verify.c - platform/external/fio - Gitiles

 /*
  * IO verification helpers
  */
 #include <unistd.h>
 #include <fcntl.h>
 #include <string.h>
 #include <assert.h>
 #include <pthread.h>

 #include "fio.h"
 #include "verify.h"
 #include "smalloc.h"

 #include "crc/md5.h"
 #include "crc/crc64.h"
 #include "crc/crc32.h"
 #include "crc/crc32c.h"
 #include "crc/crc16.h"
 #include "crc/crc7.h"
 #include "crc/sha256.h"
 #include "crc/sha512.h"
 #include "crc/sha1.h"

 static void fill_random_bytes(struct thread_data *td, void *p, unsigned int len)
 {
 	unsigned int todo;
 	int r;

 	while (len) {
 		r = os_random_long(&td->verify_state);

 		/*
 		 * lrand48_r seems to be broken and only fill the bottom
 		 * 32-bits, even on 64-bit archs with 64-bit longs
 		 */
 		todo = sizeof(r);
 		if (todo > len)
 			todo = len;

 		memcpy(p, &r, todo);

 		len -= todo;
 		p += todo;
 	}
 }

 static void fill_pattern(struct thread_data *td, void *p, unsigned int len)
 {
 	switch (td->o.verify_pattern_bytes) {
 	case 0:
 		dprint(FD_VERIFY, "fill random bytes len=%u\n", len);
 		fill_random_bytes(td, p, len);
 		break;
 	case 1:
 		dprint(FD_VERIFY, "fill verify pattern b=0 len=%u\n", len);
 		memset(p, td->o.verify_pattern[0], len);
 		break;
 	default: {
 		unsigned int i = 0, size = 0;
 		unsigned char *b = p;

 		dprint(FD_VERIFY, "fill verify pattern b=%d len=%u\n",
 					td->o.verify_pattern_bytes, len);

 		while (i < len) {
 			size = td->o.verify_pattern_bytes;
 			if (size > (len - i))
 				size = len - i;
 			memcpy(b+i, td->o.verify_pattern, size);
 			i += size;
 		}
 		break;
 		}
 	}
 }

 static void memswp(void *buf1, void *buf2, unsigned int len)
 {
 	char swap[200];

 	assert(len <= sizeof(swap));

 	memcpy(&swap, buf1, len);
 	memcpy(buf1, buf2, len);
 	memcpy(buf2, &swap, len);
 }

 static void hexdump(void *buffer, int len)
 {
 	unsigned char *p = buffer;
 	int i;

 	for (i = 0; i < len; i++)
 		log_info("%02x", p[i]);
 	log_info("\n");
 }

 /*
  * Prepare for seperation of verify_header and checksum header
  */
 static inline unsigned int __hdr_size(int verify_type)
 {
 	unsigned int len = len;

 	switch (verify_type) {
 	case VERIFY_NONE:
 	case VERIFY_NULL:
 		len = 0;
 		break;
 	case VERIFY_MD5:
 		len = sizeof(struct vhdr_md5);
 		break;
 	case VERIFY_CRC64:
 		len = sizeof(struct vhdr_crc64);
 		break;
 	case VERIFY_CRC32C:
 	case VERIFY_CRC32:
 	case VERIFY_CRC32C_INTEL:
 		len = sizeof(struct vhdr_crc32);
 		break;
 	case VERIFY_CRC16:
 		len = sizeof(struct vhdr_crc16);
 		break;
 	case VERIFY_CRC7:
 		len = sizeof(struct vhdr_crc7);
 		break;
 	case VERIFY_SHA256:
 		len = sizeof(struct vhdr_sha256);
 		break;
 	case VERIFY_SHA512:
 		len = sizeof(struct vhdr_sha512);
 		break;
 	case VERIFY_META:
 		len = sizeof(struct vhdr_meta);
 		break;
 	case VERIFY_SHA1:
 		len = sizeof(struct vhdr_sha1);
 		break;
 	default:
 		log_err("fio: unknown verify header!\n");
 		assert(0);
 	}

 	return len + sizeof(struct verify_header);
 }

 static inline unsigned int hdr_size(struct verify_header *hdr)
 {
 	return __hdr_size(hdr->verify_type);
 }

 static void *hdr_priv(struct verify_header *hdr)
 {
 	void *priv = hdr;

 	return priv + sizeof(struct verify_header);
 }

 /*
  * Return data area 'header_num'
  */
 static inline void *io_u_verify_off(struct verify_header *hdr,
 				    struct io_u *io_u, unsigned int header_num)
 {
 	return io_u->buf + header_num * hdr->len + hdr_size(hdr);
 }

 static int verify_io_u_meta(struct verify_header *hdr, struct thread_data *td,
 			    struct io_u *io_u, unsigned int header_num)
 {
 	struct vhdr_meta *vh = hdr_priv(hdr);

 	dprint(FD_VERIFY, "meta verify io_u %p, len %u\n", io_u, hdr->len);

 	if (vh->offset != io_u->offset + header_num * td->o.verify_interval) {
 		log_err("meta: verify failed at %llu/%u\n",
 				io_u->offset + header_num * hdr->len, hdr->len);
 		return EILSEQ;
 	}

 	return 0;
 }

 static int verify_io_u_sha512(struct verify_header *hdr, struct io_u *io_u,
 			      unsigned int header_num)
 {
 	void *p = io_u_verify_off(hdr, io_u, header_num);
 	struct vhdr_sha512 *vh = hdr_priv(hdr);
 	uint8_t sha512[128];
 	struct sha512_ctx sha512_ctx = {
 		.buf = sha512,
 	};

 	dprint(FD_VERIFY, "sha512 verify io_u %p, len %u\n", io_u, hdr->len);

 	sha512_init(&sha512_ctx);
 	sha512_update(&sha512_ctx, p, hdr->len - hdr_size(hdr));

 	if (memcmp(vh->sha512, sha512_ctx.buf, sizeof(sha512))) {
 		log_err("sha512: verify failed at %llu/%u\n",
 				io_u->offset + header_num * hdr->len, hdr->len);
 		hexdump(vh->sha512, sizeof(vh->sha512));
 		hexdump(sha512_ctx.buf, sizeof(sha512));
 		return EILSEQ;
 	}

 	return 0;
 }

 static int verify_io_u_sha256(struct verify_header *hdr, struct io_u *io_u,
 			      unsigned int header_num)
 {
 	void *p = io_u_verify_off(hdr, io_u, header_num);
 	struct vhdr_sha256 *vh = hdr_priv(hdr);
 	uint8_t sha256[64];
 	struct sha256_ctx sha256_ctx = {
 		.buf = sha256,
 	};

 	dprint(FD_VERIFY, "sha256 verify io_u %p, len %u\n", io_u, hdr->len);

 	sha256_init(&sha256_ctx);
 	sha256_update(&sha256_ctx, p, hdr->len - hdr_size(hdr));

 	if (memcmp(vh->sha256, sha256_ctx.buf, sizeof(sha256))) {
 		log_err("sha256: verify failed at %llu/%u\n",
 				io_u->offset + header_num * hdr->len, hdr->len);
 		hexdump(vh->sha256, sizeof(vh->sha256));
 		hexdump(sha256_ctx.buf, sizeof(sha256));
 		return EILSEQ;
 	}

 	return 0;
 }

 static int verify_io_u_sha1(struct verify_header *hdr, struct io_u *io_u,
 			    unsigned int header_num)
 {
 	void *p = io_u_verify_off(hdr, io_u, header_num);
 	struct vhdr_sha1 *vh = hdr_priv(hdr);
 	uint32_t sha1[5];
 	struct sha1_ctx sha1_ctx = {
 		.H = sha1,
 	};

 	dprint(FD_VERIFY, "sha1 verify io_u %p, len %u\n", io_u, hdr->len);

 	sha1_init(&sha1_ctx);
 	sha1_update(&sha1_ctx, p, hdr->len - hdr_size(hdr));

 	if (memcmp(vh->sha1, sha1_ctx.H, sizeof(sha1))) {
 		log_err("sha1: verify failed at %llu/%u\n",
 				io_u->offset + header_num * hdr->len, hdr->len);
 		hexdump(vh->sha1, sizeof(vh->sha1));
 		hexdump(sha1_ctx.H, sizeof(sha1));
 		return EILSEQ;
 	}

 	return 0;
 }

 static int verify_io_u_crc7(struct verify_header *hdr, struct io_u *io_u,
 			    unsigned int header_num)
 {
 	void *p = io_u_verify_off(hdr, io_u, header_num);
 	struct vhdr_crc7 *vh = hdr_priv(hdr);
 	unsigned char c;

 	dprint(FD_VERIFY, "crc7 verify io_u %p, len %u\n", io_u, hdr->len);

 	c = crc7(p, hdr->len - hdr_size(hdr));

 	if (c != vh->crc7) {
 		log_err("crc7: verify failed at %llu/%u\n",
 				io_u->offset + header_num * hdr->len, hdr->len);
 		log_err("crc7: wanted %x, got %x\n", vh->crc7, c);
 		return EILSEQ;
 	}

 	return 0;
 }

 static int verify_io_u_crc16(struct verify_header *hdr, struct io_u *io_u,
 			     unsigned int header_num)
 {
 	void *p = io_u_verify_off(hdr, io_u, header_num);
 	struct vhdr_crc16 *vh = hdr_priv(hdr);
 	unsigned short c;

 	dprint(FD_VERIFY, "crc16 verify io_u %p, len %u\n", io_u, hdr->len);

 	c = crc16(p, hdr->len - hdr_size(hdr));

 	if (c != vh->crc16) {
 		log_err("crc16: verify failed at %llu/%u\n",
 				io_u->offset + header_num * hdr->len, hdr->len);
 		log_err("crc16: wanted %x, got %x\n", vh->crc16, c);
 		return EILSEQ;
 	}

 	return 0;
 }

 static int verify_io_u_crc64(struct verify_header *hdr, struct io_u *io_u,
 			     unsigned int header_num)
 {
 	void *p = io_u_verify_off(hdr, io_u, header_num);
 	struct vhdr_crc64 *vh = hdr_priv(hdr);
 	unsigned long long c;

 	dprint(FD_VERIFY, "crc64 verify io_u %p, len %u\n", io_u, hdr->len);

 	c = crc64(p, hdr->len - hdr_size(hdr));

 	if (c != vh->crc64) {
 		log_err("crc64: verify failed at %llu/%u\n",
 				io_u->offset + header_num * hdr->len,
 				hdr->len);
 		log_err("crc64: wanted %llx, got %llx\n",
 					(unsigned long long) vh->crc64, c);
 		return EILSEQ;
 	}

 	return 0;
 }

 static int verify_io_u_crc32(struct verify_header *hdr, struct io_u *io_u,
 			     unsigned int header_num)
 {
 	void *p = io_u_verify_off(hdr, io_u, header_num);
 	struct vhdr_crc32 *vh = hdr_priv(hdr);
 	uint32_t c;

 	dprint(FD_VERIFY, "crc32 verify io_u %p, len %u\n", io_u, hdr->len);

 	c = crc32(p, hdr->len - hdr_size(hdr));

 	if (c != vh->crc32) {
 		log_err("crc32: verify failed at %llu/%u\n",
 				io_u->offset + header_num * hdr->len, hdr->len);
 		log_err("crc32: wanted %x, got %x\n", vh->crc32, c);
 		return EILSEQ;
 	}

 	return 0;
 }

 static int verify_io_u_crc32c(struct verify_header *hdr, struct io_u *io_u,
 			      unsigned int header_num)
 {
 	void *p = io_u_verify_off(hdr, io_u, header_num);
 	struct vhdr_crc32 *vh = hdr_priv(hdr);
 	uint32_t c;

 	dprint(FD_VERIFY, "crc32c verify io_u %p, len %u\n", io_u, hdr->len);

 	if (hdr->verify_type == VERIFY_CRC32C_INTEL)
 		c = crc32c_intel(p, hdr->len - hdr_size(hdr));
 	else
 		c = crc32c(p, hdr->len - hdr_size(hdr));

 	if (c != vh->crc32) {
 		log_err("crc32c: verify failed at %llu/%u\n",
 				io_u->offset + header_num * hdr->len, hdr->len);
 		log_err("crc32c: wanted %x, got %x\n", vh->crc32, c);
 		return EILSEQ;
 	}

 	return 0;
 }

 static int verify_io_u_md5(struct verify_header *hdr, struct io_u *io_u,
 			   unsigned int header_num)
 {
 	void *p = io_u_verify_off(hdr, io_u, header_num);
 	struct vhdr_md5 *vh = hdr_priv(hdr);
 	uint32_t hash[MD5_HASH_WORDS];
 	struct md5_ctx md5_ctx = {
 		.hash = hash,
 	};

 	dprint(FD_VERIFY, "md5 verify io_u %p, len %u\n", io_u, hdr->len);

 	md5_init(&md5_ctx);
 	md5_update(&md5_ctx, p, hdr->len - hdr_size(hdr));

 	if (memcmp(vh->md5_digest, md5_ctx.hash, sizeof(hash))) {
 		log_err("md5: verify failed at %llu/%u\n",
 				io_u->offset + header_num * hdr->len, hdr->len);
 		hexdump(vh->md5_digest, sizeof(vh->md5_digest));
 		hexdump(md5_ctx.hash, sizeof(hash));
 		return EILSEQ;
 	}

 	return 0;
 }

 static unsigned int hweight8(unsigned int w)
 {
 	unsigned int res = w - ((w >> 1) & 0x55);

 	res = (res & 0x33) + ((res >> 2) & 0x33);
 	return (res + (res >> 4)) & 0x0F;
 }

 int verify_io_u_pattern(char *pattern, unsigned long pattern_size,
 			char *buf, unsigned int len, unsigned int mod)
 {
 	unsigned int i;

 	for (i = 0; i < len; i++) {
 		if (buf[i] != pattern[mod]) {
 			unsigned int bits;

 			bits = hweight8(buf[i] ^ pattern[mod]);
 			log_err("fio: got pattern %x, wanted %x. Bad bits %d\n",
 				buf[i], pattern[mod], bits);
 			log_err("fio: bad pattern block offset %u\n", i);
 			return EILSEQ;
 		}
 		mod++;
 		if (mod == pattern_size)
 			mod = 0;
 	}

 	return 0;
 }

 /*
  * Push IO verification to a separate thread
  */
 int verify_io_u_async(struct thread_data *td, struct io_u *io_u)
 {
 	if (io_u->file)
 		put_file_log(td, io_u->file);

 	io_u->file = NULL;

 	pthread_mutex_lock(&td->io_u_lock);

 	if (io_u->flags & IO_U_F_IN_CUR_DEPTH) {
 		td->cur_depth--;
 		io_u->flags &= ~IO_U_F_IN_CUR_DEPTH;
 	}
 	flist_del(&io_u->list);
 	flist_add_tail(&io_u->list, &td->verify_list);
 	io_u->flags |= IO_U_F_FREE_DEF;
 	pthread_mutex_unlock(&td->io_u_lock);

 	pthread_cond_signal(&td->verify_cond);
 	return 0;
 }

 int verify_io_u(struct thread_data *td, struct io_u *io_u)
 {
 	struct verify_header *hdr;
 	unsigned int hdr_size, hdr_inc, hdr_num = 0;
 	void *p;
 	int ret;

 	if (td->o.verify == VERIFY_NULL || io_u->ddir != DDIR_READ)
 		return 0;

 	hdr_inc = io_u->buflen;
 	if (td->o.verify_interval)
 		hdr_inc = td->o.verify_interval;

 	ret = 0;
 	for (p = io_u->buf; p < io_u->buf + io_u->buflen;
 	     p += hdr_inc, hdr_num++) {
 		if (ret && td->o.verify_fatal) {
 			td->terminate = 1;
 			break;
 		}
 		hdr_size = __hdr_size(td->o.verify);
 		if (td->o.verify_offset)
 			memswp(p, p + td->o.verify_offset, hdr_size);
 		hdr = p;

 		if (hdr->fio_magic != FIO_HDR_MAGIC) {
 			log_err("Bad verify header %x at %llu\n",
 					hdr->fio_magic,
 					io_u->offset + hdr_num * hdr->len);
 			return EILSEQ;
 		}

 		if (td->o.verify_pattern_bytes) {
 			dprint(FD_VERIFY, "pattern verify io_u %p, len %u\n",
 								io_u, hdr->len);
 			ret = verify_io_u_pattern(td->o.verify_pattern,
 				  td->o.verify_pattern_bytes,
 				  p + hdr_size,
 				  hdr_inc - hdr_size,
 				  hdr_size % td->o.verify_pattern_bytes);
 			/*
 			 * Also verify the meta data, if applicable
 			 */
 			if (hdr->verify_type == VERIFY_META)
 				ret |= verify_io_u_meta(hdr, td, io_u, hdr_num);

 			if (ret)
 				log_err("fio: verify failed at %llu/%u\n",
 					io_u->offset + hdr_num * hdr->len,
 					hdr->len);
 			continue;
 		}

 		switch (hdr->verify_type) {
 		case VERIFY_MD5:
 			ret = verify_io_u_md5(hdr, io_u, hdr_num);
 			break;
 		case VERIFY_CRC64:
 			ret = verify_io_u_crc64(hdr, io_u, hdr_num);
 			break;
 		case VERIFY_CRC32C:
 		case VERIFY_CRC32C_INTEL:
 			ret = verify_io_u_crc32c(hdr, io_u, hdr_num);
 			break;
 		case VERIFY_CRC32:
 			ret = verify_io_u_crc32(hdr, io_u, hdr_num);
 			break;
 		case VERIFY_CRC16:
 			ret = verify_io_u_crc16(hdr, io_u, hdr_num);
 			break;
 		case VERIFY_CRC7:
 			ret = verify_io_u_crc7(hdr, io_u, hdr_num);
 			break;
 		case VERIFY_SHA256:
 			ret = verify_io_u_sha256(hdr, io_u, hdr_num);
 			break;
 		case VERIFY_SHA512:
 			ret = verify_io_u_sha512(hdr, io_u, hdr_num);
 			break;
 		case VERIFY_META:
 			ret = verify_io_u_meta(hdr, td, io_u, hdr_num);
 			break;
 		case VERIFY_SHA1:
 			ret = verify_io_u_sha1(hdr, io_u, hdr_num);
 			break;
 		default:
 			log_err("Bad verify type %u\n", hdr->verify_type);
 			ret = EINVAL;
 		}
 	}

 	return ret;
 }

 static void fill_meta(struct verify_header *hdr, struct thread_data *td,
 		      struct io_u *io_u, unsigned int header_num)
 {
 	struct vhdr_meta *vh = hdr_priv(hdr);

 	vh->thread = td->thread_number;

 	vh->time_sec = io_u->start_time.tv_sec;
 	vh->time_usec = io_u->start_time.tv_usec;

 	vh->numberio = td->io_issues[DDIR_WRITE];

 	vh->offset = io_u->offset + header_num * td->o.verify_interval;
 }

 static void fill_sha512(struct verify_header *hdr, void *p, unsigned int len)
 {
 	struct vhdr_sha512 *vh = hdr_priv(hdr);
 	struct sha512_ctx sha512_ctx = {
 		.buf = vh->sha512,
 	};

 	sha512_init(&sha512_ctx);
 	sha512_update(&sha512_ctx, p, len);
 }

 static void fill_sha256(struct verify_header *hdr, void *p, unsigned int len)
 {
 	struct vhdr_sha256 *vh = hdr_priv(hdr);
 	struct sha256_ctx sha256_ctx = {
 		.buf = vh->sha256,
 	};

 	sha256_init(&sha256_ctx);
 	sha256_update(&sha256_ctx, p, len);
 }

 static void fill_sha1(struct verify_header *hdr, void *p, unsigned int len)
 {
 	struct vhdr_sha1 *vh = hdr_priv(hdr);
 	struct sha1_ctx sha1_ctx = {
 		.H = vh->sha1,
 	};

 	sha1_init(&sha1_ctx);
 	sha1_update(&sha1_ctx, p, len);
 }

 static void fill_crc7(struct verify_header *hdr, void *p, unsigned int len)
 {
 	struct vhdr_crc7 *vh = hdr_priv(hdr);

 	vh->crc7 = crc7(p, len);
 }

 static void fill_crc16(struct verify_header *hdr, void *p, unsigned int len)
 {
 	struct vhdr_crc16 *vh = hdr_priv(hdr);

 	vh->crc16 = crc16(p, len);
 }

 static void fill_crc32(struct verify_header *hdr, void *p, unsigned int len)
 {
 	struct vhdr_crc32 *vh = hdr_priv(hdr);

 	vh->crc32 = crc32(p, len);
 }

 static void fill_crc32c(struct verify_header *hdr, void *p, unsigned int len)
 {
 	struct vhdr_crc32 *vh = hdr_priv(hdr);

 	if (hdr->verify_type == VERIFY_CRC32C_INTEL)
 		vh->crc32 = crc32c_intel(p, len);
 	else
 		vh->crc32 = crc32c(p, len);
 }

 static void fill_crc64(struct verify_header *hdr, void *p, unsigned int len)
 {
 	struct vhdr_crc64 *vh = hdr_priv(hdr);

 	vh->crc64 = crc64(p, len);
 }

 static void fill_md5(struct verify_header *hdr, void *p, unsigned int len)
 {
 	struct vhdr_md5 *vh = hdr_priv(hdr);
 	struct md5_ctx md5_ctx = {
 		.hash = (uint32_t *) vh->md5_digest,
 	};

 	md5_init(&md5_ctx);
 	md5_update(&md5_ctx, p, len);
 }

 /*
  * fill body of io_u->buf with random data and add a header with the
  * crc32 or md5 sum of that data.
  */
 void populate_verify_io_u(struct thread_data *td, struct io_u *io_u)
 {
 	struct verify_header *hdr;
 	void *p = io_u->buf, *data;
 	unsigned int hdr_inc, data_len, header_num = 0;

 	if (td->o.verify == VERIFY_NULL)
 		return;

 	fill_pattern(td, p, io_u->buflen);

 	hdr_inc = io_u->buflen;
 	if (td->o.verify_interval)
 		hdr_inc = td->o.verify_interval;

 	for (; p < io_u->buf + io_u->buflen; p += hdr_inc) {
 		hdr = p;

 		hdr->fio_magic = FIO_HDR_MAGIC;
 		hdr->verify_type = td->o.verify;
 		hdr->len = hdr_inc;
 		data_len = hdr_inc - hdr_size(hdr);

 		data = p + hdr_size(hdr);
 		switch (td->o.verify) {
 		case VERIFY_MD5:
 			dprint(FD_VERIFY, "fill md5 io_u %p, len %u\n",
 							io_u, hdr->len);
 			fill_md5(hdr, data, data_len);
 			break;
 		case VERIFY_CRC64:
 			dprint(FD_VERIFY, "fill crc64 io_u %p, len %u\n",
 							io_u, hdr->len);
 			fill_crc64(hdr, data, data_len);
 			break;
 		case VERIFY_CRC32C:
 		case VERIFY_CRC32C_INTEL:
 			dprint(FD_VERIFY, "fill crc32c io_u %p, len %u\n",
 							io_u, hdr->len);
 			fill_crc32c(hdr, data, data_len);
 			break;
 		case VERIFY_CRC32:
 			dprint(FD_VERIFY, "fill crc32 io_u %p, len %u\n",
 							io_u, hdr->len);
 			fill_crc32(hdr, data, data_len);
 			break;
 		case VERIFY_CRC16:
 			dprint(FD_VERIFY, "fill crc16 io_u %p, len %u\n",
 							io_u, hdr->len);
 			fill_crc16(hdr, data, data_len);
 			break;
 		case VERIFY_CRC7:
 			dprint(FD_VERIFY, "fill crc7 io_u %p, len %u\n",
 							io_u, hdr->len);
 			fill_crc7(hdr, data, data_len);
 			break;
 		case VERIFY_SHA256:
 			dprint(FD_VERIFY, "fill sha256 io_u %p, len %u\n",
 							io_u, hdr->len);
 			fill_sha256(hdr, data, data_len);
 			break;
 		case VERIFY_SHA512:
 			dprint(FD_VERIFY, "fill sha512 io_u %p, len %u\n",
 							io_u, hdr->len);
 			fill_sha512(hdr, data, data_len);
 			break;
 		case VERIFY_META:
 			dprint(FD_VERIFY, "fill meta io_u %p, len %u\n",
 							io_u, hdr->len);
 			fill_meta(hdr, td, io_u, header_num);
 			break;
 		case VERIFY_SHA1:
 			dprint(FD_VERIFY, "fill sha1 io_u %p, len %u\n",
 							io_u, hdr->len);
 			fill_sha1(hdr, data, data_len);
 			break;
 		default:
 			log_err("fio: bad verify type: %d\n", td->o.verify);
 			assert(0);
 		}
 		if (td->o.verify_offset)
 			memswp(p, p + td->o.verify_offset, hdr_size(hdr));
 		header_num++;
 	}
 }

 int get_next_verify(struct thread_data *td, struct io_u *io_u)
 {
 	struct io_piece *ipo = NULL;

 	/*
 	 * this io_u is from a requeue, we already filled the offsets
 	 */
 	if (io_u->file)
 		return 0;

 	if (!RB_EMPTY_ROOT(&td->io_hist_tree)) {
 		struct rb_node *n = rb_first(&td->io_hist_tree);

 		ipo = rb_entry(n, struct io_piece, rb_node);
 		rb_erase(n, &td->io_hist_tree);
 		td->io_hist_len--;
 	} else if (!flist_empty(&td->io_hist_list)) {
 		ipo = flist_entry(td->io_hist_list.next, struct io_piece, list);
 		td->io_hist_len--;
 		flist_del(&ipo->list);
 	}

 	if (ipo) {
 		io_u->offset = ipo->offset;
 		io_u->buflen = ipo->len;
 		io_u->file = ipo->file;

 		if (!fio_file_open(io_u->file)) {
 			int r = td_io_open_file(td, io_u->file);

 			if (r) {
 				dprint(FD_VERIFY, "failed file %s open\n",
 						io_u->file->file_name);
 				return 1;
 			}
 		}

 		get_file(ipo->file);
 		assert(fio_file_open(io_u->file));
 		io_u->ddir = DDIR_READ;
 		io_u->xfer_buf = io_u->buf;
 		io_u->xfer_buflen = io_u->buflen;
 		free(ipo);
 		dprint(FD_VERIFY, "get_next_verify: ret io_u %p\n", io_u);
 		return 0;
 	}

 	dprint(FD_VERIFY, "get_next_verify: empty\n");
 	return 1;
 }

 static void *verify_async_thread(void *data)
 {
 	struct thread_data *td = data;
 	struct io_u *io_u;
 	int ret = 0;

 	if (td->o.verify_cpumask_set &&
 	    fio_setaffinity(td->pid, td->o.verify_cpumask)) {
 		log_err("fio: failed setting verify thread affinity\n");
 		goto done;
 	}

 	do {
 		FLIST_HEAD(list);

 		read_barrier();
 		if (td->verify_thread_exit)
 			break;

 		pthread_mutex_lock(&td->io_u_lock);

 		while (flist_empty(&td->verify_list) &&
 		       !td->verify_thread_exit) {
 			ret = pthread_cond_wait(&td->verify_cond,
 							&td->io_u_lock);
 			if (ret) {
 				pthread_mutex_unlock(&td->io_u_lock);
 				break;
 			}
 		}

 		flist_splice_init(&td->verify_list, &list);
 		pthread_mutex_unlock(&td->io_u_lock);

 		if (flist_empty(&list))
 			continue;

 		while (!flist_empty(&list)) {
 			io_u = flist_entry(list.next, struct io_u, list);
 			flist_del_init(&io_u->list);

 			ret = verify_io_u(td, io_u);
 			put_io_u(td, io_u);
 			if (!ret)
 				continue;
 			if (td->o.continue_on_error &&
 			    td_non_fatal_error(ret)) {
 				update_error_count(td, ret);
 				td_clear_error(td);
 				ret = 0;
 			}
 		}
 	} while (!ret);

 	if (ret) {
 		td_verror(td, ret, "async_verify");
 		td->terminate = 1;
 	}

 done:
 	pthread_mutex_lock(&td->io_u_lock);
 	td->nr_verify_threads--;
 	pthread_mutex_unlock(&td->io_u_lock);

 	pthread_cond_signal(&td->free_cond);
 	return NULL;
 }

 int verify_async_init(struct thread_data *td)
 {
 	int i, ret;

 	td->verify_thread_exit = 0;

 	td->verify_threads = malloc(sizeof(pthread_t) * td->o.verify_async);
 	for (i = 0; i < td->o.verify_async; i++) {
 		ret = pthread_create(&td->verify_threads[i], NULL,
 					verify_async_thread, td);
 		if (ret) {
 			log_err("fio: async verify creation failed: %s\n",
 					strerror(ret));
 			break;
 		}
 		ret = pthread_detach(td->verify_threads[i]);
 		if (ret) {
 			log_err("fio: async verify thread detach failed: %s\n",
 					strerror(ret));
 			break;
 		}
 		td->nr_verify_threads++;
 	}

 	if (i != td->o.verify_async) {
 		log_err("fio: only %d verify threads started, exiting\n", i);
 		td->verify_thread_exit = 1;
 		write_barrier();
 		pthread_cond_broadcast(&td->verify_cond);
 		return 1;
 	}

 	return 0;
 }

 void verify_async_exit(struct thread_data *td)
 {
 	td->verify_thread_exit = 1;
 	write_barrier();
 	pthread_cond_broadcast(&td->verify_cond);

 	pthread_mutex_lock(&td->io_u_lock);

 	while (td->nr_verify_threads)
 		pthread_cond_wait(&td->free_cond, &td->io_u_lock);

 	pthread_mutex_unlock(&td->io_u_lock);
 	free(td->verify_threads);
 	td->verify_threads = NULL;
 }
	/*
	* IO verification helpers
	*/
	#include <unistd.h>
	#include <fcntl.h>
	#include <string.h>
	#include <assert.h>
	#include <pthread.h>

	#include "fio.h"
	#include "verify.h"
	#include "smalloc.h"

	#include "crc/md5.h"
	#include "crc/crc64.h"
	#include "crc/crc32.h"
	#include "crc/crc32c.h"
	#include "crc/crc16.h"
	#include "crc/crc7.h"
	#include "crc/sha256.h"
	#include "crc/sha512.h"
	#include "crc/sha1.h"

	static void fill_random_bytes(struct thread_data td, void p, unsigned int len)
	{
	unsigned int todo;
	int r;

	while (len) {
	r = os_random_long(&td->verify_state);

	/*
	* lrand48_r seems to be broken and only fill the bottom
	* 32-bits, even on 64-bit archs with 64-bit longs
	*/
	todo = sizeof(r);
	if (todo > len)
	todo = len;

	memcpy(p, &r, todo);

	len -= todo;
	p += todo;
	}
	}

	static void fill_pattern(struct thread_data td, void p, unsigned int len)
	{
	switch (td->o.verify_pattern_bytes) {
	case 0:
	dprint(FD_VERIFY, "fill random bytes len=%u\n", len);
	fill_random_bytes(td, p, len);
	break;
	case 1:
	dprint(FD_VERIFY, "fill verify pattern b=0 len=%u\n", len);
	memset(p, td->o.verify_pattern[0], len);
	break;
	default: {
	unsigned int i = 0, size = 0;
	unsigned char *b = p;

	dprint(FD_VERIFY, "fill verify pattern b=%d len=%u\n",
	td->o.verify_pattern_bytes, len);

	while (i < len) {
	size = td->o.verify_pattern_bytes;
	if (size > (len - i))
	size = len - i;
	memcpy(b+i, td->o.verify_pattern, size);
	i += size;
	}
	break;
	}
	}
	}

	static void memswp(void buf1, void buf2, unsigned int len)
	{
	char swap[200];

	assert(len <= sizeof(swap));

	memcpy(&swap, buf1, len);
	memcpy(buf1, buf2, len);
	memcpy(buf2, &swap, len);
	}

	static void hexdump(void *buffer, int len)
	{
	unsigned char *p = buffer;
	int i;

	for (i = 0; i < len; i++)
	log_info("%02x", p[i]);
	log_info("\n");
	}

	/*
	* Prepare for seperation of verify_header and checksum header
	*/
	static inline unsigned int __hdr_size(int verify_type)
	{
	unsigned int len = len;

	switch (verify_type) {
	case VERIFY_NONE:
	case VERIFY_NULL:
	len = 0;
	break;
	case VERIFY_MD5:
	len = sizeof(struct vhdr_md5);
	break;
	case VERIFY_CRC64:
	len = sizeof(struct vhdr_crc64);
	break;
	case VERIFY_CRC32C:
	case VERIFY_CRC32:
	case VERIFY_CRC32C_INTEL:
	len = sizeof(struct vhdr_crc32);
	break;
	case VERIFY_CRC16:
	len = sizeof(struct vhdr_crc16);
	break;
	case VERIFY_CRC7:
	len = sizeof(struct vhdr_crc7);
	break;
	case VERIFY_SHA256:
	len = sizeof(struct vhdr_sha256);
	break;
	case VERIFY_SHA512:
	len = sizeof(struct vhdr_sha512);
	break;
	case VERIFY_META:
	len = sizeof(struct vhdr_meta);
	break;
	case VERIFY_SHA1:
	len = sizeof(struct vhdr_sha1);
	break;
	default:
	log_err("fio: unknown verify header!\n");
	assert(0);
	}

	return len + sizeof(struct verify_header);
	}

	static inline unsigned int hdr_size(struct verify_header *hdr)
	{
	return __hdr_size(hdr->verify_type);
	}

	static void hdr_priv(struct verify_header hdr)
	{
	void *priv = hdr;

	return priv + sizeof(struct verify_header);
	}

	/*
	* Return data area 'header_num'
	*/
	static inline void io_u_verify_off(struct verify_header hdr,
	struct io_u *io_u, unsigned int header_num)
	{
	return io_u->buf + header_num * hdr->len + hdr_size(hdr);
	}

	static int verify_io_u_meta(struct verify_header hdr, struct thread_data td,
	struct io_u *io_u, unsigned int header_num)
	{
	struct vhdr_meta *vh = hdr_priv(hdr);

	dprint(FD_VERIFY, "meta verify io_u %p, len %u\n", io_u, hdr->len);

	if (vh->offset != io_u->offset + header_num * td->o.verify_interval) {
	log_err("meta: verify failed at %llu/%u\n",
	io_u->offset + header_num * hdr->len, hdr->len);
	return EILSEQ;
	}

	return 0;
	}

	static int verify_io_u_sha512(struct verify_header hdr, struct io_u io_u,
	unsigned int header_num)
	{
	void *p = io_u_verify_off(hdr, io_u, header_num);
	struct vhdr_sha512 *vh = hdr_priv(hdr);
	uint8_t sha512[128];
	struct sha512_ctx sha512_ctx = {
	.buf = sha512,
	};

	dprint(FD_VERIFY, "sha512 verify io_u %p, len %u\n", io_u, hdr->len);

	sha512_init(&sha512_ctx);
	sha512_update(&sha512_ctx, p, hdr->len - hdr_size(hdr));

	if (memcmp(vh->sha512, sha512_ctx.buf, sizeof(sha512))) {
	log_err("sha512: verify failed at %llu/%u\n",
	io_u->offset + header_num * hdr->len, hdr->len);
	hexdump(vh->sha512, sizeof(vh->sha512));
	hexdump(sha512_ctx.buf, sizeof(sha512));
	return EILSEQ;
	}

	return 0;
	}

	static int verify_io_u_sha256(struct verify_header hdr, struct io_u io_u,
	unsigned int header_num)
	{
	void *p = io_u_verify_off(hdr, io_u, header_num);
	struct vhdr_sha256 *vh = hdr_priv(hdr);
	uint8_t sha256[64];
	struct sha256_ctx sha256_ctx = {
	.buf = sha256,
	};

	dprint(FD_VERIFY, "sha256 verify io_u %p, len %u\n", io_u, hdr->len);

	sha256_init(&sha256_ctx);
	sha256_update(&sha256_ctx, p, hdr->len - hdr_size(hdr));

	if (memcmp(vh->sha256, sha256_ctx.buf, sizeof(sha256))) {
	log_err("sha256: verify failed at %llu/%u\n",
	io_u->offset + header_num * hdr->len, hdr->len);
	hexdump(vh->sha256, sizeof(vh->sha256));
	hexdump(sha256_ctx.buf, sizeof(sha256));
	return EILSEQ;
	}

	return 0;
	}

	static int verify_io_u_sha1(struct verify_header hdr, struct io_u io_u,
	unsigned int header_num)
	{
	void *p = io_u_verify_off(hdr, io_u, header_num);
	struct vhdr_sha1 *vh = hdr_priv(hdr);
	uint32_t sha1[5];
	struct sha1_ctx sha1_ctx = {
	.H = sha1,
	};

	dprint(FD_VERIFY, "sha1 verify io_u %p, len %u\n", io_u, hdr->len);

	sha1_init(&sha1_ctx);
	sha1_update(&sha1_ctx, p, hdr->len - hdr_size(hdr));

	if (memcmp(vh->sha1, sha1_ctx.H, sizeof(sha1))) {
	log_err("sha1: verify failed at %llu/%u\n",
	io_u->offset + header_num * hdr->len, hdr->len);
	hexdump(vh->sha1, sizeof(vh->sha1));
	hexdump(sha1_ctx.H, sizeof(sha1));
	return EILSEQ;
	}

	return 0;
	}

	static int verify_io_u_crc7(struct verify_header hdr, struct io_u io_u,
	unsigned int header_num)
	{
	void *p = io_u_verify_off(hdr, io_u, header_num);
	struct vhdr_crc7 *vh = hdr_priv(hdr);
	unsigned char c;

	dprint(FD_VERIFY, "crc7 verify io_u %p, len %u\n", io_u, hdr->len);

	c = crc7(p, hdr->len - hdr_size(hdr));

	if (c != vh->crc7) {
	log_err("crc7: verify failed at %llu/%u\n",
	io_u->offset + header_num * hdr->len, hdr->len);
	log_err("crc7: wanted %x, got %x\n", vh->crc7, c);
	return EILSEQ;
	}

	return 0;
	}

	static int verify_io_u_crc16(struct verify_header hdr, struct io_u io_u,
	unsigned int header_num)
	{
	void *p = io_u_verify_off(hdr, io_u, header_num);
	struct vhdr_crc16 *vh = hdr_priv(hdr);
	unsigned short c;

	dprint(FD_VERIFY, "crc16 verify io_u %p, len %u\n", io_u, hdr->len);

	c = crc16(p, hdr->len - hdr_size(hdr));

	if (c != vh->crc16) {
	log_err("crc16: verify failed at %llu/%u\n",
	io_u->offset + header_num * hdr->len, hdr->len);
	log_err("crc16: wanted %x, got %x\n", vh->crc16, c);
	return EILSEQ;
	}

	return 0;
	}

	static int verify_io_u_crc64(struct verify_header hdr, struct io_u io_u,
	unsigned int header_num)
	{
	void *p = io_u_verify_off(hdr, io_u, header_num);
	struct vhdr_crc64 *vh = hdr_priv(hdr);
	unsigned long long c;

	dprint(FD_VERIFY, "crc64 verify io_u %p, len %u\n", io_u, hdr->len);

	c = crc64(p, hdr->len - hdr_size(hdr));

	if (c != vh->crc64) {
	log_err("crc64: verify failed at %llu/%u\n",
	io_u->offset + header_num * hdr->len,
	hdr->len);
	log_err("crc64: wanted %llx, got %llx\n",
	(unsigned long long) vh->crc64, c);
	return EILSEQ;
	}

	return 0;
	}

	static int verify_io_u_crc32(struct verify_header hdr, struct io_u io_u,
	unsigned int header_num)
	{
	void *p = io_u_verify_off(hdr, io_u, header_num);
	struct vhdr_crc32 *vh = hdr_priv(hdr);
	uint32_t c;

	dprint(FD_VERIFY, "crc32 verify io_u %p, len %u\n", io_u, hdr->len);

	c = crc32(p, hdr->len - hdr_size(hdr));

	if (c != vh->crc32) {
	log_err("crc32: verify failed at %llu/%u\n",
	io_u->offset + header_num * hdr->len, hdr->len);
	log_err("crc32: wanted %x, got %x\n", vh->crc32, c);
	return EILSEQ;
	}

	return 0;
	}

	static int verify_io_u_crc32c(struct verify_header hdr, struct io_u io_u,
	unsigned int header_num)
	{
	void *p = io_u_verify_off(hdr, io_u, header_num);
	struct vhdr_crc32 *vh = hdr_priv(hdr);
	uint32_t c;

	dprint(FD_VERIFY, "crc32c verify io_u %p, len %u\n", io_u, hdr->len);

	if (hdr->verify_type == VERIFY_CRC32C_INTEL)
	c = crc32c_intel(p, hdr->len - hdr_size(hdr));
	else
	c = crc32c(p, hdr->len - hdr_size(hdr));

	if (c != vh->crc32) {
	log_err("crc32c: verify failed at %llu/%u\n",
	io_u->offset + header_num * hdr->len, hdr->len);
	log_err("crc32c: wanted %x, got %x\n", vh->crc32, c);
	return EILSEQ;
	}

	return 0;
	}

	static int verify_io_u_md5(struct verify_header hdr, struct io_u io_u,
	unsigned int header_num)
	{
	void *p = io_u_verify_off(hdr, io_u, header_num);
	struct vhdr_md5 *vh = hdr_priv(hdr);
	uint32_t hash[MD5_HASH_WORDS];
	struct md5_ctx md5_ctx = {
	.hash = hash,
	};

	dprint(FD_VERIFY, "md5 verify io_u %p, len %u\n", io_u, hdr->len);

	md5_init(&md5_ctx);
	md5_update(&md5_ctx, p, hdr->len - hdr_size(hdr));

	if (memcmp(vh->md5_digest, md5_ctx.hash, sizeof(hash))) {
	log_err("md5: verify failed at %llu/%u\n",
	io_u->offset + header_num * hdr->len, hdr->len);
	hexdump(vh->md5_digest, sizeof(vh->md5_digest));
	hexdump(md5_ctx.hash, sizeof(hash));
	return EILSEQ;
	}

	return 0;
	}

	static unsigned int hweight8(unsigned int w)
	{
	unsigned int res = w - ((w >> 1) & 0x55);

	res = (res & 0x33) + ((res >> 2) & 0x33);
	return (res + (res >> 4)) & 0x0F;
	}

	int verify_io_u_pattern(char *pattern, unsigned long pattern_size,
	char *buf, unsigned int len, unsigned int mod)
	{
	unsigned int i;

	for (i = 0; i < len; i++) {
	if (buf[i] != pattern[mod]) {
	unsigned int bits;

	bits = hweight8(buf[i] ^ pattern[mod]);
	log_err("fio: got pattern %x, wanted %x. Bad bits %d\n",
	buf[i], pattern[mod], bits);
	log_err("fio: bad pattern block offset %u\n", i);
	return EILSEQ;
	}
	mod++;
	if (mod == pattern_size)
	mod = 0;
	}

	return 0;
	}

	/*
	* Push IO verification to a separate thread
	*/
	int verify_io_u_async(struct thread_data td, struct io_u io_u)
	{
	if (io_u->file)
	put_file_log(td, io_u->file);

	io_u->file = NULL;

	pthread_mutex_lock(&td->io_u_lock);

	if (io_u->flags & IO_U_F_IN_CUR_DEPTH) {
	td->cur_depth--;
	io_u->flags &= ~IO_U_F_IN_CUR_DEPTH;
	}
	flist_del(&io_u->list);
	flist_add_tail(&io_u->list, &td->verify_list);
	io_u->flags \|= IO_U_F_FREE_DEF;
	pthread_mutex_unlock(&td->io_u_lock);

	pthread_cond_signal(&td->verify_cond);
	return 0;
	}

	int verify_io_u(struct thread_data td, struct io_u io_u)
	{
	struct verify_header *hdr;
	unsigned int hdr_size, hdr_inc, hdr_num = 0;
	void *p;
	int ret;

	if (td->o.verify == VERIFY_NULL \|\| io_u->ddir != DDIR_READ)
	return 0;

	hdr_inc = io_u->buflen;
	if (td->o.verify_interval)
	hdr_inc = td->o.verify_interval;

	ret = 0;
	for (p = io_u->buf; p < io_u->buf + io_u->buflen;
	p += hdr_inc, hdr_num++) {
	if (ret && td->o.verify_fatal) {
	td->terminate = 1;
	break;
	}
	hdr_size = __hdr_size(td->o.verify);
	if (td->o.verify_offset)
	memswp(p, p + td->o.verify_offset, hdr_size);
	hdr = p;

	if (hdr->fio_magic != FIO_HDR_MAGIC) {
	log_err("Bad verify header %x at %llu\n",
	hdr->fio_magic,
	io_u->offset + hdr_num * hdr->len);
	return EILSEQ;
	}

	if (td->o.verify_pattern_bytes) {
	dprint(FD_VERIFY, "pattern verify io_u %p, len %u\n",
	io_u, hdr->len);
	ret = verify_io_u_pattern(td->o.verify_pattern,
	td->o.verify_pattern_bytes,
	p + hdr_size,
	hdr_inc - hdr_size,
	hdr_size % td->o.verify_pattern_bytes);
	/*
	* Also verify the meta data, if applicable
	*/
	if (hdr->verify_type == VERIFY_META)
	ret \|= verify_io_u_meta(hdr, td, io_u, hdr_num);

	if (ret)
	log_err("fio: verify failed at %llu/%u\n",
	io_u->offset + hdr_num * hdr->len,
	hdr->len);
	continue;
	}

	switch (hdr->verify_type) {
	case VERIFY_MD5:
	ret = verify_io_u_md5(hdr, io_u, hdr_num);
	break;
	case VERIFY_CRC64:
	ret = verify_io_u_crc64(hdr, io_u, hdr_num);
	break;
	case VERIFY_CRC32C:
	case VERIFY_CRC32C_INTEL:
	ret = verify_io_u_crc32c(hdr, io_u, hdr_num);
	break;
	case VERIFY_CRC32:
	ret = verify_io_u_crc32(hdr, io_u, hdr_num);
	break;
	case VERIFY_CRC16:
	ret = verify_io_u_crc16(hdr, io_u, hdr_num);
	break;
	case VERIFY_CRC7:
	ret = verify_io_u_crc7(hdr, io_u, hdr_num);
	break;
	case VERIFY_SHA256:
	ret = verify_io_u_sha256(hdr, io_u, hdr_num);
	break;
	case VERIFY_SHA512:
	ret = verify_io_u_sha512(hdr, io_u, hdr_num);
	break;
	case VERIFY_META:
	ret = verify_io_u_meta(hdr, td, io_u, hdr_num);
	break;
	case VERIFY_SHA1:
	ret = verify_io_u_sha1(hdr, io_u, hdr_num);
	break;
	default:
	log_err("Bad verify type %u\n", hdr->verify_type);
	ret = EINVAL;
	}
	}

	return ret;
	}

	static void fill_meta(struct verify_header hdr, struct thread_data td,
	struct io_u *io_u, unsigned int header_num)
	{
	struct vhdr_meta *vh = hdr_priv(hdr);

	vh->thread = td->thread_number;

	vh->time_sec = io_u->start_time.tv_sec;
	vh->time_usec = io_u->start_time.tv_usec;

	vh->numberio = td->io_issues[DDIR_WRITE];

	vh->offset = io_u->offset + header_num * td->o.verify_interval;
	}

	static void fill_sha512(struct verify_header hdr, void p, unsigned int len)
	{
	struct vhdr_sha512 *vh = hdr_priv(hdr);
	struct sha512_ctx sha512_ctx = {
	.buf = vh->sha512,
	};

	sha512_init(&sha512_ctx);
	sha512_update(&sha512_ctx, p, len);
	}

	static void fill_sha256(struct verify_header hdr, void p, unsigned int len)
	{
	struct vhdr_sha256 *vh = hdr_priv(hdr);
	struct sha256_ctx sha256_ctx = {
	.buf = vh->sha256,
	};

	sha256_init(&sha256_ctx);
	sha256_update(&sha256_ctx, p, len);
	}

	static void fill_sha1(struct verify_header hdr, void p, unsigned int len)
	{
	struct vhdr_sha1 *vh = hdr_priv(hdr);
	struct sha1_ctx sha1_ctx = {
	.H = vh->sha1,
	};

	sha1_init(&sha1_ctx);
	sha1_update(&sha1_ctx, p, len);
	}

	static void fill_crc7(struct verify_header hdr, void p, unsigned int len)
	{
	struct vhdr_crc7 *vh = hdr_priv(hdr);

	vh->crc7 = crc7(p, len);
	}

	static void fill_crc16(struct verify_header hdr, void p, unsigned int len)
	{
	struct vhdr_crc16 *vh = hdr_priv(hdr);

	vh->crc16 = crc16(p, len);
	}

	static void fill_crc32(struct verify_header hdr, void p, unsigned int len)
	{
	struct vhdr_crc32 *vh = hdr_priv(hdr);

	vh->crc32 = crc32(p, len);
	}

	static void fill_crc32c(struct verify_header hdr, void p, unsigned int len)
	{
	struct vhdr_crc32 *vh = hdr_priv(hdr);

	if (hdr->verify_type == VERIFY_CRC32C_INTEL)
	vh->crc32 = crc32c_intel(p, len);
	else
	vh->crc32 = crc32c(p, len);
	}

	static void fill_crc64(struct verify_header hdr, void p, unsigned int len)
	{
	struct vhdr_crc64 *vh = hdr_priv(hdr);

	vh->crc64 = crc64(p, len);
	}

	static void fill_md5(struct verify_header hdr, void p, unsigned int len)
	{
	struct vhdr_md5 *vh = hdr_priv(hdr);
	struct md5_ctx md5_ctx = {
	.hash = (uint32_t *) vh->md5_digest,
	};

	md5_init(&md5_ctx);
	md5_update(&md5_ctx, p, len);
	}

	/*
	* fill body of io_u->buf with random data and add a header with the
	* crc32 or md5 sum of that data.
	*/
	void populate_verify_io_u(struct thread_data td, struct io_u io_u)
	{
	struct verify_header *hdr;
	void p = io_u->buf, data;
	unsigned int hdr_inc, data_len, header_num = 0;

	if (td->o.verify == VERIFY_NULL)
	return;

	fill_pattern(td, p, io_u->buflen);

	hdr_inc = io_u->buflen;
	if (td->o.verify_interval)
	hdr_inc = td->o.verify_interval;

	for (; p < io_u->buf + io_u->buflen; p += hdr_inc) {
	hdr = p;

	hdr->fio_magic = FIO_HDR_MAGIC;
	hdr->verify_type = td->o.verify;
	hdr->len = hdr_inc;
	data_len = hdr_inc - hdr_size(hdr);

	data = p + hdr_size(hdr);
	switch (td->o.verify) {
	case VERIFY_MD5:
	dprint(FD_VERIFY, "fill md5 io_u %p, len %u\n",
	io_u, hdr->len);
	fill_md5(hdr, data, data_len);
	break;
	case VERIFY_CRC64:
	dprint(FD_VERIFY, "fill crc64 io_u %p, len %u\n",
	io_u, hdr->len);
	fill_crc64(hdr, data, data_len);
	break;
	case VERIFY_CRC32C:
	case VERIFY_CRC32C_INTEL:
	dprint(FD_VERIFY, "fill crc32c io_u %p, len %u\n",
	io_u, hdr->len);
	fill_crc32c(hdr, data, data_len);
	break;
	case VERIFY_CRC32:
	dprint(FD_VERIFY, "fill crc32 io_u %p, len %u\n",
	io_u, hdr->len);
	fill_crc32(hdr, data, data_len);
	break;
	case VERIFY_CRC16:
	dprint(FD_VERIFY, "fill crc16 io_u %p, len %u\n",
	io_u, hdr->len);
	fill_crc16(hdr, data, data_len);
	break;
	case VERIFY_CRC7:
	dprint(FD_VERIFY, "fill crc7 io_u %p, len %u\n",
	io_u, hdr->len);
	fill_crc7(hdr, data, data_len);
	break;
	case VERIFY_SHA256:
	dprint(FD_VERIFY, "fill sha256 io_u %p, len %u\n",
	io_u, hdr->len);
	fill_sha256(hdr, data, data_len);
	break;
	case VERIFY_SHA512:
	dprint(FD_VERIFY, "fill sha512 io_u %p, len %u\n",
	io_u, hdr->len);
	fill_sha512(hdr, data, data_len);
	break;
	case VERIFY_META:
	dprint(FD_VERIFY, "fill meta io_u %p, len %u\n",
	io_u, hdr->len);
	fill_meta(hdr, td, io_u, header_num);
	break;
	case VERIFY_SHA1:
	dprint(FD_VERIFY, "fill sha1 io_u %p, len %u\n",
	io_u, hdr->len);
	fill_sha1(hdr, data, data_len);
	break;
	default:
	log_err("fio: bad verify type: %d\n", td->o.verify);
	assert(0);
	}
	if (td->o.verify_offset)
	memswp(p, p + td->o.verify_offset, hdr_size(hdr));
	header_num++;
	}
	}

	int get_next_verify(struct thread_data td, struct io_u io_u)
	{
	struct io_piece *ipo = NULL;

	/*
	* this io_u is from a requeue, we already filled the offsets
	*/
	if (io_u->file)
	return 0;

	if (!RB_EMPTY_ROOT(&td->io_hist_tree)) {
	struct rb_node *n = rb_first(&td->io_hist_tree);

	ipo = rb_entry(n, struct io_piece, rb_node);
	rb_erase(n, &td->io_hist_tree);
	td->io_hist_len--;
	} else if (!flist_empty(&td->io_hist_list)) {
	ipo = flist_entry(td->io_hist_list.next, struct io_piece, list);
	td->io_hist_len--;
	flist_del(&ipo->list);
	}

	if (ipo) {
	io_u->offset = ipo->offset;
	io_u->buflen = ipo->len;
	io_u->file = ipo->file;

	if (!fio_file_open(io_u->file)) {
	int r = td_io_open_file(td, io_u->file);

	if (r) {
	dprint(FD_VERIFY, "failed file %s open\n",
	io_u->file->file_name);
	return 1;
	}
	}

	get_file(ipo->file);
	assert(fio_file_open(io_u->file));
	io_u->ddir = DDIR_READ;
	io_u->xfer_buf = io_u->buf;
	io_u->xfer_buflen = io_u->buflen;
	free(ipo);
	dprint(FD_VERIFY, "get_next_verify: ret io_u %p\n", io_u);
	return 0;
	}

	dprint(FD_VERIFY, "get_next_verify: empty\n");
	return 1;
	}

	static void verify_async_thread(void data)
	{
	struct thread_data *td = data;
	struct io_u *io_u;
	int ret = 0;

	if (td->o.verify_cpumask_set &&
	fio_setaffinity(td->pid, td->o.verify_cpumask)) {
	log_err("fio: failed setting verify thread affinity\n");
	goto done;
	}

	do {
	FLIST_HEAD(list);

	read_barrier();
	if (td->verify_thread_exit)
	break;

	pthread_mutex_lock(&td->io_u_lock);

	while (flist_empty(&td->verify_list) &&
	!td->verify_thread_exit) {
	ret = pthread_cond_wait(&td->verify_cond,
	&td->io_u_lock);
	if (ret) {
	pthread_mutex_unlock(&td->io_u_lock);
	break;
	}
	}

	flist_splice_init(&td->verify_list, &list);
	pthread_mutex_unlock(&td->io_u_lock);

	if (flist_empty(&list))
	continue;

	while (!flist_empty(&list)) {
	io_u = flist_entry(list.next, struct io_u, list);
	flist_del_init(&io_u->list);

	ret = verify_io_u(td, io_u);
	put_io_u(td, io_u);
	if (!ret)
	continue;
	if (td->o.continue_on_error &&
	td_non_fatal_error(ret)) {
	update_error_count(td, ret);
	td_clear_error(td);
	ret = 0;
	}
	}
	} while (!ret);

	if (ret) {
	td_verror(td, ret, "async_verify");
	td->terminate = 1;
	}

	done:
	pthread_mutex_lock(&td->io_u_lock);
	td->nr_verify_threads--;
	pthread_mutex_unlock(&td->io_u_lock);

	pthread_cond_signal(&td->free_cond);
	return NULL;
	}

	int verify_async_init(struct thread_data *td)
	{
	int i, ret;

	td->verify_thread_exit = 0;

	td->verify_threads = malloc(sizeof(pthread_t) * td->o.verify_async);
	for (i = 0; i < td->o.verify_async; i++) {
	ret = pthread_create(&td->verify_threads[i], NULL,
	verify_async_thread, td);
	if (ret) {
	log_err("fio: async verify creation failed: %s\n",
	strerror(ret));
	break;
	}
	ret = pthread_detach(td->verify_threads[i]);
	if (ret) {
	log_err("fio: async verify thread detach failed: %s\n",
	strerror(ret));
	break;
	}
	td->nr_verify_threads++;
	}

	if (i != td->o.verify_async) {
	log_err("fio: only %d verify threads started, exiting\n", i);
	td->verify_thread_exit = 1;
	write_barrier();
	pthread_cond_broadcast(&td->verify_cond);
	return 1;
	}

	return 0;
	}

	void verify_async_exit(struct thread_data *td)
	{
	td->verify_thread_exit = 1;
	write_barrier();
	pthread_cond_broadcast(&td->verify_cond);

	pthread_mutex_lock(&td->io_u_lock);

	while (td->nr_verify_threads)
	pthread_cond_wait(&td->free_cond, &td->io_u_lock);

	pthread_mutex_unlock(&td->io_u_lock);
	free(td->verify_threads);
	td->verify_threads = NULL;
	}