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

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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:
Warner Losh 2019-09-02 17:11:32 +00:00
parent ab0681aac9
commit 31b11bb3f2
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=351706
1 changed files with 13 additions and 1 deletions
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14
sys/dev/nvme/nvme_private.h
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@ -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