nfsd: make sure to balance get/put_write_access

[Linux-MTD Mailing List]

Gitweb:     http://git.infradead.org/?p=mtd-2.6.git;a=commit;h=987da4791052fa298b7cfcde4dea9f6f2bbc786b
Commit:     987da4791052fa298b7cfcde4dea9f6f2bbc786b
Parent:     818e5a22e907fbae75e9c1fd78233baec9fa64b6
Author:     Christoph Hellwig <hch at infradead.org>
AuthorDate: Mon Nov 18 05:07:47 2013 -0800
Committer:  J. Bruce Fields <bfields at redhat.com>
CommitDate: Mon Nov 18 12:06:48 2013 -0500

    nfsd: make sure to balance get/put_write_access
    
    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>
    Cc: stable at vger.kernel.org
    Signed-off-by: J. Bruce Fields <bfields at redhat.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 c3f57cf..7eea63c 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, NULL);
-		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, NULL);
+	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) || \