> On Aug 06, 2009 16:37 -0400, Nick Dokos wrote:
> > I did that to begin with but the problem turns out to be much more
> > mundane: there was an IO error on one of the volumes. It wasn't quite
> > obvious (no red lights going off) but there *was* a message in
> > /var/log/messages - unfortunately I missed it. I eventually recreated
> > the error by trying to read the file with ``od -c'' and then went back
> > and found the original error. I don't know why/how ll_ver_fs managed to
> > read the offset and come up with a 1M difference[1] -- ``od -c'' failed with
> > a big thud.
>
> Can you have a look at the error handling in ll_ver_fs at that point?
> It seems that it might just have re-used the previous 1MB buffer, but
> didn't detect/report the error from the read, which would itself be bad.
>
It looks right to me:
,----
| ...
| if (read(fd, chunk_buf, chunksize) < 0) {
| fprintf(stderr, "\n%s: read %s+%llu failed: %s\n",
| progname, file, offset, strerror(errno));
| return 1;
| }
| if (verify_chunk(chunk_buf, chunksize, offset, time_st,
| inode_st, file) != 0)
| return 1;
| ...
`----
The read() should have failed (and I should have gotten a different error
message) but somehow it didn't - instead, verify_chunk() was called and
*that* detected the mismatch.
Thanks,
Nick
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
