dht - fixing a permission update issue

When bringing back a downed brick and performing lookup from the client
side, the permission on said brick aren't updated on the first lookup,
but only on the second.

This patch modifies permission update logic so the first lookup will
trigger a permission update on the downed brick.

LIMITATIONS OF THE PATCH:
As the choice of source depends on whether the directory has layout or not.
Even the directories on the newly added brick will have layout xattr[zeroed], but the same is not true for a root directory.
Hence, in case in the entire cluster only the newly added bricks are up [and others are down], then any change in permission during this time will be overwritten by the older permissions when the cluster is restarted.

fixes: #999
Change-Id: Ieb70246d41e59f9cae9f70bc203627a433dfbd33
Signed-off-by: Barak Sason Rofman <bsasonro@redhat.com>

3 files changed, 39 insertions, 18 deletions

diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index 2231af647de..22ef8200911 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -1435,15 +1435,31 @@ dht_lookup_dir_cbk(call_frame_t *frame, void *cookie, xlator_t *this,
             dht_aggregate_xattr(local->xattr, xattr);
         }
 
+        if (__is_root_gfid(stbuf->ia_gfid)) {
+            ret = dht_dir_has_layout(xattr, conf->xattr_name);
+            if (ret >= 0) {
+                if (is_greater_time(local->prebuf.ia_ctime,
+                                    local->prebuf.ia_ctime_nsec,
+                                    stbuf->ia_ctime, stbuf->ia_ctime_nsec)) {
+                    /* Choose source */
+                    local->prebuf.ia_gid = stbuf->ia_gid;
+                    local->prebuf.ia_uid = stbuf->ia_uid;
+
+                    local->prebuf.ia_ctime = stbuf->ia_ctime;
+                    local->prebuf.ia_ctime_nsec = stbuf->ia_ctime_nsec;
+                    local->prebuf.ia_prot = stbuf->ia_prot;
+                }
+            }
+        }
+
         if (local->stbuf.ia_type != IA_INVAL) {
             /* This is not the first subvol to respond
              * Compare values to see if attrs need to be healed
              */
-            if (!__is_root_gfid(stbuf->ia_gfid) &&
-                ((local->stbuf.ia_gid != stbuf->ia_gid) ||
-                 (local->stbuf.ia_uid != stbuf->ia_uid) ||
-                 (is_permission_different(&local->stbuf.ia_prot,
-                                          &stbuf->ia_prot)))) {
+            if ((local->stbuf.ia_gid != stbuf->ia_gid) ||
+                (local->stbuf.ia_uid != stbuf->ia_uid) ||
+                (is_permission_different(&local->stbuf.ia_prot,
+                                         &stbuf->ia_prot))) {
                 local->need_attrheal = 1;
             }
         }
diff --git a/xlators/cluster/dht/src/dht-selfheal.c b/xlators/cluster/dht/src/dht-selfheal.c
index eb0a853e81f..8657a22fd82 100644
--- a/xlators/cluster/dht/src/dht-selfheal.c
+++ b/xlators/cluster/dht/src/dht-selfheal.c
@@ -1941,9 +1941,18 @@ dht_selfheal_directory(call_frame_t *frame, dht_selfheal_dir_cbk_t dir_cbk,
     local->selfheal.dir_cbk = dir_cbk;
     local->selfheal.layout = dht_layout_ref(this, layout);
 
-    if (local->need_attrheal && !IA_ISINVAL(local->mds_stbuf.ia_type)) {
-        /*Use the one in the mds_stbuf*/
-        local->stbuf = local->mds_stbuf;
+    if (local->need_attrheal) {
+        if (__is_root_gfid(local->stbuf.ia_gfid)) {
+            local->stbuf.ia_gid = local->prebuf.ia_gid;
+            local->stbuf.ia_uid = local->prebuf.ia_uid;
+
+            local->stbuf.ia_ctime = local->prebuf.ia_ctime;
+            local->stbuf.ia_ctime_nsec = local->prebuf.ia_ctime_nsec;
+            local->stbuf.ia_prot = local->prebuf.ia_prot;
+
+        } else if (!IA_ISINVAL(local->mds_stbuf.ia_type)) {
+            local->stbuf = local->mds_stbuf;
+        }
     }
 
     if (!__is_root_gfid(local->stbuf.ia_gfid)) {
diff --git a/xlators/storage/posix/src/posix-common.c b/xlators/storage/posix/src/posix-common.c
index 1fc0eae2056..da9c653218f 100644
--- a/xlators/storage/posix/src/posix-common.c
+++ b/xlators/storage/posix/src/posix-common.c
@@ -611,6 +611,7 @@ posix_init(xlator_t *this)
         0,
     };
     int hdirfd = -1;
+    char value;
 
     dir_data = dict_get(this->options, "directory");
 
@@ -672,16 +673,11 @@ posix_init(xlator_t *this)
     }
 
     /* Check for Extended attribute support, if not present, log it */
-    op_ret = sys_lsetxattr(dir_data->data, "trusted.glusterfs.test", "working",
-                           8, 0);
-    if (op_ret != -1) {
-        ret = sys_lremovexattr(dir_data->data, "trusted.glusterfs.test");
-        if (ret) {
-            gf_msg(this->name, GF_LOG_DEBUG, errno, P_MSG_INVALID_OPTION,
-                   "failed to remove xattr: "
-                   "trusted.glusterfs.test");
-        }
-    } else {
+    size = sys_lgetxattr(dir_data->data, "user.x", &value, sizeof(value));
+
+    if ((size == -1) && (errno == EOPNOTSUPP)) {
+        gf_msg(this->name, GF_LOG_DEBUG, 0, P_MSG_XDATA_GETXATTR,
+               "getxattr returned %zd", size);
         tmp_data = dict_get(this->options, "mandate-attribute");
         if (tmp_data) {
             if (gf_string2boolean(tmp_data->data, &tmp_bool) == -1) {