Method and storage device for parallelly processing the deallocation command

A method for garbage collection by a storage device, including the following steps:

• selecting, according to a chunk descriptor table, a chunk to be collected;
• obtaining, according to the chunk to be collected, an address of data to be collected;
• whether a deallocation table is to be checked is identified according to a check mark, wherein the deallocation table temporarily records that the logical address is in a “deallocated” state and a check mark indicates a progress of check of the deallocation table, the check mark for indicating that the deallocation table is to be checked or check has not been completed;
• and
• in response to a deallocation table needing to be checked, accessing the deallocation table according to the address of the data to be collected, and in response to a corresponding table item of the deallocation table being marked with “deallocated”, obtaining, from the chunk to be collected, the next data to be collected.

A method for processing a deallocation command, including:

• sending a received deallocation command to multiple CPUs at the same time;
• obtaining, by the CPU which receives the deallocation command, according to an address range indicated by the deallocation command, one or more addresses belonging to a deallocation table maintained by the CPU in the address range indicated by the deallocation command, and
• updating, according to the obtained one or more addresses, the deallocation table maintained by the CPU, so that the one or more addresses are recorded as deallocated in the deallocation table;
• and
• checking the deallocation table regularly or periodically to find a first table item marked with “deallocated”,
• recording, in the FTL table, according to the first table item, that a corresponding logical address is deallocated, and clearing the “deallocated” mark of the first table item in the deallocation table,
• wherein the deallocation table temporarily records that the logical address is in a “deallocated” state and a check mark indicates a progress of check of the deallocation table, the check mark for indicating that the deallocation table is to be checked or check has not been completed.