From 0956254a2d5b9e2141385514553aeef694dfe3b5 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Mon, 8 Aug 2016 15:08:49 +0200 Subject: [PATCH] ovl: don't copy up opaqueness When a copy up of a directory occurs which has the opaque xattr set, the xattr remains in the upper directory. The immediate behavior with overlayfs is that the upper directory is not treated as opaque, however after a remount the opaque flag is used and upper directory is treated as opaque. This causes files created in the lower layer to be hidden when using multiple lower directories. Fix by not copying up the opaque flag. To reproduce: ----8<---------8<---------8<---------8<---------8<---------8<---- mkdir -p l/d/s u v w mnt mount -t overlay overlay -olowerdir=l,upperdir=u,workdir=w mnt rm -rf mnt/d/ mkdir -p mnt/d/n umount mnt mount -t overlay overlay -olowerdir=u:l,upperdir=v,workdir=w mnt touch mnt/d/foo umount mnt mount -t overlay overlay -olowerdir=u:l,upperdir=v,workdir=w mnt ls mnt/d ----8<---------8<---------8<---------8<---------8<---------8<---- output should be: "foo n" Reported-by: Derek McGowan Link: https://bugzilla.kernel.org/show_bug.cgi?id=151291 Signed-off-by: Miklos Szeredi Cc: --- fs/overlayfs/copy_up.c | 2 ++ fs/overlayfs/inode.c | 2 +- fs/overlayfs/overlayfs.h | 1 + 3 files changed, 4 insertions(+), 1 deletion(-) --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -48,6 +48,8 @@ int ovl_copy_xattr(struct dentry *old, s } for (name = buf; name < (buf + list_size); name += strlen(name) + 1) { + if (ovl_is_private_xattr(name)) + continue; retry: size = vfs_getxattr(old, name, value, value_size); if (size == -ERANGE) --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -219,7 +219,7 @@ static int ovl_readlink(struct dentry *d } -static bool ovl_is_private_xattr(const char *name) +bool ovl_is_private_xattr(const char *name) { return strncmp(name, OVL_XATTR_PRE_NAME, OVL_XATTR_PRE_LEN) == 0; } --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -175,6 +175,7 @@ ssize_t ovl_getxattr(struct dentry *dent ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); int ovl_removexattr(struct dentry *dentry, const char *name); struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags); +bool ovl_is_private_xattr(const char *name); struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, struct ovl_entry *oe);