[RFC PATCH v2 1/7] IB/mlx5: Change ib_umem_odp_map_dma_single_page() to retain umem_mutex

Daisuke Matsuda
2022-11-11T09:24:02Z

ib_umem_odp_map_dma_single_page(), which has been used only by the mlx5
driver, holds umem_mutex on success and releases on failure. This
behavior is not convenient for other drivers to use it, so change it to
always retain mutex on return.

Signed-off-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>
---
drivers/infiniband/core/umem_odp.c | 8 +++-----
drivers/infiniband/hw/mlx5/odp.c | 4 +++-
2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c
index e9fa22d31c23..49da6735f7c8 100644
--- a/drivers/infiniband/core/umem_odp.c
+++ b/drivers/infiniband/core/umem_odp.c
@@ -328,8 +328,8 @@ static int ib_umem_odp_map_dma_single_page(
*
* Maps the range passed in the argument to DMA addresses.
* The DMA addresses of the mapped pages is updated in umem_odp->dma_list.
- * Upon success the ODP MR will be locked to let caller complete its device
- * page table update.
+ * The umem mutex is locked in this function. Callers are responsible for
+ * releasing the lock.
*
* Returns the number of pages mapped in success, negative error code
* for failure.
@@ -453,11 +453,9 @@ int ib_umem_odp_map_dma_and_lock(struct ib_umem_odp *umem_odp, u64 user_virt,
break;
}
}
- /* upon success lock should stay on hold for the callee */
+
if (!ret)
ret = dma_index - start_idx;
- else
- mutex_unlock(&umem_odp->umem_mutex);

out_put_mm:
mmput_async(owning_mm);
diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c
index bc97958818bb..a0de27651586 100644
--- a/drivers/infiniband/hw/mlx5/odp.c
+++ b/drivers/infiniband/hw/mlx5/odp.c
@@ -572,8 +572,10 @@ static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
access_mask |= ODP_WRITE_ALLOWED_BIT;

np = ib_umem_odp_map_dma_and_lock(odp, user_va, bcnt, access_mask, fault);
- if (np < 0)
+ if (np < 0) {
+ mutex_unlock(&odp->umem_mutex);
return np;
+ }

/*
* No need to check whether the MTTs really belong to this MR, since
--
2.31.1