From 214b2dab8107b130deeabec6db8d18439a64e738 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 [ Upstream commit 0956254a2d5b9e2141385514553aeef694dfe3b5 ] 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: Signed-off-by: Sasha Levin --- fs/overlayfs/copy_up.c | 2 ++ fs/overlayfs/inode.c | 3 +-- fs/overlayfs/overlayfs.h | 1 + 3 files changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 758012b..4d8aa74 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -48,6 +48,8 @@ int ovl_copy_xattr(struct dentry *old, struct dentry *new) } 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) diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 97fd657..69d7151 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -221,8 +221,7 @@ static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz) return realinode->i_op->readlink(realpath.dentry, buf, bufsiz); } - -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; } diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 98354091..32b077b 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -174,6 +174,7 @@ ssize_t ovl_getxattr(struct dentry *dentry, const char *name, 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); -- 2.7.4