File synchronization fixes.

* admin/CPP-DEFINES (BSD_SYSTEM, HAVE_FSYNC): Remove.
* admin/merge-gnulib (GNULIB_MODULES): Add fsync, fdatasync.
* configure.ac (BSD_SYSTEM, BSD_SYSTEM_AHB): Remove; no longer needed.
(fsync): Remove check; now done by gnulib.
* lib/fdatasync.c, lib/fsync.c, m4/fdatasync.m4, m4/fsync.m4:
New files, from gnulib.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* lib-src/Makefile.in (LIB_FDATASYNC): New macro.
(emacsclient${EXEEXT}): Use it.
* lib-src/emacsclient.c (main): Use fdatasync, not fsync, since we don't
care about metadata.  Keep trying if interrupted.
* lib-src/movemail.c (main, popmail): Don't worry about BSD_SYSTEM, since
fsync is available everywhere (or there is a substitute).  Don't
report an error if fsync returns EINVAL.
* nt/inc/ms-w32.h (fdatasync): New macro, suggested by Eli Zaretskii.
* src/Makefile.in (LIB_FDATASYNC): New macro.
(LIBES): Use it.
* src/conf_post.h (BSD_SYSTEM, BSD_SYSTEM_AHB): Remove; no longer needed.
* src/fileio.c (Fwrite_region, write_region_inhibit_fsync):
Don't worry about HAVE_FSYNC, since a substitute fsync is
available if the system lacks one.
(Fwrite_regin): Retry fsync if interrupted.

Fixes: debbugs:13944

4 files changed, 20 insertions, 16 deletions

diff --git a/lib-src/ChangeLog b/lib-src/ChangeLog
index 6ecfb283ff6..d8ec0579422 100644
--- a/lib-src/ChangeLog
+++ b/lib-src/ChangeLog
@@ -1,5 +1,14 @@
 2013-03-13  Paul Eggert  <eggert@cs.ucla.edu>
 
+        File synchronization fixes (Bug#13944).
+        * Makefile.in (LIB_FDATASYNC): New macro.
+        (emacsclient${EXEEXT}): Use it.
+        * emacsclient.c (main): Use fdatasync, not fsync, since we don't
+        care about metadata.  Keep trying if interrupted.
+        * movemail.c (main, popmail): Don't worry about BSD_SYSTEM, since
+        fsync is available everywhere (or there is a substitute).  Don't
+        report an error if fsync returns EINVAL.
+
         Static checking by Sun C 5.12.
         * etags.c (analyse_regex): Omit unreachable code.
 
diff --git a/lib-src/Makefile.in b/lib-src/Makefile.in
index 8a6960ee2fe..7069af9767a 100644
--- a/lib-src/Makefile.in
+++ b/lib-src/Makefile.in
@@ -161,6 +161,8 @@ LIBRESOLV=@LIBRESOLV@
 LIBS_MAIL=@LIBS_MAIL@
 ## empty or -lrt or -lposix4 if HAVE_CLOCK_GETTIME
 LIB_CLOCK_GETTIME = @LIB_CLOCK_GETTIME@
+## empty or -lrt or -lposix4 if HAVE_FDATASYNC
+LIB_FDATASYNC = @LIB_FDATASYNC@
 
 ## Extra libraries to use when linking movemail.
 LIBS_MOVE = $(LIBS_MAIL) $(KRB4LIB) $(DESLIB) $(KRB5LIB) $(CRYPTOLIB) \
@@ -334,7 +336,7 @@ pop.o: ${srcdir}/pop.c ${srcdir}/../lib/min-max.h $(config_h)
 emacsclient${EXEEXT}: ${srcdir}/emacsclient.c $(config_h)
         $(CC) ${ALL_CFLAGS} ${srcdir}/emacsclient.c \
            -DVERSION="\"${version}\"" \
-           $(LOADLIBES) -o emacsclient
+           $(LOADLIBES) $(LIB_FDATASYNC) -o emacsclient
 
 hexl${EXEEXT}: ${srcdir}/hexl.c $(config_h)
         $(CC) ${ALL_CFLAGS} ${srcdir}/hexl.c $(LOADLIBES) -o hexl
diff --git a/lib-src/emacsclient.c b/lib-src/emacsclient.c
index 6feaf18ba60..898e8d69b07 100644
--- a/lib-src/emacsclient.c
+++ b/lib-src/emacsclient.c
@@ -1724,7 +1724,8 @@ main (int argc, char **argv)
       needlf = 2;
     }
   fflush (stdout);
-  fsync (1);
+  while (fdatasync (1) != 0 && errno == EINTR)
+    continue;
 
   /* Now, wait for an answer and print any messages.  */
   while (exit_status == EXIT_SUCCESS)
@@ -1825,7 +1826,8 @@ main (int argc, char **argv)
   if (needlf)
     printf ("\n");
   fflush (stdout);
-  fsync (1);
+  while (fdatasync (1) != 0 && errno == EINTR)
+    continue;
 
   if (rl < 0)
     exit_status = EXIT_FAILURE;
diff --git a/lib-src/movemail.c b/lib-src/movemail.c
index 190937d762b..81ac8aa187c 100644
--- a/lib-src/movemail.c
+++ b/lib-src/movemail.c
@@ -466,10 +466,8 @@ main (int argc, char **argv)
           }
       }
 
-#ifdef BSD_SYSTEM
-      if (fsync (outdesc) < 0)
+      if (fsync (outdesc) != 0 && errno != EINVAL)
         pfatal_and_delete (outname);
-#endif
 
       /* Prevent symlink attacks truncating other users' mailboxes */
       if (setregid (-1, real_gid) < 0)
@@ -750,21 +748,14 @@ popmail (char *mailbox, char *outfile, int preserve, char *password, int reverse
         }
     }
 
-  /* On AFS, a call to write only modifies the file in the local
-   *     workstation's AFS cache.  The changes are not written to the server
-   *      until a call to fsync or close is made.  Users with AFS home
-   *      directories have lost mail when over quota because these checks were
-   *      not made in previous versions of movemail. */
-
-#ifdef BSD_SYSTEM
-  if (fsync (mbfi) < 0)
+  if (fsync (mbfi) != 0 && errno != EINVAL)
     {
       error ("Error in fsync: %s", strerror (errno), 0);
+      close (mbfi);
       return EXIT_FAILURE;
     }
-#endif
 
-  if (close (mbfi) == -1)
+  if (close (mbfi) != 0)
     {
       error ("Error in close: %s", strerror (errno), 0);
       return EXIT_FAILURE;