On Wed, Jun 25, 2025 at 1:07 AM NeilBrown <neil@xxxxxxxxxx> wrote:
>
> Drop the locks immediately after rename, and use a separate lock for
> cleanup.
>
> This makes way for future changes where locks are taken on individual
> dentries rather than the whole directory.
>
> Note that ovl_cleanup_whiteouts() operates on "upper", a child of
> "upperdir" and does not require upperdir or workdir to be locked.
>
> Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
> fs/overlayfs/dir.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
> index 2d67704d641e..e3ea7d02219f 100644
> --- a/fs/overlayfs/dir.c
> +++ b/fs/overlayfs/dir.c
> @@ -355,7 +355,6 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
> {
> struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
> struct dentry *workdir = ovl_workdir(dentry);
> - struct inode *wdir = workdir->d_inode;
> struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
> struct inode *udir = upperdir->d_inode;
> struct path upperpath;
> @@ -408,10 +407,10 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
> err = ovl_do_rename(ofs, workdir, opaquedir, upperdir, upper, RENAME_EXCHANGE);
> if (err)
> goto out_cleanup;
> + unlock_rename(workdir, upperdir);
>
> ovl_cleanup_whiteouts(ofs, upper, list);
> - ovl_cleanup(ofs, wdir, upper);
> - unlock_rename(workdir, upperdir);
> + ovl_cleanup_unlocked(ofs, workdir, upper);
>
> /* dentry's upper doesn't match now, get rid of it */
> d_drop(dentry);
> --
> 2.49.0
>
