On Tue, 19 Aug 2025 16:43:05 Miklos wrote:
> On Mon, 18 Aug 2025 at 10:32, Chunsheng Luo <luochunsheng@xxxxxxxx> wrote:
> >
> > On Fri, 15 Aug 2025 11:25:38 Joanne Koong wrote:
> > >diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
> > >index ec248d13c8bf..1647eb7ca6fa 100644
> > >--- a/fs/fuse/fuse_i.h
> > >+++ b/fs/fuse/fuse_i.h
> > >@@ -210,6 +210,12 @@ struct fuse_inode {
> > > /** Reference to backing file in passthrough mode */
> > > struct fuse_backing *fb;
> > > #endif
> > >+
> > >+ /*
> > >+ * The underlying inode->i_blkbits value will not be modified,
> > >+ * so preserve the blocksize specified by the server.
> > >+ */
> > >+ u8 cached_i_blkbits;
> > > };
> >
> > Does the `cached_i_blkbits` member also need to be initialized in the
> > `fuse_alloc_inode` function like `orig_ino`?
> >
> > And I am also confused, why does `orig_ino` need to be initialized in
> > `fuse_alloc_inode`, but the `orig_i_mode` member does not need it?
>
> Strictly speaking neither one needs initialization, since these
> shouldn't be accessed until the in-core inode is set up in lookup or
> create.
>
> But having random values in there is not nice, so I prefer having
> everything initialized in fuse_alloc_inode(). See patch below
> (whitespace damage(TM) by gmail).
>
> Thanks,
> Miklos
>
Understood. Thanks for the explanation. The below patch looks good to me.
Thanks.
Chunsheng Luo
> diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
> index 19fc58cb84dc..9d26a5bc394d 100644
> --- a/fs/fuse/inode.c
> +++ b/fs/fuse/inode.c
> @@ -101,14 +101,11 @@ static struct inode *fuse_alloc_inode(struct
> super_block *sb)
> if (!fi)
> return NULL;
>
> - fi->i_time = 0;
> + /* Initialize private data (i.e. everything except fi->inode) */
> + BUILD_BUG_ON(offsetof(struct fuse_inode, inode) != 0);
> + memset((void *) fi + sizeof(fi->inode), 0, sizeof(*fi) -
> sizeof(fi->inode));
> +
> fi->inval_mask = ~0;
> - fi->nodeid = 0;
> - fi->nlookup = 0;
> - fi->attr_version = 0;
> - fi->orig_ino = 0;
> - fi->state = 0;
> - fi->submount_lookup = NULL;
> mutex_init(&fi->mutex);
> spin_lock_init(&fi->lock);
> fi->forget = fuse_alloc_forget();
>
