Fixes for gsyncd / geo-rep and FUSE listxattr

This patch fixes two problems with recent changes to
Geo-Replication

First:
------
Recent changes to geo-replication relies on Rsync to tranfer
extended attributes. Essentially Rsync would invoke a listxattr()
and then getxattr() the set reutrned by listxattr() and finally
transfer it to the remote slave. Xattrs like security.selinux would
create problems as they are not allowed to be set explicitly (unless
there's a rule that allows this). So, to make Rsync behave sanely we
filter out all "*.selinux*" xattrs from listxattr() (which is getxattr()
with ->name as NULL).

Second:
-------
Python's "if {..} else {..}" shortcut ".. and .. or .." was misused here.
This is a straightforward fix by interchanging last two variables (classes
in this case). Also fix a typo in sendmark_regular() definition.

Change-Id: I097b5f5d88a36c7eef5560a78d4332948a545942
BUG: 842330
Signed-off-by: Venky Shankar <vshankar@redhat.com>
Reviewed-on: http://review.gluster.com/3714
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 28 insertions, 4 deletions

diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index 2accb0a8..2948aae9 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -2830,6 +2830,24 @@ send_fuse_xattr (xlator_t *this, fuse_in_header_t *finh, const char *value,
         }
 }
 
+/* filter out xattrs that need not be visible on the
+ * mount point. this is _specifically_ for geo-rep
+ * as of now, to prevent Rsync from crying out loud
+ * when it tries to setxattr() for selinux xattrs
+ */
+static int
+fuse_filter_xattr(xlator_t *this, char *key)
+{
+        int need_filter = 0;
+        struct fuse_private *priv = this->private;
+
+        if ((priv->client_pid == GF_CLIENT_PID_GSYNCD)
+            && fnmatch ("*.selinux*", key, FNM_PERIOD) == 0)
+                need_filter = 1;
+
+        return need_filter;
+}
+
 
 static int
 fuse_xattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
@@ -2868,9 +2886,13 @@ fuse_xattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                         } /* if(value_data)...else */
                 } else {
                         /* if callback for listxattr */
+                        /* we need to invoke fuse_filter_xattr() twice. Once
+                         * while counting size and then while filling buffer
+                         */
                         trav = dict->members_list;
                         while (trav) {
-                                len += strlen (trav->key) + 1;
+                                if (!fuse_filter_xattr (this, trav->key))
+                                        len += strlen (trav->key) + 1;
                                 trav = trav->next;
                         } /* while(trav) */
                         value = alloca (len + 1);
@@ -2879,9 +2901,11 @@ fuse_xattr_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                         len = 0;
                         trav = dict->members_list;
                         while (trav) {
-                                strcpy (value + len, trav->key);
-                                value[len + strlen (trav->key)] = '\0';
-                                len += strlen (trav->key) + 1;
+                                if (!fuse_filter_xattr (this, trav->key)) {
+                                        strcpy (value + len, trav->key);
+                                        value[len + strlen (trav->key)] = '\0';
+                                        len += strlen (trav->key) + 1;
+                                }
                                 trav = trav->next;
                         } /* while(trav) */
                         send_fuse_xattr (this, finh, value, len, state->size);