Split code out into separate compilation units (first pass, anyway).

ioutil.c

@@ -0,0 +1,123 @@
+#define _LARGEFILE64_SOURCE
+#define _GNU_SOURCE
+
+#include <sys/mman.h>
+#include <sys/sendfile.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <linux/fs.h>
+#include <linux/fiemap.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include "util.h"
+#include "bitset.h"
+
+char* build_allocation_map(int fd, off64_t size, int resolution)
+{
+	int i;
+	char *allocation_map = xmalloc((size+resolution)/resolution);
+	struct fiemap *fiemap;
+
+	fiemap = (struct fiemap*) xmalloc(sizeof(struct fiemap));
+
+	fiemap->fm_start = 0;
+	fiemap->fm_length = size;
+	fiemap->fm_flags = 0;
+	fiemap->fm_extent_count = 0;
+	fiemap->fm_mapped_extents = 0;
+
+	/* Find out how many extents there are */
+	if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < 0)
+		return NULL;
+
+	/* Resize fiemap to allow us to read in the extents */
+	fiemap = (struct fiemap*)xrealloc(
+		fiemap,
+		sizeof(struct fiemap) + (
+			sizeof(struct fiemap_extent) * 
+        		fiemap->fm_mapped_extents
+        	)
+	); 
+
+	fiemap->fm_extent_count = fiemap->fm_mapped_extents;
+	fiemap->fm_mapped_extents = 0;
+
+	if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < -1)
+		return NULL;
+	
+	for (i=0;i<fiemap->fm_mapped_extents;i++) 
+		bit_set_range(
+			allocation_map, 
+			fiemap->fm_extents[i].fe_logical / resolution,
+			fiemap->fm_extents[i].fe_length / resolution
+		);
+	
+	free(fiemap);
+	
+	return allocation_map;
+}
+
+
+int writeloop(int filedes, const void *buffer, size_t size)
+{
+	size_t written=0;
+	while (written < size) {
+		size_t result = write(filedes, buffer+written, size-written);
+		if (result == -1)
+			return -1;
+		written += result;
+	}
+	return 0;
+}
+
+int readloop(int filedes, void *buffer, size_t size)
+{
+	size_t readden=0;
+	while (readden < size) {
+		size_t result = read(filedes, buffer+readden, size-readden);
+		if (result == 0 /* EOF */ || result == -1 /* error */)
+			return -1;
+		readden += result;
+	}
+	return 0;
+}
+
+int sendfileloop(int out_fd, int in_fd, off64_t *offset, size_t count)
+{
+	size_t sent=0;
+	while (sent < count) {
+		size_t result = sendfile64(out_fd, in_fd, offset+sent, count-sent);
+		if (result == -1)
+			return -1;
+		sent += result;
+	}
+	return 0;
+}
+
+int splice_via_pipe_loop(int fd_in, int fd_out, size_t len)
+{
+	int pipefd[2];
+	size_t spliced=0;
+	
+	if (pipe(pipefd) == -1)
+		return -1;
+	
+	while (spliced < len) {
+		size_t r1,r2;
+		r1 = splice(fd_in, NULL, pipefd[1], NULL, len-spliced, 0);
+		if (r1 <= 0)
+			break;
+		r2 = splice(pipefd[0], NULL, fd_out, NULL, r1, 0);
+		if (r1 != r2)
+			break;
+		spliced += r1;
+	}
+	close(pipefd[0]);
+	close(pipefd[1]);
+	
+	return spliced < len ? -1 : 0;
+}
+
+