We have btrfs_super_block::log_root_transid to record the transid of log
tree root.
However it's never populated and it's always 0, just as the following
dump-super:
log_root 30572544
log_root_transid 0
log_root_level 0
This patch will populate it with log tree root correctly, so the result
will be:
log_root 30572544
log_root_transid 6
log_root_level 0
This won't affect current kernel behavior or btrfs check result as we
already expect log tree root generation always to be super block
genration + 1.
But it could be later used to detect log tree corruption early.
Signed-off-by: Qu Wenruo <w...@suse.com>
---
fs/btrfs/transaction.c | 1 +
fs/btrfs/tree-log.c | 2 ++
2 files changed, 3 insertions(+)
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 3b84f5015029..9d4947079aa3 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -2211,6 +2211,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle
*trans)
btrfs_set_super_log_root(fs_info->super_copy, 0);
btrfs_set_super_log_root_level(fs_info->super_copy, 0);
+ btrfs_set_super_log_root_transid(fs_info->super_copy, 0);
memcpy(fs_info->super_for_commit, fs_info->super_copy,
sizeof(*fs_info->super_copy));
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 1650dc44a5e3..3e16e7b54922 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3131,6 +3131,8 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
log_root_tree->node->start);
btrfs_set_super_log_root_level(fs_info->super_for_commit,
btrfs_header_level(log_root_tree->node));
+ btrfs_set_super_log_root_transid(fs_info->super_for_commit,
+ btrfs_header_generation(log_root_tree->node));
log_root_tree->log_transid++;
mutex_unlock(&log_root_tree->log_mutex);
--
2.19.0
