Avoiding data inconsistency in a file system using 2-level synchronization

A non-transitory computer-readable medium comprising instructions that are executable in a computer system, wherein the instructions when executed cause one or more storage devices of the computer system to carry out a method of synchronously executing input/output operations (IOs) issued by a plurality of virtual computing instances to a file system implemented by the one or more storage devices, and wherein the method comprises:

• detecting a first write IO issued by one of the virtual computing instances, wherein the first write IO includes an instruction to write first data at a first address of a file data block of a file of the file system;
• determining by checking metadata of a pointer block of the file that points to the file data block, that a first address range of the file system comprising the first address is locked so as to prevent any pending unmap IOs issued by the virtual computing instances from deallocating storage space of the one or more storage devices mapped to addresses of file data blocks within the first address range;
• and
• in response to determining that the first address range is locked, writing the first data to the one or more storage devices at the first address while the first address range is locked.

One or more storage devices implementing a file system for a plurality of virtual computing instances, wherein the one or more storage devices include a processor configured to:

• detect a first write IO issued by one of the virtual computing instances, wherein the first write IO includes an instruction to write first data at a first address of a file data block of a file of the file system;
• determine by checking metadata of a pointer block of the file that points to the file data block, that a first address range of the file system comprising the first address is locked so as to prevent any pending unmap IOs issued by the virtual computing instances from deallocating storage space of the one or more storage devices mapped to addresses of file data blocks within the first address range;
• and
• in response to determining that the first address range is locked, write the first data at the first address while the first address range is locked.