diff options
| -rw-r--r-- | fs/fuse/dev.c | 40 |
1 files changed, 29 insertions, 11 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 4526da8907c..f556a0d5c0d 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -120,9 +120,9 @@ struct fuse_req *fuse_get_request(struct fuse_conn *fc) return do_get_request(fc); } +/* Must be called with fuse_lock held */ static void fuse_putback_request(struct fuse_conn *fc, struct fuse_req *req) { - spin_lock(&fuse_lock); if (req->preallocated) { atomic_dec(&fc->num_waiting); list_add(&req->list, &fc->unused_list); @@ -134,11 +134,19 @@ static void fuse_putback_request(struct fuse_conn *fc, struct fuse_req *req) fc->outstanding_debt--; else up(&fc->outstanding_sem); - spin_unlock(&fuse_lock); } void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req) { + if (atomic_dec_and_test(&req->count)) { + spin_lock(&fuse_lock); + fuse_putback_request(fc, req); + spin_unlock(&fuse_lock); + } +} + +static void fuse_put_request_locked(struct fuse_conn *fc, struct fuse_req *req) +{ if (atomic_dec_and_test(&req->count)) fuse_putback_request(fc, req); } @@ -163,26 +171,36 @@ void fuse_release_background(struct fuse_req *req) * still waiting), the 'end' callback is called if given, else the * reference to the request is released * + * Releasing extra reference for foreground requests must be done + * within the same locked region as setting state to finished. This + * is because fuse_reset_request() may be called after request is + * finished and it must be the sole possessor. If request is + * interrupted and put in the background, it will return with an error + * and hence never be reset and reused. + * * Called with fuse_lock, unlocks it */ static void request_end(struct fuse_conn *fc, struct fuse_req *req) { - void (*end) (struct fuse_conn *, struct fuse_req *) = req->end; - req->end = NULL; list_del(&req->list); req->state = FUSE_REQ_FINISHED; - spin_unlock(&fuse_lock); - if (req->background) { + if (!req->background) { + wake_up(&req->waitq); + fuse_put_request_locked(fc, req); + spin_unlock(&fuse_lock); + } else { + void (*end) (struct fuse_conn *, struct fuse_req *) = req->end; + req->end = NULL; + spin_unlock(&fuse_lock); down_read(&fc->sbput_sem); if (fc->mounted) fuse_release_background(req); up_read(&fc->sbput_sem); + if (end) + end(fc, req); + else + fuse_put_request(fc, req); } - wake_up(&req->waitq); - if (end) - end(fc, req); - else - fuse_put_request(fc, req); } /* |