From c5c1af1107d60955a265eae3437ee18b33138039 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Mon, 26 Oct 2020 15:19:31 +0200 Subject: [PATCH] RDMA/mlx5: Fix corruption of reg_pages in mlx5_ib_rereg_user_mr() [ Upstream commit fc3325701a6353594083f08e297d4c1965c601aa ] reg_pages should always contain mr->npage since when the mr is finally de-reg'd it is always subtracted out. If there were any error exits then mlx5_ib_rereg_user_mr() would leave the reg_pages adjusted and this will cause it to be double subtracted eventually. The manipulation of reg_pages is inherently connected to the umem, so lift it out of set_mr_fields() and only adjust it around creating/destroying a umem. reg_pages is only used for diagnostics in sysfs. Fixes: 7d0cc6edcc70 ("IB/mlx5: Add MR cache for large UMR regions") Link: https://lore.kernel.org/r/20201026131936.1335664-3-leon@kernel.org Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/hw/mlx5/mr.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c index b261797b258f..3468ae804eae 100644 --- a/drivers/infiniband/hw/mlx5/mr.c +++ b/drivers/infiniband/hw/mlx5/mr.c @@ -1247,10 +1247,8 @@ static struct mlx5_ib_mr *reg_create(struct ib_mr *ibmr, struct ib_pd *pd, } static void set_mr_fields(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr, - int npages, u64 length, int access_flags) + u64 length, int access_flags) { - mr->npages = npages; - atomic_add(npages, &dev->mdev->priv.reg_pages); mr->ibmr.lkey = mr->mmkey.key; mr->ibmr.rkey = mr->mmkey.key; mr->ibmr.length = length; @@ -1290,8 +1288,7 @@ static struct ib_mr *mlx5_ib_get_dm_mr(struct ib_pd *pd, u64 start_addr, kfree(in); - mr->umem = NULL; - set_mr_fields(dev, mr, 0, length, acc); + set_mr_fields(dev, mr, length, acc); return &mr->ibmr; @@ -1419,7 +1416,9 @@ struct ib_mr *mlx5_ib_reg_user_mr(struct ib_pd *pd, u64 start, u64 length, mlx5_ib_dbg(dev, "mkey 0x%x\n", mr->mmkey.key); mr->umem = umem; - set_mr_fields(dev, mr, npages, length, access_flags); + mr->npages = npages; + atomic_add(mr->npages, &dev->mdev->priv.reg_pages); + set_mr_fields(dev, mr, length, access_flags); if (xlt_with_umr && !(access_flags & IB_ACCESS_ON_DEMAND)) { /* @@ -1531,8 +1530,6 @@ int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start, mlx5_ib_dbg(dev, "start 0x%llx, virt_addr 0x%llx, length 0x%llx, access_flags 0x%x\n", start, virt_addr, length, access_flags); - atomic_sub(mr->npages, &dev->mdev->priv.reg_pages); - if (!mr->umem) return -EINVAL; @@ -1553,12 +1550,17 @@ int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start, * used. */ flags |= IB_MR_REREG_TRANS; + atomic_sub(mr->npages, &dev->mdev->priv.reg_pages); + mr->npages = 0; ib_umem_release(mr->umem); mr->umem = NULL; + err = mr_umem_get(dev, addr, len, access_flags, &mr->umem, &npages, &page_shift, &ncont, &order); if (err) goto err; + mr->npages = ncont; + atomic_add(mr->npages, &dev->mdev->priv.reg_pages); } if (!mlx5_ib_can_reconfig_with_umr(dev, mr->access_flags, @@ -1609,7 +1611,7 @@ int mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start, goto err; } - set_mr_fields(dev, mr, npages, len, access_flags); + set_mr_fields(dev, mr, len, access_flags); return 0;