On Sun, Jul 13, 2025 at 10:46:57PM +0900, Olivier Certner wrote:
> Hi Charlie,
>
> The panic you're seeing is caused by 'MPASS(*eofflag != 0);' in
> vn_dir_next_dirent(). This test is here to check that VOP_READDIR() works
> properly. In particular, if VOP_READDIR() returned 0 (no error), and the
> length it filled is 0 (nothing was added), then we must be at EOF, and
> VOP_READDIR() must have set '*eofflag' to something non-zero. UFS has been
> verified to abide by this rule (unless the directory being read is
> malformed). Which filesystem are you using?
>
> Shot in the dark & educated guess: You're using ZFS, and you've just stumbled
> on the following case (lines from 'zfs_vnops_os.c'):
>
> /*
>
> * Quit if directory has been removed (posix)
>
> */
> if ((*eofp = zp->z_unlinked) != 0) {
> zfs_exit(zfsvfs, FTAG);
> return (0);
> }
>
> which is a corner case that apparently has been missed. Just add some 'if
> (eofflag != NULL) *eofflag = 1;' inside the "then" block there and retry. It
> looks like all other cases in this function are handled correctly (but I have
> not thoroughly verified).
The store to *eofp sets eofflag, so that is not the problem.
Based on the presence of "efi" as a component name in the stack trace
that Charlie provided, I suspect the problem is rather in msdosfs, but I
don't immediately see what's wrong there.
> I'll be mostly AFK for the next 10 days, so probably won't be able to
> follow-up, but hope that will help.
>
> Thanks and regards.
>
> --
> Olivier Certner
