On Fri, Jul 11, 2025 at 1:21 AM NeilBrown <neil@xxxxxxxxxx> wrote:
>
> In ovl_copy_up_workdir() unlock immediately after the rename, and then
> use ovl_cleanup_unlocked() with separate locking rather than using the
> same lock to protect both.
>
> This makes way for future changes where locks are taken on individual
> dentries rather than the whole directory.
>
> Signed-off-by: NeilBrown <neil@xxxxxxxxxx>
> ---
> fs/overlayfs/copy_up.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
> index eafb46686854..7b84a39c081f 100644
> --- a/fs/overlayfs/copy_up.c
> +++ b/fs/overlayfs/copy_up.c
> @@ -765,7 +765,6 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c)
> {
> struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb);
> struct inode *inode;
> - struct inode *wdir = d_inode(c->workdir);
> struct path path = { .mnt = ovl_upper_mnt(ofs) };
> struct dentry *temp, *upper, *trap;
> struct ovl_cu_creds cc;
> @@ -816,9 +815,9 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c)
> /* temp or workdir moved underneath us? abort without cleanup */
> dput(temp);
> err = -EIO;
> - if (IS_ERR(trap))
> - goto out;
> - goto unlock;
> + if (!IS_ERR(trap))
> + unlock_rename(c->workdir, c->destdir);
> + goto out;
I now see that this bit was missing from my proposed patch 1
variant, but with this in patch 1, this patch becomes trivial.
Thanks,
Amir.
> }
>
> err = ovl_copy_up_metadata(c, temp);
> @@ -832,9 +831,10 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c)
> goto cleanup;
>
> err = ovl_do_rename(ofs, c->workdir, temp, c->destdir, upper, 0);
> + unlock_rename(c->workdir, c->destdir);
> dput(upper);
> if (err)
> - goto cleanup;
> + goto cleanup_unlocked;
>
> inode = d_inode(c->dentry);
> if (c->metacopy_digest)
> @@ -848,17 +848,17 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c)
> ovl_inode_update(inode, temp);
> if (S_ISDIR(inode->i_mode))
> ovl_set_flag(OVL_WHITEOUTS, inode);
> -unlock:
> - unlock_rename(c->workdir, c->destdir);
> out:
> ovl_end_write(c->dentry);
>
> return err;
>
> cleanup:
> - ovl_cleanup(ofs, wdir, temp);
> + unlock_rename(c->workdir, c->destdir);
> +cleanup_unlocked:
> + ovl_cleanup_unlocked(ofs, c->workdir, temp);
> dput(temp);
> - goto unlock;
> + goto out;
>
> cleanup_need_write:
> ovl_start_write(c->dentry);
> --
> 2.49.0
>
