Add rollback to s6rc_servicedir_manage; it should now be transactional

5 files changed, 57 insertions, 21 deletions

diff --git a/src/include/s6-rc/s6rc-servicedir.h b/src/include/s6-rc/s6rc-servicedir.h
index 93baef7..ed2f471 100644
--- a/src/include/s6-rc/s6rc-servicedir.h
+++ b/src/include/s6-rc/s6rc-servicedir.h
@@ -10,6 +10,7 @@ extern int s6rc_servicedir_unblock (char const *, int) ;
 extern int s6rc_servicedir_copy_offline (char const *, char const *) ;
 extern int s6rc_servicedir_copy_online (char const *, char const *) ;
 #define s6rc_servicedir_copy(src, dst, h) ((h) ? s6rc_servicedir_copy_online(src, dst) : s6rc_servicedir_copy_offline(src, dst))
+extern void s6rc_servicedir_unsupervise (char const *, char const *, int) ;
 
 extern int s6rc_servicedir_manage (char const *, tain_t const *, tain_t *) ;
 #define s6rc_servicedir_manage_g(live, deadline) s6rc_servicedir_manage(live, (deadline), &STAMP)
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) ;
+  }
+}
diff --git a/src/s6-rc/s6-rc-update.c b/src/s6-rc/s6-rc-update.c
index 6d8a1aa..da56250 100644
--- a/src/s6-rc/s6-rc-update.c
+++ b/src/s6-rc/s6-rc-update.c
@@ -323,23 +323,6 @@ static inline void rollback_servicedirs (char const *newlive, unsigned char cons
   }
 }
 
-static inline void unsupervise (char const *llive, char const *name, int keepsupervisor)
-{
-  unsigned int namelen = str_len(name) ;
-  unsigned int llen = str_len(llive) ;
-  char fn[llen + 14 + namelen] ;
-  byte_copy(fn, llen, llive) ;
-  byte_copy(fn + llen, 9, "/scandir/") ;
-  byte_copy(fn + llen + 9, namelen + 1, name) ;
-  unlink(fn) ;
-  if (!keepsupervisor)
-  {
-    byte_copy(fn + llen + 1, 12, "servicedirs/") ;
-    byte_copy(fn + llen + 13, namelen + 1, name) ;
-    s6_svc_writectl(fn, S6_SUPERVISE_CTLDIR, "x", 1) ;
-  }
-}
-
 static inline void make_new_livedir (unsigned char const *oldstate, s6rc_db_t const *olddb, unsigned char const *newstate, s6rc_db_t const *newdb, char const *newcompiled, unsigned int *invimage, stralloc *sa)
 {
   unsigned int tmpbase = satmp.len ;
@@ -431,7 +414,8 @@ static inline void make_new_livedir (unsigned char const *oldstate, s6rc_db_t co
   if (!stralloc_catb(sa, satmp.s + tmpbase, satmp.len - tmpbase) || !stralloc_0(sa))
     dienomem() ;
   i = olddb->nlong ;
-  while (i--) unsupervise(sa->s + sabase, olddb->string + olddb->services[i].name, (oldstate[i] & 33) == 1) ;
+  while (i--)
+    s6rc_servicedir_unsupervise(sa->s + sabase, olddb->string + olddb->services[i].name, (oldstate[i] & 33) == 1) ;
   rm_rf(sa->s + sabase) ;
 
   sa->len = sabase ;