Changes between Version 17 and Version 18 of Developer/FileSystems

Timestamp:

10/15/08 04:40:58 (16 years ago)

Author:

ChrisJohns

Comment:

Add code to sync the cache.

Developer/FileSystems

@@ -140 +140 @@
 The cache has a swap out task that collects blocks who's hold timer has expired for a specific device and writes them to disk device. Each modified block as an individual timer and the cache can be configured by the driver to only write consecutive blocks helping drivers that support the multi-sector write operations.
 
-The cache can be synchronized at the request of a user giving an application full control over the  data written to the disk media.
+The cache can be synchronized at the request of a user giving an application full control over the data written to the disk media. If you do not synchronize the data with the disk media before your applications terminates data could be lost or the file system could become corrupted. To synchronize the cache for a specific disk use the following code:
+
+  int fd = open (driver, O_WRONLY, 0);
+  if (fd < 0) {
+    fprintf( stderr, "%s: driver open failed: %s\n", argv[0], strerror (errno));
+    return 1;
+  }
+  
+  if (ioctl (fd, RTEMS_BLKIO_SYNCDEV) < 0) {
+    fprintf( stderr, "%s: driver sync failed: %s\n", argv[0], strerror (errno));
+    return 1;
+  }
+  
+  close (fd);
+  return 0;
 = Device Only File System =