diff options
| author | Sagi Grimberg <sagi@grimberg.me> | 2023-06-20 16:07:36 +0300 |
|---|---|---|
| committer | Keith Busch <kbusch@kernel.org> | 2023-06-27 18:16:26 +0300 |
| commit | 99160af413b4ff1c3b4741e8a7583f8e7197f201 (patch) | |
| tree | adf32076c3531b9da2baf01981ab261e4c6a241d /drivers/nvme | |
| parent | 86da1bae4c64ab3dcbdda0c77ce37c9bf47a501f (diff) | |
| download | linux-99160af413b4ff1c3b4741e8a7583f8e7197f201.tar.xz | |
nvme-mpath: fix I/O failure with EAGAIN when failing over I/O
It is possible that the next available path we failover to, happens to
be frozen (for example if it is during connection establishment). If
the original I/O was set with NOWAIT, this cause the I/O to unnecessarily
fail because the request queue cannot be entered, hence the I/O fails with
EAGAIN.
The NOWAIT restriction that was originally set for the I/O is no longer
relevant or needed because this is the nvme requeue context. Hence we
clear the REQ_NOWAIT flag when failing over I/O.
This fix a simple test case of nvme controller reset during I/O when the
multipath device that has only a single path and I/O fails with "Resource
temporarily unavailable" errno. Note that this reproduces with io_uring
which by default sets IOCB_NOWAIT by default.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Diffstat (limited to 'drivers/nvme')
| -rw-r--r-- | drivers/nvme/host/multipath.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 91a9a55227fa..3acb47760e24 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -106,6 +106,14 @@ void nvme_failover_req(struct request *req) bio->bi_opf &= ~REQ_POLLED; bio->bi_cookie = BLK_QC_T_NONE; } + /* + * The alternate request queue that we may end up submitting + * the bio to may be frozen temporarily, in this case REQ_NOWAIT + * will fail the I/O immediately with EAGAIN to the issuer. + * We are not in the issuer context which cannot block. Clear + * the flag to avoid spurious EAGAIN I/O failures. + */ + bio->bi_opf &= ~REQ_NOWAIT; } blk_steal_bios(&ns->head->requeue_list, req); spin_unlock_irqrestore(&ns->head->requeue_lock, flags); |