This is to document operations and to also list
their in/out arguments.
This list was auto generated and only partly verified,
use with care. Not all operations are supported by
libfuse yet.
dmask: umask applied to directories
fmask: umask applied to non-directories
to get "typical" permission bits for regular files (0644) and directories (0755), a single
umask option is not sufficient (or well, it isn't the way fuse implements it)
there is precident for separate umask and dmask options in other
filesystems (see for example fat: https://github.com/torvalds/linux/tree/master/fs/fat)
this addition should not affect backward-compatibility; the original
umask option retains the same meaning, but non-zero fmask or
dmask will override it.
After reading the file /proc/$PID/task/$PID/status the buffer wasn't
terminated with a null character. This could theoretically lead to buffer
overrun by the subsequent strstr() call.
Since the contents of the proc file are guaranteed to contain the pattern
that strstr is looking for, this doesn't happen in normal situations.
Add null termination for robustness.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The code `fuse_init_intr_signal` in `_fuse_new_317` is useless
since commit 8ee553dac ("fuse_new(): don't accept options that
don't make sense for end-users") has remove the conf.intr option
for end-users. The conf.intr is always zero (i.e., disabled) here.
Move `fuse_init_intr_signal` after the user-defined `init()` function,
so that conf.intr and conf.intr_signal has been configured by the user.
generic/003 fails currently because if you specify -o relatime we will
fail to mount, but not return an error, so the test thinks that we
support relatime and then hilarity ensues. Set ret so that if we get
any failures while trying to mount we will properly error out.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
The variable is not modified exclusively with locks since commit
cef8c8b249 ("Add support for no_interrupt") anymore.
That commit is safe, but might be error prone to future updates.
Changing it to a C11 _Atomic should avoid issues.
The function fuse_session_process_buf_int() would do much things
for FUSE_INTERRUPT requests, even there are no FUSE_INTERRUPT requests:
1. check every non-FUSE_INTERRUPT request and add these requests to the
linked list(se->list) under a big lock(se->lock).
2. the function fuse_free_req() frees every request and remove them from
the linked list(se->list) under a bing lock(se->lock).
These operations are not meaningful when there are no FUSE_INTERRUPT requests,
and have a great impact on the performance of fuse filesystem because the big
lock for each request.
In some cases, FUSE_INTERRUPT requests are infrequent, even none at all.
Besides, the user-defined filesystem may do nothing for FUSE_INTERRUPT requests.
And the kernel side has the option "no_interrupt" in struct fuse_conn. This kernel option
can be enabled by return ENOSYS in libfuse for the reply of FUSE_INTERRUPT request.
But I don't find the code to enable the "no_interrupt" kernel option in libfuse.
So add the no_interrupt support, and when this operaion is enabled:
1. remove the useless locking operaions and list operations.
2. return ENOSYS for the reply of FUSE_INTERRUPT request to inform the kernel to disable
FUSE_INTERRUPT request.
compat.c is supposed to be standalone to provide compat ABI symbols.
Including fuse header files can cause conflicts - just the opposite
of what compat.c was made for.
This is direct copy of <linux>/.clang-format as
this project was initiated with linux style. Some
lines that were auto-generated are removed
("# Taken from:...).
Some files like example/passthrough_hp.cc use
a different style - these files probably should
be cleaned up when major changes are done to them.
Add support for filesystem passthrough read/write of files.
When the FUSE_PASSTHROUGH capability is enabled, the FUSE server may
decide, while handling the "open" or "create" requests, if the given
file can be accessed by that process in "passthrough" mode, meaning that
all the further read and write operations would be forwarded by the
kernel directly to the backing file rather than to the FUSE server.
All requests other than read or write are still handled by the server.
This allows for an improved performance on reads and writes, especially
in the case of reads at random offsets, for which no (readahead)
caching mechanism would help, reducing the performance gap between FUSE
and native filesystem access.
Extend also the passthrough_hp example with the new passthrough feature.
This example opens a kernel backing file per FUSE inode on the first
FUSE file open of that inode and closes the backing file on the release
of the last FUSE file on that inode.
All opens of the same inode passthrough to the same backing file.
A combination of fi->direct_io and fi->passthrough is allowed.
It means that read/write operations go directly to the server, but mmap
is done on the backing file.
This allows to open some fds of the inode in passthrough mode and some
fd of the same inode in direct_io/passthrough_mmap mode.
Signed-off-by: Alessio Balsini <balsini@android.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
The API stays the same, the libfuse version comes from
inlined functions, which are defined fuse_lowlevel.h
and fuse.h. As these inlined functions are defined in the header
files they get added into the application, similar as if these
were preprocessor macros.
Macro vs inlined function is then just a style issue - I personally
prefer the latter.
fuse_session_new() -> static inlinei, in the application
_fuse_session_new -> inside of libfuse
fuse_new() -> static inline, in the application
_fuse_new() -> inside of libfuse
Note: Entirely untested is the fuse 30 api - we need a test
for it. And we do not have any ABI tests at all.
Signed-off-by: Bernd Schubert <bernd.schubert@fastmail.fm>
If the file system doesn't provide a ->open or an ->opendir, and the
kernel supports FUSE_CAP_NO_OPEN_SUPPORT or FUSE_CAP_NO_OPENDIR_SUPPORT,
allow the implementation to set FUSE_CAP_NO_OPEN*_SUPPORT on conn->want
in order to automatically get this behavior. Expand the documentation
to be more explicit about the behavior of libfuse in the different cases
WRT this capability.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
We already have some C11 pieces like Static_assert and we are likely
going to add more - tell meson to use C11.
Plain C11 does not work as there are several language extension,
like typeof - part of C23 only. We might be able to fix/workaround
such extensions with compiler ifdef, but then I prefer gnu11 over
checking which compiler is used (example gcc has __typeof vs
clangs __typeof++). And compiler extension would also defeat pedantic.
Despite the creation of the header file fuse_config.h during LibFUSE
version 3.16.2's Meson build process, the BSD mount_bsd.c file continues to reference config.h. Consequently, this discrepancy results in compilation failures.
FIX : Point the mount_bsd.c to correct header.
* Use single place to define the version
Defining the version in fuse_common.h, is removed, it is defined
through meson and provided by "libfuse_config.h". I.e. it avoids
to define the version twice - once in meson and once in
fuse_common.h.
Ideal would be to set integers in the meson file and create the version
string from these integers. However, meson requires that "project"
is the first meson.build keyword - with that it requires to
set the version from a string and then major/minor/hotfix integers
are created from string split.
Signed-off-by: Bernd Schubert <bernd.schubert@fastmail.fm>
* Increase the version to 3.17.0
This is to prepare the branch for the next release.
Signed-off-by: Bernd Schubert <bernd.schubert@fastmail.fm>
---------
Signed-off-by: Bernd Schubert <bernd.schubert@fastmail.fm>
By virtio-fs and libfuse fuse_custom_io, passthrough_ll could be
a virtio filesystem device backend, this bug was found when doing
mount, fsstress and umount repeatedly.
Signed-off-by: Xiaoguang Wang <lege.wang@jaguarmicro.com>
Co-authored-by: Xiaoguang Wang <lege.wang@jaguarmicro.com>
Define a new clone_fd() helper for fuse_custom_io, users
can implement their own clone fd logic.
Signed-off-by: Xiaoguang Wang <lege.wang@jaguarmicro.com>
If user updates conn->max_write in fuse_lowlevel_ops' init() method, do_init()
will miss the "conn.max_write > bufsize - FUSE_BUFFER_HEADER_SIZE" judgment,
and ->init method will be called after it, which obviously is a bug.
Signed-off-by: Xiaoguang Wang <lege.wang@jaguarmicro.com>
Co-authored-by: Xiaoguang Wang <lege.wang@jaguarmicro.com>
Add more documentation for FUSE_CAP_EXPORT_SUPPORT
Also remove the flag from passthrough_ll.c and passthrough_hp.cc
as these implementations do _not_ handle that flag. They just
cast fuse_ino_t to an inode and cause a heap buffer overflow
for unknown objects (simplest reproducer are the examples
in "man 2 open_by_handle_at", but to unmount/mount the file
system after name_to_handle_at and before open_by_handle_at).
Fixes https://github.com/libfuse/libfuse/issues/838
---------
Co-authored-by: Nikolaus Rath <Nikolaus@rath.org>
fixes#235
In fill_dir_plus(), there's a lookup for caching dirent attributes.
However, when offset = 0 the cache metadata from the lookup is lost
as only the entry attributes are passed when added to the list. Kernel
doesn't cache the attributes since .ino = 0.
This change moves the entry lookup to happen just before the relevant
fuse_add_direntry_plus() calls
User may still need to mount same fuse filesystem after umounting
it(In this case, the userspace filesystem server needs to keep live),
and after handling FUSE_DESTROY message, new FUSE_INIT message may come,
so need to reset got_init to be zero.
Signed-off-by: Xiaoguang Wang <lege.wang@jaguarmicro.com>
In order to use the fuse_fill_dir_t function in a C++ program, add the enum item:
FUSE_FILL_DIR_DEFAULTS
Without this change g++ compilation failed with
example/hello.c:94:35: error: invalid conversion from ‘int’ to ‘fuse_fill_dir_flags’ [-fpermissive]
94 | filler(buf, ".", NULL, 0, 0);
| ^
| |
| int
Similar issue as fixed in commit
3c7ba570 "examples/notify_store_retrieve: Add a clean shutdown".
Basically a clean shutdown was missing, but even with clean
shutdown it does not work, as kernel side releases inodes before
sending FUSE_DESTROY - the intervaled thread then gets
-ENOENT.
Co-authored-by: Bernd Schubert <bschubert@ddn.com>
