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>

2 files changed, 34 insertions, 1 deletions

diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 622939a23299..3b73b9992b26 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -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;
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index d86af94691c2..00405b5f624a 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -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 */