The patch below does not apply to the 4.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 9f99e50d460ac7fd5f6c9b97aad0088c28c8656d Mon Sep 17 00:00:00 2001

From: Amir Goldstein amir73il@gmail.com Date: Wed, 11 Apr 2018 20:09:29 +0300 Subject: [PATCH] ovl: set lower layer st_dev only if setting lower st_ino

For broken hardlinks, we do not return lower st_ino, so we should also not return lower pseudo st_dev.

Fixes: a0c5ad307ac0 ("ovl: relax same fs constraint for constant st_ino") Cc: stable@vger.kernel.org #v4.15 Signed-off-by: Amir Goldstein amir73il@gmail.com Signed-off-by: Miklos Szeredi mszeredi@redhat.com

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 4689716f23d8..1d75b2e96c96 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -118,13 +118,10 @@ int ovl_getattr(const struct path *path, struct kstat *stat, */ if (ovl_test_flag(OVL_INDEX, d_inode(dentry)) || (!ovl_verify_lower(dentry->d_sb) && - (is_dir || lowerstat.nlink == 1))) + (is_dir || lowerstat.nlink == 1))) { stat->ino = lowerstat.ino; - - if (samefs) - WARN_ON_ONCE(stat->dev != lowerstat.dev); - else stat->dev = ovl_get_pseudo_dev(dentry); + } } if (samefs) { /*