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      1 
      2 /*
      3  * Copyright (c) 2004 Daniel McNeil <daniel (at) osdl.org>
      4  *               2004 Open Source Development Lab
      5  *   This program is free software;  you can redistribute it and/or modify
      6  *   it under the terms of the GNU General Public License as published by
      7  *   the Free Software Foundation; either version 2 of the License, or
      8  *   (at your option) any later version.
      9  *
     10  *   This program is distributed in the hope that it will be useful,
     11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
     12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
     13  *   the GNU General Public License for more details.
     14  *
     15  *   You should have received a copy of the GNU General Public License
     16  *   along with this program;  if not, write to the Free Software
     17  *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
     18  *
     19  * Module: .c
     20  */
     21 
     22 /*
     23  * Change History:
     24  *
     25  * 2/2004  Marty Ridgeway (mridge (at) us.ibm.com) Changes to adapt to LTP
     26  *
     27  */
     28 /*
     29  * dio_append - append zeroed data to a file using O_DIRECT while
     30  *	a 2nd process is doing buffered reads and check if the buffer
     31  *	reads always see zero.
     32  */
     33 #define _GNU_SOURCE
     34 
     35 #include <stdlib.h>
     36 #include <sys/types.h>
     37 #include <signal.h>
     38 #include <errno.h>
     39 #include <fcntl.h>
     40 #include <stdio.h>
     41 #include <unistd.h>
     42 #include <memory.h>
     43 #include <limits.h>
     44 
     45 #include "test.h"
     46 #define NUM_CHILDREN 8
     47 
     48 #include "common_checkzero.h"
     49 
     50 int read_eof(char *filename)
     51 {
     52 	int fd;
     53 	int i;
     54 	int r;
     55 	char buf[4096];
     56 
     57 	while ((fd = open(filename, O_RDONLY)) < 0) {
     58 		sleep(1);	/* wait for file to be created */
     59 	}
     60 
     61 	for (i = 0; i < 1000000; i++) {
     62 		off_t offset;
     63 		char *bufoff;
     64 
     65 		offset = lseek(fd, SEEK_END, 0);
     66 		r = read(fd, buf, 4096);
     67 		if (r > 0) {
     68 			if ((bufoff = check_zero(buf, r))) {
     69 				fprintf(stderr, "non-zero read at offset %p\n",
     70 					offset + bufoff);
     71 				exit(1);
     72 			}
     73 		}
     74 	}
     75 	return 0;
     76 }
     77 
     78 void dio_append(char *filename)
     79 {
     80 	int fd;
     81 	void *bufptr;
     82 	int i;
     83 	int w;
     84 
     85 	fd = open(filename, O_DIRECT | O_WRONLY | O_CREAT, 0666);
     86 
     87 	if (fd < 0) {
     88 		perror("cannot create file");
     89 		return;
     90 	}
     91 
     92 	TEST(posix_memalign(&bufptr, 4096, 64 * 1024));
     93 	if (TEST_RETURN) {
     94 		tst_resm(TBROK | TRERRNO, "cannot malloc aligned memory");
     95 		close(fd);
     96 		return;
     97 	}
     98 
     99 	memset(bufptr, 0, 64 * 1024);
    100 	for (i = 0; i < 1000; i++) {
    101 		if ((w = write(fd, bufptr, 64 * 1024)) != 64 * 1024) {
    102 			fprintf(stderr, "write %d returned %d\n", i, w);
    103 		}
    104 	}
    105 }
    106 
    107 int main(int argc, char **argv)
    108 {
    109 	char filename[PATH_MAX];
    110 	int pid[NUM_CHILDREN];
    111 	int num_children = 1;
    112 	int i;
    113 
    114 	snprintf(filename, sizeof(filename), "%s/aiodio/file",
    115 		 getenv("TMP") ? getenv("TMP") : "/tmp");
    116 
    117 	printf("Begin dio_append test...\n");
    118 
    119 	for (i = 0; i < num_children; i++) {
    120 		if ((pid[i] = fork()) == 0) {
    121 			/* child */
    122 			return read_eof(filename);
    123 		} else if (pid[i] < 0) {
    124 			/* error */
    125 			perror("fork error");
    126 			break;
    127 		} else {
    128 			/* Parent */
    129 			continue;
    130 		}
    131 	}
    132 
    133 	/*
    134 	 * Parent appends to end of file using direct i/o
    135 	 */
    136 
    137 	dio_append(filename);
    138 
    139 	for (i = 0; i < num_children; i++) {
    140 		kill(pid[i], SIGTERM);
    141 	}
    142 	return 0;
    143 }
    144