From 2d69a0f88459fae35df3ddef4934a2dad67e2765 Mon Sep 17 00:00:00 2001 From: Yan Zheng Date: Mon, 5 Jan 2009 15:43:42 -0500 Subject: [PATCH] Btrfs: avoid potential super block corruption The data in fs_info->super_for_commit are zeros before the first transaction commit. If tree log sync and system crash both occur before the first transaction commit, super block will get corrupted. This fixes it by properly filling in the super_for_commit field at open time. Signed-off-by: Yan Zheng --- fs/btrfs/disk-io.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 40a540f31161..dae25e78a6b7 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1609,6 +1609,8 @@ struct btrfs_root *open_ctree(struct super_block *sb, goto fail_iput; memcpy(&fs_info->super_copy, bh->b_data, sizeof(fs_info->super_copy)); + memcpy(&fs_info->super_for_commit, &fs_info->super_copy, + sizeof(fs_info->super_for_commit)); brelse(bh); memcpy(fs_info->fsid, fs_info->super_copy.fsid, BTRFS_FSID_SIZE); @@ -1790,7 +1792,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, btrfs_read_block_groups(extent_root); - fs_info->generation = generation + 1; + fs_info->generation = generation; fs_info->last_trans_committed = generation; fs_info->data_alloc_profile = (u64)-1; fs_info->metadata_alloc_profile = (u64)-1; -- 2.20.1