Method and system for locking storage area in storage system
A method and a system for locking a storage area in a storage system. There is provided a method for locking a storage system in a storage system, where the storage system comprises a first controller, a second controller, a first communication area and a second communication area. The method comprises: a first lock flag associated with the storage area is written to the first communication area in response to receiving at the first controller a data access request with respect to the storage area, where the first communication area being readable and writable to the first controller and being readable to the second controller. A second lock flag associated with the storage area is read from the second communication area, where the second communication area being readable to the first controller and being readable and writable to the second controller. The storage area is locked by the first controller in response to the second lock flag indicating that the storage area is not locked by the second controller.
1. A method for locking a storage area in a storage system, the storage system comprising a first controller, a second controller, a first communication area and a second communication area, the method comprising:
in response to receiving at the first controller a data access request with respect to the storage area, writing to the first communication area a first lock flag associated with the storage area, the first communication area being readable and writable to the first controller and being readable to the second controller;
reading from the second communication area a second lock flag associated with the storage area, the second communication area being readable to the first controller and being readable and writable to the second controller;
in response to the second lock flag indicating that the storage area is not locked by the second controller, locking the storage area by the first controller; and
in response to the second lock flag indicating that the storage area is locked by the second controller:
reading from the first communication area a first priority associated with the first lock flag and reading from the second communication area a second priority associated with the second lock flag; and
locking the storage area based on a comparison between the first priority and the second priority.
2. The method according to claim 1 , wherein the locking the storage area based on a comparison between the first priority and the second priority comprises:
in response to the first priority being lower than the second priority, unlocking the storage area by the first controller, and updating the first lock flag to “unlocked”.
3. The method according to claim 1 , wherein the locking the storage area based on a comparison between the first priority and the second priority comprises:
in response to the first priority being higher than the second priority, unlocking the storage area by the second controller, and updating the second lock flag to “unlocked”.
4. The method according to claim 3 , further comprising:
locking the storage area by the first controller.
5. A method for locking a storage area in a storage system, the storage system comprising a first controller, a second controller, a first communication area and a second communication area, the method comprising:
in response to receiving at the first controller a data access request with respect to the storage area, writing to the first communication area a first lock flag associated with the storage area, the first communication area being readable and writable to the first controller and being readable to the second controller;
reading from the second communication area a second lock flag associated with the storage area, the second communication area being readable to the first controller and being readable and writable to the second controller; and
in response to the second lock flag indicating that the storage area is not locked by the second controller, locking the storage area by the first controller,
wherein the writing to the first communication area a first lock flag comprises:
determining an address of a lock flag associated with the storage area based on lock metadata contained in the storage system; and
writing the first lock flag to the address so as to indicate that the storage area is locked by the first controller.
6. The method according to claim 1 , further comprising:
in response to the data access request at the first controller with respect to the storage area having been completed, updating the first priority to be lower than the second priority.
7. A method for locking a storage area in a storage system, the storage system comprising a first controller, a second controller, a first communication area and a second communication area, the method comprising:
in response to receiving at the first controller a data access request with respect to the storage area, writing to the first communication area a first lock flag associated with the storage area, the first communication area being readable and writable to the first controller and being readable to the second controller;
reading from the second communication area a second lock flag associated with the storage area, the second communication area being readable to the first controller and being readable and writable to the second controller;
in response to the second lock flag indicating that the storage area is not locked by the second controller, locking the storage area by the first controller, wherein the storage system comprises a plurality of storage devices, and the first communication area is deployed across the plurality of storage devices, and wherein the storage system is a Redundant Array of Independent Disks; and
in response to one storage device among the plurality of storage devices degrading, recovering data in the first communication data from other storage devices among the plurality of storage devices.
8. The method according to claim 1 , wherein the storage area is one or more stripes in the storage system.
9. A system for locking a storage area in a storage system, comprising:
one or more processors;
a memory coupled to at least one processor of the one or more processors;
computer program instructions stored in the memory, when executed by the at least one processor, the computer program instructions causing the system to execute a method for locking a storage area in a storage system, the method comprising:
in a storage system comprising a first controller, a second controller, a first communication area and a second communication area, in response to receiving at the first controller a data access request with respect to the storage area, writing to the first communication area a first lock flag associated with the storage area, the first communication area being readable and writable to the first controller and being readable to the second controller;
reading from the second communication area a second lock flag associated with the storage area, the second communication area being readable to the first controller and being readable and writable to the second controller;
in response to the second lock flag indicating that the storage area is not locked by the second controller, locking the storage area by the first controller; and
in response to the second lock flag indicating that the storage area is locked by the second controller;
reading from the first communication area a first priority associated with the first lock flag and reading from the second communication area a second priority associated with the second lock flag; and
locking the storage area based on a comparison between the first priority and the second priority.
10. The system according to claim 9 , wherein the locking the storage area based on a comparison between the first priority and the second priority comprises:
in response to the first priority being lower than the second priority, unlocking the storage area by the first controller, and updating the first lock flag to “unlocked”.
11. The system according to claim 9 , wherein the locking the storage area based on a comparison between the first priority and the second priority comprises:
in response to the first priority being higher than the second priority,
unlocking the storage area by the second controller; and
updating the second lock flag to “unlocked”.
12. The system according to claim 11 , wherein the method further comprises:
locking the storage area by the first controller.
13. A system for locking a storage area in a storage system, comprising:
one or more processors;
a memory coupled to at least one processor of the one or more processors;
computer program instructions stored in the memory, when executed by the at least one processor, the computer program instructions causing the system to execute a method for locking a storage area in a storage system, the method comprising:
in a storage system comprising a first controller, a second controller, a first communication area and a second communication area, in response to receiving at the first controller a data access request with respect to the storage area, writing to the first communication area a first lock flag associated with the storage area, the first communication area being readable and writable to the first controller and being readable to the second controller;
reading from the second communication area a second lock flag associated with the storage area, the second communication area being readable to the first controller and being readable and writable to the second controller; and
in response to the second lock flag indicating that the storage area is not locked by the second controller, locking the storage area by the first controller,
wherein the writing to the first communication area a first lock flag comprises:
determining an address of a lock flag associated with the storage area based on lock metadata contained in the storage system; and
writing the first lock flag to the address so as to indicate that the storage area is locked by the first controller.
14. The system according claim 9 , wherein the method further comprises:
in response to the data access request of the first controller with respect to the storage area having been completed, updating the first priority to be lower than the second priority.
15. A system for locking a storage area in a storage system, comprising:
one or more processors;
a memory coupled to at least one processor of the one or more processors;
computer program instructions stored in the memory, when executed by the at least one processor, the computer program instructions causing the system to execute a method for locking a storage area in a storage system, the method comprising:
in a storage system comprising a first controller, a second controller, a first communication area and a second communication area, in response to receiving at the first controller a data access request with respect to the storage area, writing to the first communication area a first lock flag associated with the storage area, the first communication area being readable and writable to the first controller and being readable to the second controller;
reading from the second communication area a second lock flag associated with the storage area, the second communication area being readable to the first controller and being readable and writable to the second controller;
in response to the second lock flag indicating that the storage area is not locked by the second controller, locking the storage area by the first controller, wherein the storage system comprises a plurality of storage devices, and the first communication area is deployed across the plurality of storage devices, and wherein the storage system is a Redundant Array of Independent Disks; and
in response to one storage device among the plurality of storage devices degrading, recovering data in the first communication data from other storage devices among the plurality of storage devices.