missing files in readdir(3) on NFS export of ZFS volume (since v28?)

Hello,

I'm running a 9-current server as compiled on Sat Mar  5 02:17:14
CET 2011.

Since I upgraded to ZFS v28 I noticed missing files from NFS. The
files are still accessible through NFS but they don't show up on a
readdir(3).

On the NFS server (files are stored on a ZFS v15 volume, not yet
upgraded to the v28 format):

% cd /usr/ports/devel/autoconf
% ls -i
311401 Makefile         204505 files            204509 pkg-plist
204504 distinfo         204508 pkg-descr

On the NFS client side (FreeBSD 8.2-RELEASE):

% cd /usr/ports/devel/autoconf
% ls -i
204504 distinfo         204508 pkg-descr
204505 files            204509 pkg-plist

Yet the missing file can be accessed:
% head -3 Makefile
# New ports collection makefile for:    autoconf
# Date created:         7th December 2006
# Whom:                 ade_at_FreeBSD.org

Note that the missing files are scattered throughout the volume,
no relation to the inode number, as shown on a diff:

_at__at_ -1,8 +1,6 _at__at_
      3        7 drwxr-xr-x   70 pb               staff                  93  4 mar 19:11 /usr/ports
-     4        2 -rw-r--r--    1 pb               staff                 241 24 jan  2007 /usr/ports/astro/tclgeomap/pkg-plist
      5        3 drwxr-xr-x    2 pb               staff                   6 22 fév 12:04 /usr/ports/astro/tkgeomap
      6        3 drwxr-xr-x    4 pb               staff                   6 29 jul  2008 /usr/ports/Tools
-     7        5 drwxr-xr-x   33 pb               staff                  34 25 nov 15:59 /usr/ports/accessibility
      8        3 drwxr-xr-x   12 pb               staff                  14  9 fév  2009 /usr/ports/arabic
     11       51 drwxr-xr-x  900 pb               staff                 901  6 mar 14:36 /usr/ports/audio
     12        3 -rw-r--r--    1 pb               staff                 584 25 aoû  2006 /usr/ports/astro/tkgeomap/pkg-descr
_at__at_ -16,10 +14,8 _at__at_
     23        3 drwxr-xr-x    3 pb               staff                   7 24 mar  2010 /usr/ports/astro/wcslib
     24        4 -rw-r--r--    1 pb               staff                1414  5 jan  2010 /usr/ports/astro/wcslib/Makefile
     25        5 drwxr-xr-x   31 pb               staff                  33  1 jan 23:16 /usr/ports/french
-    26        2 -rw-r--r--    1 pb               staff                 197  5 jan  2010 /usr/ports/astro/wcslib/distinfo
     27       63 drwxr-xr-x  1110 pb               staff                1111 23 fév 15:37 /usr/ports/games
     28        3 drwxr-xr-x    2 pb               staff                   4 24 mar  2010 /usr/ports/astro/wcslib/files
-    29        2 -rw-r--r--    1 pb               staff                 236  5 jan  2010 /usr/ports/astro/wcslib/files/6-patch-configure
     30        3 -rw-r--r--    1 pb               staff                 677  5 jan  2010 /usr/ports/astro/wcslib/files/patch-GNUmakefile
     31        2 -rw-r--r--    1 pb               staff                 401 17 jul  2009 /usr/ports/astro/wcslib/pkg-descr
     32        4 -rw-r--r--    1 pb               staff                1515  5 jan  2010 /usr/ports/astro/wcslib/pkg-plist
...

Reverting to an old 9-current kernel (January 10, before the ZFS
v28 patches) fixes the problem...
-- 
Sent from my FreeBSD server
Pierre Beyssac	      	    		pb_at_fasterix.frmug.org