[PATCH] afs: check for duplicate servers in VL server list

[Yuto Ohnuki <ytohnuki@amazon.com>]

The DNS response may contain the same server more than once. Check for
duplicates by name and port before inserting into the list to avoid
duplicate entries.

Addresses the TODO comment in afs_extract_vlserver_list().

Signed-off-by: Yuto Ohnuki <ytohnuki@amazon.com>
---
 fs/afs/vl_list.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/fs/afs/vl_list.c b/fs/afs/vl_list.c
index 9b1c20daac53..b2068af9531c 100644
--- a/fs/afs/vl_list.c
+++ b/fs/afs/vl_list.c
@@ -288,8 +288,20 @@ struct afs_vlserver_list *afs_extract_vlserver_list(struct afs_cell *cell,
 			afs_put_addrlist(old, afs_alist_trace_put_vlserver_old);
 		}
 
+		/* Check for duplicates in the server list */
+		for (j = 0; j < vllist->nr_servers; j++) {
+			struct afs_vlserver *s = vllist->servers[j].server;
 
-		/* TODO: Might want to check for duplicates */
+			if (s->name_len == server->name_len &&
+			    s->port == server->port &&
+			    strncasecmp(s->name, server->name, server->name_len) == 0) {
+				afs_put_vlserver(cell->net, server);
+				server = NULL;
+				break;
+			}
+		}
+		if (!server)
+			continue;
 
 		/* Insertion-sort by priority and weight */
 		for (j = 0; j < vllist->nr_servers; j++) {
-- 
2.50.1




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