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

fuse: fix copy_file_range() in the writeback case

2019-06-11T10:19:16Z

commit a2bc92362941006830afa3dfad6caec1f99acbf5 upstream. Prior to sending COPY_FILE_RANGE to userspace filesystem, we must flush all dirty pages in both the source and destination files. This patch adds the missing flush of the source file. Tested on libfuse-3.5.0 with: libfuse/example/passthrough_ll /mnt/fuse/ -o writeback libfuse/test/test_syscalls /mnt/fuse/tmp/test Fixes: 88bc7d5097a1 ("fuse: add support for copy_file_range()") Cc: # v4.20 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: fallocate: fix return with locked inode

2019-06-11T10:19:16Z

commit 35d6fcbb7c3e296a52136347346a698a35af3fda upstream. Do the proper cleanup in case the size check fails. Tested with xfstests:generic/228 Reported-by: kbuild test robot Reported-by: Dan Carpenter Fixes: 0cbade024ba5 ("fuse: honor RLIMIT_FSIZE in fuse_file_fallocate") Cc: Liu Bo Cc: # v3.5 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: Add FOPEN_STREAM to use stream_open()

2019-05-25T16:16:47Z

commit bbd84f33652f852ce5992d65db4d020aba21f882 upstream. Starting from commit 9c225f2655e3 ("vfs: atomic f_pos accesses as per POSIX") files opened even via nonseekable_open gate read and write via lock and do not allow them to be run simultaneously. This can create read vs write deadlock if a filesystem is trying to implement a socket-like file which is intended to be simultaneously used for both read and write from filesystem client. See commit 10dce8af3422 ("fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock") for details and e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes to /proc/xen/xenbus") for a similar deadlock example on /proc/xen/xenbus. To avoid such deadlock it was tempting to adjust fuse_finish_open to use stream_open instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE, and in particular GVFS which actually uses offset in its read and write handlers https://codesearch.debian.net/search?q=-%3Enonseekable+%3D https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346 https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481 so if we would do such a change it will break a real user. Add another flag (FOPEN_STREAM) for filesystem servers to indicate that the opened handler is having stream-like semantics; does not use file position and thus the kernel is free to issue simultaneous read and write request on opened file handle. This patch together with stream_open() should be added to stable kernels starting from v3.14+. This will allow to patch OSSPD and other FUSE filesystems that provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE in open handler and this way avoid the deadlock on all kernel versions. This should work because fuse_finish_open ignores unknown open flags returned from a filesystem and so passing FOPEN_STREAM to a kernel that is not aware of this flag cannot hurt. In turn the kernel that is not aware of FOPEN_STREAM will be < v3.14 where just FOPEN_NONSEEKABLE is sufficient to implement streams without read vs write deadlock. Cc: stable@vger.kernel.org # v3.14+ Signed-off-by: Kirill Smelkov Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: honor RLIMIT_FSIZE in fuse_file_fallocate

2019-05-25T16:16:34Z

commit 0cbade024ba501313da3b7e5dd2a188a6bc491b5 upstream. fstests generic/228 reported this failure that fuse fallocate does not honor what 'ulimit -f' has set. This adds the necessary inode_newsize_ok() check. Signed-off-by: Liu Bo Fixes: 05ba1f082300 ("fuse: add FALLOCATE operation") Cc: # v3.5 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: fix writepages on 32bit

2019-05-25T16:16:34Z

commit 9de5be06d0a89ca97b5ab902694d42dfd2bb77d2 upstream. Writepage requests were cropped to i_size & 0xffffffff, which meant that mmaped writes to any file larger than 4G might be silently discarded. Fix by storing the file size in a properly sized variable (loff_t instead of size_t). Reported-by: Antonio SJ Musumeci Fixes: 6eaf4782eb09 ("fuse: writepages: crop secondary requests") Cc: # v3.13 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman

fuse: cache readdir calls if filesystem opts out of opendir

2019-02-13T12:15:15Z

If a filesystem returns ENOSYS from opendir and thus opts out of opendir and releasedir requests, it almost certainly would also like readdir results cached. Default open_flags to FOPEN_KEEP_CACHE and FOPEN_CACHE_DIR in that case. With this patch, I've measured recursive directory enumeration across large FUSE mounts to be faster than native mounts. Signed-off-by: Chad Austin Signed-off-by: Miklos Szeredi

fuse: support clients that don't implement 'opendir'

2019-02-13T12:15:15Z

Allow filesystems to return ENOSYS from opendir, preventing the kernel from sending opendir and releasedir messages in the future. This avoids userspace transitions when filesystems don't need to keep track of state per directory handle. A new capability flag, FUSE_NO_OPENDIR_SUPPORT, parallels FUSE_NO_OPEN_SUPPORT, indicating the new semantics for returning ENOSYS from opendir. Signed-off-by: Chad Austin Signed-off-by: Miklos Szeredi

fuse: lift bad inode checks into callers

2019-02-13T12:15:15Z

Bad inode checks were done done in various places, and move them into fuse_file_{read|write}_iter(). Signed-off-by: Miklos Szeredi

fuse: multiplex cached/direct_io file operations

2019-02-13T12:15:15Z

This is cleanup, as well as allowing switching between I/O modes while the file is open in the future. Signed-off-by: Miklos Szeredi

fuse add copy_file_range to direct io fops

2019-02-13T12:15:14Z

Nothing preventing copy_file_range to work on files opened with FOPEN_DIRECT_IO. Fixes: 88bc7d5097a1 ("fuse: add support for copy_file_range()") Signed-off-by: Miklos Szeredi