From 76342c9eb8e28f2e421ec7fb72bb2b9aa4d7dd77 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 16 Jul 2025 10:44:19 +1000 Subject: [PATCH] ovl: simplify gotos in ovl_rename() Rather than having three separate goto label: out_unlock, out_dput_old, and out_dput, make use of that fact that dput() happily accepts a NULL pointer to reduce this to just one goto label: out_unlock. olddentry and newdentry are initialised to NULL and only set once a value dentry is found. They are then dput() late in the function. Suggested-by: Amir Goldstein Signed-off-by: NeilBrown Link: https://lore.kernel.org/20250716004725.1206467-9-neil@brown.name Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner --- fs/overlayfs/dir.c | 54 +++++++++++++++++++++++----------------------- 1 file changed, 27 insertions(+), 27 deletions(-) diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 7c92ffb6e3124..138dd85d22423 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -1082,9 +1082,9 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, int err; struct dentry *old_upperdir; struct dentry *new_upperdir; - struct dentry *olddentry; - struct dentry *newdentry; - struct dentry *trap; + struct dentry *olddentry = NULL; + struct dentry *newdentry = NULL; + struct dentry *trap, *de; bool old_opaque; bool new_opaque; bool cleanup_whiteout = false; @@ -1197,21 +1197,23 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, goto out_revert_creds; } - olddentry = ovl_lookup_upper(ofs, old->d_name.name, old_upperdir, - old->d_name.len); - err = PTR_ERR(olddentry); - if (IS_ERR(olddentry)) + de = ovl_lookup_upper(ofs, old->d_name.name, old_upperdir, + old->d_name.len); + err = PTR_ERR(de); + if (IS_ERR(de)) goto out_unlock; + olddentry = de; err = -ESTALE; if (!ovl_matches_upper(old, olddentry)) - goto out_dput_old; + goto out_unlock; - newdentry = ovl_lookup_upper(ofs, new->d_name.name, new_upperdir, - new->d_name.len); - err = PTR_ERR(newdentry); - if (IS_ERR(newdentry)) - goto out_dput_old; + de = ovl_lookup_upper(ofs, new->d_name.name, new_upperdir, + new->d_name.len); + err = PTR_ERR(de); + if (IS_ERR(de)) + goto out_unlock; + newdentry = de; old_opaque = ovl_dentry_is_opaque(old); new_opaque = ovl_dentry_is_opaque(new); @@ -1220,28 +1222,28 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, if (d_inode(new) && ovl_dentry_upper(new)) { if (opaquedir) { if (newdentry != opaquedir) - goto out_dput; + goto out_unlock; } else { if (!ovl_matches_upper(new, newdentry)) - goto out_dput; + goto out_unlock; } } else { if (!d_is_negative(newdentry)) { if (!new_opaque || !ovl_upper_is_whiteout(ofs, newdentry)) - goto out_dput; + goto out_unlock; } else { if (flags & RENAME_EXCHANGE) - goto out_dput; + goto out_unlock; } } if (olddentry == trap) - goto out_dput; + goto out_unlock; if (newdentry == trap) - goto out_dput; + goto out_unlock; if (olddentry->d_inode == newdentry->d_inode) - goto out_dput; + goto out_unlock; err = 0; if (ovl_type_merge_or_lower(old)) @@ -1249,7 +1251,7 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, else if (is_dir && !old_opaque && ovl_type_merge(new->d_parent)) err = ovl_set_opaque_xerr(old, olddentry, -EXDEV); if (err) - goto out_dput; + goto out_unlock; if (!overwrite && ovl_type_merge_or_lower(new)) err = ovl_set_redirect(new, samedir); @@ -1257,12 +1259,12 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, ovl_type_merge(old->d_parent)) err = ovl_set_opaque_xerr(new, newdentry, -EXDEV); if (err) - goto out_dput; + goto out_unlock; err = ovl_do_rename(ofs, old_upperdir, olddentry, new_upperdir, newdentry, flags); if (err) - goto out_dput; + goto out_unlock; if (cleanup_whiteout) ovl_cleanup(ofs, old_upperdir->d_inode, newdentry); @@ -1284,10 +1286,6 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir, if (d_inode(new) && ovl_dentry_upper(new)) ovl_copyattr(d_inode(new)); -out_dput: - dput(newdentry); -out_dput_old: - dput(olddentry); out_unlock: unlock_rename(new_upperdir, old_upperdir); out_revert_creds: @@ -1297,6 +1295,8 @@ out_revert_creds: else ovl_drop_write(old); out: + dput(newdentry); + dput(olddentry); dput(opaquedir); ovl_cache_free(&list); return err; -- 2.47.2