From 9f741ad2e3925cbce5a25e9d1f37f94712eaf44b Mon Sep 17 00:00:00 2001
From: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Date: Sun, 25 Nov 2012 19:22:37 -0800
Subject: [PATCH] Remove the iscsi data alloc_size field. Avoiding to realloc
 data over and over should rather be handled with something similar to
 iovectors instead.

---
 include/iscsi.h     |  1 -
 lib/iscsi-command.c |  2 +-
 lib/pdu.c           | 31 +++++++++----------------------
 3 files changed, 10 insertions(+), 24 deletions(-)

diff --git a/include/iscsi.h b/include/iscsi.h
index 43b10cc..827b9de 100644
--- a/include/iscsi.h
+++ b/include/iscsi.h
@@ -537,7 +537,6 @@ iscsi_task_mgmt_target_cold_reset_async(struct iscsi_context *iscsi,
 
 struct iscsi_data {
        int size;
-       size_t alloc_size;
        unsigned char *data;
 };
 
diff --git a/lib/iscsi-command.c b/lib/iscsi-command.c
index c34d901..f277a27 100644
--- a/lib/iscsi-command.c
+++ b/lib/iscsi-command.c
@@ -438,7 +438,7 @@ iscsi_process_scsi_data_in(struct iscsi_context *iscsi, struct iscsi_pdu *pdu,
 	/* Dont add to reassembly buffer if we already have a user buffer */
 	if (scsi_task_get_data_in_buffer(task, 0, NULL) == NULL) {
 		if (task->expxferlen > dsl && pdu->indata.data == NULL) {
-			pdu->indata.alloc_size = task->expxferlen;
+			pdu->indata.size = task->expxferlen;
 			pdu->indata.data = iscsi_malloc(iscsi, task->expxferlen);
 			if (pdu->indata.data == NULL) {
 				iscsi_set_error(iscsi, "Out-of-memory: failed to allocate pdu indata buffer");
diff --git a/lib/pdu.c b/lib/pdu.c
index 458190a..af0d448 100644
--- a/lib/pdu.c
+++ b/lib/pdu.c
@@ -43,9 +43,7 @@ iscsi_allocate_pdu_with_itt_flags(struct iscsi_context *iscsi, enum iscsi_opcode
 	}
 
 	pdu->outdata.size = ISCSI_HEADER_SIZE;
-	pdu->outdata.alloc_size = 64;
-	
-	pdu->outdata.data = iscsi_malloc(iscsi, pdu->outdata.alloc_size);
+       	pdu->outdata.data = iscsi_malloc(iscsi, pdu->outdata.size);
 	memset(pdu->outdata.data, 0, ISCSI_HEADER_SIZE);
 
 	if (pdu->outdata.data == NULL) {
@@ -117,42 +115,31 @@ iscsi_add_data(struct iscsi_context *iscsi, struct iscsi_data *data,
 	}
 
 	len = data->size + dsize;
+
 	aligned = len;
 	if (pdualignment) {
 		aligned = (aligned+3)&0xfffffffc;
 	}
 
-	size_t new_alloc_size = data->alloc_size;
-	if (new_alloc_size < 64) new_alloc_size=64;
-	
-	while (aligned > new_alloc_size) new_alloc_size<<=1;
-
-	if (data->data != NULL && data->alloc_size == 0) data->alloc_size=data->size;
-	
-	if (data->alloc_size == 0) {
-		data->data = iscsi_malloc(iscsi, new_alloc_size);
+	if (data->size == 0) {
+		data->data = iscsi_malloc(iscsi, aligned);
+	} else {
+		data->data = iscsi_realloc(iscsi, data->data, aligned);
 	}
-	else
-		if (data->alloc_size != new_alloc_size) {
-			data->data = iscsi_realloc(iscsi, data->data, new_alloc_size);
-		}
-	
 	if (data->data == NULL) {
 		iscsi_set_error(iscsi, "failed to allocate buffer for %d "
 				"bytes", (int) len);
 		return -1;
 	}
-	
-	data->alloc_size = new_alloc_size;
+
 	memcpy(data->data + data->size, dptr, dsize);
+	data->size += dsize;
 
 	if (len != aligned) {
 		/* zero out any padding at the end */
-		memset(data->data+len, 0, aligned-len);
+		memset(data->data + len, 0, aligned - len);
 	}
 
-	data->size = len;
-
 	return 0;
 }