Show space estimate for /boot, if separate; or estimate initrd for /usr

Calculate an estimate of 110% of the biggest initrd + system.map
as the additional space a kernel needs in /boot.

If /boot is a different file system than /usr, print the size of
the kernels + the additional space they will need separately;
otherwise include it in our /usr figure.

3 files changed, 61 insertions, 1 deletions

diff --git a/apt-pkg/depcache.cc b/apt-pkg/depcache.cc
index e3e8d627c..76a5c09ba 100644
--- a/apt-pkg/depcache.cc
+++ b/apt-pkg/depcache.cc
@@ -42,6 +42,7 @@
 #include <unordered_map>
 #include <utility>
 #include <vector>
+#include <dirent.h>
 
 #include <sys/stat.h>
 
@@ -2613,3 +2614,58 @@ bool pkgDepCache::PhasingApplied(pkgCache::PkgIterator Pkg) const
    return true;
 }
 									/*}}}*/
+
+// DepCache::BootSize						/*{{{*/
+double pkgDepCache::BootSize(bool initrdOnly)
+{
+   double BootSize = 0;
+   int BootCount = 0;
+   auto VirtualKernelPkg = FindPkg("$kernel", "any");
+   if (VirtualKernelPkg.end())
+      return 0;
+
+   for (pkgCache::PrvIterator Prv = VirtualKernelPkg.ProvidesList(); Prv.end() == false; ++Prv)
+   {
+      auto Pkg = Prv.OwnerPkg();
+      if ((*this)[Pkg].NewInstall())
+	 BootSize += (*this)[Pkg].InstallVer->InstalledSize, BootCount++;
+   }
+   if (BootCount == 0)
+      return 0;
+   if (initrdOnly)
+      BootSize = 0;
+
+   DIR *boot = opendir(_config->FindDir("Dir::Boot").c_str());
+   struct dirent *ent;
+   if (boot)
+   {
+      double initrdSize = 0;
+      double mapSize = 0;
+      while ((ent = readdir(boot)))
+      {
+	 enum
+	 {
+	    INITRD,
+	    MAP
+	 } type;
+	 if (APT::String::Startswith(ent->d_name, "initrd.img-"))
+	    type = INITRD;
+	 else if (APT::String::Startswith(ent->d_name, "System.map-"))
+	    type = MAP;
+	 else
+	    continue;
+
+	 auto path = _config->FindDir("Dir::Boot") + ent->d_name;
+
+	 if (struct stat st; stat(path.c_str(), &st) == 0)
+	 {
+	    double &targetSize = type == INITRD ? initrdSize : mapSize;
+	    targetSize = std::max(targetSize, double(st.st_size));
+	 }
+      }
+      closedir(boot);
+      return initrdSize ? BootSize + BootCount * (initrdSize + mapSize) * 1.1 : 0;
+   }
+   return 0;
+}
+									/*}}}*/
diff --git a/apt-pkg/depcache.h b/apt-pkg/depcache.h
index 5dd022b56..23047b97a 100644
--- a/apt-pkg/depcache.h
+++ b/apt-pkg/depcache.h
@@ -490,7 +490,9 @@ class APT_PUBLIC pkgDepCache : protected pkgCache::Namespace
    virtual ~pkgDepCache();
 
    bool CheckConsistency(char const *const msgtag = "");
-
+#ifdef APT_COMPILING_APT
+   double BootSize(bool initrdOnly);
+#endif
    protected:
    // methods call by IsInstallOk
    bool IsInstallOkMultiArchSameVersionSynced(PkgIterator const &Pkg,
diff --git a/apt-pkg/init.cc b/apt-pkg/init.cc
index 75935404f..487f94f20 100644
--- a/apt-pkg/init.cc
+++ b/apt-pkg/init.cc
@@ -147,6 +147,8 @@ bool pkgInitConfig(Configuration &Cnf)
 
    // Configuration
    Cnf.CndSet("Dir::Etc", &CONF_DIR[1]);
+   Cnf.CndSet("Dir::Boot", "boot");
+   Cnf.CndSet("Dir::Usr", "usr");
    Cnf.CndSet("Dir::Etc::sourcelist","sources.list");
    Cnf.CndSet("Dir::Etc::sourceparts","sources.list.d");
    Cnf.CndSet("Dir::Etc::main","apt.conf");