[ Upstream commit 958f2a0f8121ae36a5cbff383ab94fadf1fba5eb ]
There was a few false alarms sighted on target side about wrong data digest while performing high throughput load to XFS filesystem shared through NVMoF TCP.
This flag tells the rest of the kernel to ensure that the data buffer does not change while the write is in flight. It incurs a performance penalty, so only enable it when it is actually needed, i.e. when we are calculating data digests.
Although even with this change in place, ext2 users can steel experience false positives, as ext2 is not respecting this flag. This may be apply to vfat as well.
Signed-off-by: Mikhail Skorzhinskii mskorzhinskiy@solarflare.com Signed-off-by: Mike Playle mplayle@solarflare.com Reviewed-by: Sagi Grimberg sagi@grimberg.me Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/core.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 22c68e3b71d5..215bef904b7b 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -11,6 +11,7 @@ #include <linux/hdreg.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/backing-dev.h> #include <linux/list_sort.h> #include <linux/slab.h> #include <linux/types.h> @@ -3256,6 +3257,10 @@ static int nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) goto out_free_ns; }
+ if (ctrl->opts->data_digest) + ns->queue->backing_dev_info->capabilities + |= BDI_CAP_STABLE_WRITES; + blk_queue_flag_set(QUEUE_FLAG_NONROT, ns->queue); if (ctrl->ops->flags & NVME_F_PCI_P2PDMA) blk_queue_flag_set(QUEUE_FLAG_PCI_P2PDMA, ns->queue);