Commit ae5252bd authored by Chris Mason's avatar Chris Mason
Browse files

Btrfs: Go back to kmaps instead of page_address in extent_buffers 



Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 6d36dcd4

fs/btrfs/extent_map.c

+19 −31
Original line number Diff line number Diff line
@@ -1867,7 +1867,6 @@ sector_t extent_bmap(struct address_space *mapping, sector_t iblock, 
	if (!em || IS_ERR(em))

		return 0;



	// XXX(hch): block 0 is valid in some cases, e.g. XFS RT device

	if (em->block_start == EXTENT_MAP_INLINE ||

	    em->block_start == EXTENT_MAP_HOLE)

		return 0;
@@ -2199,10 +2198,9 @@ void read_extent_buffer(struct extent_buffer *eb, void *dstv, 
		WARN_ON(!PageUptodate(page));



		cur = min(len, (PAGE_CACHE_SIZE - offset));

		// kaddr = kmap_atomic(page, KM_USER0);

		kaddr = page_address(page);

		kaddr = kmap_atomic(page, KM_USER0);

		memcpy(dst, kaddr + offset, cur);

		// kunmap_atomic(kaddr, KM_USER0);

		kunmap_atomic(kaddr, KM_USER0);



		dst += cur;

		len -= cur;
@@ -2237,8 +2235,7 @@ int map_extent_buffer(struct extent_buffer *eb, unsigned long start, 
		*map_start = (i << PAGE_CACHE_SHIFT) - start_offset;

	}



	// kaddr = kmap_atomic(eb->pages[i], km);

	kaddr = page_address(extent_buffer_page(eb, i));

	kaddr = kmap_atomic(extent_buffer_page(eb, i), km);

	*token = kaddr;

	*map = kaddr + offset;

	*map_len = PAGE_CACHE_SIZE - offset;
@@ -2248,7 +2245,7 @@ EXPORT_SYMBOL(map_extent_buffer); 


void unmap_extent_buffer(struct extent_buffer *eb, char *token, int km)

{

	// kunmap_atomic(token, km);

	kunmap_atomic(token, km);

}

EXPORT_SYMBOL(unmap_extent_buffer);
@@ -2278,10 +2275,9 @@ int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 


		cur = min(len, (PAGE_CACHE_SIZE - offset));



		// kaddr = kmap_atomic(page, KM_USER0);

		kaddr = page_address(page);

		kaddr = kmap_atomic(page, KM_USER0);

		ret = memcmp(ptr, kaddr + offset, cur);

		// kunmap_atomic(kaddr, KM_USER0);

		kunmap_atomic(kaddr, KM_USER0);

		if (ret)

			break;
@@ -2317,10 +2313,9 @@ void write_extent_buffer(struct extent_buffer *eb, const void *srcv, 
		WARN_ON(!PageUptodate(page));



		cur = min(len, PAGE_CACHE_SIZE - offset);

		// kaddr = kmap_atomic(page, KM_USER0);

		kaddr = page_address(page);

		kaddr = kmap_atomic(page, KM_USER0);

		memcpy(kaddr + offset, src, cur);

		// kunmap_atomic(kaddr, KM_USER0);

		kunmap_atomic(kaddr, KM_USER0);



		src += cur;

		len -= cur;
@@ -2352,10 +2347,9 @@ void memset_extent_buffer(struct extent_buffer *eb, char c, 
		WARN_ON(!PageUptodate(page));



		cur = min(len, PAGE_CACHE_SIZE - offset);

		// kaddr = kmap_atomic(page, KM_USER0);

		kaddr = page_address(page);

		kaddr = kmap_atomic(page, KM_USER0);

		memset(kaddr + offset, c, cur);

		// kunmap_atomic(kaddr, KM_USER0);

		kunmap_atomic(kaddr, KM_USER0);



		len -= cur;

		offset = 0;
@@ -2388,10 +2382,9 @@ void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src, 


		cur = min(len, (unsigned long)(PAGE_CACHE_SIZE - offset));



		// kaddr = kmap_atomic(page, KM_USER1);

		kaddr = page_address(page);

		kaddr = kmap_atomic(page, KM_USER1);

		read_extent_buffer(src, kaddr + offset, src_offset, cur);

		// kunmap_atomic(kaddr, KM_USER1);

		kunmap_atomic(kaddr, KM_USER1);



		src_offset += cur;

		len -= cur;
@@ -2405,43 +2398,38 @@ static void move_pages(struct page *dst_page, struct page *src_page, 
		       unsigned long dst_off, unsigned long src_off,

		       unsigned long len)

{

	// char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);

	char *dst_kaddr = page_address(dst_page);

	char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);

	if (dst_page == src_page) {

		memmove(dst_kaddr + dst_off, dst_kaddr + src_off, len);

	} else {

		// char *src_kaddr = kmap_atomic(src_page, KM_USER1);

		char *src_kaddr = page_address(src_page);

		char *src_kaddr = kmap_atomic(src_page, KM_USER1);

		char *p = dst_kaddr + dst_off + len;

		char *s = src_kaddr + src_off + len;



		while (len--)

			*--p = *--s;



		// kunmap_atomic(src_kaddr, KM_USER1);

		kunmap_atomic(src_kaddr, KM_USER1);

	}

	// kunmap_atomic(dst_kaddr, KM_USER0);

	kunmap_atomic(dst_kaddr, KM_USER0);

}



static void copy_pages(struct page *dst_page, struct page *src_page,

		       unsigned long dst_off, unsigned long src_off,

		       unsigned long len)

{

	//kmap_atomic(dst_page, KM_USER0);

	char *dst_kaddr = page_address(dst_page);

	char *dst_kaddr = kmap_atomic(dst_page, KM_USER0);

	char *src_kaddr;



	if (dst_page != src_page)

		src_kaddr = page_address(src_page); // kmap_atomic(src_page, KM_USER1);

		src_kaddr = kmap_atomic(src_page, KM_USER1);

	else

		src_kaddr = dst_kaddr;



	memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len);

	/*

	kunmap_atomic(dst_kaddr, KM_USER0);

	if (dst_page != src_page)

		kunmap_atomic(src_kaddr, KM_USER1);

	*/

}



void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset,
@@ -2537,7 +2525,7 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, 


		cur = min(len, src_off_in_page + 1);

		cur = min(cur, dst_off_in_page + 1);

// printk("move pages orig dst %lu src %lu len %lu, this %lu %lu %lu\n", dst_offset, src_offset, len, dst_off_in_page - cur + 1, src_off_in_page - cur + 1, cur);



		move_pages(extent_buffer_page(dst, dst_i),

			   extent_buffer_page(dst, src_i),

			   dst_off_in_page - cur + 1,