From 251f31049f29f0a8b7198d9dc645e06de8165a90 Mon Sep 17 00:00:00 2001 From: Alex Bligh Date: Sun, 5 Jun 2011 17:57:16 +0100 Subject: [PATCH] nbd-tester-client: analyse bad data using hash function huersistic The hash function used by the integrity test was designed specifically such that with < (2^32) blocks and < (2^32) read/write operations, it can accurately guess how the bad data returned was generated. This patch uses this huersistic to provide a guess as to what is wrong. EG if it prints out a correct block number but a bad sequence number, it is likely the server is disordering writes or has missed writes. --- nbd-tester-client.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/nbd-tester-client.c b/nbd-tester-client.c index fee2d87..134652c 100644 --- a/nbd-tester-client.c +++ b/nbd-tester-client.c @@ -1087,7 +1087,12 @@ int integrity_test(gchar* hostname, int port, char* name, int sock, if (checkbuf(dbuf, blkhash[blknum], blknum)) { retval=-1; - snprintf(errstr, errstr_len, "Bad reply data: seq %08x", blkhash[blknum]); + snprintf(errstr, errstr_len, "Bad reply data: I wanted blk %08x, seq %08x but I got (at a guess) blk %08x, seq %08x", + (unsigned int) blknum, + blkhash[blknum], + ((uint32_t *)(dbuf))[0], + ((uint32_t *)(dbuf))[1] + ); goto err_open; } -- 1.7.10.4