kernelsu: Backport path_umount from 5.9 kernel
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
diff --git a/fs/namespace.c b/fs/namespace.c
index 172ab4a..0f666d4 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1685,6 +1685,39 @@ static inline bool may_mandlock(void)
}
#endif
+static int can_umount(const struct path *path, int flags)
+{
+ struct mount *mnt = real_mount(path->mnt);
+
+ if (flags & ~(MNT_FORCE | MNT_DETACH | MNT_EXPIRE | UMOUNT_NOFOLLOW))
+ return -EINVAL;
+ if (!may_mount())
+ return -EPERM;
+ if (path->dentry != path->mnt->mnt_root)
+ return -EINVAL;
+ if (!check_mnt(mnt))
+ return -EINVAL;
+ if (mnt->mnt.mnt_flags & MNT_LOCKED) /* Check optimistically */
+ return -EINVAL;
+ if (flags & MNT_FORCE && !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ return 0;
+}
+
+int path_umount(struct path *path, int flags)
+{
+ struct mount *mnt = real_mount(path->mnt);
+ int ret;
+
+ ret = can_umount(path, flags);
+ if (!ret)
+ ret = do_umount(mnt, flags);
+
+ /* we mustn't call path_put() as that would clear mnt_expiry_mark */
+ dput(path->dentry);
+ mntput_no_expire(mnt);
+ return ret;
+}
/*
* Now umount can handle mount points as well as block devices.
* This is important for filesystems which use unnamed block devices.