Synchronizing storage state information

An apparatus, comprising:

• means for maintaining a master lock, a set of join locks, and a set of data locks for controlling access to configuration information usable by a plurality of servers to implement a storage system to protect the configuration information;
• means for receiving, at a first of the plurality of servers, a request to access a set of storage devices of the storage system;
• means for securing, for the first server, the master lock to facilitate modifying the configuration information by:
• setting a join lock and a data lock,
• preventing other servers from acquiring the data lock, and
• updating the state information while the first server is updating the configuration information in response to the request;
• means for securing, for the first server, a subset of the set of join locks to notify some, but not all, of the plurality of servers that the configuration information has been modified, the subset of the set of join locks indicating whether the configuration information includes invalid data and facilitating correcting any data in the configuration information determined to be invalid;
• means for securing, for the first server, a subset of the set of data locks corresponding to the subset of join locks to copy the modified configuration information to the notified servers and convey the configuration information to the first server;
• and
• means for releasing the master lock, the subset of join locks, and the subset of data locks in response to the modified configuration information being copied to the notified servers.

A non-transitory computer readable medium including program instructions stored thereon, wherein the program instructions are executable by a computing system to cause the computing system to perform operations comprising:

• receiving, by a processor, a request to alter small computer system interface (SCSI) state information distributed across a plurality of storage servers, wherein the SCSI state information is usable by the plurality of storage servers to control access to a logical unit number (LUN);
• in response to the request, converting, by the processor, a master lock that restricts altering the SCSI state information by the plurality of servers to protect the SCSI state information while the processor is updating the SCSI state information;
• altering, by the processor, the SCSI state information based on the request;
• converting, by the processor, a subset of a set of join locks associated with a subset of the plurality of servers to notify the subset of servers that the SCSI state information has been altered, the subset of join locks indicating whether the SCSI state information includes invalid data and facilitating correcting any data in the SCSI state information determined to be invalid;
• propagating, by the processor via a subset of a set of data locks corresponding to the subset of join locks, the altered SCSI state information to the notified subset of servers;
• and
• conveying, via the subset of a set of data locks, the SCSI state information to the processor.