When there are two bdevs built on the same io_device,
it is possible that one bdev entirely saturates
underlying queue, not letting the second bdev issue
a single I/O. The second bdev will silently fail any
subsequent I/O and append it to the nomem_io list.
However, since we resend I/O only from I/O completion
callback and there's no outstanding I/O for that bdev
(io_outstanding==0), the I/O will never be resent.
It'll be stuck in nomem_io forever.
This patch makes nomem_io list to be shared between
bdevs built on the same device. It is now possible
that I/O completion callback from one bdev will retry
sending I/O from other bdev.
The shared bdev data is based on thread-local
bdev_mgmt_channel, so doesn't need any external
synchronization.
Change-Id: Ia5ac3a1627ce3de4087e43907c329aa7d07ed7c7
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/394658
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ziye Yang <optimistyzy@gmail.com>
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