Conditional journal for storage class memory devices
Systems and methods are disclosed for a journal for a storage class memory device. The storage class memory device may execute an access command for a first page in the storage class memory device. The storage class memory device may also determine whether a failure occurred while executing the access command. The storage class memory device may create an entry in a journal for the storage class memory device if a failure occurred while executing the access command. The storage class memory device may refrain from creating the entry if a failure does not occur while executing the access command.
1. A storage class memory device, comprising:
a storage class memory array;
a controller coupled to the storage class memory array, the controller configured to:
execute an access command associated with a first data for a first page in the storage class memory array;
determine whether a failure occurred while executing the access command;
attempt to recover the first data based on a recovery data generated using an erasure coding scheme when the failure comprises a read failure and the access command comprises a read command to read the first data from the first page in the storage class memory array;
transmit an error message to a sender of the access command when the first data is not recoverable based on the recovery data;
create an entry in a journal for the storage class memory device when the failure occurred while executing the access command, the entry comprising information indicating that the failure occurred while executing the access command; and
refrain from creating the entry when the failure did not occur while executing the access command.
2. The storage class memory device of claim 1 , wherein the controller is further configured to:
erase the first page when the first data is not recoverable based on the recovery data.
3. The storage class memory device of claim 1 , wherein the controller is configured to execute the access command by:
determining a physical address for the first page based on a logical address indicated in the access command.
4. The storage class memory device of claim 3 , wherein the controller is further configured to:
store the first data in the journal when the first data is recoverable based on the recovery data; and
remap a logical address indicated in the access command to one or more physical addresses of one or more other pages.
5. The storage class memory device of claim 4 , wherein the controller is further configured to:
transmit the first data to a sender of the access command.
6. The storage class memory device of claim 1 , wherein the failure comprises a write failure and the access command comprises a write command to write the first data to a first page in the storage class memory array.
7. The storage class memory device of claim 6 , wherein the controller is further configured to:
store the first data in the journal; and
remap a logical address indicated in the access command to one or more physical addresses of one or more other pages.
8. The storage class memory device of claim 7 , wherein the controller is further configured to:
transmit an error message to a sender of the access command when the first data cannot be written to another page after a threshold number of attempts.
9. The storage class memory device of claim 1 , wherein the journal is stored in the storage class memory array.
10. The storage class memory device of claim 1 , wherein the entries in the journal are associated with access commands which had failures during execution.
11. The storage class memory device of claim 1 , wherein the recovery data is stored in the journal.
12. The storage class memory device of claim 1 , wherein the recovery data is distributed among a plurality of pages of the storage class memory array.
13. A method, comprising:
executing an access command associated with a first data for a first page in a storage class memory device;
determining whether a failure occurred while executing the access command;
attempting to recover the first data based on a recovery data generated using an erasure coding scheme when the failure comprises a read failure and the access command comprises a read command to read the first data from the first page in the storage class memory device;
transmitting an error message to a sender of the access command when the first data is not recoverable based on the recovery data;
creating an entry in a journal for the storage class memory device when the failure occurred while executing the access command, the entry comprising information indicating that the failure occurred while executing the access command; and
refraining from creating the entry when the failure did not occur while executing the access command.
14. The method of claim 13 , further comprising:
erasing the first page when the first data is not recoverable based on the recovery data.
15. The method of claim 13 , wherein executing the access command comprises:
determining a physical address for the first page based on a logical address indicated in the access command.
16. The method of claim 15 , further comprising:
storing the first data in the journal when the first data is recoverable based on the recovery data; and
remap a logical address indicated in the access command to one or more physical addresses of one or more other pages.
17. The method of claim 16 , further comprising:
transmitting the first data to a sender of the access command.
18. The method of claim 13 , wherein the failure comprises a write failure and the access command comprises a write command to write the first data to a first page in the storage class memory device.
19. The method of claim 18 , further comprising:
storing the first data in the journal; and
remap a logical address indicated in the access command to one or more physical addresses of one or more other pages.
20. The method of claim 19 , further comprising:
transmitting an error message to a sender of the access command when the first data cannot be written to another page after a threshold number of attempts.
21. A storage class memory device, comprising:
a storage class memory array;
means for determining whether a failure occurred while executing an access command associated with a first data for a first page in the storage class memory array;
means for attempting to recover the first data based on a recovery data generated using an erasure coding scheme when the failure comprises a read failure and the access command comprises a read command to read the first data from the first page in the storage class memory array;
means for transmitting an error message to a sender of the access command when the first data is not recoverable based on the recovery data;
means for creating an entry in a journal for the storage class memory device when the failure occurred while executing the access command, the entry comprising information indicating that the failure occurred while executing the access command; and
means for refraining from creating the entry when the failure did not occur while executing the access command.
22. The storage class memory device of claim 21 , further comprising:
means for storing the first data in the journal when the first data is recoverable based on the recovery data; and
means for remapping a logical address indicated in the access command to one or more physical addresses of one or more other pages.
23. The storage class memory device of claim 21 , wherein the failure comprises a write failure and the access command comprises a write command to write the first data to a first page in the storage class memory device.
24. The storage class memory device of claim 23 , further comprising:
means for storing the first data in the journal; and
means for remapping a logical address indicated in the access command to one or more physical addresses of one or more other pages.