From: batt <batt@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Mon, 17 Dec 2007 15:49:43 +0000 (+0000)
Subject: Handle seqnum wraparound.
X-Git-Tag: 1.0.0~203
X-Git-Url: https://codewiz.org/gitweb?a=commitdiff_plain;h=781d5135a61025caea65ef66b5c6bde2ef950e40;p=bertos.git

Handle seqnum wraparound.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@1039 38d2e660-2303-0410-9eaa-f027e97ec537
---

diff --git a/fs/battfs.c b/fs/battfs.c
index 752ec3c6..1b8bf923 100644
--- a/fs/battfs.c
+++ b/fs/battfs.c
@@ -339,8 +339,9 @@ bool battfs_init(struct BattFsSuper *disk)
 				pgcnt_t new_page, old_page;
 				fill_t old_fill;
 
-				#warning fix seq wraparound!
-				if (hdr.seq > hdr_old.seq)
+				/* Fancy check to handle seq wraparound */
+				#define HALF_SEQ ((1 << (sizeof(seq_t) * CPU_BITS_PER_CHAR)) / 2)
+				if ((hdr.seq - hdr_old.seq) < HALF_SEQ)
 				{
 					/* Actual header is newer than the previuos one */
 					old_page = disk->page_array[array_pos];