A memory system includes a volatile memory, a nonvolatile memory, and a controller. The controller is configured to set a block group of the nonvolatile memory to be in a writable state and generate in the volatile memory a list associated with the block group. The controller is configured to, with respect to a write command, add an entry to the list, which includes a first address of a host and a second address of the volatile memory, obtain the write data from the first address of the host and store the write data in the second address of the volatile memory, write the write data stored at the second address of the volatile memory into the block group, and upon the block group being fully written, set the block group to be in a non-writable state and dissociate the list from the block group.