Made test-ffop.c exhaustive by making it to test all types of fops.

Change-Id: I26052d0cbf72f81a6aa0c52498e99b635d1273e9
BUG: 861380
Signed-off-by: M S Vishwanath Bhat <vbhat@redhat.com>
Reviewed-on: http://review.gluster.org/3931
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Amar Tumballi <amarts@redhat.com>

1 files changed, 770 insertions, 7 deletions

diff --git a/extras/test/test-ffop.c b/extras/test/test-ffop.c
index 2c47ab0045b..6ce7097d5c5 100644
--- a/extras/test/test-ffop.c
+++ b/extras/test/test-ffop.c
@@ -6,20 +6,82 @@
 #include <attr/xattr.h>
 #include <errno.h>
 #include <string.h>
+#include <dirent.h>
+
+int fd_based_fops_1 (char *filename); //for fd based fops after unlink
+int fd_based_fops_2 (char *filename); //for fd based fops before unlink
+int dup_fd_based_fops (char *filename); // fops based on fd after dup
+int path_based_fops (char *filename); //for fops based on path
+int dir_based_fops (char *filename); // for fops which operate on directory
+int link_based_fops (char *filename); //for fops which operate in link files (symlinks)
+int test_open_modes (char *filename); // to test open syscall with open modes available.
+int generic_open_read_write (char *filename, int flag); // generic function which does open write and read.
 
 int
 main (int argc, char *argv[])
 {
-        int          ret      = -1;
-        int          fd       = 0;
-        char        *filename = NULL;
-        struct stat  stbuf    = {0,};
+        int   ret           = -1;
+        char  filename[255] = {0,};
 
         if (argc > 1)
-                filename = argv[1];
+                strcpy(filename, argv[1]);
+        else
+                strcpy(filename, "temp-xattr-test-file");
+
+        ret = fd_based_fops_1 (strcat(filename, "_1"));
+        if (ret < 0)
+                fprintf (stderr, "fd based file operation 1 failed\n");
+        else
+                fprintf (stdout, "fd based file operation 1 passed\n");
+
+        ret = fd_based_fops_2 (strcat(filename, "_2"));
+        if (ret < 0)
+                fprintf (stderr, "fd based file operation 2 failed\n");
+        else
+                fprintf (stdout, "fd based file operation 2 passed\n");
+
+        ret = dup_fd_based_fops (strcat (filename, "_3"));
+        if (ret < 0)
+                fprintf (stderr, "dup fd based file operation failed\n");
+        else
+                fprintf (stdout, "dup fd based file operation passed\n");
 
-        if (!filename)
-                filename = "temp-xattr-test-file";
+        ret = path_based_fops (strcat (filename, "_4"));
+        if (ret < 0)
+                fprintf (stderr, "path based file operation failed\n");
+        else
+                fprintf (stdout, "path based file operation passed\n");
+
+        ret = dir_based_fops (strcat (filename, "_5"));
+        if (ret < 0)
+                fprintf (stderr, "directory based file operation failed\n");
+        else
+                fprintf (stdout, "directory based file operation passed\n");
+
+        ret = link_based_fops (strcat (filename, "_5"));
+        if (ret < 0)
+                fprintf (stderr, "link based file operation failed\n");
+        else
+                fprintf (stdout, "link based file operation passed\n");
+
+        ret = test_open_modes (strcat (filename, "_5"));
+        if (ret < 0)
+                fprintf (stderr, "testing modes of 'open' call failed\n");
+        else
+                fprintf (stdout, "testing modes of 'open' call passed\n");
+
+out:
+        return ret;
+}
+
+int
+fd_based_fops_1 (char *filename)
+{
+        int         fd        = 0;
+        int         ret       = -1;
+        struct stat stbuf     = {0,};
+        char        wstr[50]  = {0,};
+        char        rstr[50]  = {0,};
 
         fd = open (filename, O_RDWR|O_CREAT);
         if (fd < 0) {
@@ -34,6 +96,34 @@ main (int argc, char *argv[])
                 goto out;
         }
 
+        strcpy (wstr, "This is my string\n");
+        ret = write (fd, wstr, strlen(wstr));
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "write failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = lseek (fd, 0, SEEK_SET);
+        if (ret < 0) {
+                fprintf (stderr, "lseek failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = read (fd, rstr, strlen(wstr));
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "read failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = memcmp (rstr, wstr, strlen (wstr));
+        if (ret != 0) {
+                ret = -1;
+                fprintf (stderr, "read returning junk\n");
+                goto out;
+        }
+
         ret = ftruncate (fd, 0);
         if (ret < 0) {
                 fprintf (stderr, "ftruncate failed : %s\n", strerror (errno));
@@ -103,3 +193,676 @@ out:
 
         return ret;
 }
+
+
+int
+fd_based_fops_2 (char *filename)
+{
+        int         fd    = 0;
+        int         ret   = -1;
+        struct stat stbuf = {0,};
+        char        wstr[50]  = {0,};
+        char        rstr[50]  = {0,};
+
+        fd = open (filename, O_RDWR|O_CREAT);
+        if (fd < 0) {
+                fd = 0;
+                fprintf (stderr, "open failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = ftruncate (fd, 0);
+
+        if (ret < 0) {
+                fprintf (stderr, "ftruncate failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        strcpy (wstr, "This is my second string\n");
+        ret = write (fd, wstr, strlen (wstr));
+        if (ret < 0) {
+                ret = -1;
+                fprintf (stderr, "write failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        lseek (fd, 0, SEEK_SET);
+        if (ret < 0) {
+                fprintf (stderr, "lseek failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = read (fd, rstr, strlen (wstr));
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "read failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = memcmp (rstr, wstr, strlen (wstr));
+        if (ret != 0) {
+                ret = -1;
+                fprintf (stderr, "read returning junk\n");
+                goto out;
+        }
+
+        ret = fstat (fd, &stbuf);
+        if (ret < 0) {
+                fprintf (stderr, "fstat failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fchmod (fd, 0640);
+        if (ret < 0) {
+                fprintf (stderr, "fchmod failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fchown (fd, 10001, 10001);
+        if (ret < 0) {
+                fprintf (stderr, "fchown failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fsync (fd);
+        if (ret < 0) {
+                fprintf (stderr, "fsync failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fsetxattr (fd, "trusted.xattr-test", "working", 8, 0);
+        if (ret < 0) {
+                fprintf (stderr, "fsetxattr failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fdatasync (fd);
+        if (ret < 0) {
+                fprintf (stderr, "fdatasync failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = flistxattr (fd, NULL, 0);
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "flistxattr failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fgetxattr (fd, "trusted.xattr-test", NULL, 0);
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "fgetxattr failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fremovexattr (fd, "trusted.xattr-test");
+        if (ret < 0) {
+                fprintf (stderr, "fremovexattr failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+out:
+        if (fd)
+                close (fd);
+        unlink (filename);
+
+        return ret;
+}
+
+int
+path_based_fops (char *filename)
+{
+        int         ret              = -1;
+        int         fd               = 0;
+        struct stat stbuf            = {0,};
+        char        newfilename[255] = {0,};
+
+        fd = creat (filename, 0644);
+        if (fd < 0) {
+                fprintf (stderr, "creat failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = truncate (filename, 0);
+        if (ret < 0) {
+                fprintf (stderr, "truncate failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = stat (filename, &stbuf);
+        if (ret < 0) {
+                fprintf (stderr, "stat failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = chmod (filename, 0640);
+        if (ret < 0) {
+                fprintf (stderr, "chmod failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = chown (filename, 10001, 10001);
+        if (ret < 0) {
+                fprintf (stderr, "chown failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = setxattr (filename, "trusted.xattr-test", "working", 8, 0);
+        if (ret < 0) {
+                fprintf (stderr, "setxattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = listxattr (filename, NULL, 0);
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "listxattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = getxattr (filename, "trusted.xattr-test", NULL, 0);
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "getxattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = removexattr (filename, "trusted.xattr-test");
+        if (ret < 0) {
+                fprintf (stderr, "removexattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = access (filename, R_OK|W_OK);
+        if (ret < 0) {
+                fprintf (stderr, "access failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        strcpy (newfilename, filename);
+        strcat(newfilename, "_new");
+        ret = rename (filename, newfilename);
+        if (ret < 0) {
+                fprintf (stderr, "rename failed: %s\n", strerror (errno));
+                goto out;
+        }
+        unlink (newfilename);
+
+out:
+        if (fd)
+                close (fd);
+
+        unlink (filename);
+        return ret;
+}
+
+int
+dup_fd_based_fops (char *filename)
+{
+        int         fd        = 0;
+        int         newfd     = 0;
+        int         ret       = -1;
+        struct stat stbuf     = {0,};
+        char        wstr[50]  = {0,};
+        char        rstr[50]  = {0,};
+
+        fd = open (filename, O_RDWR|O_CREAT);
+        if (fd < 0) {
+                fd = 0;
+                fprintf (stderr, "open failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        newfd = dup (fd);
+        if (newfd < 0) {
+                ret = -1;
+                fprintf (stderr, "dup failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        close (fd);
+
+        strcpy (wstr, "This is my string\n");
+        ret = write (newfd, wstr, strlen(wstr));
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "write failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = lseek (newfd, 0, SEEK_SET);
+        if (ret < 0) {
+                fprintf (stderr, "lseek failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = read (newfd, rstr, strlen(wstr));
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "read failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = memcmp (rstr, wstr, strlen (wstr));
+        if (ret != 0) {
+                ret = -1;
+                fprintf (stderr, "read returning junk\n");
+                goto out;
+        }
+
+        ret = ftruncate (newfd, 0);
+        if (ret < 0) {
+                fprintf (stderr, "ftruncate failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fstat (newfd, &stbuf);
+        if (ret < 0) {
+                fprintf (stderr, "fstat failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fchmod (newfd, 0640);
+        if (ret < 0) {
+                fprintf (stderr, "fchmod failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fchown (newfd, 10001, 10001);
+        if (ret < 0) {
+                fprintf (stderr, "fchown failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fsync (newfd);
+        if (ret < 0) {
+                fprintf (stderr, "fsync failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fsetxattr (newfd, "trusted.xattr-test", "working", 8, 0);
+        if (ret < 0) {
+                fprintf (stderr, "fsetxattr failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fdatasync (newfd);
+        if (ret < 0) {
+                fprintf (stderr, "fdatasync failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = flistxattr (newfd, NULL, 0);
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "flistxattr failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fgetxattr (newfd, "trusted.xattr-test", NULL, 0);
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "fgetxattr failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = fremovexattr (newfd, "trusted.xattr-test");
+        if (ret < 0) {
+                fprintf (stderr, "fremovexattr failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = 0;
+out:
+        if (newfd)
+                close (newfd);
+        ret = unlink (filename);
+        if (ret < 0) {
+                fprintf (stderr, "unlink failed : %s\n", strerror (errno));
+                goto out;
+        }
+
+        return ret;
+}
+
+int
+dir_based_fops (char *dirname)
+{
+        int            ret           = -1;
+        DIR           *dp            = NULL;
+        char           buff[255]     = {0,};
+        struct dirent *dbuff         = {0,};
+        struct stat    stbuff        = {0,};
+        char           newdname[255] = {0,};
+        char          *cwd           = NULL;
+
+        ret = mkdir (dirname, 0755);
+        if (ret < 0) {
+                fprintf (stderr, "mkdir failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        dp = opendir (dirname);
+        if (dp == NULL) {
+                fprintf (stderr, "opendir failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        dbuff = readdir (dp);
+        if (NULL == dbuff) {
+                fprintf (stderr, "readdir failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = closedir (dp);
+        if (ret < 0) {
+                fprintf (stderr, "closedir failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = stat (dirname, &stbuff);
+        if (ret < 0) {
+                fprintf (stderr, "stat failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = chmod (dirname, 0744);
+        if (ret < 0) {
+                fprintf (stderr, "chmod failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = chown (dirname, 10001, 10001);
+        if (ret < 0) {
+                fprintf (stderr, "chmod failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = setxattr (dirname, "trusted.xattr-test", "working", 8, 0);
+        if (ret < 0) {
+                fprintf (stderr, "setxattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = listxattr (dirname, NULL, 0);
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "listxattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = getxattr (dirname, "trusted.xattr-test", NULL, 0);
+        if (ret <= 0) {
+                ret = -1;
+                fprintf (stderr, "getxattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = removexattr (dirname, "trusted.xattr-test");
+        if (ret < 0) {
+                fprintf (stderr, "removexattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        strcpy (newdname, dirname);
+        strcat (newdname, "/../");
+        ret = chdir (newdname);
+        if (ret < 0) {
+                fprintf (stderr, "chdir failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        cwd = getcwd (buff, 255);
+        if (NULL == cwd) {
+                fprintf (stderr, "getcwd failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        strcpy (newdname, dirname);
+        strcat (newdname, "new");
+        ret = rename (dirname, newdname);
+        if (ret < 0) {
+                fprintf (stderr, "rename failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = rmdir (newdname);
+        if (ret < 0) {
+                fprintf (stderr, "rmdir failed: %s\n", strerror (errno));
+                return ret;
+        }
+
+out:
+        rmdir (dirname);
+        return ret;
+}
+
+int
+link_based_fops (char *filename)
+{
+        int         ret           = -1;
+        int         fd            = 0;
+        char        newname[255]  = {0,};
+        char        linkname[255] = {0,};
+        struct stat lstbuf        = {0,};
+
+        fd = creat (filename, 0644);
+        if (fd < 0) {
+                fd = 0;
+                fprintf (stderr, "creat failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        strcpy (newname, filename);
+        strcat (newname, "_hlink");
+        ret = link (filename, newname);
+        if (ret < 0) {
+                fprintf (stderr, "link failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = unlink (filename);
+        if (ret < 0) {
+                fprintf (stderr, "unlink failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        strcpy (linkname, filename);
+        strcat (linkname, "_slink");
+        ret = symlink (newname, linkname);
+        if (ret < 0) {
+                fprintf (stderr, "symlink failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = lstat (linkname, &lstbuf);
+        if (ret < 0) {
+                fprintf (stderr, "lstbuf failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = lchown (linkname, 10001, 10001);
+        if (ret < 0) {
+                fprintf (stderr, "lchown failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = lsetxattr (linkname, "trusted.lxattr-test", "working", 8, 0);
+        if (ret < 0) {
+                fprintf (stderr, "lsetxattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = llistxattr (linkname, NULL, 0);
+        if (ret < 0) {
+                ret = -1;
+                fprintf (stderr, "llistxattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = lgetxattr (linkname, "trusted.lxattr-test", NULL, 0);
+        if (ret < 0) {
+                ret = -1;
+                fprintf (stderr, "lgetxattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+        ret = lremovexattr (linkname, "trusted.lxattr-test");
+        if (ret < 0) {
+                fprintf (stderr, "lremovexattr failed: %s\n", strerror (errno));
+                goto out;
+        }
+
+
+out:
+        if (fd)
+                close(fd);
+        unlink (linkname);
+        unlink (newname);
+}
+
+int
+test_open_modes (char *filename)
+{
+        int ret = -1;
+
+        ret = generic_open_read_write (filename, O_CREAT|O_WRONLY);
+        if (3 != ret) {
+               fprintf (stderr, "flag O_CREAT|O_WRONLY failed: \n");
+               goto out;
+        }
+
+        ret = generic_open_read_write (filename, O_CREAT|O_RDWR);
+        if (ret != 0) {
+               fprintf (stderr, "flag O_CREAT|O_RDWR failed\n");
+               goto out;
+        }
+
+        ret = generic_open_read_write (filename, O_CREAT|O_RDONLY);
+        if (ret != 0) {
+                fprintf (stderr, "flag O_CREAT|O_RDONLY failed\n");
+                goto out;
+        }
+
+        ret = creat (filename, 0644);
+        close (ret);
+        ret = generic_open_read_write (filename, O_WRONLY);
+        if (3 != ret) {
+               fprintf (stderr, "flag O_WRONLY failed\n");
+               goto out;
+        }
+
+        ret = creat (filename, 0644);
+        close (ret);
+        ret = generic_open_read_write (filename, O_RDWR);
+        if (0 != ret) {
+               fprintf (stderr, "flag O_RDWR failed\n");
+               goto out;
+        }
+
+        ret = creat (filename, 0644);
+        close (ret);
+        ret = generic_open_read_write (filename, O_RDONLY);
+        if (0 != ret) {
+               fprintf (stderr, "flag O_RDONLY failed\n");
+               goto out;
+        }
+
+        ret = creat (filename, 0644);
+        close (ret);
+        ret = generic_open_read_write (filename, O_TRUNC|O_WRONLY);
+        if (3 != ret) {
+               fprintf (stderr, "flag O_TRUNC|O_WRONLY failed\n");
+               goto out;
+        }
+
+        ret = creat (filename, 0644);
+        close (ret);
+        ret = generic_open_read_write (filename, O_TRUNC|O_RDONLY);
+        if (0 != ret) {
+               fprintf (stderr, "flag O_TRUNC|O_RDONLY failed\n");
+               goto out;
+        }
+
+        ret = generic_open_read_write (filename, O_CREAT|O_RDWR|O_SYNC);
+        if (0 != ret) {
+               fprintf (stderr, "flag O_CREAT|O_RDWR|O_SYNC failed\n");
+               goto out;
+        }
+
+        ret = creat (filename, 0644);
+        close (ret);
+        ret = generic_open_read_write (filename, O_CREAT|O_EXCL);
+        if (0 != ret) {
+                fprintf (stderr, "flag O_CREAT|O_EXCL failed\n");
+                goto out;
+        }
+
+out:
+        return ret;
+}
+
+int generic_open_read_write (char *filename, int flag)
+{
+        int  fd          = 0;
+        int  ret         = -1;
+        char wstring[50] = {0,};
+        char rstring[50] = {0,};
+
+        fd = open (filename, flag);
+        if (fd < 0) {
+                if (flag == O_CREAT|O_EXCL && errno == EEXIST) {
+                        unlink (filename);
+                        return 0;
+                }
+                else {
+                        fd = 0;
+                        fprintf (stderr, "open failed: %s\n", strerror (errno));
+                        return 1;
+                }
+        }
+
+        strcpy (wstring, "My string to write\n");
+        ret = write (fd, wstring, strlen(wstring));
+        if (ret <= 0) {
+                if (errno != EBADF) {
+                        fprintf (stderr, "write failed: %s\n", strerror (errno));
+                        close (fd);
+                        unlink(filename);
+                        return 2;
+                }
+        }
+
+        ret = lseek (fd, 0, SEEK_SET);
+        if (ret < 0) {
+                close (fd);
+                unlink(filename);
+                return 4;
+        }
+
+        ret = read (fd, rstring, strlen(wstring));
+        if (ret < 0) {
+                close (fd);
+                unlink (filename);
+                return 3;
+        }
+
+        /* Compare the rstring with wstring. But we do not want to return
+         * error when the flag is either O_RDONLY, O_CREAT|O_RDONLY or
+         * O_TRUNC|O_RDONLY. Because in that case we are not writing
+         * anything to the file.*/
+
+        ret = memcmp (wstring, rstring, strlen (wstring));
+        if (0 != ret  && !(flag == O_CREAT|O_RDONLY || flag == O_RDONLY ||\
+            flag == O_TRUNC|O_RDONLY)) {
+                fprintf (stderr, "read is returning junk\n");
+                close (fd);
+                unlink (filename);
+                return 4;
+        }
+
+        close (fd);
+        unlink (filename);
+        return 0;
+}