From 399c109d357a7e217cf7ef551e7e234439c68c15 Mon Sep 17 00:00:00 2001 From: Chengguang Xu Date: Wed, 22 Apr 2020 12:28:43 +0800 Subject: [PATCH] ovl: sync dirty data when remounting to ro mode sync_filesystem() does not sync dirty data for readonly filesystem during umount, so before changing to readonly filesystem we should sync dirty data for data integrity. Signed-off-by: Chengguang Xu Signed-off-by: Miklos Szeredi --- fs/overlayfs/super.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index a88a7badf444..60dfb27bc12b 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -365,11 +365,20 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry) static int ovl_remount(struct super_block *sb, int *flags, char *data) { struct ovl_fs *ofs = sb->s_fs_info; + struct super_block *upper_sb; + int ret = 0; if (!(*flags & SB_RDONLY) && ovl_force_readonly(ofs)) return -EROFS; - return 0; + if (*flags & SB_RDONLY && !sb_rdonly(sb)) { + upper_sb = ofs->upper_mnt->mnt_sb; + down_read(&upper_sb->s_umount); + ret = sync_filesystem(upper_sb); + up_read(&upper_sb->s_umount); + } + + return ret; } static const struct super_operations ovl_super_operations = { -- GitLab