[PATCH 5.4 255/309] nfsd: Return the correct number of bytes written to the file

[Greg Kroah-Hartman]

From: Trond Myklebust <trondmy@xxxxxxxxx>

commit 09a80f2aef06b7c86143f5c14efd3485e0d2c139 upstream.

We must allow for the fact that iov_iter_write() could have returned
a short write (e.g. if there was an ENOSPC issue).

Fixes: d890be159a71 "nfsd: Add I/O trace points in the NFSv4 write path"
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/nfsd/vfs.c |    1 +
 1 file changed, 1 insertion(+)

--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -975,6 +975,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, s
 	host_err = vfs_iter_write(file, &iter, &pos, flags);
 	if (host_err < 0)
 		goto out_nfserr;
+	*cnt = host_err;
 	nfsdstats.io_write += *cnt;
 	fsnotify_modify(file);