Re: [PATCH v3 1/5] vfs: Add file timestamp range support

From: Al Viro
Date: Sat Feb 18 2017 - 20:57:42 EST


On Sat, Feb 18, 2017 at 03:30:04PM -0800, Deepa Dinamani wrote:
> Add fields to the superblock to track the min and max
> timestamps supported by filesystems.
>
> Initially, when a superblock is allocated, initialize
> it to the max and min values the fields can hold.
> Individual filesystems override these to match their
> actual limits.
>
> Pseudo filesystems are assumed to always support the
> min and max allowable values for the fields.

> @@ -257,6 +257,8 @@ struct dentry *mount_pseudo_xattr(struct file_system_type *fs_type, char *name,
> + s->s_time_min = TIME64_MIN;
> + s->s_time_max = TIME64_MAX;
> @@ -518,6 +520,8 @@ int simple_fill_super(struct super_block *s, unsigned long magic,
> + s->s_time_min = TIME64_MIN;
> + s->s_time_max = TIME64_MAX;
> @@ -247,6 +247,8 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags,
> + s->s_time_min = TIME64_MIN;
> + s->s_time_max = TIME64_MAX;

If we always initialize them that way, why does libfs.c code bother
reassign the same values?