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

[Kamal Mostafa]

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-3.8.y-queue branch of the 3.8.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-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.14.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From d40399557ae140e026b1c976839a200150bd6aa9 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>
[ kamal: backport to 3.8 (notify_change args) ]
Signed-off-by: Kamal Mostafa <kamal 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 4fc2843..59f1e77 100644
--- 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) || \
--
1.8.3.2