fsnotify: make fasync generic for both inotify and fanotify

inotify is supposed to support async signal notification when information
is available on the inotify fd.  This patch moves that support to generic
fsnotify functions so it can be used by all notification mechanisms.

Signed-off-by: Eric Paris <eparis@redhat.com>

4 files changed, 16 insertions, 9 deletions

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 1218d10424d0..f0e7a57bc899 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -414,6 +414,10 @@ static int fanotify_release(struct inode *ignored, struct file *file)
 
         wake_up(&group->fanotify_data.access_waitq);
 #endif
+
+        if (file->f_flags & FASYNC)
+                fsnotify_fasync(-1, file, 0);
+
         /* matches the fanotify_init->fsnotify_alloc_group */
         fsnotify_destroy_group(group);
 
diff --git a/fs/notify/group.c b/fs/notify/group.c
index 1f7305711fc9..bd2625bd88b4 100644
--- a/fs/notify/group.c
+++ b/fs/notify/group.c
@@ -102,3 +102,10 @@ struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops)
 
         return group;
 }
+
+int fsnotify_fasync(int fd, struct file *file, int on)
+{
+        struct fsnotify_group *group = file->private_data;
+
+        return fasync_helper(fd, file, on, &group->fsn_fa) >= 0 ? 0 : -EIO;
+}
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 00ff82ff7c9f..68f7bec1e664 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -280,19 +280,15 @@ static ssize_t inotify_read(struct file *file, char __user *buf,
         return ret;
 }
 
-static int inotify_fasync(int fd, struct file *file, int on)
-{
-        struct fsnotify_group *group = file->private_data;
-
-        return fasync_helper(fd, file, on, &group->inotify_data.fa) >= 0 ? 0 : -EIO;
-}
-
 static int inotify_release(struct inode *ignored, struct file *file)
 {
         struct fsnotify_group *group = file->private_data;
 
         pr_debug("%s: group=%p\n", __func__, group);
 
+        if (file->f_flags & FASYNC)
+                fsnotify_fasync(-1, file, 0);
+
         /* free this group, matching get was inotify_init->fsnotify_obtain_group */
         fsnotify_destroy_group(group);
 
@@ -335,7 +331,7 @@ static long inotify_ioctl(struct file *file, unsigned int cmd,
 static const struct file_operations inotify_fops = {
         .poll           = inotify_poll,
         .read           = inotify_read,
-        .fasync         = inotify_fasync,
+        .fasync         = fsnotify_fasync,
         .release        = inotify_release,
         .unlocked_ioctl = inotify_ioctl,
         .compat_ioctl   = inotify_ioctl,
@@ -706,7 +702,6 @@ static struct fsnotify_group *inotify_new_group(unsigned int max_events)
         spin_lock_init(&group->inotify_data.idr_lock);
         idr_init(&group->inotify_data.idr);
         group->inotify_data.last_wd = 0;
-        group->inotify_data.fa = NULL;
         group->inotify_data.user = get_current_user();
 
         if (atomic_inc_return(&group->inotify_data.user->inotify_devs) >
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index c887b1378f7e..b3963d8c9988 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -225,6 +225,7 @@ alloc_holder:
         mutex_unlock(&group->notification_mutex);
 
         wake_up(&group->notification_waitq);
+        kill_fasync(&group->fsn_fa, SIGIO, POLL_IN);
         return return_event;
 }