`nix-store --verify' improvements:

* If a path has disappeared, check its referrers first, and don't try
  to invalidate paths that have valid referrers.  Otherwise we get a
  foreign key constraint violation.
* Read the whole Nix store directory instead of statting each valid
  path, which is slower.
* Acquire the global GC lock.
This commit is contained in:
Eelco Dolstra 2010-08-31 11:47:31 +00:00
parent 80e722278c
commit e2e168f7c2
3 changed files with 62 additions and 20 deletions

View file

@ -1,6 +1,5 @@
#include "globals.hh"
#include "misc.hh"
#include "pathlocks.hh"
#include "local-store.hh"
#include <boost/shared_ptr.hpp>
@ -31,7 +30,7 @@ static const int defaultGcLevel = 1000;
read. To be precise: when they try to create a new temporary root
file, they will block until the garbage collector has finished /
yielded the GC lock. */
static int openGCLock(LockType lockType)
int LocalStore::openGCLock(LockType lockType)
{
Path fnGCLock = (format("%1%/%2%")
% nixStateDir % gcLockName).str();

View file

@ -1226,27 +1226,25 @@ void LocalStore::deleteFromStore(const Path & path, unsigned long long & bytesFr
void LocalStore::verifyStore(bool checkContents)
{
/* Check whether all valid paths actually exist. */
printMsg(lvlInfo, "checking path existence");
printMsg(lvlError, format("reading the Nix store..."));
PathSet validPaths2 = queryValidPaths(), validPaths;
/* Acquire the global GC lock to prevent a garbage collection. */
AutoCloseFD fdGCLock = openGCLock(ltWrite);
foreach (PathSet::iterator, i, validPaths2) {
checkInterrupt();
/* !!! invalidatePath() will probably fail due to the foreign
key constraints on the Ref table. */
if (!isStorePath(*i)) {
printMsg(lvlError, format("path `%1%' is not in the Nix store") % *i);
invalidatePath(*i);
} else if (!pathExists(*i)) {
printMsg(lvlError, format("path `%1%' disappeared") % *i);
invalidatePath(*i);
} else validPaths.insert(*i);
}
Paths entries = readDirectory(nixStore);
PathSet store(entries.begin(), entries.end());
/* Check whether all valid paths actually exist. */
printMsg(lvlInfo, "checking path existence...");
PathSet validPaths2 = queryValidPaths(), validPaths, done;
foreach (PathSet::iterator, i, validPaths2)
verifyPath(*i, store, done, validPaths);
/* Optionally, check the content hashes (slow). */
if (checkContents) {
printMsg(lvlInfo, "checking hashes");
printMsg(lvlInfo, "checking hashes...");
foreach (PathSet::iterator, i, validPaths) {
ValidPathInfo info = queryPathInfo(*i);
@ -1264,6 +1262,45 @@ void LocalStore::verifyStore(bool checkContents)
}
void LocalStore::verifyPath(const Path & path, const PathSet & store,
PathSet & done, PathSet & validPaths)
{
checkInterrupt();
if (done.find(path) != done.end()) return;
done.insert(path);
if (!isStorePath(path)) {
printMsg(lvlError, format("path `%1%' is not in the Nix store") % path);
invalidatePath(path);
return;
}
if (store.find(baseNameOf(path)) == store.end()) {
/* Check any referrers first. If we can invalidate them
first, then we can invalidate this path as well. */
bool canInvalidate = true;
PathSet referrers; queryReferrers(path, referrers);
foreach (PathSet::iterator, i, referrers)
if (*i != path) {
verifyPath(*i, store, done, validPaths);
if (validPaths.find(*i) != validPaths.end())
canInvalidate = false;
}
if (canInvalidate) {
printMsg(lvlError, format("path `%1%' disappeared, removing from database...") % path);
invalidatePath(path);
} else
printMsg(lvlError, format("path `%1%' disappeared, but it still has valid referrers!") % path);
return;
}
validPaths.insert(path);
}
/* Functions for upgrading from the pre-SQLite database. */
PathSet LocalStore::queryValidPathsOld()

View file

@ -5,6 +5,7 @@
#include "store-api.hh"
#include "util.hh"
#include "pathlocks.hh"
class sqlite3;
@ -16,8 +17,8 @@ namespace nix {
/* Nix store and database schema version. Version 1 (or 0) was Nix <=
0.7. Version 2 was Nix 0.8 and 0.9. Version 3 is Nix 0.10.
Version 4 is Nix 0.11. Version 5 is Nix 0.12-0.14. Version 6 is
Nix 0.15. */
Version 4 is Nix 0.11. Version 5 is Nix 0.12-0.16. Version 6 is
Nix 1.0. */
const int nixSchemaVersion = 6;
@ -233,6 +234,9 @@ private:
void invalidatePath(const Path & path);
void verifyPath(const Path & path, const PathSet & store,
PathSet & done, PathSet & validPaths);
void upgradeStore6();
PathSet queryValidPathsOld();
ValidPathInfo queryPathInfoOld(const Path & path);
@ -244,6 +248,8 @@ private:
bool isActiveTempFile(const GCState & state,
const Path & path, const string & suffix);
int openGCLock(LockType lockType);
void startSubstituter(const Path & substituter,
RunningSubstituter & runningSubstituter);