From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [PATCH for-next V5 1/5] IB/uverbs: Fix reference counting usage of event files Date: Mon, 29 Jun 2015 11:40:38 -0600 Message-ID: <20150629174038.GB2755@obsidianresearch.com> References: <1434984438-21733-1-git-send-email-yishaih@mellanox.com> <1434984438-21733-2-git-send-email-yishaih@mellanox.com> <20150624175738.GC21033@obsidianresearch.com> <558BE9FA.9060402@dev.mellanox.co.il> <20150625175228.GF21033@obsidianresearch.com> <559005A0.4070800@dev.mellanox.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <559005A0.4070800-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Yishai Hadas Cc: Yishai Hadas , dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, raindel-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, jackm-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org List-Id: linux-rdma@vger.kernel.org On Sun, Jun 28, 2015 at 05:33:04PM +0300, Yishai Hadas wrote: > You are wrong here, we have here balanced put, the first is done as > part of fput(filp) -> ib_uverbs_event_close_file -> > kref_put(&file->ref, ib_uverbs_release_event_file) and the second at > the end of this function as part of the err: label > kref_put(&ev_file->ref, ib_uverbs_release_event_file); Ugh, that is so gross, seriously? Sure, the counts work out, but that is *totally unreadable*. Sigh, just use this: struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file, int is_async) { struct ib_uverbs_event_file *ev_file; struct file *filp; + int ret; - ev_file = kmalloc(sizeof *ev_file, GFP_KERNEL); + ev_file = kzalloc(sizeof(*ev_file), GFP_KERNEL); if (!ev_file) return ERR_PTR(-ENOMEM); @@ -555,15 +561,41 @@ struct file *ib_uverbs_alloc_event_file(struct ib_uverbs_file *uverbs_file, INIT_LIST_HEAD(&ev_file->event_list); init_waitqueue_head(&ev_file->poll_wait); ev_file->uverbs_file = uverbs_file; + kref_get(&ev_file->uverbs_file->ref); ev_file->async_queue = NULL; - ev_file->is_async = is_async; ev_file->is_closed = 0; filp = anon_inode_getfile("[infinibandevent]", &uverbs_event_fops, ev_file, O_RDONLY); if (IS_ERR(filp)) - kfree(ev_file); + goto err_put_refs; + + if (is_async) { + WARN_ON(uverbs_file->async_file); + uverbs_file->async_file = ev_file; + kref_get(&uverbs_file->async_file->ref); + INIT_IB_EVENT_HANDLER(&uverbs_file->event_handler, + uverbs_file->device->ib_dev, + ib_uverbs_event_handler); + ret = ib_register_event_handler(&uverbs_file->event_handler); + if (ret) + goto err_put_file; + + /* At that point async file stuff was fully set */ + ev_file->is_async = 1; + } + + return filp; + +err_put_file: + fput(filp); + kref_put(&uverbs_file->async_file->ref, ib_uverbs_release_file); + uverbs_file->async_file = NULL; + return ERR_PTR(ret); +err_put_refs: + kref_put(&ev_file->uverbs_file->ref, ib_uverbs_release_file); + kref_put(&ev_file->ref, ib_uverbs_release_event_file); return filp; } Jason -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html