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zfs/module/splat/splat-rwlock.c

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/*
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* 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) Read/Writer Lock Tests.
*/
#include <sys/random.h>
#include <sys/rwlock.h>
#include <sys/taskq.h>
#include <linux/delay.h>
#include <linux/mm_compat.h>
#include "splat-internal.h"
#define SPLAT_RWLOCK_NAME "rwlock"
#define SPLAT_RWLOCK_DESC "Kernel RW Lock Tests"
#define SPLAT_RWLOCK_TEST1_ID 0x0701
#define SPLAT_RWLOCK_TEST1_NAME "N-rd/1-wr"
#define SPLAT_RWLOCK_TEST1_DESC "Multiple readers one writer"
#define SPLAT_RWLOCK_TEST2_ID 0x0702
#define SPLAT_RWLOCK_TEST2_NAME "0-rd/N-wr"
#define SPLAT_RWLOCK_TEST2_DESC "Multiple writers"
#define SPLAT_RWLOCK_TEST3_ID 0x0703
#define SPLAT_RWLOCK_TEST3_NAME "held"
#define SPLAT_RWLOCK_TEST3_DESC "RW_{LOCK|READ|WRITE}_HELD"
#define SPLAT_RWLOCK_TEST4_ID 0x0704
#define SPLAT_RWLOCK_TEST4_NAME "tryenter"
#define SPLAT_RWLOCK_TEST4_DESC "Tryenter"
#define SPLAT_RWLOCK_TEST5_ID 0x0705
#define SPLAT_RWLOCK_TEST5_NAME "rw_downgrade"
#define SPLAT_RWLOCK_TEST5_DESC "Write downgrade"
#define SPLAT_RWLOCK_TEST6_ID 0x0706
#define SPLAT_RWLOCK_TEST6_NAME "rw_tryupgrade-1"
#define SPLAT_RWLOCK_TEST6_DESC "rwsem->count value"
#define SPLAT_RWLOCK_TEST7_ID 0x0707
#define SPLAT_RWLOCK_TEST7_NAME "rw_tryupgrade-2"
#define SPLAT_RWLOCK_TEST7_DESC "Read upgrade"
#define SPLAT_RWLOCK_TEST_MAGIC 0x115599DDUL
#define SPLAT_RWLOCK_TEST_NAME "rwlock_test"
#define SPLAT_RWLOCK_TEST_TASKQ "rwlock_taskq"
#define SPLAT_RWLOCK_TEST_COUNT 8
#define SPLAT_RWLOCK_RELEASE_INIT 0
#define SPLAT_RWLOCK_RELEASE_WR 1
#define SPLAT_RWLOCK_RELEASE_RD 2
typedef struct rw_priv {
unsigned long rw_magic;
struct file *rw_file;
krwlock_t rw_rwlock;
spinlock_t rw_lock;
spl_wait_queue_head_t rw_waitq;
int rw_completed;
int rw_holders;
int rw_waiters;
int rw_release;
int rw_rc;
krw_t rw_type;
} rw_priv_t;
typedef struct rw_thr {
const char *rwt_name;
rw_priv_t *rwt_rwp;
struct task_struct *rwt_thread;
} rw_thr_t;
void splat_init_rw_priv(rw_priv_t *rwp, struct file *file)
{
rwp->rw_magic = SPLAT_RWLOCK_TEST_MAGIC;
rwp->rw_file = file;
rw_init(&rwp->rw_rwlock, SPLAT_RWLOCK_TEST_NAME, RW_DEFAULT, NULL);
spin_lock_init(&rwp->rw_lock);
init_waitqueue_head(&rwp->rw_waitq);
rwp->rw_completed = 0;
rwp->rw_holders = 0;
rwp->rw_waiters = 0;
rwp->rw_release = SPLAT_RWLOCK_RELEASE_INIT;
rwp->rw_rc = 0;
rwp->rw_type = 0;
}
#if defined(CONFIG_PREEMPT_RT_FULL)
static int
splat_rwlock_test1(struct file *file, void *arg)
{
/*
* This test will never succeed on PREEMPT_RT_FULL because these
* kernels only allow a single thread to hold the lock.
*/
return 0;
}
#else
static int
splat_rwlock_wr_thr(void *arg)
{
rw_thr_t *rwt = (rw_thr_t *)arg;
rw_priv_t *rwp = rwt->rwt_rwp;
uint8_t rnd;
ASSERT(rwp->rw_magic == SPLAT_RWLOCK_TEST_MAGIC);
get_random_bytes((void *)&rnd, 1);
msleep((unsigned int)rnd);
splat_vprint(rwp->rw_file, rwt->rwt_name,
"%s trying to acquire rwlock (%d holding/%d waiting)\n",
rwt->rwt_thread->comm, rwp->rw_holders, rwp->rw_waiters);
spin_lock(&rwp->rw_lock);
rwp->rw_waiters++;
spin_unlock(&rwp->rw_lock);
rw_enter(&rwp->rw_rwlock, RW_WRITER);
spin_lock(&rwp->rw_lock);
rwp->rw_waiters--;
rwp->rw_holders++;
spin_unlock(&rwp->rw_lock);
splat_vprint(rwp->rw_file, rwt->rwt_name,
"%s acquired rwlock (%d holding/%d waiting)\n",
rwt->rwt_thread->comm, rwp->rw_holders, rwp->rw_waiters);
/* Wait for control thread to signal we can release the write lock */
wait_event_interruptible(rwp->rw_waitq, splat_locked_test(&rwp->rw_lock,
rwp->rw_release == SPLAT_RWLOCK_RELEASE_WR));
spin_lock(&rwp->rw_lock);
rwp->rw_completed++;
rwp->rw_holders--;
spin_unlock(&rwp->rw_lock);
splat_vprint(rwp->rw_file, rwt->rwt_name,
"%s dropped rwlock (%d holding/%d waiting)\n",
rwt->rwt_thread->comm, rwp->rw_holders, rwp->rw_waiters);
rw_exit(&rwp->rw_rwlock);
return 0;
}
static int
splat_rwlock_rd_thr(void *arg)
{
rw_thr_t *rwt = (rw_thr_t *)arg;
rw_priv_t *rwp = rwt->rwt_rwp;
uint8_t rnd;
ASSERT(rwp->rw_magic == SPLAT_RWLOCK_TEST_MAGIC);
get_random_bytes((void *)&rnd, 1);
msleep((unsigned int)rnd);
/* Don't try and take the semaphore until after someone has it */
wait_event_interruptible(rwp->rw_waitq,
splat_locked_test(&rwp->rw_lock, rwp->rw_holders > 0));
splat_vprint(rwp->rw_file, rwt->rwt_name,
"%s trying to acquire rwlock (%d holding/%d waiting)\n",
rwt->rwt_thread->comm, rwp->rw_holders, rwp->rw_waiters);
spin_lock(&rwp->rw_lock);
rwp->rw_waiters++;
spin_unlock(&rwp->rw_lock);
rw_enter(&rwp->rw_rwlock, RW_READER);
spin_lock(&rwp->rw_lock);
rwp->rw_waiters--;
rwp->rw_holders++;
spin_unlock(&rwp->rw_lock);
splat_vprint(rwp->rw_file, rwt->rwt_name,
"%s acquired rwlock (%d holding/%d waiting)\n",
rwt->rwt_thread->comm, rwp->rw_holders, rwp->rw_waiters);
/* Wait for control thread to signal we can release the read lock */
wait_event_interruptible(rwp->rw_waitq, splat_locked_test(&rwp->rw_lock,
rwp->rw_release == SPLAT_RWLOCK_RELEASE_RD));
spin_lock(&rwp->rw_lock);
rwp->rw_completed++;
rwp->rw_holders--;
spin_unlock(&rwp->rw_lock);
splat_vprint(rwp->rw_file, rwt->rwt_name,
"%s dropped rwlock (%d holding/%d waiting)\n",
rwt->rwt_thread->comm, rwp->rw_holders, rwp->rw_waiters);
rw_exit(&rwp->rw_rwlock);
return 0;
}
static int
splat_rwlock_test1(struct file *file, void *arg)
{
int i, count = 0, rc = 0;
rw_thr_t rwt[SPLAT_RWLOCK_TEST_COUNT];
rw_priv_t *rwp;
rwp = (rw_priv_t *)kmalloc(sizeof(*rwp), GFP_KERNEL);
if (rwp == NULL)
return -ENOMEM;
splat_init_rw_priv(rwp, file);
/* Create some threads, the exact number isn't important just as
* long as we know how many we managed to create and should expect. */
for (i = 0; i < SPLAT_RWLOCK_TEST_COUNT; i++) {
rwt[i].rwt_rwp = rwp;
rwt[i].rwt_name = SPLAT_RWLOCK_TEST1_NAME;
/* The first thread will be the writer */
if (i == 0)
rwt[i].rwt_thread = spl_kthread_create(splat_rwlock_wr_thr,
&rwt[i], "%s/%d", SPLAT_RWLOCK_TEST_NAME, i);
else
rwt[i].rwt_thread = spl_kthread_create(splat_rwlock_rd_thr,
&rwt[i], "%s/%d", SPLAT_RWLOCK_TEST_NAME, i);
if (!IS_ERR(rwt[i].rwt_thread)) {
wake_up_process(rwt[i].rwt_thread);
count++;
}
}
/* Wait for the writer */
while (splat_locked_test(&rwp->rw_lock, rwp->rw_holders == 0)) {
wake_up_interruptible(&rwp->rw_waitq);
msleep(100);
}
/* Wait for 'count-1' readers */
while (splat_locked_test(&rwp->rw_lock, rwp->rw_waiters < count - 1)) {
wake_up_interruptible(&rwp->rw_waitq);
msleep(100);
}
/* Verify there is only one lock holder */
if (splat_locked_test(&rwp->rw_lock, rwp->rw_holders) != 1) {
splat_vprint(file, SPLAT_RWLOCK_TEST1_NAME, "Only 1 holder "
"expected for rwlock (%d holding/%d waiting)\n",
rwp->rw_holders, rwp->rw_waiters);
rc = -EINVAL;
}
/* Verify 'count-1' readers */
if (splat_locked_test(&rwp->rw_lock, rwp->rw_waiters != count - 1)) {
splat_vprint(file, SPLAT_RWLOCK_TEST1_NAME, "Only %d waiters "
"expected for rwlock (%d holding/%d waiting)\n",
count - 1, rwp->rw_holders, rwp->rw_waiters);
rc = -EINVAL;
}
/* Signal the writer to release, allows readers to acquire */
spin_lock(&rwp->rw_lock);
rwp->rw_release = SPLAT_RWLOCK_RELEASE_WR;
wake_up_interruptible(&rwp->rw_waitq);
spin_unlock(&rwp->rw_lock);
/* Wait for 'count-1' readers to hold the lock */
while (splat_locked_test(&rwp->rw_lock, rwp->rw_holders < count - 1)) {
wake_up_interruptible(&rwp->rw_waitq);
msleep(100);
}
/* Verify there are 'count-1' readers */
if (splat_locked_test(&rwp->rw_lock, rwp->rw_holders != count - 1)) {
splat_vprint(file, SPLAT_RWLOCK_TEST1_NAME, "Only %d holders "
"expected for rwlock (%d holding/%d waiting)\n",
count - 1, rwp->rw_holders, rwp->rw_waiters);
rc = -EINVAL;
}
/* Release 'count-1' readers */
spin_lock(&rwp->rw_lock);
rwp->rw_release = SPLAT_RWLOCK_RELEASE_RD;
wake_up_interruptible(&rwp->rw_waitq);
spin_unlock(&rwp->rw_lock);
/* Wait for the test to complete */
while (splat_locked_test(&rwp->rw_lock,
rwp->rw_holders>0 || rwp->rw_waiters>0))
msleep(100);
rw_destroy(&(rwp->rw_rwlock));
kfree(rwp);
return rc;
}
#endif
static void
splat_rwlock_test2_func(void *arg)
{
rw_priv_t *rwp = (rw_priv_t *)arg;
int rc;
ASSERT(rwp->rw_magic == SPLAT_RWLOCK_TEST_MAGIC);
/* Read the value before sleeping and write it after we wake up to
* maximize the chance of a race if rwlocks are not working properly */
rw_enter(&rwp->rw_rwlock, RW_WRITER);
rc = rwp->rw_rc;
set_current_state(TASK_INTERRUPTIBLE);
schedule_timeout(HZ / 100); /* 1/100 of a second */
VERIFY(rwp->rw_rc == rc);
rwp->rw_rc = rc + 1;
rw_exit(&rwp->rw_rwlock);
}
static int
splat_rwlock_test2(struct file *file, void *arg)
{
rw_priv_t *rwp;
taskq_t *tq;
int i, rc = 0, tq_count = 256;
rwp = (rw_priv_t *)kmalloc(sizeof(*rwp), GFP_KERNEL);
if (rwp == NULL)
return -ENOMEM;
splat_init_rw_priv(rwp, file);
/* Create several threads allowing tasks to race with each other */
tq = taskq_create(SPLAT_RWLOCK_TEST_TASKQ, num_online_cpus(),
defclsyspri, 50, INT_MAX, TASKQ_PREPOPULATE);
if (tq == NULL) {
rc = -ENOMEM;
goto out;
}
/*
* Schedule N work items to the work queue each of which enters the
* writer rwlock, sleeps briefly, then exits the writer rwlock. On a
* multiprocessor box these work items will be handled by all available
* CPUs. The task function checks to ensure the tracked shared variable
* is always only incremented by one. Additionally, the rwlock itself
* is instrumented such that if any two processors are in the
* critical region at the same time the system will panic. If the
* rwlock is implemented right this will never happy, that's a pass.
*/
for (i = 0; i < tq_count; i++) {
if (taskq_dispatch(tq, splat_rwlock_test2_func, rwp,
TQ_SLEEP) == TASKQID_INVALID) {
splat_vprint(file, SPLAT_RWLOCK_TEST2_NAME,
"Failed to queue task %d\n", i);
rc = -EINVAL;
}
}
taskq_wait(tq);
if (rwp->rw_rc == tq_count) {
splat_vprint(file, SPLAT_RWLOCK_TEST2_NAME, "%d racing threads "
"correctly entered/exited the rwlock %d times\n",
num_online_cpus(), rwp->rw_rc);
} else {
splat_vprint(file, SPLAT_RWLOCK_TEST2_NAME, "%d racing threads "
"only processed %d/%d w rwlock work items\n",
num_online_cpus(), rwp->rw_rc, tq_count);
rc = -EINVAL;
}
taskq_destroy(tq);
rw_destroy(&(rwp->rw_rwlock));
out:
kfree(rwp);
return rc;
}
#define splat_rwlock_test3_helper(rwp,rex1,rex2,wex1,wex2,held_func,rc) \
do { \
int result, _rc1_, _rc2_, _rc3_, _rc4_; \
\
rc = 0; \
rw_enter(&(rwp)->rw_rwlock, RW_READER); \
_rc1_ = ((result = held_func(&(rwp)->rw_rwlock)) != rex1); \
splat_vprint(file, SPLAT_RWLOCK_TEST3_NAME, "%s" #held_func \
" returned %d (expected %d) when RW_READER\n", \
_rc1_ ? "Fail " : "", result, rex1); \
rw_exit(&(rwp)->rw_rwlock); \
_rc2_ = ((result = held_func(&(rwp)->rw_rwlock)) != rex2); \
splat_vprint(file, SPLAT_RWLOCK_TEST3_NAME, "%s" #held_func \
" returned %d (expected %d) when !RW_READER\n", \
_rc2_ ? "Fail " : "", result, rex2); \
\
rw_enter(&(rwp)->rw_rwlock, RW_WRITER); \
_rc3_ = ((result = held_func(&(rwp)->rw_rwlock)) != wex1); \
splat_vprint(file, SPLAT_RWLOCK_TEST3_NAME, "%s" #held_func \
" returned %d (expected %d) when RW_WRITER\n", \
_rc3_ ? "Fail " : "", result, wex1); \
rw_exit(&(rwp)->rw_rwlock); \
_rc4_ = ((result = held_func(&(rwp)->rw_rwlock)) != wex2); \
splat_vprint(file, SPLAT_RWLOCK_TEST3_NAME, "%s" #held_func \
" returned %d (expected %d) when !RW_WRITER\n", \
_rc4_ ? "Fail " : "", result, wex2); \
\
rc = ((_rc1_ || _rc2_ || _rc3_ || _rc4_) ? -EINVAL : 0); \
} while(0);
static int
splat_rwlock_test3(struct file *file, void *arg)
{
rw_priv_t *rwp;
int rc1, rc2, rc3;
rwp = (rw_priv_t *)kmalloc(sizeof(*rwp), GFP_KERNEL);
if (rwp == NULL)
return -ENOMEM;
splat_init_rw_priv(rwp, file);
splat_rwlock_test3_helper(rwp, 1, 0, 1, 0, RW_LOCK_HELD, rc1);
splat_rwlock_test3_helper(rwp, 1, 0, 0, 0, RW_READ_HELD, rc2);
splat_rwlock_test3_helper(rwp, 0, 0, 1, 0, RW_WRITE_HELD, rc3);
rw_destroy(&rwp->rw_rwlock);
kfree(rwp);
return ((rc1 || rc2 || rc3) ? -EINVAL : 0);
}
static void
splat_rwlock_test4_func(void *arg)
{
rw_priv_t *rwp = (rw_priv_t *)arg;
ASSERT(rwp->rw_magic == SPLAT_RWLOCK_TEST_MAGIC);
if (rw_tryenter(&rwp->rw_rwlock, rwp->rw_type)) {
rwp->rw_rc = 0;
rw_exit(&rwp->rw_rwlock);
} else {
rwp->rw_rc = -EBUSY;
}
}
static char *
splat_rwlock_test4_name(krw_t type)
{
switch (type) {
case RW_NONE: return "RW_NONE";
case RW_WRITER: return "RW_WRITER";
case RW_READER: return "RW_READER";
}
return NULL;
}
static int
splat_rwlock_test4_type(taskq_t *tq, rw_priv_t *rwp, int expected_rc,
krw_t holder_type, krw_t try_type)
{
int id, rc = 0;
/* Schedule a task function which will try and acquire the rwlock
* using type try_type while the rwlock is being held as holder_type.
* The result must match expected_rc for the test to pass */
rwp->rw_rc = -EINVAL;
rwp->rw_type = try_type;
if (holder_type == RW_WRITER || holder_type == RW_READER)
rw_enter(&rwp->rw_rwlock, holder_type);
id = taskq_dispatch(tq, splat_rwlock_test4_func, rwp, TQ_SLEEP);
if (id == TASKQID_INVALID) {
splat_vprint(rwp->rw_file, SPLAT_RWLOCK_TEST4_NAME, "%s",
"taskq_dispatch() failed\n");
rc = -EINVAL;
goto out;
}
taskq_wait_id(tq, id);
if (rwp->rw_rc != expected_rc)
rc = -EINVAL;
splat_vprint(rwp->rw_file, SPLAT_RWLOCK_TEST4_NAME,
"%srw_tryenter(%s) returned %d (expected %d) when %s\n",
rc ? "Fail " : "", splat_rwlock_test4_name(try_type),
rwp->rw_rc, expected_rc,
splat_rwlock_test4_name(holder_type));
out:
if (holder_type == RW_WRITER || holder_type == RW_READER)
rw_exit(&rwp->rw_rwlock);
return rc;
}
static int
splat_rwlock_test4(struct file *file, void *arg)
{
rw_priv_t *rwp;
taskq_t *tq;
int rc = 0, rc1, rc2, rc3, rc4, rc5, rc6;
rwp = (rw_priv_t *)kmalloc(sizeof(*rwp), GFP_KERNEL);
if (rwp == NULL)
return -ENOMEM;
tq = taskq_create(SPLAT_RWLOCK_TEST_TASKQ, 1, defclsyspri,
50, INT_MAX, TASKQ_PREPOPULATE);
if (tq == NULL) {
rc = -ENOMEM;
goto out;
}
splat_init_rw_priv(rwp, file);
/*
* Validate all combinations of rw_tryenter() contention.
*
* The concurrent reader test is modified for PREEMPT_RT_FULL
* kernels which do not permit concurrent read locks to be taken
* from different threads. The same thread is allowed to take
* the read lock multiple times.
*/
rc1 = splat_rwlock_test4_type(tq, rwp, -EBUSY, RW_WRITER, RW_WRITER);
rc2 = splat_rwlock_test4_type(tq, rwp, -EBUSY, RW_WRITER, RW_READER);
rc3 = splat_rwlock_test4_type(tq, rwp, -EBUSY, RW_READER, RW_WRITER);
#if defined(CONFIG_PREEMPT_RT_FULL)
rc4 = splat_rwlock_test4_type(tq, rwp, -EBUSY, RW_READER, RW_READER);
#else
rc4 = splat_rwlock_test4_type(tq, rwp, 0, RW_READER, RW_READER);
#endif
rc5 = splat_rwlock_test4_type(tq, rwp, 0, RW_NONE, RW_WRITER);
rc6 = splat_rwlock_test4_type(tq, rwp, 0, RW_NONE, RW_READER);
if (rc1 || rc2 || rc3 || rc4 || rc5 || rc6)
rc = -EINVAL;
taskq_destroy(tq);
out:
rw_destroy(&(rwp->rw_rwlock));
kfree(rwp);
return rc;
}
static int
splat_rwlock_test5(struct file *file, void *arg)
{
rw_priv_t *rwp;
int rc = -EINVAL;
rwp = (rw_priv_t *)kmalloc(sizeof(*rwp), GFP_KERNEL);
if (rwp == NULL)
return -ENOMEM;
splat_init_rw_priv(rwp, file);
rw_enter(&rwp->rw_rwlock, RW_WRITER);
if (!RW_WRITE_HELD(&rwp->rw_rwlock)) {
splat_vprint(file, SPLAT_RWLOCK_TEST5_NAME,
"rwlock should be write lock: %d\n",
RW_WRITE_HELD(&rwp->rw_rwlock));
goto out;
}
rw_downgrade(&rwp->rw_rwlock);
if (!RW_READ_HELD(&rwp->rw_rwlock)) {
splat_vprint(file, SPLAT_RWLOCK_TEST5_NAME,
"rwlock should be read lock: %d\n",
RW_READ_HELD(&rwp->rw_rwlock));
goto out;
}
rc = 0;
splat_vprint(file, SPLAT_RWLOCK_TEST5_NAME, "%s",
"rwlock properly downgraded\n");
out:
rw_exit(&rwp->rw_rwlock);
rw_destroy(&rwp->rw_rwlock);
kfree(rwp);
return rc;
}
static int
splat_rwlock_test6(struct file *file, void *arg)
{
rw_priv_t *rwp;
int rc;
rwp = (rw_priv_t *)kmalloc(sizeof(*rwp), GFP_KERNEL);
if (rwp == NULL)
return -ENOMEM;
splat_init_rw_priv(rwp, file);
rw_enter(&rwp->rw_rwlock, RW_READER);
if (RWSEM_COUNT(SEM(&rwp->rw_rwlock)) !=
SPL_RWSEM_SINGLE_READER_VALUE) {
splat_vprint(file, SPLAT_RWLOCK_TEST6_NAME,
"We assumed single reader rwsem->count "
"should be %ld, but is %ld\n",
(long int)SPL_RWSEM_SINGLE_READER_VALUE,
(long int)RWSEM_COUNT(SEM(&rwp->rw_rwlock)));
rc = -ENOLCK;
goto out;
}
rw_exit(&rwp->rw_rwlock);
rw_enter(&rwp->rw_rwlock, RW_WRITER);
if (RWSEM_COUNT(SEM(&rwp->rw_rwlock)) !=
SPL_RWSEM_SINGLE_WRITER_VALUE) {
splat_vprint(file, SPLAT_RWLOCK_TEST6_NAME,
"We assumed single writer rwsem->count "
"should be %ld, but is %ld\n",
(long int)SPL_RWSEM_SINGLE_WRITER_VALUE,
(long int)RWSEM_COUNT(SEM(&rwp->rw_rwlock)));
rc = -ENOLCK;
goto out;
}
rc = 0;
splat_vprint(file, SPLAT_RWLOCK_TEST6_NAME, "%s",
"rwsem->count same as we assumed\n");
out:
rw_exit(&rwp->rw_rwlock);
rw_destroy(&rwp->rw_rwlock);
kfree(rwp);
return rc;
}
static int
splat_rwlock_test7(struct file *file, void *arg)
{
rw_priv_t *rwp;
int rc;
rwp = (rw_priv_t *)kmalloc(sizeof(*rwp), GFP_KERNEL);
if (rwp == NULL)
return -ENOMEM;
splat_init_rw_priv(rwp, file);
rw_enter(&rwp->rw_rwlock, RW_READER);
if (!RW_READ_HELD(&rwp->rw_rwlock)) {
splat_vprint(file, SPLAT_RWLOCK_TEST7_NAME,
"rwlock should be read lock: %d\n",
RW_READ_HELD(&rwp->rw_rwlock));
rc = -ENOLCK;
goto out;
}
/* With one reader upgrade should never fail. */
rc = rw_tryupgrade(&rwp->rw_rwlock);
if (!rc) {
splat_vprint(file, SPLAT_RWLOCK_TEST7_NAME,
"rwlock failed upgrade from reader: %d\n",
RW_READ_HELD(&rwp->rw_rwlock));
rc = -ENOLCK;
goto out;
}
if (RW_READ_HELD(&rwp->rw_rwlock) || !RW_WRITE_HELD(&rwp->rw_rwlock)) {
splat_vprint(file, SPLAT_RWLOCK_TEST7_NAME, "rwlock should "
"have 0 (not %d) reader and 1 (not %d) writer\n",
RW_READ_HELD(&rwp->rw_rwlock),
RW_WRITE_HELD(&rwp->rw_rwlock));
goto out;
}
rc = 0;
splat_vprint(file, SPLAT_RWLOCK_TEST7_NAME, "%s",
"rwlock properly upgraded\n");
out:
rw_exit(&rwp->rw_rwlock);
rw_destroy(&rwp->rw_rwlock);
kfree(rwp);
return rc;
}
splat_subsystem_t *
splat_rwlock_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_RWLOCK_NAME, SPLAT_NAME_SIZE);
strncpy(sub->desc.desc, SPLAT_RWLOCK_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_RWLOCK;
splat_test_init(sub, SPLAT_RWLOCK_TEST1_NAME, SPLAT_RWLOCK_TEST1_DESC,
SPLAT_RWLOCK_TEST1_ID, splat_rwlock_test1);
splat_test_init(sub, SPLAT_RWLOCK_TEST2_NAME, SPLAT_RWLOCK_TEST2_DESC,
SPLAT_RWLOCK_TEST2_ID, splat_rwlock_test2);
splat_test_init(sub, SPLAT_RWLOCK_TEST3_NAME, SPLAT_RWLOCK_TEST3_DESC,
SPLAT_RWLOCK_TEST3_ID, splat_rwlock_test3);
splat_test_init(sub, SPLAT_RWLOCK_TEST4_NAME, SPLAT_RWLOCK_TEST4_DESC,
SPLAT_RWLOCK_TEST4_ID, splat_rwlock_test4);
splat_test_init(sub, SPLAT_RWLOCK_TEST5_NAME, SPLAT_RWLOCK_TEST5_DESC,
SPLAT_RWLOCK_TEST5_ID, splat_rwlock_test5);
splat_test_init(sub, SPLAT_RWLOCK_TEST6_NAME, SPLAT_RWLOCK_TEST6_DESC,
SPLAT_RWLOCK_TEST6_ID, splat_rwlock_test6);
splat_test_init(sub, SPLAT_RWLOCK_TEST7_NAME, SPLAT_RWLOCK_TEST7_DESC,
SPLAT_RWLOCK_TEST7_ID, splat_rwlock_test7);
return sub;
}
void
splat_rwlock_fini(splat_subsystem_t *sub)
{
ASSERT(sub);
splat_test_fini(sub, SPLAT_RWLOCK_TEST7_ID);
splat_test_fini(sub, SPLAT_RWLOCK_TEST6_ID);
splat_test_fini(sub, SPLAT_RWLOCK_TEST5_ID);
splat_test_fini(sub, SPLAT_RWLOCK_TEST4_ID);
splat_test_fini(sub, SPLAT_RWLOCK_TEST3_ID);
splat_test_fini(sub, SPLAT_RWLOCK_TEST2_ID);
splat_test_fini(sub, SPLAT_RWLOCK_TEST1_ID);
kfree(sub);
}
int
splat_rwlock_id(void) {
return SPLAT_SUBSYSTEM_RWLOCK;
}
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