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author | 2009-10-01 21:16:13 +0200 | |
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committer | 2009-10-01 21:19:34 +0200 | |
commit | b0da3f0dada78832c9da03ad2152ae76bd9a2496 (patch) | |
tree | 58380f5d8f3c313fbb9fd0310509a408b38a0399 /kernel | |
parent | block: allow large discard requests (diff) | |
download | linux-b0da3f0dada78832c9da03ad2152ae76bd9a2496.tar.gz linux-b0da3f0dada78832c9da03ad2152ae76bd9a2496.tar.bz2 linux-b0da3f0dada78832c9da03ad2152ae76bd9a2496.zip |
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: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'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: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/trace/blktrace.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 60b5c5a3d4b4..d9d6206e0b14 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -856,6 +856,37 @@ static void blk_add_trace_remap(struct request_queue *q, struct bio *bio, } /** + * 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 * @rq: io request @@ -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); |