Commit 9b1215c1 authored by NeilBrown's avatar NeilBrown
Browse files

md/bitmap: store bytes in file rather than just in last page. 



This number is more generally useful, and bytes-in-last-page is
easily extracted from it.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 1ec885cd

drivers/md/bitmap.c

+9 −7
Original line number Diff line number Diff line
@@ -203,9 +203,13 @@ static int write_sb_page(struct bitmap *bitmap, struct page *page, int wait) 


		bdev = (rdev->meta_bdev) ? rdev->meta_bdev : rdev->bdev;



		if (page->index == store->file_pages-1)

			size = roundup(store->last_page_size,

		if (page->index == store->file_pages-1) {

			int last_page_size = store->bytes & (PAGE_SIZE-1);

			if (last_page_size == 0)

				last_page_size = PAGE_SIZE;

			size = roundup(last_page_size,

				       bdev_logical_block_size(bdev));

		}

		/* Just make sure we aren't corrupting data or

		 * metadata

		 */
@@ -973,6 +977,8 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) 
	if (!bitmap->mddev->bitmap_info.external)

		bytes += sizeof(bitmap_super_t);



	store->bytes = bytes;



	num_pages = DIV_ROUND_UP(bytes, PAGE_SIZE);



	if (file && i_size_read(file->f_mapping->host) < bytes) {
@@ -1042,8 +1048,6 @@ static int bitmap_init_from_disk(struct bitmap *bitmap, sector_t start) 


			oldindex = index;



			store->last_page_size = count;



			if (outofdate) {

				/*

				 * if bitmap is out of date, dirty the
@@ -1965,9 +1969,7 @@ space_store(struct mddev *mddev, const char *buf, size_t len) 
		return -EINVAL;



	if (mddev->bitmap &&

	    sectors  < ((mddev->bitmap->storage.file_pages - 1)

			      * PAGE_SIZE

			+ mddev->bitmap->storage.last_page_size + 511) >> 9)

	    sectors < (mddev->bitmap->storage.bytes + 511) >> 9)

		return -EFBIG; /* Bitmap is too big for this small space */



	/* could make sure it isn't too big, but that isn't really

drivers/md/bitmap.h

+1 −1
Original line number Diff line number Diff line
@@ -197,7 +197,7 @@ struct bitmap { 
		unsigned long *filemap_attr;	/* attributes associated

						 * w/ filemap pages */

		unsigned long file_pages;	/* number of pages in the file*/

		int last_page_size;		/* bytes in the last page */

		unsigned long bytes;		/* total bytes in the bitmap */

	} storage;



	unsigned long flags;