From: Wei Yongjun Subject: Re: [PATCH] nfsd: fix hung up of nfs client while sync write data to nfs server Date: Thu, 28 May 2009 20:45:50 +0800 Message-ID: <4A1E877E.8080007@cn.fujitsu.com> References: <4A122F83.4020606@cn.fujitsu.com> <20090527224845.GE29565@fieldses.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Cc: linux-nfs@vger.kernel.org, nfsv4@linux-nfs.org To: "J. Bruce Fields" Return-path: In-Reply-To: <20090527224845.GE29565@fieldses.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfsv4-bounces@linux-nfs.org Errors-To: nfsv4-bounces@linux-nfs.org List-ID: J. Bruce Fields wrote: > On Tue, May 19, 2009 at 12:03:15PM +0800, Wei Yongjun wrote: > >> Commit 'Short write in nfsd becomes a full write to the client' >> (31dec2538e45e9fff2007ea1f4c6bae9f78db724) broken the sync write. >> With the following commands to reproduce: >> >> $ mount -t nfs -o sync 192.168.0.21:/nfsroot /mnt >> $ cd /mnt >> $ echo aaaa > temp.txt >> >> Then nfs client is hung up. >> >> In SYNC mode the server alaways return the write count 0 to the >> client. This is because the value of host_err in nfsd_vfs_write() >> will be overwrite in SYNC mode by 'host_err=nfsd_sync(file);', >> and then we return host_err(which is now 0) as write count. >> > > Undoubtedly correct--applied, thanks! > > (But it bugs me that I can't reproduce this: I see the client (mounting > with -osync, as above) send an unstable write followed by an immediate > commit, instead of a stable write. This is with 2.6.29.30-rc7 on client > and server.) > I used 2.6.29.30-rc7 on server and RHEL5GA as client.^_^ > --b. > > >> This patch fixed the problem. >> >> Signed-off-by: Wei Yongjun >> --- >> fs/nfsd/vfs.c | 6 +++--- >> 1 files changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c >> index 6c68ffd..b660435 100644 >> --- a/fs/nfsd/vfs.c >> +++ b/fs/nfsd/vfs.c >> @@ -1015,6 +1015,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, >> host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset); >> set_fs(oldfs); >> if (host_err >= 0) { >> + *cnt = host_err; >> nfsdstats.io_write += host_err; >> fsnotify_modify(file->f_path.dentry); >> } >> @@ -1060,10 +1061,9 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, >> } >> >> dprintk("nfsd: write complete host_err=%d\n", host_err); >> - if (host_err >= 0) { >> + if (host_err >= 0) >> err = 0; >> - *cnt = host_err; >> - } else >> + else >> err = nfserrno(host_err); >> out: >> return err; >> -- >> 1.5.3.8 >> >> >> >> > > >