File-system requests supported in user space for enhanced efficiency

• US 9,455,914 B2
• Filed: 05/12/2014
• Issued: 09/27/2016
• Est. Priority Date: 09/10/2013
• Status: Active Grant

• Current Assignee: Rakuten Symphony Incorporated (Rakuten Group, Inc.)
• Original Assignee: Robin Systems, Inc. (Rakuten Group, Inc.)
• Inventors: Singh, Gurmeet, Yeddanapudi, Krishna Satyasai, Venkatesan, Dhanashankar
• Primary Examiner(s): DAO, TUAN C.
• Application Number:
  US14/275,666
• Publication Number:
  US 20150074683A1
• Time in Patent Office: 869 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 11/34 Recording or statistical evaluation of computer activity, e.g. of down time, of input/output operation ; Recording or statistical evaluation of user activity, e.g. usability assessment
• CPC Class Codes: G06F 11/3409 for performance assessment
• CPC Class Codes: G06F 11/3495 for systems
• CPC Class Codes: G06F 2201/815 Virtual
• CPC Class Codes: G06F 9/455 Emulation; Interpretation; Software simulation, e.g. virtualisation or emulation of application or operating system execution engines
• CPC Class Codes: G06F 9/5038 considering the execution order of a plurality of tasks, e.g. taking priority or time dependency constraints into consideration scheduling strategies G06F9/4881 and subgroups
• CPC Class Codes: G06F 9/544 Buffers; Shared memory; Pipes
• CPC Class Codes: G06F 9/546 Message passing systems or structures, e.g. queues
• CPC Class Codes: H04L 47/11 Identifying congestion
• CPC Class Codes: H04L 47/2441 relying on flow classification, e.g. using integrated services [IntServ]

Abstract

Systems and methods are disclosed for interacting with a file system. The file system is operable to reside in user space of a computing system. A module, also within user space, may provide a messaging service supporting requests from an application to the file system. By bypassing a System-Call Interface (SCI) of the computing system'"'"'s kernel space, the module may support requests from the application to the file system with enhanced efficiency and/or customizable features not provided by the SCI. In some examples, the module may include a library in an independent layer within user space and below the application, allowing the library to provide an application-independent messaging service for different applications. Furthermore, in some examples, the module may include a segment of memory, within user space, shared between the application and the file system for passing data involved in requests and/or responses to and/or from the file system.

Claims

1. A system for handling file-system requests comprising:

an application residing in user space of a computing system, the computing system comprising processing logic and memory;

a file system residing in the user space of the computing system; and

a customizing-interface module also residing in the user space and operable to provide a messaging service, within the user space, between the application and the file system, the messaging service supporting a file-system request from the application to the file system, the file-system request providing a non-standard system call, with functionality beyond options offered by a System Call Interface (SCI), newly customized to more efficiently meet requirements of the application, the messaging service made customizable by bypassing the SCI of kernel space pertaining to the computing system.

2. The system of claim 1, further comprising:

library layer within the user space and below the application;

a collection module operable to trap, from the application, system calls sent by the application to the SCI for implementation of file-system requests; and

the library layer comprising the customizing-interface module, the customizing-interface module being application agnostic, as enabled by the library layer being separate from the application, the customizing-interface module further comprising;

a library with a set of system-call emulations supported within the messaging service;

the set of system-call emulations comprising a first subset of emulations of standard system calls and a second subset of emulations of non-standard system calls offering customizable options for the file-system request beyond options offered by the SCI of the computing system'"'"'s kernel space.

3. The system of claim 2, wherein the library matches application-identification information from the system-call requests to the non-standard system calls to provide enhanced interactions between the application and the file system through the messaging service to customize the messaging service to the file-system request.

4. The system of claim 2, the library further comprising:

an analysis module operable to analyze the file-system requests from the application to identify the requirements of the application; and

a generation module operable to generate the non-standard system call with new functionalities tailored to the application.

5. The system of claim 2, the library further comprising:

an analysis module operable to analyze the file-system requests from the application to detect a pattern; and

an anticipation module operable to implement at least one of caching and pre-fetching of data at the library layer, the data anticipated by the pattern, in a segment of library memory locally shared with the file system.

6. The system of claim 1, wherein:

the computing system supports virtual computing nodes; and

the file system and the customizing-interface module reside within an isolated instance of user space pertaining to a particular virtual computing node supported by the computing system.

7. The system of claim 1, further comprising a shared memory segment within the customizing-interface module, the shared memory segment:

accessible by both the application and the file system; and

operable to support the messaging service by storing data from the application written to the shared memory segment and read by the file system for storage by the file system, by storing a request from the application for reading by the file system, and by storing data written by the file system for the application and responsive to the request.

8. The system of claim 7, the shared memory segment further comprising:

a ring buffer, the ring buffer comprising;

an array of message-request slots, a message-request slot operable to implement a message service between an application and the file system such that multiple message-request slots from the array implement messaging services between the file system and multiple applications concurrently.

9. The system of claim 8, further comprising a coordination module operable to arbitrate between quality of service demands for file-system requests from the multiple applications for which the ring buffer concurrently supports messaging services, thereby customizing the messaging services to the file-system requests.

10. The system of claim 8, further comprising a header section within the shared memory segment, the header operable to mitigate a need to traverse the ring buffer to find an available message-request slot and comprising at least one of:

a read index, indexing individual applications to individual message-request slots in the array providing messaging services for system call emulations related to data retrieval for the individual applications;

a write index, indexing individual applications to individual message-request slots in the array providing messaging services for system call emulations related to data storage for the individual applications; and

a linked list of free message-request slots not currently used to implement a messaging service for an application.

11. A method for providing enhanced file-system services to an application, comprising:

receiving, by shared memory in user space, shared by an application and a messaging module and a file system residing at a computing system, comprising a processor and memory, a-request parameters for the file system, the application, the messaging module, and the file system also residing in the user space;

providing, by the messaging module, at least one efficiency gain for a request from the application to the file system by providing the request parameters to the shared memory to the request through the messaging module in the user space to the file system and bypass a system call interface for a kernel space pertaining to the computing system;

interacting with a storage media device for storage retrieval operations, consistent with the request parameters, by a user-space device driver in the messaging module, operable to perform I/O operations on the storage media device in the user space without first writing the data to kernel space; and

reading, by the application, responses to the request parameters retrieved from the storage media device by the user-space device driver, without use of a buffer in kernel space.

12. The method of claim 11, further comprising:

providing, a library within the messaging module,

including in the library, a non-standard system-call tailored to respond to application-specific needs for at least one of reading from and writing to storage;

matching the request to the non-standard system call; and

carrying out the non-standard system call by providing the request parameters, corresponding to the non-standard system-call, to the shared memory,

the library residing within a messaging layer below the application, the messaging layer remaining within the user space and allowing the messaging module to be independent of an approach to formulating the request to the file system utilized by the application.

13. The method of claim 12, further comprising:

analyzing, by the library, requests from the application to detect a pattern of requests from the application to the file system;

pre-fetching, by the library, data into memory for anticipated requests to anticipate the pattern of requests.

14. A system for providing enhanced file-system services to an application in a data-center computing system, further comprising:

a local file system operable to function within user space of memory of at least one hardware processor of a compute node, the compute node within a data-center comprising multiple computing nodes, each compute node having a hardware processor and memory;

a messaging module also operable to function in user space of the memory of the at least one hardware processor of the compute node and to broker requests from an application to the local file system and responses to the requests within user space, avoiding constraints on interactions imposed by a kernel-space interface for system calls;

a library within the messaging module operable to provide storage and retrieval interactions on and from, respectively, a storage media device by handling I/O operations in user space with a user-space device driver for an efficiency not offered by the kernel-space interface for system calls; and

shared memory, in the user space, shared by the application and the library and the file system and operable to receive request parameters for the file system and responses to the request parameters retrieved from the storage medium device by the user-space device driver, without use of a buffer in kernel space, for reading by the application.

15. The system of claim 14, further comprising an independent layer within user space and below the application, the messaging module and the library separated from the application by the independent layer and operable to service different applications;

an analysis module in the library and in the memory of the at least one hardware processor of the compute node, the analysis module operable to analyze the requests from the application for a pattern among the requests;

a segment of shared memory operable to receive data from the file system; and

the library operable to provide at the least one service customized to the application by at least one of caching and pre-fetching data from a local storage device by the file system, the data anticipated by the pattern detected among the requests.

16. The system of claim 14, further comprising an array of support slots within the shared memory, each support slot operable to hold data for a distinct application, the data to be both retrieved from the storage medium device and stored on the storage medium device by the user-space device driver in accordance with requests by the distinct application to the library for the file system.

17. The system of claim 16, further comprising a concurrency module in the memory of the at least one hardware processor of the compute node and operable to provide a customized service by implementing a quality of service parameter for at least one of an application, a request, and a group of requests, the quality of service parameter dictating a priority relative to other demands placed upon the file system by additional requests concurrently directed to the file system.

18. The system of claim 14, wherein:

the computing nodes of the data center include multiple virtual computing nodes supported by a virtual computing environment;

the file system resides in an instance of user space unique to an individual virtual computing node; and

the messaging module also resides in the instance of user space unique to the individual virtual computing node.