VxWorks
Kernel Programmer's Guide, 6.9
xvi
Deleting Devices ................................................................................................ 314
12.14.3 File Descriptors .................................................................................................. 316
File Descriptor Table ......................................................................................... 317
Example of Opening a File ............................................................................... 317
Example of Reading Data from the File ......................................................... 319
Example of Closing a File ................................................................................. 320
Implementing select( ) ...................................................................................... 320
Cache Coherency ............................................................................................... 323
13 Local File Systems ..................................................................................... 327
13.1 Introduction ...................................................................................................................... 327
13.2 File System Monitor ...................................................................................................... 329
Device Insertion Events .................................................................................... 330
XBD Name Mapping Facility .......................................................................... 331
13.3 Virtual Root File System: VRFS ................................................................................... 331
13.4 Highly Reliable File System: HRFS ............................................................................ 332
13.4.1 Configuring VxWorks for HRFS ..................................................................... 333
13.4.2 Configuring HRFS ............................................................................................ 334
13.4.3 Creating an HRFS File System ....................................................................... 334
Overview of HRFS File System Creation ....................................................... 335
HRFS File System Creation Steps ................................................................... 335
13.4.4 HRFS, ATA, and RAM Disk Examples .......................................................... 336
13.4.5 Optimizing HRFS Performance ...................................................................... 341
13.4.6 Transactional Operations and Commit Policies ......................................... 341
Automatic Commit Policy ............................................................................... 341
High-Speed Commit Policy ............................................................................. 342
Mandatory Commits ......................................................................................... 342
Rollbacks ............................................................................................................. 342
Programmatically Initiating Commits ........................................................... 343
13.4.7 File Access Time Stamps .................................................................................. 343
13.4.8 Maximum Number of Files and Directories ................................................. 343
13.4.9 Working with Directories ................................................................................ 343
Creating Subdirectories .................................................................................... 343
Removing Subdirectories ................................................................................. 344
Reading Directory Entries ................................................................................ 344
13.4.10 Working with Files ............................................................................................ 344
File I/O Routines ............................................................................................... 344
File Linking and Unlinking ............................................................................. 344
File Permissions ................................................................................................. 345
13.4.11 I/O Control Functions Supported by HRFS ................................................. 345
13.4.12 Crash Recovery and Volume Consistency .................................................... 346