
TRACE_EVENT(block_rq_remap,
TP_PROTO(struct request_queue *q, struct request *rq, dev_t dev,
sector_t from),
TP_ARGS(q, rq, dev, from),
TP_STRUCT__entry(
__field( dev_t, dev )
__field( sector_t, sector )
__field( unsigned int, nr_sector )
__field( dev_t, old_dev )
__field( sector_t, old_sector )
__array( char, rwbs, 6 )
),
TP_fast_assign(
__entry->dev = disk_devt(rq->rq_disk);
__entry->sector = blk_rq_pos(rq);
__entry->nr_sector = blk_rq_sectors(rq);
__entry->old_dev = dev;
__entry->old_sector = from;
blk_fill_rwbs_rq(__entry->rwbs, rq);
),
TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu",
MAJOR(__entry->dev), MINOR(__entry->dev), __entry->rwbs,
(unsigned long long)__entry->sector,
__entry->nr_sector,
MAJOR(__entry->old_dev), MINOR(__entry->old_dev),
(unsigned long long)__entry->old_sector)
);
#endif /* _TRACE_BLOCK_H */
/* This part must be outside protection */
......
......@@ -855,6 +855,37 @@ static void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
sizeof(r), &r);
}
/**
* blk_add_trace_rq_remap - Add a trace for a request-remap operation
* @q: queue the io is for
* @rq: the source request
* @dev: target device
* @from: source sector
*
* Description:
* Device mapper remaps request to other devices.
* Add a trace for that action.
*
**/
static void blk_add_trace_rq_remap(struct request_queue *q,
struct request *rq, dev_t dev,
sector_t from)
{
struct blk_trace *bt = q->blk_trace;
struct blk_io_trace_remap r;
if (likely(!bt))
return;
r.device_from = cpu_to_be32(dev);
r.device_to = cpu_to_be32(disk_devt(rq->rq_disk));
r.sector_from = cpu_to_be64(from);
__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
rq_data_dir(rq), BLK_TA_REMAP, !!rq->errors,
sizeof(r), &r);
}
/**
* blk_add_driver_data - Add binary message with driver-specific data
* @q: queue the io is for
......@@ -922,10 +953,13 @@ static void blk_register_tracepoints(void)
WARN_ON(ret);
ret = register_trace_block_remap(blk_add_trace_remap);
WARN_ON(ret);
ret = register_trace_block_rq_remap(blk_add_trace_rq_remap);
WARN_ON(ret);
}
static void blk_unregister_tracepoints(void)
{
unregister_trace_block_rq_remap(blk_add_trace_rq_remap);
unregister_trace_block_remap(blk_add_trace_remap);
unregister_trace_block_split(blk_add_trace_split);
unregister_trace_block_unplug_io(blk_add_trace_unplug_io);
......
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