diff --git a/src/client.c b/src/client.c
index 1189a42..6917a93 100644
--- a/src/client.c
+++ b/src/client.c
@@ -387,26 +387,28 @@ void client_reply_to_write( struct client* client, struct nbd_request request )
 		write_not_zeroes( client, request.from, request.len );
 	}
 	else {
-		FATAL_IF_NEGATIVE(
-				readloop(
-					client->socket,
-					client->mapped + request.from,
-					request.len),
-				"read failed from=%ld, len=%d",
-				request.from,
-				request.len );
+		debug("No allocation map, writing directly.");
+		/* If we get cut off partway through reading this data
+		 * */
+		ERROR_IF_NEGATIVE(
+			readloop( client->socket,
+				client->mapped + request.from,
+				request.len),
+			"reading write data failed from=%ld, len=%d",
+			request.from,
+			request.len 
+		);
 		server_dirty(client->serve, request.from, request.len);
 	}
-	
+
 	if (1) /* not sure whether this is necessary... */
 	{
 		/* multiple of 4K page size */
 		uint64_t from_rounded = request.from & (!0xfff);
 		uint64_t len_rounded = request.len + (request.from - from_rounded);
-		
+
 		FATAL_IF_NEGATIVE(
-			msync(
-				client->mapped + from_rounded, 
+			msync( client->mapped + from_rounded, 
 				len_rounded, 
 				MS_SYNC),
 			"msync failed %ld %ld", request.from, request.len
diff --git a/src/ioutil.c b/src/ioutil.c
index 8c7df08..336bbba 100644
--- a/src/ioutil.c
+++ b/src/ioutil.c
@@ -15,7 +15,7 @@ struct bitset_mapping* build_allocation_map(int fd, uint64_t size, int resolutio
 {
 	unsigned int i;
 	struct bitset_mapping* allocation_map = bitset_alloc(size, resolution);
-	struct fiemap *fiemap_count, *fiemap;
+	struct fiemap *fiemap_count = NULL, *fiemap = NULL;
 
 	fiemap_count = (struct fiemap*) xmalloc(sizeof(struct fiemap));
 
@@ -27,17 +27,18 @@ struct bitset_mapping* build_allocation_map(int fd, uint64_t size, int resolutio
 
 	/* Find out how many extents there are */
 	if (ioctl(fd, FS_IOC_FIEMAP, fiemap_count) < 0) {
-		return NULL;
+		debug( "Couldn't get fiemap_count, returning no allocation_map" );
+		goto no_map;
 	}
 
 	/* Resize fiemap to allow us to read in the extents */
 	fiemap = (struct fiemap*)xmalloc(
-		sizeof(struct fiemap) + (
-			sizeof(struct fiemap_extent) * 
-        		fiemap_count->fm_mapped_extents
-        	)
-	); 
-	
+			sizeof(struct fiemap) + (
+				sizeof(struct fiemap_extent) * 
+				fiemap_count->fm_mapped_extents
+				)
+			); 
+
 	/* realloc makes valgrind complain a lot */
 	memcpy(fiemap, fiemap_count, sizeof(struct fiemap));
 	free( fiemap_count );
@@ -45,7 +46,10 @@ struct bitset_mapping* build_allocation_map(int fd, uint64_t size, int resolutio
 	fiemap->fm_extent_count = fiemap->fm_mapped_extents;
 	fiemap->fm_mapped_extents = 0;
 
-	if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < 0) { return NULL; }
+	if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < 0) { 
+		debug( "Couldn't get fiemap, returning no allocation_map" );
+		goto no_map;
+	}
 
 	for (i=0;i<fiemap->fm_mapped_extents;i++) {
 		bitset_set_range(
@@ -54,7 +58,7 @@ struct bitset_mapping* build_allocation_map(int fd, uint64_t size, int resolutio
 			fiemap->fm_extents[i].fe_length
 		);
 	}
-	
+
 	/* This is pointlessly verbose for real discs, it's here as a
 	 * reference for pulling data out of the allocation map */
 	if ( 0 ) {
@@ -72,13 +76,22 @@ struct bitset_mapping* build_allocation_map(int fd, uint64_t size, int resolutio
 			     );
 		}
 	}
-	
-	
+
+
 	free(fiemap);
-	
+
+	debug("Successfully built allocation map");
 	return allocation_map;
+
+no_map:
+	fprintf(stderr, "Freeing");
+	free( allocation_map );
+	if ( NULL != fiemap ) { free( fiemap ); }
+	if ( NULL != fiemap_count ) { free( fiemap_count ); }
+	return NULL;
 }
 
+
 int open_and_mmap(const char* filename, int* out_fd, off64_t *out_size, void **out_map)
 {
 	off64_t size;