nfsd: make sure to balance get/put_write_access

commit 987da4791052fa298b7cfcde4dea9f6f2bbc786b upstream.

Use a straight goto error label style in nfsd_setattr to make sure
we always do the put_write_access call after we got it earlier.

Note that the we have been failing to do that in the case
nfsd_break_lease() returns an error, a bug introduced into 2.6.38 with
6a76bebefe15d9a08864f824d7f8d5beaf37c997 "nfsd4: break lease on nfsd
setattr".

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
[bwh: Backported to 3.2: notify_change() takes only 2 arguments]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 307f37a..6a66fc0 100644 (file)
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -443,27 +443,28 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
 
        iap->ia_valid |= ATTR_CTIME;
 
-       err = nfserr_notsync;
-       if (!check_guard || guardtime == inode->i_ctime.tv_sec) {
-               host_err = nfsd_break_lease(inode);
-               if (host_err)
-                       goto out_nfserr;
-               fh_lock(fhp);
-
-               host_err = notify_change(dentry, iap);
-               err = nfserrno(host_err);
-               fh_unlock(fhp);
+       if (check_guard && guardtime != inode->i_ctime.tv_sec) {
+               err = nfserr_notsync;
+               goto out_put_write_access;
        }
+
+       host_err = nfsd_break_lease(inode);
+       if (host_err)
+               goto out_put_write_access_nfserror;
+
+       fh_lock(fhp);
+       host_err = notify_change(dentry, iap);
+       fh_unlock(fhp);
+
+out_put_write_access_nfserror:
+       err = nfserrno(host_err);
+out_put_write_access:
        if (size_change)
                put_write_access(inode);
        if (!err)
                commit_metadata(fhp);
 out:
        return err;
-
-out_nfserr:
-       err = nfserrno(host_err);
-       goto out;
 }
 
 #if defined(CONFIG_NFSD_V2_ACL) || \