No reason to prevent upper layer being a remote filesystem. Do the revalidation in that case, just as we already do for lower layers. This lets virtiofs be used as upper layer, which appears to be a real use case. Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx> --- fs/overlayfs/namei.c | 3 +-- fs/overlayfs/super.c | 8 ++++++-- fs/overlayfs/util.c | 2 ++ 3 files changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 76e61cc27822..0db23baf98e7 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -845,8 +845,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, if (err) goto out; - if (upperdentry && (upperdentry->d_flags & DCACHE_OP_REAL || - unlikely(ovl_dentry_remote(upperdentry)))) { + if (upperdentry && upperdentry->d_flags & DCACHE_OP_REAL) { dput(upperdentry); err = -EREMOTE; goto out; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 26d4153240a8..ed3a11db9039 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -135,9 +135,14 @@ static int ovl_dentry_revalidate_common(struct dentry *dentry, unsigned int flags, bool weak) { struct ovl_entry *oe = dentry->d_fsdata; + struct dentry *upper; unsigned int i; int ret = 1; + upper = ovl_dentry_upper(dentry); + if (upper) + ret = ovl_revalidate_real(upper, flags, weak); + for (i = 0; ret > 0 && i < oe->numlower; i++) { ret = ovl_revalidate_real(oe->lowerstack[i].dentry, flags, weak); @@ -747,8 +752,7 @@ static int ovl_mount_dir(const char *name, struct path *path) ovl_unescape(tmp); err = ovl_mount_dir_noesc(tmp, path); - if (!err && (ovl_dentry_remote(path->dentry) || - path->dentry->d_flags & DCACHE_OP_REAL)) { + if (!err && path->dentry->d_flags & DCACHE_OP_REAL) { pr_err("filesystem on '%s' not supported as upperdir\n", tmp); path_put_init(path); diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 3ad8fb291f7d..c793722739e1 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -96,6 +96,8 @@ void ovl_dentry_update_reval(struct dentry *dentry, struct dentry *upperdentry, struct ovl_entry *oe = OVL_E(dentry); unsigned int i, flags = 0; + if (upperdentry) + flags |= upperdentry->d_flags; for (i = 0; i < oe->numlower; i++) flags |= oe->lowerstack[i].dentry->d_flags; -- 2.21.1