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 <yjwei@xxxxxxxxxxxxxx>
---
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
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