From: "J. Bruce Fields" Subject: Re: [PATCH 1/1] nfsd(v2/v3): fix the failure of creation from HPUX client Date: Sun, 4 Jan 2009 16:38:01 -0500 Message-ID: <20090104213801.GA4148@fieldses.org> References: <200812240537.mBO5blpr005502@acsinet13.oracle.com> <49601688.2040301@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-nfs@vger.kernel.org To: wengang wang Return-path: Received: from mail.fieldses.org ([141.211.133.115]:48154 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750706AbZADViF (ORCPT ); Sun, 4 Jan 2009 16:38:05 -0500 In-Reply-To: <49601688.2040301@oracle.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Sun, Jan 04, 2009 at 09:53:12AM +0800, wengang wang wrote: > Hi, > Finally, how about this patch? > for this problem, the solution is either to fix HPUX or to fix linux. > are we going to fix linux? > > any comment is appreciated. On my list, sorry, I just haven't gotten to it--bug me again if I haven't dealt with it by the end of the week.--b. > > thanks, > wengang. > > wengang wang wrote: >> 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 >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html