Subject: Re: linux-next: build warning after merge of the xfs tree

From: Brian Foster <[email-masked]>
Date: Mon, 25 Jan 2021 08:26:16 -0500

On Mon, Jan 25, 2021 at 09:55:32AM +1100, Stephen Rothwell wrote:
> Hi all,
> 
> After merging the xfs tree, today's linux-next build (powerpc
> ppc64_defconfig) produced this warning:
> 
> fs/xfs/xfs_log.c: In function 'xfs_log_cover':
> fs/xfs/xfs_log.c:1111:16: warning: unused variable 'log' [-Wunused-variable]
>  1111 |  struct xlog  *log = mp->m_log;
>       |                ^~~
> 
> Introduced by commit
> 
>   303591a0a947 ("xfs: cover the log during log quiesce")
> 

Oops, patch below. Feel free to apply or squash into the original
commit.

Brian

--- 8< ---

>From 6078f06e2bd4c82111a85a2032c39a56654b0be6 Mon Sep 17 00:00:00 2001
From: Brian Foster <[email-masked]>
Date: Mon, 25 Jan 2021 08:22:56 -0500
Subject: [PATCH] xfs: fix unused log variable in xfs_log_cover()

The log variable is only used in kernels with asserts enabled.
Remove it and open code the dereference to avoid unused variable
warnings.

Signed-off-by: Brian Foster <[email-masked]>
---
 fs/xfs/xfs_log.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 58699881c100..d8b814227734 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1108,12 +1108,11 @@ static int
 xfs_log_cover(
 	struct xfs_mount	*mp)
 {
-	struct xlog		*log = mp->m_log;
 	int			error = 0;
 	bool			need_covered;
 
-	ASSERT((xlog_cil_empty(log) && xlog_iclogs_empty(log) &&
-	        !xfs_ail_min_lsn(log->l_ailp)) ||
+	ASSERT((xlog_cil_empty(mp->m_log) && xlog_iclogs_empty(mp->m_log) &&
+	        !xfs_ail_min_lsn(mp->m_log->l_ailp)) ||
 	       XFS_FORCED_SHUTDOWN(mp));
 
 	if (!xfs_log_writable(mp))
-- 
2.26.2