md: Don't read past end of bitmap when reading bitmap. (a2ed9615) · Commits · 戴 / test

drivers/md/bitmap.c

+17 −5

Original line number	Diff line number	Diff line
		@@ -208,15 +208,18 @@ static void bitmap_checkfree(struct bitmap *bitmap, unsigned long page)
		*/

		/* IO operations when bitmap is stored near all superblocks */
		static struct page read_sb_page(mddev_t mddev, long offset, unsigned long index)
		static struct page read_sb_page(mddev_t mddev, long offset,
		struct page *page,
		unsigned long index, int size)
		{
		/* choose a good rdev and read the page from there */

		mdk_rdev_t *rdev;
		struct list_head *tmp;
		struct page *page = alloc_page(GFP_KERNEL);
		sector_t target;

		if (!page)
		page = alloc_page(GFP_KERNEL);
		if (!page)
		return ERR_PTR(-ENOMEM);

		@@ -227,7 +230,9 @@ static struct page read_sb_page(mddev_t mddev, long offset, unsigned long inde

		target = rdev->sb_start + offset + index * (PAGE_SIZE/512);

		if (sync_page_io(rdev->bdev, target, PAGE_SIZE, page, READ)) {
		if (sync_page_io(rdev->bdev, target,
		roundup(size, bdev_hardsect_size(rdev->bdev)),
		page, READ)) {
		page->index = index;
		attach_page_buffers(page, NULL); /* so that free_buffer will
		* quietly no-op */
		@@ -544,7 +549,9 @@ static int bitmap_read_sb(struct bitmap *bitmap)

		bitmap->sb_page = read_page(bitmap->file, 0, bitmap, bytes);
		} else {
		bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset, 0);
		bitmap->sb_page = read_sb_page(bitmap->mddev, bitmap->offset,
		NULL,
		0, sizeof(bitmap_super_t));
		}
		if (IS_ERR(bitmap->sb_page)) {
		err = PTR_ERR(bitmap->sb_page);
		@@ -957,11 +964,16 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start)
		*/
		page = bitmap->sb_page;
		offset = sizeof(bitmap_super_t);
		read_sb_page(bitmap->mddev, bitmap->offset,
		page,
		index, count);
		} else if (file) {
		page = read_page(file, index, bitmap, count);
		offset = 0;
		} else {
		page = read_sb_page(bitmap->mddev, bitmap->offset, index);
		page = read_sb_page(bitmap->mddev, bitmap->offset,
		NULL,
		index, count);
		offset = 0;
		}
		if (IS_ERR(page)) { /* read error */

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