--- /dev/null
+/*****************************************************************************\
+ * Copyright (C) 2011 Lawrence Livermore National Security, LLC.
+ * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
+ * Written by Brian Behlendorf <behlendorf1@llnl.gov>.
+ * UCRL-CODE-235197
+ *
+ * This file is part of the SPL, Solaris Porting Layer.
+ * For details, see <http://zfsonlinux.org/>.
+ *
+ * The SPL 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.
+ *
+ * The SPL 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 the SPL. If not, see <http://www.gnu.org/licenses/>.
+ *****************************************************************************
+ * Solaris Porting LAyer Tests (SPLAT) Kernel Compatibility Tests.
+\*****************************************************************************/
+
+#include <sys/kmem.h>
+#include <linux/mm_compat.h>
+#include "splat-internal.h"
+
+#define SPLAT_LINUX_NAME "linux"
+#define SPLAT_LINUX_DESC "Kernel Compatibility Tests"
+
+#define SPLAT_LINUX_TEST1_ID 0x1001
+#define SPLAT_LINUX_TEST1_NAME "shrinker"
+#define SPLAT_LINUX_TEST1_DESC "Shrinker test"
+
+/*
+ * Wait queue used to eliminate race between dropping of slab
+ * and execution of the shrinker callback
+ */
+DECLARE_WAIT_QUEUE_HEAD(shrinker_wait);
+
+SPL_SHRINKER_CALLBACK_FWD_DECLARE(splat_linux_shrinker_fn);
+SPL_SHRINKER_DECLARE(splat_linux_shrinker, splat_linux_shrinker_fn, 1);
+static unsigned long splat_linux_shrinker_size = 0;
+static struct file *splat_linux_shrinker_file = NULL;
+
+static spl_shrinker_t
+__splat_linux_shrinker_fn(struct shrinker *shrink, struct shrink_control *sc)
+{
+ static int failsafe = 0;
+ static unsigned long last_splat_linux_shrinker_size = 0;
+ unsigned long size;
+ spl_shrinker_t count;
+
+ /*
+ * shrinker_size can only decrease or stay the same between callbacks
+ * in the same run, so Reset failsafe whenever shrinker increases
+ * as this indicates a new run.
+ */
+ if (last_splat_linux_shrinker_size < splat_linux_shrinker_size)
+ failsafe = 0;
+
+ last_splat_linux_shrinker_size = splat_linux_shrinker_size;
+
+ if (sc->nr_to_scan) {
+ size = MIN(sc->nr_to_scan, splat_linux_shrinker_size);
+ splat_linux_shrinker_size -= size;
+
+ splat_vprint(splat_linux_shrinker_file, SPLAT_LINUX_TEST1_NAME,
+ "Reclaimed %lu objects, size now %lu\n",
+ size, splat_linux_shrinker_size);
+
+#ifdef HAVE_SPLIT_SHRINKER_CALLBACK
+ count = size;
+#else
+ count = splat_linux_shrinker_size;
+#endif /* HAVE_SPLIT_SHRINKER_CALLBACK */
+
+ } else {
+ count = splat_linux_shrinker_size;
+ splat_vprint(splat_linux_shrinker_file, SPLAT_LINUX_TEST1_NAME,
+ "Cache size is %lu\n", splat_linux_shrinker_size);
+ }
+
+ /* Far more calls than expected abort drop_slab as a failsafe */
+ if (failsafe > 100) {
+ splat_vprint(splat_linux_shrinker_file, SPLAT_LINUX_TEST1_NAME,
+ "Far more calls than expected (%d), size now %lu\n",
+ failsafe, splat_linux_shrinker_size);
+ return (SHRINK_STOP);
+ } else {
+ /*
+ * We only increment failsafe if it doesn't trigger. This
+ * makes any failsafe failure persistent until the next test.
+ */
+ failsafe++;
+ }
+
+ /* Shrinker has run, so signal back to test. */
+ wake_up(&shrinker_wait);
+
+ return (count);
+}
+
+SPL_SHRINKER_CALLBACK_WRAPPER(splat_linux_shrinker_fn);
+
+#define DROP_SLAB_CMD \
+ "exec 0</dev/null " \
+ " 1>/proc/sys/vm/drop_caches " \
+ " 2>/dev/null; " \
+ "echo 2"
+
+static int
+splat_linux_drop_slab(struct file *file)
+{
+ char *argv[] = { "/bin/sh",
+ "-c",
+ DROP_SLAB_CMD,
+ NULL };
+ char *envp[] = { "HOME=/",
+ "TERM=linux",
+ "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
+ NULL };
+ int rc;
+
+ rc = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+ if (rc)
+ splat_vprint(file, SPLAT_LINUX_TEST1_NAME,
+ "Failed user helper '%s %s %s', rc = %d\n",
+ argv[0], argv[1], argv[2], rc);
+
+ return rc;
+}
+
+/*
+ * Verify correct shrinker functionality by registering a shrinker
+ * with the required compatibility macros. We then use a simulated
+ * cache and force the systems caches to be dropped. The shrinker
+ * should be repeatedly called until it reports that the cache is
+ * empty. It is then cleanly unregistered and correct behavior is
+ * verified. There are now four slightly different supported shrinker
+ * API and this test ensures the compatibility code is correct.
+ */
+static int
+splat_linux_test1(struct file *file, void *arg)
+{
+ int rc = -EINVAL;
+
+ /*
+ * Globals used by the shrinker, it is not safe to run this
+ * test concurrently this is a safe assumption for SPLAT tests.
+ * Regardless we do some minimal checking a bail if concurrent
+ * use is detected.
+ */
+ if (splat_linux_shrinker_size || splat_linux_shrinker_file) {
+ splat_vprint(file, SPLAT_LINUX_TEST1_NAME,
+ "Failed due to concurrent shrinker test, rc = %d\n", rc);
+ return (rc);
+ }
+
+ splat_linux_shrinker_size = 1024;
+ splat_linux_shrinker_file = file;
+
+ spl_register_shrinker(&splat_linux_shrinker);
+ rc = splat_linux_drop_slab(file);
+ if (rc)
+ goto out;
+
+ /*
+ * By the time we get here, it is possible that the shrinker has not
+ * yet run. splat_linux_drop_slab sends a signal for it to run, but
+ * there is no guarantee of when it will actually run. We wait for it
+ * to run here, terminating when either the shrinker size is now 0 or
+ * we timeout after 1 second, which should be an eternity (error).
+ */
+ rc = wait_event_timeout(shrinker_wait, !splat_linux_shrinker_size, HZ);
+ if (!rc) {
+ splat_vprint(file, SPLAT_LINUX_TEST1_NAME,
+ "Failed cache shrinking timed out, size now %lu",
+ splat_linux_shrinker_size);
+ rc = -ETIMEDOUT;
+ } else {
+ rc = 0;
+ }
+
+ if (!rc && splat_linux_shrinker_size != 0) {
+ splat_vprint(file, SPLAT_LINUX_TEST1_NAME,
+ "Failed cache was not shrunk to 0, size now %lu",
+ splat_linux_shrinker_size);
+ rc = -EDOM;
+ }
+out:
+ spl_unregister_shrinker(&splat_linux_shrinker);
+
+ splat_linux_shrinker_size = 0;
+ splat_linux_shrinker_file = NULL;
+
+ return rc;
+}
+
+splat_subsystem_t *
+splat_linux_init(void)
+{
+ splat_subsystem_t *sub;
+
+ sub = kmalloc(sizeof(*sub), GFP_KERNEL);
+ if (sub == NULL)
+ return NULL;
+
+ memset(sub, 0, sizeof(*sub));
+ strncpy(sub->desc.name, SPLAT_LINUX_NAME, SPLAT_NAME_SIZE);
+ strncpy(sub->desc.desc, SPLAT_LINUX_DESC, SPLAT_DESC_SIZE);
+ INIT_LIST_HEAD(&sub->subsystem_list);
+ INIT_LIST_HEAD(&sub->test_list);
+ spin_lock_init(&sub->test_lock);
+ sub->desc.id = SPLAT_SUBSYSTEM_LINUX;
+
+ SPLAT_TEST_INIT(sub, SPLAT_LINUX_TEST1_NAME, SPLAT_LINUX_TEST1_DESC,
+ SPLAT_LINUX_TEST1_ID, splat_linux_test1);
+
+ return sub;
+}
+
+void
+splat_linux_fini(splat_subsystem_t *sub)
+{
+ ASSERT(sub);
+ SPLAT_TEST_FINI(sub, SPLAT_LINUX_TEST1_ID);
+
+ kfree(sub);
+}
+
+int
+splat_linux_id(void) {
+ return SPLAT_SUBSYSTEM_LINUX;
+}
projects / mirror_ubuntu-bionic-kernel.git / blobdiff