linux-stable.git/fs/fuse/file.c, branch linux-3.16.y

fuse: truncate pending writes on O_TRUNC

2019-12-19T15:58:42+00:00

commit e4648309b85a78f8c787457832269a8712a8673e upstream.

Make sure cached writes are not reordered around open(..., O_TRUNC), with
the obvious wrong results.

Fixes: 4d99ff8f12eb ("fuse: Turn writeback cache on")
Signed-off-by: Miklos Szeredi 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

fuse: fix missing unlock_page in fuse_writepage()

2019-12-10T18:01:26+00:00

commit d5880c7a8620290a6c90ced7a0e8bd0ad9419601 upstream.

unlock_page() was missing in case of an already in-flight write against the
same page.

Signed-off-by: Vasily Averin 
Fixes: ff17be086477 ("fuse: writepage: skip already in flight")
Signed-off-by: Miklos Szeredi 
Signed-off-by: Ben Hutchings

fuse: fallocate: fix return with locked inode

2019-09-23T20:11:48+00:00

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 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Ben Hutchings

fuse: honor RLIMIT_FSIZE in fuse_file_fallocate

2019-09-23T20:11:48+00:00

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")
Signed-off-by: Miklos Szeredi 
Signed-off-by: Ben Hutchings

fuse: fix writepages on 32bit

2019-09-23T20:11:47+00:00

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")
Signed-off-by: Miklos Szeredi 
Signed-off-by: Ben Hutchings

fuse: Add FOPEN_STREAM to use stream_open()

2019-07-09T21:04:19+00:00

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: Ben Hutchings

fuse: decrement NR_WRITEBACK_TEMP on the right page

2019-05-02T20:41:23+00:00

commit a2ebba824106dabe79937a9f29a875f837e1b6d4 upstream.

NR_WRITEBACK_TEMP is accounted on the temporary page in the request, not
the page cache page.

Fixes: 8b284dc47291 ("fuse: writepages: handle same page rewrites")
Signed-off-by: Miklos Szeredi 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

fuse: continue to send FUSE_RELEASEDIR when FUSE_OPEN returns ENOSYS

2019-02-11T17:54:24+00:00

commit 2e64ff154ce6ce9a8dc0f9556463916efa6ff460 upstream.

When FUSE_OPEN returns ENOSYS, the no_open bit is set on the connection.

Because the FUSE_RELEASE and FUSE_RELEASEDIR paths share code, this
incorrectly caused the FUSE_RELEASEDIR request to be dropped and never sent
to userspace.

Pass an isdir bool to distinguish between FUSE_RELEASE and FUSE_RELEASEDIR
inside of fuse_file_put.

Fixes: 7678ac50615d ("fuse: support clients that don't implement 'open'")
Signed-off-by: Chad Austin 
Signed-off-by: Miklos Szeredi 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

fuse: cleanup fuse_file refcounting

2019-02-11T17:54:24+00:00

commit 267d84449f52349ee252db684ed95ede18e51744 upstream.

struct fuse_file is stored in file->private_data.  Make this always be a
counting reference for consistency.

This also allows fuse_sync_release() to call fuse_file_put() instead of
partially duplicating its functionality.

Signed-off-by: Miklos Szeredi 
[bwh: Backported to 3.16: force and background flags are bitfields]
Signed-off-by: Ben Hutchings

fuse: Add missed unlock_page() to fuse_readpages_fill()

2018-12-16T22:08:26+00:00

commit 109728ccc5933151c68d1106e4065478a487a323 upstream.

The above error path returns with page unlocked, so this place seems also
to behave the same.

Fixes: f8dbdf81821b ("fuse: rework fuse_readpages()")
Signed-off-by: Kirill Tkhai 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Ben Hutchings