From 595afaf9e6ee1b48e13ec4b8bcc8c7dee888161a Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 7 Sep 2010 13:42:41 +0200 Subject: [PATCH] fuse: flush background queue on connection close David Bartly reported that fuse can hang in fuse_get_req_nofail() when the connection to the filesystem server is no longer active. If bg_queue is not empty then flush_bg_queue() called from request_end() can put more requests on to the pending queue. If this happens while ending requests on the processing queue then those background requests will be queued to the pending list and never ended. Another problem is that fuse_dev_release() didn't wake up processes sleeping on blocked_waitq. Solve this by: a) flushing the background queue before calling end_requests() on the pending and processing queues b) setting blocked = 0 and waking up processes waiting on blocked_waitq() Thanks to David for an excellent bug report. Reported-by: David Bartley Signed-off-by: Miklos Szeredi CC: stable@kernel.org --- fs/fuse/dev.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 69ad053..b4fc47f 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1769,6 +1769,14 @@ __acquires(&fc->lock) } } +static void end_queued_requests(struct fuse_conn *fc) +{ + fc->max_background = UINT_MAX; + flush_bg_queue(fc); + end_requests(fc, &fc->pending); + end_requests(fc, &fc->processing); +} + /* * Abort all requests. * @@ -1795,8 +1803,7 @@ void fuse_abort_conn(struct fuse_conn *fc) fc->connected = 0; fc->blocked = 0; end_io_requests(fc); - end_requests(fc, &fc->pending); - end_requests(fc, &fc->processing); + end_queued_requests(fc); wake_up_all(&fc->waitq); wake_up_all(&fc->blocked_waitq); kill_fasync(&fc->fasync, SIGIO, POLL_IN); @@ -1811,8 +1818,9 @@ int fuse_dev_release(struct inode *inode, struct file *file) if (fc) { spin_lock(&fc->lock); fc->connected = 0; - end_requests(fc, &fc->pending); - end_requests(fc, &fc->processing); + fc->blocked = 0; + end_queued_requests(fc); + wake_up_all(&fc->blocked_waitq); spin_unlock(&fc->lock); fuse_conn_put(fc); } -- 2.7.4