From b74fd2826c5acce20e6f691437b2d19372bc2057 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 7 May 2009 12:47:19 +1000 Subject: md: fix loading of out-of-date bitmap. When md is loading a bitmap which it knows is out of date, it fills each page with 1s and writes it back out again.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. Cc: stable@kernel.org Reported-by: Vojtech Pavlik Signed-off-by: NeilBrown --- 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 1fb91edc7de2..bc1d64b7b63b 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -986,6 +986,9 @@ 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last_page_size = count; + if (outofdate) { /* * if bitmap is out of date, dirty the @@ -998,15 +1001,9 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) write_page(bitmap, page, 1); ret = -EIO; - if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) -- cgit v1.2.3-59-g8ed1b