Unverified Commit f4d3cde4 authored by Zilin Guan's avatar Zilin Guan Committed by Christian Brauner
Browse files

netfs: Remove redundant use of smp_rmb() 



The function netfs_unbuffered_write_iter_locked() in
fs/netfs/direct_write.c contains an unnecessary smp_rmb() call after
wait_on_bit(). Since wait_on_bit() already incorporates a memory barrier
that ensures the flag update is visible before the function returns, the
smp_rmb() provides no additional benefit and incurs unnecessary overhead.

This patch removes the redundant barrier to simplify and optimize the code.

Signed-off-by: default avatarZilin Guan <zilin@seu.edu.cn>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241207021952.2978530-1-zilin@seu.edu.cn/
Link: https://lore.kernel.org/r/20241213135013.2964079-7-dhowells@redhat.com


Reviewed-by: default avatarAkira Yokosawa <akiyks@gmail.com>
cc: Akira Yokosawa <akiyks@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent e5a8b644

fs/netfs/direct_write.c

+0 −1
Original line number Diff line number Diff line
@@ -104,7 +104,6 @@ ssize_t netfs_unbuffered_write_iter_locked(struct kiocb *iocb, struct iov_iter * 
		trace_netfs_rreq(wreq, netfs_rreq_trace_wait_ip);

		wait_on_bit(&wreq->flags, NETFS_RREQ_IN_PROGRESS,

			    TASK_UNINTERRUPTIBLE);

		smp_rmb(); /* Read error/transferred after RIP flag */

		ret = wreq->error;

		if (ret == 0) {

			ret = wreq->transferred;