/bin/pwd causes a fstat on all autofs mounted volumes

[Paul Raines]

When one runs /bin/pwd (using coreutils 5.97) on an autofs mounted
volume, it causes an fstat to be run on all autofs mounted volumes
on that automount's mount point.  THis is not only a big waste but
if a NFS mount server down it causes /bin/pwd to hang.  /bin/pwd
in perfectly working NFS mount should not hang because some other
mount is down.

I have an autofs mount point at /autofs/space.  THe autofs map for this mount 
point has over a thousand entries.  If I am in /autofs/space/pgolland_001
for instance I do a 'strace /bin/pwd' I see a thousand lines like:

fstatat64(4, "meso_018", {st_mode=S_IFDIR|0555, st_size=0, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
fstatat64(4, "47tuser_006", {st_mode=S_IFDIR|0555, st_size=0, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
fstatat64(4, "bomba_036", {st_mode=S_IFDIR|0555, st_size=0, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
fstatat64(4, "pimlico_004", {st_mode=S_IFDIR|0555, st_size=0, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
fstatat64(4, "tadasana_001", {st_mode=S_IFDIR|0555, st_size=0, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
fstatat64(4, "acumonk_003", {st_mode=S_IFDIR|0555, st_size=0, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
fstatat64(4, "mody_004", {st_mode=S_IFDIR|0555, st_size=0, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
fstatat64(4, "soulenoid_006", {st_mode=S_IFDIR|0555, st_size=0, ...}, 
AT_SYMLINK_NOFOLLOW) = 0
fstatat64(4, "madrc_003", {st_mode=S_IFDIR|0555, st_size=0, ...}, 
AT_SYMLINK_NOFOLLOW) = 0

until it hangs on one that is mounted but down at the moment.

--
---------------------------------------------------------------
Paul Raines                email: raines at nmr.mgh.harvard.edu
MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging
149 (2301) 13th Street     Charlestown, MA 02129            USA