From ea6b64b18b4cddbd66bb0a2e6e4d99584caa1483 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@suse.de>
Date: Tue, 29 Nov 2005 20:30:41 +0100
Subject: [PATCH] [PATCH] fio: extend file if it's too small

---
 fio.c | 43 ++++++++++++++++++++++++-------------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/fio.c b/fio.c
index f2ec8bb..52b3aae 100644
--- a/fio.c
+++ b/fio.c
@@ -1238,12 +1238,13 @@ static int init_io_u(struct thread_data *td)
 	return 0;
 }
 
-static int create_file(struct thread_data *td)
+static int create_file(struct thread_data *td, unsigned long long size,
+		       int extend)
 {
 	unsigned long long left;
 	unsigned int bs;
+	int r, oflags;
 	char *b;
-	int r;
 
 	/*
 	 * unless specifically asked for overwrite, let normal io extend it
@@ -1251,21 +1252,27 @@ static int create_file(struct thread_data *td)
 	if (td_write(td) && !td->overwrite)
 		return 0;
 
-	if (!td->file_size) {
+	if (!size) {
 		fprintf(stderr, "Need size for create\n");
 		td->error = EINVAL;
 		return 1;
 	}
 
-	printf("Client%d: Laying out IO file\n", td->thread_number);
+	if (!extend) {
+		oflags = O_CREAT | O_TRUNC;
+		printf("Client%d: Laying out IO file (%LuMiB)\n", td->thread_number, size >> 20);
+	} else {
+		oflags = O_APPEND;
+		printf("Client%d: Extending IO file (%Lu -> %LuMiB)\n", td->thread_number, (td->file_size - size) >> 20, td->file_size >> 20);
+	}
 
-	td->fd = open(td->file_name, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+	td->fd = open(td->file_name, O_WRONLY | oflags, 0644);
 	if (td->fd < 0) {
 		td->error = errno;
 		return 1;
 	}
 
-	if (ftruncate(td->fd, td->file_size) == -1) {
+	if (!extend && ftruncate(td->fd, td->file_size) == -1) {
 		td->error = errno;
 		return 1;
 	}
@@ -1274,7 +1281,7 @@ static int create_file(struct thread_data *td)
 	b = malloc(td->max_bs);
 	memset(b, 0, td->max_bs);
 
-	left = td->file_size;
+	left = size;
 	while (left && !td->terminate) {
 		bs = td->max_bs;
 		if (bs > left)
@@ -1306,16 +1313,6 @@ static int create_file(struct thread_data *td)
 	return 0;
 }
 
-static int file_exists(struct thread_data *td)
-{
-	struct stat st;
-
-	if (stat(td->file_name, &st) != -1)
-		return 1;
-
-	return errno != ENOENT;
-}
-
 static int file_size(struct thread_data *td)
 {
 	struct stat st;
@@ -1446,14 +1443,22 @@ static int setup_file_plain(struct thread_data *td)
 
 static int setup_file(struct thread_data *td)
 {
+	struct stat st;
 	int flags = 0;
 
-	if (!file_exists(td)) {
+	if (stat(td->file_name, &st) == -1) {
+		if (errno != ENOENT) {
+			td->error = errno;
+			return 1;
+		}
 		if (!td->create_file) {
 			td->error = ENOENT;
 			return 1;
 		}
-		if (create_file(td))
+		if (create_file(td, td->file_size, 0))
+			return 1;
+	} else if (st.st_size < td->file_size) {
+		if (create_file(td, td->file_size - st.st_size, 1))
 			return 1;
 	}
 
-- 
2.25.1