Discussion:
[PATCH] tests: fix race in dirrem01 and dirrem02
(too old to reply)
Pavel Raiskup
2018-01-04 17:55:12 UTC
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Previously the '--checkpoint-action=echo' was triggered after
'--checkpoint-action=sleep=1' - so the order of events *usually*
was (for --format='gnu'):

...
1. checkpoint handler before write of 'dir/sub' member
2. one-second delay
3. stderr write: 'tar: Write checkpoint 3'
4. write the member 'dir/sub' into the archive
5. check that the member's ctime has not been changed
6. genfile's detecting 'Write checkpoint', doing unlink
...

But sometimes, the genfile was fast enough to win the race and
unlinked the directory before the member was written into the
archive (IOW, the order was 1-2-3-6-4-5). This led to the
occasional warning 'tar: dir/sub: file changed as we read it'.

Swap the order of 'sleep=1' and 'echo' actions so the genfile
utility has (hopefully) enough time to do the unlink before
writing the file into the archive (enforce 1-2-3-6-4-5 order).

* tests/dirrem01.at: Swap 'sleep=1' and 'echo' actions.
* tests/dirrem02.at: Likewise.
---
tests/dirrem01.at | 5 +++--
tests/dirrem02.at | 7 ++++---
2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/tests/dirrem01.at b/tests/dirrem01.at
index 40344dc..dabc206 100644
--- a/tests/dirrem01.at
+++ b/tests/dirrem01.at
@@ -47,14 +47,15 @@ gnu) CPT=3;;
esac

genfile --run --checkpoint=$CPT --unlink dir/sub/file2 --unlink dir/sub -- \
- tar --blocking-factor=1 --checkpoint=1 --checkpoint-action='sleep=1' \
- --checkpoint-action='echo' -c -f archive.tar \
+ tar --blocking-factor=1 --checkpoint=1 --checkpoint-action='echo' \
+ --checkpoint-action='sleep=1' -c -f archive.tar \
--listed-incremental db -v dir >/dev/null
],
[1],
[ignore],
[tar: dir: Directory is new
tar: dir/sub: Directory is new
+tar: dir/sub: file changed as we read it
tar: dir/sub: File removed before we read it
],[],[],[gnu,posix])

diff --git a/tests/dirrem02.at b/tests/dirrem02.at
index e1cf9ef..924454f 100644
--- a/tests/dirrem02.at
+++ b/tests/dirrem02.at
@@ -20,7 +20,7 @@

# Description:
#
-# When an explicitley named directory disappears during creation
+# When an explicitly named directory disappears during creation
# of incremental dump, tar should still exit with TAREXIT_FAILURE (2).
#
# For further details see dirrem01.at
@@ -44,14 +44,15 @@ gnu) CPT=3;;
esac

genfile --run --checkpoint=$CPT --unlink dir/sub/file2 --unlink dir/sub -- \
- tar --blocking-factor=1 --checkpoint=1 --checkpoint-action='sleep=1' \
- --checkpoint-action='echo' -c -f archive.tar \
+ tar --blocking-factor=1 --checkpoint=1 --checkpoint-action='echo' \
+ --checkpoint-action='sleep=1' -c -f archive.tar \
--listed-incremental db -v dir dir/sub >/dev/null
],
[2],
[ignore],
[tar: dir: Directory is new
tar: dir/sub: Directory is new
+tar: dir/sub: file changed as we read it
tar: dir/sub: Cannot open: No such file or directory
tar: Exiting with failure status due to previous errors
],[],[],[gnu,posix])
--
2.14.3
Eric Blake
2018-01-04 18:08:41 UTC
Permalink
Post by Pavel Raiskup
Previously the '--checkpoint-action=echo' was triggered after
'--checkpoint-action=sleep=1' - so the order of events *usually*
Did you mean for this to go to bug-tar instead of bug-gnulib?
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
Pavel Raiskup
2018-01-04 18:23:30 UTC
Permalink
Post by Eric Blake
Post by Pavel Raiskup
Previously the '--checkpoint-action=echo' was triggered after
'--checkpoint-action=sleep=1' - so the order of events *usually*
Did you mean for this to go to bug-tar instead of bug-gnulib?
Yes, sorry, resent here:
https://www.mail-archive.com/bug-***@gnu.org/msg05451.html

Pavel

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