[IB/uverbs]: Add O_ASYNC support

Add support for O_ASYNC notifications on userspace verbs
completion and asynchronous event file descriptors.

Signed-off-by: Gleb Natapov <glebn@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 14 insertions, 1 deletions

diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h
index 57347f1e82c1..7696022f9a4e 100644
--- a/drivers/infiniband/core/uverbs.h
+++ b/drivers/infiniband/core/uverbs.h
@@ -61,6 +61,7 @@ struct ib_uverbs_event_file {
         int                                     fd;
         int                                     is_async;
         wait_queue_head_t                       poll_wait;
+        struct fasync_struct                   *async_queue;
         struct list_head                        event_list;
 };
 
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index fbbe03d8c901..eb99e693dec2 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -257,11 +257,19 @@ static void ib_uverbs_event_release(struct ib_uverbs_event_file *file)
         spin_unlock_irq(&file->lock);
 }
 
+static int ib_uverbs_event_fasync(int fd, struct file *filp, int on)
+{
+        struct ib_uverbs_event_file *file = filp->private_data;
+
+        return fasync_helper(fd, filp, on, &file->async_queue);
+}
+
 static int ib_uverbs_event_close(struct inode *inode, struct file *filp)
 {
         struct ib_uverbs_event_file *file = filp->private_data;
 
         ib_uverbs_event_release(file);
+        ib_uverbs_event_fasync(-1, filp, 0);
         kref_put(&file->uverbs_file->ref, ib_uverbs_release_file);
 
         return 0;
@@ -276,7 +284,8 @@ static struct file_operations uverbs_event_fops = {
          */
         .read    = ib_uverbs_event_read,
         .poll    = ib_uverbs_event_poll,
-        .release = ib_uverbs_event_close
+        .release = ib_uverbs_event_close,
+        .fasync  = ib_uverbs_event_fasync
 };
 
 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
@@ -296,6 +305,7 @@ void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
         spin_unlock_irqrestore(&file->comp_file[0].lock, flags);
 
         wake_up_interruptible(&file->comp_file[0].poll_wait);
+        kill_fasync(&file->comp_file[0].async_queue, SIGIO, POLL_IN);
 }
 
 static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
@@ -316,6 +326,7 @@ static void ib_uverbs_async_handler(struct ib_uverbs_file *file,
         spin_unlock_irqrestore(&file->async_file.lock, flags);
 
         wake_up_interruptible(&file->async_file.poll_wait);
+        kill_fasync(&file->async_file.async_queue, SIGIO, POLL_IN);
 }
 
 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
@@ -350,6 +361,7 @@ static int ib_uverbs_event_init(struct ib_uverbs_event_file *file,
         INIT_LIST_HEAD(&file->event_list);
         init_waitqueue_head(&file->poll_wait);
         file->uverbs_file = uverbs_file;
+        file->async_queue = NULL;
 
         file->fd = get_unused_fd();
         if (file->fd < 0)