Commit 66231ad3 authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

block: null_blk: fix 'Invalid parameters' when loading module 



On ARM64, the default page size has been 64K on some distributions, and
we should allow ARM64 people to play null_blk.

This patch fixes the issue by extend page bitmap size for supporting
other non-4KB PAGE_SIZE.

Cc: Bart Van Assche <Bart.VanAssche@wdc.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Kyungchan Koh <kkc6196@fb.com>,
Cc: weiping zhang <zhangweiping@didichuxing.com>
Cc: Yi Zhang <yi.zhang@redhat.com>
Reported-by: default avatarYi Zhang <yi.zhang@redhat.com>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent b5d013bc

drivers/block/null_blk.c

+25 −21
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ enum nullb_device_flags { 
	NULLB_DEV_FL_CACHE	= 3,

};



#define MAP_SZ		((PAGE_SIZE >> SECTOR_SHIFT) + 2)

/*

 * nullb_page is a page in memory for nullb devices.

 *
@@ -88,10 +89,10 @@ enum nullb_device_flags { 
 */

struct nullb_page {

	struct page *page;

	unsigned long bitmap;

	DECLARE_BITMAP(bitmap, MAP_SZ);

};

#define NULLB_PAGE_LOCK (sizeof(unsigned long) * 8 - 1)

#define NULLB_PAGE_FREE (sizeof(unsigned long) * 8 - 2)

#define NULLB_PAGE_LOCK (MAP_SZ - 1)

#define NULLB_PAGE_FREE (MAP_SZ - 2)



struct nullb_device {

	struct nullb *nullb;
@@ -733,7 +734,7 @@ static struct nullb_page *null_alloc_page(gfp_t gfp_flags) 
	if (!t_page->page)

		goto out_freepage;



	t_page->bitmap = 0;

	memset(t_page->bitmap, 0, sizeof(t_page->bitmap));

	return t_page;

out_freepage:

	kfree(t_page);
@@ -743,13 +744,20 @@ out: 


static void null_free_page(struct nullb_page *t_page)

{

	__set_bit(NULLB_PAGE_FREE, &t_page->bitmap);

	if (test_bit(NULLB_PAGE_LOCK, &t_page->bitmap))

	__set_bit(NULLB_PAGE_FREE, t_page->bitmap);

	if (test_bit(NULLB_PAGE_LOCK, t_page->bitmap))

		return;

	__free_page(t_page->page);

	kfree(t_page);

}



static bool null_page_empty(struct nullb_page *page)

{

	int size = MAP_SZ - 2;



	return find_first_bit(page->bitmap, size) == size;

}



static void null_free_sector(struct nullb *nullb, sector_t sector,

	bool is_cache)

{
@@ -764,9 +772,9 @@ static void null_free_sector(struct nullb *nullb, sector_t sector, 


	t_page = radix_tree_lookup(root, idx);

	if (t_page) {

		__clear_bit(sector_bit, &t_page->bitmap);

		__clear_bit(sector_bit, t_page->bitmap);



		if (!t_page->bitmap) {

		if (null_page_empty(t_page)) {

			ret = radix_tree_delete_item(root, idx, t_page);

			WARN_ON(ret != t_page);

			null_free_page(ret);
@@ -837,7 +845,7 @@ static struct nullb_page *__null_lookup_page(struct nullb *nullb, 
	t_page = radix_tree_lookup(root, idx);

	WARN_ON(t_page && t_page->page->index != idx);



	if (t_page && (for_write || test_bit(sector_bit, &t_page->bitmap)))

	if (t_page && (for_write || test_bit(sector_bit, t_page->bitmap)))

		return t_page;



	return NULL;
@@ -900,10 +908,10 @@ static int null_flush_cache_page(struct nullb *nullb, struct nullb_page *c_page) 


	t_page = null_insert_page(nullb, idx << PAGE_SECTORS_SHIFT, true);



	__clear_bit(NULLB_PAGE_LOCK, &c_page->bitmap);

	if (test_bit(NULLB_PAGE_FREE, &c_page->bitmap)) {

	__clear_bit(NULLB_PAGE_LOCK, c_page->bitmap);

	if (test_bit(NULLB_PAGE_FREE, c_page->bitmap)) {

		null_free_page(c_page);

		if (t_page && t_page->bitmap == 0) {

		if (t_page && null_page_empty(t_page)) {

			ret = radix_tree_delete_item(&nullb->dev->data,

				idx, t_page);

			null_free_page(t_page);
@@ -919,11 +927,11 @@ static int null_flush_cache_page(struct nullb *nullb, struct nullb_page *c_page) 


	for (i = 0; i < PAGE_SECTORS;

			i += (nullb->dev->blocksize >> SECTOR_SHIFT)) {

		if (test_bit(i, &c_page->bitmap)) {

		if (test_bit(i, c_page->bitmap)) {

			offset = (i << SECTOR_SHIFT);

			memcpy(dst + offset, src + offset,

				nullb->dev->blocksize);

			__set_bit(i, &t_page->bitmap);

			__set_bit(i, t_page->bitmap);

		}

	}
@@ -960,10 +968,10 @@ again: 
		 * We found the page which is being flushed to disk by other

		 * threads

		 */

		if (test_bit(NULLB_PAGE_LOCK, &c_pages[i]->bitmap))

		if (test_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap))

			c_pages[i] = NULL;

		else

			__set_bit(NULLB_PAGE_LOCK, &c_pages[i]->bitmap);

			__set_bit(NULLB_PAGE_LOCK, c_pages[i]->bitmap);

	}



	one_round = 0;
@@ -1016,7 +1024,7 @@ static int copy_to_nullb(struct nullb *nullb, struct page *source, 
		kunmap_atomic(dst);

		kunmap_atomic(src);



		__set_bit(sector & SECTOR_MASK, &t_page->bitmap);

		__set_bit(sector & SECTOR_MASK, t_page->bitmap);



		if (is_fua)

			null_free_sector(nullb, sector, true);
@@ -1846,10 +1854,6 @@ static int __init null_init(void) 
	struct nullb *nullb;

	struct nullb_device *dev;



	/* check for nullb_page.bitmap */

	if (sizeof(unsigned long) * 8 - 2 < (PAGE_SIZE >> SECTOR_SHIFT))

		return -EINVAL;



	if (g_bs > PAGE_SIZE) {

		pr_warn("null_blk: invalid block size\n");

		pr_warn("null_blk: defaults block size to %lu\n", PAGE_SIZE);

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