Add rollback to s6rc_servicedir_manage; it should now be transactional

3 files changed, 54 insertions, 3 deletions

diff --git a/src/libs6rc/deps-lib/s6rc b/src/libs6rc/deps-lib/s6rc
index 2390c75..5e6263d 100644
--- a/src/libs6rc/deps-lib/s6rc
+++ b/src/libs6rc/deps-lib/s6rc
@@ -14,5 +14,6 @@ s6rc_servicedir_unblock.o
 s6rc_servicedir_copy_offline.o
 s6rc_servicedir_copy_online.o
 s6rc_servicedir_manage.o
+s6rc_servicedir_unsupervise.o
 -ls6
 -lskarnet
diff --git a/src/libs6rc/s6rc_servicedir_manage.c b/src/libs6rc/s6rc_servicedir_manage.c
index a6775f1..795c982 100644
--- a/src/libs6rc/s6rc_servicedir_manage.c
+++ b/src/libs6rc/s6rc_servicedir_manage.c
@@ -9,15 +9,27 @@
 #include <skalibs/tai.h>
 #include <skalibs/direntry.h>
 #include <skalibs/djbunix.h>
+#include <skalibs/stralloc.h>
 #include <skalibs/genalloc.h>
 #include <s6/s6-supervise.h>
 #include <s6/ftrigr.h>
 #include <s6/ftrigw.h>
 #include <s6-rc/s6rc-servicedir.h>
 
+static void rollback (char const *live, char const *s, unsigned int len)
+{
+  while (len)
+  {
+    unsigned int n = str_len(s) + 1 ;
+    s6rc_servicedir_unsupervise(live, s, 0) ;
+    s += n ; len -= n ;
+  }
+}
+
 int s6rc_servicedir_manage (char const *live, tain_t const *deadline, tain_t *stamp)
 {
   ftrigr_t a = FTRIGR_ZERO ;
+  stralloc newnames = STRALLOC_ZERO ;
   genalloc ids = GENALLOC_ZERO ; /* uint16 */
   gid_t gid = getgid() ;
   unsigned int livelen = str_len(live) ;
@@ -62,7 +74,19 @@ int s6rc_servicedir_manage (char const *live, tain_t const *deadline, tain_t *st
       byte_copy(dstfn, livelen, live) ;
       byte_copy(dstfn + livelen, 9, "/scandir/") ;
       byte_copy(dstfn + livelen + 9, len + 1, d->d_name) ;
-      if (symlink(srcfn, dstfn) < 0 && (!r || errno != EEXIST)) { e = errno ; goto err ; }
+      if (symlink(srcfn, dstfn) < 0)
+      {
+        if (!r || errno != EEXIST) { e = errno ; goto err ; }
+      }
+      else if (!r)
+      {
+        if (!stralloc_catb(&newnames, d->d_name, len + 1))
+        {
+          e = errno ;
+          s6rc_servicedir_unsupervise(live, d->d_name, 0) ;
+          goto err ;
+        }
+      }
     }
   }
   if (errno) { e = errno ; goto err ; }
@@ -79,15 +103,18 @@ int s6rc_servicedir_manage (char const *live, tain_t const *deadline, tain_t *st
     { e = errno ; goto closederr ; }
   }
 
-  genalloc_free(uint16, &ids) ;
   ftrigr_end(&a) ;
+  genalloc_free(uint16, &ids) ;
+  stralloc_free(&newnames) ;
   return ok ;
 
  err:
   dir_close(dir) ;
  closederr:
-  genalloc_free(uint16, &ids) ;
   ftrigr_end(&a) ;
+  genalloc_free(uint16, &ids) ;
+  rollback(live, newnames.s, newnames.len) ;
+  stralloc_free(&newnames) ;
   errno = e ;  
   return 0 ;
 }
diff --git a/src/libs6rc/s6rc_servicedir_unsupervise.c b/src/libs6rc/s6rc_servicedir_unsupervise.c
new file mode 100644
index 0000000..14a1164
--- /dev/null
+++ b/src/libs6rc/s6rc_servicedir_unsupervise.c
@@ -0,0 +1,23 @@
+/* ISC license. */
+
+#include <unistd.h>
+#include <skalibs/bytestr.h>
+#include <s6/s6-supervise.h>
+#include <s6-rc/s6rc-servicedir.h>
+
+void s6rc_servicedir_unsupervise (char const *live, char const *name, int keepsupervisor)
+{
+  unsigned int namelen = str_len(name) ;
+  unsigned int livelen = str_len(live) ;
+  char fn[livelen + 14 + namelen] ;
+  byte_copy(fn, livelen, live) ;
+  byte_copy(fn + livelen, 9, "/scandir/") ;
+  byte_copy(fn + livelen + 9, namelen + 1, name) ;
+  unlink(fn) ;
+  if (!keepsupervisor)
+  {
+    byte_copy(fn + livelen + 1, 12, "servicedirs/") ;
+    byte_copy(fn + livelen + 13, namelen + 1, name) ;
+    s6_svc_writectl(fn, S6_SUPERVISE_CTLDIR, "x", 1) ;
+  }
+}