Index: src/network_posix_aio.c
===================================================================
--- src/network_posix_aio.c	(revision 1702)
+++ src/network_posix_aio.c	(working copy)
@@ -37,6 +37,10 @@
 #include "sys-files.h"
 #include "status_counter.h"
 
+#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
 typedef struct {
 	server *srv;
 	connection *con;
@@ -233,33 +237,15 @@
 					 * read()
 					 *  */
 					if (-1 == c->file.copy.fd ) {
-						int mmap_fd = -1;
+						c->file.mmap.offset = 0;
+						c->file.mmap.length = toSend;
 
-						/* open a file in /dev/shm to write to */
-						if (-1 == (mmap_fd = open("/dev/zero", O_RDWR))) {
+						c->file.mmap.start = mmap(0, c->file.mmap.length,
+								PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+						if (c->file.mmap.start == MAP_FAILED) {
 							async_error = 1;
-
-							if (errno != EMFILE) {
-								TRACE("open(/dev/zero) returned: %d (%s), falling back to sync-io",
-									errno, strerror(errno));
-							} else {
-								return NETWORK_STATUS_WAIT_FOR_FD;
-							}
 						} else {
-							c->file.mmap.offset = 0;
-							c->file.mmap.length = toSend;
-
-							c->file.mmap.start = mmap(0, c->file.mmap.length,
-									PROT_READ | PROT_WRITE, MAP_SHARED, mmap_fd, 0);
-							if (c->file.mmap.start == MAP_FAILED) {
-								async_error = 1;
-							} else {
-								c->file.copy.length = toSend;
-							}
-
-							close(mmap_fd);
-							mmap_fd = -1;
-						
+							c->file.copy.length = toSend;
 						}
 					}
 
Index: src/network_gthread_aio.c
===================================================================
--- src/network_gthread_aio.c	(revision 1702)
+++ src/network_gthread_aio.c	(working copy)
@@ -26,6 +26,10 @@
 #include "sys-files.h"
 #include "sys-socket.h"
 
+#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON)
+#define MAP_ANONYMOUS MAP_ANON
+#endif
+
 typedef struct {
 	chunk *c;
 
@@ -74,7 +78,6 @@
 			size_t toSend;
 			const off_t max_toSend = 4 * 256 * 1024; /** should be larger than the send buffer */
 			chunk *c = wj->c;
-			int mmap_fd;
 			
 			offset = c->file.start + c->offset;
 
@@ -86,26 +89,13 @@
 
 			/* open a file in /dev/shm to write to */
 			if (c->file.mmap.start == MAP_FAILED) {
-				if (-1 == (mmap_fd = open("/dev/zero", O_RDWR))) {
-					if (errno != EMFILE) {
-						TRACE("open(/dev/zero) returned: %d (%s)",
-							errno, strerror(errno));
-						c->async.ret_val = NETWORK_STATUS_FATAL_ERROR;
-					} else {
-						c->async.ret_val = NETWORK_STATUS_WAIT_FOR_FD;
-					}
-				} else {
-					c->file.mmap.offset = 0;
-					c->file.mmap.length = toSend;
-	
-					c->file.mmap.start = mmap(0, c->file.mmap.length,
-							PROT_READ | PROT_WRITE, MAP_SHARED, mmap_fd, 0);
-					if (c->file.mmap.start == MAP_FAILED) {
-						c->async.ret_val = NETWORK_STATUS_FATAL_ERROR;
-					}
-	
-					close(mmap_fd);
-					mmap_fd = -1;
+				c->file.mmap.offset = 0;
+				c->file.mmap.length = toSend;
+
+				c->file.mmap.start = mmap(0, c->file.mmap.length,
+						PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+				if (c->file.mmap.start == MAP_FAILED) {
+					c->async.ret_val = NETWORK_STATUS_FATAL_ERROR;
 				}
 			}
 		
@@ -210,33 +200,18 @@
 
 				/* we small files don't take the overhead of a full async-loop */
 				if (toSend < 4 * 1024) {
-					int mmap_fd;
-			
 					c->file.copy.offset = 0;
 					c->file.copy.length = toSend;
 			
 					/* open a file in /dev/shm to write to */
 					if (c->file.mmap.start == MAP_FAILED) {
-						if (-1 == (mmap_fd = open("/dev/zero", O_RDWR))) {
-							if (errno != EMFILE) {
-								TRACE("open(/dev/zero) returned: %d (%s), open fds: %d",
-									errno, strerror(errno));
-								return NETWORK_STATUS_FATAL_ERROR;
-							} else {
-								return NETWORK_STATUS_WAIT_FOR_FD;
-							}
-						} else {
-							c->file.mmap.offset = 0;
-							c->file.mmap.length = c->file.copy.length; /* align to page-size */
-				
-							c->file.mmap.start = mmap(0, c->file.mmap.length,
-									PROT_READ | PROT_WRITE, MAP_SHARED, mmap_fd, 0);
-							if (c->file.mmap.start == MAP_FAILED) {
-								return NETWORK_STATUS_FATAL_ERROR;
-							}
-				
-							close(mmap_fd);
-							mmap_fd = -1;
+						c->file.mmap.offset = 0;
+						c->file.mmap.length = c->file.copy.length; /* align to page-size */
+			
+						c->file.mmap.start = mmap(0, c->file.mmap.length,
+								PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+						if (c->file.mmap.start == MAP_FAILED) {
+							return NETWORK_STATUS_FATAL_ERROR;
 						}
 					}