Commit a0d24b29 authored May 19, 2009 by Wei Yongjun Committed by J. Bruce Fields May 27, 2009

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'
(31dec253) 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>

parent 59a3759d

fs/nfsd/vfs.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -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;

Admin message