[fio.git] / smalloc.c

/*
 * simple memory allocator, backed by mmap() so that it hands out memory
 * that can be shared across processes and threads
 */
#include <sys/mman.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <unistd.h>
#include <inttypes.h>
#include <sys/types.h>
#include <limits.h>
#include <fcntl.h>

#include "mutex.h"
#include "arch/arch.h"
#include "os/os.h"
#include "smalloc.h"
#include "log.h"

#define SMALLOC_REDZONE		/* define to detect memory corruption */

#define SMALLOC_BPB	32	/* block size, bytes-per-bit in bitmap */
#define SMALLOC_BPI	(sizeof(unsigned int) * 8)
#define SMALLOC_BPL	(SMALLOC_BPB * SMALLOC_BPI)

#define INITIAL_SIZE	16*1024*1024	/* new pool size */
#define MAX_POOLS	8		/* maximum number of pools to setup */

#define SMALLOC_PRE_RED		0xdeadbeefU
#define SMALLOC_POST_RED	0x5aa55aa5U

unsigned int smalloc_pool_size = INITIAL_SIZE;
#ifdef SMALLOC_REDZONE
static const int int_mask = sizeof(int) - 1;
#endif

struct pool {
	struct fio_mutex *lock;			/* protects this pool */
	void *map;				/* map of blocks */
	unsigned int *bitmap;			/* blocks free/busy map */
	size_t free_blocks;		/* free blocks */
	size_t nr_blocks;			/* total blocks */
	size_t next_non_full;
	size_t mmap_size;
};

struct block_hdr {
	size_t size;
#ifdef SMALLOC_REDZONE
	unsigned int prered;
#endif
};

static struct pool mp[MAX_POOLS];
static unsigned int nr_pools;
static unsigned int last_pool;

static inline int ptr_valid(struct pool *pool, void *ptr)
{
	unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;

	return (ptr >= pool->map) && (ptr < pool->map + pool_size);
}

static inline size_t size_to_blocks(size_t size)
{
	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
}

static int blocks_iter(struct pool *pool, unsigned int pool_idx,
		       unsigned int idx, size_t nr_blocks,
		       int (*func)(unsigned int *map, unsigned int mask))
{

	while (nr_blocks) {
		unsigned int this_blocks, mask;
		unsigned int *map;

		if (pool_idx >= pool->nr_blocks)
			return 0;

		map = &pool->bitmap[pool_idx];

		this_blocks = nr_blocks;
		if (this_blocks + idx > SMALLOC_BPI) {
			this_blocks = SMALLOC_BPI - idx;
			idx = SMALLOC_BPI - this_blocks;
		}

		if (this_blocks == SMALLOC_BPI)
			mask = -1U;
		else
			mask = ((1U << this_blocks) - 1) << idx;

		if (!func(map, mask))
			return 0;

		nr_blocks -= this_blocks;
		idx = 0;
		pool_idx++;
	}

	return 1;
}

static int mask_cmp(unsigned int *map, unsigned int mask)
{
	return !(*map & mask);
}

static int mask_clear(unsigned int *map, unsigned int mask)
{
	assert((*map & mask) == mask);
	*map &= ~mask;
	return 1;
}

static int mask_set(unsigned int *map, unsigned int mask)
{
	assert(!(*map & mask));
	*map |= mask;
	return 1;
}

static int blocks_free(struct pool *pool, unsigned int pool_idx,
		       unsigned int idx, size_t nr_blocks)
{
	return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
}

static void set_blocks(struct pool *pool, unsigned int pool_idx,
		       unsigned int idx, size_t nr_blocks)
{
	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
}

static void clear_blocks(struct pool *pool, unsigned int pool_idx,
			 unsigned int idx, size_t nr_blocks)
{
	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
}

static int find_next_zero(int word, int start)
{
	assert(word != -1U);
	word >>= start;
	return ffz(word) + start;
}

static int add_pool(struct pool *pool, unsigned int alloc_size)
{
	int bitmap_blocks;
	int mmap_flags;
	void *ptr;

#ifdef SMALLOC_REDZONE
	alloc_size += sizeof(unsigned int);
#endif
	alloc_size += sizeof(struct block_hdr);
	if (alloc_size < INITIAL_SIZE)
		alloc_size = INITIAL_SIZE;

	/* round up to nearest full number of blocks */
	alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
	bitmap_blocks = alloc_size / SMALLOC_BPL;
	alloc_size += bitmap_blocks * sizeof(unsigned int);
	pool->mmap_size = alloc_size;

	pool->nr_blocks = bitmap_blocks;
	pool->free_blocks = bitmap_blocks * SMALLOC_BPB;

	mmap_flags = OS_MAP_ANON;
#ifdef CONFIG_ESX
	mmap_flags |= MAP_PRIVATE;
#else
	mmap_flags |= MAP_SHARED;
#endif
	ptr = mmap(NULL, alloc_size, PROT_READ|PROT_WRITE, mmap_flags, -1, 0);

	if (ptr == MAP_FAILED)
		goto out_fail;

	pool->map = ptr;
	pool->bitmap = (void *) ptr + (pool->nr_blocks * SMALLOC_BPL);
	memset(pool->bitmap, 0, bitmap_blocks * sizeof(unsigned int));

	pool->lock = fio_mutex_init(FIO_MUTEX_UNLOCKED);
	if (!pool->lock)
		goto out_fail;

	nr_pools++;
	return 0;
out_fail:
	log_err("smalloc: failed adding pool\n");
	if (pool->map)
		munmap(pool->map, pool->mmap_size);
	return 1;
}

void sinit(void)
{
	int i, ret;

	for (i = 0; i < MAX_POOLS; i++) {
		ret = add_pool(&mp[i], smalloc_pool_size);
		if (ret)
			break;
	}

	/*
	 * If we added at least one pool, we should be OK for most
	 * cases.
	 */
	assert(i);
}

static void cleanup_pool(struct pool *pool)
{
	/*
	 * This will also remove the temporary file we used as a backing
	 * store, it was already unlinked
	 */
	munmap(pool->map, pool->mmap_size);

	if (pool->lock)
		fio_mutex_remove(pool->lock);
}

void scleanup(void)
{
	unsigned int i;

	for (i = 0; i < nr_pools; i++)
		cleanup_pool(&mp[i]);
}

#ifdef SMALLOC_REDZONE
static void *postred_ptr(struct block_hdr *hdr)
{
	uintptr_t ptr;

	ptr = (uintptr_t) hdr + hdr->size - sizeof(unsigned int);
	ptr = (ptr + int_mask) & ~int_mask;

	return (void *) ptr;
}

static void fill_redzone(struct block_hdr *hdr)
{
	unsigned int *postred = postred_ptr(hdr);

	hdr->prered = SMALLOC_PRE_RED;
	*postred = SMALLOC_POST_RED;
}

static void sfree_check_redzone(struct block_hdr *hdr)
{
	unsigned int *postred = postred_ptr(hdr);

	if (hdr->prered != SMALLOC_PRE_RED) {
		log_err("smalloc pre redzone destroyed!\n"
			" ptr=%p, prered=%x, expected %x\n",
				hdr, hdr->prered, SMALLOC_PRE_RED);
		assert(0);
	}
	if (*postred != SMALLOC_POST_RED) {
		log_err("smalloc post redzone destroyed!\n"
			"  ptr=%p, postred=%x, expected %x\n",
				hdr, *postred, SMALLOC_POST_RED);
		assert(0);
	}
}
#else
static void fill_redzone(struct block_hdr *hdr)
{
}

static void sfree_check_redzone(struct block_hdr *hdr)
{
}
#endif

static void sfree_pool(struct pool *pool, void *ptr)
{
	struct block_hdr *hdr;
	unsigned int i, idx;
	unsigned long offset;

	if (!ptr)
		return;

	ptr -= sizeof(*hdr);
	hdr = ptr;

	assert(ptr_valid(pool, ptr));

	sfree_check_redzone(hdr);

	offset = ptr - pool->map;
	i = offset / SMALLOC_BPL;
	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;

	fio_mutex_down(pool->lock);
	clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
	if (i < pool->next_non_full)
		pool->next_non_full = i;
	pool->free_blocks += size_to_blocks(hdr->size);
	fio_mutex_up(pool->lock);
}

void sfree(void *ptr)
{
	struct pool *pool = NULL;
	unsigned int i;

	if (!ptr)
		return;

	for (i = 0; i < nr_pools; i++) {
		if (ptr_valid(&mp[i], ptr)) {
			pool = &mp[i];
			break;
		}
	}

	if (pool) {
		sfree_pool(pool, ptr);
		return;
	}

	log_err("smalloc: ptr %p not from smalloc pool\n", ptr);
}

static void *__smalloc_pool(struct pool *pool, size_t size)
{
	size_t nr_blocks;
	unsigned int i;
	unsigned int offset;
	unsigned int last_idx;
	void *ret = NULL;

	fio_mutex_down(pool->lock);

	nr_blocks = size_to_blocks(size);
	if (nr_blocks > pool->free_blocks)
		goto fail;

	i = pool->next_non_full;
	last_idx = 0;
	offset = -1U;
	while (i < pool->nr_blocks) {
		unsigned int idx;

		if (pool->bitmap[i] == -1U) {
			i++;
			pool->next_non_full = i;
			last_idx = 0;
			continue;
		}

		idx = find_next_zero(pool->bitmap[i], last_idx);
		if (!blocks_free(pool, i, idx, nr_blocks)) {
			idx += nr_blocks;
			if (idx < SMALLOC_BPI)
				last_idx = idx;
			else {
				last_idx = 0;
				while (idx >= SMALLOC_BPI) {
					i++;
					idx -= SMALLOC_BPI;
				}
			}
			continue;
		}
		set_blocks(pool, i, idx, nr_blocks);
		offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
		break;
	}

	if (i < pool->nr_blocks) {
		pool->free_blocks -= nr_blocks;
		ret = pool->map + offset;
	}
fail:
	fio_mutex_up(pool->lock);
	return ret;
}

static void *smalloc_pool(struct pool *pool, size_t size)
{
	size_t alloc_size = size + sizeof(struct block_hdr);
	void *ptr;

	/*
	 * Round to int alignment, so that the postred pointer will
	 * be naturally aligned as well.
	 */
#ifdef SMALLOC_REDZONE
	alloc_size += sizeof(unsigned int);
	alloc_size = (alloc_size + int_mask) & ~int_mask;
#endif

	ptr = __smalloc_pool(pool, alloc_size);
	if (ptr) {
		struct block_hdr *hdr = ptr;

		hdr->size = alloc_size;
		fill_redzone(hdr);

		ptr += sizeof(*hdr);
		memset(ptr, 0, size);
	}

	return ptr;
}

void *smalloc(size_t size)
{
	unsigned int i, end_pool;

	if (size != (unsigned int) size)
		return NULL;

	i = last_pool;
	end_pool = nr_pools;

	do {
		for (; i < end_pool; i++) {
			void *ptr = smalloc_pool(&mp[i], size);

			if (ptr) {
				last_pool = i;
				return ptr;
			}
		}
		if (last_pool) {
			end_pool = last_pool;
			last_pool = i = 0;
			continue;
		}

		break;
	} while (1);

	return NULL;
}

void *scalloc(size_t nmemb, size_t size)
{
	return smalloc(nmemb * size);
}

char *smalloc_strdup(const char *str)
{
	char *ptr = NULL;

	ptr = smalloc(strlen(str) + 1);
	if (ptr)
		strcpy(ptr, str);
	return ptr;
}
Commit	Line	Data
	1	/*
	2	* simple memory allocator, backed by mmap() so that it hands out memory
	3	* that can be shared across processes and threads
	4	*/
	5	#include <sys/mman.h>
	6	#include <stdio.h>
	7	#include <stdlib.h>
	8	#include <assert.h>
	9	#include <string.h>
	10	#include <unistd.h>
	11	#include <inttypes.h>
	12	#include <sys/types.h>
	13	#include <limits.h>
	14	#include <fcntl.h>
	15
	16	#include "mutex.h"
	17	#include "arch/arch.h"
	18	#include "os/os.h"
	19	#include "smalloc.h"
	20	#include "log.h"
	21
	22	#define SMALLOC_REDZONE /* define to detect memory corruption */
	23
	24	#define SMALLOC_BPB 32 /* block size, bytes-per-bit in bitmap */
	25	#define SMALLOC_BPI (sizeof(unsigned int) * 8)
	26	#define SMALLOC_BPL (SMALLOC_BPB * SMALLOC_BPI)
	27
	28	#define INITIAL_SIZE 1610241024 /* new pool size */
	29	#define MAX_POOLS 8 /* maximum number of pools to setup */
	30
	31	#define SMALLOC_PRE_RED 0xdeadbeefU
	32	#define SMALLOC_POST_RED 0x5aa55aa5U
	33
	34	unsigned int smalloc_pool_size = INITIAL_SIZE;
	35	#ifdef SMALLOC_REDZONE
	36	static const int int_mask = sizeof(int) - 1;
	37	#endif
	38
	39	struct pool {
	40	struct fio_mutex lock; / protects this pool */
	41	void map; / map of blocks */
	42	unsigned int bitmap; / blocks free/busy map */
	43	size_t free_blocks; /* free blocks */
	44	size_t nr_blocks; /* total blocks */
	45	size_t next_non_full;
	46	size_t mmap_size;
	47	};
	48
	49	struct block_hdr {
	50	size_t size;
	51	#ifdef SMALLOC_REDZONE
	52	unsigned int prered;
	53	#endif
	54	};
	55
	56	static struct pool mp[MAX_POOLS];
	57	static unsigned int nr_pools;
	58	static unsigned int last_pool;
	59
	60	static inline int ptr_valid(struct pool pool, void ptr)
	61	{
	62	unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;
	63
	64	return (ptr >= pool->map) && (ptr < pool->map + pool_size);
	65	}
	66
	67	static inline size_t size_to_blocks(size_t size)
	68	{
	69	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
	70	}
	71
	72	static int blocks_iter(struct pool *pool, unsigned int pool_idx,
	73	unsigned int idx, size_t nr_blocks,
	74	int (func)(unsigned int map, unsigned int mask))
	75	{
	76
	77	while (nr_blocks) {
	78	unsigned int this_blocks, mask;
	79	unsigned int *map;
	80
	81	if (pool_idx >= pool->nr_blocks)
	82	return 0;
	83
	84	map = &pool->bitmap[pool_idx];
	85
	86	this_blocks = nr_blocks;
	87	if (this_blocks + idx > SMALLOC_BPI) {
	88	this_blocks = SMALLOC_BPI - idx;
	89	idx = SMALLOC_BPI - this_blocks;
	90	}
	91
	92	if (this_blocks == SMALLOC_BPI)
	93	mask = -1U;
	94	else
	95	mask = ((1U << this_blocks) - 1) << idx;
	96
	97	if (!func(map, mask))
	98	return 0;
	99
	100	nr_blocks -= this_blocks;
	101	idx = 0;
	102	pool_idx++;
	103	}
	104
	105	return 1;
	106	}
	107
	108	static int mask_cmp(unsigned int *map, unsigned int mask)
	109	{
	110	return !(*map & mask);
	111	}
	112
	113	static int mask_clear(unsigned int *map, unsigned int mask)
	114	{
	115	assert((*map & mask) == mask);
	116	*map &= ~mask;
	117	return 1;
	118	}
	119
	120	static int mask_set(unsigned int *map, unsigned int mask)
	121	{
	122	assert(!(*map & mask));
	123	*map \|= mask;
	124	return 1;
	125	}
	126
	127	static int blocks_free(struct pool *pool, unsigned int pool_idx,
	128	unsigned int idx, size_t nr_blocks)
	129	{
	130	return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
	131	}
	132
	133	static void set_blocks(struct pool *pool, unsigned int pool_idx,
	134	unsigned int idx, size_t nr_blocks)
	135	{
	136	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
	137	}
	138
	139	static void clear_blocks(struct pool *pool, unsigned int pool_idx,
	140	unsigned int idx, size_t nr_blocks)
	141	{
	142	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
	143	}
	144
	145	static int find_next_zero(int word, int start)
	146	{
	147	assert(word != -1U);
	148	word >>= start;
	149	return ffz(word) + start;
	150	}
	151
	152	static int add_pool(struct pool *pool, unsigned int alloc_size)
	153	{
	154	int bitmap_blocks;
	155	int mmap_flags;
	156	void *ptr;
	157
	158	#ifdef SMALLOC_REDZONE
	159	alloc_size += sizeof(unsigned int);
	160	#endif
	161	alloc_size += sizeof(struct block_hdr);
	162	if (alloc_size < INITIAL_SIZE)
	163	alloc_size = INITIAL_SIZE;
	164
	165	/* round up to nearest full number of blocks */
	166	alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
	167	bitmap_blocks = alloc_size / SMALLOC_BPL;
	168	alloc_size += bitmap_blocks * sizeof(unsigned int);
	169	pool->mmap_size = alloc_size;
	170
	171	pool->nr_blocks = bitmap_blocks;
	172	pool->free_blocks = bitmap_blocks * SMALLOC_BPB;
	173
	174	mmap_flags = OS_MAP_ANON;
	175	#ifdef CONFIG_ESX
	176	mmap_flags \|= MAP_PRIVATE;
	177	#else
	178	mmap_flags \|= MAP_SHARED;
	179	#endif
	180	ptr = mmap(NULL, alloc_size, PROT_READ\|PROT_WRITE, mmap_flags, -1, 0);
	181
	182	if (ptr == MAP_FAILED)
	183	goto out_fail;
	184
	185	pool->map = ptr;
	186	pool->bitmap = (void ) ptr + (pool->nr_blocks SMALLOC_BPL);
	187	memset(pool->bitmap, 0, bitmap_blocks * sizeof(unsigned int));
	188
	189	pool->lock = fio_mutex_init(FIO_MUTEX_UNLOCKED);
	190	if (!pool->lock)
	191	goto out_fail;
	192
	193	nr_pools++;
	194	return 0;
	195	out_fail:
	196	log_err("smalloc: failed adding pool\n");
	197	if (pool->map)
	198	munmap(pool->map, pool->mmap_size);
	199	return 1;
	200	}
	201
	202	void sinit(void)
	203	{
	204	int i, ret;
	205
	206	for (i = 0; i < MAX_POOLS; i++) {
	207	ret = add_pool(&mp[i], smalloc_pool_size);
	208	if (ret)
	209	break;
	210	}
	211
	212	/*
	213	* If we added at least one pool, we should be OK for most
	214	* cases.
	215	*/
	216	assert(i);
	217	}
	218
	219	static void cleanup_pool(struct pool *pool)
	220	{
	221	/*
	222	* This will also remove the temporary file we used as a backing
	223	* store, it was already unlinked
	224	*/
	225	munmap(pool->map, pool->mmap_size);
	226
	227	if (pool->lock)
	228	fio_mutex_remove(pool->lock);
	229	}
	230
	231	void scleanup(void)
	232	{
	233	unsigned int i;
	234
	235	for (i = 0; i < nr_pools; i++)
	236	cleanup_pool(&mp[i]);
	237	}
	238
	239	#ifdef SMALLOC_REDZONE
	240	static void postred_ptr(struct block_hdr hdr)
	241	{
	242	uintptr_t ptr;
	243
	244	ptr = (uintptr_t) hdr + hdr->size - sizeof(unsigned int);
	245	ptr = (ptr + int_mask) & ~int_mask;
	246
	247	return (void *) ptr;
	248	}
	249
	250	static void fill_redzone(struct block_hdr *hdr)
	251	{
	252	unsigned int *postred = postred_ptr(hdr);
	253
	254	hdr->prered = SMALLOC_PRE_RED;
	255	*postred = SMALLOC_POST_RED;
	256	}
	257
	258	static void sfree_check_redzone(struct block_hdr *hdr)
	259	{
	260	unsigned int *postred = postred_ptr(hdr);
	261
	262	if (hdr->prered != SMALLOC_PRE_RED) {
	263	log_err("smalloc pre redzone destroyed!\n"
	264	" ptr=%p, prered=%x, expected %x\n",
	265	hdr, hdr->prered, SMALLOC_PRE_RED);
	266	assert(0);
	267	}
	268	if (*postred != SMALLOC_POST_RED) {
	269	log_err("smalloc post redzone destroyed!\n"
	270	" ptr=%p, postred=%x, expected %x\n",
	271	hdr, *postred, SMALLOC_POST_RED);
	272	assert(0);
	273	}
	274	}
	275	#else
	276	static void fill_redzone(struct block_hdr *hdr)
	277	{
	278	}
	279
	280	static void sfree_check_redzone(struct block_hdr *hdr)
	281	{
	282	}
	283	#endif
	284
	285	static void sfree_pool(struct pool pool, void ptr)
	286	{
	287	struct block_hdr *hdr;
	288	unsigned int i, idx;
	289	unsigned long offset;
	290
	291	if (!ptr)
	292	return;
	293
	294	ptr -= sizeof(*hdr);
	295	hdr = ptr;
	296
	297	assert(ptr_valid(pool, ptr));
	298
	299	sfree_check_redzone(hdr);
	300
	301	offset = ptr - pool->map;
	302	i = offset / SMALLOC_BPL;
	303	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;
	304
	305	fio_mutex_down(pool->lock);
	306	clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
	307	if (i < pool->next_non_full)
	308	pool->next_non_full = i;
	309	pool->free_blocks += size_to_blocks(hdr->size);
	310	fio_mutex_up(pool->lock);
	311	}
	312
	313	void sfree(void *ptr)
	314	{
	315	struct pool *pool = NULL;
	316	unsigned int i;
	317
	318	if (!ptr)
	319	return;
	320
	321	for (i = 0; i < nr_pools; i++) {
	322	if (ptr_valid(&mp[i], ptr)) {
	323	pool = &mp[i];
	324	break;
	325	}
	326	}
	327
	328	if (pool) {
	329	sfree_pool(pool, ptr);
	330	return;
	331	}
	332
	333	log_err("smalloc: ptr %p not from smalloc pool\n", ptr);
	334	}
	335
	336	static void __smalloc_pool(struct pool pool, size_t size)
	337	{
	338	size_t nr_blocks;
	339	unsigned int i;
	340	unsigned int offset;
	341	unsigned int last_idx;
	342	void *ret = NULL;
	343
	344	fio_mutex_down(pool->lock);
	345
	346	nr_blocks = size_to_blocks(size);
	347	if (nr_blocks > pool->free_blocks)
	348	goto fail;
	349
	350	i = pool->next_non_full;
	351	last_idx = 0;
	352	offset = -1U;
	353	while (i < pool->nr_blocks) {
	354	unsigned int idx;
	355
	356	if (pool->bitmap[i] == -1U) {
	357	i++;
	358	pool->next_non_full = i;
	359	last_idx = 0;
	360	continue;
	361	}
	362
	363	idx = find_next_zero(pool->bitmap[i], last_idx);
	364	if (!blocks_free(pool, i, idx, nr_blocks)) {
	365	idx += nr_blocks;
	366	if (idx < SMALLOC_BPI)
	367	last_idx = idx;
	368	else {
	369	last_idx = 0;
	370	while (idx >= SMALLOC_BPI) {
	371	i++;
	372	idx -= SMALLOC_BPI;
	373	}
	374	}
	375	continue;
	376	}
	377	set_blocks(pool, i, idx, nr_blocks);
	378	offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
	379	break;
	380	}
	381
	382	if (i < pool->nr_blocks) {
	383	pool->free_blocks -= nr_blocks;
	384	ret = pool->map + offset;
	385	}
	386	fail:
	387	fio_mutex_up(pool->lock);
	388	return ret;
	389	}
	390
	391	static void smalloc_pool(struct pool pool, size_t size)
	392	{
	393	size_t alloc_size = size + sizeof(struct block_hdr);
	394	void *ptr;
	395
	396	/*
	397	* Round to int alignment, so that the postred pointer will
	398	* be naturally aligned as well.
	399	*/
	400	#ifdef SMALLOC_REDZONE
	401	alloc_size += sizeof(unsigned int);
	402	alloc_size = (alloc_size + int_mask) & ~int_mask;
	403	#endif
	404
	405	ptr = __smalloc_pool(pool, alloc_size);
	406	if (ptr) {
	407	struct block_hdr *hdr = ptr;
	408
	409	hdr->size = alloc_size;
	410	fill_redzone(hdr);
	411
	412	ptr += sizeof(*hdr);
	413	memset(ptr, 0, size);
	414	}
	415
	416	return ptr;
	417	}
	418
	419	void *smalloc(size_t size)
	420	{
	421	unsigned int i, end_pool;
	422
	423	if (size != (unsigned int) size)
	424	return NULL;
	425
	426	i = last_pool;
	427	end_pool = nr_pools;
	428
	429	do {
	430	for (; i < end_pool; i++) {
	431	void *ptr = smalloc_pool(&mp[i], size);
	432
	433	if (ptr) {
	434	last_pool = i;
	435	return ptr;
	436	}
	437	}
	438	if (last_pool) {
	439	end_pool = last_pool;
	440	last_pool = i = 0;
	441	continue;
	442	}
	443
	444	break;
	445	} while (1);
	446
	447	return NULL;
	448	}
	449
	450	void *scalloc(size_t nmemb, size_t size)
	451	{
	452	return smalloc(nmemb * size);
	453	}
	454
	455	char smalloc_strdup(const char str)
	456	{
	457	char *ptr = NULL;
	458
	459	ptr = smalloc(strlen(str) + 1);
	460	if (ptr)
	461	strcpy(ptr, str);
	462	return ptr;
	463	}