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(-) diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 54e5d6681786..43fdc2765aea 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -80,6 +80,8 @@ 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 1b885c156028..024352f1d405 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -191,7 +191,7 @@ static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz) return err; } -static bool ovl_is_private_xattr(const char *name) +bool ovl_is_private_xattr(const char *name) { #define OVL_XATTR_PRE_NAME OVL_XATTR_PREFIX "." return strncmp(name, OVL_XATTR_PRE_NAME, diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index e4f5c9536bfe..34839bd2b6b8 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -193,6 +193,7 @@ int ovl_removexattr(struct dentry *dentry, const char *name); struct posix_acl *ovl_get_acl(struct inode *inode, int type); int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags); int ovl_update_time(struct inode *inode, struct timespec *ts, int flags); +bool ovl_is_private_xattr(const char *name); struct inode *ovl_new_inode(struct super_block *sb, umode_t mode); struct inode *ovl_get_inode(struct super_block *sb, struct inode *realinode); -- 2.20.1