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: f30bceab16 ("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: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
This commit is contained in:
Jason Gunthorpe 2022-08-16 11:03:20 -03:00 committed by Leon Romanovsky
parent 6cd8351c4e
commit b16de8b9e7

View file

@ -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);