On Wed, Jun 25, 2025 at 1:07 AM NeilBrown <neil@xxxxxxxxxx> wrote:
>
> Rather than lock the directory for the whole operation, use
> ovl_lookup_upper_unlocked() and ovl_cleanup_unlocked() to take the lock
> only when needed.
>
> This makes way for future changes where locks are taken on individual
> dentries rather than the whole directory.
>
> Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
> fs/overlayfs/readdir.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
> index 68cca52ae2ac..2a222b8185a3 100644
> --- a/fs/overlayfs/readdir.c
> +++ b/fs/overlayfs/readdir.c
> @@ -1034,14 +1034,13 @@ void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper,
> {
> struct ovl_cache_entry *p;
>
> - inode_lock_nested(upper->d_inode, I_MUTEX_CHILD);
> list_for_each_entry(p, list, l_node) {
> struct dentry *dentry;
>
> if (WARN_ON(!p->is_whiteout || !p->is_upper))
> continue;
>
> - dentry = ovl_lookup_upper(ofs, p->name, upper, p->len);
> + dentry = ovl_lookup_upper_unlocked(ofs, p->name, upper, p->len);
> if (IS_ERR(dentry)) {
> pr_err("lookup '%s/%.*s' failed (%i)\n",
> upper->d_name.name, p->len, p->name,
> @@ -1049,10 +1048,9 @@ void ovl_cleanup_whiteouts(struct ovl_fs *ofs, struct dentry *upper,
> continue;
> }
> if (dentry->d_inode)
> - ovl_cleanup(ofs, upper->d_inode, dentry);
> + ovl_cleanup_unlocked(ofs, upper, dentry);
> dput(dentry);
> }
> - inode_unlock(upper->d_inode);
> }
>
> static bool ovl_check_d_type(struct dir_context *ctx, const char *name,
> --
> 2.49.0
>
