[Virtio-fs] [PATCH 1/3] Use helper function to get forget requests from fuse

[Vivek Goyal]

stacked file systems like virtio-fs do not have to play directly with
forget list data structures. There is a helper function use that instead.

Rename dequeue_forget() to fuse_dequeue_forget() and export it so that
stacked filesystems can use it.

Signed-off-by: Vivek Goyal <vgoyal at redhat.com>
---
 fs/fuse/dev.c       | 9 +++++----
 fs/fuse/fuse_i.h    | 3 +++
 fs/fuse/virtio_fs.c | 7 +------
 3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ee9dd38bc0f0..39da7ec19fa2 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1203,7 +1203,7 @@ __releases(fiq->waitq.lock)
 	return err ? err : reqsize;
 }
 
-static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq,
+struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
 					       unsigned max,
 					       unsigned *countp)
 {
@@ -1224,6 +1224,7 @@ static struct fuse_forget_link *dequeue_forget(struct fuse_iqueue *fiq,
 
 	return head;
 }
+EXPORT_SYMBOL(fuse_dequeue_forget);
 
 static int fuse_read_single_forget(struct fuse_iqueue *fiq,
 				   struct fuse_copy_state *cs,
@@ -1231,7 +1232,7 @@ static int fuse_read_single_forget(struct fuse_iqueue *fiq,
 __releases(fiq->waitq.lock)
 {
 	int err;
-	struct fuse_forget_link *forget = dequeue_forget(fiq, 1, NULL);
+	struct fuse_forget_link *forget = fuse_dequeue_forget(fiq, 1, NULL);
 	struct fuse_forget_in arg = {
 		.nlookup = forget->forget_one.nlookup,
 	};
@@ -1279,7 +1280,7 @@ __releases(fiq->waitq.lock)
 	}
 
 	max_forgets = (nbytes - ih.len) / sizeof(struct fuse_forget_one);
-	head = dequeue_forget(fiq, max_forgets, &count);
+	head = fuse_dequeue_forget(fiq, max_forgets, &count);
 	spin_unlock(&fiq->waitq.lock);
 
 	arg.count = count;
@@ -2249,7 +2250,7 @@ void fuse_abort_conn(struct fuse_conn *fc)
 			clear_bit(FR_PENDING, &req->flags);
 		list_splice_tail_init(&fiq->pending, &to_end);
 		while (forget_pending(fiq))
-			kfree(dequeue_forget(fiq, 1, NULL));
+			kfree(fuse_dequeue_forget(fiq, 1, NULL));
 		wake_up_all_locked(&fiq->waitq);
 		spin_unlock(&fiq->waitq.lock);
 		kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 7ac7f9a0b81b..ad8272c98c82 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -972,6 +972,9 @@ void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
 
 struct fuse_forget_link *fuse_alloc_forget(void);
 
+struct fuse_forget_link *fuse_dequeue_forget(struct fuse_iqueue *fiq,
+					     unsigned max, unsigned *countp);
+
 /* Used by READDIRPLUS */
 void fuse_force_forget(struct file *file, u64 nodeid);
 
diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 18fc0dca0abc..cbda7ebd5bf9 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -697,12 +697,7 @@ __releases(fiq->waitq.lock)
 	u64 unique;
 	int ret;
 
-	BUG_ON(!fiq->forget_list_head.next);
-	link = fiq->forget_list_head.next;
-	BUG_ON(link->next);
-	fiq->forget_list_head.next = NULL;
-	fiq->forget_list_tail = &fiq->forget_list_head;
-
+	link = fuse_dequeue_forget(fiq, 1, NULL);
 	unique = fuse_get_unique(fiq);
 
 	fs = fiq->priv;
-- 
2.20.1