Re: [PATCH v2] fstests: btrfs/143: make test case more reliable

[Nikolay Borisov]

On 16.11.2017 01:47, Liu Bo wrote:
> This changes to use '_scratch_cycle_mount' to drop all caches btrfs could have
> in order to avoid an issue that drop_caches somehow doesn't work on Nikolay's
> box.
> 
> Also use bash -c to run 'read' only when %pid is odd so that we can read the
> faulty disk.
> 
> Reported-by: Nikolay Borisov 
> Signed-off-by: Liu Bo 
> ---
> v2: Change 'fadvise -d' to _scratch_cycle_mount.
> 
> To Nikolay,
> 
> I didn't add your tested-by, but could you please verify if this also
> works on your test box?

Just did around 50 runs and didn't fail once. Without it failed on the
second iteration so :

Tested-by: Nikolay Borisov 

> 
> 
>  tests/btrfs/143 | 20 ++--
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/tests/btrfs/143 b/tests/btrfs/143
> index da7bfd8..3875b6c 100755
> --- a/tests/btrfs/143
> +++ b/tests/btrfs/143
> @@ -127,16 +127,16 @@ echo "step 3..repair the bad copy" >>$seqres.full
>  # since raid1 consists of two copies, and the bad copy was put on stripe #1
>  # while the good copy lies on stripe #0, the bad copy only gets access when 
> the
>  # reader's pid % 2 == 1 is true
> -while true; do
> - # start_fail only fails the following buffered read so the repair is
> - # supposed to work.
> - echo 3 > /proc/sys/vm/drop_caches
> - start_fail
> - $XFS_IO_PROG -c "pread 0 4K" "$SCRATCH_MNT/foobar" > /dev/null &
> - pid=$!
> - wait
> - stop_fail
> - [ $((pid % 2)) == 1 ] && break
> +while [[ -z ${result} ]]; do
> +# invalidate the page cache.
> +_scratch_cycle_mount
> +
> +start_fail
> +result=$(bash -c "
> +if [[ \$((\$\$ % 2)) -eq 1 ]]; then
> +exec $XFS_IO_PROG -c \"pread 0 4K\" \"$SCRATCH_MNT/foobar\"
> +fi");
> +stop_fail
>  done
>  
>  _scratch_unmount
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH v2] fstests: btrfs/143: make test case more reliable

[Liu Bo]

This changes to use '_scratch_cycle_mount' to drop all caches btrfs could have
in order to avoid an issue that drop_caches somehow doesn't work on Nikolay's
box.

Also use bash -c to run 'read' only when %pid is odd so that we can read the
faulty disk.

Reported-by: Nikolay Borisov 
Signed-off-by: Liu Bo 
---
v2: Change 'fadvise -d' to _scratch_cycle_mount.

To Nikolay,

I didn't add your tested-by, but could you please verify if this also
works on your test box?


 tests/btrfs/143 | 20 ++--
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/tests/btrfs/143 b/tests/btrfs/143
index da7bfd8..3875b6c 100755
--- a/tests/btrfs/143
+++ b/tests/btrfs/143
@@ -127,16 +127,16 @@ echo "step 3..repair the bad copy" >>$seqres.full
 # since raid1 consists of two copies, and the bad copy was put on stripe #1
 # while the good copy lies on stripe #0, the bad copy only gets access when the
 # reader's pid % 2 == 1 is true
-while true; do
-   # start_fail only fails the following buffered read so the repair is
-   # supposed to work.
-   echo 3 > /proc/sys/vm/drop_caches
-   start_fail
-   $XFS_IO_PROG -c "pread 0 4K" "$SCRATCH_MNT/foobar" > /dev/null &
-   pid=$!
-   wait
-   stop_fail
-   [ $((pid % 2)) == 1 ] && break
+while [[ -z ${result} ]]; do
+# invalidate the page cache.
+_scratch_cycle_mount
+
+start_fail
+result=$(bash -c "
+if [[ \$((\$\$ % 2)) -eq 1 ]]; then
+exec $XFS_IO_PROG -c \"pread 0 4K\" \"$SCRATCH_MNT/foobar\"
+fi");
+stop_fail
 done
 
 _scratch_unmount
-- 
2.5.0

--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html