SUNRPC: Skip zero-refcount transports

When looking for the next transport to use for an RPC call, skip those
that are in the process of being destroyed and that have a zero refcount.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust 2019-07-16 07:07:28 -04:00
parent 3cf7292280
commit 163f88211c

View File

@ -193,10 +193,22 @@ void xprt_iter_default_rewind(struct rpc_xprt_iter *xpi)
WRITE_ONCE(xpi->xpi_cursor, NULL);
}
static
bool xprt_is_active(const struct rpc_xprt *xprt)
{
return kref_read(&xprt->kref) != 0;
}
static
struct rpc_xprt *xprt_switch_find_first_entry(struct list_head *head)
{
return list_first_or_null_rcu(head, struct rpc_xprt, xprt_switch);
struct rpc_xprt *pos;
list_for_each_entry_rcu(pos, head, xprt_switch) {
if (xprt_is_active(pos))
return pos;
}
return NULL;
}
static
@ -214,9 +226,12 @@ struct rpc_xprt *xprt_switch_find_current_entry(struct list_head *head,
const struct rpc_xprt *cur)
{
struct rpc_xprt *pos;
bool found = false;
list_for_each_entry_rcu(pos, head, xprt_switch) {
if (cur == pos)
found = true;
if (found && xprt_is_active(pos))
return pos;
}
return NULL;
@ -261,9 +276,12 @@ struct rpc_xprt *xprt_switch_find_next_entry(struct list_head *head,
const struct rpc_xprt *cur)
{
struct rpc_xprt *pos, *prev = NULL;
bool found = false;
list_for_each_entry_rcu(pos, head, xprt_switch) {
if (cur == prev)
found = true;
if (found && xprt_is_active(pos))
return pos;
prev = pos;
}