ref: 2c61a24dfa6b65ae4292915c7ede68f01005bfa5
parent: 0f1cc07213540e99bdfe5c4ee6c49b6e583ffbb7
author: gkostka <kostka.grzegorz@gmail.com>
date: Sun Oct 27 10:50:30 EDT 2013
Disable buffering for filedev and raw_io.
--- a/blockdev/filedev/ext4_filedev.c
+++ b/blockdev/filedev/ext4_filedev.c
@@ -31,6 +31,7 @@
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
+#include <fcntl.h>
/**@brief Default filename.*/
static const char *fname = "ext2";
@@ -41,7 +42,9 @@
/**@brief Image file descriptor.*/
static FILE *dev_file;
+#define DROP_LINUXCACHE_BUFFERS 0
+
/**********************BLOCKDEV INTERFACE**************************************/
static int filedev_open(struct ext4_blockdev *bdev);
static int filedev_bread(struct ext4_blockdev *bdev, void *buf, uint64_t blk_id,
@@ -98,18 +101,32 @@
return EOK;
}
+static void drop_cache(void)
+{+#if defined(LINUX) && DROP_LINUXCACHE_BUFFERS
+ int fd;
+ char* data = "3";
+
+ sync();
+ fd = open("/proc/sys/vm/drop_caches", O_WRONLY);+ write(fd, data, sizeof(char));
+ close(fd);
+#endif
+}
+
/******************************************************************************/
static int filedev_bwrite(struct ext4_blockdev *bdev, const void *buf,
- uint64_t blk_id, uint32_t blk_cnt)
+ uint64_t blk_id, uint32_t blk_cnt)
{- if(fseek(dev_file, blk_id * bdev->ph_bsize, SEEK_SET))
- return EIO;
+ if(fseek(dev_file, blk_id * bdev->ph_bsize, SEEK_SET))
+ return EIO;
- if(!fwrite(buf, bdev->ph_bsize * blk_cnt, 1, dev_file))
- return EIO;
- return EOK;
-}
+ if(!fwrite(buf, bdev->ph_bsize * blk_cnt, 1, dev_file))
+ return EIO;
+ drop_cache();
+ return EOK;
+}
/******************************************************************************/
static int filedev_close(struct ext4_blockdev *bdev)
{--- a/blockdev/io_raw/io_raw.c
+++ b/blockdev/io_raw/io_raw.c
@@ -89,7 +89,7 @@
FILE_SHARE_WRITE | FILE_SHARE_READ,
NULL,
OPEN_EXISTING,
- 0,
+ FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH,
NULL);
if (dev_file == INVALID_HANDLE_VALUE){