On Fri 26-11-21 21:06:10, Chengguang Xu wrote:
> ---- 在 星期五, 2021-11-26 17:10:07 Jan Kara <jack@xxxxxxx> 撰写 ----
> > On Mon 22-11-21 11:00:33, Chengguang Xu wrote:
> > > From: Chengguang Xu <charliecgxu@xxxxxxxxxxx>
> > >
> > > We simply mark overlayfs inode dirty when it has upper,
> > > it's much simpler than mark dirtiness on modification.
> > >
> > > Signed-off-by: Chengguang Xu <charliecgxu@xxxxxxxxxxx>
> > > ---
> > > fs/overlayfs/inode.c | 4 +++-
> > > fs/overlayfs/util.c | 1 +
> > > 2 files changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> > > index 1f36158c7dbe..027ffc0a2539 100644
> > > --- a/fs/overlayfs/inode.c
> > > +++ b/fs/overlayfs/inode.c
> > > @@ -778,8 +778,10 @@ void ovl_inode_init(struct inode *inode, struct ovl_inode_params *oip,
> > > {
> > > struct inode *realinode;
> > >
> > > - if (oip->upperdentry)
> > > + if (oip->upperdentry) {
> > > OVL_I(inode)->__upperdentry = oip->upperdentry;
> > > + mark_inode_dirty(inode);
> > > + }
> > > if (oip->lowerpath && oip->lowerpath->dentry)
> > > OVL_I(inode)->lower = igrab(d_inode(oip->lowerpath->dentry));
> > > if (oip->lowerdata)
> >
> > Hum, does this get called only for inodes with upper inode existing? I
> > suppose we do not need to track inodes that were not copied up because they
> > cannot be dirty? I'm sorry, my knowledge of overlayfs is rather limited so
> > I may be missing something basic.
> >
>
> Well, as long as overly inode has upper it can be modified without copy-up,
> so we need to track all overlay inodes which have upper inode.
OK, and oip->upperdentry is set only if there's upper inode, now I
understand. Thanks for explanation and feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
