Method for controlling write and read operations in the nonvolatile memory by a host, using an identifier for a region
According to one embodiment, a memory system determines a write destination block and a write destination location in the write destination block to which write data is to be written, and notifies a host of an identifier of the write data, a block address of the write destination block, and an offset indicative of the write destination location. The memory system retrieves the write data from a write buffer of the host, and writes the write data to the write destination location. In a case where a read command to designate a physical address of first data is received before a write operation of the first data is finished, the memory system reads the first data from the write buffer of the host.
1. A method of controlling a nonvolatile memory including a plurality of blocks, the method comprising:
receiving from a host a write command to designate a first identifier of a plurality of identifiers to access a plurality of regions each being a subset of the plurality of blocks, an identifier of write data, and storage location information indicative of a storage location in a write buffer of the host where the write data is stored;
allocating one of blocks of a common free block group shared by the plurality of regions as a write destination block for a region corresponding to the first identifier, and determining a write destination location in the write destination block to which the write data is to be written;
notifying the host of an identifier of the write data, a block address of the write destination block, and an offset indicative of the write destination location in the write destination block;
retrieving the write data from the write buffer of the host on a basis of the storage location information, and writing the write data to the write destination location in the write destination block;
receiving from the host a read command to designate a physical address indicative of a storage location where first data to be read is stored;
in a case that a write operation of the first data is already finished such that the first data is readable from the nonvolatile memory, reading the first data from the nonvolatile memory; and
in a case that the read command is received before the write operation of the first data is finished such that the first data becomes readable, reading the first data from the write buffer of the host.
2. The method of claim 1 , further comprising:
in a case that the write operation of the write data is failed, writing the write data to a write destination location in an other block that is different from the write destination block, and notifying the host of an identifier of the write data, a block address of the other block, and an offset indicative of the write destination location the other block, as an address change request.
3. The method of claim 2 , further comprising:
in a case that the write operation of the write data is failed, retrieving again the write data from the write buffer.
4. The method of claim 1 , further comprising:
transmitting to the host a release request to release a region in the write buffer where the write data is stored, after the write operation of the write data is finished such that the write data becomes readable.
5. The method of claim 1 , wherein
the offset is indicative of an offset from a beginning of the write destination block to the write destination location, and the offset from the beginning of the write destination block is represented by a multiple of a granularity having a certain size.
6. The method of claim 1 , wherein
the offset is represented by a page address of one page of pages included in the write destination block and a page offset in the one page.