From 588cb0eade0c14acdf4a20dfec5678715cc6542e Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Thu, 15 Jun 2006 11:56:49 +0000 Subject: [PATCH] * In `nix-env -i|-u|-e', lock the profile to prevent races between concurrent nix-env operations on the same profile. Fixes NIX-7. --- src/libstore/pathlocks.cc | 11 +++++++---- src/libstore/pathlocks.hh | 6 ++++-- src/nix-env/main.cc | 15 +++++++++++++++ 3 files changed, 26 insertions(+), 6 deletions(-) diff --git a/src/libstore/pathlocks.cc b/src/libstore/pathlocks.cc index 3beb49aac..7f7cbdf15 100644 --- a/src/libstore/pathlocks.cc +++ b/src/libstore/pathlocks.cc @@ -51,14 +51,14 @@ PathLocks::PathLocks() } -PathLocks::PathLocks(const PathSet & paths) +PathLocks::PathLocks(const PathSet & paths, const string & waitMsg) : deletePaths(false) { - lockPaths(paths); + lockPaths(paths, waitMsg); } -void PathLocks::lockPaths(const PathSet & _paths) +void PathLocks::lockPaths(const PathSet & _paths, const string & waitMsg) { /* May be called only once! */ assert(fds.empty()); @@ -94,7 +94,10 @@ void PathLocks::lockPaths(const PathSet & _paths) throw SysError(format("opening lock file `%1%'") % lockPath); /* Acquire an exclusive lock. */ - lockFile(fd, ltWrite, true); + if (!lockFile(fd, ltWrite, false)) { + if (waitMsg != "") printMsg(lvlError, waitMsg); + lockFile(fd, ltWrite, true); + } debug(format("lock acquired on `%1%'") % lockPath); diff --git a/src/libstore/pathlocks.hh b/src/libstore/pathlocks.hh index 42ebe58df..2fd0e0d1e 100644 --- a/src/libstore/pathlocks.hh +++ b/src/libstore/pathlocks.hh @@ -18,8 +18,10 @@ private: public: PathLocks(); - PathLocks(const PathSet & paths); - void lockPaths(const PathSet & _paths); + PathLocks(const PathSet & paths, + const string & waitMsg = ""); + void lockPaths(const PathSet & _paths, + const string & waitMsg = ""); ~PathLocks(); void setDeletion(bool deletePaths); }; diff --git a/src/nix-env/main.cc b/src/nix-env/main.cc index 560612825..0198aed57 100644 --- a/src/nix-env/main.cc +++ b/src/nix-env/main.cc @@ -10,6 +10,7 @@ #include "help.txt.hh" #include "nixexpr-ast.hh" #include "get-drvs.hh" +#include "pathlocks.hh" #include #include @@ -411,6 +412,14 @@ static void printMissing(EvalState & state, const DrvInfos & elems) } +static void lockProfile(PathLocks & lock, const Path & profile) +{ + lock.lockPaths(singleton(profile), + (format("waiting for lock on profile `%1%'") % profile).str()); + lock.setDeletion(true); +} + + static void installDerivations(Globals & globals, const Strings & args, const Path & profile) { @@ -426,6 +435,8 @@ static void installDerivations(Globals & globals, /* Add in the already installed derivations, unless they have the same name as a to-be-installed element. */ + PathLocks lock; + lockProfile(lock, profile); DrvInfos installedElems = queryInstalled(globals.state, profile); DrvInfos allElems(newElems); @@ -480,6 +491,8 @@ static void upgradeDerivations(Globals & globals, name and a higher version number. */ /* Load the currently installed derivations. */ + PathLocks lock; + lockProfile(lock, profile); DrvInfos installedElems = queryInstalled(globals.state, profile); /* Fetch all derivations from the input file. */ @@ -559,6 +572,8 @@ static void opUpgrade(Globals & globals, static void uninstallDerivations(Globals & globals, DrvNames & selectors, Path & profile) { + PathLocks lock; + lockProfile(lock, profile); DrvInfos installedElems = queryInstalled(globals.state, profile); DrvInfos newElems;