diff mbox series

[1/3] runqemu: keep generating tap devices

Message ID GV1PR07MB9120F7AFD75828EBBA300C9AA8992@GV1PR07MB9120.eurprd07.prod.outlook.com
State New
Headers show
Series [1/3] runqemu: keep generating tap devices | expand

Commit Message

Konrad Weihmann Sept. 9, 2024, 8:32 a.m. UTC
in case there is no tap device the script tries to
generate a new one.
The new device is then unguarded for a moment, so
the newly generated device could be acquired
by a different instance or user, before it is locked to
the instance with acquire_taplock.
To fix that keep generating new tap devices in case
the lock can't be acquired up to 5 times.
If no tap device can be locked it fails in the existing
error handling

Signed-off-by: Konrad Weihmann <kweihmann@outlook.com>
---
 scripts/runqemu | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)
diff mbox series

Patch

diff --git a/scripts/runqemu b/scripts/runqemu
index 2817acb19f..cdbb625505 100755
--- a/scripts/runqemu
+++ b/scripts/runqemu
@@ -1195,16 +1195,20 @@  to your build configuration.
             uid = os.getuid()
             logger.info("Setting up tap interface under sudo")
             cmd = ('sudo', self.qemuifup, str(gid))
-            try:
-                tap = subprocess.check_output(cmd).decode('utf-8').strip()
-            except subprocess.CalledProcessError as e:
-                logger.error('Setting up tap device failed:\n%s\nRun runqemu-gen-tapdevs to manually create one.' % str(e))
-                sys.exit(1)
-            lockfile = os.path.join(lockdir, tap)
-            self.taplock = lockfile + '.lock'
-            self.acquire_taplock()
-            self.cleantap = True
-            logger.debug('Created tap: %s' % tap)
+            for _ in range(5):
+                try:
+                    tap = subprocess.check_output(cmd).decode('utf-8').strip()
+                except subprocess.CalledProcessError as e:
+                    logger.error('Setting up tap device failed:\n%s\nRun runqemu-gen-tapdevs to manually create one.' % str(e))
+                    sys.exit(1)
+                lockfile = os.path.join(lockdir, tap)
+                self.taplock = lockfile + '.lock'
+                if self.acquire_taplock():
+                    self.cleantap = True
+                    logger.debug('Created tap: %s' % tap)
+                    break
+                else:
+                    tap = None
 
         if not tap:
             logger.error("Failed to setup tap device. Run runqemu-gen-tapdevs to manually create.")