Commit b16de8b9 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Leon Romanovsky
Browse files

RDMA: Handle the return code from dma_resv_wait_timeout() properly 

ib_umem_dmabuf_map_pages() returns 0 on success and -ERRNO on failure.

dma_resv_wait_timeout() uses a different scheme:

 * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or
 * greater than zero on success.

This results in ib_umem_dmabuf_map_pages() being non-functional as a
positive return will be understood to be an error by drivers.

Fixes: f30bceab ("RDMA: use dma_resv_wait() instead of extracting the fence")
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/0-v1-d8f4e1fa84c8+17-rdma_dmabuf_fix_jgg@nvidia.com


Tested-by: default avatarMaor Gottlieb <maorg@nvidia.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
parent 6cd8351c

drivers/infiniband/core/umem_dmabuf.c

+7 −1
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf) 
	struct scatterlist *sg;

	unsigned long start, end, cur = 0;

	unsigned int nmap = 0;

	long ret;

	int i;



	dma_resv_assert_held(umem_dmabuf->attach->dmabuf->resv);
@@ -67,9 +68,14 @@ int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf) 
	 * may be not up-to-date. Wait for the exporter to finish

	 * the migration.

	 */

	return dma_resv_wait_timeout(umem_dmabuf->attach->dmabuf->resv,

	ret = dma_resv_wait_timeout(umem_dmabuf->attach->dmabuf->resv,

				     DMA_RESV_USAGE_KERNEL,

				     false, MAX_SCHEDULE_TIMEOUT);

	if (ret < 0)

		return ret;

	if (ret == 0)

		return -ETIMEDOUT;

	return 0;

}

EXPORT_SYMBOL(ib_umem_dmabuf_map_pages);