md: don't write more than is required of the last page of a bitmap

It is possible that real data or metadata follows the bitmap without full page
alignment.

So limit the last write to be only the required number of bytes, rounded up to
the hard sector size of the device.

Signed-off-by: Neil Brown <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
NeilBrown 2007-05-23 13:58:10 -07:00 • committed by Linus Torvalds
commit ab6085c795
2 changed files with 13 additions and 5 deletions

View file

@ -255,19 +255,25 @@ static struct page *read_sb_page(mddev_t *mddev, long offset, unsigned long inde
}
static int write_sb_page(mddev_t *mddev, long offset, struct page *page, int wait)
static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait)
{
mdk_rdev_t *rdev;
struct list_head *tmp;
mddev_t *mddev = bitmap->mddev;
ITERATE_RDEV(mddev, rdev, tmp)
if (test_bit(In_sync, &rdev->flags)
&& !test_bit(Faulty, &rdev->flags))
&& !test_bit(Faulty, &rdev->flags)) {
int size = PAGE_SIZE;
if (page->index == bitmap->file_pages-1)
size = roundup(bitmap->last_page_size,
bdev_hardsect_size(rdev->bdev));
md_super_write(mddev, rdev,
(rdev->sb_offset<<1) + offset
(rdev->sb_offset<<1) + bitmap->offset
+ page->index * (PAGE_SIZE/512),
PAGE_SIZE,
size,
page);
}
if (wait)
md_super_wait(mddev);
@ -282,7 +288,7 @@ static int write_page(struct bitmap *bitmap, struct page *page, int wait)
struct buffer_head *bh;
if (bitmap->file == NULL)
return write_sb_page(bitmap->mddev, bitmap->offset, page, wait);
return write_sb_page(bitmap, page, wait);
bh = page_buffers(page);
@ -923,6 +929,7 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
}
bitmap->filemap[bitmap->file_pages++] = page;
bitmap->last_page_size = count;
}
paddr = kmap_atomic(page, KM_USER0);
if (bitmap->flags & BITMAP_HOSTENDIAN)