IFS - FS Service Routines

Installable File Systems for OS/2
Installable File System Mechanism Installable File System Overview Extended Attributes FSD File Image FSD Initialization IFS Commands File System Function Calls FSD System Interfaces FSD Calling Conventions and Requirements FS Service Routines FS Helper Functions Remote IPL / Bootable IFS mini-FDS Entry Points mini-FDS Helper Routines

Reprint Courtesy of International Business Machines Corporation, © International Business Machines Corporation The following table summarizes the entry points that make up the interface between the kernel and the FSD.

Note

Names must be in all upper case, as required by OS/2 naming conventions.

FS Entry Point       Description                         FSDs Required
                                                         to export
────────────────────────────────────────────────────────────────────────
FS_ALLOCATEPAGESPACE Adjust the size of paging file      PAGE I/O
────────────────────────────────────────────────────────────────────────
FS_ATTACH            Attach to an FSD                    ALL
────────────────────────────────────────────────────────────────────────
FS_CANCELLOCKREQUEST Cancel file record lock request     FILE I/O
────────────────────────────────────────────────────────────────────────
FS_CHDIR             Change/Verify directory path        ALL
────────────────────────────────────────────────────────────────────────
FS_CHGFILEPTR        Move a file's position pointer      ALL
────────────────────────────────────────────────────────────────────────
FS_CLOSE             Release a file handle               ALL
────────────────────────────────────────────────────────────────────────
FS_COMMIT            Flush a file's buffer to disk       ALL
────────────────────────────────────────────────────────────────────────
FS_COPY              Copy a file                         ALL
────────────────────────────────────────────────────────────────────────
FS_DELETE            Delete a file                       ALL
────────────────────────────────────────────────────────────────────────
FS_DOPAGEIO          Perform paging I/O operations       PAGE I/O
────────────────────────────────────────────────────────────────────────
FS_EXIT              End of a process cleanup            ALL
────────────────────────────────────────────────────────────────────────
FS_FILEATTRIBUTE     Query/Set file's attributes         ALL
────────────────────────────────────────────────────────────────────────
FS_FILEINFO          Query/Set file's information        ALL
────────────────────────────────────────────────────────────────────────
FS_FILEIO            Multi-function file I/O             ALL
────────────────────────────────────────────────────────────────────────
FS_FILELOCKS         Request a file record lock/unlock   FILE I/O
────────────────────────────────────────────────────────────────────────
FS_FINDCLOSE         Directory search close              ALL
────────────────────────────────────────────────────────────────────────
FS_FINDFIRST         Find first matching filename        ALL
────────────────────────────────────────────────────────────────────────
FS_FINDFROMNAME      Find matching filename from name    ALL
────────────────────────────────────────────────────────────────────────
FS_FINDNEXT          Find next matching filename         ALL
────────────────────────────────────────────────────────────────────────
FS_FINDNOTIFYCLOSE   Close FindNotify handle             ALL
────────────────────────────────────────────────────────────────────────
FS_FINDNOTIFYFIRST   Monitor a directory for changes     ALL
────────────────────────────────────────────────────────────────────────
FS_FINDNOTIFYNEXT    Resume reporting directory changes  ALL
────────────────────────────────────────────────────────────────────────
FS_FLUSHBUF          Commit file buffers to disk         ALL
────────────────────────────────────────────────────────────────────────
FS_FSCTL             File system control                 ALL
────────────────────────────────────────────────────────────────────────
FS_FSINFO            Query/Set file system information   ALL
────────────────────────────────────────────────────────────────────────
FS_INIT              FSD initialization                  ALL
────────────────────────────────────────────────────────────────────────
FS_IOCTL             I/O device control                  ALL
────────────────────────────────────────────────────────────────────────
FS_MKDIR             Make a directory                    ALL
────────────────────────────────────────────────────────────────────────
FS_MOUNT             Mount/unmount volumes               ALL
────────────────────────────────────────────────────────────────────────
FS_MOVE              Move a file or subdirectory         ALL
────────────────────────────────────────────────────────────────────────
FS_NEWSIZE           Change a file's logical size        ALL
────────────────────────────────────────────────────────────────────────
FS_NMPIPE            Do a named pipe operation           ALL
────────────────────────────────────────────────────────────────────────
FS_OPENCREATE        Open/create/replace files           ALL
────────────────────────────────────────────────────────────────────────
FS_OPENPAGEFILE      Create paging file and handle       PAGE I/O
────────────────────────────────────────────────────────────────────────
FS_PATHINFO          Query/Set a file's information      ALL
────────────────────────────────────────────────────────────────────────
FS_PROCESSNAME       FSD unique name canonicalization    ALL
────────────────────────────────────────────────────────────────────────
FS_READ              Read data from a file               ALL
────────────────────────────────────────────────────────────────────────
FS_RMDIR             Remove a subdirectory               ALL
────────────────────────────────────────────────────────────────────────
FS_SETSWAP           Notification of swapfile ownership  ALL
────────────────────────────────────────────────────────────────────────
FS_SHUTDOWN          Shutdown file system                ALL
────────────────────────────────────────────────────────────────────────
FS_VERIFYUNCNAME     Verify UNC server ownership         UNC
────────────────────────────────────────────────────────────────────────
FS_WRITE             Write data to a file                ALL

Each FS entry point has a distinct parameter list composed of those parameters needed by that particular entry. Parameters include:

• File pathname
• Current disk/directory information
• Open file information
• Application data buffers
• Descriptions of file extended attributes
• Other parameters specific to an individual call

Most of the FS entry points have a level parameter for specifying the level of information they are provided or have to supply. FSDs must provide for additional levels which may be added in future versions of OS/2 by returning ERROR_NOT_ SUPPORTED for any level they do not recognize.

File system drivers which support hierarchical directory structures must use '\' and '/' as path name component separators. File system drivers which do not support hierarchical directory structures must reject as illegal any use of '\' or '/' in path names. The file names '.' and '..' are reserved for use in hierarchical directory structures for the current directory and the parent of the current directory, respectively.

Unless otherwise specified in the descriptions below, data buffers may be accessed without concern for the accessibility of the data. OS/2 will either check buffers for accessibility and lock them, or transfer them into locally accessible data areas.

Simple parameters will be verified by the IFS router before the FS service routine is called.

Note

New with 2.0, some entry points need only be exported and supported by those FSDs which desire to service the pager (PAGE I/0), UNC servers (UNC) and/or file locking (FILE I/O). With these new entry point groups, a FSD must export all or none of the entry points within a particular group.

These optional entry points are:

FS_ALLOCATEPAGESPACE    (PAGE I/O)
FS_CANCELLOCKREQUEST    (FILE I/O)
FS_DOPAGEIO             (PAGE I/O)
FS_FILELOCKS            (FILE I/O)
FS_OPENPAGEFILE         (PAGE I/O)
FS_VERIFYUNCNAME        (UNC)