Am Sa, den 03.01.2004 schrieb Joe Thornber um 11:47:
> > I've folded my last changes on dm-crypt into a patchset (like Joe does).
>
> Excellent, this makes my job a lot easier. I presume you found the
> 'pm' tool on my webpage ?
Yes, I've seen that, looks nice. But I actually didn't use it for this.
I did play a lot with the source and kept some copies from time to time.
I then used these copies to track my changes and clean them up.
Sometimes I find out that I've got very long shell commands in my bash
history (which grow over time) and I then decide to turm them into a
useful script. I always had some that dealt with your patchsets and so I
ended up with my own little tool. ;)
Well, keeping a copy of the whole kernel around for every change isn't
really an option. I'll always use what comes in handy.
BTW: If you're interested in a tool that creates large BIOs, I've
attached a small test program that uses Direct-IO. It doesn't actually
write something useful, just some random memory.
bio-test <device> <sector> [<offset>]
If you use it on top of a striped target with large and odd sector
numbers and offsets you'll end up having all kind of BIOs, not just the
usual page sized ones with only a single bvec.
#define _GNU_SOURCE
#define _FILE_OFFSET_BITS 64
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#include <errno.h>
#define SECTOR_SHIFT 9
int main(int argc, char **argv)
{
int f, r;
unsigned long size;
unsigned long bufsize;
unsigned int pagesize;
off_t offset;
char *endptr;
char *buffer;
if (argc < 3)
return 1;
size = strtol(argv[2], &endptr, 10);
if (*endptr || !size || size > 4096)
return 1;
size <<= SECTOR_SHIFT;
bufsize = (size + pagesize - 1) & ~(pagesize - 1);
if (argc >= 4) {
offset = (off_t)strtoll(argv[3], &endptr, 10);
if (*endptr)
return 1;
offset <<= SECTOR_SHIFT;
} else
offset = 0;
f = open(argv[1], O_WRONLY | O_DIRECT | O_SYNC);
if (f < 0) {
perror("fopen");
return 1;
}
if (offset) {
if (lseek(f, offset, SEEK_SET) != offset) {
perror("lseek");
return 1;
}
}
buffer = mmap(NULL, bufsize, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
if (!buffer) {
perror("mmap");
close(f);
return 1;
}
r = write(f, buffer, size);
munmap(buffer, bufsize);
close(f);
if (r < 0) {
perror("write");
return 1;
}
printf("Result: %d\n", r);
return 0;
}
