From mboxrd@z Thu Jan 1 00:00:00 1970 From: Trond Myklebust Subject: Re: [PATCH][Resend] coredump: call vfs_getattr() to get inode attributes Date: Tue, 28 Jun 2011 19:26:01 -0400 Message-ID: <1309303561.27467.9.camel@lade.trondhjem.org> References: <87tyb9r6wh.fsf@free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Cc: Alexander Viro , linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Arnaud Giersch Return-path: In-Reply-To: <87tyb9r6wh.fsf-GANU6spQydw@public.gmane.org> Sender: linux-nfs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org On Tue, 2011-06-28 at 23:19 +0200, Arnaud Giersch wrote: > From: Arnaud Giersch > > In do_coredump(), call vfs_getattr() to get inode attributes, and do not > get them directly from the fields of the inode struct. > > Without this patch, when dumping core on an NFSv4 mount, and the i_uid > field is not correctly filled at open time, the uid check fails, and an > empty core dump is produced. > > This apparently only happens when there was no "core" file before the > dump. If a "core" file owned by the current user is already present, it > is correctly filled. > > The reason is that decode_attr_owner() in fs/nfs/nfs4xdr.c is not > allowed to call the idmapper when it receives may_sleep = 0 (see commit > 80e52aced138bb41b045a8595a87510f27d8d8c5, and some explanations in > http://article.gmane.org/gmane.linux.nfs/33391). > > Signed-off-by: Arnaud Giersch This wants to be fixed in the NFS layer, not the VFS. What we should do is the following: 1. Save the string versions of user@domain/group@domain in the struct nfs4_opendata so that we can resolve them from the process context in _nfs4_proc_open(). 2. Fix nfs4_atomic_open() so that it revalidates any inode that has the NFS_INO_INVALID_ATTR flag set. Cheers Trond -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust-HgOvQuBEEgTQT0dZR+AlfA@public.gmane.org www.netapp.com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html