fuse: allow interrupt queuing without fc->lock

[deliverable/linux.git] / fs / fuse / dev.c

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 65ad9b1e055de4df3b2f17ddf20dbc011ca1b3e9..c7f1a633239fdca2e53b5d88e4917dd751862ac7 100644 (file)
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -423,8 +423,10 @@ __releases(fc->lock)
 static void queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
 {
        spin_lock(&fiq->waitq.lock);
-       list_add_tail(&req->intr_entry, &fiq->interrupts);
-       wake_up_locked(&fiq->waitq);
+       if (list_empty(&req->intr_entry)) {
+               list_add_tail(&req->intr_entry, &fiq->interrupts);
+               wake_up_locked(&fiq->waitq);
+       }
        spin_unlock(&fiq->waitq.lock);
        kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
 }
@@ -443,6 +445,8 @@ static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
 
                spin_lock(&fc->lock);
                set_bit(FR_INTERRUPTED, &req->flags);
+               /* matches barrier in fuse_dev_do_read() */
+               smp_mb__after_atomic();
                if (test_bit(FR_SENT, &req->flags))
                        queue_interrupt(fiq, req);
                spin_unlock(&fc->lock);
@@ -1358,8 +1362,10 @@ static ssize_t fuse_dev_do_read(struct fuse_conn *fc, struct file *file,
        if (!test_bit(FR_ISREPLY, &req->flags)) {
                request_end(fc, req);
        } else {
-               set_bit(FR_SENT, &req->flags);
                list_move_tail(&req->list, &fc->processing);
+               set_bit(FR_SENT, &req->flags);
+               /* matches barrier in request_wait_answer() */
+               smp_mb__after_atomic();
                if (test_bit(FR_INTERRUPTED, &req->flags))
                        queue_interrupt(fiq, req);
                spin_unlock(&fc->lock);