[PATCH][next] fs: namespace: Avoid -Wflex-array-member-not-at-end warning

[PATCH][next] fs: namespace: Avoid -Wflex-array-member-not-at-end warning

[Gustavo A. R. Silva]

-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

Move the conflicting declaration to the end of the structure. Notice
that `struct statmount` is a flexible structure --a structure that
contains a flexible-array member.

Fix the following warning:

fs/namespace.c:5329:26: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 fs/namespace.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/namespace.c b/fs/namespace.c
index 6100e5b962a6..16292ff760c9 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -5326,8 +5326,10 @@ struct kstatmount {
 	struct mnt_idmap *idmap;
 	u64 mask;
 	struct path root;
-	struct statmount sm;
 	struct seq_file seq;
+
+	/* Must be last --ends in a flexible-array member. */
+	struct statmount sm;
 };
 
 static u64 mnt_to_attr_flags(struct vfsmount *mnt)
-- 
2.43.0

Re: [PATCH][next] fs: namespace: Avoid -Wflex-array-member-not-at-end warning

[Christian Brauner]

On Wed, 26 Mar 2025 18:17:44 -0600, Gustavo A. R. Silva wrote:
> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> getting ready to enable it, globally.
> 
> Move the conflicting declaration to the end of the structure. Notice
> that `struct statmount` is a flexible structure --a structure that
> contains a flexible-array member.
> 
> [...]

Applied to the vfs.fixes branch of the vfs/vfs.git tree.
Patches in the vfs.fixes branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs.fixes

[1/1] fs: namespace: Avoid -Wflex-array-member-not-at-end warning
      https://git.kernel.org/vfs/vfs/c/9e6901f17a71