lightnvm: pblk: gc all lines in the pipeline before exit

Finish garbage collect of the lines that are in the gc pipeline
before exiting. Ensure that all lines already in in the pipeline
goes through, from read to write.

Do this by keeping track of how many lines are in the pipeline
and waiting for that number to reach zero before exiting the gc
reader task.

Since we're adding a new gc line counter, change the name of
inflight_gc to read_inflight_gc to make the distinction clear.

Signed-off-by: Hans Holmberg <hans.holmberg@cnexlabs.com>
Signed-off-by: Matias Bjørling <m@bjorling.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index 29ba7ec32b20..c6f8841973a0 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -238,7 +238,10 @@ struct pblk_gc {
 	struct timer_list gc_timer;
 
 	struct semaphore gc_sem;
-	atomic_t inflight_gc;
+	atomic_t read_inflight_gc; /* Number of lines with inflight GC reads */
+	atomic_t pipeline_gc;	   /* Number of lines in the GC pipeline -
+				    * started reads to finished writes
+				    */
 	int w_entries;
 
 	struct list_head w_list;