On Wed, 2026-02-04 at 15:57 +1100, NeilBrown wrote:
> From: NeilBrown <[email protected]>
> 
> Instead of explicitly locking the parent and performing a lookup in
> selinux, use simple_start_creating(), and then use
> simple_done_creating() to unlock.
> 
> This extends the region that the directory is locked for, and also
> performs a lookup.
> The lock extension is of no real consequence.
> The lookup uses simple_lookup() and so always succeeds.  Thus when
> d_make_persistent() is called the dentry will already be hashed.
> d_make_persistent() handles this case.
> 
> Signed-off-by: NeilBrown <[email protected]>
> ---
>  security/selinux/selinuxfs.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
> index 896acad1f5f7..97e02cd5a9dc 100644
> --- a/security/selinux/selinuxfs.c
> +++ b/security/selinux/selinuxfs.c
> @@ -1930,15 +1930,16 @@ static const struct inode_operations 
> swapover_dir_inode_operations = {
>  static struct dentry *sel_make_swapover_dir(struct super_block *sb,
>                                               unsigned long *ino)
>  {
> -     struct dentry *dentry = d_alloc_name(sb->s_root, ".swapover");
> +     struct dentry *dentry;
>       struct inode *inode;
>  
> -     if (!dentry)
> +     inode = sel_make_inode(sb, S_IFDIR);
> +     if (!inode)
>               return ERR_PTR(-ENOMEM);
>  
> -     inode = sel_make_inode(sb, S_IFDIR);
> -     if (!inode) {
> -             dput(dentry);
> +     dentry = simple_start_creating(sb->s_root, ".swapover");
> +     if (!dentry) {
> +             iput(inode);
>               return ERR_PTR(-ENOMEM);
>       }
>  
> @@ -1946,11 +1947,9 @@ static struct dentry *sel_make_swapover_dir(struct 
> super_block *sb,
>       inode->i_ino = ++(*ino);
>       /* directory inodes start off with i_nlink == 2 (for "." entry) */
>       inc_nlink(inode);
> -     inode_lock(sb->s_root->d_inode);
>       d_make_persistent(dentry, inode);
>       inc_nlink(sb->s_root->d_inode);
> -     inode_unlock(sb->s_root->d_inode);
> -     dput(dentry);
> +     simple_done_creating(dentry);
>       return dentry;  // borrowed
>  }
>  

Reviewed-by: Jeff Layton <[email protected]>

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