From 0aeff37abada9f8c08d2b10481a43d3ae406c823 Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zyan@redhat.com>
Date: Wed, 17 Dec 2014 21:26:47 +0800
Subject: [PATCH] ceph: fix setting empty extended attribute

make sure 'value' is not null. otherwise __ceph_setxattr will remove
the extended attribute.

Signed-off-by: Yan, Zheng <zyan@redhat.com>
Reviewed-by: Sage Weil <sage@redhat.com>
---
 fs/ceph/xattr.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 678b0d2bbbc4..5a492caf34cb 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -854,7 +854,7 @@ static int ceph_sync_setxattr(struct dentry *dentry, const char *name,
 	struct ceph_pagelist *pagelist = NULL;
 	int err;
 
-	if (value) {
+	if (size > 0) {
 		/* copy value into pagelist */
 		pagelist = kmalloc(sizeof(*pagelist), GFP_NOFS);
 		if (!pagelist)
@@ -864,7 +864,7 @@ static int ceph_sync_setxattr(struct dentry *dentry, const char *name,
 		err = ceph_pagelist_append(pagelist, value, size);
 		if (err)
 			goto out;
-	} else {
+	} else if (!value) {
 		flags |= CEPH_XATTR_REMOVE;
 	}
 
@@ -1001,6 +1001,9 @@ int ceph_setxattr(struct dentry *dentry, const char *name,
 	if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
 		return generic_setxattr(dentry, name, value, size, flags);
 
+	if (size == 0)
+		value = "";  /* empty EA, do not remove */
+
 	return __ceph_setxattr(dentry, name, value, size, flags);
 }
 
-- 
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