Synchronously performing commit records operations

A computer system, comprising:

• one or more processors, one or more computer-readable memories and one or more computer-readable, tangible storage devices;
• and
• program instructions, stored on at least one of the one or more computer-readable, tangible storage devices for execution by at least one of the one or more processors via at least one of the one or more memories, to perform operations comprising:
• providing, in Non-Volatile Storage (NVS), a plurality of track buffers, NVS tracks, and a mail message array, wherein each of the plurality of track buffers stores real segments, a real sector structure, alternate segments, and an alternate sector structure, wherein the real sector structure has an indicator for each sector of each segment in the real segments that indicates whether data for that sector is stored in the real segments, and wherein the alternate sector structure has an indicator for each sector of each segment in the alternate segments that indicates whether data for that sector is stored in the alternate segments;
• and
• under control of a commands component,
• building a local copy of a commit records message for a an NVS track, wherein the commit records message comprises:
• a valid indicator set to indicate that this commit records message is valid and has not been processed yet, an indicator of a track buffer of the plurality of track buffers, and a use real or alternate segments indicator that indicates whether the data for each record is to be stored in the real segments or the alternate segments;
• executing a Direct Memory Access (DMA) chain to transfer customer data from a host to the real segments and the alternate segments of the track buffer and to transfer the local copy of the commit records message to a mail message structure of the mail message array;
• at DMA completion, synchronously calling an NVS manager to execute a commit records operation with the commit records message in the mail message structure, wherein the NVS manager updates the real sector structure and the alternate sector structure to indicate whether new data for each record is stored in the real segments or in the alternate segments, resets the valid indicator to indicate that the commit records message has been processed, and synchronously returns control to the commands component;
• and
• in response to the commit records operation completing and receiving control, indicating that a new write DMA is allowed to proceed for the NVS track.

A computer-implemented method, comprising:

• providing, in Non-Volatile Storage (NVS), a plurality of track buffers, NVS tracks, and a mail message array, wherein each of the plurality of track buffers stores real segments, a real sector structure, alternate segments, and an alternate sector structure, wherein the real sector structure has an indicator for each sector of each segment in the real segments that indicates whether data for that sector is stored in the real segments, and wherein the alternate sector structure has an indicator for each sector of each segment in the alternate segments that indicates whether data for that sector is stored in the alternate segments;
• and
• under control of a commands component,
• building a local copy of a commit records message for a an NVS track, wherein the commit records message comprises:
• a valid indicator set to indicate that this commit records message is valid and has not been processed yet, an indicator of a track buffer of the plurality of track buffers, and a use real or alternate segments indicator that indicates whether the data for each record is to be stored in the real segments or the alternate segments;
• executing a Direct Memory Access (DMA) chain to transfer customer data from a host to the real segments and the alternate segments of the track buffer and to transfer the local copy of the commit records message to a mail message structure of the mail message array;
• at DMA completion, synchronously calling an NVS manager to execute a commit records operation with the commit records message in the mail message structure, wherein the NVS manager updates the real sector structure and the alternate sector structure to indicate whether new data for each record is stored in the real segments or in the alternate segments, resets the valid indicator to indicate that the commit records message has been processed, and synchronously returns control to the commands component;
• and
• in response to the commit records operation completing and receiving control, indicating that a new write DMA is allowed to proceed for the NVS track.