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-rw-r--r--tools/testing/selftests/cachestat/.gitignore2
-rw-r--r--tools/testing/selftests/cachestat/Makefile8
-rw-r--r--tools/testing/selftests/cachestat/test_cachestat.c318
3 files changed, 328 insertions, 0 deletions
diff --git a/tools/testing/selftests/cachestat/.gitignore b/tools/testing/selftests/cachestat/.gitignore
new file mode 100644
index 0000000000..d6c30b43a4
--- /dev/null
+++ b/tools/testing/selftests/cachestat/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+test_cachestat
diff --git a/tools/testing/selftests/cachestat/Makefile b/tools/testing/selftests/cachestat/Makefile
new file mode 100644
index 0000000000..778b54ebb0
--- /dev/null
+++ b/tools/testing/selftests/cachestat/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+TEST_GEN_PROGS := test_cachestat
+
+CFLAGS += $(KHDR_INCLUDES)
+CFLAGS += -Wall
+LDLIBS += -lrt
+
+include ../lib.mk
diff --git a/tools/testing/selftests/cachestat/test_cachestat.c b/tools/testing/selftests/cachestat/test_cachestat.c
new file mode 100644
index 0000000000..4804c7dc7b
--- /dev/null
+++ b/tools/testing/selftests/cachestat/test_cachestat.c
@@ -0,0 +1,318 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <linux/kernel.h>
+#include <linux/magic.h>
+#include <linux/mman.h>
+#include <sys/mman.h>
+#include <sys/shm.h>
+#include <sys/syscall.h>
+#include <sys/vfs.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include "../kselftest.h"
+
+#define NR_TESTS 9
+
+static const char * const dev_files[] = {
+ "/dev/zero", "/dev/null", "/dev/urandom",
+ "/proc/version", "/proc"
+};
+
+void print_cachestat(struct cachestat *cs)
+{
+ ksft_print_msg(
+ "Using cachestat: Cached: %lu, Dirty: %lu, Writeback: %lu, Evicted: %lu, Recently Evicted: %lu\n",
+ cs->nr_cache, cs->nr_dirty, cs->nr_writeback,
+ cs->nr_evicted, cs->nr_recently_evicted);
+}
+
+bool write_exactly(int fd, size_t filesize)
+{
+ int random_fd = open("/dev/urandom", O_RDONLY);
+ char *cursor, *data;
+ int remained;
+ bool ret;
+
+ if (random_fd < 0) {
+ ksft_print_msg("Unable to access urandom.\n");
+ ret = false;
+ goto out;
+ }
+
+ data = malloc(filesize);
+ if (!data) {
+ ksft_print_msg("Unable to allocate data.\n");
+ ret = false;
+ goto close_random_fd;
+ }
+
+ remained = filesize;
+ cursor = data;
+
+ while (remained) {
+ ssize_t read_len = read(random_fd, cursor, remained);
+
+ if (read_len <= 0) {
+ ksft_print_msg("Unable to read from urandom.\n");
+ ret = false;
+ goto out_free_data;
+ }
+
+ remained -= read_len;
+ cursor += read_len;
+ }
+
+ /* write random data to fd */
+ remained = filesize;
+ cursor = data;
+ while (remained) {
+ ssize_t write_len = write(fd, cursor, remained);
+
+ if (write_len <= 0) {
+ ksft_print_msg("Unable write random data to file.\n");
+ ret = false;
+ goto out_free_data;
+ }
+
+ remained -= write_len;
+ cursor += write_len;
+ }
+
+ ret = true;
+out_free_data:
+ free(data);
+close_random_fd:
+ close(random_fd);
+out:
+ return ret;
+}
+
+/*
+ * fsync() is implemented via noop_fsync() on tmpfs. This makes the fsync()
+ * test fail below, so we need to check for test file living on a tmpfs.
+ */
+static bool is_on_tmpfs(int fd)
+{
+ struct statfs statfs_buf;
+
+ if (fstatfs(fd, &statfs_buf))
+ return false;
+
+ return statfs_buf.f_type == TMPFS_MAGIC;
+}
+
+/*
+ * Open/create the file at filename, (optionally) write random data to it
+ * (exactly num_pages), then test the cachestat syscall on this file.
+ *
+ * If test_fsync == true, fsync the file, then check the number of dirty
+ * pages.
+ */
+static int test_cachestat(const char *filename, bool write_random, bool create,
+ bool test_fsync, unsigned long num_pages,
+ int open_flags, mode_t open_mode)
+{
+ size_t PS = sysconf(_SC_PAGESIZE);
+ int filesize = num_pages * PS;
+ int ret = KSFT_PASS;
+ long syscall_ret;
+ struct cachestat cs;
+ struct cachestat_range cs_range = { 0, filesize };
+
+ int fd = open(filename, open_flags, open_mode);
+
+ if (fd == -1) {
+ ksft_print_msg("Unable to create/open file.\n");
+ ret = KSFT_FAIL;
+ goto out;
+ } else {
+ ksft_print_msg("Create/open %s\n", filename);
+ }
+
+ if (write_random) {
+ if (!write_exactly(fd, filesize)) {
+ ksft_print_msg("Unable to access urandom.\n");
+ ret = KSFT_FAIL;
+ goto out1;
+ }
+ }
+
+ syscall_ret = syscall(__NR_cachestat, fd, &cs_range, &cs, 0);
+
+ ksft_print_msg("Cachestat call returned %ld\n", syscall_ret);
+
+ if (syscall_ret) {
+ ksft_print_msg("Cachestat returned non-zero.\n");
+ ret = KSFT_FAIL;
+ goto out1;
+
+ } else {
+ print_cachestat(&cs);
+
+ if (write_random) {
+ if (cs.nr_cache + cs.nr_evicted != num_pages) {
+ ksft_print_msg(
+ "Total number of cached and evicted pages is off.\n");
+ ret = KSFT_FAIL;
+ }
+ }
+ }
+
+ if (test_fsync) {
+ if (is_on_tmpfs(fd)) {
+ ret = KSFT_SKIP;
+ } else if (fsync(fd)) {
+ ksft_print_msg("fsync fails.\n");
+ ret = KSFT_FAIL;
+ } else {
+ syscall_ret = syscall(__NR_cachestat, fd, &cs_range, &cs, 0);
+
+ ksft_print_msg("Cachestat call (after fsync) returned %ld\n",
+ syscall_ret);
+
+ if (!syscall_ret) {
+ print_cachestat(&cs);
+
+ if (cs.nr_dirty) {
+ ret = KSFT_FAIL;
+ ksft_print_msg(
+ "Number of dirty should be zero after fsync.\n");
+ }
+ } else {
+ ksft_print_msg("Cachestat (after fsync) returned non-zero.\n");
+ ret = KSFT_FAIL;
+ goto out1;
+ }
+ }
+ }
+
+out1:
+ close(fd);
+
+ if (create)
+ remove(filename);
+out:
+ return ret;
+}
+
+bool test_cachestat_shmem(void)
+{
+ size_t PS = sysconf(_SC_PAGESIZE);
+ size_t filesize = PS * 512 * 2; /* 2 2MB huge pages */
+ int syscall_ret;
+ size_t compute_len = PS * 512;
+ struct cachestat_range cs_range = { PS, compute_len };
+ char *filename = "tmpshmcstat";
+ struct cachestat cs;
+ bool ret = true;
+ unsigned long num_pages = compute_len / PS;
+ int fd = shm_open(filename, O_CREAT | O_RDWR, 0600);
+
+ if (fd < 0) {
+ ksft_print_msg("Unable to create shmem file.\n");
+ ret = false;
+ goto out;
+ }
+
+ if (ftruncate(fd, filesize)) {
+ ksft_print_msg("Unable to truncate shmem file.\n");
+ ret = false;
+ goto close_fd;
+ }
+
+ if (!write_exactly(fd, filesize)) {
+ ksft_print_msg("Unable to write to shmem file.\n");
+ ret = false;
+ goto close_fd;
+ }
+
+ syscall_ret = syscall(__NR_cachestat, fd, &cs_range, &cs, 0);
+
+ if (syscall_ret) {
+ ksft_print_msg("Cachestat returned non-zero.\n");
+ ret = false;
+ goto close_fd;
+ } else {
+ print_cachestat(&cs);
+ if (cs.nr_cache + cs.nr_evicted != num_pages) {
+ ksft_print_msg(
+ "Total number of cached and evicted pages is off.\n");
+ ret = false;
+ }
+ }
+
+close_fd:
+ shm_unlink(filename);
+out:
+ return ret;
+}
+
+int main(void)
+{
+ int ret;
+
+ ksft_print_header();
+
+ ret = syscall(__NR_cachestat, -1, NULL, NULL, 0);
+ if (ret == -1 && errno == ENOSYS)
+ ksft_exit_skip("cachestat syscall not available\n");
+
+ ksft_set_plan(NR_TESTS);
+
+ if (ret == -1 && errno == EBADF) {
+ ksft_test_result_pass("bad file descriptor recognized\n");
+ ret = 0;
+ } else {
+ ksft_test_result_fail("bad file descriptor ignored\n");
+ ret = 1;
+ }
+
+ for (int i = 0; i < 5; i++) {
+ const char *dev_filename = dev_files[i];
+
+ if (test_cachestat(dev_filename, false, false, false,
+ 4, O_RDONLY, 0400) == KSFT_PASS)
+ ksft_test_result_pass("cachestat works with %s\n", dev_filename);
+ else {
+ ksft_test_result_fail("cachestat fails with %s\n", dev_filename);
+ ret = 1;
+ }
+ }
+
+ if (test_cachestat("tmpfilecachestat", true, true,
+ false, 4, O_CREAT | O_RDWR, 0600) == KSFT_PASS)
+ ksft_test_result_pass("cachestat works with a normal file\n");
+ else {
+ ksft_test_result_fail("cachestat fails with normal file\n");
+ ret = 1;
+ }
+
+ switch (test_cachestat("tmpfilecachestat", true, true,
+ true, 4, O_CREAT | O_RDWR, 0600)) {
+ case KSFT_FAIL:
+ ksft_test_result_fail("cachestat fsync fails with normal file\n");
+ ret = KSFT_FAIL;
+ break;
+ case KSFT_PASS:
+ ksft_test_result_pass("cachestat fsync works with a normal file\n");
+ break;
+ case KSFT_SKIP:
+ ksft_test_result_skip("tmpfilecachestat is on tmpfs\n");
+ break;
+ }
+
+ if (test_cachestat_shmem())
+ ksft_test_result_pass("cachestat works with a shmem file\n");
+ else {
+ ksft_test_result_fail("cachestat fails with a shmem file\n");
+ ret = 1;
+ }
+
+ return ret;
+}