IB/core: Make ib_dealloc_pd return void

The majority of callers never check the return value, and even if they
did, they can't do anything about a failure.

All possible failure cases represent a bug in the caller, so just
WARN_ON inside the function instead.

This fixes a few random errors:
 net/rd/iw.c infinite loops while it fails. (racing with EBUSY?)

This also lays the ground work to get rid of error return from the
drivers. Most drivers do not error, the few that do are broken since
it cannot be handled.

Since uverbs can legitimately make use of EBUSY, open code the
check.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 16 insertions, 6 deletions

diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 258485ee46b2..4c98696e3626 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -606,6 +606,7 @@ ssize_t ib_uverbs_dealloc_pd(struct ib_uverbs_file *file,
 {
 	struct ib_uverbs_dealloc_pd cmd;
 	struct ib_uobject          *uobj;
+	struct ib_pd		   *pd;
 	int                         ret;
 
 	if (copy_from_user(&cmd, buf, sizeof cmd))
@@ -614,15 +615,20 @@ ssize_t ib_uverbs_dealloc_pd(struct ib_uverbs_file *file,
 	uobj = idr_write_uobj(&ib_uverbs_pd_idr, cmd.pd_handle, file->ucontext);
 	if (!uobj)
 		return -EINVAL;
+	pd = uobj->object;
 
-	ret = ib_dealloc_pd(uobj->object);
-	if (!ret)
-		uobj->live = 0;
-
-	put_uobj_write(uobj);
+	if (atomic_read(&pd->usecnt)) {
+		ret = -EBUSY;
+		goto err_put;
+	}
 
+	ret = pd->device->dealloc_pd(uobj->object);
+	WARN_ONCE(ret, "Infiniband HW driver failed dealloc_pd");
 	if (ret)
-		return ret;
+		goto err_put;
+
+	uobj->live = 0;
+	put_uobj_write(uobj);
 
 	idr_remove_uobj(&ib_uverbs_pd_idr, uobj);
 
@@ -633,6 +639,10 @@ ssize_t ib_uverbs_dealloc_pd(struct ib_uverbs_file *file,
 	put_uobj(uobj);
 
 	return in_len;
+
+err_put:
+	put_uobj_write(uobj);
+	return ret;
 }
 
 struct xrcd_table_entry {