The initial FUSE passthrough interface has the issue of introducing an
ioctl which receives as a parameter a data structure containing a
pointer. What happens is that, depending on the architecture, the size
of this struct might change, and especially for 32-bit userspace running
on 64-bit kernel, the size mismatch results into different a single
ioctl the behavior of which depends on the data that is passed (e.g.,
with an enum). This is just a poor ioctl design as mentioned by Arnd
Bergmann [1].
Introduce the new FUSE_PASSTHROUGH_OPEN ioctl which only gets the fd of
the lower file system, which is a fixed-size __u32, dropping the
confusing fuse_passthrough_out data structure.
[1] https://lore.kernel.org/lkml/CAK8P3a2K2FzPvqBYL9W=Yut58SFXyetXwU4Fz50G5O3TsS0pPQ@mail.gmail.com/
Bug: 175195837
Signed-off-by: Alessio Balsini <balsini@google.com>
Change-Id: I486d71cbe20f3c0c87544fa75da4e2704fe57c7c
[cyberknight777: backport to 4.14]
Signed-off-by: Cyber Knight <cyberknight755@gmail.com>
Signed-off-by: onettboots <blackcocopet@gmail.com>
In general, as of now, in FUSE, direct writes on the same file are
serialized over inode lock i.e we hold inode lock for the full duration
of the write request. I could not found in fuse code a comment which
clearly explains why this exclusive lock is taken for direct writes.
Our guess is some USER space fuse implementations might be relying
on this lock for seralization and also it protects for the issues
arising due to file size assumption or write failures. This patch
relaxes this exclusive lock in some cases of direct writes.
With these changes, we allows non-extending parallel direct writes
on the same file with the help of a flag called FOPEN_PARALLEL_WRITES.
If this flag is set on the file (flag is passed from libfuse to fuse
kernel as part of file open/create), we do not take exclusive lock instead
use shared lock so that all non-extending writes can run in parallel.
Best practise would be to enable parallel direct writes of all kinds
including extending writes as well but we see some issues such as
when one write completes and other fails, how we should truncate(if
needed) the file if underlying file system does not support holes
(For file systems which supports holes, there might be a possibility
of enabling parallel writes for all cases).
FUSE implementations which rely on this inode lock for serialisation
can continue to do so and this is default behaviour i.e no parallel
direct writes.
Signed-off-by: Dharmendra Singh <dsingh@ddn.com>
[cyberknight777: backport and adapt to 4.14 fuse implementation]
Signed-off-by: Cyber Knight <cyberknight755@gmail.com>
Expose the FUSE_PASSTHROUGH interface to user space and declare all the
basic data structures and functions as the skeleton on top of which the
FUSE passthrough functionality will be built.
As part of this, introduce the new FUSE passthrough ioctl, which allows
the FUSE daemon to specify a direct connection between a FUSE file and a
lower file system file. Such ioctl requires user space to pass the file
descriptor of one of its opened files through the fuse_passthrough_out
data structure introduced in this patch. This structure includes extra
fields for possible future extensions.
Also, add the passthrough functions for the set-up and tear-down of the
data structures and locks that will be used both when fuse_conns and
fuse_files are created/deleted.
Bug: 179164095
Link: https://lore.kernel.org/lkml/20210125153057.3623715-4-balsini@android.com/
Signed-off-by: Alessio Balsini <balsini@android.com>
Change-Id: I732532581348adadda5b5048a9346c2b0868d539
Signed-off-by: Alessio Balsini <balsini@google.com>
(cherry picked from commit d02368d67989781a3484cd8dd71e0079d0d1bda2)
Signed-off-by: alk3pInjection <webmaster@raspii.tech>
With a 64-bit kernel build the FUSE device cannot handle ioctl requests
coming from 32-bit user space.
This is due to the ioctl command translation that generates different
command identifiers that thus cannot be used for direct comparisons
without proper manipulation.
Explicitly extract type and number from the ioctl command to enable
32-bit user space compatibility on 64-bit kernel builds.
Bug: 179164095
Link: https://lore.kernel.org/lkml/20210125153057.3623715-3-balsini@android.com/
Signed-off-by: Alessio Balsini <balsini@android.com>
Change-Id: I595517c54d551be70e83c7fcb4b62397a3615004
Signed-off-by: Alessio Balsini <balsini@google.com>
(cherry picked from commit af4048924e191bda0bb85b4bf127f22cf3c70fba)
Signed-off-by: alk3pInjection <webmaster@raspii.tech>
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 <noh4hss@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
(cherry picked from commit 3b7008b226f3de811d4ac34238e9cf670f7c9fe7)
Signed-off-by: alk3pInjection <webmaster@raspii.tech>
Change-Id: I3819b6c695b74887d93d9d274114d31384ff7803
Changes in 4.14.125
ethtool: fix potential userspace buffer overflow
Fix memory leak in sctp_process_init
neighbor: Call __ipv4_neigh_lookup_noref in neigh_xmit
net/mlx4_en: ethtool, Remove unsupported SFP EEPROM high pages query
net: rds: fix memory leak in rds_ib_flush_mr_pool
pktgen: do not sleep with the thread lock held.
ipv6: fix EFAULT on sendto with icmpv6 and hdrincl
ipv6: use READ_ONCE() for inet->hdrincl as in ipv4
net: sfp: read eeprom in maximum 16 byte increments
ipv6: fix the check before getting the cookie in rt6_get_cookie
Revert "fib_rules: fix error in backport of e9919a24d302 ("fib_rules: return 0...")"
Revert "fib_rules: return 0 directly if an exactly same rule exists when NLM_F_EXCL not supplied"
rcu: locking and unlocking need to always be at least barriers
parisc: Use implicit space register selection for loading the coherence index of I/O pdirs
fuse: fallocate: fix return with locked inode
pstore: Remove needless lock during console writes
pstore: Convert buf_lock to semaphore
pstore/ram: Run without kernel crash dump region
x86/power: Fix 'nosmt' vs hibernation triple fault during resume
i2c: xiic: Add max_read_len quirk
MIPS: Bounds check virt_addr_valid
MIPS: pistachio: Build uImage.gz by default
Revert "MIPS: perf: ath79: Fix perfcount IRQ assignment"
genwqe: Prevent an integer overflow in the ioctl
test_firmware: Use correct snprintf() limit
drm/gma500/cdv: Check vbt config bits when detecting lvds panels
drm/nouveau: add kconfig option to turn off nouveau legacy contexts. (v3)
drm/amdgpu/psp: move psp version specific function pointers to early_init
drm/radeon: prefer lower reference dividers
drm/i915: Fix I915_EXEC_RING_MASK
drm/i915/fbc: disable framebuffer compression on GeminiLake
TTY: serial_core, add ->install
qmi_wwan: Add quirk for Quectel dynamic config
fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock
fuse: Add FOPEN_STREAM to use stream_open()
ipv4: Define __ipv4_neigh_lookup_noref when CONFIG_INET is disabled
ethtool: check the return value of get_regs_len
Linux 4.14.125
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
commit bbd84f33652f852ce5992d65db4d020aba21f882 upstream.
Starting from commit 9c225f2655 ("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 581d21a2d0 ("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+%3Dhttps://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346https://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 <kirr@nexedi.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allows FUSE to report to inotify that it is acting
as a layered filesystem. The userspace component
returns a string representing the location of the
underlying file. If the string cannot be resolved
into a path, the top level path is returned instead.
bug: 23904372
Change-Id: Iabdca0bbedfbff59e9c820c58636a68ef9683d9f
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be. This makes it hard for
compliance tools to determine the correct license.
Update these files with an SPDX license identifier. The identifier was
chosen based on the license information in the file.
GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:
NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".
This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.
Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier. The format
is:
((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)
SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text. The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a new INIT flag, FUSE_POSIX_ACL, for negotiating ACL support with
userspace. When it is set in the INIT response, ACL support will be
enabled. ACL support also implies "default_permissions".
When ACL support is enabled, the kernel will cache and have responsibility
for enforcing ACLs. ACL xattrs will be passed to userspace, which is
responsible for updating the ACLs in the filesystem, keeping the file mode
in sync, and inheritance of default ACLs when new filesystem nodes are
created.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Only userspace filesystem can do the killing of suid/sgid without races.
So introduce an INIT flag and negotiate support for this.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Negotiate with userspace filesystems whether they support parallel readdir
and lookup. Disable parallelism by default for fear of breaking fuse
filesystems.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 9902af79c0 ("parallel lookups: actual switch to rwsem")
Fixes: d9b3dbdcfd ("fuse: switch to ->iterate_shared()")
Allow an open fuse device to be "cloned". Userspace can create a clone by:
newfd = open("/dev/fuse", O_RDWR)
ioctl(newfd, FUSE_DEV_IOC_CLONE, &oldfd);
At this point newfd will refer to the same fuse connection as oldfd.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: Ashish Samant <ashish.samant@oracle.com>
Here some additional changes to set a capability flag so that clients can
detect when it's appropriate to return -ENOSYS from open.
This amends the following commit introduced in 3.14:
7678ac5061 fuse: support clients that don't implement 'open'
However we can only add the flag to 3.15 and later since there was no
protocol version update in 3.14.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: <stable@vger.kernel.org> # v3.15+
The patch extends fuse_setattr_in, and extends the flush procedure
(fuse_flush_times()) called on ->write_inode() to send the ctime as well as
mtime.
Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Allow userspace fs to specify time granularity.
This is needed because with writeback_cache mode the kernel is responsible
for generating mtime and ctime, but if the underlying filesystem doesn't
support nanosecond granularity then the cache will contain a different
value from the one stored on the filesystem resulting in a change of times
after a cache flush.
Make the default granularity 1s.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Introduce a bit kernel and userspace exchange between each-other on
the init stage and turn writeback on if the userspace want this and
mount option 'allow_wbcache' is present (controlled by fusermount).
Also add each writable file into per-inode write list and call the
generic_file_aio_write to make use of the Linux page cache engine.
Signed-off-by: Maxim Patlasov <MPatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Without async DIO write requests to a single file were always serialized.
With async DIO that's no longer the case.
So don't turn on async DIO by default for fear of breaking backward
compatibility.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Commit 7e98d53086 (Synchronize fuse header with
one used in library) added #ifdef __linux__ around defines if it is not set.
The kernel build is self-contained and can be built on non-Linux toolchains.
After the mentioned commit builds on non-Linux toolchains will try to include
stdint.h and fail due to -nostdinc, and then fail with a bunch of undefined type
errors.
Fix by checking for __KERNEL__ instead of __linux__ and using the standard int
types instead of the linux specific ones.
Reported-by: Arve Hjønnevåg <arve@android.com>
Reported-by: Colin Cross <ccross@android.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
For some filesystems (e.g. GlusterFS), the cost of performing a
normal readdir and readdirplus are identical. Since adaptively
using readdirplus has no benefit for those systems, give
users/filesystems the option to control adaptive readdirplus use.
v2 of this patch incorporates Miklos's suggestion to simplify the code,
as well as improving consistency of macro names and documentation.
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
The library one has provisions for use in *BSD, add them to the kernel one too.
They don't hurt and ease maintenance.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
commit 626cf23660 "poll: add poll_requested_events()..." enabled us to send the
requested events to the filesystem.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Yeah, we have a capability flag for this as well, so this is not strictly
necessary, but it doesn't hurt either.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
This patch implements readdirplus support in FUSE, similar to NFS.
The payload returned in the readdirplus call contains
'fuse_entry_out' structure thereby providing all the necessary inputs
for 'faking' a lookup() operation on the spot.
If the dentry and inode already existed (for e.g. in a re-run of ls -l)
then just the inode attributes timeout and dentry timeout are refreshed.
With a simple client->network->server implementation of a FUSE based
filesystem, the following performance observations were made:
Test: Performing a filesystem crawl over 20,000 files with
sh# time ls -lR /mnt
Without readdirplus:
Run 1: 18.1s
Run 2: 16.0s
Run 3: 16.2s
With readdirplus:
Run 1: 4.1s
Run 2: 3.8s
Run 3: 3.8s
The performance improvement is significant as it avoided 20,000 upcalls
calls (lookup). Cache consistency is no worse than what already is.
Signed-off-by: Anand V. Avati <avati@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
