mount/fuse: expose 'glusterfs.gfid*' virtual xattr key

currently two keys are exposed:

'glusterfs.gfid' : output is 16byte binary gfid
'glusterfs.gfid.string' : output is 36 byte canonical format of gfid

e.g.
[root@supernova glusterfs]# getfattr -n glusterfs.gfid -e hex f0
glusterfs.gfid=0x68305acb73e541719804fcf36a4857e8

[root@supernova glusterfs]# getfattr -n glusterfs.gfid.string f0
glusterfs.gfid.string="68305acb-73e5-4171-9804-fcf36a4857e8"

early consumers for this key would be geo-replication
(as it has being designed to do namespace operations on
gfid from the mount point, thereby needing the GFID for
entry operations on the slave).

Change-Id: I10b23dbd11628566ad6924334253f5d85d01a519
BUG: 847839
Original Author: Venky Shankar <vshankar@redhat.com>
Signed-off-by: Avra Sengupta <asengupt@redhat.com>
Reviewed-on: http://review.gluster.org/5129
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c
index 1b97d4302c4..5b6fed9fe76 100644
--- a/xlators/mount/fuse/src/fuse-bridge.c
+++ b/xlators/mount/fuse/src/fuse-bridge.c
@@ -11,6 +11,7 @@
 #include <sys/wait.h>
 #include "fuse-bridge.h"
 #include "mount-gluster-compat.h"
+#include "glusterfs.h"
 
 #ifdef __NetBSD__
 #undef open /* in perfuse.h, pulled from mount-gluster-compat.h */
@@ -3161,6 +3162,8 @@ out:
 void
 fuse_getxattr_resume (fuse_state_t *state)
 {
+        char *value  = NULL;
+
         if (!state->loc.inode) {
                 gf_log ("glusterfs-fuse", GF_LOG_WARNING,
                         "%"PRIu64": GETXATTR %s/%"PRIu64" (%s) "
@@ -3178,6 +3181,46 @@ fuse_getxattr_resume (fuse_state_t *state)
         state->fd = fd_lookup (state->loc.inode, state->finh->pid);
 #endif /* GF_TEST_FFOP */
 
+        if (state->name &&
+            (strcmp (state->name, VIRTUAL_GFID_XATTR_KEY) == 0)) {
+                /* send glusterfs gfid in binary form */
+
+                value = GF_CALLOC (16 + 1, sizeof(char),
+                                   gf_common_mt_char);
+                if (!value) {
+                        send_fuse_err (state->this, state->finh, ENOMEM);
+                        goto internal_out;
+                }
+                memcpy (value, state->loc.inode->gfid, 16);
+
+                send_fuse_xattr (THIS, state->finh, value, 16, state->size);
+                GF_FREE (value);
+        internal_out:
+                free_fuse_state (state);
+                return;
+        }
+
+        if (state->name &&
+            (strcmp (state->name, VIRTUAL_GFID_XATTR_KEY_STR) == 0)) {
+                /* transform binary gfid to canonical form */
+
+                value = GF_CALLOC (UUID_CANONICAL_FORM_LEN + 1, sizeof(char),
+                                   gf_common_mt_char);
+                if (!value) {
+                        send_fuse_err (state->this, state->finh, ENOMEM);
+                        goto internal_out1;
+                }
+                uuid_utoa_r (state->loc.inode->gfid, value);
+
+                send_fuse_xattr (THIS, state->finh, value,
+                                 UUID_CANONICAL_FORM_LEN, state->size);
+                GF_FREE (value);
+        internal_out1:
+                free_fuse_state (state);
+                return;
+        }
+
+
         if (state->fd) {
                 gf_log ("glusterfs-fuse", GF_LOG_TRACE,
                         "%"PRIu64": GETXATTR %p/%"PRIu64" (%s)", state->finh->unique,