diff mbox

[08/12] btrfs: introduce helpers for updating eb uuids

Message ID 77d3ede388ba26b93ead0afb8c7f5e6af3a10c35.1478710770.git.dsterba@suse.com (mailing list archive)
State Accepted
Headers show

Commit Message

David Sterba Nov. 9, 2016, 5:04 p.m. UTC 
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: David Sterba <dsterba@suse.com>
---
 fs/btrfs/extent_io.c | 21 +++++++++++++++++++++
 fs/btrfs/extent_io.h |  3 +++
 2 files changed, 24 insertions(+)
diff mbox

Patch

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 8ed05d95584a..45a986791fe0 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -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)
 {
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index ab31d145227e..065c77d43921 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -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,