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authorNeilBrown <neilb@suse.de>2007-05-23 22:58:10 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-24 05:14:14 +0200
commitab6085c795a71b6a21afe7469d30a365338add7a (patch)
treed9d901ea1c3401906553ef9e684a1094a1b3083a /drivers/md/bitmap.c
parentmd: avoid overflow in raid0 calculation with large components (diff)
downloadlinux-ab6085c795a71b6a21afe7469d30a365338add7a.tar.xz
linux-ab6085c795a71b6a21afe7469d30a365338add7a.zip
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 <neilb@suse.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/md/bitmap.c')
-rw-r--r--drivers/md/bitmap.c17
1 files changed, 12 insertions, 5 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 5a4a74c1097c..9620d452d030 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -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)