NAS-139155 / None / nvme-pci: use NSSR to avoid CAP.TO and optimize timeout handling#238
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Reduce hung device recovery time using NSSR and optimized timeouts: - Skip abort commands and go directly to reset (following FreeBSD) - Trigger NSSR on hotplug-capable slots for fast device removal - Skip explicit queue deletion during reset (saves admin_timeout) - Detect hung devices after first CAP.TO by checking controller state - Skip re-enable in reset_work for hung devices (saves second CAP.TO) - Remove namespaces immediately for hung devices after DEAD state NSSR path (NSSR supported + hotplug-capable): After io_timeout (30s), trigger NSSR which causes PCIe link down. pciehp detects link state change and calls nvme_remove() for immediate device removal. Total recovery time: ~30s. Non-NSSR path (NSSR not supported or non-hotplug slot): After io_timeout (30s), proceed with controller reset. Hung device detection after first CAP.TO prevents second CAP.TO wait in reset_work. With default CAP.TO (~45s), total recovery time: ~75s. Previously, hung device recovery took io_timeout×2 + admin_timeout + CAP.TO×2. With defaults (io_timeout=30s, admin_timeout=60s, CAP.TO=45s), this was ~210s. Namespace removal for hung devices cleans up stale block devices that previously remained visible despite dead controller, enabling proper drive replacement workflows. Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
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Reduce hung device recovery time using
NSSRand optimized timeouts:NSSRon hotplug-capable slots for fast device removaladmin_timeout)CAP.TOby checking controller stateCAP.TO)DEADstateNSSR path (NSSR supported + hotplug-capable):
After io_timeout (30s), trigger NSSR which causes PCIe link down. pciehp detects link state change and calls nvme_remove() for immediate device removal. Total recovery time: ~30s.
Non-NSSR path (NSSR not supported or non-hotplug slot):
After
io_timeout(30s), proceed with controller reset. Hung device detection after firstCAP.TOprevents secondCAP.TOwait inreset_work(). With defaultCAP.TO(~45s), total recovery time: ~75s.Previously, hung device recovery took
io_timeout×2+admin_timeout+CAP.TO×2. With defaults (io_timeout=30s, admin_timeout=60s, CAP.TO=45s), this was ~210s.Namespace removal for hung devices cleans up stale block devices that previously remained visible despite dead controller, enabling proper drive replacement workflows.
Testing