Btrfs: set UUID in root_item for created trees (6463fe58) · Commits · 戴 / test

It is a rare exception that a new tree is created, like the qgroups tree. So far these new trees have an all-zero UUID in their root items. All trees that mkfs.btrfs has created get an UUID during the first mount when btrfs_read_root_item() rewrites the root_item to the v2 structure style. These UUID are never used so far, but anyway, since it is better to have it uniform for all trees, this commit adds some lines that generate and write an UUID for newly created trees. Signed-off-by:

Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by:

Josef Bacik <jbacik@fusionio.com>

fs/btrfs/disk-io.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -30,6 +30,7 @@
		#include <linux/slab.h>
		#include <linux/migrate.h>
		#include <linux/ratelimit.h>
		#include <linux/uuid.h>
		#include <asm/unaligned.h>
		#include "compat.h"
		#include "ctree.h"
		@@ -1280,6 +1281,7 @@ struct btrfs_root btrfs_create_tree(struct btrfs_trans_handle trans,
		struct btrfs_key key;
		int ret = 0;
		u64 bytenr;
		uuid_le uuid;

		root = btrfs_alloc_root(fs_info);
		if (!root)
		@@ -1329,6 +1331,8 @@ struct btrfs_root btrfs_create_tree(struct btrfs_trans_handle trans,
		btrfs_set_root_used(&root->root_item, leaf->len);
		btrfs_set_root_last_snapshot(&root->root_item, 0);
		btrfs_set_root_dirid(&root->root_item, 0);
		uuid_le_gen(&uuid);
		memcpy(root->root_item.uuid, uuid.b, BTRFS_UUID_SIZE);
		root->root_item.drop_level = 0;

		key.objectid = objectid;

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