On Tue, May 23, 2017 at 12:41:12AM -0700, Christoph Hellwig wrote: > On Mon, May 22, 2017 at 03:53:05PM -0700, Shaohua Li wrote: > > Set i_generation for kernfs inod. This is required to implement exportfs > > operations. > > > > Signed-off-by: Shaohua Li <[email protected]> > > --- > > fs/kernfs/dir.c | 2 ++ > > fs/kernfs/inode.c | 1 + > > include/linux/kernfs.h | 2 ++ > > 3 files changed, 5 insertions(+) > > > > diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c > > index db5900aaa..09d093e 100644 > > --- a/fs/kernfs/dir.c > > +++ b/fs/kernfs/dir.c > > @@ -634,6 +634,7 @@ static struct kernfs_node *__kernfs_new_node(struct > > kernfs_root *root, > > if (ret < 0) > > goto err_out2; > > kn->ino = ret; > > + kn->generation = atomic_inc_return(&root->next_generation); > > i_generation is only supposed to be valid on a per-inode basis, so this > global counter seems really odd.
What's the difference between per-inode or per-super? The i_generation doesn't need to be consecutive for an inode. I checked other fs, a lot of filesystems implement i_generation in this way, for example, f2fs, ext4. Thanks, Shaohua
