[PATCH v1] Btrfs: Switch to use new generic UUID API

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

There are new types and helpers that are supposed to be used in new code.

As a preparation to get rid of legacy types and API functions do
the conversion here.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
- not tested on actual FS
 fs/btrfs/disk-io.c     |  6 +++---
 fs/btrfs/ioctl.c       | 12 ++----------
 fs/btrfs/root-tree.c   |  4 +---
 fs/btrfs/transaction.c |  7 +++----
 4 files changed, 9 insertions(+), 20 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index e0ad52804c26..f618661f5fa4 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1259,7 +1259,6 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 	struct btrfs_root *root;
 	struct btrfs_key key;
 	int ret = 0;
-	uuid_le uuid = NULL_UUID_LE;
 
 	root = btrfs_alloc_root(fs_info, GFP_KERNEL);
 	if (!root)
@@ -1293,8 +1292,9 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans,
 	btrfs_set_root_last_snapshot(&root->root_item, 0);
 	btrfs_set_root_dirid(&root->root_item, 0);
 	if (is_fstree(objectid))
-		uuid_le_gen(&uuid);
-	memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
+		guid_gen((guid_t *)&root->root_item.uuid);
+	else
+		guid_copy((guid_t *)&root->root_item.uuid, &guid_null);
 	root->root_item.drop_level = 0;
 
 	key.objectid = objectid;
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 9c8e1734429c..a40bf7ea9393 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -541,13 +541,7 @@ static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
 
 int btrfs_is_empty_uuid(u8 *uuid)
 {
-	int i;
-
-	for (i = 0; i < BTRFS_UUID_SIZE; i++) {
-		if (uuid[i])
-			return 0;
-	}
-	return 1;
+	return guid_is_null((guid_t *)uuid);
 }
 
 static noinline int create_subvol(struct inode *dir,
@@ -572,7 +566,6 @@ static noinline int create_subvol(struct inode *dir,
 	u64 objectid;
 	u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
 	u64 index = 0;
-	uuid_le new_uuid;
 
 	root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
 	if (!root_item)
@@ -642,8 +635,7 @@ static noinline int create_subvol(struct inode *dir,
 
 	btrfs_set_root_generation_v2(root_item,
 			btrfs_root_generation(root_item));
-	uuid_le_gen(&new_uuid);
-	memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
+	guid_gen((guid_t *)&root_item->uuid);
 	btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
 	btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
 	root_item->ctime = root_item->otime;
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 65bda0682928..b797792d66bf 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -20,7 +20,6 @@
 static void btrfs_read_root_item(struct extent_buffer *eb, int slot,
 				struct btrfs_root_item *item)
 {
-	uuid_le uuid;
 	int len;
 	int need_reset = 0;
 
@@ -42,8 +41,7 @@ static void btrfs_read_root_item(struct extent_buffer *eb, int slot,
 			sizeof(*item) - offsetof(struct btrfs_root_item,
 					generation_v2));
 
-		uuid_le_gen(&uuid);
-		memcpy(item->uuid, uuid.b, BTRFS_UUID_SIZE);
+		guid_gen((guid_t *)&item->uuid);
 	}
 }
 
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 127fa1535f58..394120c9c1f3 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1422,7 +1422,6 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 	u64 index = 0;
 	u64 objectid;
 	u64 root_flags;
-	uuid_le new_uuid;
 
 	ASSERT(pending->path);
 	path = pending->path;
@@ -1515,8 +1514,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 
 	btrfs_set_root_generation_v2(new_root_item,
 			trans->transid);
-	uuid_le_gen(&new_uuid);
-	memcpy(new_root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
+	guid_gen((guid_t *)&new_root_item->uuid);
 	memcpy(new_root_item->parent_uuid, root->root_item.uuid,
 			BTRFS_UUID_SIZE);
 	if (!(root_flags & BTRFS_ROOT_SUBVOL_RDONLY)) {
@@ -1627,7 +1625,8 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
 		btrfs_abort_transaction(trans, ret);
 		goto fail;
 	}
-	ret = btrfs_uuid_tree_add(trans, new_uuid.b, BTRFS_UUID_KEY_SUBVOL,
+	ret = btrfs_uuid_tree_add(trans, new_root_item->uuid,
+				  BTRFS_UUID_KEY_SUBVOL,
 				  objectid);
 	if (ret) {
 		btrfs_abort_transaction(trans, ret);
-- 
2.20.1