upcall: pass dict with xattrs on xattr invalidation

In case of xattr invalidation, return a dict containing
the updated xattrs.

[ndevos: move chunks to change 12995 and only address the xattrs-dict here]

Change-Id: I8733f06a519a9a0f24be1bb4b2c38c9c9dce0ce2
BUG: 1211863
Signed-off-by: Poornima G <pgurusid@redhat.com>
Reviewed-on: http://review.gluster.org/12996
Smoke: Gluster Build System <jenkins@build.gluster.com>
CentOS-regression: Gluster Build System <jenkins@build.gluster.com>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Reviewed-by: soumya k <skoduri@redhat.com>
Tested-by: soumya k <skoduri@redhat.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/libglusterfs/src/common-utils.c b/libglusterfs/src/common-utils.c
index 45886dae3ee..a225c957f2e 100644
--- a/libglusterfs/src/common-utils.c
+++ b/libglusterfs/src/common-utils.c
@@ -36,6 +36,7 @@
 #endif
 #include <libgen.h>
 
+#include "glusterfs-acl.h"
 #include "compat-errno.h"
 #include "logging.h"
 #include "common-utils.h"
@@ -4449,3 +4450,36 @@ gf_zero_fill_stat (struct iatt *buf)
         buf->ia_nlink = 0;
         buf->ia_ctime = 0;
 }
+
+/* This function checks if the input key is a virtual or on disk xattr.
+ * Its not simple to identify a virtual xattr as there is no common
+ * format used to identify virtual xattrs. One way is to list each of the
+ * xattrs in different categories and compare the input against every xattr
+ * in the list, this is very inefficient as there are 100s of xattrs.
+ *
+ * Currently the only consumer of this function is upcall and md-cache,
+ * hence tailoring this function to their needs; in their case its allowed
+ * to consider disk xattrs as virtual xattrs, but not vice versa, i.e.
+ * virtual xattrs should not be considered as on disk xattr. Hence, being
+ * conservative, we consider anything that starts from user.*, security.*,
+ * system.* as on disk xattrs. trusted.* and glusterfs.* cannot be considered
+ * as virtual xattrs as there are some on disk xattrs which start from
+ * glusterfs.* and trusted.*
+ *
+ * Hence, this function could return an on disk xattr as virtual xattr but
+ * never a virtual xattr as on disk xattr.
+ */
+gf_boolean_t
+is_virtual_xattr (const char *k)
+{
+        gf_boolean_t ret = _gf_true;
+
+        if ((strncmp (k, "user.", strlen ("user.")) == 0) ||
+            (strncmp (k, "security.", strlen ("security.")) == 0) ||
+            (strncmp (k, "system.", strlen ("system.")) == 0) ||
+            (GF_POSIX_ACL_REQUEST (k))) {
+                ret = _gf_false;
+        }
+
+        return ret;
+}