[3.11.y.z extended stable] Patch "nfsd: make sure to balance get/put_write_access" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    nfsd: make sure to balance get/put_write_access

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From c21bd80fe9bdcb3585790bc98d0206c0dd7a451c Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch at infradead.org>
Date: Mon, 18 Nov 2013 05:07:47 -0800
Subject: 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 at lst.de>
Signed-off-by: J. Bruce Fields <bfields at redhat.com>
[ luis: backported to 3.11:
  - dropped 3rd parameter to notify_change() ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/nfsd/vfs.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 2e27c0c..72cb28e 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -444,27 +444,28 @@ 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) || \
--
1.8.3.2