Commit f261c168 authored Aug 20, 2020 by Pavel Begunkov Committed by Jens Axboe Aug 20, 2020

io_uring: comment on kfree(iovec) checks



kfree() handles NULL pointers well, but io_{read,write}() checks it
because of performance reasons. Leave a comment there for those who are
tempted to patch it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent bb175342

fs/io_uring.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -3204,6 +3204,7 @@ done:
		kiocb_done(kiocb, ret, cs);
		ret = 0;
		out_free:
		/* it's reportedly faster than delegating the null check to kfree() */
		if (iovec)
		kfree(iovec);
		return ret;
		@@ -3300,6 +3301,7 @@ copy_iov:
		return -EAGAIN;
		}
		out_free:
		/* it's reportedly faster than delegating the null check to kfree() */
		if (iovec)
		kfree(iovec);
		return ret;

Admin message