James Bottomley wrote:
> > Is it possible to flush all entries in the buffer cache corresponding
> > to a single block device (i.e. simply drop them if they aren't dirty,
> > or write them to disk and drop them after this if they are dirty)?
>
> Yes, just send the BLKFLSBUF ioctl to the device this syncs the device then
> removes all the buffers from the cache. We use it as a tool to move a SAN
> device around a cluster, which is similar to what you want to do.
Last time this question was raised, someone mentioned
a little utility called flushb . Here is its source:
/*
* flushb.c --- This routine flushes the disk buffers for a disk
*/
/*
* modified August 2000 by Juri Haberland
* juri.haberland@innominate.de
*/
#include <stdio.h>
#include <fcntl.h>
#include <linux/fs.h>
#define NOARGS void
const char *progname;
static void usage(NOARGS)
{
fprintf(stderr, "Usage: %s disk\n", progname);
exit(1);
}
int main(int argc, char **argv)
{
int fd;
progname = argv[0];
if (argc != 2)
usage();
fd = open(argv[1], O_RDONLY, 0);
if (fd < 0) {
perror("open");
exit(1);
}
/*
* Note: to reread the partition table, use the ioctl
* BLKRRPART instead of BLKFSLBUF.
*/
if (ioctl(fd, BLKFLSBUF, 0) < 0) {
perror("ioctl BLKFLSBUF");
exit(1);
}
return 0;
}
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This archive was generated by hypermail 2b29 : Sat Feb 17 2001 - 13:31:33 EST