int io_space ( resmgr_context_t *ctp, io_space_t *msg, RESMGR_OCB_T *ocb )
Classification: I/O
Default handler: none
Helper functions: iofunc_space_verify()
Client functions: chsize(), fcntl(), ftruncate(), ltrunc()
Messages: _IO_SPACE
Data structure:
struct _io_space { uint16_t type; uint16_t combine_len; uint16_t subtype; short whence; uint64_t start; uint64_t len; }; typedef union { struct _io_space i; uint64_t o; } io_space_t;
Description: This is used to allocate or free space occupied by the resource. The subtype parameter indicates whether to allocate (if set to F_ALLOCSP) or deallocate (if set to F_FREESP) storage space. The combination of whence and start give the location where the beginning of the allocation or deallocation should occur; the member len indicates the size of the operation.
Returns: The number of bytes (size of the resource) via the helper macro _RESMGR_STATUS().