Seth Forshee bbd5f23b1e fuse: Add reference counting for fuse_io_priv ... [ Upstream commit 744742d692 ] The 'reqs' member of fuse_io_priv serves two purposes. First is to track the number of oustanding async requests to the server and to signal that the io request is completed. The second is to be a reference count on the structure to know when it can be freed. For sync io requests these purposes can be at odds. fuse_direct_IO() wants to block until the request is done, and since the signal is sent when 'reqs' reaches 0 it cannot keep a reference to the object. Yet it needs to use the object after the userspace server has completed processing requests. This leads to some handshaking and special casing that it needlessly complicated and responsible for at least one race condition. It's much cleaner and safer to maintain a separate reference count for the object lifecycle and to let 'reqs' just be a count of outstanding requests to the userspace server. Then we can know for sure when it is safe to free the object without any handshaking or special cases. The catch here is that most of the time these objects are stack allocated and should not be freed. Initializing these objects with a single reference that is never released prevents accidental attempts to free the objects. Fixes: 9d5722b777 ("fuse: handle synchronous iocbs internally") Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>		2016-04-18 08:50:57 -04:00
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Kconfig	fuse: Move CUSE Kconfig entry from fs/Kconfig into fs/fuse/Kconfig	2013-01-17 13:08:45 +01:00
Makefile	CUSE: implement CUSE - Character device in Userspace	2009-06-09 11:24:11 +02:00
control.c	VFS: normal filesystems (and lustre): d_inode() annotations	2015-04-15 15:06:57 -04:00
cuse.c	fuse: Add reference counting for fuse_io_priv	2016-04-18 08:50:57 -04:00
dev.c	fuse: use iov_iter_get_pages() for non-splice path	2015-04-11 22:29:41 -04:00
dir.c	VFS: normal filesystems (and lustre): d_inode() annotations	2015-04-15 15:06:57 -04:00
file.c	fuse: Add reference counting for fuse_io_priv	2016-04-18 08:50:57 -04:00
fuse_i.h	fuse: Add reference counting for fuse_io_priv	2016-04-18 08:50:57 -04:00
inode.c	fuse: initialize fc->release before calling it	2015-08-03 09:29:14 -07:00