fs: dlm: update comments about recovery and membership handling

Make clear that a particular recovery iteration must not be aborted before membership changes are applied to the members list (ls_nodes) and midcomms layer. Interrupting recovery before this can result in missing node-specific changes in midcomms or through lsops. Signed-off-by: Alexander Aring <[email protected]> Signed-off-by: David Teigland <[email protected]>
niw · Jun 24, 2022 · ca8031d · ca8031d
1 parent 5d92a30
commit ca8031d
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Showing 2 changed files with 9 additions and 1 deletion.
diff --git a/fs/dlm/member.c b/fs/dlm/member.c
@@ -534,7 +534,11 @@ int dlm_recover_members(struct dlm_ls *ls, struct dlm_recover *rv, int *neg_out)
 	int i, error, neg = 0, low = -1;
 
 	/* previously removed members that we've not finished removing need to
-	   count as a negative change so the "neg" recovery steps will happen */
+	 * count as a negative change so the "neg" recovery steps will happen
+	 *
+	 * This functionality must report all member changes to lsops or
+	 * midcomms layer and must never return before.
+	 */
 
 	list_for_each_entry(memb, &ls->ls_nodes_gone, list) {
 		log_rinfo(ls, "prev removed member %d", memb->nodeid);

diff --git a/fs/dlm/recoverd.c b/fs/dlm/recoverd.c
@@ -70,6 +70,10 @@ static int ls_recover(struct dlm_ls *ls, struct dlm_recover *rv)
 
 	/*
 	 * Add or remove nodes from the lockspace's ls_nodes list.
+	 *
+	 * Due to the fact that we must report all membership changes to lsops
+	 * or midcomms layer, it is not permitted to abort ls_recover() until
+	 * this is done.
 	 */
 
 	error = dlm_recover_members(ls, rv, &neg);