Most recent kernel where this bug did not occur: don't know
Distribution: SUSE 10.0
Hardware Environment: x86
Software Environment:
Problem Description:
POSIX requires that truncate() only change the ctime and mtime on the file if
the file size actually change.  On ext2 and ext3, this seems to work as required. 

However, Reiserfs is broken: it only updates the file timestamps if a file is
shrunk.  If the file size remains the same the timestamps are not changed
(correct), but if the file size increases, the timestamps are also not changed
(wrong).

Steps to reproduce:

Something like the following can be used to test:
...

int main(int argc, char *argv[])
{
    if (truncate(argv[1], atoi(argv[2])) == -1) 
        perror("truncate")
}