ERROR: "__tracepoint_block_unplug" [drivers/md/raid456.ko] undefined!

Hi NeilBrown,

FYI, kernel build failed on

tree:   git://neil.brown.name/md for-next/14817e9
head:   14817e9a6dab027db44783d28429d14f601547a2
commit: 14817e9a6dab027db44783d28429d14f601547a2 [29/29] md/raid5: add blktrace calls
config: sparc64-defconfig

ERROR: "__tracepoint_block_unplug" [drivers/md/raid456.ko] undefined!

The root cause is, the block trace points are only available when block/blk-core.c is compiled in.

---
0-DAY kernel build testing backend Open Source Technology Centre
Fengguang Wu <[email protected]> Intel Corporation

Hi,
thanks for this.
blk-core must be compiled in, else raid456 wouldn't get compiled CONFIG_MD_RAID456 eventually depends on CONFIG_BLOCK.

The problem is simply that tracepoint_block_unplug hasn't been exported. This fixes it:

index 4b4dbdf..ef55ae0 100644
@@ -40,6 +40,7 @@
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
+EXPORT_TRACEPOINT_SYMBOL_GPL(block_unplug);
 
 DEFINE_IDA(blk_queue_ida);
 

I'll see if Jens will take it.

Thanks,
NeilBrown