From 4f622bd9f3e5dd1e882ee8f4194ea1d95dcf752f Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 16 Jul 2025 10:44:17 +1000 Subject: [PATCH] ovl: narrow locking in ovl_clear_empty() 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. Reviewed-by: Amir Goldstein Signed-off-by: NeilBrown Link: https://lore.kernel.org/20250716004725.1206467-7-neil@brown.name Signed-off-by: Christian Brauner --- fs/overlayfs/dir.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 1a146a71993a6..540b67f5cdf5d 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -353,7 +353,6 @@ 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 path upperpath; struct dentry *upper; @@ -399,12 +398,12 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry, goto out_cleanup; err = ovl_do_rename(ofs, workdir, opaquedir, upperdir, upper, RENAME_EXCHANGE); + unlock_rename(workdir, upperdir); if (err) - goto out_cleanup; + goto out_cleanup_unlocked; 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); -- 2.47.2