view tests/test-verify.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

#require reporevlogstore

prepare repo

  $ hg init a
  $ cd a
  $ echo "some text" > FOO.txt
  $ echo "another text" > bar.txt
  $ echo "more text" > QUICK.txt
  $ hg add
  adding FOO.txt
  adding QUICK.txt
  adding bar.txt
  $ hg ci -mtest1

verify

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 3 changes to 3 files

verify with journal

  $ touch .hg/store/journal
  $ hg verify
  abandoned transaction found - run hg recover
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 3 changes to 3 files
  $ rm .hg/store/journal

introduce some bugs in repo

  $ cd .hg/store/data
  $ mv _f_o_o.txt.i X_f_o_o.txt.i
  $ mv bar.txt.i xbar.txt.i
  $ rm _q_u_i_c_k.txt.i

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
   warning: revlog 'data/FOO.txt.i' not in fncache!
   0: empty or missing FOO.txt
   FOO.txt@0: manifest refers to unknown revision f62022d3d590
   warning: revlog 'data/QUICK.txt.i' not in fncache!
   0: empty or missing QUICK.txt
   QUICK.txt@0: manifest refers to unknown revision 88b857db8eba
   warning: revlog 'data/bar.txt.i' not in fncache!
   0: empty or missing bar.txt
   bar.txt@0: manifest refers to unknown revision 256559129457
  checked 1 changesets with 0 changes to 3 files
  3 warnings encountered!
  hint: run "hg debugrebuildfncache" to recover from corrupt fncache
  6 integrity errors encountered!
  (first damaged changeset appears to be 0)
  [1]

  $ cd ../../..
  $ cd ..

Set up a repo for testing missing revlog entries

  $ hg init missing-entries
  $ cd missing-entries
  $ echo 0 > file
  $ hg ci -Aqm0
  $ cp -R .hg/store .hg/store-partial
  $ echo 1 > file
  $ hg ci -Aqm1
  $ cp -R .hg/store .hg/store-full

Entire changelog missing

  $ rm .hg/store/00changelog.*
  $ hg verify -q
   0: empty or missing changelog
   manifest@0: d0b6632564d4 not in changesets
   manifest@1: 941fc4534185 not in changesets
  3 integrity errors encountered!
  (first damaged changeset appears to be 0)
  [1]
  $ cp -R .hg/store-full/. .hg/store

Entire manifest log missing

  $ rm .hg/store/00manifest.*
  $ hg verify -q
   0: empty or missing manifest
  1 integrity errors encountered!
  (first damaged changeset appears to be 0)
  [1]
  $ cp -R .hg/store-full/. .hg/store

Entire filelog missing

  $ rm .hg/store/data/file.*
  $ hg verify -q
   warning: revlog 'data/file.i' not in fncache!
   0: empty or missing file
   file@0: manifest refers to unknown revision 362fef284ce2
   file@1: manifest refers to unknown revision c10f2164107d
  1 warnings encountered!
  hint: run "hg debugrebuildfncache" to recover from corrupt fncache
  3 integrity errors encountered!
  (first damaged changeset appears to be 0)
  [1]
  $ cp -R .hg/store-full/. .hg/store

Entire changelog and manifest log missing

  $ rm .hg/store/00changelog.*
  $ rm .hg/store/00manifest.*
  $ hg verify -q
  warning: orphan data file 'data/file.i'
  1 warnings encountered!
  $ cp -R .hg/store-full/. .hg/store

Entire changelog and filelog missing

  $ rm .hg/store/00changelog.*
  $ rm .hg/store/data/file.*
  $ hg verify -q
   0: empty or missing changelog
   manifest@0: d0b6632564d4 not in changesets
   manifest@1: 941fc4534185 not in changesets
   warning: revlog 'data/file.i' not in fncache!
   ?: empty or missing file
   file@0: manifest refers to unknown revision 362fef284ce2
   file@1: manifest refers to unknown revision c10f2164107d
  1 warnings encountered!
  hint: run "hg debugrebuildfncache" to recover from corrupt fncache
  6 integrity errors encountered!
  (first damaged changeset appears to be 0)
  [1]
  $ cp -R .hg/store-full/. .hg/store

Entire manifest log and filelog missing

  $ rm .hg/store/00manifest.*
  $ rm .hg/store/data/file.*
  $ hg verify -q
   0: empty or missing manifest
   warning: revlog 'data/file.i' not in fncache!
   0: empty or missing file
  1 warnings encountered!
  hint: run "hg debugrebuildfncache" to recover from corrupt fncache
  2 integrity errors encountered!
  (first damaged changeset appears to be 0)
  [1]
  $ cp -R .hg/store-full/. .hg/store

Changelog missing entry

  $ cp -f .hg/store-partial/00changelog.* .hg/store
  $ hg verify -q
   manifest@?: rev 1 points to nonexistent changeset 1
   manifest@?: 941fc4534185 not in changesets
   file@?: rev 1 points to nonexistent changeset 1
   (expected 0)
  1 warnings encountered!
  3 integrity errors encountered!
  [1]
  $ cp -R .hg/store-full/. .hg/store

Manifest log missing entry

  $ cp -f .hg/store-partial/00manifest.* .hg/store
  $ hg verify -q
   manifest@1: changeset refers to unknown revision 941fc4534185
   file@1: c10f2164107d not in manifests
  2 integrity errors encountered!
  (first damaged changeset appears to be 1)
  [1]
  $ cp -R .hg/store-full/. .hg/store

Filelog missing entry

  $ cp -f .hg/store-partial/data/file.* .hg/store/data
  $ hg verify -q
   file@1: manifest refers to unknown revision c10f2164107d
  1 integrity errors encountered!
  (first damaged changeset appears to be 1)
  [1]
  $ cp -R .hg/store-full/. .hg/store

Changelog and manifest log missing entry

  $ cp -f .hg/store-partial/00changelog.* .hg/store
  $ cp -f .hg/store-partial/00manifest.* .hg/store
  $ hg verify -q
   file@?: rev 1 points to nonexistent changeset 1
   (expected 0)
   file@?: c10f2164107d not in manifests
  1 warnings encountered!
  2 integrity errors encountered!
  [1]
  $ cp -R .hg/store-full/. .hg/store

Changelog and filelog missing entry

  $ cp -f .hg/store-partial/00changelog.* .hg/store
  $ cp -f .hg/store-partial/data/file.* .hg/store/data
  $ hg verify -q
   manifest@?: rev 1 points to nonexistent changeset 1
   manifest@?: 941fc4534185 not in changesets
   file@?: manifest refers to unknown revision c10f2164107d
  3 integrity errors encountered!
  [1]
  $ cp -R .hg/store-full/. .hg/store

Manifest and filelog missing entry

  $ cp -f .hg/store-partial/00manifest.* .hg/store
  $ cp -f .hg/store-partial/data/file.* .hg/store/data
  $ hg verify -q
   manifest@1: changeset refers to unknown revision 941fc4534185
  1 integrity errors encountered!
  (first damaged changeset appears to be 1)
  [1]
  $ cp -R .hg/store-full/. .hg/store

Corrupt changelog base node to cause failure to read revision

  $ printf abcd | dd conv=notrunc of=.hg/store/00changelog.i bs=1 seek=16 \
  >   2> /dev/null
  $ hg verify -q
   0: unpacking changeset 08b1860757c2: * (glob)
   manifest@?: rev 0 points to unexpected changeset 0
   manifest@?: d0b6632564d4 not in changesets
   file@?: rev 0 points to unexpected changeset 0
   (expected 1)
  1 warnings encountered!
  4 integrity errors encountered!
  (first damaged changeset appears to be 0)
  [1]
  $ cp -R .hg/store-full/. .hg/store

Corrupt manifest log base node to cause failure to read revision

  $ printf abcd | dd conv=notrunc of=.hg/store/00manifest.i bs=1 seek=16 \
  >   2> /dev/null
  $ hg verify -q
   manifest@0: reading delta d0b6632564d4: * (glob)
   file@0: 362fef284ce2 not in manifests
  2 integrity errors encountered!
  (first damaged changeset appears to be 0)
  [1]
  $ cp -R .hg/store-full/. .hg/store

Corrupt filelog base node to cause failure to read revision

  $ printf abcd | dd conv=notrunc of=.hg/store/data/file.i bs=1 seek=16 \
  >   2> /dev/null
  $ hg verify -q
   file@0: unpacking 362fef284ce2: * (glob)
  1 integrity errors encountered!
  (first damaged changeset appears to be 0)
  [1]
  $ cp -R .hg/store-full/. .hg/store

  $ cd ..

test changelog without a manifest

  $ hg init b
  $ cd b
  $ hg branch foo
  marked working directory as branch foo
  (branches are permanent and global, did you want a bookmark?)
  $ hg ci -m branchfoo
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 0 changes to 0 files

test revlog corruption

  $ touch a
  $ hg add a
  $ hg ci -m a

  $ echo 'corrupted' > b
  $ dd if=.hg/store/data/a.i of=start bs=1 count=20 2>/dev/null
  $ cat start b > .hg/store/data/a.i

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
   a@1: broken revlog! (index data/a.i is corrupted)
  warning: orphan data file 'data/a.i'
  checked 2 changesets with 0 changes to 1 files
  1 warnings encountered!
  1 integrity errors encountered!
  (first damaged changeset appears to be 1)
  [1]

  $ cd ..

test revlog format 0

  $ revlog-formatv0.py
  $ cd formatv0
  $ hg verify
  repository uses revlog format 0
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 1 changes to 1 files
  $ cd ..

test flag processor and skipflags

  $ hg init skipflags
  $ cd skipflags
  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > flagprocessor=$RUNTESTDIR/flagprocessorext.py
  > EOF
  $ echo '[BASE64]content' > base64
  $ hg commit -Aqm 'flag processor content' base64
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 1 changes to 1 files

  $ cat >> $TESTTMP/break-base64.py <<EOF
  > from __future__ import absolute_import
  > import base64
  > base64.b64decode=lambda x: x
  > EOF
  $ cat >> .hg/hgrc <<EOF
  > breakbase64=$TESTTMP/break-base64.py
  > EOF

  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
   base64@0: unpacking 794cee7777cb: integrity check failed on data/base64.i:0
  checked 1 changesets with 1 changes to 1 files
  1 integrity errors encountered!
  (first damaged changeset appears to be 0)
  [1]
  $ hg verify --config verify.skipflags=2147483647
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 1 changes to 1 files