inotify: stop active watchers when sync is disabled - #115
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When sync is disabled, active DataWatcher instances may remain blocked waiting for an inotify event in onDataChange(). This prevents the monitor coroutines from exiting immediately. If sync is re-enabled before the old monitor coroutine exits, the code can still use the existing watcher. The new monitor task can enter onDataChange() while the old monitor task is already waiting on the same fdio object. sdbusplus fdio rejects a second pending await on the same fdio object, so the service terminates with: ``` what(): fdio_completion started with another await already pending! ``` Add DataWatcher::stop() to remove the active inotify watch descriptors. Removing a watch generates an IN_IGNORED event, which makes the inotify file descriptor readable and wakes the pending fdio::next() operation. IN_IGNORED is not treated as a data change, so no sync operation is triggered. Once onDataChange() returns, the monitor loop observes that sync is disabled and exits. The existing scope cleanup then removes the DataWatcher from the active watcher map. During failover, the passive BMC becomes active without restarting the application. Any watcher created for the previous BMC role may therefore remain active. Stopping the existing watchers ensures that they are removed before sync events are started again for the new BMC role. Call stop() for all active watchers when the DisableSync property is set. Change-Id: I7e21ded548ff56eeaf7885aeafdefc7fd3a3c13c Signed-off-by: Manish Tiwari <tmanish.in@gmail.com>
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…bm-openbmc#110)" This fix is no longer needed as the root cause is addressed in the commit c0eeccb. This reverts commit 79c8879. Change-Id: I79a55c8dcecac6f1ed05c674546953077a45861b Signed-off-by: Manish Tiwari <tmanish.in@gmail.com>
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When sync is disabled, active DataWatcher instances may remain blocked waiting for an inotify event in onDataChange(). This prevents the monitor coroutines from exiting immediately.
Add DataWatcher::stop() to remove the active inotify watch descriptors. Removing a watch generates an IN_IGNORED event, which makes the inotify file descriptor readable and wakes the pending fdio::next() operation.
IN_IGNORED is not treated as a data change, so no sync operation is triggered. Once onDataChange() returns, the monitor loop observes that sync is disabled and exits. The existing scope cleanup then removes the DataWatcher from the active watcher map.
During failover, the passive BMC becomes active without restarting the application. Any watcher created for the previous BMC role may therefore remain active. Stopping the existing watchers ensures that they are removed before sync events are started again for the new BMC role.
Call stop() for all active watchers when the DisableSync property is set.