From 7523d834dd1573610078eb1ac0933f6490232f90 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 16 Mar 2011 16:43:40 -0400 Subject: [PATCH] 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: Matthew Wilcox --- drivers/block/nvme.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c index 0d5c918b7d59..cf89db8c41ee 100644 --- a/drivers/block/nvme.c +++ b/drivers/block/nvme.c @@ -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; -- 2.39.5