RDMA/umem: Do not use current->tgid to track the mm_struct

This is just wrong, the process that calls into the reg_mr is the process
associated with the umem, and that does not have to be the same process
that created the context.

When this code was first written mmgrab() didn't exist, however these days
we can just directly hold the mm_struct pointer in the umem and have no
ambiguity when it comes to releasing the umem as to which mm it was
associated with.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/include/rdma/ib_umem.h b/include/rdma/ib_umem.h
index a1fd63871d17..e1c00b2ead19 100644
--- a/include/rdma/ib_umem.h
+++ b/include/rdma/ib_umem.h
@@ -42,14 +42,13 @@ struct ib_umem_odp;
 
 struct ib_umem {
 	struct ib_ucontext     *context;
+	struct mm_struct       *owning_mm;
 	size_t			length;
 	unsigned long		address;
 	int			page_shift;
 	int                     writable;
 	int                     hugetlb;
 	struct work_struct	work;
-	struct mm_struct       *mm;
-	unsigned long		diff;
 	struct ib_umem_odp     *odp_data;
 	struct sg_table sg_head;
 	int             nmap;