Commit 7523d834 authored by Matthew Wilcox's avatar Matthew Wilcox
Browse files

NVMe: Fix off-by-one when filling in PRP lists 



If the last element in the PRP list fits on the end of the page, there's
no need to allocate an extra page to put that single element in.  It can
fit on the end of the page.

Signed-off-by: default avatarMatthew Wilcox <matthew.r.wilcox@intel.com>
parent ac88c36a

drivers/block/nvme.c

+4 −3
Original line number Diff line number Diff line
@@ -376,12 +376,13 @@ static struct nvme_prps *nvme_setup_prps(struct nvme_dev *dev, 
	cmd->prp2 = cpu_to_le64(prp_dma);

	i = 0;

	for (;;) {

		if (i == PAGE_SIZE / 8 - 1) {

		if (i == PAGE_SIZE / 8) {

			__le64 *old_prp_list = prp_list;

			prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma);

			prps->list[prp_page++] = prp_list;

			old_prp_list[i] = cpu_to_le64(prp_dma);

			i = 0;

			prp_list[0] = old_prp_list[i - 1];

			old_prp_list[i - 1] = cpu_to_le64(prp_dma);

			i = 1;

		}

		prp_list[i++] = cpu_to_le64(dma_addr);

		dma_len -= PAGE_SIZE;

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