Providing restartable file systems within computing devices

A computing device comprising:

• a processor;
• a storage device that stores at least some of a plurality of files;
• and
• an operating system executed by the processor to provide an operating environment for execution of a software application and receive a request from the software application executing in the operating environment, wherein the request specifies an operation to be performed by the operating system with respect to one of the plurality of files managed by a file system of the operating system,
• wherein the processor executes one or more kernel functions of the operating system and one or more file system functions provided by program code of the file system to perform the operation, wherein the kernel functions call the file system functions to perform the operation, and wherein the file system functions also call the kernel functions to perform the operation,
• wherein the operating system maintains a stack that stores data identifying those of the kernel functions that called the file system functions but not those of the file system functions that called the kernel functions, in response to determining that a first one of the file system functions that was called has failed, accesses the stack to identify a first one of the kernel functions that most recently called the first one of the file system functions, returns control of execution to the identified first one of the kernel functions that most recently called the first one of the file system functions without executing any of the file system functions called after the first one of the kernel functions that most recently called the first one of the file system functions but before the first one of the file system functions that failed, detects attempted execution of a second one of the file system functions after returning control of execution to the identified first one of the kernel functions, in response to detecting the attempted execution of the second one of the file system functions, accessing the stack to identify a second one of the kernel functions that most recently called the second one of the file system functions for which execution was attempted, and returns control of execution to the identified second one of the kernel functions without executing the second one of the file system functions.

A non-transitory computer-readable medium comprising instructions that, when executed, cause one or more processors to:

• execute an operating system to provide an operating environment for execution of a software application;
• receive a request from the software application with the operating system, wherein the request specifies an operation to be performed by the operating system with respect to one of the plurality of files managed by a file system of the operating system;
• execute one or more kernel functions of the operating system and one or more file system functions provided by program code of the file system to perform the operation, wherein the kernel functions call the file system functions to perform the operation, and wherein the file system functions also call the kernel functions to perform the operation;
• maintain a stack that stores data identifying those of the kernel functions that called the file system functions but not those of the file system functions that called the kernel functions;
• in response to determining that a first one of the file system functions that was called has failed, access the stack to identify a first one of the kernel functions that most recently called one of the file system functions;
• return control of execution to the identified first one of the kernel functions that most recently called the first one of the file system functions without executing any of the file system functions called after the first one of the kernel functions that most recently called the first one of the file system functions that failed but before the first one of the file system functions that failed;
• detect attempted execution of a second one of the file system functions after returning control of execution to the identified first one of the kernel functions;
• in response to detecting the attempted execution of the second one of the file system functions, access the stack to identify a second one of the kernel functions that most recently called the second one of the file system functions for which execution was attempted;
• and
• return control of execution to the identified second one of the kernel functions without executing the second one of the file system functions.

A method comprising:

• executing a first software module with one or more computing devices;
• executing a second software module different than the first software module with the one or more computing devices;
• wherein the first software module calls one or more functions of the second software module to perform an operation, and wherein the second software module calls one or more functions of the first software module to perform the operation;
• maintaining a stack with the one or more computing devices that stores data identifying those of the one or more functions of the first software module that called the one or more functions of the second software module but not those of the one or more functions of the second software module that called the one or more functions of the first software module;
• in response to determining that one of the one or more functions of the second software module that was called has failed, accessing the stack with the one or more computing devices to identify a first one of the one or more functions of the first software module that most recently called a first one of the one or more functions of the second software module;
• and
• returning control of execution to the identified first one of the one or more functions of the first software module that most recently called the first one of the one or more functions of the second software module without executing any of the one or more functions of the second software module called after the first one of the one or more functions of the first software module that most recently called the first one of the one or more functions of the second software module but before the first one of the one or more functions of the second software module that failed;
• detecting attempted execution of a second one of the functions of the second software module after returning control of execution to the identified first one of the functions of the first software module;
• in response to detecting the attempted execution of the second one of the functions of the second software module, accessing the stack to identify a second one of the functions of the first software module that most recently called the second one of the functions of the second software module for which execution was attempted;
• and
• returning control of execution to the identified second one of the functions of the first software module without executing the second one of the functions of the second software module.