diff options
Diffstat (limited to 'fs/btrfs/qgroup.c')
| -rw-r--r-- | fs/btrfs/qgroup.c | 39 |
1 files changed, 29 insertions, 10 deletions
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index d275bf24b250..af97413abcf4 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -2765,9 +2765,19 @@ int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans) /* * Old roots should be searched when inserting qgroup - * extent record + * extent record. + * + * But for INCONSISTENT (NO_ACCOUNTING) -> rescan case, + * we may have some record inserted during + * NO_ACCOUNTING (thus no old_roots populated), but + * later we start rescan, which clears NO_ACCOUNTING, + * leaving some inserted records without old_roots + * populated. + * + * Those cases are rare and should not cause too much + * time spent during commit_transaction(). */ - if (WARN_ON(!record->old_roots)) { + if (!record->old_roots) { /* Search commit root to find old_roots */ ret = btrfs_find_all_roots(&ctx, false); if (ret < 0) @@ -3357,6 +3367,7 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work) int err = -ENOMEM; int ret = 0; bool stopped = false; + bool did_leaf_rescans = false; path = btrfs_alloc_path(); if (!path) @@ -3377,6 +3388,7 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work) } err = qgroup_rescan_leaf(trans, path); + did_leaf_rescans = true; if (err > 0) btrfs_commit_transaction(trans); @@ -3397,16 +3409,23 @@ out: mutex_unlock(&fs_info->qgroup_rescan_lock); /* - * only update status, since the previous part has already updated the - * qgroup info. + * Only update status, since the previous part has already updated the + * qgroup info, and only if we did any actual work. This also prevents + * race with a concurrent quota disable, which has already set + * fs_info->quota_root to NULL and cleared BTRFS_FS_QUOTA_ENABLED at + * btrfs_quota_disable(). */ - trans = btrfs_start_transaction(fs_info->quota_root, 1); - if (IS_ERR(trans)) { - err = PTR_ERR(trans); + if (did_leaf_rescans) { + trans = btrfs_start_transaction(fs_info->quota_root, 1); + if (IS_ERR(trans)) { + err = PTR_ERR(trans); + trans = NULL; + btrfs_err(fs_info, + "fail to start transaction for status update: %d", + err); + } + } else { trans = NULL; - btrfs_err(fs_info, - "fail to start transaction for status update: %d", - err); } mutex_lock(&fs_info->qgroup_rescan_lock); |