kernel/fs/fuse/cuse.c, branch linux-5.1.y

fuse: clean up aborted

2019-02-13T12:15:14Z

The only caller that needs fc->aborted set is fuse_conn_abort_write(). Setting fc->aborted is now racy (fuse_abort_conn() may already be in progress or finished) but there's no reason to care. Signed-off-by: Miklos Szeredi

fuse: Add fuse_inode argument to fuse_prepare_release()

2019-02-13T12:15:13Z

Here is preparation for next patches, which introduce new fi->lock for protection of ff->write_entry linked into fi->write_files. This patch just passes new argument to the function. Signed-off-by: Kirill Tkhai Signed-off-by: Miklos Szeredi

fuse: Support fuse filesystems outside of init_user_ns

2018-03-20T16:11:44Z

In order to support mounts from namespaces other than init_user_ns, fuse must translate uids and gids to/from the userns of the process servicing requests on /dev/fuse. This patch does that, with a couple of restrictions on the namespace: - The userns for the fuse connection is fixed to the namespace from which /dev/fuse is opened. - The namespace must be the same as s_user_ns. These restrictions simplify the implementation by avoiding the need to pass around userns references and by allowing fuse to rely on the checks in setattr_prepare for ownership changes. Either restriction could be relaxed in the future if needed. For cuse the userns used is the opener of /dev/cuse. Semantically the cuse support does not appear safe for unprivileged users. Practically the permissions on /dev/cuse only make it accessible to the global root user. If something slips through the cracks in a user namespace the only users who will be able to use the cuse device are those users mapped into the user namespace. Translation in the posix acl is updated to use the uuser namespace of the filesystem. Avoiding cases which might bypass this translation is handled in a following change. This change is stronlgy based on a similar change from Seth Forshee and Dongsu Park. Cc: Seth Forshee Cc: Dongsu Park Signed-off-by: Eric W. Biederman Signed-off-by: Miklos Szeredi

fuse: return -ECONNABORTED on /dev/fuse read after abort

2018-03-20T16:11:44Z

Currently the userspace has no way of knowing whether the fuse connection ended because of umount or abort via sysfs. It makes it hard for filesystems to free the mountpoint after abort without worrying about removing some new mount. The patch fixes it by returning different errors when userspace reads from /dev/fuse (-ENODEV for umount and -ECONNABORTED for abort). Add a new capability flag FUSE_ABORT_ERROR. If set and the connection is gone because of sysfs abort, reading from the device will return -ECONNABORTED. Signed-off-by: Szymon Lukasz Signed-off-by: Miklos Szeredi

fuse: honor iocb sync flags on write

2017-09-12T14:57:53Z

If the IOCB_DSYNC flag is set a sync is not being performed by fuse_file_write_iter. Honor IOCB_DSYNC/IOCB_SYNC by setting O_DYSNC/O_SYNC respectively in the flags filed of the write request. We don't need to sync data or metadata, since fuse_perform_write() does write-through and the filesystem is responsible for updating file times. Original patch by Vitaly Zolotusky. Reported-by: Nate Clark Cc: Vitaly Zolotusky . Signed-off-by: Miklos Szeredi

fuse: Add reference counting for fuse_io_priv

2016-03-14T14:02:51Z

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: 9d5722b7777e ("fuse: handle synchronous iocbs internally") Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Seth Forshee Signed-off-by: Miklos Szeredi

cuse: fix memory leak

2015-11-10T09:32:36Z

The problem is that fuse_dev_alloc() acquires an extra reference to cc.fc, and the original ref count is never dropped. Reported-by: Colin Ian King Signed-off-by: Miklos Szeredi Fixes: cc080e9e9be1 ("fuse: introduce per-instance fuse_dev structure") Cc: # v4.2+

fuse: introduce per-instance fuse_dev structure

2015-07-01T14:26:08Z

Allow fuse device clones to refer to be distinguished. This patch just adds the infrastructure by associating a separate "struct fuse_dev" with each clone. Signed-off-by: Miklos Szeredi Reviewed-by: Ashish Samant

fuse: duplicate ->connected in iqueue

2015-07-01T14:26:01Z

This will allow checking ->connected just with the input queue lock. Signed-off-by: Miklos Szeredi Reviewed-by: Ashish Samant

make new_sync_{read,write}() static

2015-04-12T02:29:40Z

All places outside of core VFS that checked ->read and ->write for being NULL or called the methods directly are gone now, so NULL {read,write} with non-NULL {read,write}_iter will do the right thing in all cases. Signed-off-by: Al Viro