The patch below does not apply to the 5.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7608bf40cf2480057ec0da31456cc428791c32ef Mon Sep 17 00:00:00 2001

From: Jason Gunthorpe jgg@mellanox.com Date: Tue, 11 Jun 2019 13:09:51 -0300 Subject: [PATCH] RDMA/odp: Fix missed unlock in non-blocking invalidate_start

If invalidate_start returns with EAGAIN then the umem_rwsem needs to be unlocked as no invalidate_end will be called.

Cc: stable@vger.kernel.org Fixes: ca748c39ea3f ("RDMA/umem: Get rid of per_mm->notifier_count") Signed-off-by: Jason Gunthorpe jgg@mellanox.com Reviewed-by: Leon Romanovsky leonro@mellanox.com Signed-off-by: Doug Ledford dledford@redhat.com

diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c index 9001cc10770a..eb9939d52818 100644 --- a/drivers/infiniband/core/umem_odp.c +++ b/drivers/infiniband/core/umem_odp.c @@ -149,6 +149,7 @@ static int ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn, { struct ib_ucontext_per_mm *per_mm = container_of(mn, struct ib_ucontext_per_mm, mn); + int rc;

if (mmu_notifier_range_blockable(range)) down_read(&per_mm->umem_rwsem); @@ -165,11 +166,14 @@ static int ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn, return 0; }

- return rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, range->start, - range->end, - invalidate_range_start_trampoline, - mmu_notifier_range_blockable(range), - NULL); + rc = rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, range->start, + range->end, + invalidate_range_start_trampoline, + mmu_notifier_range_blockable(range), + NULL); + if (rc) + up_read(&per_mm->umem_rwsem); + return rc; }

static int invalidate_range_end_trampoline(struct ib_umem_odp *item, u64 start,