fanotify: Add pids to events

Pass the process identifiers of the triggering processes to fanotify
listeners: this information is useful for event filtering and logging.

Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Eric Paris <eparis@redhat.com>

5 files changed, 9 insertions, 2 deletions

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 5b0b6b485a9c..881067dc7923 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -10,8 +10,9 @@ static bool should_merge(struct fsnotify_event *old, struct fsnotify_event *new)
 {
         pr_debug("%s: old=%p new=%p\n", __func__, old, new);
 
-        if ((old->to_tell == new->to_tell) &&
-            (old->data_type == new->data_type)) {
+        if (old->to_tell == new->to_tell &&
+            old->data_type == new->data_type &&
+            old->tgid == new->tgid) {
                 switch (old->data_type) {
                 case (FSNOTIFY_EVENT_PATH):
                         if ((old->path.mnt == new->path.mnt) &&
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index cf9c30009825..66e38fc052b2 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -103,6 +103,7 @@ static ssize_t fill_event_metadata(struct fsnotify_group *group,
         metadata->event_len = FAN_EVENT_METADATA_LEN;
         metadata->vers = FANOTIFY_METADATA_VERSION;
         metadata->mask = fanotify_outgoing_mask(event->mask);
+        metadata->pid = pid_vnr(event->tgid);
         metadata->fd = create_fd(group, event);
 
         return metadata->fd;
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index 066f1f988bac..7fc8d004084c 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -93,6 +93,7 @@ void fsnotify_put_event(struct fsnotify_event *event)
                 BUG_ON(!list_empty(&event->private_data_list));
 
                 kfree(event->file_name);
+                put_pid(event->tgid);
                 kmem_cache_free(fsnotify_event_cachep, event);
         }
 }
@@ -346,6 +347,7 @@ struct fsnotify_event *fsnotify_clone_event(struct fsnotify_event *old_event)
                         return NULL;
                 }
         }
+        event->tgid = get_pid(old_event->tgid);
         if (event->data_type == FSNOTIFY_EVENT_PATH)
                 path_get(&event->path);
 
@@ -385,6 +387,7 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
                 event->name_len = strlen(event->file_name);
         }
 
+        event->tgid = get_pid(task_tgid(current));
         event->sync_cookie = cookie;
         event->to_tell = to_tell;
         event->data_type = data_type;
diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index c1c66162a46c..5f633af4d1b0 100644
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -62,6 +62,7 @@ struct fanotify_event_metadata {
         __u32 vers;
         __s32 fd;
         __u64 mask;
+        __s64 pid;
 } __attribute__ ((packed));
 
 /* Helper functions to deal with fanotify_event_metadata buffers */
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index ff654c1932f2..7d93572ec568 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -221,6 +221,7 @@ struct fsnotify_event {
         u32 sync_cookie;        /* used to corrolate events, namely inotify mv events */
         char *file_name;
         size_t name_len;
+        struct pid *tgid;
 
         struct list_head private_data_list;     /* groups can store private data here */
 };