Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
md: fix loading of out-of-date bitmap.
When md is loading a bitmap which it knows is out of date, it fills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 <vojtech@suse.cz>
Signed-off-by: NeilBrown <neilb@suse.de>
+4
-7
drivers/md/bitmap.c
+4
-7
drivers/md/bitmap.c
···
986
986
oldindex = index;
987
987
oldpage = page;
988
988
989
+
bitmap->filemap[bitmap->file_pages++] = page;
990
+
bitmap->last_page_size = count;
991
+
989
992
if (outofdate) {
990
993
/*
991
994
* if bitmap is out of date, dirty the
···
1001
998
write_page(bitmap, page, 1);
1002
999
1003
1000
ret = -EIO;
1004
-
if (bitmap->flags & BITMAP_WRITE_ERROR) {
1005
-
/* release, page not in filemap yet */
1006
-
put_page(page);
1001
+
if (bitmap->flags & BITMAP_WRITE_ERROR)
1007
1002
goto err;
1008
-
}
1009
1003
}
1010
-
1011
-
bitmap->filemap[bitmap->file_pages++] = page;
1012
-
bitmap->last_page_size = count;
1013
1004
}
1014
1005
paddr = kmap_atomic(page, KM_USER0);
1015
1006
if (bitmap->flags & BITMAP_HOSTENDIAN)