[PATCH] util: retry open() when it gets interrupted by a signal

[Philipp Reisner]

As with many syscalls, open() might be interrupted by a signal.

The experienced logfile entry is:

qemu-system-x86_64: -device 
virtio-blk-pci,bus=pci.0,addr=0x7,drive=libvirt-2-format,id=virtio-disk0,bootindex=2,write-cache=on,serial=1b990c4d13b74a4e90ea:
 Could not open '/dev/drbd1003': Interrupted system call

Retry it until it is not interrupted by a signal.
FYI, dd has the same kind of loop aroud open().
https://github.com/coreutils/coreutils/blob/1ae98dbda7322427e8226356fd110d2553f5fac9/src/dd.c#L1294-L1299

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
---
 util/osdep.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/util/osdep.c b/util/osdep.c
index 770369831b..a1269d9345 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -294,14 +294,17 @@ bool qemu_has_direct_io(void)
 static int qemu_open_cloexec(const char *name, int flags, mode_t mode)
 {
     int ret;
+    do  {
 #ifdef O_CLOEXEC
-    ret = open(name, flags | O_CLOEXEC, mode);
+        ret = open(name, flags | O_CLOEXEC, mode);
 #else
-    ret = open(name, flags, mode);
-    if (ret >= 0) {
-        qemu_set_cloexec(ret);
-    }
+        ret = open(name, flags, mode);
+        if (ret >= 0) {
+            qemu_set_cloexec(ret);
+        }
 #endif
+    } while (ret == -1 && errno == EINTR);
+
     return ret;
 }
 
-- 
2.45.2