* Allow unprivileged users to run the garbage collector and to do

`nix-store --delete'.  But unprivileged users are not allowed to
  ignore liveness.
* `nix-store --delete --ignore-liveness': ignore the runtime roots as
  well.
This commit is contained in:
Eelco Dolstra 2006-12-05 02:18:46 +00:00
parent 29cf434a35
commit a9c4f66cfb
16 changed files with 106 additions and 56 deletions

View file

@ -1,6 +1,5 @@
#include "shared.hh"
#include "globals.hh"
#include "gc.hh"
#include "store-api.hh"
#include "util.hh"

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@ -6,7 +6,7 @@ libstore_la_SOURCES = \
pkginclude_HEADERS = \
store-api.hh local-store.hh remote-store.hh derivations.hh misc.hh \
globals.hh db.hh references.hh pathlocks.hh gc.hh \
globals.hh db.hh references.hh pathlocks.hh \
worker-protocol.hh
libstore_la_LIBADD = ../libutil/libutil.la ../boost/format/libformat.la

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@ -2,7 +2,6 @@
#include "pathlocks.hh"
#include "misc.hh"
#include "globals.hh"
#include "gc.hh"
#include "local-store.hh"
#include "db.hh"
#include "util.hh"

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@ -1,4 +1,3 @@
#include "gc.hh"
#include "globals.hh"
#include "misc.hh"
#include "pathlocks.hh"
@ -428,7 +427,7 @@ static Paths topoSort(const PathSet & paths)
}
void collectGarbage(GCAction action, const PathSet & pathsToDelete,
void LocalStore::collectGarbage(GCAction action, const PathSet & pathsToDelete,
bool ignoreLiveness, PathSet & result, unsigned long long & bytesFreed)
{
result.clear();
@ -446,7 +445,7 @@ void collectGarbage(GCAction action, const PathSet & pathsToDelete,
/* Find the roots. Since we've grabbed the GC lock, the set of
permanent roots cannot increase now. */
Roots rootMap = ignoreLiveness ? Roots() : findRoots(true);
Roots rootMap = ignoreLiveness ? Roots() : nix::findRoots(true);
PathSet roots;
for (Roots::iterator i = rootMap.begin(); i != rootMap.end(); ++i)
@ -456,6 +455,7 @@ void collectGarbage(GCAction action, const PathSet & pathsToDelete,
NIX_ROOT_FINDER environment variable. This is typically used
to add running programs to the set of roots (to prevent them
from being garbage collected). */
if (!ignoreLiveness)
addAdditionalRoots(roots);
if (action == gcReturnRoots) {

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@ -1,42 +0,0 @@
#ifndef __GC_H
#define __GC_H
#include "types.hh"
namespace nix {
/* Garbage collector operation. */
typedef enum {
gcReturnRoots,
gcReturnLive,
gcReturnDead,
gcDeleteDead,
gcDeleteSpecific,
} GCAction;
/* If `action' is set to `gcReturnRoots', find and return the set of
roots for the garbage collector. These are the store paths
symlinked to in the `gcroots' directory. If `action' is
`gcReturnLive', return the set of paths reachable from (i.e. in the
closure of) the roots. If `action' is `gcReturnDead', return the
set of paths not reachable from the roots. If `action' is
`gcDeleteDead', actually delete the latter set. */
void collectGarbage(GCAction action, const PathSet & pathsToDelete,
bool ignoreLiveness, PathSet & result, unsigned long long & bytesFreed);
/* Remove the temporary roots file for this process. Any temporary
root becomes garbage after this point unless it has been registered
as a (permanent) root. */
void removeTempRoots();
/* Register a permanent GC root. */
Path addPermRoot(const Path & storePath, const Path & gcRoot,
bool indirect, bool allowOutsideRootsDir = false);
}
#endif /* !__GC_H */

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@ -4,7 +4,6 @@
#include "db.hh"
#include "archive.hh"
#include "pathlocks.hh"
#include "gc.hh"
#include "aterm.hh"
#include "derivations-ast.hh"

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@ -66,6 +66,9 @@ public:
void syncWithGC();
Roots findRoots();
void collectGarbage(GCAction action, const PathSet & pathsToDelete,
bool ignoreLiveness, PathSet & result, unsigned long long & bytesFreed);
};

View file

@ -302,6 +302,27 @@ Roots RemoteStore::findRoots()
}
void RemoteStore::collectGarbage(GCAction action, const PathSet & pathsToDelete,
bool ignoreLiveness, PathSet & result, unsigned long long & bytesFreed)
{
result.clear();
bytesFreed = 0;
writeInt(wopCollectGarbage, to);
writeInt(action, to);
writeStringSet(pathsToDelete, to);
writeInt(ignoreLiveness, to);
processStderr();
result = readStringSet(from);
/* Ugh - NAR integers are 64 bits, but read/writeInt() aren't. */
unsigned int lo = readInt(from);
unsigned int hi = readInt(from);
bytesFreed = (((unsigned long long) hi) << 32) | lo;
}
void RemoteStore::processStderr()
{
unsigned int msg;

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@ -55,6 +55,9 @@ public:
Roots findRoots();
void collectGarbage(GCAction action, const PathSet & pathsToDelete,
bool ignoreLiveness, PathSet & result, unsigned long long & bytesFreed);
private:
AutoCloseFD fdSocket;
FdSink to;

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@ -37,6 +37,16 @@ typedef list<Substitute> Substitutes;
typedef std::map<Path, Path> Roots;
/* Garbage collector operation. */
typedef enum {
gcReturnRoots,
gcReturnLive,
gcReturnDead,
gcDeleteDead,
gcDeleteSpecific,
} GCAction;
class StoreAPI
{
public:
@ -127,6 +137,33 @@ public:
outside of the Nix store that point to `storePath'. */
virtual Roots findRoots() = 0;
/* Depending on `action', this function does the following:
- `gcReturnRoots': find and return the set of roots for the
garbage collector. These are the store paths symlinked to in
the `gcroots' directory.
- `gcReturnLive': return the set of paths reachable from
(i.e. in the closure of) the roots.
- `gcReturnDead': return the set of paths not reachable from
the roots.
- `gcDeleteDead': actually delete the latter set.
- `gcDeleteSpecific': delete the paths listed in
`pathsToDelete', insofar as they are not reachable.
If `ignoreLiveness' is set, then reachability from the roots is
ignored (dangerous!). However, the paths must still be
unreferenced *within* the store (i.e., there can be no other
store paths that depend on them).
For `gcReturnDead', `gcDeleteDead' and `gcDeleteSpecific', the
number of bytes that would be or was freed is returned in
`bytesFreed'. */
virtual void collectGarbage(GCAction action, const PathSet & pathsToDelete,
bool ignoreLiveness, PathSet & result, unsigned long long & bytesFreed) = 0;
};
@ -177,6 +214,17 @@ std::pair<Path, Hash> computeStorePathForPath(const Path & srcPath,
Path computeStorePathForText(const string & suffix, const string & s);
/* Remove the temporary roots file for this process. Any temporary
root becomes garbage after this point unless it has been registered
as a (permanent) root. */
void removeTempRoots();
/* Register a permanent GC root. */
Path addPermRoot(const Path & storePath, const Path & gcRoot,
bool indirect, bool allowOutsideRootsDir = false);
/* For now, there is a single global store API object, but we'll
purify that in the future. */
extern boost::shared_ptr<StoreAPI> store;

View file

@ -25,6 +25,7 @@ typedef enum {
wopAddIndirectRoot,
wopSyncWithGC,
wopFindRoots,
wopCollectGarbage,
} WorkerOp;

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@ -2,7 +2,6 @@
#include "names.hh"
#include "globals.hh"
#include "misc.hh"
#include "gc.hh"
#include "shared.hh"
#include "parser.hh"
#include "eval.hh"

View file

@ -1,6 +1,6 @@
#include "profiles.hh"
#include "store-api.hh"
#include "util.hh"
#include "gc.hh"
#include <sys/types.h>
#include <sys/stat.h>

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@ -2,7 +2,6 @@
#include <iostream>
#include "globals.hh"
#include "gc.hh"
#include "shared.hh"
#include "eval.hh"
#include "parser.hh"

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@ -3,7 +3,6 @@
#include "globals.hh"
#include "misc.hh"
#include "gc.hh"
#include "archive.hh"
#include "shared.hh"
#include "dotgraph.hh"
@ -573,7 +572,7 @@ static void opGC(Strings opFlags, Strings opArgs)
PathSet result;
PrintFreed freed(action == gcDeleteDead || action == gcReturnDead,
action == gcReturnDead);
collectGarbage(action, PathSet(), false, result, freed.bytesFreed);
store->collectGarbage(action, PathSet(), false, result, freed.bytesFreed);
if (action != gcDeleteDead) {
for (PathSet::iterator i = result.begin(); i != result.end(); ++i)
@ -601,7 +600,7 @@ static void opDelete(Strings opFlags, Strings opArgs)
PathSet dummy;
PrintFreed freed(true, false);
collectGarbage(gcDeleteSpecific, pathsToDelete, ignoreLiveness,
store->collectGarbage(gcDeleteSpecific, pathsToDelete, ignoreLiveness,
dummy, freed.bytesFreed);
}

View file

@ -281,6 +281,28 @@ static void performOp(Source & from, Sink & to, unsigned int op)
break;
}
case wopCollectGarbage: {
GCAction action = (GCAction) readInt(from);
PathSet pathsToDelete = readStorePaths(from);
bool ignoreLiveness = readInt(from);
PathSet result;
unsigned long long bytesFreed;
startWork();
if (ignoreLiveness)
throw Error("you are not allowed to ignore liveness");
store->collectGarbage(action, pathsToDelete, ignoreLiveness,
result, bytesFreed);
stopWork();
writeStringSet(result, to);
writeInt(bytesFreed & 0xffffffff, to);
writeInt(bytesFreed >> 32, to);
break;
}
default:
throw Error(format("invalid operation %1%") % op);
}