diff --git a/ChangeLog b/ChangeLog
index 791fd9416..757b1e6c1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-10-16  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	* grub-core/osdep/unix/hostdisk.c (grub_util_fd_read): Return correct
+	value in case of incomplete read.
+	(grub_util_fd_write): Likewise.
+
 2013-10-15  Vladimir Serbinenko  <phcoder@gmail.com>
 
 	* util/editenv.c (grub_util_create_envblk_file): Use grub_util_rename.
diff --git a/grub-core/osdep/unix/hostdisk.c b/grub-core/osdep/unix/hostdisk.c
index 9734a1db5..fe87855e2 100644
--- a/grub-core/osdep/unix/hostdisk.c
+++ b/grub-core/osdep/unix/hostdisk.c
@@ -115,13 +115,16 @@ grub_util_fd_seek (grub_util_fd_t fd, grub_uint64_t off)
 ssize_t
 grub_util_fd_read (grub_util_fd_t fd, char *buf, size_t len)
 {
-  ssize_t size = len;
+  ssize_t size = 0;
 
   while (len)
     {
       ssize_t ret = read (fd, buf, len);
 
-      if (ret <= 0)
+      if (ret == 0)
+	break;
+
+      if (ret < 0)
         {
           if (errno == EINTR)
             continue;
@@ -131,6 +134,7 @@ grub_util_fd_read (grub_util_fd_t fd, char *buf, size_t len)
 
       len -= ret;
       buf += ret;
+      size += ret;
     }
 
   return size;
@@ -141,13 +145,16 @@ grub_util_fd_read (grub_util_fd_t fd, char *buf, size_t len)
 ssize_t
 grub_util_fd_write (grub_util_fd_t fd, const char *buf, size_t len)
 {
-  ssize_t size = len;
+  ssize_t size = 0;
 
   while (len)
     {
       ssize_t ret = write (fd, buf, len);
 
-      if (ret <= 0)
+      if (ret == 0)
+	break;
+
+      if (ret < 0)
         {
           if (errno == EINTR)
             continue;
@@ -157,6 +164,7 @@ grub_util_fd_write (grub_util_fd_t fd, const char *buf, size_t len)
 
       len -= ret;
       buf += ret;
+      size += ret;
     }
 
   return size;