Shuhei Matsumoto 576a373d58 lib/nvme: Abort queued requests whose cb_arg matches
Use another list dedicated to hold queued requests being aborted
to avoid potential infinite recursive calls.

Add a helper function nvme_qpair_abort_queued_req() to move requests
whose cb_arg matches from qpair->queued_req to qpair->aborted_queued_req.
Then nvme_qpair_resubmit_requests() aborts all requests in
qpair->aborted_queued_req.

The first idea was that nvme_qpair_abort_queued_req() aborts queued
requests directly. However, this caused infinite recursive calls.
Hence separate requesting abort to queued requests and actually
aborting queued requests.

The detail of the infinite recursive calls is as follows:

Some SPDK tool submits the next request from the callback to the completion
of a request in the completion polling loop. For such tool, if the callback
submits a request and then aborts the request immediately, and the request
could not be submitted but queued, it will create infinite recursive calls
by request submit and abort, and it will not be able to get out of
completion polling loop.

Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: I8196182b981bc52dee2074d7642498a5d6ef97d4
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/2891
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Mellanox Build Bot
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
2020-07-13 08:40:42 +00:00
..
2020-06-18 07:28:04 +00:00