On Mon 24-02-25 21:20:31, Al Viro wrote:
> It has two possible values - one for "forced lookup" entries, another
> for the normal ones. We'd be better off with that as an explicit
> flag anyway and in addition to that it opens some fun possibilities
> with ->d_op and ->d_flags handling.
>
> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
FWIW I went through the patches and I like them. They look mostly
straightforward enough to me and as good simplifications.
Honza
> ---
> fs/proc/generic.c | 8 +++++---
> fs/proc/internal.h | 5 +++--
> 2 files changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/fs/proc/generic.c b/fs/proc/generic.c
> index 8ec90826a49e..499c2bf67488 100644
> --- a/fs/proc/generic.c
> +++ b/fs/proc/generic.c
> @@ -254,7 +254,10 @@ struct dentry *proc_lookup_de(struct inode *dir, struct dentry *dentry,
> inode = proc_get_inode(dir->i_sb, de);
> if (!inode)
> return ERR_PTR(-ENOMEM);
> - d_set_d_op(dentry, de->proc_dops);
> + if (de->flags & PROC_ENTRY_FORCE_LOOKUP)
> + d_set_d_op(dentry, &proc_net_dentry_ops);
> + else
> + d_set_d_op(dentry, &proc_misc_dentry_ops);
> return d_splice_alias(inode, dentry);
> }
> read_unlock(&proc_subdir_lock);
> @@ -448,9 +451,8 @@ static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
> INIT_LIST_HEAD(&ent->pde_openers);
> proc_set_user(ent, (*parent)->uid, (*parent)->gid);
>
> - ent->proc_dops = &proc_misc_dentry_ops;
> /* Revalidate everything under /proc/${pid}/net */
> - if ((*parent)->proc_dops == &proc_net_dentry_ops)
> + if ((*parent)->flags & PROC_ENTRY_FORCE_LOOKUP)
> pde_force_lookup(ent);
>
> out:
> diff --git a/fs/proc/internal.h b/fs/proc/internal.h
> index 1695509370b8..07f75c959173 100644
> --- a/fs/proc/internal.h
> +++ b/fs/proc/internal.h
> @@ -44,7 +44,6 @@ struct proc_dir_entry {
> const struct proc_ops *proc_ops;
> const struct file_operations *proc_dir_ops;
> };
> - const struct dentry_operations *proc_dops;
> union {
> const struct seq_operations *seq_ops;
> int (*single_show)(struct seq_file *, void *);
> @@ -67,6 +66,8 @@ struct proc_dir_entry {
> char inline_name[];
> } __randomize_layout;
>
> +#define PROC_ENTRY_FORCE_LOOKUP 2 /* same space as PROC_ENTRY_PERMANENT */
> +
> #define SIZEOF_PDE ( \
> sizeof(struct proc_dir_entry) < 128 ? 128 : \
> sizeof(struct proc_dir_entry) < 192 ? 192 : \
> @@ -346,7 +347,7 @@ extern const struct dentry_operations proc_net_dentry_ops;
> static inline void pde_force_lookup(struct proc_dir_entry *pde)
> {
> /* /proc/net/ entries can be changed under us by setns(CLONE_NEWNET) */
> - pde->proc_dops = &proc_net_dentry_ops;
> + pde->flags |= PROC_ENTRY_FORCE_LOOKUP;
> }
>
> /*
> --
> 2.39.5
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
