view tests/test-chg.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 chg

  $ mkdir log
  $ cp $HGRCPATH $HGRCPATH.unconfigured
  $ cat <<'EOF' >> $HGRCPATH
  > [cmdserver]
  > log = $TESTTMP/log/server.log
  > max-log-files = 1
  > max-log-size = 10 kB
  > EOF
  $ cp $HGRCPATH $HGRCPATH.orig

  $ filterlog () {
  >   sed -e 's!^[0-9/]* [0-9:]* ([0-9]*)>!YYYY/MM/DD HH:MM:SS (PID)>!' \
  >       -e 's!\(setprocname\|received fds\|setenv\): .*!\1: ...!' \
  >       -e 's!\(confighash\|mtimehash\) = [0-9a-f]*!\1 = ...!g' \
  >       -e 's!\(in \)[0-9.]*s\b!\1 ...s!g' \
  >       -e 's!\(pid\)=[0-9]*!\1=...!g' \
  >       -e 's!\(/server-\)[0-9a-f]*!\1...!g'
  > }

init repo

  $ chg init foo
  $ cd foo

ill-formed config

  $ chg status
  $ echo '=brokenconfig' >> $HGRCPATH
  $ chg status
  config error at * =brokenconfig (glob)
  [30]

  $ cp $HGRCPATH.orig $HGRCPATH

long socket path

  $ sockpath=$TESTTMP/this/path/should/be/longer/than/one-hundred-and-seven/characters/where/107/is/the/typical/size/limit/of/unix-domain-socket
  $ mkdir -p $sockpath
  $ bakchgsockname=$CHGSOCKNAME
  $ CHGSOCKNAME=$sockpath/server
  $ export CHGSOCKNAME
  $ chg root
  $TESTTMP/foo
  $ rm -rf $sockpath
  $ CHGSOCKNAME=$bakchgsockname
  $ export CHGSOCKNAME

  $ cd ..

editor
------

  $ cat >> pushbuffer.py <<EOF
  > def reposetup(ui, repo):
  >     repo.ui.pushbuffer(subproc=True)
  > EOF

  $ chg init editor
  $ cd editor

by default, system() should be redirected to the client:

  $ touch foo
  $ CHGDEBUG= HGEDITOR=cat chg ci -Am channeled --edit 2>&1 \
  > | egrep "HG:|run 'cat"
  chg: debug: * run 'cat "*"' at '$TESTTMP/editor' (glob)
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: added foo

but no redirection should be made if output is captured:

  $ touch bar
  $ CHGDEBUG= HGEDITOR=cat chg ci -Am bufferred --edit \
  > --config extensions.pushbuffer="$TESTTMP/pushbuffer.py" 2>&1 \
  > | egrep "HG:|run 'cat"
  [1]

check that commit commands succeeded:

  $ hg log -T '{rev}:{desc}\n'
  1:bufferred
  0:channeled

  $ cd ..

pager
-----

  $ cat >> fakepager.py <<EOF
  > import sys
  > for line in sys.stdin:
  >     sys.stdout.write('paged! %r\n' % line)
  > EOF

enable pager extension globally, but spawns the master server with no tty:

  $ chg init pager
  $ cd pager
  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > pager =
  > [pager]
  > pager = "$PYTHON" $TESTTMP/fakepager.py
  > EOF
  $ chg version > /dev/null
  $ touch foo
  $ chg ci -qAm foo

pager should be enabled if the attached client has a tty:

  $ chg log -l1 -q --config ui.formatted=True
  paged! '0:1f7b0de80e11\n'
  $ chg log -l1 -q --config ui.formatted=False
  0:1f7b0de80e11

chg waits for pager if runcommand raises

  $ cat > $TESTTMP/crash.py <<EOF
  > from mercurial import registrar
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > @command(b'crash')
  > def pagercrash(ui, repo, *pats, **opts):
  >     ui.write(b'going to crash\n')
  >     raise Exception('.')
  > EOF

  $ cat > $TESTTMP/fakepager.py <<EOF
  > from __future__ import absolute_import
  > import sys
  > import time
  > for line in iter(sys.stdin.readline, ''):
  >     if 'crash' in line: # only interested in lines containing 'crash'
  >         # if chg exits when pager is sleeping (incorrectly), the output
  >         # will be captured by the next test case
  >         time.sleep(1)
  >         sys.stdout.write('crash-pager: %s' % line)
  > EOF

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > crash = $TESTTMP/crash.py
  > EOF

  $ chg crash --pager=on --config ui.formatted=True 2>/dev/null
  crash-pager: going to crash
  [255]

no stdout data should be printed after pager quits, and the buffered data
should never persist (issue6207)

"killed!" may be printed if terminated by SIGPIPE, which isn't important
in this test.

  $ cat > $TESTTMP/bulkwrite.py <<'EOF'
  > import time
  > from mercurial import error, registrar
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > @command(b'bulkwrite')
  > def bulkwrite(ui, repo, *pats, **opts):
  >     ui.write(b'going to write massive data\n')
  >     ui.flush()
  >     t = time.time()
  >     while time.time() - t < 2:
  >         ui.write(b'x' * 1023 + b'\n')  # will be interrupted by SIGPIPE
  >     raise error.Abort(b"write() doesn't block")
  > EOF

  $ cat > $TESTTMP/fakepager.py <<'EOF'
  > import sys
  > import time
  > sys.stdout.write('paged! %r\n' % sys.stdin.readline())
  > time.sleep(1)  # new data will be written
  > EOF

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > bulkwrite = $TESTTMP/bulkwrite.py
  > EOF

  $ chg bulkwrite --pager=on --color no --config ui.formatted=True
  paged! 'going to write massive data\n'
  killed! (?)
  [255]

  $ chg bulkwrite --pager=on --color no --config ui.formatted=True
  paged! 'going to write massive data\n'
  killed! (?)
  [255]

  $ cd ..

missing stdio
-------------

  $ CHGDEBUG=1 chg version -q 0<&-
  chg: debug: * stdio fds are missing (glob)
  chg: debug: * execute original hg (glob)
  Mercurial Distributed SCM * (glob)

server lifecycle
----------------

chg server should be restarted on code change, and old server will shut down
automatically. In this test, we use the following time parameters:

 - "sleep 1" to make mtime different
 - "sleep 2" to notice mtime change (polling interval is 1 sec)

set up repository with an extension:

  $ chg init extreload
  $ cd extreload
  $ touch dummyext.py
  $ cat <<EOF >> .hg/hgrc
  > [extensions]
  > dummyext = dummyext.py
  > EOF

isolate socket directory for stable result:

  $ OLDCHGSOCKNAME=$CHGSOCKNAME
  $ mkdir chgsock
  $ CHGSOCKNAME=`pwd`/chgsock/server

warm up server:

  $ CHGDEBUG= chg log 2>&1 | egrep 'instruction|start'
  chg: debug: * start cmdserver at $TESTTMP/extreload/chgsock/server.* (glob)

new server should be started if extension modified:

  $ sleep 1
  $ touch dummyext.py
  $ CHGDEBUG= chg log 2>&1 | egrep 'instruction|start'
  chg: debug: * instruction: unlink $TESTTMP/extreload/chgsock/server-* (glob)
  chg: debug: * instruction: reconnect (glob)
  chg: debug: * start cmdserver at $TESTTMP/extreload/chgsock/server.* (glob)

old server will shut down, while new server should still be reachable:

  $ sleep 2
  $ CHGDEBUG= chg log 2>&1 | (egrep 'instruction|start' || true)

socket file should never be unlinked by old server:
(simulates unowned socket by updating mtime, which makes sure server exits
at polling cycle)

  $ ls chgsock/server-*
  chgsock/server-* (glob)
  $ touch chgsock/server-*
  $ sleep 2
  $ ls chgsock/server-*
  chgsock/server-* (glob)

since no server is reachable from socket file, new server should be started:
(this test makes sure that old server shut down automatically)

  $ CHGDEBUG= chg log 2>&1 | egrep 'instruction|start'
  chg: debug: * start cmdserver at $TESTTMP/extreload/chgsock/server.* (glob)

shut down servers and restore environment:

  $ rm -R chgsock
  $ sleep 2
  $ CHGSOCKNAME=$OLDCHGSOCKNAME
  $ cd ..

check that server events are recorded:

  $ ls log
  server.log
  server.log.1

print only the last 10 lines, since we aren't sure how many records are
preserved (since setprocname isn't available on py3 and pure version,
the 10th-most-recent line is different when using py3):

  $ cat log/server.log.1 log/server.log | tail -10 | filterlog
  YYYY/MM/DD HH:MM:SS (PID)> confighash = ... mtimehash = ... (no-setprocname !)
  YYYY/MM/DD HH:MM:SS (PID)> forked worker process (pid=...)
  YYYY/MM/DD HH:MM:SS (PID)> setprocname: ... (setprocname !)
  YYYY/MM/DD HH:MM:SS (PID)> received fds: ...
  YYYY/MM/DD HH:MM:SS (PID)> chdir to '$TESTTMP/extreload'
  YYYY/MM/DD HH:MM:SS (PID)> setumask 18
  YYYY/MM/DD HH:MM:SS (PID)> setenv: ...
  YYYY/MM/DD HH:MM:SS (PID)> confighash = ... mtimehash = ...
  YYYY/MM/DD HH:MM:SS (PID)> validate: []
  YYYY/MM/DD HH:MM:SS (PID)> worker process exited (pid=...)
  YYYY/MM/DD HH:MM:SS (PID)> $TESTTMP/extreload/chgsock/server-... is not owned, exiting.

global data mutated by schems
-----------------------------

  $ hg init schemes
  $ cd schemes

initial state

  $ cat > .hg/hgrc <<'EOF'
  > [extensions]
  > schemes =
  > [schemes]
  > foo = https://foo.example.org/
  > EOF
  $ hg debugexpandscheme foo://expanded
  https://foo.example.org/expanded
  $ hg debugexpandscheme bar://unexpanded
  bar://unexpanded

add bar

  $ cat > .hg/hgrc <<'EOF'
  > [extensions]
  > schemes =
  > [schemes]
  > foo = https://foo.example.org/
  > bar = https://bar.example.org/
  > EOF
  $ hg debugexpandscheme foo://expanded
  https://foo.example.org/expanded
  $ hg debugexpandscheme bar://expanded
  https://bar.example.org/expanded

remove foo

  $ cat > .hg/hgrc <<'EOF'
  > [extensions]
  > schemes =
  > [schemes]
  > bar = https://bar.example.org/
  > EOF
  $ hg debugexpandscheme foo://unexpanded
  foo://unexpanded
  $ hg debugexpandscheme bar://expanded
  https://bar.example.org/expanded

  $ cd ..

repository cache
----------------

  $ rm log/server.log*
  $ cp $HGRCPATH.unconfigured $HGRCPATH
  $ cat <<'EOF' >> $HGRCPATH
  > [cmdserver]
  > log = $TESTTMP/log/server.log
  > max-repo-cache = 1
  > track-log = command, repocache
  > EOF

isolate socket directory for stable result:

  $ OLDCHGSOCKNAME=$CHGSOCKNAME
  $ mkdir chgsock
  $ CHGSOCKNAME=`pwd`/chgsock/server

create empty repo and cache it:

  $ hg init cached
  $ hg id -R cached
  000000000000 tip
  $ sleep 1

modify repo (and cache will be invalidated):

  $ touch cached/a
  $ hg ci -R cached -Am 'add a'
  adding a
  $ sleep 1

read cached repo:

  $ hg log -R cached
  changeset:   0:ac82d8b1f7c4
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
  $ sleep 1

discard cached from LRU cache:

  $ hg clone cached cached2
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg id -R cached2
  ac82d8b1f7c4 tip
  $ sleep 1

read uncached repo:

  $ hg log -R cached
  changeset:   0:ac82d8b1f7c4
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     add a
  
  $ sleep 1

shut down servers and restore environment:

  $ rm -R chgsock
  $ sleep 2
  $ CHGSOCKNAME=$OLDCHGSOCKNAME

check server log:

  $ cat log/server.log | filterlog
  YYYY/MM/DD HH:MM:SS (PID)> worker process exited (pid=...)
  YYYY/MM/DD HH:MM:SS (PID)> worker process exited (pid=...) (?)
  YYYY/MM/DD HH:MM:SS (PID)> init cached
  YYYY/MM/DD HH:MM:SS (PID)> id -R cached
  YYYY/MM/DD HH:MM:SS (PID)> loaded repo into cache: $TESTTMP/cached (in  ...s)
  YYYY/MM/DD HH:MM:SS (PID)> repo from cache: $TESTTMP/cached
  YYYY/MM/DD HH:MM:SS (PID)> ci -R cached -Am 'add a'
  YYYY/MM/DD HH:MM:SS (PID)> loaded repo into cache: $TESTTMP/cached (in  ...s)
  YYYY/MM/DD HH:MM:SS (PID)> repo from cache: $TESTTMP/cached
  YYYY/MM/DD HH:MM:SS (PID)> log -R cached
  YYYY/MM/DD HH:MM:SS (PID)> loaded repo into cache: $TESTTMP/cached (in  ...s)
  YYYY/MM/DD HH:MM:SS (PID)> clone cached cached2
  YYYY/MM/DD HH:MM:SS (PID)> id -R cached2
  YYYY/MM/DD HH:MM:SS (PID)> loaded repo into cache: $TESTTMP/cached2 (in  ...s)
  YYYY/MM/DD HH:MM:SS (PID)> log -R cached
  YYYY/MM/DD HH:MM:SS (PID)> loaded repo into cache: $TESTTMP/cached (in  ...s)

Test that chg works (sets to the user's actual LC_CTYPE) even when python
"coerces" the locale (py3.7+)

  $ cat > $TESTTMP/debugenv.py <<EOF
  > from mercurial import encoding
  > from mercurial import registrar
  > cmdtable = {}
  > command = registrar.command(cmdtable)
  > @command(b'debugenv', [], b'', norepo=True)
  > def debugenv(ui):
  >     for k in [b'LC_ALL', b'LC_CTYPE', b'LANG']:
  >         v = encoding.environ.get(k)
  >         if v is not None:
  >             ui.write(b'%s=%s\n' % (k, encoding.environ[k]))
  > EOF
(hg keeps python's modified LC_CTYPE, chg doesn't)
  $ (unset LC_ALL; unset LANG; LC_CTYPE= "$CHGHG" \
  >    --config extensions.debugenv=$TESTTMP/debugenv.py debugenv)
  LC_CTYPE=C.UTF-8 (py37 !)
  LC_CTYPE= (no-py37 !)
  $ (unset LC_ALL; unset LANG; LC_CTYPE= chg \
  >    --config extensions.debugenv=$TESTTMP/debugenv.py debugenv)
  LC_CTYPE=
  $ (unset LC_ALL; unset LANG; LC_CTYPE=unsupported_value chg \
  >    --config extensions.debugenv=$TESTTMP/debugenv.py debugenv)
  LC_CTYPE=unsupported_value
  $ (unset LC_ALL; unset LANG; LC_CTYPE= chg \
  >    --config extensions.debugenv=$TESTTMP/debugenv.py debugenv)
  LC_CTYPE=
  $ LANG= LC_ALL= LC_CTYPE= chg \
  >    --config extensions.debugenv=$TESTTMP/debugenv.py debugenv
  LC_ALL=
  LC_CTYPE=
  LANG=