From fc3325701a6353594083f08e297d4c1965c601aa Mon Sep 17 00:00:00 2001
From: Jason Gunthorpe <jgg@nvidia.com>
Date: Mon, 26 Oct 2020 15:19:31 +0200
Subject: [PATCH 1/1] RDMA/mlx5: Fix corruption of reg_pages in
Git-commit: fc3325701a6353594083f08e297d4c1965c601aa
Patch-mainline: v5.11
References: git-fixes
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 <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Nicolas Morey-Chaisemartin <nmoreychaisemartin@suse.com>
---
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 50bbd07b9747..f3a28119d145 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -1248,10 +1248,8 @@ err_1:
}
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;
@@ -1291,8 +1289,7 @@ 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;
@@ -1420,7 +1417,9 @@ 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 (use_umr) {
int update_xlt_flags = MLX5_IB_UPD_XLT_ENABLE;
@@ -1524,8 +1523,6 @@ 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;
@@ -1554,12 +1551,17 @@ 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_use_umr(dev, true, access_flags) ||
@@ -1610,7 +1612,7 @@ 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;
--
2.31.1.5.g533053588dc3