rmdir bug?

[Bruce Janson]

Hi,
    We are using Coda under Linux 2.2.13.  The link count of a directory
in a Coda file system does not appear to be updated when a subdirectory
is removed.  Assuming that "/" is a Coda file system, the following probe
program should be silent.  When the bug is present it prints an error
message:

        #include        <sys/types.h>
        #include        <sys/stat.h>

        main()
        {
                char            *dir    = "/a";
                char            *subdir = "/a/b";
                struct stat     statb;

                (void)mkdir(dir, 0755);
                (void)mkdir(subdir, 0755);
                (void)stat(dir, &statb);
                (void)rmdir(subdir);
                (void)stat(dir, &statb);
                if (statb.st_nlink != 2)
                {
                        printf("bug\n");
                        exit(1);
                }

                exit(0);
        }

If .../linux-2.2.13/fs/coda/dir.c:487-488 are changed from

        if (de->d_inode->i_nlink)
                de->d_inode->i_nlink --;

to

        if (de->d_inode->i_nlink)
                de->d_inode->i_nlink --;
        dir->i_nlink--;

then the above probe becomes silent.

This change makes the Coda kernel code track the ext2 `template'
more closely (fs/ext2/namei.c:638) but deviate further from the
NFS code (fs/nfs/dir.c:nfs_rmdir()).

Regards,
bruce.