nvme: fix setting the queue depth in nvme_alloc_io_tag_set

While the CAP.MQES field in NVMe is a 0s based filed with a natural one
off, we also need to account for the queue wrap condition and fix undo
the one off again in nvme_alloc_io_tag_set.  This was never properly
done by the fabrics drivers, but they don't seem to care because there
is no actual physical queue that can wrap around, but it became a
problem when converting over the PCIe driver.  Also add back the
BLK_MQ_MAX_DEPTH check that was lost in the same commit.

Fixes: 0da7feaa59 ("nvme-pci: use the tagset alloc/free helpers")
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Hugh Dickins <hughd@google.com>
Link: https://lore.kernel.org/r/20221225103234.226794-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig 2022-12-25 11:32:31 +01:00 committed by Jens Axboe
parent 246cf66e30
commit 33b93727ce

View File

@ -4897,7 +4897,7 @@ int nvme_alloc_io_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
memset(set, 0, sizeof(*set));
set->ops = ops;
set->queue_depth = ctrl->sqsize + 1;
set->queue_depth = min_t(unsigned, ctrl->sqsize, BLK_MQ_MAX_DEPTH - 1);
/*
* Some Apple controllers requires tags to be unique across admin and
* the (only) I/O queue, so reserve the first 32 tags of the I/O queue.