no such file or directory on concurrent dd to new directory

[carns]

Reported by David Metheny. Use two separate PVFS clients. Alternate running the following two scripts:

#!/bin/bash

sudo dmesg -c
dd if=/dev/zero of=/mnt/pvfs2/dir/subdir/subsubdir/foo1 bs=10M count=2 &
dd if=/dev/zero of=/mnt/pvfs2/dir/subdir/subsubdir/foo2 bs=10M count=2 &
dd if=/dev/zero of=/mnt/pvfs2/dir/subdir/subsubdir/foo3 bs=10M count=2 &
dd if=/dev/zero of=/mnt/pvfs2/dir/subdir/subsubdir/foo4 bs=10M count=2 &

wait

#!/bin/bash
rm -rf /mnt/pvfs2/dir
mkdir -p /mnt/pvfs2/dir/subdir/subsubdir

The ampersands are important. If the dd's are not run in the background, then everything works fine. If they are run in the background, then at least one of them will occasionally get "no such file or directory" errors.

The issue appears to be handling the case in which two processes are simultaneously trying to revalidate the same dentry?

[carns]

Added d_put() call in the revalidation failure path to try to make sure that dentry is flushed. Appears to work. Committed to cvs.

Will reopen ticket if anything turns up in testing or nightlies.

[carns]

previous comment should have said "d_drop()" rather than "d_put()".