[Ocfs2-tools-devel] [PATCH 3/7] libdefrag.c

[Larry Chen]

Signed-off-by: Larry Chen <lchen at suse.com>
---
 defragfs.ocfs2/libdefrag.c | 126 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 126 insertions(+)
 create mode 100644 defragfs.ocfs2/libdefrag.c

diff --git a/defragfs.ocfs2/libdefrag.c b/defragfs.ocfs2/libdefrag.c
new file mode 100644
index 00000000..200370c2
--- /dev/null
+++ b/defragfs.ocfs2/libdefrag.c
@@ -0,0 +1,126 @@
+#include <libdefrag.h>
+#include <unistd.h>
+
+void *do_malloc(size_t size)
+{
+	void *buf;
+
+	buf = calloc(size, 1);
+
+	if (buf == NULL) {
+		fprintf(stderr, "No mem\n");
+		exit(-1);
+	}
+
+	return buf;
+}
+
+int do_read(int fd, void *bytes, size_t count)
+{
+	int total = 0;
+	int ret;
+
+
+	while (total < count) {
+		ret = read(fd, bytes + total, count - total);
+		if (ret < 0) {
+			ret = -errno;
+			if ((ret == -EAGAIN) || (ret == -EINTR))
+				continue;
+			total = ret;
+			break;
+		}
+		if (ret == 0)
+			break;
+		total += ret;
+	}
+
+	return total;
+}
+
+int do_write(int fd, const void *bytes, size_t count)
+{
+	int total = 0;
+	int ret;
+
+	while (total < count) {
+		ret = write(fd, bytes + total, count - total);
+		if (ret < 0) {
+			ret = -errno;
+			if ((ret == -EAGAIN) || (ret == -EINTR))
+				continue;
+			else
+				goto error;
+		}
+
+		total += ret;
+	}
+	return total;
+error:
+	return ret;
+}
+
+static inline unsigned short from32to16(unsigned int x)
+{
+	/* add up 16-bit and 16-bit for 16+c bit */
+	x = (x & 0xffff) + (x >> 16);
+	/* add up carry.. */
+	x = (x & 0xffff) + (x >> 16);
+	return x;
+}
+
+unsigned int do_csum(const unsigned char *buff, int len)
+{
+	int odd;
+	unsigned int result = 0;
+
+	if (len <= 0)
+		goto out;
+	odd = 1 & (unsigned long) buff;
+	if (odd) {
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+		result += (*buff << 8);
+#else
+		result = *buff;
+#endif
+		len--;
+		buff++;
+	}
+	if (len >= 2) {
+		if (2 & (unsigned long) buff) {
+			result += *(unsigned short *) buff;
+			len -= 2;
+			buff += 2;
+		}
+		if (len >= 4) {
+			const unsigned char *end = buff + ((unsigned)len & ~3);
+			unsigned int carry = 0;
+
+			do {
+				unsigned int w = *(unsigned int *) buff;
+
+				buff += 4;
+				result += carry;
+				result += w;
+				carry = (w > result);
+			} while (buff < end);
+			result += carry;
+			result = (result & 0xffff) + (result >> 16);
+		}
+		if (len & 2) {
+			result += *(unsigned short *) buff;
+			buff += 2;
+		}
+	}
+	if (len & 1)
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+		result += *buff;
+#else
+		result += (*buff << 8);
+#endif
+	result = from32to16(result);
+	if (odd)
+		result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
+out:
+	return result;
+}
-- 
2.13.7