2002-10-08 02:55:06

by Andrew Morton

Subject: Re: The reason to call it 3.0 is the desktop (was Re: [OT] 2.6 not 3.0 - (NUMA))

Simon Kirby wrote:
>
> On Mon, Oct 07, 2002 at 07:50:27PM -0700, Andrew Morton wrote:
>
> > Oh tell me about it.
> >
> > Appended is the offset->block mapping for my "linux-kernel" mailbox.
> > Read it and weep...
>
> Eep. :) Just out of interest, how did you get these mappings?
>

/*
* Show file blocks
*/

#include <unistd.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>

#include <linux/fs.h>

static const char *myname;

int main(int argc, char **argv)
{
int i, err = 0;
int fd;
long blksize;
off_t filesz;
long fileblks, blk;
long start = -1, end = -1;
long first_logical = -1;

myname = argv[0];

while((i = getopt(argc, argv, "")) != EOF) {
switch(i) {
default:
err++;
break;
}
}

if (err || optind != argc-1) {
fprintf(stderr, "Usage: %s file\n",
myname);
exit(1);
}

fd = open(argv[optind], O_RDONLY);
if (fd == -1) {
perror(argv[optind]);
exit(1);
}

if (ioctl(fd, FIGETBSZ, &blksize) == -1) {
perror("FIGETBSZ");
fprintf(stderr, "assuming 4096\n");
blksize = 4096;
}

filesz = lseek(fd, 0, SEEK_END);
lseek(fd, 0, SEEK_SET);
fileblks = (filesz + blksize-1) / blksize;

err = 0;
for(blk = 0; blk < fileblks; blk++) {
long devblk = blk;

if (ioctl(fd, FIBMAP, &devblk) == -1) {
if (errno == -EPERM) {
fprintf(stderr, "got root?\n");
exit(1);
}
printf("%ld: %d (%s)\n",
blk, errno, strerror(errno));
err++;
} else {
if (start == -1) {
start = devblk;
end = devblk;
first_logical = blk;
} else {
if (devblk == end + 1) {
end++;
} else {
printf("%ld-%ld: %ld-%ld (%ld)\n",
first_logical,
first_logical+(end-start),
start, end,
end - start + 1);
start = devblk;
end = devblk;
first_logical = blk;
}
}
}
}

if (start != -1)
printf("%ld-%ld: %ld-%ld (%ld)\n",
first_logical,
first_logical+(end-start),
start, end,
end - start + 1);

exit(err ? 1 : 0);
}

2002-10-08 16:11:48

by Theodore Ts'o

Subject: Re: The reason to call it 3.0 is the desktop (was Re: [OT] 2.6 not 3.0 - (NUMA))

On Mon, Oct 07, 2002 at 08:00:30PM -0700, Andrew Morton wrote:
> Simon Kirby wrote:
> >
> > On Mon, Oct 07, 2002 at 07:50:27PM -0700, Andrew Morton wrote:
> >
> > > Oh tell me about it.
> > >
> > > Appended is the offset->block mapping for my "linux-kernel" mailbox.
> > > Read it and weep...
> >
> > Eep. :) Just out of interest, how did you get these mappings?
> >

Debugfs will also show the mappings, although it's less reliable when
used on a mounted filesystem....

- Ted