Merge pull request #35 from robertbaldyga/add-posix-env

Introduce default POSIX environment

Makefile

@@ -24,6 +24,14 @@ else
 $(error Not allowed program command)
 endif
 
+ifneq ($(strip $(ENV)),)
+ifeq ($(strip $(ENV)),posix)
+ENVDIR=$(PWD)/env/posix
+else
+$(error Invalid environment selected)
+endif
+endif
+
 #
 # Installing headers
 #
@@ -68,6 +76,35 @@ $(SRC_RM): validate
 	$(if $(shell readlink $@ | grep $(PWD)/src), \
 		@echo "  RM      $@"; rm $@,)
 
+#
+# Installing environment
+#
+ENV_IN=$(shell find $(ENVDIR) -name '*.[c|h]' -type f)
+ENV_OUT=$(patsubst $(ENVDIR)%,$(OUTDIR)/src/ocf/env/%,$(ENV_IN))
+ENV_RM=$(shell find $(OUTDIR)/src/ocf/env -name '*.[c|h]' -xtype l 2>/dev/null)
+
+env: | env_check env_dep
+	@$(MAKE) distcleandir
+
+env_check:
+ifeq ($(ENVDIR),)
+	$(error No environment selected)
+endif
+
+env_dep: $(ENV_OUT) $(ENV_RM)
+
+$(ENV_OUT):
+ifeq ($(strip $(OUTDIR)),)
+	$(error No output specified for installing sources)
+endif
+	@echo " INSTALL  $@"
+	@mkdir -p $(dir $@)
+	@$(INSTALL) $(subst $(OUTDIR)/src/ocf/env,$(ENVDIR),$@) $@
+
+$(ENV_RM): validate
+	$(if $(shell readlink $@ | grep $(ENVDIR)), \
+		@echo "  RM      $@"; rm $@,)
+
 #
 # Distclean
 #
@@ -96,5 +133,5 @@ doc: validate
 	@mkdir -p $(OUTDIR)/doc
 	@cd doc && mv html $(OUTDIR)/doc/ocf
 
-.PHONY: inc src validate help distclean distcleandir doc \
-    $(INC_RM) $(SRC_RM) $(DIST_DIR)
+.PHONY: inc src env env_check env_dep validate help distclean distcleandir doc \
+    $(INC_RM) $(SRC_RM) $(ENV_RM) $(DIST_DIR)

env/posix/ocf_env.c

@@ -0,0 +1,142 @@
+/*
+ * Copyright(c) 2019 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause-Clear
+ */
+
+#include "ocf_env.h"
+#include <sched.h>
+#include <execinfo.h>
+
+struct _env_allocator {
+	/*!< Memory pool ID unique name */
+	char *name;
+
+	/*!< Size of specific item of memory pool */
+	uint32_t item_size;
+
+	/*!< Number of currently allocated items in pool */
+	env_atomic count;
+};
+
+static inline size_t env_allocator_align(size_t size)
+{
+	if (size <= 2)
+		return size;
+	return (1ULL << 32) >> __builtin_clz(size - 1);
+}
+
+struct _env_allocator_item {
+	uint32_t flags;
+	uint32_t cpu;
+	char data[];
+};
+
+void *env_allocator_new(env_allocator *allocator)
+{
+	struct _env_allocator_item *item = NULL;
+
+	item = calloc(1, allocator->item_size);
+
+	if (item) {
+		item->cpu = 0;
+		env_atomic_inc(&allocator->count);
+	}
+
+	return &item->data;
+}
+
+
+env_allocator *env_allocator_create(uint32_t size, const char *fmt_name, ...)
+{
+	char name[OCF_ALLOCATOR_NAME_MAX] = { '\0' };
+	int result, error = -1;
+	va_list args;
+
+	env_allocator *allocator = calloc(1, sizeof(*allocator));
+	if (!allocator) {
+		error = __LINE__;
+		goto err;
+	}
+
+	allocator->item_size = size + sizeof(struct _env_allocator_item);
+
+	/* Format allocator name */
+	va_start(args, fmt_name);
+	result = vsnprintf(name, sizeof(name), fmt_name, args);
+	va_end(args);
+
+	if ((result > 0) && (result < sizeof(name))) {
+		allocator->name = strdup(name);
+
+		if (!allocator->name) {
+			error = __LINE__;
+			goto err;
+		}
+	} else {
+		/* Formated string name exceed max allowed size of name */
+		error = __LINE__;
+		goto err;
+	}
+
+	return allocator;
+
+err:
+	printf("Cannot create memory allocator, ERROR %d", error);
+	env_allocator_destroy(allocator);
+
+	return NULL;
+}
+
+void env_allocator_del(env_allocator *allocator, void *obj)
+{
+	struct _env_allocator_item *item =
+		container_of(obj, struct _env_allocator_item, data);
+
+	env_atomic_dec(&allocator->count);
+
+	free(item);
+}
+
+void env_allocator_destroy(env_allocator *allocator)
+{
+	if (allocator) {
+		if (env_atomic_read(&allocator->count)) {
+			printf("Not all objects deallocated\n");
+			ENV_WARN(true, OCF_PREFIX_SHORT" Cleanup problem\n");
+		}
+
+		free(allocator->name);
+		free(allocator);
+	}
+}
+
+uint32_t env_allocator_item_count(env_allocator *allocator)
+{
+	return env_atomic_read(&allocator->count);
+}
+
+/* *** DEBUGING *** */
+
+#define ENV_TRACE_DEPTH	16
+
+void env_stack_trace(void)
+{
+	void *trace[ENV_TRACE_DEPTH];
+	char **messages = NULL;
+	int i, size;
+
+	size = backtrace(trace, ENV_TRACE_DEPTH);
+	messages = backtrace_symbols(trace, size);
+	printf("[stack trace]>>>\n");
+	for (i = 0; i < size; ++i)
+		printf("%s\n", messages[i]);
+	printf("<<<[stack trace]\n");
+	free(messages);
+}
+
+/* *** CRC *** */
+
+uint32_t env_crc32(uint32_t crc, uint8_t const *data, size_t len)
+{
+	return crc32(crc, data, len);
+}

env/posix/ocf_env.h

@@ -0,0 +1,658 @@
+/*
+ * Copyright(c) 2019 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause-Clear
+ */
+
+#ifndef __OCF_ENV_H__
+#define __OCF_ENV_H__
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#ifndef __USE_GNU
+#define __USE_GNU
+#endif
+
+#include <linux/limits.h>
+#include <linux/stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <string.h>
+#include <pthread.h>
+#include <assert.h>
+#include <semaphore.h>
+#include <errno.h>
+#include <limits.h>
+#include <unistd.h>
+#include <inttypes.h>
+#include <sys/time.h>
+#include <sys/param.h>
+#include <zlib.h>
+
+#include "ocf_env_list.h"
+#include "ocf_env_headers.h"
+
+/* linux sector 512-bytes */
+#define ENV_SECTOR_SHIFT	9
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+
+typedef uint64_t sector_t;
+
+#define __packed	__attribute__((packed))
+#define __aligned(x)	__attribute__((aligned(x)))
+
+#define likely(cond)       __builtin_expect(!!(cond), 1)
+#define unlikely(cond)     __builtin_expect(!!(cond), 0)
+
+#define min(a,b) MIN(a,b)
+
+#define OCF_ALLOCATOR_NAME_MAX 128
+
+#define PAGE_SIZE 4096
+
+/* *** MEMORY MANAGEMENT *** */
+#define ENV_MEM_NORMAL	0
+#define ENV_MEM_NOIO	0
+#define ENV_MEM_ATOMIC	0
+
+static inline void *env_malloc(size_t size, int flags)
+{
+	return malloc(size);
+}
+
+static inline void *env_zalloc(size_t size, int flags)
+{
+	void *ptr = malloc(size);
+
+	if (ptr)
+		memset(ptr, 0, size);
+
+	return ptr;
+}
+
+static inline void env_free(const void *ptr)
+{
+	free((void *)ptr);
+}
+
+static inline void *env_vmalloc(size_t size)
+{
+	return malloc(size);
+}
+
+static inline void *env_vzalloc(size_t size)
+{
+	return env_zalloc(size, 0);
+}
+
+static inline void env_vfree(const void *ptr)
+{
+	free((void *)ptr);
+}
+
+static inline uint64_t env_get_free_memory(void)
+{
+	return sysconf(_SC_PAGESIZE) * sysconf(_SC_AVPHYS_PAGES);
+}
+
+/* *** ALLOCATOR *** */
+
+typedef struct _env_allocator env_allocator;
+
+env_allocator *env_allocator_create(uint32_t size, const char *fmt_name, ...);
+
+void env_allocator_destroy(env_allocator *allocator);
+
+void *env_allocator_new(env_allocator *allocator);
+
+void env_allocator_del(env_allocator *allocator, void *item);
+
+uint32_t env_allocator_item_count(env_allocator *allocator);
+
+/* *** MUTEX *** */
+
+typedef struct {
+	pthread_mutex_t m;
+} env_mutex;
+
+#define env_cond_resched()      ({})
+
+static inline int env_mutex_init(env_mutex *mutex)
+{
+	if(pthread_mutex_init(&mutex->m, NULL))
+		return 1;
+
+	return 0;
+}
+
+static inline void env_mutex_lock(env_mutex *mutex)
+{
+	pthread_mutex_lock(&mutex->m);
+}
+
+static inline int env_mutex_lock_interruptible(env_mutex *mutex)
+{
+	env_mutex_lock(mutex);
+	return 0;
+}
+
+static inline int env_mutex_trylock(env_mutex *mutex)
+{
+	if (pthread_mutex_trylock(&mutex->m) == 0)
+		return 1;
+	return 0;
+}
+
+static inline void env_mutex_unlock(env_mutex *mutex)
+{
+	pthread_mutex_unlock(&mutex->m);
+}
+
+static inline int env_mutex_is_locked(env_mutex *mutex)
+{
+	if (env_mutex_trylock(mutex)) {
+		env_mutex_unlock(mutex);
+		return 1;
+	}
+
+	return 0;
+}
+
+/* *** RECURSIVE MUTEX *** */
+
+typedef env_mutex env_rmutex;
+
+static inline int env_rmutex_init(env_rmutex *rmutex)
+{
+	env_mutex_init(rmutex);
+	return 0;
+}
+
+static inline void env_rmutex_lock(env_rmutex *rmutex)
+{
+	env_mutex_lock(rmutex);
+}
+
+static inline int env_rmutex_lock_interruptible(env_rmutex *rmutex)
+{
+	return env_mutex_lock_interruptible(rmutex);
+}
+
+static inline int env_rmutex_trylock(env_rmutex *rmutex)
+{
+	return env_mutex_trylock(rmutex);
+}
+
+static inline void env_rmutex_unlock(env_rmutex *rmutex)
+{
+	env_mutex_unlock(rmutex);
+}
+
+static inline int env_rmutex_is_locked(env_rmutex *rmutex)
+{
+	return env_mutex_is_locked(rmutex);
+}
+
+/* *** RW SEMAPHORE *** */
+typedef struct {
+	 pthread_rwlock_t lock;
+} env_rwsem;
+
+static inline int env_rwsem_init(env_rwsem *s)
+{
+	return pthread_rwlock_init(&s->lock, NULL);
+}
+
+static inline void env_rwsem_up_read(env_rwsem *s)
+{
+	pthread_rwlock_unlock(&s->lock);
+}
+
+static inline void env_rwsem_down_read(env_rwsem *s)
+{
+	pthread_rwlock_rdlock(&s->lock);
+}
+
+static inline int env_rwsem_down_read_trylock(env_rwsem *s)
+{
+	int result = pthread_rwlock_tryrdlock(&s->lock);
+
+	if (result == 0)
+		return 1;
+	else
+		return 0;
+}
+
+static inline void env_rwsem_up_write(env_rwsem *s)
+{
+	pthread_rwlock_unlock(&s->lock);
+}
+
+static inline void env_rwsem_down_write(env_rwsem *s)
+{
+	pthread_rwlock_wrlock(&s->lock);
+}
+
+static inline int env_rwsem_down_write_trylock(env_rwsem *s)
+{
+	int result = pthread_rwlock_trywrlock(&s->lock);
+
+	if (result == 0)
+		return 1;
+	else
+		return 0;
+}
+
+static inline int env_rwsem_is_locked(env_rwsem *s)
+{
+	if (env_rwsem_down_read_trylock(s)) {
+		env_rwsem_up_read(s);
+		return 0;
+	}
+
+	return 1;
+}
+
+static inline int env_rwsem_down_write_interruptible(env_rwsem *s)
+{
+	env_rwsem_down_write(s);
+	return 0;
+}
+
+static inline int env_rwsem_down_read_interruptible(env_rwsem *s)
+{
+	env_rwsem_down_read(s);
+	return 0;
+}
+
+/* *** COMPLETION *** */
+struct completion {
+	sem_t sem;
+};
+
+typedef struct completion env_completion;
+
+static inline void env_completion_init(env_completion *completion)
+{
+	sem_init(&completion->sem, 0, 0);
+}
+
+static inline void env_completion_wait(env_completion *completion)
+{
+	sem_wait(&completion->sem);
+}
+
+static inline void env_completion_complete(env_completion *completion)
+{
+	sem_post(&completion->sem);
+}
+
+static inline void env_completion_complete_and_exit(
+		env_completion *completion, int ret)
+{
+	env_completion_complete(completion); /* TODO */
+}
+
+/* *** ATOMIC VARIABLES *** */
+
+typedef struct {
+	volatile int counter;
+} env_atomic;
+
+typedef struct {
+	volatile long counter;
+} env_atomic64;
+
+static inline int env_atomic_read(const env_atomic *a)
+{
+	return a->counter; /* TODO */
+}
+
+static inline void env_atomic_set(env_atomic *a, int i)
+{
+	a->counter = i; /* TODO */
+}
+
+static inline void env_atomic_add(int i, env_atomic *a)
+{
+	__sync_add_and_fetch(&a->counter, i);
+}
+
+static inline void env_atomic_sub(int i, env_atomic *a)
+{
+	__sync_sub_and_fetch(&a->counter, i);
+}
+
+static inline bool env_atomic_sub_and_test(int i, env_atomic *a)
+{
+	return __sync_sub_and_fetch(&a->counter, i) == 0;
+}
+
+static inline void env_atomic_inc(env_atomic *a)
+{
+	env_atomic_add(1, a);
+}
+
+static inline void env_atomic_dec(env_atomic *a)
+{
+	env_atomic_sub(1, a);
+}
+
+static inline bool env_atomic_dec_and_test(env_atomic *a)
+{
+	return __sync_sub_and_fetch(&a->counter, 1) == 0;
+}
+
+static inline bool env_atomic_inc_and_test(env_atomic *a)
+{
+	return __sync_add_and_fetch(&a->counter, 1) == 0;
+}
+
+static inline int env_atomic_add_return(int i, env_atomic *a)
+{
+	return __sync_add_and_fetch(&a->counter, i);
+}
+
+static inline int env_atomic_sub_return(int i, env_atomic *a)
+{
+	return __sync_sub_and_fetch(&a->counter, i);
+}
+
+static inline int env_atomic_inc_return(env_atomic *a)
+{
+	return env_atomic_add_return(1, a);
+}
+
+static inline int env_atomic_dec_return(env_atomic *a)
+{
+	return env_atomic_sub_return(1, a);
+}
+
+static inline int env_atomic_cmpxchg(env_atomic *a, int old, int new_value)
+{
+	return __sync_val_compare_and_swap(&a->counter, old, new_value);
+}
+
+static inline int env_atomic_add_unless(env_atomic *a, int i, int u)
+{
+	int c, old;
+	c = env_atomic_read(a);
+	for (;;) {
+		if (unlikely(c == (u)))
+			break;
+		old = env_atomic_cmpxchg((a), c, c + (i));
+		if (likely(old == c))
+			break;
+		c = old;
+	}
+	return c != (u);
+}
+
+static inline long env_atomic64_read(const env_atomic64 *a)
+{
+	return a->counter; /* TODO */
+}
+
+static inline void env_atomic64_set(env_atomic64 *a, long i)
+{
+	a->counter = i; /* TODO */
+}
+
+static inline void env_atomic64_add(long i, env_atomic64 *a)
+{
+	__sync_add_and_fetch(&a->counter, i);
+}
+
+static inline void env_atomic64_sub(long i, env_atomic64 *a)
+{
+	__sync_sub_and_fetch(&a->counter, i);
+}
+
+static inline void env_atomic64_inc(env_atomic64 *a)
+{
+	env_atomic64_add(1, a);
+}
+
+static inline void env_atomic64_dec(env_atomic64 *a)
+{
+	env_atomic64_sub(1, a);
+}
+
+static inline long env_atomic64_cmpxchg(env_atomic64 *a, long old, long new)
+{
+	return __sync_val_compare_and_swap(&a->counter, old, new);
+}
+
+/* *** SPIN LOCKS *** */
+
+typedef struct {
+	pthread_spinlock_t lock;
+} env_spinlock;
+
+static inline void env_spinlock_init(env_spinlock *l)
+{
+	pthread_spin_init(&l->lock, 0);
+}
+
+static inline void env_spinlock_lock(env_spinlock *l)
+{
+	pthread_spin_lock(&l->lock);
+}
+
+static inline void env_spinlock_unlock(env_spinlock *l)
+{
+	pthread_spin_unlock(&l->lock);
+}
+
+static inline void env_spinlock_lock_irq(env_spinlock *l)
+{
+	env_spinlock_lock(l);
+}
+
+static inline void env_spinlock_unlock_irq(env_spinlock *l)
+{
+	env_spinlock_unlock(l);
+}
+
+#define env_spinlock_lock_irqsave(l, flags) \
+		(void)flags; \
+		env_spinlock_lock(l)
+
+#define env_spinlock_unlock_irqrestore(l, flags) \
+		(void)flags; \
+		env_spinlock_unlock(l)
+
+/* *** RW LOCKS *** */
+
+typedef struct {
+	pthread_rwlock_t lock;
+} env_rwlock;
+
+static inline void env_rwlock_init(env_rwlock *l)
+{
+	pthread_rwlock_init(&l->lock, NULL);
+}
+
+static inline void env_rwlock_read_lock(env_rwlock *l)
+{
+	pthread_rwlock_rdlock(&l->lock);
+}
+
+static inline void env_rwlock_read_unlock(env_rwlock *l)
+{
+	pthread_rwlock_unlock(&l->lock);
+}
+
+static inline void env_rwlock_write_lock(env_rwlock *l)
+{
+	pthread_rwlock_wrlock(&l->lock);
+}
+
+static inline void env_rwlock_write_unlock(env_rwlock *l)
+{
+	pthread_rwlock_unlock(&l->lock);
+}
+
+/* *** WAITQUEUE *** */
+
+typedef struct {
+	sem_t sem;
+} env_waitqueue;
+
+static inline void env_waitqueue_init(env_waitqueue *w)
+{
+	sem_init(&w->sem, 0, 0);
+}
+
+static inline void env_waitqueue_wake_up(env_waitqueue *w)
+{
+	sem_post(&w->sem);
+}
+
+#define env_waitqueue_wait(w, condition)	\
+({						\
+	int __ret = 0;				\
+	if (!(condition))			\
+		sem_wait(&w.sem);		\
+	__ret = __ret;				\
+})
+
+/* *** BIT OPERATIONS *** */
+
+static inline void env_bit_set(int nr, volatile void *addr)
+{
+	char *byte = (char *)addr + (nr >> 3);
+	char mask = 1 << (nr & 7);
+
+	__sync_or_and_fetch(byte, mask);
+}
+
+static inline void env_bit_clear(int nr, volatile void *addr)
+{
+	char *byte = (char *)addr + (nr >> 3);
+	char mask = 1 << (nr & 7);
+
+	mask = ~mask;
+	__sync_and_and_fetch(byte, mask);
+}
+
+static inline bool env_bit_test(int nr, const volatile unsigned long *addr)
+{
+	const char *byte = (char *)addr + (nr >> 3);
+	char mask = 1 << (nr & 7);
+
+	return !!(*byte & mask);
+}
+
+/* *** SCHEDULING *** */
+static inline void env_schedule(void)
+{
+	sched_yield();
+}
+
+static inline int env_in_interrupt(void)
+{
+	return 0;
+}
+
+/* TODO(mwysocza): Is this really needed? */
+static inline void env_touch_lockup_watchdog(void)
+{
+}
+
+static inline uint64_t env_get_tick_count(void)
+{
+	struct timeval tv;
+	gettimeofday(&tv, NULL);
+	return tv.tv_sec * 1000 + tv.tv_usec / 1000;
+}
+
+static inline uint64_t env_ticks_to_msecs(uint64_t j)
+{
+	return j;
+}
+
+static inline uint64_t env_ticks_to_secs(uint64_t j)
+{
+	return j / 1000;
+}
+
+static inline uint64_t env_secs_to_ticks(uint64_t j)
+{
+	return j * 1000;
+}
+
+/* *** SORTING *** */
+
+static inline void env_sort(void *base, size_t num, size_t size,
+		int (*cmp_fn)(const void *, const void *),
+		void (*swap_fn)(void *, void *, int size))
+{
+	qsort(base, num, size, cmp_fn);
+}
+
+/* *** STRING OPERATIONS *** */
+#define env_memset(dest, dmax, val) ({ \
+		memset(dest, val, dmax); \
+		0; \
+	})
+#define env_memcpy(dest, dmax, src, slen) ({ \
+		memcpy(dest, src, min(dmax, slen)); \
+		0; \
+	})
+#define env_memcmp(s1, s1max, s2, s2max, diff) ({ \
+		*diff = memcmp(s1, s2, min(s1max, s2max)); \
+		0; \
+	})
+#define env_strdup strndup
+#define env_strnlen(s, smax) strnlen(s, smax)
+#define env_strncmp strncmp
+#define env_strncpy(dest, dmax, src, slen) ({ \
+		strncpy(dest, src, min(dmax, slen)); \
+		0; \
+	})
+/* *** DEBUGING *** */
+
+#define ENV_WARN(cond, fmt...)		printf(fmt)
+#define ENV_WARN_ON(cond)		;
+#define ENV_WARN_ONCE(cond, fmt...)	ENV_WARN(cond, fmt)
+
+#define ENV_BUG()			assert(0)
+#define ENV_BUG_ON(cond)		assert(!(cond))
+
+#define container_of(ptr, type, member) ({          \
+	const typeof(((type *)0)->member)*__mptr = (ptr);    \
+	(type *)((char *)__mptr - offsetof(type, member)); })
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
+
+static inline void env_msleep(uint64_t n)
+{
+	usleep(n * 1000);
+}
+
+struct env_timeval {
+	uint64_t sec, usec;
+};
+
+static inline void env_gettimeofday(struct env_timeval *tv)
+{
+	struct timeval t;
+	gettimeofday(&t, NULL);
+	tv->sec = t.tv_sec;
+	tv->usec = t.tv_usec;
+}
+
+uint32_t env_crc32(uint32_t crc, uint8_t const *data, size_t len);
+
+#define ENV_PRIu64 "lu"
+
+#endif /* __OCF_ENV_H__ */

env/posix/ocf_env_headers.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright(c) 2019 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause-Clear
+ */
+
+#ifndef __OCF_ENV_HEADERS_H__
+#define __OCF_ENV_HEADERS_H__
+
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+
+/* TODO: Move prefix printing to context logger. */
+#define OCF_LOGO "Intel(R) OCF"
+#define OCF_PREFIX_SHORT "[" OCF_LOGO "] "
+#define OCF_PREFIX_LONG "Open CAS Framework"
+
+#define OCF_VERSION_MAIN 1
+#define OCF_VERSION_MAJOR 1
+#define OCF_VERSION_MINOR 1
+
+#endif /* __OCF_ENV_HEADERS_H__ */

env/posix/ocf_env_list.h

@@ -0,0 +1,168 @@
+/*
+ * Copyright(c) 2019 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause-Clear
+ */
+
+#ifndef __OCF_ENV_LIST__
+#define __OCF_ENV_LIST__
+
+#define LIST_POISON1  ((void *)0x101)
+#define LIST_POISON2  ((void *)0x202)
+
+/**
+ * List entry structure mimicking linux kernel based one.
+ */
+struct list_head {
+	struct list_head *next;
+	struct list_head *prev;
+};
+
+/**
+ * start an empty list
+ */
+#define INIT_LIST_HEAD(l) { (l)->prev = l; (l)->next = l; }
+
+/**
+ * Add item to list head.
+ * @param it list entry to be added
+ * @param l1 list main node (head)
+ */
+static inline void list_add(struct list_head *it, struct list_head *l1)
+{
+	it->prev = l1;
+	it->next = l1->next;
+
+	l1->next->prev = it;
+	l1->next = it;
+}
+
+/**
+ * Add item it to tail.
+ * @param it list entry to be added
+ * @param l1 list main node (head)
+ */
+static inline void list_add_tail(struct list_head *it, struct list_head *l1)
+{
+	it->prev = l1->prev;
+	it->next = l1;
+
+	l1->prev->next = it;
+	l1->prev = it;
+}
+
+/**
+ * check if a list is empty (return true)
+ * @param l1 list main node (head)
+ */
+static inline int list_empty(struct list_head *l1)
+{
+	return l1->next == l1;
+}
+
+/**
+ * delete an entry from a list
+ * @param it list entry to be deleted
+ */
+static inline void list_del(struct list_head *it)
+{
+	it->next->prev = it->prev;
+	it->prev->next = it->next;
+}
+
+/**
+ * Move element to list head.
+ * @param it list entry to be moved
+ * @param l1 list main node (head)
+ */
+static inline void list_move(struct list_head *it, struct list_head *l1)
+{
+	list_del(it);
+	list_add(it, l1);
+}
+
+/**
+ * Move element to list tail.
+ * @param it list entry to be moved
+ * @param l1 list main node (head)
+ */
+static inline void list_move_tail(struct list_head *it, struct list_head *l1)
+{
+	list_del(it);
+	list_add_tail(it, l1);
+}
+
+/**
+ * Extract an entry.
+ * @param list_head_i list head item, from which entry is extracted
+ * @param item_type type (struct) of list entry
+ * @param field_name name of list_head field within item_type
+ */
+#define list_entry(list_head_i, item_type, field_name) \
+	(item_type *)(((void*)(list_head_i)) - offsetof(item_type, field_name))
+
+#define list_first_entry(list_head_i, item_type, field_name) \
+	list_entry((list_head_i)->next, item_type, field_name)
+
+/**
+ * @param iterator uninitialized list_head pointer, to be used as iterator
+ * @param plist list head (main node)
+ */
+#define list_for_each(iterator, plist) \
+	for (iterator = (plist)->next; \
+	     (iterator)->next != (plist)->next; \
+	     iterator = (iterator)->next)
+
+/**
+ * Safe version of list_for_each which works even if entries are deleted during
+ * loop.
+ * @param iterator uninitialized list_head pointer, to be used as iterator
+ * @param q another uninitialized list_head, used as helper
+ * @param plist list head (main node)
+ */
+/*
+ * Algorithm handles situation, where q is deleted.
+ * consider in example 3 element list with header h:
+ *
+ *   h -> 1 -> 2 -> 3 ->
+ *1.      i    q
+ *
+ *2.           i    q
+ *
+ *3. q              i
+ */
+#define list_for_each_safe(iterator, q, plist) \
+	for (iterator = (q = (plist)->next->next)->prev; \
+	     (q) != (plist)->next; \
+	     iterator = (q = (q)->next)->prev)
+
+#define _list_entry_helper(item, head, field_name) \
+		list_entry(head, typeof(*item), field_name)
+
+/**
+ * Iterate over list entries.
+ * @param list pointer to list item (iterator)
+ * @param plist pointer to list_head item
+ * @param field_name name of list_head field in list entry
+ */
+#define list_for_each_entry(item, plist, field_name) \
+	for (item = _list_entry_helper(item, (plist)->next, field_name); \
+	     _list_entry_helper(item, (item)->field_name.next, field_name) !=\
+		     _list_entry_helper(item, (plist)->next, field_name); \
+	     item = _list_entry_helper(item, (item)->field_name.next, field_name))
+
+/**
+ * Safe version of list_for_each_entry which works even if entries are deleted
+ * during loop.
+ * @param list pointer to list item (iterator)
+ * @param q another pointer to list item, used as helper
+ * @param plist pointer to list_head item
+ * @param field_name name of list_head field in list entry
+ */
+#define list_for_each_entry_safe(item, q, plist, field_name)		\
+	for (item = _list_entry_helper(item, (plist)->next, field_name), \
+	     q = _list_entry_helper(item, (item)->field_name.next, field_name); \
+	     _list_entry_helper(item, (item)->field_name.next, field_name) != \
+		     _list_entry_helper(item, (plist)->next, field_name); \
+	     item = q, q = _list_entry_helper(q, (q)->field_name.next, field_name))
+
+#endif // __OCF_ENV_LIST__