On Mon, Jun 1, 2015 at 3:52 PM, David Howells <dhowells@xxxxxxxxxx> wrote: > In ovl_dentry_open(), ovl_drop_write() is called after vfs_open() - but is > this actually necessary? Can't we just drop it post-copyup? After all, > that's all we wanted the write lock for, right? Hmm, that could result in a race where remount r/o of upper fs comes in between copy-up and vfs_open() so copy-up succeeds but the actual open fails. It's harmless, though, and not very likely. So I guess your patch is OK. Thanks, Miklos > > David > --- > --- a/fs/overlayfs/inode.c > +++ b/fs/overlayfs/inode.c > @@ -356,16 +356,14 @@ static int ovl_dentry_open(struct dentry *dentry, struct inode *inode, > err = ovl_copy_up_last(dentry, NULL, true); > else > err = ovl_copy_up(dentry); > + ovl_drop_write(dentry); > if (err) > - goto out_drop_write; > + goto out; > > ovl_path_upper(dentry, &realpath); > } > > err = vfs_open(&realpath, d_backing_inode(realpath.dentry), file, cred); > -out_drop_write: > - if (want_write) > - ovl_drop_write(dentry); > out: > return err; > } -- 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
