Clear any immutable bits in the Nix store

Doing this once makes subsequent operations like garbage collecting
more efficient since we don't have to call makeMutable() first.

10 files changed, 76 insertions, 89 deletions

diff --git a/doc/manual/release-notes.xml b/doc/manual/release-notes.xml
index 9560c055ba..60c119cb73 100644
--- a/doc/manual/release-notes.xml
+++ b/doc/manual/release-notes.xml
@@ -8,10 +8,17 @@
 
 <!--==================================================================-->
 
-<section xml:id="ssec-relnotes-1.3"><title>Release 1.3 (January 2, 2013)</title>
+<section xml:id="ssec-relnotes-1.3"><title>Release 1.3 (January 3, 2013)</title>
 
-<para>This is primarily a bug fix release.  It has contributions from
-Eelco Dolstra and Stuart Pernsteiner.</para>
+<para>This is primarily a bug fix release.  When this version is first
+run on Linux, it removes any immutable bits from the Nix store and
+increases the schema version of the Nix store.  (The previous release
+removed support for setting the immutable bit; this release clears any
+remaining immutable bits to make certain operations more
+efficient.)</para>
+
+<para>This release has contributions from Eelco Dolstra and Stuart
+Pernsteiner.</para>
 
 </section>
 
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index 6ff38b0c04..75802c324e 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -7,7 +7,6 @@
 #include "local-store.hh"
 #include "util.hh"
 #include "archive.hh"
-#include "immutable.hh"
 
 #include <map>
 #include <sstream>
@@ -1383,10 +1382,8 @@ void replaceValidPath(const Path & storePath, const Path tmpPath)
        way first.  We'd better not be interrupted here, because if
        we're repairing (say) Glibc, we end up with a broken system. */
     Path oldPath = (format("%1%.old-%2%-%3%") % storePath % getpid() % rand()).str();
-    if (pathExists(storePath)) {
-        makeMutable(storePath);
+    if (pathExists(storePath))
         rename(storePath.c_str(), oldPath.c_str());
-    }
     if (rename(tmpPath.c_str(), storePath.c_str()) == -1)
         throw SysError(format("moving `%1%' to `%2%'") % tmpPath % storePath);
     if (pathExists(oldPath))
@@ -1911,10 +1908,6 @@ void DerivationGoal::startBuilder()
             if (S_ISDIR(st.st_mode))
                 dirsInChroot[*i] = *i;
             else {
-                /* Creating a hard link to *i is impossible if its
-                   immutable bit is set.  So clear it first. */
-                makeMutable(*i);
-
                 Path p = chrootRootDir + *i;
                 if (link(i->c_str(), p.c_str()) == -1) {
                     /* Hard-linking fails if we exceed the maximum
diff --git a/src/libstore/gc.cc b/src/libstore/gc.cc
index 4385e4456f..a8fa1108bf 100644
--- a/src/libstore/gc.cc
+++ b/src/libstore/gc.cc
@@ -1,7 +1,6 @@
 #include "globals.hh"
 #include "misc.hh"
 #include "local-store.hh"
-#include "immutable.hh"
 
 #include <boost/shared_ptr.hpp>
 
@@ -456,7 +455,6 @@ void LocalStore::deletePathRecursive(GCState & state, const Path & path)
         // if the path was not valid, need to determine the actual
         // size.
         state.bytesInvalidated += size;
-        makeMutable(path.c_str());
         // Mac OS X cannot rename directories if they are read-only.
         if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1)
             throw SysError(format("making `%1%' writable") % path);
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 26b4cfd8c2..87d6e6a944 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -5,7 +5,6 @@
 #include "pathlocks.hh"
 #include "worker-protocol.hh"
 #include "derivations.hh"
-#include "immutable.hh"
 
 #include <iostream>
 #include <algorithm>
@@ -25,6 +24,12 @@
 #include <sys/mount.h>
 #endif
 
+#if HAVE_LINUX_FS_H
+#include <linux/fs.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+#endif
+
 #include <sqlite3.h>
 
 
@@ -292,6 +297,7 @@ LocalStore::LocalStore(bool reserveSpace)
         curSchema = getSchema();
 
         if (curSchema < 6) upgradeStore6();
+        else if (curSchema < 7) upgradeStore7();
 
         writeFile(schemaPath, (format("%1%") % nixSchemaVersion).str());
 
@@ -1787,6 +1793,59 @@ void LocalStore::upgradeStore6()
 }
 
 
+#if defined(FS_IOC_SETFLAGS) && defined(FS_IOC_GETFLAGS) && defined(FS_IMMUTABLE_FL)
+
+static void makeMutable(const Path & path)
+{
+    checkInterrupt();
+
+    struct stat st = lstat(path);
+
+    if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode)) return;
+
+    if (S_ISDIR(st.st_mode)) {
+        Strings names = readDirectory(path);
+        foreach (Strings::iterator, i, names)
+            makeMutable(path + "/" + *i);
+    }
+
+    /* The O_NOFOLLOW is important to prevent us from changing the
+       mutable bit on the target of a symlink (which would be a
+       security hole). */
+    AutoCloseFD fd = open(path.c_str(), O_RDONLY | O_NOFOLLOW);
+    if (fd == -1) {
+        if (errno == ELOOP) return; // it's a symlink
+        throw SysError(format("opening file `%1%'") % path);
+    }
+
+    unsigned int flags = 0, old;
+
+    /* Silently ignore errors getting/setting the immutable flag so
+       that we work correctly on filesystems that don't support it. */
+    if (ioctl(fd, FS_IOC_GETFLAGS, &flags)) return;
+    old = flags;
+    flags &= ~FS_IMMUTABLE_FL;
+    if (old == flags) return;
+    if (ioctl(fd, FS_IOC_SETFLAGS, &flags)) return;
+}
+
+/* Upgrade from schema 6 (Nix 0.15) to schema 7 (Nix >= 1.3). */
+void LocalStore::upgradeStore7()
+{
+    if (getuid() != 0) return;
+    printMsg(lvlError, "removing immutable bits from the Nix store (this may take a while)...");
+    makeMutable(settings.nixStore);
+}
+
+#else
+
+void LocalStore::upgradeStore7()
+{
+}
+
+#endif
+
+
 void LocalStore::vacuumDB()
 {
     if (sqlite3_exec(db, "vacuum;", 0, 0, 0) != SQLITE_OK)
diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh
index 82ca791a3f..2b0d713809 100644
--- a/src/libstore/local-store.hh
+++ b/src/libstore/local-store.hh
@@ -17,8 +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 0.12-0.16.  Version 6 is
-   Nix 1.0. */
-const int nixSchemaVersion = 6;
+   Nix 1.0.  Version 7 is Nix 1.3. */
+const int nixSchemaVersion = 7;
 
 
 extern string drvsLogDir;
@@ -265,6 +265,7 @@ private:
     void updatePathInfo(const ValidPathInfo & info);
 
     void upgradeStore6();
+    void upgradeStore7();
     PathSet queryValidPathsOld();
     ValidPathInfo queryPathInfoOld(const Path & path);
 
diff --git a/src/libstore/optimise-store.cc b/src/libstore/optimise-store.cc
index 43b3c9b4fb..e91c2b1ce5 100644
--- a/src/libstore/optimise-store.cc
+++ b/src/libstore/optimise-store.cc
@@ -2,7 +2,6 @@
 
 #include "util.hh"
 #include "local-store.hh"
-#include "immutable.hh"
 #include "globals.hh"
 
 #include <sys/types.h>
@@ -20,7 +19,6 @@ static void makeWritable(const Path & path)
     struct stat st;
     if (lstat(path.c_str(), &st))
         throw SysError(format("getting attributes of path `%1%'") % path);
-    if (S_ISDIR(st.st_mode) || S_ISREG(st.st_mode)) makeMutable(path);
     if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1)
         throw SysError(format("changing writability of `%1%'") % path);
 }
@@ -91,7 +89,6 @@ void LocalStore::optimisePath_(OptimiseStats & stats, const Path & path)
 
     if (!pathExists(linkPath)) {
         /* Nope, create a hard link in the links directory. */
-        makeMutable(path);
         if (link(path.c_str(), linkPath.c_str()) == 0) return;
         if (errno != EEXIST)
             throw SysError(format("cannot link `%1%' to `%2%'") % linkPath % path);
@@ -123,12 +120,6 @@ void LocalStore::optimisePath_(OptimiseStats & stats, const Path & path)
        its timestamp back to 0. */
     MakeReadOnly makeReadOnly(mustToggle ? dirOf(path) : "");
 
-    /* If ‘linkPath’ is immutable, we can't create hard links to it,
-       so make it mutable first.  We also have to make ‘path’ mutable,
-       otherwise rename() will fail to delete it. */
-    makeMutable(path);
-    makeMutable(linkPath);
-
     Path tempLink = (format("%1%/.tmp-link-%2%-%3%")
         % settings.nixStore % getpid() % rand()).str();
 
diff --git a/src/libutil/Makefile.am b/src/libutil/Makefile.am
index 4a3523f3be..fe896eec50 100644
--- a/src/libutil/Makefile.am
+++ b/src/libutil/Makefile.am
@@ -1,12 +1,12 @@
 pkglib_LTLIBRARIES = libutil.la
 
 libutil_la_SOURCES = util.cc hash.cc serialise.cc \
-  archive.cc xml-writer.cc immutable.cc
+  archive.cc xml-writer.cc
 
 libutil_la_LIBADD = ../boost/format/libformat.la
 
 pkginclude_HEADERS = util.hh hash.hh serialise.hh \
-  archive.hh xml-writer.hh types.hh immutable.hh
+  archive.hh xml-writer.hh types.hh
 
 if !HAVE_OPENSSL
 libutil_la_SOURCES += \
diff --git a/src/libutil/immutable.cc b/src/libutil/immutable.cc
deleted file mode 100644
index 766af49393..0000000000
--- a/src/libutil/immutable.cc
+++ /dev/null
@@ -1,49 +0,0 @@
-#include "config.h"
-
-#include "immutable.hh"
-#include "util.hh"
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-
-#if HAVE_LINUX_FS_H
-#include <linux/fs.h>
-#include <sys/ioctl.h>
-#include <errno.h>
-#endif
-
-namespace nix {
-
-
-void makeMutable(const Path & path)
-{
-#if defined(FS_IOC_SETFLAGS) && defined(FS_IOC_GETFLAGS) && defined(FS_IMMUTABLE_FL)
-
-    /* Don't even try if we're not root.  One day we should support
-       the CAP_LINUX_IMMUTABLE capability. */
-    if (getuid() != 0) return;
-
-    /* The O_NOFOLLOW is important to prevent us from changing the
-       mutable bit on the target of a symlink (which would be a
-       security hole). */
-    AutoCloseFD fd = open(path.c_str(), O_RDONLY | O_NOFOLLOW);
-    if (fd == -1) {
-        if (errno == ELOOP) return; // it's a symlink
-        throw SysError(format("opening file `%1%'") % path);
-    }
-
-    unsigned int flags = 0, old;
-
-    /* Silently ignore errors getting/setting the immutable flag so
-       that we work correctly on filesystems that don't support it. */
-    if (ioctl(fd, FS_IOC_GETFLAGS, &flags)) return;
-    old = flags;
-    flags &= ~FS_IMMUTABLE_FL;
-    if (old == flags) return;
-    if (ioctl(fd, FS_IOC_SETFLAGS, &flags)) return;
-#endif
-}
-
-
-}
diff --git a/src/libutil/immutable.hh b/src/libutil/immutable.hh
deleted file mode 100644
index 8e98b76a41..0000000000
--- a/src/libutil/immutable.hh
+++ /dev/null
@@ -1,10 +0,0 @@
-#pragma once
-
-#include <types.hh>
-
-namespace nix {
-
-/* Make the given path mutable. */
-void makeMutable(const Path & path);
-
-}
diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 1308eac312..7874329c76 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -13,7 +13,6 @@
 #include <limits.h>
 
 #include "util.hh"
-#include "immutable.hh"
 
 
 extern char * * environ;
@@ -305,8 +304,6 @@ static void _deletePath(const Path & path, unsigned long long & bytesFreed)
 
     struct stat st = lstat(path);
 
-    if (S_ISDIR(st.st_mode) || S_ISREG(st.st_mode)) makeMutable(path);
-
     if (!S_ISDIR(st.st_mode) && st.st_nlink == 1)
         bytesFreed += st.st_blocks * 512;