1 files changed, 24 insertions, 5 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index d692b85115bd..367310588962 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -147,7 +147,7 @@ static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
                 int intr;
 
                 block_sigs(&oldset);
-                intr = wait_event_interruptible(fc->blocked_waitq,
+                intr = wait_event_interruptible_exclusive(fc->blocked_waitq,
                                 !fuse_block_alloc(fc, for_background));
                 restore_sigs(&oldset);
                 err = -EINTR;
@@ -161,8 +161,11 @@ static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
 
         req = fuse_request_alloc(npages);
         err = -ENOMEM;
-        if (!req)
+        if (!req) {
+                if (for_background)
+                        wake_up(&fc->blocked_waitq);
                 goto out;
+        }
 
         fuse_req_init_context(req);
         req->waiting = 1;
@@ -262,6 +265,17 @@ struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
 {
         if (atomic_dec_and_test(&req->count)) {
+                if (unlikely(req->background)) {
+                        /*
+                         * We get here in the unlikely case that a background
+                         * request was allocated but not sent
+                         */
+                        spin_lock(&fc->lock);
+                        if (!fc->blocked)
+                                wake_up(&fc->blocked_waitq);
+                        spin_unlock(&fc->lock);
+                }
+
                 if (req->waiting)
                         atomic_dec(&fc->num_waiting);
 
@@ -359,10 +373,15 @@ __releases(fc->lock)
         list_del(&req->intr_entry);
         req->state = FUSE_REQ_FINISHED;
         if (req->background) {
-                if (fc->num_background == fc->max_background) {
+                req->background = 0;
+
+                if (fc->num_background == fc->max_background)
                         fc->blocked = 0;
-                        wake_up_all(&fc->blocked_waitq);
-                }
+
+                /* Wake up next waiter, if any */
+                if (!fc->blocked)
+                        wake_up(&fc->blocked_waitq);
+
                 if (fc->num_background == fc->congestion_threshold &&
                     fc->connected && fc->bdi_initialized) {
                         clear_bdi_congested(&fc->bdi, BLK_RW_SYNC);