Commit 80609448 authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs: enhance the bit operation for SSR 



This patch enhances the existing bit operation when f2fs allocates SSR
blocks.

Reviewed-by: default avatarChao Yu <chao2.yu@samsung.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 0cab80ee

fs/f2fs/segment.c

+20 −30
Original line number Diff line number Diff line
@@ -132,47 +132,37 @@ static unsigned long __find_rev_next_zero_bit(const unsigned long *addr, 
			unsigned long size, unsigned long offset)

{

	const unsigned long *p = addr + BIT_WORD(offset);

	unsigned long result = offset & ~(BITS_PER_LONG - 1);

	unsigned long result = size;

	unsigned long tmp;



	if (offset >= size)

		return size;



	size -= result;

	size -= (offset & ~(BITS_PER_LONG - 1));

	offset %= BITS_PER_LONG;

	if (!offset)

		goto aligned;



	while (1) {

		if (*p == ~0UL)

			goto pass;



		tmp = __reverse_ulong((unsigned char *)p);

	tmp |= ~((~0UL << offset) >> offset);



		if (offset)

			tmp |= ~0UL << (BITS_PER_LONG - offset);

		if (size < BITS_PER_LONG)

		goto found_first;

	if (tmp != ~0UL)

		goto found_middle;



	size -= BITS_PER_LONG;

	result += BITS_PER_LONG;

	p++;

aligned:

	while (size & ~(BITS_PER_LONG - 1)) {

		tmp = __reverse_ulong((unsigned char *)p);

			tmp |= ~0UL >> size;

		if (tmp != ~0UL)

			goto found_middle;

		result += BITS_PER_LONG;

			goto found;

pass:

		if (size <= BITS_PER_LONG)

			break;

		size -= BITS_PER_LONG;

		offset = 0;

		p++;

	}

	if (!size)

	return result;



	tmp = __reverse_ulong((unsigned char *)p);

found_first:

	tmp |= ~(~0UL << (BITS_PER_LONG - size));

	if (tmp == ~0UL)	/* Are any bits zero? */

		return result + size;   /* Nope. */

found_middle:

	return result + __reverse_ffz(tmp);

found:

	return result - size + __reverse_ffz(tmp);

}



void register_inmem_page(struct inode *inode, struct page *page)