公开(公告)号：US09575976B2

公开(公告)日：2017-02-21

申请号：US14489372

申请日：2014-09-17

Applicant: Apple Inc.

Inventor： Wenguang Wang ,  Deric Horn ,  David Alexander Majnemer ,  Owen Strain

IPC: G06F12/00 ,  G06F17/30 ,  G06F13/14

CPC classification number: G06F17/30082 ,  G06F17/30 ,  G06F17/30088 ,  G06F17/30115 ,  G06F17/3012

Abstract: Methods and apparatuses that maintain birth time for a file system to optimize file update operations are described. The file system can include a plurality of snapshots or clones of data stored in one or more extents of blocks allocated in a storage device. Each extent may be associated with a time stamp according to the birth time. A request may be received from an executable using the file system to update data in a particular extent associated with a particular time stamp. In response, the current birth time in the file system and the particular time stamp may be compared to determine if the particular extent is not shared by more than one of the snapshots. If the particular time stamp is equal to the current birth time, the particular extent may be updated directly without performing an expensive operation to check whether a reference count of the particular extent is equal to one.

Abstract translation: 描述了保持文件系统的出生时间来优化文件更新操作的方法和装置。 文件系统可以包括存储在存储设备中分配的块的一个或多个范围中的数据的多个快照或克隆。 每个范围可以根据出生时间与时间戳相关联。 可以使用文件系统从可执行程序接收请求以更新与特定时间戳相关联的特定范围内的数据。 作为响应，可以比较文件系统中的当前出生时间和特定时间戳，以确定特定范围是否不被多于一个快照共享。 如果特定时间戳等于当前出生时间，则可以直接更新特定范围，而不执行昂贵的操作来检查特定范围的引用计数是否等于1。