fanotify: break up fanotify_alloc_event()

Break up fanotify_alloc_event() into helpers by event struct type.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/notify/fanotify/fanotify.c

@@ -344,15 +344,84 @@ static struct inode *fanotify_fid_inode(struct inode *to_tell, u32 event_mask,
 	return fsnotify_data_inode(data, data_type);
 }
 
+static struct fanotify_event *fanotify_alloc_path_event(const struct path *path,
+							gfp_t gfp)
+{
+	struct fanotify_path_event *pevent;
+
+	pevent = kmem_cache_alloc(fanotify_path_event_cachep, gfp);
+	if (!pevent)
+		return NULL;
+
+	pevent->fae.type = FANOTIFY_EVENT_TYPE_PATH;
+	pevent->path = *path;
+	path_get(path);
+
+	return &pevent->fae;
+}
+
+static struct fanotify_event *fanotify_alloc_perm_event(const struct path *path,
+							gfp_t gfp)
+{
+	struct fanotify_perm_event *pevent;
+
+	pevent = kmem_cache_alloc(fanotify_perm_event_cachep, gfp);
+	if (!pevent)
+		return NULL;
+
+	pevent->fae.type = FANOTIFY_EVENT_TYPE_PATH_PERM;
+	pevent->response = 0;
+	pevent->state = FAN_EVENT_INIT;
+	pevent->path = *path;
+	path_get(path);
+
+	return &pevent->fae;
+}
+
+static struct fanotify_event *fanotify_alloc_fid_event(struct inode *id,
+						       __kernel_fsid_t *fsid,
+						       gfp_t gfp)
+{
+	struct fanotify_fid_event *ffe;
+
+	ffe = kmem_cache_alloc(fanotify_fid_event_cachep, gfp);
+	if (!ffe)
+		return NULL;
+
+	ffe->fae.type = FANOTIFY_EVENT_TYPE_FID;
+	ffe->fsid = *fsid;
+	fanotify_encode_fh(&ffe->object_fh, id, gfp);
+
+	return &ffe->fae;
+}
+
+static struct fanotify_event *fanotify_alloc_name_event(struct inode *id,
+							__kernel_fsid_t *fsid,
+							const struct qstr *file_name,
+							gfp_t gfp)
+{
+	struct fanotify_name_event *fne;
+
+	fne = kmalloc(sizeof(*fne) + file_name->len + 1, gfp);
+	if (!fne)
+		return NULL;
+
+	fne->fae.type = FANOTIFY_EVENT_TYPE_FID_NAME;
+	fne->fsid = *fsid;
+	fanotify_encode_fh(&fne->dir_fh, id, gfp);
+	fne->name_len = file_name->len;
+	strcpy(fne->name, file_name->name);
+
+	return &fne->fae;
+}
+
 static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
-						struct inode *inode, u32 mask,
-						const void *data, int data_type,
-						const struct qstr *file_name,
-						__kernel_fsid_t *fsid)
+						   struct inode *inode, u32 mask,
+						   const void *data, int data_type,
+						   const struct qstr *file_name,
+						   __kernel_fsid_t *fsid)
 {
 	struct fanotify_event *event = NULL;
-	struct fanotify_fid_event *ffe = NULL;
-	struct fanotify_name_event *fne = NULL;
 	gfp_t gfp = GFP_KERNEL_ACCOUNT;
 	struct inode *id = fanotify_fid_inode(inode, mask, data, data_type);
 	const struct path *path = fsnotify_data_path(data, data_type);
@@ -372,55 +441,23 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
 	memalloc_use_memcg(group->memcg);
 
 	if (fanotify_is_perm_event(mask)) {
-		struct fanotify_perm_event *pevent;
-
-		pevent = kmem_cache_alloc(fanotify_perm_event_cachep, gfp);
-		if (!pevent)
-			goto out;
-
-		event = &pevent->fae;
-		event->type = FANOTIFY_EVENT_TYPE_PATH_PERM;
-		pevent->response = 0;
-		pevent->state = FAN_EVENT_INIT;
-		goto init;
-	}
-
-	/*
-	 * For FAN_DIR_MODIFY event, we report the fid of the directory and
-	 * the name of the modified entry.
-	 * Allocate an fanotify_name_event struct and copy the name.
-	 */
-	if (mask & FAN_DIR_MODIFY && !(WARN_ON_ONCE(!file_name))) {
-		fne = kmalloc(sizeof(*fne) + file_name->len + 1, gfp);
-		if (!fne)
-			goto out;
-
-		event = &fne->fae;
-		event->type = FANOTIFY_EVENT_TYPE_FID_NAME;
-		fne->name_len = file_name->len;
-		strcpy(fne->name, file_name->name);
-		goto init;
-	}
-
-	if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) {
-		ffe = kmem_cache_alloc(fanotify_fid_event_cachep, gfp);
-		if (!ffe)
-			goto out;
-
-		event = &ffe->fae;
-		event->type = FANOTIFY_EVENT_TYPE_FID;
+		event = fanotify_alloc_perm_event(path, gfp);
+	} else if (mask & FAN_DIR_MODIFY && !(WARN_ON_ONCE(!file_name))) {
+		/*
+		 * For FAN_DIR_MODIFY event, we report the fid of the directory
+		 * and the name of the modified entry.
+		 * Allocate an fanotify_name_event struct and copy the name.
+		 */
+		event = fanotify_alloc_name_event(id, fsid, file_name, gfp);
+	} else if (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) {
+		event = fanotify_alloc_fid_event(id, fsid, gfp);
 	} else {
-		struct fanotify_path_event *pevent;
-
-		pevent = kmem_cache_alloc(fanotify_path_event_cachep, gfp);
-		if (!pevent)
-			goto out;
-
-		event = &pevent->fae;
-		event->type = FANOTIFY_EVENT_TYPE_PATH;
+		event = fanotify_alloc_path_event(path, gfp);
 	}
 
-init:
+	if (!event)
+		goto out;
+
 	/*
 	 * Use the victim inode instead of the watching inode as the id for
 	 * event queue, so event reported on parent is merged with event
@@ -432,19 +469,6 @@ static struct fanotify_event *fanotify_alloc_event(struct fsnotify_group *group,
 	else
 		event->pid = get_pid(task_tgid(current));
 
-	if (fsid && fanotify_event_fsid(event))
-		*fanotify_event_fsid(event) = *fsid;
-
-	if (fanotify_event_object_fh(event))
-		fanotify_encode_fh(fanotify_event_object_fh(event), id, gfp);
-
-	if (fanotify_event_dir_fh(event))
-		fanotify_encode_fh(fanotify_event_dir_fh(event), id, gfp);
-
-	if (fanotify_event_has_path(event)) {
-		*fanotify_event_path(event) = *path;
-		path_get(path);
-	}
 out:
 	memalloc_unuse_memcg();
 	return event;