* [PATCH] generic/670: allow _mread_range() races with reflink_range()
@ 2022-01-12 9:28 Shiyang Ruan
2022-01-13 21:09 ` Darrick J. Wong
0 siblings, 1 reply; 2+ messages in thread
From: Shiyang Ruan @ 2022-01-12 9:28 UTC (permalink / raw)
To: fstests; +Cc: ruansy.fnst, Darrick J . Wong
mread copies data one-byte-at-a-time, so it may races with
reflink_range() who invalidates page cache of the dest file.
Allow this race by adjusting the egrep regexp.
Reported-by: Darrick J. Wong <djwong@kernel.org>
Suggested-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
---
tests/generic/670 | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/tests/generic/670 b/tests/generic/670
index 83fbd0b9..4a895d90 100755
--- a/tests/generic/670
+++ b/tests/generic/670
@@ -40,7 +40,10 @@ _cp_reflink $testdir/file1 $testdir/file3
_scratch_cycle_mount
fbytes() {
- egrep -v '(61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61|62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62)'
+ # Different with generic/164,165, mread copies data from mmapped area
+ # one-byte-at-a-time, which may cause races during reflink_range().
+ # So the result of _mread_range() may be a mix of 61 and 62.
+ egrep -v '((61|62) ){15}(61|62)'
}
reader() {
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] generic/670: allow _mread_range() races with reflink_range()
2022-01-12 9:28 [PATCH] generic/670: allow _mread_range() races with reflink_range() Shiyang Ruan
@ 2022-01-13 21:09 ` Darrick J. Wong
0 siblings, 0 replies; 2+ messages in thread
From: Darrick J. Wong @ 2022-01-13 21:09 UTC (permalink / raw)
To: Shiyang Ruan; +Cc: fstests
On Wed, Jan 12, 2022 at 05:28:46PM +0800, Shiyang Ruan wrote:
> mread copies data one-byte-at-a-time, so it may races with
> reflink_range() who invalidates page cache of the dest file.
> Allow this race by adjusting the egrep regexp.
>
> Reported-by: Darrick J. Wong <djwong@kernel.org>
> Suggested-by: Darrick J. Wong <djwong@kernel.org>
> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Looks reasonable; I'll put this in the test system for tonight and
report back if I see anything strange. I didn't see anything obvious
after a dozen or so rounds.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
--D
> ---
> tests/generic/670 | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/tests/generic/670 b/tests/generic/670
> index 83fbd0b9..4a895d90 100755
> --- a/tests/generic/670
> +++ b/tests/generic/670
> @@ -40,7 +40,10 @@ _cp_reflink $testdir/file1 $testdir/file3
> _scratch_cycle_mount
>
> fbytes() {
> - egrep -v '(61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61|62 62 62 62 62 62 62 62 62 62 62 62 62 62 62 62)'
> + # Different with generic/164,165, mread copies data from mmapped area
> + # one-byte-at-a-time, which may cause races during reflink_range().
> + # So the result of _mread_range() may be a mix of 61 and 62.
> + egrep -v '((61|62) ){15}(61|62)'
> }
>
> reader() {
> --
> 2.34.1
>
>
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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