annotate tests/test-remotefilelog-hgweb.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 9e63108123a4
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
44569
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
1 #require no-windows serve
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
2
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
3 $ . "$TESTDIR/remotefilelog-library.sh"
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
4
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
5 $ cat >> $HGRCPATH <<EOF
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
6 > [extensions]
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
7 > remotefilelog=
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
8 > share=
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
9 > EOF
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
10
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
11 $ hg init master
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
12 $ cd master
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
13 $ cat >> .hg/hgrc <<EOF
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
14 > [remotefilelog]
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
15 > server=True
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
16 > EOF
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
17 $ echo x > x
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
18 $ hg commit -qAm x
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
19
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
20 $ cd ..
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
21
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
22
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
23 $ hgcloneshallow ssh://user@dummy/master wdir --noupdate -q
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
24 $ cd wdir
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
25 $ hg serve -n test -p $HGPORT -d --pid-file=hg.pid -E errors.log
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
26 $ cat hg.pid >> $DAEMON_PIDS
44570
9e63108123a4 remotefilelog: add fake heads() method that allows viewing a file in hgweb
Augie Fackler <augie@google.com>
parents: 44569
diff changeset
27 $ get-with-headers.py localhost:$HGPORT 'file/tip/x' | head -n 10
9e63108123a4 remotefilelog: add fake heads() method that allows viewing a file in hgweb
Augie Fackler <augie@google.com>
parents: 44569
diff changeset
28 200 Script output follows
44569
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
29
44570
9e63108123a4 remotefilelog: add fake heads() method that allows viewing a file in hgweb
Augie Fackler <augie@google.com>
parents: 44569
diff changeset
30 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
9e63108123a4 remotefilelog: add fake heads() method that allows viewing a file in hgweb
Augie Fackler <augie@google.com>
parents: 44569
diff changeset
31 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">
9e63108123a4 remotefilelog: add fake heads() method that allows viewing a file in hgweb
Augie Fackler <augie@google.com>
parents: 44569
diff changeset
32 <head>
9e63108123a4 remotefilelog: add fake heads() method that allows viewing a file in hgweb
Augie Fackler <augie@google.com>
parents: 44569
diff changeset
33 <link rel="icon" href="/static/hgicon.png" type="image/png" />
9e63108123a4 remotefilelog: add fake heads() method that allows viewing a file in hgweb
Augie Fackler <augie@google.com>
parents: 44569
diff changeset
34 <meta name="robots" content="index, nofollow" />
9e63108123a4 remotefilelog: add fake heads() method that allows viewing a file in hgweb
Augie Fackler <augie@google.com>
parents: 44569
diff changeset
35 <link rel="stylesheet" href="/static/style-paper.css" type="text/css" />
9e63108123a4 remotefilelog: add fake heads() method that allows viewing a file in hgweb
Augie Fackler <augie@google.com>
parents: 44569
diff changeset
36 <script type="text/javascript" src="/static/mercurial.js"></script>
9e63108123a4 remotefilelog: add fake heads() method that allows viewing a file in hgweb
Augie Fackler <augie@google.com>
parents: 44569
diff changeset
37
44569
5483e9c759e4 tests: add test for remotefilelog interactions with hgweb
Augie Fackler <augie@google.com>
parents:
diff changeset
38