[BUG]
After creating a dirty log tree, although
btrfs_super_block::log_root and log_root_level is correctly populated,
its generation is still left 0:
log_root 30474240
log_root_transid 0 <<<
log_root_level 0
[CAUSE]
We just forgot to update btrfs_super_block::log_root_transid completely.
Thus it's always the original value (0) from the initial super block.
Thankfully this old behavior won't break log replay, as in
btrfs_read_tree(), parent generation 0 means we just skip the generation
check.
And per-root log tree is still done properly using the root generation,
so here we really only missed the generation check for log tree root,
and even we fixed it, it should not cause any compatible problem.
[FIX]
Just update btrfs_super_block::log_root_transid properly.
Cc: stable@xxxxxxxxxxxxxxx #4.9+
Signed-off-by: Qu Wenruo <wqu@xxxxxxxx>
---
fs/btrfs/tree-log.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 370388fadf96..27a76d6fef8c 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3083,7 +3083,8 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
struct btrfs_log_ctx root_log_ctx;
struct blk_plug plug;
u64 log_root_start;
- u64 log_root_level;
+ u64 log_root_transid;
+ u8 log_root_level;
mutex_lock(&root->log_mutex);
log_transid = ctx->log_transid;
@@ -3297,6 +3298,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
log_root_start = log_root_tree->node->start;
log_root_level = btrfs_header_level(log_root_tree->node);
+ log_root_transid = btrfs_header_generation(log_root_tree->node);
log_root_tree->log_transid++;
mutex_unlock(&log_root_tree->log_mutex);
@@ -3334,6 +3336,7 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
btrfs_set_super_log_root(fs_info->super_for_commit, log_root_start);
btrfs_set_super_log_root_level(fs_info->super_for_commit, log_root_level);
+ btrfs_set_super_log_root_transid(fs_info->super_for_commit, log_root_transid);
ret = write_all_supers(fs_info, 1);
mutex_unlock(&fs_info->tree_log_mutex);
if (ret) {
--
2.36.1
