Abstract: Processing for file system volume error detection and processing for resultant error correction are separated to support system availability and user satisfaction. File system volumes for storing data structures are proactively scanned while the volumes remain online to search for errors or corruptions thereon. Found errors are scheduled to be corrected, i.e., spot corrected, dependent on the severity of the identified errors, error correction scheduling and/or at the determination of a file system administrator and/or user, to assist in maintaining minimal user and file system impact. When spot correction is initialized, one file system volume at a time is taken offline for correction. Spot correction verifies prior logged corruptions for the offline volume, and if independently verified, attempts to correct the prior noted corruptions. Volumes are retained offline only for the time necessary to verify and attempt to correct prior noted volume corruptions.

Abstract: Perceived corruptions encountered on file system volumes, and which cannot be initially remedied online, are processed to verify whether they are true, existing volume data structure corruptions or, alternatively, false positives. Upon the verification of one or more of a volume's corruptions, error scanning is performed to check for, and attempt to remedy online, all the existing corruptions on the volume. Subsequent to error scanning processing, if one or more verified corruptions continue to exist on a file system volume, at file system boot up time spot corruption correction is performed to attempt to remedy the existing, verified corruptions on the volume. Spot corruption correction is performed to attempt to correct verified data structure corruptions on a volume of the file system while the volume is maintained offline for the time necessary to attempt to correct its prior identified corruptions.

Abstract: Data structure errors, or corruptions, identified during, e.g., normal computing device system processing, file system processing or user access processing, are verified prior to the file system identifying the error for offline correction or notifying the user or system administrator a data structure error exists. Identified data structure corruptions are verified while the file system volumes are maintained online and otherwise accessible to other processing tasks and user access. Verified data structure corruptions are logged for further corrective processing. Data structure corruptions that cannot be verified, i.e., false positives, are not further processed and are not identified to file system administrators or users as corruptions, freeing the file system to concentrate on normal processing and true, verifiable errors.

Abstract: Data structure errors, or corruptions, identified during, e.g., normal computing device system processing, file system processing or user access processing, are verified prior to the file system identifying the error for offline correction or notifying the user or system administrator a data structure error exists. Identified data structure corruptions are verified while the file system volumes are maintained online and otherwise accessible to other processing tasks and user access. Verified data structure corruptions are logged for further corrective processing. Data structure corruptions that cannot be verified, i.e., false positives, are not further processed and are not identified to file system administrators or users as corruptions, freeing the file system to concentrate on normal processing and true, verifiable errors.

Abstract: Processing for file system volume error detection and processing for resultant error correction are separated to support system availability and user satisfaction. File system volumes for storing data structures are proactively scanned while the volumes remain online to search for errors or corruptions thereon. Found errors are scheduled to be corrected, i.e., spot corrected, dependent on the severity of the identified errors, error correction scheduling and/or at the determination of a file system administrator and/or user, to assist in maintaining minimal user and file system impact. When spot correction is initialized, one file system volume at a time is taken offline for correction. Spot correction verifies prior logged corruptions for the offline volume, and if independently verified, attempts to correct the prior noted corruptions. Volumes are retained offline only for the time necessary to verify and attempt to correct prior noted volume corruptions.

Abstract: Perceived corruptions encountered on file system volumes, and which cannot be initially remedied online, are processed to verify whether they are true, existing volume data structure corruptions or, alternatively, false positives. Upon the verification of one or more of a volume's corruptions, error scanning is performed to check for, and attempt to remedy online, all the existing corruptions on the volume. Subsequent to error scanning processing, if one or more verified corruptions continue to exist on a file system volume, at file system boot up time spot corruption correction is performed to attempt to remedy the existing, verified corruptions on the volume. Spot corruption correction is performed to attempt to correct verified data structure corruptions on a volume of the file system while the volume is maintained offline for the time necessary to attempt to correct its prior identified corruptions.

Abstract: A substantially zero overhead mutual-exclusion apparatus and method (90, 120) is provided that allows concurrent reading and updating data while maintaining data coherency. That is, a data reading process executes the same sequence of instructions that would be executed if the data were never updated. Rather than depending exclusively on overhead-imposing locks, this mutual-exclusion mechanism tracks an execution history (138) of a thread (16, 112) to determine safe times for processing a current generation (108, 130, 131) of data updates while a next generation (110, 132, 133) of data updates is concurrently being saved. A thread is any locus of control, such as a processor. A summary of thread activity (106, 122) tracks which threads have passed through a quiescent state after the current generation of updates was started.

Abstract: A substantially zero overhead mutual-exclusion apparatus and method (90, 120) is provided that allows concurrent reading and updating data while maintaining data coherency. That is, a data reading process executes the same sequence of instructions that would be executed if the data were never updated. Rather than depending exclusively on overhead-imposing locks, this mutual-exclusion mechanism tracks an execution history (138) of a thread (16, 112) to determine safe times for processing a current generation (108, 130, 131) of data updates while a next generation (110, 132, 133) of data updates is concurrently being saved. A thread is any locus of control, such as a processor. A summary of thread activity (106, 122) tracks which threads have passed through a quiescent state after the current generation of updates was started.

Abstract: A substantially zero overhead mutual-exclusion apparatus and method (90, 120) is provided that allows concurrent reading and updating data while maintaining data coherency. That is, a data reading process executes the same sequence of instructions that would be executed if the data were never updated. Rather than depending exclusively on overhead-imposing locks, this mutual-exclusion mechanism tracks an execution history (138) of a thread (16, 112) to determine safe times for processing a current generation (108, 130, 131) of data updates while a next generation (110, 132, 133) of data updates is concurrently being saved. A thread is any locus of control, such as a processor. A summary of thread activity (106, 122) tracks which threads have passed through a quiescent state after the current generation of updates was started.

Abstract: A substantially zero overhead mutual-exclusion apparatus and method (90, 120) is provided that allows concurrent reading and updating data while maintaining data coherency. That is, a data reading process executes the same sequence of instructions that would be executed if the data were never updated. Rather than depending exclusively on overhead-imposing locks, this mutual-exclusion mechanism tracks an execution history (138) of a thread (16, 112) to determine safe times for processing a current generation (108, 130, 131) of data updates while a next generation (110, 132, 133) of data updates is concurrently being saved. A thread is any locus of control, such as a processor. A summary of thread activity (106, 122) tracks which threads have passed through a quiescent state after the current generation of updates was started.