Commit f157bf76 authored by David Sterba's avatar David Sterba
Browse files

btrfs: introduce helpers for updating eb uuids 



The fsid and chunk tree uuid are always located in the first page,
we don't need the to use write_extent_buffer.

Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 2230adff

fs/btrfs/extent_io.c

+21 −0
Original line number Diff line number Diff line
@@ -5465,6 +5465,27 @@ int memcmp_extent_buffer(struct extent_buffer *eb, const void *ptrv, 
	return ret;

}



void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,

		const void *srcv)

{

	char *kaddr;



	WARN_ON(!PageUptodate(eb->pages[0]));

	kaddr = page_address(eb->pages[0]);

	memcpy(kaddr + offsetof(struct btrfs_header, chunk_tree_uuid), srcv,

			BTRFS_FSID_SIZE);

}



void write_extent_buffer_fsid(struct extent_buffer *eb, const void *srcv)

{

	char *kaddr;



	WARN_ON(!PageUptodate(eb->pages[0]));

	kaddr = page_address(eb->pages[0]);

	memcpy(kaddr + offsetof(struct btrfs_header, fsid), srcv,

			BTRFS_FSID_SIZE);

}



void write_extent_buffer(struct extent_buffer *eb, const void *srcv,

			 unsigned long start, unsigned long len)

{

fs/btrfs/extent_io.h

+3 −0
Original line number Diff line number Diff line
@@ -405,6 +405,9 @@ void read_extent_buffer(struct extent_buffer *eb, void *dst, 
int read_extent_buffer_to_user(struct extent_buffer *eb, void __user *dst,

			       unsigned long start,

			       unsigned long len);

void write_extent_buffer_fsid(struct extent_buffer *eb, const void *src);

void write_extent_buffer_chunk_tree_uuid(struct extent_buffer *eb,

		const void *src);

void write_extent_buffer(struct extent_buffer *eb, const void *src,

			 unsigned long start, unsigned long len);

void copy_extent_buffer(struct extent_buffer *dst, struct extent_buffer *src,