--- /dev/null
+/*
+ * Takes page fault while writev is iterating over the vectors in the IOV
+ *
+ * Copyright (C) 2017 Red Hat, Inc. All Rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/uio.h>
+#include <limits.h>
+
+#ifndef IOV_MAX
+#define IOV_MAX 1024
+#endif
+#define DEF_IOV_CNT 3
+
+
+void usage(char *progname)
+{
+ fprintf(stderr, "usage: %s [-i iovcnt] filename\n", progname);
+ fprintf(stderr, "\t-i iovcnt: the count of io vectors (max is 1024), 3 by default\n");
+ exit(1);
+}
+
+int main(int argc, char *argv[])
+{
+ int fd, i, c;
+ size_t ret;
+ struct iovec *iov;
+ int pagesz = 4096;
+ char *data = NULL;
+ char *filename = NULL;
+ int iov_cnt = DEF_IOV_CNT;
+
+
+ while ((c = getopt(argc, argv, "i:")) != -1) {
+ char *endp;
+
+ switch (c) {
+ case 'i':
+ iov_cnt = strtol(optarg, &endp, 0);
+ if (*endp) {
+ fprintf(stderr, "Invalid iov count %s\n", optarg);
+ usage(argv[0]);
+ }
+ break;
+ default:
+ usage(argv[0]);
+ }
+ }
+
+ if (iov_cnt > IOV_MAX || iov_cnt <= 0)
+ usage(argv[0]);
+
+ if (optind == argc - 1)
+ filename = argv[optind];
+ else
+ usage(argv[0]);
+
+ pagesz = getpagesize();
+ data = malloc(pagesz * iov_cnt);
+ if (!data) {
+ perror("malloc failed");
+ return 1;
+ }
+
+ /*
+ * NOTE: no pre-writing/reading on the buffer before writev, to prevent
+ * page prefault from happening, we need it happen at writev time.
+ */
+
+ iov = calloc(iov_cnt, sizeof(struct iovec));
+ if (!iov) {
+ perror("calloc failed");
+ return 1;
+ }
+
+ for (i = 0; i < iov_cnt; i++) {
+ (iov + i)->iov_base = (data + pagesz * i);
+ (iov + i)->iov_len = 1;
+ }
+
+ if ((fd = open(filename, O_TRUNC|O_CREAT|O_RDWR, 0644)) < 0) {
+ perror("open failed");
+ return 1;
+ }
+
+ ret = writev(fd, iov, iov_cnt);
+ if (ret < 0)
+ perror("writev failed");
+ else
+ printf("wrote %d bytes\n", (int)ret);
+
+ close(fd);
+ return 0;
+}
--- /dev/null
+#! /bin/bash
+# FS QA Test 443
+#
+# Takes page fault while writev is iterating over the vectors in the IOV
+#
+#-----------------------------------------------------------------------
+# Copyright (c) 2017 Red Hat, Inc. All Rights Reserved.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it would be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write the Free Software Foundation,
+# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+#-----------------------------------------------------------------------
+#
+
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1 # failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+ cd /
+ rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+_supported_fs generic
+_supported_os Linux
+_require_test
+_require_test_program "writev_on_pagefault"
+
+# This program use several vectors for writev(), the kernel goes over them
+# one at a time, copying them from userspace, getting the user data ready
+# for IO. If it takes a page fault while iterating over the vectors in the
+# IOV, it stops, and sends what it got so far. We try to find a bug at this
+# moment.
+$here/src/writev_on_pagefault $TEST_DIR/testfile.$seq
+
+# success, all done
+status=0
+exit
projects / xfstests-dev.git / commitdiff