Abstract: Aspects of the subject matter described herein relate to file system filters and transactions. In aspects, a filter may enlist to receive notification of events associated with a transaction. Afterwards, the filter may receive notification of a transaction event for which it has enlisted. In response to receiving notification of the transaction the filter may perform an action as appropriate. Aspects of the subject matter described herein may be applied to stacked and managed filters.

Abstract: Aspects of the subject matter described herein relate to transactions. In aspects, a consistency requester such as a shadow copy service requests to have a consistent view of a set of resources. In response, transactions that are in a problematic state are allowed to exit the problematic state while new and existing transactions that are not in the problematic state are allowed to perform any work except work that takes them into the problematic state. After no transactions are in the problematic state, a consistent view of the set of resources is available. This view may be used by the consistency requester as desired. Afterwards, the consistency requester may indicate that a consistent view is no longer needed. Transactions are then allowed to enter the problematic state. Transactions may also be allowed to enter the problematic state if a timeout elapses.

Abstract: Aspects of the subject matter described herein relate to file system filters and transactions. In aspects, a filter may enlist to receive notification of events associated with a transaction. Afterwards, the filter may receive notification of a transaction event for which it has enlisted. In response to receiving notification of the transaction the filter may perform an action as appropriate. Aspects of the subject matter described herein may be applied to stacked and managed filters.

Abstract: Aspects of the subject matter described herein relate to antivirus protection and transactions. In aspects, a filter detects that a file is participating in a transaction and then may cause the file to be scanned together with any changes that have made to the file during the transaction. After a file is scanned, a cache entry may be updated to indicate that the file is clean. The cache entry may be used subsequently for like-type states. For example, if the file was scanned inside a transaction, the cache entry may be used later in the transaction. If the file was scanned outside a transaction, the cache entry may be used later for requests pertaining to files not in a transaction. Cache entries may be discarded when they are invalid or no longer useful.

Abstract: Minimizing transaction managers. A method that may be practiced in a commit tree topology including a plurality of transaction managers to manage transactions. The transactions include a set of operations that are all performed if a transaction is completed or all aborted if a transaction is not completed. The transaction managers store transaction result information to allow recovery of a transaction in case of system failure. The method includes acts for minimizing storage overhead by minimizing the number of transaction managers used to coordinate transactions. The method includes identifying a set of transaction managers. A first transaction manager is selected from among the set of transaction managers. A second transaction manager is identified from among the set of transaction managers that is always available when the first transaction manager is available. Messages are redirected from a subordinate associated with the first transaction manager to the second transaction manager.