[PATCH] tracing: Do not clean up hiter in mmiotrace read function

From: Steven Rostedt <[email protected]>

When the mmiotrace trace was first created, it allocated a descriptor in
its pipe_open() method. Since there was no pipe_close() method when it was
created (in May of 2008, and pipe_close() was added in December of 2009),
it cleaned up the allocated descriptors in the read.

Now that the clean up is in the pipe_close() method that now exists,
remove the clean up from the read as it is no longer needed.

Also simplify the code by inverting the early exit conditional into a
conditional to perform the logic and get rid of the goto.

Link: https://lore.kernel.org/all/[email protected]/
Link: https://lore.kernel.org/all/[email protected]/

Signed-off-by: Steven Rostedt <[email protected]>
---
 kernel/trace/trace_mmiotrace.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index b88b8d9923ad..ba604c22d2d2 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -142,21 +142,13 @@ static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
 		if (!overrun_detected)
 			pr_warn("mmiotrace has lost events\n");
 		overrun_detected = true;
-		goto print_out;
 	}
 
-	if (!hiter || !hiter->dev)
-		return 0;
-
-	mmio_print_pcidev(s, hiter->dev);
-	hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev);
-
-	if (!hiter->dev) {
-		destroy_header_iter(hiter);
-		iter->private = NULL;
+	if (hiter && hiter->dev) {
+		mmio_print_pcidev(s, hiter->dev);
+		hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev);
 	}
 
-print_out:
 	ret = trace_seq_to_user(s, ubuf, cnt);
 	return (ret == -EBUSY) ? 0 : ret;
 }
-- 
2.53.0