Mercurial > hg
changeset 44515:6c906eaedd0d
nodemap: track the tip_node for validation
Differential Revision: https://phab.mercurial-scm.org/D8184
| author | Pierre-Yves David <pierre-yves.david@octobus.net> |
|---|---|
| date | Thu, 27 Feb 2020 16:32:43 +0100 |
| parents | 15a033cabc19 |
| children | 64e2f603de9d |
| files | mercurial/configitems.py mercurial/debugcommands.py mercurial/revlog.py mercurial/revlogutils/nodemap.py tests/test-persistent-nodemap.t |
| diffstat | 5 files changed, 77 insertions(+), 8 deletions(-) [+] |
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--- a/mercurial/configitems.py Thu Feb 27 15:42:04 2020 +0100 +++ b/mercurial/configitems.py Thu Feb 27 16:32:43 2020 +0100 @@ -409,8 +409,6 @@ # # * code/tests around aborted transaction # * code/tests around pending data for hooks -# * code/tests around detection of invalid cache -# (eg: after strip from an incompatible client) # * regenerate a new nodemap when the unused/total ration is to high # * decide for a "status" of the persistent nodemap and associated location # - part of the store next the revlog itself (new requirements)
--- a/mercurial/debugcommands.py Thu Feb 27 15:42:04 2020 +0100 +++ b/mercurial/debugcommands.py Thu Feb 27 16:32:43 2020 +0100 @@ -2136,6 +2136,7 @@ docket, data = nm_data ui.write((b"uid: %s\n") % docket.uid) ui.write((b"tip-rev: %d\n") % docket.tip_rev) + ui.write((b"tip-node: %s\n") % hex(docket.tip_node)) ui.write((b"data-length: %d\n") % docket.data_length) ui.write((b"data-unused: %d\n") % docket.data_unused)
--- a/mercurial/revlog.py Thu Feb 27 15:42:04 2020 +0100 +++ b/mercurial/revlog.py Thu Feb 27 16:32:43 2020 +0100 @@ -643,8 +643,11 @@ if use_nodemap: nodemap_data = nodemaputil.persisted_data(self) if nodemap_data is not None: - self._nodemap_docket = nodemap_data[0] - index.update_nodemap_data(*nodemap_data) + docket = nodemap_data[0] + if d[0][docket.tip_rev][7] == docket.tip_node: + # no changelog tampering + self._nodemap_docket = docket + index.update_nodemap_data(*nodemap_data) except (ValueError, IndexError): raise error.RevlogError( _(b"index %s is corrupted") % self.indexfile
--- a/mercurial/revlogutils/nodemap.py Thu Feb 27 15:42:04 2020 +0100 +++ b/mercurial/revlogutils/nodemap.py Thu Feb 27 16:32:43 2020 +0100 @@ -38,10 +38,12 @@ return None offset += S_VERSION.size headers = S_HEADER.unpack(pdata[offset : offset + S_HEADER.size]) - uid_size, tip_rev, data_length, data_unused = headers + uid_size, tip_rev, data_length, data_unused, tip_node_size = headers offset += S_HEADER.size docket = NodeMapDocket(pdata[offset : offset + uid_size]) + offset += uid_size docket.tip_rev = tip_rev + docket.tip_node = pdata[offset : offset + tip_node_size] docket.data_length = data_length docket.data_unused = data_unused @@ -164,6 +166,7 @@ new_data = util.buffer(util.mmapread(fd, len(data))) target_docket.data_length = len(data) target_docket.tip_rev = revlog.tiprev() + target_docket.tip_node = revlog.node(target_docket.tip_rev) # EXP-TODO: if this is a cache, this should use a cache vfs, not a # store vfs with revlog.opener(revlog.nodemap_file, b'w', atomictemp=True) as fp: @@ -214,7 +217,7 @@ # version 0 is experimental, no BC garantee, do no use outside of tests. ONDISK_VERSION = 0 S_VERSION = struct.Struct(">B") -S_HEADER = struct.Struct(">BQQQ") +S_HEADER = struct.Struct(">BQQQQ") ID_SIZE = 8 @@ -242,6 +245,15 @@ # the tipmost revision stored in the data file. This revision and all # revision before it are expected to be encoded in the data file. self.tip_rev = None + # the node of that tipmost revision, if it mismatch the current index + # data the docket is not valid for the current index and should be + # discarded. + # + # note: this method is not perfect as some destructive operation could + # preserve the same tip_rev + tip_node while altering lower revision. + # However this multiple other caches have the same vulnerability (eg: + # brancmap cache). + self.tip_node = None # the size (in bytes) of the persisted data to encode the nodemap valid # for `tip_rev`. # - data file shorter than this are corrupted, @@ -254,6 +266,7 @@ def copy(self): new = NodeMapDocket(uid=self.uid) new.tip_rev = self.tip_rev + new.tip_node = self.tip_node new.data_length = self.data_length new.data_unused = self.data_unused return new @@ -281,9 +294,11 @@ self.tip_rev, self.data_length, self.data_unused, + len(self.tip_node), ) data.append(S_HEADER.pack(*headers)) data.append(self.uid) + data.append(self.tip_node) return b''.join(data)
--- a/tests/test-persistent-nodemap.t Thu Feb 27 15:42:04 2020 +0100 +++ b/tests/test-persistent-nodemap.t Thu Feb 27 16:32:43 2020 +0100 @@ -14,10 +14,11 @@ $ hg debugnodemap --metadata uid: ???????????????? (glob) tip-rev: 5000 + tip-node: 06ddac466af534d365326c13c3879f97caca3cb1 data-length: 122880 data-unused: 0 $ f --size .hg/store/00changelog.n - .hg/store/00changelog.n: size=42 + .hg/store/00changelog.n: size=70 Simple lookup works @@ -95,18 +96,20 @@ $ hg debugnodemap --metadata uid: ???????????????? (glob) tip-rev: 5001 + tip-node: 2dd9b5258caa46469ff07d4a3da1eb3529a51f49 data-length: 122880 data-unused: 0 #else $ hg debugnodemap --metadata uid: ???????????????? (glob) tip-rev: 5001 + tip-node: 2dd9b5258caa46469ff07d4a3da1eb3529a51f49 data-length: 123072 data-unused: 192 #endif $ f --size .hg/store/00changelog.n - .hg/store/00changelog.n: size=42 + .hg/store/00changelog.n: size=70 (The pure code use the debug code that perform incremental update, the C code reencode from scratch) @@ -148,6 +151,7 @@ $ hg debugnodemap --metadata uid: ???????????????? (glob) tip-rev: 5002 + tip-node: 6ce944fafcee85af91f29ea5b51654cc6101ad7e data-length: 123328 data-unused: 384 $ f --sha256 .hg/store/00changelog-*.nd --size @@ -157,6 +161,7 @@ $ hg debugnodemap --metadata uid: ???????????????? (glob) tip-rev: 5002 + tip-node: 6ce944fafcee85af91f29ea5b51654cc6101ad7e data-length: 123328 data-unused: 384 $ f --sha256 .hg/store/00changelog-*.nd --size @@ -166,6 +171,7 @@ $ hg debugnodemap --metadata uid: ???????????????? (glob) tip-rev: 5002 + tip-node: 6ce944fafcee85af91f29ea5b51654cc6101ad7e data-length: 122944 data-unused: 0 $ f --sha256 .hg/store/00changelog-*.nd --size @@ -181,12 +187,14 @@ $ hg debugnodemap --metadata uid: ???????????????? (glob) tip-rev: 5002 + tip-node: 6ce944fafcee85af91f29ea5b51654cc6101ad7e data-length: 122944 data-unused: 0 #else $ hg debugnodemap --metadata uid: ???????????????? (glob) tip-rev: 5002 + tip-node: 6ce944fafcee85af91f29ea5b51654cc6101ad7e data-length: 122944 data-unused: 0 #endif @@ -215,6 +223,7 @@ $ hg debugnodemap --metadata uid: ???????????????? (glob) tip-rev: 5003 + tip-node: 5c049e9c4a4af159bdcd65dce1b6bf303a0da6cf data-length: 123200 (pure !) data-length: 123200 (rust !) data-length: 122944 (no-rust no-pure !) @@ -225,7 +234,50 @@ $ hg debugnodemap --metadata uid: ???????????????? (glob) tip-rev: 5002 + tip-node: 6ce944fafcee85af91f29ea5b51654cc6101ad7e data-length: 122944 data-unused: 0 $ hg log -r "$NODE" -T '{rev}\n' 5003 + +changelog altered +----------------- + +If the nodemap is not gated behind a requirements, an unaware client can alter +the repository so the revlog used to generate the nodemap is not longer +compatible with the persistent nodemap. We need to detect that. + + $ hg up "$NODE~5" + 0 files updated, 0 files merged, 2 files removed, 0 files unresolved + $ echo bar > babar + $ hg add babar + $ hg ci -m 'babar' + created new head + $ OTHERNODE=`hg log -r tip -T '{node}\n'` + $ hg log -r "$OTHERNODE" -T '{rev}\n' + 5004 + + $ hg --config extensions.strip= strip --rev "$NODE~1" --no-backup + +the nodemap should detect the changelog have been tampered with and recover. + + $ hg debugnodemap --metadata + uid: ???????????????? (glob) + tip-rev: 5002 + tip-node: 42bf3068c7ddfdfded53c4eb11d02266faeebfee + data-length: 123456 (pure !) + data-length: 246464 (rust !) + data-length: 123008 (no-pure no-rust !) + data-unused: 448 (pure !) + data-unused: 123904 (rust !) + data-unused: 0 (no-pure no-rust !) + + $ cp -f ../tmp-copies/* .hg/store/ + $ hg debugnodemap --metadata + uid: ???????????????? (glob) + tip-rev: 5002 + tip-node: 6ce944fafcee85af91f29ea5b51654cc6101ad7e + data-length: 122944 + data-unused: 0 + $ hg log -r "$OTHERNODE" -T '{rev}\n' + 5002