Messages in this thread Patch in this message | | | Date | Wed, 16 Sep 2009 15:13:30 -0700 | From | Greg KH <> | Subject | [patch 10/10] nfsd: fix hung up of nfs client while sync write data to nfs server |
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2.6.27-stable review patch. If anyone has any objections, please let us know.
------------------ From: Wei Yongjun <yjwei@cn.fujitsu.com>
commit a0d24b295aed7a9daf4ca36bd4784e4d40f82303 upstream.
nfsd: fix hung up of nfs client while sync write data to nfs server
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.
This patch fixed the problem.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu> Cc: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- fs/nfsd/vfs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1003,6 +1003,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s 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); } @@ -1048,10 +1049,9 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s } 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;
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