From 2b4db79618ade14a9566455cbbea339f74674789 Mon Sep 17 00:00:00 2001 From: Amir Goldstein <amir73il@gmail.com> Date: Thu, 18 May 2017 15:29:33 +0300 Subject: [PATCH] tmpfs: generate random sb->s_uuid This is used by overlayfs to encode intrasystem unique file handles. Suggested-by: Miklos Szeredi <mszeredi@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> --- mm/shmem.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/shmem.c b/mm/shmem.c index e67d6ba4e98e7..391f2dcca7278 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -75,6 +75,7 @@ static struct vfsmount *shm_mnt; #include <uapi/linux/memfd.h> #include <linux/userfaultfd_k.h> #include <linux/rmap.h> +#include <linux/uuid.h> #include <linux/uaccess.h> #include <asm/pgtable.h> @@ -3761,6 +3762,7 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent) #ifdef CONFIG_TMPFS_POSIX_ACL sb->s_flags |= MS_POSIXACL; #endif + uuid_gen(&sb->s_uuid); inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE); if (!inode) -- 2.30.2