add qemu-img dd stdin/stdout pipe patch

[pve-qemu.git] / debian / patches / pve / 0048-vma-don-t-use-O_DIRECT-on-pipes.patch

From 47d2445ffc83bba6066beb67fa34075d75b5b4c2 Mon Sep 17 00:00:00 2001
From: Wolfgang Bumiller <w.bumiller@proxmox.com>
Date: Thu, 30 Mar 2017 16:05:34 +0200
Subject: [PATCH 48/49] vma: don't use O_DIRECT on pipes

It puts them in packet mode which potentially discards data.
(since kernel 4.5)
---
 vma-writer.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/vma-writer.c b/vma-writer.c
index 70dcca0771..9001cbdd2b 100644
--- a/vma-writer.c
+++ b/vma-writer.c
@@ -283,9 +283,8 @@ VmaWriter *vma_writer_create(const char *filename, uuid_t uuid, Error **errp)
         }
         vmaw->fd = fileno(vmaw->cmd);
 
-        /* try to use O_NONBLOCK and O_DIRECT */
+        /* try to use O_NONBLOCK */
         fcntl(vmaw->fd, F_SETFL, fcntl(vmaw->fd, F_GETFL)|O_NONBLOCK);
-        fcntl(vmaw->fd, F_SETFL, fcntl(vmaw->fd, F_GETFL)|O_DIRECT);
 
     } else {
         struct stat st;
@@ -293,19 +292,18 @@ VmaWriter *vma_writer_create(const char *filename, uuid_t uuid, Error **errp)
         const char *tmp_id_str;
 
         if ((stat(filename, &st) == 0) && S_ISFIFO(st.st_mode)) {
-            oflags = O_NONBLOCK|O_DIRECT|O_WRONLY;
+            oflags = O_NONBLOCK|O_WRONLY;
             vmaw->fd = qemu_open(filename, oflags, 0644);
         } else if (strstart(filename, "/dev/fdset/", &tmp_id_str)) {
-            oflags = O_NONBLOCK|O_DIRECT|O_WRONLY;
+            oflags = O_NONBLOCK|O_WRONLY;
             vmaw->fd = qemu_open(filename, oflags, 0644);
         } else if (strstart(filename, "/dev/fdname/", &tmp_id_str)) {
             vmaw->fd = monitor_get_fd(cur_mon, tmp_id_str, errp);
             if (vmaw->fd < 0) {
                 goto err;
             }
-            /* try to use O_NONBLOCK and O_DIRECT */
+            /* try to use O_NONBLOCK */
             fcntl(vmaw->fd, F_SETFL, fcntl(vmaw->fd, F_GETFL)|O_NONBLOCK);
-            fcntl(vmaw->fd, F_SETFL, fcntl(vmaw->fd, F_GETFL)|O_DIRECT);
         } else  {
             oflags = O_NONBLOCK|O_DIRECT|O_WRONLY|O_CREAT|O_EXCL;
             vmaw->fd = qemu_open(filename, oflags, 0644);
-- 
2.11.0