1 files changed, 233 insertions, 90 deletions

diff --git a/src/repo/s6-rc-set-install.c b/src/repo/s6-rc-set-install.c
index e2ecd6f..3940aba 100644
--- a/src/repo/s6-rc-set-install.c
+++ b/src/repo/s6-rc-set-install.c
@@ -36,6 +36,7 @@ enum golb_e
   GOLB_KEEPOLD = 0x02,
   GOLB_NOUPDATE = 0x04,
   GOLB_NOFORCEESSENTIALS = 0x08,
+  GOLB_NOSNAP = 0x10,
 } ;
 
 enum gola_e
@@ -48,6 +49,104 @@ enum gola_e
   GOLA_N
 } ;
 
+#define DSTFNLEN(bootdir, set) (strlen(bootdir) + strlen(set) + 36)
+
+static int install_needs_upgrade (char const *livedir)
+{
+  size_t llen = strlen(livedir) ;
+  char livedb[llen + 10] ;
+  memcpy(livedb, livedir, llen) ;
+  memcpy(livedb + llen, "/compiled", 10) ;
+  return s6rc_repo_read_major(livedb) < s6rc_get_major(S6RC_VERSION) ;
+}
+
+static void snapcompile (char const *livedir, char const *repo, unsigned int verbosity, stralloc *sa)
+{
+  int r ;
+  size_t llen = strlen(livedir) ;
+  size_t snappos = sa->len, fdhuserpos, catchallpos, defbundlepos ;
+  char fn[llen + 28] ;
+  memcpy(fn, livedir, llen) ;
+  memcpy(fn + llen, "/compiled", 10) ;
+  if (!stralloc_catb(sa, ".snapshot.", 10)) strerr_diefusys(111, "stralloc_catb") ;
+  if (sareadlink(sa, fn) == -1 || !stralloc_0(sa)) strerr_diefusys(111, "readlink ", fn) ;
+  fdhuserpos = sa->len ;
+  memcpy(fn + llen + 9, "metainfo/fdhuser", 17) ;
+  if (!openslurpnclose(fn, sa, 4096) || !stralloc_0(sa)) strerr_diefusys(111, "read ", fn) ;
+  catchallpos = sa->len ;
+  memcpy(fn + llen + 18, "catchall", 9) ;
+  if (!openslurpnclose(fn, sa, 4096) || !stralloc_0(sa)) strerr_diefusys(111, "read ", fn) ;
+  defbundlepos = sa->len ;
+  memcpy(fn + llen + 18, "defbundle", 10) ;
+  if (!openslurpnclose(fn, sa, 4096) || !stralloc_0(sa)) strerr_diefusys(111, "read ", fn) ;
+
+  size_t oldclen = S6RC_REPO_COMPILE_BUFLEN(strlen(repo), fdhuserpos - 1) ;
+  char oldc[oldclen] ;
+
+  r = s6rc_repo_setcompile(repo, sa->s + snappos, sa->s + defbundlepos, oldc, verbosity, sa->s + fdhuserpos, sa->s + catchallpos, 1) ;
+  if (r == -1) _exit(111) ;
+  if (!r) _exit(1) ;
+  if (r == 2) rm_rf(oldc) ;
+  sa->len = fdhuserpos ;
+}
+
+static void copy_compiled_to_bootdir (char *dstfn, char const *repo, char const *set, char const *bootdir, char const *livedir, stralloc *olddbsa)
+{
+  size_t repolen = strlen(repo) ;
+  size_t setlen = strlen(set) ;
+  size_t bootdirlen = strlen(bootdir) ;
+  size_t clen = S6RC_REPO_COMPILE_BUFLEN(repolen, setlen) ;
+  ssize_t l ;
+  char clink[repolen + setlen + 11] ;
+  char cfull[clen] ;
+  memcpy(clink, repo, repolen) ;
+  memcpy(clink + repolen, "/compiled/", 10) ;
+  memcpy(clink + repolen + 10, set, setlen + 1) ;
+  memcpy(cfull, clink, repolen + 10) ;
+  memcpy(dstfn, bootdir, bootdirlen) ;
+  dstfn[bootdirlen] = '/' ;
+  l = readlink(clink, cfull + repolen + 10, setlen + 35) ;
+  if (l == -1) strerr_diefusys(111, "readlink ", clink) ;
+  if (l >= setlen + 35) strerr_dief(102, "incorrect/unexpected link contents for ", clink) ;
+  cfull[repolen + 10 + l] = 0 ;
+  memcpy(dstfn + bootdirlen + 1, cfull + repolen + 10, l+1) ;
+  l = 0 ;
+
+  {
+    struct stat stsource, stdest ;
+    if (stat(cfull, &stsource) == -1) strerr_diefusys(111, "stat ", cfull) ;
+    if (stat(dstfn, &stdest) == -1)
+    {
+      if (errno != ENOENT)
+        strerr_diefusys(111, "stat ", dstfn) ;
+    }
+    else if (stdest.st_mtim.tv_sec > stsource.st_mtim.tv_sec || (stdest.st_mtim.tv_sec == stsource.st_mtim.tv_sec && stdest.st_mtim.tv_nsec >= stsource.st_mtim.tv_nsec))
+    {
+      strerr_warni("set ", set, " is already installed as ", dstfn) ;
+      _exit(0) ;
+    }
+    else strerr_dief(102, "huh? ", dstfn, " already exists") ;
+  }
+
+  {
+    size_t llen = strlen(livedir) ;
+    char cfn[llen + 10] ;
+    memcpy(cfn, livedir, llen) ;
+    memcpy(cfn + llen, "/compiled", 10) ;
+    if (sarealpath(olddbsa, cfn) == -1 && errno != ENOENT)
+      strerr_diefusys(111, "realpath ", cfn) ;
+    if (!stralloc_0(olddbsa)) strerr_diefusys(111, "stralloc_catb") ;
+  }
+
+  if (!hiercopy(cfull, dstfn))
+  {
+    int e = errno ;
+    rm_rf(dstfn) ;
+    errno = e ;
+    strerr_diefusys(111, "recursively copy ", cfull, " to ", dstfn) ;
+  }
+}
+
 int main (int argc, char const *const *argv)
 {
   static gol_bool const rgolb[] =
@@ -57,6 +156,8 @@ int main (int argc, char const *const *argv)
     { .so = 0, .lo = "no-update", .set = GOLB_NOUPDATE },
     { .so = 'e', .lo = "force-essentials", .clear = GOLB_NOFORCEESSENTIALS, .set = 0 },
     { .so = 'E', .lo = "no-force-essentials", .clear = 0, .set = GOLB_NOFORCEESSENTIALS },
+    { .so = 0, .lo = "snapshot", .clear = GOLB_NOSNAP, .set = 0 },
+    { .so = 0, .lo = "no-snapshot", .clear = 0, .set = GOLB_NOSNAP },
   } ;
   static gol_arg const rgola[] =
   {
@@ -73,7 +174,7 @@ int main (int argc, char const *const *argv)
   uint64_t wgolb = 0 ;
   unsigned int golc ;
   int r ;
-  stralloc sa = STRALLOC_ZERO ;
+  stralloc bootdirsa = STRALLOC_ZERO ;
 
   PROG = "s6-rc-set-install" ;
   wgola[GOLA_BOOTDB] = S6RC_BOOTDB ;
@@ -97,139 +198,181 @@ int main (int argc, char const *const *argv)
   r = s6rc_repo_checkset(wgola[GOLA_REPODIR], argv[0]) ;
   if (r) _exit(r) ;
  
-  r = s6rc_repo_setuptodate(wgola[GOLA_REPODIR], argv[0]) ;
+  r = s6rc_repo_setuptodate(wgola[GOLA_REPODIR], argv[0], !!(wgolb & GOLB_NOSNAP)) ;
   if (r == -1) _exit(111) ;
   if (!r) strerr_dief3x(7, "set ", argv[0], " is not up-to-date; commit it first") ;
 
-  if (!sadirname(&sa, wgola[GOLA_BOOTDB], strlen(wgola[GOLA_BOOTDB]))
-   || !stralloc_0(&sa)) strerr_diefu1sys(111, "sadirname") ;
-  sa.len-- ;
+  if (!sadirname(&bootdirsa, wgola[GOLA_BOOTDB], strlen(wgola[GOLA_BOOTDB]))
+   || !stralloc_0(&bootdirsa)) strerr_diefu1sys(111, "sadirname") ;
+  bootdirsa.len-- ;
 
   {
-    size_t repolen = strlen(wgola[GOLA_REPODIR]) ;
-    size_t setlen = strlen(argv[0]) ;
-    size_t clen = S6RC_REPO_COMPILE_BUFLEN(repolen, setlen) ;
-    ssize_t l ;
-    pid_t pid ;
-    int wstat ;
-    char *olddb = 0 ;
-    char const *uargv[12] ;
+    int needupgrade = install_needs_upgrade(wgola[GOLA_LIVEDIR]) ;
+    stralloc olddbsa = STRALLOC_ZERO ;
+    char dstfn[DSTFNLEN(bootdirsa.s, argv[0])] ;
     char fmtv[UINT_FMT] ;
-    char clink[repolen + setlen + 11] ;
-    char cfull[clen] ;
-    char dstfn[sa.len + setlen + 36] ;
     fmtv[uint_fmt(fmtv, verbosity)] = 0 ;
-    memcpy(clink, wgola[GOLA_REPODIR], repolen) ;
-    memcpy(clink + repolen, "/compiled/", 10) ;
-    memcpy(clink + repolen + 10, argv[0], setlen + 1) ;
-    memcpy(cfull, clink, repolen + 10) ;
-    memcpy(dstfn, sa.s, sa.len) ;
-    dstfn[sa.len] = '/' ;
-    l = readlink(clink, cfull + repolen + 10, setlen + 35) ;
-    if (l == -1) strerr_diefu2sys(111, "readlink ", clink) ;
-    if (l >= setlen + 35) strerr_diefu2x(102, "incorrect/unexpected link contents for ", clink) ;
-    cfull[repolen + 10 + l] = 0 ;
-    memcpy(dstfn + sa.len + 1, cfull + repolen + 10, l+1) ;
-    l = 0 ;
-    {    
-      struct stat stsource, stdest ;
-      if (stat(cfull, &stsource) == -1) strerr_diefu2sys(111, "stat ", cfull) ;
-      if (stat(dstfn, &stdest) == -1)
-      {
-        if (errno != ENOENT)
-          strerr_diefu2sys(111, "stat ", dstfn) ;
-      }
-      else if (stdest.st_mtim.tv_sec > stsource.st_mtim.tv_sec || (stdest.st_mtim.tv_sec == stsource.st_mtim.tv_sec && stdest.st_mtim.tv_nsec >= stsource.st_mtim.tv_nsec))
-      {
-        strerr_warni(0, "set ", argv[0], " is already installed as ", dstfn) ;
-        _exit(0) ;
-      }
-      else strerr_dief(102, "huh? ", dstfn, " already exists") ;
-    }
-    {
-      size_t llen = strlen(wgola[GOLA_LIVEDIR]) ;
-      char cfn[llen + 10] ;
-      memcpy(cfn, wgola[GOLA_LIVEDIR], llen) ;
-      memcpy(cfn + llen, "/compiled", 10) ;
-      olddb = realpath(cfn, 0) ;
-      if (!olddb && errno != ENOENT) strerr_diefu2sys(111, "realpath ", cfn) ;
-    }
 
-    if (!hiercopy(cfull, dstfn))
-    {
-      int e = errno ;
-      rm_rf(dstfn) ;
-      errno = e ;
-      strerr_diefu4sys(111, "recursively copy ", cfull, " to ", dstfn) ;
-    }
 
-    if (!(wgolb & GOLB_NOUPDATE))
+   /* If we need a format-upgrade and the user isn't opposed to it */
+    if (needupgrade && !(wgolb & GOLB_NOUPDATE) && !(wgolb & GOLB_NOSNAP))
     {
-      uargv[l++] = S6RC_BINPREFIX "s6-rc-update" ;
-      if (wgolb & GOLB_BLOCK) uargv[l++] = "-b" ;
-      uargv[l++] = wgolb & GOLB_NOFORCEESSENTIALS ? "-E" : "-e" ;
+      pid_t pid ;
+      int wstat ;
+      char const *uargv[9] ;
+      unsigned int l = 0 ;
+      char snapfn[DSTFNLEN(bootdirsa.s, olddbsa.s)] ;
+
+     /* We find the snapshot corresponding to the current live db and we compile it */
+      snapcompile(wgola[GOLA_LIVEDIR], wgola[GOLA_REPODIR], verbosity, &olddbsa) ;
+      olddbsa.len = 0 ;
+
+     /* We copy the compiled snapshot to the bootdir. It has the correct major. */
+      copy_compiled_to_bootdir(snapfn, wgola[GOLA_REPODIR], olddbsa.s, bootdirsa.s, wgola[GOLA_LIVEDIR], &olddbsa) ;
+
+     /* We perform the format-upgrade */
+      uargv[l++] = S6RC_BINPREFIX "s6-rc-format-upgrade" ;
       uargv[l++] = "-v" ;
       uargv[l++] = fmtv ;
       uargv[l++] = "-l" ;
       uargv[l++] = wgola[GOLA_LIVEDIR] ;
-      if (wgola[GOLA_CONVFILE])
-      {
-        uargv[l++] = "-f" ;
-        uargv[l++] = wgola[GOLA_CONVFILE] ;
-      }
+      if (wgolb & GOLB_BLOCK) uargv[l++] = "-b" ;
       uargv[l++] = "--" ;
-      uargv[l++] = dstfn ;
+      uargv[l++] = snapfn ;
       uargv[l++] = 0 ;
-
       pid = cspawn(uargv[0], uargv, (char const *const *)environ, 0, 0, 0) ;
       if (!pid)
       {
         int e = errno ;
-        rm_rf(dstfn) ;
+        rm_rf(snapfn) ;
         errno = e ;
-        strerr_diefu2sys(111, "spawn ", uargv[0]) ;
+        strerr_diefusys(111, "spawn ", uargv[0]) ;
       }
       r = wait_pid(pid, &wstat) ;
-      if (r == -1) strerr_diefu3sys(111, "wait for the ", uargv[0], " process (updating may yet succeed)") ;
+      if (r == -1) strerr_diefusys(111, "wait for the ", uargv[0], " process") ;
       if (WIFSIGNALED(wstat))
       {
         char fmt[INT_FMT] ;
         fmt[int_fmt(fmt, WTERMSIG(wstat))] = 0 ;
-        strerr_dief3x(wait_estatus(wstat), uargv[0], " crashed with signal ", fmt) ;
+        strerr_dief(wait_estatus(wstat), uargv[0], " crashed with signal ", fmt) ;
       }
-      r = WEXITSTATUS(wstat) ;
-      if (r == 111)
-        strerr_dief2x(111, uargv[0], " exited 111, unable to know the state of the live db or clean up") ;
-      if ((r >= 3 && r <= 10) || r == 100)
+      if (WEXITSTATUS(wstat))
       {
-        int e = errno ;
         char fmt[INT_FMT] ;
-        fmt[int_fmt(fmt, r)] = 0 ;
+        fmt[int_fmt(fmt, WEXITSTATUS(wstat))] = 0 ;
+        strerr_dief(wait_estatus(wstat), uargv[0], " exited with signal ", fmt) ;
+      }
+
+     /* Now the live db has the same major version number as the new db we want. */
+
+      if (!atomic_symlink4(snapfn + bootdirsa.len + 1, wgola[GOLA_BOOTDB], 0, 0))
+        strerr_diefusys(111, "symlink ", snapfn + bootdirsa.len + 1, " to ", wgola[GOLA_BOOTDB], " (live database switch was performed to snapshot, not to new set)", " (update that link manually then retry the command)") ;
+      if (olddbsa.s[0]) rm_rf(olddbsa.s) ;  /* we don't keep the db with the obsolete major */
+      olddbsa.len = 0 ;
+
+     /* The compiled snapshot is now in place and serves as the db to update from. */
+    }
+
+   /* We copy the compiled committed set to the bootdir */
+    copy_compiled_to_bootdir(dstfn, wgola[GOLA_REPODIR], argv[0], bootdirsa.s, wgola[GOLA_LIVEDIR], &olddbsa) ;
+
+    if (!(wgolb & GOLB_NOUPDATE))
+    {
+      pid_t pid ;
+      int wstat ;
+      char const *uargv[12] ;
+      unsigned int l = 0 ;
+
+     /* If --no-snapshot AND we need an upgrade, we assume the user knows what they're doing
+        and the dbs represent the same state: so we just format-upgrade directly to the new compiled db */
+      if (needupgrade && wgolb & GOLB_NOSNAP)
+      {
+        uargv[l++] = S6RC_BINPREFIX "s6-rc-format-upgrade" ;
+        uargv[l++] = "-v" ;
+        uargv[l++] = fmtv ;
+        uargv[l++] = "-l" ;
+        uargv[l++] = wgola[GOLA_LIVEDIR] ;
+        if (wgolb & GOLB_BLOCK) uargv[l++] = "-b" ;
+        uargv[l++] = "--" ;
+        uargv[l++] = dstfn ;
+        uargv[l++] = 0 ;
+        if (verbosity)
+          strerr_warnw("installing set without a snapshot after a major version update; assuming the same service state") ;
+      }
+      else
+     /* We know the new db has the same major as the live db (either naturally or after a format-upgrade
+        via a snapshot), but we don't know if they represent the same state. This is the common case.
+        So we s6-rc-update, to switch live dbs. */
+      {
+        uargv[l++] = S6RC_BINPREFIX "s6-rc-update" ;
+        if (wgolb & GOLB_BLOCK) uargv[l++] = "-b" ;
+        uargv[l++] = wgolb & GOLB_NOFORCEESSENTIALS ? "-E" : "-e" ;
+        uargv[l++] = "-v" ;
+        uargv[l++] = fmtv ;
+        uargv[l++] = "-l" ;
+        uargv[l++] = wgola[GOLA_LIVEDIR] ;
+        if (wgola[GOLA_CONVFILE])
+        {
+          uargv[l++] = "-f" ;
+          uargv[l++] = wgola[GOLA_CONVFILE] ;
+        }
+        uargv[l++] = "--" ;
+        uargv[l++] = dstfn ;
+        uargv[l++] = 0 ;
+      }
+
+      pid = cspawn(uargv[0], uargv, (char const *const *)environ, 0, 0, 0) ;
+      if (!pid)
+      {
+        int e = errno ;
         rm_rf(dstfn) ;
         errno = e ;
-        strerr_dief4x(r, uargv[0], " exited with code ", fmt, " (live database switch was NOT performed)") ;
+        strerr_diefusys(111, "spawn ", uargv[0]) ;
+      }
+      r = wait_pid(pid, &wstat) ;
+      if (r == -1) strerr_diefusys(111, "wait for the ", uargv[0], " process (updating may yet succeed)") ;
+      if (WIFSIGNALED(wstat))
+      {
+        char fmt[INT_FMT] ;
+        fmt[int_fmt(fmt, WTERMSIG(wstat))] = 0 ;
+        strerr_dief(wait_estatus(wstat), uargv[0], " crashed with signal ", fmt) ;
       }
-      if (olddb)
+      r = WEXITSTATUS(wstat) ;
+      if (!needupgrade || !(wgolb & GOLB_NOSNAP))
       {
-        if (wgolb & GOLB_KEEPOLD)
+        if (r == 111)
+          strerr_dief(111, uargv[0], " exited 111, unable to know the state of the live db or clean up") ;
+        if ((r >= 3 && r <= 10) || r == 100)
         {
-          if (buffer_puts(buffer_1small, olddb) == -1
-           || !buffer_putflush(buffer_1small, "\n", 1))
-            strerr_diefu2sys(111, "write to stdout", " (live database switch was performed)") ;
+          int e = errno ;
+          char fmt[INT_FMT] ;
+          fmt[int_fmt(fmt, r)] = 0 ;
+          rm_rf(dstfn) ;
+          errno = e ;
+          strerr_dief(r, uargv[0], " exited with code ", fmt, " (live database switch was NOT performed)") ;
         }
-        else rm_rf(olddb) ;
       }
       if (r)
       {
         char fmt[INT_FMT] ;
         fmt[int_fmt(fmt, r)] = 0 ;
-        strerr_dief4x(r, uargv[0], " exited with code ", fmt, " (live database switch was performed") ;
+        strerr_dief(r, uargv[0], " exited with code ", fmt, " (live database switch was performed") ;
       }
     }
 
-    if (!atomic_symlink4(dstfn + sa.len + 1, wgola[GOLA_BOOTDB], 0, 0))
-      strerr_diefu6sys(111, "symlink ", dstfn + sa.len + 1, " to ", wgola[GOLA_BOOTDB], " (live database switch was performed)", " (update that link manually or next boot might fail)") ;
+    if (!atomic_symlink4(dstfn + bootdirsa.len + 1, wgola[GOLA_BOOTDB], 0, 0))
+      strerr_diefusys(111, "symlink ", dstfn + bootdirsa.len + 1, " to ", wgola[GOLA_BOOTDB], " (live database switch was performed)", " (update that link manually or next boot might fail)") ;
+
+    if (olddbsa.s[0])
+    {
+      if (wgolb & GOLB_KEEPOLD)
+      {
+        if (buffer_puts(buffer_1small, olddbsa.s) == -1
+         || !buffer_putflush(buffer_1small, "\n", 1))
+          strerr_diefusys(111, "write to stdout", " (live database switch was performed)") ;
+      }
+      else rm_rf(olddbsa.s) ;
+    }
   }
-  // stralloc_free(&sa) ;
   _exit(0) ;
 }