From: NeilBrown <neilb@suse.de>
Date: Tue, 8 Jun 2010 08:15:54 +0000 (+1000)
Subject: walk_extent:  don't keep walking past the end of the list of addresses
X-Git-Url: http://git.neil.brown.name/?a=commitdiff_plain;h=4ce6d5adfb95ef7ec43a078eeec2012fb38223b5;p=LaFS.git

walk_extent:  don't keep walking past the end of the list of addresses

Once we find a len of 0, there is nothing more worth finding.

Signed-off-by: NeilBrown <neilb@suse.de>
---

diff --git a/modify.c b/modify.c
index 2d88024..0508e61 100644
--- a/modify.c
+++ b/modify.c
@@ -878,22 +878,30 @@ static u32 walk_extent(char **bufp, int len, struct uninc *ui,
 	u64 ephys = 0;
 	u32 eaddr = 0;
 	int elen = 0;
+	int found_end = 0;
 	int handled;
 	char *buf = *bufp;
 
 	handle(data, 0, 0, len); /* initialise */
 
-	while (len >= 12 || uinum < ui->pending_cnt || elen) {
+	while (uinum < ui->pending_cnt || ! found_end) {
 
-		if (elen == 0) {
+		if (elen == 0 && !found_end) {
 			if (len >= 12) {
 				ephys = decode48(buf);
 				elen = decode16(buf);
 				eaddr = decode32(buf);
 				len -= 12;
 				BUG_ON(ephys == 0 && elen != 0); // FIXME fail gracefully
-			} else
+				if (ephys == 0) {
+					eaddr = 0xFFFFFFFFUL;
+					found_end = 1;
+				}
+			} else {
 				eaddr = 0xFFFFFFFFUL;
+				elen = 0;
+				found_end = 1;
+			}
 		}
 
 		/* Handle all pending extents that start before (or at) here */