The Virtual File System (VFS) kernel services are provided as fundamental building blocks for use when writing a virtual file system. These services present a standard interface for such functions as configuring file systems, creating and freeing v-nodes, and looking up path names.
Most functions involved in the writing of a file system are specific to that file system type. But a limited number of functions must be performed in a consistent manner across the various file system types to enable the logical file system to operate independently of the file system type.
The VFS kernel services are:
| common_reclock | Implements a generic interface to the record locking functions. |
| fidtovp | Maps a file system structure to a file ID. |
| gfsadd | Adds a file system type to the gfs table. |
| gfsdel | Removes a file system type from the gfs table. |
| vfs_hold | Holds a vfs structure and increments the structure's use count. |
| vfs_unhold | Releases a vfs structure and decrements the structure's use count. |
| vfsrele | Releases all resources associated with a virtual file system. |
| vfs_search | Searches the vfs list. |
| vn_free | Frees a v-node previously allocated by the vn_get kernel service. |
| vn_get | Allocates a virtual node and associates it with the designated virtual file system. |
| lookupvp | Retrieves the v-node that corresponds to the named path. |
Block I/O Buffer Cache Kernel Services: Overview
Understanding Execution Environments
Understanding Exception Handling
Understanding the Virtual File System Interface
Communications Physical Device Handler Model Overview
Understanding File Descriptors in AIX 5L Version 5.2 General Programming Concepts: Writing and Debugging Programs.
The msgctl subroutine, msgget subroutine, msgsnd subroutine, msgxrcv subroutine in AIX 5L Version 5.2 Technical Reference: Base Operating System and Extensions Volume 1.
The trchook subroutine in AIX 5L Version 5.2 Technical Reference: Base Operating System and Extensions Volume 2.
The iostat command in AIX 5L Version 5.2 Commands Reference, Volume 3.
The vmstat command in AIX 5L Version 5.2 Commands Reference, Volume 6.
The talloc kernel service, tfree kernel service, tstart kernel service, tstop kernel service in AIX 5L Version 5.2 Technical Reference: Kernel and Subsystems Volume 1.