badblocks: attempt to merge adjacent badblocks during ack_all_badblocks

If ack and unack badblocks are adjacent, they will not be merged and will
remain as two separate badblocks. Even after the bad blocks are written
to disk and both become ack, they will still remain as two independent
bad blocks. This is not ideal as it wastes the limited space for
badblocks. Therefore, during ack_all_badblocks(), attempt to merge
badblocks if they are adjacent.

Fixes: aa511ff ("badblocks: switch to the improved badblock handling code")
Signed-off-by: Li Nan <[email protected]>
Reviewed-by: Yu Kuai <[email protected]>
Acked-by: Coly Li <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>

Author: Li Nan

block/badblocks.c

@@ -1491,6 +1491,11 @@ void ack_all_badblocks(struct badblocks *bb)
 				p[i] = BB_MAKE(start, len, 1);
 			}
 		}
+
+		for (i = 0; i < bb->count ; i++)
+			while (try_adjacent_combine(bb, i))
+				;
+
 		bb->unacked_exist = 0;
 	}
 	write_sequnlock_irq(&bb->lock);