From 192966f9f34028e04437e29afc0d936be2fc7052 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 7 May 2009 12:47:19 +1000 Subject: [PATCH] md: fix loading of out-of-date bitmap. commit b74fd2826c5acce20e6f691437b2d19372bc2057 upstream. When md is loading a bitmap which it knows is out of date, it fills each page with 1s and writes it back out again. However the write_page call makes used of bitmap->file_pages and bitmap->last_page_size which haven't been set correctly yet. So this can sometimes fail. Move the setting of file_pages and last_page_size to before the call to write_page. This bug can cause the assembly on an array to fail, thus making the data inaccessible. Hence I think it is a suitable candidate for -stable. Reported-by: Vojtech Pavlik Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/md/bitmap.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 6d33d8acd205f..b411249b1922a 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -985,6 +985,9 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) oldindex = index; oldpage = page; + bitmap->filemap[bitmap->file_pages++] = page; + bitmap->last_page_size = count; + if (outofdate) { /* * if bitmap is out of date, dirty the @@ -997,15 +1000,9 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) write_page(bitmap, page, 1); ret = -EIO; - if (bitmap->flags & BITMAP_WRITE_ERROR) { - /* release, page not in filemap yet */ - put_page(page); + if (bitmap->flags & BITMAP_WRITE_ERROR) goto err; - } } - - bitmap->filemap[bitmap->file_pages++] = page; - bitmap->last_page_size = count; } paddr = kmap_atomic(page, KM_USER0); if (bitmap->flags & BITMAP_HOSTENDIAN) -- 2.47.2