[PATCH] [JFFS2] Non-contiguous write bug fix (Sibley)

[David Woodhouse]

On Wed, 2007-05-02 at 18:53 +0400, Alexander Belyakov wrote:
> 'wbuf_ofs' is set to the first page in block quite often in
> __jffs2_flush_wbuf(), but this doesn't always lead to
> jffs2_flash_writev() failure. If 'to' is pointing to the different
> block, condition (SECTOR_ADDR(to) != SECTOR_ADDR(wbuf_ofs)) works fine
> and we don't hit BUG() despite 'wbuf_ofs' points to the first page in
> block.
> 
> Probably we should put additional 'wbuf_ofs' adjustment to the
> __jffs2_flush_wbuf() checking if we're moving to the new erseblock. 

Ah, I understand. So this should fix it?

diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
index c556e85..91d1d0f 100644
--- a/fs/jffs2/wbuf.c
+++ b/fs/jffs2/wbuf.c
@@ -637,7 +637,10 @@ static int __jffs2_flush_wbuf(struct jffs2_sb_info *c, int pad)
 
 	memset(c->wbuf,0xff,c->wbuf_pagesize);
 	/* adjust write buffer offset, else we get a non contiguous write bug */
-	c->wbuf_ofs += c->wbuf_pagesize;
+	if (SECTOR_ADDR(c->wbuf_ofs) == SECTOR_ADDR(c->wbuf_ofs+c->wbuf_pagesize))
+		c->wbuf_ofs += c->wbuf_pagesize;
+	else
+		c->wbuf_ofs = 0xffffffff;
 	c->wbuf_len = 0;
 	return 0;
 }

-- 
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