[pve-devel] [PATCH common 1/1] sync_mountpoint: open path so that sync works

[Stoiko Ivanov <s.ivanov@proxmox.com>]

sync_mountpoint takes a path, gets an open filedescriptor and calls
syncfs(2) on it.
by opening with O_PATH the syncfs call fails with EBADF (see open(2)).

found by running:
```
pkill -f 'pvedaemon worker';
strace -yyttT -s 512 -o /tmp/trace -fp $(pgrep -f pvedaemon$)
```

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
---
 src/PVE/Tools.pm | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/PVE/Tools.pm b/src/PVE/Tools.pm
index e04b504..7eb1197 100644
--- a/src/PVE/Tools.pm
+++ b/src/PVE/Tools.pm
@@ -94,6 +94,7 @@ use constant {CLONE_NEWNS   => 0x00020000,
               CLONE_NEWNET  => 0x40000000};
 
 use constant {O_PATH    => 0x00200000,
+              O_CLOEXEC => 0x00080000,
               O_TMPFILE => 0x00410000}; # This includes O_DIRECTORY
 
 use constant {AT_EMPTY_PATH => 0x1000,
@@ -1432,7 +1433,7 @@ sub fsync($) {
 
 sub sync_mountpoint {
     my ($path) = @_;
-    sysopen my $fd, $path, O_PATH or die "failed to open $path: $!\n";
+    sysopen my $fd, $path, O_RDONLY|O_CLOEXEC or die "failed to open $path: $!\n";
     my $result = syncfs(fileno($fd));
     close($fd);
     return $result;
-- 
2.20.1