Module org.cryptomator.jfuse.api

Package org.cryptomator.jfuse.api

Interface FuseConfig

public interface FuseConfig

Configuration of the high-level API

This structure is initialized from the arguments passed to fuse_new(), and then passed to the file system's init() handler which should ensure that the configuration is compatible with the file system implementation.

Since:

libFUSE 3.0

Method Summary

Modifier and Type	Method	Description
double	acAttrTimeout()	The timeout in seconds for which file attributes are cached for the purpose of checking if auto_cache should flush the file data on open.
int	acAttrTimeoutSet()	If ac_attr_timeout_set is non-zero, the acAttrTimeout() ac_attr_timeout} is applied.
double	attrTimeout()	The timeout in seconds for which file/directory attributes (as returned by e.g.
int	autoCache()	This option is an alternative to kernel_cache.
int	directIo()	This option disables the use of page cache (file content cache) in the kernel for this filesystem.
double	entryTimeout()	The timeout in seconds for which name lookups will be cached.
int	gid()	The value used to overwrite st_gid during getattr calls.
int	hardRemove()	The default behavior is that if an open file is deleted, the file is renamed to a hidden file (.fuse_hiddenXXX), and only removed when the file is finally released.
int	intr()	Allow requests to be interrupted
int	intrSignal()	Specify which signal number to send to the filesystem when a request is interrupted.
int	kernelCache()	This option disables flushing the cache of the file contents on every open(2).
double	negativeTimeout()	The timeout in seconds for which a negative lookup will be cached.
int	noRofdFlush()	By default, fuse waits for all pending writes to complete and calls the FLUSH operation on close(2) of every fuse fd.
int	nullpathOk()	If this option is given the file-system handlers for the following operations will not receive path information: read, write, flush, release, fallocate, fsync, readdir, releasedir, fsyncdir, lock, ioctl and poll.
int	readdirIno()	If use_ino option is not given, still try to fill in the d_ino field in readdir(2).
int	remember()	Normally, FUSE assigns inodes to paths only for as long as the kernel is aware of them.
int	setGid()	If set_gid is non-zero, the st_gid attribute of each file is overwritten with the value of gid().
int	setMode()	If set_mode is non-zero, the any permissions bits set in umask() are unset in the st_mode attribute of each file.
int	setUid()	If set_uid is non-zero, the st_uid attribute of each file is overwritten with the value of uid().
int	uid()	The value used to overwrite st_uid during getattr calls.
int	umask()	The bits to unset in st_mode
int	useIno()	Honor the st_ino field in the functions getattr() and fill_dir().

Method Details

setGid

int setGid()

If set_gid is non-zero, the st_gid attribute of each file is overwritten with the value of gid().

Returns:

set_gid value

See Also:

• gid()

gid

int gid()

The value used to overwrite st_gid during getattr calls.

Returns:

gid value

See Also:

• setGid()

setUid

int setUid()

If set_uid is non-zero, the st_uid attribute of each file is overwritten with the value of uid().

Returns:

set_uid value

See Also:

• uid()

uid

int uid()

The value used to overwrite st_uid during getattr calls.

Returns:

gid value

See Also:

• setUid()

setMode

int setMode()

If set_mode is non-zero, the any permissions bits set in umask() are unset in the st_mode attribute of each file.

Returns:

set_mode value

See Also:

• umask()

umask

int umask()

The bits to unset in st_mode

Returns:

umask value

See Also:

• setMode()

entryTimeout

double entryTimeout()

The timeout in seconds for which name lookups will be cached.

Returns:

entry_timeout value

negativeTimeout

double negativeTimeout()

The timeout in seconds for which a negative lookup will be cached. This means, that if file did not exist (lookup returned ENOENT), the lookup will only be redone after the timeout, and the file/directory will be assumed to not exist until then. A value of zero means that negative lookups are not cached.

Returns:

negative_timeout value

attrTimeout

double attrTimeout()

The timeout in seconds for which file/directory attributes (as returned by e.g. the getattr handler) are cached.

Returns:

attr_timeout value

intr

int intr()

Allow requests to be interrupted

Returns:

intr value

intrSignal

int intrSignal()

Specify which signal number to send to the filesystem when a request is interrupted.

The default is hardcoded to USR1.

Returns:

intr_signal value

remember

int remember()

Normally, FUSE assigns inodes to paths only for as long as the kernel is aware of them. With this option inodes are instead remembered for at least this many seconds. This will require more memory, but may be necessary when using applications that make use of inode numbers.

A number of -1 means that inodes will be remembered for the entire life-time of the file-system process.

Returns:

remember value

hardRemove

int hardRemove()

The default behavior is that if an open file is deleted, the file is renamed to a hidden file (.fuse_hiddenXXX), and only removed when the file is finally released. This relieves the filesystem implementation of having to deal with this problem. This option disables the hiding behavior, and files are removed immediately in an unlink operation (or in a rename operation which overwrites an existing file).

It is recommended that you not use the hard_remove option. When hard_remove is set, the following libc functions fail on unlinked files (returning errno of ENOENT): read(2), write(2), fsync(2), close(2), f*xattr(2), ftruncate(2), fstat(2), fchmod(2), fchown(2)

Returns:

hard_remove value

useIno

int useIno()

Honor the st_ino field in the functions getattr() and fill_dir(). This value is used to fill in the st_ino field in the stat(2), lstat(2), fstat(2) functions and the d_ino field in the readdir(2) function. The filesystem does not have to guarantee uniqueness, however some applications rely on this value being unique for the whole filesystem.

Note that this does *not* affect the inode that libfuse and the kernel use internally (also called the "nodeid").

Returns:

use_ino value

readdirIno

int readdirIno()

If use_ino option is not given, still try to fill in the d_ino field in readdir(2). If the name was previously looked up, and is still in the cache, the inode number found there will be used. Otherwise it will be set to -1. If use_ino option is given, this option is ignored.

Returns:

readdir_ino value

directIo

int directIo()

This option disables the use of page cache (file content cache) in the kernel for this filesystem. This has several affects:

1. Each read(2) or write(2) system call will initiate one or more read or write operations, data will not be cached in the kernel.
2. The return value of the read() and write() system calls will correspond to the return values of the read and write operations. This is useful for example if the file size is not known in advance (before reading it).

Internally, enabling this option causes fuse to set the direct_io field of fuse_file_info - overwriting any value that was put there by the file system.

Returns:

direct_io value

kernelCache

int kernelCache()

This option disables flushing the cache of the file contents on every open(2). This should only be enabled on filesystems where the file data is never changed externally (not through the mounted FUSE filesystem). Thus it is not suitable for network filesystems and other intermediate filesystems.

NOTE: if this option is not specified (and neither direct_io) data is still cached after the open(2), so a read(2) system call will not always initiate a read operation.

Internally, enabling this option causes fuse to set the keep_cache field of fuse_file_info - overwriting any value that was put there by the file system.

Returns:

kernel_cache value

autoCache

int autoCache()

This option is an alternative to kernel_cache. Instead of unconditionally keeping cached data, the cached data is invalidated on open(2) if if the modification time or the size of the file has changed since it was last opened.

Returns:

auto_cache value

noRofdFlush

int noRofdFlush()

By default, fuse waits for all pending writes to complete and calls the FLUSH operation on close(2) of every fuse fd. With this option, wait and FLUSH are not done for read-only fuse fd, similar to the behavior of NFS/SMB clients.

Returns:

no_rofd_flush value or 0 if not supported

Since:

libFUSE 3.3

acAttrTimeoutSet

int acAttrTimeoutSet()

If ac_attr_timeout_set is non-zero, the acAttrTimeout() ac_attr_timeout} is applied.

Returns:

ac_attr_timeout_set value

See Also:

• acAttrTimeout()

acAttrTimeout

double acAttrTimeout()

The timeout in seconds for which file attributes are cached for the purpose of checking if auto_cache should flush the file data on open.

Returns:

ac_attr_timeout value

See Also:

• acAttrTimeoutSet()

nullpathOk

int nullpathOk()

If this option is given the file-system handlers for the following operations will not receive path information: read, write, flush, release, fallocate, fsync, readdir, releasedir, fsyncdir, lock, ioctl and poll.

For the truncate, getattr, chmod, chown and utimens operations the path will be provided only if the struct fuse_file_info argument is NULL.

Returns:

nullpath_ok value