Currently, blktrace will not show requests that don't have any data as
rq->__sector is initialized to -1 which is out of device range and thus
discarded by act_log_check(). This is most notably the case for cache
flush requests sent to the device. Fix the problem by making
blk_rq_trace_sector() return 0 for requests without initialized sector.
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
include/linux/blktrace_api.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 8804753805ac..353fd8c70760 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -116,7 +116,8 @@ extern void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes);
static inline sector_t blk_rq_trace_sector(struct request *rq)
{
- return blk_rq_is_passthrough(rq) ? 0 : blk_rq_pos(rq);
+ return (blk_rq_is_passthrough(rq) || blk_rq_pos(rq) == (sector_t)-1) ?
+ 0 : blk_rq_pos(rq);
}
static inline unsigned int blk_rq_trace_nr_sectors(struct request *rq)
--
2.16.4
