Commit ebee41c8 authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
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tty: tty_buffer: invert conditions in __tty_buffer_request_room() 



We are used to handle "bad" states in the 'if's in the kernel. Refactor
(invert the two conditions in) __tty_buffer_request_room(), so that the
code returns from the fast paths immediately instead of postponing to
the heavy end of the function.

Signed-off-by: default avatar"Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230816105530.3335-11-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 035197c9

drivers/tty/tty_buffer.c

+22 −22
Original line number Diff line number Diff line
@@ -266,10 +266,14 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size, 
	size_t left = (b->flags ? 1 : 2) * b->size - b->used;

	bool change = !b->flags && flags;



	if (change || left < size) {

	if (!change && left >= size)

		return size;



	/* This is the slow path - looking for new buffers to use */

	n = tty_buffer_alloc(port, size);

		if (n != NULL) {

	if (n == NULL)

		return change ? 0 : left;



	n->flags = flags;

	buf->tail = n;

	/*
@@ -283,11 +287,7 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size, 
	 * is advanced to the next buffer.

	 */

	smp_store_release(&b->next, n);

		} else if (change)

			size = 0;

		else

			size = left;

	}



	return size;

}