On Wed, Jul 16, 2025 at 2:47 AM NeilBrown <neil@xxxxxxxxxx> wrote:
>
> Instead of taking the directory lock for the whole cleanup, only take it
> when needed.
>
> Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
> fs/overlayfs/readdir.c | 20 +++++++++++++-------
> 1 file changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
> index 2a222b8185a3..95d5284daf8d 100644
> --- a/fs/overlayfs/readdir.c
> +++ b/fs/overlayfs/readdir.c
> @@ -1194,7 +1194,6 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs)
> if (err)
> goto out;
>
> - inode_lock_nested(dir, I_MUTEX_PARENT);
> list_for_each_entry(p, &list, l_node) {
> if (p->name[0] == '.') {
> if (p->len == 1)
> @@ -1202,7 +1201,7 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs)
> if (p->len == 2 && p->name[1] == '.')
> continue;
> }
> - index = ovl_lookup_upper(ofs, p->name, indexdir, p->len);
> + index = ovl_lookup_upper_unlocked(ofs, p->name, indexdir, p->len);
> if (IS_ERR(index)) {
> err = PTR_ERR(index);
> index = NULL;
> @@ -1210,7 +1209,11 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs)
> }
> /* Cleanup leftover from index create/cleanup attempt */
> if (index->d_name.name[0] == '#') {
> - err = ovl_workdir_cleanup(ofs, dir, path.mnt, index, 1);
> + err = ovl_parent_lock(indexdir, index);
> + if (!err) {
> + err = ovl_workdir_cleanup(ofs, dir, path.mnt, index, 1);
> + ovl_parent_unlock(indexdir);
> + }
> if (err)
> break;
> goto next;
> @@ -1220,7 +1223,7 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs)
> goto next;
> } else if (err == -ESTALE) {
> /* Cleanup stale index entries */
> - err = ovl_cleanup(ofs, dir, index);
> + err = ovl_cleanup_unlocked(ofs, indexdir, index);
> } else if (err != -ENOENT) {
> /*
> * Abort mount to avoid corrupting the index if
> @@ -1233,10 +1236,14 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs)
> * Whiteout orphan index to block future open by
> * handle after overlay nlink dropped to zero.
> */
> - err = ovl_cleanup_and_whiteout(ofs, indexdir, index);
> + err = ovl_parent_lock(indexdir, index);
> + if (!err) {
> + err = ovl_cleanup_and_whiteout(ofs, indexdir, index);
> + ovl_parent_unlock(indexdir);
> + }
> } else {
> /* Cleanup orphan index entries */
> - err = ovl_cleanup(ofs, dir, index);
> + err = ovl_cleanup_unlocked(ofs, indexdir, index);
> }
>
> if (err)
> @@ -1247,7 +1254,6 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs)
> index = NULL;
> }
> dput(index);
> - inode_unlock(dir);
> out:
> ovl_cache_free(&list);
> if (err)
> --
> 2.49.0
>
