diff options
| author | Jason Gunthorpe <jgg@nvidia.com> | 2020-08-18 15:05:18 +0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2020-08-27 08:38:15 -0300 |
| commit | d114c6feedfe0600c19b9f9479a4026354d1f7fd (patch) | |
| tree | 14e0ad035061b8d22bf950bb0de6a7977fee2fd0 /drivers/infiniband/core/ucma.c | |
| parent | 95fe51096b7adf1d1e7315c49c75e2f75f162584 (diff) | |
RDMA/cma: Add missing locking to rdma_accept()
In almost all cases rdma_accept() is called under the handler_mutex by
ULPs from their handler callbacks. The one exception was ucma which did
not get the handler_mutex.
To improve the understand-ability of the locking scheme obtain the mutex
for ucma as well.
This improves how ucma works by allowing it to directly use handler_mutex
for some of its internal locking against the handler callbacks intead of
the global file->mut lock.
There does not seem to be a serious bug here, other than a DISCONNECT event
can be delivered concurrently with accept succeeding.
Link: https://lore.kernel.org/r/20200818120526.702120-7-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband/core/ucma.c')
| -rw-r--r-- | drivers/infiniband/core/ucma.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c index dd12931f3038..add1ece38739 100644 --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -1162,16 +1162,20 @@ static ssize_t ucma_accept(struct ucma_file *file, const char __user *inbuf, if (cmd.conn_param.valid) { ucma_copy_conn_param(ctx->cm_id, &conn_param, &cmd.conn_param); - mutex_lock(&file->mut); mutex_lock(&ctx->mutex); + rdma_lock_handler(ctx->cm_id); ret = __rdma_accept_ece(ctx->cm_id, &conn_param, NULL, &ece); - mutex_unlock(&ctx->mutex); - if (!ret) + if (!ret) { + /* The uid must be set atomically with the handler */ ctx->uid = cmd.uid; - mutex_unlock(&file->mut); + } + rdma_unlock_handler(ctx->cm_id); + mutex_unlock(&ctx->mutex); } else { mutex_lock(&ctx->mutex); + rdma_lock_handler(ctx->cm_id); ret = __rdma_accept_ece(ctx->cm_id, NULL, NULL, &ece); + rdma_unlock_handler(ctx->cm_id); mutex_unlock(&ctx->mutex); } ucma_put_ctx(ctx); |