1 files changed, 58 insertions, 23 deletions

diff --git a/fs/namei.c b/fs/namei.c
index 8510ff53f12e..84a0e0b0111c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1665,27 +1665,20 @@ static struct dentry *lookup_dcache(const struct qstr *name,
 	return dentry;
 }
 
-/*
- * Parent directory has inode locked exclusive.  This is one
- * and only case when ->lookup() gets called on non in-lookup
- * dentries - as the matter of fact, this only gets called
- * when directory is guaranteed to have no in-lookup children
- * at all.
- * Will return -ENOENT if name isn't found and LOOKUP_CREATE wasn't passed.
- * Will return -EEXIST if name is found and LOOKUP_EXCL was passed.
- */
-struct dentry *lookup_one_qstr_excl(const struct qstr *name,
-				    struct dentry *base,
-				    unsigned int flags)
+static struct dentry *lookup_one_qstr_excl_raw(const struct qstr *name,
+					       struct dentry *base,
+					       unsigned int flags)
 {
-	struct dentry *dentry = lookup_dcache(name, base, flags);
+	struct dentry *dentry;
 	struct dentry *old;
-	struct inode *dir = base->d_inode;
+	struct inode *dir;
 
+	dentry = lookup_dcache(name, base, flags);
 	if (dentry)
-		goto found;
+		return dentry;
 
 	/* Don't create child dentry for a dead directory. */
+	dir = base->d_inode;
 	if (unlikely(IS_DEADDIR(dir)))
 		return ERR_PTR(-ENOENT);
 
@@ -1698,7 +1691,24 @@ struct dentry *lookup_one_qstr_excl(const struct qstr *name,
 		dput(dentry);
 		dentry = old;
 	}
-found:
+	return dentry;
+}
+
+/*
+ * Parent directory has inode locked exclusive.  This is one
+ * and only case when ->lookup() gets called on non in-lookup
+ * dentries - as the matter of fact, this only gets called
+ * when directory is guaranteed to have no in-lookup children
+ * at all.
+ * Will return -ENOENT if name isn't found and LOOKUP_CREATE wasn't passed.
+ * Will return -EEXIST if name is found and LOOKUP_EXCL was passed.
+ */
+struct dentry *lookup_one_qstr_excl(const struct qstr *name,
+				    struct dentry *base, unsigned int flags)
+{
+	struct dentry *dentry;
+
+	dentry = lookup_one_qstr_excl_raw(name, base, flags);
 	if (IS_ERR(dentry))
 		return dentry;
 	if (d_is_negative(dentry) && !(flags & LOOKUP_CREATE)) {
@@ -2742,23 +2752,48 @@ static int filename_parentat(int dfd, struct filename *name,
 /* does lookup, returns the object with parent locked */
 static struct dentry *__kern_path_locked(int dfd, struct filename *name, struct path *path)
 {
+	struct path parent_path __free(path_put) = {};
 	struct dentry *d;
 	struct qstr last;
 	int type, error;
 
-	error = filename_parentat(dfd, name, 0, path, &last, &type);
+	error = filename_parentat(dfd, name, 0, &parent_path, &last, &type);
 	if (error)
 		return ERR_PTR(error);
-	if (unlikely(type != LAST_NORM)) {
-		path_put(path);
+	if (unlikely(type != LAST_NORM))
 		return ERR_PTR(-EINVAL);
+	inode_lock_nested(parent_path.dentry->d_inode, I_MUTEX_PARENT);
+	d = lookup_one_qstr_excl(&last, parent_path.dentry, 0);
+	if (IS_ERR(d)) {
+		inode_unlock(parent_path.dentry->d_inode);
+		return d;
 	}
-	inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT);
-	d = lookup_one_qstr_excl(&last, path->dentry, 0);
+	path->dentry = no_free_ptr(parent_path.dentry);
+	path->mnt = no_free_ptr(parent_path.mnt);
+	return d;
+}
+
+struct dentry *kern_path_locked_negative(const char *name, struct path *path)
+{
+	struct path parent_path __free(path_put) = {};
+	struct filename *filename __free(putname) = getname_kernel(name);
+	struct dentry *d;
+	struct qstr last;
+	int type, error;
+
+	error = filename_parentat(AT_FDCWD, filename, 0, &parent_path, &last, &type);
+	if (error)
+		return ERR_PTR(error);
+	if (unlikely(type != LAST_NORM))
+		return ERR_PTR(-EINVAL);
+	inode_lock_nested(parent_path.dentry->d_inode, I_MUTEX_PARENT);
+	d = lookup_one_qstr_excl_raw(&last, parent_path.dentry, 0);
 	if (IS_ERR(d)) {
-		inode_unlock(path->dentry->d_inode);
-		path_put(path);
+		inode_unlock(parent_path.dentry->d_inode);
+		return d;
 	}
+	path->dentry = no_free_ptr(parent_path.dentry);
+	path->mnt = no_free_ptr(parent_path.mnt);
 	return d;
 }