Hi André,
On Thu, Oct 31, 2024 at 10:37:41PM -0300, André Almeida wrote:
> Instead of using fs_initcall(), initialize sysfs with the rest of the
> filesystem. This is the right way to do it because otherwise any error
> during tmpfs_sysfs_init() would get silently ignored. It's also useful
> if tmpfs' sysfs ever need to display runtime information.
>
> Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
> ---
> mm/shmem.c | 130 ++++++++++++++++++++++++++++-------------------------
> 1 file changed, 68 insertions(+), 62 deletions(-)
>
> diff --git a/mm/shmem.c b/mm/shmem.c
> index 6038e1d11987..8ff2f619f531 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -5126,6 +5126,66 @@ static struct file_system_type shmem_fs_type = {
> .fs_flags = FS_USERNS_MOUNT | FS_ALLOW_IDMAP | FS_MGTIME,
> };
>
> +#if defined(CONFIG_SYSFS) && defined(CONFIG_TMPFS)
This condition...
> +static int __init tmpfs_sysfs_init(void)
> +{
> + int ret;
> +
> + tmpfs_kobj = kobject_create_and_add("tmpfs", fs_kobj);
> + if (!tmpfs_kobj)
> + return -ENOMEM;
> +
> + ret = sysfs_create_group(tmpfs_kobj, &tmpfs_attribute_group);
> + if (ret)
> + kobject_put(tmpfs_kobj);
> +
> + return ret;
> +}
> +#endif /* CONFIG_SYSFS && CONFIG_TMPFS */
> +
> void __init shmem_init(void)
> {
> int error;
> @@ -5149,6 +5209,14 @@ void __init shmem_init(void)
> goto out1;
> }
>
> +#ifdef CONFIG_SYSFS
and this condition are not the same, so there will be a compile error if
CONFIG_SHMEM and CONFIG_SYSFS are enabled but CONFIG_TMPFS is not, such
as with ARCH=x86_64 allnoconfig for me:
mm/shmem.c: In function 'shmem_init':
mm/shmem.c:5243:17: error: implicit declaration of function 'tmpfs_sysfs_init'; did you mean 'uids_sysfs_init'? [-Wimplicit-function-declaration]
5243 | error = tmpfs_sysfs_init();
| ^~~~~~~~~~~~~~~~
| uids_sysfs_init
> + error = tmpfs_sysfs_init();
> + if (error) {
> + pr_err("Could not init tmpfs sysfs\n");
> + goto out1;
> + }
> +#endif
Cheers,
Nathan
