Struct fuse_backend_rs::abi::linux_abi::FsOptions [−][src]
pub struct FsOptions { /* fields omitted */ }
Expand description
A bitfield passed in as a parameter to and returned from the init
method of the
FileSystem
trait.
Implementations
Indicates that the filesystem supports asynchronous read requests.
If this capability is not requested/available, the kernel will ensure that there is at most one pending read request per file-handle at any time, and will attempt to order read requests by increasing offset.
This feature is enabled by default when supported by the kernel.
Indicates that the filesystem supports “remote” locking.
This feature is not enabled by default and should only be set if the filesystem
implements the getlk
and setlk
methods of the FileSystem
trait.
Indicates that the filesystem supports the O_TRUNC
open flag. If disabled, and an
application specifies O_TRUNC
, fuse first calls setattr
to truncate the file and
then calls open
with O_TRUNC
filtered out.
This feature is enabled by default when supported by the kernel.
Indicates that the filesystem supports lookups of “.” and “..”.
This feature is disabled by default.
FileSystem can handle write size larger than 4kB.
Indicates that the kernel should not apply the umask to the file mode on create operations.
This feature is disabled by default.
Indicates that the server should try to use splice(2)
when writing to the fuse device.
This may improve performance.
This feature is not currently supported.
Indicates that the server should try to move pages instead of copying when writing to / reading from the fuse device. This may improve performance.
This feature is not currently supported.
Indicates that the server should try to use splice(2)
when reading from the fuse
device. This may improve performance.
This feature is not currently supported.
If set, then calls to flock
will be emulated using POSIX locks and must
then be handled by the filesystem’s setlock()
handler.
If not set, flock
calls will be handled by the FUSE kernel module internally (so any
access that does not go through the kernel cannot be taken into account).
This feature is disabled by default.
Indicates that the filesystem supports ioctl’s on directories.
This feature is enabled by default when supported by the kernel.
Traditionally, while a file is open the FUSE kernel module only asks the filesystem for an update of the file’s attributes when a client attempts to read beyond EOF. This is unsuitable for e.g. network filesystems, where the file contents may change without the kernel knowing about it.
If this flag is set, FUSE will check the validity of the attributes on every read. If
the attributes are no longer valid (i.e., if the attribute timeout has expired) then
FUSE will first send another getattr
request. If the new mtime differs from the
previous value, any cached file contents will be invalidated as well.
This flag should always be set when available. If all file changes go through the
kernel, attribute validity should be set to a very large number to avoid unnecessary
getattr()
calls.
This feature is enabled by default when supported by the kernel.
Indicates that the filesystem supports readdirplus.
The feature is not enabled by default and should only be set if the filesystem
implements the readdirplus
method of the FileSystem
trait.
Indicates that the filesystem supports adaptive readdirplus.
If DO_READDIRPLUS
is not set, this flag has no effect.
If DO_READDIRPLUS
is set and this flag is not set, the kernel will always issue
readdirplus()
requests to retrieve directory contents.
If DO_READDIRPLUS
is set and this flag is set, the kernel will issue both readdir()
and readdirplus()
requests, depending on how much information is expected to be
required.
This feature is not enabled by default and should only be set if the file system
implements both the readdir
and readdirplus
methods of the FileSystem
trait.
Indicates that the filesystem supports asynchronous direct I/O submission.
If this capability is not requested/available, the kernel will ensure that there is at most one pending read and one pending write request per direct I/O file-handle at any time.
This feature is enabled by default when supported by the kernel.
Indicates that writeback caching should be enabled. This means that individual write request may be buffered and merged in the kernel before they are sent to the file system.
This feature is disabled by default.
Indicates support for zero-message opens. If this flag is set in the capable
parameter
of the init
trait method, then the file system may return ENOSYS
from the open() handler
to indicate success. Further attempts to open files will be handled in the kernel. (If
this flag is not set, returning ENOSYS will be treated as an error and signaled to the
caller).
Setting (or not setting) the field in the FsOptions
returned from the init
method
has no effect.
Indicates support for parallel directory operations. If this flag is unset, the FUSE kernel module will ensure that lookup() and readdir() requests are never issued concurrently for the same directory.
This feature is enabled by default when supported by the kernel.
Indicates that the file system is responsible for unsetting setuid and setgid bits when a file is written, truncated, or its owner is changed.
This feature is enabled by default when supported by the kernel.
Indicates support for POSIX ACLs.
If this feature is enabled, the kernel will cache and have responsibility for enforcing ACLs. ACL will be stored as xattrs and passed to userspace, which is responsible for updating the ACLs in the filesystem, keeping the file mode in sync with the ACL, and ensuring inheritance of default ACLs when new filesystem nodes are created. Note that this requires that the file system is able to parse and interpret the xattr representation of ACLs.
Enabling this feature implicitly turns on the default_permissions
mount option (even
if it was not passed to mount(2)).
This feature is disabled by default.
Indicates support for fuse device abort error.
If this feature is enabled, the kernel will return ECONNABORTED to daemon when a fuse connection is aborted. Otherwise, ENODEV is returned.
This feature is enabled by default.
Indicate support for max number of req pages negotiation during INIT request handling.
If this feature is enabled, FUSE INIT response init_out.max_pages will contain the max number of req pages.
This feature is enabled by default.
Indicate support for kernel caching symlinks.
If this feature is enabled, the kernel will cache symlink contents.
This feature is enabled by default.
Indicates support for zero-message opens. If this flag is set in the capable
parameter
of the init
trait method, then the file system may return ENOSYS
from the opendir()
handler to indicate success. Further attempts to open files will be handled in the kernel
(If this flag is not set, returning ENOSYS will be treated as an error and signaled to the
caller).
Setting (or not setting) the field in the FsOptions
returned from the init
method
has no effect.
This feature is enabled by default.
Indicates to kernel that it is fully responsible for data cache invalidation, then the kernel won’t invalidate files data cache on size change and only truncate that cache to new size in case the size decreased.
If this feature is enabled, FileSystem should notify kernel when a file’s data is changed outside of fuse.
This feature is enabled by default.
Indicate support for byte alignment negotiation during INIT request handling.
If this feature is enabled, the INIT response init_out.map_alignment contains byte alignment for foffset and moffset fields in fuse_setupmapping_out and fuse_removemapping_one.
This feature is enabled by default.
Filesystem responsible for clearing security.capability xattr and setuid/setgid bits.
- clear “security.capability” on write, truncate and chown unconditionally
- sgid is cleared only if group executable bit is set
- clear suid/sgid when one of the following is true: -. setattr has FATTR_SIZE and FATTR_KILL_SUIDGID set. -. setattr has FATTR_UID or FATTR_GID -. open has O_TRUNC and FOPEN_IN_KILL_SUIDGID -. create has O_TRUNC and FOPEN_IN_KILL_SUIDGID flag set. -. write has WRITE_KILL_PRIV
Convert from underlying bit representation, unless that representation contains bits that do not correspond to a flag.
Convert from underlying bit representation, dropping any bits that do not correspond to flags.
Convert from underlying bit representation, preserving all bits (even those not corresponding to a defined flag).
Returns true
if there are flags common to both self
and other
.
Returns true
all of the flags in other
are contained within self
.
Trait Implementations
Disables all flags disabled in the set.
Adds the set of flags.
Toggles the set of flags.
Extends a collection with the contents of an iterator. Read more
extend_one
)Extends a collection with exactly one element.
extend_one
)Reserves capacity in a collection for the given number of additional elements. Read more
This method returns an ordering between self
and other
values if one exists. Read more
This method tests less than (for self
and other
) and is used by the <
operator. Read more
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
This method tests greater than (for self
and other
) and is used by the >
operator. Read more
Disables all flags enabled in the set.
Auto Trait Implementations
impl RefUnwindSafe for FsOptions
impl UnwindSafe for FsOptions
Blanket Implementations
Mutably borrows from an owned value. Read more