diff options
| author |   Jason Gunthorpe <jgg@nvidia.com> | 2020-08-18 15:05:23 +0300 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2020-08-27 08:38:16 -0300 |
| commit | 26c15dec490c3a65f4eba6704c6648c299adb7a6 (patch) | |
| tree | ba5c6ab32a6711bbf49afc7c1fb18bee8982c648 /drivers/infiniband/core | |
| parent | RDMA/ucma: Add missing locking around rdma_leave_multicast() (diff) | |
| download | linux-dev-26c15dec490c3a65f4eba6704c6648c299adb7a6.tar.xz linux-dev-26c15dec490c3a65f4eba6704c6648c299adb7a6.zip | |
RDMA/ucma: Change backlog into an atomic
There is no reason to grab the file->mut just to do this inc/dec work. Use
an atomic.
Link: https://lore.kernel.org/r/20200818120526.702120-12-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')
| -rw-r--r-- | drivers/infiniband/core/ucma.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c index ad78b05de656..8be8ff14ab62 100644 --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -88,7 +88,7 @@ struct ucma_context { struct completion comp; refcount_t ref; int events_reported; - int backlog; + atomic_t backlog; struct ucma_file *file; struct rdma_cm_id *cm_id; @@ -348,12 +348,11 @@ static int ucma_event_handler(struct rdma_cm_id *cm_id, uevent->resp.ece.attr_mod = event->ece.attr_mod; if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST) { - if (!ctx->backlog) { + if (!atomic_add_unless(&ctx->backlog, -1, 0)) { ret = -ENOMEM; kfree(uevent); goto out; } - ctx->backlog--; } else if (!ctx->uid || ctx->cm_id != cm_id) { /* * We ignore events for new connections until userspace has set @@ -432,7 +431,7 @@ static ssize_t ucma_get_event(struct ucma_file *file, const char __user *inbuf, } if (ctx) { - uevent->ctx->backlog++; + atomic_inc(&uevent->ctx->backlog); uevent->cm_id->context = ctx; ucma_finish_ctx(ctx); } @@ -1136,10 +1135,12 @@ static ssize_t ucma_listen(struct ucma_file *file, const char __user *inbuf, if (IS_ERR(ctx)) return PTR_ERR(ctx); - ctx->backlog = cmd.backlog > 0 && cmd.backlog < max_backlog ? - cmd.backlog : max_backlog; + if (cmd.backlog <= 0 || cmd.backlog > max_backlog) + cmd.backlog = max_backlog; + atomic_set(&ctx->backlog, cmd.backlog); + mutex_lock(&ctx->mutex); - ret = rdma_listen(ctx->cm_id, ctx->backlog); + ret = rdma_listen(ctx->cm_id, cmd.backlog); mutex_unlock(&ctx->mutex); ucma_put_ctx(ctx); return ret; |