Re: [PATCH] libfrog: pass correct structure to FS_IOC_FSSETXATTR

["Darrick J. Wong" <djwong@kernel.org>]

On Thu, Dec 04, 2025 at 08:28:27PM +0100, Arkadiusz Miśkiewicz wrote:
> Commit 56af42ac ("libfrog: add wrappers for file_getattr/file_setattr syscalls")
> introduced the xfrog_file_setattr() framework, which was then wired up for
> xfs_quota in 961e42e0.
> 
> However, the wrong structure is passed to FS_IOC_FSSETXATTR, which breaks the
> xfs_quota "project" subcommand:
> 
>     # LC_ALL=C /usr/sbin/xfs_quota -x -c 'project -s -p /home/xxx 389701' /home
>     Setting up project 389701 (path /home/xxx)...
>     xfs_quota: cannot set project on /home/xxx: Invalid argument
>     Processed 1 (/etc/projects and cmdline) paths for project 389701 with recursion depth infinite (-1).
> 
> strace:
>     ioctl(5, FS_IOC_FSSETXATTR,
>           {fsx_xflags=FS_XFLAG_PROJINHERIT|FS_XFLAG_HASATTR,
>            fsx_extsize=0, fsx_projid=0, fsx_cowextsize=389701}) = -1 EINVAL (Invalid argument)
> 
> Fix the call to pass the correct structure so that the project ID is set
> properly.
> 
> Fixes: 56af42ac ("libfrog: add wrappers for file_getattr/file_setattr syscalls")
> Signed-off-by: Arkadiusz Miśkiewicz <arekm@maven.pl>

That's correct, thanks for the fix patch.
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

I'm kinda surprised gcc didn't warn about the set-but-unused variable.
Maybe the call to file_attr_to_fsxattr confused it or something.

> ---
>  libfrog/file_attr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> 
> Note: the tests need to be updated, as they didn’t catch this problem.

Yep. :/

--D

> diff --git a/libfrog/file_attr.c b/libfrog/file_attr.c
> index c2cbcb4e..6801c545 100644
> --- a/libfrog/file_attr.c
> +++ b/libfrog/file_attr.c
> @@ -114,7 +114,7 @@ xfrog_file_setattr(
>  
>  	file_attr_to_fsxattr(fa, &fsxa);
>  
> -	error = ioctl(fd, FS_IOC_FSSETXATTR, fa);
> +	error = ioctl(fd, FS_IOC_FSSETXATTR, &fsxa);
>  	close(fd);
>  
>  	return error;
> -- 
> 2.52.0
> 
>