diff options
| author | Chris Mason <chris.mason@oracle.com> | 2011-11-06 18:50:56 -0500 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2011-11-06 18:50:56 -0500 |
| commit | 7c7e82a77fe3d89ae50824aa7c897454675eb4c4 (patch) | |
| tree | de7ac71aa9fa00d3ce2b1849c97733f37799900c /fs | |
| parent | d43317dcd074818d4bd12ddd4184a29aff98907b (diff) | |
| download | lwn-7c7e82a77fe3d89ae50824aa7c897454675eb4c4.tar.gz lwn-7c7e82a77fe3d89ae50824aa7c897454675eb4c4.zip | |
Btrfs: check for a null fs root when writing to the backup root log
During log replay, can commit the transaction before the fs_root
pointers are setup, so we have to make sure they are not null before
trying to use them.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/disk-io.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index e532892431f4..e53a5bb85670 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1754,11 +1754,18 @@ static void backup_super_roots(struct btrfs_fs_info *info) btrfs_set_backup_extent_root_level(root_backup, btrfs_header_level(info->extent_root->node)); - btrfs_set_backup_fs_root(root_backup, info->fs_root->node->start); - btrfs_set_backup_fs_root_gen(root_backup, + /* + * we might commit during log recovery, which happens before we set + * the fs_root. Make sure it is valid before we fill it in. + */ + if (info->fs_root && info->fs_root->node) { + btrfs_set_backup_fs_root(root_backup, + info->fs_root->node->start); + btrfs_set_backup_fs_root_gen(root_backup, btrfs_header_generation(info->fs_root->node)); - btrfs_set_backup_fs_root_level(root_backup, + btrfs_set_backup_fs_root_level(root_backup, btrfs_header_level(info->fs_root->node)); + } btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start); btrfs_set_backup_dev_root_gen(root_backup, |