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Diffstat (limited to 'testing/sg_tst_excl3.cpp')
| -rw-r--r-- | testing/sg_tst_excl3.cpp | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/testing/sg_tst_excl3.cpp b/testing/sg_tst_excl3.cpp new file mode 100644 index 00000000..b1cbf130 --- /dev/null +++ b/testing/sg_tst_excl3.cpp @@ -0,0 +1,561 @@ +/* + * Copyright (c) 2013-2022 Douglas Gilbert. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * SPDX-License-Identifier: BSD-2-Clause + */ + +#include <iostream> +#include <vector> +#include <system_error> +#include <thread> +#include <mutex> +#include <chrono> + +#include <unistd.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <ctype.h> +#include <sys/ioctl.h> +#include <sys/types.h> +#include <sys/stat.h> + +#include "sg_lib.h" +#include "sg_pt.h" +#include "sg_unaligned.h" + +static const char * version_str = "1.11 20220425"; +static const char * util_name = "sg_tst_excl3"; + +/* This is a test program for checking O_EXCL on open() works. It uses + * multiple threads and can be run as multiple processes and attempts + * to "break" O_EXCL. The strategy is to open a device O_EXCL|O_NONBLOCK + * and do a double increment on a LB then close it from a single thread. + * the remaining threads open that device O_NONBLOCK and do a read and + * note if the number is odd. Assuming the count starts as an even + * (typically 0) then it should remain even. Odd instances + * are counted and reported at the end of the program, after all threads + * have completed. + * + * This is C++ code with some things from C++11 (e.g. threads) and was + * only just able to compile (when some things were reverted) with gcc/g++ + * version 4.7.3 found in Ubuntu 13.04 . C++11 "feature complete" support + * was not available until g++ version 4.8.1 and that is found in Fedora + * 19 and Ubuntu 13.10 . + * + * The build uses various object files from the <sg3_utils>/lib directory + * which is assumed to be a sibling of this examples directory. Those + * object files in the lib directory can be built with: + * cd <sg3_utils> ; ./configure ; cd lib; make + * Then: + * cd ../testing + * make sg_tst_excl3 + * + * BEWARE: this utility modifies a logical block (default LBA 1000) on the + * given device. + * + */ + +using namespace std; +using namespace std::chrono; + +#define DEF_NUM_PER_THREAD 200 +#define DEF_NUM_THREADS 4 +#define DEF_WAIT_MS 0 /* 0: yield; -1: don't wait; -2: sleep(0) */ + +#define DEF_LBA 1000 + +#define EBUFF_SZ 256 + + +static mutex odd_count_mutex; +static mutex console_mutex; +static unsigned int odd_count; +static unsigned int ebusy_count; + + +static void +usage(void) +{ + printf("Usage: %s [-b] [-f] [-h] [-l <lba>] [-n <n_per_thr>]\n" + " [-R] [-t <num_thrs>] [-V] [-w <wait_ms>] " + "[-x]\n" + " <disk_device>\n", util_name); + printf(" where\n"); + printf(" -b block on open (def: O_NONBLOCK)\n"); + printf(" -f force: any SCSI disk (def: only " + "scsi_debug)\n"); + printf(" WARNING: <lba> written to\n"); + printf(" -h print this usage message then exit\n"); + printf(" -l <lba> logical block to increment (def: %u)\n", + DEF_LBA); + printf(" -n <n_per_thr> number of loops per thread " + "(def: %d)\n", DEF_NUM_PER_THREAD); + printf(" -R all readers; so first thread (id=0) " + "just reads\n"); + printf(" -t <num_thrs> number of threads (def: %d)\n", + DEF_NUM_THREADS); + printf(" -V print version number then exit\n"); + printf(" -w <wait_ms> >0: sleep_for(<wait_ms>); =0: " + "yield(); -1: no\n" + " wait; -2: sleep(0) (def: %d)\n", + DEF_WAIT_MS); + printf(" -x don't use O_EXCL on first thread " + "(def: use\n" + " O_EXCL on first thread)\n\n"); + printf("Test O_EXCL open flag with pass-through drivers. First thread " + "(id=0) does\nopen/close cycle with the O_EXCL flag then does a " + "double increment on\nlba (using its first 4 bytes). Remaining " + "theads read (without\nO_EXCL flag on open) and check the " + "value is even.\n"); +} + +/* Assumed a lock (mutex) held when pt_err() is called */ +static int +pt_err(int res) +{ + if (res < 0) + fprintf(stderr, " pass through os error: %s\n", safe_strerror(-res)); + else if (SCSI_PT_DO_BAD_PARAMS == res) + fprintf(stderr, " bad pass through setup\n"); + else if (SCSI_PT_DO_TIMEOUT == res) + fprintf(stderr, " pass through timeout\n"); + else + fprintf(stderr, " do_scsi_pt error=%d\n", res); + return -1; +} + +/* Assumed a lock (mutex) held when pt_cat_no_good() is called */ +static int +pt_cat_no_good(int cat, struct sg_pt_base * ptp, const unsigned char * sbp) +{ + int slen; + char b[256]; + const int bl = (int)sizeof(b); + + switch (cat) { + case SCSI_PT_RESULT_STATUS: /* other than GOOD and CHECK CONDITION */ + sg_get_scsi_status_str(get_scsi_pt_status_response(ptp), bl, b); + fprintf(stderr, " scsi status: %s\n", b); + break; + case SCSI_PT_RESULT_SENSE: + slen = get_scsi_pt_sense_len(ptp); + sg_get_sense_str("", sbp, slen, 1, bl, b); + fprintf(stderr, "%s", b); + break; + case SCSI_PT_RESULT_TRANSPORT_ERR: + get_scsi_pt_transport_err_str(ptp, bl, b); + fprintf(stderr, " transport: %s", b); + break; + case SCSI_PT_RESULT_OS_ERR: + get_scsi_pt_os_err_str(ptp, bl, b); + fprintf(stderr, " os: %s", b); + break; + default: + fprintf(stderr, " unknown pt result category (%d)\n", cat); + break; + } + return -1; +} + +#define READ16_REPLY_LEN 512 +#define READ16_CMD_LEN 16 +#define WRITE16_REPLY_LEN 512 +#define WRITE16_CMD_LEN 16 + +/* Opens dev_name and spins if busy (i.e. gets EBUSY), sleeping for + * wait_ms milliseconds if wait_ms is positive. Reads lba and treats the + * first 4 bytes as an int (SCSI endian), increments it and writes it back. + * Repeats so that happens twice. Then closes dev_name. If an error occurs + * returns -1 else returns 0 if first int read is even otherwise returns 1. */ +static int +do_rd_inc_wr_twice(const char * dev_name, int read_only, unsigned int lba, + int block, int excl, int wait_ms, unsigned int & ebusys) +{ + int k, sg_fd, res, cat; + int odd = 0; + unsigned int u = 0; + struct sg_pt_base * ptp = NULL; + unsigned char r16CmdBlk [READ16_CMD_LEN] = + {0x88, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0}; + unsigned char w16CmdBlk [WRITE16_CMD_LEN] = + {0x8a, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0}; + unsigned char sense_buffer[64] SG_C_CPP_ZERO_INIT; + unsigned char lb[READ16_REPLY_LEN]; + char ebuff[EBUFF_SZ]; + int open_flags = O_RDWR; + + sg_put_unaligned_be64(lba, r16CmdBlk + 2); + sg_put_unaligned_be64(lba, w16CmdBlk + 2); + if (! block) + open_flags |= O_NONBLOCK; + if (excl) + open_flags |= O_EXCL; + + while (((sg_fd = scsi_pt_open_flags(dev_name, open_flags, 0)) < 0) && + (-EBUSY == sg_fd)) { + ++ebusys; + if (wait_ms > 0) + this_thread::sleep_for(milliseconds{wait_ms}); + else if (0 == wait_ms) + this_thread::yield(); // thread yield + else if (-2 == wait_ms) + sleep(0); // process yield ?? + } + if (sg_fd < 0) { + snprintf(ebuff, EBUFF_SZ, + "do_rd_inc_wr_twice: error opening file: %s", dev_name); + { + lock_guard<mutex> lg(console_mutex); + + perror(ebuff); + } + return -1; + } + + ptp = construct_scsi_pt_obj(); + for (k = 0; k < 2; ++k) { + /* Prepare READ_16 command */ + clear_scsi_pt_obj(ptp); + set_scsi_pt_cdb(ptp, r16CmdBlk, sizeof(r16CmdBlk)); + set_scsi_pt_sense(ptp, sense_buffer, sizeof(sense_buffer)); + set_scsi_pt_data_in(ptp, lb, READ16_REPLY_LEN); + res = do_scsi_pt(ptp, sg_fd, 20 /* secs timeout */, 1); + if (res) { + { + lock_guard<mutex> lg(console_mutex); + + fprintf(stderr, "READ_16 do_scsi_pt() submission error\n"); + res = pt_err(res); + } + goto err; + } + cat = get_scsi_pt_result_category(ptp); + if (SCSI_PT_RESULT_GOOD != cat) { + { + lock_guard<mutex> lg(console_mutex); + + fprintf(stderr, "READ_16 do_scsi_pt() category problem\n"); + res = pt_cat_no_good(cat, ptp, sense_buffer); + } + goto err; + } + + u = sg_get_unaligned_be32(lb); + // Assuming u starts test as even (probably 0), expect it to stay even + if (0 == k) + odd = (1 == (u % 2)); + + if (wait_ms > 0) /* allow daylight for bad things ... */ + this_thread::sleep_for(milliseconds{wait_ms}); + else if (0 == wait_ms) + this_thread::yield(); // thread yield + else if (-2 == wait_ms) + sleep(0); // process yield ?? + + if (read_only) + break; + ++u; + sg_put_unaligned_be32(u, lb); + + /* Prepare WRITE_16 command */ + clear_scsi_pt_obj(ptp); + set_scsi_pt_cdb(ptp, w16CmdBlk, sizeof(w16CmdBlk)); + set_scsi_pt_sense(ptp, sense_buffer, sizeof(sense_buffer)); + set_scsi_pt_data_out(ptp, lb, WRITE16_REPLY_LEN); + res = do_scsi_pt(ptp, sg_fd, 20 /* secs timeout */, 1); + if (res) { + { + lock_guard<mutex> lg(console_mutex); + + fprintf(stderr, "WRITE_16 do_scsi_pt() submission error\n"); + res = pt_err(res); + } + goto err; + } + cat = get_scsi_pt_result_category(ptp); + if (SCSI_PT_RESULT_GOOD != cat) { + { + lock_guard<mutex> lg(console_mutex); + + fprintf(stderr, "WRITE_16 do_scsi_pt() category problem\n"); + res = pt_cat_no_good(cat, ptp, sense_buffer); + } + goto err; + } + } +err: + if (ptp) + destruct_scsi_pt_obj(ptp); + scsi_pt_close_device(sg_fd); + return odd; +} + + +#define INQ_REPLY_LEN 96 +#define INQ_CMD_LEN 6 + +/* Send INQUIRY and fetches response. If okay puts PRODUCT ID field + * in b (up to m_blen bytes). Does not use O_EXCL flag. Returns 0 on success, + * else -1 . */ +static int +do_inquiry_prod_id(const char * dev_name, int block, int wait_ms, + unsigned int & ebusys, char * b, int b_mlen) +{ + int sg_fd, res, cat; + struct sg_pt_base * ptp = NULL; + unsigned char inqCmdBlk [INQ_CMD_LEN] = + {0x12, 0, 0, 0, INQ_REPLY_LEN, 0}; + unsigned char inqBuff[INQ_REPLY_LEN]; + unsigned char sense_buffer[64] SG_C_CPP_ZERO_INIT; + char ebuff[EBUFF_SZ]; + int open_flags = O_RDWR; /* since O_EXCL | O_RDONLY gives EPERM */ + + if (! block) + open_flags |= O_NONBLOCK; + while (((sg_fd = scsi_pt_open_flags(dev_name, open_flags, 0)) < 0) && + (-EBUSY == sg_fd)) { + ++ebusys; + if (wait_ms > 0) + this_thread::sleep_for(milliseconds{wait_ms}); + else if (0 == wait_ms) + this_thread::yield(); // thread yield + else if (-2 == wait_ms) + sleep(0); // process yield ?? + } + if (sg_fd < 0) { + snprintf(ebuff, EBUFF_SZ, + "do_inquiry_prod_id: error opening file: %s", dev_name); + perror(ebuff); + return -1; + } + /* Prepare INQUIRY command */ + ptp = construct_scsi_pt_obj(); + clear_scsi_pt_obj(ptp); + set_scsi_pt_cdb(ptp, inqCmdBlk, sizeof(inqCmdBlk)); + set_scsi_pt_sense(ptp, sense_buffer, sizeof(sense_buffer)); + set_scsi_pt_data_in(ptp, inqBuff, INQ_REPLY_LEN); + res = do_scsi_pt(ptp, sg_fd, 20 /* secs timeout */, 1); + if (res) { + fprintf(stderr, "INQUIRY do_scsi_pt() submission error\n"); + res = pt_err(res); + goto err; + } + cat = get_scsi_pt_result_category(ptp); + if (SCSI_PT_RESULT_GOOD != cat) { + fprintf(stderr, "INQUIRY do_scsi_pt() category problem\n"); + res = pt_cat_no_good(cat, ptp, sense_buffer); + goto err; + } + + /* Good, so fetch Product ID from response, copy to 'b' */ + if (b_mlen > 0) { + if (b_mlen > 16) { + memcpy(b, inqBuff + 16, 16); + b[16] = '\0'; + } else { + memcpy(b, inqBuff + 16, b_mlen - 1); + b[b_mlen - 1] = '\0'; + } + } +err: + if (ptp) + destruct_scsi_pt_obj(ptp); + close(sg_fd); + return res; +} + +static void +work_thread(const char * dev_name, unsigned int lba, int id, int block, + int excl, bool all_readers, int num, int wait_ms) +{ + unsigned int thr_odd_count = 0; + unsigned int thr_ebusy_count = 0; + int k, res; + int reader = ((id > 0) || (all_readers)); + + { + lock_guard<mutex> lg(console_mutex); + + cerr << "Enter work_thread id=" << id << " excl=" << excl << " block=" + << block << " reader=" << reader << endl; + } + for (k = 0; k < num; ++k) { + res = do_rd_inc_wr_twice(dev_name, reader, lba, block, excl, + wait_ms, thr_ebusy_count); + if (res < 0) + break; + if (res) + ++thr_odd_count; + } + { + lock_guard<mutex> lg(console_mutex); + + if (k < num) + cerr << "thread id=" << id << " FAILed at iteration: " << k + << '\n'; + else + cerr << "thread id=" << id << " normal exit" << '\n'; + } + + { + lock_guard<mutex> lg(odd_count_mutex); + + odd_count += thr_odd_count; + ebusy_count += thr_ebusy_count; + } +} + + +int +main(int argc, char * argv[]) +{ + int k, res; + int block = 0; + int force = 0; + unsigned int lba = DEF_LBA; + int num_per_thread = DEF_NUM_PER_THREAD; + bool all_readers = false; + int num_threads = DEF_NUM_THREADS; + int wait_ms = DEF_WAIT_MS; + int exclude_o_excl = 0; + char * dev_name = NULL; + char b[64]; + + for (k = 1; k < argc; ++k) { + if (0 == memcmp("-b", argv[k], 2)) + ++block; + else if (0 == memcmp("-f", argv[k], 2)) + ++force; + else if (0 == memcmp("-h", argv[k], 2)) { + usage(); + return 0; + } else if (0 == memcmp("-l", argv[k], 2)) { + ++k; + if ((k < argc) && isdigit(*argv[k])) + lba = (unsigned int)atoi(argv[k]); + else + break; + } else if (0 == memcmp("-n", argv[k], 2)) { + ++k; + if ((k < argc) && isdigit(*argv[k])) + num_per_thread = atoi(argv[k]); + else + break; + } else if (0 == memcmp("-t", argv[k], 2)) { + ++k; + if ((k < argc) && isdigit(*argv[k])) + num_threads = atoi(argv[k]); + else + break; + } else if (0 == memcmp("-R", argv[k], 2)) + all_readers = true; + else if (0 == memcmp("-V", argv[k], 2)) { + printf("%s version: %s\n", util_name, version_str); + return 0; + } else if (0 == memcmp("-w", argv[k], 2)) { + ++k; + if ((k < argc) && (isdigit(*argv[k]) || ('-' == *argv[k]))) { + if ('-' == *argv[k]) + wait_ms = - atoi(argv[k] + 1); + else + wait_ms = atoi(argv[k]); + } else + break; + } else if (0 == memcmp("-x", argv[k], 2)) + ++exclude_o_excl; + else if (*argv[k] == '-') { + printf("Unrecognized switch: %s\n", argv[k]); + dev_name = NULL; + break; + } + else if (! dev_name) + dev_name = argv[k]; + else { + printf("too many arguments\n"); + dev_name = 0; + break; + } + } + if (0 == dev_name) { + usage(); + return 1; + } + try { + + if (! force) { + res = do_inquiry_prod_id(dev_name, block, wait_ms, ebusy_count, + b, sizeof(b)); + if (res) { + fprintf(stderr, "INQUIRY failed on %s\n", dev_name); + return 1; + } + // For safety, since <lba> written to, only permit scsi_debug + // devices. Bypass this with '-f' option. + if (0 != memcmp("scsi_debug", b, 10)) { + fprintf(stderr, "Since this utility writes to LBA %d, only " + "devices with scsi_debug\nproduct ID accepted.\n", + lba); + return 2; + } + } + + vector<thread *> vt; + + for (k = 0; k < num_threads; ++k) { + int excl = ((0 == k) && (! exclude_o_excl)) ? 1 : 0; + + thread * tp = new thread {work_thread, dev_name, lba, k, block, + excl, all_readers, num_per_thread, + wait_ms}; + vt.push_back(tp); + } + + for (k = 0; k < (int)vt.size(); ++k) + vt[k]->join(); + + for (k = 0; k < (int)vt.size(); ++k) + delete vt[k]; + + cout << "Expecting odd count of 0, got " << odd_count << endl; + cout << "Number of EBUSYs: " << ebusy_count << endl; + + } + catch(system_error& e) { + cerr << "got a system_error exception: " << e.what() << '\n'; + auto ec = e.code(); + cerr << "category: " << ec.category().name() << '\n'; + cerr << "value: " << ec.value() << '\n'; + cerr << "message: " << ec.message() << '\n'; + cerr << "\nNote: if g++ may need '-pthread' or similar in " + "compile/link line" << '\n'; + } + catch(...) { + cerr << "got another exception: " << '\n'; + } + return 0; +} |