On 2017/07/25 14:31, Eryu Guan wrote:
On Tue, Jul 25, 2017 at 09:39:28AM +0800, Xiao Yang wrote:
On 2017/07/24 18:11, Eryu Guan wrote:
The $dread_pid refers to the while-true-do loop, wait for $dread_pid
doesn't mean the xfs_io direct read process is already dead,
sometimes xfs_io process is still running and blocking
_scratch_unmount.
Hi Eryu,
Could you tell me what can i do to trigger this block?
I don't have a reliable reproducer, I hit this in my automated tests,
perhaps easier to hit with slow disks. You can try replace the fpunch
operation with a pwrite, I can hit the block much easier this way.
Hi Eryu,
Thanks for your explanation. I can hit this block easily when replacing
the fpunch
operation with a pwrite.
Fix it by making the direct read does a fixed number of loop and
break out the second mmap-fpunch loop if the first loop exits. At
Does it break out the second mmap-fpunch loop if the first loop doesn't
exit?
The second mmap-fpunch loop won't break until it finds the first loop
exits.
got it. :-)
this point we're sure that there's no unfinished background process
blocking the umount.
The others look fine.
Thanks!
Eryu
Thanks,
Xiao Yang.
Signed-off-by: Eryu Guan<eguan@xxxxxxxxxx>
---
tests/generic/446 | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/tests/generic/446 b/tests/generic/446
index 62ae449de6b1..83ff4ac9edd3 100755
--- a/tests/generic/446
+++ b/tests/generic/446
@@ -61,20 +61,22 @@ filesz=$((65536 * 2))
$XFS_IO_PROG -f -c "truncate $((filesz * 2))" $SCRATCH_MNT/file>> $seqres.full
# run a background dio read to a hole in a loop
-while true; do
+for i in `seq 0 999`; do
$XFS_IO_PROG -d -c "pread 0 $filesz" $SCRATCH_MNT/file> /dev/null 2>&1
done&
dread_pid=$!
# run mapped write to the same hole as dio read
-for i in `seq 0 999`; do
+while true; do
$XFS_IO_PROG -c "mmap 0 $filesz" -c "mwrite 0 $filesz" $SCRATCH_MNT/file \
> /dev/null
$XFS_IO_PROG -c "fpunch 0 $filesz" $SCRATCH_MNT/file> /dev/null
+ if ! kill -s 0 $dread_pid>/dev/null 2>&1; then
+ break
+ fi
done
Could we simplify this break, as below:
while kill -s 0 $dread_pid >/dev/null 2>&1; do
$XFS_IO_PROG -c "mmap 0 $filesz" -c "mwrite 0 $filesz"
$SCRATCH_MNT/file \
> /dev/null
$XFS_IO_PROG -c "fpunch 0 $filesz" $SCRATCH_MNT/file > /dev/null
done
Thanks,
Xiao Yang.
-kill -9 $dread_pid> /dev/null 2>&1
wait $dread_pid> /dev/null 2>&1
echo "Silence is golden"
.
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