cmd/dir_rd_update/dir_rd_update.c

	dir_rd_update.c revision d583b39bfb4e2571d3e41097c5c357ffe353ad45
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Assertion:
 *
 *  A read operation and directory update operation performed
 *      concurrently on the same directory can lead to deadlock
 *  on a UFS logging file system, but not on a ZFS file system.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define TMP_DIR /tmp

static char dirpath[256];

int
main(int argc, char **argv)
{
    char *cp1 = "";
    int i = 0;
    int ret = 0;
    int testdd = 0;
    pid_t pid;
    static const int op_num = 5;

    if (argc == 1) {
        (void) printf("Usage: %s <mount point>\n", argv[0]);
        exit(-1);
    }
    for (i = 0; i < 256; i++) {
        dirpath[i] = 0;
    }

    cp1 = argv[1];
    (void) strcpy(&dirpath[0], (const char *)cp1);
    (void) strcat(&dirpath[strlen(dirpath)], "TMP_DIR");

    ret = mkdir(dirpath, 0777);
    if (ret != 0) {
        if (errno != EEXIST) {
            (void) printf("%s: mkdir(<%s>, 0777) failed: errno "
                "(decimal)=%d\n", argv[0], dirpath, errno);
            exit(-1);
        }
    }
    testdd = open(dirpath, O_RDONLY|O_RSYNC|O_SYNC|O_DSYNC);
    if (testdd < 0) {
        (void) printf("%s: open(<%s>, O_RDONLY|O_RSYNC|O_SYNC|O_DSYNC)"
            " failed: errno (decimal)=%d\n", argv[0], dirpath, errno);
        exit(-1);
    } else {
        (void) close(testdd);
    }
    pid = fork();
    if (pid > 0) {
        int fd = open(dirpath, O_RDONLY|O_RSYNC|O_SYNC|O_DSYNC);
        char buf[16];
        int rdret;
        int j = 0;

        while (j < op_num) {
            (void) sleep(1);
            rdret = read(fd, buf, 16);
            if (rdret == -1) {
                (void) printf("readdir failed");
            }
            j++;
        }
    } else if (pid == 0) {
        int fd = open(dirpath, O_RDONLY);
        int chownret;
        int k = 0;

        while (k < op_num) {
            (void) sleep(1);
            chownret = fchown(fd, 0, 0);
            if (chownret == -1) {
                (void) printf("chown failed");
            }

            k++;
        }
    }

    return (0);
}