From 620158475f462251c996901a8e24306ef6cb4c42 Mon Sep 17 00:00:00 2001
From: Barak Sason Rofman <bsasonro@redhat.com>
Date: Sun, 21 Jun 2020 14:38:56 +0300
Subject: dht - fixing xattr inconsistency

The scenario of setting an xattr to a dir, killing one of the bricks,
removing the xattr, bringing back the brick results in xattr
inconsistency - The downed brick will still have the xattr, but the rest
won't.
This patch add a mechanism that will remove the extra xattrs during
lookup.

fixes: #1324
Change-Id: Ibcc449bad6c7cb46bcae380e42e4496d733b453d
Signed-off-by: Barak Sason Rofman <bsasonro@redhat.com>
---
 xlators/cluster/dht/src/dht-selfheal.c | 63 ++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

(limited to 'xlators/cluster')

diff --git a/xlators/cluster/dht/src/dht-selfheal.c b/xlators/cluster/dht/src/dht-selfheal.c
index 6004ab09ff6..dfc44dbbb47 100644
--- a/xlators/cluster/dht/src/dht-selfheal.c
+++ b/xlators/cluster/dht/src/dht-selfheal.c
@@ -2053,6 +2053,61 @@ dht_selfheal_restore(call_frame_t *frame, dht_selfheal_dir_cbk_t dir_cbk,
     return ret;
 }
 
+/* List xattrs of a subvols and compare with mds xattrs.
+ * If there are differences, remove extra xattrs from the subvol */
+int
+dht_dir_remove_extra_xattrs(xlator_t *this, xlator_t *subvol,
+                            dht_local_t *local, dict_t *mds_xattr)
+{
+    dict_t *subvol_xattr = NULL;
+    data_pair_t *subvol_xattrs = NULL;
+    data_pair_t *mds_xattrs = NULL;
+    int ret = 0;
+
+    /* List the xattrs of the subvol */
+    ret = syncop_listxattr(subvol, &local->loc, &subvol_xattr, NULL, NULL);
+    if (ret < 0) {
+        gf_smsg(this->name, GF_LOG_ERROR, -ret, DHT_MSG_LIST_XATTRS_FAILED,
+                "path=%s", local->loc.path, "name=%s", local->mds_subvol->name,
+                NULL);
+        goto out;
+    }
+
+    subvol_xattrs = subvol_xattr->members_list;
+
+    /* While the subvol still has xattrs, try to find a matching xattrs in mds
+     */
+    while (subvol_xattrs != NULL) {
+        mds_xattrs = mds_xattr->members_list;
+
+        /* While mds still has xattrs, check if the current xattrs is a match */
+        while (mds_xattrs != NULL &&
+               strcmp(subvol_xattrs->key, mds_xattrs->key) != 0) {
+            mds_xattrs = mds_xattrs->next;
+        }
+
+        if (mds_xattrs == NULL) {
+            /* No xattrs matched, remove the extra xattrs from the subvol and
+             * it's dict */
+            ret = syncop_removexattr(subvol, &local->loc, subvol_xattrs->key,
+                                     NULL, NULL);
+            if (ret < 0) {
+                gf_msg(this->name, GF_LOG_ERROR, -ret, 0,
+                       "%s: removexattr failed key %s", local->loc.path,
+                       subvol_xattrs->key);
+                goto out;
+            }
+
+            dict_del(subvol_xattr, subvol_xattrs->key);
+        }
+
+        subvol_xattrs = subvol_xattrs->next;
+    }
+
+out:
+    return ret;
+}
+
 int
 dht_dir_heal_xattrs(void *data)
 {
@@ -2155,6 +2210,14 @@ dht_dir_heal_xattrs(void *data)
         subvol = conf->subvolumes[i];
         if (subvol == mds_subvol)
             continue;
+
+        ret = dht_dir_remove_extra_xattrs(this, subvol, local, mds_xattr);
+        if (ret < 0) {
+            gf_msg(this->name, GF_LOG_ERROR, -ret, 0,
+                   "removing extra xattrs from subvol %s failed on path %s",
+                   subvol->name, local->loc.path);
+        }
+
         if (uret || uflag) {
             ret = syncop_setxattr(subvol, &local->loc, user_xattr, 0, xdata,
                                   NULL);
-- 
cgit