In nvme_completion_poll, add a sanity check to make sure that we complete the

polling within a second. Panic if we don't. All the commands that use this
interface should typically complete within a few tens to hundreds of
microseconds. Panic rather than return ETIMEDOUT because if the command somehow
does later complete, it will randomly corrupt memory. Also, it helps to get a
traceback from where the unexpected failure happens, rather than an infinite
loop.
This commit is contained in:
imp 2019-09-02 17:11:32 +00:00
parent 2672b80261
commit 2d33613528

View File

@ -446,12 +446,24 @@ int nvme_attach(device_t dev);
int nvme_shutdown(device_t dev);
int nvme_detach(device_t dev);
/*
* Wait for a command to complete using the nvme_completion_poll_cb.
* Used in limited contexts where the caller knows it's OK to block
* briefly while the command runs. The ISR will run the callback which
* will set status->done to true.usually within microseconds. A 1s
* pause means something is seriously AFU and we should panic to
* provide the proper context to diagnose.
*/
static __inline
void
nvme_completion_poll(struct nvme_completion_poll_status *status)
{
while (!atomic_load_acq_int(&status->done))
int sanity = hz * 1;
while (!atomic_load_acq_int(&status->done) && --sanity > 0)
pause("nvme", 1);
if (sanity <= 0)
panic("NVME polled command failed to complete within 1s.");
}
static __inline void