util: Detect more I/O errors

Many of GRUB's utilities don't check anywhere near all the possible
write errors.  For example, if grub-install runs out of space when
copying a file, it won't notice.  There were missing checks for the
return values of write, fflush, fsync, and close (or the equivalents on
other OSes), all of which must be checked.

I tried to be consistent with the existing logging practices of the
various hostdisk implementations, but they weren't entirely consistent
to start with so I used my judgement.  The result at least looks
reasonable on GNU/Linux when I provoke a write error:

  Installing for x86_64-efi platform.
  grub-install: error: cannot copy `/usr/lib/grub/x86_64-efi-signed/grubx64.efi.signed' to `/boot/efi/EFI/debian/grubx64.efi': No space left on device.

There are more missing checks in other utilities, but this should fix
the most critical ones.

Fixes Debian bug #922741.

Signed-off-by: Colin Watson <cjwatson@ubuntu.com>
Reviewed-by: Steve McIntyre <93sam@debian.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

grub-core/osdep/aros/hostdisk.c

@@ -439,36 +439,44 @@ grub_util_get_fd_size (grub_util_fd_t fd,
   return -1;
 }
 
-void
+int
 grub_util_fd_close (grub_util_fd_t fd)
 {
   switch (fd->type)
     {
     case GRUB_UTIL_FD_FILE:
-      close (fd->fd);
+      return close (fd->fd);
-      return;
     case GRUB_UTIL_FD_DISK:
       CloseDevice ((struct IORequest *) fd->ioreq);
       DeleteIORequest((struct IORequest *) fd->ioreq);
       DeleteMsgPort (fd->mp);
-      return;
+      return 0;
     }
+  return 0;
 }
 
 static int allow_fd_syncs = 1;
 
-static void
+static int
 grub_util_fd_sync_volume (grub_util_fd_t fd)
 {
+  LONG err;
+
   fd->ioreq->iotd_Req.io_Command = CMD_UPDATE;
   fd->ioreq->iotd_Req.io_Length = 0;
   fd->ioreq->iotd_Req.io_Data = 0;
   fd->ioreq->iotd_Req.io_Offset = 0;
   fd->ioreq->iotd_Req.io_Actual = 0;
-  DoIO ((struct IORequest *) fd->ioreq);
+  err = DoIO ((struct IORequest *) fd->ioreq);
+  if (err)
+    {
+      grub_util_info ("I/O failed with error %d, IoErr=%d", (int)err, (int) IoErr ());
+      return -1;
+    }
+  return 0;
 }
 
-void
+int
 grub_util_fd_sync (grub_util_fd_t fd)
 {
   if (allow_fd_syncs)
@@ -476,22 +484,22 @@ grub_util_fd_sync (grub_util_fd_t fd)
       switch (fd->type)
 	{
 	case GRUB_UTIL_FD_FILE:
-	  fsync (fd->fd);
+	  return fsync (fd->fd);
-	  return;
 	case GRUB_UTIL_FD_DISK:
-	  grub_util_fd_sync_volume (fd);
+	  return grub_util_fd_sync_volume (fd);
-	  return;
 	}
     }
+  return 0;
 }
 
-void
+int
 grub_util_file_sync (FILE *f)
 {
-  fflush (f);
+  if (fflush (f) != 0)
+    return -1;
   if (!allow_fd_syncs)
-    return;
+    return 0;
-  fsync (fileno (f));
+  return fsync (fileno (f));
 }
 
 void

grub-core/osdep/unix/hostdisk.c

@@ -177,20 +177,22 @@ grub_util_fd_strerror (void)
 
 static int allow_fd_syncs = 1;
 
-void
+int
 grub_util_fd_sync (grub_util_fd_t fd)
 {
   if (allow_fd_syncs)
-    fsync (fd);
+    return fsync (fd);
+  return 0;
 }
 
-void
+int
 grub_util_file_sync (FILE *f)
 {
-  fflush (f);
+  if (fflush (f) != 0)
+    return -1;
   if (!allow_fd_syncs)
-    return;
+    return 0;
-  fsync (fileno (f));
+  return fsync (fileno (f));
 }
 
 void
@@ -199,10 +201,10 @@ grub_util_disable_fd_syncs (void)
   allow_fd_syncs = 0;
 }
 
-void
+int
 grub_util_fd_close (grub_util_fd_t fd)
 {
-  close (fd);
+  return close (fd);
 }
 
 char *

grub-core/osdep/windows/hostdisk.c

@@ -275,11 +275,18 @@ grub_util_fd_write (grub_util_fd_t fd, const char *buf, size_t len)
 
 static int allow_fd_syncs = 1;
 
-void
+int
 grub_util_fd_sync (grub_util_fd_t fd)
 {
   if (allow_fd_syncs)
-    FlushFileBuffers (fd);
+    {
+      if (!FlushFileBuffers (fd))
+	{
+	  grub_util_info ("flush err %x", (int) GetLastError ());
+	  return -1;
+	}
+    }
+  return 0;
 }
 
 void
@@ -288,10 +295,15 @@ grub_util_disable_fd_syncs (void)
   allow_fd_syncs = 0;
 }
 
-void
+int
 grub_util_fd_close (grub_util_fd_t fd)
 {
-  CloseHandle (fd);
+  if (!CloseHandle (fd))
+    {
+      grub_util_info ("close err %x", (int) GetLastError ());
+      return -1;
+    }
+  return 0;
 }
 
 const char *
@@ -620,16 +632,25 @@ grub_util_fopen (const char *path, const char *mode)
   return ret;
 }
 
-void
+int
 grub_util_file_sync (FILE *f)
 {
   HANDLE hnd;
 
-  fflush (f);
+  if (fflush (f) != 0)
+    {
+      grub_util_info ("fflush err %x", (int) GetLastError ());
+      return -1;
+    }
   if (!allow_fd_syncs)
-    return;
+    return 0;
   hnd = (HANDLE) _get_osfhandle (fileno (f));
-  FlushFileBuffers (hnd);
+  if (!FlushFileBuffers (hnd))
+    {
+      grub_util_info ("flush err %x", (int) GetLastError ());
+      return -1;
+    }
+  return 0;
 }
 
 int

include/grub/emu/hostfile.h

@@ -47,11 +47,11 @@ grub_util_fd_t
 EXPORT_FUNC(grub_util_fd_open) (const char *os_dev, int flags);
 const char *
 EXPORT_FUNC(grub_util_fd_strerror) (void);
-void
+int
 grub_util_fd_sync (grub_util_fd_t fd);
 void
 grub_util_disable_fd_syncs (void);
-void
+int
 EXPORT_FUNC(grub_util_fd_close) (grub_util_fd_t fd);
 
 grub_uint64_t

include/grub/emu/misc.h

@@ -73,6 +73,6 @@ FILE *
 grub_util_fopen (const char *path, const char *mode);
 #endif
 
-void grub_util_file_sync (FILE *f);
+int grub_util_file_sync (FILE *f);
 
 #endif /* GRUB_EMU_MISC_H */

util/editenv.c

@@ -55,7 +55,8 @@ grub_util_create_envblk_file (const char *name)
 		     strerror (errno));
 
 
-  grub_util_file_sync (fp);
+  if (grub_util_file_sync (fp) < 0)
+    grub_util_error (_("cannot sync `%s': %s"), namenew, strerror (errno));
   free (buf);
   fclose (fp);
 

util/grub-editenv.c

@@ -197,7 +197,8 @@ write_envblk (const char *name, grub_envblk_t envblk)
     grub_util_error (_("cannot write to `%s': %s"), name,
 		     strerror (errno));
 
-  grub_util_file_sync (fp);
+  if (grub_util_file_sync (fp) < 0)
+    grub_util_error (_("cannot sync `%s': %s"), name, strerror (errno));
   fclose (fp);
 }
 

util/grub-install-common.c

@@ -112,11 +112,16 @@ grub_install_copy_file (const char *src,
       r = grub_util_fd_read (in, grub_install_copy_buffer, GRUB_INSTALL_COPY_BUFFER_SIZE);
       if (r <= 0)
 	break;
-      grub_util_fd_write (out, grub_install_copy_buffer, r);
+      r = grub_util_fd_write (out, grub_install_copy_buffer, r);
+      if (r <= 0)
+	break;
     }
-  grub_util_fd_sync (out);
+  if (grub_util_fd_sync (out) < 0)
-  grub_util_fd_close (in);
+    r = -1;
-  grub_util_fd_close (out);
+  if (grub_util_fd_close (in) < 0)
+    r = -1;
+  if (grub_util_fd_close (out) < 0)
+    r = -1;
 
   if (r < 0)
     grub_util_error (_("cannot copy `%s' to `%s': %s"),
@@ -526,7 +531,8 @@ grub_install_make_image_wrap (const char *dir, const char *prefix,
   grub_install_make_image_wrap_file (dir, prefix, fp, outname,
 				     memdisk_path, config_path,
 				     mkimage_target, note);
-  grub_util_file_sync (fp);
+  if (grub_util_file_sync (fp) < 0)
+    grub_util_error (_("cannot sync `%s': %s"), outname, strerror (errno));
   fclose (fp);
 }
 

util/grub-mkimage.c

@@ -311,8 +311,12 @@ main (int argc, char *argv[])
 			       arguments.image_target, arguments.note,
 			       arguments.comp, arguments.dtb);
 
-  grub_util_file_sync  (fp);
+  if (grub_util_file_sync (fp) < 0)
-  fclose (fp);
+    grub_util_error (_("cannot sync `%s': %s"), arguments.output ? : "stdout",
+		     strerror (errno));
+  if (fclose (fp) == EOF)
+    grub_util_error (_("cannot close `%s': %s"), arguments.output ? : "stdout",
+		     strerror (errno));
 
   for (i = 0; i < arguments.nmodules; i++)
     free (arguments.modules[i]);

util/setup.c

@@ -728,8 +728,10 @@ unable_to_embed:
       != GRUB_DISK_SECTOR_SIZE * 2)
     grub_util_error (_("cannot write to `%s': %s"),
 		     core_path, strerror (errno));
-  grub_util_fd_sync (fp);
+  if (grub_util_fd_sync (fp) < 0)
-  grub_util_fd_close (fp);
+    grub_util_error (_("cannot sync `%s': %s"), core_path, strerror (errno));
+  if (grub_util_fd_close (fp) < 0)
+    grub_util_error (_("cannot close `%s': %s"), core_path, strerror (errno));
   grub_util_biosdisk_flush (root_dev->disk);
 
   grub_disk_cache_invalidate_all ();