From: wengang wang Subject: [PATCH 1/1] nfsd(v2/v3): fix the failure of creation from HPUX client Date: Wed, 24 Dec 2008 13:36:16 +0800 Message-ID: <200812240537.mBO5blpr005502@acsinet13.oracle.com> To: linux-nfs@vger.kernel.org Return-path: Received: from rcsinet14.oracle.com ([148.87.113.126]:36944 "EHLO rgminet14.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751146AbYLXFib (ORCPT ); Wed, 24 Dec 2008 00:38:31 -0500 Received: from rgminet13.oracle.com (rcsinet13.oracle.com [148.87.113.125]) by rgminet14.oracle.com (Switch-3.3.1/Switch-3.3.1) with ESMTP id mBO5eGJh021275 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 24 Dec 2008 05:40:17 GMT Received: from acsinet13.oracle.com (acsinet13.oracle.com [141.146.126.235]) by rgminet13.oracle.com (Switch-3.3.1/Switch-3.3.1) with ESMTP id mBO5brrb024001 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 24 Dec 2008 05:37:55 GMT Received: from acsmt707.oracle.com (acsmt707.oracle.com [141.146.40.85]) by acsinet13.oracle.com (Switch-3.3.1/Switch-3.3.1) with ESMTP id mBO5blpr005502 for ; Wed, 24 Dec 2008 05:37:48 GMT Sender: linux-nfs-owner@vger.kernel.org List-ID: please ignore the email sent from wwg@oracle.com and reply to this post if you will. thanks. sometimes HPUX nfs client sends a create request to linux nfs server(v2/v3). the dump of the request is like: obj_attributes mode: value follows set_it: value follows (1) mode: 00 uid: no value set_it: no value (0) gid: value follows set_it: value follows (1) gid: 8030 size: value follows set_it: value follows (1) size: 0 atime: don't change set_it: don't change (0) mtime: don't change set_it: don't change (0) note that mode is 00(havs no rwx privilege even for the owner) and it requires to set size to 0. as current nfsd(v2/v3) implementation, the server does mainly 2 steps: 1) creates the file in mode specified by calling vfs_create(). 2) sets attributes for the file by calling nfsd_setattr(). at step 2), it finally calls file system specific setattr() function which may fails when checking permission because changing size needs WRITE privilege but it has no since mode is 000. for this case, a new file created, we may simply ignore the request of setting size to 0. so that the WRITE privilege is not needed and finally success. the patch is based on 2.6.27.10. Signed-off-by: Wengang Wang -- vfs.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff -up ./fs/nfsd/vfs.c.orig ./fs/nfsd/vfs.c --- ./fs/nfsd/vfs.c.orig 2008-12-23 14:11:14.000000000 +0800 +++ ./fs/nfsd/vfs.c 2008-12-23 14:54:16.000000000 +0800 @@ -1268,6 +1268,16 @@ nfsd_create(struct svc_rqst *rqstp, stru switch (type) { case S_IFREG: host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); + /* HPUX client sometimes creates a file in mode 000, and set + * size to 0. setting size to 0 may fail for some spcific + * file systems by the permission checking which requires + * WRITE privilege but the mode is 000. + * we ignore setting size to 0 for the creation, since it's + * just 0 after created. + * */ + if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) + iap->ia_valid &= ~ATTR_SIZE; + break; case S_IFDIR: host_err = vfs_mkdir(dirp, dchild, iap->ia_mode); @@ -1421,6 +1431,16 @@ nfsd_create_v3(struct svc_rqst *rqstp, s /* setattr will sync the child (or not) */ } + /* HPUX client sometimes creates a file in mode 000, and set size to 0. + * setting size to 0 may fail for some spcific file systems by the + * permission checking which requires WRITE privilege but the mode is + * 000. + * we ignore setting size to 0 for the creation, since it's just 0 + * after created. + * */ + if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) + iap->ia_valid &= ~ATTR_SIZE; + if (createmode == NFS3_CREATE_EXCLUSIVE) { /* Cram the verifier into atime/mtime */ iap->ia_valid = ATTR_MTIME|ATTR_ATIME