ceph: remove xattr when null value is given to setxattr()

For the setxattr request, introduce a new flag CEPH_XATTR_REMOVE
to distinguish null value case from the zero-length value case.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>

1 files changed, 14 insertions, 2 deletions

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 28f9793b9167..231c02b16c0c 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -12,6 +12,9 @@
 #define XATTR_CEPH_PREFIX "ceph."
 #define XATTR_CEPH_PREFIX_LEN (sizeof (XATTR_CEPH_PREFIX) - 1)
 
+static int __remove_xattr(struct ceph_inode_info *ci,
+                          struct ceph_inode_xattr *xattr);
+
 /*
  * List of handlers for synthetic system.* attributes. Other
  * attributes are handled directly.
@@ -359,6 +362,12 @@ static int __set_xattr(struct ceph_inode_info *ci,
                         kfree(val);
                         return err;
                 }
+                if (update_xattr < 0) {
+                        if (xattr)
+                                __remove_xattr(ci, xattr);
+                        kfree(name);
+                        return 0;
+                }
         }
 
         if (!xattr) {
@@ -862,6 +871,9 @@ static int ceph_sync_setxattr(struct dentry *dentry, const char *name,
 
         dout("setxattr value=%.*s\n", (int)size, value);
 
+        if (!value)
+                flags |= CEPH_XATTR_REMOVE;
+
         /* do request */
         req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SETXATTR,
                                        USE_AUTH_MDS);
@@ -965,8 +977,8 @@ retry:
                 goto retry;
         }
 
-        err = __set_xattr(ci, newname, name_len, newval,
-                          val_len, flags, 1, &xattr);
+        err = __set_xattr(ci, newname, name_len, newval, val_len,
+                          flags, value ? 1 : -1, &xattr);
 
         if (!err) {
                 dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL);