On Tue, Mar 6, 2018 at 10:54 PM, Vivek Goyal <vgoyal@xxxxxxxxxx> wrote: > When a metacopy file is no longer a metacopy and data has been copied up, > remove REDIRECT xattr. Its not needed anymore. > > Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx> > --- > fs/overlayfs/copy_up.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c > index 0c8d2755bd25..704febd2e2fa 100644 > --- a/fs/overlayfs/copy_up.c > +++ b/fs/overlayfs/copy_up.c > @@ -775,6 +775,15 @@ static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) > if (err) > return err; > > + /* > + * A metacopy files does not need redirect xattr once data has > + * been copied up. > + */ > + err = vfs_removexattr(upperpath.dentry, OVL_XATTR_REDIRECT); > + if (err && err != -ENODATA && err != -EOPNOTSUPP) > + return err; > + > + err = 0; > ovl_set_upperdata(d_inode(c->dentry)); > return err; By intuition, I would say that removing redirect should be done after setting upperdata flag. Not sure if it really matters in real life. Maybe when racing a lookup of a metacopy hardlink and copy up data of an upper alias? Also, it would make sense to also ovl_dentry_set_redirect(c->dentry, NULL) probably use a helper ovl_clear_redirect() for the locking. But that highlights a serious problem with current patches - Access to OVL_I(inode)->redirect is protected with parent mutex in ovl_lookup() and additionally with dentry->d_lock in ovl_rename() That is sufficient for directories which can only have a single dentry alias to an inode but not at all sufficient for non-directories. Thanks, Amir. -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
