Mercurial > hg
view tests/test-obsolete-check-push.t @ 46607:e9901d01d135
revlog: add a mechanism to verify expected file position before appending
If someone uses `hg debuglocks`, or some non-hg process writes to the .hg
directory without respecting the locks, or if the repo's on a networked
filesystem, it's possible for the revlog code to write out corrupted data.
The form of this corruption can vary depending on what data was written and how
that happened. We are in the "networked filesystem" case (though I've had users
also do this to themselves with the "`hg debuglocks`" scenario), and most often
see this with the changelog. What ends up happening is we produce two items
(let's call them rev1 and rev2) in the .i file that have the same linkrev,
baserev, and offset into the .d file, while the data in the .d file is appended
properly. rev2's compressed_size is accurate for rev2, but when we go to
decompress the data in the .d file, we use the offset that's recorded in the
index file, which is the same as rev1, and attempt to decompress
rev2.compressed_size bytes of rev1's data. This usually does not succeed. :)
When using inline data, this also fails, though I haven't investigated why too
closely. This shows up as a "patch decode" error. I believe what's happening
there is that we're basically ignoring the offset field, getting the data
properly, but since baserev != rev, it thinks this is a delta based on rev
(instead of a full text) and can't actually apply it as such.
For now, I'm going to make this an optional component and default it to entirely
off. I may increase the default severity of this in the future, once I've
enabled it for my users and we gain more experience with it. Luckily, most of my
users have a versioned filesystem and can roll back to before the corruption has
been written, it's just a hassle to do so and not everyone knows how (so it's a
support burden). Users on other filesystems will not have that luxury, and this
can cause them to have a corrupted repository that they are unlikely to know how
to resolve, and they'll see this as a data-loss event. Refusing to create the
corruption is a much better user experience.
This mechanism is not perfect. There may be false-negatives (racy writes that
are not detected). There should not be any false-positives (non-racy writes that
are detected as such). This is not a mechanism that makes putting a repo on a
networked filesystem "safe" or "supported", just *less* likely to cause
corruption.
Differential Revision: https://phab.mercurial-scm.org/D9952
author | Kyle Lippincott <spectral@google.com> |
---|---|
date | Wed, 03 Feb 2021 16:33:10 -0800 |
parents | 559ebfb5a58e |
children |
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======================================================= Test check for obsolescence and instability during push ======================================================= $ . $TESTDIR/testlib/obsmarker-common.sh $ cat >> $HGRCPATH << EOF > [phases] > publish=false > [experimental] > evolution = all > EOF Tests that pushing orphaness to the server is detected ====================================================== initial setup $ mkdir base $ cd base $ hg init server $ cd server $ mkcommit root $ hg phase --public . $ mkcommit commit_A0_ $ mkcommit commit_B0_ $ cd .. $ hg init client $ cd client $ echo '[paths]' >> .hg/hgrc $ echo 'default=../server' >> .hg/hgrc $ hg pull pulling from $TESTTMP/base/server requesting all changes adding changesets adding manifests adding file changes added 3 changesets with 3 changes to 3 files new changesets 1e4be0697311:c09d8ab29fda (2 drafts) (run 'hg update' to get a working copy) $ hg up 'desc("root")' 1 files updated, 0 files merged, 0 files removed, 0 files unresolved (having some unrelated change affects discovery result, we should ideally test both case) $ hg branch unrelated --quiet $ mkcommit unrelated $ hg up null 0 files updated, 0 files merged, 2 files removed, 0 files unresolved $ hg log -G o changeset: 3:16affbe0f986 | branch: unrelated | tag: tip | parent: 0:1e4be0697311 | user: test | date: Thu Jan 01 00:00:00 1970 +0000 | summary: unrelated | | o changeset: 2:c09d8ab29fda | | user: test | | date: Thu Jan 01 00:00:00 1970 +0000 | | summary: commit_B0_ | | | o changeset: 1:37624bf21024 |/ user: test | date: Thu Jan 01 00:00:00 1970 +0000 | summary: commit_A0_ | o changeset: 0:1e4be0697311 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: root $ cd .. $ cd .. Orphan from pruning ------------------- Setup $ cp -R base check-pruned $ cd check-pruned/client $ hg debugobsolete --record-parents `getid 'desc("commit_A0_")'` 1 new obsolescence markers obsoleted 1 changesets 1 new orphan changesets $ hg log -G o changeset: 3:16affbe0f986 | branch: unrelated | tag: tip | parent: 0:1e4be0697311 | user: test | date: Thu Jan 01 00:00:00 1970 +0000 | summary: unrelated | | * changeset: 2:c09d8ab29fda | | user: test | | date: Thu Jan 01 00:00:00 1970 +0000 | | instability: orphan | | summary: commit_B0_ | | | x changeset: 1:37624bf21024 |/ user: test | date: Thu Jan 01 00:00:00 1970 +0000 | obsolete: pruned | summary: commit_A0_ | o changeset: 0:1e4be0697311 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: root Pushing the result is prevented with a message $ hg push --new-branch pushing to $TESTTMP/check-pruned/server searching for changes abort: push includes orphan changeset: c09d8ab29fda! [255] $ cd ../.. Orphan from superseding ----------------------- Setup $ cp -R base check-superseded $ cd check-superseded/client $ hg up 'desc("commit_A0_")' 2 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg branch other marked working directory as branch other $ hg commit --amend -m commit_A1_ 1 new orphan changesets $ hg log -G @ changeset: 4:df9b82a99e21 | branch: other | tag: tip | parent: 0:1e4be0697311 | user: test | date: Thu Jan 01 00:00:00 1970 +0000 | summary: commit_A1_ | | o changeset: 3:16affbe0f986 |/ branch: unrelated | parent: 0:1e4be0697311 | user: test | date: Thu Jan 01 00:00:00 1970 +0000 | summary: unrelated | | * changeset: 2:c09d8ab29fda | | user: test | | date: Thu Jan 01 00:00:00 1970 +0000 | | instability: orphan | | summary: commit_B0_ | | | x changeset: 1:37624bf21024 |/ user: test | date: Thu Jan 01 00:00:00 1970 +0000 | obsolete: rewritten using amend as 4:df9b82a99e21 | summary: commit_A0_ | o changeset: 0:1e4be0697311 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: root Pushing the result is prevented with a message $ hg push --new-branch pushing to $TESTTMP/check-superseded/server searching for changes abort: push includes orphan changeset: c09d8ab29fda! [255] $ cd ../.. Tests that user get warned if it is about to publish obsolete/unstable content ------------------------------------------------------------------------------ Orphan from pruning ------------------- Make sure the only difference is phase: $ cd check-pruned/client $ hg push --force --rev 'not desc("unrelated")' pushing to $TESTTMP/check-pruned/server searching for changes no changes found 1 new obsolescence markers obsoleted 1 changesets 1 new orphan changesets [1] Check something prevents a silent publication of the obsolete changeset $ hg push --publish --new-branch pushing to $TESTTMP/check-pruned/server searching for changes abort: push includes orphan changeset: c09d8ab29fda! [255] $ cd ../.. Orphan from superseding ----------------------- Make sure the only difference is phase: $ cd check-superseded/client $ hg push --force --rev 'not desc("unrelated")' pushing to $TESTTMP/check-superseded/server searching for changes adding changesets adding manifests adding file changes added 1 changesets with 0 changes to 0 files (+1 heads) 1 new obsolescence markers obsoleted 1 changesets 1 new orphan changesets Check something prevents a silent publication of the obsolete changeset $ hg push --publish --new-branch pushing to $TESTTMP/check-superseded/server searching for changes abort: push includes orphan changeset: c09d8ab29fda! [255] $ cd ../..