kernel/drivers/nvme/host/multipath.c, branch linux-6.9.y

nvme-multipath: find NUMA path only for online numa-node

2024-07-11T10:51:21Z

[ Upstream commit d3a043733f25d743f3aa617c7f82dbcb5ee2211a ] In current native multipath design when a shared namespace is created, we loop through each possible numa-node, calculate the NUMA distance of that node from each nvme controller and then cache the optimal IO path for future reference while sending IO. The issue with this design is that we may refer to the NUMA distance table for an offline node which may not be populated at the time and so we may inadvertently end up finding and caching a non-optimal path for IO. Then latter when the corresponding numa-node becomes online and hence the NUMA distance table entry for that node is created, ideally we should re-calculate the multipath node distance for the newly added node however that doesn't happen unless we rescan/reset the controller. So essentially, we may keep using non-optimal IO path for a node which is made online after namespace is created. This patch helps fix this issue ensuring that when a shared namespace is created, we calculate the multipath node distance for each online numa-node instead of each possible numa-node. Then latter when a node becomes online and we receive any IO on that newly added node, we would calculate the multipath node distance for newly added node but this time NUMA distance table would have been already populated for newly added node. Hence we would be able to correctly calculate the multipath node distance and choose the optimal path for the IO. Signed-off-by: Nilay Shroff Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch Signed-off-by: Sasha Levin

nvme-multipath: fix io accounting on failover

2024-06-12T09:39:46Z

[ Upstream commit a2e4c5f5f68dbd206f132bc709b98dea64afc3b8 ] There are io stats accounting that needs to be handled, so don't call blk_mq_end_request() directly. Use the existing nvme_end_req() helper that already handles everything. Fixes: d4d957b53d91ee ("nvme-multipath: support io stats on the mpath device") Reviewed-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Signed-off-by: Keith Busch Signed-off-by: Sasha Levin

nvme: find numa distance only if controller has valid numa id

2024-05-01T09:58:42Z

On system where native nvme multipath is configured and iopolicy is set to numa but the nvme controller numa node id is undefined or -1 (NUMA_NO_NODE) then avoid calculating node distance for finding optimal io path. In such case we may access numa distance table with invalid index and that may potentially refer to incorrect memory. So this patch ensures that if the nvme controller numa node id is -1 then instead of calculating node distance for finding optimal io path, we set the numa node distance of such controller to default 10 (LOCAL_DISTANCE). Link: https://lore.kernel.org/all/20240413090614.678353-1-nilay@linux.ibm.com/ Signed-off-by: Nilay Shroff Reviewed-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Chaitanya Kulkarni Signed-off-by: Keith Busch

nvme-multipath: pass queue_limits to blk_alloc_disk

2024-03-04T16:24:56Z

The multipath disk starts out with the stacking default limits. The one interesting part here is that blk_set_stacking_limits sets the max_zone_append_sectorts to UINT_MAX, which fails the validation for non-zoned devices. With the old one call per limit scheme this was fine because no one verified this weird mismatch and it was fixed by blk_stack_limits a little later before I/O could be issued. Signed-off-by: Christoph Hellwig Signed-off-by: Keith Busch

block: pass a queue_limits argument to blk_alloc_disk

2024-02-19T23:58:23Z

Pass a queue_limits to blk_alloc_disk and apply it if non-NULL. This will allow allocating queues with valid queue limits instead of setting the values one at a time later. Also change blk_alloc_disk to return an ERR_PTR instead of just NULL which can't distinguish errors. Signed-off-by: Christoph Hellwig Reviewed-by: Dan Williams Reviewed-by: Himanshu Madhani Link: https://lore.kernel.org/r/20240215071055.2201424-2-hch@lst.de Signed-off-by: Jens Axboe

nvme: use ctrl state accessor

2024-01-29T15:02:50Z

The ctrl->state value is updated in another thread using WRITE_ONCE, so ensure all the readers use the appropriate accessor. Reviewed-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Signed-off-by: Keith Busch

nvme: rename ns attribute group

2023-12-19T17:10:05Z

Drop the 'id' part of the attribute group name because we want to expose non 'id' related attributes via the ns attribute group. Reviewed-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Hannes Reinecke Signed-off-by: Daniel Wagner Signed-off-by: Keith Busch

Merge tag 'nvme-6.5-2023-06-30' of git://git.infradead.org/nvme into block-6.5

2023-06-30T20:04:08Z

Pull NVMe fixes from Keith: "nvme fixes for Linux 6.5 - Reduce spamming kernel logs on repeated controller updates (Breno) - Improved struct packing (Christophe JAILLET) - Misspelled command name in error logging (Damien) - Failover fix for temporary frozen queue (Sagi) - Reset error handling fixes (Keith)" * tag 'nvme-6.5-2023-06-30' of git://git.infradead.org/nvme: nvme: disable controller on reset state failure nvme: sync timeout work on failed reset nvme: ensure unquiesce on teardown nvme-mpath: fix I/O failure with EAGAIN when failing over I/O nvme: host: fix command name spelling nvmet: Reorder fields in 'struct nvmet_ns' nvme: Print capabilities changes just once

nvme: improved uring polling

2023-06-28T22:09:41Z

Drivers can poll requests directly, so use that. We just need to ensure the driver's request was allocated from a polled hctx, so a special driver flag is added to struct io_uring_cmd. The allows unshared and multipath namespaces to use the same polling callback, and multipath is guaranteed to get the same queue as the command was submitted on. Previously multipath polling might check a different path and poll the wrong info. The other bonus is we don't need a bio payload in order to poll, allowing commands like 'flush' and 'write zeroes' to be submitted on the same high priority queue as read and write commands. Finally, using the request based polling skips the unnecessary bio overhead. Signed-off-by: Keith Busch Reviewed-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230612190343.2087040-3-kbusch@meta.com Signed-off-by: Jens Axboe

nvme-mpath: fix I/O failure with EAGAIN when failing over I/O

2023-06-27T15:16:26Z

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 Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch